How to print a stack trace whenever a certain function is called

ghz 1years ago ⋅ 8642 views

Question

Is there any way to dump the call stack in a running process in C or C++ every time a certain function is called? What I have in mind is something like this:

void foo()
{
   print_stack_trace();

   // foo's body

   return
}

Where print_stack_trace works similarly to caller in Perl.

Or something like this:

int main (void)
{
    // will print out debug info every time foo() is called
    register_stack_trace_function(foo); 

    // etc...
}

where register_stack_trace_function puts some sort of internal breakpoint that will cause a stack trace to be printed whenever foo is called.

Does anything like this exist in some standard C library?

I am working on Linux, using GCC.

Background

I have a test run that behaves differently based on some commandline switches that shouldn't affect this behavior. My code has a pseudo-random number generator that I assume is being called differently based on these switches. I want to be able to run the test with each set of switches and see if the random number generator is called differently for each one.

Answer

For a linux-only solution you can use [backtrace(3)](http://www.kernel.org/doc/man- pages/online/pages/man3/backtrace.3.html) that simply returns an array of void * (in fact each of these point to the return address from the corresponding stack frame). To translate these to something of use, there's backtrace_symbols(3).

Pay attention to the [notes section in backtrace(3)](http://www.kernel.org/doc/man- pages/online/pages/man3/backtrace.3.html#NOTES):

The symbol names may be unavailable without the use of special linker options. For systems using the GNU linker, it is necessary to use the -rdynamic linker option. Note that names of "static" functions are not exposed, and won't be available in the backtrace.

#c