scripts/objdiff

   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
  28 SRCTREE=$(cd $(git rev-parse --show-toplevel 2>/dev/null); pwd)
  29
  30 if [ -z "$SRCTREE" ]; then
  31         echo >&2 "ERROR: Not a git repository."
  32         exit 1
  33 fi
  34
  35 TMPD=$SRCTREE/.tmp_objdiff
  36
  37 usage() {
  38         echo >&2 "Usage: $0 <command> <args>"
  39         echo >&2 "  record    <list of object files>"
  40         echo >&2 "  diff      <commitA> <commitB>"
  41         echo >&2 "  clean     all | <commit>"
  42         exit 1
  43 }
  44
  45 get_output_dir() {
  46         dir=${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
  57 dorecord() {
  58         [ $# -eq 0 ] && usage
  59
  60         FILES="$*"
  61
  62         CMT="`git rev-parse --short HEAD`"
  63
  64         OBJDUMP="${CROSS_COMPILE}objdump"
  65
  66         for f in $FILES; do
  67                 dir=$(get_output_dir $f)
  68                 bn="${f##*/}"
  69
  70                 [ ! -d "$dir" ] && mkdir -p $dir
  71
  72                 # remove addresses for a more clear diff
  73                 # http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
  74                 $OBJDUMP -D $f | sed "s/^[[:space:]]\+[0-9a-f]\+//" > $dir/$bn
  75         done
  76 }
  77
  78 dodiff() {
  79         [ $# -ne 2 ] && [ $# -ne 0 ] && usage
  80
  81         if [ $# -eq 0 ]; then
  82                 SRC="`git rev-parse --short HEAD^`"
  83                 DST="`git rev-parse --short HEAD`"
  84         else
  85                 SRC="`git rev-parse --short $1`"
  86                 DST="`git rev-parse --short $2`"
  87         fi
  88
  89         DIFF="`which colordiff`"
  90
  91         if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
  92                 DIFF="`which diff`"
  93         fi
  94
  95         SRCD="$TMPD/$SRC"
  96         DSTD="$TMPD/$DST"
  97
  98         if [ ! -d "$SRCD" ]; then
  99                 echo >&2 "ERROR: $SRCD doesn't exist"
 100                 exit 1
 101         fi
 102
 103         if [ ! -d "$DSTD" ]; then
 104                 echo >&2 "ERROR: $DSTD doesn't exist"
 105                 exit 1
 106         fi
 107
 108         $DIFF -Nurd $SRCD $DSTD
 109 }
 110
 111 doclean() {
 112         [ $# -eq 0 ] && usage
 113         [ $# -gt 1 ] && usage
 114
 115         if [ "x$1" = "xall" ]; then
 116                 rm -rf $TMPD/*
 117         else
 118                 CMT="`git rev-parse --short $1`"
 119
 120                 if [ -d "$TMPD/$CMT" ]; then
 121                         rm -rf $TMPD/$CMT
 122                 else
 123                         echo >&2 "$CMT not found"
 124                 fi
 125         fi
 126 }
 127
 128 [ $# -eq 0 ] && usage
 129
 130 case "$1" in
 131         record)
 132                 shift
 133                 dorecord $*
 134                 ;;
 135         diff)
 136                 shift
 137                 dodiff $*
 138                 ;;
 139         clean)
 140                 shift
 141                 doclean $*
 142                 ;;
 143         *)
 144                 echo >&2 "Unrecognized command '$1'"
 145                 exit 1
 146                 ;;
 147 esac