xref: /openbmc/linux/scripts/objdiff (revision 4beec1d7) 
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=$(cd $(git rev-parse --show-toplevel 2>/dev/null); pwd)
29
30if [ -z "$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: $0 <command> <args>"
39	echo >&2 "  record    <list of object files or directories>"
40	echo >&2 "  diff      <commitA> <commitB>"
41	echo >&2 "  clean     all | <commit>"
42	exit 1
43}
44
45get_output_dir() {
46	dir=${1%/*}
47
48	if [ "$dir" = "$1" ]; then
49		dir=.
50	fi
51
52	dir=$(cd $dir; pwd)
53
54	echo $TMPD/$CMT${dir#$SRCTREE}
55}
56
57do_objdump() {
58	dir=$(get_output_dir $1)
59	base=${1##*/}
60	dis=$dir/${base%.o}.dis
61
62	[ ! -d "$dir" ] && mkdir -p $dir
63
64	# remove addresses for a cleaner diff
65	# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
66	$OBJDUMP -D $1 | sed "s/^[[:space:]]\+[0-9a-f]\+//" > $dis
67}
68
69dorecord() {
70	[ $# -eq 0 ] && usage
71
72	FILES="$*"
73
74	CMT="`git rev-parse --short HEAD`"
75
76	OBJDUMP="${CROSS_COMPILE}objdump"
77
78	for d in $FILES; do
79		if [ -d "$d" ]; then
80			for f in $(find $d -name '*.o')
81			do
82				do_objdump $f
83			done
84		else
85			do_objdump $d
86		fi
87	done
88}
89
90dodiff() {
91	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
92
93	if [ $# -eq 0 ]; then
94		SRC="`git rev-parse --short HEAD^`"
95		DST="`git rev-parse --short HEAD`"
96	else
97		SRC="`git rev-parse --short $1`"
98		DST="`git rev-parse --short $2`"
99	fi
100
101	DIFF="`which colordiff`"
102
103	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
104		DIFF="`which diff`"
105	fi
106
107	SRCD="$TMPD/$SRC"
108	DSTD="$TMPD/$DST"
109
110	if [ ! -d "$SRCD" ]; then
111		echo >&2 "ERROR: $SRCD doesn't exist"
112		exit 1
113	fi
114
115	if [ ! -d "$DSTD" ]; then
116		echo >&2 "ERROR: $DSTD doesn't exist"
117		exit 1
118	fi
119
120	$DIFF -Nurd $SRCD $DSTD
121}
122
123doclean() {
124	[ $# -eq 0 ] && usage
125	[ $# -gt 1 ] && usage
126
127	if [ "x$1" = "xall" ]; then
128		rm -rf $TMPD/*
129	else
130		CMT="`git rev-parse --short $1`"
131
132		if [ -d "$TMPD/$CMT" ]; then
133			rm -rf $TMPD/$CMT
134		else
135			echo >&2 "$CMT not found"
136		fi
137	fi
138}
139
140[ $# -eq 0 ] &&	usage
141
142case "$1" in
143	record)
144		shift
145		dorecord $*
146		;;
147	diff)
148		shift
149		dodiff $*
150		;;
151	clean)
152		shift
153		doclean $*
154		;;
155	*)
156		echo >&2 "Unrecognized command '$1'"
157		exit 1
158		;;
159esac
160