Various bug-fixes for W3C test conformance and stack traces with exceptions and segfaults

1 files changed, 75 insertions, 0 deletions

diff --git a/apps/mmi-browser.cpp b/apps/mmi-browser.cpp
index 56d7f02..6f997e7 100644
--- a/apps/mmi-browser.cpp
+++ b/apps/mmi-browser.cpp
@@ -6,6 +6,14 @@
 #include <signal.h>
 #endif
 
+#ifdef HAS_EXECINFO_H
+#include <execinfo.h>
+#endif
+
+#ifdef HAS_DLFCN_H
+#include <dlfcn.h>
+#endif
+
 #ifdef _WIN32
 #include "XGetopt.h"
 #endif
@@ -30,6 +38,71 @@ class VerboseMonitor : public uscxml::InterpreterMonitor {
 	}
 };
 
+
+#ifdef HAS_EXECINFO_H
+void printBacktrace(void** array, int size) {
+	char** messages = backtrace_symbols(array, size);
+	for (int i = 0; i < size && messages != NULL; ++i) {
+		std::cerr << "\t" << messages[i] << std::endl;
+	}
+	std::cerr << std::endl;
+	free(messages);
+}
+
+#ifdef HAS_DLFCN_H
+// see https://gist.github.com/nkuln/2020860
+typedef void (*cxa_throw_type)(void *, void *, void (*) (void *));
+cxa_throw_type orig_cxa_throw = 0;
+
+void load_orig_throw_code() {
+	orig_cxa_throw = (cxa_throw_type) dlsym(RTLD_NEXT, "__cxa_throw");
+}
+
+extern "C"
+void __cxa_throw (void *thrown_exception, void *pvtinfo, void (*dest)(void *)) {
+	std::cerr << __FUNCTION__ << " will throw exception from " << std::endl;
+	if (orig_cxa_throw == 0)
+	load_orig_throw_code();
+
+	void *array[50];
+	size_t size = backtrace(array, 50);
+	printBacktrace(array, size);
+	orig_cxa_throw(thrown_exception, pvtinfo, dest);
+}
+#endif
+#endif
+
+
+// see http://stackoverflow.com/questions/2443135/how-do-i-find-where-an-exception-was-thrown-in-c
+void customTerminate() {
+	static bool tried_throw = false;
+	try {
+		// try once to re-throw currently active exception
+		if (!tried_throw) {
+			throw;
+			tried_throw = true;
+		} else {
+			tried_throw = false;
+		};
+	}
+	catch (const std::exception &e) {
+		std::cerr << __FUNCTION__ << " caught unhandled exception. what(): "
+		<< e.what() << std::endl;
+	}
+	catch (...) {
+		std::cerr << __FUNCTION__ << " caught unknown/unhandled exception."
+		<< std::endl;
+	}
+	
+#ifdef HAS_EXECINFO_H
+	void * array[50];
+	int size = backtrace(array, 50);
+
+	printBacktrace(array, size);
+#endif
+	abort();
+}
+
 void printUsageAndExit() {
 	printf("mmi-browser version " USCXML_VERSION " (" CMAKE_BUILD_TYPE " build - " CMAKE_COMPILER_STRING ")\n");
 	printf("Usage\n");
@@ -48,6 +121,8 @@ void printUsageAndExit() {
 int main(int argc, char** argv) {
 	using namespace uscxml;
 
+	std::set_terminate(customTerminate);
+	
 #ifdef HAS_SIGNAL_H
 	signal(SIGPIPE, SIG_IGN);
 #endif