stack_trace.cpp

#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#define UNW_LOCAL_ONLY
#include <libunwind.h>

#include <cxxabi.h>

#include <stdio.h>
#include <stdlib.h>

#define RESERVE_SIZE 256

int __attribute__((noinline)) backtrace(char* stacks[], int stack_len) {
    unw_cursor_t cursor;
    unw_context_t context;

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

    int n=0;
    while ( unw_step(&cursor) && n < stack_len) {
        unw_word_t off;

        char symbol[256] = {"<unknown>"};
        char *name = symbol;

        if ( !unw_get_proc_name(&cursor, symbol, sizeof(symbol), &off) ) {
            int status;
            if ( (name = abi::__cxa_demangle(symbol, NULL, NULL, &status)) == 0 )
                name = symbol;
        }

        char* p = (char*)malloc(sizeof(char*) * RESERVE_SIZE * 2);
        if (p == NULL) {
            return n;
        }
        sprintf(p, "#%-2d" PRIxPTR "%s + 0x%" PRIxPTR "\n",
                n,
                name,
                static_cast<uintptr_t>(off));
        stacks[n++] = p;

        if ( name != symbol ) {
            free(name);
        }
    }
    return n;
}