sysdeps/generic/elf/backtracesyms.c

   1 /* Return list with names for address in backtrace.
   2    Copyright (C) 1998, 1999 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <execinfo.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <elf/ldsodefs.h>
  27
  28 #if __ELF_NATIVE_CLASS == 32
  29 # define WORD_WIDTH 8
  30 #else
  31 /* We assyme 64bits.  */
  32 # define WORD_WIDTH 16
  33 #endif
  34
  35
  36 char **
  37 __backtrace_symbols (array, size)
  38      void *const *array;
  39      int size;
  40 {
  41   Dl_info info[size];
  42   int status[size];
  43   int cnt;
  44   size_t total = 0;
  45   char **result;
  46
  47   /* Fill in the information we can get from `dladdr'.  */
  48   for (cnt = 0; cnt < size; ++cnt)
  49     {
  50       status[cnt] = _dl_addr (array[cnt], &info[cnt]);
  51       if (status[cnt] && info[cnt].dli_fname && info[cnt].dli_fname[0] != '\0')
  52         /* We have some info, compute the length of the string which will be
  53            "<fct-name>(<sym-name>)[+offset].  */
  54         total += (strlen (info[cnt].dli_fname ?: "")
  55                   + (info[cnt].dli_sname
  56                      ? strlen (info[cnt].dli_sname) + 3 + WORD_WIDTH + 3
  57                      : 1)
  58                   + WORD_WIDTH + 5);
  59       else
  60         total += 5 + WORD_WIDTH;
  61     }
  62
  63   /* Allocate memory for the result.  */
  64   result = malloc (size * sizeof (char *) + total);
  65   if (result != NULL)
  66     {
  67       char *last = (char *) (result + size);
  68
  69       for (cnt = 0; cnt < size; ++cnt)
  70         {
  71           result[cnt] = last;
  72
  73           if (status[cnt] && info[cnt].dli_fname
  74               && info[cnt].dli_fname[0] != '\0')
  75             {
  76               char buf[20];
  77
  78               if (array[cnt] >= (void *) info[cnt].dli_saddr)
  79                 sprintf (buf, "+%#lx",
  80                          (unsigned long)(array[cnt] - info[cnt].dli_saddr));
  81               else
  82                 sprintf (buf, "-%#lx",
  83                          (unsigned long)(info[cnt].dli_saddr - array[cnt]));
  84
  85               last += 1 + sprintf (last, "%s%s%s%s%s[%p]",
  86                                    info[cnt].dli_fname ?: "",
  87                                    info[cnt].dli_sname ? "(" : "",
  88                                    info[cnt].dli_sname ?: "",
  89                                    info[cnt].dli_sname ? buf : "",
  90                                    info[cnt].dli_sname ? ") " : " ",
  91                                    array[cnt]);
  92             }
  93           else
  94             last += 1 + sprintf (last, "[%p]", array[cnt]);
  95         }
  96     }
  97
  98   return result;
  99 }
 100 weak_alias (__backtrace_symbols, backtrace_symbols)