How to Handle SIGSEGV and print back trace on receiving SIGSEGV in c/C++ program?

Question

Hi Guys,

I m constructing a C++ program in which I need to handle SIGSEGV and Signal handler should be able to print the Back Trace. Can any one help in this.

Regards

Answer 1

The best way to get a SIGSEV backtrace is generating a core file more than printing a backtrace; and if you handle the SIGSEV the system will not call the default core generator, take care with it.

If you want to handle the SIGSEV anyway (as have been commented before this is system deppendant), see the libc backtrace function [http://www.gnu.org/s/libc/manual/html_node/Backtraces.html ] , it culd be useful.

Answer 2

Adding to what Jon replied, you basically need a function like this to print backtrace. This function shoudl be called on the SIGSEGV. But I second Jon's point that letting the system generate corefile would be a much better debugging mechanism for you

void print_trace(int nSig)
{
  printf("print_trace: got signal %d\n", nSig);

  void           *array[32];    /* Array to store backtrace symbols */
  size_t          size;     /* To store the exact no of values stored */
  char          **strings;    /* To store functions from the backtrace list in ARRAY */
  size_t          nCnt;

  size = backtrace(array, 32);

  strings = backtrace_symbols(array, size);

  /* prints each string of function names of trace*/
  for (nCnt = 0; nCnt < size; nCnt++)
    fprintf(stderr, "%s\n", strings[nCnt]);


  exit(-1);
}