contrib/compare-debug

   1 #! /bin/sh
   2
   3 # Compare stripped copies of two given object files.
   4
   5 # Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation
   6 # Originally by Alexandre Oliva <aoliva@redhat.com>
   7
   8 # This file is part of GCC.
   9
  10 # GCC is free software; you can redistribute it and/or modify it under
  11 # the terms of the GNU General Public License as published by the Free
  12 # Software Foundation; either version 3, or (at your option) any later
  13 # version.
  14
  15 # GCC is distributed in the hope that it will be useful, but WITHOUT
  16 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17 # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  18 # License for more details.
  19
  20 # You should have received a copy of the GNU General Public License
  21 # along with GCC; see the file COPYING3.  If not see
  22 # <http://www.gnu.org/licenses/>.
  23
  24 rm='rm -f'
  25
  26 case $1 in
  27 -p | --preserve)
  28   rm='echo preserving'
  29   shift
  30   ;;
  31 esac
  32
  33 if test $# != 2; then
  34   echo 'usage: compare-debug file1.o file2.o' >&2
  35   exit 1
  36 fi
  37
  38 if test ! -f "$1"; then
  39   echo "$1" does not exist >&2
  40   exit 1
  41 fi
  42
  43 if test ! -f "$2"; then
  44   echo "$2" does not exist >&2
  45   exit 1
  46 fi
  47
  48 suf1=stripped
  49 while test -f "$1.$suf1"; do
  50   suf1=$suf1.
  51 done
  52
  53 suf2=stripped
  54 while test -f "$2.$suf2"; do
  55   suf2=$suf2.
  56 done
  57
  58 trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
  59
  60 case `uname -s` in
  61 Darwin)
  62   # The strip command on darwin does not remove all debug info.
  63   # Fortunately, we can use ld to do it instead.
  64   ld -S -r -no_uuid "$1" -o "$1.$suf1"
  65   ld -S -r -no_uuid "$2" -o "$2.$suf2"
  66   ;;
  67 *)
  68   cp "$1" "$1.$suf1"
  69   strip "$1.$suf1"
  70
  71   cp "$2" "$2.$suf2"
  72   strip "$2.$suf2"
  73   ;;
  74 esac
  75
  76 if cmp "$1.$suf1" "$2.$suf2"; then
  77   status=0
  78 else
  79   status=1
  80
  81   # Assembler-generated CFI will add an .eh_frame section for -g not
  82   # present in -g0.  Try to cope with it by checking that an .eh_frame
  83   # section is present in either object file, and then stripping it
  84   # off before re-comparing.
  85
  86   cmd=
  87   cmp1=
  88   cmp2=
  89
  90   for t in objdump readelf eu-readelf; do
  91     if ($t --help) 2>&1 | grep ' --\[*section-\]*headers' > /dev/null; then
  92       cmd=$t
  93
  94       $cmd --section-headers "$1.$suf1" | grep '\.eh_frame' > /dev/null
  95       cmp1=$?
  96
  97       $cmd --section-headers "$2.$suf2" | grep '\.eh_frame' > /dev/null
  98       cmp2=$?
  99
 100       break
 101     fi
 102   done
 103
 104   # If we found .eh_frame in one but not the other, or if we could not
 105   # find a command to tell, or if there are LTO sections, try to strip
 106   # off the .eh_frame and LTO sections from both.
 107   if test "x$cmp1" != "x$cmp2" || test "x$cmd" = "x" ||
 108      $cmd --section-headers "$1.$suf1" | grep '.gnu.lto_' > /dev/null ||
 109      $cmd --section-headers "$2.$suf2" | grep '.gnu.lto_' > /dev/null ; then
 110     suf3=$suf1.
 111     while test -f "$1.$suf3"; do
 112       suf3=$suf3.
 113     done
 114
 115     suf4=$suf2.
 116     while test -f "$2.$suf4"; do
 117       suf4=$suf4.
 118     done
 119
 120     trap 'rm -f "$1.$suf1" "$2.$suf2" "$1.$suf3" "$2.$suf4"' 0 1 2 15
 121
 122     echo stripping off .eh_frame and LTO sections, then retrying >&2
 123
 124     seclist=".eh_frame .rel.eh_frame .rela.eh_frame"
 125     if test "x$cmd" != "x"; then
 126       seclist="$seclist "`{ $cmd --section-headers "$1.$suf1"; $cmd --section-headers "$2.$suf2"; } | sed -n 's,.* \(\.gnu\.lto_[^      ]*\).*,\1,p' | sort -u`
 127     fi
 128     rsopts=`for sec in $seclist; do echo " --remove-section $sec"; done`
 129
 130     if (objcopy -v) 2>&1 | grep ' --remove-section' > /dev/null; then
 131       objcopy $rsopts "$1.$suf1" "$1.$suf3"
 132       mv "$1.$suf3" "$1.$suf1"
 133
 134       objcopy $rsopts "$2.$suf2" "$2.$suf4"
 135       mv "$2.$suf4" "$2.$suf2"
 136     elif (strip --help) 2>&1 | grep ' --remove-section' > /dev/null; then
 137       cp "$1.$suf1" "$1.$suf3"
 138       strip $rsopts "$1.$suf3"
 139       mv "$1.$suf3" "$1.$suf1"
 140
 141       cp "$2.$suf2" "$2.$suf4"
 142       strip $rsopts "$2.$suf4"
 143       mv "$2.$suf4" "$2.$suf2"
 144     else
 145       echo failed to strip off .eh_frame >&2
 146     fi
 147
 148     trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
 149
 150     if cmp "$1.$suf1" "$2.$suf2"; then
 151       status=0
 152     else
 153       status=1
 154     fi
 155   fi
 156 fi
 157
 158 $rm "$1.$suf1" "$2.$suf2"
 159
 160 trap "exit $status; exit" 0 1 2 15
 161
 162 if test -f "$1".gkd || test -f "$2".gkd; then
 163   if cmp "$1".gkd "$2".gkd; then
 164     :
 165   else
 166     status=$?
 167   fi
 168 fi
 169
 170 exit $status