From d4f6c8b91fb6c85bbb5d2ba3477c14fc10383c44 Mon Sep 17 00:00:00 2001
From: Brian Norris <banorris@uci.edu>
Date: Fri, 5 Oct 2012 19:28:19 -0700
Subject: [PATCH] add stacktrace header, under WTFPL

Download:
http://idlebox.net/2008/0901-stacktrace-demangled/stacktrace.h

WTFPL:
http://sam.zoy.org/wtfpl/
---
 stacktrace.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 stacktrace.h

diff --git a/stacktrace.h b/stacktrace.h
new file mode 100644
index 0000000..01d31d2
--- /dev/null
+++ b/stacktrace.h
@@ -0,0 +1,86 @@
+// stacktrace.h (c) 2008, Timo Bingmann from http://idlebox.net/
+// published under the WTFPL v2.0
+
+#ifndef __STACKTRACE_H__
+#define __STACKTRACE_H__
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <execinfo.h>
+#include <cxxabi.h>
+
+/** Print a demangled stack backtrace of the caller function to FILE* out. */
+static inline void print_stacktrace(FILE *out = stderr, unsigned int max_frames = 63)
+{
+	fprintf(out, "stack trace:\n");
+
+	// storage array for stack trace address data
+	void* addrlist[max_frames+1];
+
+	// retrieve current stack addresses
+	int addrlen = backtrace(addrlist, sizeof(addrlist) / sizeof(void*));
+
+	if (addrlen == 0) {
+		fprintf(out, "  <empty, possibly corrupt>\n");
+		return;
+	}
+
+	// resolve addresses into strings containing "filename(function+address)",
+	// this array must be free()-ed
+	char** symbollist = backtrace_symbols(addrlist, addrlen);
+
+	// allocate string which will be filled with the demangled function name
+	size_t funcnamesize = 256;
+	char* funcname = (char*)malloc(funcnamesize);
+
+	// iterate over the returned symbol lines. skip the first, it is the
+	// address of this function.
+	for (int i = 1; i < addrlen; i++) {
+		char *begin_name = 0, *begin_offset = 0, *end_offset = 0;
+
+		// find parentheses and +address offset surrounding the mangled name:
+		// ./module(function+0x15c) [0x8048a6d]
+		for (char *p = symbollist[i]; *p; ++p) {
+			if (*p == '(')
+				begin_name = p;
+			else if (*p == '+')
+				begin_offset = p;
+			else if (*p == ')' && begin_offset) {
+				end_offset = p;
+				break;
+			}
+		}
+
+		if (begin_name && begin_offset && end_offset && begin_name < begin_offset) {
+			*begin_name++ = '\0';
+			*begin_offset++ = '\0';
+			*end_offset = '\0';
+
+			// mangled name is now in [begin_name, begin_offset) and caller
+			// offset in [begin_offset, end_offset). now apply
+			// __cxa_demangle():
+
+			int status;
+			char* ret = abi::__cxa_demangle(begin_name,
+					funcname, &funcnamesize, &status);
+			if (status == 0) {
+				funcname = ret; // use possibly realloc()-ed string
+				fprintf(out, "  %s : %s+%s\n",
+						symbollist[i], funcname, begin_offset);
+			} else {
+				// demangling failed. Output function name as a C function with
+				// no arguments.
+				fprintf(out, "  %s : %s()+%s\n",
+						symbollist[i], begin_name, begin_offset);
+			}
+		} else {
+			// couldn't parse the line? print the whole line.
+			fprintf(out, "  %s\n", symbollist[i]);
+		}
+	}
+
+	free(funcname);
+	free(symbollist);
+}
+
+#endif // __STACKTRACE_H__
-- 
2.34.1