Getting the backtrace from the catch block

Question

I am using backtrace to get the information from where the exception is thrown. In the constructor of my exception, I am storing the backtrace in a std::string, and in the catch block for exceptions of this type, I am printing this backtrace.

But I was wondering, is it possible to somehow get the same backtrace in the catch block for other exception types?

Answer 1

I don't think so. When executons stops in catch block the stack is unwound, and all that has happened before is not in stack anymore.

Answer 2

You might be interested in a Boost library under development: Portable Backtrace. Example:

#include <boost/backtrace.hpp>
#include <iostream>

int foo()
{
    throw boost::runtime_error("My Error");
    return 10;
}

int bar()
{
    return foo()+20;
}


int main()
{
    try {
        std::cout << bar() << std::endl;
    }
    catch(std::exception const &e)
    {
        std::cerr << e.what() << std::endl;
        std::cerr << boost::trace(e);
    }
}

Prints:

My Error
0x403fe1: boost::stack_trace::trace(void**, int) + 0x1b in ./test_backtrace
0x405451: boost::backtrace::backtrace(unsigned long) + 0x65 in ./test_backtrace
0x4054d2: boost::runtime_error::runtime_error(std::string const&) + 0x32 in ./test_backtrace
0x40417e: foo() + 0x44 in ./test_backtrace
0x40425c: bar() + 0x9 in ./test_backtrace
0x404271: main + 0x10 in ./test_backtrace
0x7fd612ecd1a6: __libc_start_main + 0xe6 in /lib/libc.so.6
0x403b39: __gxx_personality_v0 + 0x99 in ./test_backtrace

Hope this helps!

Answer 3

Do the classes in question share a common base you can edit?

Otherwise, I provided a wonderful but terribly underappreciated answer at How can some code be run each time an exception is thrown in a Visual C++ program? ;-P Some others opined too.