1#! /bin/sh
2
3# Compare stripped copies of two given object files.
4
5# Copyright (C) 2007, 2008, 2009, 2010, 2012 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
24rm='rm -f'
25
26case $1 in
27-p | --preserve)
28  rm='echo preserving'
29  shift
30  ;;
31esac
32
33if test $# != 2; then
34  echo 'usage: compare-debug file1.o file2.o' >&2
35  exit 1
36fi
37
38if test ! -f "$1"; then
39  echo "$1" does not exist >&2
40  exit 1
41fi
42
43if test ! -f "$2"; then
44  echo "$2" does not exist >&2
45  exit 1
46fi
47
48suf1=stripped
49while test -f "$1.$suf1"; do
50  suf1=$suf1.
51done
52
53suf2=stripped
54while test -f "$2.$suf2"; do
55  suf2=$suf2.
56done
57
58trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
59
60case `uname -s` in
61Darwin)
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  ;;
74esac
75
76remove_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
90if cmp "$1.$suf1" "$2.$suf2"; then
91  status=0
92else
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
180fi
181
182$rm "$1.$suf1" "$2.$suf2"
183
184trap "exit $status; exit" 0 1 2 15
185
186if test -f "$1".gkd || test -f "$2".gkd; then
187  if cmp "$1".gkd "$2".gkd; then
188    :
189  else
190    status=$?
191  fi
192fi
193
194exit $status
195