Programmatic access to the call stack in C++

[kilimchoi]

http://eli.thegreenplace.net/2015/programmatic-access-to-the-call-stack-in-c/

[forrestthewoods]

I find it pretty annoying how often things are advertised as C++ but are Unix specific. As someone who ships Windows + OS X + Linux I'm pretty biased though.

Anyhow, there's pretty good support for stack traces on Win64. For 32 bit it's less good. https://msdn.microsoft.com/en-us/library/windows/desktop/ms6...

[nwmcsween → forrestthewoods]

dwarf debug info is a part of x86_64 abi

[mzs]

Cool thanks for mentioning libunwind. I had used backtrace() and libexecinfo where that was not available with not as good results.

[chuckcode → mzs]

gperftools also uses libunwind and does some nice timing and performance analysis for cpu and heap. https://code.google.com/p/gperftools/

[eliben → mzs]

libunwind is awesome. It uses the same information for its job that the actual compiler uses for unwinding exceptions in C++, etc (DWARF .eh_frame & co). It's also much more portable these days (I believe backtrace() is glibc-specific). There are also remote unwinding capabilities I want to play with

[cokernel_hacker → eliben]

Darwin (iOS and Mac OS) have it too: https://developer.apple.com/library/mac/documentation/Darwin...

[eliben → cokernel_hacker]

Ah cool.

But I'm fairly sure that these days os x uses libcxx which uses libunwind

[boulos → eliben]

I seem to recall them implementing the unwind interface but with standard rbp/ebp unwinding. As in http://www.opensource.apple.com/source/Libc/Libc-498.1.1/gen... and http://www.opensource.apple.com/source/Libc/Libc-825.25/gen/...

My biggest problem with "standard" libunwind is how slow it is compared to a whole loop against the registers (which of course isn't reliable with -fomit-frame-pointer). IIRC, the gcc's call to backtrace actually parses DWARF to work around this (and thus is super slow).

[mzs → eliben]

Yes backtrace() and friends is a glibc thing, but libexecinfo tries to be compatible and portable. Back when I used backtrace(), that was about the best there was, and it was not that great really. I'm glad I know about libunwind now thanks to this post.