Move system signal related functions to its own file

And revise "signal safe print" function.
PR #16953.

src/app/CMakeLists.txt

@@ -28,6 +28,7 @@ target_sources(qbt_app PRIVATE
     cmdoptions.h
     filelogger.h
     qtlocalpeer/qtlocalpeer.h
+    signalhandler.h
     upgrade.h
 
     # sources
@@ -37,6 +38,7 @@ target_sources(qbt_app PRIVATE
     filelogger.cpp
     main.cpp
     qtlocalpeer/qtlocalpeer.cpp
+    signalhandler.cpp
     upgrade.cpp
 
     # resources

src/app/app.pri

@@ -6,6 +6,7 @@ HEADERS += \
     $$PWD/cmdoptions.h \
     $$PWD/filelogger.h \
     $$PWD/qtlocalpeer/qtlocalpeer.h \
+    $$PWD/signalhandler.h \
     $$PWD/upgrade.h
 
 SOURCES += \
@@ -15,6 +16,7 @@ SOURCES += \
     $$PWD/filelogger.cpp \
     $$PWD/main.cpp \
     $$PWD/qtlocalpeer/qtlocalpeer.cpp \
+    $$PWD/signalhandler.cpp \
     $$PWD/upgrade.cpp
 
 stacktrace {

src/app/main.cpp

@@ -29,17 +29,18 @@
 
 #include <QtGlobal>
 
-#include <csignal>
 #include <cstdlib>
 #include <memory>
-#include <tuple>
 
-#if defined(Q_OS_UNIX)
+#ifdef Q_OS_UNIX
 #include <sys/resource.h>
 #endif
-#if !defined Q_OS_WIN && !defined Q_OS_HAIKU
+
+#ifndef Q_OS_WIN
+#ifndef Q_OS_HAIKU
 #include <unistd.h>
-#elif defined Q_OS_WIN && defined DISABLE_GUI
+#endif // Q_OS_HAIKU
+#elif defined DISABLE_GUI
 #include <io.h>
 #endif
 
@@ -61,75 +62,39 @@
 Q_IMPORT_PLUGIN(QICOPlugin)
 #endif // QBT_STATIC_QT
 
-#else
+#else // DISABLE_GUI
-// NoGUI-only includes
 #include <cstdio>
 #endif // DISABLE_GUI
 
-#ifdef STACKTRACE
-#ifdef Q_OS_UNIX
-#include "stacktrace.h"
-#else
-#include "stacktrace_win.h"
-#ifndef DISABLE_GUI
-#include "stacktracedialog.h"
-#endif // DISABLE_GUI
-#endif // Q_OS_UNIX
-#endif //STACKTRACE
-
 #include "base/global.h"
 #include "base/preferences.h"
 #include "base/profile.h"
 #include "base/version.h"
 #include "application.h"
 #include "cmdoptions.h"
+#include "signalhandler.h"
 #include "upgrade.h"
 
 #ifndef DISABLE_GUI
 #include "gui/utils.h"
 #endif
 
-// Signal handlers
-void sigNormalHandler(int signum);
-#ifdef STACKTRACE
-void sigAbnormalHandler(int signum);
-#endif
-// sys_signame[] is only defined in BSD
-const char *const sysSigName[] =
-{
-#if defined(Q_OS_WIN)
-    "", "", "SIGINT", "", "SIGILL", "", "SIGABRT_COMPAT", "", "SIGFPE", "",
-    "", "SIGSEGV", "", "", "", "SIGTERM", "", "", "", "",
-    "", "SIGBREAK", "SIGABRT", "", "", "", "", "", "", "",
-    "", ""
-#else
-    "", "SIGHUP", "SIGINT", "SIGQUIT", "SIGILL", "SIGTRAP", "SIGABRT", "SIGBUS", "SIGFPE", "SIGKILL",
-    "SIGUSR1", "SIGSEGV", "SIGUSR2", "SIGPIPE", "SIGALRM", "SIGTERM", "SIGSTKFLT", "SIGCHLD", "SIGCONT", "SIGSTOP",
-    "SIGTSTP", "SIGTTIN", "SIGTTOU", "SIGURG", "SIGXCPU", "SIGXFSZ", "SIGVTALRM", "SIGPROF", "SIGWINCH", "SIGIO",
-    "SIGPWR", "SIGUNUSED"
-#endif
-};
-
-#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
-void reportToUser(const char *str);
-#endif
-
 void displayVersion();
 bool userAgreesWithLegalNotice();
 void displayBadArgMessage(const QString &message);
 
-#if !defined(DISABLE_GUI)
+#ifndef DISABLE_GUI
 void showSplashScreen();
 #endif  // DISABLE_GUI
 
-#if defined(Q_OS_UNIX)
+#ifdef Q_OS_UNIX
 void adjustFileDescriptorLimit();
 #endif
 
 // Main
 int main(int argc, char *argv[])
 {
-#if defined(Q_OS_UNIX)
+#ifdef Q_OS_UNIX
     adjustFileDescriptorLimit();
 #endif
 
@@ -219,7 +184,7 @@ int main(int argc, char *argv[])
             return EXIT_SUCCESS;
         }
 
-#if defined(Q_OS_WIN)
+#ifdef Q_OS_WIN
         // This affects only Windows apparently and Qt5.
         // When QNetworkAccessManager is instantiated it regularly starts polling
         // the network interfaces to see what's available and their status.
@@ -238,7 +203,7 @@ int main(int argc, char *argv[])
 #endif
 #endif // Q_OS_WIN
 
-#if defined(Q_OS_MACOS)
+#ifdef Q_OS_MACOS
         // Since Apple made difficult for users to set PATH, we set here for convenience.
         // Users are supposed to install Homebrew Python for search function.
         // For more info see issue #5571.
@@ -297,12 +262,7 @@ int main(int argc, char *argv[])
             showSplashScreen();
 #endif
 
-        signal(SIGINT, sigNormalHandler);
+        registerSignalHandlers();
-        signal(SIGTERM, sigNormalHandler);
-#ifdef STACKTRACE
-        signal(SIGABRT, sigAbnormalHandler);
-        signal(SIGSEGV, sigAbnormalHandler);
-#endif
 
         return app->exec(params.paramList());
     }
@@ -313,61 +273,6 @@ int main(int argc, char *argv[])
     }
 }
 
-#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
-void reportToUser(const char *str)
-{
-    const size_t strLen = strlen(str);
-#ifdef Q_OS_WIN
-    if (_write(_fileno(stderr), str, strLen) < static_cast<int>(strLen))
-        std::ignore = _write(_fileno(stdout), str, strLen);
-#else
-    if (write(STDERR_FILENO, str, strLen) < static_cast<ssize_t>(strLen))
-        std::ignore = write(STDOUT_FILENO, str, strLen);
-#endif
-}
-#endif
-
-void sigNormalHandler(int signum)
-{
-#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
-    const char msg1[] = "Catching signal: ";
-    const char msg2[] = "\nExiting cleanly\n";
-    reportToUser(msg1);
-    reportToUser(sysSigName[signum]);
-    reportToUser(msg2);
-#endif // !defined Q_OS_WIN && !defined Q_OS_HAIKU
-    signal(signum, SIG_DFL);
-    qApp->exit();  // unsafe, but exit anyway
-}
-
-#ifdef STACKTRACE
-void sigAbnormalHandler(int signum)
-{
-    const char *sigName = sysSigName[signum];
-#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
-    const char msg[] = "\n\n*************************************************************\n"
-        "Please file a bug report at http://bug.qbittorrent.org and provide the following information:\n\n"
-        "qBittorrent version: " QBT_VERSION "\n\n"
-        "Caught signal: ";
-    reportToUser(msg);
-    reportToUser(sigName);
-    reportToUser("\n");
-#if !defined Q_OS_WIN
-    print_stacktrace();  // unsafe
-#endif
-#endif
-
-#if defined Q_OS_WIN && !defined DISABLE_GUI
-    StacktraceDialog dlg;  // unsafe
-    dlg.setStacktraceString(QString::fromLatin1(sigName), straceWin::getBacktrace());
-    dlg.exec();
-#endif
-
-    signal(signum, SIG_DFL);
-    raise(signum);
-}
-#endif // STACKTRACE
-
 #if !defined(DISABLE_GUI)
 void showSplashScreen()
 {
@@ -445,7 +350,7 @@ bool userAgreesWithLegalNotice()
     return false;
 }
 
-#if defined(Q_OS_UNIX)
+#ifdef Q_OS_UNIX
 void adjustFileDescriptorLimit()
 {
     rlimit limit {};

src/app/signalhandler.cpp

@@ -0,0 +1,141 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2022  Mike Tzou (Chocobo1)
+ * Copyright (C) 2014  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
+ *
+ * This program 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include "signalhandler.h"
+
+#include <QtGlobal>
+
+#include <algorithm>
+#include <csignal>
+#include <tuple>
+
+#ifndef Q_OS_WIN
+#ifndef Q_OS_HAIKU
+#include <unistd.h>
+#endif
+#elif defined DISABLE_GUI
+#include <io.h>
+#endif
+
+#include <QCoreApplication>
+
+#include "base/version.h"
+
+#ifdef STACKTRACE
+#ifdef Q_OS_UNIX
+#include "stacktrace.h"
+#else
+#include "stacktrace_win.h"
+#ifndef DISABLE_GUI
+#include "stacktracedialog.h"
+#endif // DISABLE_GUI
+#endif // Q_OS_UNIX
+#endif //STACKTRACE
+
+namespace
+{
+    // sys_signame[] is only defined in BSD
+    const char *const sysSigName[] =
+    {
+#ifdef Q_OS_WIN
+        "", "", "SIGINT", "", "SIGILL", "", "SIGABRT_COMPAT", "", "SIGFPE", "",
+        "", "SIGSEGV", "", "", "", "SIGTERM", "", "", "", "",
+        "", "SIGBREAK", "SIGABRT", "", "", "", "", "", "", "",
+        "", ""
+#else
+        "", "SIGHUP", "SIGINT", "SIGQUIT", "SIGILL", "SIGTRAP", "SIGABRT", "SIGBUS", "SIGFPE", "SIGKILL",
+        "SIGUSR1", "SIGSEGV", "SIGUSR2", "SIGPIPE", "SIGALRM", "SIGTERM", "SIGSTKFLT", "SIGCHLD", "SIGCONT", "SIGSTOP",
+        "SIGTSTP", "SIGTTIN", "SIGTTOU", "SIGURG", "SIGXCPU", "SIGXFSZ", "SIGVTALRM", "SIGPROF", "SIGWINCH", "SIGIO",
+        "SIGPWR", "SIGUNUSED"
+#endif
+    };
+
+#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
+    void safePrint(const char *str)
+    {
+        const size_t strLen = strlen(str);
+#ifdef Q_OS_WIN
+        if (_write(_fileno(stderr), str, strLen) < static_cast<int>(strLen))
+            std::ignore = _write(_fileno(stdout), str, strLen);
+#else
+        if (write(STDERR_FILENO, str, strLen) < static_cast<ssize_t>(strLen))
+            std::ignore = write(STDOUT_FILENO, str, strLen);
+#endif
+    }
+#endif
+
+    void normalExitHandler(const int signum)
+    {
+#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
+        const char *msgs[] = {"Catching signal: ", sysSigName[signum], "\nExiting cleanly\n"};
+        std::for_each(std::begin(msgs), std::end(msgs), safePrint);
+#endif // !defined Q_OS_WIN && !defined Q_OS_HAIKU
+        signal(signum, SIG_DFL);
+        QCoreApplication::exit();  // unsafe, but exit anyway
+    }
+
+#ifdef STACKTRACE
+    void abnormalExitHandler(const int signum)
+    {
+        const char *sigName = sysSigName[signum];
+
+#if !(defined Q_OS_WIN && !defined DISABLE_GUI) && !defined Q_OS_HAIKU
+        const char msg[] = "\n\n*************************************************************\n"
+            "Please file a bug report at http://bug.qbittorrent.org and provide the following information:\n\n"
+            "qBittorrent version: " QBT_VERSION "\n\n"
+            "Caught signal: ";
+        const char *msgs[] = {msg, sigName, "\n"};
+        std::for_each(std::begin(msgs), std::end(msgs), safePrint);
+#if !defined Q_OS_WIN
+        print_stacktrace();  // unsafe
+#endif
+#endif
+
+#if defined Q_OS_WIN && !defined DISABLE_GUI
+        StacktraceDialog dlg;  // unsafe
+        dlg.setStacktraceString(QString::fromLatin1(sigName), straceWin::getBacktrace());
+        dlg.exec();
+#endif
+
+        signal(signum, SIG_DFL);
+        raise(signum);
+    }
+#endif // STACKTRACE
+}
+
+void registerSignalHandlers()
+{
+    signal(SIGINT, normalExitHandler);
+    signal(SIGTERM, normalExitHandler);
+#ifdef STACKTRACE
+    signal(SIGABRT, abnormalExitHandler);
+    signal(SIGSEGV, abnormalExitHandler);
+#endif
+}

src/app/signalhandler.h

@@ -0,0 +1,33 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2022  Mike Tzou (Chocobo1)
+ * Copyright (C) 2014  Vladimir Golovnev <glassez@yandex.ru>
+ * Copyright (C) 2006  Christophe Dumez <chris@qbittorrent.org>
+ *
+ * This program 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#pragma once
+
+void registerSignalHandlers();