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 # The following functions will also be available in the commit filter:
  12
  13 functions=$(cat << \EOF
  14 warn () {
  15         echo "$*" >&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 "$1"
  26         fi
  27 }
  28
  29 # if you run 'skip_commit "$@"' in a commit filter, it will print
  30 # the (mapped) parents, effectively skipping the commit.
  31
  32 skip_commit()
  33 {
  34         shift;
  35         while [ -n "$1" ];
  36         do
  37                 shift;
  38                 map "$1";
  39                 shift;
  40         done;
  41 }
  42
  43 # if you run 'git_commit_non_empty_tree "$@"' in a commit filter,
  44 # it will skip commits that leave the tree untouched, commit the other.
  45 git_commit_non_empty_tree()
  46 {
  47         if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
  48                 map "$3"
  49         else
  50                 git commit-tree "$@"
  51         fi
  52 }
  53 # override die(): this version puts in an extra line break, so that
  54 # the progress is still visible
  55
  56 die()
  57 {
  58         echo >&2
  59         echo "$*" >&2
  60         exit 1
  61 }
  62 EOF
  63 )
  64
  65 eval "$functions"
  66
  67 finish_ident() {
  68         # Ensure non-empty id name.
  69         echo "case \"\$GIT_$1_NAME\" in \"\") GIT_$1_NAME=\"\${GIT_$1_EMAIL%%@*}\" && export GIT_$1_NAME;; esac"
  70         # And make sure everything is exported.
  71         echo "export GIT_$1_NAME"
  72         echo "export GIT_$1_EMAIL"
  73         echo "export GIT_$1_DATE"
  74 }
  75
  76 set_ident () {
  77         parse_ident_from_commit author AUTHOR committer COMMITTER
  78         finish_ident AUTHOR
  79         finish_ident COMMITTER
  80 }
  81
  82 USAGE="[--env-filter <command>] [--tree-filter <command>]
  83         [--index-filter <command>] [--parent-filter <command>]
  84         [--msg-filter <command>] [--commit-filter <command>]
  85         [--tag-name-filter <command>] [--subdirectory-filter <directory>]
  86         [--original <namespace>] [-d <directory>] [-f | --force]
  87         [<rev-list options>...]"
  88
  89 OPTIONS_SPEC=
  90 . git-sh-setup
  91
  92 if [ "$(is_bare_repository)" = false ]; then
  93         require_clean_work_tree 'rewrite branches'
  94 fi
  95
  96 tempdir=.git-rewrite
  97 filter_env=
  98 filter_tree=
  99 filter_index=
 100 filter_parent=
 101 filter_msg=cat
 102 filter_commit=
 103 filter_tag_name=
 104 filter_subdir=
 105 orig_namespace=refs/original/
 106 force=
 107 prune_empty=
 108 remap_to_ancestor=
 109 while :
 110 do
 111         case "$1" in
 112         --)
 113                 shift
 114                 break
 115                 ;;
 116         --force|-f)
 117                 shift
 118                 force=t
 119                 continue
 120                 ;;
 121         --remap-to-ancestor)
 122                 # deprecated ($remap_to_ancestor is set now automatically)
 123                 shift
 124                 remap_to_ancestor=t
 125                 continue
 126                 ;;
 127         --prune-empty)
 128                 shift
 129                 prune_empty=t
 130                 continue
 131                 ;;
 132         -*)
 133                 ;;
 134         *)
 135                 break;
 136         esac
 137
 138         # all switches take one argument
 139         ARG="$1"
 140         case "$#" in 1) usage ;; esac
 141         shift
 142         OPTARG="$1"
 143         shift
 144
 145         case "$ARG" in
 146         -d)
 147                 tempdir="$OPTARG"
 148                 ;;
 149         --env-filter)
 150                 filter_env="$OPTARG"
 151                 ;;
 152         --tree-filter)
 153                 filter_tree="$OPTARG"
 154                 ;;
 155         --index-filter)
 156                 filter_index="$OPTARG"
 157                 ;;
 158         --parent-filter)
 159                 filter_parent="$OPTARG"
 160                 ;;
 161         --msg-filter)
 162                 filter_msg="$OPTARG"
 163                 ;;
 164         --commit-filter)
 165                 filter_commit="$functions; $OPTARG"
 166                 ;;
 167         --tag-name-filter)
 168                 filter_tag_name="$OPTARG"
 169                 ;;
 170         --subdirectory-filter)
 171                 filter_subdir="$OPTARG"
 172                 remap_to_ancestor=t
 173                 ;;
 174         --original)
 175                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
 176                 ;;
 177         *)
 178                 usage
 179                 ;;
 180         esac
 181 done
 182
 183 case "$prune_empty,$filter_commit" in
 184 ,)
 185         filter_commit='git commit-tree "$@"';;
 186 t,)
 187         filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
 188 ,*)
 189         ;;
 190 *)
 191         die "Cannot set --prune-empty and --commit-filter at the same time"
 192 esac
 193
 194 case "$force" in
 195 t)
 196         rm -rf "$tempdir"
 197 ;;
 198 '')
 199         test -d "$tempdir" &&
 200                 die "$tempdir already exists, please remove it"
 201 esac
 202 mkdir -p "$tempdir/t" &&
 203 tempdir="$(cd "$tempdir"; pwd)" &&
 204 cd "$tempdir/t" &&
 205 workdir="$(pwd)" ||
 206 die ""
 207
 208 # Remove tempdir on exit
 209 trap 'cd ../..; rm -rf "$tempdir"' 0
 210
 211 ORIG_GIT_DIR="$GIT_DIR"
 212 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
 213 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
 214 GIT_WORK_TREE=.
 215 export GIT_DIR GIT_WORK_TREE
 216
 217 # Make sure refs/original is empty
 218 git for-each-ref > "$tempdir"/backup-refs || exit
 219 while read sha1 type name
 220 do
 221         case "$force,$name" in
 222         ,$orig_namespace*)
 223                 die "Cannot create a new backup.
 224 A previous backup already exists in $orig_namespace
 225 Force overwriting the backup with -f"
 226         ;;
 227         t,$orig_namespace*)
 228                 git update-ref -d "$name" $sha1
 229         ;;
 230         esac
 231 done < "$tempdir"/backup-refs
 232
 233 # The refs should be updated if their heads were rewritten
 234 git rev-parse --no-flags --revs-only --symbolic-full-name \
 235         --default HEAD "$@" > "$tempdir"/raw-heads || exit
 236 sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
 237
 238 test -s "$tempdir"/heads ||
 239         die "Which ref do you want to rewrite?"
 240
 241 GIT_INDEX_FILE="$(pwd)/../index"
 242 export GIT_INDEX_FILE
 243
 244 # map old->new commit ids for rewriting parents
 245 mkdir ../map || die "Could not create map/ directory"
 246
 247 # we need "--" only if there are no path arguments in $@
 248 nonrevs=$(git rev-parse --no-revs "$@") || exit
 249 if test -z "$nonrevs"
 250 then
 251         dashdash=--
 252 else
 253         dashdash=
 254         remap_to_ancestor=t
 255 fi
 256
 257 rev_args=$(git rev-parse --revs-only "$@")
 258
 259 case "$filter_subdir" in
 260 "")
 261         eval set -- "$(git rev-parse --sq --no-revs "$@")"
 262         ;;
 263 *)
 264         eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
 265                 "$filter_subdir")"
 266         ;;
 267 esac
 268
 269 git rev-list --reverse --topo-order --default HEAD \
 270         --parents --simplify-merges $rev_args "$@" > ../revs ||
 271         die "Could not get the commits"
 272 commits=$(wc -l <../revs | tr -d " ")
 273
 274 test $commits -eq 0 && die "Found nothing to rewrite"
 275
 276 # Rewrite the commits
 277
 278 git_filter_branch__commit_count=0
 279 while read commit parents; do
 280         git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
 281         printf "\rRewrite $commit ($git_filter_branch__commit_count/$commits)"
 282
 283         case "$filter_subdir" in
 284         "")
 285                 git read-tree -i -m $commit
 286                 ;;
 287         *)
 288                 # The commit may not have the subdirectory at all
 289                 err=$(git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
 290                         if ! git rev-parse -q --verify $commit:"$filter_subdir"
 291                         then
 292                                 rm -f "$GIT_INDEX_FILE"
 293                         else
 294                                 echo >&2 "$err"
 295                                 false
 296                         fi
 297                 }
 298         esac || die "Could not initialize the index"
 299
 300         GIT_COMMIT=$commit
 301         export GIT_COMMIT
 302         git cat-file commit "$commit" >../commit ||
 303                 die "Cannot read commit $commit"
 304
 305         eval "$(set_ident <../commit)" ||
 306                 die "setting author/committer failed for commit $commit"
 307         eval "$filter_env" < /dev/null ||
 308                 die "env filter failed: $filter_env"
 309
 310         if [ "$filter_tree" ]; then
 311                 git checkout-index -f -u -a ||
 312                         die "Could not checkout the index"
 313                 # files that $commit removed are now still in the working tree;
 314                 # remove them, else they would be added again
 315                 git clean -d -q -f -x
 316                 eval "$filter_tree" < /dev/null ||
 317                         die "tree filter failed: $filter_tree"
 318
 319                 (
 320                         git diff-index -r --name-only --ignore-submodules $commit &&
 321                         git ls-files --others
 322                 ) > "$tempdir"/tree-state || exit
 323                 git update-index --add --replace --remove --stdin \
 324                         < "$tempdir"/tree-state || exit
 325         fi
 326
 327         eval "$filter_index" < /dev/null ||
 328                 die "index filter failed: $filter_index"
 329
 330         parentstr=
 331         for parent in $parents; do
 332                 for reparent in $(map "$parent"); do
 333                         parentstr="$parentstr -p $reparent"
 334                 done
 335         done
 336         if [ "$filter_parent" ]; then
 337                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 338                                 die "parent filter failed: $filter_parent"
 339         fi
 340
 341         sed -e '1,/^$/d' <../commit | \
 342                 eval "$filter_msg" > ../message ||
 343                         die "msg filter failed: $filter_msg"
 344         workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
 345                 $(git write-tree) $parentstr < ../message > ../map/$commit ||
 346                         die "could not write rewritten commit"
 347 done <../revs
 348
 349 # If we are filtering for paths, as in the case of a subdirectory
 350 # filter, it is possible that a specified head is not in the set of
 351 # rewritten commits, because it was pruned by the revision walker.
 352 # Ancestor remapping fixes this by mapping these heads to the unique
 353 # nearest ancestor that survived the pruning.
 354
 355 if test "$remap_to_ancestor" = t
 356 then
 357         while read ref
 358         do
 359                 sha1=$(git rev-parse "$ref"^0)
 360                 test -f "$workdir"/../map/$sha1 && continue
 361                 ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
 362                 test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
 363         done < "$tempdir"/heads
 364 fi
 365
 366 # Finally update the refs
 367
 368 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 369 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 370 echo
 371 while read ref
 372 do
 373         # avoid rewriting a ref twice
 374         test -f "$orig_namespace$ref" && continue
 375
 376         sha1=$(git rev-parse "$ref"^0)
 377         rewritten=$(map $sha1)
 378
 379         test $sha1 = "$rewritten" &&
 380                 warn "WARNING: Ref '$ref' is unchanged" &&
 381                 continue
 382
 383         case "$rewritten" in
 384         '')
 385                 echo "Ref '$ref' was deleted"
 386                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
 387                         die "Could not delete $ref"
 388         ;;
 389         $_x40)
 390                 echo "Ref '$ref' was rewritten"
 391                 if ! git update-ref -m "filter-branch: rewrite" \
 392                                         "$ref" $rewritten $sha1 2>/dev/null; then
 393                         if test $(git cat-file -t "$ref") = tag; then
 394                                 if test -z "$filter_tag_name"; then
 395                                         warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
 396                                         warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
 397                                 fi
 398                         else
 399                                 die "Could not rewrite $ref"
 400                         fi
 401                 fi
 402         ;;
 403         *)
 404                 # NEEDSWORK: possibly add -Werror, making this an error
 405                 warn "WARNING: '$ref' was rewritten into multiple commits:"
 406                 warn "$rewritten"
 407                 warn "WARNING: Ref '$ref' points to the first one now."
 408                 rewritten=$(echo "$rewritten" | head -n 1)
 409                 git update-ref -m "filter-branch: rewrite to first" \
 410                                 "$ref" $rewritten $sha1 ||
 411                         die "Could not rewrite $ref"
 412         ;;
 413         esac
 414         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
 415                  exit
 416 done < "$tempdir"/heads
 417
 418 # TODO: This should possibly go, with the semantics that all positive given
 419 #       refs are updated, and their original heads stored in refs/original/
 420 # Filter tags
 421
 422 if [ "$filter_tag_name" ]; then
 423         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 424         while read sha1 type ref; do
 425                 ref="${ref#refs/tags/}"
 426                 # XXX: Rewrite tagged trees as well?
 427                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
 428                         continue;
 429                 fi
 430
 431                 if [ "$type" = "tag" ]; then
 432                         # Dereference to a commit
 433                         sha1t="$sha1"
 434                         sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
 435                 fi
 436
 437                 [ -f "../map/$sha1" ] || continue
 438                 new_sha1="$(cat "../map/$sha1")"
 439                 GIT_COMMIT="$sha1"
 440                 export GIT_COMMIT
 441                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 442                         die "tag name filter failed: $filter_tag_name"
 443
 444                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 445
 446                 if [ "$type" = "tag" ]; then
 447                         new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
 448                                                 "$new_sha1" "$new_ref"
 449                                 git cat-file tag "$ref" |
 450                                 sed -n \
 451                                     -e '1,/^$/{
 452                                           /^object /d
 453                                           /^type /d
 454                                           /^tag /d
 455                                         }' \
 456                                     -e '/^-----BEGIN PGP SIGNATURE-----/q' \
 457                                     -e 'p' ) |
 458                                 git mktag) ||
 459                                 die "Could not create new tag object for $ref"
 460                         if git cat-file tag "$ref" | \
 461                            sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
 462                         then
 463                                 warn "gpg signature stripped from tag object $sha1t"
 464                         fi
 465                 fi
 466
 467                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
 468                         die "Could not write tag $new_ref"
 469         done
 470 fi
 471
 472 cd ../..
 473 rm -rf "$tempdir"
 474
 475 trap - 0
 476
 477 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
 478 test -z "$ORIG_GIT_DIR" || {
 479         GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
 480 }
 481 test -z "$ORIG_GIT_WORK_TREE" || {
 482         GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
 483         export GIT_WORK_TREE
 484 }
 485 test -z "$ORIG_GIT_INDEX_FILE" || {
 486         GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
 487         export GIT_INDEX_FILE
 488 }
 489
 490 if [ "$(is_bare_repository)" = false ]; then
 491         git read-tree -u -m HEAD || exit
 492 fi
 493
 494 exit 0