axolm / libsfe

Library for extracting stacktrace from exception.

Just playground. Do not use in production!

libsfe

Library for extracting stacktrace from exception.

Install (Tested only for Linux)

$ # depends on `libboost-stacktrace-dev`
$ git clone [e-mail]:axolm/libsfe.git
$ cd libsfe
$ make build-release
$ sudo make install

Motivational example

basic.cpp file

#include <iostream>
#include <sfe/sfe.hpp>
#include <stdexcept>

void throw_something() {
  throw std::runtime_error("SOME ERROR");
}

int main() {
  try {
    throw_something();
  } catch (const std::exception& exc) {
    auto trace = sfe::get_current_exception_stacktrace();
    std::cerr << "Caught exception. Err: `" << exc.what() << "`, Trace:\n"
              << trace;
  }
  return 0;
}

Compiling and runing

$ g++ -g -DBOOST_STACKTRACE_DYN_LINK basic.cpp -obasic -lsfe_basic -lboost_stacktrace_backtrace

$ ./basic
Caught exception. Err: `SOME ERROR`, Trace:

# Debug info without recompiling!
$ LD_PRELOAD=/usr/local/lib/libsfe_preload.so ./basic
Caught exception. Err: `SOME ERROR`, Trace:
 0# throw_something() at /home/axolm/basic.cpp:6
 1# main at /home/axolm/basic.cpp:17
 2# 0x00007FB823D77BF7 in /lib/x86_64-linux-gnu/libc.so.6
 3# 0x0000558E89A2202A in ./basic

How does it work

• libsfe_basic.so just returns empty stacktrace from sfe::get_current_exception_stacktrace().
• libsfe_preload.so overrides function __cxa_allocate_exception, dumps boost::stacktrace near exception obj and in sfe::get_current_exception_stacktrace() loads it and returns.

Deps

• libdl
• boost/stacktrace