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 $f)
  68                 base=${f##*/}
  69                 dis=$dir/${base%.o}.dis
  70
  71                 [ ! -d "$dir" ] && mkdir -p $dir
  72
  73                 # remove addresses for a cleaner diff
  74                 # http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
  75                 $OBJDUMP -D $f | sed "s/^[[:space:]]\+[0-9a-f]\+//" > $dis
  76         done
  77 }
  78
  79 dodiff() {
  80         [ $# -ne 2 ] && [ $# -ne 0 ] && usage
  81
  82         if [ $# -eq 0 ]; then
  83                 SRC="`git rev-parse --short HEAD^`"
  84                 DST="`git rev-parse --short HEAD`"
  85         else
  86                 SRC="`git rev-parse --short $1`"
  87                 DST="`git rev-parse --short $2`"
  88         fi
  89
  90         DIFF="`which colordiff`"
  91
  92         if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
  93                 DIFF="`which diff`"
  94         fi
  95
  96         SRCD="$TMPD/$SRC"
  97         DSTD="$TMPD/$DST"
  98
  99         if [ ! -d "$SRCD" ]; then
 100                 echo >&2 "ERROR: $SRCD doesn't exist"
 101                 exit 1
 102         fi
 103
 104         if [ ! -d "$DSTD" ]; then
 105                 echo >&2 "ERROR: $DSTD doesn't exist"
 106                 exit 1
 107         fi
 108
 109         $DIFF -Nurd $SRCD $DSTD
 110 }
 111
 112 doclean() {
 113         [ $# -eq 0 ] && usage
 114         [ $# -gt 1 ] && usage
 115
 116         if [ "x$1" = "xall" ]; then
 117                 rm -rf $TMPD/*
 118         else
 119                 CMT="`git rev-parse --short $1`"
 120
 121                 if [ -d "$TMPD/$CMT" ]; then
 122                         rm -rf $TMPD/$CMT
 123                 else
 124                         echo >&2 "$CMT not found"
 125                 fi
 126         fi
 127 }
 128
 129 [ $# -eq 0 ] && usage
 130
 131 case "$1" in
 132         record)
 133                 shift
 134                 dorecord $*
 135                 ;;
 136         diff)
 137                 shift
 138                 dodiff $*
 139                 ;;
 140         clean)
 141                 shift
 142                 doclean $*
 143                 ;;
 144         *)
 145                 echo >&2 "Unrecognized command '$1'"
 146                 exit 1
 147                 ;;
 148 esac