Apply patch #1078: Expand the GDB exceptionhandler.

With our current backtrace dumps I quite oftenly find that in case of segfaults, which combined with assert failures are the most common crash cause, I cannot easily see what value the dereferenced pointer held.

To be able to see this the exception handler will now invoke the "disassemble" and "info registers" commands when producing a back trace using GDB. This gives us the ability to see the precise assembly instruction that triggered the crash, together with the value of the register that was used as pointer.


git-svn-id: svn+ssh://svn.gna.org/svn/warzone/trunk@5352 4a71c877-e1ca-e34f-864e-861f7616d084

lib/exceptionhandler/exceptionhandler.c

@@ -461,10 +461,16 @@ static void posixExceptionHandler(int signum, siginfo_t * siginfo, WZ_DECL_UNUSE
 			}
 			else if (pid > (pid_t)0)
 			{
+				static const char gdbCommands[] = "backtrace full\n"
+				                                  "frame 3\n"
+				                                  "disassemble\n"
+				                                  "info registers\n"
+				                                  "quit\n";
+
 				close(gdbPipe[0]); // No input from pipe
 
-				write(gdbPipe[1], "backtrace full\n" "quit\n",
-					  strlen("backtrace full\n" "quit\n"));
+				write(gdbPipe[1], gdbCommands,
+					  sizeof(gdbCommands));
 
 				if (waitpid(pid, NULL, 0) < 0)
 				{