Merge branch 'e-kwsm-tautologically-false'

Add python3 to the list of badShells

.dockerignore

@@ -0,0 +1,6 @@
+*
+!LICENSE
+!Setup.hs
+!ShellCheck.cabal
+!shellcheck.hs
+!src

.ghci

@@ -1 +1 @@
-:set -idist/build/autogen
+:set -idist/build/autogen -isrc

.github/ISSUE_TEMPLATE.md

@@ -1,11 +1,11 @@
 #### For bugs
 - Rule Id (if any, e.g. SC1000):
 - My shellcheck version (`shellcheck --version` or "online"):
-- [ ] I tried on shellcheck.net and verified that this is still a problem on the latest commit
+- [ ] The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086)
-- [ ] It's not reproducible on shellcheck.net, but I think that's because it's an OS, configuration or encoding issue
+- [ ] I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit
 
 #### For new checks and feature suggestions
-- [ ] shellcheck.net (i.e. the latest commit) currently gives no useful warnings about this
+- [ ] https://www.shellcheck.net/ (i.e. the latest commit) currently gives no useful warnings about this
 - [ ] I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related
 
 

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/workflows/build.yml

@@ -0,0 +1,159 @@
+name: Build ShellCheck
+
+# Run this workflow every time a new commit pushed to your repository
+on: push
+
+jobs:
+  package_source:
+    name: Package Source Code
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-mark manual ghc # Don't bother installing ghc just to tar up source
+          sudo apt-get install cabal-install
+
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Deduce tags
+        run: |
+          mkdir source
+          echo "latest" > source/tags
+          if tag=$(git describe --exact-match --tags)
+          then
+            echo "stable" >> source/tags
+            echo "$tag" >> source/tags
+          fi
+          cat source/tags
+
+      - name: Package Source
+        run: |
+          grep "stable" source/tags || ./setgitversion
+          cabal sdist
+          mv dist-newstyle/sdist/*.tar.gz source/source.tar.gz
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: source
+          path: source/
+
+  run_tests:
+    name: Run tests
+    needs: package_source
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download artifacts
+        uses: actions/download-artifact@v4
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update && sudo apt-get install ghc cabal-install
+          cabal update
+
+      - name: Unpack source
+        run: |
+          cd source
+          tar xvf source.tar.gz --strip-components=1
+
+      - name: Build and run tests
+        run: |
+          cd source
+          cabal test
+
+  build_source:
+    name: Build
+    needs: package_source
+    strategy:
+      matrix:
+        build: [linux.x86_64, linux.aarch64, linux.armv6hf, linux.riscv64, darwin.x86_64, darwin.aarch64, windows.x86_64]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Download artifacts
+        uses: actions/download-artifact@v4
+
+      - name: Build source
+        run: |
+          mkdir -p bin
+          mkdir -p bin/${{matrix.build}}
+          ( cd bin && ../build/run_builder ../source/source.tar.gz ../build/${{matrix.build}} )
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{matrix.build}}.bin
+          path: bin/
+
+  package_binary:
+    name: Package Binaries
+    needs: build_source
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Download artifacts
+        uses: actions/download-artifact@v4
+
+      - name: Work around GitHub permissions bug
+        run: chmod +x *.bin/*/shellcheck*
+
+      - name: Package binaries
+        run: |
+          export TAGS="$(cat source/tags)"
+          mkdir -p deploy
+          cp -r *.bin/* deploy
+          cd deploy
+          ../.prepare_deploy
+          rm -rf */ README* LICENSE*
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: deploy
+          path: deploy/
+
+  deploy:
+    name: Deploy binaries
+    needs: package_binary
+    runs-on: ubuntu-latest
+    environment: Deploy
+    steps:
+      - name: Install Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install hub
+
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Download artifacts
+        uses: actions/download-artifact@v4
+
+      - name: Upload to GitHub
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          export TAGS="$(cat source/tags)"
+          ./.github_deploy
+
+      - name: Waiting for GitHub to replicate uploaded releases
+        run: |
+          sleep 300
+
+      - name: Upload to Docker Hub
+        env:
+          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+          DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
+          DOCKER_EMAIL: ${{ secrets.DOCKER_EMAIL }}
+          DOCKER_BASE: ${{ secrets.DOCKER_USERNAME }}/shellcheck
+        run: |
+          export TAGS="$(cat source/tags)"
+          ( source ./.multi_arch_docker && set -eux && multi_arch_docker::main )

.github_deploy

@@ -0,0 +1,28 @@
+#!/bin/bash
+set -x
+shopt -s extglob
+
+export EDITOR="touch"
+
+# Sanity check
+gh --version || exit 1
+hub release show latest || exit 1
+
+for tag in $TAGS
+do
+  if ! hub release show "$tag"
+  then
+    echo "Creating new release $tag"
+    git show --no-patch  --format='format:%B' > description
+    hub release create -F description "$tag"
+  fi
+
+  files=()
+  for file in deploy/*
+  do
+    [[ $file == *.@(xz|gz|zip) ]] || continue
+    [[ $file == *"$tag"* ]] || continue
+    files+=("$file")
+  done
+  gh release upload "$tag" "${files[@]}" --clobber || exit 1
+done

.gitignore

@@ -1,4 +1,4 @@
-# Created by http://www.gitignore.io
+# Created by https://www.gitignore.io
 
 ### Haskell ###
 dist
@@ -13,3 +13,11 @@ cabal-dev
 cabal.sandbox.config
 cabal.config
 .stack-work
+
+### Snap ###
+/snap/.snapcraft/
+/stage/
+/parts/
+/prime/
+*.snap
+/dist-newstyle/

.multi_arch_docker

@@ -0,0 +1,89 @@
+#!/bin/bash
+# This script builds and deploys multi-architecture docker images from the
+# binaries previously built and deployed to GitHub.
+
+function multi_arch_docker::install_docker_buildx() {
+  # Install QEMU multi-architecture support for docker buildx.
+  docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+
+  # Instantiate docker buildx builder with multi-architecture support.
+  docker buildx create --name mybuilder
+  docker buildx use mybuilder
+  # Start up buildx and verify that all is OK.
+  docker buildx inspect --bootstrap
+}
+
+# Log in to Docker Hub for deployment.
+function multi_arch_docker::login_to_docker_hub() {
+  echo "$DOCKER_PASSWORD" | docker login -u="$DOCKER_USERNAME" --password-stdin
+}
+
+# Run buildx build and push. Passed in arguments augment the command line.
+function multi_arch_docker::buildx() {
+  mkdir -p /tmp/empty
+  docker buildx build \
+    --platform "${DOCKER_PLATFORMS// /,}" \
+    --push \
+    --progress plain \
+    -f Dockerfile.multi-arch \
+    "$@" \
+    /tmp/empty
+  rmdir /tmp/empty
+}
+
+# Build and push plain and alpine docker images for all tags.
+function multi_arch_docker::build_and_push_all() {
+  for tag in $TAGS; do
+    multi_arch_docker::buildx -t "$DOCKER_BASE:$tag" --build-arg "tag=$tag"
+    multi_arch_docker::buildx -t "$DOCKER_BASE-alpine:$tag" \
+      --build-arg "tag=$tag" --target alpine
+  done
+}
+
+# Test all pushed docker images.
+function multi_arch_docker::test_all() {
+  printf '%s\n' "#!/bin/sh" "echo 'hello world'" > myscript
+
+  for platform in $DOCKER_PLATFORMS; do
+    for tag in $TAGS; do
+      for ext in '-alpine' ''; do
+        image="${DOCKER_BASE}${ext}:${tag}"
+        msg="Testing docker image $image on platform $platform"
+        line="${msg//?/=}"
+        printf '\n%s\n%s\n%s\n' "${line}" "${msg}" "${line}"
+        docker pull -q --platform "$platform" "$image"
+        if [ -n "$ext" ]; then
+          echo -n "Image architecture: "
+          docker run --rm --entrypoint /bin/sh "$image" -c 'uname -m'
+          version=$(docker run --rm "$image" shellcheck --version \
+            | grep 'version:')
+        else
+          version=$(docker run --rm "$image" --version | grep 'version:')
+        fi
+        version=${version/#version: /v}
+        echo "shellcheck version: $version"
+        if [[ ! ("$tag" =~ ^(latest|stable)$) && "$tag" != "$version" ]]; then
+          echo "Version mismatch: shellcheck $version tagged as $tag"
+          exit 1
+        fi
+        if [ -n "$ext" ]; then
+          docker run --rm -v "$PWD:/mnt" -w /mnt "$image" shellcheck myscript
+        else
+          docker run --rm -v "$PWD:/mnt" "$image" myscript
+        fi
+      done
+    done
+  done
+}
+
+function multi_arch_docker::main() {
+  export DOCKER_PLATFORMS='linux/amd64'
+  DOCKER_PLATFORMS+=' linux/arm64'
+  DOCKER_PLATFORMS+=' linux/arm/v6'
+  DOCKER_PLATFORMS+=' linux/riscv64'
+
+  multi_arch_docker::install_docker_buildx
+  multi_arch_docker::login_to_docker_hub
+  multi_arch_docker::build_and_push_all
+  multi_arch_docker::test_all
+}

.prepare_deploy

@@ -1,13 +1,14 @@
 #!/bin/bash
-# This script packages up Travis compiled binaries
+# This script packages up compiled binaries
 set -ex
-shopt -s nullglob
+shopt -s nullglob extglob
-cd deploy
+
+ls -l
 
 cp ../LICENSE LICENSE.txt
 sed -e $'s/$/\r/' > README.txt << END
 This is a precompiled ShellCheck binary.
-      http://www.shellcheck.net/
+      https://www.shellcheck.net/
 
 ShellCheck is a static analysis tool for shell scripts.
 It's licensed under the GNU General Public License v3.0.
@@ -22,21 +23,32 @@ This binary was compiled on $(date -u).
 $(git log -n 3)
 END
 
-for file in ./*.exe
+for dir in */
 do
-  zip "${file%.*}.zip" README.txt LICENSE.txt "$file"
+  cp LICENSE.txt README.txt "$dir"
 done
 
-for file in *.linux
+echo "Tags are $TAGS"
+
+for tag in $TAGS
 do
-  base="${file%.*}"
+
-  cp "$file" "shellcheck"
+  for dir in windows.*/
-  tar -cJf "$base.linux.x86_64.tar.xz" --transform="s:^:$base/:" README.txt LICENSE.txt shellcheck
+  do
-  rm "shellcheck"
+    ( cd "$dir" && zip "../shellcheck-$tag.zip" * )
+  done
+
+  for dir in {linux,darwin}.*/
+  do
+    base="${dir%/}"
+    ( cd "$dir" && tar -cJf "../shellcheck-$tag.$base.tar.xz" --transform="s:^:shellcheck-$tag/:" * )
+  done
 done
 
 for file in ./*
 do
+  [[ -f "$file" ]] || continue
   sha512sum "$file" > "$file.sha512sum"
 done
 
+ls -l

.travis.yml

@@ -1,72 +0,0 @@
-sudo: required
-
-language: sh
-
-services:
-  - docker
-
-before_install:
-  - DOCKER_BASE="$DOCKER_USERNAME/shellcheck"
-  - DOCKER_BUILDS=""
-  - TAGS=""
-  - test "$TRAVIS_BRANCH" = master && TAGS="$TAGS latest" || true
-  - test -n "$TRAVIS_TAG"          && TAGS="$TAGS $TRAVIS_TAG" || true
-  - test "$TRAVIS_BRANCH" = master && test -n "$TRAVIS_TAG" && TAGS="$TAGS stable" || true
-
-script:
-  - mkdir deploy
-  # Windows .exe
-  - docker pull koalaman/winghc
-  - docker run --user="$UID" --rm -v "$PWD:/appdata" koalaman/winghc cuib
-  - for tag in $TAGS; do cp "dist/build/ShellCheck/shellcheck.exe" "deploy/shellcheck-$tag.exe"; done
-  - rm -rf dist || true
-  # Linux static executable
-  - docker pull koalaman/scbuilder
-  - docker run --user="$UID" --rm -v "$PWD:/mnt" koalaman/scbuilder
-  - for tag in $TAGS; do cp "shellcheck" "deploy/shellcheck-$tag.linux"; done
-  - ./shellcheck --version
-  - rm -rf dist || true
-  # Linux Docker image
-  - name="$DOCKER_BASE"
-  - DOCKER_BUILDS="$DOCKER_BUILDS $name"
-  - docker build -t "$name:current" .
-  - docker run "$name:current" --version
-  # Linux Alpine based Docker image
-  - name="$DOCKER_BASE-alpine"
-  - DOCKER_BUILDS="$DOCKER_BUILDS $name"
-  - sed 's/^FROM .*/FROM alpine:latest/' Dockerfile > Dockerfile.alpine
-  - docker build -f Dockerfile.alpine -t "$name:current" .
-  - docker run "$name:current" --version
-  # Misc packaging
-  - ./.prepare_deploy
-
-after_success:
-  - docker login -e="$DOCKER_EMAIL" -u="$DOCKER_USERNAME" -p="$DOCKER_PASSWORD"
-  - for repo in $DOCKER_BUILDS;
-    do
-      for tag in $TAGS;
-      do
-        echo "Deploying $repo:current as $repo:$tag...";
-        docker tag "$repo:current" "$repo:$tag";
-        docker push "$repo:$tag";
-      done;
-    done;
-
-after_failure:
-  - id
-  - pwd
-  - df -h
-  - find . -name '*.log' -type f -exec grep "" /dev/null {} +
-  - find . -ls
-
-deploy:
-  provider: gcs
-  skip_cleanup: true
-  access_key_id: GOOG7MDN7WEH6IIGBDCA
-  secret_access_key:
-    secure: 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
-  bucket: shellcheck
-  local-dir: deploy
-  on:
-    repo: koalaman/shellcheck
-    all_branches: true

CHANGELOG.md

@@ -1,3 +1,241 @@
+## Git
+### Added
+- SC2327/SC2328: Warn about capturing the output of redirected commands.
+- SC2329: Warn when (non-escaping) functions are never invoked.
+- SC2330: Warn about unsupported glob matches with [[ .. ]] in BusyBox.
+- SC2331: Suggest using standard -e instead of unary -a in tests.
+- SC2332: Warn about `[ ! -o opt ]` being unconditionally true in Bash.
+- SC3062: Warn about bashism `[ -o opt ]`.
+- Precompiled binaries for Linux riscv64 (linux.riscv64)
+### Changed
+- SC2002 about Useless Use Of Cat is now disabled by default. It can be
+  re-enabled with `--enable=useless-use-of-cat` or equivalent directive.
+- SC2015 about `A && B || C` no longer triggers when B is a test command.
+- SC3012: Do not warn about `\<` and `\>` in test/[] as specified in POSIX.1-2024
+### Fixed
+- SC2218 about function use-before-define is now more accurate.
+- SC2317 about unreachable commands is now less spammy for nested ones.
+- SC2292, optional suggestion for [[ ]], now triggers for Busybox.
+
+### Removed
+- SC3013: removed since the operators `-ot/-nt/-ef` are specified in POSIX.1-2024
+
+## v0.10.0 - 2024-03-07
+### Added
+- Precompiled binaries for macOS ARM64 (darwin.aarch64)
+- Added support for busybox sh
+- Added flag --rcfile to specify an rc file by name.
+- Added `extended-analysis=true` directive to enable/disable dataflow analysis
+  (with a corresponding --extended-analysis flag).
+- SC2324: Warn when x+=1 appends instead of increments
+- SC2325: Warn about multiple `!`s in dash/sh.
+- SC2326: Warn about `foo | ! bar` in bash/dash/sh.
+- SC3012: Warn about lexicographic-compare bashism in test like in [ ]
+- SC3013: Warn bashism `test _ -op/-nt/-ef _` like in [ ]
+- SC3014: Warn bashism `test _ == _` like in [ ]
+- SC3015: Warn bashism `test _ =~ _` like in [ ]
+- SC3016: Warn bashism `test -v _` like in [ ]
+- SC3017: Warn bashism `test -a _` like in [ ]
+
+### Fixed
+- source statements with here docs now work correctly
+- "(Array.!): undefined array element" error should no longer occur
+
+
+## v0.9.0 - 2022-12-12
+### Added
+- SC2316: Warn about 'local readonly foo' and similar (thanks, patrickxia!)
+- SC2317: Warn about unreachable commands
+- SC2318: Warn about backreferences in 'declare x=1 y=$x'
+- SC2319/SC2320: Warn when $? refers to echo/printf/[ ]/[[ ]]/test
+- SC2321: Suggest removing $((..)) in array[$((idx))]=val
+- SC2322: Suggest collapsing double parentheses in arithmetic contexts
+- SC2323: Suggest removing wrapping parentheses in a[(x+1)]=val
+
+### Fixed
+- SC2086: Now uses DFA to make more accurate predictions about values
+- SC2086: No longer warns about values declared as integer with declare -i
+
+### Changed
+- ShellCheck now has a Data Flow Analysis engine to make smarter decisions
+  based on control flow rather than just syntax. Existing checks will
+  gradually start using it, which may cause them to trigger differently
+  (but more accurately).
+- Values in directives/shellcheckrc can now be quoted with '' or ""
+
+
+## v0.8.0 - 2021-11-06
+### Added
+- `disable=all` now conveniently disables all warnings
+- `external-sources=true` directive can be added to .shellcheckrc to make
+  shellcheck behave as if `-x` was specified.
+- Optional `check-extra-masked-returns` for pointing out commands with
+  suppressed exit codes (SC2312).
+- Optional `require-double-brackets` for recommending \[\[ ]] (SC2292).
+- SC2286-SC2288: Warn when command name ends in a symbol like `/.)'"`
+- SC2289: Warn when command name contains tabs or linefeeds
+- SC2291: Warn about repeated unquoted spaces between words in echo
+- SC2292: Suggest [[ over [ in Bash/Ksh scripts (optional)
+- SC2293/SC2294: Warn when calling `eval` with arrays
+- SC2295: Warn about "${x#$y}" treating $y as a pattern when not quoted
+- SC2296-SC2301: Improved warnings for bad parameter expansions
+- SC2302/SC2303: Warn about loops over array values when using them as keys
+- SC2304-SC2306: Warn about unquoted globs in expr arguments
+- SC2307: Warn about insufficient number of arguments to expr
+- SC2308: Suggest other approaches for non-standard expr extensions
+- SC2313: Warn about `read` with unquoted, array indexed variable
+
+### Fixed
+- SC2102 about repetitions in ranges no longer triggers on [[ -v arr[xx] ]]
+- SC2155 now recognizes `typeset` and local read-only `declare` statements
+- SC2181 now tries to avoid triggering for error handling functions
+- SC2290: Warn about misused = in declare & co, which were not caught by SC2270+
+- The flag --color=auto no longer outputs color when TERM is "dumb" or unset
+
+### Changed
+- SC2048: Warning about $\* now also applies to ${array[\*]}
+- SC2181 now only triggers on single condition tests like `[ $? = 0 ]`.
+- Quote warnings are now emitted for declaration utilities in sh
+- Leading `_` can now be used to suppress warnings about unused variables
+- TTY output now includes warning level in text as well as color
+
+### Removed
+- SC1004: Literal backslash+linefeed in '' was found to be usually correct
+
+
+## v0.7.2 - 2021-04-19
+### Added
+- `disable` directives can now be a range, e.g. `disable=SC3000-SC4000`
+- SC1143: Warn about line continuations in comments
+- SC2259/SC2260: Warn when redirections override pipes
+- SC2261: Warn about multiple competing redirections
+- SC2262/SC2263: Warn about aliases declared and used in the same parsing unit
+- SC2264: Warn about wrapper functions that blatantly recurse
+- SC2265/SC2266: Warn when using & or | with test statements
+- SC2267: Warn when using xargs -i instead of -I
+- SC2268: Warn about unnecessary x-comparisons like `[ x$var = xval ]`
+
+### Fixed
+- SC1072/SC1073 now respond to disable annotations, though ignoring parse errors
+  is still purely cosmetic and does not allow ShellCheck to continue.
+- Improved error reporting for trailing tokens after ]/]] and compound commands
+- `#!/usr/bin/env -S shell` is now handled correctly
+- Here docs with \r are now parsed correctly and give better warnings
+
+### Changed
+- Assignments are now parsed to spec, without leniency for leading $ or spaces
+- POSIX/dash unsupported feature warnings now have individual SC3xxx codes
+- SC1090: A leading `$x/` or `$(x)/` is now treated as `./` when locating files
+- SC2154: Variables appearing in -z/-n tests are no longer considered unassigned
+- SC2270-SC2285: Improved warnings about misused `=`, e.g. `${var}=42`
+
+
+## v0.7.1 - 2020-04-04
+### Fixed
+- `-f diff` no longer claims that it found more issues when it didn't
+- Known empty variables now correctly trigger SC2086
+- ShellCheck should now be compatible with Cabal 3
+- SC2154 and all command-specific checks now trigger for builtins
+  called with `builtin`
+
+### Added
+- SC1136: Warn about unexpected characters after ]/]]
+- SC2254: Suggest quoting expansions in case statements
+- SC2255: Suggest using `$((..))` in `[ 2*3 -eq 6 ]`
+- SC2256: Warn about translated strings that are known variables
+- SC2257: Warn about arithmetic mutation in redirections
+- SC2258: Warn about trailing commas in for loop elements
+
+### Changed
+- SC2230: 'command -v' suggestion is now off by default (-i deprecate-which)
+- SC1081: Keywords are now correctly parsed case sensitively, with a warning
+
+
+## v0.7.0 - 2019-07-28
+### Added
+- Precompiled binaries for macOS and Linux aarch64
+- Preliminary support for fix suggestions
+- New `-f diff` unified diff format for auto-fixes
+- Files containing Bats tests can now be checked
+- Directory wide directives can now be placed in a `.shellcheckrc`
+- Optional checks: Use `--list-optional` to show a list of tests,
+                   Enable with `-o` flags or `enable=name` directives
+- Source paths: Use `-P dir1:dir2` or a `source-path=dir1` directive
+                to specify search paths for sourced files.
+- json1 format like --format=json but treats tabs as single characters
+- Recognize FLAGS variables created by the shflags library.
+- Site-specific changes can now be made in Custom.hs for ease of patching
+- SC2154: Also warn about unassigned uppercase variables (optional)
+- SC2252: Warn about `[ $a != x ] || [ $a != y ]`, similar to SC2055
+- SC2251: Inform about ineffectual ! in front of commands
+- SC2250: Warn about variable references without braces (optional)
+- SC2249: Warn about `case` with missing default case (optional)
+- SC2248: Warn about unquoted variables without special chars (optional)
+- SC2247: Warn about $"(cmd)" and $"{var}"
+- SC2246: Warn if a shebang's interpreter ends with /
+- SC2245: Warn that Ksh ignores all but the first glob result in `[`
+- SC2243/SC2244: Suggest using explicit -n for `[ $foo ]` (optional)
+- SC1135: Suggest not ending double quotes just to make $ literal
+
+### Changed
+- If a directive or shebang is not specified, a `.bash/.bats/.dash/.ksh`
+  extension will be used to infer the shell type when present.
+- Disabling SC2120 on a function now disables SC2119 on call sites
+
+### Fixed
+- SC2183 no longer warns about missing printf args for `%()T`
+
+## v0.6.0 - 2018-12-02
+### Added
+- Command line option --severity/-S for filtering by minimum severity
+- Command line option --wiki-link-count/-W for showing wiki links
+- SC2152/SC2151: Warn about bad `exit` values like `1234` and `"foo"`
+- SC2236/SC2237: Suggest -n/-z instead of ! -z/-n
+- SC2238: Warn when redirecting to a known command name, e.g. ls > rm
+- SC2239: Warn if the shebang is not an absolute path, e.g. #!bin/sh
+- SC2240: Warn when passing additional arguments to dot (.) in sh/dash
+- SC1133: Better diagnostics when starting a line with |/||/&&
+
+### Changed
+- Most warnings now have useful end positions
+- SC1117 about unknown double-quoted escape sequences has been retired
+
+### Fixed
+- SC2021 no longer triggers for equivalence classes like `[=e=]`
+- SC2221/SC2222 no longer mistriggers on fall-through case branches
+- SC2081 about glob matches in `[ .. ]` now also triggers for `!=`
+- SC2086 no longer warns about spaces in `$#`
+- SC2164 no longer suggests subshells for `cd ..; cmd; cd ..`
+- `read -a` is now correctly considered an array assignment
+- SC2039 no longer warns about LINENO now that it's POSIX
+
+## v0.5.0 - 2018-05-31
+### Added
+- SC2233/SC2234/SC2235: Suggest removing or replacing (..) around tests
+- SC2232: Warn about invalid arguments to sudo
+- SC2231: Suggest quoting expansions in for loop globs
+- SC2229: Warn about 'read $var'
+- SC2227: Warn about redirections in the middle of 'find' commands
+- SC2224/SC2225/SC2226: Warn when using mv/cp/ln without a destination
+- SC2223: Quote warning specific to `: ${var=value}`
+- SC1131: Warn when using `elseif` or `elsif`
+- SC1128: Warn about blanks/comments before shebang
+- SC1127: Warn about C-style comments
+
+### Fixed
+- Annotations intended for a command's here documents now work
+- Escaped characters inside groups in =~ regexes now parse
+- Associative arrays are now respected in arithmetic contexts
+- SC1087 about `$var[@]` now correctly triggers on any index
+- Bad expansions in here documents are no longer ignored
+- FD move operations like {fd}>1- now parse correctly
+
+### Changed
+- Here docs are now terminated as per spec, rather than by presumed intent
+- SC1073: 'else if' is now parsed correctly and not like 'elif'
+- SC2163: 'export $name' can now be silenced with 'export ${name?}'
+- SC2183: Now warns when printf arg count is not a multiple of format count
+
 ## v0.4.7 - 2017-12-08
 ### Added
 - Statically linked binaries for Linux and Windows (see README.md)!
@@ -32,7 +270,7 @@
 - SC2204/SC2205: Warn about `( -z foo )` and `( foo -eq bar )`
 - SC2200/SC2201: Warn about brace expansion in [/[[
 - SC2198/SC2199: Warn about arrays in [/[[
-- SC2196/SC2197: Warn about deprected egrep/fgrep
+- SC2196/SC2197: Warn about deprecated egrep/fgrep
 - SC2195: Warn about unmatchable case branches
 - SC2194: Warn about constant 'case' statements
 - SC2193: Warn about `[[ file.png == *.mp3 ]]` and other unmatchables
@@ -49,7 +287,7 @@
 ### Fixed
 - `-c` no longer suggested when using `grep -o | wc`
 - Comments and whitespace are now allowed before filewide directives
-- Here doc delimters with esoteric quoting like `foo""` are now handled
+- Here doc delimiters with esoteric quoting like `foo""` are now handled
 - SC2095 about `ssh` in while read loops is now suppressed when using `-n`
 - `%(%Y%M%D)T` now recognized as a single formatter in `printf` checks
 - `grep -F` now suppresses regex related suggestions

Dockerfile

@@ -1,10 +0,0 @@
-FROM scratch
-
-LABEL maintainer="Vidar Holen <vidar@vidarholen.net>"
-
-# This file assumes ShellCheck has already been built.
-# See https://github.com/koalaman/scbuilder
-COPY shellcheck /bin/shellcheck
-
-WORKDIR /mnt
-ENTRYPOINT ["/bin/shellcheck"]

Dockerfile.multi-arch

@@ -0,0 +1,26 @@
+# Alpine image
+FROM alpine:latest AS alpine
+LABEL maintainer="Vidar Holen <vidar@vidarholen.net>"
+ARG tag
+
+# Put the right binary for each architecture into place for the
+# multi-architecture docker image.
+RUN set -x; \
+  arch="$(uname -m)"; \
+  echo "arch is $arch"; \
+  if [ "${arch}" = 'armv7l' ]; then \
+    arch='armv6hf'; \
+  fi; \
+  url_base='https://github.com/koalaman/shellcheck/releases/download/'; \
+  tar_file="${tag}/shellcheck-${tag}.linux.${arch}.tar.xz"; \
+  wget "${url_base}${tar_file}" -O - | tar xJf -; \
+  mv "shellcheck-${tag}/shellcheck" /bin/; \
+  rm -rf "shellcheck-${tag}"; \
+  ls -laF /bin/shellcheck
+
+# ShellCheck image
+FROM scratch
+LABEL maintainer="Vidar Holen <vidar@vidarholen.net>"
+WORKDIR /mnt
+COPY --from=alpine /bin/shellcheck /bin/
+ENTRYPOINT ["/bin/shellcheck"]

LICENSE

@@ -1,7 +1,7 @@
                     GNU GENERAL PUBLIC LICENSE
                        Version 3, 29 June 2007
 
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
@@ -645,7 +645,7 @@ the "copyright" line and a pointer to where the full notice is found.
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 Also add information on how to contact you by electronic and paper mail.
 
@@ -664,11 +664,11 @@ might be different; for a GUI interface, you would use an "about box".
   You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
 For more information on this, and how to apply and follow the GNU GPL, see
-<http://www.gnu.org/licenses/>.
+<https://www.gnu.org/licenses/>.
 
   The GNU General Public License does not permit incorporating your program
 into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

README.md

@@ -1,50 +1,53 @@
+[![Build Status](https://github.com/koalaman/shellcheck/actions/workflows/build.yml/badge.svg)](https://github.com/koalaman/shellcheck/actions/workflows/build.yml)
+
+
 # ShellCheck - A shell script static analysis tool
 
 ShellCheck is a GPLv3 tool that gives warnings and suggestions for bash/sh shell scripts:
 
-![Screenshot of a terminal showing problematic shell script lines highlighted](doc/terminal.png).
+![Screenshot of a terminal showing problematic shell script lines highlighted](doc/terminal.png)
 
 The goals of ShellCheck are
 
-- To point out and clarify typical beginner's syntax issues that cause a shell
+* To point out and clarify typical beginner's syntax issues that cause a shell
   to give cryptic error messages.
 
-- To point out and clarify typical intermediate level semantic problems that
+* To point out and clarify typical intermediate level semantic problems that
   cause a shell to behave strangely and counter-intuitively.
 
-- To point out subtle caveats, corner cases and pitfalls that may cause an
+* To point out subtle caveats, corner cases and pitfalls that may cause an
   advanced user's otherwise working script to fail under future circumstances.
 
 See [the gallery of bad code](README.md#user-content-gallery-of-bad-code) for examples of what ShellCheck can help you identify!
 
 ## Table of Contents
 
-- [How to use](#how-to-use)
+* [How to use](#how-to-use)
-  - [On the web](#on-the-web)
+  * [On the web](#on-the-web)
-  - [From your terminal](#from-your-terminal)
+  * [From your terminal](#from-your-terminal)
-  - [In your editor](#in-your-editor)
+  * [In your editor](#in-your-editor)
-  - [In your build or test suites](#in-your-build-or-test-suites)
+  * [In your build or test suites](#in-your-build-or-test-suites)
-- [Installing](#installing)
+* [Installing](#installing)
-- [Travis CI Setup](#travis-ci-setup)
+* [Compiling from source](#compiling-from-source)
-- [Compiling from source](#compiling-from-source)
+  * [Installing Cabal](#installing-cabal)
-  - [Installing Cabal](#installing-cabal)
+  * [Compiling ShellCheck](#compiling-shellcheck)
-  - [Compiling ShellCheck](#compiling-shellcheck)
+  * [Running tests](#running-tests)
-  - [Running tests](#running-tests)
+* [Gallery of bad code](#gallery-of-bad-code)
-- [Gallery of bad code](#gallery-of-bad-code)
+  * [Quoting](#quoting)
-  - [Quoting](#quoting)
+  * [Conditionals](#conditionals)
-  - [Conditionals](#conditionals)
+  * [Frequently misused commands](#frequently-misused-commands)
-  - [Frequently misused commands](#frequently-misused-commands)
+  * [Common beginner's mistakes](#common-beginners-mistakes)
-  - [Common beginner's mistakes](#common-beginners-mistakes)
+  * [Style](#style)
-  - [Style](#style)
+  * [Data and typing errors](#data-and-typing-errors)
-  - [Data and typing errors](#data-and-typing-errors)
+  * [Robustness](#robustness)
-  - [Robustness](#robustness)
+  * [Portability](#portability)
-  - [Portability](#portability)
+  * [Miscellaneous](#miscellaneous)
-  - [Miscellaneous](#miscellaneous)
+* [Testimonials](#testimonials)
-- [Testimonials](#testimonials)
+* [Ignoring issues](#ignoring-issues)
-- [Ignoring issues](#ignoring-issues)
+* [Reporting bugs](#reporting-bugs)
-- [Reporting bugs](#reporting-bugs)
+* [Contributing](#contributing)
-- [Contributing](#contributing)
+* [Copyright](#copyright)
-- [Copyright](#copyright)
+* [Other Resources](#other-resources)
 
 ## How to use
 
@@ -52,9 +55,9 @@ There are a number of ways to use ShellCheck!
 
 ### On the web
 
-Paste a shell script on http://www.shellcheck.net for instant feedback.
+Paste a shell script on <https://www.shellcheck.net> for instant feedback.
 
-[ShellCheck.net](http://www.shellcheck.net) is always synchronized to the latest git commit, and is the easiest way to give ShellCheck a go. Tell your friends!
+[ShellCheck.net](https://www.shellcheck.net) is always synchronized to the latest git commit, and is the easiest way to give ShellCheck a go. Tell your friends!
 
 ### From your terminal
 
@@ -68,13 +71,13 @@ You can see ShellCheck suggestions directly in a variety of editors.
 
 ![Screenshot of Vim showing inlined shellcheck feedback](doc/vim-syntastic.png).
 
-* Emacs, through [Flycheck](https://github.com/flycheck/flycheck):
+* Emacs, through [Flycheck](https://github.com/flycheck/flycheck) or [Flymake](https://github.com/federicotdn/flymake-shellcheck):
 
 ![Screenshot of emacs showing inlined shellcheck feedback](doc/emacs-flycheck.png).
 
 * Sublime, through [SublimeLinter](https://github.com/SublimeLinter/SublimeLinter-shellcheck).
 
-* Atom, through [Linter](https://github.com/AtomLinter/linter-shellcheck).
+* Pulsar Edit (former Atom), through [linter-shellcheck-pulsar](https://github.com/pulsar-cooperative/linter-shellcheck-pulsar).
 
 * VSCode, through [vscode-shellcheck](https://github.com/timonwong/vscode-shellcheck).
 
@@ -83,8 +86,46 @@ You can see ShellCheck suggestions directly in a variety of editors.
 ### In your build or test suites
 
 While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites.
+It makes canonical use of exit codes, so you can just add a `shellcheck` command as part of the process.
 
-ShellCheck makes canonical use of exit codes, and can output simple JSON, CheckStyle compatible XML, GCC compatible warnings as well as human readable text (with or without ANSI colors). See the [Integration](https://github.com/koalaman/shellcheck/wiki/Integration) wiki page for more documentation.
+For example, in a Makefile:
+
+```Makefile
+check-scripts:
+    # Fail if any of these files have warnings
+    shellcheck myscripts/*.sh
+```
+
+or in a Travis CI `.travis.yml` file:
+
+```yaml
+script:
+  # Fail if any of these files have warnings
+  - shellcheck myscripts/*.sh
+```
+
+Services and platforms that have ShellCheck pre-installed and ready to use:
+
+* [Travis CI](https://travis-ci.org/)
+* [Codacy](https://www.codacy.com/)
+* [Code Climate](https://codeclimate.com/)
+* [Code Factor](https://www.codefactor.io/)
+* [Codety](https://www.codety.io/) via the [Codety Scanner](https://github.com/codetyio/codety-scanner)
+* [CircleCI](https://circleci.com) via the [ShellCheck Orb](https://circleci.com/orbs/registry/orb/circleci/shellcheck)
+* [Github](https://github.com/features/actions) (only Linux)
+* [Trunk Check](https://trunk.io/products/check) (universal linter; [allows you to explicitly version your shellcheck install](https://github.com/trunk-io/plugins/blob/bcbb361dcdbe4619af51ea7db474d7fb87540d20/.trunk/trunk.yaml#L32)) via the [shellcheck plugin](https://github.com/trunk-io/plugins/blob/main/linters/shellcheck/plugin.yaml)
+* [CodeRabbit](https://coderabbit.ai/)
+
+Most other services, including [GitLab](https://about.gitlab.com/), let you install
+ShellCheck yourself, either through the system's package manager (see [Installing](#installing)),
+or by downloading and unpacking a [binary release](#installing-a-pre-compiled-binary).
+
+It's a good idea to manually install a specific ShellCheck version regardless. This avoids
+any surprise build breaks when a new version with new warnings is published.
+
+For customized filtering or reporting, ShellCheck can output simple JSON, CheckStyle compatible XML,
+GCC compatible warnings as well as human readable text (with or without ANSI colors). See the
+[Integration](https://github.com/koalaman/shellcheck/wiki/Integration) wiki page for more documentation.
 
 ## Installing
 
@@ -102,80 +143,155 @@ On systems with Stack (installs to `~/.local/bin`):
 
 On Debian based distros:
 
-    apt-get install shellcheck
+    sudo apt install shellcheck
 
 On Arch Linux based distros:
 
     pacman -S shellcheck
 
+or get the dependency free [shellcheck-bin](https://aur.archlinux.org/packages/shellcheck-bin/) from the AUR.
+
 On Gentoo based distros:
 
     emerge --ask shellcheck
 
 On EPEL based distros:
 
-    yum -y install epel-release
+    sudo yum -y install epel-release
-    yum install ShellCheck
+    sudo yum install ShellCheck
 
 On Fedora based distros:
 
     dnf install ShellCheck
 
-On OS X with homebrew:
+On FreeBSD:
+
+    pkg install hs-ShellCheck
+
+On macOS (OS X) with Homebrew:
 
     brew install shellcheck
 
-On OS X with MacPorts:
+Or with MacPorts:
 
-    port install shellcheck
+    sudo port install shellcheck
 
-On openSUSE:Tumbleweed:
+On OpenBSD:
+
+    pkg_add shellcheck
+
+On openSUSE
 
     zypper in ShellCheck
 
-On other openSUSE distributions:
+Or use OneClickInstall - <https://software.opensuse.org/package/ShellCheck>
-
-Add OBS devel:languages:haskell repository from https://build.opensuse.org/project/repositories/devel:languages:haskell
-
-    zypper ar http://download.opensuse.org/repositories/devel:/languages:/haskell/openSUSE_$(version)/devel:languages:haskell.repo
-    zypper in ShellCheck
-
-Or use OneClickInstall - https://software.opensuse.org/package/ShellCheck
 
 On Solus:
 
     eopkg install shellcheck
 
+On Windows (via [chocolatey](https://chocolatey.org/packages/shellcheck)):
+
+```cmd
+C:\> choco install shellcheck
+```
+
+Or Windows (via [winget](https://github.com/microsoft/winget-pkgs)):
+
+```cmd
+C:\> winget install --id koalaman.shellcheck
+```
+
+Or Windows (via [scoop](http://scoop.sh)):
+
+```cmd
+C:\> scoop install shellcheck
+```
+
+From [conda-forge](https://anaconda.org/conda-forge/shellcheck):
+
+    conda install -c conda-forge shellcheck
+
+From Snap Store:
+
+    snap install --channel=edge shellcheck
+
 From Docker Hub:
 
 ```sh
-docker pull koalaman/shellcheck:latest  # Or  :v0.4.6  for a release version
+docker run --rm -v "$PWD:/mnt" koalaman/shellcheck:stable myscript
-docker run -v "$PWD:/mnt" koalaman/shellcheck myscript
+# Or :v0.4.7 for that version, or :latest for daily builds
 ```
 
-or use `koalaman/shellcheck-alpine` if you want a larger Alpine Linux based image to extend.
+or use `koalaman/shellcheck-alpine` if you want a larger Alpine Linux based image to extend. It works exactly like a regular Alpine image, but has shellcheck preinstalled.
 
-Alternatively, get freshly built binaries for the latest commit here:
+Using the [nix package manager](https://nixos.org/nix):
-
+```sh
-* [Linux, x86_64](https://storage.googleapis.com/shellcheck/shellcheck-latest.linux.x86_64.tar.xz) (statically linked)
+nix-env -iA nixpkgs.shellcheck
-* [Windows, x86](https://storage.googleapis.com/shellcheck/shellcheck-latest.zip)
-
-or see the [storage bucket listing](https://shellcheck.storage.googleapis.com/index.html) for checksums and release builds.
-
-## Travis CI Setup
-
-If you want to use ShellCheck in Travis CI, you can most easily install it via `apt`:
-
-```yml
-language: bash
-addons:
-  apt:
-    sources:
-    - debian-sid    # Grab ShellCheck from the Debian repo
-    packages:
-    - shellcheck
 ```
 
+Using the [Flox package manager](https://flox.dev/)
+```sh
+flox install shellcheck
+```
+
+Alternatively, you can download pre-compiled binaries for the latest release here:
+
+* [Linux, x86_64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.x86_64.tar.xz) (statically linked)
+* [Linux, armv6hf](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.armv6hf.tar.xz), i.e. Raspberry Pi (statically linked)
+* [Linux, aarch64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.aarch64.tar.xz) aka ARM64 (statically linked)
+* [macOS, aarch64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.darwin.aarch64.tar.xz)
+* [macOS, x86_64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.darwin.x86_64.tar.xz)
+* [Windows, x86](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.zip)
+
+or see the [GitHub Releases](https://github.com/koalaman/shellcheck/releases) for other releases
+(including the [latest](https://github.com/koalaman/shellcheck/releases/tag/latest) meta-release for daily git builds).
+
+There are currently no official binaries for Apple Silicon, but third party builds are available via
+[ShellCheck for Visual Studio Code](https://github.com/vscode-shellcheck/shellcheck-binaries/releases).
+
+Distro packages already come with a `man` page. If you are building from source, it can be installed with:
+
+```console
+pandoc -s -f markdown-smart -t man shellcheck.1.md -o shellcheck.1
+sudo mv shellcheck.1 /usr/share/man/man1
+```
+
+### pre-commit
+
+To run ShellCheck via [pre-commit](https://pre-commit.com/), add the hook to your `.pre-commit-config.yaml`:
+
+```
+repos:
+-   repo: https://github.com/koalaman/shellcheck-precommit
+    rev: v0.7.2
+    hooks:
+    -   id: shellcheck
+#       args: ["--severity=warning"]  # Optionally only show errors and warnings
+```
+
+### Travis CI
+
+Travis CI has now integrated ShellCheck by default, so you don't need to manually install it.
+
+If you still want to do so in order to upgrade at your leisure or ensure you're
+using the latest release, follow the steps below to install a binary version.
+
+### Installing a pre-compiled binary
+
+The pre-compiled binaries come in `tar.xz` files. To decompress them, make sure
+`xz` is installed.
+On Debian/Ubuntu/Mint, you can `apt install xz-utils`.
+On Redhat/Fedora/CentOS, `yum -y install xz`.
+
+A simple installer may do something like:
+
+```bash
+scversion="stable" # or "v0.4.7", or "latest"
+wget -qO- "https://github.com/koalaman/shellcheck/releases/download/${scversion?}/shellcheck-${scversion?}.linux.x86_64.tar.xz" | tar -xJv
+cp "shellcheck-${scversion}/shellcheck" /usr/bin/
+shellcheck --version
+```
 
 ## Compiling from source
 
@@ -185,13 +301,11 @@ This section describes how to build ShellCheck from a source directory. ShellChe
 
 ShellCheck is built and packaged using Cabal. Install the package `cabal-install` from your system's package manager (with e.g. `apt-get`, `brew`, `emerge`, `yum`, or `zypper`).
 
-On MacOS (OS X), you can do a fast install of Cabal using brew, which takes a couple of minutes instead of more than 30 minutes if you try to compile it from source.
+On macOS (OS X), you can do a fast install of Cabal using brew, which takes a couple of minutes instead of more than 30 minutes if you try to compile it from source.
 
-    brew install cask
+    $ brew install cabal-install
-    brew cask install haskell-platform
-    cabal install cabal-install
 
-On MacPorts, the package is instead called `hs-cabal-install`, while native Windows users should install the latest version of the Haskell platform from https://www.haskell.org/platform/
+On MacPorts, the package is instead called `hs-cabal-install`, while native Windows users should install the latest version of the Haskell platform from <https://www.haskell.org/platform/>
 
 Verify that `cabal` is installed and update its dependency list with
 
@@ -203,10 +317,6 @@ Verify that `cabal` is installed and update its dependency list with
 
     $ cabal install
 
-Or if you intend to run the tests:
-
-    $ cabal install --enable-tests
-
 This will compile ShellCheck and install it to your `~/.cabal/bin` directory.
 
 Add this directory to your `PATH` (for bash, add this to your `~/.bashrc`):
@@ -227,12 +337,15 @@ may use a legacy codepage. In `cmd.exe`, `powershell.exe` and Powershell ISE,
 make sure to use a TrueType font, not a Raster font, and set the active
 codepage to UTF-8 (65001) with `chcp`:
 
-    > chcp 65001
+```cmd
-    Active code page: 65001
+chcp 65001
+```
 
 In Powershell ISE, you may need to additionally update the output encoding:
 
-    > [Console]::OutputEncoding = [System.Text.Encoding]::UTF8
+```powershell
+[Console]::OutputEncoding = [System.Text.Encoding]::UTF8
+```
 
 ### Running tests
 
@@ -259,6 +372,7 @@ echo 'Don't forget to restart!'   # Singlequote closed by apostrophe
 echo 'Don\'t try this at home'    # Attempting to escape ' in ''
 echo 'Path is $PATH'              # Variables in single quotes
 trap "echo Took ${SECONDS}s" 0    # Prematurely expanded trap
+unset var[i]                      # Array index treated as glob
 ```
 
 ### Conditionals
@@ -277,6 +391,7 @@ ShellCheck can recognize many types of incorrect test statements.
 [ grep -q foo file ]              # Command without $(..)
 [[ "$$file" == *.jpg ]]           # Comparisons that can't succeed
 (( 1 -lt 2 ))                     # Using test operators in ((..))
+[ x ] & [ y ] | [ z ]             # Accidental backgrounding and piping
 ```
 
 ### Frequently misused commands
@@ -293,6 +408,7 @@ alias archive='mv $1 /backup'     # Defining aliases with arguments
 tr -cd '[a-zA-Z0-9]'              # [] around ranges in tr
 exec foo; echo "Done!"            # Misused 'exec'
 find -name \*.bak -o -name \*~ -delete  # Implicit precedence in find
+# find . -exec foo > bar \;       # Redirections in find
 f() { whoami; }; sudo f           # External use of internal functions
 ```
 
@@ -308,9 +424,13 @@ var$n="Hello"                     # Wrong indirect assignment
 echo ${var$n}                     # Wrong indirect reference
 var=(1, 2, 3)                     # Comma separated arrays
 array=( [index] = value )         # Incorrect index initialization
+echo $var[14]                     # Missing {} in array references
 echo "Argument 10 is $10"         # Positional parameter misreference
 if $(myfunction); then ..; fi     # Wrapping commands in $()
 else if othercondition; then ..   # Using 'else if'
+f; f() { echo "hello world; }     # Using function before definition
+[ false ]                         # 'false' being true
+if ( -f file )                    # Using (..) instead of test
 ```
 
 ### Style
@@ -341,6 +461,10 @@ printf "%s\n" "Arguments: $@."    # Concatenating strings and arrays
 var=World; echo "Hello " var      # Unused lowercase variables
 echo "Hello $name"                # Unassigned lowercase variables
 cmd | read bar; echo $bar         # Assignments in subshells
+cat foo | cp bar                  # Piping to commands that don't read
+printf '%s: %s\n' foo             # Mismatches in printf argument count
+eval "${array[@]}"                # Lost word boundaries in array eval
+for i in "${x[@]}"; do ${x[$i]}   # Using array value as key
 ```
 
 ### Robustness
@@ -354,6 +478,7 @@ find . -exec sh -c 'a && b {}' \; # Find -exec shell injection
 printf "Hello $name"             # Variables in printf format
 for f in $(ls *.txt); do         # Iterating over ls output
 export MYVAR=$(cmd)              # Masked exit codes
+case $version in 2.*) :;; 2.6.*) # Shadowed case branches
 ```
 
 ### Portability
@@ -364,6 +489,7 @@ ShellCheck will warn when using features not supported by the shebang. For examp
 echo {1..$n}                     # Works in ksh, but not bash/dash/sh
 echo {1..10}                     # Works in ksh and bash, but not dash/sh
 echo -n 42                       # Works in ksh, bash and dash, undefined in sh
+expr match str regex             # Unportable alias for `expr str : regex`
 trap 'exit 42' sigint            # Unportable signal spec
 cmd &> file                      # Unportable redirection operator
 read foo < /dev/tcp/host/22      # Unportable intercepted files
@@ -384,10 +510,16 @@ rm “file”                         # Unicode quotes
 echo "Hello world"                # Carriage return / DOS line endings
 echo hello \                      # Trailing spaces after \
 var=42 echo $var                  # Expansion of inlined environment
-#!/bin/bash -x -e                 # Common shebang errors
+!# bin/bash -x -e                 # Common shebang errors
 echo $((n/180*100))               # Unnecessary loss of precision
 ls *[:digit:].txt                 # Bad character class globs
 sed 's/foo/bar/' file > file      # Redirecting to input
+var2=$var2                        # Variable assigned to itself
+[ x$var = xval ]                  # Antiquated x-comparisons
+ls() { ls -l "$@"; }              # Infinitely recursive wrapper
+alias ls='ls -l'; ls foo          # Alias used before it takes effect
+for x; do for x; do               # Nested loop uses same variable
+while getopts "a" f; do case $f in "b") # Unhandled getopts flags
 ```
 
 ## Testimonials
@@ -401,13 +533,13 @@ Alexander Tarasikov,
 
 Issues can be ignored via environmental variable, command line, individually or globally within a file:
 
-https://github.com/koalaman/shellcheck/wiki/Ignore
+<https://github.com/koalaman/shellcheck/wiki/Ignore>
 
 ## Reporting bugs
 
 Please use the GitHub issue tracker for any bugs or feature suggestions:
 
-https://github.com/koalaman/shellcheck/issues
+<https://github.com/koalaman/shellcheck/issues>
 
 ## Contributing
 
@@ -422,6 +554,11 @@ The contributor retains the copyright.
 
 ShellCheck is licensed under the GNU General Public License, v3. A copy of this license is included in the file [LICENSE](LICENSE).
 
-Copyright 2012-2015, Vidar 'koala_man' Holen and contributors.
+Copyright 2012-2019, [Vidar 'koala_man' Holen](https://github.com/koalaman/) and contributors.
 
 Happy ShellChecking!
+
+## Other Resources
+
+* The wiki has [long form descriptions](https://github.com/koalaman/shellcheck/wiki/Checks) for each warning, e.g. [SC2221](https://github.com/koalaman/shellcheck/wiki/SC2221).
+* ShellCheck does not attempt to enforce any kind of formatting or indenting style, so also check out [shfmt](https://github.com/mvdan/sh)!

Setup.hs

@@ -1,36 +0,0 @@
-import Distribution.PackageDescription (
-  HookedBuildInfo,
-  emptyHookedBuildInfo )
-import Distribution.Simple (
-  Args,
-  UserHooks ( preSDist ),
-  defaultMainWithHooks,
-  simpleUserHooks )
-import Distribution.Simple.Setup ( SDistFlags )
-
-import System.Process ( system )
-
-
-main = defaultMainWithHooks myHooks
-  where
-    myHooks = simpleUserHooks { preSDist = myPreSDist }
-
--- | This hook will be executed before e.g. @cabal sdist@. It runs
---   pandoc to create the man page from shellcheck.1.md. If the pandoc
---   command is not found, this will fail with an error message:
---
---     /bin/sh: pandoc: command not found
---
---   Since the man page is listed in the Extra-Source-Files section of
---   our cabal file, a failure here should result in a failure to
---   create the distribution tarball (that's a good thing).
---
-myPreSDist :: Args -> SDistFlags -> IO HookedBuildInfo
-myPreSDist _ _ = do
-  putStrLn "Building the man page (shellcheck.1) with pandoc..."
-  putStrLn pandoc_cmd
-  result <- system pandoc_cmd
-  putStrLn $ "pandoc exited with " ++ show result
-  return emptyHookedBuildInfo
-  where
-    pandoc_cmd = "pandoc -s -t man shellcheck.1.md -o shellcheck.1"

ShellCheck.cabal

@@ -1,14 +1,14 @@
 Name:             ShellCheck
-Version:          0.4.7
+Version:          0.10.0
 Synopsis:         Shell script analysis tool
 License:          GPL-3
 License-file:     LICENSE
 Category:         Static Analysis
 Author:           Vidar Holen
 Maintainer:       vidar@vidarholen.net
-Homepage:         http://www.shellcheck.net/
+Homepage:         https://www.shellcheck.net/
-Build-Type:       Custom
+Build-Type:       Simple
-Cabal-Version:    >= 1.8
+Cabal-Version:    1.18
 Bug-reports:      https://github.com/koalaman/shellcheck/issues
 Description:
   The goals of ShellCheck are:
@@ -22,12 +22,16 @@ Description:
   * To point out subtle caveats, corner cases and pitfalls, that may cause an
     advanced user's otherwise working script to fail under future circumstances.
 
+Extra-Doc-Files:
+    README.md
+    CHANGELOG.md
 Extra-Source-Files:
     -- documentation
-    README.md
     shellcheck.1.md
-    -- built with a cabal sdist hook
+    -- A script to build the man page using pandoc
-    shellcheck.1
+    manpage
+    -- convenience script for stripping tests
+    striptests
     -- tests
     test/shellcheck.hs
 
@@ -36,15 +40,31 @@ source-repository head
     location: git://github.com/koalaman/shellcheck.git
 
 library
+    hs-source-dirs: src
+    if impl(ghc < 8.0)
       build-depends:
-      base >= 4 && < 5,
+        semigroups
-      containers,
+    build-depends:
-      directory,
+      -- The lower bounds are based on GHC 7.10.3
-      json,
+      -- The upper bounds are based on GHC 9.8.1
-      mtl >= 2.2.1,
+      aeson                >= 1.4.0 && < 2.3,
-      parsec,
+      array                >= 0.5.1 && < 0.6,
-      regex-tdfa,
+      base                 >= 4.8.0.0 && < 5,
-      QuickCheck >= 2.7.4,
+      bytestring           >= 0.10.6 && < 0.13,
+      containers           >= 0.5.6 && < 0.8,
+      deepseq              >= 1.4.1 && < 1.6,
+      Diff                 >= 0.4.0 && < 1.1,
+      fgl                  (>= 5.7.0 && < 5.8.1.0) || (>= 5.8.1.1 && < 5.9),
+      filepath             >= 1.4.0 && < 1.6,
+      mtl                  >= 2.2.2 && < 2.4,
+      parsec               >= 3.1.14 && < 3.2,
+      QuickCheck           >= 2.14.2 && < 2.16,
+      regex-tdfa           >= 1.2.0 && < 1.4,
+      transformers         >= 0.4.2 && < 0.7,
+
+      -- getXdgDirectory from 1.2.3.0
+      directory            >= 1.2.3 && < 1.4,
+
       -- When cabal supports it, move this to setup-depends:
       process
     exposed-modules:
@@ -53,43 +73,74 @@ library
       ShellCheck.Analytics
       ShellCheck.Analyzer
       ShellCheck.AnalyzerLib
+      ShellCheck.CFG
+      ShellCheck.CFGAnalysis
       ShellCheck.Checker
       ShellCheck.Checks.Commands
+      ShellCheck.Checks.ControlFlow
+      ShellCheck.Checks.Custom
       ShellCheck.Checks.ShellSupport
       ShellCheck.Data
+      ShellCheck.Debug
+      ShellCheck.Fixer
       ShellCheck.Formatter.Format
       ShellCheck.Formatter.CheckStyle
+      ShellCheck.Formatter.Diff
       ShellCheck.Formatter.GCC
       ShellCheck.Formatter.JSON
+      ShellCheck.Formatter.JSON1
       ShellCheck.Formatter.TTY
+      ShellCheck.Formatter.Quiet
       ShellCheck.Interface
       ShellCheck.Parser
+      ShellCheck.Prelude
       ShellCheck.Regex
     other-modules:
       Paths_ShellCheck
+    default-language: Haskell98
 
 executable shellcheck
+    if impl(ghc < 8.0)
       build-depends:
-      base >= 4 && < 5,
+        semigroups
+    build-depends:
+      aeson,
+      array,
+      base,
+      bytestring,
       containers,
+      deepseq,
+      Diff,
       directory,
-      json,
+      fgl,
-      mtl >= 2.2.1,
+      mtl,
+      filepath,
       parsec,
+      QuickCheck,
       regex-tdfa,
-      QuickCheck >= 2.7.4
+      transformers,
+      ShellCheck
+    default-language: Haskell98
     main-is: shellcheck.hs
 
 test-suite test-shellcheck
     type: exitcode-stdio-1.0
     build-depends:
-      base >= 4 && < 5,
+      aeson,
+      array,
+      base,
+      bytestring,
       containers,
+      deepseq,
+      Diff,
       directory,
-      json,
+      fgl,
-      mtl >= 2.2.1,
+      filepath,
+      mtl,
       parsec,
+      QuickCheck,
       regex-tdfa,
-      QuickCheck >= 2.7.4
+      transformers,
+      ShellCheck
+    default-language: Haskell98
     main-is: test/shellcheck.hs
-

ShellCheck/AST.hs

@@ -1,386 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-module ShellCheck.AST where
-
-import Control.Monad.Identity
-import Text.Parsec
-import qualified ShellCheck.Regex as Re
-import Prelude hiding (id)
-
-newtype Id = Id Int deriving (Show, Eq, Ord)
-
-data Quoted = Quoted | Unquoted deriving (Show, Eq)
-data Dashed = Dashed | Undashed deriving (Show, Eq)
-data AssignmentMode = Assign | Append deriving (Show, Eq)
-newtype FunctionKeyword = FunctionKeyword Bool deriving (Show, Eq)
-newtype FunctionParentheses = FunctionParentheses Bool deriving (Show, Eq)
-data CaseType = CaseBreak | CaseFallThrough | CaseContinue deriving (Show, Eq)
-
-newtype Root = Root Token
-data Token =
-    TA_Binary Id String Token Token
-    | TA_Assignment Id String Token Token
-    | TA_Expansion Id [Token]
-    | TA_Index Id Token
-    | TA_Sequence Id [Token]
-    | TA_Trinary Id Token Token Token
-    | TA_Unary Id String Token
-    | TC_And Id ConditionType String Token Token
-    | TC_Binary Id ConditionType String Token Token
-    | TC_Group Id ConditionType Token
-    | TC_Nullary Id ConditionType Token
-    | TC_Or Id ConditionType String Token Token
-    | TC_Unary Id ConditionType String Token
-    | TC_Empty Id ConditionType
-    | T_AND_IF Id
-    | T_AndIf Id Token Token
-    | T_Arithmetic Id Token
-    | T_Array Id [Token]
-    | T_IndexedElement Id [Token] Token
-    -- Store the index as string, and parse as arithmetic or string later
-    | T_UnparsedIndex Id SourcePos String
-    | T_Assignment Id AssignmentMode String [Token] Token
-    | T_Backgrounded Id Token
-    | T_Backticked Id [Token]
-    | T_Bang Id
-    | T_Banged Id Token
-    | T_BraceExpansion Id [Token]
-    | T_BraceGroup Id [Token]
-    | T_CLOBBER Id
-    | T_Case Id
-    | T_CaseExpression Id Token [(CaseType, [Token], [Token])]
-    | T_Condition Id ConditionType Token
-    | T_DGREAT Id
-    | T_DLESS Id
-    | T_DLESSDASH Id
-    | T_DSEMI Id
-    | T_Do Id
-    | T_DollarArithmetic Id Token
-    | T_DollarBraced Id Token
-    | T_DollarBracket Id Token
-    | T_DollarDoubleQuoted Id [Token]
-    | T_DollarExpansion Id [Token]
-    | T_DollarSingleQuoted Id String
-    | T_DollarBraceCommandExpansion Id [Token]
-    | T_Done Id
-    | T_DoubleQuoted Id [Token]
-    | T_EOF Id
-    | T_Elif Id
-    | T_Else Id
-    | T_Esac Id
-    | T_Extglob Id String [Token]
-    | T_FdRedirect Id String Token
-    | T_Fi Id
-    | T_For Id
-    | T_ForArithmetic Id Token Token Token [Token]
-    | T_ForIn Id String [Token] [Token]
-    | T_Function Id FunctionKeyword FunctionParentheses String Token
-    | T_GREATAND Id
-    | T_Glob Id String
-    | T_Greater Id
-    | T_HereDoc Id Dashed Quoted String [Token]
-    | T_HereString Id Token
-    | T_If Id
-    | T_IfExpression Id [([Token],[Token])] [Token]
-    | T_In  Id
-    | T_IoFile Id Token Token
-    | T_IoDuplicate Id Token String
-    | T_LESSAND Id
-    | T_LESSGREAT Id
-    | T_Lbrace Id
-    | T_Less Id
-    | T_Literal Id String
-    | T_Lparen Id
-    | T_NEWLINE Id
-    | T_NormalWord Id [Token]
-    | T_OR_IF Id
-    | T_OrIf Id Token Token
-    | T_ParamSubSpecialChar Id String -- e.g. '%' in ${foo%bar}  or '/' in ${foo/bar/baz}
-    | T_Pipeline Id [Token] [Token] -- [Pipe separators] [Commands]
-    | T_ProcSub Id String [Token]
-    | T_Rbrace Id
-    | T_Redirecting Id [Token] Token
-    | T_Rparen Id
-    | T_Script Id String [Token]
-    | T_Select Id
-    | T_SelectIn Id String [Token] [Token]
-    | T_Semi Id
-    | T_SimpleCommand Id [Token] [Token]
-    | T_SingleQuoted Id String
-    | T_Subshell Id [Token]
-    | T_Then Id
-    | T_Until Id
-    | T_UntilExpression Id [Token] [Token]
-    | T_While Id
-    | T_WhileExpression Id [Token] [Token]
-    | T_Annotation Id [Annotation] Token
-    | T_Pipe Id String
-    | T_CoProc Id (Maybe String) Token
-    | T_CoProcBody Id Token
-    | T_Include Id Token Token -- . & source: SimpleCommand T_Script
-    deriving (Show)
-
-data Annotation =
-    DisableComment Integer
-    | SourceOverride String
-    | ShellOverride String
-    deriving (Show, Eq)
-data ConditionType = DoubleBracket | SingleBracket deriving (Show, Eq)
-
--- This is an abomination.
-tokenEquals :: Token -> Token -> Bool
-tokenEquals a b = kludge a == kludge b
-    where kludge s = Re.subRegex (Re.mkRegex "\\(Id [0-9]+\\)") (show s) "(Id 0)"
-
-instance Eq Token where
-    (==) = tokenEquals
-
-analyze :: Monad m => (Token -> m ()) -> (Token -> m ()) -> (Token -> m Token) -> Token -> m Token
-analyze f g i =
-    round
-  where
-    round t = do
-        f t
-        newT <- delve t
-        g t
-        i newT
-    roundAll = mapM round
-
-    dl l v = do
-        x <- roundAll l
-        return $ v x
-    dll l m v = do
-        x <- roundAll l
-        y <- roundAll m
-        return $ v x y
-    d1 t v = do
-        x <- round t
-        return $ v x
-    d2 t1 t2 v = do
-        x <- round t1
-        y <- round t2
-        return $ v x y
-
-    delve (T_NormalWord id list) = dl list $ T_NormalWord id
-    delve (T_DoubleQuoted id list) = dl list $ T_DoubleQuoted id
-    delve (T_DollarDoubleQuoted id list) = dl list $ T_DollarDoubleQuoted id
-    delve (T_DollarExpansion id list) = dl list $ T_DollarExpansion id
-    delve (T_DollarBraceCommandExpansion id list) = dl list $ T_DollarBraceCommandExpansion id
-    delve (T_BraceExpansion id list) = dl list $ T_BraceExpansion id
-    delve (T_Backticked id list) = dl list $ T_Backticked id
-    delve (T_DollarArithmetic id c) = d1 c $ T_DollarArithmetic id
-    delve (T_DollarBracket id c) = d1 c $ T_DollarBracket id
-    delve (T_IoFile id op file) = d2 op file $ T_IoFile id
-    delve (T_IoDuplicate id op num) = d1 op $ \x -> T_IoDuplicate id x num
-    delve (T_HereString id word) = d1 word $ T_HereString id
-    delve (T_FdRedirect id v t) = d1 t $ T_FdRedirect id v
-    delve (T_Assignment id mode var indices value) = do
-        a <- roundAll indices
-        b <- round value
-        return $ T_Assignment id mode var a b
-    delve (T_Array id t) = dl t $ T_Array id
-    delve (T_IndexedElement id indices t) = do
-        a <- roundAll indices
-        b <- round t
-        return $ T_IndexedElement id a b
-    delve (T_Redirecting id redirs cmd) = do
-        a <- roundAll redirs
-        b <- round cmd
-        return $ T_Redirecting id a b
-    delve (T_SimpleCommand id vars cmds) = dll vars cmds $ T_SimpleCommand id
-    delve (T_Pipeline id l1 l2) = dll l1 l2 $ T_Pipeline id
-    delve (T_Banged id l) = d1 l $ T_Banged id
-    delve (T_AndIf id t u) = d2 t u $ T_AndIf id
-    delve (T_OrIf id t u) = d2 t u $ T_OrIf id
-    delve (T_Backgrounded id l) = d1 l $ T_Backgrounded id
-    delve (T_Subshell id l) = dl l $ T_Subshell id
-    delve (T_ProcSub id typ l) = dl l $ T_ProcSub id typ
-    delve (T_Arithmetic id c) = d1 c $ T_Arithmetic id
-    delve (T_IfExpression id conditions elses) = do
-        newConds <- mapM (\(c, t) -> do
-                            x <- mapM round c
-                            y <- mapM round t
-                            return (x,y)
-                    ) conditions
-        newElses <- roundAll elses
-        return $ T_IfExpression id newConds newElses
-    delve (T_BraceGroup id l) = dl l $ T_BraceGroup id
-    delve (T_WhileExpression id c l) = dll c l $ T_WhileExpression id
-    delve (T_UntilExpression id c l) = dll c l $ T_UntilExpression id
-    delve (T_ForIn id v w l) = dll w l $ T_ForIn id v
-    delve (T_SelectIn id v w l) = dll w l $ T_SelectIn id v
-    delve (T_CaseExpression id word cases) = do
-        newWord <- round word
-        newCases <- mapM (\(o, c, t) -> do
-                            x <- mapM round c
-                            y <- mapM round t
-                            return (o, x,y)
-                        ) cases
-        return $ T_CaseExpression id newWord newCases
-
-    delve (T_ForArithmetic id a b c group) = do
-        x <- round a
-        y <- round b
-        z <- round c
-        list <- mapM round group
-        return $ T_ForArithmetic id x y z list
-
-    delve (T_Script id s l) = dl l $ T_Script id s
-    delve (T_Function id a b name body) = d1 body $ T_Function id a b name
-    delve (T_Condition id typ token) = d1 token $ T_Condition id typ
-    delve (T_Extglob id str l) = dl l $ T_Extglob id str
-    delve (T_DollarBraced id op) = d1 op $ T_DollarBraced id
-    delve (T_HereDoc id d q str l) = dl l $ T_HereDoc id d q str
-
-    delve (TC_And id typ str t1 t2) = d2 t1 t2 $ TC_And id typ str
-    delve (TC_Or id typ str t1 t2) = d2 t1 t2 $ TC_Or id typ str
-    delve (TC_Group id typ token) = d1 token $ TC_Group id typ
-    delve (TC_Binary id typ op lhs rhs) = d2 lhs rhs $ TC_Binary id typ op
-    delve (TC_Unary id typ op token) = d1 token $ TC_Unary id typ op
-    delve (TC_Nullary id typ token) = d1 token $ TC_Nullary id typ
-
-    delve (TA_Binary id op t1 t2) = d2 t1 t2 $ TA_Binary id op
-    delve (TA_Assignment id op t1 t2) = d2 t1 t2 $ TA_Assignment id op
-    delve (TA_Unary id op t1) = d1 t1 $ TA_Unary id op
-    delve (TA_Sequence id l) = dl l $ TA_Sequence id
-    delve (TA_Trinary id t1 t2 t3) = do
-        a <- round t1
-        b <- round t2
-        c <- round t3
-        return $ TA_Trinary id a b c
-    delve (TA_Expansion id t) = dl t $ TA_Expansion id
-    delve (TA_Index id t) = d1 t $ TA_Index id
-    delve (T_Annotation id anns t) = d1 t $ T_Annotation id anns
-    delve (T_CoProc id var body) = d1 body $ T_CoProc id var
-    delve (T_CoProcBody id t) = d1 t $ T_CoProcBody id
-    delve (T_Include id includer script) = d2 includer script $ T_Include id
-    delve t = return t
-
-getId :: Token -> Id
-getId t = case t of
-        T_AND_IF id  -> id
-        T_OR_IF id  -> id
-        T_DSEMI id  -> id
-        T_Semi id  -> id
-        T_DLESS id  -> id
-        T_DGREAT id  -> id
-        T_LESSAND id  -> id
-        T_GREATAND id  -> id
-        T_LESSGREAT id  -> id
-        T_DLESSDASH id  -> id
-        T_CLOBBER id  -> id
-        T_If id  -> id
-        T_Then id  -> id
-        T_Else id  -> id
-        T_Elif id  -> id
-        T_Fi id  -> id
-        T_Do id  -> id
-        T_Done id  -> id
-        T_Case id  -> id
-        T_Esac id  -> id
-        T_While id  -> id
-        T_Until id  -> id
-        T_For id  -> id
-        T_Select id  -> id
-        T_Lbrace id  -> id
-        T_Rbrace id  -> id
-        T_Lparen id  -> id
-        T_Rparen id  -> id
-        T_Bang id  -> id
-        T_In  id  -> id
-        T_NEWLINE id  -> id
-        T_EOF id  -> id
-        T_Less id  -> id
-        T_Greater id  -> id
-        T_SingleQuoted id _  -> id
-        T_Literal id _  -> id
-        T_NormalWord id _  -> id
-        T_DoubleQuoted id _  -> id
-        T_DollarExpansion id _  -> id
-        T_DollarBraced id _  -> id
-        T_DollarArithmetic id _  -> id
-        T_BraceExpansion id _  -> id
-        T_ParamSubSpecialChar id _ -> id
-        T_DollarBraceCommandExpansion id _  -> id
-        T_IoFile id _ _  -> id
-        T_IoDuplicate id _ _  -> id
-        T_HereDoc id _ _ _ _ -> id
-        T_HereString id _  -> id
-        T_FdRedirect id _ _  -> id
-        T_Assignment id _ _ _ _  -> id
-        T_Array id _  -> id
-        T_IndexedElement id _ _  -> id
-        T_Redirecting id _ _  -> id
-        T_SimpleCommand id _ _  -> id
-        T_Pipeline id _ _  -> id
-        T_Banged id _  -> id
-        T_AndIf id _ _ -> id
-        T_OrIf id _ _ -> id
-        T_Backgrounded id _  -> id
-        T_IfExpression id _ _  -> id
-        T_Subshell id _  -> id
-        T_BraceGroup id _  -> id
-        T_WhileExpression id _ _  -> id
-        T_UntilExpression id _ _  -> id
-        T_ForIn id _ _ _  -> id
-        T_SelectIn id _ _ _  -> id
-        T_CaseExpression id _ _ -> id
-        T_Function id _ _ _ _  -> id
-        T_Arithmetic id _  -> id
-        T_Script id _ _  -> id
-        T_Condition id _ _  -> id
-        T_Extglob id _ _ -> id
-        T_Backticked id _ -> id
-        TC_And id _ _ _ _  -> id
-        TC_Or id _ _ _ _  -> id
-        TC_Group id _ _  -> id
-        TC_Binary id _ _ _ _  -> id
-        TC_Unary id _ _ _  -> id
-        TC_Nullary id _ _  -> id
-        TA_Binary id _ _ _  -> id
-        TA_Assignment id _ _ _  -> id
-        TA_Unary id _ _  -> id
-        TA_Sequence id _  -> id
-        TA_Trinary id _ _ _  -> id
-        TA_Expansion id _  -> id
-        TA_Index id _  -> id
-        T_ProcSub id _ _ -> id
-        T_Glob id _ -> id
-        T_ForArithmetic id _ _ _ _ -> id
-        T_DollarSingleQuoted id _ -> id
-        T_DollarDoubleQuoted id _ -> id
-        T_DollarBracket id _ -> id
-        T_Annotation id _ _ -> id
-        T_Pipe id _ -> id
-        T_CoProc id _ _ -> id
-        T_CoProcBody id _ -> id
-        T_Include id _ _ -> id
-        T_UnparsedIndex id _ _ -> id
-        TC_Empty id _ -> id
-
-blank :: Monad m => Token -> m ()
-blank = const $ return ()
-doAnalysis :: Monad m => (Token -> m ()) -> Token -> m Token
-doAnalysis f = analyze f blank return
-doStackAnalysis :: Monad m => (Token -> m ()) -> (Token -> m ()) -> Token -> m Token
-doStackAnalysis startToken endToken = analyze startToken endToken return
-doTransform :: (Token -> Token) -> Token -> Token
-doTransform i = runIdentity . analyze blank blank (return . i)
-

ShellCheck/ASTLib.hs

@@ -1,436 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-module ShellCheck.ASTLib where
-
-import ShellCheck.AST
-
-import Control.Monad.Writer
-import Control.Monad
-import Data.Functor
-import Data.List
-import Data.Maybe
-
--- Is this a type of loop?
-isLoop t = case t of
-        T_WhileExpression {} -> True
-        T_UntilExpression {} -> True
-        T_ForIn {} -> True
-        T_ForArithmetic {} -> True
-        T_SelectIn {}  -> True
-        _ -> False
-
--- Will this split into multiple words when used as an argument?
-willSplit x =
-  case x of
-    T_DollarBraced {} -> True
-    T_DollarExpansion {} -> True
-    T_Backticked {} -> True
-    T_BraceExpansion {} -> True
-    T_Glob {} -> True
-    T_Extglob {} -> True
-    T_NormalWord _ l -> any willSplit l
-    _ -> False
-
-isGlob T_Extglob {} = True
-isGlob T_Glob {} = True
-isGlob (T_NormalWord _ l) = any isGlob l
-isGlob _ = False
-
--- Is this shell word a constant?
-isConstant token =
-    case token of
-        -- This ignores some cases like ~"foo":
-        T_NormalWord _ (T_Literal _ ('~':_) : _)  -> False
-        T_NormalWord _ l   -> all isConstant l
-        T_DoubleQuoted _ l -> all isConstant l
-        T_SingleQuoted _ _ -> True
-        T_Literal _ _ -> True
-        _ -> False
-
--- Is this an empty literal?
-isEmpty token =
-    case token of
-        T_NormalWord _ l   -> all isEmpty l
-        T_DoubleQuoted _ l -> all isEmpty l
-        T_SingleQuoted _ "" -> True
-        T_Literal _ "" -> True
-        _ -> False
-
--- Quick&lazy oversimplification of commands, throwing away details
--- and returning a list like  ["find", ".", "-name", "${VAR}*" ].
-oversimplify token =
-    case token of
-        (T_NormalWord _ l) -> [concat (concatMap oversimplify l)]
-        (T_DoubleQuoted _ l) -> [concat (concatMap oversimplify l)]
-        (T_SingleQuoted _ s) -> [s]
-        (T_DollarBraced _ _) -> ["${VAR}"]
-        (T_DollarArithmetic _ _) -> ["${VAR}"]
-        (T_DollarExpansion _ _) -> ["${VAR}"]
-        (T_Backticked _ _) -> ["${VAR}"]
-        (T_Glob _ s) -> [s]
-        (T_Pipeline _ _ [x]) -> oversimplify x
-        (T_Literal _ x) -> [x]
-        (T_ParamSubSpecialChar _ x) -> [x]
-        (T_SimpleCommand _ vars words) -> concatMap oversimplify words
-        (T_Redirecting _ _ foo) -> oversimplify foo
-        (T_DollarSingleQuoted _ s) -> [s]
-        (T_Annotation _ _ s) -> oversimplify s
-        -- Workaround for let "foo = bar" parsing
-        (TA_Sequence _ [TA_Expansion _ v]) -> concatMap oversimplify v
-        _ -> []
-
-
--- Turn a SimpleCommand foo -avz --bar=baz into args "a", "v", "z", "bar",
--- each in a tuple of (token, stringFlag). Non-flag arguments are added with
--- stringFlag == "".
-getFlagsUntil stopCondition (T_SimpleCommand _ _ (_:args)) =
-    let tokenAndText = map (\x -> (x, concat $ oversimplify x)) args
-        (flagArgs, rest) = break (stopCondition . snd) tokenAndText
-    in
-        concatMap flag flagArgs ++ map (\(t, _) -> (t, "")) rest
-  where
-    flag (x, '-':'-':arg) = [ (x, takeWhile (/= '=') arg) ]
-    flag (x, '-':args) = map (\v -> (x, [v])) args
-    flag (x, _) = [ (x, "") ]
-getFlagsUntil _ _ = error "Internal shellcheck error, please report! (getFlags on non-command)"
-
--- Get all flags in a GNU way, up until --
-getAllFlags = getFlagsUntil (== "--")
--- Get all flags in a BSD way, up until first non-flag argument or --
-getLeadingFlags = getFlagsUntil (\x -> x == "--" || (not $ "-" `isPrefixOf` x))
-
--- Check if a command has a flag.
-hasFlag cmd str = str `elem` (map snd $ getAllFlags cmd)
-
--- Is this token a word that starts with a dash?
-isFlag token =
-    case getWordParts token of
-        T_Literal _ ('-':_) : _ -> True
-        _ -> False
-
--- Is this token a flag where the - is unquoted?
-isUnquotedFlag token = fromMaybe False $ do
-    str <- getLeadingUnquotedString token
-    return $ "-" `isPrefixOf` str
-
--- Given a T_DollarBraced, return a simplified version of the string contents.
-bracedString (T_DollarBraced _ l) = concat $ oversimplify l
-bracedString _ = error "Internal shellcheck error, please report! (bracedString on non-variable)"
-
--- Is this an expansion of multiple items of an array?
-isArrayExpansion t@(T_DollarBraced _ _) =
-    let string = bracedString t in
-        "@" `isPrefixOf` string ||
-            not ("#" `isPrefixOf` string) && "[@]" `isInfixOf` string
-isArrayExpansion _ = False
-
--- Is it possible that this arg becomes multiple args?
-mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f t
-  where
-    f t@(T_DollarBraced _ _) =
-        let string = bracedString t in
-            "!" `isPrefixOf` string
-    f (T_DoubleQuoted _ parts) = any f parts
-    f (T_NormalWord _ parts) = any f parts
-    f _ = False
-
--- Is it certain that this word will becomes multiple words?
-willBecomeMultipleArgs t = willConcatInAssignment t || f t
-  where
-    f T_Extglob {} = True
-    f T_Glob {} = True
-    f T_BraceExpansion {} = True
-    f (T_DoubleQuoted _ parts) = any f parts
-    f (T_NormalWord _ parts) = any f parts
-    f _ = False
-
--- This does token cause implicit concatenation in assignments?
-willConcatInAssignment token =
-    case token of
-        t@T_DollarBraced {} -> isArrayExpansion t
-        (T_DoubleQuoted _ parts) -> any willConcatInAssignment parts
-        (T_NormalWord _ parts) -> any willConcatInAssignment parts
-        _ -> False
-
--- Maybe get the literal string corresponding to this token
-getLiteralString :: Token -> Maybe String
-getLiteralString = getLiteralStringExt (const Nothing)
-
--- Definitely get a literal string, skipping over all non-literals
-onlyLiteralString :: Token -> String
-onlyLiteralString = fromJust . getLiteralStringExt (const $ return "")
-
--- Maybe get a literal string, but only if it's an unquoted argument.
-getUnquotedLiteral (T_NormalWord _ list) =
-    concat <$> mapM str list
-  where
-    str (T_Literal _ s) = return s
-    str _ = Nothing
-getUnquotedLiteral _ = Nothing
-
--- Get the last unquoted T_Literal in a word like "${var}foo"THIS
--- or nothing if the word does not end in an unquoted literal.
-getTrailingUnquotedLiteral :: Token -> Maybe Token
-getTrailingUnquotedLiteral t =
-    case t of
-        (T_NormalWord _ list@(_:_)) ->
-            from (last list)
-        _ -> Nothing
-  where
-    from t =
-        case t of
-            T_Literal {} -> return t
-            _ -> Nothing
-
--- Get the leading, unquoted, literal string of a token (if any).
-getLeadingUnquotedString :: Token -> Maybe String
-getLeadingUnquotedString t =
-    case t of
-        T_NormalWord _ ((T_Literal _ s) : _) -> return s
-        _ -> Nothing
-
--- Maybe get the literal string of this token and any globs in it.
-getGlobOrLiteralString = getLiteralStringExt f
-  where
-    f (T_Glob _ str) = return str
-    f _ = Nothing
-
--- Maybe get the literal value of a token, using a custom function
--- to map unrecognized Tokens into strings.
-getLiteralStringExt :: (Token -> Maybe String) -> Token -> Maybe String
-getLiteralStringExt more = g
-  where
-    allInList = fmap concat . mapM g
-    g (T_DoubleQuoted _ l) = allInList l
-    g (T_DollarDoubleQuoted _ l) = allInList l
-    g (T_NormalWord _ l) = allInList l
-    g (TA_Expansion _ l) = allInList l
-    g (T_SingleQuoted _ s) = return s
-    g (T_Literal _ s) = return s
-    g (T_ParamSubSpecialChar _ s) = return s
-    g x = more x
-
--- Is this token a string literal?
-isLiteral t = isJust $ getLiteralString t
-
-
--- Turn a NormalWord like foo="bar $baz" into a series of constituent elements like [foo=,bar ,$baz]
-getWordParts (T_NormalWord _ l)   = concatMap getWordParts l
-getWordParts (T_DoubleQuoted _ l) = l
--- TA_Expansion is basically T_NormalWord for arithmetic expressions
-getWordParts (TA_Expansion _ l)   = concatMap getWordParts l
-getWordParts other                = [other]
-
--- Return a list of NormalWords that would result from brace expansion
-braceExpand (T_NormalWord id list) = take 1000 $ do
-    items <- mapM part list
-    return $ T_NormalWord id items
-  where
-    part (T_BraceExpansion id items) = do
-        item <- items
-        braceExpand item
-    part x = return x
-
--- Maybe get a SimpleCommand from immediate wrappers like T_Redirections
-getCommand t =
-    case t of
-        T_Redirecting _ _ w -> getCommand w
-        T_SimpleCommand _ _ (w:_) -> return t
-        T_Annotation _ _ t -> getCommand t
-        _ -> Nothing
-
--- Maybe get the command name of a token representing a command
-getCommandName t = do
-    (T_SimpleCommand _ _ (w:rest)) <- getCommand t
-    s <- getLiteralString w
-    if "busybox" `isSuffixOf` s
-        then
-            case rest of
-                (applet:_) -> getLiteralString applet
-                _ -> return s
-        else
-            return s
-
--- If a command substitution is a single command, get its name.
---  $(date +%s) = Just "date"
-getCommandNameFromExpansion :: Token -> Maybe String
-getCommandNameFromExpansion t =
-    case t of
-        T_DollarExpansion _ [c] -> extract c
-        T_Backticked _ [c] -> extract c
-        T_DollarBraceCommandExpansion _ [c] -> extract c
-        _ -> Nothing
-  where
-    extract (T_Pipeline _ _ [cmd]) = getCommandName cmd
-    extract _ = Nothing
-
--- Get the basename of a token representing a command
-getCommandBasename = fmap basename . getCommandName
-  where
-    basename = reverse . takeWhile (/= '/') . reverse
-
-isAssignment t =
-    case t of
-        T_Redirecting _ _ w -> isAssignment w
-        T_SimpleCommand _ (w:_) [] -> True
-        T_Assignment {} -> True
-        T_Annotation _ _ w -> isAssignment w
-        _ -> False
-
-isOnlyRedirection t =
-    case t of
-        T_Pipeline _ _ [x] -> isOnlyRedirection x
-        T_Annotation _ _ w -> isOnlyRedirection w
-        T_Redirecting _ (_:_) c -> isOnlyRedirection c
-        T_SimpleCommand _ [] [] -> True
-        _ -> False
-
-isFunction t = case t of T_Function {} -> True; _ -> False
-
-isBraceExpansion t = case t of T_BraceExpansion {} -> True; _ -> False
-
--- Get the lists of commands from tokens that contain them, such as
--- the body of while loops or branches of if statements.
-getCommandSequences :: Token -> [[Token]]
-getCommandSequences t =
-    case t of
-        T_Script _ _ cmds -> [cmds]
-        T_BraceGroup _ cmds -> [cmds]
-        T_Subshell _ cmds -> [cmds]
-        T_WhileExpression _ _ cmds -> [cmds]
-        T_UntilExpression _ _ cmds -> [cmds]
-        T_ForIn _ _ _ cmds -> [cmds]
-        T_ForArithmetic _ _ _ _ cmds -> [cmds]
-        T_IfExpression _ thens elses -> map snd thens ++ [elses]
-        T_Annotation _ _ t -> getCommandSequences t
-        _ -> []
-
--- Get a list of names of associative arrays
-getAssociativeArrays t =
-    nub . execWriter $ doAnalysis f t
-  where
-    f :: Token -> Writer [String] ()
-    f t@T_SimpleCommand {} = fromMaybe (return ()) $ do
-        name <- getCommandName t
-        let assocNames = ["declare","local","typeset"]
-        guard $ elem name assocNames
-        let flags = getAllFlags t
-        guard $ elem "A" $ map snd flags
-        let args = map fst . filter ((==) "" . snd) $ flags
-        let names = mapMaybe (getLiteralStringExt nameAssignments) args
-        return $ tell names
-    f _ = return ()
-
-    nameAssignments t =
-        case t of
-            T_Assignment _ _ name _ _ -> return name
-            _ -> Nothing
-
--- A Pseudoglob is a wildcard pattern used for checking if a match can succeed.
--- For example, [[ $(cmd).jpg == [a-z] ]] will give the patterns *.jpg and ?, which
--- can be proven never to match.
-data PseudoGlob = PGAny | PGMany | PGChar Char
-    deriving (Eq, Show)
-
--- Turn a word into a PG pattern, replacing all unknown/runtime values with
--- PGMany.
-wordToPseudoGlob :: Token -> Maybe [PseudoGlob]
-wordToPseudoGlob word =
-    simplifyPseudoGlob . concat <$> mapM f (getWordParts word)
-  where
-    f x = case x of
-        T_Literal _ s -> return $ map PGChar s
-        T_SingleQuoted _ s -> return $ map PGChar s
-
-        T_DollarBraced {} -> return [PGMany]
-        T_DollarExpansion {} -> return [PGMany]
-        T_Backticked {} -> return [PGMany]
-
-        T_Glob _ "?" -> return [PGAny]
-        T_Glob _ ('[':_)  -> return [PGAny]
-        T_Glob {} -> return [PGMany]
-
-        T_Extglob {} -> return [PGMany]
-
-        _ -> return [PGMany]
-
--- Turn a word into a PG pattern, but only if we can preserve
--- exact semantics.
-wordToExactPseudoGlob :: Token -> Maybe [PseudoGlob]
-wordToExactPseudoGlob word =
-    simplifyPseudoGlob . concat <$> mapM f (getWordParts word)
-  where
-    f x = case x of
-        T_Literal _ s -> return $ map PGChar s
-        T_SingleQuoted _ s -> return $ map PGChar s
-        T_Glob _ "?" -> return [PGAny]
-        T_Glob _ "*" -> return [PGMany]
-        _ -> fail "Unknown token type"
-
--- Reorder a PseudoGlob for more efficient matching, e.g.
--- f?*?**g -> f??*g
-simplifyPseudoGlob :: [PseudoGlob] -> [PseudoGlob]
-simplifyPseudoGlob = f
-  where
-    f [] = []
-    f (x@(PGChar _) : rest ) = x : f rest
-    f list =
-        let (anys, rest) = span (\x -> x == PGMany || x == PGAny) list in
-            order anys ++ f rest
-
-    order s = let (any, many) = partition (== PGAny) s in
-        any ++ take 1 many
-
--- Check whether the two patterns can ever overlap.
-pseudoGlobsCanOverlap :: [PseudoGlob] -> [PseudoGlob] -> Bool
-pseudoGlobsCanOverlap = matchable
-  where
-    matchable x@(xf:xs) y@(yf:ys) =
-        case (xf, yf) of
-            (PGMany, _) -> matchable x ys || matchable xs y
-            (_, PGMany) -> matchable x ys || matchable xs y
-            (PGAny, _) -> matchable xs ys
-            (_, PGAny) -> matchable xs ys
-            (_, _) -> xf == yf && matchable xs ys
-
-    matchable [] [] = True
-    matchable (PGMany : rest) [] = matchable rest []
-    matchable (_:_) [] = False
-    matchable [] r = matchable r []
-
--- Check whether the first pattern always overlaps the second.
-pseudoGlobIsSuperSetof :: [PseudoGlob] -> [PseudoGlob] -> Bool
-pseudoGlobIsSuperSetof = matchable
-  where
-    matchable x@(xf:xs) y@(yf:ys) =
-        case (xf, yf) of
-            (PGMany, PGMany) -> matchable x ys
-            (PGMany, _) -> matchable x ys || matchable xs y
-            (_, PGMany) -> False
-            (PGAny, _) -> matchable xs ys
-            (_, PGAny) -> False
-            (_, _) -> xf == yf && matchable xs ys
-
-    matchable [] [] = True
-    matchable (PGMany : rest) [] = matchable rest []
-    matchable _ _ = False
-
-wordsCanBeEqual x y = fromMaybe True $
-    liftM2 pseudoGlobsCanOverlap (wordToPseudoGlob x) (wordToPseudoGlob y)

ShellCheck/AnalyzerLib.hs

@@ -1,843 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-{-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE FlexibleContexts #-}
-module ShellCheck.AnalyzerLib where
-import ShellCheck.AST
-import ShellCheck.ASTLib
-import ShellCheck.Data
-import ShellCheck.Interface
-import ShellCheck.Parser
-import ShellCheck.Regex
-
-import Control.Arrow (first)
-import Control.Monad.Identity
-import Control.Monad.RWS
-import Control.Monad.State
-import Control.Monad.Writer
-import Data.Char
-import Data.List
-import Data.Maybe
-import qualified Data.Map as Map
-
-import Test.QuickCheck.All (forAllProperties)
-import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
-
-type Analysis = AnalyzerM ()
-type AnalyzerM a = RWS Parameters [TokenComment] Cache a
-nullCheck = const $ return ()
-
-
-data Checker = Checker {
-    perScript :: Root -> Analysis,
-    perToken :: Token -> Analysis
-}
-
-runChecker :: Parameters -> Checker -> [TokenComment]
-runChecker params checker = notes
-    where
-        root = rootNode params
-        check = perScript checker `composeAnalyzers` (\(Root x) -> void $ doAnalysis (perToken checker) x)
-        notes = snd $ evalRWS (check $ Root root) params Cache
-
-instance Monoid Checker where
-    mempty = Checker {
-        perScript = nullCheck,
-        perToken = nullCheck
-        }
-    mappend x y = Checker {
-        perScript = perScript x `composeAnalyzers` perScript y,
-        perToken = perToken x `composeAnalyzers` perToken y
-        }
-
-
-composeAnalyzers :: (a -> Analysis) -> (a -> Analysis) -> a -> Analysis
-composeAnalyzers f g x = f x >> g x
-
-data Parameters = Parameters {
-    hasLastpipe :: Bool,           -- Whether this script has the 'lastpipe' option set/default.
-    hasSetE     :: Bool,           -- Whether this script has 'set -e' anywhere.
-    variableFlow :: [StackData],   -- A linear (bad) analysis of data flow
-    parentMap :: Map.Map Id Token, -- A map from Id to parent Token
-    shellType :: Shell,            -- The shell type, such as Bash or Ksh
-    shellTypeSpecified :: Bool,    -- True if shell type was forced via flags
-    rootNode :: Token              -- The root node of the AST
-    }
-
--- TODO: Cache results of common AST ops here
-data Cache = Cache {}
-
-data Scope = SubshellScope String | NoneScope deriving (Show, Eq)
-data StackData =
-    StackScope Scope
-    | StackScopeEnd
-    -- (Base expression, specific position, var name, assigned values)
-    | Assignment (Token, Token, String, DataType)
-    | Reference (Token, Token, String)
-  deriving (Show)
-
-data DataType = DataString DataSource | DataArray DataSource
-  deriving (Show)
-
-data DataSource =
-    SourceFrom [Token]
-    | SourceExternal
-    | SourceDeclaration
-    | SourceInteger
-    | SourceChecked
-  deriving (Show)
-
-data VariableState = Dead Token String | Alive deriving (Show)
-
-defaultSpec root = AnalysisSpec {
-    asScript = root,
-    asShellType = Nothing,
-    asCheckSourced = False,
-    asExecutionMode = Executed
-}
-
-pScript s =
-  let
-    pSpec = ParseSpec {
-        psFilename = "script",
-        psScript = s,
-        psCheckSourced = False
-    }
-  in prRoot . runIdentity $ parseScript (mockedSystemInterface []) pSpec
-
--- For testing. If parsed, returns whether there are any comments
-producesComments :: Checker -> String -> Maybe Bool
-producesComments c s = do
-        root <- pScript s
-        let spec = defaultSpec root
-        let params = makeParameters spec
-        return . not . null $ runChecker params c
-
-makeComment :: Severity -> Id -> Code -> String -> TokenComment
-makeComment severity id code note =
-    TokenComment id $ Comment severity code note
-
-addComment note = tell [note]
-
-warn :: MonadWriter [TokenComment] m => Id -> Code -> String -> m ()
-warn  id code str = addComment $ makeComment WarningC id code str
-err   id code str = addComment $ makeComment ErrorC id code str
-info  id code str = addComment $ makeComment InfoC id code str
-style id code str = addComment $ makeComment StyleC id code str
-
-makeParameters spec =
-    let params = Parameters {
-        rootNode = root,
-        shellType = fromMaybe (determineShell root) $ asShellType spec,
-        hasSetE = containsSetE root,
-        hasLastpipe =
-            case shellType params of
-                Bash -> containsLastpipe root
-                Dash -> False
-                Sh -> False
-                Ksh -> True,
-
-        shellTypeSpecified = isJust $ asShellType spec,
-        parentMap = getParentTree root,
-        variableFlow = getVariableFlow params root
-    } in params
-  where root = asScript spec
-
-
--- Does this script mention 'set -e' anywhere?
--- Used as a hack to disable certain warnings.
-containsSetE root = isNothing $ doAnalysis (guard . not . isSetE) root
-  where
-    isSetE t =
-        case t of
-            T_Script _ str _ -> str `matches` re
-            T_SimpleCommand {}  ->
-                t `isUnqualifiedCommand` "set" &&
-                    ("errexit" `elem` oversimplify t ||
-                        "e" `elem` map snd (getAllFlags t))
-            _ -> False
-    re = mkRegex "[[:space:]]-[^-]*e"
-
--- Does this script mention 'shopt -s lastpipe' anywhere?
--- Also used as a hack.
-containsLastpipe root =
-        isNothing $ doAnalysis (guard . not . isShoptLastPipe) root
-    where
-        isShoptLastPipe t =
-            case t of
-                T_SimpleCommand {}  ->
-                    t `isUnqualifiedCommand` "shopt" &&
-                        ("lastpipe" `elem` oversimplify t)
-                _ -> False
-
-
-prop_determineShell0 = determineShell (fromJust $ pScript "#!/bin/sh") == Sh
-prop_determineShell1 = determineShell (fromJust $ pScript "#!/usr/bin/env ksh") == Ksh
-prop_determineShell2 = determineShell (fromJust $ pScript "") == Bash
-prop_determineShell3 = determineShell (fromJust $ pScript "#!/bin/sh -e") == Sh
-prop_determineShell4 = determineShell (fromJust $ pScript
-    "#!/bin/ksh\n#shellcheck shell=sh\nfoo") == Sh
-prop_determineShell5 = determineShell (fromJust $ pScript
-    "#shellcheck shell=sh\nfoo") == Sh
-prop_determineShell6 = determineShell (fromJust $ pScript "#! /bin/sh") == Sh
-prop_determineShell7 = determineShell (fromJust $ pScript "#! /bin/ash") == Dash
-determineShell t = fromMaybe Bash $ do
-    shellString <- foldl mplus Nothing $ getCandidates t
-    shellForExecutable shellString
-  where
-    forAnnotation t =
-        case t of
-            (ShellOverride s) -> return s
-            _ -> fail ""
-    getCandidates :: Token -> [Maybe String]
-    getCandidates t@T_Script {} = [Just $ fromShebang t]
-    getCandidates (T_Annotation _ annotations s) =
-        map forAnnotation annotations ++
-           [Just $ fromShebang s]
-    fromShebang (T_Script _ s t) = executableFromShebang s
-
--- Given a string like "/bin/bash" or "/usr/bin/env dash",
--- return the shell basename like "bash" or "dash"
-executableFromShebang :: String -> String
-executableFromShebang = shellFor
-  where
-    shellFor s | "/env " `isInfixOf` s = head (drop 1 (words s)++[""])
-    shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
-    shellFor s = reverse . takeWhile (/= '/') . reverse $ s
-
-
-
--- Given a root node, make a map from Id to parent Token.
--- This is used to populate parentMap in Parameters
-getParentTree :: Token -> Map.Map Id Token
-getParentTree t =
-    snd . snd $ runState (doStackAnalysis pre post t) ([], Map.empty)
-  where
-    pre t = modify (first ((:) t))
-    post t = do
-        (_:rest, map) <- get
-        case rest of [] -> put (rest, map)
-                     (x:_) -> put (rest, Map.insert (getId t) x map)
-
--- Given a root node, make a map from Id to Token
-getTokenMap :: Token -> Map.Map Id Token
-getTokenMap t =
-    execState (doAnalysis f t) Map.empty
-  where
-    f t = modify (Map.insert (getId t) t)
-
-
--- Is this token in a quoting free context? (i.e. would variable expansion split)
--- True:  Assignments, [[ .. ]], here docs, already in double quotes
--- False: Regular words
-isStrictlyQuoteFree = isQuoteFreeNode True
-
--- Like above, but also allow some cases where splitting may be desired.
--- True:  Like above + for loops
--- False: Like above
-isQuoteFree = isQuoteFreeNode False
-
-
-isQuoteFreeNode strict tree t =
-    (isQuoteFreeElement t == Just True) ||
-        head (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t) ++ [False])
-  where
-    -- Is this node self-quoting in itself?
-    isQuoteFreeElement t =
-        case t of
-            T_Assignment {} -> return True
-            T_FdRedirect {} -> return True
-            _ -> Nothing
-
-    -- Are any subnodes inherently self-quoting?
-    isQuoteFreeContext t =
-        case t of
-            TC_Nullary _ DoubleBracket _ -> return True
-            TC_Unary _ DoubleBracket _ _ -> return True
-            TC_Binary _ DoubleBracket _ _ _ -> return True
-            TA_Sequence {} -> return True
-            T_Arithmetic {} -> return True
-            T_Assignment {} -> return True
-            T_Redirecting {} -> return False
-            T_DoubleQuoted _ _ -> return True
-            T_DollarDoubleQuoted _ _ -> return True
-            T_CaseExpression {} -> return True
-            T_HereDoc {} -> return True
-            T_DollarBraced {} -> return True
-            -- When non-strict, pragmatically assume it's desirable to split here
-            T_ForIn {} -> return (not strict)
-            T_SelectIn {} -> return (not strict)
-            _ -> Nothing
-
--- Check if a token is a parameter to a certain command by name:
--- Example: isParamTo (parentMap params) "sed" t
-isParamTo :: Map.Map Id Token -> String -> Token -> Bool
-isParamTo tree cmd =
-    go
-  where
-    go x = case Map.lookup (getId x) tree of
-                Nothing -> False
-                Just parent -> check parent
-    check t =
-        case t of
-            T_SingleQuoted _ _ -> go t
-            T_DoubleQuoted _ _ -> go t
-            T_NormalWord _ _ -> go t
-            T_SimpleCommand {} -> isCommand t cmd
-            T_Redirecting {} -> isCommand t cmd
-            _ -> False
-
--- Get the parent command (T_Redirecting) of a Token, if any.
-getClosestCommand :: Map.Map Id Token -> Token -> Maybe Token
-getClosestCommand tree t =
-    findFirst findCommand $ getPath tree t
-  where
-    findCommand t =
-        case t of
-            T_Redirecting {} -> return True
-            T_Script {} -> return False
-            _ -> Nothing
-
--- Like above, if koala_man knew Haskell when starting this project.
-getClosestCommandM t = do
-    tree <- asks parentMap
-    return $ getClosestCommand tree t
-
--- Is the token used as a command name (the first word in a T_SimpleCommand)?
-usedAsCommandName tree token = go (getId token) (tail $ getPath tree token)
-  where
-    go currentId (T_NormalWord id [word]:rest)
-        | currentId == getId word = go id rest
-    go currentId (T_DoubleQuoted id [word]:rest)
-        | currentId == getId word = go id rest
-    go currentId (T_SimpleCommand _ _ (word:_):_)
-        | currentId == getId word = True
-    go _ _ = False
-
--- A list of the element and all its parents up to the root node.
-getPath tree t = t :
-    case Map.lookup (getId t) tree of
-        Nothing -> []
-        Just parent -> getPath tree parent
-
--- Version of the above taking the map from the current context
--- Todo: give this the name "getPath"
-getPathM t = do
-    map <- asks parentMap
-    return $ getPath map t
-
-isParentOf tree parent child =
-    elem (getId parent) . map getId $ getPath tree child
-
-parents params = getPath (parentMap params)
-
-pathTo t = do
-    parents <- reader parentMap
-    return $ getPath parents t
-
--- Find the first match in a list where the predicate is Just True.
--- Stops if it's Just False and ignores Nothing.
-findFirst :: (a -> Maybe Bool) -> [a] -> Maybe a
-findFirst p l =
-    case l of
-        [] -> Nothing
-        (x:xs) ->
-            case p x of
-                Just True -> return x
-                Just False -> Nothing
-                Nothing -> findFirst p xs
-
--- Check whether a word is entirely output from a single command
-tokenIsJustCommandOutput t = case t of
-    T_NormalWord id [T_DollarExpansion _ cmds] -> check cmds
-    T_NormalWord id [T_DoubleQuoted _ [T_DollarExpansion _ cmds]] -> check cmds
-    T_NormalWord id [T_Backticked _ cmds] -> check cmds
-    T_NormalWord id [T_DoubleQuoted _ [T_Backticked _ cmds]] -> check cmds
-    _ -> False
-  where
-    check [x] = not $ isOnlyRedirection x
-    check _ = False
-
--- TODO: Replace this with a proper Control Flow Graph
-getVariableFlow params t =
-    let (_, stack) = runState (doStackAnalysis startScope endScope t) []
-    in reverse stack
-  where
-    startScope t =
-        let scopeType = leadType params t
-        in do
-            when (scopeType /= NoneScope) $ modify (StackScope scopeType:)
-            when (assignFirst t) $ setWritten t
-
-    endScope t =
-        let scopeType = leadType params t
-        in do
-            setRead t
-            unless (assignFirst t) $ setWritten t
-            when (scopeType /= NoneScope) $ modify (StackScopeEnd:)
-
-    assignFirst T_ForIn {} = True
-    assignFirst T_SelectIn {} = True
-    assignFirst _ = False
-
-    setRead t =
-        let read    = getReferencedVariables (parentMap params) t
-        in mapM_ (\v -> modify (Reference v:)) read
-
-    setWritten t =
-        let written = getModifiedVariables t
-        in mapM_ (\v -> modify (Assignment v:)) written
-
-
-leadType params t =
-    case t of
-        T_DollarExpansion _ _  -> SubshellScope "$(..) expansion"
-        T_Backticked _ _  -> SubshellScope "`..` expansion"
-        T_Backgrounded _ _  -> SubshellScope "backgrounding &"
-        T_Subshell _ _  -> SubshellScope "(..) group"
-        T_CoProcBody _ _  -> SubshellScope "coproc"
-        T_Redirecting {}  ->
-            if fromMaybe False causesSubshell
-            then SubshellScope "pipeline"
-            else NoneScope
-        _ -> NoneScope
-  where
-    parentPipeline = do
-        parent <- Map.lookup (getId t) (parentMap params)
-        case parent of
-            T_Pipeline {} -> return parent
-            _ -> Nothing
-
-    causesSubshell = do
-        (T_Pipeline _ _ list) <- parentPipeline
-        if length list <= 1
-            then return False
-            else if not $ hasLastpipe params
-                then return True
-                else return . not $ (getId . head $ reverse list) == getId t
-
-getModifiedVariables t =
-    case t of
-        T_SimpleCommand _ vars [] ->
-            concatMap (\x -> case x of
-                                T_Assignment id _ name _ w  ->
-                                    [(x, x, name, dataTypeFrom DataString w)]
-                                _ -> []
-                      ) vars
-        c@T_SimpleCommand {} ->
-            getModifiedVariableCommand c
-
-        TA_Unary _ "++|" var -> maybeToList $ do
-            name <- getLiteralString var
-            return (t, t, name, DataString $ SourceFrom [t])
-        TA_Unary _ "|++" var -> maybeToList $ do
-            name <- getLiteralString var
-            return (t, t, name, DataString $ SourceFrom [t])
-        TA_Assignment _ op lhs rhs -> maybeToList $ do
-            guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
-            name <- getLiteralString lhs
-            return (t, t, name, DataString $ SourceFrom [rhs])
-
-        -- Count [[ -v foo ]] as an "assignment".
-        -- This is to prevent [ -v foo ] being unassigned or unused.
-        TC_Unary id _ "-v" token -> maybeToList $ do
-            str <- fmap (takeWhile (/= '[')) $ -- Quoted index
-                    flip getLiteralStringExt token $ \x ->
-                case x of
-                    T_Glob _ s -> return s -- Unquoted index
-                    _ -> Nothing
-
-            guard . not . null $ str
-            return (t, token, str, DataString $ SourceChecked)
-
-        T_DollarBraced _ l -> maybeToList $ do
-            let string = bracedString t
-            let modifier = getBracedModifier string
-            guard $ ":=" `isPrefixOf` modifier
-            return (t, t, getBracedReference string, DataString $ SourceFrom [l])
-
-        t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&2 modifies foo
-            [(t, t, takeWhile (/= '}') var, DataString SourceInteger) | not $ isClosingFileOp op]
-
-        t@(T_CoProc _ name _) ->
-            [(t, t, fromMaybe "COPROC" name, DataArray SourceInteger)]
-
-        --Points to 'for' rather than variable
-        T_ForIn id str [] _ -> [(t, t, str, DataString SourceExternal)]
-        T_ForIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
-        T_SelectIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
-        _ -> []
-
-isClosingFileOp op =
-    case op of
-        T_IoDuplicate _ (T_GREATAND _) "-" -> True
-        T_IoDuplicate _ (T_LESSAND  _) "-" -> True
-        _ -> False
-
-
--- Consider 'export/declare -x' a reference, since it makes the var available
-getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
-    case x of
-        "export" -> if "f" `elem` flags
-            then []
-            else concatMap getReference rest
-        "declare" -> if any (`elem` flags) ["x", "p"]
-            then concatMap getReference rest
-            else []
-        "readonly" ->
-            if any (`elem` flags) ["f", "p"]
-            then []
-            else concatMap getReference rest
-        "trap" ->
-            case rest of
-                head:_ -> map (\x -> (head, head, x)) $ getVariablesFromLiteralToken head
-                _ -> []
-        _ -> []
-  where
-    getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)]
-    getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)]
-    getReference _ = []
-    flags = map snd $ getAllFlags base
-
-getReferencedVariableCommand _ = []
-
-getModifiedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
-   filter (\(_,_,s,_) -> not ("-" `isPrefixOf` s)) $
-    case x of
-        "read" ->
-            let params = map getLiteral rest in
-                catMaybes . takeWhile isJust . reverse $ params
-        "getopts" ->
-            case rest of
-                opts:var:_ -> maybeToList $ getLiteral var
-                _ -> []
-
-        "let" -> concatMap letParamToLiteral rest
-
-        "export" ->
-            if "f" `elem` flags then [] else concatMap getModifierParamString rest
-
-        "declare" -> if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
-        "typeset" -> declaredVars
-
-        "local" -> concatMap getModifierParamString rest
-        "readonly" ->
-            if any (`elem` flags) ["f", "p"]
-            then []
-            else concatMap getModifierParamString rest
-        "set" -> maybeToList $ do
-            params <- getSetParams rest
-            return (base, base, "@", DataString $ SourceFrom params)
-
-        "printf" -> maybeToList $ getPrintfVariable rest
-
-        "mapfile" -> maybeToList $ getMapfileArray base rest
-        "readarray" -> maybeToList $ getMapfileArray base rest
-
-        _ -> []
-  where
-    flags = map snd $ getAllFlags base
-    stripEquals s = let rest = dropWhile (/= '=') s in
-        if rest == "" then "" else tail rest
-    stripEqualsFrom (T_NormalWord id1 (T_Literal id2 s:rs)) =
-        T_NormalWord id1 (T_Literal id2 (stripEquals s):rs)
-    stripEqualsFrom (T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 s]]) =
-        T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 (stripEquals s)]]
-    stripEqualsFrom t = t
-
-    declaredVars = concatMap (getModifierParam defaultType) rest
-      where
-        defaultType = if any (`elem` flags) ["a", "A"] then DataArray else DataString
-
-    getLiteral t = do
-        s <- getLiteralString t
-        when ("-" `isPrefixOf` s) $ fail "argument"
-        return (base, t, s, DataString SourceExternal)
-
-    getModifierParamString = getModifierParam DataString
-
-    getModifierParam def t@(T_Assignment _ _ name _ value) =
-        [(base, t, name, dataTypeFrom def value)]
-    getModifierParam def t@T_NormalWord {} = maybeToList $ do
-        name <- getLiteralString t
-        guard $ isVariableName name
-        return (base, t, name, def SourceDeclaration)
-    getModifierParam _ _ = []
-
-    letParamToLiteral token =
-          if var == ""
-            then []
-            else [(base, token, var, DataString $ SourceFrom [stripEqualsFrom token])]
-        where var = takeWhile isVariableChar $ dropWhile (`elem` "+-") $ concat $ oversimplify token
-
-    getSetParams (t:_:rest) | getLiteralString t == Just "-o" = getSetParams rest
-    getSetParams (t:rest) =
-        let s = getLiteralString t in
-            case s of
-                Just "--" -> return rest
-                Just ('-':_) -> getSetParams rest
-                _ -> return (t:fromMaybe [] (getSetParams rest))
-    getSetParams [] = Nothing
-
-    getPrintfVariable list = f $ map (\x -> (x, getLiteralString x)) list
-      where
-        f ((_, Just "-v") : (t, Just var) : _) = return (base, t, var, DataString $ SourceFrom list)
-        f (_:rest) = f rest
-        f [] = fail "not found"
-
-    -- mapfile has some curious syntax allowing flags plus 0..n variable names
-    -- where only the first non-option one is used if any. Here we cheat and
-    -- just get the last one, if it's a variable name.
-    getMapfileArray base arguments = do
-        lastArg <- listToMaybe (reverse arguments)
-        name <- getLiteralString lastArg
-        guard $ isVariableName name
-        return (base, lastArg, name, DataArray SourceExternal)
-
-getModifiedVariableCommand _ = []
-
-getIndexReferences s = fromMaybe [] $ do
-    match <- matchRegex re s
-    index <- match !!! 0
-    return $ matchAllStrings variableNameRegex index
-  where
-    re = mkRegex "(\\[.*\\])"
-
-getOffsetReferences mods = fromMaybe [] $ do
-    match <- matchRegex re mods
-    offsets <- match !!! 0
-    return $ matchAllStrings variableNameRegex offsets
-  where
-    re = mkRegex "^ *:([^-=?+].*)"
-
-getReferencedVariables parents t =
-    case t of
-        T_DollarBraced id l -> let str = bracedString t in
-            (t, t, getBracedReference str) :
-                map (\x -> (l, l, x)) (
-                    getIndexReferences str
-                    ++ getOffsetReferences (getBracedModifier str))
-        TA_Expansion id _ ->
-            if isArithmeticAssignment t
-            then []
-            else getIfReference t t
-        T_Assignment id mode str _ word ->
-            [(t, t, str) | mode == Append] ++ specialReferences str t word
-
-        TC_Unary id _ "-v" token -> getIfReference t token
-        TC_Unary id _ "-R" token -> getIfReference t token
-        TC_Binary id DoubleBracket op lhs rhs ->
-            if isDereferencing op
-            then concatMap (getIfReference t) [lhs, rhs]
-            else []
-
-        t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&- references and closes foo
-            [(t, t, takeWhile (/= '}') var) | isClosingFileOp op]
-        x -> getReferencedVariableCommand x
-  where
-    -- Try to reduce false positives for unused vars only referenced from evaluated vars
-    specialReferences name base word =
-        if name `elem` [
-            "PS1", "PS2", "PS3", "PS4",
-            "PROMPT_COMMAND"
-          ]
-        then
-            map (\x -> (base, base, x)) $
-                getVariablesFromLiteralToken word
-        else []
-
-    literalizer t = case t of
-        TA_Index {} -> return ""  -- x[0] becomes a reference of x
-        T_Glob _ s -> return s    -- Also when parsed as globs
-        _ -> Nothing
-
-    getIfReference context token = maybeToList $ do
-            str <- getLiteralStringExt literalizer token
-            guard . not $ null str
-            when (isDigit $ head str) $ fail "is a number"
-            return (context, token, getBracedReference str)
-
-    isDereferencing = (`elem` ["-eq", "-ne", "-lt", "-le", "-gt", "-ge"])
-
-    isArithmeticAssignment t = case getPath parents t of
-        this: TA_Assignment _ "=" lhs _ :_ -> lhs == t
-        _ -> False
-
-dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
-
-
---- Command specific checks
-
--- Compare a command to a string: t `isCommand` "sed" (also matches /usr/bin/sed)
-isCommand token str = isCommandMatch token (\cmd -> cmd  == str || ('/' : str) `isSuffixOf` cmd)
-
--- Compare a command to a literal. Like above, but checks full path.
-isUnqualifiedCommand token str = isCommandMatch token (== str)
-
-isCommandMatch token matcher = fromMaybe False $ do
-    cmd <- getCommandName token
-    return $ matcher cmd
-
--- Does this regex look like it was intended as a glob?
--- True:  *foo*
--- False: .*foo.*
-isConfusedGlobRegex :: String -> Bool
-isConfusedGlobRegex ('*':_) = True
-isConfusedGlobRegex [x,'*'] | x /= '\\' = True
-isConfusedGlobRegex _ = False
-
-isVariableStartChar x = x == '_' || isAsciiLower x || isAsciiUpper x
-isVariableChar x = isVariableStartChar x || isDigit x
-variableNameRegex = mkRegex "[_a-zA-Z][_a-zA-Z0-9]*"
-
-prop_isVariableName1 = isVariableName "_fo123"
-prop_isVariableName2 = not $ isVariableName "4"
-prop_isVariableName3 = not $ isVariableName "test: "
-isVariableName (x:r) = isVariableStartChar x && all isVariableChar r
-isVariableName _ = False
-
-getVariablesFromLiteralToken token =
-    getVariablesFromLiteral (fromJust $ getLiteralStringExt (const $ return " ") token)
-
--- Try to get referenced variables from a literal string like "$foo"
--- Ignores tons of cases like arithmetic evaluation and array indices.
-prop_getVariablesFromLiteral1 =
-    getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
-getVariablesFromLiteral string =
-    map (!! 0) $ matchAllSubgroups variableRegex string
-  where
-    variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
-
--- Get the variable name from an expansion like ${var:-foo}
-prop_getBracedReference1 = getBracedReference "foo" == "foo"
-prop_getBracedReference2 = getBracedReference "#foo" == "foo"
-prop_getBracedReference3 = getBracedReference "#" == "#"
-prop_getBracedReference4 = getBracedReference "##" == "#"
-prop_getBracedReference5 = getBracedReference "#!" == "!"
-prop_getBracedReference6 = getBracedReference "!#" == "#"
-prop_getBracedReference7 = getBracedReference "!foo#?" == "foo"
-prop_getBracedReference8 = getBracedReference "foo-bar" == "foo"
-prop_getBracedReference9 = getBracedReference "foo:-bar" == "foo"
-prop_getBracedReference10= getBracedReference "foo: -1" == "foo"
-prop_getBracedReference11= getBracedReference "!os*" == ""
-prop_getBracedReference12= getBracedReference "!os?bar**" == ""
-prop_getBracedReference13= getBracedReference "foo[bar]" == "foo"
-getBracedReference s = fromMaybe s $
-    nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
-  where
-    noPrefix = dropPrefix s
-    dropPrefix (c:rest) = if c `elem` "!#" then rest else c:rest
-    dropPrefix "" = ""
-    takeName s = do
-        let name = takeWhile isVariableChar s
-        guard . not $ null name
-        return name
-    getSpecial (c:_) =
-        if c `elem` "*@#?-$!" then return [c] else fail "not special"
-    getSpecial _ = fail "empty"
-
-    nameExpansion ('!':rest) = do -- e.g. ${!foo*bar*}
-        let suffix = dropWhile isVariableChar rest
-        guard $ suffix /= rest -- e.g. ${!@}
-        first <- suffix !!! 0
-        guard $ first `elem` "*?"
-        return ""
-    nameExpansion _ = Nothing
-
-prop_getBracedModifier1 = getBracedModifier "foo:bar:baz" == ":bar:baz"
-prop_getBracedModifier2 = getBracedModifier "!var:-foo" == ":-foo"
-prop_getBracedModifier3 = getBracedModifier "foo[bar]" == "[bar]"
-getBracedModifier s = fromMaybe "" . listToMaybe $ do
-    let var = getBracedReference s
-    a <- dropModifier s
-    dropPrefix var a
-  where
-    dropPrefix [] t = return t
-    dropPrefix (a:b) (c:d) | a == c = dropPrefix b d
-    dropPrefix _ _ = []
-
-    dropModifier (c:rest) | c `elem` "#!" = [rest, c:rest]
-    dropModifier x = [x]
-
--- Useful generic functions.
-
--- Run an action in a Maybe (or do nothing).
--- Example:
--- potentially $ do
---   s <- getLiteralString cmd
---   guard $ s `elem` ["--recursive", "-r"]
---   return $ warn .. "Something something recursive"
-potentially :: Monad m => Maybe (m ()) -> m ()
-potentially = fromMaybe (return ())
-
--- Get element 0 or a default. Like `head` but safe.
-headOrDefault _ (a:_) = a
-headOrDefault def _ = def
-
---- Get element n of a list, or Nothing. Like `!!` but safe.
-(!!!) list i =
-    case drop i list of
-        [] -> Nothing
-        (r:_) -> Just r
-
--- Run a command if the shell is in the given list
-whenShell l c = do
-    shell <- asks shellType
-    when (shell `elem` l ) c
-
-
-filterByAnnotation asSpec params =
-    filter (not . shouldIgnore)
-  where
-    token = asScript asSpec
-    idFor (TokenComment id _) = id
-    shouldIgnore note =
-        any (shouldIgnoreFor (getCode note)) $
-            getPath parents (T_Bang $ idFor note)
-    shouldIgnoreFor num (T_Annotation _ anns _) =
-        any hasNum anns
-      where
-        hasNum (DisableComment ts) = num == ts
-        hasNum _ = False
-    shouldIgnoreFor _ T_Include {} = not $ asCheckSourced asSpec
-    shouldIgnoreFor _ _ = False
-    parents = parentMap params
-    getCode (TokenComment _ (Comment _ c _)) = c
-
--- Is this a ${#anything}, to get string length or array count?
-isCountingReference (T_DollarBraced id token) =
-    case concat $ oversimplify token of
-        '#':_ -> True
-        _ -> False
-isCountingReference _ = False
-
--- FIXME: doesn't handle ${a:+$var} vs ${a:+"$var"}
-isQuotedAlternativeReference t =
-    case t of
-        T_DollarBraced _ _ ->
-            getBracedModifier (bracedString t) `matches` re
-        _ -> False
-  where
-    re = mkRegex "(^|\\]):?\\+"
-
-
-
-return []
-runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

ShellCheck/Checker.hs

@@ -1,198 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-{-# LANGUAGE TemplateHaskell #-}
-module ShellCheck.Checker (checkScript, ShellCheck.Checker.runTests) where
-
-import ShellCheck.Interface
-import ShellCheck.Parser
-import ShellCheck.Analyzer
-
-import Data.Either
-import Data.Functor
-import Data.List
-import Data.Maybe
-import Data.Ord
-import Control.Monad.Identity
-import qualified Data.Map as Map
-import qualified System.IO
-import Prelude hiding (readFile)
-import Control.Monad
-
-import Test.QuickCheck.All
-
-tokenToPosition map (TokenComment id c) = fromMaybe fail $ do
-    position <- Map.lookup id map
-    return $ PositionedComment position position c
-  where
-    fail = error "Internal shellcheck error: id doesn't exist. Please report!"
-
-checkScript :: Monad m => SystemInterface m -> CheckSpec -> m CheckResult
-checkScript sys spec = do
-    results <- checkScript (csScript spec)
-    return CheckResult {
-        crFilename = csFilename spec,
-        crComments = results
-    }
-  where
-    checkScript contents = do
-        result <- parseScript sys ParseSpec {
-            psFilename = csFilename spec,
-            psScript = contents,
-            psCheckSourced = csCheckSourced spec
-        }
-        let parseMessages = prComments result
-        let analysisMessages =
-                fromMaybe [] $
-                    (arComments . analyzeScript . analysisSpec)
-                        <$> prRoot result
-        let translator = tokenToPosition (prTokenPositions result)
-        return . nub . sortMessages . filter shouldInclude $
-            (parseMessages ++ map translator analysisMessages)
-
-    shouldInclude (PositionedComment _ _ (Comment _ code _)) =
-        code `notElem` csExcludedWarnings spec
-
-    sortMessages = sortBy (comparing order)
-    order (PositionedComment pos _ (Comment severity code message)) =
-        (posFile pos, posLine pos, posColumn pos, severity, code, message)
-    getPosition (PositionedComment pos _ _) = pos
-
-    analysisSpec root =
-        AnalysisSpec {
-            asScript = root,
-            asShellType = csShellTypeOverride spec,
-            asCheckSourced = csCheckSourced spec,
-            asExecutionMode = Executed
-         }
-
-getErrors sys spec =
-    sort . map getCode . crComments $
-        runIdentity (checkScript sys spec)
-  where
-    getCode (PositionedComment _ _ (Comment _ code _)) = code
-
-check = checkWithIncludes []
-
-checkWithSpec includes =
-    getErrors (mockedSystemInterface includes)
-
-checkWithIncludes includes src =
-    checkWithSpec includes emptyCheckSpec {
-        csScript = src,
-        csExcludedWarnings = [2148]
-    }
-
-checkRecursive includes src =
-    checkWithSpec includes emptyCheckSpec {
-        csScript = src,
-        csExcludedWarnings = [2148],
-        csCheckSourced = True
-    }
-
-prop_findsParseIssue = check "echo \"$12\"" == [1037]
-
-prop_commentDisablesParseIssue1 =
-    null $ check "#shellcheck disable=SC1037\necho \"$12\""
-prop_commentDisablesParseIssue2 =
-    null $ check "#shellcheck disable=SC1037\n#lol\necho \"$12\""
-
-prop_findsAnalysisIssue =
-    check "echo $1" == [2086]
-prop_commentDisablesAnalysisIssue1 =
-    null $ check "#shellcheck disable=SC2086\necho $1"
-prop_commentDisablesAnalysisIssue2 =
-    null $ check "#shellcheck disable=SC2086\n#lol\necho $1"
-
-prop_optionDisablesIssue1 =
-    null $ getErrors
-                (mockedSystemInterface [])
-                emptyCheckSpec {
-                    csScript = "echo $1",
-                    csExcludedWarnings = [2148, 2086]
-                }
-
-prop_optionDisablesIssue2 =
-    null $ getErrors
-                (mockedSystemInterface [])
-                emptyCheckSpec {
-                    csScript = "echo \"$10\"",
-                    csExcludedWarnings = [2148, 1037]
-                }
-
-prop_canParseDevNull =
-    [] == check "source /dev/null"
-
-prop_failsWhenNotSourcing =
-    [1091, 2154] == check "source lol; echo \"$bar\""
-
-prop_worksWhenSourcing =
-    null $ checkWithIncludes [("lib", "bar=1")] "source lib; echo \"$bar\""
-
-prop_worksWhenDotting =
-    null $ checkWithIncludes [("lib", "bar=1")] ". lib; echo \"$bar\""
-
-prop_noInfiniteSourcing =
-    [] == checkWithIncludes  [("lib", "source lib")] "source lib"
-
-prop_canSourceBadSyntax =
-    [1094, 2086] == checkWithIncludes [("lib", "for f; do")] "source lib; echo $1"
-
-prop_cantSourceDynamic =
-    [1090] == checkWithIncludes [("lib", "")] ". \"$1\""
-
-prop_cantSourceDynamic2 =
-    [1090] == checkWithIncludes [("lib", "")] "source ~/foo"
-
-prop_canSourceDynamicWhenRedirected =
-    null $ checkWithIncludes [("lib", "")] "#shellcheck source=lib\n. \"$1\""
-
-prop_recursiveAnalysis =
-    [2086] == checkRecursive [("lib", "echo $1")] "source lib"
-
-prop_recursiveParsing =
-    [1037] == checkRecursive [("lib", "echo \"$10\"")] "source lib"
-
-prop_sourceDirectiveDoesntFollowFile =
-    null $ checkWithIncludes
-                [("foo", "source bar"), ("bar", "baz=3")]
-                "#shellcheck source=foo\n. \"$1\"; echo \"$baz\""
-
-prop_filewideAnnotationBase = [2086] == check "#!/bin/sh\necho $1"
-prop_filewideAnnotation1 = null $
-    check "#!/bin/sh\n# shellcheck disable=2086\necho $1"
-prop_filewideAnnotation2 = null $
-    check "#!/bin/sh\n# shellcheck disable=2086\ntrue\necho $1"
-prop_filewideAnnotation3 = null $
-    check "#!/bin/sh\n#unerlated\n# shellcheck disable=2086\ntrue\necho $1"
-prop_filewideAnnotation4 = null $
-    check "#!/bin/sh\n# shellcheck disable=2086\n#unrelated\ntrue\necho $1"
-prop_filewideAnnotation5 = null $
-    check "#!/bin/sh\n\n\n\n#shellcheck disable=2086\ntrue\necho $1"
-prop_filewideAnnotation6 = null $
-    check "#shellcheck shell=sh\n#unrelated\n#shellcheck disable=2086\ntrue\necho $1"
-prop_filewideAnnotation7 = null $
-    check "#!/bin/sh\n# shellcheck disable=2086\n#unrelated\ntrue\necho $1"
-
-prop_filewideAnnotationBase2 = [2086, 2181] == check "true\n[ $? == 0 ] && echo $1"
-prop_filewideAnnotation8 = null $
-    check "# Disable $? warning\n#shellcheck disable=SC2181\n# Disable quoting warning\n#shellcheck disable=2086\ntrue\n[ $? == 0 ] && echo $1"
-
-return []
-runTests = $quickCheckAll

ShellCheck/Checks/Commands.hs

@@ -1,854 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-{-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE FlexibleContexts #-}
-
--- This module contains checks that examine specific commands by name.
-module ShellCheck.Checks.Commands (checker
-    , ShellCheck.Checks.Commands.runTests
-) where
-
-import ShellCheck.AST
-import ShellCheck.ASTLib
-import ShellCheck.AnalyzerLib
-import ShellCheck.Data
-import ShellCheck.Interface
-import ShellCheck.Parser
-import ShellCheck.Regex
-
-import Control.Monad
-import Control.Monad.RWS
-import Data.Char
-import Data.List
-import Data.Maybe
-import qualified Data.Map.Strict as Map
-import Test.QuickCheck.All (forAllProperties)
-import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
-
-data CommandName = Exactly String | Basename String
-    deriving (Eq, Ord)
-
-data CommandCheck =
-    CommandCheck CommandName (Token -> Analysis)
-
-
-verify :: CommandCheck -> String -> Bool
-verify f s = producesComments (getChecker [f]) s == Just True
-verifyNot f s = producesComments (getChecker [f]) s == Just False
-
-arguments (T_SimpleCommand _ _ (cmd:args)) = args
-
-commandChecks :: [CommandCheck]
-commandChecks = [
-    checkTr
-    ,checkFindNameGlob
-    ,checkNeedlessExpr
-    ,checkGrepRe
-    ,checkTrapQuotes
-    ,checkReturn
-    ,checkFindExecWithSingleArgument
-    ,checkUnusedEchoEscapes
-    ,checkInjectableFindSh
-    ,checkFindActionPrecedence
-    ,checkMkdirDashPM
-    ,checkNonportableSignals
-    ,checkInteractiveSu
-    ,checkSshCommandString
-    ,checkPrintfVar
-    ,checkUuoeCmd
-    ,checkSetAssignment
-    ,checkExportedExpansions
-    ,checkAliasesUsesArgs
-    ,checkAliasesExpandEarly
-    ,checkUnsetGlobs
-    ,checkFindWithoutPath
-    ,checkTimeParameters
-    ,checkTimedCommand
-    ,checkLocalScope
-    ,checkDeprecatedTempfile
-    ,checkDeprecatedEgrep
-    ,checkDeprecatedFgrep
-    ,checkWhileGetoptsCase
-    ,checkCatastrophicRm
-    ,checkLetUsage
-    ]
-
-buildCommandMap :: [CommandCheck] -> Map.Map CommandName (Token -> Analysis)
-buildCommandMap = foldl' addCheck Map.empty
-  where
-    addCheck map (CommandCheck name function) =
-        Map.insertWith composeAnalyzers name function map
-
-
-checkCommand :: Map.Map CommandName (Token -> Analysis) -> Token -> Analysis
-checkCommand map t@(T_SimpleCommand id _ (cmd:rest)) = fromMaybe (return ()) $ do
-    name <- getLiteralString cmd
-    return $
-        if '/' `elem` name
-        then
-            Map.findWithDefault nullCheck (Basename $ basename name) map t
-        else do
-            Map.findWithDefault nullCheck (Exactly name) map t
-            Map.findWithDefault nullCheck (Basename name) map t
-
-  where
-    basename = reverse . takeWhile (/= '/') . reverse
-checkCommand _ _ = return ()
-
-getChecker :: [CommandCheck] -> Checker
-getChecker list = Checker {
-    perScript = const $ return (),
-    perToken = checkCommand map
-    }
-  where
-    map = buildCommandMap list
-
-
-checker :: Parameters -> Checker
-checker params = getChecker commandChecks
-
-prop_checkTr1 = verify checkTr "tr [a-f] [A-F]"
-prop_checkTr2 = verify checkTr "tr 'a-z' 'A-Z'"
-prop_checkTr2a= verify checkTr "tr '[a-z]' '[A-Z]'"
-prop_checkTr3 = verifyNot checkTr "tr -d '[:lower:]'"
-prop_checkTr3a= verifyNot checkTr "tr -d '[:upper:]'"
-prop_checkTr3b= verifyNot checkTr "tr -d '|/_[:upper:]'"
-prop_checkTr4 = verifyNot checkTr "ls [a-z]"
-prop_checkTr5 = verify checkTr "tr foo bar"
-prop_checkTr6 = verify checkTr "tr 'hello' 'world'"
-prop_checkTr8 = verifyNot checkTr "tr aeiou _____"
-prop_checkTr9 = verifyNot checkTr "a-z n-za-m"
-prop_checkTr10= verifyNot checkTr "tr --squeeze-repeats rl lr"
-prop_checkTr11= verifyNot checkTr "tr abc '[d*]'"
-checkTr = CommandCheck (Basename "tr") (mapM_ f . arguments)
-  where
-    f w | isGlob w = -- The user will go [ab] -> '[ab]' -> 'ab'. Fixme?
-        warn (getId w) 2060 "Quote parameters to tr to prevent glob expansion."
-    f word =
-      case getLiteralString word of
-        Just "a-z" -> info (getId word) 2018 "Use '[:lower:]' to support accents and foreign alphabets."
-        Just "A-Z" -> info (getId word) 2019 "Use '[:upper:]' to support accents and foreign alphabets."
-        Just s -> do  -- Eliminate false positives by only looking for dupes in SET2?
-          when (not ("-" `isPrefixOf` s || "[:" `isInfixOf` s) && duplicated s) $
-            info (getId word) 2020 "tr replaces sets of chars, not words (mentioned due to duplicates)."
-          unless ("[:" `isPrefixOf` s) $
-            when ("[" `isPrefixOf` s && "]" `isSuffixOf` s && (length s > 2) && ('*' `notElem` s)) $
-              info (getId word) 2021 "Don't use [] around classes in tr, it replaces literal square brackets."
-        Nothing -> return ()
-
-    duplicated s =
-        let relevant = filter isAlpha s
-        in relevant /= nub relevant
-
-prop_checkFindNameGlob1 = verify checkFindNameGlob "find / -name *.php"
-prop_checkFindNameGlob2 = verify checkFindNameGlob "find / -type f -ipath *(foo)"
-prop_checkFindNameGlob3 = verifyNot checkFindNameGlob "find * -name '*.php'"
-checkFindNameGlob = CommandCheck (Basename "find") (f . arguments)  where
-    acceptsGlob (Just s) = s `elem` [ "-ilname", "-iname", "-ipath", "-iregex", "-iwholename", "-lname", "-name", "-path", "-regex", "-wholename" ]
-    acceptsGlob _ = False
-    f [] = return ()
-    f [x] = return ()
-    f (a:b:r) = do
-        when (acceptsGlob (getLiteralString a) && isGlob b) $ do
-            let (Just s) = getLiteralString a
-            warn (getId b) 2061 $ "Quote the parameter to " ++ s ++ " so the shell won't interpret it."
-        f (b:r)
-
-
-prop_checkNeedlessExpr = verify checkNeedlessExpr "foo=$(expr 3 + 2)"
-prop_checkNeedlessExpr2 = verify checkNeedlessExpr "foo=`echo \\`expr 3 + 2\\``"
-prop_checkNeedlessExpr3 = verifyNot checkNeedlessExpr "foo=$(expr foo : regex)"
-prop_checkNeedlessExpr4 = verifyNot checkNeedlessExpr "foo=$(expr foo \\< regex)"
-checkNeedlessExpr = CommandCheck (Basename "expr") f where
-    f t =
-        when (all (`notElem` exceptions) (words $ arguments t)) $
-            style (getId t) 2003
-                "expr is antiquated. Consider rewriting this using $((..)), ${} or [[ ]]."
-    -- These operators are hard to replicate in POSIX
-    exceptions = [ ":", "<", ">", "<=", ">=" ]
-    words = mapMaybe getLiteralString
-
-
-prop_checkGrepRe1 = verify checkGrepRe "cat foo | grep *.mp3"
-prop_checkGrepRe2 = verify checkGrepRe "grep -Ev cow*test *.mp3"
-prop_checkGrepRe3 = verify checkGrepRe "grep --regex=*.mp3 file"
-prop_checkGrepRe4 = verifyNot checkGrepRe "grep foo *.mp3"
-prop_checkGrepRe5 = verifyNot checkGrepRe "grep-v  --regex=moo *"
-prop_checkGrepRe6 = verifyNot checkGrepRe "grep foo \\*.mp3"
-prop_checkGrepRe7 = verify checkGrepRe "grep *foo* file"
-prop_checkGrepRe8 = verify checkGrepRe "ls | grep foo*.jpg"
-prop_checkGrepRe9 = verifyNot checkGrepRe "grep '[0-9]*' file"
-prop_checkGrepRe10= verifyNot checkGrepRe "grep '^aa*' file"
-prop_checkGrepRe11= verifyNot checkGrepRe "grep --include=*.png foo"
-prop_checkGrepRe12= verifyNot checkGrepRe "grep -F 'Foo*' file"
-prop_checkGrepRe13= verifyNot checkGrepRe "grep -- -foo bar*"
-prop_checkGrepRe14= verifyNot checkGrepRe "grep -e -foo bar*"
-prop_checkGrepRe15= verifyNot checkGrepRe "grep --regex -foo bar*"
-
-checkGrepRe = CommandCheck (Basename "grep") check where
-    check cmd = f cmd (arguments cmd)
-    -- --regex=*(extglob) doesn't work. Fixme?
-    skippable (Just s) = not ("--regex=" `isPrefixOf` s) && "-" `isPrefixOf` s
-    skippable _ = False
-    f _ [] = return ()
-    f cmd (x:r) =
-        let str = getLiteralStringExt (const $ return "_") x
-        in
-            if str `elem` [Just "--", Just "-e", Just "--regex"]
-            then checkRE cmd r -- Regex is *after* this
-            else
-                if skippable str
-                then f cmd r           -- Regex is elsewhere
-                else checkRE cmd (x:r) -- Regex is this
-
-    checkRE _ [] = return ()
-    checkRE cmd (re:_) = do
-        when (isGlob re) $
-            warn (getId re) 2062 "Quote the grep pattern so the shell won't interpret it."
-
-        unless (cmd `hasFlag` "F") $ do
-            let string = concat $ oversimplify re
-            if isConfusedGlobRegex string then
-                warn (getId re) 2063 "Grep uses regex, but this looks like a glob."
-              else potentially $ do
-                char <- getSuspiciousRegexWildcard string
-                return $ info (getId re) 2022 $
-                    "Note that unlike globs, " ++ [char] ++ "* here matches '" ++ [char, char, char] ++ "' but not '" ++ wordStartingWith char ++ "'."
-
-    wordStartingWith c =
-        head . filter ([c] `isPrefixOf`) $ candidates
-      where
-        candidates =
-            sampleWords ++ map (\(x:r) -> toUpper x : r) sampleWords ++ [c:"test"]
-
-    getSuspiciousRegexWildcard str =
-        if not $ str `matches` contra
-        then do
-            match <- matchRegex suspicious str
-            str <- match !!! 0
-            str !!! 0
-        else
-            fail "looks good"
-      where
-        suspicious = mkRegex "([A-Za-z1-9])\\*"
-        contra = mkRegex "[^a-zA-Z1-9]\\*|[][^$+\\\\]"
-
-
-prop_checkTrapQuotes1 = verify checkTrapQuotes "trap \"echo $num\" INT"
-prop_checkTrapQuotes1a= verify checkTrapQuotes "trap \"echo `ls`\" INT"
-prop_checkTrapQuotes2 = verifyNot checkTrapQuotes "trap 'echo $num' INT"
-prop_checkTrapQuotes3 = verify checkTrapQuotes "trap \"echo $((1+num))\" EXIT DEBUG"
-checkTrapQuotes = CommandCheck (Exactly "trap") (f . arguments) where
-    f (x:_) = checkTrap x
-    f _ = return ()
-    checkTrap (T_NormalWord _ [T_DoubleQuoted _ rs]) = mapM_ checkExpansions rs
-    checkTrap _ = return ()
-    warning id = warn id 2064 "Use single quotes, otherwise this expands now rather than when signalled."
-    checkExpansions (T_DollarExpansion id _) = warning id
-    checkExpansions (T_Backticked id _) = warning id
-    checkExpansions (T_DollarBraced id _) = warning id
-    checkExpansions (T_DollarArithmetic id _) = warning id
-    checkExpansions _ = return ()
-
-
-prop_checkReturn1 = verifyNot checkReturn "return"
-prop_checkReturn2 = verifyNot checkReturn "return 1"
-prop_checkReturn3 = verifyNot checkReturn "return $var"
-prop_checkReturn4 = verifyNot checkReturn "return $((a|b))"
-prop_checkReturn5 = verify checkReturn "return -1"
-prop_checkReturn6 = verify checkReturn "return 1000"
-prop_checkReturn7 = verify checkReturn "return 'hello world'"
-checkReturn = CommandCheck (Exactly "return") (f . arguments)
-  where
-    f (first:second:_) =
-        err (getId second) 2151
-            "Only one integer 0-255 can be returned. Use stdout for other data."
-    f [value] =
-        when (isInvalid $ literal value) $
-            err (getId value) 2152
-                "Can only return 0-255. Other data should be written to stdout."
-    f _ = return ()
-
-    isInvalid s = s == "" || any (not . isDigit) s || length s > 5
-        || let value = (read s :: Integer) in value > 255
-
-    literal token = fromJust $ getLiteralStringExt lit token
-    lit (T_DollarBraced {}) = return "0"
-    lit (T_DollarArithmetic {}) = return "0"
-    lit (T_DollarExpansion {}) = return "0"
-    lit (T_Backticked {}) = return "0"
-    lit _ = return "WTF"
-
-
-prop_checkFindExecWithSingleArgument1 = verify checkFindExecWithSingleArgument "find . -exec 'cat {} | wc -l' \\;"
-prop_checkFindExecWithSingleArgument2 = verify checkFindExecWithSingleArgument "find . -execdir 'cat {} | wc -l' +"
-prop_checkFindExecWithSingleArgument3 = verifyNot checkFindExecWithSingleArgument "find . -exec wc -l {} \\;"
-checkFindExecWithSingleArgument = CommandCheck (Basename "find") (f . arguments)
-  where
-    f = void . sequence . mapMaybe check . tails
-    check (exec:arg:term:_) = do
-        execS <- getLiteralString exec
-        termS <- getLiteralString term
-        cmdS <- getLiteralStringExt (const $ return " ") arg
-
-        guard $ execS `elem` ["-exec", "-execdir"] && termS `elem` [";", "+"]
-        guard $ cmdS `matches` commandRegex
-        return $ warn (getId exec) 2150 "-exec does not invoke a shell. Rewrite or use -exec sh -c .. ."
-    check _ = Nothing
-    commandRegex = mkRegex "[ |;]"
-
-
-prop_checkUnusedEchoEscapes1 = verify checkUnusedEchoEscapes "echo 'foo\\nbar\\n'"
-prop_checkUnusedEchoEscapes2 = verifyNot checkUnusedEchoEscapes "echo -e 'foi\\nbar'"
-prop_checkUnusedEchoEscapes3 = verify checkUnusedEchoEscapes "echo \"n:\\t42\""
-prop_checkUnusedEchoEscapes4 = verifyNot checkUnusedEchoEscapes "echo lol"
-prop_checkUnusedEchoEscapes5 = verifyNot checkUnusedEchoEscapes "echo -n -e '\n'"
-checkUnusedEchoEscapes = CommandCheck (Basename "echo") (f . arguments)
-  where
-    isDashE = mkRegex "^-.*e"
-    hasEscapes = mkRegex "\\\\[rnt]"
-    f args | concat (concatMap oversimplify allButLast) `matches` isDashE =
-        return ()
-      where allButLast = reverse . drop 1 . reverse $ args
-    f args = mapM_ checkEscapes args
-
-    checkEscapes (T_NormalWord _ args) =
-        mapM_ checkEscapes args
-    checkEscapes (T_DoubleQuoted id args) =
-        mapM_ checkEscapes args
-    checkEscapes (T_Literal id str) = examine id str
-    checkEscapes (T_SingleQuoted id str) = examine id str
-    checkEscapes _ = return ()
-
-    examine id str =
-        when (str `matches` hasEscapes) $
-            info id 2028 "echo won't expand escape sequences. Consider printf."
-
-
-prop_checkInjectableFindSh1 = verify checkInjectableFindSh "find . -exec sh -c 'echo {}' \\;"
-prop_checkInjectableFindSh2 = verify checkInjectableFindSh "find . -execdir bash -c 'rm \"{}\"' ';'"
-prop_checkInjectableFindSh3 = verifyNot checkInjectableFindSh "find . -exec sh -c 'rm \"$@\"' _ {} \\;"
-checkInjectableFindSh = CommandCheck (Basename "find") (check . arguments)
-  where
-    check args = do
-        let idStrings = map (\x -> (getId x, onlyLiteralString x)) args
-        match pattern idStrings
-
-    match _ [] = return ()
-    match [] (next:_) = action next
-    match (p:tests) ((id, arg):args) = do
-        when (p arg) $ match tests args
-        match (p:tests) args
-
-    pattern = [
-        (`elem` ["-exec", "-execdir"]),
-        (`elem` ["sh", "bash", "dash", "ksh"]),
-        (== "-c")
-        ]
-    action (id, arg) =
-        when ("{}" `isInfixOf` arg) $
-            warn id 2156 "Injecting filenames is fragile and insecure. Use parameters."
-
-
-prop_checkFindActionPrecedence1 = verify checkFindActionPrecedence "find . -name '*.wav' -o -name '*.au' -exec rm {} +"
-prop_checkFindActionPrecedence2 = verifyNot checkFindActionPrecedence "find . -name '*.wav' -o \\( -name '*.au' -exec rm {} + \\)"
-prop_checkFindActionPrecedence3 = verifyNot checkFindActionPrecedence "find . -name '*.wav' -o -name '*.au'"
-checkFindActionPrecedence = CommandCheck (Basename "find") (f . arguments)
-  where
-    pattern = [isMatch, const True, isParam ["-o", "-or"], isMatch, const True, isAction]
-    f list | length list < length pattern = return ()
-    f list@(_:rest) =
-        if and (zipWith ($) pattern list)
-        then warnFor (list !! (length pattern - 1))
-        else f rest
-    isMatch = isParam [ "-name", "-regex", "-iname", "-iregex", "-wholename", "-iwholename" ]
-    isAction = isParam [ "-exec", "-execdir", "-delete", "-print", "-print0", "-fls", "-fprint", "-fprint0", "-fprintf", "-ls", "-ok", "-okdir", "-printf" ]
-    isParam strs t = fromMaybe False $ do
-        param <- getLiteralString t
-        return $ param `elem` strs
-    warnFor t = warn (getId t) 2146 "This action ignores everything before the -o. Use \\( \\) to group."
-
-
-prop_checkMkdirDashPM0 = verify checkMkdirDashPM "mkdir -p -m 0755 a/b"
-prop_checkMkdirDashPM1 = verify checkMkdirDashPM "mkdir -pm 0755 $dir"
-prop_checkMkdirDashPM2 = verify checkMkdirDashPM "mkdir -vpm 0755 a/b"
-prop_checkMkdirDashPM3 = verify checkMkdirDashPM "mkdir -pm 0755 -v a/b"
-prop_checkMkdirDashPM4 = verify checkMkdirDashPM "mkdir --parents --mode=0755 a/b"
-prop_checkMkdirDashPM5 = verify checkMkdirDashPM "mkdir --parents --mode 0755 a/b"
-prop_checkMkdirDashPM6 = verify checkMkdirDashPM "mkdir -p --mode=0755 a/b"
-prop_checkMkdirDashPM7 = verify checkMkdirDashPM "mkdir --parents -m 0755 a/b"
-prop_checkMkdirDashPM8 = verifyNot checkMkdirDashPM "mkdir -p a/b"
-prop_checkMkdirDashPM9 = verifyNot checkMkdirDashPM "mkdir -m 0755 a/b"
-prop_checkMkdirDashPM10 = verifyNot checkMkdirDashPM "mkdir a/b"
-prop_checkMkdirDashPM11 = verifyNot checkMkdirDashPM "mkdir --parents a/b"
-prop_checkMkdirDashPM12 = verifyNot checkMkdirDashPM "mkdir --mode=0755 a/b"
-prop_checkMkdirDashPM13 = verifyNot checkMkdirDashPM "mkdir_func -pm 0755 a/b"
-prop_checkMkdirDashPM14 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 singlelevel"
-prop_checkMkdirDashPM15 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 ../bin"
-prop_checkMkdirDashPM16 = verify checkMkdirDashPM "mkdir -p -m 0755 ../bin/laden"
-prop_checkMkdirDashPM17 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 ./bin"
-prop_checkMkdirDashPM18 = verify checkMkdirDashPM "mkdir -p -m 0755 ./bin/laden"
-prop_checkMkdirDashPM19 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 ./../bin"
-prop_checkMkdirDashPM20 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 .././bin"
-prop_checkMkdirDashPM21 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 ../../bin"
-checkMkdirDashPM = CommandCheck (Basename "mkdir") check
-  where
-    check t = potentially $ do
-        let flags = getAllFlags t
-        dashP <- find ((\f -> f == "p" || f == "parents") . snd) flags
-        dashM <- find ((\f -> f == "m" || f == "mode") . snd) flags
-        -- mkdir -pm 0700 dir  is fine, so is ../dir, but dir/subdir is not.
-        guard $ any couldHaveSubdirs (drop 1 $ arguments t)
-        return $ warn (getId $ fst dashM) 2174 "When used with -p, -m only applies to the deepest directory."
-    couldHaveSubdirs t = fromMaybe True $ do
-        name <- getLiteralString t
-        return $ '/' `elem` name && not (name `matches` re)
-    re = mkRegex "^(\\.\\.?\\/)+[^/]+$"
-
-
-prop_checkNonportableSignals1 = verify checkNonportableSignals "trap f 8"
-prop_checkNonportableSignals2 = verifyNot checkNonportableSignals "trap f 0"
-prop_checkNonportableSignals3 = verifyNot checkNonportableSignals "trap f 14"
-prop_checkNonportableSignals4 = verify checkNonportableSignals "trap f SIGKILL"
-prop_checkNonportableSignals5 = verify checkNonportableSignals "trap f 9"
-prop_checkNonportableSignals6 = verify checkNonportableSignals "trap f stop"
-prop_checkNonportableSignals7 = verifyNot checkNonportableSignals "trap 'stop' int"
-checkNonportableSignals = CommandCheck (Exactly "trap") (f . arguments)
-  where
-    f args = case args of
-        first:rest -> unless (isFlag first) $ mapM_ check rest
-        _ -> return ()
-
-    check param = potentially $ do
-        str <- getLiteralString param
-        let id = getId param
-        return $ sequence_ $ mapMaybe (\f -> f id str) [
-            checkNumeric,
-            checkUntrappable
-            ]
-
-    checkNumeric id str = do
-        guard $ not (null str)
-        guard $ all isDigit str
-        guard $ str /= "0" -- POSIX exit trap
-        guard $ str `notElem` ["1", "2", "3", "6", "9", "14", "15" ] -- XSI
-        return $ warn id 2172
-            "Trapping signals by number is not well defined. Prefer signal names."
-
-    checkUntrappable id str = do
-        guard $ map toLower str `elem` ["kill", "9", "sigkill", "stop", "sigstop"]
-        return $ err id 2173
-            "SIGKILL/SIGSTOP can not be trapped."
-
-
-prop_checkInteractiveSu1 = verify checkInteractiveSu "su; rm file; su $USER"
-prop_checkInteractiveSu2 = verify checkInteractiveSu "su foo; something; exit"
-prop_checkInteractiveSu3 = verifyNot checkInteractiveSu "echo rm | su foo"
-prop_checkInteractiveSu4 = verifyNot checkInteractiveSu "su root < script"
-checkInteractiveSu = CommandCheck (Basename "su") f
-  where
-    f cmd = when (length (arguments cmd) <= 1) $ do
-        path <- pathTo cmd
-        when (all undirected path) $
-            info (getId cmd) 2117
-                "To run commands as another user, use su -c or sudo."
-
-    undirected (T_Pipeline _ _ l) = length l <= 1
-    -- This should really just be modifications to stdin, but meh
-    undirected (T_Redirecting _ list _) = null list
-    undirected _ = True
-
-
--- This is hard to get right without properly parsing ssh args
-prop_checkSshCmdStr1 = verify checkSshCommandString "ssh host \"echo $PS1\""
-prop_checkSshCmdStr2 = verifyNot checkSshCommandString "ssh host \"ls foo\""
-prop_checkSshCmdStr3 = verifyNot checkSshCommandString "ssh \"$host\""
-checkSshCommandString = CommandCheck (Basename "ssh") (f . arguments)
-  where
-    nonOptions =
-        filter (\x -> not $ "-" `isPrefixOf` concat (oversimplify x))
-    f args =
-        case nonOptions args of
-            (hostport:r@(_:_)) -> checkArg $ last r
-            _ -> return ()
-    checkArg (T_NormalWord _ [T_DoubleQuoted id parts]) =
-        case filter (not . isConstant) parts of
-            [] -> return ()
-            (x:_) -> info (getId x) 2029
-                "Note that, unescaped, this expands on the client side."
-    checkArg _ = return ()
-
-
-prop_checkPrintfVar1 = verify checkPrintfVar "printf \"Lol: $s\""
-prop_checkPrintfVar2 = verifyNot checkPrintfVar "printf 'Lol: $s'"
-prop_checkPrintfVar3 = verify checkPrintfVar "printf -v cow $(cmd)"
-prop_checkPrintfVar4 = verifyNot checkPrintfVar "printf \"%${count}s\" var"
-prop_checkPrintfVar5 = verify checkPrintfVar "printf '%s %s %s' foo bar"
-prop_checkPrintfVar6 = verify checkPrintfVar "printf foo bar baz"
-prop_checkPrintfVar7 = verify checkPrintfVar "printf -- foo bar baz"
-prop_checkPrintfVar8 = verifyNot checkPrintfVar "printf '%s %s %s' \"${var[@]}\""
-prop_checkPrintfVar9 = verifyNot checkPrintfVar "printf '%s %s %s\\n' *.png"
-prop_checkPrintfVar10= verifyNot checkPrintfVar "printf '%s %s %s' foo bar baz"
-prop_checkPrintfVar11= verifyNot checkPrintfVar "printf '%(%s%s)T' -1"
-checkPrintfVar = CommandCheck (Exactly "printf") (f . arguments) where
-    f (doubledash:rest) | getLiteralString doubledash == Just "--" = f rest
-    f (dashv:var:rest) | getLiteralString dashv == Just "-v" = f rest
-    f (format:params) = check format params
-    f _ = return ()
-
-    countFormats string =
-        case string of
-            '%':'%':rest -> countFormats rest
-            '%':'(':rest -> 1 + countFormats (dropWhile (/= ')') rest)
-            '%':rest -> 1 + countFormats rest
-            _:rest -> countFormats rest
-            [] -> 0
-
-    check format more = do
-        fromMaybe (return ()) $ do
-            string <- getLiteralString format
-            let vars = countFormats string
-
-            return $ do
-                when (vars == 0 && more /= []) $
-                    err (getId format) 2182
-                        "This printf format string has no variables. Other arguments are ignored."
-
-                when (vars > 0
-                        && length more < vars
-                        && all (not . mayBecomeMultipleArgs) more) $
-                    warn (getId format) 2183 $
-                        "This format string has " ++ show vars ++ " variables, but is passed " ++ show (length more) ++ " arguments."
-
-
-        unless ('%' `elem` concat (oversimplify format) || isLiteral format) $
-          info (getId format) 2059
-              "Don't use variables in the printf format string. Use printf \"..%s..\" \"$foo\"."
-
-
-
-
-prop_checkUuoeCmd1 = verify checkUuoeCmd "echo $(date)"
-prop_checkUuoeCmd2 = verify checkUuoeCmd "echo `date`"
-prop_checkUuoeCmd3 = verify checkUuoeCmd "echo \"$(date)\""
-prop_checkUuoeCmd4 = verify checkUuoeCmd "echo \"`date`\""
-prop_checkUuoeCmd5 = verifyNot checkUuoeCmd "echo \"The time is $(date)\""
-prop_checkUuoeCmd6 = verifyNot checkUuoeCmd "echo \"$(<file)\""
-checkUuoeCmd = CommandCheck (Exactly "echo") (f . arguments) where
-    msg id = style id 2005 "Useless echo? Instead of 'echo $(cmd)', just use 'cmd'."
-    f [token] = when (tokenIsJustCommandOutput token) $ msg (getId token)
-    f _ = return ()
-
-
-prop_checkSetAssignment1 = verify checkSetAssignment "set foo 42"
-prop_checkSetAssignment2 = verify checkSetAssignment "set foo = 42"
-prop_checkSetAssignment3 = verify checkSetAssignment "set foo=42"
-prop_checkSetAssignment4 = verifyNot checkSetAssignment "set -- if=/dev/null"
-prop_checkSetAssignment5 = verifyNot checkSetAssignment "set 'a=5'"
-prop_checkSetAssignment6 = verifyNot checkSetAssignment "set"
-checkSetAssignment = CommandCheck (Exactly "set") (f . arguments)
-  where
-    f (var:value:rest) =
-        let str = literal var in
-            when (isVariableName str || isAssignment str) $
-                msg (getId var)
-    f (var:_) =
-        when (isAssignment $ literal var) $
-            msg (getId var)
-    f _ = return ()
-
-    msg id = warn id 2121 "To assign a variable, use just 'var=value', no 'set ..'."
-
-    isAssignment str = '=' `elem` str
-    literal (T_NormalWord _ l) = concatMap literal l
-    literal (T_Literal _ str) = str
-    literal _ = "*"
-
-
-prop_checkExportedExpansions1 = verify checkExportedExpansions "export $foo"
-prop_checkExportedExpansions2 = verify checkExportedExpansions "export \"$foo\""
-prop_checkExportedExpansions3 = verifyNot checkExportedExpansions "export foo"
-checkExportedExpansions = CommandCheck (Exactly "export") (check . arguments)
-  where
-    check = mapM_ checkForVariables
-    checkForVariables f =
-        case getWordParts f of
-            [t@(T_DollarBraced {})] ->
-                warn (getId t) 2163 "Exporting an expansion rather than a variable."
-            _ -> return ()
-
-
-prop_checkAliasesUsesArgs1 = verify checkAliasesUsesArgs "alias a='cp $1 /a'"
-prop_checkAliasesUsesArgs2 = verifyNot checkAliasesUsesArgs "alias $1='foo'"
-prop_checkAliasesUsesArgs3 = verify checkAliasesUsesArgs "alias a=\"echo \\${@}\""
-checkAliasesUsesArgs = CommandCheck (Exactly "alias") (f . arguments)
-  where
-    re = mkRegex "\\$\\{?[0-9*@]"
-    f = mapM_ checkArg
-    checkArg arg =
-        let string = fromJust $ getLiteralStringExt (const $ return "_") arg in
-            when ('=' `elem` string && string `matches` re) $
-                err (getId arg) 2142
-                    "Aliases can't use positional parameters. Use a function."
-
-
-prop_checkAliasesExpandEarly1 = verify checkAliasesExpandEarly "alias foo=\"echo $PWD\""
-prop_checkAliasesExpandEarly2 = verifyNot checkAliasesExpandEarly "alias -p"
-prop_checkAliasesExpandEarly3 = verifyNot checkAliasesExpandEarly "alias foo='echo {1..10}'"
-checkAliasesExpandEarly = CommandCheck (Exactly "alias") (f . arguments)
-  where
-    f = mapM_ checkArg
-    checkArg arg | '=' `elem` concat (oversimplify arg) =
-        forM_ (take 1 $ filter (not . isLiteral) $ getWordParts arg) $
-            \x -> warn (getId x) 2139 "This expands when defined, not when used. Consider escaping."
-    checkArg _ = return ()
-
-
-prop_checkUnsetGlobs1 = verify checkUnsetGlobs "unset foo[1]"
-prop_checkUnsetGlobs2 = verifyNot checkUnsetGlobs "unset foo"
-checkUnsetGlobs = CommandCheck (Exactly "unset") (mapM_ check . arguments)
-  where
-    check arg =
-        when (isGlob arg) $
-            warn (getId arg) 2184 "Quote arguments to unset so they're not glob expanded."
-
-
-prop_checkFindWithoutPath1 = verify checkFindWithoutPath "find -type f"
-prop_checkFindWithoutPath2 = verify checkFindWithoutPath "find"
-prop_checkFindWithoutPath3 = verifyNot checkFindWithoutPath "find . -type f"
-prop_checkFindWithoutPath4 = verifyNot checkFindWithoutPath "find -H -L \"$path\" -print"
-prop_checkFindWithoutPath5 = verifyNot checkFindWithoutPath "find -O3 ."
-prop_checkFindWithoutPath6 = verifyNot checkFindWithoutPath "find -D exec ."
-checkFindWithoutPath = CommandCheck (Basename "find") f
-  where
-    f (T_SimpleCommand _ _ (cmd:args)) =
-        unless (hasPath args) $
-            info (getId cmd) 2185 "Some finds don't have a default path. Specify '.' explicitly."
-
-    -- This is a bit of a kludge. find supports flag arguments both before and after the path,
-    -- as well as multiple non-flag arguments that are not the path. We assume that all the
-    -- pre-path flags are single characters, which is generally the case except for -O3.
-    hasPath (first:rest) =
-        let flag = fromJust $ getLiteralStringExt (const $ return "___") first in
-            not ("-" `isPrefixOf` flag) || isLeadingFlag flag && hasPath rest
-    hasPath [] = False
-    isLeadingFlag flag = length flag <= 2 || "-O" `isPrefixOf` flag
-
-
-prop_checkTimeParameters1 = verify checkTimeParameters "time -f lol sleep 10"
-prop_checkTimeParameters2 = verifyNot checkTimeParameters "time sleep 10"
-prop_checkTimeParameters3 = verifyNot checkTimeParameters "time -p foo"
-prop_checkTimeParameters4 = verifyNot checkTimeParameters "command time -f lol sleep 10"
-checkTimeParameters = CommandCheck (Exactly "time") f
-  where
-    f (T_SimpleCommand _ _ (cmd:args:_)) =
-        whenShell [Bash, Sh] $
-            let s = concat $ oversimplify args in
-                when ("-" `isPrefixOf` s && s /= "-p") $
-                    info (getId cmd) 2023 "The shell may override 'time' as seen in man time(1). Use 'command time ..' for that one."
-
-    f _ = return ()
-
-prop_checkTimedCommand1 = verify checkTimedCommand "#!/bin/sh\ntime -p foo | bar"
-prop_checkTimedCommand2 = verify checkTimedCommand "#!/bin/dash\ntime ( foo; bar; )"
-prop_checkTimedCommand3 = verifyNot checkTimedCommand "#!/bin/sh\ntime sleep 1"
-checkTimedCommand = CommandCheck (Exactly "time") f where
-    f (T_SimpleCommand _ _ (c:args@(_:_))) =
-        whenShell [Sh, Dash] $ do
-            let cmd = last args -- "time" is parsed with a command as argument
-            when (isPiped cmd) $
-                warn (getId c) 2176 "'time' is undefined for pipelines. time single stage or bash -c instead."
-            when (isSimple cmd == Just False) $
-                warn (getId cmd) 2177 "'time' is undefined for compound commands, time sh -c instead."
-    f _ = return ()
-    isPiped cmd =
-        case cmd of
-            T_Pipeline _ _ (_:_:_) -> True
-            _ -> False
-    getCommand cmd =
-        case cmd of
-            T_Pipeline _ _ (T_Redirecting _ _ a : _) -> return a
-            _ -> fail ""
-    isSimple cmd = do
-        innerCommand <- getCommand cmd
-        case innerCommand of
-            T_SimpleCommand {} -> return True
-            _ -> return False
-
-prop_checkLocalScope1 = verify checkLocalScope "local foo=3"
-prop_checkLocalScope2 = verifyNot checkLocalScope "f() { local foo=3; }"
-checkLocalScope = CommandCheck (Exactly "local") $ \t ->
-    whenShell [Bash, Dash] $ do -- Ksh allows it, Sh doesn't support local
-        path <- getPathM t
-        unless (any isFunction path) $
-            err (getId t) 2168 "'local' is only valid in functions."
-
-prop_checkDeprecatedTempfile1 = verify checkDeprecatedTempfile "var=$(tempfile)"
-prop_checkDeprecatedTempfile2 = verifyNot checkDeprecatedTempfile "tempfile=$(mktemp)"
-checkDeprecatedTempfile = CommandCheck (Basename "tempfile") $
-    \t -> warn (getId t) 2186 "tempfile is deprecated. Use mktemp instead."
-
-prop_checkDeprecatedEgrep = verify checkDeprecatedEgrep "egrep '.+'"
-checkDeprecatedEgrep = CommandCheck (Basename "egrep") $
-    \t -> info (getId t) 2196 "egrep is non-standard and deprecated. Use grep -E instead."
-
-prop_checkDeprecatedFgrep = verify checkDeprecatedFgrep "fgrep '*' files"
-checkDeprecatedFgrep = CommandCheck (Basename "fgrep") $
-    \t -> info (getId t) 2197 "fgrep is non-standard and deprecated. Use grep -F instead."
-
-prop_checkWhileGetoptsCase1 = verify checkWhileGetoptsCase "while getopts 'a:b' x; do case $x in a) foo;; esac; done"
-prop_checkWhileGetoptsCase2 = verify checkWhileGetoptsCase "while getopts 'a:' x; do case $x in a) foo;; b) bar;; esac; done"
-prop_checkWhileGetoptsCase3 = verifyNot checkWhileGetoptsCase "while getopts 'a:b' x; do case $x in a) foo;; b) bar;; *) :;esac; done"
-prop_checkWhileGetoptsCase4 = verifyNot checkWhileGetoptsCase "while getopts 'a:123' x; do case $x in a) foo;; [0-9]) bar;; esac; done"
-prop_checkWhileGetoptsCase5 = verifyNot checkWhileGetoptsCase "while getopts 'a:' x; do case $x in a) foo;; \\?) bar;; *) baz;; esac; done"
-checkWhileGetoptsCase = CommandCheck (Exactly "getopts") f
-  where
-    f :: Token -> Analysis
-    f t@(T_SimpleCommand _ _ (cmd:arg1:_))  = do
-        path <- getPathM t
-        potentially $ do
-            options <- getLiteralString arg1
-            (T_WhileExpression _ _ body) <- findFirst whileLoop path
-            caseCmd <- mapMaybe findCase body !!! 0
-            return $ check (getId arg1) (map (:[]) $ filter (/= ':') options) caseCmd
-    f _ = return ()
-
-    check :: Id -> [String] -> Token -> Analysis
-    check optId opts (T_CaseExpression id _ list) = do
-            unless (Nothing `Map.member` handledMap) $ do
-                mapM_ (warnUnhandled optId id) $ catMaybes $ Map.keys notHandled
-
-                unless (any (`Map.member` handledMap) [Just "*",Just "?"]) $
-                    warn id 2220 "Invalid flags are not handled. Add a *) case."
-
-            mapM_ warnRedundant $ Map.toList notRequested
-
-        where
-            handledMap = Map.fromList (concatMap getHandledStrings list)
-            requestedMap = Map.fromList $ map (\x -> (Just x, ())) opts
-
-            notHandled = Map.difference requestedMap handledMap
-            notRequested = Map.difference handledMap requestedMap
-
-    warnUnhandled optId caseId str =
-        warn caseId 2213 $ "getopts specified -" ++ str ++ ", but it's not handled by this 'case'."
-
-    warnRedundant (key, expr) = potentially $ do
-        str <- key
-        guard $ str `notElem` ["*", ":", "?"]
-        return $ warn (getId expr) 2214 "This case is not specified by getopts."
-
-    getHandledStrings (_, globs, _) =
-        map (\x -> (literal x, x)) globs
-
-    literal :: Token -> Maybe String
-    literal t = do
-        getLiteralString t <> fromGlob t
-
-    fromGlob t =
-        case t of
-            T_Glob _ ('[':c:']':[]) -> return [c]
-            T_Glob _ "*" -> return "*"
-            T_Glob _ "?" -> return "?"
-            _ -> Nothing
-
-    whileLoop t =
-        case t of
-            T_WhileExpression {} -> return True
-            T_Script {} -> return False
-            _ -> Nothing
-
-    findCase t =
-        case t of
-            T_Annotation _ _ x -> findCase x
-            T_Pipeline _ _ [x] -> findCase x
-            T_Redirecting _ _ x@(T_CaseExpression {}) -> return x
-            _ -> Nothing
-
-prop_checkCatastrophicRm1 = verify checkCatastrophicRm "rm -r $1/$2"
-prop_checkCatastrophicRm2 = verify checkCatastrophicRm "rm -r /home/$foo"
-prop_checkCatastrophicRm3 = verifyNot checkCatastrophicRm "rm -r /home/${USER:?}/*"
-prop_checkCatastrophicRm4 = verify checkCatastrophicRm "rm -fr /home/$(whoami)/*"
-prop_checkCatastrophicRm5 = verifyNot checkCatastrophicRm "rm -r /home/${USER:-thing}/*"
-prop_checkCatastrophicRm6 = verify checkCatastrophicRm "rm --recursive /etc/*$config*"
-prop_checkCatastrophicRm8 = verify checkCatastrophicRm "rm -rf /home"
-prop_checkCatastrophicRm10= verifyNot checkCatastrophicRm "rm -r \"${DIR}\"/{.gitignore,.gitattributes,ci}"
-prop_checkCatastrophicRm11= verify checkCatastrophicRm "rm -r /{bin,sbin}/$exec"
-prop_checkCatastrophicRm12= verify checkCatastrophicRm "rm -r /{{usr,},{bin,sbin}}/$exec"
-prop_checkCatastrophicRm13= verifyNot checkCatastrophicRm "rm -r /{{a,b},{c,d}}/$exec"
-prop_checkCatastrophicRmA = verify checkCatastrophicRm "rm -rf /usr /lib/nvidia-current/xorg/xorg"
-prop_checkCatastrophicRmB = verify checkCatastrophicRm "rm -rf \"$STEAMROOT/\"*"
-checkCatastrophicRm = CommandCheck (Basename "rm") $ \t ->
-    when (isRecursive t) $
-        mapM_ (mapM_ checkWord . braceExpand) $ arguments t
-  where
-    isRecursive = any (`elem` ["r", "R", "recursive"]) . map snd . getAllFlags
-
-    checkWord token =
-        case getLiteralString token of
-            Just str ->
-                when (fixPath str `elem` importantPaths) $
-                    warn (getId token) 2114 "Warning: deletes a system directory."
-            Nothing ->
-                checkWord' token
-
-    checkWord' token = fromMaybe (return ()) $ do
-        filename <- getPotentialPath token
-        let path = fixPath filename
-        return . when (path `elem` importantPaths) $
-            warn (getId token) 2115 $ "Use \"${var:?}\" to ensure this never expands to " ++ path ++ " ."
-
-    fixPath filename =
-        let normalized = skipRepeating '/' . skipRepeating '*' $ filename in
-            if normalized == "/" then normalized else stripTrailing '/' normalized
-
-    getPotentialPath = getLiteralStringExt f
-      where
-        f (T_Glob _ str) = return str
-        f (T_DollarBraced _ word) =
-            let var = onlyLiteralString word in
-                -- This shouldn't handle non-colon cases.
-                if any (`isInfixOf` var) [":?", ":-", ":="]
-                then Nothing
-                else return ""
-        f _ = return ""
-
-    stripTrailing c = reverse . dropWhile (== c) . reverse
-    skipRepeating c (a:b:rest) | a == b && b == c = skipRepeating c (b:rest)
-    skipRepeating c (a:r) = a:skipRepeating c r
-    skipRepeating _ [] = []
-
-    paths = [
-        "", "/bin", "/etc", "/home", "/mnt", "/usr", "/usr/share", "/usr/local",
-        "/var", "/lib", "/dev", "/media", "/boot", "/lib64", "/usr/bin"
-        ]
-    importantPaths = filter (not . null) $
-        ["", "/", "/*", "/*/*"] >>= (\x -> map (++x) paths)
-
-
-prop_checkLetUsage1 = verify checkLetUsage "let a=1"
-prop_checkLetUsage2 = verifyNot checkLetUsage "(( a=1 ))"
-checkLetUsage = CommandCheck (Exactly "let") f
-  where
-    f t = whenShell [Bash,Ksh] $ do
-        style (getId t) 2219 $ "Instead of 'let expr', prefer (( expr )) ."
-
-return []
-runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

ShellCheck/Checks/ShellSupport.hs

@@ -1,420 +0,0 @@
-{-
-    Copyright 2012-2016 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-{-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE FlexibleContexts #-}
-module ShellCheck.Checks.ShellSupport (checker
-    , ShellCheck.Checks.ShellSupport.runTests
-) where
-
-import ShellCheck.AST
-import ShellCheck.ASTLib
-import ShellCheck.AnalyzerLib
-import ShellCheck.Interface
-import ShellCheck.Regex
-
-import Control.Monad
-import Control.Monad.RWS
-import Data.Char
-import Data.List
-import Data.Maybe
-import qualified Data.Map as Map
-import Test.QuickCheck.All (forAllProperties)
-import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
-
-data ForShell = ForShell [Shell] (Token -> Analysis)
-
-getChecker params list = Checker {
-        perScript = nullCheck,
-        perToken = foldl composeAnalyzers nullCheck $ mapMaybe include list
-    }
-  where
-    shell = shellType params
-    include (ForShell list a) = do
-        guard $ shell `elem` list
-        return a
-
-checker params = getChecker params checks
-
-checks = [
-    checkForDecimals
-    ,checkBashisms
-    ,checkEchoSed
-    ,checkBraceExpansionVars
-    ,checkMultiDimensionalArrays
-    ,checkPS1Assignments
-    ]
-
-testChecker (ForShell _ t) =
-    Checker {
-        perScript = nullCheck,
-        perToken = t
-    }
-verify c s = producesComments (testChecker c) s == Just True
-verifyNot c s = producesComments (testChecker c) s == Just False
-
-prop_checkForDecimals1 = verify checkForDecimals "((3.14*c))"
-prop_checkForDecimals2 = verify checkForDecimals "foo[1.2]=bar"
-prop_checkForDecimals3 = verifyNot checkForDecimals "declare -A foo; foo[1.2]=bar"
-checkForDecimals = ForShell [Sh, Dash, Bash] f
-  where
-    f t@(TA_Expansion id _) = potentially $ do
-        str <- getLiteralString t
-        first <- str !!! 0
-        guard $ isDigit first && '.' `elem` str
-        return $ err id 2079 "(( )) doesn't support decimals. Use bc or awk."
-    f _ = return ()
-
-
-prop_checkBashisms = verify checkBashisms "while read a; do :; done < <(a)"
-prop_checkBashisms2 = verify checkBashisms "[ foo -nt bar ]"
-prop_checkBashisms3 = verify checkBashisms "echo $((i++))"
-prop_checkBashisms4 = verify checkBashisms "rm !(*.hs)"
-prop_checkBashisms5 = verify checkBashisms "source file"
-prop_checkBashisms6 = verify checkBashisms "[ \"$a\" == 42 ]"
-prop_checkBashisms7 = verify checkBashisms "echo ${var[1]}"
-prop_checkBashisms8 = verify checkBashisms "echo ${!var[@]}"
-prop_checkBashisms9 = verify checkBashisms "echo ${!var*}"
-prop_checkBashisms10= verify checkBashisms "echo ${var:4:12}"
-prop_checkBashisms11= verifyNot checkBashisms "echo ${var:-4}"
-prop_checkBashisms12= verify checkBashisms "echo ${var//foo/bar}"
-prop_checkBashisms13= verify checkBashisms "exec -c env"
-prop_checkBashisms14= verify checkBashisms "echo -n \"Foo: \""
-prop_checkBashisms15= verify checkBashisms "let n++"
-prop_checkBashisms16= verify checkBashisms "echo $RANDOM"
-prop_checkBashisms17= verify checkBashisms "echo $((RANDOM%6+1))"
-prop_checkBashisms18= verify checkBashisms "foo &> /dev/null"
-prop_checkBashisms19= verify checkBashisms "foo > file*.txt"
-prop_checkBashisms20= verify checkBashisms "read -ra foo"
-prop_checkBashisms21= verify checkBashisms "[ -a foo ]"
-prop_checkBashisms22= verifyNot checkBashisms "[ foo -a bar ]"
-prop_checkBashisms23= verify checkBashisms "trap mything ERR INT"
-prop_checkBashisms24= verifyNot checkBashisms "trap mything INT TERM"
-prop_checkBashisms25= verify checkBashisms "cat < /dev/tcp/host/123"
-prop_checkBashisms26= verify checkBashisms "trap mything ERR SIGTERM"
-prop_checkBashisms27= verify checkBashisms "echo *[^0-9]*"
-prop_checkBashisms28= verify checkBashisms "exec {n}>&2"
-prop_checkBashisms29= verify checkBashisms "echo ${!var}"
-prop_checkBashisms30= verify checkBashisms "printf -v '%s' \"$1\""
-prop_checkBashisms31= verify checkBashisms "printf '%q' \"$1\""
-prop_checkBashisms32= verifyNot checkBashisms "#!/bin/dash\n[ foo -nt bar ]"
-prop_checkBashisms33= verify checkBashisms "#!/bin/sh\necho -n foo"
-prop_checkBashisms34= verifyNot checkBashisms "#!/bin/dash\necho -n foo"
-prop_checkBashisms35= verifyNot checkBashisms "#!/bin/dash\nlocal foo"
-prop_checkBashisms36= verifyNot checkBashisms "#!/bin/dash\nread -p foo -r bar"
-prop_checkBashisms37= verifyNot checkBashisms "HOSTNAME=foo; echo $HOSTNAME"
-prop_checkBashisms38= verify checkBashisms "RANDOM=9; echo $RANDOM"
-prop_checkBashisms39= verify checkBashisms "foo-bar() { true; }"
-prop_checkBashisms40= verify checkBashisms "echo $(<file)"
-prop_checkBashisms41= verify checkBashisms "echo `<file`"
-prop_checkBashisms42= verify checkBashisms "trap foo int"
-prop_checkBashisms43= verify checkBashisms "trap foo sigint"
-prop_checkBashisms44= verifyNot checkBashisms "#!/bin/dash\ntrap foo int"
-prop_checkBashisms45= verifyNot checkBashisms "#!/bin/dash\ntrap foo INT"
-prop_checkBashisms46= verify checkBashisms "#!/bin/dash\ntrap foo SIGINT"
-prop_checkBashisms47= verify checkBashisms "#!/bin/dash\necho foo 42>/dev/null"
-prop_checkBashisms48= verifyNot checkBashisms "#!/bin/dash\necho $LINENO"
-prop_checkBashisms49= verify checkBashisms "#!/bin/dash\necho $MACHTYPE"
-prop_checkBashisms50= verify checkBashisms "#!/bin/sh\ncmd >& file"
-prop_checkBashisms51= verifyNot checkBashisms "#!/bin/sh\ncmd 2>&1"
-prop_checkBashisms52= verifyNot checkBashisms "#!/bin/sh\ncmd >&2"
-prop_checkBashisms53= verifyNot checkBashisms "#!/bin/sh\nprintf -- -f\n"
-prop_checkBashisms54= verify checkBashisms "#!/bin/sh\nfoo+=bar"
-checkBashisms = ForShell [Sh, Dash] $ \t -> do
-    params <- ask
-    kludge params t
- where
-  -- This code was copy-pasted from Analytics where params was a variable
-  kludge params = bashism
-   where
-    isDash = shellType params == Dash
-    warnMsg id s =
-        if isDash
-        then warn id 2169 $ "In dash, " ++ s ++ " not supported."
-        else warn id 2039 $ "In POSIX sh, " ++ s ++ " undefined."
-
-    bashism (T_ProcSub id _ _) = warnMsg id "process substitution is"
-    bashism (T_Extglob id _ _) = warnMsg id "extglob is"
-    bashism (T_DollarSingleQuoted id _) = warnMsg id "$'..' is"
-    bashism (T_DollarDoubleQuoted id _) = warnMsg id "$\"..\" is"
-    bashism (T_ForArithmetic id _ _ _ _) = warnMsg id "arithmetic for loops are"
-    bashism (T_Arithmetic id _) = warnMsg id "standalone ((..)) is"
-    bashism (T_DollarBracket id _) = warnMsg id "$[..] in place of $((..)) is"
-    bashism (T_SelectIn id _ _ _) = warnMsg id "select loops are"
-    bashism (T_BraceExpansion id _) = warnMsg id "brace expansion is"
-    bashism (T_Condition id DoubleBracket _) = warnMsg id "[[ ]] is"
-    bashism (T_HereString id _) = warnMsg id "here-strings are"
-    bashism (TC_Binary id SingleBracket op _ _)
-        | op `elem` [ "<", ">", "\\<", "\\>", "<=", ">=", "\\<=", "\\>="] =
-            unless isDash $ warnMsg id $ "lexicographical " ++ op ++ " is"
-    bashism (TC_Binary id SingleBracket op _ _)
-        | op `elem` [ "-nt", "-ef" ] =
-            unless isDash $ warnMsg id $ op ++ " is"
-    bashism (TC_Binary id SingleBracket "==" _ _) =
-            warnMsg id "== in place of = is"
-    bashism (TC_Binary id SingleBracket "=~" _ _) =
-            warnMsg id "=~ regex matching is"
-    bashism (TC_Unary id _ "-a" _) =
-            warnMsg id "unary -a in place of -e is"
-    bashism (TA_Unary id op _)
-        | op `elem` [ "|++", "|--", "++|", "--|"] =
-            warnMsg id $ filter (/= '|') op ++ " is"
-    bashism (TA_Binary id "**" _ _) = warnMsg id "exponentials are"
-    bashism (T_FdRedirect id "&" (T_IoFile _ (T_Greater _) _)) = warnMsg id "&> is"
-    bashism (T_FdRedirect id "" (T_IoFile _ (T_GREATAND _) _)) = warnMsg id ">& is"
-    bashism (T_FdRedirect id ('{':_) _) = warnMsg id "named file descriptors are"
-    bashism (T_FdRedirect id num _)
-        | all isDigit num && length num > 1 = warnMsg id "FDs outside 0-9 are"
-    bashism (T_Assignment id Append _ _ _) =
-        warnMsg id "+= is"
-    bashism (T_IoFile id _ word) | isNetworked =
-            warnMsg id "/dev/{tcp,udp} is"
-        where
-            file = onlyLiteralString word
-            isNetworked = any (`isPrefixOf` file) ["/dev/tcp", "/dev/udp"]
-    bashism (T_Glob id str) | "[^" `isInfixOf` str =
-            warnMsg id "^ in place of ! in glob bracket expressions is"
-
-    bashism t@(TA_Expansion id _) | isBashism =
-        warnMsg id $ fromJust str ++ " is"
-      where
-        str = getLiteralString t
-        isBashism = isJust str && isBashVariable (fromJust str)
-    bashism t@(T_DollarBraced id token) = do
-        mapM_ check expansion
-        when (isBashVariable var) $
-                    warnMsg id $ var ++ " is"
-      where
-        str = bracedString t
-        var = getBracedReference str
-        check (regex, feature) =
-            when (isJust $ matchRegex regex str) $ warnMsg id feature
-
-    bashism t@(T_Pipe id "|&") =
-        warnMsg id "|& in place of 2>&1 | is"
-    bashism (T_Array id _) =
-        warnMsg id "arrays are"
-    bashism (T_IoFile id _ t) | isGlob t =
-        warnMsg id "redirecting to/from globs is"
-    bashism (T_CoProc id _ _) =
-        warnMsg id "coproc is"
-
-    bashism (T_Function id _ _ str _) | not (isVariableName str) =
-        warnMsg id "naming functions outside [a-zA-Z_][a-zA-Z0-9_]* is"
-
-    bashism (T_DollarExpansion id [x]) | isOnlyRedirection x =
-        warnMsg id "$(<file) to read files is"
-    bashism (T_Backticked id [x]) | isOnlyRedirection x =
-        warnMsg id "`<file` to read files is"
-
-    bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
-        | t `isCommand` "echo" && "-" `isPrefixOf` argString =
-            unless ("--" `isPrefixOf` argString) $ -- echo "-----"
-                if isDash
-                then
-                    when (argString /= "-n") $
-                        warnMsg (getId arg) "echo flags besides -n"
-                else
-                    warnMsg (getId arg) "echo flags are"
-      where argString = concat $ oversimplify arg
-    bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
-        | t `isCommand` "exec" && "-" `isPrefixOf` concat (oversimplify arg) =
-            warnMsg (getId arg) "exec flags are"
-    bashism t@(T_SimpleCommand id _ _)
-        | t `isCommand` "let" = warnMsg id "'let' is"
-
-    bashism t@(T_SimpleCommand id _ (cmd:rest)) =
-        let name = fromMaybe "" $ getCommandName t
-            flags = getLeadingFlags t
-        in do
-            when (name `elem` unsupportedCommands) $
-                warnMsg id $ "'" ++ name ++ "' is"
-            potentially $ do
-                allowed <- Map.lookup name allowedFlags
-                (word, flag) <- listToMaybe $
-                    filter (\x -> (not . null . snd $ x) && snd x `notElem` allowed) flags
-                return . warnMsg (getId word) $ name ++ " -" ++ flag ++ " is"
-
-            when (name == "source") $ warnMsg id "'source' in place of '.' is"
-            when (name == "trap") $
-                let
-                    check token = potentially $ do
-                        str <- getLiteralString token
-                        let upper = map toUpper str
-                        return $ do
-                            when (upper `elem` ["ERR", "DEBUG", "RETURN"]) $
-                                warnMsg (getId token) $ "trapping " ++ str ++ " is"
-                            when ("SIG" `isPrefixOf` upper) $
-                                warnMsg (getId token)
-                                    "prefixing signal names with 'SIG' is"
-                            when (not isDash && upper /= str) $
-                                warnMsg (getId token)
-                                    "using lower/mixed case for signal names is"
-                in
-                    mapM_ check (drop 1 rest)
-
-            when (name == "printf") $ potentially $ do
-                format <- rest !!! 0  -- flags are covered by allowedFlags
-                let literal = onlyLiteralString format
-                guard $ "%q" `isInfixOf` literal
-                return $ warnMsg (getId format) "printf %q is"
-      where
-        unsupportedCommands = [
-            "let", "caller", "builtin", "complete", "compgen", "declare", "dirs", "disown",
-            "enable", "mapfile", "readarray", "pushd", "popd", "shopt", "suspend",
-            "typeset"
-            ] ++ if not isDash then ["local", "type"] else []
-        allowedFlags = Map.fromList [
-            ("read", if isDash then ["r", "p"] else ["r"]),
-            ("ulimit", ["f"]),
-            ("printf", []),
-            ("exec", [])
-            ]
-
-    bashism _ = return ()
-
-    varChars="_0-9a-zA-Z"
-    expansion = let re = mkRegex in [
-        (re $ "^![" ++ varChars ++ "]", "indirect expansion is"),
-        (re $ "^[" ++ varChars ++ "]+\\[.*\\]$", "array references are"),
-        (re $ "^![" ++ varChars ++ "]+\\[[*@]]$", "array key expansion is"),
-        (re $ "^![" ++ varChars ++ "]+[*@]$", "name matching prefixes are"),
-        (re $ "^[" ++ varChars ++ "]+:[^-=?+]", "string indexing is"),
-        (re $ "^[" ++ varChars ++ "]+(\\[.*\\])?/", "string replacement is")
-        ]
-    bashVars = [
-        "LINENO", "OSTYPE", "MACHTYPE", "HOSTTYPE", "HOSTNAME",
-        "DIRSTACK", "EUID", "UID", "SHLVL", "PIPESTATUS", "SHELLOPTS"
-        ]
-    bashDynamicVars = [ "RANDOM", "SECONDS" ]
-    dashVars = [ "LINENO" ]
-    isBashVariable var =
-        (var `elem` bashDynamicVars
-            || var `elem` bashVars && not (isAssigned var))
-        && not (isDash && var `elem` dashVars)
-    isAssigned var = any f (variableFlow params)
-      where
-        f x = case x of
-                Assignment (_, _, name, _) -> name == var
-                _ -> False
-
-prop_checkEchoSed1 = verify checkEchoSed "FOO=$(echo \"$cow\" | sed 's/foo/bar/g')"
-prop_checkEchoSed2 = verify checkEchoSed "rm $(echo $cow | sed -e 's,foo,bar,')"
-checkEchoSed = ForShell [Bash, Ksh] f
-  where
-    f (T_Pipeline id _ [a, b]) =
-        when (acmd == ["echo", "${VAR}"]) $
-            case bcmd of
-                ["sed", v] -> checkIn v
-                ["sed", "-e", v] -> checkIn v
-                _ -> return ()
-      where
-        -- This should have used backreferences, but TDFA doesn't support them
-        sedRe = mkRegex "^s(.)([^\n]*)g?$"
-        isSimpleSed s = fromMaybe False $ do
-            [first,rest] <- matchRegex sedRe s
-            let delimiters = filter (== head first) rest
-            guard $ length delimiters == 2
-            return True
-
-        acmd = oversimplify a
-        bcmd = oversimplify b
-        checkIn s =
-            when (isSimpleSed s) $
-                style id 2001 "See if you can use ${variable//search/replace} instead."
-    f _ = return ()
-
-
-prop_checkBraceExpansionVars1 = verify checkBraceExpansionVars "echo {1..$n}"
-prop_checkBraceExpansionVars2 = verifyNot checkBraceExpansionVars "echo {1,3,$n}"
-prop_checkBraceExpansionVars3 = verify checkBraceExpansionVars "eval echo DSC{0001..$n}.jpg"
-prop_checkBraceExpansionVars4 = verify checkBraceExpansionVars "echo {$i..100}"
-checkBraceExpansionVars = ForShell [Bash] f
-  where
-    f t@(T_BraceExpansion id list) = mapM_ check list
-      where
-        check element =
-            when (any (`isInfixOf` toString element) ["$..", "..$"]) $ do
-                c <- isEvaled element
-                if c
-                    then style id 2175 "Quote this invalid brace expansion since it should be passed literally to eval."
-                    else warn id 2051 "Bash doesn't support variables in brace range expansions."
-    f _ = return ()
-
-    literalExt t =
-        case t of
-            T_DollarBraced {} -> return "$"
-            T_DollarExpansion {} -> return "$"
-            T_DollarArithmetic {} -> return "$"
-            otherwise -> return "-"
-    toString t = fromJust $ getLiteralStringExt literalExt t
-    isEvaled t = do
-        cmd <- getClosestCommandM t
-        return $ isJust cmd && fromJust cmd `isUnqualifiedCommand` "eval"
-
-
-prop_checkMultiDimensionalArrays1 = verify checkMultiDimensionalArrays "foo[a][b]=3"
-prop_checkMultiDimensionalArrays2 = verifyNot checkMultiDimensionalArrays "foo[a]=3"
-prop_checkMultiDimensionalArrays3 = verify checkMultiDimensionalArrays "foo=( [a][b]=c )"
-prop_checkMultiDimensionalArrays4 = verifyNot checkMultiDimensionalArrays "foo=( [a]=c )"
-prop_checkMultiDimensionalArrays5 = verify checkMultiDimensionalArrays "echo ${foo[bar][baz]}"
-prop_checkMultiDimensionalArrays6 = verifyNot checkMultiDimensionalArrays "echo ${foo[bar]}"
-checkMultiDimensionalArrays = ForShell [Bash] f
-  where
-    f token =
-        case token of
-            T_Assignment _ _ name (first:second:_) _ -> about second
-            T_IndexedElement _ (first:second:_) _ -> about second
-            T_DollarBraced {} ->
-                when (isMultiDim token) $ about token
-            _ -> return ()
-    about t = warn (getId t) 2180 "Bash does not support multidimensional arrays. Use 1D or associative arrays."
-
-    re = mkRegex "^\\[.*\\]\\[.*\\]"  -- Fixme, this matches ${foo:- [][]} and such as well
-    isMultiDim t = getBracedModifier (bracedString t) `matches` re
-
-prop_checkPS11 = verify checkPS1Assignments "PS1='\\033[1;35m\\$ '"
-prop_checkPS11a= verify checkPS1Assignments "export PS1='\\033[1;35m\\$ '"
-prop_checkPSf2 = verify checkPS1Assignments "PS1='\\h \\e[0m\\$ '"
-prop_checkPS13 = verify checkPS1Assignments "PS1=$'\\x1b[c '"
-prop_checkPS14 = verify checkPS1Assignments "PS1=$'\\e[3m; '"
-prop_checkPS14a= verify checkPS1Assignments "export PS1=$'\\e[3m; '"
-prop_checkPS15 = verifyNot checkPS1Assignments "PS1='\\[\\033[1;35m\\]\\$ '"
-prop_checkPS16 = verifyNot checkPS1Assignments "PS1='\\[\\e1m\\e[1m\\]\\$ '"
-prop_checkPS17 = verifyNot checkPS1Assignments "PS1='e033x1B'"
-prop_checkPS18 = verifyNot checkPS1Assignments "PS1='\\[\\e\\]'"
-checkPS1Assignments = ForShell [Bash] f
-  where
-    f token = case token of
-        (T_Assignment _ _ "PS1" _ word) -> warnFor word
-        _ -> return ()
-
-    warnFor word =
-        let contents = concat $ oversimplify word in
-            when (containsUnescaped contents) $
-                info (getId word) 2025 "Make sure all escape sequences are enclosed in \\[..\\] to prevent line wrapping issues"
-    containsUnescaped s =
-        let unenclosed = subRegex enclosedRegex s "" in
-           isJust $ matchRegex escapeRegex unenclosed
-    enclosedRegex = mkRegex "\\\\\\[.*\\\\\\]" -- FIXME: shouldn't be eager
-    escapeRegex = mkRegex "\\\\x1[Bb]|\\\\e|\x1B|\\\\033"
-
-
-return []
-runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

ShellCheck/Formatter/Format.hs

@@ -1,67 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-module ShellCheck.Formatter.Format where
-
-import ShellCheck.Data
-import ShellCheck.Interface
-
--- A formatter that carries along an arbitrary piece of data
-data Formatter = Formatter {
-    header ::  IO (),
-    onResult :: CheckResult -> SystemInterface IO -> IO (),
-    onFailure :: FilePath -> ErrorMessage -> IO (),
-    footer :: IO ()
-}
-
-sourceFile (PositionedComment pos _ _) = posFile pos
-lineNo (PositionedComment pos _ _) = posLine pos
-endLineNo (PositionedComment _ end _) = posLine end
-colNo  (PositionedComment pos _ _) = posColumn pos
-endColNo  (PositionedComment _ end _) = posColumn end
-codeNo (PositionedComment _ _ (Comment _ code _)) = code
-messageText (PositionedComment _ _ (Comment _ _ t)) = t
-
-severityText :: PositionedComment -> String
-severityText (PositionedComment _ _ (Comment c _ _)) =
-    case c of
-        ErrorC   -> "error"
-        WarningC -> "warning"
-        InfoC    -> "info"
-        StyleC   -> "style"
-
--- Realign comments from a tabstop of 8 to 1
-makeNonVirtual comments contents =
-    map fix comments
-  where
-    ls = lines contents
-    fix c@(PositionedComment start end comment) = PositionedComment start {
-        posColumn = realignColumn lineNo colNo c
-    } end {
-        posColumn = realignColumn endLineNo endColNo c
-    } comment
-    realignColumn lineNo colNo c =
-      if lineNo c > 0 && lineNo c <= fromIntegral (length ls)
-      then real (ls !! fromIntegral (lineNo c - 1)) 0 0 (colNo c)
-      else colNo c
-    real _ r v target | target <= v = r
-    real [] r v _ = r -- should never happen
-    real ('\t':rest) r v target =
-        real rest (r+1) (v + 8 - (v `mod` 8)) target
-    real (_:rest) r v target = real rest (r+1) (v+1) target

ShellCheck/Formatter/JSON.hs

@@ -1,60 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-module ShellCheck.Formatter.JSON (format) where
-
-import ShellCheck.Interface
-import ShellCheck.Formatter.Format
-
-import Data.IORef
-import GHC.Exts
-import System.IO
-import Text.JSON
-
-format = do
-    ref <- newIORef []
-    return Formatter {
-        header = return (),
-        onResult = collectResult ref,
-        onFailure = outputError,
-        footer = finish ref
-    }
-
-instance JSON (PositionedComment) where
-  showJSON comment@(PositionedComment start end (Comment level code string)) = makeObj [
-      ("file", showJSON $ posFile start),
-      ("line", showJSON $ posLine start),
-      ("endLine", showJSON $ posLine end),
-      ("column", showJSON $ posColumn start),
-      ("endColumn", showJSON $ posColumn end),
-      ("level", showJSON $ severityText comment),
-      ("code", showJSON code),
-      ("message", showJSON string)
-      ]
-
-  readJSON = undefined
-
-outputError file msg = hPutStrLn stderr $ file ++ ": " ++ msg
-collectResult ref result _ =
-    modifyIORef ref (\x -> crComments result ++ x)
-
-finish ref = do
-    list <- readIORef ref
-    putStrLn $ encodeStrict list
-

ShellCheck/Formatter/TTY.hs

@@ -1,98 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-module ShellCheck.Formatter.TTY (format) where
-
-import ShellCheck.Interface
-import ShellCheck.Formatter.Format
-
-import Data.List
-import GHC.Exts
-import System.Info
-import System.IO
-
-format :: FormatterOptions -> IO Formatter
-format options = return Formatter {
-    header = return (),
-    footer = return (),
-    onFailure = outputError options,
-    onResult = outputResult options
-}
-
-colorForLevel level =
-    case level of
-        "error"   -> 31 -- red
-        "warning" -> 33 -- yellow
-        "info"    -> 32 -- green
-        "style"   -> 32 -- green
-        "message" -> 1 -- bold
-        "source"  -> 0 -- none
-        _ -> 0         -- none
-
-outputError options file error = do
-    color <- getColorFunc $ foColorOption options
-    hPutStrLn stderr $ color "error" $ file ++ ": " ++ error
-
-outputResult options result sys = do
-    color <- getColorFunc $ foColorOption options
-    let comments = crComments result
-    let fileGroups = groupWith sourceFile comments
-    mapM_ (outputForFile color sys) fileGroups
-
-outputForFile color sys comments = do
-    let fileName = sourceFile (head comments)
-    result <- (siReadFile sys) fileName
-    let contents = either (const "") id result
-    let fileLines = lines contents
-    let lineCount = fromIntegral $ length fileLines
-    let groups = groupWith lineNo comments
-    mapM_ (\x -> do
-        let lineNum = lineNo (head x)
-        let line = if lineNum < 1 || lineNum > lineCount
-                        then ""
-                        else fileLines !! fromIntegral (lineNum - 1)
-        putStrLn ""
-        putStrLn $ color "message" $
-           "In " ++ fileName ++" line " ++ show lineNum ++ ":"
-        putStrLn (color "source" line)
-        mapM_ (\c -> putStrLn (color (severityText c) $ cuteIndent c)) x
-        putStrLn ""
-      ) groups
-
-cuteIndent :: PositionedComment -> String
-cuteIndent comment =
-    replicate (fromIntegral $ colNo comment - 1) ' ' ++
-        "^-- " ++ code (codeNo comment) ++ ": " ++ messageText comment
-
-code code = "SC" ++ show code
-
-getColorFunc colorOption = do
-    term <- hIsTerminalDevice stdout
-    let windows = "mingw" `isPrefixOf` os
-    let isUsableTty = term && not windows
-    let useColor = case colorOption of
-                       ColorAlways -> True
-                       ColorNever -> False
-                       ColorAuto -> isUsableTty
-    return $ if useColor then colorComment else const id
-  where
-    colorComment level comment =
-        ansi (colorForLevel level) ++ comment ++ clear
-    clear = ansi 0
-    ansi n = "\x1B[" ++ show n ++ "m"

ShellCheck/Interface.hs

@@ -1,121 +0,0 @@
-{-
-    Copyright 2012-2015 Vidar Holen
-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    ShellCheck is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-module ShellCheck.Interface where
-
-import ShellCheck.AST
-import Control.Monad.Identity
-import qualified Data.Map as Map
-
-
-newtype SystemInterface m = SystemInterface {
-    -- Read a file by filename, or return an error
-    siReadFile :: String -> m (Either ErrorMessage String)
-}
-
--- ShellCheck input and output
-data CheckSpec = CheckSpec {
-    csFilename :: String,
-    csScript :: String,
-    csCheckSourced :: Bool,
-    csExcludedWarnings :: [Integer],
-    csShellTypeOverride :: Maybe Shell
-} deriving (Show, Eq)
-
-data CheckResult = CheckResult {
-    crFilename :: String,
-    crComments :: [PositionedComment]
-} deriving (Show, Eq)
-
-emptyCheckSpec :: CheckSpec
-emptyCheckSpec = CheckSpec {
-    csFilename = "",
-    csScript = "",
-    csCheckSourced = False,
-    csExcludedWarnings = [],
-    csShellTypeOverride = Nothing
-}
-
--- Parser input and output
-data ParseSpec = ParseSpec {
-    psFilename :: String,
-    psScript :: String,
-    psCheckSourced :: Bool
-} deriving (Show, Eq)
-
-data ParseResult = ParseResult {
-    prComments :: [PositionedComment],
-    prTokenPositions :: Map.Map Id Position,
-    prRoot :: Maybe Token
-} deriving (Show, Eq)
-
--- Analyzer input and output
-data AnalysisSpec = AnalysisSpec {
-    asScript :: Token,
-    asShellType :: Maybe Shell,
-    asExecutionMode :: ExecutionMode,
-    asCheckSourced :: Bool
-}
-
-newtype AnalysisResult = AnalysisResult {
-    arComments :: [TokenComment]
-}
-
-
--- Formatter options
-newtype FormatterOptions = FormatterOptions {
-    foColorOption :: ColorOption
-}
-
-
--- Supporting data types
-data Shell = Ksh | Sh | Bash | Dash deriving (Show, Eq)
-data ExecutionMode = Executed | Sourced deriving (Show, Eq)
-
-type ErrorMessage = String
-type Code = Integer
-
-data Severity = ErrorC | WarningC | InfoC | StyleC deriving (Show, Eq, Ord)
-data Position = Position {
-    posFile :: String,    -- Filename
-    posLine :: Integer,   -- 1 based source line
-    posColumn :: Integer  -- 1 based source column, where tabs are 8
-} deriving (Show, Eq)
-
-data Comment = Comment Severity Code String deriving (Show, Eq)
-data PositionedComment = PositionedComment Position Position Comment deriving (Show, Eq)
-data TokenComment = TokenComment Id Comment deriving (Show, Eq)
-
-data ColorOption =
-    ColorAuto
-    | ColorAlways
-    | ColorNever
-  deriving (Ord, Eq, Show)
-
--- For testing
-mockedSystemInterface :: [(String, String)] -> SystemInterface Identity
-mockedSystemInterface files = SystemInterface {
-    siReadFile = rf
-}
-  where
-    rf file =
-        case filter ((== file) . fst) files of
-            [] -> return $ Left "File not included in mock."
-            [(_, contents)] -> return $ Right contents
-

build/README.md

@@ -0,0 +1,17 @@
+This directory contains Dockerfiles for all builds.
+
+A build image will:
+
+* Run on Linux x86\_64 with vanilla Docker (no exceptions)
+* Not contain any software that would restrict easy modification or copying
+* Take a `cabal sdist` style tar.gz of the ShellCheck directory on stdin
+* Output a tar.gz of artifacts on stdout, in a directory named for the arch
+
+This makes it simple to build any release without exotic hardware or software.
+
+An image can be built and tagged using `build_builder`,
+and run on a source tarball using `run_builder`.
+
+Tip: Are you developing an image that relies on QEmu usermode emulation?
+     It's easy to accidentally depend on binfmt\_misc on the host OS.
+     Do a `echo 0 | sudo tee /proc/sys/fs/binfmt_misc/status` before testing.

build/build_builder

@@ -0,0 +1,12 @@
+#!/bin/sh
+if [ $# -eq 0 ]
+then
+  echo >&2 "No build image directories specified"
+  echo >&2 "Example: $0 build/*/"
+  exit 1
+fi
+
+for dir
+do
+  ( cd "$dir" && docker build -t "$(cat tag)" . ) || exit 1
+done

build/darwin.aarch64/Dockerfile

@@ -0,0 +1,40 @@
+FROM ghcr.io/shepherdjerred/macos-cross-compiler:latest
+
+ENV TARGET aarch64-apple-darwin22
+ENV TARGETNAME darwin.aarch64
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+ENV LC_ALL C.utf8
+
+# Install basic deps
+RUN apt-get update && apt-get install -y automake autoconf build-essential curl xz-utils qemu-user-static
+
+# Install a more suitable host compiler
+WORKDIR /host-ghc
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.9.0.0/cabal-install-3.9-x86_64-linux-alpine.tar.xz" | tar xJv -C /usr/local/bin
+RUN curl -L 'https://downloads.haskell.org/~ghc/8.10.7/ghc-8.10.7-x86_64-deb10-linux.tar.xz' | tar xJ --strip-components=1
+RUN ./configure && make install
+
+# Build GHC. We have to use an old version because cross-compilation across OS has since broken.
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/8.10.7/ghc-8.10.7-src.tar.xz" | tar xJ --strip-components=1
+RUN apt-get install -y llvm-12
+RUN ./boot && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
+RUN make install
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS "--ghc-options;-optc-Os -optc-fPIC;--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg;--constraint=hashable==1.3.5.0"
+
+# Prebuild the dependencies
+RUN cabal update
+RUN IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

build/darwin.aarch64/build

@@ -0,0 +1,16 @@
+#!/bin/sh
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  ( IFS=';'; cabal build $CABALOPTS )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  # Stripping invalidates the code signature and the build image does
+  # not appear to have anything similar to the 'codesign' tool.
+  # "$TARGET-strip" "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  file "$TARGETNAME/shellcheck" | grep "Mach-O 64-bit arm64 executable"
+} >&2
+tar czv "$TARGETNAME"

build/darwin.aarch64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-darwin-aarch64

build/darwin.x86_64/Dockerfile

@@ -0,0 +1,33 @@
+FROM liushuyu/osxcross@sha256:fa32af4677e2860a1c5950bc8c360f309e2a87e2ddfed27b642fddf7a6093b76
+
+ENV TARGET x86_64-apple-darwin18
+ENV TARGETNAME darwin.x86_64
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+RUN sed -e 's/focal/kinetic/g' -i /etc/apt/sources.list
+RUN apt-get update
+RUN apt-get dist-upgrade -y
+RUN apt-get install -y ghc automake autoconf llvm curl alex happy
+
+# Build GHC
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/9.2.5/ghc-9.2.5-src.tar.xz" | tar xJ --strip-components=1
+RUN ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
+RUN make install
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.9.0.0/cabal-install-3.9-x86_64-linux-alpine.tar.xz" | tar xJv -C /usr/local/bin
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS "--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg"
+
+# Prebuild the dependencies
+RUN cabal update && IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

build/darwin.x86_64/build

@@ -0,0 +1,13 @@
+#!/bin/sh
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  ( IFS=';'; cabal build $CABALOPTS )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  "$TARGET-strip" -Sx "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+} >&2
+tar czv "$TARGETNAME"

build/darwin.x86_64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-darwin-x86_64

build/linux.aarch64/Dockerfile

@@ -0,0 +1,40 @@
+FROM ubuntu:20.04
+
+ENV TARGET aarch64-linux-gnu
+ENV TARGETNAME linux.aarch64
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+
+# These deps are from 20.04, because GHC's compiler/llvm support moves slowly
+RUN apt-get update && apt-get install -y llvm gcc-$TARGET
+
+# The rest are from 22.10
+RUN sed -e 's/focal/kinetic/g' -i /etc/apt/sources.list
+# Kinetic does not receive updates anymore, switch to last available
+RUN sed -e 's/archive.ubuntu.com/old-releases.ubuntu.com/g' -i /etc/apt/sources.list
+RUN sed -e 's/security.ubuntu.com/old-releases.ubuntu.com/g' -i /etc/apt/sources.list
+
+RUN apt-get update && apt-get install -y ghc alex happy automake autoconf build-essential curl qemu-user-static
+
+# Build GHC
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/9.2.8/ghc-9.2.8-src.tar.xz" | tar xJ --strip-components=1
+RUN ./boot && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
+RUN make install
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.9.0.0/cabal-install-3.9-x86_64-linux-alpine.tar.xz" | tar xJv -C /usr/local/bin
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections -optc-fPIC;--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg;-c;hashable -arch-native"
+
+# Prebuild the dependencies
+RUN cabal update && IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

build/linux.aarch64/build

@@ -0,0 +1,14 @@
+#!/bin/sh
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  "$TARGET-strip" -s "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  qemu-aarch64-static "$TARGETNAME/shellcheck" --version
+} >&2
+tar czv "$TARGETNAME"

build/linux.aarch64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-linux-aarch64

build/linux.armv6hf/Dockerfile

@@ -0,0 +1,42 @@
+# This Docker file uses a custom QEmu fork with patches to follow execve
+# to build all of ShellCheck emulated.
+
+FROM ubuntu:24.04
+
+ENV TARGETNAME linux.armv6hf
+
+# Build QEmu with execve follow support
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+RUN apt-get update
+RUN apt-get install -y --no-install-recommends build-essential git ninja-build python3 pkg-config libglib2.0-dev libpixman-1-dev python3-setuptools ca-certificates debootstrap
+WORKDIR /qemu
+RUN git clone --depth 1 https://github.com/koalaman/qemu .
+RUN ./configure --static --disable-werror && cd build && ninja qemu-arm
+ENV QEMU_EXECVE 1
+
+# Convenience utility
+COPY scutil /bin/scutil
+COPY scutil /chroot/bin/scutil
+RUN chmod +x /bin/scutil /chroot/bin/scutil
+
+# Set up an armv6 userspace
+WORKDIR /
+RUN debootstrap --arch armhf --variant=minbase --foreign bookworm /chroot http://mirrordirector.raspbian.org/raspbian
+RUN cp /qemu/build/qemu-arm /chroot/bin/qemu
+RUN scutil emu /debootstrap/debootstrap --second-stage
+
+# Install deps in the chroot
+RUN scutil emu apt-get update
+RUN scutil emu apt-get install -y --no-install-recommends ghc cabal-install
+RUN scutil emu cabal update
+
+# Finally we can build the current dependencies. This takes hours.
+ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections;--gcc-options;-Os -Wl,--gc-sections -ffunction-sections -fdata-sections"
+# Generated with `cabal freeze --constraint 'hashable -arch-native'`
+COPY cabal.project.freeze /chroot/etc
+RUN IFS=";" && scutil install_from_freeze /chroot/etc/cabal.project.freeze emu cabal install $CABALOPTS
+
+# Copy the build script
+COPY build /chroot/bin
+ENTRYPOINT ["/bin/scutil", "emu", "/bin/build"]

build/linux.armv6hf/build

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -xe
+mkdir /scratch && cd /scratch
+{
+  tar xzv --strip-components=1
+  cp /etc/cabal.project.freeze .
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  # This script does not cabal update because compiling anything new is slow
+  ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  strip -s "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  "$TARGETNAME/shellcheck" --version
+} >&2
+tar czv "$TARGETNAME"

build/linux.armv6hf/cabal.project.freeze

@@ -0,0 +1,93 @@
+active-repositories: hackage.haskell.org:merge
+constraints: any.Diff ==0.5,
+             any.OneTuple ==0.4.2,
+             any.QuickCheck ==2.14.3,
+             QuickCheck -old-random +templatehaskell,
+             any.StateVar ==1.2.2,
+             any.aeson ==2.2.3.0,
+             aeson +ordered-keymap,
+             any.array ==0.5.4.0,
+             any.assoc ==1.1.1,
+             assoc -tagged,
+             any.base ==4.15.1.0,
+             any.base-orphans ==0.9.2,
+             any.bifunctors ==5.6.2,
+             bifunctors +tagged,
+             any.binary ==0.8.8.0,
+             any.bytestring ==0.10.12.1,
+             any.character-ps ==0.1,
+             any.comonad ==5.0.8,
+             comonad +containers +distributive +indexed-traversable,
+             any.containers ==0.6.4.1,
+             any.contravariant ==1.5.5,
+             contravariant +semigroups +statevar +tagged,
+             any.data-array-byte ==0.1.0.1,
+             any.data-fix ==0.3.3,
+             any.deepseq ==1.4.5.0,
+             any.directory ==1.3.6.2,
+             any.distributive ==0.6.2.1,
+             distributive +semigroups +tagged,
+             any.dlist ==1.0,
+             dlist -werror,
+             any.exceptions ==0.10.4,
+             any.fgl ==5.8.2.0,
+             fgl +containers042,
+             any.filepath ==1.4.2.1,
+             any.foldable1-classes-compat ==0.1,
+             foldable1-classes-compat +tagged,
+             any.generically ==0.1.1,
+             any.ghc-bignum ==1.1,
+             any.ghc-boot-th ==9.0.2,
+             any.ghc-prim ==0.7.0,
+             any.hashable ==1.4.6.0,
+             hashable -arch-native +integer-gmp -random-initial-seed,
+             any.indexed-traversable ==0.1.4,
+             any.indexed-traversable-instances ==0.1.2,
+             any.integer-conversion ==0.1.1,
+             any.integer-logarithms ==1.0.3.1,
+             integer-logarithms -check-bounds +integer-gmp,
+             any.mtl ==2.2.2,
+             any.network-uri ==2.6.4.2,
+             any.parsec ==3.1.14.0,
+             any.pretty ==1.1.3.6,
+             any.primitive ==0.9.0.0,
+             any.process ==1.6.13.2,
+             any.random ==1.2.1.2,
+             any.regex-base ==0.94.0.2,
+             any.regex-tdfa ==1.3.2.2,
+             regex-tdfa +doctest -force-o2,
+             any.rts ==1.0.2,
+             any.scientific ==0.3.8.0,
+             scientific -integer-simple,
+             any.semialign ==1.3.1,
+             semialign +semigroupoids,
+             any.semigroupoids ==6.0.1,
+             semigroupoids +comonad +containers +contravariant +distributive +tagged +unordered-containers,
+             any.splitmix ==0.1.0.5,
+             splitmix -optimised-mixer,
+             any.stm ==2.5.0.0,
+             any.strict ==0.5,
+             any.tagged ==0.8.8,
+             tagged +deepseq +transformers,
+             any.template-haskell ==2.17.0.0,
+             any.text ==1.2.5.0,
+             any.text-iso8601 ==0.1.1,
+             any.text-short ==0.1.6,
+             text-short -asserts,
+             any.th-abstraction ==0.7.0.0,
+             any.th-compat ==0.1.5,
+             any.these ==1.2.1,
+             any.time ==1.9.3,
+             any.time-compat ==1.9.7,
+             any.transformers ==0.5.6.2,
+             any.transformers-compat ==0.7.2,
+             transformers-compat -five +five-three -four +generic-deriving +mtl -three -two,
+             any.unix ==2.7.2.2,
+             any.unordered-containers ==0.2.20,
+             unordered-containers -debug,
+             any.uuid-types ==1.0.6,
+             any.vector ==0.13.1.0,
+             vector +boundschecks -internalchecks -unsafechecks -wall,
+             any.vector-stream ==0.1.0.1,
+             any.witherable ==0.5
+index-state: hackage.haskell.org 2024-06-18T02:21:19Z

build/linux.armv6hf/scutil

@@ -0,0 +1,48 @@
+#!/bin/dash
+# Various ShellCheck build utility functions
+
+# Generally set a ulimit to avoid QEmu using too much memory
+ulimit -v "$((10*1024*1024))"
+# If we happen to invoke or run under QEmu, make sure to follow execve.
+# This requires a patched QEmu.
+export QEMU_EXECVE=1
+
+# Retry a command until it succeeds
+# Usage: scutil retry 3 mycmd
+retry() {
+  n="$1"
+  ret=1
+  shift
+  while [ "$n" -gt 0 ]
+  do
+    "$@"
+    ret=$?
+    [ "$ret" = 0 ] && break
+    n=$((n-1))
+  done
+  return "$ret"
+}
+
+# Install all dependencies from a freeze file
+# Usage: scutil install_from_freeze /path/cabal.project.freeze cabal install
+install_from_freeze() {
+  linefeed=$(printf '\nx')
+  linefeed=${linefeed%x}
+  flags=$(
+    sed 's/constraints:/&\n /' "$1" |
+    grep -vw -e rts -e base |
+    sed -n -e 's/^  *\([^,]*\).*/\1/p' |
+    sed -e 's/any\.\([^ ]*\) ==\(.*\)/\1-\2/; te; s/.*/--constraint\n&/; :e')
+  shift
+  # shellcheck disable=SC2086
+  ( IFS=$linefeed; set -x; "$@" $flags )
+}
+
+# Run a command under emulation.
+# This assumes the correct emulator is named 'qemu' and the chroot is /chroot
+# Usage: scutil emu echo "Hello World"
+emu() {
+  chroot /chroot /bin/qemu /usr/bin/env "$@"
+}
+
+"$@"

build/linux.armv6hf/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-linux-armv6hf

build/linux.riscv64/Dockerfile

@@ -0,0 +1,46 @@
+FROM ubuntu:24.04
+
+ENV TARGETNAME linux.riscv64
+ENV TARGET riscv64-linux-gnu
+
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+
+# Init base
+RUN apt-get update -y
+
+# Install qemu
+RUN apt-get install -y --no-install-recommends build-essential ninja-build python3 pkg-config libglib2.0-dev libpixman-1-dev curl ca-certificates python3-virtualenv git python3-setuptools debootstrap
+WORKDIR /qemu
+RUN git clone --depth 1 https://github.com/koalaman/qemu .
+RUN ./configure --target-list=riscv64-linux-user --static --disable-system --disable-pie --disable-werror
+RUN cd build && ninja qemu-riscv64
+ENV QEMU_EXECVE 1
+
+# Convenience utility
+COPY scutil /bin/scutil
+# We have to copy to /usr/bin because debootstrap will try to symlink /bin and fail if it exists
+COPY scutil /chroot/usr/bin/scutil
+RUN chmod +x /bin/scutil /chroot/usr/bin/scutil
+
+# Set up a riscv64 userspace
+WORKDIR /
+RUN debootstrap --arch=riscv64 --variant=minbase --components=main,universe --foreign noble /chroot http://ports.ubuntu.com/ubuntu-ports
+RUN cp /qemu/build/qemu-riscv64 /chroot/bin/qemu
+RUN scutil emu /debootstrap/debootstrap --second-stage
+
+# Install deps in the chroot
+RUN scutil emu apt-get update
+RUN scutil emu apt-get install -y --no-install-recommends ghc cabal-install
+RUN scutil emu cabal update
+
+# Generated with: cabal freeze -c 'hashable -arch-native'. We put it in /etc so cabal won't find it.
+COPY cabal.project.freeze /chroot/etc
+
+# Build all dependencies from the freeze file. The emulator segfaults at random,
+# so retry a few times.
+RUN scutil install_from_freeze /chroot/etc/cabal.project.freeze retry 5 emu cabal install --keep-going
+
+# Copy the build script
+COPY build /chroot/bin/build
+ENTRYPOINT ["/bin/scutil", "emu", "/bin/build"]

build/linux.riscv64/build

@@ -0,0 +1,21 @@
+#!/bin/sh
+set -xe
+IFS=';'
+{
+  mkdir -p /tmp/scratch
+  cd /tmp/scratch
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  # Use a freeze file to ensure we use the same dependencies we cached during
+  # the docker image build. We don't want to spend time compiling anything new.
+  cp /etc/cabal.project.freeze .
+  mkdir "$TARGETNAME"
+  # Retry in case of random segfault
+  scutil retry 3 cabal build --enable-executable-static
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  "$TARGET-strip" -s "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  "$TARGETNAME/shellcheck" --version
+} >&2
+tar czv "$TARGETNAME"

build/linux.riscv64/cabal.project.freeze

@@ -0,0 +1,93 @@
+active-repositories: hackage.haskell.org:merge
+constraints: any.Diff ==0.5,
+             any.OneTuple ==0.4.2,
+             any.QuickCheck ==2.14.3,
+             QuickCheck -old-random +templatehaskell,
+             any.StateVar ==1.2.2,
+             any.aeson ==2.2.3.0,
+             aeson +ordered-keymap,
+             any.array ==0.5.4.0,
+             any.assoc ==1.1.1,
+             assoc -tagged,
+             any.base ==4.17.2.0,
+             any.base-orphans ==0.9.2,
+             any.bifunctors ==5.6.2,
+             bifunctors +tagged,
+             any.binary ==0.8.9.1,
+             any.bytestring ==0.11.5.2,
+             any.character-ps ==0.1,
+             any.comonad ==5.0.8,
+             comonad +containers +distributive +indexed-traversable,
+             any.containers ==0.6.7,
+             any.contravariant ==1.5.5,
+             contravariant +semigroups +statevar +tagged,
+             any.data-fix ==0.3.3,
+             any.deepseq ==1.4.8.0,
+             any.directory ==1.3.7.1,
+             any.distributive ==0.6.2.1,
+             distributive +semigroups +tagged,
+             any.dlist ==1.0,
+             dlist -werror,
+             any.exceptions ==0.10.5,
+             any.fgl ==5.8.2.0,
+             fgl +containers042,
+             any.filepath ==1.4.2.2,
+             any.foldable1-classes-compat ==0.1,
+             foldable1-classes-compat +tagged,
+             any.generically ==0.1.1,
+             any.ghc-bignum ==1.3,
+             any.ghc-boot-th ==9.4.7,
+             any.ghc-prim ==0.9.1,
+             any.hashable ==1.4.6.0,
+             hashable -arch-native +integer-gmp -random-initial-seed,
+             any.indexed-traversable ==0.1.4,
+             any.indexed-traversable-instances ==0.1.2,
+             any.integer-conversion ==0.1.1,
+             any.integer-logarithms ==1.0.3.1,
+             integer-logarithms -check-bounds +integer-gmp,
+             any.mtl ==2.2.2,
+             any.network-uri ==2.6.4.2,
+             any.os-string ==2.0.3,
+             any.parsec ==3.1.16.1,
+             any.pretty ==1.1.3.6,
+             any.primitive ==0.9.0.0,
+             any.process ==1.6.17.0,
+             any.random ==1.2.1.2,
+             any.regex-base ==0.94.0.2,
+             any.regex-tdfa ==1.3.2.2,
+             regex-tdfa +doctest -force-o2,
+             any.rts ==1.0.2,
+             any.scientific ==0.3.8.0,
+             scientific -integer-simple,
+             any.semialign ==1.3.1,
+             semialign +semigroupoids,
+             any.semigroupoids ==6.0.1,
+             semigroupoids +comonad +containers +contravariant +distributive +tagged +unordered-containers,
+             any.splitmix ==0.1.0.5,
+             splitmix -optimised-mixer,
+             any.stm ==2.5.1.0,
+             any.strict ==0.5,
+             any.tagged ==0.8.8,
+             tagged +deepseq +transformers,
+             any.template-haskell ==2.19.0.0,
+             any.text ==2.0.2,
+             any.text-iso8601 ==0.1.1,
+             any.text-short ==0.1.6,
+             text-short -asserts,
+             any.th-abstraction ==0.7.0.0,
+             any.th-compat ==0.1.5,
+             any.these ==1.2.1,
+             any.time ==1.12.2,
+             any.time-compat ==1.9.7,
+             any.transformers ==0.5.6.2,
+             any.transformers-compat ==0.7.2,
+             transformers-compat -five +five-three -four +generic-deriving +mtl -three -two,
+             any.unix ==2.7.3,
+             any.unordered-containers ==0.2.20,
+             unordered-containers -debug,
+             any.uuid-types ==1.0.6,
+             any.vector ==0.13.1.0,
+             vector +boundschecks -internalchecks -unsafechecks -wall,
+             any.vector-stream ==0.1.0.1,
+             any.witherable ==0.5
+index-state: hackage.haskell.org 2024-06-17T00:48:51Z

build/linux.riscv64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-linux-riscv64

build/linux.x86_64/Dockerfile

@@ -0,0 +1,24 @@
+FROM alpine:3.16
+# alpine:3.16 (GHC 9.0.1):  5.8 megabytes
+# alpine:3.17 (GHC 9.0.2): 15.0 megabytes
+# alpine:3.18 (GHC 9.4.4): 29.0 megabytes
+# alpine:3.19 (GHC 9.4.7): 29.0 megabytes
+
+ENV TARGETNAME linux.x86_64
+
+# Install GHC and cabal
+USER root
+RUN apk add ghc cabal g++ libffi-dev curl bash
+
+# Use ld.bfd instead of ld.gold due to
+# x86_64-linux-gnu/libpthread.a(pthread_cond_init.o)(.note.stapsdt+0x14): error:
+#    relocation refers to local symbol "" [2], which is defined in a discarded section
+ENV CABALOPTS "--ghc-options;-optl-Wl,-fuse-ld=bfd -split-sections -optc-Os -optc-Wl,--gc-sections"
+
+# Other archs pre-build dependencies here, but this one doesn't to detect ecosystem movement
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

build/linux.x86_64/build

@@ -0,0 +1,15 @@
+#!/bin/sh
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  cabal update
+  ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  strip -s "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  "$TARGETNAME/shellcheck" --version
+} >&2
+tar czv "$TARGETNAME"

build/linux.x86_64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-linux-x86_64

build/run_builder

@@ -0,0 +1,30 @@
+#!/bin/bash
+if [ $# -lt 2 ]
+then
+  echo >&2 "This script builds a source archive (as produced by cabal sdist)"
+  echo >&2 "Usage: $0 sourcefile.tar.gz builddir..."
+  exit 1
+fi
+
+file=$(realpath "$1")
+shift
+
+if [ ! -e "$file" ]
+then
+  echo >&2 "$file does not exist"
+  exit 1
+fi
+
+set -ex -o pipefail
+
+for dir
+do
+  tagfile="$dir/tag"
+  if [ ! -e "$tagfile" ]
+  then
+    echo >&2 "$tagfile does not exist"
+    exit 2
+  fi
+
+  docker run -i "$(< "$tagfile")" < "$file" | tar xz
+done

build/windows.x86_64/Dockerfile

@@ -0,0 +1,27 @@
+FROM ubuntu:20.04
+
+ENV TARGETNAME windows.x86_64
+
+# We don't need wine32, even though it complains
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+RUN apt-get update && apt-get install -y curl busybox wine winbind
+
+# Fetch Windows version, will be available under z:\haskell
+WORKDIR /haskell
+RUN curl -L "https://downloads.haskell.org/~ghc/8.10.4/ghc-8.10.4-x86_64-unknown-mingw32.tar.xz" | tar xJ --strip-components=1
+WORKDIR /haskell/bin
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/cabal-install-3.2.0.0-x86_64-unknown-mingw32.zip" | busybox unzip -
+RUN curl -L "https://curl.se/windows/dl-8.7.1_7/curl-8.7.1_7-win64-mingw.zip" | busybox unzip - && mv curl-*-win64-mingw/bin/* .
+ENV WINEPATH /haskell/bin
+
+# It's unknown whether Cabal on Windows suffers from the same issue
+# that necessitated this but I don't care enough to find out
+ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections"
+
+# Precompile some deps to speed up later builds
+RUN wine /haskell/bin/cabal.exe update && IFS=';' && wine /haskell/bin/cabal.exe install --lib --dependencies-only $CABALOPTS ShellCheck
+
+COPY build /usr/bin
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

build/windows.x86_64/build

@@ -0,0 +1,18 @@
+#!/bin/sh
+cabal() {
+  wine /haskell/bin/cabal.exe  "$@"
+}
+
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  ( IFS=';'; cabal build $CABALOPTS )
+  find dist*/ -name shellcheck.exe -type f -ls -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  wine "/haskell/mingw/bin/strip.exe" -s "$TARGETNAME/shellcheck.exe"
+  ls -l "$TARGETNAME"
+  wine "$TARGETNAME/shellcheck.exe" --version
+} >&2
+tar czv "$TARGETNAME"

build/windows.x86_64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-windows-x86_64

manpage

@@ -0,0 +1,4 @@
+#!/bin/sh
+echo >&2 "Generating man page using pandoc"
+pandoc -s -f markdown-smart -t man shellcheck.1.md -o shellcheck.1 || exit
+echo >&2 "Done. You can read it with:   man ./shellcheck.1"

nextnumber

@@ -1,10 +1,13 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # TODO: Find a less trashy way to get the next available error code
+if ! shopt -s globstar
+then
+  echo "Error: This script depends on Bash 4." >&2
+  exit 1
+fi
 
-shopt -s globstar
+for i in 1 2 3
-
-for i in 1 2
 do
-  last=$(grep -hv "^prop" ./**/*.hs | grep -Ewo "$i[0-9]{3}" | sort -n | tail -n 1)
+  last=$(grep -hv "^prop" ./**/*.hs | grep -Ewo "${i}[0-9]{3}" | sort -n | tail -n 1)
   echo "Next ${i}xxx: $((last+1))"
 done

quickrun

@@ -1,5 +1,13 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # quickrun runs ShellCheck in an interpreted mode.
 # This allows testing changes without recompiling.
 
-runghc -idist/build/autogen shellcheck.hs "$@"
+path=$(find . -type f -path './dist*/Paths_ShellCheck.hs' | sort | head -n 1)
+if [ -z "$path" ]
+then
+  echo >&2 "Unable to find Paths_ShellCheck.hs. Please 'cabal build' once."
+  exit 1
+fi
+path="${path%/*}"
+
+exec runghc -isrc -i"$path" shellcheck.hs "$@"

quicktest

@@ -1,18 +1,20 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # quicktest runs the ShellCheck unit tests in an interpreted mode.
 # This allows running tests without compiling, which can be faster.
 # 'cabal test' remains the source of truth.
 
+path=$(find . -type f -path './dist*/Paths_ShellCheck.hs' | sort | head -n 1)
+if [ -z "$path" ]
+then
+    echo >&2 "Unable to find Paths_ShellCheck.hs. Please 'cabal build' once."
+      exit 1
+fi
+path="${path%/*}"
+
+
 (
- var=$(echo 'liftM and $ sequence [
+var=$(echo 'main' | ghci -isrc -i"$path" test/shellcheck.hs 2>&1 | tee /dev/stderr)
-  ShellCheck.Analytics.runTests
+if [[ $var == *ExitSuccess* ]]
-  ,ShellCheck.Parser.runTests
-  ,ShellCheck.Checker.runTests
-  ,ShellCheck.Checks.Commands.runTests
-  ,ShellCheck.Checks.ShellSupport.runTests
-  ,ShellCheck.AnalyzerLib.runTests
-    ]' | tr -d '\n' | cabal repl 2>&1 | tee /dev/stderr)
-if [[ $var == *$'\nTrue'* ]]
 then
   exit 0
 else

setgitversion

@@ -0,0 +1,11 @@
+#!/bin/sh -xe
+# This script hardcodes the `git describe` version as ShellCheck's version number.
+# This is done to allow shellcheck --version to differ from the cabal version when
+# building git snapshots.
+
+file="src/ShellCheck/Data.hs"
+test -e "$file"
+tmp=$(mktemp)
+version=$(git describe)
+sed -e "s/=.*VERSIONSTRING.*/= \"$version\" -- VERSIONSTRING, DO NOT SUBMIT/" "$file" > "$tmp"
+mv "$tmp" "$file"

shellcheck.1.md

@@ -29,14 +29,13 @@ will warn that decimals are not supported.
 + For scripts starting with `#!/bin/ksh` (or using `-s ksh`), ShellCheck will
 not warn at all, as `ksh` supports decimals in arithmetic contexts.
 
-
 # OPTIONS
 
 **-a**,\ **--check-sourced**
 
 :   Emit warnings in sourced files. Normally, `shellcheck` will only warn
     about issues in the specified files. With this option, any issues in
-    sourced files files will also be reported.
+    sourced files will also be reported.
 
 **-C**[*WHEN*],\ **--color**[=*WHEN*]
 
@@ -44,35 +43,95 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
     is *auto*. **--color** without an argument is equivalent to
     **--color=always**.
 
+**-i**\ *CODE1*[,*CODE2*...],\ **--include=***CODE1*[,*CODE2*...]
+
+:   Explicitly include only the specified codes in the report. Subsequent **-i**
+    options are cumulative, but all the codes can be specified at once,
+    comma-separated as a single argument. Include options override any provided
+    exclude options.
+
 **-e**\ *CODE1*[,*CODE2*...],\ **--exclude=***CODE1*[,*CODE2*...]
 
 :   Explicitly exclude the specified codes from the report. Subsequent **-e**
     options are cumulative, but all the codes can be specified at once,
     comma-separated as a single argument.
 
+**--extended-analysis=true/false**
+
+:   Enable/disable Dataflow Analysis to identify more issues (default true). If
+    ShellCheck uses too much CPU/RAM when checking scripts with several
+    thousand lines of code, extended analysis can be disabled with this flag
+    or a directive. This flag overrides directives and rc files.
+
 **-f** *FORMAT*, **--format=***FORMAT*
 
 :   Specify the output format of shellcheck, which prints its results in the
     standard output. Subsequent **-f** options are ignored, see **FORMATS**
     below for more information.
 
+**--list-optional**
+
+:   Output a list of known optional checks. These can be enabled with **-o**
+    flags or **enable** directives.
+
+**--norc**
+
+:   Don't try to look for .shellcheckrc configuration files.
+
+**--rcfile** *RCFILE*
+
+:   Prefer the specified configuration file over searching for one
+    in the default locations.
+
+**-o**\ *NAME1*[,*NAME2*...],\ **--enable=***NAME1*[,*NAME2*...]
+
+:   Enable optional checks. The special name *all* enables all of them.
+    Subsequent **-o** options accumulate. This is equivalent to specifying
+    **enable** directives.
+
+**-P**\ *SOURCEPATH*,\ **--source-path=***SOURCEPATH*
+
+:   Specify paths to search for sourced files, separated by `:` on Unix and
+    `;` on Windows. This is equivalent to specifying `search-path`
+    directives.
+
 **-s**\ *shell*,\ **--shell=***shell*
 
-:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *dash* and *ksh*.
+:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *dash*, *ksh*,
-    The default is to use the file's shebang, or *bash* if the target shell
+    and *busybox*.
-    can't be determined.
+    The default is to deduce the shell from the file's `shell` directive,
+    shebang, or `.bash/.bats/.dash/.ksh` extension, in that order. *sh* refers to
+    POSIX `sh` (not the system's), and will warn of portability issues.
+
+**-S**\ *SEVERITY*,\ **--severity=***severity*
+
+:   Specify minimum severity of errors to consider. Valid values in order of
+    severity are *error*, *warning*, *info* and *style*.
+    The default is *style*.
 
 **-V**,\ **--version**
 
 :   Print version information and exit.
 
+**-W** *NUM*,\ **--wiki-link-count=NUM**
+
+:   For TTY output, show *NUM* wiki links to more information about mentioned
+    warnings. Set to 0 to disable them entirely.
+
 **-x**,\ **--external-sources**
 
-:   Follow 'source' statements even when the file is not specified as input.
+:   Follow `source` statements even when the file is not specified as input.
     By default, `shellcheck` will only follow files specified on the command
     line (plus `/dev/null`). This option allows following any file the script
     may `source`.
 
+    This option may also be enabled using `external-sources=true` in
+    `.shellcheckrc`. This flag takes precedence.
+
+**FILES...**
+
+:   One or more script files to check, or "-" for standard input.
+
 
 # FORMATS
 
@@ -109,13 +168,31 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
           ...
         </checkstyle>
 
-**json**
+**diff**
+
+:   Auto-fixes in unified diff format. Can be piped to `git apply` or `patch -p1`
+    to automatically apply fixes.
+
+        --- a/test.sh
+        +++ b/test.sh
+        @@ -2,6 +2,6 @@
+         ## Example of a broken script.
+         for f in $(ls *.m3u)
+         do
+        -  grep -qi hq.*mp3 $f \
+        +  grep -qi hq.*mp3 "$f" \
+             && echo -e 'Playlist $f contains a HQ file in mp3 format'
+         done
+
+
+**json1**
 
 :   Json is a popular serialization format that is more suitable for web
     applications. ShellCheck's json is compact and contains only the bare
-    minimum.
+    minimum.  Tabs are counted as 1 character.
 
-        [
+        {
+          comments: [
             {
               "file": "filename",
               "line": lineNumber,
@@ -126,10 +203,24 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
             },
             ...
           ]
+        }
+
+**json**
+
+:   This is a legacy version of the **json1** format. It's a raw array of
+    comments, and all offsets have a tab stop of 8.
+
+**quiet**
+
+:   Suppress all normal output. Exit with zero if no issues are found,
+    otherwise exit with one. Stops processing after the first issue.
+
 
 # DIRECTIVES
-ShellCheck directives can be specified as comments in the shell script
+
-before a command or block:
+ShellCheck directives can be specified as comments in the shell script.
+If they appear before the first command, they are considered file-wide.
+Otherwise, they apply to the immediately following command or block:
 
     # shellcheck key=value key=value
     command-or-structure
@@ -157,19 +248,88 @@ Valid keys are:
 **disable**
 :   Disables a comma separated list of error codes for the following command.
     The command can be a simple command like `echo foo`, or a compound command
-    like a function definition, subshell block or loop.
+    like a function definition, subshell block or loop. A range can be
+    be specified with a dash, e.g. `disable=SC3000-SC4000` to exclude 3xxx.
+    All warnings can be disabled with `disable=all`.
+
+**enable**
+:   Enable an optional check by name, as listed with **--list-optional**.
+    Only file-wide `enable` directives are considered.
+
+**extended-analysis**
+:   Set to true/false to enable/disable dataflow analysis. Specifying
+    `# shellcheck extended-analysis=false` in particularly large (2000+ line)
+    auto-generated scripts will reduce ShellCheck's resource usage at the
+    expense of certain checks. Extended analysis is enabled by default.
+
+**external-sources**
+:   Set to `true` in `.shellcheckrc` to always allow ShellCheck to open
+    arbitrary files from 'source' statements (the way most tools do).
+
+    This option defaults to `false` only due to ShellCheck's origin as a
+    remote service for checking untrusted scripts. It can safely be enabled
+    for normal development.
 
 **source**
 :   Overrides the filename included by a `source`/`.` statement. This can be
     used to tell shellcheck where to look for a file whose name is determined
     at runtime, or to skip a source by telling it to use `/dev/null`.
 
+**source-path**
+:   Add a directory to the search path for `source`/`.` statements (by default,
+    only ShellCheck's working directory is included). Absolute paths will also
+    be rooted in these paths. The special path `SCRIPTDIR` can be used to
+    specify the currently checked script's directory, as in
+    `source-path=SCRIPTDIR` or `source-path=SCRIPTDIR/../libs`. Multiple
+    paths accumulate, and `-P` takes precedence over them.
+
 **shell**
 :   Overrides the shell detected from the shebang.  This is useful for
     files meant to be included (and thus lacking a shebang), or possibly
-    as a more targeted alternative to 'disable=2039'.
+    as a more targeted alternative to 'disable=SC2039'.
+
+# RC FILES
+
+Unless `--norc` is used, ShellCheck will look for a file `.shellcheckrc` or
+`shellcheckrc` in the script's directory and each parent directory. If found,
+it will read `key=value` pairs from it and treat them as file-wide directives.
+
+Here is an example `.shellcheckrc`:
+
+    # Look for 'source'd files relative to the checked script,
+    # and also look for absolute paths in /mnt/chroot
+    source-path=SCRIPTDIR
+    source-path=/mnt/chroot
+
+    # Since 0.9.0, values can be quoted with '' or "" to allow spaces
+    source-path="My Documents/scripts"
+
+    # Allow opening any 'source'd file, even if not specified as input
+    external-sources=true
+
+    # Turn on warnings for unquoted variables with safe values
+    enable=quote-safe-variables
+
+    # Turn on warnings for unassigned uppercase variables
+    enable=check-unassigned-uppercase
+
+    # Allow [ ! -z foo ] instead of suggesting -n
+    disable=SC2236
+
+If no `.shellcheckrc` is found in any of the parent directories, ShellCheck
+will look in `~/.shellcheckrc` followed by the `$XDG_CONFIG_HOME`
+(usually `~/.config/shellcheckrc`) on Unix, or `%APPDATA%/shellcheckrc` on
+Windows. Only the first file found will be used.
+
+Note for Snap users: the Snap sandbox disallows access to hidden files.
+Use `shellcheckrc` without the dot instead.
+
+Note for Docker users: ShellCheck will only be able to look for files that
+are mounted in the container, so `~/.shellcheckrc` will not be read.
+
 
 # ENVIRONMENT VARIABLES
+
 The environment variable `SHELLCHECK_OPTS` can be set with default flags:
 
     export SHELLCHECK_OPTS='--shell=bash --exclude=SC2016'
@@ -179,7 +339,7 @@ invocation.
 
 # RETURN VALUES
 
-ShellCheck uses the follow exit codes:
+ShellCheck uses the following exit codes:
 
 + 0: All files successfully scanned with no issues.
 + 1: All files successfully scanned with some issues.
@@ -188,6 +348,7 @@ ShellCheck uses the follow exit codes:
 + 4: ShellCheck was invoked with bad options (e.g. unknown formatter).
 
 # LOCALE
+
 This version of ShellCheck is only available in English. All files are
 leniently decoded as UTF-8, with a fallback of ISO-8859-1 for invalid
 sequences. `LC_CTYPE` is respected for output, and defaults to UTF-8 for
@@ -196,20 +357,50 @@ locales where encoding is unspecified (such as the `C` locale).
 Windows users seeing `commitBuffer: invalid argument (invalid character)`
 should set their terminal to use UTF-8 with `chcp 65001`.
 
-# AUTHOR
+# KNOWN INCOMPATIBILITIES
-ShellCheck is written and maintained by Vidar Holen.
+
+(If nothing in this section makes sense, you are unlikely to be affected by it)
+
+To avoid confusing and misguided suggestions, ShellCheck requires function
+bodies to be either `{ brace groups; }` or `( subshells )`, and function names
+containing `[]*=!` are only recognized after a `function` keyword.
+
+The following unconventional function definitions are identical in Bash,
+but ShellCheck only recognizes the latter.
+
+    [x!=y] () [[ $1 ]]
+    function [x!=y] () { [[ $1 ]]; }
+
+Shells without the `function` keyword do not allow these characters in function
+names to begin with.  Function names containing `{}` are not supported at all.
+
+Further, if ShellCheck sees `[x!=y]` it will assume this is an invalid
+comparison. To invoke the above function, quote the command as in `'[x!=y]'`,
+or to retain the same globbing behavior, use `command [x!=y]`.
+
+ShellCheck imposes additional restrictions on the `[` command to help diagnose
+common invalid uses. While `[ $x= 1 ]` is defined in POSIX, ShellCheck will
+assume it was intended as the much more likely comparison `[ "$x" = 1 ]` and
+fail accordingly. For unconventional or dynamic uses of the `[` command, use
+`test` or `\[` instead.
 
 # REPORTING BUGS
+
 Bugs and issues can be reported on GitHub:
 
 https://github.com/koalaman/shellcheck/issues
 
-# COPYRIGHT
+# AUTHORS
-Copyright 2012-2015, Vidar Holen.
-Licensed under the GNU General Public License version 3 or later,
-see http://gnu.org/licenses/gpl.html
 
+ShellCheck is developed and maintained by Vidar Holen, with assistance from a
+long list of wonderful contributors.
+
+# COPYRIGHT
+
+Copyright 2012-2024, Vidar Holen and contributors.
+Licensed under the GNU General Public License version 3 or later,
+see https://gnu.org/licenses/gpl.html
 
 # SEE ALSO
 
-sh(1) bash(1)
+sh(1) bash(1) dash(1) ksh(1)

shellcheck.hs

@@ -1,8 +1,8 @@
 {-
-    Copyright 2012-2015 Vidar Holen
+    Copyright 2012-2019 Vidar Holen
 
     This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
+    https://www.shellcheck.net
 
     ShellCheck is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -15,21 +15,27 @@
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -}
-import ShellCheck.Data
+import qualified ShellCheck.Analyzer
 import           ShellCheck.Checker
+import           ShellCheck.Data
 import           ShellCheck.Interface
 import           ShellCheck.Regex
 
-import ShellCheck.Formatter.Format
 import qualified ShellCheck.Formatter.CheckStyle
+import           ShellCheck.Formatter.Format
+import qualified ShellCheck.Formatter.Diff
 import qualified ShellCheck.Formatter.GCC
 import qualified ShellCheck.Formatter.JSON
+import qualified ShellCheck.Formatter.JSON1
 import qualified ShellCheck.Formatter.TTY
+import qualified ShellCheck.Formatter.Quiet
 
 import           Control.Exception
 import           Control.Monad
+import           Control.Monad.IO.Class
+import           Control.Monad.Trans.Class
 import           Control.Monad.Except
 import           Data.Bits
 import           Data.Char
@@ -40,11 +46,13 @@ import Data.List
 import qualified Data.Map                        as Map
 import           Data.Maybe
 import           Data.Monoid
+import           Data.Semigroup                  (Semigroup (..))
 import           Prelude                         hiding (catch)
 import           System.Console.GetOpt
 import           System.Directory
 import           System.Environment
 import           System.Exit
+import           System.FilePath
 import           System.IO
 
 data Flag = Flag String String
@@ -56,22 +64,31 @@ data Status =
     | RuntimeException
   deriving (Ord, Eq, Show)
 
+instance Semigroup Status where
+    (<>) = max
+
 instance Monoid Status where
     mempty = NoProblems
-    mappend = max
+    mappend = (Data.Semigroup.<>)
 
 data Options = Options {
     checkSpec        :: CheckSpec,
     externalSources  :: Bool,
-    formatterOptions :: FormatterOptions
+    sourcePaths      :: [FilePath],
+    formatterOptions :: FormatterOptions,
+    minSeverity      :: Severity,
+    rcfile           :: Maybe FilePath
 }
 
 defaultOptions = Options {
     checkSpec = emptyCheckSpec,
     externalSources = False,
-    formatterOptions = FormatterOptions {
+    sourcePaths = [],
+    formatterOptions = newFormatterOptions {
         foColorOption = ColorAuto
-    }
+    },
+    minSeverity = StyleC,
+    rcfile = Nothing
 }
 
 usageHeader = "Usage: shellcheck [OPTIONS...] FILES..."
@@ -81,19 +98,45 @@ options = [
     Option "C" ["color"]
         (OptArg (maybe (Flag "color" "always") (Flag "color")) "WHEN")
         "Use color (auto, always, never)",
+    Option "i" ["include"]
+        (ReqArg (Flag "include") "CODE1,CODE2..") "Consider only given types of warnings",
     Option "e" ["exclude"]
         (ReqArg (Flag "exclude") "CODE1,CODE2..") "Exclude types of warnings",
+    Option "" ["extended-analysis"]
+        (ReqArg (Flag "extended-analysis") "bool") "Perform dataflow analysis (default true)",
     Option "f" ["format"]
         (ReqArg (Flag "format") "FORMAT") $
         "Output format (" ++ formatList ++ ")",
+    Option "" ["list-optional"]
+        (NoArg $ Flag "list-optional" "true") "List checks disabled by default",
+    Option "" ["norc"]
+        (NoArg $ Flag "norc" "true") "Don't look for .shellcheckrc files",
+    Option "" ["rcfile"]
+        (ReqArg (Flag "rcfile") "RCFILE")
+        "Prefer the specified configuration file over searching for one",
+    Option "o" ["enable"]
+        (ReqArg (Flag "enable") "check1,check2..")
+        "List of optional checks to enable (or 'all')",
+    Option "P" ["source-path"]
+        (ReqArg (Flag "source-path") "SOURCEPATHS")
+        "Specify path when looking for sourced files (\"SCRIPTDIR\" for script's dir)",
     Option "s" ["shell"]
         (ReqArg (Flag "shell") "SHELLNAME")
-        "Specify dialect (sh, bash, dash, ksh)",
+        "Specify dialect (sh, bash, dash, ksh, busybox)",
+    Option "S" ["severity"]
+        (ReqArg (Flag "severity") "SEVERITY")
+        "Minimum severity of errors to consider (error, warning, info, style)",
     Option "V" ["version"]
         (NoArg $ Flag "version" "true") "Print version information",
+    Option "W" ["wiki-link-count"]
+        (ReqArg (Flag "wiki-link-count") "NUM")
+        "The number of wiki links to show, when applicable",
     Option "x" ["external-sources"]
-        (NoArg $ Flag "externals" "true") "Allow 'source' outside of FILES"
+        (NoArg $ Flag "externals" "true") "Allow 'source' outside of FILES",
+    Option "" ["help"]
+        (NoArg $ Flag "help" "true") "Show this usage summary and exit"
     ]
+getUsageInfo = usageInfo usageHeader options
 
 printErr = lift . hPutStrLn stderr
 
@@ -102,15 +145,18 @@ parseArguments argv =
     case getOpt Permute options argv of
         (opts, files, []) -> return (opts, files)
         (_, _, errors) -> do
-            printErr $ concat errors ++ "\n" ++ usageInfo usageHeader options
+            printErr $ concat errors ++ "\n" ++ getUsageInfo
             throwError SyntaxFailure
 
 formats :: FormatterOptions -> Map.Map String (IO Formatter)
 formats options = Map.fromList [
     ("checkstyle", ShellCheck.Formatter.CheckStyle.format),
+    ("diff",  ShellCheck.Formatter.Diff.format options),
     ("gcc",  ShellCheck.Formatter.GCC.format),
     ("json", ShellCheck.Formatter.JSON.format),
-    ("tty",  ShellCheck.Formatter.TTY.format options)
+    ("json1", ShellCheck.Formatter.JSON1.format),
+    ("tty",  ShellCheck.Formatter.TTY.format options),
+    ("quiet",  ShellCheck.Formatter.Quiet.format options)
     ]
 
 formatList = intercalate ", " names
@@ -133,12 +179,6 @@ split char str =
         else split' rest (a:element)
     split' [] element = [reverse element]
 
-getExclusions options =
-    let elements = concatMap (split ',') $ getOptions options "exclude"
-        clean = dropWhile (not . isDigit)
-    in
-        map (Prelude.read . clean) elements :: [Int]
-
 toStatus = fmap (either id id) . runExceptT
 
 getEnvArgs = do
@@ -194,7 +234,7 @@ runFormatter sys format options files = do
     f :: Status -> FilePath -> IO Status
     f status file = do
         newStatus <- process file `catch` handler file
-        return $ status `mappend` newStatus
+        return $! status `mappend` newStatus
     handler :: FilePath -> IOException -> IO Status
     handler file e = reportFailure file (show e)
     reportFailure file str = do
@@ -203,7 +243,7 @@ runFormatter sys format options files = do
 
     process :: FilePath -> IO Status
     process filename = do
-        input <- (siReadFile sys) filename
+        input <- siReadFile sys Nothing filename
         either (reportFailure filename) check input
       where
         check contents = do
@@ -218,12 +258,28 @@ runFormatter sys format options files = do
                 then NoProblems
                 else SomeProblems
 
-parseColorOption colorOption =
+parseEnum name value list =
-    case colorOption of
+    case lookup value list of
-        "auto" -> ColorAuto
+        Just value -> return value
-        "always" -> ColorAlways
+        Nothing -> do
-        "never" -> ColorNever
+            printErr $ "Unknown value for --" ++ name ++ ". " ++
-        _ -> error $ "Bad value for --color `" ++ colorOption ++ "'"
+                       "Valid options are: " ++ (intercalate ", " $ map fst list)
+            throwError SupportFailure
+
+parseColorOption value =
+    parseEnum "color" value [
+        ("auto",   ColorAuto),
+        ("always", ColorAlways),
+        ("never",  ColorNever)
+        ]
+
+parseSeverityOption value =
+    parseEnum "severity" value [
+        ("error",   ErrorC),
+        ("warning", WarningC),
+        ("info",    InfoC),
+        ("style",   StyleC)
+        ]
 
 parseOption flag options =
     case flag of
@@ -237,7 +293,7 @@ parseOption flag options =
                         }
 
         Flag "exclude" str -> do
-            new <- mapM parseNum $ split ',' str
+            new <- mapM parseNum $ filter (not . null) $ split ',' str
             let old = csExcludedWarnings . checkSpec $ options
             return options {
                 checkSpec = (checkSpec options) {
@@ -245,22 +301,49 @@ parseOption flag options =
                 }
             }
 
+        Flag "include" str -> do
+            new <- mapM parseNum $ filter (not . null) $ split ',' str
+            let old = csIncludedWarnings . checkSpec $ options
+            return options {
+                checkSpec = (checkSpec options) {
+                    csIncludedWarnings =
+                      if null new
+                        then old
+                        else Just new `mappend` old
+                }
+            }
+
         Flag "version" _ -> do
             liftIO printVersion
             throwError NoProblems
 
+        Flag "list-optional" _ -> do
+            liftIO printOptional
+            throwError NoProblems
+
+        Flag "help" _ -> do
+            liftIO $ putStrLn getUsageInfo
+            throwError NoProblems
+
         Flag "externals" _ ->
             return options {
                 externalSources = True
             }
 
-        Flag "color" color ->
+        Flag "color" color -> do
+            option <- parseColorOption color
             return options {
                 formatterOptions = (formatterOptions options) {
-                    foColorOption = parseColorOption color
+                    foColorOption = option
                 }
             }
 
+        Flag "source-path" str -> do
+            let paths = splitSearchPath str
+            return options {
+                sourcePaths = (sourcePaths options) ++ paths
+            }
+
         Flag "sourced" _ ->
             return options {
                 checkSpec = (checkSpec options) {
@@ -268,7 +351,55 @@ parseOption flag options =
                 }
             }
 
-        _ -> return options
+        Flag "severity" severity -> do
+            option <- parseSeverityOption severity
+            return options {
+                checkSpec = (checkSpec options) {
+                    csMinSeverity = option
+                }
+            }
+
+        Flag "wiki-link-count" countString -> do
+            count <- parseNum countString
+            return options {
+                formatterOptions = (formatterOptions options) {
+                    foWikiLinkCount = count
+                }
+            }
+
+        Flag "norc" _ ->
+            return options {
+                checkSpec = (checkSpec options) {
+                    csIgnoreRC = True
+                }
+            }
+
+        Flag "rcfile" str -> do
+            return options {
+                rcfile = Just str
+            }
+
+        Flag "enable" value ->
+            let cs = checkSpec options in return options {
+                checkSpec = cs {
+                    csOptionalChecks = (csOptionalChecks cs) ++ split ',' value
+                }
+            }
+
+        Flag "extended-analysis" str -> do
+            value <- parseBool str
+            return options {
+                checkSpec = (checkSpec options) {
+                    csExtendedAnalysis = Just value
+                }
+            }
+
+        -- This flag is handled specially in 'process'
+        Flag "format" _ -> return options
+
+        Flag str _ -> do
+            printErr $ "Internal error for --" ++ str ++ ". Please file a bug :("
+            return options
   where
     die s = do
         printErr s
@@ -276,27 +407,40 @@ parseOption flag options =
     parseNum ('S':'C':str) = parseNum str
     parseNum num = do
         unless (all isDigit num) $ do
-            printErr $ "Bad exclusion: " ++ num
+            printErr $ "Invalid number: " ++ num
             throwError SyntaxFailure
         return (Prelude.read num :: Integer)
 
+    parseBool str = do
+        case str of
+            "true" -> return True
+            "false" -> return False
+            _ -> do
+                printErr $ "Invalid boolean, expected true/false: " ++ str
+                throwError SyntaxFailure
+
+ioInterface :: Options -> [FilePath] -> IO (SystemInterface IO)
 ioInterface options files = do
     inputs <- mapM normalize files
     cache <- newIORef emptyCache
-    return SystemInterface {
+    configCache <- newIORef ("", Nothing)
-        siReadFile = get cache inputs
+    return (newSystemInterface :: SystemInterface IO) {
+        siReadFile = get cache inputs,
+        siFindSource = findSourceFile inputs (sourcePaths options),
+        siGetConfig = getConfig configCache
     }
   where
     emptyCache :: Map.Map FilePath String
     emptyCache = Map.empty
-    get cache inputs file = do
+
+    get cache inputs rcSuggestsExternal file = do
         map <- readIORef cache
         case Map.lookup file map of
             Just x  -> return $ Right x
-            Nothing -> fetch cache inputs file
+            Nothing -> fetch cache inputs rcSuggestsExternal file
 
-    fetch cache inputs file = do
+    fetch cache inputs rcSuggestsExternal file = do
-        ok <- allowable inputs file
+        ok <- allowable rcSuggestsExternal inputs file
         if ok
           then (do
             (contents, shouldCache) <- inputFile file
@@ -304,14 +448,16 @@ ioInterface options files = do
                 modifyIORef cache $ Map.insert file contents
             return $ Right contents
             ) `catch` handler
+          else
+            if rcSuggestsExternal == Just False
+            then return $ Left (file ++ " was not specified as input, and external files were disabled via directive.")
             else return $ Left (file ++ " was not specified as input (see shellcheck -x).")
-
       where
         handler :: IOException -> IO (Either ErrorMessage String)
         handler ex = return . Left $ show ex
 
-    allowable inputs x =
+    allowable rcSuggestsExternal inputs x =
-        if externalSources options
+        if fromMaybe (externalSources options) rcSuggestsExternal
         then return True
         else do
             path <- normalize x
@@ -323,6 +469,103 @@ ioInterface options files = do
         fallback :: FilePath -> IOException -> IO FilePath
         fallback path _ = return path
 
+
+    -- Returns the name and contents of .shellcheckrc for the given file
+    getConfig cache filename =
+        case rcfile options of
+            Just file -> do
+                -- We have a specified rcfile. Ignore normal rcfile resolution.
+                (path, result) <- readIORef cache
+                if path == "/"
+                  then return result
+                  else do
+                    result <- readConfig file
+                    when (isNothing result) $
+                        hPutStrLn stderr $ "Warning: unable to read --rcfile " ++ file
+                    writeIORef cache ("/", result)
+                    return result
+
+            Nothing -> do
+                path <- normalize filename
+                let dir = takeDirectory path
+                (previousPath, result) <- readIORef cache
+                if dir == previousPath
+                  then return result
+                  else do
+                    paths <- getConfigPaths dir
+                    result <- findConfig paths
+                    writeIORef cache (dir, result)
+                    return result
+
+    findConfig paths =
+        case paths of
+            (file:rest) -> do
+                contents <- readConfig file
+                if isJust contents
+                  then return contents
+                  else findConfig rest
+            [] -> return Nothing
+
+    -- Get a list of candidate filenames. This includes .shellcheckrc
+    -- in all parent directories, plus the user's home dir and xdg dir.
+    -- The dot is optional for Windows and Snap users.
+    getConfigPaths dir = do
+        let next = takeDirectory dir
+        rest <- if next /= dir
+                then getConfigPaths next
+                else defaultPaths `catch`
+                        ((const $ return []) :: IOException -> IO [FilePath])
+        return $ (dir </> ".shellcheckrc") : (dir </> "shellcheckrc") : rest
+
+    defaultPaths = do
+        home <- getAppUserDataDirectory "shellcheckrc"
+        xdg <- getXdgDirectory XdgConfig "shellcheckrc"
+        return [home, xdg]
+
+    readConfig file = do
+        exists <- doesFileExist file
+        if exists
+          then do
+            (contents, _) <- inputFile file `catch` handler file
+            return $ Just (file, contents)
+          else
+            return Nothing
+      where
+        handler :: FilePath -> IOException -> IO (String, Bool)
+        handler file err = do
+            hPutStrLn stderr $ file ++ ": " ++ show err
+            return ("", True)
+
+    andM a b arg = do
+        first <- a arg
+        if not first then return False else b arg
+
+    findM p = foldr go (pure Nothing)
+      where
+        go x acc = do
+            b <- p x
+            if b then pure (Just x) else acc
+
+    findSourceFile inputs sourcePathFlag currentScript rcSuggestsExternal sourcePathAnnotation original =
+        if isAbsolute original
+        then
+            let (_, relative) = splitDrive original
+            in find relative original
+        else
+            find original original
+      where
+        find filename deflt = do
+            sources <- findM ((allowable rcSuggestsExternal inputs) `andM` doesFileExist) $
+                        (adjustPath filename):(map ((</> filename) . adjustPath) $ sourcePathFlag ++ sourcePathAnnotation)
+            case sources of
+                Nothing -> return deflt
+                Just first -> return first
+        scriptdir = dropFileName currentScript
+        adjustPath str =
+            case (splitDirectories str) of
+                ("SCRIPTDIR":rest) -> joinPath (scriptdir:rest)
+                _ -> str
+
 inputFile file = do
     (handle, shouldCache) <-
             if file == "-"
@@ -378,4 +621,15 @@ printVersion = do
     putStrLn   "ShellCheck - shell script analysis tool"
     putStrLn $ "version: " ++ shellcheckVersion
     putStrLn   "license: GNU General Public License, version 3"
-    putStrLn   "website: http://www.shellcheck.net"
+    putStrLn   "website: https://www.shellcheck.net"
+
+printOptional = do
+    mapM f list
+  where
+    list = sortOn cdName ShellCheck.Analyzer.optionalChecks
+    f item = do
+        putStrLn $ "name:    " ++ cdName item
+        putStrLn $ "desc:    " ++ cdDescription item
+        putStrLn $ "example: " ++ cdPositive item
+        putStrLn $ "fix:     " ++ cdNegative item
+        putStrLn ""

snap/snapcraft.yaml

@@ -0,0 +1,56 @@
+name: shellcheck
+summary: A shell script static analysis tool
+description: |
+  ShellCheck is a GPLv3 tool that gives warnings and suggestions for bash/sh
+  shell scripts.
+
+  The goals of ShellCheck are
+
+  - To point out and clarify typical beginner's syntax issues that cause a
+    shell to give cryptic error messages.
+
+  - To point out and clarify typical intermediate level semantic problems that
+    cause a shell to behave strangely and counter-intuitively.
+
+  - To point out subtle caveats, corner cases and pitfalls that may cause an
+    advanced user's otherwise working script to fail under future
+    circumstances.
+
+  By default ShellCheck can only check non-hidden files under /home, to make
+  ShellCheck be able to check files under /media and /run/media you must
+  connect it to the `removable-media` interface manually:
+
+      # snap connect shellcheck:removable-media
+
+version: git
+base: core20
+grade: stable
+confinement: strict
+
+apps:
+  shellcheck:
+    command: usr/bin/shellcheck
+    plugs: [home, removable-media]
+    environment:
+      LANG: C.UTF-8
+
+parts:
+  shellcheck:
+    plugin: dump
+    source: .
+    build-packages:
+      - cabal-install
+    stage-packages:
+      - libatomic1
+    override-build: |
+      # Give ourselves enough memory to build
+      dd if=/dev/zero of=/tmp/swap bs=1M count=2000
+      mkswap /tmp/swap
+      swapon /tmp/swap
+
+      cabal sandbox init
+      cabal update
+      cabal install -j
+
+      install -d $SNAPCRAFT_PART_INSTALL/usr/bin
+      install .cabal-sandbox/bin/shellcheck $SNAPCRAFT_PART_INSTALL/usr/bin

src/ShellCheck/AST.hs

@@ -0,0 +1,288 @@
+{-
+    Copyright 2012-2019 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE DeriveGeneric, DeriveAnyClass, DeriveTraversable, PatternSynonyms #-}
+module ShellCheck.AST where
+
+import GHC.Generics (Generic)
+import Control.Monad.Identity
+import Control.DeepSeq
+import Text.Parsec
+import qualified ShellCheck.Regex as Re
+import Prelude hiding (id)
+
+newtype Id = Id Int deriving (Show, Eq, Ord, Generic, NFData)
+
+data Quoted = Quoted | Unquoted deriving (Show, Eq)
+data Dashed = Dashed | Undashed deriving (Show, Eq)
+data AssignmentMode = Assign | Append deriving (Show, Eq)
+newtype FunctionKeyword = FunctionKeyword Bool deriving (Show, Eq)
+newtype FunctionParentheses = FunctionParentheses Bool deriving (Show, Eq)
+data CaseType = CaseBreak | CaseFallThrough | CaseContinue deriving (Show, Eq)
+
+newtype Root = Root Token
+data Token = OuterToken Id (InnerToken Token) deriving (Show)
+
+data InnerToken t =
+    Inner_TA_Binary String t t
+    | Inner_TA_Assignment String t t
+    | Inner_TA_Variable String [t]
+    | Inner_TA_Expansion [t]
+    | Inner_TA_Sequence [t]
+    | Inner_TA_Parenthesis t
+    | Inner_TA_Trinary t t t
+    | Inner_TA_Unary String t
+    | Inner_TC_And ConditionType String t t
+    | Inner_TC_Binary ConditionType String t t
+    | Inner_TC_Group ConditionType t
+    | Inner_TC_Nullary ConditionType t
+    | Inner_TC_Or ConditionType String t t
+    | Inner_TC_Unary ConditionType String t
+    | Inner_TC_Empty ConditionType
+    | Inner_T_AND_IF
+    | Inner_T_AndIf t t
+    | Inner_T_Arithmetic t
+    | Inner_T_Array [t]
+    | Inner_T_IndexedElement [t] t
+    -- Store the index as string, and parse as arithmetic or string later
+    | Inner_T_UnparsedIndex SourcePos String
+    | Inner_T_Assignment AssignmentMode String [t] t
+    | Inner_T_Backgrounded t
+    | Inner_T_Backticked [t]
+    | Inner_T_Bang
+    | Inner_T_Banged t
+    | Inner_T_BraceExpansion [t]
+    | Inner_T_BraceGroup [t]
+    | Inner_T_CLOBBER
+    | Inner_T_Case
+    | Inner_T_CaseExpression t [(CaseType, [t], [t])]
+    | Inner_T_Condition ConditionType t
+    | Inner_T_DGREAT
+    | Inner_T_DLESS
+    | Inner_T_DLESSDASH
+    | Inner_T_DSEMI
+    | Inner_T_Do
+    | Inner_T_DollarArithmetic t
+    | Inner_T_DollarBraced Bool t
+    | Inner_T_DollarBracket t
+    | Inner_T_DollarDoubleQuoted [t]
+    | Inner_T_DollarExpansion [t]
+    | Inner_T_DollarSingleQuoted String
+    | Inner_T_DollarBraceCommandExpansion [t]
+    | Inner_T_Done
+    | Inner_T_DoubleQuoted [t]
+    | Inner_T_EOF
+    | Inner_T_Elif
+    | Inner_T_Else
+    | Inner_T_Esac
+    | Inner_T_Extglob String [t]
+    | Inner_T_FdRedirect String t
+    | Inner_T_Fi
+    | Inner_T_For
+    | Inner_T_ForArithmetic t t t [t]
+    | Inner_T_ForIn String [t] [t]
+    | Inner_T_Function FunctionKeyword FunctionParentheses String t
+    | Inner_T_GREATAND
+    | Inner_T_Glob String
+    | Inner_T_Greater
+    | Inner_T_HereDoc Dashed Quoted String [t]
+    | Inner_T_HereString t
+    | Inner_T_If
+    | Inner_T_IfExpression [([t],[t])] [t]
+    | Inner_T_In
+    | Inner_T_IoFile t t
+    | Inner_T_IoDuplicate t String
+    | Inner_T_LESSAND
+    | Inner_T_LESSGREAT
+    | Inner_T_Lbrace
+    | Inner_T_Less
+    | Inner_T_Literal String
+    | Inner_T_Lparen
+    | Inner_T_NEWLINE
+    | Inner_T_NormalWord [t]
+    | Inner_T_OR_IF
+    | Inner_T_OrIf t t
+    | Inner_T_ParamSubSpecialChar String -- e.g. '%' in ${foo%bar}  or '/' in ${foo/bar/baz}
+    | Inner_T_Pipeline [t] [t] -- [Pipe separators] [Commands]
+    | Inner_T_ProcSub String [t]
+    | Inner_T_Rbrace
+    | Inner_T_Redirecting [t] t
+    | Inner_T_Rparen
+    | Inner_T_Script t [t] -- Shebang T_Literal, followed by script.
+    | Inner_T_Select
+    | Inner_T_SelectIn String [t] [t]
+    | Inner_T_Semi
+    | Inner_T_SimpleCommand [t] [t]
+    | Inner_T_SingleQuoted String
+    | Inner_T_Subshell [t]
+    | Inner_T_Then
+    | Inner_T_Until
+    | Inner_T_UntilExpression [t] [t]
+    | Inner_T_While
+    | Inner_T_WhileExpression [t] [t]
+    | Inner_T_Annotation [Annotation] t
+    | Inner_T_Pipe String
+    | Inner_T_CoProc (Maybe Token) t
+    | Inner_T_CoProcBody t
+    | Inner_T_Include t
+    | Inner_T_SourceCommand t t
+    | Inner_T_BatsTest String t
+    deriving (Show, Eq, Functor, Foldable, Traversable)
+
+data Annotation =
+    DisableComment Integer Integer -- [from, to)
+    | EnableComment String
+    | SourceOverride String
+    | ShellOverride String
+    | SourcePath String
+    | ExternalSources Bool
+    | ExtendedAnalysis Bool
+    deriving (Show, Eq)
+data ConditionType = DoubleBracket | SingleBracket deriving (Show, Eq)
+
+pattern T_AND_IF id = OuterToken id Inner_T_AND_IF
+pattern T_Bang id = OuterToken id Inner_T_Bang
+pattern T_Case id = OuterToken id Inner_T_Case
+pattern TC_Empty id typ = OuterToken id (Inner_TC_Empty typ)
+pattern T_CLOBBER id = OuterToken id Inner_T_CLOBBER
+pattern T_DGREAT id = OuterToken id Inner_T_DGREAT
+pattern T_DLESS id = OuterToken id Inner_T_DLESS
+pattern T_DLESSDASH id = OuterToken id Inner_T_DLESSDASH
+pattern T_Do id = OuterToken id Inner_T_Do
+pattern T_DollarSingleQuoted id str = OuterToken id (Inner_T_DollarSingleQuoted str)
+pattern T_Done id = OuterToken id Inner_T_Done
+pattern T_DSEMI id = OuterToken id Inner_T_DSEMI
+pattern T_Elif id = OuterToken id Inner_T_Elif
+pattern T_Else id = OuterToken id Inner_T_Else
+pattern T_EOF id = OuterToken id Inner_T_EOF
+pattern T_Esac id = OuterToken id Inner_T_Esac
+pattern T_Fi id = OuterToken id Inner_T_Fi
+pattern T_For id = OuterToken id Inner_T_For
+pattern T_Glob id str = OuterToken id (Inner_T_Glob str)
+pattern T_GREATAND id = OuterToken id Inner_T_GREATAND
+pattern T_Greater id = OuterToken id Inner_T_Greater
+pattern T_If id = OuterToken id Inner_T_If
+pattern T_In id = OuterToken id Inner_T_In
+pattern T_Lbrace id = OuterToken id Inner_T_Lbrace
+pattern T_Less id = OuterToken id Inner_T_Less
+pattern T_LESSAND id = OuterToken id Inner_T_LESSAND
+pattern T_LESSGREAT id = OuterToken id Inner_T_LESSGREAT
+pattern T_Literal id str = OuterToken id (Inner_T_Literal str)
+pattern T_Lparen id = OuterToken id Inner_T_Lparen
+pattern T_NEWLINE id = OuterToken id Inner_T_NEWLINE
+pattern T_OR_IF id = OuterToken id Inner_T_OR_IF
+pattern T_ParamSubSpecialChar id str = OuterToken id (Inner_T_ParamSubSpecialChar str)
+pattern T_Pipe id str = OuterToken id (Inner_T_Pipe str)
+pattern T_Rbrace id = OuterToken id Inner_T_Rbrace
+pattern T_Rparen id = OuterToken id Inner_T_Rparen
+pattern T_Select id = OuterToken id Inner_T_Select
+pattern T_Semi id = OuterToken id Inner_T_Semi
+pattern T_SingleQuoted id str = OuterToken id (Inner_T_SingleQuoted str)
+pattern T_Then id = OuterToken id Inner_T_Then
+pattern T_UnparsedIndex id pos str = OuterToken id (Inner_T_UnparsedIndex pos str)
+pattern T_Until id = OuterToken id Inner_T_Until
+pattern T_While id = OuterToken id Inner_T_While
+pattern TA_Assignment id op t1 t2 = OuterToken id (Inner_TA_Assignment op t1 t2)
+pattern TA_Binary id op t1 t2 = OuterToken id (Inner_TA_Binary op t1 t2)
+pattern TA_Expansion id t = OuterToken id (Inner_TA_Expansion t)
+pattern T_AndIf id t u = OuterToken id (Inner_T_AndIf t u)
+pattern T_Annotation id anns t = OuterToken id (Inner_T_Annotation anns t)
+pattern T_Arithmetic id c = OuterToken id (Inner_T_Arithmetic c)
+pattern T_Array id t = OuterToken id (Inner_T_Array t)
+pattern TA_Sequence id l = OuterToken id (Inner_TA_Sequence l)
+pattern TA_Parenthesis id t = OuterToken id (Inner_TA_Parenthesis t)
+pattern T_Assignment id mode var indices value = OuterToken id (Inner_T_Assignment mode var indices value)
+pattern TA_Trinary id t1 t2 t3 = OuterToken id (Inner_TA_Trinary t1 t2 t3)
+pattern TA_Unary id op t1 = OuterToken id (Inner_TA_Unary op t1)
+pattern TA_Variable id str t = OuterToken id (Inner_TA_Variable str t)
+pattern T_Backgrounded id l = OuterToken id (Inner_T_Backgrounded l)
+pattern T_Backticked id list = OuterToken id (Inner_T_Backticked list)
+pattern T_Banged id l = OuterToken id (Inner_T_Banged l)
+pattern T_BatsTest id name t = OuterToken id (Inner_T_BatsTest name t)
+pattern T_BraceExpansion id list = OuterToken id (Inner_T_BraceExpansion list)
+pattern T_BraceGroup id l = OuterToken id (Inner_T_BraceGroup l)
+pattern TC_And id typ str t1 t2 = OuterToken id (Inner_TC_And typ str t1 t2)
+pattern T_CaseExpression id word cases = OuterToken id (Inner_T_CaseExpression word cases)
+pattern TC_Binary id typ op lhs rhs = OuterToken id (Inner_TC_Binary typ op lhs rhs)
+pattern TC_Group id typ token = OuterToken id (Inner_TC_Group typ token)
+pattern TC_Nullary id typ token = OuterToken id (Inner_TC_Nullary typ token)
+pattern T_Condition id typ token = OuterToken id (Inner_T_Condition typ token)
+pattern T_CoProcBody id t = OuterToken id (Inner_T_CoProcBody t)
+pattern T_CoProc id var body = OuterToken id (Inner_T_CoProc var body)
+pattern TC_Or id typ str t1 t2 = OuterToken id (Inner_TC_Or typ str t1 t2)
+pattern TC_Unary id typ op token = OuterToken id (Inner_TC_Unary typ op token)
+pattern T_DollarArithmetic id c = OuterToken id (Inner_T_DollarArithmetic c)
+pattern T_DollarBraceCommandExpansion id list = OuterToken id (Inner_T_DollarBraceCommandExpansion list)
+pattern T_DollarBraced id braced op = OuterToken id (Inner_T_DollarBraced braced op)
+pattern T_DollarBracket id c = OuterToken id (Inner_T_DollarBracket c)
+pattern T_DollarDoubleQuoted id list = OuterToken id (Inner_T_DollarDoubleQuoted list)
+pattern T_DollarExpansion id list = OuterToken id (Inner_T_DollarExpansion list)
+pattern T_DoubleQuoted id list = OuterToken id (Inner_T_DoubleQuoted list)
+pattern T_Extglob id str l = OuterToken id (Inner_T_Extglob str l)
+pattern T_FdRedirect id v t = OuterToken id (Inner_T_FdRedirect v t)
+pattern T_ForArithmetic id a b c group = OuterToken id (Inner_T_ForArithmetic a b c group)
+pattern T_ForIn id v w l = OuterToken id (Inner_T_ForIn v w l)
+pattern T_Function id a b name body = OuterToken id (Inner_T_Function a b name body)
+pattern T_HereDoc id d q str l = OuterToken id (Inner_T_HereDoc d q str l)
+pattern T_HereString id word = OuterToken id (Inner_T_HereString word)
+pattern T_IfExpression id conditions elses = OuterToken id (Inner_T_IfExpression conditions elses)
+pattern T_Include id script = OuterToken id (Inner_T_Include script)
+pattern T_IndexedElement id indices t = OuterToken id (Inner_T_IndexedElement indices t)
+pattern T_IoDuplicate id op num = OuterToken id (Inner_T_IoDuplicate op num)
+pattern T_IoFile id op file = OuterToken id (Inner_T_IoFile op file)
+pattern T_NormalWord id list = OuterToken id (Inner_T_NormalWord list)
+pattern T_OrIf id t u = OuterToken id (Inner_T_OrIf t u)
+pattern T_Pipeline id l1 l2 = OuterToken id (Inner_T_Pipeline l1 l2)
+pattern T_ProcSub id typ l = OuterToken id (Inner_T_ProcSub typ l)
+pattern T_Redirecting id redirs cmd = OuterToken id (Inner_T_Redirecting redirs cmd)
+pattern T_Script id shebang list = OuterToken id (Inner_T_Script shebang list)
+pattern T_SelectIn id v w l = OuterToken id (Inner_T_SelectIn v w l)
+pattern T_SimpleCommand id vars cmds = OuterToken id (Inner_T_SimpleCommand vars cmds)
+pattern T_SourceCommand id includer t_include = OuterToken id (Inner_T_SourceCommand includer t_include)
+pattern T_Subshell id l = OuterToken id (Inner_T_Subshell l)
+pattern T_UntilExpression id c l = OuterToken id (Inner_T_UntilExpression c l)
+pattern T_WhileExpression id c l = OuterToken id (Inner_T_WhileExpression c l)
+
+{-# COMPLETE T_AND_IF, T_Bang, T_Case, TC_Empty, T_CLOBBER, T_DGREAT, T_DLESS, T_DLESSDASH, T_Do, T_DollarSingleQuoted, T_Done, T_DSEMI, T_Elif, T_Else, T_EOF, T_Esac, T_Fi, T_For, T_Glob, T_GREATAND, T_Greater, T_If, T_In, T_Lbrace, T_Less, T_LESSAND, T_LESSGREAT, T_Literal, T_Lparen, T_NEWLINE, T_OR_IF, T_ParamSubSpecialChar, T_Pipe, T_Rbrace, T_Rparen, T_Select, T_Semi, T_SingleQuoted, T_Then, T_UnparsedIndex, T_Until, T_While, TA_Assignment, TA_Binary, TA_Expansion, T_AndIf, T_Annotation, T_Arithmetic, T_Array, TA_Sequence, TA_Parenthesis, T_Assignment, TA_Trinary, TA_Unary, TA_Variable, T_Backgrounded, T_Backticked, T_Banged, T_BatsTest, T_BraceExpansion, T_BraceGroup, TC_And, T_CaseExpression, TC_Binary, TC_Group, TC_Nullary, T_Condition, T_CoProcBody, T_CoProc, TC_Or, TC_Unary, T_DollarArithmetic, T_DollarBraceCommandExpansion, T_DollarBraced, T_DollarBracket, T_DollarDoubleQuoted, T_DollarExpansion, T_DoubleQuoted, T_Extglob, T_FdRedirect, T_ForArithmetic, T_ForIn, T_Function, T_HereDoc, T_HereString, T_IfExpression, T_Include, T_IndexedElement, T_IoDuplicate, T_IoFile, T_NormalWord, T_OrIf, T_Pipeline, T_ProcSub, T_Redirecting, T_Script, T_SelectIn, T_SimpleCommand, T_SourceCommand, T_Subshell, T_UntilExpression, T_WhileExpression #-}
+
+instance Eq Token where
+    OuterToken _ a == OuterToken _ b = a == b
+
+analyze :: Monad m => (Token -> m ()) -> (Token -> m ()) -> (Token -> m Token) -> Token -> m Token
+analyze f g i =
+    round
+  where
+    round t@(OuterToken id it) = do
+        f t
+        newIt <- traverse round it
+        g t
+        i (OuterToken id newIt)
+
+getId :: Token -> Id
+getId (OuterToken id _) = id
+
+blank :: Monad m => Token -> m ()
+blank = const $ return ()
+doAnalysis :: Monad m => (Token -> m ()) -> Token -> m Token
+doAnalysis f = analyze f blank return
+doStackAnalysis :: Monad m => (Token -> m ()) -> (Token -> m ()) -> Token -> m Token
+doStackAnalysis startToken endToken = analyze startToken endToken return
+doTransform :: (Token -> Token) -> Token -> Token
+doTransform i = runIdentity . analyze blank blank (return . i)
+

src/ShellCheck/ASTLib.hs

@@ -0,0 +1,926 @@
+{-
+    Copyright 2012-2021 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.ASTLib where
+
+import ShellCheck.AST
+import ShellCheck.Prelude
+import ShellCheck.Regex
+
+import Control.Monad.Writer
+import Control.Monad
+import Data.Char
+import Data.Functor
+import Data.Functor.Identity
+import Data.List
+import Data.Maybe
+import qualified Data.List.NonEmpty as NE
+import qualified Data.Map as Map
+import Numeric (showHex)
+
+import Test.QuickCheck
+
+arguments (T_SimpleCommand _ _ (cmd:args)) = args
+
+-- Is this a type of loop?
+isLoop t = case t of
+        T_WhileExpression {} -> True
+        T_UntilExpression {} -> True
+        T_ForIn {} -> True
+        T_ForArithmetic {} -> True
+        T_SelectIn {}  -> True
+        _ -> False
+
+-- Will this split into multiple words when used as an argument?
+willSplit x =
+  case x of
+    T_DollarBraced {} -> True
+    T_DollarExpansion {} -> True
+    T_Backticked {} -> True
+    T_BraceExpansion {} -> True
+    T_Glob {} -> True
+    T_Extglob {} -> True
+    T_DoubleQuoted _ l -> any willBecomeMultipleArgs l
+    T_NormalWord _ l -> any willSplit l
+    _ -> False
+
+isGlob t = case t of
+    T_Extglob {} -> True
+    T_Glob {} -> True
+    T_NormalWord _ l -> any isGlob l || hasSplitRange l
+    _ -> False
+  where
+    -- foo[x${var}y] gets parsed as foo,[,x,$var,y],
+    -- so check if there's such an interval
+    hasSplitRange l =
+        let afterBracket = dropWhile (not . isHalfOpenRange) l
+        in any isClosingRange afterBracket
+
+    isHalfOpenRange t =
+        case t of
+            T_Literal _ "[" -> True
+            _ -> False
+
+    isClosingRange t =
+        case t of
+            T_Literal _ str -> ']' `elem` str
+            _ -> False
+
+
+-- Is this shell word a constant?
+isConstant token =
+    case token of
+        -- This ignores some cases like ~"foo":
+        T_NormalWord _ (T_Literal _ ('~':_) : _)  -> False
+        T_NormalWord _ l   -> all isConstant l
+        T_DoubleQuoted _ l -> all isConstant l
+        T_SingleQuoted _ _ -> True
+        T_Literal _ _ -> True
+        _ -> False
+
+-- Is this an empty literal?
+isEmpty token =
+    case token of
+        T_NormalWord _ l   -> all isEmpty l
+        T_DoubleQuoted _ l -> all isEmpty l
+        T_SingleQuoted _ "" -> True
+        T_Literal _ "" -> True
+        _ -> False
+
+-- Quick&lazy oversimplification of commands, throwing away details
+-- and returning a list like  ["find", ".", "-name", "${VAR}*" ].
+oversimplify token =
+    case token of
+        (T_NormalWord _ l) -> [concat (concatMap oversimplify l)]
+        (T_DoubleQuoted _ l) -> [concat (concatMap oversimplify l)]
+        (T_SingleQuoted _ s) -> [s]
+        (T_DollarBraced _ _ _) -> ["${VAR}"]
+        (T_DollarArithmetic _ _) -> ["${VAR}"]
+        (T_DollarExpansion _ _) -> ["${VAR}"]
+        (T_Backticked _ _) -> ["${VAR}"]
+        (T_Glob _ s) -> [s]
+        (T_Pipeline _ _ [x]) -> oversimplify x
+        (T_Literal _ x) -> [x]
+        (T_ParamSubSpecialChar _ x) -> [x]
+        (T_SimpleCommand _ vars words) -> concatMap oversimplify words
+        (T_Redirecting _ _ foo) -> oversimplify foo
+        (T_DollarSingleQuoted _ s) -> [s]
+        (T_Annotation _ _ s) -> oversimplify s
+        -- Workaround for let "foo = bar" parsing
+        (TA_Sequence _ [TA_Expansion _ v]) -> concatMap oversimplify v
+        _ -> []
+
+
+-- Turn a SimpleCommand foo -avz --bar=baz into args "a", "v", "z", "bar",
+-- each in a tuple of (token, stringFlag). Non-flag arguments are added with
+-- stringFlag == "".
+getFlagsUntil stopCondition (T_SimpleCommand _ _ (_:args)) =
+    let tokenAndText = map (\x -> (x, concat $ oversimplify x)) args
+        (flagArgs, rest) = break (stopCondition . snd) tokenAndText
+    in
+        concatMap flag flagArgs ++ map (\(t, _) -> (t, "")) rest
+  where
+    flag (x, '-':'-':arg) = [ (x, takeWhile (/= '=') arg) ]
+    flag (x, '-':args) = map (\v -> (x, [v])) args
+    flag (x, _) = [ (x, "") ]
+getFlagsUntil _ _ = error $ pleaseReport "getFlags on non-command"
+
+-- Get all flags in a GNU way, up until --
+getAllFlags :: Token -> [(Token, String)]
+getAllFlags = getFlagsUntil (== "--")
+-- Get all flags in a BSD way, up until first non-flag argument or --
+getLeadingFlags = getFlagsUntil (\x -> x == "--" || (not $ "-" `isPrefixOf` x))
+
+-- Check if a command has a flag.
+hasFlag cmd str = str `elem` (map snd $ getAllFlags cmd)
+
+-- Is this token a word that starts with a dash?
+isFlag token =
+    case getWordParts token of
+        T_Literal _ ('-':_) : _ -> True
+        _ -> False
+
+-- Is this token a flag where the - is unquoted?
+isUnquotedFlag token =
+    case getLeadingUnquotedString token of
+        Just ('-':_) -> True
+        _ -> False
+
+-- getGnuOpts "erd:u:" will parse a list of arguments tokens like `read`
+--     -re -d : -u 3 bar
+-- into
+--     Just [("r", (-re, -re)), ("e", (-re, -re)), ("d", (-d,:)), ("u", (-u,3)), ("", (bar,bar))]
+--
+-- Each string flag maps to a tuple of (flag, argument), where argument=flag if it
+-- doesn't take a specific one.
+--
+-- Any unrecognized flag will result in Nothing. The exception is if arbitraryLongOpts
+-- is set, in which case --anything will map to "anything".
+getGnuOpts :: String -> [Token] -> Maybe [(String, (Token, Token))]
+getGnuOpts str args = getOpts (True, False) str [] args
+
+-- As above, except the first non-arg string will treat the rest as arguments
+getBsdOpts :: String -> [Token] -> Maybe [(String, (Token, Token))]
+getBsdOpts str args = getOpts (False, False) str [] args
+
+-- Tests for this are in Commands.hs where it's more frequently used
+getOpts ::
+    -- Behavioral config: gnu style, allow arbitrary long options
+    (Bool, Bool)
+    -- A getopts style string
+    -> String
+    -- List of long options and whether they take arguments
+    -> [(String, Bool)]
+    -- List of arguments (excluding command)
+    -> [Token]
+    -- List of flags to tuple of (optionToken, valueToken)
+    -> Maybe [(String, (Token, Token))]
+
+getOpts (gnu, arbitraryLongOpts) string longopts args = process args
+  where
+    flagList (c:':':rest) = ([c], True) : flagList rest
+    flagList (c:rest)     = ([c], False) : flagList rest
+    flagList []           = longopts
+    flagMap = Map.fromList $ ("", False) : flagList string
+
+    process [] = return []
+    process (token:rest) = do
+        case getLiteralStringDef "\0" token of
+            "--" -> return $ listToArgs rest
+            '-':'-':word -> do
+                let (name, arg) = span (/= '=') word
+                needsArg <-
+                    if arbitraryLongOpts
+                    then return $ Map.findWithDefault False name flagMap
+                    else Map.lookup name flagMap
+
+                if needsArg && null arg
+                  then
+                    case rest of
+                        (arg:rest2) -> do
+                            more <- process rest2
+                            return $ (name, (token, arg)) : more
+                        _ -> fail "Missing arg"
+                  else do
+                    more <- process rest
+                    -- Consider splitting up token to get arg
+                    return $ (name, (token, token)) : more
+            '-':opts -> shortToOpts opts token rest
+            arg ->
+                if gnu
+                then do
+                    more <- process rest
+                    return $ ("", (token, token)):more
+                else return $ listToArgs (token:rest)
+
+    shortToOpts opts token args =
+        case opts of
+            c:rest -> do
+                needsArg <- Map.lookup [c] flagMap
+                case () of
+                    _ | needsArg && null rest -> do
+                        (next:restArgs) <- return args
+                        more <- process restArgs
+                        return $ ([c], (token, next)):more
+                    _ | needsArg -> do
+                        more <- process args
+                        return $ ([c], (token, token)):more
+                    _ -> do
+                        more <- shortToOpts rest token args
+                        return $ ([c], (token, token)):more
+            [] -> process args
+
+    listToArgs = map (\x -> ("", (x, x)))
+
+
+-- Generic getOpts that doesn't rely on a format string, but may also be inaccurate.
+-- This provides a best guess interpretation instead of failing when new options are added.
+--
+--    "--" is treated as end of arguments
+--    "--anything[=foo]" is treated as a long option without argument
+--    "-any" is treated as -a -n -y, with the next arg as an option to -y unless it starts with -
+--    anything else is an argument
+getGenericOpts :: [Token] -> [(String, (Token, Token))]
+getGenericOpts = process
+  where
+    process (token:rest) =
+        case getLiteralStringDef "\0" token of
+            "--" -> map (\c -> ("", (c,c))) rest
+            '-':'-':word -> (takeWhile (`notElem` "\0=") word, (token, token)) : process rest
+            '-':optString ->
+                let opts = takeWhile (/= '\0') optString
+                in
+                    case rest of
+                        next:_ | "-" `isPrefixOf` getLiteralStringDef "\0" next  ->
+                            map (\c -> ([c], (token, token))) opts ++ process rest
+                        next:remainder ->
+                            case reverse opts of
+                                last:initial ->
+                                    map (\c -> ([c], (token, token))) (reverse initial)
+                                        ++ [([last], (token, next))]
+                                        ++ process remainder
+                                [] -> process remainder
+                        [] -> map (\c -> ([c], (token, token))) opts
+            _ -> ("", (token, token)) : process rest
+    process [] = []
+
+
+-- Is this an expansion of multiple items of an array?
+isArrayExpansion (T_DollarBraced _ _ l) =
+    let string = concat $ oversimplify l in
+        "@" `isPrefixOf` string ||
+            not ("#" `isPrefixOf` string) && "[@]" `isInfixOf` string
+isArrayExpansion _ = False
+
+-- Is it possible that this arg becomes multiple args?
+mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f False t
+  where
+    f quoted (T_DollarBraced _ _ l) =
+        let string = concat $ oversimplify l in
+            not quoted || "!" `isPrefixOf` string
+    f quoted (T_DoubleQuoted _ parts) = any (f True) parts
+    f quoted (T_NormalWord _ parts) = any (f quoted) parts
+    f _ _ = False
+
+-- Is it certain that this word will becomes multiple words?
+willBecomeMultipleArgs t = willConcatInAssignment t || f t
+  where
+    f T_Extglob {} = True
+    f T_Glob {} = True
+    f T_BraceExpansion {} = True
+    f (T_NormalWord _ parts) = any f parts
+    f _ = False
+
+-- This does token cause implicit concatenation in assignments?
+willConcatInAssignment token =
+    case token of
+        t@T_DollarBraced {} -> isArrayExpansion t
+        (T_DoubleQuoted _ parts) -> any willConcatInAssignment parts
+        (T_NormalWord _ parts) -> any willConcatInAssignment parts
+        _ -> False
+
+-- Maybe get the literal string corresponding to this token
+getLiteralString :: Token -> Maybe String
+getLiteralString = getLiteralStringExt (const Nothing)
+
+-- Definitely get a literal string, with a given default for all non-literals
+getLiteralStringDef :: String -> Token -> String
+getLiteralStringDef x = runIdentity . getLiteralStringExt (const $ return x)
+
+-- Definitely get a literal string, skipping over all non-literals
+onlyLiteralString :: Token -> String
+onlyLiteralString = getLiteralStringDef ""
+
+-- Maybe get a literal string, but only if it's an unquoted argument.
+getUnquotedLiteral (T_NormalWord _ list) =
+    concat <$> mapM str list
+  where
+    str (T_Literal _ s) = return s
+    str _ = Nothing
+getUnquotedLiteral _ = Nothing
+
+isQuotes t =
+    case t of
+        T_DoubleQuoted {} -> True
+        T_SingleQuoted {} -> True
+        _ -> False
+
+-- Get the last unquoted T_Literal in a word like "${var}foo"THIS
+-- or nothing if the word does not end in an unquoted literal.
+getTrailingUnquotedLiteral :: Token -> Maybe Token
+getTrailingUnquotedLiteral t =
+    case t of
+        (T_NormalWord _ list@(_:_)) ->
+            from (last list)
+        _ -> Nothing
+  where
+    from t =
+        case t of
+            T_Literal {} -> return t
+            _ -> Nothing
+
+-- Get the leading, unquoted, literal string of a token (if any).
+getLeadingUnquotedString :: Token -> Maybe String
+getLeadingUnquotedString t =
+    case t of
+        T_NormalWord _ ((T_Literal _ s) : rest) -> return $ s ++ from rest
+        _ -> Nothing
+  where
+    from ((T_Literal _ s):rest) = s ++ from rest
+    from _ = ""
+
+-- Maybe get the literal string of this token and any globs in it.
+getGlobOrLiteralString = getLiteralStringExt f
+  where
+    f (T_Glob _ str) = return str
+    f _ = Nothing
+
+
+prop_getLiteralString1 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x01") == Just "\1"
+prop_getLiteralString2 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\xyz") == Just "\\xyz"
+prop_getLiteralString3 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x1") == Just "\x1"
+prop_getLiteralString4 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x1y") == Just "\x1y"
+prop_getLiteralString5 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\xy") == Just "\\xy"
+prop_getLiteralString6 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x") == Just "\\x"
+prop_getLiteralString7 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\1x") == Just "\1x"
+prop_getLiteralString8 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\12x") == Just "\o12x"
+prop_getLiteralString9 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\123x") == Just "\o123x"
+prop_getLiteralString10 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\1234") == Just "\o123\&4"
+prop_getLiteralString11 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\1") == Just "\1"
+prop_getLiteralString12 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\12") == Just "\o12"
+prop_getLiteralString13 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\123") == Just "\o123"
+
+-- Maybe get the literal value of a token, using a custom function
+-- to map unrecognized Tokens into strings.
+getLiteralStringExt :: Monad m => (Token -> m String) -> Token -> m String
+getLiteralStringExt more = g
+  where
+    allInList = fmap concat . mapM g
+    g (T_DoubleQuoted _ l) = allInList l
+    g (T_DollarDoubleQuoted _ l) = allInList l
+    g (T_NormalWord _ l) = allInList l
+    g (TA_Expansion _ l) = allInList l
+    g (T_SingleQuoted _ s) = return s
+    g (T_Literal _ s) = return s
+    g (T_ParamSubSpecialChar _ s) = return s
+    g (T_DollarSingleQuoted _ s) = return $ decodeEscapes s
+    g x = more x
+
+    -- Bash style $'..' decoding
+    decodeEscapes ('\\':c:cs) =
+        case c of
+            'a' -> '\a' : rest
+            'b' -> '\b' : rest
+            'e' -> '\x1B' : rest
+            'f' -> '\f' : rest
+            'n' -> '\n' : rest
+            'r' -> '\r' : rest
+            't' -> '\t' : rest
+            'v' -> '\v' : rest
+            '\'' -> '\'' : rest
+            '"' -> '"' : rest
+            '\\' -> '\\' : rest
+            'x' ->
+                case cs of
+                    (x:y:more) | isHexDigit x && isHexDigit y ->
+                        chr (16*(digitToInt x) + (digitToInt y)) : decodeEscapes more
+                    (x:more) | isHexDigit x ->
+                        chr (digitToInt x) : decodeEscapes more
+                    more -> '\\' : 'x' : decodeEscapes more
+            _ | isOctDigit c ->
+                let (digits, more) = spanMax isOctDigit 3 (c:cs)
+                    num = (parseOct digits) `mod` 256
+                in (chr num) : decodeEscapes more
+            _ -> '\\' : c : rest
+      where
+        rest = decodeEscapes cs
+        parseOct = f 0
+          where
+            f n "" = n
+            f n (c:rest) = f (n * 8 + digitToInt c) rest
+        spanMax f n list =
+            let (first, second) = span f list
+                (prefix, suffix) = splitAt n first
+            in
+                (prefix, suffix ++ second)
+    decodeEscapes (c:cs) = c : decodeEscapes cs
+    decodeEscapes [] = []
+
+-- Is this token a string literal?
+isLiteral t = isJust $ getLiteralString t
+
+-- Is this token a string literal number?
+isLiteralNumber t = fromMaybe False $ do
+    s <- getLiteralString t
+    guard $ all isDigit s
+    return True
+
+-- Escape user data for messages.
+-- Messages generally avoid repeating user data, but sometimes it's helpful.
+e4m = escapeForMessage
+escapeForMessage :: String -> String
+escapeForMessage str = concatMap f str
+  where
+    f '\\' = "\\\\"
+    f '\n' = "\\n"
+    f '\r' = "\\r"
+    f '\t' = "\\t"
+    f '\x1B' = "\\e"
+    f c =
+        if shouldEscape c
+        then
+            if ord c < 256
+            then "\\x" ++ (pad0 2 $ toHex c)
+            else "\\U" ++ (pad0 4 $ toHex c)
+        else [c]
+
+    shouldEscape c =
+        (not $ isPrint c)
+        || (not (isAscii c) && not (isLetter c))
+
+    pad0 :: Int -> String -> String
+    pad0 n s =
+        let l = length s in
+            if l < n
+            then (replicate (n-l) '0') ++ s
+            else s
+    toHex :: Char -> String
+    toHex c = map toUpper $ showHex (ord c) ""
+
+-- Turn a NormalWord like foo="bar $baz" into a series of constituent elements like [foo=,bar ,$baz]
+getWordParts (T_NormalWord _ l)   = concatMap getWordParts l
+getWordParts (T_DoubleQuoted _ l) = l
+-- TA_Expansion is basically T_NormalWord for arithmetic expressions
+getWordParts (TA_Expansion _ l)   = concatMap getWordParts l
+getWordParts other                = [other]
+
+-- Return a list of NormalWords that would result from brace expansion
+braceExpand (T_NormalWord id list) = take 1000 $ do
+    items <- mapM part list
+    return $ T_NormalWord id items
+  where
+    part (T_BraceExpansion id items) = do
+        item <- items
+        braceExpand item
+    part x = return x
+
+-- Maybe get a SimpleCommand from immediate wrappers like T_Redirections
+getCommand t =
+    case t of
+        T_Redirecting _ _ w -> getCommand w
+        T_SimpleCommand _ _ (w:_) -> return t
+        T_Annotation _ _ t -> getCommand t
+        _ -> Nothing
+
+-- Maybe get the command name string of a token representing a command
+getCommandName :: Token -> Maybe String
+getCommandName = fst . getCommandNameAndToken False
+
+-- Maybe get the name+arguments of a command.
+getCommandArgv t = do
+    (T_SimpleCommand _ _ args@(_:_)) <- getCommand t
+    return args
+
+-- Get the command name token from a command, i.e.
+-- the token representing 'ls' in 'ls -la 2> foo'.
+-- If it can't be determined, return the original token.
+getCommandTokenOrThis = snd . getCommandNameAndToken False
+
+-- Given a command, get the string and token that represents the command name.
+-- If direct, return the actual command (e.g. exec in 'exec ls')
+-- If not, return the logical command (e.g. 'ls' in 'exec ls')
+
+getCommandNameAndToken :: Bool -> Token -> (Maybe String, Token)
+getCommandNameAndToken direct t = fromMaybe (Nothing, t) $ do
+    cmd@(T_SimpleCommand _ _ (w:rest)) <- getCommand t
+    s <- getLiteralString w
+    return $ fromMaybe (Just s, w) $ do
+        guard $ not direct
+        actual <- getEffectiveCommandToken s cmd rest
+        return (getLiteralString actual, actual)
+  where
+    getEffectiveCommandToken str cmd args =
+        let
+            firstArg = do
+                arg <- listToMaybe args
+                guard . not $ isFlag arg
+                return arg
+        in
+            case str of
+                "busybox" -> firstArg
+                "builtin" -> firstArg
+                "command" -> firstArg
+                "run" -> firstArg -- Used by bats
+                "exec" -> do
+                    opts <- getBsdOpts "cla:" args
+                    (_, (t, _)) <- find (null . fst) opts
+                    return t
+                _ -> fail ""
+
+-- If a command substitution is a single command, get its name.
+--  $(date +%s) = Just "date"
+getCommandNameFromExpansion :: Token -> Maybe String
+getCommandNameFromExpansion t =
+    case t of
+        T_DollarExpansion _ [c] -> extract c
+        T_Backticked _ [c] -> extract c
+        T_DollarBraceCommandExpansion _ [c] -> extract c
+        _ -> Nothing
+  where
+    extract (T_Pipeline _ _ [cmd]) = getCommandName cmd
+    extract _ = Nothing
+
+-- Get the basename of a token representing a command
+getCommandBasename = fmap basename . getCommandName
+
+basename = reverse . takeWhile (/= '/') . reverse
+
+isAssignment t =
+    case t of
+        T_Redirecting _ _ w -> isAssignment w
+        T_SimpleCommand _ (w:_) [] -> True
+        T_Assignment {} -> True
+        T_Annotation _ _ w -> isAssignment w
+        _ -> False
+
+isOnlyRedirection t =
+    case t of
+        T_Pipeline _ _ [x] -> isOnlyRedirection x
+        T_Annotation _ _ w -> isOnlyRedirection w
+        T_Redirecting _ (_:_) c -> isOnlyRedirection c
+        T_SimpleCommand _ [] [] -> True
+        _ -> False
+
+isFunction t = case t of T_Function {} -> True; _ -> False
+
+-- Bats tests are functions for the purpose of 'local' and such
+isFunctionLike t =
+    case t of
+        T_Function {} -> True
+        T_BatsTest {} -> True
+        _ -> False
+
+
+isBraceExpansion t = case t of T_BraceExpansion {} -> True; _ -> False
+
+-- Get the lists of commands from tokens that contain them, such as
+-- the conditions and bodies of while loops or branches of if statements.
+getCommandSequences :: Token -> [[Token]]
+getCommandSequences t =
+    case t of
+        T_Script _ _ cmds -> [cmds]
+        T_BraceGroup _ cmds -> [cmds]
+        T_Subshell _ cmds -> [cmds]
+        T_WhileExpression _ cond cmds -> [cond, cmds]
+        T_UntilExpression _ cond cmds -> [cond, cmds]
+        T_ForIn _ _ _ cmds -> [cmds]
+        T_ForArithmetic _ _ _ _ cmds -> [cmds]
+        T_IfExpression _ thens elses -> (concatMap (\(a,b) -> [a,b]) thens) ++ [elses]
+        T_Annotation _ _ t -> getCommandSequences t
+
+        T_DollarExpansion _ cmds -> [cmds]
+        T_DollarBraceCommandExpansion _ cmds -> [cmds]
+        T_Backticked _ cmds -> [cmds]
+        _ -> []
+
+-- Get a list of names of associative arrays
+getAssociativeArrays t =
+    nub . execWriter $ doAnalysis f t
+  where
+    f :: Token -> Writer [String] ()
+    f t@T_SimpleCommand {} = sequence_ $ do
+        name <- getCommandName t
+        let assocNames = ["declare","local","typeset"]
+        guard $ name `elem` assocNames
+        let flags = getAllFlags t
+        guard $ "A" `elem` map snd flags
+        let args = [arg | (arg, "") <- flags]
+        let names = mapMaybe (getLiteralStringExt nameAssignments) args
+        return $ tell names
+    f _ = return ()
+
+    nameAssignments t =
+        case t of
+            T_Assignment _ _ name _ _ -> return name
+            _ -> Nothing
+
+-- A Pseudoglob is a wildcard pattern used for checking if a match can succeed.
+-- For example, [[ $(cmd).jpg == [a-z] ]] will give the patterns *.jpg and ?, which
+-- can be proven never to match.
+data PseudoGlob = PGAny | PGMany | PGChar Char
+    deriving (Eq, Show)
+
+-- Turn a word into a PG pattern, replacing all unknown/runtime values with
+-- PGMany.
+wordToPseudoGlob :: Token -> [PseudoGlob]
+wordToPseudoGlob = fromMaybe [PGMany] . wordToPseudoGlob' False
+
+-- Turn a word into a PG pattern, but only if we can preserve
+-- exact semantics.
+wordToExactPseudoGlob :: Token -> Maybe [PseudoGlob]
+wordToExactPseudoGlob = wordToPseudoGlob' True
+
+wordToPseudoGlob' :: Bool -> Token -> Maybe [PseudoGlob]
+wordToPseudoGlob' exact word =
+    simplifyPseudoGlob <$> toGlob word
+  where
+    toGlob :: Token -> Maybe [PseudoGlob]
+    toGlob word =
+        case word of
+            T_NormalWord _ (T_Literal _ ('~':str):rest) -> do
+                guard $ not exact
+                let this = (PGMany : (map PGChar $ dropWhile (/= '/') str))
+                tail <- concat <$> (mapM f $ concatMap getWordParts rest)
+                return $ this ++ tail
+            _ -> concat <$> (mapM f $ getWordParts word)
+
+    f x = case x of
+        T_Literal _ s      -> return $ map PGChar s
+        T_SingleQuoted _ s -> return $ map PGChar s
+        T_Glob _ "?"       -> return [PGAny]
+        T_Glob _ "*"       -> return [PGMany]
+        T_Glob _ ('[':_) | not exact -> return [PGAny]
+        _ -> if exact then fail "" else return [PGMany]
+
+
+-- Reorder a PseudoGlob for more efficient matching, e.g.
+-- f?*?**g -> f??*g
+simplifyPseudoGlob :: [PseudoGlob] -> [PseudoGlob]
+simplifyPseudoGlob = f
+  where
+    f [] = []
+    f (x@(PGChar _) : rest ) = x : f rest
+    f list =
+        let (anys, rest) = span (\x -> x == PGMany || x == PGAny) list in
+            order anys ++ f rest
+
+    order s = let (any, many) = partition (== PGAny) s in
+        any ++ take 1 many
+
+-- Check whether the two patterns can ever overlap.
+pseudoGlobsCanOverlap :: [PseudoGlob] -> [PseudoGlob] -> Bool
+pseudoGlobsCanOverlap = matchable
+  where
+    matchable x@(xf:xs) y@(yf:ys) =
+        case (xf, yf) of
+            (PGMany, _) -> matchable x ys || matchable xs y
+            (_, PGMany) -> matchable x ys || matchable xs y
+            (PGAny, _) -> matchable xs ys
+            (_, PGAny) -> matchable xs ys
+            (_, _) -> xf == yf && matchable xs ys
+
+    matchable [] [] = True
+    matchable (PGMany : rest) [] = matchable rest []
+    matchable (_:_) [] = False
+    matchable [] r = matchable r []
+
+-- Check whether the first pattern always overlaps the second.
+pseudoGlobIsSuperSetof :: [PseudoGlob] -> [PseudoGlob] -> Bool
+pseudoGlobIsSuperSetof = matchable
+  where
+    matchable x@(xf:xs) y@(yf:ys) =
+        case (xf, yf) of
+            (PGMany, PGMany) -> matchable x ys
+            (PGMany, _) -> matchable x ys || matchable xs y
+            (_, PGMany) -> False
+            (PGAny, _) -> matchable xs ys
+            (_, PGAny) -> False
+            (_, _) -> xf == yf && matchable xs ys
+
+    matchable [] [] = True
+    matchable (PGMany : rest) [] = matchable rest []
+    matchable _ _ = False
+
+wordsCanBeEqual x y = pseudoGlobsCanOverlap (wordToPseudoGlob x) (wordToPseudoGlob y)
+
+-- Is this an expansion that can be quoted,
+-- e.g. $(foo) `foo` $foo (but not {foo,})?
+isQuoteableExpansion t = case t of
+    T_DollarBraced {} -> True
+    _ -> isCommandSubstitution t
+
+isCommandSubstitution t = case t of
+    T_DollarExpansion {} -> True
+    T_DollarBraceCommandExpansion {} -> True
+    T_Backticked {} -> True
+    _ -> False
+
+-- Is this an expansion that results in a simple string?
+isStringExpansion t = isCommandSubstitution t || case t of
+    T_DollarArithmetic {} -> True
+    T_DollarBraced {} -> not (isArrayExpansion t)
+    _ -> False
+
+-- Is this a T_Annotation that ignores a specific code?
+isAnnotationIgnoringCode code t =
+    case t of
+        T_Annotation _ anns _ -> any hasNum anns
+        _ -> False
+  where
+    hasNum (DisableComment from to) = code >= from && code < to
+    hasNum _                   = False
+
+prop_executableFromShebang1 = executableFromShebang "/bin/sh" == "sh"
+prop_executableFromShebang2 = executableFromShebang "/bin/bash" == "bash"
+prop_executableFromShebang3 = executableFromShebang "/usr/bin/env ksh" == "ksh"
+prop_executableFromShebang4 = executableFromShebang "/usr/bin/env -S foo=bar bash -x" == "bash"
+prop_executableFromShebang5 = executableFromShebang "/usr/bin/env --split-string=bash -x" == "bash"
+prop_executableFromShebang6 = executableFromShebang "/usr/bin/env --split-string=foo=bar bash -x" == "bash"
+prop_executableFromShebang7 = executableFromShebang "/usr/bin/env --split-string bash -x" == "bash"
+prop_executableFromShebang8 = executableFromShebang "/usr/bin/env --split-string foo=bar bash -x" == "bash"
+prop_executableFromShebang9 = executableFromShebang "/usr/bin/env foo=bar dash" == "dash"
+prop_executableFromShebang10 = executableFromShebang "/bin/busybox sh" == "busybox sh"
+prop_executableFromShebang11 = executableFromShebang "/bin/busybox ash" == "busybox ash"
+
+-- Get the shell executable from a string like '/usr/bin/env bash'
+executableFromShebang :: String -> String
+executableFromShebang = shellFor
+  where
+    re = mkRegex "/env +(-S|--split-string=?)? *(.*)"
+    shellFor s | s `matches` re =
+        case matchRegex re s of
+            Just [flag, shell] -> fromEnvArgs (words shell)
+            _ -> ""
+    shellFor sb =
+        case words sb of
+            [] -> ""
+            [x] -> basename x
+            (first:second:args) | basename first == "busybox" ->
+                case basename second of
+                   "sh" -> "busybox sh"
+                   "ash" -> "busybox ash"
+                   x -> x
+            (first:args) | basename first == "env" ->
+                fromEnvArgs args
+            (first:_) -> basename first
+
+    fromEnvArgs args = fromMaybe "" $ find (notElem '=') $ skipFlags args
+    basename s = reverse . takeWhile (/= '/') . reverse $ s
+    skipFlags = dropWhile ("-" `isPrefixOf`)
+
+
+-- Determining if a name is a variable
+isVariableStartChar x = x == '_' || isAsciiLower x || isAsciiUpper x
+isVariableChar x = isVariableStartChar x || isDigit x
+isSpecialVariableChar = (`elem` "*@#?-$!")
+variableNameRegex = mkRegex "[_a-zA-Z][_a-zA-Z0-9]*"
+
+prop_isVariableName1 = isVariableName "_fo123"
+prop_isVariableName2 = not $ isVariableName "4"
+prop_isVariableName3 = not $ isVariableName "test: "
+isVariableName (x:r) = isVariableStartChar x && all isVariableChar r
+isVariableName _     = False
+
+
+-- Get the variable name from an expansion like ${var:-foo}
+prop_getBracedReference1 = getBracedReference "foo" == "foo"
+prop_getBracedReference2 = getBracedReference "#foo" == "foo"
+prop_getBracedReference3 = getBracedReference "#" == "#"
+prop_getBracedReference4 = getBracedReference "##" == "#"
+prop_getBracedReference5 = getBracedReference "#!" == "!"
+prop_getBracedReference6 = getBracedReference "!#" == "#"
+prop_getBracedReference7 = getBracedReference "!foo#?" == "foo"
+prop_getBracedReference8 = getBracedReference "foo-bar" == "foo"
+prop_getBracedReference9 = getBracedReference "foo:-bar" == "foo"
+prop_getBracedReference10 = getBracedReference "foo: -1" == "foo"
+prop_getBracedReference11 = getBracedReference "!os*" == ""
+prop_getBracedReference11b = getBracedReference "!os@" == ""
+prop_getBracedReference12 = getBracedReference "!os?bar**" == ""
+prop_getBracedReference13 = getBracedReference "foo[bar]" == "foo"
+getBracedReference s = fromMaybe s $
+    nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
+  where
+    noPrefix = dropPrefix s
+    dropPrefix (c:rest) | c `elem` "!#" = rest
+    dropPrefix cs = cs
+    takeName s = do
+        let name = takeWhile isVariableChar s
+        guard . not $ null name
+        return name
+    getSpecial (c:_) | isSpecialVariableChar c = return [c]
+    getSpecial _ = fail "empty or not special"
+
+    nameExpansion ('!':next:rest) = do -- e.g. ${!foo*bar*}
+        guard $ isVariableChar next -- e.g. ${!@}
+        first <- find (not . isVariableChar) rest
+        guard $ first `elem` "*?@"
+        return ""
+    nameExpansion _ = Nothing
+
+-- Get the variable modifier like /a/b in ${var/a/b}
+prop_getBracedModifier1 = getBracedModifier "foo:bar:baz" == ":bar:baz"
+prop_getBracedModifier2 = getBracedModifier "!var:-foo" == ":-foo"
+prop_getBracedModifier3 = getBracedModifier "foo[bar]" == "[bar]"
+prop_getBracedModifier4 = getBracedModifier "foo[@]@Q" == "[@]@Q"
+prop_getBracedModifier5 = getBracedModifier "@@Q" == "@Q"
+getBracedModifier s = headOrDefault "" $ do
+    let var = getBracedReference s
+    a <- dropModifier s
+    dropPrefix var a
+  where
+    dropPrefix [] t        = return t
+    dropPrefix (a:b) (c:d) | a == c = dropPrefix b d
+    dropPrefix _ _         = []
+
+    dropModifier (c:rest) | c `elem` "#!" = [rest, c:rest]
+    dropModifier x        = [x]
+
+-- Get the variables from indices like ["x", "y"] in ${var[x+y+1]}
+prop_getIndexReferences1 = getIndexReferences "var[x+y+1]" == ["x", "y"]
+getIndexReferences s = fromMaybe [] $ do
+    index:_ <- matchRegex re s
+    return $ matchAllStrings variableNameRegex index
+  where
+    re = mkRegex "(\\[.*\\])"
+
+prop_getOffsetReferences1 = getOffsetReferences ":bar" == ["bar"]
+prop_getOffsetReferences2 = getOffsetReferences ":bar:baz" == ["bar", "baz"]
+prop_getOffsetReferences3 = getOffsetReferences "[foo]:bar" == ["bar"]
+prop_getOffsetReferences4 = getOffsetReferences "[foo]:bar:baz" == ["bar", "baz"]
+getOffsetReferences mods = fromMaybe [] $ do
+-- if mods start with [, then drop until ]
+    _:offsets:_ <- matchRegex re mods
+    return $ matchAllStrings variableNameRegex offsets
+  where
+    re = mkRegex "^(\\[.+\\])? *:([^-=?+].*)"
+
+
+-- Returns whether a token is a parameter expansion without any modifiers.
+-- True for $var ${var} $1 $#
+-- False for ${#var} ${var[x]} ${var:-0}
+isUnmodifiedParameterExpansion t =
+    case t of
+        T_DollarBraced _ False _ -> True
+        T_DollarBraced _ _ list ->
+            let str = concat $ oversimplify list
+            in getBracedReference str == str
+        _ -> False
+
+-- Return the referenced variable if (and only if) it's an unmodified parameter expansion.
+getUnmodifiedParameterExpansion t =
+    case t of
+        T_DollarBraced _ _ list -> do
+            let str = concat $ oversimplify list
+            guard $ getBracedReference str == str
+            return str
+        _ -> Nothing
+
+--- A list of the element and all its parents up to the root node.
+getPath tree = NE.unfoldr $ \t -> (t, Map.lookup (getId t) tree)
+
+isClosingFileOp op =
+    case op of
+        T_IoDuplicate _ (T_GREATAND _) "-" -> True
+        T_IoDuplicate _ (T_LESSAND  _) "-" -> True
+        _                                  -> False
+
+getEnableDirectives root =
+    case root of
+        T_Annotation _ list _ -> [s | EnableComment s <- list]
+        _ -> []
+
+getExtendedAnalysisDirective :: Token -> Maybe Bool
+getExtendedAnalysisDirective root =
+    case root of
+        T_Annotation _ list _ -> listToMaybe $ [s | ExtendedAnalysis s <- list]
+        _ -> Nothing
+
+return []
+runTests = $quickCheckAll

src/ShellCheck/Analyzer.hs

@@ -1,8 +1,8 @@
 {-
-    Copyright 2012-2015 Vidar Holen
+    Copyright 2012-2022 Vidar Holen
 
     This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
+    https://www.shellcheck.net
 
     ShellCheck is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -15,9 +15,9 @@
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -}
-module ShellCheck.Analyzer (analyzeScript) where
+module ShellCheck.Analyzer (analyzeScript, ShellCheck.Analyzer.optionalChecks) where
 
 import ShellCheck.Analytics
 import ShellCheck.AnalyzerLib
@@ -25,21 +25,31 @@ import ShellCheck.Interface
 import Data.List
 import Data.Monoid
 import qualified ShellCheck.Checks.Commands
+import qualified ShellCheck.Checks.ControlFlow
+import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
 
 
 -- TODO: Clean up the cruft this is layered on
 analyzeScript :: AnalysisSpec -> AnalysisResult
-analyzeScript spec = AnalysisResult {
+analyzeScript spec = newAnalysisResult {
     arComments =
         filterByAnnotation spec params . nub $
-            runAnalytics spec
+            runChecker params (checkers spec params)
-            ++ runChecker params (checkers params)
 }
   where
     params = makeParameters spec
 
-checkers params = mconcat $ map ($ params) [
+checkers spec params = mconcat $ map ($ params) [
-    ShellCheck.Checks.Commands.checker,
+    ShellCheck.Analytics.checker spec,
+    ShellCheck.Checks.Commands.checker spec,
+    ShellCheck.Checks.ControlFlow.checker spec,
+    ShellCheck.Checks.Custom.checker,
     ShellCheck.Checks.ShellSupport.checker
     ]
+
+optionalChecks = mconcat $ [
+    ShellCheck.Analytics.optionalChecks,
+    ShellCheck.Checks.Commands.optionalChecks,
+    ShellCheck.Checks.ControlFlow.optionalChecks
+    ]

src/ShellCheck/AnalyzerLib.hs

@@ -0,0 +1,944 @@
+{-
+    Copyright 2012-2022 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE TemplateHaskell  #-}
+module ShellCheck.AnalyzerLib where
+
+import ShellCheck.AST
+import ShellCheck.ASTLib
+import qualified ShellCheck.CFGAnalysis as CF
+import ShellCheck.Data
+import ShellCheck.Interface
+import ShellCheck.Parser
+import ShellCheck.Prelude
+import ShellCheck.Regex
+
+import Control.Arrow (first)
+import Control.DeepSeq
+import Control.Monad
+import Control.Monad.Identity
+import Control.Monad.RWS
+import Control.Monad.State
+import Control.Monad.Writer
+import Data.Char
+import Data.List
+import Data.Maybe
+import Data.Semigroup
+import qualified Data.List.NonEmpty as NE
+import qualified Data.Map as Map
+
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (maxSuccess, quickCheckWithResult, stdArgs)
+
+type Analysis = AnalyzerM ()
+type AnalyzerM a = RWS Parameters [TokenComment] Cache a
+nullCheck = const $ return ()
+
+
+data Checker = Checker {
+    perScript :: Root -> Analysis,
+    perToken  :: Token -> Analysis
+}
+
+runChecker :: Parameters -> Checker -> [TokenComment]
+runChecker params checker = notes
+    where
+        root = rootNode params
+        check = perScript checker `composeAnalyzers` (\(Root x) -> void $ doAnalysis (perToken checker) x)
+        notes = snd $ evalRWS (check $ Root root) params Cache
+
+instance Semigroup Checker where
+    (<>) x y = Checker {
+        perScript = perScript x `composeAnalyzers` perScript y,
+        perToken = perToken x `composeAnalyzers` perToken y
+        }
+
+instance Monoid Checker where
+    mempty = Checker {
+        perScript = nullCheck,
+        perToken = nullCheck
+        }
+    mappend = (Data.Semigroup.<>)
+
+composeAnalyzers :: (a -> Analysis) -> (a -> Analysis) -> a -> Analysis
+composeAnalyzers f g x = f x >> g x
+
+data Parameters = Parameters {
+    -- Whether this script has the 'lastpipe' option set/default.
+    hasLastpipe        :: Bool,
+    -- Whether this script has the 'inherit_errexit' option set/default.
+    hasInheritErrexit  :: Bool,
+    -- Whether this script has 'set -e' anywhere.
+    hasSetE            :: Bool,
+    -- Whether this script has 'set -o pipefail' anywhere.
+    hasPipefail        :: Bool,
+    -- Whether this script has 'shopt -s execfail' anywhere.
+    hasExecfail        :: Bool,
+    -- A linear (bad) analysis of data flow
+    variableFlow       :: [StackData],
+    -- A map from Id to Token
+    idMap              :: Map.Map Id Token,
+    -- A map from Id to parent Token
+    parentMap          :: Map.Map Id Token,
+    -- The shell type, such as Bash or Ksh
+    shellType          :: Shell,
+    -- True if shell type was forced via flags
+    shellTypeSpecified :: Bool,
+    -- The root node of the AST
+    rootNode           :: Token,
+    -- map from token id to start and end position
+    tokenPositions     :: Map.Map Id (Position, Position),
+    -- Result from Control Flow Graph analysis (including data flow analysis)
+    cfgAnalysis :: Maybe CF.CFGAnalysis
+    } deriving (Show)
+
+-- TODO: Cache results of common AST ops here
+data Cache = Cache {}
+
+data Scope = SubshellScope String | NoneScope deriving (Show, Eq)
+data StackData =
+    StackScope Scope
+    | StackScopeEnd
+    -- (Base expression, specific position, var name, assigned values)
+    | Assignment (Token, Token, String, DataType)
+    | Reference (Token, Token, String)
+  deriving (Show)
+
+data DataType = DataString DataSource | DataArray DataSource
+  deriving (Show)
+
+data DataSource =
+    SourceFrom [Token]
+    | SourceExternal
+    | SourceDeclaration
+    | SourceInteger
+    | SourceChecked
+  deriving (Show)
+
+data VariableState = Dead Token String | Alive deriving (Show)
+
+defaultSpec pr = spec {
+    asShellType = Nothing,
+    asCheckSourced = False,
+    asExecutionMode = Executed,
+    asTokenPositions = prTokenPositions pr
+} where spec = newAnalysisSpec (fromJust $ prRoot pr)
+
+pScript s =
+  let
+    pSpec = newParseSpec {
+        psFilename = "script",
+        psScript = s
+    }
+  in runIdentity $ parseScript (mockedSystemInterface []) pSpec
+
+-- For testing. If parsed, returns whether there are any comments
+producesComments :: Checker -> String -> Maybe Bool
+producesComments c s = do
+        let pr = pScript s
+        prRoot pr
+        let spec = defaultSpec pr
+        let params = makeParameters spec
+        return . not . null $ filterByAnnotation spec params $ runChecker params c
+
+makeComment :: Severity -> Id -> Code -> String -> TokenComment
+makeComment severity id code note =
+    newTokenComment {
+        tcId = id,
+        tcComment = newComment {
+            cSeverity = severity,
+            cCode = code,
+            cMessage = note
+        }
+    }
+
+addComment note = note `deepseq` tell [note]
+
+warn :: MonadWriter [TokenComment] m => Id -> Code -> String -> m ()
+warn  id code str = addComment $ makeComment WarningC id code str
+err   id code str = addComment $ makeComment ErrorC id code str
+info  id code str = addComment $ makeComment InfoC id code str
+style id code str = addComment $ makeComment StyleC id code str
+
+errWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
+errWithFix  = addCommentWithFix ErrorC
+warnWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
+warnWithFix  = addCommentWithFix WarningC
+infoWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
+infoWithFix = addCommentWithFix InfoC
+styleWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
+styleWithFix = addCommentWithFix StyleC
+
+addCommentWithFix :: MonadWriter [TokenComment] m => Severity -> Id -> Code -> String -> Fix -> m ()
+addCommentWithFix severity id code str fix =
+    addComment $ makeCommentWithFix severity id code str fix
+
+makeCommentWithFix :: Severity -> Id -> Code -> String -> Fix -> TokenComment
+makeCommentWithFix severity id code str fix =
+    let comment = makeComment severity id code str
+        withFix = comment {
+            -- If fix is empty, pretend it wasn't there.
+            tcFix = if null (fixReplacements fix) then Nothing else Just fix
+        }
+    in force withFix
+
+-- makeParameters :: CheckSpec -> Parameters
+makeParameters spec = params
+  where
+    extendedAnalysis = fromMaybe True $ msum [asExtendedAnalysis spec, getExtendedAnalysisDirective root]
+    params = Parameters {
+        rootNode = root,
+        shellType = fromMaybe (determineShell (asFallbackShell spec) root) $ asShellType spec,
+        hasSetE = containsSetE root,
+        hasLastpipe =
+            case shellType params of
+                Bash -> isOptionSet "lastpipe" root
+                Dash -> False
+                BusyboxSh -> False
+                Sh   -> False
+                Ksh  -> True,
+        hasInheritErrexit =
+            case shellType params of
+                Bash -> isOptionSet "inherit_errexit" root
+                Dash -> True
+                BusyboxSh -> True
+                Sh   -> True
+                Ksh  -> False,
+        hasPipefail =
+            case shellType params of
+                Bash -> isOptionSet "pipefail" root
+                Dash -> True
+                BusyboxSh -> isOptionSet "pipefail" root
+                Sh   -> True
+                Ksh  -> isOptionSet "pipefail" root,
+        hasExecfail =
+            case shellType params of
+                Bash -> isOptionSet "execfail" root
+                _ -> False,
+        shellTypeSpecified = isJust (asShellType spec) || isJust (asFallbackShell spec),
+        idMap = getTokenMap root,
+        parentMap = getParentTree root,
+        variableFlow = getVariableFlow params root,
+        tokenPositions = asTokenPositions spec,
+        cfgAnalysis = do
+            guard extendedAnalysis
+            return $ CF.analyzeControlFlow cfParams root
+    }
+    cfParams = CF.CFGParameters {
+        CF.cfLastpipe = hasLastpipe params,
+        CF.cfPipefail = hasPipefail params
+    }
+    root = asScript spec
+
+
+-- Does this script mention 'set -e' anywhere?
+-- Used as a hack to disable certain warnings.
+containsSetE root = isNothing $ doAnalysis (guard . not . isSetE) root
+  where
+    isSetE t =
+        case t of
+            T_Script _ (T_Literal _ str) _ -> str `matches` re
+            T_SimpleCommand {}  ->
+                t `isUnqualifiedCommand` "set" &&
+                    ("errexit" `elem` oversimplify t ||
+                        "e" `elem` map snd (getAllFlags t))
+            _ -> False
+    re = mkRegex "[[:space:]]-[^-]*e"
+
+
+containsSetOption opt root = isNothing $ doAnalysis (guard . not . isPipefail) root
+  where
+    isPipefail t =
+        case t of
+            T_SimpleCommand {}  ->
+                t `isUnqualifiedCommand` "set" &&
+                    (opt `elem` oversimplify t ||
+                        "o" `elem` map snd (getAllFlags t))
+            _ -> False
+
+containsShopt shopt root =
+        isNothing $ doAnalysis (guard . not . isShoptLastPipe) root
+    where
+        isShoptLastPipe t =
+            case t of
+                T_SimpleCommand {}  ->
+                    t `isUnqualifiedCommand` "shopt" &&
+                        (shopt `elem` oversimplify t)
+                _ -> False
+
+-- Does this script mention 'shopt -s $opt' or 'set -o $opt' anywhere?
+isOptionSet opt root = containsShopt opt root || containsSetOption opt root
+
+
+prop_determineShell0 = determineShellTest "#!/bin/sh" == Sh
+prop_determineShell1 = determineShellTest "#!/usr/bin/env ksh" == Ksh
+prop_determineShell2 = determineShellTest "" == Bash
+prop_determineShell3 = determineShellTest "#!/bin/sh -e" == Sh
+prop_determineShell4 = determineShellTest "#!/bin/ksh\n#shellcheck shell=sh\nfoo" == Sh
+prop_determineShell5 = determineShellTest "#shellcheck shell=sh\nfoo" == Sh
+prop_determineShell6 = determineShellTest "#! /bin/sh" == Sh
+prop_determineShell7 = determineShellTest "#! /bin/ash" == Dash
+prop_determineShell8 = determineShellTest' (Just Ksh) "#!/bin/sh" == Sh
+prop_determineShell9 = determineShellTest "#!/bin/env -S dash -x" == Dash
+prop_determineShell10 = determineShellTest "#!/bin/env --split-string= dash -x" == Dash
+prop_determineShell11 = determineShellTest "#!/bin/busybox sh" == BusyboxSh -- busybox sh is a specific shell, not posix sh
+prop_determineShell12 = determineShellTest "#!/bin/busybox ash" == BusyboxSh
+
+determineShellTest = determineShellTest' Nothing
+determineShellTest' fallbackShell = determineShell fallbackShell . fromJust . prRoot . pScript
+determineShell fallbackShell t = fromMaybe Bash $
+    shellForExecutable shellString `mplus` fallbackShell
+  where
+    shellString = getCandidate t
+    getCandidate :: Token -> String
+    getCandidate t@T_Script {} = fromShebang t
+    getCandidate (T_Annotation _ annotations s) =
+        headOrDefault (fromShebang s) [s | ShellOverride s <- annotations]
+    fromShebang (T_Script _ (T_Literal _ s) _) = executableFromShebang s
+
+-- Given a root node, make a map from Id to parent Token.
+-- This is used to populate parentMap in Parameters
+getParentTree :: Token -> Map.Map Id Token
+getParentTree t =
+    snd $ execState (doStackAnalysis pre post t) ([], Map.empty)
+  where
+    pre t = modify (first ((:) t))
+    post t = do
+        (x, map) <- get
+        case x of
+          _:rest -> case rest of []    -> put (rest, map)
+                                 (x:_) -> put (rest, Map.insert (getId t) x map)
+
+-- Given a root node, make a map from Id to Token
+getTokenMap :: Token -> Map.Map Id Token
+getTokenMap t =
+    execState (doAnalysis f t) Map.empty
+  where
+    f t = modify (Map.insert (getId t) t)
+
+
+-- Is this token in a quoting free context? (i.e. would variable expansion split)
+-- True:  Assignments, [[ .. ]], here docs, already in double quotes
+-- False: Regular words
+isStrictlyQuoteFree = isQuoteFreeNode True
+
+-- Like above, but also allow some cases where splitting may be desired.
+-- True:  Like above + for loops
+-- False: Like above
+isQuoteFree = isQuoteFreeNode False
+
+
+isQuoteFreeNode strict shell tree t =
+    isQuoteFreeElement t ||
+        (fromMaybe False $ msum $ map isQuoteFreeContext $ NE.tail $ getPath tree t)
+  where
+    -- Is this node self-quoting in itself?
+    isQuoteFreeElement t =
+        case t of
+            T_Assignment id _ _ _ _ -> assignmentIsQuoting id
+            T_FdRedirect {}         -> True
+            _                       -> False
+
+    -- Are any subnodes inherently self-quoting?
+    isQuoteFreeContext t =
+        case t of
+            TC_Nullary _ DoubleBracket _    -> return True
+            TC_Unary _ DoubleBracket _ _    -> return True
+            TC_Binary _ DoubleBracket _ _ _ -> return True
+            TA_Sequence {}                  -> return True
+            T_Arithmetic {}                 -> return True
+            T_Assignment id _ _ _ _         -> return $ assignmentIsQuoting id
+            T_Redirecting {}                -> return False
+            T_DoubleQuoted _ _              -> return True
+            T_DollarDoubleQuoted _ _        -> return True
+            T_CaseExpression {}             -> return True
+            T_HereDoc {}                    -> return True
+            T_DollarBraced {}               -> return True
+            -- When non-strict, pragmatically assume it's desirable to split here
+            T_ForIn {}                      -> return (not strict)
+            T_SelectIn {}                   -> return (not strict)
+            _                               -> Nothing
+
+    -- Check whether this assignment is self-quoting due to being a recognized
+    -- assignment passed to a Declaration Utility. This will soon be required
+    -- by POSIX: https://austingroupbugs.net/view.php?id=351
+    assignmentIsQuoting id = shellParsesParamsAsAssignments || not (isAssignmentParamToCommand id)
+    shellParsesParamsAsAssignments = shell /= Sh
+
+    -- Is this assignment a parameter to a command like export/typeset/etc?
+    isAssignmentParamToCommand id =
+        case Map.lookup id tree of
+            Just (T_SimpleCommand _ _ (_:args)) -> id `elem` (map getId args)
+            _ -> False
+
+-- Check if a token is a parameter to a certain command by name:
+-- Example: isParamTo (parentMap params) "sed" t
+isParamTo :: Map.Map Id Token -> String -> Token -> Bool
+isParamTo tree cmd =
+    go
+  where
+    go x = case Map.lookup (getId x) tree of
+                Nothing     -> False
+                Just parent -> check parent
+    check t =
+        case t of
+            T_SingleQuoted _ _ -> go t
+            T_DoubleQuoted _ _ -> go t
+            T_NormalWord _ _   -> go t
+            T_SimpleCommand {} -> isCommand t cmd
+            T_Redirecting {}   -> isCommand t cmd
+            _                  -> False
+
+-- Get the parent command (T_Redirecting) of a Token, if any.
+getClosestCommand :: Map.Map Id Token -> Token -> Maybe Token
+getClosestCommand tree t =
+    findFirst findCommand $ NE.toList $ getPath tree t
+  where
+    findCommand t =
+        case t of
+            T_Redirecting {} -> return True
+            T_Script {}      -> return False
+            _                -> Nothing
+
+-- Like above, if koala_man knew Haskell when starting this project.
+getClosestCommandM t = do
+    params <- ask
+    return $ getClosestCommand (parentMap params) t
+
+-- Is the token used as a command name (the first word in a T_SimpleCommand)?
+usedAsCommandName tree token = go (getId token) (NE.tail $ getPath tree token)
+  where
+    go currentId (T_NormalWord id [word]:rest)
+        | currentId == getId word = go id rest
+    go currentId (T_DoubleQuoted id [word]:rest)
+        | currentId == getId word = go id rest
+    go currentId (t@(T_SimpleCommand _ _ (word:_)):_) =
+        getId word == currentId || getId (getCommandTokenOrThis t) == currentId
+    go _ _ = False
+
+-- Version of the above taking the map from the current context
+-- Todo: give this the name "getPath"
+getPathM t = do
+    params <- ask
+    return $ getPath (parentMap params) t
+
+isParentOf tree parent child =
+    any (\t -> parentId == getId t) (getPath tree child)
+  where
+    parentId = getId parent
+
+parents params = getPath (parentMap params)
+
+-- Find the first match in a list where the predicate is Just True.
+-- Stops if it's Just False and ignores Nothing.
+findFirst :: (a -> Maybe Bool) -> [a] -> Maybe a
+findFirst p = foldr go Nothing
+  where
+    go x acc =
+      case p x of
+        Just True  -> return x
+        Just False -> Nothing
+        Nothing    -> acc
+
+-- Check whether a word is entirely output from a single command
+tokenIsJustCommandOutput t = case t of
+    T_NormalWord id [T_DollarExpansion _ cmds] -> check cmds
+    T_NormalWord id [T_DoubleQuoted _ [T_DollarExpansion _ cmds]] -> check cmds
+    T_NormalWord id [T_Backticked _ cmds] -> check cmds
+    T_NormalWord id [T_DoubleQuoted _ [T_Backticked _ cmds]] -> check cmds
+    _ -> False
+  where
+    check [x] = not $ isOnlyRedirection x
+    check _   = False
+
+-- TODO: Replace this with a proper Control Flow Graph
+getVariableFlow params t =
+    reverse $ execState (doStackAnalysis startScope endScope t) []
+  where
+    startScope t =
+        let scopeType = leadType params t
+        in do
+            when (scopeType /= NoneScope) $ modify (StackScope scopeType:)
+            when (assignFirst t) $ setWritten t
+
+    endScope t =
+        let scopeType = leadType params t
+        in do
+            setRead t
+            unless (assignFirst t) $ setWritten t
+            when (scopeType /= NoneScope) $ modify (StackScopeEnd:)
+
+    assignFirst T_ForIn {}    = True
+    assignFirst T_SelectIn {} = True
+    assignFirst (T_BatsTest {}) = True
+    assignFirst _             = False
+
+    setRead t =
+        let read    = getReferencedVariables (parentMap params) t
+        in mapM_ (\v -> modify (Reference v:)) read
+
+    setWritten t =
+        let written = getModifiedVariables t
+        in mapM_ (\v -> modify (Assignment v:)) written
+
+
+leadType params t =
+    case t of
+        T_DollarExpansion _ _  -> SubshellScope "$(..) expansion"
+        T_Backticked _ _  -> SubshellScope "`..` expansion"
+        T_Backgrounded _ _  -> SubshellScope "backgrounding &"
+        T_Subshell _ _  -> SubshellScope "(..) group"
+        T_BatsTest {} -> SubshellScope "@bats test"
+        T_CoProcBody _ _  -> SubshellScope "coproc"
+        T_Redirecting {}  ->
+            if causesSubshell == Just True
+            then SubshellScope "pipeline"
+            else NoneScope
+        _ -> NoneScope
+  where
+    parentPipeline = do
+        parent <- Map.lookup (getId t) (parentMap params)
+        case parent of
+            T_Pipeline {} -> return parent
+            _             -> Nothing
+
+    causesSubshell = do
+        (T_Pipeline _ _ list) <- parentPipeline
+        return $ case list of
+            _:_:_ -> not (hasLastpipe params) || getId (last list) /= getId t
+            _ -> False
+
+getModifiedVariables t =
+    case t of
+        T_SimpleCommand _ vars [] ->
+            [(x, x, name, dataTypeFrom DataString w) | x@(T_Assignment id _ name _ w) <- vars]
+        T_SimpleCommand {} ->
+            getModifiedVariableCommand t
+
+        TA_Unary _ op v@(TA_Variable _ name _) | "--" `isInfixOf` op || "++" `isInfixOf` op ->
+            [(t, v, name, DataString SourceInteger)]
+        TA_Assignment _ op (TA_Variable _ name _) rhs -> do
+            guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
+            return (t, t, name, DataString SourceInteger)
+
+        T_BatsTest {} -> [
+            (t, t, "lines", DataArray SourceExternal),
+            (t, t, "status", DataString SourceInteger),
+            (t, t, "output", DataString SourceExternal),
+            (t, t, "stderr", DataString SourceExternal),
+            (t, t, "stderr_lines", DataArray SourceExternal)
+            ]
+
+        -- Count [[ -v foo ]] as an "assignment".
+        -- This is to prevent [ -v foo ] being unassigned or unused.
+        TC_Unary id _ "-v" token -> maybeToList $ do
+            str <- getVariableForTestDashV token
+            return (t, token, str, DataString SourceChecked)
+
+        TC_Unary _ _ "-n" token -> markAsChecked t token
+        TC_Unary _ _ "-z" token -> markAsChecked t token
+        TC_Nullary _ _ token -> markAsChecked t token
+
+        T_DollarBraced _ _ l -> maybeToList $ do
+            let string = concat $ oversimplify l
+            let modifier = getBracedModifier string
+            guard $ any (`isPrefixOf` modifier) ["=", ":="]
+            return (t, t, getBracedReference string, DataString $ SourceFrom [l])
+
+        T_FdRedirect _ ('{':var) op -> -- {foo}>&2 modifies foo
+            [(t, t, takeWhile (/= '}') var, DataString SourceInteger) | not $ isClosingFileOp op]
+
+        T_CoProc _ Nothing _ ->
+            [(t, t, "COPROC", DataArray SourceInteger)]
+
+        T_CoProc _ (Just token) _ -> do
+            name <- maybeToList $ getLiteralString token
+            [(t, t, name, DataArray SourceInteger)]
+
+        --Points to 'for' rather than variable
+        T_ForIn id str [] _ -> [(t, t, str, DataString SourceExternal)]
+        T_ForIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
+        T_SelectIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
+        _ -> []
+  where
+    markAsChecked place token = mapMaybe (f place) $ getWordParts token
+    f place t = case t of
+            T_DollarBraced _ _ l ->
+                let str = getBracedReference $ concat $ oversimplify l in do
+                    guard $ isVariableName str
+                    return (place, t, str, DataString SourceChecked)
+            _ -> Nothing
+
+
+-- Consider 'export/declare -x' a reference, since it makes the var available
+getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
+    case x of
+        "declare" -> forDeclare
+        "typeset" -> forDeclare
+
+        "export" -> if "f" `elem` flags
+            then []
+            else concatMap getReference rest
+        "local" -> if "x" `elem` flags
+            then concatMap getReference rest
+            else []
+        "trap" ->
+            case rest of
+                head:_ -> map (\x -> (base, head, x)) $ getVariablesFromLiteralToken head
+                _ -> []
+        "alias" -> [(base, token, name) | token <- rest, name <- getVariablesFromLiteralToken token]
+        _ -> []
+  where
+    forDeclare =
+            if
+                any (`elem` flags) ["x", "p"] &&
+                    (not $ any (`elem` flags) ["f", "F"])
+            then concatMap getReference rest
+            else []
+
+    getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)]
+    getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)]
+    getReference _ = []
+    flags = map snd $ getAllFlags base
+
+getReferencedVariableCommand _ = []
+
+-- The function returns a tuple consisting of four items describing an assignment.
+-- Given e.g. declare foo=bar
+-- (
+--   BaseCommand :: Token,     -- The command/structure assigning the variable, i.e. declare foo=bar
+--   AssignmentToken :: Token, -- The specific part that assigns this variable, i.e. foo=bar
+--   VariableName :: String,   -- The variable name, i.e. foo
+--   VariableValue :: DataType -- A description of the value being assigned, i.e. "Literal string with value foo"
+-- )
+getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T_Literal _ x:_):rest)) =
+   filter (\(_,_,s,_) -> not ("-" `isPrefixOf` s)) $
+    case x of
+        "builtin" ->
+            getModifiedVariableCommand $ T_SimpleCommand id cmdPrefix rest
+        "read" ->
+            let fallback = catMaybes $ takeWhile isJust (reverse $ map getLiteral rest)
+            in fromMaybe fallback $ do
+                parsed <- getGnuOpts flagsForRead rest
+                case lookup "a" parsed of
+                    Just (_, var) -> (:[]) <$> getLiteralArray var
+                    Nothing -> return $ catMaybes $
+                        map (getLiteral . snd . snd) $ filter (null . fst) parsed
+
+        "getopts" ->
+            case rest of
+                opts:var:_ -> maybeToList $ getLiteral var
+                _          -> []
+
+        "let" -> concatMap letParamToLiteral rest
+
+        "export" ->
+            if "f" `elem` flags then [] else concatMap getModifierParamString rest
+
+        "declare" -> forDeclare
+        "typeset" -> forDeclare
+
+        "local" -> concatMap getModifierParamString rest
+        "readonly" ->
+            if any (`elem` flags) ["f", "p"]
+            then []
+            else concatMap getModifierParamString rest
+        "set" -> maybeToList $ do
+            params <- getSetParams rest
+            return (base, base, "@", DataString $ SourceFrom params)
+
+        "printf" -> maybeToList $ getPrintfVariable rest
+        "wait" ->   maybeToList $ getWaitVariable rest
+
+        "mapfile" -> maybeToList $ getMapfileArray base rest
+        "readarray" -> maybeToList $ getMapfileArray base rest
+
+        "DEFINE_boolean" -> maybeToList $ getFlagVariable rest
+        "DEFINE_float" -> maybeToList $ getFlagVariable rest
+        "DEFINE_integer" -> maybeToList $ getFlagVariable rest
+        "DEFINE_string" -> maybeToList $ getFlagVariable rest
+
+        _ -> []
+  where
+    flags = map snd $ getAllFlags base
+    stripEquals s = drop 1 $ dropWhile (/= '=') s
+    stripEqualsFrom (T_NormalWord id1 (T_Literal id2 s:rs)) =
+        T_NormalWord id1 (T_Literal id2 (stripEquals s):rs)
+    stripEqualsFrom (T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 s]]) =
+        T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 (stripEquals s)]]
+    stripEqualsFrom t = t
+
+    forDeclare = if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
+
+    declaredVars = concatMap (getModifierParam defaultType) rest
+      where
+        defaultType = if any (`elem` flags) ["a", "A"] then DataArray else DataString
+
+    getLiteralOfDataType t d = do
+        s <- getLiteralString t
+        when ("-" `isPrefixOf` s) $ fail "argument"
+        return (base, t, s, d)
+
+    getLiteral t = getLiteralOfDataType t (DataString SourceExternal)
+
+    getLiteralArray t = getLiteralOfDataType t (DataArray SourceExternal)
+
+    getModifierParamString = getModifierParam DataString
+
+    getModifierParam def t@(T_Assignment _ _ name _ value) =
+        [(base, t, name, dataTypeFrom def value)]
+    getModifierParam def t@T_NormalWord {} = maybeToList $ do
+        name <- getLiteralString t
+        guard $ isVariableName name
+        return (base, t, name, def SourceDeclaration)
+    getModifierParam _ _ = []
+
+    letParamToLiteral token =
+          if null var
+            then []
+            else [(base, token, var, DataString $ SourceFrom [stripEqualsFrom token])]
+        where var = takeWhile isVariableChar $ dropWhile (`elem` "+-") $ concat $ oversimplify token
+
+    getSetParams (t:_:rest) | getLiteralString t == Just "-o" = getSetParams rest
+    getSetParams (t:rest) =
+        let s = getLiteralString t in
+            case s of
+                Just "--"    -> return rest
+                Just ('-':_) -> getSetParams rest
+                _            -> return (t:fromMaybe [] (getSetParams rest))
+    getSetParams [] = Nothing
+
+    getPrintfVariable list = getFlagAssignedVariable "v" (SourceFrom list) $ getBsdOpts "v:" list
+    getWaitVariable   list = getFlagAssignedVariable "p" SourceInteger     $ return $ getGenericOpts list
+
+    getFlagAssignedVariable str dataSource maybeFlags = do
+        flags <- maybeFlags
+        (_, (flag, value)) <- find ((== str) . fst) flags
+        variableName <- getLiteralStringExt (const $ return "!") value
+        let (baseName, index) = span (/= '[') variableName
+        return (base, value, baseName, (if null index then DataString else DataArray) dataSource)
+
+    -- mapfile has some curious syntax allowing flags plus 0..n variable names
+    -- where only the first non-option one is used if any.
+    getMapfileArray base rest = parseArgs `mplus` fallback
+      where
+        parseArgs :: Maybe (Token, Token, String, DataType)
+        parseArgs = do
+            args <- getGnuOpts "d:n:O:s:u:C:c:t" rest
+            case [y | ("",(_,y)) <- args] of
+                [] ->
+                    return (base, base, "MAPFILE", DataArray SourceExternal)
+                first:_ -> do
+                    name <- getLiteralString first
+                    guard $ isVariableName name
+                    return (base, first, name, DataArray SourceExternal)
+        -- If arg parsing fails (due to bad or new flags), get the last variable name
+        fallback :: Maybe (Token, Token, String, DataType)
+        fallback = do
+            (name, token) <- listToMaybe . mapMaybe f $ reverse rest
+            return (base, token, name, DataArray SourceExternal)
+        f arg = do
+            name <- getLiteralString arg
+            guard $ isVariableName name
+            return (name, arg)
+
+    -- get the FLAGS_ variable created by a shflags DEFINE_ call
+    getFlagVariable (n:v:_) = do
+        name <- getLiteralString n
+        return (base, n, "FLAGS_" ++ name, DataString $ SourceExternal)
+    getFlagVariable _ = Nothing
+
+getModifiedVariableCommand _ = []
+
+-- Given a NormalWord like foo or foo[$bar], get foo.
+-- Primarily used to get references for [[ -v foo[bar] ]]
+getVariableForTestDashV :: Token -> Maybe String
+getVariableForTestDashV t = do
+    str <- takeWhile ('[' /=) <$> getLiteralStringExt toStr t
+    guard $ isVariableName str
+    return str
+  where
+    -- foo[bar] gets parsed with [bar] as a glob, so undo that
+    toStr (T_Glob _ s) = return s
+    -- Turn foo[$x] into foo[\0] so that we can get the constant array name
+    -- in a non-constant expression (while filtering out foo$x[$y])
+    toStr _ = return "\0"
+
+getReferencedVariables parents t =
+    case t of
+        T_DollarBraced id _ l -> let str = concat $ oversimplify l in
+            (t, t, getBracedReference str) :
+                map (\x -> (l, l, x)) (
+                    getIndexReferences str
+                    ++ getOffsetReferences (getBracedModifier str))
+        TA_Variable id name _ ->
+            if isArithmeticAssignment t
+            then []
+            else [(t, t, name)]
+        T_Assignment id mode str _ word ->
+            [(t, t, str) | mode == Append] ++ specialReferences str t word
+
+        TC_Unary id _ "-v" token -> getIfReference t token
+        TC_Unary id _ "-R" token -> getIfReference t token
+        TC_Binary id DoubleBracket op lhs rhs ->
+            if isDereferencingBinaryOp op
+            then concatMap (getIfReference t) [lhs, rhs]
+            else []
+
+        T_BatsTest {} -> [ -- pretend @test references vars to avoid warnings
+            (t, t, "lines"),
+            (t, t, "status"),
+            (t, t, "output")
+            ]
+
+        T_FdRedirect _ ('{':var) op -> -- {foo}>&- references and closes foo
+            [(t, t, takeWhile (/= '}') var) | isClosingFileOp op]
+        x -> getReferencedVariableCommand x
+  where
+    -- Try to reduce false positives for unused vars only referenced from evaluated vars
+    specialReferences name base word =
+        if name `elem` [
+            "PS1", "PS2", "PS3", "PS4",
+            "PROMPT_COMMAND"
+          ]
+        then
+            map (\x -> (base, base, x)) $
+                getVariablesFromLiteralToken word
+        else []
+
+    literalizer t = case t of
+        T_Glob _ s -> return s    -- Also when parsed as globs
+        _          -> []
+
+    getIfReference context token = maybeToList $ do
+            str <- getVariableForTestDashV token
+            return (context, token, getBracedReference str)
+
+    isArithmeticAssignment t = case getPath parents t of
+        this NE.:| TA_Assignment _ "=" lhs _ :_ -> lhs == t
+        _                                  -> False
+
+isDereferencingBinaryOp = (`elem` ["-eq", "-ne", "-lt", "-le", "-gt", "-ge"])
+
+dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
+
+
+--- Command specific checks
+
+-- Compare a command to a string: t `isCommand` "sed" (also matches /usr/bin/sed)
+isCommand token str = isCommandMatch token (\cmd -> cmd  == str || ('/' : str) `isSuffixOf` cmd)
+
+-- Compare a command to a literal. Like above, but checks full path.
+isUnqualifiedCommand token str = isCommandMatch token (== str)
+
+isCommandMatch token matcher = maybe False
+    matcher (getCommandName token)
+
+-- Does this regex look like it was intended as a glob?
+-- True:  *foo*
+-- False: .*foo.*
+isConfusedGlobRegex :: String -> Bool
+isConfusedGlobRegex ('*':_) = True
+isConfusedGlobRegex [x,'*'] | x `notElem` "\\." = True
+isConfusedGlobRegex _       = False
+
+getVariablesFromLiteralToken token =
+    getVariablesFromLiteral (getLiteralStringDef " " token)
+
+-- Try to get referenced variables from a literal string like "$foo"
+-- Ignores tons of cases like arithmetic evaluation and array indices.
+prop_getVariablesFromLiteral1 =
+    getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
+getVariablesFromLiteral string =
+    map head $ matchAllSubgroups variableRegex string
+  where
+    variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
+
+
+-- Run a command if the shell is in the given list
+whenShell l c = do
+    params <- ask
+    when (shellType params `elem` l ) c
+
+
+filterByAnnotation asSpec params =
+    filter (not . shouldIgnore)
+  where
+    token = asScript asSpec
+    shouldIgnore note =
+        any (shouldIgnoreFor (getCode note)) $
+            getPath parents (T_Bang $ tcId note)
+    shouldIgnoreFor _ T_Include {} = not $ asCheckSourced asSpec
+    shouldIgnoreFor code t = isAnnotationIgnoringCode code t
+    parents = parentMap params
+    getCode = cCode . tcComment
+
+shouldIgnoreCode params code t =
+    any (isAnnotationIgnoringCode code) $
+        getPath (parentMap params) t
+
+-- Is this a ${#anything}, to get string length or array count?
+isCountingReference (T_DollarBraced id _ token) =
+    case concat $ oversimplify token of
+        '#':_ -> True
+        _     -> False
+isCountingReference _ = False
+
+-- FIXME: doesn't handle ${a:+$var} vs ${a:+"$var"}
+isQuotedAlternativeReference t =
+    case t of
+        T_DollarBraced _ _ l ->
+            getBracedModifier (concat $ oversimplify l) `matches` re
+        _ -> False
+  where
+    re = mkRegex "(^|\\]):?\\+"
+
+supportsArrays Bash = True
+supportsArrays Ksh = True
+supportsArrays _ = False
+
+isTrueAssignmentSource c =
+    case c of
+        DataString SourceChecked -> False
+        DataString SourceDeclaration -> False
+        DataArray SourceChecked -> False
+        DataArray SourceDeclaration -> False
+        _ -> True
+
+modifiesVariable params token name =
+    or $ map check flow
+  where
+    flow = getVariableFlow params token
+    check t =
+        case t of
+            Assignment (_, _, n, source) -> isTrueAssignmentSource source && n == name
+            _ -> False
+
+isTestCommand t =
+    case t of
+        T_Condition {} -> True
+        T_SimpleCommand {} -> t `isCommand` "test"
+        T_Redirecting _ _ t -> isTestCommand t
+        T_Annotation _ _ t -> isTestCommand t
+        T_Pipeline _ _ [t] -> isTestCommand t
+        _ -> False
+
+return []
+runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Checker.hs

@@ -0,0 +1,564 @@
+{-
+    Copyright 2012-2022 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.Checker (checkScript, ShellCheck.Checker.runTests) where
+
+import ShellCheck.Analyzer
+import ShellCheck.ASTLib
+import ShellCheck.Interface
+import ShellCheck.Parser
+
+import Debug.Trace -- DO NOT SUBMIT
+import Data.Either
+import Data.Functor
+import Data.List
+import Data.Maybe
+import Data.Ord
+import Control.Monad.Identity
+import qualified Data.Map as Map
+import qualified System.IO
+import Prelude hiding (readFile)
+import Control.Monad
+
+import Test.QuickCheck.All
+
+tokenToPosition startMap t = fromMaybe fail $ do
+    span <- Map.lookup (tcId t) startMap
+    return $ newPositionedComment {
+        pcStartPos = fst span,
+        pcEndPos = snd span,
+        pcComment = tcComment t,
+        pcFix = tcFix t
+    }
+  where
+    fail = error "Internal shellcheck error: id doesn't exist. Please report!"
+
+shellFromFilename filename = listToMaybe candidates
+  where
+    shellExtensions = [(".ksh", Ksh)
+                      ,(".bash", Bash)
+                      ,(".bats", Bash)
+                      ,(".dash", Dash)]
+                      -- The `.sh` is too generic to determine the shell:
+                      -- We fallback to Bash in this case and emit SC2148 if there is no shebang
+    candidates =
+        [sh | (ext,sh) <- shellExtensions, ext `isSuffixOf` filename]
+
+checkScript :: Monad m => SystemInterface m -> CheckSpec -> m CheckResult
+checkScript sys spec = do
+    results <- checkScript (csScript spec)
+    return emptyCheckResult {
+        crFilename = csFilename spec,
+        crComments = results
+    }
+  where
+    checkScript contents = do
+        result <- parseScript sys newParseSpec {
+            psFilename = csFilename spec,
+            psScript = contents,
+            psCheckSourced = csCheckSourced spec,
+            psIgnoreRC = csIgnoreRC spec,
+            psShellTypeOverride = csShellTypeOverride spec
+        }
+        let parseMessages = prComments result
+        let tokenPositions = prTokenPositions result
+        let analysisSpec root =
+                as {
+                    asScript = root,
+                    asShellType = csShellTypeOverride spec,
+                    asFallbackShell = shellFromFilename $ csFilename spec,
+                    asCheckSourced = csCheckSourced spec,
+                    asExecutionMode = Executed,
+                    asTokenPositions = tokenPositions,
+                    asExtendedAnalysis = csExtendedAnalysis spec,
+                    asOptionalChecks = getEnableDirectives root ++ csOptionalChecks spec
+                } where as = newAnalysisSpec root
+        let analysisMessages =
+                maybe []
+                    (arComments . analyzeScript . analysisSpec)
+                        $ prRoot result
+        let translator = tokenToPosition tokenPositions
+        return . nub . sortMessages . filter shouldInclude $
+            (parseMessages ++ map translator analysisMessages)
+
+    shouldInclude pc =
+            severity <= csMinSeverity spec &&
+            case csIncludedWarnings spec of
+                Nothing -> code `notElem` csExcludedWarnings spec
+                Just includedWarnings -> code `elem` includedWarnings
+        where
+            code     = cCode (pcComment pc)
+            severity = cSeverity (pcComment pc)
+
+    sortMessages = sortOn order
+    order pc =
+        let pos = pcStartPos pc
+            comment = pcComment pc in
+        (posFile pos,
+         posLine pos,
+         posColumn pos,
+         cSeverity comment,
+         cCode comment,
+         cMessage comment)
+    getPosition = pcStartPos
+
+
+getErrors sys spec =
+    sort . map getCode . crComments $
+        runIdentity (checkScript sys spec)
+  where
+    getCode = cCode . pcComment
+
+check = checkWithIncludes []
+
+checkWithSpec includes =
+    getErrors (mockedSystemInterface includes)
+
+checkWithIncludes includes src =
+    checkWithSpec includes emptyCheckSpec {
+        csScript = src,
+        csExcludedWarnings = [2148]
+    }
+
+checkRecursive includes src =
+    checkWithSpec includes emptyCheckSpec {
+        csScript = src,
+        csExcludedWarnings = [2148],
+        csCheckSourced = True
+    }
+
+checkOptionIncludes includes src =
+    checkWithSpec [] emptyCheckSpec {
+        csScript = src,
+        csIncludedWarnings = includes,
+        csCheckSourced = True
+    }
+
+checkWithRc rc = getErrors
+    (mockRcFile rc $ mockedSystemInterface [])
+
+checkWithIncludesAndSourcePath includes mapper = getErrors
+    (mockedSystemInterface includes) {
+        siFindSource = mapper
+    }
+
+checkWithRcIncludesAndSourcePath rc includes mapper = getErrors
+    (mockRcFile rc $ mockedSystemInterface includes) {
+        siFindSource = mapper
+    }
+
+prop_findsParseIssue = check "echo \"$12\"" == [1037]
+
+prop_commentDisablesParseIssue1 =
+    null $ check "#shellcheck disable=SC1037\necho \"$12\""
+prop_commentDisablesParseIssue2 =
+    null $ check "#shellcheck disable=SC1037\n#lol\necho \"$12\""
+
+prop_findsAnalysisIssue =
+    check "echo $1" == [2086]
+prop_commentDisablesAnalysisIssue1 =
+    null $ check "#shellcheck disable=SC2086\necho $1"
+prop_commentDisablesAnalysisIssue2 =
+    null $ check "#shellcheck disable=SC2086\n#lol\necho $1"
+
+prop_optionDisablesIssue1 =
+    null $ getErrors
+                (mockedSystemInterface [])
+                emptyCheckSpec {
+                    csScript = "echo $1",
+                    csExcludedWarnings = [2148, 2086]
+                }
+
+prop_optionDisablesIssue2 =
+    null $ getErrors
+                (mockedSystemInterface [])
+                emptyCheckSpec {
+                    csScript = "echo \"$10\"",
+                    csExcludedWarnings = [2148, 1037]
+                }
+
+prop_wontParseBadShell =
+    [1071] == check "#!/usr/bin/python\ntrue $1\n"
+
+prop_optionDisablesBadShebang =
+    null $ getErrors
+                (mockedSystemInterface [])
+                emptyCheckSpec {
+                    csScript = "#!/usr/bin/python\ntrue\n",
+                    csShellTypeOverride = Just Sh
+                }
+
+prop_annotationDisablesBadShebang =
+    null $ check "#!/usr/bin/python\n# shellcheck shell=sh\ntrue\n"
+
+
+prop_canParseDevNull =
+    null $ check "source /dev/null"
+
+prop_failsWhenNotSourcing =
+    [1091, 2154] == check "source lol; echo \"$bar\""
+
+prop_worksWhenSourcing =
+    null $ checkWithIncludes [("lib", "bar=1")] "source lib; echo \"$bar\""
+
+prop_worksWhenSourcingWithDashDash =
+    null $ checkWithIncludes [("lib", "bar=1")] "source -- lib; echo \"$bar\""
+
+prop_worksWhenDotting =
+    null $ checkWithIncludes [("lib", "bar=1")] ". lib; echo \"$bar\""
+
+-- FIXME: This should really be giving [1093], "recursively sourced"
+prop_noInfiniteSourcing =
+    null $ checkWithIncludes  [("lib", "source lib")] "source lib"
+
+prop_canSourceBadSyntax =
+    [1094, 2086] == checkWithIncludes [("lib", "for f; do")] "source lib; echo $1"
+
+prop_cantSourceDynamic =
+    [1090] == checkWithIncludes [("lib", "")] ". \"$1\""
+
+prop_cantSourceDynamic2 =
+    [1090] == checkWithIncludes [("lib", "")] "source ~/foo"
+
+prop_canStripPrefixAndSource =
+    null $ checkWithIncludes [("./lib", "")] "source \"$MYDIR/lib\""
+
+prop_canStripPrefixAndSource2 =
+    null $ checkWithIncludes [("./utils.sh", "")] "source \"$(dirname \"${BASH_SOURCE[0]}\")/utils.sh\""
+
+prop_canSourceDynamicWhenRedirected =
+    null $ checkWithIncludes [("lib", "")] "#shellcheck source=lib\n. \"$1\""
+
+prop_canRedirectWithSpaces =
+    null $ checkWithIncludes [("my file", "")] "#shellcheck source=\"my file\"\n. \"$1\""
+
+prop_recursiveAnalysis =
+    [2086] == checkRecursive [("lib", "echo $1")] "source lib"
+
+prop_recursiveParsing =
+    [1037] == checkRecursive [("lib", "echo \"$10\"")] "source lib"
+
+prop_nonRecursiveAnalysis =
+    null $ checkWithIncludes [("lib", "echo $1")] "source lib"
+
+prop_nonRecursiveParsing =
+    null $ checkWithIncludes [("lib", "echo \"$10\"")] "source lib"
+
+prop_sourceDirectiveDoesntFollowFile =
+    null $ checkWithIncludes
+                [("foo", "source bar"), ("bar", "baz=3")]
+                "#shellcheck source=foo\n. \"$1\"; echo \"$baz\""
+
+prop_filewideAnnotationBase = [2086] == check "#!/bin/sh\necho $1"
+prop_filewideAnnotation1 = null $
+    check "#!/bin/sh\n# shellcheck disable=2086\necho $1"
+prop_filewideAnnotation2 = null $
+    check "#!/bin/sh\n# shellcheck disable=2086\ntrue\necho $1"
+prop_filewideAnnotation3 = null $
+    check "#!/bin/sh\n#unrelated\n# shellcheck disable=2086\ntrue\necho $1"
+prop_filewideAnnotation4 = null $
+    check "#!/bin/sh\n# shellcheck disable=2086\n#unrelated\ntrue\necho $1"
+prop_filewideAnnotation5 = null $
+    check "#!/bin/sh\n\n\n\n#shellcheck disable=2086\ntrue\necho $1"
+prop_filewideAnnotation6 = null $
+    check "#shellcheck shell=sh\n#unrelated\n#shellcheck disable=2086\ntrue\necho $1"
+prop_filewideAnnotation7 = null $
+    check "#!/bin/sh\n# shellcheck disable=2086\n#unrelated\ntrue\necho $1"
+
+prop_filewideAnnotationBase2 = [2086, 2181] == check "true\n[ $? == 0 ] && echo $1"
+prop_filewideAnnotation8 = null $
+    check "# Disable $? warning\n#shellcheck disable=SC2181\n# Disable quoting warning\n#shellcheck disable=2086\ntrue\n[ $? == 0 ] && echo $1"
+
+prop_sourcePartOfOriginalScript = -- #1181: -x disabled posix warning for 'source'
+    3046 `elem` checkWithIncludes [("./saywhat.sh", "echo foo")] "#!/bin/sh\nsource ./saywhat.sh"
+
+prop_spinBug1413 = null $ check "fun() {\n# shellcheck disable=SC2188\n> /dev/null\n}\n"
+
+prop_deducesTypeFromExtension = null result
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.ksh",
+        csScript = "(( 3.14 ))"
+    }
+
+prop_deducesTypeFromExtension2 = result == [2079]
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.bash",
+        csScript = "(( 3.14 ))"
+    }
+
+prop_canDisableShebangWarning = null $ result
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.sh",
+        csScript = "#shellcheck disable=SC2148\nfoo"
+    }
+
+prop_canDisableAllWarnings = result == [2086]
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.sh",
+        csScript = "#!/bin/sh\necho $1\n#shellcheck disable=all\necho `echo $1`"
+    }
+
+prop_canDisableParseErrors = null $ result
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.sh",
+        csScript = "#shellcheck disable=SC1073,SC1072,SC2148\n()"
+    }
+
+prop_shExtensionDoesntMatter = result == [2148]
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.sh",
+        csScript = "echo 'hello world'"
+    }
+
+prop_sourcedFileUsesOriginalShellExtension = result == [2079]
+  where
+    result = checkWithSpec [("file.ksh", "(( 3.14 ))")] emptyCheckSpec {
+        csFilename = "file.bash",
+        csScript = "source file.ksh",
+        csCheckSourced = True
+    }
+
+prop_canEnableOptionalsWithSpec = result == [2244]
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.sh",
+        csScript = "#!/bin/sh\n[ \"$1\" ]",
+        csOptionalChecks = ["avoid-nullary-conditions"]
+    }
+
+prop_optionIncludes1 =
+    -- expect 2086, but not included, so nothing reported
+    null $ checkOptionIncludes (Just [2080]) "#!/bin/sh\n var='a b'\n echo $var"
+
+prop_optionIncludes2 =
+    -- expect 2086, included, so it is reported
+    [2086] == checkOptionIncludes (Just [2086]) "#!/bin/sh\n var='a b'\n echo $var"
+
+prop_optionIncludes3 =
+    -- expect 2086, no inclusions provided, so it is reported
+    [2086] == checkOptionIncludes Nothing "#!/bin/sh\n var='a b'\n echo $var"
+
+prop_optionIncludes4 =
+    -- expect 2086 & 2154, only 2154 included, so only that's reported
+    [2154] == checkOptionIncludes (Just [2154]) "#!/bin/sh\n var='a b'\n echo $var\n echo $bar"
+
+
+prop_readsRcFile = null result
+  where
+    result = checkWithRc "disable=2086" emptyCheckSpec {
+        csScript = "#!/bin/sh\necho $1",
+        csIgnoreRC = False
+    }
+
+prop_canUseNoRC = result == [2086]
+  where
+    result = checkWithRc "disable=2086" emptyCheckSpec {
+        csScript = "#!/bin/sh\necho $1",
+        csIgnoreRC = True
+    }
+
+prop_NoRCWontLookAtFile = result == [2086]
+  where
+    result = checkWithRc (error "Fail") emptyCheckSpec {
+        csScript = "#!/bin/sh\necho $1",
+        csIgnoreRC = True
+    }
+
+prop_brokenRcGetsWarning = result == [1134, 2086]
+  where
+    result = checkWithRc "rofl" emptyCheckSpec {
+        csScript = "#!/bin/sh\necho $1",
+        csIgnoreRC = False
+    }
+
+prop_canEnableOptionalsWithRc = result == [2244]
+  where
+    result = checkWithRc "enable=avoid-nullary-conditions" emptyCheckSpec {
+        csScript = "#!/bin/sh\n[ \"$1\" ]"
+    }
+
+prop_sourcePathRedirectsName = result == [2086]
+  where
+    f "dir/myscript" _ _ "lib" = return "foo/lib"
+    result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource lib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_sourcePathAddsAnnotation = result == [2086]
+  where
+    f "dir/myscript" _ ["mypath"] "lib" = return "foo/lib"
+    result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck source-path=mypath\nsource lib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_sourcePathWorksWithSpaces = result == [2086]
+  where
+    f "dir/myscript" _ ["my path"] "lib" = return "foo/lib"
+    result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck source-path='my path'\nsource lib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_sourcePathRedirectsDirective = result == [2086]
+  where
+    f "dir/myscript" _ _ "lib" = return "foo/lib"
+    f _ _ _ _ = return "/dev/null"
+    result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck source=lib\nsource kittens",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanAllowExternalSources = result == [2086]
+  where
+    f "dir/myscript" (Just True) _ "mylib" = return "resolved/mylib"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=true" [("resolved/mylib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource mylib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanDenyExternalSources = result == [2086]
+  where
+    f "dir/myscript" (Just False) _ "mylib" = return "resolved/mylib"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=false" [("resolved/mylib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource mylib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanLeaveExternalSourcesUnspecified = result == [2086]
+  where
+    f "dir/myscript" Nothing _ "mylib" = return "resolved/mylib"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "" [("resolved/mylib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource mylib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_fileCanDisableExternalSources = result == [2006, 2086]
+  where
+    f "dir/myscript" (Just True) _ "withExternal" = return "withExternal"
+    f "dir/myscript" (Just False) _ "withoutExternal" = return "withoutExternal"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=true" [("withExternal", "echo $1"), ("withoutExternal", "_=`foo`")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\ntrue\nsource withExternal\n# shellcheck external-sources=false\nsource withoutExternal",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_fileCannotEnableExternalSources = result == [1144]
+  where
+    f "dir/myscript" Nothing _ "foo" = return "foo"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "" [("foo", "true")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck external-sources=true\nsource foo",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_fileCannotEnableExternalSources2 = result == [1144]
+  where
+    f "dir/myscript" (Just False) _ "foo" = return "foo"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=false" [("foo", "true")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck external-sources=true\nsource foo",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanSuppressEarlyProblems1 = null result
+  where
+    result = checkWithRc "disable=1071" emptyCheckSpec {
+        csScript = "#!/bin/zsh\necho $1"
+    }
+
+prop_rcCanSuppressEarlyProblems2 = null result
+  where
+    result = checkWithRc "disable=1104" emptyCheckSpec {
+        csScript = "!/bin/bash\necho 'hello world'"
+    }
+
+prop_sourceWithHereDocWorks = null result
+  where
+    result = checkWithIncludes [("bar", "true\n")] "source bar << eof\nlol\neof"
+
+prop_hereDocsAreParsedWithoutTrailingLinefeed = 1044 `elem` result
+  where
+    result = check "cat << eof"
+
+prop_hereDocsWillHaveParsedIndices = null result
+  where
+    result = check "#!/bin/bash\nmy_array=(a b)\ncat <<EOF >> ./test\n $(( 1 + my_array[1] ))\nEOF"
+
+prop_rcCanSuppressDfa = null result
+  where
+    result = checkWithRc "extended-analysis=false" emptyCheckSpec {
+        csScript = "#!/bin/sh\nexit; foo;"
+    }
+
+prop_fileCanSuppressDfa = null $ traceShowId result
+  where
+    result = checkWithRc "" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=false\nexit; foo;"
+    }
+
+prop_fileWinsWhenSuppressingDfa1 = null result
+  where
+    result = checkWithRc "extended-analysis=true" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=false\nexit; foo;"
+    }
+
+prop_fileWinsWhenSuppressingDfa2 = result == [2317]
+  where
+    result = checkWithRc "extended-analysis=false" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=true\nexit; foo;"
+    }
+
+prop_flagWinsWhenSuppressingDfa1 = result == [2317]
+  where
+    result = checkWithRc "extended-analysis=false" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=false\nexit; foo;",
+        csExtendedAnalysis = Just True
+    }
+
+prop_flagWinsWhenSuppressingDfa2 = null result
+  where
+    result = checkWithRc "extended-analysis=true" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=true\nexit; foo;",
+        csExtendedAnalysis = Just False
+    }
+
+return []
+runTests = $quickCheckAll

src/ShellCheck/Checks/ControlFlow.hs

@@ -0,0 +1,101 @@
+{-
+    Copyright 2022 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+
+-- Checks that run on the Control Flow Graph (as opposed to the AST)
+-- This is scaffolding for a work in progress.
+
+module ShellCheck.Checks.ControlFlow (checker, optionalChecks, ShellCheck.Checks.ControlFlow.runTests) where
+
+import ShellCheck.AST
+import ShellCheck.ASTLib
+import ShellCheck.CFG hiding (cfgAnalysis)
+import ShellCheck.CFGAnalysis
+import ShellCheck.AnalyzerLib
+import ShellCheck.Data
+import ShellCheck.Interface
+
+import Control.Monad
+import Control.Monad.Reader
+import Data.Graph.Inductive.Graph
+import qualified Data.Map as M
+import qualified Data.Set as S
+import Data.List
+import Data.Maybe
+
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
+
+
+optionalChecks :: [CheckDescription]
+optionalChecks = []
+
+-- A check that runs on the entire graph
+type ControlFlowCheck = Analysis
+-- A check invoked once per node, with its (pre,post) data
+type ControlFlowNodeCheck = LNode CFNode -> (ProgramState, ProgramState) -> Analysis
+-- A check invoked once per effect, with its node's (pre,post) data
+type ControlFlowEffectCheck = IdTagged CFEffect -> Node -> (ProgramState, ProgramState) -> Analysis
+
+
+checker :: AnalysisSpec -> Parameters -> Checker
+checker spec params = Checker {
+    perScript = const $ sequence_ controlFlowChecks,
+    perToken = const $ return ()
+}
+
+controlFlowChecks :: [ControlFlowCheck]
+controlFlowChecks = [
+        runNodeChecks controlFlowNodeChecks
+    ]
+
+controlFlowNodeChecks :: [ControlFlowNodeCheck]
+controlFlowNodeChecks = [
+    runEffectChecks controlFlowEffectChecks
+    ]
+
+controlFlowEffectChecks :: [ControlFlowEffectCheck]
+controlFlowEffectChecks = [
+    ]
+
+runNodeChecks :: [ControlFlowNodeCheck] -> ControlFlowCheck
+runNodeChecks perNode = do
+    cfg <- asks cfgAnalysis
+    mapM_ runOnAll cfg
+  where
+    getData datas n@(node, label) = do
+        (pre, post) <- M.lookup node datas
+        return (n, (pre, post))
+
+    runOn :: (LNode CFNode, (ProgramState, ProgramState)) -> Analysis
+    runOn (node, prepost) = mapM_ (\c -> c node prepost) perNode
+    runOnAll cfg = mapM_ runOn $ mapMaybe (getData $ nodeToData cfg) $ labNodes (graph cfg)
+
+runEffectChecks :: [ControlFlowEffectCheck] -> ControlFlowNodeCheck
+runEffectChecks list = checkNode
+  where
+    checkNode (node, label) prepost =
+        case label of
+            CFApplyEffects effects -> mapM_ (\effect -> mapM_ (\c -> c effect node prepost) list) effects
+            _ -> return ()
+
+
+return []
+runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Checks/Custom.hs

@@ -0,0 +1,21 @@
+{-
+    This empty file is provided for ease of patching in site specific checks.
+    However, there are no guarantees regarding compatibility between versions.
+-}
+
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.Checks.Custom (checker, ShellCheck.Checks.Custom.runTests) where
+
+import ShellCheck.AnalyzerLib
+import Test.QuickCheck
+
+checker :: Parameters -> Checker
+checker params = Checker {
+    perScript = const $ return (),
+    perToken = const $ return ()
+  }
+
+prop_CustomTestsWork = True
+
+return []
+runTests = $quickCheckAll

src/ShellCheck/Checks/ShellSupport.hs

@@ -0,0 +1,701 @@
+{-
+    Copyright 2012-2020 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE ViewPatterns #-}
+module ShellCheck.Checks.ShellSupport (checker , ShellCheck.Checks.ShellSupport.runTests) where
+
+import ShellCheck.AST
+import ShellCheck.ASTLib
+import ShellCheck.AnalyzerLib
+import ShellCheck.Interface
+import ShellCheck.Prelude
+import ShellCheck.Regex
+
+import Control.Monad
+import Control.Monad.RWS
+import Data.Char
+import Data.Functor.Identity
+import Data.List
+import Data.Maybe
+import qualified Data.Map as Map
+import qualified Data.Set as Set
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
+
+data ForShell = ForShell [Shell] (Token -> Analysis)
+
+getChecker params list = Checker {
+        perScript = nullCheck,
+        perToken = foldl composeAnalyzers nullCheck $ mapMaybe include list
+    }
+  where
+    shell = shellType params
+    include (ForShell list a) = do
+        guard $ shell `elem` list
+        return a
+
+checker params = getChecker params checks
+
+checks = [
+    checkForDecimals
+    ,checkBashisms
+    ,checkEchoSed
+    ,checkBraceExpansionVars
+    ,checkMultiDimensionalArrays
+    ,checkPS1Assignments
+    ,checkMultipleBangs
+    ,checkBangAfterPipe
+    ,checkNegatedUnaryOps
+    ]
+
+testChecker (ForShell _ t) =
+    Checker {
+        perScript = nullCheck,
+        perToken = t
+    }
+verify c s = producesComments (testChecker c) s == Just True
+verifyNot c s = producesComments (testChecker c) s == Just False
+
+prop_checkForDecimals1 = verify checkForDecimals "((3.14*c))"
+prop_checkForDecimals2 = verify checkForDecimals "foo[1.2]=bar"
+prop_checkForDecimals3 = verifyNot checkForDecimals "declare -A foo; foo[1.2]=bar"
+checkForDecimals = ForShell [Sh, Dash, BusyboxSh, Bash] f
+  where
+    f t@(TA_Expansion id _) = sequence_ $ do
+        first:rest <- getLiteralString t
+        guard $ isDigit first && '.' `elem` rest
+        return $ err id 2079 "(( )) doesn't support decimals. Use bc or awk."
+    f _ = return ()
+
+
+prop_checkBashisms = verify checkBashisms "while read a; do :; done < <(a)"
+prop_checkBashisms2 = verifyNot checkBashisms "[ foo -nt bar ]"
+prop_checkBashisms3 = verify checkBashisms "echo $((i++))"
+prop_checkBashisms4 = verify checkBashisms "rm !(*.hs)"
+prop_checkBashisms5 = verify checkBashisms "source file"
+prop_checkBashisms6 = verify checkBashisms "[ \"$a\" == 42 ]"
+prop_checkBashisms6b = verify checkBashisms "test \"$a\" == 42"
+prop_checkBashisms6c = verify checkBashisms "[ foo =~ bar ]"
+prop_checkBashisms6d = verify checkBashisms "test foo =~ bar"
+prop_checkBashisms7 = verify checkBashisms "echo ${var[1]}"
+prop_checkBashisms8 = verify checkBashisms "echo ${!var[@]}"
+prop_checkBashisms9 = verify checkBashisms "echo ${!var*}"
+prop_checkBashisms10 = verify checkBashisms "echo ${var:4:12}"
+prop_checkBashisms11 = verifyNot checkBashisms "echo ${var:-4}"
+prop_checkBashisms12 = verify checkBashisms "echo ${var//foo/bar}"
+prop_checkBashisms13 = verify checkBashisms "exec -c env"
+prop_checkBashisms14 = verify checkBashisms "echo -n \"Foo: \""
+prop_checkBashisms15 = verify checkBashisms "let n++"
+prop_checkBashisms16 = verify checkBashisms "echo $RANDOM"
+prop_checkBashisms17 = verify checkBashisms "echo $((RANDOM%6+1))"
+prop_checkBashisms18 = verify checkBashisms "foo &> /dev/null"
+prop_checkBashisms19 = verify checkBashisms "foo > file*.txt"
+prop_checkBashisms20 = verify checkBashisms "read -ra foo"
+prop_checkBashisms21 = verify checkBashisms "[ -a foo ]"
+prop_checkBashisms21b = verify checkBashisms "test -a foo"
+prop_checkBashisms22 = verifyNot checkBashisms "[ foo -a bar ]"
+prop_checkBashisms23 = verify checkBashisms "trap mything ERR INT"
+prop_checkBashisms24 = verifyNot checkBashisms "trap mything INT TERM"
+prop_checkBashisms25 = verify checkBashisms "cat < /dev/tcp/host/123"
+prop_checkBashisms26 = verify checkBashisms "trap mything ERR SIGTERM"
+prop_checkBashisms27 = verify checkBashisms "echo *[^0-9]*"
+prop_checkBashisms28 = verify checkBashisms "exec {n}>&2"
+prop_checkBashisms29 = verify checkBashisms "echo ${!var}"
+prop_checkBashisms30 = verify checkBashisms "printf -v '%s' \"$1\""
+prop_checkBashisms31 = verify checkBashisms "printf '%q' \"$1\""
+prop_checkBashisms32 = verifyNot checkBashisms "#!/bin/dash\n[ foo -nt bar ]"
+prop_checkBashisms33 = verify checkBashisms "#!/bin/sh\necho -n foo"
+prop_checkBashisms34 = verifyNot checkBashisms "#!/bin/dash\necho -n foo"
+prop_checkBashisms35 = verifyNot checkBashisms "#!/bin/dash\nlocal foo"
+prop_checkBashisms36 = verifyNot checkBashisms "#!/bin/dash\nread -p foo -r bar"
+prop_checkBashisms37 = verifyNot checkBashisms "HOSTNAME=foo; echo $HOSTNAME"
+prop_checkBashisms38 = verify checkBashisms "RANDOM=9; echo $RANDOM"
+prop_checkBashisms39 = verify checkBashisms "foo-bar() { true; }"
+prop_checkBashisms40 = verify checkBashisms "echo $(<file)"
+prop_checkBashisms41 = verify checkBashisms "echo `<file`"
+prop_checkBashisms42 = verify checkBashisms "trap foo int"
+prop_checkBashisms43 = verify checkBashisms "trap foo sigint"
+prop_checkBashisms44 = verifyNot checkBashisms "#!/bin/dash\ntrap foo int"
+prop_checkBashisms45 = verifyNot checkBashisms "#!/bin/dash\ntrap foo INT"
+prop_checkBashisms46 = verify checkBashisms "#!/bin/dash\ntrap foo SIGINT"
+prop_checkBashisms47 = verify checkBashisms "#!/bin/dash\necho foo 42>/dev/null"
+prop_checkBashisms48 = verifyNot checkBashisms "#!/bin/sh\necho $LINENO"
+prop_checkBashisms49 = verify checkBashisms "#!/bin/dash\necho $MACHTYPE"
+prop_checkBashisms50 = verify checkBashisms "#!/bin/sh\ncmd >& file"
+prop_checkBashisms51 = verifyNot checkBashisms "#!/bin/sh\ncmd 2>&1"
+prop_checkBashisms52 = verifyNot checkBashisms "#!/bin/sh\ncmd >&2"
+prop_checkBashisms52b = verifyNot checkBashisms "#!/bin/sh\ncmd >& $var"
+prop_checkBashisms52c = verify checkBashisms "#!/bin/sh\ncmd >& $dir/$var"
+prop_checkBashisms53 = verifyNot checkBashisms "#!/bin/sh\nprintf -- -f\n"
+prop_checkBashisms54 = verify checkBashisms "#!/bin/sh\nfoo+=bar"
+prop_checkBashisms55 = verify checkBashisms "#!/bin/sh\necho ${@%foo}"
+prop_checkBashisms56 = verifyNot checkBashisms "#!/bin/sh\necho ${##}"
+prop_checkBashisms57 = verifyNot checkBashisms "#!/bin/dash\nulimit -c 0"
+prop_checkBashisms58 = verify checkBashisms "#!/bin/sh\nulimit -c 0"
+prop_checkBashisms59 = verify checkBashisms "#!/bin/sh\njobs -s"
+prop_checkBashisms60 = verifyNot checkBashisms "#!/bin/sh\njobs -p"
+prop_checkBashisms61 = verifyNot checkBashisms "#!/bin/sh\njobs -lp"
+prop_checkBashisms62 = verify checkBashisms "#!/bin/sh\nexport -f foo"
+prop_checkBashisms63 = verifyNot checkBashisms "#!/bin/sh\nexport -p"
+prop_checkBashisms64 = verify checkBashisms "#!/bin/sh\nreadonly -a"
+prop_checkBashisms65 = verifyNot checkBashisms "#!/bin/sh\nreadonly -p"
+prop_checkBashisms66 = verifyNot checkBashisms "#!/bin/sh\ncd -P ."
+prop_checkBashisms67 = verify checkBashisms "#!/bin/sh\ncd -P -e ."
+prop_checkBashisms68 = verify checkBashisms "#!/bin/sh\numask -p"
+prop_checkBashisms69 = verifyNot checkBashisms "#!/bin/sh\numask -S"
+prop_checkBashisms70 = verify checkBashisms "#!/bin/sh\ntrap -l"
+prop_checkBashisms71 = verify checkBashisms "#!/bin/sh\ntype -a ls"
+prop_checkBashisms72 = verifyNot checkBashisms "#!/bin/sh\ntype ls"
+prop_checkBashisms73 = verify checkBashisms "#!/bin/sh\nunset -n namevar"
+prop_checkBashisms74 = verifyNot checkBashisms "#!/bin/sh\nunset -f namevar"
+prop_checkBashisms75 = verifyNot checkBashisms "#!/bin/sh\necho \"-n foo\""
+prop_checkBashisms76 = verifyNot checkBashisms "#!/bin/sh\necho \"-ne foo\""
+prop_checkBashisms77 = verifyNot checkBashisms "#!/bin/sh\necho -Q foo"
+prop_checkBashisms78 = verify checkBashisms "#!/bin/sh\necho -ne foo"
+prop_checkBashisms79 = verify checkBashisms "#!/bin/sh\nhash -l"
+prop_checkBashisms80 = verifyNot checkBashisms "#!/bin/sh\nhash -r"
+prop_checkBashisms81 = verifyNot checkBashisms "#!/bin/dash\nhash -v"
+prop_checkBashisms82 = verifyNot checkBashisms "#!/bin/sh\nset -v +o allexport -o errexit -C"
+prop_checkBashisms83 = verifyNot checkBashisms "#!/bin/sh\nset --"
+prop_checkBashisms84 = verify checkBashisms "#!/bin/sh\nset -o pipefail"
+prop_checkBashisms85 = verify checkBashisms "#!/bin/sh\nset -B"
+prop_checkBashisms86 = verifyNot checkBashisms "#!/bin/dash\nset -o emacs"
+prop_checkBashisms87 = verify checkBashisms "#!/bin/sh\nset -o emacs"
+prop_checkBashisms88 = verifyNot checkBashisms "#!/bin/sh\nset -- wget -o foo 'https://some.url'"
+prop_checkBashisms89 = verifyNot checkBashisms "#!/bin/sh\nopts=$-\nset -\"$opts\""
+prop_checkBashisms90 = verifyNot checkBashisms "#!/bin/sh\nset -o \"$opt\""
+prop_checkBashisms91 = verify checkBashisms "#!/bin/sh\nwait -n"
+prop_checkBashisms92 = verify checkBashisms "#!/bin/sh\necho $((16#FF))"
+prop_checkBashisms93 = verify checkBashisms "#!/bin/sh\necho $(( 10#$(date +%m) ))"
+prop_checkBashisms94 = verify checkBashisms "#!/bin/sh\n[ -v var ]"
+prop_checkBashisms95 = verify checkBashisms "#!/bin/sh\necho $_"
+prop_checkBashisms96 = verifyNot checkBashisms "#!/bin/dash\necho $_"
+prop_checkBashisms97 = verify checkBashisms "#!/bin/sh\necho ${var,}"
+prop_checkBashisms98 = verify checkBashisms "#!/bin/sh\necho ${var^^}"
+prop_checkBashisms99 = verify checkBashisms "#!/bin/dash\necho [^f]oo"
+prop_checkBashisms100 = verify checkBashisms "read -r"
+prop_checkBashisms101 = verify checkBashisms "read"
+prop_checkBashisms102 = verifyNot checkBashisms "read -r foo"
+prop_checkBashisms103 = verifyNot checkBashisms "read foo"
+prop_checkBashisms104 = verifyNot checkBashisms "read ''"
+prop_checkBashisms105 = verifyNot checkBashisms "#!/bin/busybox sh\nset -o pipefail"
+prop_checkBashisms106 = verifyNot checkBashisms "#!/bin/busybox sh\nx=x\n[[ \"$x\" = \"$x\" ]]"
+prop_checkBashisms107 = verifyNot checkBashisms "#!/bin/busybox sh\nx=x\n[ \"$x\" == \"$x\" ]"
+prop_checkBashisms108 = verifyNot checkBashisms "#!/bin/busybox sh\necho magic &> /dev/null"
+prop_checkBashisms109 = verifyNot checkBashisms "#!/bin/busybox sh\ntrap stop EXIT SIGTERM"
+prop_checkBashisms110 = verifyNot checkBashisms "#!/bin/busybox sh\nsource /dev/null"
+prop_checkBashisms111 = verify checkBashisms "#!/bin/dash\nx='test'\n${x:0:3}" -- SC3057
+prop_checkBashisms112 = verifyNot checkBashisms "#!/bin/busybox sh\nx='test'\n${x:0:3}" -- SC3057
+prop_checkBashisms113 = verify checkBashisms "#!/bin/dash\nx='test'\n${x/st/xt}" -- SC3060
+prop_checkBashisms114 = verifyNot checkBashisms "#!/bin/busybox sh\nx='test'\n${x/st/xt}" -- SC3060
+prop_checkBashisms115 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${!x}" -- SC3053
+prop_checkBashisms116 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${x[1]}" -- SC3054
+prop_checkBashisms117 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${!x[@]}" -- SC3055
+prop_checkBashisms118 = verify checkBashisms "#!/bin/busybox sh\nxyz=1\n${!x*}" -- SC3056
+prop_checkBashisms119 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${x^^[t]}" -- SC3059
+prop_checkBashisms120 = verify checkBashisms "#!/bin/sh\n[ x == y ]"
+prop_checkBashisms121 = verifyNot checkBashisms "#!/bin/sh\n# shellcheck shell=busybox\n[ x == y ]"
+prop_checkBashisms122 = verify checkBashisms "#!/bin/dash\n$'a'"
+prop_checkBashisms123 = verifyNot checkBashisms "#!/bin/busybox sh\n$'a'"
+prop_checkBashisms124 = verify checkBashisms "#!/bin/dash\ntype -p test"
+prop_checkBashisms125 = verifyNot checkBashisms "#!/bin/busybox sh\ntype -p test"
+prop_checkBashisms126 = verifyNot checkBashisms "#!/bin/busybox sh\nread -p foo -r bar"
+prop_checkBashisms127 = verifyNot checkBashisms "#!/bin/busybox sh\necho -ne foo"
+prop_checkBashisms128 = verify checkBashisms "#!/bin/dash\ntype -p test"
+prop_checkBashisms129 = verify checkBashisms "#!/bin/sh\n[ -k /tmp ]"
+prop_checkBashisms130 = verifyNot checkBashisms "#!/bin/dash\ntest -k /tmp"
+prop_checkBashisms131 = verify checkBashisms "#!/bin/sh\n[ -o errexit ]"
+checkBashisms = ForShell [Sh, Dash, BusyboxSh] $ \t -> do
+    params <- ask
+    kludge params t
+ where
+  -- This code was copy-pasted from Analytics where params was a variable
+  kludge params = bashism
+   where
+    isBusyboxSh = shellType params == BusyboxSh
+    isDash = shellType params == Dash || isBusyboxSh
+    warnMsg id code s =
+        if isDash
+        then err  id code $ "In dash, " ++ s ++ " not supported."
+        else warn id code $ "In POSIX sh, " ++ s ++ " undefined."
+    asStr = getLiteralString
+
+    bashism (T_ProcSub id _ _) = warnMsg id 3001 "process substitution is"
+    bashism (T_Extglob id _ _) = warnMsg id 3002 "extglob is"
+    bashism (T_DollarSingleQuoted id _) =
+        unless isBusyboxSh $ warnMsg id 3003 "$'..' is"
+    bashism (T_DollarDoubleQuoted id _) = warnMsg id 3004 "$\"..\" is"
+    bashism (T_ForArithmetic id _ _ _ _) = warnMsg id 3005 "arithmetic for loops are"
+    bashism (T_Arithmetic id _) = warnMsg id 3006 "standalone ((..)) is"
+    bashism (T_DollarBracket id _) = warnMsg id 3007 "$[..] in place of $((..)) is"
+    bashism (T_SelectIn id _ _ _) = warnMsg id 3008 "select loops are"
+    bashism (T_BraceExpansion id _) = warnMsg id 3009 "brace expansion is"
+    bashism (T_Condition id DoubleBracket _) =
+        unless isBusyboxSh $ warnMsg id 3010 "[[ ]] is"
+    bashism (T_HereString id _) = warnMsg id 3011 "here-strings are"
+
+    bashism (TC_Binary id _ op _ _) =
+        checkTestOp bashismBinaryTestFlags op id
+    bashism (T_SimpleCommand id _ [asStr -> Just "test", lhs, asStr -> Just op, rhs]) =
+        checkTestOp bashismBinaryTestFlags op id
+    bashism (TC_Unary id _ op _) =
+        checkTestOp bashismUnaryTestFlags op id
+    bashism (T_SimpleCommand id _ [asStr -> Just "test", asStr -> Just op, _]) =
+        checkTestOp bashismUnaryTestFlags op id
+
+    bashism (TA_Unary id op _)
+        | op `elem` [ "|++", "|--", "++|", "--|"] =
+            warnMsg id 3018 $ filter (/= '|') op ++ " is"
+    bashism (TA_Binary id "**" _ _) = warnMsg id 3019 "exponentials are"
+    bashism (T_FdRedirect id "&" (T_IoFile _ (T_Greater _) _)) =
+        unless isBusyboxSh $ warnMsg id 3020 "&> is"
+    bashism (T_FdRedirect id "" (T_IoFile _ (T_GREATAND _) file)) =
+        unless (all isDigit $ onlyLiteralString file) $ warnMsg id 3021 ">& filename (as opposed to >& fd) is"
+    bashism (T_FdRedirect id ('{':_) _) = warnMsg id 3022 "named file descriptors are"
+    bashism (T_FdRedirect id num _)
+        | all isDigit num && length num > 1 = warnMsg id 3023 "FDs outside 0-9 are"
+    bashism (T_Assignment id Append _ _ _) =
+        warnMsg id 3024 "+= is"
+    bashism (T_IoFile id _ word) | isNetworked =
+            warnMsg id 3025 "/dev/{tcp,udp} is"
+        where
+            file = onlyLiteralString word
+            isNetworked = any (`isPrefixOf` file) ["/dev/tcp", "/dev/udp"]
+    bashism (T_Glob id str) | "[^" `isInfixOf` str =
+            warnMsg id 3026 "^ in place of ! in glob bracket expressions is"
+
+    bashism t@(TA_Variable id str _) | isBashVariable str =
+        warnMsg id 3028 $ str ++ " is"
+
+    bashism t@(T_DollarBraced id _ token) = do
+        unless isBusyboxSh $ mapM_ check simpleExpansions
+        mapM_ check advancedExpansions
+        when (isBashVariable var) $
+            warnMsg id 3028 $ var ++ " is"
+      where
+        str = concat $ oversimplify token
+        var = getBracedReference str
+        check (regex, code, feature) =
+            when (isJust $ matchRegex regex str) $ warnMsg id code feature
+
+    bashism t@(T_Pipe id "|&") =
+        warnMsg id 3029 "|& in place of 2>&1 | is"
+    bashism (T_Array id _) =
+        warnMsg id 3030 "arrays are"
+    bashism (T_IoFile id _ t) | isGlob t =
+        warnMsg id 3031 "redirecting to/from globs is"
+    bashism (T_CoProc id _ _) =
+        warnMsg id 3032 "coproc is"
+
+    bashism (T_Function id _ _ str _) | not (isVariableName str) =
+        warnMsg id 3033 "naming functions outside [a-zA-Z_][a-zA-Z0-9_]* is"
+
+    bashism (T_DollarExpansion id [x]) | isOnlyRedirection x =
+        warnMsg id 3034 "$(<file) to read files is"
+    bashism (T_Backticked id [x]) | isOnlyRedirection x =
+        warnMsg id 3035 "`<file` to read files is"
+
+    bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
+        | t `isCommand` "echo" && argString `matches` flagRegex =
+            if isBusyboxSh
+            then
+                unless (argString `matches` busyboxFlagRegex) $
+                    warnMsg (getId arg) 3036 "echo flags besides -n and -e"
+            else if isDash
+            then
+                when (argString /= "-n") $
+                    warnMsg (getId arg) 3036 "echo flags besides -n"
+            else
+                warnMsg (getId arg) 3037 "echo flags are"
+      where
+          argString = concat $ oversimplify arg
+          flagRegex = mkRegex "^-[eEsn]+$"
+          busyboxFlagRegex = mkRegex "^-[en]+$"
+
+    bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
+        | getLiteralString cmd == Just "exec" && "-" `isPrefixOf` concat (oversimplify arg) =
+            warnMsg (getId arg) 3038 "exec flags are"
+    bashism t@(T_SimpleCommand id _ _)
+        | t `isCommand` "let" = warnMsg id 3039 "'let' is"
+    bashism t@(T_SimpleCommand _ _ (cmd:args))
+        | t `isCommand` "set" = unless isDash $
+            checkOptions $ getLiteralArgs args
+      where
+        -- Get the literal options from a list of arguments,
+        -- up until the first non-literal one
+        getLiteralArgs :: [Token] -> [(Id, String)]
+        getLiteralArgs = foldr go []
+          where
+            go first rest = case getLiteralString first of
+                Just str -> (getId first, str) : rest
+                Nothing -> []
+
+        -- Check a flag-option pair (such as -o errexit)
+        checkOptions (flag@(fid,flag') : opt@(oid,opt') : rest)
+            | flag' `matches` oFlagRegex = do
+                when (opt' `notElem` longOptions) $
+                  warnMsg oid 3040 $ "set option " <> opt' <> " is"
+                checkFlags (flag:rest)
+            | otherwise = checkFlags (flag:opt:rest)
+        checkOptions (flag:rest) = checkFlags (flag:rest)
+        checkOptions _           = return ()
+
+        -- Check that each option in a sequence of flags
+        -- (such as -aveo) is valid
+        checkFlags (flag@(fid, flag'):rest)
+            | startsOption flag' = do
+                unless (flag' `matches` validFlagsRegex) $
+                  forM_ (tail flag') $ \letter ->
+                    when (letter `notElem` optionsSet) $
+                      warnMsg fid 3041 $ "set flag " <> ('-':letter:" is")
+                checkOptions rest
+            | beginsWithDoubleDash flag' = do
+                warnMsg fid 3042 $ "set flag " <> flag' <> " is"
+                checkOptions rest
+            -- Either a word that doesn't start with a dash, or simply '--',
+            -- so stop checking.
+            | otherwise = return ()
+        checkFlags [] = return ()
+
+        options              = "abCefhmnuvxo"
+        optionsSet           = Set.fromList options
+        startsOption         = (`matches` mkRegex "^(\\+|-[^-])")
+        oFlagRegex           = mkRegex $ "^[-+][" <> options <> "]*o$"
+        validFlagsRegex      = mkRegex $ "^[-+]([" <> options <> "]+o?|o)$"
+        beginsWithDoubleDash = (`matches` mkRegex "^--.+$")
+        longOptions          = Set.fromList
+            [ "allexport", "errexit", "ignoreeof", "monitor", "noclobber"
+            , "noexec", "noglob", "nolog", "notify" , "nounset", "verbose"
+            , "vi", "xtrace" ]
+
+    bashism t@(T_SimpleCommand id _ (cmd:rest)) =
+        let name = fromMaybe "" $ getCommandName t
+            flags = getLeadingFlags t
+        in do
+            when (name == "local" && not isDash) $
+                -- This is so commonly accepted that we'll make it a special case
+                warnMsg id 3043 $ "'local' is"
+            when (name `elem` unsupportedCommands) $
+                warnMsg id 3044 $ "'" ++ name ++ "' is"
+            sequence_ $ do
+                allowed' <- Map.lookup name allowedFlags
+                allowed <- allowed'
+                (word, flag) <- find
+                    (\x -> (not . null . snd $ x) && snd x `notElem` allowed) flags
+                return . warnMsg (getId word) 3045 $ name ++ " -" ++ flag ++ " is"
+
+            when (name == "source" && not isBusyboxSh) $
+                warnMsg id 3046 "'source' in place of '.' is"
+            when (name == "trap") $
+                let
+                    check token = sequence_ $ do
+                        str <- getLiteralString token
+                        let upper = map toUpper str
+                        return $ do
+                            when (upper `elem` ["ERR", "DEBUG", "RETURN"]) $
+                                warnMsg (getId token) 3047 $ "trapping " ++ str ++ " is"
+                            when (not isBusyboxSh && "SIG" `isPrefixOf` upper) $
+                                warnMsg (getId token) 3048
+                                    "prefixing signal names with 'SIG' is"
+                            when (not isDash && upper /= str) $
+                                warnMsg (getId token) 3049
+                                    "using lower/mixed case for signal names is"
+                in
+                    mapM_ check (drop 1 rest)
+
+            when (name == "printf") $ sequence_ $ do
+                format <- rest !!! 0  -- flags are covered by allowedFlags
+                let literal = onlyLiteralString format
+                guard $ "%q" `isInfixOf` literal
+                return $ warnMsg (getId format) 3050 "printf %q is"
+
+            when (name == "read" && all isFlag rest) $
+                warnMsg (getId cmd) 3061 "read without a variable is"
+      where
+        unsupportedCommands = [
+            "let", "caller", "builtin", "complete", "compgen", "declare", "dirs", "disown",
+            "enable", "mapfile", "readarray", "pushd", "popd", "shopt", "suspend",
+            "typeset"
+            ]
+        allowedFlags = Map.fromList [
+            ("cd", Just ["L", "P"]),
+            ("exec", Just []),
+            ("export", Just ["p"]),
+            ("hash", Just $ if isDash then ["r", "v"] else ["r"]),
+            ("jobs", Just ["l", "p"]),
+            ("printf", Just []),
+            ("read", Just $ if isDash || isBusyboxSh then ["r", "p"] else ["r"]),
+            ("readonly", Just ["p"]),
+            ("trap", Just []),
+            ("type", Just $ if isBusyboxSh then ["p"] else []),
+            ("ulimit", if isDash then Nothing else Just ["f"]),
+            ("umask", Just ["S"]),
+            ("unset", Just ["f", "v"]),
+            ("wait", Just [])
+            ]
+    bashism t@(T_SourceCommand id src _)
+      | getCommandName src == Just "source" =
+          unless isBusyboxSh $
+            warnMsg id 3051 "'source' in place of '.' is"
+    bashism (TA_Expansion _ (T_Literal id str : _))
+        | str `matches` radix = warnMsg id 3052 "arithmetic base conversion is"
+      where
+        radix = mkRegex "^[0-9]+#"
+    bashism _ = return ()
+
+    varChars="_0-9a-zA-Z"
+    advancedExpansions = let re = mkRegex in [
+        (re $ "^![" ++ varChars ++ "]", 3053, "indirect expansion is"),
+        (re $ "^[" ++ varChars ++ "]+\\[.*\\]$", 3054, "array references are"),
+        (re $ "^![" ++ varChars ++ "]+\\[[*@]]$", 3055, "array key expansion is"),
+        (re $ "^![" ++ varChars ++ "]+[*@]$", 3056, "name matching prefixes are"),
+        (re $ "^[" ++ varChars ++ "*@]+(\\[.*\\])?[,^]", 3059, "case modification is")
+        ]
+    simpleExpansions = let re = mkRegex in [
+        (re $ "^[" ++ varChars ++ "*@]+:[^-=?+]", 3057, "string indexing is"),
+        (re $ "^([*@][%#]|#[@*])", 3058, "string operations on $@/$* are"),
+        (re $ "^[" ++ varChars ++ "*@]+(\\[.*\\])?/", 3060, "string replacement is")
+        ]
+    bashVars = [
+        -- This list deliberately excludes $BASH_VERSION as it's often used
+        -- for shell identification.
+        "OSTYPE", "MACHTYPE", "HOSTTYPE", "HOSTNAME",
+        "DIRSTACK", "EUID", "UID", "SHLVL", "PIPESTATUS", "SHELLOPTS",
+        "_", "BASHOPTS", "BASHPID", "BASH_ALIASES", "BASH_ARGC",
+        "BASH_ARGV", "BASH_ARGV0", "BASH_CMDS", "BASH_COMMAND",
+        "BASH_EXECUTION_STRING", "BASH_LINENO", "BASH_REMATCH", "BASH_SOURCE",
+        "BASH_SUBSHELL", "BASH_VERSINFO", "EPOCHREALTIME", "EPOCHSECONDS",
+        "FUNCNAME", "GROUPS", "MACHTYPE", "MAPFILE"
+        ]
+    bashDynamicVars = [ "RANDOM", "SECONDS" ]
+    dashVars = [ "_" ]
+    isBashVariable var =
+        (var `elem` bashDynamicVars
+            || var `elem` bashVars && not (isAssigned var))
+        && not (isDash && var `elem` dashVars)
+    isAssigned var = any f (variableFlow params)
+      where
+        f x = case x of
+                Assignment (_, _, name, _) -> name == var
+                _ -> False
+
+    checkTestOp table op id = sequence_ $ do
+        (code, shells, msg) <- Map.lookup op table
+        guard . not $ shellType params `elem` shells
+        return $ warnMsg id code (msg op)
+
+
+buildTestFlagMap list = Map.fromList $ concatMap (\(x,y) -> map (\c -> (c,y)) x) list
+bashismBinaryTestFlags = buildTestFlagMap [
+    -- ([list of applicable flags],
+    --     (error code, exempt shells, message builder :: String -> String)),
+    --
+    -- Distinct error codes allow the wiki to give more helpful, targeted
+    -- information.
+    (["<", ">", "\\<", "\\>", "<=", ">=", "\\<=", "\\>="],
+        (3012, [Dash, BusyboxSh], \op -> "lexicographical " ++ op ++ " is")),
+    (["=="],
+        (3014, [BusyboxSh], \op -> op ++ " in place of = is")),
+    (["=~"],
+        (3015, [], \op -> op ++ " regex matching is")),
+
+    ([], (0,[],const ""))
+  ]
+bashismUnaryTestFlags = buildTestFlagMap [
+    (["-v"],
+        (3016, [], \op -> "test " ++ op ++ " (in place of [ -n \"${var+x}\" ]) is")),
+    (["-a"],
+        (3017, [], \op -> "unary " ++ op ++ " in place of -e is")),
+    (["-o"],
+        (3062, [], \op -> "test " ++ op ++ " to check options is")),
+    (["-R"],
+        (3063, [], \op -> "test " ++ op ++ " and namerefs in general are")),
+    (["-N"],
+        (3064, [], \op -> "test " ++ op ++ " is")),
+    (["-k"],
+        (3065, [Dash, BusyboxSh], \op -> "test " ++ op ++ " is")),
+    (["-G"],
+        (3066, [Dash, BusyboxSh], \op -> "test " ++ op ++ " is")),
+    (["-O"],
+        (3067, [Dash, BusyboxSh], \op -> "test " ++ op ++ " is")),
+
+    ([], (0,[],const ""))
+  ]
+
+
+prop_checkEchoSed1 = verify checkEchoSed "FOO=$(echo \"$cow\" | sed 's/foo/bar/g')"
+prop_checkEchoSed1b = verify checkEchoSed "FOO=$(sed 's/foo/bar/g' <<< \"$cow\")"
+prop_checkEchoSed2 = verify checkEchoSed "rm $(echo $cow | sed -e 's,foo,bar,')"
+prop_checkEchoSed2b = verify checkEchoSed "rm $(sed -e 's,foo,bar,' <<< $cow)"
+checkEchoSed = ForShell [Bash, Ksh] f
+  where
+    f (T_Redirecting id lefts r) =
+        when (any redirectHereString lefts) $
+            checkSed id rcmd
+      where
+        redirectHereString :: Token -> Bool
+        redirectHereString t = case t of
+            (T_FdRedirect _ _ T_HereString{}) -> True
+            _                                 -> False
+        rcmd = oversimplify r
+
+    f (T_Pipeline id _ [a, b]) =
+        when (acmd == ["echo", "${VAR}"]) $
+            checkSed id bcmd
+      where
+        acmd = oversimplify a
+        bcmd = oversimplify b
+
+    f _ = return ()
+
+    checkSed id ["sed", v]       = checkIn id v
+    checkSed id ["sed", "-e", v] = checkIn id v
+    checkSed _ _                 = return ()
+
+    -- This should have used backreferences, but TDFA doesn't support them
+    sedRe = mkRegex "^s(.)([^\n]*)g?$"
+    isSimpleSed s = isJust $ do
+        [h:_,rest] <- matchRegex sedRe s
+        let delimiters = filter (== h) rest
+        guard $ length delimiters == 2
+    checkIn id s =
+        when (isSimpleSed s) $
+            style id 2001 "See if you can use ${variable//search/replace} instead."
+
+
+prop_checkBraceExpansionVars1 = verify checkBraceExpansionVars "echo {1..$n}"
+prop_checkBraceExpansionVars2 = verifyNot checkBraceExpansionVars "echo {1,3,$n}"
+prop_checkBraceExpansionVars3 = verify checkBraceExpansionVars "eval echo DSC{0001..$n}.jpg"
+prop_checkBraceExpansionVars4 = verify checkBraceExpansionVars "echo {$i..100}"
+checkBraceExpansionVars = ForShell [Bash] f
+  where
+    f t@(T_BraceExpansion id list) = mapM_ check list
+      where
+        check element =
+            when (any (`isInfixOf` toString element) ["$..", "..$"]) $ do
+                c <- isEvaled element
+                if c
+                    then style id 2175 "Quote this invalid brace expansion since it should be passed literally to eval."
+                    else warn id 2051 "Bash doesn't support variables in brace range expansions."
+    f _ = return ()
+
+    literalExt t =
+        case t of
+            T_DollarBraced {} -> return "$"
+            T_DollarExpansion {} -> return "$"
+            T_DollarArithmetic {} -> return "$"
+            _ -> return "-"
+    toString t = runIdentity $ getLiteralStringExt literalExt t
+    isEvaled t = do
+        cmd <- getClosestCommandM t
+        return $ maybe False (`isUnqualifiedCommand` "eval") cmd
+
+
+prop_checkMultiDimensionalArrays1 = verify checkMultiDimensionalArrays "foo[a][b]=3"
+prop_checkMultiDimensionalArrays2 = verifyNot checkMultiDimensionalArrays "foo[a]=3"
+prop_checkMultiDimensionalArrays3 = verify checkMultiDimensionalArrays "foo=( [a][b]=c )"
+prop_checkMultiDimensionalArrays4 = verifyNot checkMultiDimensionalArrays "foo=( [a]=c )"
+prop_checkMultiDimensionalArrays5 = verify checkMultiDimensionalArrays "echo ${foo[bar][baz]}"
+prop_checkMultiDimensionalArrays6 = verifyNot checkMultiDimensionalArrays "echo ${foo[bar]}"
+checkMultiDimensionalArrays = ForShell [Bash] f
+  where
+    f token =
+        case token of
+            T_Assignment _ _ name (first:second:_) _ -> about second
+            T_IndexedElement _ (first:second:_) _ -> about second
+            T_DollarBraced _ _ l ->
+                when (isMultiDim l) $ about token
+            _ -> return ()
+    about t = warn (getId t) 2180 "Bash does not support multidimensional arrays. Use 1D or associative arrays."
+
+    re = mkRegex "^\\[.*\\]\\[.*\\]"  -- Fixme, this matches ${foo:- [][]} and such as well
+    isMultiDim l = getBracedModifier (concat $ oversimplify l) `matches` re
+
+prop_checkPS11 = verify checkPS1Assignments "PS1='\\033[1;35m\\$ '"
+prop_checkPS11a = verify checkPS1Assignments "export PS1='\\033[1;35m\\$ '"
+prop_checkPSf2 = verify checkPS1Assignments "PS1='\\h \\e[0m\\$ '"
+prop_checkPS13 = verify checkPS1Assignments "PS1=$'\\x1b[c '"
+prop_checkPS14 = verify checkPS1Assignments "PS1=$'\\e[3m; '"
+prop_checkPS14a = verify checkPS1Assignments "export PS1=$'\\e[3m; '"
+prop_checkPS15 = verifyNot checkPS1Assignments "PS1='\\[\\033[1;35m\\]\\$ '"
+prop_checkPS16 = verifyNot checkPS1Assignments "PS1='\\[\\e1m\\e[1m\\]\\$ '"
+prop_checkPS17 = verifyNot checkPS1Assignments "PS1='e033x1B'"
+prop_checkPS18 = verifyNot checkPS1Assignments "PS1='\\[\\e\\]'"
+checkPS1Assignments = ForShell [Bash] f
+  where
+    f token = case token of
+        (T_Assignment _ _ "PS1" _ word) -> warnFor word
+        _ -> return ()
+
+    warnFor word =
+        let contents = concat $ oversimplify word in
+            when (containsUnescaped contents) $
+                info (getId word) 2025 "Make sure all escape sequences are enclosed in \\[..\\] to prevent line wrapping issues"
+    containsUnescaped s =
+        let unenclosed = subRegex enclosedRegex s "" in
+           isJust $ matchRegex escapeRegex unenclosed
+    enclosedRegex = mkRegex "\\\\\\[.*\\\\\\]" -- FIXME: shouldn't be eager
+    escapeRegex = mkRegex "\\\\x1[Bb]|\\\\e|\x1B|\\\\033"
+
+
+prop_checkMultipleBangs1 = verify checkMultipleBangs "! ! true"
+prop_checkMultipleBangs2 = verifyNot checkMultipleBangs "! true"
+checkMultipleBangs = ForShell [Dash, BusyboxSh, Sh] f
+  where
+    f token = case token of
+        T_Banged id (T_Banged _ _) ->
+            err id 2325 "Multiple ! in front of pipelines are a bash/ksh extension. Use only 0 or 1."
+        _ -> return ()
+
+
+prop_checkBangAfterPipe1 = verify checkBangAfterPipe "true | ! true"
+prop_checkBangAfterPipe2 = verifyNot checkBangAfterPipe "true | ( ! true )"
+prop_checkBangAfterPipe3 = verifyNot checkBangAfterPipe "! ! true | true"
+checkBangAfterPipe = ForShell [Dash, BusyboxSh, Sh, Bash] f
+  where
+    f token = case token of
+        T_Pipeline _ _ cmds -> mapM_ check cmds
+        _ -> return ()
+
+    check token = case token of
+        T_Banged id _ ->
+            err id 2326 "! is not allowed in the middle of pipelines. Use command group as in cmd | { ! cmd; } if necessary."
+        _ -> return ()
+
+
+prop_checkNegatedUnaryOps1 = verify checkNegatedUnaryOps "[ ! -o braceexpand ]"
+prop_checkNegatedUnaryOps2 = verifyNot checkNegatedUnaryOps "[ -o braceexpand ]"
+prop_checkNegatedUnaryOps3 = verifyNot checkNegatedUnaryOps "[[ ! -o braceexpand ]]"
+prop_checkNegatedUnaryOps4 = verifyNot checkNegatedUnaryOps "! [ -o braceexpand ]"
+prop_checkNegatedUnaryOps5 = verify checkNegatedUnaryOps "[ ! -a file ]"
+checkNegatedUnaryOps = ForShell [Bash] f
+  where
+    f token = case token of
+        TC_Unary id SingleBracket "!" (TC_Unary _ _ op _) | op `elem` ["-a", "-o"] ->
+            err id 2332 $ msg op
+        _ -> return ()
+
+    msg "-o" = "[ ! -o opt ] is always true because -o becomes logical OR. Use [[ ]] or ! [ -o opt ]."
+    msg "-a" = "[ ! -a file ] is always true because -a becomes logical AND. Use -e instead."
+    msg _ = pleaseReport "unhandled negated unary message"
+
+return []
+runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Data.hs

@@ -2,9 +2,27 @@ module ShellCheck.Data where
 
 import ShellCheck.Interface
 import Data.Version (showVersion)
-import Paths_ShellCheck (version)
 
-shellcheckVersion = showVersion version
+
+{-
+If you are here because you saw an error about Paths_ShellCheck in this file,
+simply comment out the import below and define the version as a constant string.
+
+Instead of:
+
+    import Paths_ShellCheck (version)
+    shellcheckVersion = showVersion version
+
+Use:
+
+    -- import Paths_ShellCheck (version)
+    shellcheckVersion = "kludge"
+
+-}
+
+import Paths_ShellCheck (version)
+shellcheckVersion = showVersion version  -- VERSIONSTRING
+
 
 internalVariables = [
     -- Generic
@@ -12,23 +30,27 @@ internalVariables = [
 
     -- Bash
     "BASH", "BASHOPTS", "BASHPID", "BASH_ALIASES", "BASH_ARGC",
-    "BASH_ARGV", "BASH_CMDS", "BASH_COMMAND", "BASH_EXECUTION_STRING",
+    "BASH_ARGV", "BASH_ARGV0", "BASH_CMDS", "BASH_COMMAND",
-    "BASH_LINENO", "BASH_REMATCH", "BASH_SOURCE", "BASH_SUBSHELL",
+    "BASH_EXECUTION_STRING", "BASH_LINENO", "BASH_LOADABLES_PATH",
-    "BASH_VERSINFO", "BASH_VERSION", "COMP_CWORD", "COMP_KEY",
+    "BASH_REMATCH", "BASH_SOURCE", "BASH_SUBSHELL", "BASH_VERSINFO",
-    "COMP_LINE", "COMP_POINT", "COMP_TYPE", "COMP_WORDBREAKS",
+    "BASH_VERSION", "COMP_CWORD", "COMP_KEY", "COMP_LINE", "COMP_POINT",
-    "COMP_WORDS", "COPROC", "DIRSTACK", "EUID", "FUNCNAME", "GROUPS",
+    "COMP_TYPE", "COMP_WORDBREAKS", "COMP_WORDS", "COPROC", "DIRSTACK",
-    "HISTCMD", "HOSTNAME", "HOSTTYPE", "LINENO", "MACHTYPE", "MAPFILE",
+    "EPOCHREALTIME", "EPOCHSECONDS", "EUID", "FUNCNAME", "GROUPS", "HISTCMD",
-    "OLDPWD", "OPTARG", "OPTIND", "OSTYPE", "PIPESTATUS", "PPID", "PWD",
+    "HOSTNAME", "HOSTTYPE", "LINENO", "MACHTYPE", "MAPFILE", "OLDPWD",
-    "RANDOM", "READLINE_LINE", "READLINE_POINT", "REPLY", "SECONDS",
+    "OPTARG", "OPTIND", "OSTYPE", "PIPESTATUS", "PPID", "PWD", "RANDOM",
-    "SHELLOPTS", "SHLVL", "UID", "BASH_ENV", "BASH_XTRACEFD", "CDPATH",
+    "READLINE_ARGUMENT", "READLINE_LINE", "READLINE_MARK", "READLINE_POINT",
-    "COLUMNS", "COMPREPLY", "EMACS", "ENV", "FCEDIT", "FIGNORE",
+    "REPLY", "SECONDS", "SHELLOPTS", "SHLVL", "SRANDOM", "UID", "BASH_COMPAT",
+    "BASH_ENV", "BASH_XTRACEFD", "CDPATH", "CHILD_MAX", "COLUMNS",
+    "COMPREPLY", "EMACS", "ENV", "EXECIGNORE", "FCEDIT", "FIGNORE",
     "FUNCNEST", "GLOBIGNORE", "HISTCONTROL", "HISTFILE", "HISTFILESIZE",
     "HISTIGNORE", "HISTSIZE", "HISTTIMEFORMAT", "HOME", "HOSTFILE", "IFS",
-    "IGNOREEOF", "INPUTRC", "LANG", "LC_ALL", "LC_COLLATE", "LC_CTYPE",
+    "IGNOREEOF", "INPUTRC", "INSIDE_EMACS", "LANG", "LC_ALL", "LC_COLLATE",
-    "LC_MESSAGES", "LC_MONETARY", "LC_NUMERIC", "LC_TIME", "LINES", "MAIL",
+    "LC_CTYPE", "LC_MESSAGES", "LC_MONETARY", "LC_NUMERIC", "LC_TIME",
-    "MAILCHECK", "MAILPATH", "OPTERR", "PATH", "POSIXLY_CORRECT",
+    "LINES", "MAIL", "MAILCHECK", "MAILPATH", "OPTERR", "PATH",
-    "PROMPT_COMMAND", "PROMPT_DIRTRIM", "PS1", "PS2", "PS3", "PS4", "SHELL",
+    "POSIXLY_CORRECT", "PROMPT_COMMAND", "PROMPT_DIRTRIM", "PS0", "PS1",
-    "TIMEFORMAT", "TMOUT", "TMPDIR", "auto_resume", "histchars", "COPROC",
+    "PS2", "PS3", "PS4", "SHELL", "TIMEFORMAT", "TMOUT", "TMPDIR",
+    "BASH_MONOSECONDS", "BASH_TRAPSIG", "GLOBSORT",
+    "auto_resume", "histchars",
 
     -- Other
     "USER", "TZ", "TERM", "LOGNAME", "LD_LIBRARY_PATH", "LANGUAGE", "DISPLAY",
@@ -36,13 +58,37 @@ internalVariables = [
 
     -- Ksh
     , ".sh.version"
+
+    -- shflags
+    , "FLAGS_ARGC", "FLAGS_ARGV", "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_HELP",
+    "FLAGS_PARENT", "FLAGS_RESERVED", "FLAGS_TRUE", "FLAGS_VERSION",
+    "flags_error", "flags_return"
+
+    -- Bats
+    ,"stderr", "stderr_lines"
   ]
 
-variablesWithoutSpaces = [
+specialIntegerVariables = [
-    "$", "-", "?", "!",
+    "$", "?", "!", "#"
-    "BASHPID", "BASH_ARGC", "BASH_LINENO", "BASH_SUBSHELL", "EUID", "LINENO",
+  ]
-    "OPTIND", "PPID", "RANDOM", "SECONDS", "SHELLOPTS", "SHLVL", "UID",
+
-    "COLUMNS", "HISTFILESIZE", "HISTSIZE", "LINES"
+specialVariablesWithoutSpaces = "-" : specialIntegerVariables
+
+variablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
+    "BASHPID", "BASH_ARGC", "BASH_LINENO", "BASH_SUBSHELL", "EUID",
+    "EPOCHREALTIME", "EPOCHSECONDS", "LINENO", "OPTIND", "PPID", "RANDOM",
+    "READLINE_ARGUMENT", "READLINE_MARK", "READLINE_POINT", "SECONDS",
+    "SHELLOPTS", "SHLVL", "SRANDOM", "UID", "COLUMNS", "HISTFILESIZE",
+    "HISTSIZE", "LINES", "BASH_MONOSECONDS", "BASH_TRAPSIG"
+
+    -- shflags
+    , "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_TRUE"
+  ]
+
+specialVariables = specialVariablesWithoutSpaces ++ ["@", "*"]
+
+unbracedVariables = specialVariables ++ [
+    "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
   ]
 
 arrayVariables = [
@@ -79,10 +125,10 @@ commonCommands = [
 
 nonReadingCommands = [
     "alias", "basename", "bg", "cal", "cd", "chgrp", "chmod", "chown",
-    "cp", "du", "echo", "export", "fg", "fuser", "getconf", "getopt",
+    "cp", "du", "echo", "export", "fg", "fuser", "getconf",
-    "getopts", "ipcrm", "ipcs", "jobs", "kill", "ln", "ls", "locale", "mv",
+    "getopt", "getopts", "ipcrm", "ipcs", "jobs", "kill", "ln", "ls",
-    "nice", "printf", "ps", "pwd", "renice", "rm", "rmdir", "set", "sleep",
+    "locale", "mv", "printf", "ps", "pwd", "renice", "rm", "rmdir",
-    "touch", "trap", "ulimit", "unalias", "uname"
+    "set", "sleep", "touch", "trap", "ulimit", "unalias", "uname"
     ]
 
 sampleWords = [
@@ -98,6 +144,10 @@ binaryTestOps = [
     "-gt", "-ge", "=~", ">", "<", "=", "\\<", "\\>", "\\<=", "\\>="
   ]
 
+arithmeticBinaryTestOps = [
+    "-eq", "-ne", "-lt", "-le", "-gt", "-ge"
+  ]
+
 unaryTestOps = [
     "!", "-a", "-b", "-c", "-d", "-e", "-f", "-g", "-h", "-L", "-k", "-p",
     "-r", "-s", "-S", "-t", "-u", "-w", "-x", "-O", "-G", "-N", "-z", "-n",
@@ -109,9 +159,19 @@ shellForExecutable name =
     case name of
         "sh"    -> return Sh
         "bash"  -> return Bash
+        "bats"  -> return Bash
+        "busybox"  -> return BusyboxSh -- Used for directives and --shell=busybox
+        "busybox sh"  -> return BusyboxSh
+        "busybox ash"  -> return BusyboxSh
         "dash"  -> return Dash
         "ash"   -> return Dash -- There's also a warning for this.
         "ksh"   -> return Ksh
         "ksh88" -> return Ksh
         "ksh93" -> return Ksh
-        otherwise -> Nothing
+        "oksh"  -> return Ksh
+        _ -> Nothing
+
+flagsForRead = "sreu:n:N:i:p:a:t:"
+flagsForMapfile = "d:n:O:s:u:C:c:t"
+
+declaringCommands = ["local", "declare", "export", "readonly", "typeset", "let"]

src/ShellCheck/Debug.hs

@@ -0,0 +1,313 @@
+{-
+
+This file contains useful functions for debugging and developing ShellCheck.
+
+To invoke them interactively, run:
+
+    cabal repl
+
+At the ghci prompt, enter:
+
+    :load ShellCheck.Debug
+
+You can now invoke the functions. Here are some examples:
+
+    shellcheckString "echo $1"
+    stringToAst "(( x+1 ))"
+    stringToCfg "if foo; then bar; else baz; fi"
+    writeFile "/tmp/test.dot" $ stringToCfgViz "while foo; do bar; done"
+
+The latter file can be rendered to png with GraphViz:
+
+    dot -Tpng /tmp/test.dot > /tmp/test.png
+
+To run all unit tests in a module:
+
+    ShellCheck.Parser.runTests
+    ShellCheck.Analytics.runTests
+
+To run a specific test:
+
+    :load ShellCheck.Analytics
+    prop_checkUuoc3
+
+If you make code changes, reload in seconds at any time with:
+
+    :r
+
+===========================================================================
+
+Crash course in printf debugging in Haskell:
+
+    import Debug.Trace
+
+    greet 0 = return ()
+    -- Print when a function is invoked
+    greet n | trace ("calling greet " ++ show n) False = undefined
+    greet n = do
+        putStrLn "Enter name"
+        name <- getLine
+        -- Print at some point in any monadic function
+        traceM $ "user entered " ++ name
+        putStrLn $ "Hello " ++ name
+        -- Print a value before passing it on
+        greet $ traceShowId (n - 1)
+
+
+===========================================================================
+
+If you want to invoke `ghci` directly, such as on `shellcheck.hs`, to
+debug all of ShellCheck including I/O, you may see an error like this:
+
+    src/ShellCheck/Data.hs:5:1: error:
+        Could not load module ‘Paths_ShellCheck’
+    it is a hidden module in the package ‘ShellCheck-0.8.0’
+
+This can easily be circumvented by running `./setgitversion` or manually
+editing src/ShellCheck/Data.hs to replace the auto-deduced version number
+with a constant string as indicated.
+
+Afterwards, you can run the ShellCheck tool, as if from the shell, with:
+
+    $ ghci shellcheck.hs
+    ghci> runMain ["-x", "file.sh"]
+
+-}
+
+module ShellCheck.Debug () where
+
+import ShellCheck.Analyzer
+import ShellCheck.AST
+import ShellCheck.CFG
+import ShellCheck.Checker
+import ShellCheck.CFGAnalysis as CF
+import ShellCheck.Interface
+import ShellCheck.Parser
+import ShellCheck.Prelude
+
+import Control.Monad
+import Control.Monad.Identity
+import Control.Monad.RWS
+import Control.Monad.Writer
+import Data.Graph.Inductive.Graph as G
+import Data.List
+import Data.Maybe
+import qualified Data.Map as M
+import qualified Data.Set as S
+
+
+-- Run all of ShellCheck (minus output formatters)
+shellcheckString :: String -> CheckResult
+shellcheckString scriptString =
+    runIdentity $ checkScript dummySystemInterface checkSpec
+  where
+    checkSpec :: CheckSpec
+    checkSpec = emptyCheckSpec {
+        csScript = scriptString
+    }
+
+dummySystemInterface :: SystemInterface Identity
+dummySystemInterface = mockedSystemInterface [
+    -- A tiny, fake filesystem for sourced files
+    ("lib/mylib1.sh", "foo=$(cat $1 | wc -l)"),
+    ("lib/mylib2.sh", "bar=42")
+    ]
+
+-- Parameters used when generating Control Flow Graphs
+cfgParams :: CFGParameters
+cfgParams = CFGParameters {
+    cfLastpipe = False,
+    cfPipefail = False
+}
+
+-- An example script to play with
+exampleScript :: String
+exampleScript = unlines [
+    "#!/bin/sh",
+    "count=0",
+    "for file in *",
+    "do",
+    "  (( count++ ))",
+    "done",
+    "echo $count"
+    ]
+
+-- Parse the script string into ShellCheck's ParseResult
+parseScriptString :: String -> ParseResult
+parseScriptString scriptString =
+    runIdentity $ parseScript dummySystemInterface parseSpec
+  where
+    parseSpec :: ParseSpec
+    parseSpec = newParseSpec {
+        psFilename = "myscript",
+        psScript = scriptString
+    }
+
+
+-- Parse the script string into an Abstract Syntax Tree
+stringToAst :: String -> Token
+stringToAst scriptString =
+    case maybeRoot of
+        Just root -> root
+        Nothing -> error $ "Script failed to parse: " ++ show parserWarnings
+  where
+    parseResult :: ParseResult
+    parseResult = parseScriptString scriptString
+
+    maybeRoot :: Maybe Token
+    maybeRoot = prRoot parseResult
+
+    parserWarnings :: [PositionedComment]
+    parserWarnings = prComments parseResult
+
+
+astToCfgResult :: Token -> CFGResult
+astToCfgResult = buildGraph cfgParams
+
+astToDfa :: Token -> CFGAnalysis
+astToDfa = analyzeControlFlow cfgParams
+
+astToCfg :: Token -> CFGraph
+astToCfg = cfGraph . astToCfgResult
+
+stringToCfg :: String -> CFGraph
+stringToCfg = astToCfg . stringToAst
+
+stringToDfa :: String -> CFGAnalysis
+stringToDfa = astToDfa . stringToAst
+
+cfgToGraphViz :: CFGraph -> String
+cfgToGraphViz = cfgToGraphVizWith show
+
+stringToCfgViz :: String -> String
+stringToCfgViz = cfgToGraphViz . stringToCfg
+
+stringToDfaViz :: String -> String
+stringToDfaViz = dfaToGraphViz . stringToDfa
+
+-- Dump a Control Flow Graph as GraphViz with extended information
+stringToDetailedCfgViz :: String -> String
+stringToDetailedCfgViz scriptString = cfgToGraphVizWith nodeLabel graph
+  where
+    ast :: Token
+    ast = stringToAst scriptString
+
+    cfgResult :: CFGResult
+    cfgResult = astToCfgResult ast
+
+    graph :: CFGraph
+    graph = cfGraph cfgResult
+
+    idToToken :: M.Map Id Token
+    idToToken = M.fromList $ execWriter $ doAnalysis (\c -> tell [(getId c, c)]) ast
+
+    idToNode :: M.Map Id (Node, Node)
+    idToNode = cfIdToRange cfgResult
+
+    nodeToStartIds :: M.Map Node (S.Set Id)
+    nodeToStartIds =
+        M.fromListWith S.union $
+            map (\(id, (start, _)) -> (start, S.singleton id)) $
+                M.toList idToNode
+
+    nodeToEndIds :: M.Map Node (S.Set Id)
+    nodeToEndIds =
+        M.fromListWith S.union $
+            map (\(id, (_, end)) -> (end, S.singleton id)) $
+                M.toList idToNode
+
+    formatId :: Id -> String
+    formatId id = fromMaybe ("Unknown " ++ show id) $ do
+        (OuterToken _ token) <- M.lookup id idToToken
+        firstWord <- words (show token) !!! 0
+        -- Strip off "Inner_"
+        (_ : tokenName) <- return $ dropWhile (/= '_') firstWord
+        return $ tokenName ++ " " ++ show id
+
+    formatGroup :: S.Set Id -> String
+    formatGroup set = intercalate ", " $ map formatId $ S.toList set
+
+    nodeLabel (node, label) = unlines [
+        show node ++ ". " ++ show label,
+        "Begin: " ++ formatGroup (M.findWithDefault S.empty node nodeToStartIds),
+        "End: " ++ formatGroup (M.findWithDefault S.empty node nodeToEndIds)
+        ]
+
+
+-- Dump a Control Flow Graph with Data Flow Analysis as GraphViz
+dfaToGraphViz :: CF.CFGAnalysis -> String
+dfaToGraphViz analysis = cfgToGraphVizWith label $ CF.graph analysis
+  where
+    label (node, label) =
+        let
+            desc = show node ++ ". " ++ show label
+        in
+            fromMaybe ("No DFA available\n\n" ++ desc) $ do
+                (pre, post) <- M.lookup node $ CF.nodeToData analysis
+                return $ unlines [
+                    "Precondition: " ++ show pre,
+                    "",
+                    desc,
+                    "",
+                    "Postcondition: " ++ show post
+                    ]
+
+
+-- Dump an Control Flow Graph to GraphViz with a given node formatter
+cfgToGraphVizWith :: (LNode CFNode -> String) -> CFGraph -> String
+cfgToGraphVizWith nodeLabel graph = concat [
+    "digraph {\n",
+    concatMap dumpNode (labNodes graph),
+    concatMap dumpLink (labEdges graph),
+    tagVizEntries graph,
+    "}\n"
+    ]
+  where
+    dumpNode l@(node, label) = show node ++ " [label=" ++ quoteViz (nodeLabel l) ++ "]\n"
+    dumpLink (from, to, typ) = show from ++ " -> " ++ show to ++ " [style=" ++ quoteViz (edgeStyle typ)  ++ "]\n"
+    edgeStyle CFEFlow = "solid"
+    edgeStyle CFEExit = "bold"
+    edgeStyle CFEFalseFlow = "dotted"
+
+quoteViz str = "\"" ++ escapeViz str ++ "\""
+escapeViz [] = []
+escapeViz (c:rest) =
+    case c of
+        '\"' -> '\\' : '\"' : escapeViz rest
+        '\n' -> '\\' : 'l' : escapeViz rest
+        '\\' -> '\\' : '\\' : escapeViz rest
+        _ -> c : escapeViz rest
+
+
+-- Dump an Abstract Syntax Tree (or branch thereof) to GraphViz format
+astToGraphViz :: Token -> String
+astToGraphViz token = concat [
+    "digraph {\n",
+    formatTree token,
+    "}\n"
+    ]
+  where
+    formatTree :: Token -> String
+    formatTree t = snd $ execRWS (doStackAnalysis push pop t) () []
+
+    push :: Token -> RWS () String [Int] ()
+    push (OuterToken (Id n) inner) = do
+        stack <- get
+        put (n : stack)
+        case stack of
+            [] -> return ()
+            (top:_) -> tell $ show top ++ " -> " ++ show n ++ "\n"
+        tell $ show n ++ " [label=" ++ quoteViz (show n ++ ": " ++ take 32 (show inner)) ++ "]\n"
+
+    pop :: Token -> RWS () String [Int] ()
+    pop _ = modify tail
+
+
+-- For each entry point, set the rank so that they'll align in the graph
+tagVizEntries :: CFGraph -> String
+tagVizEntries graph = "{ rank=same " ++ rank ++ " }"
+  where
+    entries = mapMaybe find $ labNodes graph
+    find (node, CFEntryPoint name) = return (node, name)
+    find _ = Nothing
+    rank = unwords $ map (\(c, _) -> show c) entries

src/ShellCheck/Fixer.hs

@@ -0,0 +1,412 @@
+{-
+    Copyright 2018-2019 Vidar Holen, Ng Zhi An
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.Fixer (applyFix, removeTabStops, mapPositions, Ranged(..), runTests) where
+
+import ShellCheck.Interface
+import ShellCheck.Prelude
+import Control.Monad
+import Control.Monad.State
+import Data.Array
+import Data.List
+import Data.Semigroup
+import GHC.Exts (sortWith)
+import Test.QuickCheck
+
+-- The Ranged class is used for types that has a start and end position.
+class Ranged a where
+    start   :: a -> Position
+    end     :: a -> Position
+    overlap :: a -> a -> Bool
+    overlap x y =
+        xEnd > yStart && yEnd > xStart
+        where
+            yStart = start y
+            yEnd = end y
+            xStart = start x
+            xEnd = end x
+    -- Set a new start and end position on a Ranged
+    setRange :: (Position, Position) -> a -> a
+
+-- Tests auto-verify that overlap commutes
+assertOverlap x y = overlap x y && overlap y x
+assertNoOverlap x y = not (overlap x y) && not (overlap y x)
+
+prop_overlap_contiguous = assertNoOverlap
+        (tFromStart 10 12 "foo" 1)
+        (tFromStart 12 14 "bar" 2)
+
+prop_overlap_adjacent_zerowidth = assertNoOverlap
+        (tFromStart 3 3 "foo" 1)
+        (tFromStart 3 3 "bar" 2)
+
+prop_overlap_enclosed = assertOverlap
+        (tFromStart 3 5 "foo" 1)
+        (tFromStart 1 10 "bar" 2)
+
+prop_overlap_partial = assertOverlap
+        (tFromStart 1 5 "foo" 1)
+        (tFromStart 3 7 "bar" 2)
+
+
+instance Ranged PositionedComment where
+    start = pcStartPos
+    end = pcEndPos
+    setRange (s, e) pc = pc {
+        pcStartPos = s,
+        pcEndPos = e
+    }
+
+instance Ranged Replacement where
+    start = repStartPos
+    end   = repEndPos
+    setRange (s, e) r = r {
+        repStartPos = s,
+        repEndPos = e
+    }
+
+-- The Monoid instance for Fix merges fixes that do not conflict.
+-- TODO: Make an efficient 'mconcat'
+instance Monoid Fix where
+    mempty = newFix
+    mappend = (<>)
+    mconcat = foldl mappend mempty -- fold left to right since <> discards right on overlap
+
+instance Semigroup Fix where
+    f1 <> f2 =
+        -- FIXME: This might need to also discard adjacent zero-width ranges for
+        --        when two fixes change the same AST node, e.g. `foo` -> "$(foo)"
+        if or [ r2 `overlap` r1 | r1 <- fixReplacements f1, r2 <- fixReplacements f2 ]
+        then f1
+        else newFix {
+            fixReplacements = fixReplacements f1 ++ fixReplacements f2
+            }
+
+-- Conveniently apply a transformation to positions in a Fix
+mapPositions :: (Position -> Position) -> Fix -> Fix
+mapPositions f = adjustFix
+  where
+    adjustReplacement rep =
+        rep {
+            repStartPos = f $ repStartPos rep,
+            repEndPos = f $ repEndPos rep
+        }
+    adjustFix fix =
+        fix {
+            fixReplacements = map adjustReplacement $ fixReplacements fix
+        }
+
+-- Rewrite a Ranged from a tabstop of 8 to 1
+removeTabStops :: Ranged a => a -> Array Int String -> a
+removeTabStops range ls =
+    let startColumn = realignColumn lineNo colNo range
+        endColumn = realignColumn endLineNo endColNo range
+        startPosition = (start range) { posColumn = startColumn }
+        endPosition = (end range) { posColumn = endColumn } in
+    setRange (startPosition, endPosition) range
+  where
+    realignColumn lineNo colNo c =
+      if lineNo c > 0 && lineNo c <= fromIntegral (length ls)
+      then real (ls ! fromIntegral (lineNo c)) 0 0 (colNo c)
+      else colNo c
+    real _ r v target | target <= v = r
+    -- hit this case at the end of line, and if we don't hit the target
+    -- return real + (target - v)
+    real [] r v target = r + (target - v)
+    real ('\t':rest) r v target = real rest (r+1) (v + 8 - (v `mod` 8)) target
+    real (_:rest) r v target = real rest (r+1) (v+1) target
+    lineNo = posLine . start
+    endLineNo = posLine . end
+    colNo = posColumn . start
+    endColNo = posColumn . end
+
+
+-- A replacement that spans multiple line is applied by:
+-- 1. merging the affected lines into a single string using `unlines`
+-- 2. apply the replacement as if it only spanned a single line
+-- The tricky part is adjusting the end column of the replacement
+-- (the end line doesn't matter because there is only one line)
+--
+--   aaS  <--- start of replacement (row 1 column 3)
+--   bbbb
+--   cEc
+--    \------- end of replacement (row 3 column 2)
+--
+-- a flattened string will look like:
+--
+--   "aaS\nbbbb\ncEc\n"
+--
+-- The column of E has to be adjusted by:
+-- 1. lengths of lines to be replaced, except the end row itself
+-- 2. end column of the replacement
+-- 3. number of '\n' by `unlines`
+multiToSingleLine :: [Fix] -> Array Int String -> ([Fix], String)
+multiToSingleLine fixes lines =
+    (map (mapPositions adjust) fixes, unlines $ elems lines)
+  where
+    -- A prefix sum tree from line number to column shift.
+    -- FIXME: The tree will be totally unbalanced.
+    shiftTree :: PSTree Int
+    shiftTree =
+        foldl (\t (n,s) -> addPSValue (n+1) (length s + 1) t) newPSTree $
+            assocs lines
+    singleString = unlines $ elems lines
+    adjust pos =
+        pos {
+            posLine = 1,
+            posColumn = (posColumn pos) +
+                (fromIntegral $ getPrefixSum (fromIntegral $ posLine pos) shiftTree)
+        }
+
+-- Apply a fix and return resulting lines.
+-- The number of lines can increase or decrease with no obvious mapping back, so
+-- the function does not return an array.
+applyFix :: Fix -> Array Int String -> [String]
+applyFix fix fileLines =
+    let
+        untabbed = fix {
+            fixReplacements =
+                map (\c -> removeTabStops c fileLines) $
+                    fixReplacements fix
+            }
+        (adjustedFixes, singleLine) = multiToSingleLine [untabbed] fileLines
+    in
+        lines . runFixer $ applyFixes2 adjustedFixes singleLine
+
+
+-- start and end comes from pos, which is 1 based
+prop_doReplace1 = doReplace 0 0 "1234" "A" == "A1234" -- technically not valid
+prop_doReplace2 = doReplace 1 1 "1234" "A" == "A1234"
+prop_doReplace3 = doReplace 1 2 "1234" "A" == "A234"
+prop_doReplace4 = doReplace 3 3 "1234" "A" == "12A34"
+prop_doReplace5 = doReplace 4 4 "1234" "A" == "123A4"
+prop_doReplace6 = doReplace 5 5 "1234" "A" == "1234A"
+doReplace start end o r =
+    let si = fromIntegral (start-1)
+        ei = fromIntegral (end-1)
+        (x, xs) = splitAt si o
+        z = drop (ei - si) xs
+    in
+    x ++ r ++ z
+
+-- Fail if the 'expected' string is not result when applying 'fixes' to 'original'.
+testFixes :: String -> String -> [Fix] -> Bool
+testFixes expected original fixes =
+    actual == expected
+  where
+    actual = runFixer (applyFixes2 fixes original)
+
+
+-- A Fixer allows doing repeated modifications of a string where each
+-- replacement automatically accounts for shifts from previous ones.
+type Fixer a =  State (PSTree Int) a
+
+-- Apply a single replacement using its indices into the original string.
+-- It does not handle multiple lines, all line indices must be 1.
+applyReplacement2 :: Replacement -> String -> Fixer String
+applyReplacement2 rep string = do
+    tree <- get
+    let transform pos = pos + getPrefixSum pos tree
+    let originalPos = (repStartPos rep, repEndPos rep)
+        (oldStart, oldEnd) = tmap (fromInteger . posColumn) originalPos
+        (newStart, newEnd) = tmap transform (oldStart, oldEnd)
+
+    let (l1, l2) = tmap posLine originalPos in
+        when (l1 /= 1 || l2 /= 1) $
+            error $ pleaseReport "bad cross-line fix"
+
+    let replacer = repString rep
+    let shift = (length replacer) - (oldEnd - oldStart)
+    let insertionPoint =
+          case repInsertionPoint rep of
+              InsertBefore -> oldStart
+              InsertAfter  -> oldEnd+1
+    put $ addPSValue insertionPoint shift tree
+
+    return $ doReplace newStart newEnd string replacer
+  where
+    tmap f (a,b) = (f a, f b)
+
+-- Apply a list of Replacements in the correct order
+applyReplacements2 :: [Replacement] -> String -> Fixer String
+applyReplacements2 reps str =
+    foldM (flip applyReplacement2) str $
+        reverse $ sortWith repPrecedence reps
+
+-- Apply all fixes with replacements in the correct order
+applyFixes2 :: [Fix] -> String -> Fixer String
+applyFixes2 fixes = applyReplacements2 (concatMap fixReplacements fixes)
+
+-- Get the final value of a Fixer.
+runFixer :: Fixer a -> a
+runFixer f = evalState f newPSTree
+
+
+
+-- A Prefix Sum Tree that lets you look up the sum of values at and below an index.
+-- It's implemented essentially as a Fenwick tree without the bit-based balancing.
+-- The last Num is the sum of the left branch plus current element.
+data PSTree n = PSBranch n (PSTree n) (PSTree n) n | PSLeaf
+    deriving (Show)
+
+newPSTree :: Num n => PSTree n
+newPSTree = PSLeaf
+
+-- Get the sum of values whose keys are <= 'target'
+getPrefixSum :: (Ord n, Num n) => n -> PSTree n -> n
+getPrefixSum = f 0
+  where
+    f sum _ PSLeaf = sum
+    f sum target (PSBranch pivot left right cumulative) =
+        case target `compare` pivot of
+            LT -> f sum target left
+            GT -> f (sum+cumulative) target right
+            EQ -> sum+cumulative
+
+-- Add a value to the Prefix Sum tree at the given index.
+-- Values accumulate: addPSValue 42 2 . addPSValue 42 3 == addPSValue 42 5
+addPSValue :: (Ord n, Num n) => n -> n -> PSTree n -> PSTree n
+addPSValue key value tree = if value == 0 then tree else f tree
+  where
+    f PSLeaf = PSBranch key PSLeaf PSLeaf value
+    f (PSBranch pivot left right sum) =
+        case key `compare` pivot of
+            LT -> PSBranch pivot (f left) right (sum + value)
+            GT -> PSBranch pivot left (f right) sum
+            EQ -> PSBranch pivot left right (sum + value)
+
+prop_pstreeSumsCorrectly kvs targets =
+  let
+    -- Trivial O(n * m) implementation
+    dumbPrefixSums :: [(Int, Int)] -> [Int] -> [Int]
+    dumbPrefixSums kvs targets =
+        let prefixSum target = sum [v | (k,v) <- kvs, k <= target]
+        in map prefixSum targets
+    -- PSTree O(n * log m) implementation
+    smartPrefixSums :: [(Int, Int)] -> [Int] -> [Int]
+    smartPrefixSums kvs targets =
+        let tree = foldl (\tree (pos, shift) -> addPSValue pos shift tree) PSLeaf kvs
+        in map (\x -> getPrefixSum x tree) targets
+  in smartPrefixSums kvs targets == dumbPrefixSums kvs targets
+
+
+-- Semi-convenient functions for constructing tests.
+testFix :: [Replacement] -> Fix
+testFix list = newFix {
+        fixReplacements = list
+    }
+
+tFromStart :: Int -> Int -> String -> Int -> Replacement
+tFromStart start end repl order =
+    newReplacement {
+        repStartPos = newPosition {
+            posLine = 1,
+            posColumn = fromIntegral start
+        },
+        repEndPos = newPosition {
+            posLine = 1,
+            posColumn = fromIntegral end
+        },
+        repString = repl,
+        repPrecedence = order,
+        repInsertionPoint = InsertAfter
+    }
+
+tFromEnd start end repl order =
+    (tFromStart start end repl order) {
+        repInsertionPoint = InsertBefore
+    }
+
+prop_simpleFix1 = testFixes "hello world" "hell world" [
+    testFix [
+        tFromEnd 5 5 "o" 1
+    ]]
+
+prop_anchorsLeft = testFixes "-->foobar<--" "--><--" [
+    testFix [
+        tFromStart 4 4 "foo" 1,
+        tFromStart 4 4 "bar" 2
+    ]]
+
+prop_anchorsRight = testFixes "-->foobar<--" "--><--" [
+    testFix [
+        tFromEnd 4 4 "bar" 1,
+        tFromEnd 4 4 "foo" 2
+    ]]
+
+prop_anchorsBoth1 = testFixes "-->foobar<--" "--><--" [
+    testFix [
+        tFromStart 4 4 "bar" 2,
+        tFromEnd 4 4 "foo" 1
+    ]]
+
+prop_anchorsBoth2 = testFixes "-->foobar<--" "--><--" [
+    testFix [
+        tFromEnd 4 4 "foo" 2,
+        tFromStart 4 4 "bar" 1
+    ]]
+
+prop_composeFixes1 = testFixes "cd \"$1\" || exit" "cd $1" [
+    testFix [
+        tFromStart 4 4 "\"" 10,
+        tFromEnd   6 6 "\"" 10
+    ],
+    testFix [
+        tFromEnd 6 6 " || exit" 5
+    ]]
+
+prop_composeFixes2 = testFixes "$(\"$1\")" "`$1`" [
+    testFix [
+        tFromStart 1 2 "$(" 5,
+        tFromEnd   4 5 ")" 5
+    ],
+    testFix [
+        tFromStart 2 2 "\"" 10,
+        tFromEnd 4 4 "\"" 10
+    ]]
+
+prop_composeFixes3 = testFixes "(x)[x]" "xx" [
+    testFix [
+        tFromStart 1 1 "(" 4,
+        tFromEnd   2 2 ")" 3,
+        tFromStart 2 2 "[" 2,
+        tFromEnd   3 3 "]" 1
+    ]]
+
+prop_composeFixes4 = testFixes "(x)[x]" "xx" [
+    testFix [
+        tFromStart 1 1 "(" 4,
+        tFromStart 2 2 "[" 3,
+        tFromEnd   2 2 ")" 2,
+        tFromEnd   3 3 "]" 1
+    ]]
+
+prop_composeFixes5 = testFixes "\"$(x)\"" "`x`" [
+    testFix [
+        tFromStart 1 2 "$(" 2,
+        tFromEnd   3 4 ")"  2,
+        tFromStart 1 1 "\"" 1,
+        tFromEnd   4 4 "\"" 1
+    ]]
+
+
+return []
+runTests = $quickCheckAll

src/ShellCheck/Formatter/CheckStyle.hs

@@ -1,8 +1,8 @@
 {-
-    Copyright 2012-2015 Vidar Holen
+    Copyright 2012-2019 Vidar Holen
 
     This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
+    https://www.shellcheck.net
 
     ShellCheck is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -}
 module ShellCheck.Formatter.CheckStyle (format) where
 
@@ -24,8 +24,8 @@ import ShellCheck.Formatter.Format
 
 import Data.Char
 import Data.List
-import GHC.Exts
 import System.IO
+import qualified Data.List.NonEmpty as NE
 
 format :: IO Formatter
 format = return Formatter {
@@ -45,12 +45,12 @@ outputResults cr sys =
     else mapM_ outputGroup fileGroups
   where
     comments = crComments cr
-    fileGroups = groupWith sourceFile comments
+    fileGroups = NE.groupWith sourceFile comments
     outputGroup group = do
-        let filename = sourceFile (head group)
+        let filename = sourceFile (NE.head group)
-        result <- (siReadFile sys) filename
+        result <- siReadFile sys (Just True) filename
         let contents = either (const "") id result
-        outputFile filename contents group
+        outputFile filename contents (NE.toList group)
 
 outputFile filename contents warnings = do
     let comments = makeNonVirtual warnings contents
@@ -88,7 +88,7 @@ outputError file error = putStrLn $ concat [
 attr s v = concat [ s, "='", escape v, "' " ]
 escape = concatMap escape'
 escape' c = if isOk c then [c] else "&#" ++ show (ord c) ++ ";"
-isOk x = any ($x) [isAsciiUpper, isAsciiLower, isDigit, (`elem` " ./")]
+isOk x = any ($ x) [isAsciiUpper, isAsciiLower, isDigit, (`elem` " ./")]
 
 severity "error" = "error"
 severity "warning" = "warning"

src/ShellCheck/Formatter/Diff.hs

@@ -0,0 +1,254 @@
+{-
+    Copyright 2019 Vidar 'koala_man' Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.Formatter.Diff (format, ShellCheck.Formatter.Diff.runTests) where
+
+import ShellCheck.Interface
+import ShellCheck.Fixer
+import ShellCheck.Formatter.Format
+
+import Control.Monad
+import Data.Algorithm.Diff
+import Data.Array
+import Data.IORef
+import Data.List
+import qualified Data.Monoid as Monoid
+import Data.Maybe
+import qualified Data.Map as M
+import GHC.Exts (sortWith)
+import System.IO
+import System.FilePath
+
+import Test.QuickCheck
+
+format :: FormatterOptions -> IO Formatter
+format options = do
+    foundIssues <- newIORef False
+    reportedIssues <- newIORef False
+    shouldColor <- shouldOutputColor (foColorOption options)
+    let color = if shouldColor then colorize else nocolor
+    return Formatter {
+        header = return (),
+        footer = checkFooter foundIssues reportedIssues color,
+        onFailure = reportFailure color,
+        onResult  = reportResult foundIssues reportedIssues color
+    }
+
+
+contextSize = 3
+red = 31
+green = 32
+yellow = 33
+cyan = 36
+bold = 1
+
+nocolor n = id
+colorize n s = (ansi n) ++ s ++ (ansi 0)
+ansi n = "\x1B[" ++ show n ++ "m"
+
+printErr :: ColorFunc -> String -> IO ()
+printErr color = hPutStrLn stderr . color bold . color red
+reportFailure color file msg = printErr color $ file ++ ": " ++ msg
+
+checkFooter foundIssues reportedIssues color = do
+    found <- readIORef foundIssues
+    output <- readIORef reportedIssues
+    when (found && not output) $
+            printErr color "Issues were detected, but none were auto-fixable. Use another format to see them."
+
+type ColorFunc = (Int -> String -> String)
+data LFStatus = LinefeedMissing | LinefeedOk
+data DiffDoc a = DiffDoc String LFStatus [DiffRegion a]
+data DiffRegion a = DiffRegion (Int, Int) (Int, Int) [Diff a]
+
+reportResult :: (IORef Bool) -> (IORef Bool) -> ColorFunc -> CheckResult -> SystemInterface IO -> IO ()
+reportResult foundIssues reportedIssues color result sys = do
+    let comments = crComments result
+    unless (null comments) $ writeIORef foundIssues True
+    let suggestedFixes = mapMaybe pcFix comments
+    let fixmap = buildFixMap suggestedFixes
+    mapM_ output $ M.toList fixmap
+  where
+    output (name, fix) = do
+        file <- siReadFile sys (Just True) name
+        case file of
+            Right contents -> do
+                putStrLn $ formatDoc color $ makeDiff name contents fix
+                writeIORef reportedIssues True
+            Left msg -> reportFailure color name msg
+
+hasTrailingLinefeed str =
+    case str of
+        [] -> True
+        _ -> last str == '\n'
+
+coversLastLine regions =
+    case regions of
+        [] -> False
+        _ -> (fst $ last regions)
+
+-- TODO: Factor this out into a unified diff library because we're doing a lot
+-- of the heavy lifting anyways.
+makeDiff :: String -> String -> Fix -> DiffDoc String
+makeDiff name contents fix = do
+    let hunks = groupDiff $ computeDiff contents fix
+    let lf = if coversLastLine hunks && not (hasTrailingLinefeed contents)
+             then LinefeedMissing
+             else LinefeedOk
+    DiffDoc name lf $ findRegions hunks
+
+computeDiff :: String -> Fix -> [Diff String]
+computeDiff contents fix =
+    let old = lines contents
+        array = listArray (1, fromIntegral $ (length old)) old
+        new = applyFix fix array
+    in getDiff old new
+
+-- Group changes into hunks
+groupDiff :: [Diff a] -> [(Bool, [Diff a])]
+groupDiff = filter (\(_, l) -> not (null l)) . hunt []
+  where
+    -- Churn through 'Both's until we find a difference
+    hunt current [] = [(False, reverse current)]
+    hunt current (x@Both {}:rest) = hunt (x:current) rest
+    hunt current list =
+        let (context, previous) = splitAt contextSize current
+        in (False, reverse previous) : gather context 0 list
+
+    -- Pick out differences until we find a run of Both's
+    gather current n [] =
+        let (extras, patch) = splitAt (max 0 $ n - contextSize) current
+        in [(True, reverse patch), (False, reverse extras)]
+
+    gather current n list@(Both {}:_) | n == contextSize*2 =
+        let (context, previous) = splitAt contextSize current
+        in (True, reverse previous) : hunt context list
+
+    gather current n (x@Both {}:rest) = gather (x:current) (n+1) rest
+    gather current n (x:rest) = gather (x:current) 0 rest
+
+-- Get line numbers for hunks
+findRegions :: [(Bool, [Diff String])] -> [DiffRegion String]
+findRegions = find' 1 1
+  where
+    find' _ _ [] = []
+    find' left right ((output, run):rest) =
+        let (dl, dr) = countDelta run
+            remainder = find' (left+dl) (right+dr) rest
+        in
+            if output
+            then DiffRegion (left, dl) (right, dr) run : remainder
+            else remainder
+
+-- Get left/right line counts for a hunk
+countDelta :: [Diff a] -> (Int, Int)
+countDelta = count' 0 0
+  where
+    count' left right [] = (left, right)
+    count' left right (x:rest) =
+        case x of
+            Both {} -> count' (left+1) (right+1) rest
+            First {} -> count' (left+1) right rest
+            Second {} -> count' left (right+1) rest
+
+formatRegion :: ColorFunc -> LFStatus -> DiffRegion String -> String
+formatRegion color lf (DiffRegion left right diffs) =
+    let header = color cyan ("@@ -" ++ (tup left) ++ " +" ++ (tup right) ++" @@")
+    in
+        unlines $ header : reverse (getStrings lf (reverse diffs))
+  where
+    noLF = "\\ No newline at end of file"
+
+    getStrings LinefeedOk list = map format list
+    getStrings LinefeedMissing list@((Both _ _):_) = noLF : map format list
+    getStrings LinefeedMissing list@((First _):_) = noLF : map format list
+    getStrings LinefeedMissing (last:rest) = format last : getStrings LinefeedMissing rest
+
+    tup (a,b) = (show a) ++ "," ++ (show b)
+    format (Both x _) = ' ':x
+    format (First x) = color red $ '-':x
+    format (Second x) = color green $ '+':x
+
+splitLast [] = ([], [])
+splitLast x =
+    let (last, rest) = splitAt 1 $ reverse x
+    in (reverse rest, last)
+
+formatDoc color (DiffDoc name lf regions) =
+    let (most, last) = splitLast regions
+    in
+          (color bold $ "--- " ++ ("a" </> name)) ++ "\n" ++
+          (color bold $ "+++ " ++ ("b" </> name)) ++ "\n" ++
+          concatMap (formatRegion color LinefeedOk) most ++
+          concatMap (formatRegion color lf) last
+
+-- Create a Map from filename to Fix
+buildFixMap :: [Fix] -> M.Map String Fix
+buildFixMap fixes = perFile
+  where
+    splitFixes = splitFixByFile $ mconcat fixes
+    perFile = groupByMap (posFile . repStartPos . head . fixReplacements) splitFixes
+
+splitFixByFile :: Fix -> [Fix]
+splitFixByFile fix = map makeFix $ groupBy sameFile (fixReplacements fix)
+  where
+    sameFile rep1 rep2 = (posFile $ repStartPos rep1) == (posFile $ repStartPos rep2)
+    makeFix reps = newFix { fixReplacements = reps }
+
+groupByMap :: (Ord k, Monoid v) => (v -> k) -> [v] -> M.Map k v
+groupByMap f = M.fromListWith Monoid.mappend . map (\x -> (f x, x))
+
+-- For building unit tests
+b n = Both n n
+l = First
+r = Second
+
+prop_identifiesProperContext = groupDiff [b 1, b 2, b 3, b 4, l 5, b 6, b 7, b 8, b 9] ==
+    [(False, [b 1]), -- Omitted
+    (True, [b 2, b 3, b 4, l 5, b 6, b 7, b 8]), -- A change with three lines of context
+    (False, [b 9])]  -- Omitted
+
+prop_includesContextFromStartIfNecessary = groupDiff [b 4, l 5, b 6, b 7, b 8, b 9] ==
+    [ -- Nothing omitted
+    (True, [b 4, l 5, b 6, b 7, b 8]), -- A change with three lines of context
+    (False, [b 9])]  -- Omitted
+
+prop_includesContextUntilEndIfNecessary = groupDiff [b 4, l 5] ==
+    [ -- Nothing omitted
+        (True, [b 4, l 5])
+    ] -- Nothing Omitted
+
+prop_splitsIntoMultipleHunks = groupDiff [l 1, b 1, b 2, b 3, b 4, b 5, b 6, b 7, r 8] ==
+    [ -- Nothing omitted
+        (True, [l 1, b 1, b 2, b 3]),
+        (False, [b 4]),
+        (True, [b 5, b 6, b 7, r 8])
+    ] -- Nothing Omitted
+
+prop_splitsIntoMultipleHunksUnlessTouching = groupDiff [l 1, b 1, b 2, b 3, b 4, b 5, b 6, r 7] ==
+    [
+        (True, [l 1, b 1, b 2, b 3, b 4, b 5, b 6, r 7])
+    ]
+
+prop_countDeltasWorks = countDelta [b 1, l 2, r 3, r 4, b 5] == (3,4)
+prop_countDeltasWorks2 = countDelta [] == (0,0)
+
+return []
+runTests = $quickCheckAll

src/ShellCheck/Formatter/Format.hs

@@ -0,0 +1,82 @@
+{-
+    Copyright 2012-2019 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.Format where
+
+import ShellCheck.Data
+import ShellCheck.Interface
+import ShellCheck.Fixer
+
+import Control.Monad
+import Data.Array
+import Data.List
+import System.IO
+import System.Info
+import System.Environment
+
+-- A formatter that carries along an arbitrary piece of data
+data Formatter = Formatter {
+    header ::  IO (),
+    onResult :: CheckResult -> SystemInterface IO -> IO (),
+    onFailure :: FilePath -> ErrorMessage -> IO (),
+    footer :: IO ()
+}
+
+sourceFile = posFile . pcStartPos
+lineNo = posLine . pcStartPos
+endLineNo = posLine . pcEndPos
+colNo  = posColumn . pcStartPos
+endColNo = posColumn . pcEndPos
+codeNo = cCode . pcComment
+messageText = cMessage . pcComment
+
+severityText :: PositionedComment -> String
+severityText pc =
+    case cSeverity (pcComment pc) of
+        ErrorC   -> "error"
+        WarningC -> "warning"
+        InfoC    -> "info"
+        StyleC   -> "style"
+
+-- Realign comments from a tabstop of 8 to 1
+makeNonVirtual comments contents =
+    map fix comments
+  where
+    list = lines contents
+    arr = listArray (1, length list) list
+    untabbedFix f = newFix {
+      fixReplacements = map (\r -> removeTabStops r arr) (fixReplacements f)
+    }
+    fix c = (removeTabStops c arr) {
+      pcFix = fmap untabbedFix (pcFix c)
+    }
+
+
+shouldOutputColor :: ColorOption -> IO Bool
+shouldOutputColor colorOption =
+    case colorOption of
+        ColorAlways -> return True
+        ColorNever -> return False
+        ColorAuto -> do
+            isTerminal <- hIsTerminalDevice stdout
+            term <- lookupEnv "TERM"
+            let windows = "mingw" `isPrefixOf` os
+            let dumbTerm = term `elem` [Just "dumb", Just "", Nothing]
+            let isUsableTty = isTerminal && not windows && not dumbTerm
+            return isUsableTty

src/ShellCheck/Formatter/GCC.hs

@@ -1,8 +1,8 @@
 {-
-    Copyright 2012-2015 Vidar Holen
+    Copyright 2012-2019 Vidar Holen
 
     This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
+    https://www.shellcheck.net
 
     ShellCheck is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -}
 module ShellCheck.Formatter.GCC (format) where
 
@@ -23,8 +23,8 @@ import ShellCheck.Interface
 import ShellCheck.Formatter.Format
 
 import Data.List
-import GHC.Exts
 import System.IO
+import qualified Data.List.NonEmpty as NE
 
 format :: IO Formatter
 format = return Formatter {
@@ -39,13 +39,13 @@ outputError file error = hPutStrLn stderr $ file ++ ": " ++ error
 outputAll cr sys = mapM_ f groups
   where
     comments = crComments cr
-    groups = groupWith sourceFile comments
+    groups = NE.groupWith sourceFile comments
-    f :: [PositionedComment] -> IO ()
+    f :: NE.NonEmpty PositionedComment -> IO ()
     f group = do
-        let filename = sourceFile (head group)
+        let filename = sourceFile (NE.head group)
-        result <- (siReadFile sys) filename
+        result <- siReadFile sys (Just True) filename
         let contents = either (const "") id result
-        outputResult filename contents group
+        outputResult filename contents (NE.toList group)
 
 outputResult filename contents warnings = do
     let comments = makeNonVirtual warnings contents

src/ShellCheck/Formatter/JSON.hs

@@ -0,0 +1,111 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-
+    Copyright 2012-2019 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.JSON (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Control.DeepSeq
+import Data.Aeson
+import Data.IORef
+import Data.Monoid
+import GHC.Exts
+import System.IO
+import qualified Data.ByteString.Lazy.Char8 as BL
+
+format :: IO Formatter
+format = do
+    ref <- newIORef []
+    return Formatter {
+        header = return (),
+        onResult = collectResult ref,
+        onFailure = outputError,
+        footer = finish ref
+    }
+
+instance ToJSON Replacement where
+    toJSON replacement =
+        let start = repStartPos replacement
+            end = repEndPos replacement
+            str = repString replacement in
+        object [
+          "precedence" .= repPrecedence replacement,
+          "insertionPoint"  .=
+            case repInsertionPoint replacement of
+                InsertBefore -> "beforeStart" :: String
+                InsertAfter  -> "afterEnd",
+          "line" .= posLine start,
+          "column" .= posColumn start,
+          "endLine" .= posLine end,
+          "endColumn" .= posColumn end,
+          "replacement" .= str
+        ]
+
+instance ToJSON PositionedComment where
+  toJSON comment =
+    let start = pcStartPos comment
+        end = pcEndPos comment
+        c = pcComment comment in
+    object [
+      "file" .= posFile start,
+      "line" .= posLine start,
+      "endLine" .= posLine end,
+      "column" .= posColumn start,
+      "endColumn" .= posColumn end,
+      "level" .= severityText comment,
+      "code" .= cCode c,
+      "message" .= cMessage c,
+      "fix" .= pcFix comment
+    ]
+
+  toEncoding comment =
+    let start = pcStartPos comment
+        end = pcEndPos comment
+        c = pcComment comment in
+    pairs (
+         "file" .= posFile start
+      <> "line" .= posLine start
+      <> "endLine" .= posLine end
+      <> "column" .= posColumn start
+      <> "endColumn" .= posColumn end
+      <> "level" .= severityText comment
+      <> "code" .= cCode c
+      <> "message" .= cMessage c
+      <> "fix" .= pcFix comment
+    )
+
+instance ToJSON Fix where
+    toJSON fix = object [
+        "replacements" .= fixReplacements fix
+        ]
+
+outputError file msg = hPutStrLn stderr $ file ++ ": " ++ msg
+
+collectResult ref cr sys = mapM_ f groups
+  where
+    comments = crComments cr
+    groups = groupWith sourceFile comments
+    f :: [PositionedComment] -> IO ()
+    f group = deepseq comments $ modifyIORef ref (\x -> comments ++ x)
+
+finish ref = do
+    list <- readIORef ref
+    BL.putStrLn $ encode list

src/ShellCheck/Formatter/JSON1.hs

@@ -0,0 +1,128 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-
+    Copyright 2012-2019 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.JSON1 (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Control.DeepSeq
+import Data.Aeson
+import Data.IORef
+import Data.Monoid
+import System.IO
+import qualified Data.ByteString.Lazy.Char8 as BL
+import qualified Data.List.NonEmpty as NE
+
+format :: IO Formatter
+format = do
+    ref <- newIORef []
+    return Formatter {
+        header = return (),
+        onResult = collectResult ref,
+        onFailure = outputError,
+        footer = finish ref
+    }
+
+data Json1Output = Json1Output {
+    comments :: [PositionedComment]
+    }
+
+instance ToJSON Json1Output where
+    toJSON result = object [
+        "comments" .= comments result
+        ]
+    toEncoding result = pairs (
+        "comments" .= comments result
+        )
+
+instance ToJSON Replacement where
+    toJSON replacement =
+        let start = repStartPos replacement
+            end = repEndPos replacement
+            str = repString replacement in
+        object [
+          "precedence" .= repPrecedence replacement,
+          "insertionPoint"  .=
+            case repInsertionPoint replacement of
+                InsertBefore -> "beforeStart" :: String
+                InsertAfter  -> "afterEnd",
+          "line" .= posLine start,
+          "column" .= posColumn start,
+          "endLine" .= posLine end,
+          "endColumn" .= posColumn end,
+          "replacement" .= str
+        ]
+
+instance ToJSON PositionedComment where
+  toJSON comment =
+    let start = pcStartPos comment
+        end = pcEndPos comment
+        c = pcComment comment in
+    object [
+      "file" .= posFile start,
+      "line" .= posLine start,
+      "endLine" .= posLine end,
+      "column" .= posColumn start,
+      "endColumn" .= posColumn end,
+      "level" .= severityText comment,
+      "code" .= cCode c,
+      "message" .= cMessage c,
+      "fix" .= pcFix comment
+    ]
+
+  toEncoding comment =
+    let start = pcStartPos comment
+        end = pcEndPos comment
+        c = pcComment comment in
+    pairs (
+         "file" .= posFile start
+      <> "line" .= posLine start
+      <> "endLine" .= posLine end
+      <> "column" .= posColumn start
+      <> "endColumn" .= posColumn end
+      <> "level" .= severityText comment
+      <> "code" .= cCode c
+      <> "message" .= cMessage c
+      <> "fix" .= pcFix comment
+    )
+
+instance ToJSON Fix where
+    toJSON fix = object [
+        "replacements" .= fixReplacements fix
+        ]
+
+outputError file msg = hPutStrLn stderr $ file ++ ": " ++ msg
+
+collectResult ref cr sys = mapM_ f groups
+  where
+    comments = crComments cr
+    groups = NE.groupWith sourceFile comments
+    f :: NE.NonEmpty PositionedComment -> IO ()
+    f group = do
+        let filename = sourceFile (NE.head group)
+        result <- siReadFile sys (Just True) filename
+        let contents = either (const "") id result
+        let comments' = makeNonVirtual comments contents
+        deepseq comments' $ modifyIORef ref (\x -> comments' ++ x)
+
+finish ref = do
+    list <- readIORef ref
+    BL.putStrLn $ encode $ Json1Output { comments = list }

src/ShellCheck/Formatter/Quiet.hs

@@ -0,0 +1,36 @@
+{-
+    Copyright 2019 Austin Voecks
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.Quiet (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Control.Monad
+import Data.IORef
+import System.Exit
+
+format :: FormatterOptions -> IO Formatter
+format options =
+    return Formatter {
+        header = return (),
+        footer = return (),
+        onFailure = \ _ _ -> exitFailure,
+        onResult  = \ result _ -> unless (null $ crComments result) exitFailure
+    }

src/ShellCheck/Formatter/TTY.hs

@@ -0,0 +1,197 @@
+{-
+    Copyright 2012-2019 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.TTY (format) where
+
+import ShellCheck.Fixer
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Control.DeepSeq
+import Control.Monad
+import Data.Array
+import Data.Foldable
+import Data.Ord
+import Data.IORef
+import Data.List
+import Data.Maybe
+import System.IO
+import System.Info
+import qualified Data.List.NonEmpty as NE
+
+wikiLink = "https://www.shellcheck.net/wiki/"
+
+-- An arbitrary Ord thing to order warnings
+type Ranking = (Char, Severity, Integer)
+-- Ansi coloring function
+type ColorFunc = (String -> String -> String)
+
+format :: FormatterOptions -> IO Formatter
+format options = do
+    topErrorRef <- newIORef []
+    return Formatter {
+        header = return (),
+        footer = outputWiki topErrorRef,
+        onFailure = outputError options,
+        onResult = outputResult options topErrorRef
+    }
+
+colorForLevel level =
+    case level of
+        "error"   -> 31 -- red
+        "warning" -> 33 -- yellow
+        "info"    -> 32 -- green
+        "style"   -> 32 -- green
+        "verbose" -> 32 -- green
+        "message" -> 1 -- bold
+        "source"  -> 0 -- none
+        _ -> 0         -- none
+
+rankError :: PositionedComment -> Ranking
+rankError err = (ranking, cSeverity $ pcComment err, cCode $ pcComment err)
+  where
+    ranking =
+        if cCode (pcComment err) `elem` uninteresting
+        then 'Z'
+        else 'A'
+
+    -- A list of the most generic, least directly helpful
+    -- error codes to downrank.
+    uninteresting = [
+        1009, -- Mentioned parser error was..
+        1019, -- Expected this to be an argument
+        1036, -- ( is invalid here
+        1047, -- Expected 'fi'
+        1062, -- Expected 'done'
+        1070, -- Parsing stopped here (generic)
+        1072, -- Missing/unexpected ..
+        1073, -- Couldn't parse this ..
+        1088, -- Parsing stopped here (paren)
+        1089  -- Parsing stopped here (keyword)
+        ]
+
+appendComments errRef comments max = do
+    previous <- readIORef errRef
+    let current = map (\x -> (rankError x, cCode $ pcComment x, cMessage $ pcComment x)) comments
+    writeIORef errRef $! force . take max . nubBy equal . sort $ previous ++ current
+  where
+    fst3 (x,_,_) = x
+    equal x y = fst3 x == fst3 y
+
+outputWiki :: IORef [(Ranking, Integer, String)] -> IO ()
+outputWiki errRef = do
+    issues <- readIORef errRef
+    unless (null issues) $ do
+        putStrLn "For more information:"
+        mapM_ showErr issues
+  where
+    showErr (_, code, msg) =
+        putStrLn $ "  " ++ wikiLink ++ "SC" ++ show code ++ " -- " ++ shorten msg
+    limit = 36
+    shorten msg =
+        if length msg < limit
+        then msg
+        else (take (limit-3) msg) ++ "..."
+
+outputError options file error = do
+    color <- getColorFunc $ foColorOption options
+    hPutStrLn stderr $ color "error" $ file ++ ": " ++ error
+
+outputResult options ref result sys = do
+    color <- getColorFunc $ foColorOption options
+    let comments = crComments result
+    appendComments ref comments (fromIntegral $ foWikiLinkCount options)
+    let fileGroups = NE.groupWith sourceFile comments
+    mapM_ (outputForFile color sys) fileGroups
+
+outputForFile color sys comments = do
+    let fileName = sourceFile (NE.head comments)
+    result <- siReadFile sys (Just True) fileName
+    let contents = either (const "") id result
+    let fileLinesList = lines contents
+    let lineCount = length fileLinesList
+    let fileLines = listArray (1, lineCount) fileLinesList
+    let groups = NE.groupWith lineNo comments
+    forM_ groups $ \commentsForLine -> do
+        let lineNum = fromIntegral $ lineNo (NE.head commentsForLine)
+        let line = if lineNum < 1 || lineNum > lineCount
+                        then ""
+                        else fileLines ! fromIntegral lineNum
+        putStrLn ""
+        putStrLn $ color "message" $
+           "In " ++ fileName ++" line " ++ show lineNum ++ ":"
+        putStrLn (color "source" line)
+        forM_ commentsForLine $ \c -> putStrLn $ color (severityText c) $ cuteIndent c
+        putStrLn ""
+        showFixedString color (toList commentsForLine) (fromIntegral lineNum) fileLines
+
+-- Pick out only the lines necessary to show a fix in action
+sliceFile :: Fix -> Array Int String -> (Fix, Array Int String)
+sliceFile fix lines =
+    (mapPositions adjust fix, sliceLines lines)
+  where
+    (minLine, maxLine) =
+        foldl (\(mm, mx) pos -> ((min mm $ fromIntegral $ posLine pos), (max mx $ fromIntegral $ posLine pos)))
+                (maxBound, minBound) $
+            concatMap (\x -> [repStartPos x, repEndPos x]) $ fixReplacements fix
+    sliceLines :: Array Int String -> Array Int String
+    sliceLines = ixmap (1, maxLine - minLine + 1) (\x -> x + minLine - 1)
+    adjust pos =
+        pos {
+            posLine = posLine pos - (fromIntegral minLine) + 1
+        }
+
+showFixedString :: ColorFunc -> [PositionedComment] -> Int -> Array Int String -> IO ()
+showFixedString color comments lineNum fileLines =
+    let line = fileLines ! fromIntegral lineNum in
+    case mapMaybe pcFix comments of
+        [] -> return ()
+        fixes -> do
+            -- Folding automatically removes overlap
+            let mergedFix = fold fixes
+            -- We show the complete, associated fixes, whether or not it includes this
+            -- and/or other unrelated lines.
+            let (excerptFix, excerpt) = sliceFile mergedFix fileLines
+            -- in the spirit of error prone
+            putStrLn $ color "message" "Did you mean:"
+            putStrLn $ unlines $ applyFix excerptFix excerpt
+
+cuteIndent :: PositionedComment -> String
+cuteIndent comment =
+    replicate (fromIntegral $ colNo comment - 1) ' ' ++
+        makeArrow ++ " " ++ code (codeNo comment) ++ " (" ++ severityText comment ++ "): " ++ messageText comment
+  where
+    arrow n = '^' : replicate (fromIntegral $ n-2) '-' ++ "^"
+    makeArrow =
+        let sameLine = lineNo comment == endLineNo comment
+            delta = endColNo comment - colNo comment
+        in
+            if sameLine && delta > 2 && delta < 32 then arrow delta else "^--"
+
+code num = "SC" ++ show num
+
+getColorFunc :: ColorOption -> IO ColorFunc
+getColorFunc colorOption = do
+    useColor <- shouldOutputColor colorOption
+    return $ if useColor then colorComment else const id
+  where
+    colorComment level comment =
+        ansi (colorForLevel level) ++ comment ++ clear
+    clear = ansi 0
+    ansi n = "\x1B[" ++ show n ++ "m"

src/ShellCheck/Interface.hs

@@ -0,0 +1,341 @@
+{-
+    Copyright 2012-2024 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
+module ShellCheck.Interface
+    (
+    SystemInterface(..)
+    , CheckSpec(csFilename, csScript, csCheckSourced, csIncludedWarnings, csExcludedWarnings, csShellTypeOverride, csMinSeverity, csIgnoreRC, csExtendedAnalysis, csOptionalChecks)
+    , CheckResult(crFilename, crComments)
+    , ParseSpec(psFilename, psScript, psCheckSourced, psIgnoreRC, psShellTypeOverride)
+    , ParseResult(prComments, prTokenPositions, prRoot)
+    , AnalysisSpec(asScript, asShellType, asFallbackShell, asExecutionMode, asCheckSourced, asTokenPositions, asExtendedAnalysis, asOptionalChecks)
+    , AnalysisResult(arComments)
+    , FormatterOptions(foColorOption, foWikiLinkCount)
+    , Shell(Ksh, Sh, Bash, Dash, BusyboxSh)
+    , ExecutionMode(Executed, Sourced)
+    , ErrorMessage
+    , Code
+    , Severity(ErrorC, WarningC, InfoC, StyleC)
+    , Position(posFile, posLine, posColumn)
+    , Comment(cSeverity, cCode, cMessage)
+    , PositionedComment(pcStartPos , pcEndPos , pcComment, pcFix)
+    , ColorOption(ColorAuto, ColorAlways, ColorNever)
+    , TokenComment(tcId, tcComment, tcFix)
+    , emptyCheckResult
+    , newAnalysisResult
+    , newAnalysisSpec
+    , newFormatterOptions
+    , newParseResult
+    , newPosition
+    , newSystemInterface
+    , newTokenComment
+    , mockedSystemInterface
+    , mockRcFile
+    , newParseSpec
+    , emptyCheckSpec
+    , newPositionedComment
+    , newComment
+    , Fix(fixReplacements)
+    , newFix
+    , InsertionPoint(InsertBefore, InsertAfter)
+    , Replacement(repStartPos, repEndPos, repString, repPrecedence, repInsertionPoint)
+    , newReplacement
+    , CheckDescription(cdName, cdDescription, cdPositive, cdNegative)
+    , newCheckDescription
+    ) where
+
+import ShellCheck.AST
+
+import Control.DeepSeq
+import Control.Monad.Identity
+import Data.List
+import Data.Monoid
+import Data.Ord
+import Data.Semigroup
+import GHC.Generics (Generic)
+import qualified Data.Map as Map
+
+
+data SystemInterface m = SystemInterface {
+    -- | Given:
+    --   What annotations say about including external files (if anything)
+    --   A resolved filename from siFindSource
+    --   Read the file or return an error
+    siReadFile :: Maybe Bool -> String -> m (Either ErrorMessage String),
+    -- | Given:
+    --   the current script,
+    --   what annotations say about including external files (if anything)
+    --   a list of source-path annotations in effect,
+    --   and a sourced file,
+    --   find the sourced file
+    siFindSource :: String -> Maybe Bool -> [String] -> String -> m FilePath,
+    -- | Get the configuration file (name, contents) for a filename
+    siGetConfig :: String -> m (Maybe (FilePath, String))
+}
+
+-- ShellCheck input and output
+data CheckSpec = CheckSpec {
+    csFilename :: String,
+    csScript :: String,
+    csCheckSourced :: Bool,
+    csIgnoreRC :: Bool,
+    csExcludedWarnings :: [Integer],
+    csIncludedWarnings :: Maybe [Integer],
+    csShellTypeOverride :: Maybe Shell,
+    csMinSeverity :: Severity,
+    csExtendedAnalysis :: Maybe Bool,
+    csOptionalChecks :: [String]
+} deriving (Show, Eq)
+
+data CheckResult = CheckResult {
+    crFilename :: String,
+    crComments :: [PositionedComment]
+} deriving (Show, Eq)
+
+emptyCheckResult :: CheckResult
+emptyCheckResult = CheckResult {
+    crFilename = "",
+    crComments = []
+}
+
+emptyCheckSpec :: CheckSpec
+emptyCheckSpec = CheckSpec {
+    csFilename = "",
+    csScript = "",
+    csCheckSourced = False,
+    csIgnoreRC = False,
+    csExcludedWarnings = [],
+    csIncludedWarnings = Nothing,
+    csShellTypeOverride = Nothing,
+    csMinSeverity = StyleC,
+    csExtendedAnalysis = Nothing,
+    csOptionalChecks = []
+}
+
+newParseSpec :: ParseSpec
+newParseSpec = ParseSpec {
+    psFilename = "",
+    psScript = "",
+    psCheckSourced = False,
+    psIgnoreRC = False,
+    psShellTypeOverride = Nothing
+}
+
+newSystemInterface :: Monad m => SystemInterface m
+newSystemInterface =
+    SystemInterface {
+        siReadFile = \_ _ -> return $ Left "Not implemented",
+        siFindSource = \_ _ _ name -> return name,
+        siGetConfig = \_ -> return Nothing
+    }
+
+-- Parser input and output
+data ParseSpec = ParseSpec {
+    psFilename :: String,
+    psScript :: String,
+    psCheckSourced :: Bool,
+    psIgnoreRC :: Bool,
+    psShellTypeOverride :: Maybe Shell
+} deriving (Show, Eq)
+
+data ParseResult = ParseResult {
+    prComments :: [PositionedComment],
+    prTokenPositions :: Map.Map Id (Position, Position),
+    prRoot :: Maybe Token
+} deriving (Show, Eq)
+
+newParseResult :: ParseResult
+newParseResult = ParseResult {
+    prComments = [],
+    prTokenPositions = Map.empty,
+    prRoot = Nothing
+}
+
+-- Analyzer input and output
+data AnalysisSpec = AnalysisSpec {
+    asScript :: Token,
+    asShellType :: Maybe Shell,
+    asFallbackShell :: Maybe Shell,
+    asExecutionMode :: ExecutionMode,
+    asCheckSourced :: Bool,
+    asOptionalChecks :: [String],
+    asExtendedAnalysis :: Maybe Bool,
+    asTokenPositions :: Map.Map Id (Position, Position)
+}
+
+newAnalysisSpec token = AnalysisSpec {
+    asScript = token,
+    asShellType = Nothing,
+    asFallbackShell = Nothing,
+    asExecutionMode = Executed,
+    asCheckSourced = False,
+    asOptionalChecks = [],
+    asExtendedAnalysis = Nothing,
+    asTokenPositions = Map.empty
+}
+
+newtype AnalysisResult = AnalysisResult {
+    arComments :: [TokenComment]
+}
+
+newAnalysisResult = AnalysisResult {
+    arComments = []
+}
+
+-- Formatter options
+data FormatterOptions = FormatterOptions {
+    foColorOption :: ColorOption,
+    foWikiLinkCount :: Integer
+}
+
+newFormatterOptions = FormatterOptions {
+    foColorOption = ColorAuto,
+    foWikiLinkCount = 3
+}
+
+data CheckDescription = CheckDescription {
+    cdName :: String,
+    cdDescription :: String,
+    cdPositive :: String,
+    cdNegative :: String
+    }
+
+newCheckDescription = CheckDescription {
+    cdName = "",
+    cdDescription = "",
+    cdPositive = "",
+    cdNegative = ""
+    }
+
+-- Supporting data types
+data Shell = Ksh | Sh | Bash | Dash | BusyboxSh deriving (Show, Eq)
+data ExecutionMode = Executed | Sourced deriving (Show, Eq)
+
+type ErrorMessage = String
+type Code = Integer
+
+data Severity = ErrorC | WarningC | InfoC | StyleC
+    deriving (Show, Eq, Ord, Generic, NFData)
+data Position = Position {
+    posFile :: String,    -- Filename
+    posLine :: Integer,   -- 1 based source line
+    posColumn :: Integer  -- 1 based source column, where tabs are 8
+} deriving (Show, Eq, Generic, NFData, Ord)
+
+newPosition :: Position
+newPosition = Position {
+    posFile   = "",
+    posLine   = 1,
+    posColumn = 1
+}
+
+data Comment = Comment {
+    cSeverity :: Severity,
+    cCode     :: Code,
+    cMessage  :: String
+} deriving (Show, Eq, Generic, NFData)
+
+newComment :: Comment
+newComment = Comment {
+    cSeverity = StyleC,
+    cCode     = 0,
+    cMessage  = ""
+}
+
+-- only support single line for now
+data Replacement = Replacement {
+    repStartPos :: Position,
+    repEndPos :: Position,
+    repString :: String,
+    -- Order in which the replacements should happen: highest precedence first.
+    repPrecedence :: Int,
+    -- Whether to insert immediately before or immediately after the specified region.
+    repInsertionPoint :: InsertionPoint
+} deriving (Show, Eq, Generic, NFData)
+
+data InsertionPoint = InsertBefore | InsertAfter
+    deriving (Show, Eq, Generic, NFData)
+
+newReplacement = Replacement {
+    repStartPos = newPosition,
+    repEndPos = newPosition,
+    repString = "",
+    repPrecedence = 1,
+    repInsertionPoint = InsertAfter
+}
+
+data Fix = Fix {
+    fixReplacements :: [Replacement]
+} deriving (Show, Eq, Generic, NFData)
+
+newFix = Fix {
+    fixReplacements = []
+}
+
+data PositionedComment = PositionedComment {
+    pcStartPos :: Position,
+    pcEndPos   :: Position,
+    pcComment  :: Comment,
+    pcFix      :: Maybe Fix
+} deriving (Show, Eq, Generic, NFData)
+
+newPositionedComment :: PositionedComment
+newPositionedComment = PositionedComment {
+    pcStartPos = newPosition,
+    pcEndPos   = newPosition,
+    pcComment  = newComment,
+    pcFix      = Nothing
+}
+
+data TokenComment = TokenComment {
+    tcId :: Id,
+    tcComment :: Comment,
+    tcFix :: Maybe Fix
+} deriving (Show, Eq, Generic, NFData)
+
+newTokenComment = TokenComment {
+    tcId = Id 0,
+    tcComment = newComment,
+    tcFix = Nothing
+}
+
+data ColorOption =
+    ColorAuto
+    | ColorAlways
+    | ColorNever
+  deriving (Ord, Eq, Show)
+
+-- For testing
+mockedSystemInterface :: [(String, String)] -> SystemInterface Identity
+mockedSystemInterface files = (newSystemInterface :: SystemInterface Identity) {
+    siReadFile = rf,
+    siFindSource = fs,
+    siGetConfig = const $ return Nothing
+}
+  where
+    rf _ file = return $
+        case find ((== file) . fst) files of
+            Nothing -> Left "File not included in mock."
+            Just (_, contents) -> Right contents
+    fs _ _ _ file = return file
+
+mockRcFile rcfile mock = mock {
+    siGetConfig = const . return $ Just (".shellcheckrc", rcfile)
+}

src/ShellCheck/Prelude.hs

@@ -0,0 +1,51 @@
+{-
+    Copyright 2022 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+
+-- Generic basic utility functions
+module ShellCheck.Prelude where
+
+import Data.Semigroup
+
+
+-- Get element 0 or a default. Like `head` but safe.
+headOrDefault _ (a:_) = a
+headOrDefault def _   = def
+
+-- Get the last element or a default. Like `last` but safe.
+lastOrDefault def [] = def
+lastOrDefault _ list = last list
+
+--- Get element n of a list, or Nothing. Like `!!` but safe.
+(!!!) list i =
+    case drop i list of
+        []    -> Nothing
+        (r:_) -> Just r
+
+
+-- Like mconcat but for Semigroups
+sconcat1 :: (Semigroup t) => [t] -> t
+sconcat1 [x] = x
+sconcat1 (x:xs) = x <> sconcat1 xs
+
+sconcatOrDefault def [] = def
+sconcatOrDefault _ list = sconcat1 list
+
+-- For more actionable "impossible" errors
+pleaseReport str = "ShellCheck internal error, please report: " ++ str

src/ShellCheck/Regex.hs

@@ -1,8 +1,8 @@
 {-
-    Copyright 2012-2015 Vidar Holen
+    Copyright 2012-2019 Vidar Holen
 
     This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
+    https://www.shellcheck.net
 
     ShellCheck is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -}
 {-# LANGUAGE FlexibleContexts #-}
 
@@ -30,7 +30,7 @@ import Text.Regex.TDFA
 -- Precompile the regex
 mkRegex :: String -> Regex
 mkRegex str =
-    let make :: RegexMaker Regex CompOption ExecOption String => String -> Regex
+    let make :: String -> Regex
         make = makeRegex
     in
         make str

stack.yaml

@@ -1,8 +1,8 @@
 # This file was automatically generated by stack init
-# For more information, see: http://docs.haskellstack.org/en/stable/yaml_configuration/
+# For more information, see: https://docs.haskellstack.org/en/stable/yaml_configuration/
 
 # Specifies the GHC version and set of packages available (e.g., lts-3.5, nightly-2015-09-21, ghc-7.10.2)
-resolver: lts-8.5
+resolver: lts-18.15
 
 # Local packages, usually specified by relative directory name
 packages:

striptests

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+# This file strips all unit tests from ShellCheck, removing
+# the dependency on QuickCheck and Template Haskell and
+# reduces the binary size considerably.
+set -o pipefail
+
+sponge() {
+  local data
+  data="$(cat)"
+  printf '%s\n' "$data" > "$1"
+}
+
+modify() {
+  if ! "${@:2}" < "$1" | sponge "$1"
+  then
+    {
+      printf 'Failed to modify %s: ' "$1"
+      printf '%q ' "${@:2}"
+      printf '\n'
+    } >&2
+    exit 1
+  fi
+}
+
+detestify() {
+  printf '%s\n' '-- AUTOGENERATED from ShellCheck by striptests. Do not modify.'
+  awk '
+    BEGIN {
+      state = 0;
+    }
+
+    /STRIP/ { next; }
+    /LANGUAGE TemplateHaskell/ { next; }
+    /^import.*Test\./ { next; }
+
+    /^module/ {
+      sub(/,[^,)]*runTests/, "");
+    }
+
+    # Delete tests
+    /^prop_/ { state = 1; next; }
+
+    # ..and any blank lines following them.
+    state == 1 && /^ / { next; }
+
+    # Template Haskell marker
+    /^return / {
+      exit;
+    }
+
+    { state = 0; print; }
+    '
+}
+
+
+
+if [[ ! -e 'ShellCheck.cabal' ]]
+then
+  echo "Run me from the ShellCheck directory." >&2
+  exit 1
+fi
+
+if [[ -d '.git' ]] && ! git diff --exit-code > /dev/null 2>&1
+then
+  echo "You have local changes! These may be overwritten." >&2
+  exit 2
+fi
+
+modify 'ShellCheck.cabal' sed -e '
+  /QuickCheck/d
+  /^test-suite/{ s/.*//; q; }
+  '
+
+find . -name '.git' -prune -o -type f -name '*.hs' -print |
+  while IFS= read -r file
+  do
+    modify "$file" detestify
+  done

test/buildtest

@@ -0,0 +1,51 @@
+#!/bin/bash
+# This script configures, builds and runs tests.
+# It's meant for automatic cross-distro testing.
+
+die() { echo "$*" >&2; exit 1; }
+
+[ -e "ShellCheck.cabal" ] ||
+  die "ShellCheck.cabal not in current dir"
+command -v cabal ||
+  die "cabal is missing"
+
+cabal update ||
+  die "can't update"
+
+if [ -e /etc/arch-release ]
+then
+  # Arch has an unconventional packaging setup
+  flags=(--disable-library-vanilla --enable-shared --enable-executable-dynamic --ghc-options=-dynamic)
+else
+  flags=()
+fi
+
+cabal install --dependencies-only --enable-tests "${flags[@]}" ||
+  cabal install --dependencies-only "${flags[@]}" ||
+    cabal install --dependencies-only --max-backjumps -1 "${flags[@]}" ||
+      die "can't install dependencies"
+cabal configure --enable-tests "${flags[@]}" ||
+  die "configure failed"
+cabal build ||
+  die "build failed"
+cabal test ||
+  die "test failed"
+cabal haddock ||
+  die "haddock failed"
+
+sc="$(find . -name shellcheck -type f -perm -111)"
+[ -x "$sc" ] || die "Can't find executable"
+
+"$sc" - << 'EOF' || die "execution failed"
+#!/bin/sh
+echo "Hello World"
+EOF
+
+"$sc" - << 'EOF' && die "negative execution failed"
+#!/bin/sh
+echo $1
+EOF
+
+
+echo "Success"
+exit 0

test/check_release

@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC2257
+
+failed=0
+fail() {
+  echo "$(tput setaf 1)$*$(tput sgr0)"
+  failed=1
+}
+
+if git diff | grep -q ""
+then
+  fail "There are uncommitted changes"
+fi
+
+version=${current#v}
+if ! grep "Version:" ShellCheck.cabal | grep -qFw "$version"
+then
+  fail "The cabal file does not match tag version $version"
+fi
+
+if ! grep -qF "## $current" CHANGELOG.md
+then
+  fail "CHANGELOG.md does not contain '## $current'"
+fi
+
+current=$(git tag --points-at)
+if [[ -z "$current" ]]
+then
+  fail "No git tag on the current commit"
+  echo "Create one with:   git tag -a v0.0.0"
+fi
+
+if [[ "$current" != v* ]]
+then
+  fail "Bad tag format: expected v0.0.0"
+fi
+
+if [[ "$(git cat-file -t "$current")" != "tag" ]]
+then
+  fail "Current tag is not annotated (required for Snap)."
+fi
+
+if [[ "$(git tag --points-at master)" != "$current" ]]
+then
+  fail "You are not on master"
+fi
+
+if [[ $(git log -1 --pretty=%B) != "Stable version "* ]]
+then
+  fail "Expected git log message to be 'Stable version ...'"
+fi
+
+if [[ $(git log -1 --pretty=%B) != *"CHANGELOG"* ]]
+then
+  fail "Expected git log message to contain CHANGELOG"
+fi
+
+i=1 j=1
+cat << EOF
+
+Manual Checklist
+
+$((i++)). Make sure none of the automated checks above failed
+$((i++)). Run \`build/build_builder build/*/\` to update all builder images.
+$((j++)). \`build/run_builder dist-newstyle/sdist/ShellCheck-*.tar.gz build/*/\` to verify that they work.
+$((j++)). \`for f in \$(cat build/*/tag); do docker push "\$f"; done\` to upload them.
+$((i++)). Run test/distrotest to ensure that most distros can build OOTB.
+$((i++)). Make sure GitHub Build currently passes: https://github.com/koalaman/shellcheck/actions
+$((i++)). Make sure SnapCraft build currently works: https://build.snapcraft.io/user/koalaman
+$((i++)). Format and read over the manual for bad formatting and outdated info.
+$((i++)). Make sure the Hackage package builds locally.
+
+Release Steps
+
+$((j++)). \`cabal sdist\` to generate a Hackage package
+$((j++)). \`git push --follow-tags\` to push commit
+$((j++)). Wait for GitHub Actions to build.
+$((j++)). Verify release:
+  a. Check that the new versions are uploaded: https://github.com/koalaman/shellcheck/tags
+  b. Check that the docker images have version tags: https://hub.docker.com/u/koalaman
+$((j++)). If no disaster, upload to Hackage: http://hackage.haskell.org/upload
+$((j++)). Push a new commit that updates CHANGELOG.md
+EOF
+exit "$failed"

test/distrotest

@@ -0,0 +1,85 @@
+#!/bin/bash
+# This script runs 'buildtest' on each of several distros
+# via Docker.
+set -o pipefail
+
+exec 3>&1 4>&2
+die() { echo "$*" >&4; exit 1; }
+
+[ -e "ShellCheck.cabal" ] || die "ShellCheck.cabal not in this dir"
+
+[ "$1" = "--run" ] || {
+cat << EOF
+This script pulls multiple distros via Docker and compiles
+ShellCheck and dependencies for each one. It takes hours,
+and is still highly experimental.
+
+Make sure you're plugged in and have screen/tmux in place,
+then re-run with $0 --run to continue.
+
+Also note that dist*/ and .stack-work/ will be deleted.
+EOF
+exit 0
+}
+
+echo "Deleting 'dist', 'dist-newstyle', and '.stack-work'..."
+rm -rf dist dist-newstyle .stack-work
+
+execs=$(find . -name shellcheck)
+
+if [ -n "$execs" ]
+then
+  die "Found unexpected executables. Remove and try again: $execs"
+fi
+
+log=$(mktemp) || die "Can't create temp file"
+date >> "$log" || die "Can't write to log"
+
+echo "Logging to $log" >&3
+exec >> "$log" 2>&1
+
+final=0
+while read -r distro setup
+do
+  [[ "$distro" = "#"* || -z "$distro" ]] && continue
+  printf '%s ' "$distro" >&3
+  docker pull "$distro" || die "Can't pull $distro"
+  printf 'pulled. ' >&3
+
+  tmp=$(mktemp -d) || die "Can't make temp dir"
+  cp -r . "$tmp/" || die "Can't populate test dir"
+  printf 'Result: ' >&3
+  < /dev/null docker run -v "$tmp:/mnt" "$distro" sh -c "
+    $setup
+    cd /mnt || exit 1
+    test/buildtest
+    "
+  ret=$?
+  if [ "$ret" = 0 ]
+  then
+    echo "OK" >&3
+  else
+    echo "FAIL with $ret. See $log" >&3
+    final=1
+  fi
+  rm -rf "$tmp"
+done << EOF
+# Docker tag          Setup command
+debian:stable         apt-get update && apt-get install -y cabal-install
+debian:testing        apt-get update && apt-get install -y cabal-install
+ubuntu:latest         apt-get update && apt-get install -y cabal-install
+haskell:latest        true
+opensuse/leap:latest  zypper install -y cabal-install ghc
+fedora:latest         dnf install -y cabal-install ghc-template-haskell-devel findutils libstdc++-static gcc-c++
+archlinux:latest      pacman -S -y --noconfirm cabal-install ghc-static base-devel
+
+# Ubuntu LTS
+ubuntu:24.04          apt-get update && apt-get install -y cabal-install
+ubuntu:22.04          apt-get update && apt-get install -y cabal-install
+ubuntu:20.04          apt-get update && apt-get install -y cabal-install
+
+# Stack on Ubuntu LTS
+ubuntu:24.04          set -e; apt-get update && apt-get install -y curl && curl -sSL https://get.haskellstack.org/ | sh -s - -f && cd /mnt && exec test/stacktest
+EOF
+
+exit "$final"

test/shellcheck.hs

@@ -2,23 +2,40 @@ module Main where
 
 import Control.Monad
 import System.Exit
-import qualified ShellCheck.Checker
 import qualified ShellCheck.Analytics
 import qualified ShellCheck.AnalyzerLib
-import qualified ShellCheck.Parser
+import qualified ShellCheck.ASTLib
+import qualified ShellCheck.CFG
+import qualified ShellCheck.CFGAnalysis
+import qualified ShellCheck.Checker
 import qualified ShellCheck.Checks.Commands
+import qualified ShellCheck.Checks.ControlFlow
+import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
+import qualified ShellCheck.Fixer
+import qualified ShellCheck.Formatter.Diff
+import qualified ShellCheck.Parser
 
 main = do
     putStrLn "Running ShellCheck tests..."
-    results <- sequence [
+    failures <- filter (not . snd) <$> mapM sequenceA tests
-        ShellCheck.Checker.runTests,
+    if null failures then exitSuccess else do
-        ShellCheck.Checks.Commands.runTests,
+      putStrLn "Tests failed for the following module(s):"
-        ShellCheck.Checks.ShellSupport.runTests,
+      mapM (putStrLn . ("- ShellCheck." ++) . fst) failures
-        ShellCheck.Analytics.runTests,
+      exitFailure
-        ShellCheck.AnalyzerLib.runTests,
+  where
-        ShellCheck.Parser.runTests
+    tests =
+      [ ("Analytics"          , ShellCheck.Analytics.runTests)
+      , ("AnalyzerLib"        , ShellCheck.AnalyzerLib.runTests)
+      , ("ASTLib"             , ShellCheck.ASTLib.runTests)
+      , ("CFG"                , ShellCheck.CFG.runTests)
+      , ("CFGAnalysis"        , ShellCheck.CFGAnalysis.runTests)
+      , ("Checker"            , ShellCheck.Checker.runTests)
+      , ("Checks.Commands"    , ShellCheck.Checks.Commands.runTests)
+      , ("Checks.ControlFlow" , ShellCheck.Checks.ControlFlow.runTests)
+      , ("Checks.Custom"      , ShellCheck.Checks.Custom.runTests)
+      , ("Checks.ShellSupport", ShellCheck.Checks.ShellSupport.runTests)
+      , ("Fixer"              , ShellCheck.Fixer.runTests)
+      , ("Formatter.Diff"     , ShellCheck.Formatter.Diff.runTests)
+      , ("Parser"             , ShellCheck.Parser.runTests)
       ]
-    if and results
-      then exitSuccess
-      else exitFailure

test/stacktest

@@ -0,0 +1,28 @@
+#!/bin/bash
+# This script builds ShellCheck through `stack` using
+# various resolvers. It's run via distrotest.
+
+resolvers=(
+#  nightly-"$(date -d "3 days ago" +"%Y-%m-%d")"
+)
+
+die() { echo "$*" >&2; exit 1; }
+
+[ -e "ShellCheck.cabal" ] ||
+  die "ShellCheck.cabal not in current dir"
+[ -e "stack.yaml" ] ||
+  die "stack.yaml not in current dir"
+command -v stack ||
+  die "stack is missing"
+
+stack setup --allow-different-user || die "Failed to setup with default resolver"
+stack build --test || die "Failed to build/test with default resolver"
+
+# Nice to haves, but not necessary
+for resolver in "${resolvers[@]}"
+do
+  stack --resolver="$resolver" setup        || die "Failed to setup $resolver. This probably doesn't matter."
+  stack --resolver="$resolver" build --test || die "Failed build/test with $resolver! This probably doesn't matter."
+done
+
+echo "Success"