comparison: src/crashcatcher.cpp
src/crashcatcher.cpp
- changeset 513
- 29eb671b34f6
- child 514
- d78fea0f664c
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| 512:adab82ab13a5 | 513:29eb671b34f6 |
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| 1 #ifdef __unix__ | |
| 2 | |
| 3 #include <QString> | |
| 4 #include <QProcess> | |
| 5 #include <QTemporaryFile> | |
| 6 #include <QMessageBox> | |
| 7 #include <unistd.h> | |
| 8 #include <signal.h> | |
| 9 #include <sys/prctl.h> | |
| 10 #include "crashcatcher.h" | |
| 11 #include "types.h" | |
| 12 #include "dialogs.h" | |
| 13 | |
| 14 // Is the crash catcher active now? | |
| 15 static bool g_crashCatcherActive = false; | |
| 16 | |
| 17 // If an assertion failed, what was it? | |
| 18 static str g_assertionFailure; | |
| 19 | |
| 20 // List of signals to catch and crash on | |
| 21 static QList<int> g_signalsToCatch ({ | |
| 22 SIGSEGV, // segmentation fault | |
| 23 SIGABRT, // abort() calls | |
| 24 SIGFPE, // floating point exceptions (e.g. division by zero) | |
| 25 SIGILL, // illegal instructions | |
| 26 }); | |
| 27 | |
| 28 // ============================================================================= | |
| 29 // ----------------------------------------------------------------------------- | |
| 30 static void handleSignal (int sig) | |
| 31 { printf ("caught signal %d\n", sig); | |
| 32 | |
| 33 if (g_crashCatcherActive) | |
| 34 { printf ("caught signal while crash catcher is active!\n"); | |
| 35 return; | |
| 36 } | |
| 37 | |
| 38 if (g_signalsToCatch.indexOf (sig) != -1) | |
| 39 { const pid_t pid = getpid(); | |
| 40 QProcess proc; | |
| 41 QTemporaryFile commandsFile; | |
| 42 | |
| 43 g_crashCatcherActive = true; | |
| 44 printf ("%s: crashed with signal %d, launching gdb\n", __func__, sig); | |
| 45 | |
| 46 if (commandsFile.open()) | |
| 47 { commandsFile.write (fmt ("attach %1\n", pid).toLocal8Bit()); | |
| 48 commandsFile.write (str ("backtrace full\n").toLocal8Bit()); | |
| 49 commandsFile.write (str ("detach\n").toLocal8Bit()); | |
| 50 commandsFile.write (str ("quit").toLocal8Bit()); | |
| 51 commandsFile.flush(); | |
| 52 commandsFile.close(); | |
| 53 } | |
| 54 | |
| 55 QStringList args ({"-x", commandsFile.fileName()}); | |
| 56 | |
| 57 proc.start ("gdb", args); | |
| 58 | |
| 59 // Linux doesn't allow ptrace to be used on anything but direct child processes | |
| 60 // so we need to use prctl to register an exception to this to allow GDB attach to us. | |
| 61 // We need to do this now and no earlier because only now we actually know GDB's PID. | |
| 62 prctl (PR_SET_PTRACER, proc.pid(), 0, 0, 0); | |
| 63 | |
| 64 proc.waitForFinished (5000); | |
| 65 str output = QString (proc.readAllStandardOutput()); | |
| 66 str err = QString (proc.readAllStandardError()); | |
| 67 | |
| 68 bombBox (fmt ("<h3>Program crashed with signal %1</h3>\n\n" | |
| 69 "%2" | |
| 70 "<p><b>GDB <tt>stdout</tt>:</b></p><pre>%3</pre>\n" | |
| 71 "<p><b>GDB <tt>stderr</tt>:</b></p><pre>%4</pre>", | |
| 72 sig, (!g_assertionFailure.isEmpty()) ? g_assertionFailure : "", output, err)); | |
| 73 exit (137); | |
| 74 } | |
| 75 } | |
| 76 | |
| 77 // ============================================================================= | |
| 78 // ----------------------------------------------------------------------------- | |
| 79 void initCrashCatcher() | |
| 80 { struct sigaction sighandler; | |
| 81 sighandler.sa_handler = &handleSignal; | |
| 82 sighandler.sa_flags = 0; | |
| 83 sigemptyset (&sighandler.sa_mask); | |
| 84 | |
| 85 for (int sig : g_signalsToCatch) | |
| 86 sigaction (sig, &sighandler, null); | |
| 87 | |
| 88 log ("%1: crash catcher hooked to signals: %2\n", __func__, g_signalsToCatch); | |
| 89 } | |
| 90 #endif // #ifdef __unix__ | |
| 91 | |
| 92 // ============================================================================= | |
| 93 // This function must be readily available in both Windows and Linux. We display | |
| 94 // the bomb box straight in Windows while in Linux we let abort() trigger the | |
| 95 // signal handler, which will cause the usual bomb box with GDB diagnostics. | |
| 96 // Said prompt will embed the assertion failure information. | |
| 97 // ----------------------------------------------------------------------------- | |
| 98 void assertionFailure (const char* file, int line, const char* funcname, const char* expr) | |
| 99 { str errmsg = fmt ( | |
| 100 "<p><b>File</b>: <tt>%1</tt><br />" | |
| 101 "<b>Line</b>: <tt>%2</tt><br />" | |
| 102 "<b>Function:</b> <tt>%3</tt></p>" | |
| 103 "<p>Assertion <b><tt>`%4'</tt></b> failed.</p>", | |
| 104 file, line, funcname, expr); | |
| 105 | |
| 106 g_assertionFailure = errmsg; | |
| 107 | |
| 108 #ifndef __unix__ | |
| 109 bombBox (errmsg); | |
| 110 #endif | |
| 111 | |
| 112 abort(); | |
| 113 } |
