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 GIT_DIR="`git rev-parse --git-dir`"
  29
  30 if [ -d "$GIT_DIR" ]; then
  31         TMPD="${GIT_DIR%git}tmp_objdiff"
  32
  33         [ -d "$TMPD" ] || mkdir "$TMPD"
  34 else
  35         echo "ERROR: git directory not found."
  36         exit 1
  37 fi
  38
  39 usage() {
  40         echo "Usage: $0 <command> <args>"
  41         echo "  record    <list of object files>"
  42         echo "  diff      <commitA> <commitB>"
  43         echo "  clean     all | <commit>"
  44         exit 1
  45 }
  46
  47 dorecord() {
  48         [ $# -eq 0 ] && usage
  49
  50         FILES="$*"
  51
  52         CMT="`git rev-parse --short HEAD`"
  53
  54         OBJDUMP="${CROSS_COMPILE}objdump"
  55         OBJDIFFD="$TMPD/$CMT"
  56
  57         [ ! -d "$OBJDIFFD" ] && mkdir -p "$OBJDIFFD"
  58
  59         for f in $FILES; do
  60                 dn="${f%/*}"
  61                 bn="${f##*/}"
  62
  63                 [ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
  64
  65                 # remove addresses for a more clear diff
  66                 # http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
  67                 $OBJDUMP -D "$f" | sed "s/^[[:space:]]\+[0-9a-f]\+//" \
  68                         >"$OBJDIFFD/$dn/$bn"
  69         done
  70 }
  71
  72 dodiff() {
  73         [ $# -ne 2 ] && [ $# -ne 0 ] && usage
  74
  75         if [ $# -eq 0 ]; then
  76                 SRC="`git rev-parse --short HEAD^`"
  77                 DST="`git rev-parse --short HEAD`"
  78         else
  79                 SRC="`git rev-parse --short $1`"
  80                 DST="`git rev-parse --short $2`"
  81         fi
  82
  83         DIFF="`which colordiff`"
  84
  85         if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
  86                 DIFF="`which diff`"
  87         fi
  88
  89         SRCD="$TMPD/$SRC"
  90         DSTD="$TMPD/$DST"
  91
  92         if [ ! -d "$SRCD" ]; then
  93                 echo "ERROR: $SRCD doesn't exist"
  94                 exit 1
  95         fi
  96
  97         if [ ! -d "$DSTD" ]; then
  98                 echo "ERROR: $DSTD doesn't exist"
  99                 exit 1
 100         fi
 101
 102         $DIFF -Nurd $SRCD $DSTD
 103 }
 104
 105 doclean() {
 106         [ $# -eq 0 ] && usage
 107         [ $# -gt 1 ] && usage
 108
 109         if [ "x$1" = "xall" ]; then
 110                 rm -rf $TMPD/*
 111         else
 112                 CMT="`git rev-parse --short $1`"
 113
 114                 if [ -d "$TMPD/$CMT" ]; then
 115                         rm -rf $TMPD/$CMT
 116                 else
 117                         echo "$CMT not found"
 118                 fi
 119         fi
 120 }
 121
 122 [ $# -eq 0 ] && usage
 123
 124 case "$1" in
 125         record)
 126                 shift
 127                 dorecord $*
 128                 ;;
 129         diff)
 130                 shift
 131                 dodiff $*
 132                 ;;
 133         clean)
 134                 shift
 135                 doclean $*
 136                 ;;
 137         *)
 138                 echo "Unrecognized command '$1'"
 139                 exit 1
 140                 ;;
 141 esac