Question

Looking at this question and this question I can see that for backtrace_symbols() to work, one must compile with the -rdynamic flag.

I’ve tried it into a test program and it works, but I’m writing a program that is also compiled with -static and this page says that backtrace_symbols() doesn’t work when -static is passed to the compiler/linker.

Is there any quick workaround to this or I’ll never have a human-readable backtrace function in my statically linked program?

Answer 1

The answer was already at hand: it was in the same page I linked in the question. At the end, I successfully used libunwind.

#include <libunwind.h>
#include <stdio.h>

void do_backtrace()
{
    unw_cursor_t    cursor;
    unw_context_t   context;

    unw_getcontext(&context);
    unw_init_local(&cursor, &context);

    while (unw_step(&cursor) > 0)
    {
        unw_word_t  offset, pc;
        char        fname[64];

        unw_get_reg(&cursor, UNW_REG_IP, &pc);

        fname[0] = '\0';
        (void) unw_get_proc_name(&cursor, fname, sizeof(fname), &offset);

        printf ("%p : (%s+0x%x) [%p]\n", pc, fname, offset, pc);
    }
}

int main()
{
 do_backtrace();
 return 0;
}

I was getting linking errors because I was (again) forgotting to place linker options at the end of the command line. I really don’t understand why g++/gcc don’t issue at least a warning when ignoring command line options. The correct command line to compile is (-g isn’t needed):

g++ -static unwind.cpp -o unwind -lunwind -lunwind-x86