contrib/compare-debug

   1 #! /bin/sh
   2
   3 # Compare stripped copies of two given object files.
   4
   5 # Copyright (C) 2007-2023 Free Software Foundation, Inc.
   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 remove_comment ()
  77 {
  78   file=$1
  79   opts=
  80   for s in `objdump --section-headers "$file" | awk '{ print $2 }'`; do
  81     case "$s" in
  82     .comment*)
  83       opts="$opts --remove-section $s"
  84       ;;
  85     esac
  86   done
  87   [ -n "$opts" ] && objcopy $opts $file
  88 }
  89
  90 if cmp "$1.$suf1" "$2.$suf2"; then
  91   status=0
  92 else
  93   status=1
  94
  95   # Remove any .comment sections.
  96   if (objcopy -v) 2>&1 | grep ' --remove-section' > /dev/null \
  97      && (objdump --help) 2>&1 | grep ' --\[*section-\]*headers' > /dev/null; then
  98     remove_comment "$1.$suf1"
  99     remove_comment "$2.$suf2"
 100     if cmp "$1.$suf1" "$2.$suf2"; then
 101       status=0
 102     fi
 103   fi
 104
 105   # Assembler-generated CFI will add an .eh_frame section for -g not
 106   # present in -g0.  Try to cope with it by checking that an .eh_frame
 107   # section is present in either object file, and then stripping it
 108   # off before re-comparing.
 109
 110   cmd=
 111   cmp1=
 112   cmp2=
 113
 114   for t in objdump readelf eu-readelf; do
 115     if ($t --help) 2>&1 | grep ' --\[*section-\]*headers' > /dev/null; then
 116       cmd=$t
 117
 118       $cmd --section-headers "$1.$suf1" | grep '\.eh_frame' > /dev/null
 119       cmp1=$?
 120
 121       $cmd --section-headers "$2.$suf2" | grep '\.eh_frame' > /dev/null
 122       cmp2=$?
 123
 124       break
 125     fi
 126   done
 127
 128   # If we found .eh_frame in one but not the other, or if we could not
 129   # find a command to tell, or if there are LTO sections, try to strip
 130   # off the .eh_frame and LTO sections from both.
 131   if test "x$cmp1" != "x$cmp2" || test "x$cmd" = "x" ||
 132      $cmd --section-headers "$1.$suf1" | grep '.gnu.lto_' > /dev/null ||
 133      $cmd --section-headers "$2.$suf2" | grep '.gnu.lto_' > /dev/null ; then
 134     suf3=$suf1.
 135     while test -f "$1.$suf3"; do
 136       suf3=$suf3.
 137     done
 138
 139     suf4=$suf2.
 140     while test -f "$2.$suf4"; do
 141       suf4=$suf4.
 142     done
 143
 144     trap 'rm -f "$1.$suf1" "$2.$suf2" "$1.$suf3" "$2.$suf4"' 0 1 2 15
 145
 146     echo stripping off .eh_frame and LTO sections, then retrying >&2
 147
 148     seclist=".eh_frame .rel.eh_frame .rela.eh_frame"
 149     if test "x$cmd" != "x"; then
 150       seclist="$seclist "`{ $cmd --section-headers "$1.$suf1"; $cmd --section-headers "$2.$suf2"; } | sed -n 's,.* \(\.gnu\.lto_[^      ]*\).*,\1,p' | sort -u`
 151     fi
 152     rsopts=`for sec in $seclist; do echo " --remove-section $sec"; done`
 153
 154     if (objcopy -v) 2>&1 | grep ' --remove-section' > /dev/null; then
 155       objcopy $rsopts "$1.$suf1" "$1.$suf3"
 156       mv "$1.$suf3" "$1.$suf1"
 157
 158       objcopy $rsopts "$2.$suf2" "$2.$suf4"
 159       mv "$2.$suf4" "$2.$suf2"
 160     elif (strip --help) 2>&1 | grep ' --remove-section' > /dev/null; then
 161       cp "$1.$suf1" "$1.$suf3"
 162       strip $rsopts "$1.$suf3"
 163       mv "$1.$suf3" "$1.$suf1"
 164
 165       cp "$2.$suf2" "$2.$suf4"
 166       strip $rsopts "$2.$suf4"
 167       mv "$2.$suf4" "$2.$suf2"
 168     else
 169       echo failed to strip off .eh_frame >&2
 170     fi
 171
 172     trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
 173
 174     if cmp "$1.$suf1" "$2.$suf2"; then
 175       status=0
 176     else
 177       status=1
 178     fi
 179   fi
 180 fi
 181
 182 $rm "$1.$suf1" "$2.$suf2"
 183
 184 trap "exit $status; exit" 0 1 2 15
 185
 186 # Replace the suffix in $1 and $2 with .*.gkd, compare them if a
 187 # single file is found by the globbing.
 188 base1=`echo "$1" | sed '$s,\.[^.]*$,,'` gkd1=
 189 for f in "$base1".*.gkd; do
 190   if test "x$gkd1" != x; then
 191     gkd1=
 192     break
 193   elif test -f "$f"; then
 194     gkd1=$f
 195   fi
 196 done
 197 base2=`echo "$2" | sed '$s,\.[^.]*$,,'` gkd2=
 198 for f in "$base2".*.gkd; do
 199   if test "x$gkd2" != x; then
 200     gkd2=
 201     break
 202   elif test -f "$f"; then
 203     gkd2=$f
 204   fi
 205 done
 206 if test "x$gkd1" != x || test "x$gkd2" != x; then
 207   if cmp "${gkd1-/dev/null}" "${gkd2-/dev/null}"; then
 208     :
 209   else
 210     status=$?
 211   fi
 212 fi
 213
 214 exit $status