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@fmela
Last active September 22, 2023 10:58
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A C++ function that produces a stack backtrace with demangled function & method names.
/*
* Copyright (c) 2009-2017, Farooq Mela
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <execinfo.h> // for backtrace
#include <dlfcn.h> // for dladdr
#include <cxxabi.h> // for __cxa_demangle
#include <cstdio>
#include <cstdlib>
#include <string>
#include <sstream>
// This function produces a stack backtrace with demangled function & method names.
std::string Backtrace(int skip = 1)
{
void *callstack[128];
const int nMaxFrames = sizeof(callstack) / sizeof(callstack[0]);
char buf[1024];
int nFrames = backtrace(callstack, nMaxFrames);
char **symbols = backtrace_symbols(callstack, nFrames);
std::ostringstream trace_buf;
for (int i = skip; i < nFrames; i++) {
printf("%s\n", symbols[i]);
Dl_info info;
if (dladdr(callstack[i], &info) && info.dli_sname) {
char *demangled = NULL;
int status = -1;
if (info.dli_sname[0] == '_')
demangled = abi::__cxa_demangle(info.dli_sname, NULL, 0, &status);
snprintf(buf, sizeof(buf), "%-3d %*p %s + %zd\n",
i, int(2 + sizeof(void*) * 2), callstack[i],
status == 0 ? demangled :
info.dli_sname == 0 ? symbols[i] : info.dli_sname,
(char *)callstack[i] - (char *)info.dli_saddr);
free(demangled);
} else {
snprintf(buf, sizeof(buf), "%-3d %*p %s\n",
i, int(2 + sizeof(void*) * 2), callstack[i], symbols[i]);
}
trace_buf << buf;
}
free(symbols);
if (nFrames == nMaxFrames)
trace_buf << "[truncated]\n";
return trace_buf.str();
}
@Qwlouse
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Qwlouse commented Mar 12, 2013

Awesome! YMMD ^^

@fmela
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fmela commented Apr 22, 2013

Glad you found it useful. :)

@dholm
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dholm commented May 21, 2013

Thanks for this very useful gist!
If you are linking your binary using GNU ld you need to add --export-dynamic or most of your symbols will just be resolved to the name of the binary.

@fmela
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fmela commented Oct 28, 2013

Good point @dholm, thank you.

@dgotwisner
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I'm wanting to use a modification of this in some commercial software (saves a bit of re-inventing). What copyright and license is this released with?

@fmela
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fmela commented Jul 8, 2017

@dgotwisner In the past I've favored the BSD 2-clause license, so I've updated the gist to reflect this. I hope this works for you!

@pabitrad
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I am not getting correct function names of a C++ program.

funcname

@pthalamy
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@pabitrad, this is probably due the missing -export-dynamic GCC flag.
Trying rebuilding with : g++ -g -fpic -std=c++14 -export-dynamic Main.cpp -ldl -o Main.

That did it for me. It works like a charm, thanks @fmela! 😉

@drhongo
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drhongo commented Feb 26, 2019

pabitrad's problem is due to an error in the code: In snprintf format string replace '%*0p' by '%0*p'. That will fix it.

@franku
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franku commented Jun 18, 2019

Thanks for this useful piece of code! We changed it a little to return a std::vector instead of a string buffer.
https://github.com/bareos/bareos

@xiaozhuai
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Awesome! It would be better if it supported pretty print c++ method name.

__ZN4wuta12WTFaceModule14rendererUpdateENS_11RenderSceneENS_10RenderModeERNS_10InputFrameEiiii

wuta::WTFaceModule::rendererUpdate(wuta::RenderScene, wuta::RenderMode, wuta::InputFrame&, int, int, int, int)

Like what c++filt do

@fmela
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fmela commented Aug 13, 2020

@xiaozhuai, it should be de-mangling the names. Would you share your compiler, compiler flags, and linker flags here?

@xiaozhuai
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@fmela Android NDK 15 with clang.

-D__ANDROID_API__=21 -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes  -mfloat-abi=softfp -mfpu=vfpv3-d16 -fno-integrated-as -mthumb -mfpu=neon -Wa,--noexecstack -Wformat -Werror=format-security -std=c++11  -O3

@fmela
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fmela commented Aug 18, 2020

Sorry @xiaozhuai, I'm not familiar with compilation on Android. I did notice that --export-dynamic is not present in your flags. Did you try that?

@xiaozhuai
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@fmela I use clang, there is no --export-dynamic supported : (

@xiaozhuai
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xiaozhuai commented Aug 19, 2020

1   14_framebuffer                      0x00000001024de654 _Z11initProgramv + 52
2   14_framebuffer                      0x00000001024e47f6 main + 1206
3   libdyld.dylib                       0x00007fff6ce713d5 start + 1

I also try it on my mac. It seems abi::__cxa_demangle not working.

Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

@fmela
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fmela commented Aug 19, 2020

@xiaozhuai Sorry, I should have mentioned that that is a linker flag, not a compiler flag. You might need to try -Wl,--export-dynamic.

@xiaozhuai
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@fmela It works now, it should be -Wl,-export-dynamic. Thank you very much!

@N1coc4colA
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As this code work just... perfectly, can I add it to a library addon that have to make C++ development easier with a this library?

@zwimer
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zwimer commented Jun 28, 2021

Would it be possible to add an open source license to this so other projects can more freely use it? If you don't know which you prefer, this is a really simple guide to help: https://choosealicense.com/

@haseeb-heaven
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It doesn't work in Windows , you should state it only work in Linux

@f18m
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f18m commented Nov 22, 2021

This solution is nice but it's lacking the source code file and line number... I found backward-cpp (https://github.com/bombela/backward-cpp) to be better fitting my needs.,

@cppcooper
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This solution is nice but it's lacking the source code file and line number... I found backward-cpp (https://github.com/bombela/backward-cpp) to be better fitting my needs.,

nice, thanks for updating the thread here!

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