Example
#include <stdio.h>
#include <backtrace.h>
static struct backtrace_state *g_state = NULL;
int cb_frame(
void *data,
uintptr_t pc,
const char *filename,
int lineno,
const char *function
) {
// In c++, you might want to use (include <cxxabi.h>)
// int status;
// char *demangled = abi::__cxa_demangle(function, NULL, NULL, &status);
const char *func_name = function; // (status == 0 && demangled) ? demangled : function;
printf("%-25s %16lx %4d %-32s %s\n",
(char*) data, // cast data to char* in order to prevent warning format ‘%s’ expects argument of type ‘char *
pc,
lineno,
func_name ? func_name : "??",
filename ? filename : "??"
);
// free(demangled);
return 0;
}
void cb_error(
void *data,
const char *msg,
int errnum
) {
printf("Error %d occurred: %s (%s)\n",
errnum,
msg,
(char*) data // cast data to char* in order to prevent warning format ‘%s’ expects argument of type ‘char *
);
}
void start_backtrace(char* data) {
printf("\n");
printf("data pc line function source file\n");
printf("========================== ================ ==== ================================ ==========================\n");
backtrace_full(
g_state,
1, // number of frames to skip skip
cb_frame,
cb_error,
data
);
printf("\n");
}
void third_func() {
start_backtrace("backtrace from func_c");
}
void second_func() {
third_func();
}
void first_func() {
second_func();
}
int main(int argc __attribute__((unused)), char **argv) {
g_state = backtrace_create_state(
argv[0],
0, // threaded
cb_error,
NULL // data. What is this used for.
);
first_func();
return 0;
}
Use -g when compiling and link with backtrace. This example can be compiled, for example, with
$ gcc -g -fdebug-prefix-map=$PWD=. -Wall -Wextra backtrace-test.c -o backtrace-test -lbacktrace
The -fdebug-prefix-map option is used to cut the path of source file backtrace-test.c to make the output a bit tidier.
When running, the example prints something similar to
data pc line function source file
========================== ================ ==== ================================ ==========================
backtrace from func_c 5596a41403f9 63 third_func ./backtrace-test.c
backtrace from func_c 5596a414040a 67 second_func ./backtrace-test.c
backtrace from func_c 5596a414041b 71 first_func ./backtrace-test.c
backtrace from func_c 5596a414045e 83 main ./backtrace-test.c
backtrace from func_c 7f059ea42249 58 __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h
backtrace from func_c 7f059ea42304 360 __libc_start_main_impl ../csu/libc-start.c
backtrace from func_c 5596a4140200 0 ?? ??
backtrace from func_c ffffffffffffffff 0 ?? ??