glibc/sysdeps/generic/elf/backtracesyms.c

/* Return list with names for address in backtrace.
   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <assert.h>
#include <execinfo.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <ldsodefs.h>

#if __ELF_NATIVE_CLASS == 32
# define WORD_WIDTH 8
#else
/* We assyme 64bits.  */
# define WORD_WIDTH 16
#endif


char **
__backtrace_symbols (array, size)
     void *const *array;
     int size;
{
  Dl_info info[size];
  int status[size];
  int cnt;
  size_t total = 0;
  char **result;

  /* Fill in the information we can get from `dladdr'.  */
  for (cnt = 0; cnt < size; ++cnt)
    {
      status[cnt] = _dl_addr (array[cnt], &info[cnt]);
      if (status[cnt] && info[cnt].dli_fname && info[cnt].dli_fname[0] != '\0')
	/* We have some info, compute the length of the string which will be
	   "<file-name>(<sym-name>) [+offset].  */
	total += (strlen (info[cnt].dli_fname ?: "")
		  + (info[cnt].dli_sname
		     ? strlen (info[cnt].dli_sname) + 3 + WORD_WIDTH + 3
		     : 1)
		  + WORD_WIDTH + 5);
      else
	total += 5 + WORD_WIDTH;
    }

  /* Allocate memory for the result.  */
  result = (char **) malloc (size * sizeof (char *) + total);
  if (result != NULL)
    {
      char *last = (char *) (result + size);

      for (cnt = 0; cnt < size; ++cnt)
	{
	  result[cnt] = last;

	  if (status[cnt] && info[cnt].dli_fname
	      && info[cnt].dli_fname[0] != '\0')
	    {
	      char buf[20];

	      if (array[cnt] >= (void *) info[cnt].dli_saddr)
		sprintf (buf, "+%#lx",
			 (unsigned long)(array[cnt] - info[cnt].dli_saddr));
	      else
		sprintf (buf, "-%#lx",
			 (unsigned long)(info[cnt].dli_saddr - array[cnt]));

	      last += 1 + sprintf (last, "%s%s%s%s%s[%p]",
				   info[cnt].dli_fname ?: "",
				   info[cnt].dli_sname ? "(" : "",
				   info[cnt].dli_sname ?: "",
				   info[cnt].dli_sname ? buf : "",
				   info[cnt].dli_sname ? ") " : " ",
				   array[cnt]);
	    }
	  else
	    last += 1 + sprintf (last, "[%p]", array[cnt]);
	}
      assert (last <= (char *) result + size * sizeof (char *) + total);
    }

  return result;
}
weak_alias (__backtrace_symbols, backtrace_symbols)