How to traceback call stack on MIPS arch?

[Andrew Haley]

PRC writes:

 > Gcc saves the frame pointer to fp(s8) register at the beginning of
 > each function if compiling source with -O0.  But it won't do so if
 > compiling source with -O2. Without frame pointers, can I trace back
 > call stacks in current function context? Or is there any option
 > which forces gcc to save frame pointers for MIPS arch?

You need to use the unwinder.

#include <unwind.h>
#include <stdio.h>

static _Unwind_Reason_Code
backtrace_helper (struct _Unwind_Context *ctx, void *a)
{
  void *ip = (void*)_Unwind_GetIP (ctx);
  fprintf (stdout, "   %p\n", ip);
  return _URC_NO_REASON;
}  

void
print_backtrace (void)
{
  _Unwind_Backtrace (backtrace_helper, NULL);
}

int
main (int argc, char **argv)
{
  print_backtrace ();  
  return 0;
}

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