Add predefined portage variables

When running through portage, 50+ predefined variables are created
and/or consumed by the build system outside of the ebuild script.  Some
of them are common words that might be likely to be used by non-portage
shell scripts, so we don't want to simply declare them as internal shell
variables.

Instead, parameterize the functions that return internal lists based on
the Parameters in use and only include portage variables when
isPortageBuild is true.

src/ShellCheck/Analytics.hs

@@ -831,6 +831,10 @@ checkArrayAsString _ (T_Assignment id _ _ _ word) =
           "Brace expansions and globs are literal in assignments. Quote it or use an array."
 checkArrayAsString _ _ = return ()
 
+arrayVariables params =
+    shellArrayVariables ++
+    if isPortageBuild params then shellArrayVariables else []
+
 prop_checkArrayWithoutIndex1 = verifyTree checkArrayWithoutIndex "foo=(a b); echo $foo"
 prop_checkArrayWithoutIndex2 = verifyNotTree checkArrayWithoutIndex "foo='bar baz'; foo=($foo); echo ${foo[0]}"
 prop_checkArrayWithoutIndex3 = verifyTree checkArrayWithoutIndex "coproc foo while true; do echo cow; done; echo $foo"
@@ -844,7 +848,7 @@ prop_checkArrayWithoutIndex10= verifyTree checkArrayWithoutIndex "read -ra arr <
 checkArrayWithoutIndex params _ =
     doVariableFlowAnalysis readF writeF defaultMap (variableFlow params)
   where
-    defaultMap = Map.fromList $ map (\x -> (x,())) arrayVariables
+    defaultMap = Map.fromList $ map (\x -> (x,())) (arrayVariables params)
     readF _ (T_DollarBraced id _ token) _ = do
         map <- get
         return . maybeToList $ do
@@ -1813,6 +1817,10 @@ checkSpacefulness params = checkSpacefulness' onFind params
             && isParamTo parents ":" token
 
 
+variablesWithoutSpaces params =
+    shellVariablesWithoutSpaces ++
+    if isPortageBuild params then portageVariablesWithoutSpaces else []
+
 prop_checkSpacefulness4v= verifyTree checkVerboseSpacefulness "foo=3; foo=$(echo $foo)"
 prop_checkSpacefulness8v= verifyTree checkVerboseSpacefulness "a=foo\\ bar; a=foo; rm $a"
 prop_checkSpacefulness28v = verifyTree checkVerboseSpacefulness "exec {n}>&1; echo $n"
@@ -1832,7 +1840,7 @@ checkSpacefulness'
 checkSpacefulness' onFind params t =
     doVariableFlowAnalysis readF writeF (Map.fromList defaults) (variableFlow params)
   where
-    defaults = zip variablesWithoutSpaces (repeat False)
+    defaults = zip (variablesWithoutSpaces params) (repeat False)
 
     hasSpaces name = gets (Map.findWithDefault True name)
 
@@ -2044,6 +2052,11 @@ checkFunctionsUsedExternally params t =
             info definitionId 2032 $
               "Use own script or sh -c '..' to run this from " ++ cmd ++ "."
 
+internalVariables params =
+    genericInternalVariables ++
+    if shellType params == Ksh then kshInternalVariables else [] ++
+    if isPortageBuild params then portageInternalVariables else []
+
 prop_checkUnused0 = verifyNotTree checkUnusedAssignments "var=foo; echo $var"
 prop_checkUnused1 = verifyTree checkUnusedAssignments "var=foo; echo $bar"
 prop_checkUnused2 = verifyNotTree checkUnusedAssignments "var=foo; export var;"
@@ -2111,7 +2124,7 @@ checkUnusedAssignments params t = execWriter (mapM_ warnFor unused)
             name ++ " appears unused. Verify use (or export if used externally)."
 
     stripSuffix = takeWhile isVariableChar
-    defaultMap = Map.fromList $ zip internalVariables $ repeat ()
+    defaultMap = Map.fromList $ zip (internalVariables params) $ repeat ()
 
 prop_checkUnassignedReferences1 = verifyTree checkUnassignedReferences "echo $foo"
 prop_checkUnassignedReferences2 = verifyNotTree checkUnassignedReferences "foo=hello; echo $foo"
@@ -2156,7 +2169,7 @@ checkUnassignedReferences = checkUnassignedReferences' False
 checkUnassignedReferences' includeGlobals params t = warnings
   where
     (readMap, writeMap) = execState (mapM tally $ variableFlow params) (Map.empty, Map.empty)
-    defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) internalVariables
+    defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) (internalVariables params)
 
     tally (Assignment (_, _, name, _))  =
         modify (\(read, written) -> (read, Map.insert name () written))
@@ -3095,7 +3108,7 @@ checkSplittingInArrays params t =
         T_DollarBraced id _ str |
             not (isCountingReference part)
             && not (isQuotedAlternativeReference part)
-            && not (getBracedReference (bracedString part) `elem` variablesWithoutSpaces)
+            && not (getBracedReference (bracedString part) `elem` (variablesWithoutSpaces params))
             -> warn id 2206 $
                 if shellType params == Ksh
                 then "Quote to prevent word splitting/globbing, or split robustly with read -A or while read."

src/ShellCheck/Data.hs

@@ -6,7 +6,7 @@ import Paths_ShellCheck (version)
 
 shellcheckVersion = showVersion version
 
-internalVariables = [
+genericInternalVariables = [
     -- Generic
     "", "_", "rest", "REST",
 
@@ -34,19 +34,34 @@ internalVariables = [
     "USER", "TZ", "TERM", "LOGNAME", "LD_LIBRARY_PATH", "LANGUAGE", "DISPLAY",
     "HOSTNAME", "KRB5CCNAME", "XAUTHORITY"
 
-    -- 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"
   ]
 
+kshInternalVariables = [
+    ".sh.version"
+  ]
+
+portageInternalVariables = [
+    "A", "BDEPEND", "BROOT", "CATEGORY", "D", "DEPEND", "DESCRIPTION",
+    "DISTDIR", "DOCS", "EAPI", "ED", "EPREFIX", "EROOT", "ESYSROOT", "FILESDIR",
+    "HOME", "HOMEPAGE", "HTML_DOCS", "IUSE", "KEYWORDS", "LICENSE", "P",
+    "PATCHES", "PDEPEND", "PF", "PN", "PR", "PROPERTIES", "PV", "PVR",
+    "QA_AM_MAINTAINER_MODE", "QA_CONFIGURE_OPTIONS", "QA_DESKTOP_FILE",
+    "QA_DT_NEEDED", "QA_EXECSTACK", "QA_FLAGS_IGNORED", "QA_MULTILIB_PATHS",
+    "QA_PREBUILT", "QA_PRESTRIPPED", "QA_SONAME", "QA_SONAME_NO_SYMLINK",
+    "QA_TEXTRELS", "QA_WX_LOAD", "RDEPEND", "REQUIRED_USE", "RESTRICT", "ROOT",
+    "S", "SLOT", "SRC_TEST", "SRC_URI", "STRIP_MASK", "SUBSLOT", "SYSROOT",
+    "T", "WORKDIR"
+  ]
+
 specialVariablesWithoutSpaces = [
     "$", "-", "?", "!", "#"
   ]
-variablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
+
+shellVariablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
     "BASHPID", "BASH_ARGC", "BASH_LINENO", "BASH_SUBSHELL", "EUID", "LINENO",
     "OPTIND", "PPID", "RANDOM", "SECONDS", "SHELLOPTS", "SHLVL", "UID",
     "COLUMNS", "HISTFILESIZE", "HISTSIZE", "LINES"
@@ -55,18 +70,26 @@ variablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
     , "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_TRUE"
   ]
 
+portageVariablesWithoutSpaces = [
+    "EAPI", "P", "PF", "PN", "PR", "PV", "PVR", "SLOT"
+  ]
+
 specialVariables = specialVariablesWithoutSpaces ++ ["@", "*"]
 
 unbracedVariables = specialVariables ++ [
     "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
   ]
 
-arrayVariables = [
+shellArrayVariables = [
     "BASH_ALIASES", "BASH_ARGC", "BASH_ARGV", "BASH_CMDS", "BASH_LINENO",
     "BASH_REMATCH", "BASH_SOURCE", "BASH_VERSINFO", "COMP_WORDS", "COPROC",
     "DIRSTACK", "FUNCNAME", "GROUPS", "MAPFILE", "PIPESTATUS", "COMPREPLY"
   ]
 
+portageArrayVariables = [
+    "PATCHES"
+  ]
+
 commonCommands = [
     "admin", "alias", "ar", "asa", "at", "awk", "basename", "batch",
     "bc", "bg", "break", "c99", "cal", "cat", "cd", "cflow", "chgrp",