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