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