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 "$1"
  28         fi
  29 }
  30
  31 # override die(): this version puts in an extra line break, so that
  32 # the progress is still visible
  33
  34 die()
  35 {
  36         echo >&2
  37         echo "$*" >&2
  38         exit 1
  39 }
  40
  41 # When piped a commit, output a script to set the ident of either
  42 # "author" or "committer
  43
  44 set_ident () {
  45         lid="$(echo "$1" | tr "A-Z" "a-z")"
  46         uid="$(echo "$1" | tr "a-z" "A-Z")"
  47         pick_id_script='
  48                 /^'$lid' /{
  49                         s/'\''/'\''\\'\'\''/g
  50                         h
  51                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  52                         s/'\''/'\''\'\'\''/g
  53                         s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  54
  55                         g
  56                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  57                         s/'\''/'\''\'\'\''/g
  58                         s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  59
  60                         g
  61                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  62                         s/'\''/'\''\'\'\''/g
  63                         s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  64
  65                         q
  66                 }
  67         '
  68
  69         LANG=C LC_ALL=C sed -ne "$pick_id_script"
  70         # Ensure non-empty id name.
  71         echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  72 }
  73
  74 tempdir=.git-rewrite
  75 filter_env=
  76 filter_tree=
  77 filter_index=
  78 filter_parent=
  79 filter_msg=cat
  80 filter_commit='git commit-tree "$@"'
  81 filter_tag_name=
  82 filter_subdir=
  83 while case "$#" in 0) usage;; esac
  84 do
  85         case "$1" in
  86         --)
  87                 shift
  88                 break
  89                 ;;
  90         -*)
  91                 ;;
  92         *)
  93                 break;
  94         esac
  95
  96         # all switches take one argument
  97         ARG="$1"
  98         case "$#" in 1) usage ;; esac
  99         shift
 100         OPTARG="$1"
 101         shift
 102
 103         case "$ARG" in
 104         -d)
 105                 tempdir="$OPTARG"
 106                 ;;
 107         --env-filter)
 108                 filter_env="$OPTARG"
 109                 ;;
 110         --tree-filter)
 111                 filter_tree="$OPTARG"
 112                 ;;
 113         --index-filter)
 114                 filter_index="$OPTARG"
 115                 ;;
 116         --parent-filter)
 117                 filter_parent="$OPTARG"
 118                 ;;
 119         --msg-filter)
 120                 filter_msg="$OPTARG"
 121                 ;;
 122         --commit-filter)
 123                 filter_commit="$OPTARG"
 124                 ;;
 125         --tag-name-filter)
 126                 filter_tag_name="$OPTARG"
 127                 ;;
 128         --subdirectory-filter)
 129                 filter_subdir="$OPTARG"
 130                 ;;
 131         *)
 132                 usage
 133                 ;;
 134         esac
 135 done
 136
 137 dstbranch="$1"
 138 shift
 139 test -n "$dstbranch" || die "missing branch name"
 140 git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
 141         die "branch $dstbranch already exists"
 142
 143 test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
 144 mkdir -p "$tempdir/t"
 145 cd "$tempdir/t"
 146 workdir="$(pwd)"
 147
 148 case "$GIT_DIR" in
 149 /*)
 150         ;;
 151 *)
 152         GIT_DIR="$(pwd)/../../$GIT_DIR"
 153         ;;
 154 esac
 155 export GIT_DIR GIT_WORK_TREE=.
 156
 157 export GIT_INDEX_FILE="$(pwd)/../index"
 158 git read-tree # seed the index file
 159
 160 ret=0
 161
 162
 163 mkdir ../map # map old->new commit ids for rewriting parents
 164
 165 case "$filter_subdir" in
 166 "")
 167         git rev-list --reverse --topo-order --default HEAD \
 168                 --parents "$@"
 169         ;;
 170 *)
 171         git rev-list --reverse --topo-order --default HEAD \
 172                 --parents --full-history "$@" -- "$filter_subdir"
 173 esac > ../revs
 174 commits=$(wc -l <../revs | tr -d " ")
 175
 176 test $commits -eq 0 && die "Found nothing to rewrite"
 177
 178 i=0
 179 while read commit parents; do
 180         i=$(($i+1))
 181         printf "\rRewrite $commit ($i/$commits)"
 182
 183         case "$filter_subdir" in
 184         "")
 185                 git read-tree -i -m $commit
 186                 ;;
 187         *)
 188                 git read-tree -i -m $commit:"$filter_subdir"
 189         esac
 190
 191         export GIT_COMMIT=$commit
 192         git cat-file commit "$commit" >../commit
 193
 194         eval "$(set_ident AUTHOR <../commit)" ||
 195                 die "setting author failed for commit $commit"
 196         eval "$(set_ident COMMITTER <../commit)" ||
 197                 die "setting committer failed for commit $commit"
 198         eval "$filter_env" < /dev/null ||
 199                 die "env filter failed: $filter_env"
 200
 201         if [ "$filter_tree" ]; then
 202                 git checkout-index -f -u -a
 203                 # files that $commit removed are now still in the working tree;
 204                 # remove them, else they would be added again
 205                 git ls-files -z --others | xargs -0 rm -f
 206                 eval "$filter_tree" < /dev/null ||
 207                         die "tree filter failed: $filter_tree"
 208
 209                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 210                         xargs -0 git update-index --add --replace --remove
 211                 git ls-files -z --others | \
 212                         xargs -0 git update-index --add --replace --remove
 213         fi
 214
 215         eval "$filter_index" < /dev/null ||
 216                 die "index filter failed: $filter_index"
 217
 218         parentstr=
 219         for parent in $parents; do
 220                 for reparent in $(map "$parent"); do
 221                         parentstr="$parentstr -p $reparent"
 222                 done
 223         done
 224         if [ "$filter_parent" ]; then
 225                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 226                                 die "parent filter failed: $filter_parent"
 227         fi
 228
 229         sed -e '1,/^$/d' <../commit | \
 230                 eval "$filter_msg" > ../message ||
 231                         die "msg filter failed: $filter_msg"
 232         sh -c "$filter_commit" "git commit-tree" \
 233                 $(git write-tree) $parentstr < ../message > ../map/$commit
 234 done <../revs
 235
 236 src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
 237 target_head=$(head -n 1 ../map/$src_head)
 238 case "$target_head" in
 239 '')
 240         echo Nothing rewritten
 241         ;;
 242 *)
 243         git update-ref refs/heads/"$dstbranch" $target_head
 244         if [ $(wc -l <../map/$src_head) -gt 1 ]; then
 245                 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 $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
 246                 sed 's/^/       /' ../map/$src_head >&2
 247                 ret=1
 248         fi
 249         ;;
 250 esac
 251
 252 if [ "$filter_tag_name" ]; then
 253         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 254         while read sha1 type ref; do
 255                 ref="${ref#refs/tags/}"
 256                 # XXX: Rewrite tagged trees as well?
 257                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
 258                         continue;
 259                 fi
 260
 261                 if [ "$type" = "tag" ]; then
 262                         # Dereference to a commit
 263                         sha1t="$sha1"
 264                         sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 265                 fi
 266
 267                 [ -f "../map/$sha1" ] || continue
 268                 new_sha1="$(cat "../map/$sha1")"
 269                 export GIT_COMMIT="$sha1"
 270                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 271                         die "tag name filter failed: $filter_tag_name"
 272
 273                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 274
 275                 if [ "$type" = "tag" ]; then
 276                         # Warn that we are not rewriting the tag object itself.
 277                         warn "unreferencing tag object $sha1t"
 278                 fi
 279
 280                 git update-ref "refs/tags/$new_ref" "$new_sha1"
 281         done
 282 fi
 283
 284 cd ../..
 285 rm -rf "$tempdir"
 286 printf "\nRewritten history saved to the $dstbranch branch\n"
 287
 288 exit $ret