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