BUGFIX: qBittorrent now prints backtrace in terminal when segfaulting

Changelog

@@ -1,5 +1,6 @@
 * Unknown - Christophe Dumez <chris@qbittorrent.org> - v1.3.1
     - BUGFIX: Torrents paused due to an I/O error were displayed as queued
+    - BUGFIX: qBittorrent now prints backtrace in terminal when segfaulting
     - I18N: Updated Bulgarian and Greek translations
 
 * Fri Jan 9 2009 - Christophe Dumez <chris@qbittorrent.org> - v1.3.0

qcm/libtorrent-rasterbar.qcm

@@ -6,6 +6,7 @@ arg: with-libtorrent-lib=[path], Path to libtorrent-rasterbar library files
 arg: with-libtorrent-static-lib=[path], Path to libtorrent-rasterbar .a file
 -----END QCMOD-----
 */
+// see  Conf::findPkgConfig
 class qc_libtorrent_rasterbar : public ConfObj
 {
 public:

src/main.cpp

@@ -45,6 +45,8 @@
 #endif
 #ifndef Q_WS_WIN
   #include <signal.h>
+  #include <execinfo.h>
+  #include "stacktrace.h"
 #endif
 
 #include <stdlib.h>
@@ -59,6 +61,13 @@ QApplication *app;
     qDebug("Catching SIGTERM, exiting cleanly");
     app->exit();
   }
+  void sigsegvHandler(int) {
+    std::cerr << "\n\n*************************************************************\n";
+    std::cerr << "Catching SIGSEGV, please report a bug at http://bug.qbittorrent.org\nand provide the following backtrace:\n";
+    print_stacktrace();
+    std::raise(SIGINT);
+    std::abort();
+  }
 #endif
 
 void useStyle(QApplication *app, int style){
@@ -177,6 +186,10 @@ int main(int argc, char *argv[]){
   app->installTranslator(&translator);
   app->setApplicationName(QString::fromUtf8("qBittorrent"));
   app->setQuitOnLastWindowClosed(false);
+#ifndef Q_WS_WIN
+  signal(SIGTERM, sigtermHandler);
+  signal(SIGSEGV, sigsegvHandler);
+#endif
   // Read torrents given on command line
   QStringList torrentCmdLine = app->arguments();
   // Remove first argument (program name)
@@ -184,9 +197,6 @@ int main(int argc, char *argv[]){
   GUI *window = new GUI(0, torrentCmdLine);
   splash->finish(window);
   delete splash;
-#ifndef Q_WS_WIN
-  signal(SIGTERM, sigtermHandler);
-#endif
   int ret =  app->exec();
   delete window;
   delete app;

src/src.pro

@@ -87,6 +87,7 @@ contains(DEBUG_MODE, 0) {
 }
 #QMAKE_CXXFLAGS_RELEASE += -fwrapv
 #QMAKE_CXXFLAGS_DEBUG += -fwrapv
+unix:QMAKE_LFLAGS_SHAPP += -rdynamic
 
 CONFIG += link_pkgconfig
 PKGCONFIG += "libtorrent-rasterbar libcurl"
@@ -177,7 +178,8 @@ HEADERS += GUI.h \
     TrackersAdditionDlg.h \
     searchTab.h \
     console_imp.h \
-    ico.h
+    ico.h \
+    stacktrace.h
 FORMS += MainWindow.ui \
     options.ui \
     about.ui \

src/stacktrace.h

@@ -0,0 +1,94 @@
+// stacktrace.h (c) 2008, Timo Bingmann from http://idlebox.net/
+// published under the WTFPL v2.0
+
+#ifndef _STACKTRACE_H_
+#define _STACKTRACE_H_
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <execinfo.h>
+#include <cxxabi.h>
+
+/** Print a demangled stack backtrace of the caller function to FILE* out. */
+static inline void print_stacktrace(FILE *out = stderr, unsigned int max_frames = 63)
+{
+    fprintf(out, "stack trace:\n");
+
+    // storage array for stack trace address data
+    void* addrlist[max_frames+1];
+
+    // retrieve current stack addresses
+    int addrlen = backtrace(addrlist, sizeof(addrlist) / sizeof(void*));
+
+    if (addrlen == 0) {
+	fprintf(out, "  <empty, possibly corrupt>\n");
+	return;
+    }
+
+    // resolve addresses into strings containing "filename(function+address)",
+    // this array must be free()-ed
+    char** symbollist = backtrace_symbols(addrlist, addrlen);
+
+    // allocate string which will be filled with the demangled function name
+    size_t funcnamesize = 256;
+    char* funcname = (char*)malloc(funcnamesize);
+
+    // iterate over the returned symbol lines. skip the first, it is the
+    // address of this function.
+    for (int i = 2; i < addrlen; i++)
+    {
+	char *begin_name = 0, *begin_offset = 0, *end_offset = 0;
+
+	// find parentheses and +address offset surrounding the mangled name:
+	// ./module(function+0x15c) [0x8048a6d]
+	//fprintf(out, "%s TT\n", symbollist[i]);
+	for (char *p = symbollist[i]; *p; ++p)
+	{
+	    if (*p == '(')
+		begin_name = p;
+	    else if (*p == '+')
+		begin_offset = p;
+	    else if (*p == ')' && begin_offset) {
+		end_offset = p;
+		break;
+	    }
+	}
+
+	if (begin_name && begin_offset && end_offset
+	    && begin_name < begin_offset)
+	{
+	    *begin_name++ = '\0';
+	    *begin_offset++ = '\0';
+	    *end_offset = '\0';
+
+	    // mangled name is now in [begin_name, begin_offset) and caller
+	    // offset in [begin_offset, end_offset). now apply
+	    // __cxa_demangle():
+
+	    int status;
+	    char* ret = abi::__cxa_demangle(begin_name,
+					    funcname, &funcnamesize, &status);
+	    if (status == 0) {
+		funcname = ret; // use possibly realloc()-ed string
+		fprintf(out, "  %s : %s+%s %s\n",
+			symbollist[i], funcname, begin_offset, ++end_offset);
+	    }
+	    else {
+		// demangling failed. Output function name as a C function with
+		// no arguments.
+		fprintf(out, "  %s : %s()+%s %s\n",
+			symbollist[i], begin_name, begin_offset, ++end_offset);
+	    }
+	}
+	else
+	{
+	    // couldn't parse the line? print the whole line.
+	    fprintf(out, "  %s\n", symbollist[i]);
+	}
+    }
+
+    free(funcname);
+    free(symbollist);
+}
+
+#endif // _STACKTRACE_H_