xref: /linux/scripts/objdiff (revision 1ecc8e489abfdaa6d8d1689f7ff62fdf1adda30c)
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	for f in $FILES; do
56		dn="${f%/*}"
57		bn="${f##*/}"
58
59		[ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
60
61		# remove addresses for a more clear diff
62		# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
63		$OBJDUMP -D "$f" | sed "s/^[[:space:]]\+[0-9a-f]\+//" \
64			>"$OBJDIFFD/$dn/$bn"
65	done
66}
67
68dodiff() {
69	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
70
71	if [ $# -eq 0 ]; then
72		SRC="`git rev-parse --short HEAD^`"
73		DST="`git rev-parse --short HEAD`"
74	else
75		SRC="`git rev-parse --short $1`"
76		DST="`git rev-parse --short $2`"
77	fi
78
79	DIFF="`which colordiff`"
80
81	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
82		DIFF="`which diff`"
83	fi
84
85	SRCD="$TMPD/$SRC"
86	DSTD="$TMPD/$DST"
87
88	if [ ! -d "$SRCD" ]; then
89		echo >&2 "ERROR: $SRCD doesn't exist"
90		exit 1
91	fi
92
93	if [ ! -d "$DSTD" ]; then
94		echo >&2 "ERROR: $DSTD doesn't exist"
95		exit 1
96	fi
97
98	$DIFF -Nurd $SRCD $DSTD
99}
100
101doclean() {
102	[ $# -eq 0 ] && usage
103	[ $# -gt 1 ] && usage
104
105	if [ "x$1" = "xall" ]; then
106		rm -rf $TMPD/*
107	else
108		CMT="`git rev-parse --short $1`"
109
110		if [ -d "$TMPD/$CMT" ]; then
111			rm -rf $TMPD/$CMT
112		else
113			echo >&2 "$CMT not found"
114		fi
115	fi
116}
117
118[ $# -eq 0 ] &&	usage
119
120case "$1" in
121	record)
122		shift
123		dorecord $*
124		;;
125	diff)
126		shift
127		dodiff $*
128		;;
129	clean)
130		shift
131		doclean $*
132		;;
133	*)
134		echo >&2 "Unrecognized command '$1'"
135		exit 1
136		;;
137esac
138