xref: /linux/scripts/objdiff (revision 5ab370e91af70d5f1b1dbaec78798a2ff236a2d5)
1#!/bin/bash
2
3# objdiff - a small script for validating that a commit or series of commits
4# didn't change object code.
5#
6# Copyright 2014, Jason Cooper <jason@lakedaemon.net>
7#
8# Licensed under the terms of the GNU GPL version 2
9
10# usage example:
11#
12# $ git checkout COMMIT_A
13# $ <your fancy build command here>
14# $ ./scripts/objdiff record path/to/*.o
15#
16# $ git checkout COMMIT_B
17# $ <your fancy build command here>
18# $ ./scripts/objdiff record path/to/*.o
19#
20# $ ./scripts/objdiff diff COMMIT_A COMMIT_B
21# $
22
23# And to clean up (everything is in .tmp_objdiff/*)
24# $ ./scripts/objdiff clean all
25#
26# Note: 'make mrproper' will also remove .tmp_objdiff
27
28SRCTREE=$(git rev-parse --show-toplevel 2>/dev/null)
29
30if [ -z "$SRCTREE" ]; then
31	echo >&2 "ERROR: Not a git repository."
32	exit 1
33fi
34
35TMPD=$SRCTREE/.tmp_objdiff
36
37usage() {
38	echo >&2 "Usage: $0 <command> <args>"
39	echo >&2 "  record    <list of object files>"
40	echo >&2 "  diff      <commitA> <commitB>"
41	echo >&2 "  clean     all | <commit>"
42	exit 1
43}
44
45dorecord() {
46	[ $# -eq 0 ] && usage
47
48	FILES="$*"
49
50	CMT="`git rev-parse --short HEAD`"
51
52	OBJDUMP="${CROSS_COMPILE}objdump"
53	OBJDIFFD="$TMPD/$CMT"
54
55	[ ! -d "$OBJDIFFD" ] && mkdir -p "$OBJDIFFD"
56
57	for f in $FILES; do
58		dn="${f%/*}"
59		bn="${f##*/}"
60
61		[ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
62
63		# remove addresses for a more clear diff
64		# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
65		$OBJDUMP -D "$f" | sed "s/^[[:space:]]\+[0-9a-f]\+//" \
66			>"$OBJDIFFD/$dn/$bn"
67	done
68}
69
70dodiff() {
71	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
72
73	if [ $# -eq 0 ]; then
74		SRC="`git rev-parse --short HEAD^`"
75		DST="`git rev-parse --short HEAD`"
76	else
77		SRC="`git rev-parse --short $1`"
78		DST="`git rev-parse --short $2`"
79	fi
80
81	DIFF="`which colordiff`"
82
83	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
84		DIFF="`which diff`"
85	fi
86
87	SRCD="$TMPD/$SRC"
88	DSTD="$TMPD/$DST"
89
90	if [ ! -d "$SRCD" ]; then
91		echo >&2 "ERROR: $SRCD doesn't exist"
92		exit 1
93	fi
94
95	if [ ! -d "$DSTD" ]; then
96		echo >&2 "ERROR: $DSTD doesn't exist"
97		exit 1
98	fi
99
100	$DIFF -Nurd $SRCD $DSTD
101}
102
103doclean() {
104	[ $# -eq 0 ] && usage
105	[ $# -gt 1 ] && usage
106
107	if [ "x$1" = "xall" ]; then
108		rm -rf $TMPD/*
109	else
110		CMT="`git rev-parse --short $1`"
111
112		if [ -d "$TMPD/$CMT" ]; then
113			rm -rf $TMPD/$CMT
114		else
115			echo >&2 "$CMT not found"
116		fi
117	fi
118}
119
120[ $# -eq 0 ] &&	usage
121
122case "$1" in
123	record)
124		shift
125		dorecord $*
126		;;
127	diff)
128		shift
129		dodiff $*
130		;;
131	clean)
132		shift
133		doclean $*
134		;;
135	*)
136		echo >&2 "Unrecognized command '$1'"
137		exit 1
138		;;
139esac
140