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: $0 <command> <args>"
  39         echo >&2 "  record    <list of object files or directories>"
  40         echo >&2 "  diff      <commitA> <commitB>"
  41         echo >&2 "  clean     all | <commit>"
  42         exit 1
  43 }
  44
  45 get_output_dir() {
  46         dir=${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 do_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
  69 dorecord() {
  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
  90 dodiff() {
  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
 123 doclean() {
 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
 142 case "$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                 ;;
 159 esac