sys: implement signal handling on all platforms

[xonotic/darkplaces.git] / sys_shared.c

diff --git a/sys_shared.c b/sys_shared.c
index 457abe36a9a26e1776b2158698b3a014662daad3..e92eb94f71296215231e8fa58e41199245f51a08 100644 (file)
--- a/sys_shared.c
+++ b/sys_shared.c
@@ -890,10 +890,83 @@ void Sys_MakeProcessMean (void)
 }
 #endif
 
-int main (int argc, char **argv)
+/** Halt and try not to catch fire.
+ * Writing to any file could corrupt it,
+ * any uneccessary code could crash while we crash.
+ * No malloc() (libgcc should be loaded already) or Con_Printf() allowed here.
+ */
+static void Sys_HandleCrash(int sig)
+{
+#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1
+       // Before doing anything else grab the stack frame addresses
+       #include <execinfo.h>
+       void *stackframes[32];
+       int framecount = backtrace(stackframes, 32);
+#endif
+
+       // Windows doesn't have strsignal()
+       const char *sigdesc;
+       switch (sig)
+       {
+#ifndef WIN32 // or SIGBUS
+               case SIGBUS:  sigdesc = "Bus error"; break;
+#endif
+               case SIGILL:  sigdesc = "Illegal instruction"; break;
+               case SIGABRT: sigdesc = "Aborted"; break;
+               case SIGFPE:  sigdesc = "Floating point exception"; break;
+               case SIGSEGV: sigdesc = "Segmentation fault"; break;
+               default:      sigdesc = "Yo dawg, we hit a bug while hitting a bug";
+       }
+
+       fprintf(stderr, "\n\n\e[1;37;41m    Engine Crash: %s (%d)    \e[m\n", sigdesc, sig);
+#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1
+       // the first two addresses will be in this function and in signal() in libc
+       backtrace_symbols_fd(stackframes + 2, framecount - 2, fileno(stderr));
+#endif
+       fprintf(stderr, "\e[1m%s\e[m\n", engineversion);
+
+       // DP8 TODO: send a disconnect message indicating we crashed, see CL_DisconnectEx()
+
+       // don't want a dead window left blocking the OS UI or the crash dialog
+       VID_Shutdown();
+       S_StopAllSounds();
+
+       Sys_SDL_Dialog("Engine Crash", sigdesc);
+
+       exit (sig);
+}
+
+static void Sys_HandleSignal(int sig)
+{
+#ifdef WIN32
+       // Windows users will likely never see this so no point replicating strsignal()
+       Con_Printf("\nReceived signal %d, exiting...\n", sig);
+#else
+       Con_Printf("\nReceived %s signal (%d), exiting...\n", strsignal(sig), sig);
+#endif
+       host.state = host_shutdown;
+}
+
+/// SDL2 only handles SIGINT and SIGTERM by default and doesn't log anything
+static void Sys_InitSignals(void)
 {
-       signal(SIGFPE, SIG_IGN);
+// Windows docs say its signal() only accepts these ones
+       signal(SIGABRT, Sys_HandleCrash);
+       signal(SIGFPE,  Sys_HandleCrash);
+       signal(SIGILL,  Sys_HandleCrash);
+       signal(SIGINT,  Sys_HandleSignal);
+       signal(SIGSEGV, Sys_HandleCrash);
+       signal(SIGTERM, Sys_HandleSignal);
+#ifndef WIN32
+       signal(SIGHUP,  Sys_HandleSignal);
+       signal(SIGQUIT, Sys_HandleSignal);
+       signal(SIGBUS,  Sys_HandleCrash);
+       signal(SIGPIPE, Sys_HandleSignal);
+#endif
+}
 
+int main (int argc, char **argv)
+{
        sys.argc = argc;
        sys.argv = (const char **)argv;
 
@@ -917,6 +990,8 @@ int main (int argc, char **argv)
        Sys_AllowProfiling(true);
 #endif
 
+       Sys_InitSignals();
+
        Host_Main();
 
        Sys_Quit(0);