sysdeps/generic/elf/backtracesyms.c

   1 /* Return list with names for address in backtrace.
   2    Copyright (C) 1998,1999,2000,2001,2003 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 Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the 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    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <assert.h>
  22 #include <execinfo.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include <ldsodefs.h>
  28
  29 #if __ELF_NATIVE_CLASS == 32
  30 # define WORD_WIDTH 8
  31 #else
  32 /* We assyme 64bits.  */
  33 # define WORD_WIDTH 16
  34 #endif
  35
  36
  37 char **
  38 __backtrace_symbols (array, size)
  39      void *const *array;
  40      int size;
  41 {
  42   Dl_info info[size];
  43   int status[size];
  44   int cnt;
  45   size_t total = 0;
  46   char **result;
  47
  48   /* Fill in the information we can get from `dladdr'.  */
  49   for (cnt = 0; cnt < size; ++cnt)
  50     {
  51       status[cnt] = _dl_addr (array[cnt], &info[cnt], NULL, NULL);
  52       if (status[cnt] && info[cnt].dli_fname && info[cnt].dli_fname[0] != '\0')
  53         /* We have some info, compute the length of the string which will be
  54            "<file-name>(<sym-name>) [+offset].  */
  55         total += (strlen (info[cnt].dli_fname ?: "")
  56                   + (info[cnt].dli_sname
  57                      ? strlen (info[cnt].dli_sname) + 3 + WORD_WIDTH + 3
  58                      : 1)
  59                   + WORD_WIDTH + 5);
  60       else
  61         total += 5 + WORD_WIDTH;
  62     }
  63
  64   /* Allocate memory for the result.  */
  65   result = (char **) malloc (size * sizeof (char *) + total);
  66   if (result != NULL)
  67     {
  68       char *last = (char *) (result + size);
  69
  70       for (cnt = 0; cnt < size; ++cnt)
  71         {
  72           result[cnt] = last;
  73
  74           if (status[cnt] && info[cnt].dli_fname
  75               && info[cnt].dli_fname[0] != '\0')
  76             {
  77               char buf[20];
  78
  79               if (array[cnt] >= (void *) info[cnt].dli_saddr)
  80                 sprintf (buf, "+%#lx",
  81                          (unsigned long)(array[cnt] - info[cnt].dli_saddr));
  82               else
  83                 sprintf (buf, "-%#lx",
  84                          (unsigned long)(info[cnt].dli_saddr - array[cnt]));
  85
  86               last += 1 + sprintf (last, "%s%s%s%s%s[%p]",
  87                                    info[cnt].dli_fname ?: "",
  88                                    info[cnt].dli_sname ? "(" : "",
  89                                    info[cnt].dli_sname ?: "",
  90                                    info[cnt].dli_sname ? buf : "",
  91                                    info[cnt].dli_sname ? ") " : " ",
  92                                    array[cnt]);
  93             }
  94           else
  95             last += 1 + sprintf (last, "[%p]", array[cnt]);
  96         }
  97       assert (last <= (char *) result + size * sizeof (char *) + total);
  98     }
  99
 100   return result;
 101 }
 102 weak_alias (__backtrace_symbols, backtrace_symbols)