Added a simple module that handles segfaults: print a message and provide a backtrace.

I grew tired of always starting gdb when it would've sufficed to know the function.
This routine will demangle C++ symbols, so you can see in which function we crashed.

src/storm.cpp

@@ -28,6 +28,7 @@
 #include "src/parser/AutoParser.h"
 #include "src/parser/PrctlParser.h"
 #include "src/utility/Settings.h"
+#include "src/utility/ErrorHandling.h"
 #include "src/formula/Formulas.h"
 
 #include "log4cplus/logger.h"
@@ -458,6 +459,9 @@ void testChecking() {
  * Main entry point.
  */
 int main(const int argc, const char* argv[]) {
+	// Catch segfaults and display a backtrace.
+	installSignalHandler();
+
 	printHeader(argc, argv);
 
 	initializeLogger();

src/utility/ErrorHandling.h

@@ -0,0 +1,64 @@
+/* 
+ * File:   ErrorHandling.h
+ * Author: Gereon Kremer
+ *
+ * Created on March 15, 2013, 4:10 PM
+ */
+
+#ifndef ERRORHANDLING_H
+#define	ERRORHANDLING_H
+
+#include <signal.h>
+#include <execinfo.h>
+#include <cxxabi.h>
+
+std::string demangle(const char* symbol) {
+	int status;
+	// Attention: sscanf format strings rely on size being 128
+	char temp[128];
+	char* demangled;
+	// Check for C++ symbol
+	if (sscanf(symbol, "%*[^(]%*[^_]%127[^)+]", temp) == 1) {
+		if (NULL != (demangled = abi::__cxa_demangle(temp, NULL, NULL, &status))) {
+			std::string result(demangled);
+			free(demangled);
+			return result;
+		}
+	}
+	// Check for C symbol
+	if (sscanf(symbol, "%127s", temp) == 1) {
+		return temp;
+	}
+	// Return plain symbol
+	return symbol;
+}
+
+void signalHandler(int sig) {
+#define SIZE 128
+	LOG4CPLUS_FATAL(logger, "We recieved a segfault. To start with, here is a backtrace.");
+
+	void *buffer[SIZE];
+ 	char **strings;
+	int nptrs;
+	nptrs = backtrace(buffer, SIZE);
+
+	strings = backtrace_symbols(buffer, nptrs);
+	if (strings == nullptr) {
+		std::cerr << "Obtaining the backtrace symbols failed. Well, shit." << std::endl;
+		exit(2);
+	}
+	// j = 2: skip the handler itself.
+	for (int j = 1; j < nptrs; j++) {
+		LOG4CPLUS_FATAL(logger, nptrs-j << ": " << demangle(strings[j]));
+	}
+	free(strings);
+	LOG4CPLUS_FATAL(logger, "That's all we can do. Bye.");
+	exit(2);
+}
+
+void installSignalHandler() {
+	signal(SIGSEGV, signalHandler);
+}
+
+#endif	/* ERRORHANDLING_H */
+