linux-yocto/scripts/objdiff

#!/bin/bash

SPDX-License-Identifier: GPL-2.0-only

objdiff - a small script for validating that a commit or series of commits

didn't change object code.

Copyright 2014, Jason Cooper jason@lakedaemon.net

usage example:

$ git checkout COMMIT_A

$

$ ./scripts/objdiff record path/to/*.o

$ git checkout COMMIT_B

$

$ ./scripts/objdiff record path/to/*.o

$ ./scripts/objdiff diff COMMIT_A COMMIT_B

$

And to clean up (everything is in .objdiff/*)

$ ./scripts/objdiff clean all

Note: 'make mrproper' will also remove .objdiff

SRCTREE=$(cd $(git rev-parse --show-toplevel 2>/dev/null); pwd)

if [ -z "$SRCTREE" ]; then echo >&2 "ERROR: Not a git repository." exit 1 fi

TMPD=$SRCTREE/.objdiff

usage() { echo >&2 "Usage: $0 " echo >&2 " record " echo >&2 " diff " echo >&2 " clean all | " exit 1 }

get_output_dir() { dir=${1%/*}

if [ "$dir" = "$1" ]; then
	dir=.
fi

dir=$(cd $dir; pwd)

echo $TMPD/$CMT${dir#$SRCTREE}

}

do_objdump() { dir=$(get_output_dir $1) base=${1##*/} stripped=$dir/${base%.o}.stripped dis=$dir/${base%.o}.dis

[ ! -d "$dir" ] && mkdir -p $dir

# remove addresses for a cleaner diff
# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
$STRIP -g $1 -R __bug_table -R .note -R .comment -o $stripped
$OBJDUMP -D $stripped | sed -e "s/^[[:space:]]\+[0-9a-f]\+//" -e "s:^$stripped:$1:" > $dis

}

dorecord() { [ $# -eq 0 ] && usage

FILES="$*"

CMT="`git rev-parse --short HEAD`"

STRIP="${CROSS_COMPILE}strip"
OBJDUMP="${CROSS_COMPILE}objdump"

for d in $FILES; do
	if [ -d "$d" ]; then
		for f in $(find $d -name '*.o')
		do
			do_objdump $f
		done
	else
		do_objdump $d
	fi
done

}

dodiff() { [ $# -ne 2 ] && [ $# -ne 0 ] && usage

if [ $# -eq 0 ]; then
	SRC="`git rev-parse --short HEAD^`"
	DST="`git rev-parse --short HEAD`"
else
	SRC="`git rev-parse --short $1`"
	DST="`git rev-parse --short $2`"
fi

DIFF="`which colordiff`"

if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
	DIFF="`which diff`"
fi

SRCD="$TMPD/$SRC"
DSTD="$TMPD/$DST"

if [ ! -d "$SRCD" ]; then
	echo >&2 "ERROR: $SRCD doesn't exist"
	exit 1
fi

if [ ! -d "$DSTD" ]; then
	echo >&2 "ERROR: $DSTD doesn't exist"
	exit 1
fi

$DIFF -Nurd $SRCD $DSTD

}

doclean() { [ $# -eq 0 ] && usage [ $# -gt 1 ] && usage

if [ "x$1" = "xall" ]; then
	rm -rf $TMPD/*
else
	CMT="`git rev-parse --short $1`"

	if [ -d "$TMPD/$CMT" ]; then
		rm -rf $TMPD/$CMT
	else
		echo >&2 "$CMT not found"
	fi
fi

}

[ $# -eq 0 ] && usage

case "$1" in record) shift dorecord $* ;; diff) shift dodiff $* ;; clean) shift doclean $* ;; *) echo >&2 "Unrecognized command '$1'" exit 1 ;; esac