git-filter-branch.sh

   1 #!/bin/sh
   2 #
   3 # Rewrite revision history
   4 # Copyright (c) Petr Baudis, 2006
   5 # Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
   6 #
   7 # Lets you rewrite the revision history of the current branch, creating
   8 # a new branch. You can specify a number of filters to modify the commits,
   9 # files and trees.
  10
  11 set -e
  12
  13 USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
  14 . git-sh-setup
  15
  16 warn () {
  17         echo "$*" >&2
  18 }
  19
  20 map()
  21 {
  22         # if it was not rewritten, take the original
  23         if test -r "$workdir/../map/$1"
  24         then
  25                 cat "$workdir/../map/$1"
  26         else
  27                 echo "$1"
  28         fi
  29 }
  30
  31 # When piped a commit, output a script to set the ident of either
  32 # "author" or "committer
  33
  34 set_ident () {
  35         lid="$(echo "$1" | tr "A-Z" "a-z")"
  36         uid="$(echo "$1" | tr "a-z" "A-Z")"
  37         pick_id_script='
  38                 /^'$lid' /{
  39                         s/'\''/'\''\\'\'\''/g
  40                         h
  41                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  42                         s/'\''/'\''\'\'\''/g
  43                         s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  44
  45                         g
  46                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  47                         s/'\''/'\''\'\'\''/g
  48                         s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  49
  50                         g
  51                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  52                         s/'\''/'\''\'\'\''/g
  53                         s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  54
  55                         q
  56                 }
  57         '
  58
  59         LANG=C LC_ALL=C sed -ne "$pick_id_script"
  60         # Ensure non-empty id name.
  61         echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  62 }
  63
  64 tempdir=.git-rewrite
  65 filter_env=
  66 filter_tree=
  67 filter_index=
  68 filter_parent=
  69 filter_msg=cat
  70 filter_commit='git commit-tree "$@"'
  71 filter_tag_name=
  72 filter_subdir=
  73 while case "$#" in 0) usage;; esac
  74 do
  75         case "$1" in
  76         --)
  77                 shift
  78                 break
  79                 ;;
  80         -*)
  81                 ;;
  82         *)
  83                 break;
  84         esac
  85
  86         # all switches take one argument
  87         ARG="$1"
  88         case "$#" in 1) usage ;; esac
  89         shift
  90         OPTARG="$1"
  91         shift
  92
  93         case "$ARG" in
  94         -d)
  95                 tempdir="$OPTARG"
  96                 ;;
  97         --env-filter)
  98                 filter_env="$OPTARG"
  99                 ;;
 100         --tree-filter)
 101                 filter_tree="$OPTARG"
 102                 ;;
 103         --index-filter)
 104                 filter_index="$OPTARG"
 105                 ;;
 106         --parent-filter)
 107                 filter_parent="$OPTARG"
 108                 ;;
 109         --msg-filter)
 110                 filter_msg="$OPTARG"
 111                 ;;
 112         --commit-filter)
 113                 filter_commit="$OPTARG"
 114                 ;;
 115         --tag-name-filter)
 116                 filter_tag_name="$OPTARG"
 117                 ;;
 118         --subdirectory-filter)
 119                 filter_subdir="$OPTARG"
 120                 ;;
 121         *)
 122                 usage
 123                 ;;
 124         esac
 125 done
 126
 127 dstbranch="$1"
 128 shift
 129 test -n "$dstbranch" || die "missing branch name"
 130 git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
 131         die "branch $dstbranch already exists"
 132
 133 test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
 134 mkdir -p "$tempdir/t"
 135 cd "$tempdir/t"
 136 workdir="$(pwd)"
 137
 138 case "$GIT_DIR" in
 139 /*)
 140         ;;
 141 *)
 142         GIT_DIR="$(pwd)/../../$GIT_DIR"
 143         ;;
 144 esac
 145 export GIT_DIR GIT_WORK_TREE=.
 146
 147 export GIT_INDEX_FILE="$(pwd)/../index"
 148 git read-tree # seed the index file
 149
 150 ret=0
 151
 152
 153 mkdir ../map # map old->new commit ids for rewriting parents
 154
 155 case "$filter_subdir" in
 156 "")
 157         git rev-list --reverse --topo-order --default HEAD \
 158                 --parents "$@"
 159         ;;
 160 *)
 161         git rev-list --reverse --topo-order --default HEAD \
 162                 --parents --full-history "$@" -- "$filter_subdir"
 163 esac > ../revs
 164 commits=$(cat ../revs | wc -l | tr -d " ")
 165
 166 test $commits -eq 0 && die "Found nothing to rewrite"
 167
 168 i=0
 169 while read commit parents; do
 170         i=$(($i+1))
 171         printf "\rRewrite $commit ($i/$commits)"
 172
 173         case "$filter_subdir" in
 174         "")
 175                 git read-tree -i -m $commit
 176                 ;;
 177         *)
 178                 git read-tree -i -m $commit:"$filter_subdir"
 179         esac
 180
 181         export GIT_COMMIT=$commit
 182         git cat-file commit "$commit" >../commit
 183
 184         eval "$(set_ident AUTHOR <../commit)"
 185         eval "$(set_ident COMMITTER <../commit)"
 186         eval "$filter_env" < /dev/null
 187
 188         if [ "$filter_tree" ]; then
 189                 git checkout-index -f -u -a
 190                 # files that $commit removed are now still in the working tree;
 191                 # remove them, else they would be added again
 192                 git ls-files -z --others | xargs -0 rm -f
 193                 eval "$filter_tree" < /dev/null
 194                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 195                         xargs -0 git update-index --add --replace --remove
 196                 git ls-files -z --others | \
 197                         xargs -0 git update-index --add --replace --remove
 198         fi
 199
 200         eval "$filter_index" < /dev/null
 201
 202         parentstr=
 203         for parent in $parents; do
 204                 for reparent in $(map "$parent"); do
 205                         parentstr="$parentstr -p $reparent"
 206                 done
 207         done
 208         if [ "$filter_parent" ]; then
 209                 parentstr="$(echo "$parentstr" | eval "$filter_parent")"
 210         fi
 211
 212         sed -e '1,/^$/d' <../commit | \
 213                 eval "$filter_msg" | \
 214                 sh -c "$filter_commit" "git commit-tree" $(git write-tree) \
 215                         $parentstr > ../map/$commit
 216 done <../revs
 217
 218 src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
 219 target_head=$(head -n 1 ../map/$src_head)
 220 case "$target_head" in
 221 '')
 222         echo Nothing rewritten
 223         ;;
 224 *)
 225         git update-ref refs/heads/"$dstbranch" $target_head
 226         if [ $(cat ../map/$src_head | wc -l) -gt 1 ]; then
 227                 echo "WARNING: Your commit filter caused the head commit to expand to several rewritten commits. Only the first such commit was recorded as the current $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
 228                 sed 's/^/       /' ../map/$src_head >&2
 229                 ret=1
 230         fi
 231         ;;
 232 esac
 233
 234 if [ "$filter_tag_name" ]; then
 235         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 236         while read sha1 type ref; do
 237                 ref="${ref#refs/tags/}"
 238                 # XXX: Rewrite tagged trees as well?
 239                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
 240                         continue;
 241                 fi
 242
 243                 if [ "$type" = "tag" ]; then
 244                         # Dereference to a commit
 245                         sha1t="$sha1"
 246                         sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 247                 fi
 248
 249                 [ -f "../map/$sha1" ] || continue
 250                 new_sha1="$(cat "../map/$sha1")"
 251                 export GIT_COMMIT="$sha1"
 252                 new_ref="$(echo "$ref" | eval "$filter_tag_name")"
 253
 254                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 255
 256                 if [ "$type" = "tag" ]; then
 257                         # Warn that we are not rewriting the tag object itself.
 258                         warn "unreferencing tag object $sha1t"
 259                 fi
 260
 261                 git update-ref "refs/tags/$new_ref" "$new_sha1"
 262         done
 263 fi
 264
 265 cd ../..
 266 rm -rf "$tempdir"
 267 printf "\nRewritten history saved to the $dstbranch branch\n"
 268
 269 exit $ret