gcc/contrib/compare-debug
2024-01-03 12:19:35 +01:00

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#! /bin/sh
# Compare stripped copies of two given object files.
# Copyright (C) 2007-2024 Free Software Foundation, Inc.
# Originally by Alexandre Oliva <aoliva@redhat.com>
# This file is part of GCC.
# GCC is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
# GCC is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
# License for more details.
# You should have received a copy of the GNU General Public License
# along with GCC; see the file COPYING3. If not see
# <http://www.gnu.org/licenses/>.
rm='rm -f'
case $1 in
-p | --preserve)
rm='echo preserving'
shift
;;
esac
if test $# != 2; then
echo 'usage: compare-debug file1.o file2.o' >&2
exit 1
fi
if test ! -f "$1"; then
echo "$1" does not exist >&2
exit 1
fi
if test ! -f "$2"; then
echo "$2" does not exist >&2
exit 1
fi
suf1=stripped
while test -f "$1.$suf1"; do
suf1=$suf1.
done
suf2=stripped
while test -f "$2.$suf2"; do
suf2=$suf2.
done
trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
case `uname -s` in
Darwin)
# The strip command on darwin does not remove all debug info.
# Fortunately, we can use ld to do it instead.
ld -S -r -no_uuid "$1" -o "$1.$suf1"
ld -S -r -no_uuid "$2" -o "$2.$suf2"
;;
*)
cp "$1" "$1.$suf1"
strip "$1.$suf1"
cp "$2" "$2.$suf2"
strip "$2.$suf2"
;;
esac
remove_comment ()
{
file=$1
opts=
for s in `objdump --section-headers "$file" | awk '{ print $2 }'`; do
case "$s" in
.comment*)
opts="$opts --remove-section $s"
;;
esac
done
[ -n "$opts" ] && objcopy $opts $file
}
if cmp "$1.$suf1" "$2.$suf2"; then
status=0
else
status=1
# Remove any .comment sections.
if (objcopy -v) 2>&1 | grep ' --remove-section' > /dev/null \
&& (objdump --help) 2>&1 | grep ' --\[*section-\]*headers' > /dev/null; then
remove_comment "$1.$suf1"
remove_comment "$2.$suf2"
if cmp "$1.$suf1" "$2.$suf2"; then
status=0
fi
fi
# Assembler-generated CFI will add an .eh_frame section for -g not
# present in -g0. Try to cope with it by checking that an .eh_frame
# section is present in either object file, and then stripping it
# off before re-comparing.
cmd=
cmp1=
cmp2=
for t in objdump readelf eu-readelf; do
if ($t --help) 2>&1 | grep ' --\[*section-\]*headers' > /dev/null; then
cmd=$t
$cmd --section-headers "$1.$suf1" | grep '\.eh_frame' > /dev/null
cmp1=$?
$cmd --section-headers "$2.$suf2" | grep '\.eh_frame' > /dev/null
cmp2=$?
break
fi
done
# If we found .eh_frame in one but not the other, or if we could not
# find a command to tell, or if there are LTO sections, try to strip
# off the .eh_frame and LTO sections from both.
if test "x$cmp1" != "x$cmp2" || test "x$cmd" = "x" ||
$cmd --section-headers "$1.$suf1" | grep '.gnu.lto_' > /dev/null ||
$cmd --section-headers "$2.$suf2" | grep '.gnu.lto_' > /dev/null ; then
suf3=$suf1.
while test -f "$1.$suf3"; do
suf3=$suf3.
done
suf4=$suf2.
while test -f "$2.$suf4"; do
suf4=$suf4.
done
trap 'rm -f "$1.$suf1" "$2.$suf2" "$1.$suf3" "$2.$suf4"' 0 1 2 15
echo stripping off .eh_frame and LTO sections, then retrying >&2
seclist=".eh_frame .rel.eh_frame .rela.eh_frame"
if test "x$cmd" != "x"; then
seclist="$seclist "`{ $cmd --section-headers "$1.$suf1"; $cmd --section-headers "$2.$suf2"; } | sed -n 's,.* \(\.gnu\.lto_[^ ]*\).*,\1,p' | sort -u`
fi
rsopts=`for sec in $seclist; do echo " --remove-section $sec"; done`
if (objcopy -v) 2>&1 | grep ' --remove-section' > /dev/null; then
objcopy $rsopts "$1.$suf1" "$1.$suf3"
mv "$1.$suf3" "$1.$suf1"
objcopy $rsopts "$2.$suf2" "$2.$suf4"
mv "$2.$suf4" "$2.$suf2"
elif (strip --help) 2>&1 | grep ' --remove-section' > /dev/null; then
cp "$1.$suf1" "$1.$suf3"
strip $rsopts "$1.$suf3"
mv "$1.$suf3" "$1.$suf1"
cp "$2.$suf2" "$2.$suf4"
strip $rsopts "$2.$suf4"
mv "$2.$suf4" "$2.$suf2"
else
echo failed to strip off .eh_frame >&2
fi
trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
if cmp "$1.$suf1" "$2.$suf2"; then
status=0
else
status=1
fi
fi
fi
$rm "$1.$suf1" "$2.$suf2"
trap "exit $status; exit" 0 1 2 15
# Replace the suffix in $1 and $2 with .*.gkd, compare them if a
# single file is found by the globbing.
base1=`echo "$1" | sed '$s,\.[^.]*$,,'` gkd1=
for f in "$base1".*.gkd; do
if test "x$gkd1" != x; then
gkd1=
break
elif test -f "$f"; then
gkd1=$f
fi
done
base2=`echo "$2" | sed '$s,\.[^.]*$,,'` gkd2=
for f in "$base2".*.gkd; do
if test "x$gkd2" != x; then
gkd2=
break
elif test -f "$f"; then
gkd2=$f
fi
done
if test "x$gkd1" != x || test "x$gkd2" != x; then
if cmp "${gkd1-/dev/null}" "${gkd2-/dev/null}"; then
:
else
status=$?
fi
fi
exit $status