From 05e2e7b9c0dfa157f450d38d05a7e10fe3788d4f Mon Sep 17 00:00:00 2001
From: Andrew Belt <andrewpbelt@gmail.com>
Date: Sat, 13 Jul 2019 22:56:13 -0700
Subject: [PATCH] Reenable backtrace printing in log. Demangle symbols on
 Linux.

---
 src/main.cpp   |  5 ++---
 src/system.cpp | 26 +++++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 961e490b..94b54c0d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -22,7 +22,6 @@
 #include <thread>
 #include <unistd.h> // for getopt
 #include <signal.h> // for signal
-
 #if defined ARCH_WIN
 	#include <windows.h> // for CreateMutex
 #endif
@@ -40,7 +39,7 @@ static void fatalSignalHandler(int sig) {
 
 	FATAL("Fatal signal %d. Stack trace:\n%s", sig, system::getStackTrace().c_str());
 
-	// osdialog_message(OSDIALOG_ERROR, OSDIALOG_OK, "Rack has crashed. See log.txt for details.");
+	osdialog_message(OSDIALOG_ERROR, OSDIALOG_OK, "Rack has crashed. See log.txt for details.");
 
 	exit(1);
 }
@@ -99,7 +98,7 @@ int main(int argc, char *argv[]) {
 
 	// We can now install a signal handler and log the output
 	// Mac has its own decent crash handler
-#if 0
+#if defined ARCH_LIN
 	if (!settings::devMode) {
 		signal(SIGABRT, fatalSignalHandler);
 		signal(SIGFPE, fatalSignalHandler);
diff --git a/src/system.cpp b/src/system.cpp
index 29737277..d864964d 100644
--- a/src/system.cpp
+++ b/src/system.cpp
@@ -2,8 +2,10 @@
 #include <string.hpp>
 
 #include <thread>
+#include <regex>
 #include <dirent.h>
 #include <sys/stat.h>
+#include <cxxabi.h> // for __cxxabiv1::__cxa_demangle
 
 #if defined ARCH_LIN || defined ARCH_MAC
 	#include <pthread.h>
@@ -166,10 +168,32 @@ std::string getStackTrace() {
 	stackLen = backtrace(stack, stackLen);
 	char **strings = backtrace_symbols(stack, stackLen);
 
+	// Skip the first line because it's this function.
 	for (int i = 1; i < stackLen; i++) {
-		s += string::f("%d: %s\n", stackLen - i - 1, strings[i]);
+		s += string::f("%d: ", stackLen - i - 1);
+		// Parse line
+		std::regex r(R"((.*)\((.*)\+(.*)\) (.*))");
+		std::smatch match;
+		std::string line = strings[i];
+		if (std::regex_search(line, match, r)) {
+			s += match[1].str();
+			s += "(";
+			std::string symbol = match[2].str();
+			// Demangle symbol
+			char *symbolD = __cxxabiv1::__cxa_demangle(symbol.c_str(), NULL, NULL, NULL);
+			if (symbolD) {
+				symbol = symbolD;
+				free(symbolD);
+			}
+			s += symbol;
+			s += "+";
+			s += match[3].str();
+			s += ")";
+		}
+		s += "\n";
 	}
 	free(strings);
+
 #elif defined ARCH_WIN
 	HANDLE process = GetCurrentProcess();
 	SymInitialize(process, NULL, true);