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 USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
  12 . git-sh-setup
  13
  14 warn () {
  15         echo "$*" >&2
  16 }
  17
  18 map()
  19 {
  20         # if it was not rewritten, take the original
  21         if test -r "$workdir/../map/$1"
  22         then
  23                 cat "$workdir/../map/$1"
  24         else
  25                 echo "$1"
  26         fi
  27 }
  28
  29 # override die(): this version puts in an extra line break, so that
  30 # the progress is still visible
  31
  32 die()
  33 {
  34         echo >&2
  35         echo "$*" >&2
  36         exit 1
  37 }
  38
  39 # When piped a commit, output a script to set the ident of either
  40 # "author" or "committer
  41
  42 set_ident () {
  43         lid="$(echo "$1" | tr "A-Z" "a-z")"
  44         uid="$(echo "$1" | tr "a-z" "A-Z")"
  45         pick_id_script='
  46                 /^'$lid' /{
  47                         s/'\''/'\''\\'\'\''/g
  48                         h
  49                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  50                         s/'\''/'\''\'\'\''/g
  51                         s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  52
  53                         g
  54                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  55                         s/'\''/'\''\'\'\''/g
  56                         s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  57
  58                         g
  59                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  60                         s/'\''/'\''\'\'\''/g
  61                         s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  62
  63                         q
  64                 }
  65         '
  66
  67         LANG=C LC_ALL=C sed -ne "$pick_id_script"
  68         # Ensure non-empty id name.
  69         echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  70 }
  71
  72 tempdir=.git-rewrite
  73 filter_env=
  74 filter_tree=
  75 filter_index=
  76 filter_parent=
  77 filter_msg=cat
  78 filter_commit='git commit-tree "$@"'
  79 filter_tag_name=
  80 filter_subdir=
  81 while case "$#" in 0) usage;; esac
  82 do
  83         case "$1" in
  84         --)
  85                 shift
  86                 break
  87                 ;;
  88         -*)
  89                 ;;
  90         *)
  91                 break;
  92         esac
  93
  94         # all switches take one argument
  95         ARG="$1"
  96         case "$#" in 1) usage ;; esac
  97         shift
  98         OPTARG="$1"
  99         shift
 100
 101         case "$ARG" in
 102         -d)
 103                 tempdir="$OPTARG"
 104                 ;;
 105         --env-filter)
 106                 filter_env="$OPTARG"
 107                 ;;
 108         --tree-filter)
 109                 filter_tree="$OPTARG"
 110                 ;;
 111         --index-filter)
 112                 filter_index="$OPTARG"
 113                 ;;
 114         --parent-filter)
 115                 filter_parent="$OPTARG"
 116                 ;;
 117         --msg-filter)
 118                 filter_msg="$OPTARG"
 119                 ;;
 120         --commit-filter)
 121                 filter_commit="$OPTARG"
 122                 ;;
 123         --tag-name-filter)
 124                 filter_tag_name="$OPTARG"
 125                 ;;
 126         --subdirectory-filter)
 127                 filter_subdir="$OPTARG"
 128                 ;;
 129         *)
 130                 usage
 131                 ;;
 132         esac
 133 done
 134
 135 dstbranch="$1"
 136 shift
 137 test -n "$dstbranch" || die "missing branch name"
 138 git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
 139         die "branch $dstbranch already exists"
 140
 141 test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
 142 mkdir -p "$tempdir/t" &&
 143 cd "$tempdir/t" &&
 144 workdir="$(pwd)" ||
 145 die ""
 146
 147 case "$GIT_DIR" in
 148 /*)
 149         ;;
 150 *)
 151         GIT_DIR="$(pwd)/../../$GIT_DIR"
 152         ;;
 153 esac
 154 export GIT_DIR GIT_WORK_TREE=.
 155
 156 export GIT_INDEX_FILE="$(pwd)/../index"
 157 git read-tree || die "Could not seed the index"
 158
 159 ret=0
 160
 161 # map old->new commit ids for rewriting parents
 162 mkdir ../map || die "Could not create map/ directory"
 163
 164 case "$filter_subdir" in
 165 "")
 166         git rev-list --reverse --topo-order --default HEAD \
 167                 --parents "$@"
 168         ;;
 169 *)
 170         git rev-list --reverse --topo-order --default HEAD \
 171                 --parents --full-history "$@" -- "$filter_subdir"
 172 esac > ../revs || die "Could not get the commits"
 173 commits=$(wc -l <../revs | tr -d " ")
 174
 175 test $commits -eq 0 && die "Found nothing to rewrite"
 176
 177 i=0
 178 while read commit parents; do
 179         i=$(($i+1))
 180         printf "\rRewrite $commit ($i/$commits)"
 181
 182         case "$filter_subdir" in
 183         "")
 184                 git read-tree -i -m $commit
 185                 ;;
 186         *)
 187                 git read-tree -i -m $commit:"$filter_subdir"
 188         esac || die "Could not initialize the index"
 189
 190         export GIT_COMMIT=$commit
 191         git cat-file commit "$commit" >../commit ||
 192                 die "Cannot read 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                         die "Could not checkout the index"
 204                 # files that $commit removed are now still in the working tree;
 205                 # remove them, else they would be added again
 206                 git ls-files -z --others | xargs -0 rm -f
 207                 eval "$filter_tree" < /dev/null ||
 208                         die "tree filter failed: $filter_tree"
 209
 210                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 211                         xargs -0 git update-index --add --replace --remove
 212                 git ls-files -z --others | \
 213                         xargs -0 git update-index --add --replace --remove
 214         fi
 215
 216         eval "$filter_index" < /dev/null ||
 217                 die "index filter failed: $filter_index"
 218
 219         parentstr=
 220         for parent in $parents; do
 221                 for reparent in $(map "$parent"); do
 222                         parentstr="$parentstr -p $reparent"
 223                 done
 224         done
 225         if [ "$filter_parent" ]; then
 226                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 227                                 die "parent filter failed: $filter_parent"
 228         fi
 229
 230         sed -e '1,/^$/d' <../commit | \
 231                 eval "$filter_msg" > ../message ||
 232                         die "msg filter failed: $filter_msg"
 233         sh -c "$filter_commit" "git commit-tree" \
 234                 $(git write-tree) $parentstr < ../message > ../map/$commit
 235 done <../revs
 236
 237 src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
 238 target_head=$(head -n 1 ../map/$src_head)
 239 case "$target_head" in
 240 '')
 241         echo Nothing rewritten
 242         ;;
 243 *)
 244         git update-ref refs/heads/"$dstbranch" $target_head ||
 245                 die "Could not update $dstbranch with $target_head"
 246         if [ $(wc -l <../map/$src_head) -gt 1 ]; then
 247                 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 $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
 248                 sed 's/^/       /' ../map/$src_head >&2
 249                 ret=1
 250         fi
 251         ;;
 252 esac
 253
 254 if [ "$filter_tag_name" ]; then
 255         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 256         while read sha1 type ref; do
 257                 ref="${ref#refs/tags/}"
 258                 # XXX: Rewrite tagged trees as well?
 259                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
 260                         continue;
 261                 fi
 262
 263                 if [ "$type" = "tag" ]; then
 264                         # Dereference to a commit
 265                         sha1t="$sha1"
 266                         sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 267                 fi
 268
 269                 [ -f "../map/$sha1" ] || continue
 270                 new_sha1="$(cat "../map/$sha1")"
 271                 export GIT_COMMIT="$sha1"
 272                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 273                         die "tag name filter failed: $filter_tag_name"
 274
 275                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 276
 277                 if [ "$type" = "tag" ]; then
 278                         # Warn that we are not rewriting the tag object itself.
 279                         warn "unreferencing tag object $sha1t"
 280                 fi
 281
 282                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
 283                         die "Could not write tag $new_ref"
 284         done
 285 fi
 286
 287 cd ../..
 288 rm -rf "$tempdir"
 289 printf "\nRewritten history saved to the $dstbranch branch\n"
 290
 291 exit $ret