xref: /openbmc/linux/scripts/objdiff (revision afb46f79) 
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
28GIT_DIR="`git rev-parse --git-dir`"
29
30if [ -d "$GIT_DIR" ]; then
31	TMPD="${GIT_DIR%git}tmp_objdiff"
32
33	[ -d "$TMPD" ] || mkdir "$TMPD"
34else
35	echo "ERROR: git directory not found."
36	exit 1
37fi
38
39usage() {
40	echo "Usage: $0 <command> <args>"
41	echo "  record    <list of object files>"
42	echo "  diff      <commitA> <commitB>"
43	echo "  clean     all | <commit>"
44	exit 1
45}
46
47dorecord() {
48	[ $# -eq 0 ] && usage
49
50	FILES="$*"
51
52	CMT="`git rev-parse --short HEAD`"
53
54	OBJDUMP="${CROSS_COMPILE}objdump"
55	OBJDIFFD="$TMPD/$CMT"
56
57	[ ! -d "$OBJDIFFD" ] && mkdir -p "$OBJDIFFD"
58
59	for f in $FILES; do
60		dn="${f%/*}"
61		bn="${f##*/}"
62
63		[ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
64
65		# remove addresses for a more clear diff
66		# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
67		$OBJDUMP -D "$f" | sed "s/^[[:space:]]\+[0-9a-f]\+//" \
68			>"$OBJDIFFD/$dn/$bn"
69	done
70}
71
72dodiff() {
73	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
74
75	if [ $# -eq 0 ]; then
76		SRC="`git rev-parse --short HEAD^`"
77		DST="`git rev-parse --short HEAD`"
78	else
79		SRC="`git rev-parse --short $1`"
80		DST="`git rev-parse --short $2`"
81	fi
82
83	DIFF="`which colordiff`"
84
85	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
86		DIFF="`which diff`"
87	fi
88
89	SRCD="$TMPD/$SRC"
90	DSTD="$TMPD/$DST"
91
92	if [ ! -d "$SRCD" ]; then
93		echo "ERROR: $SRCD doesn't exist"
94		exit 1
95	fi
96
97	if [ ! -d "$DSTD" ]; then
98		echo "ERROR: $DSTD doesn't exist"
99		exit 1
100	fi
101
102	$DIFF -Nurd $SRCD $DSTD
103}
104
105doclean() {
106	[ $# -eq 0 ] && usage
107	[ $# -gt 1 ] && usage
108
109	if [ "x$1" = "xall" ]; then
110		rm -rf $TMPD/*
111	else
112		CMT="`git rev-parse --short $1`"
113
114		if [ -d "$TMPD/$CMT" ]; then
115			rm -rf $TMPD/$CMT
116		else
117			echo "$CMT not found"
118		fi
119	fi
120}
121
122[ $# -eq 0 ] &&	usage
123
124case "$1" in
125	record)
126		shift
127		dorecord $*
128		;;
129	diff)
130		shift
131		dodiff $*
132		;;
133	clean)
134		shift
135		doclean $*
136		;;
137	*)
138		echo "Unrecognized command '$1'"
139		exit 1
140		;;
141esac
142