Merge branch 'rr/rerere-libify-clear-gc'
[git] / 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 # When piped a commit, output a script to set the ident of either
68 # "author" or "committer
69
70 set_ident () {
71         lid="$(echo "$1" | tr "[A-Z]" "[a-z]")"
72         uid="$(echo "$1" | tr "[a-z]" "[A-Z]")"
73         pick_id_script='
74                 /^'$lid' /{
75                         s/'\''/'\''\\'\'\''/g
76                         h
77                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
78                         s/'\''/'\''\'\'\''/g
79                         s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
80
81                         g
82                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
83                         s/'\''/'\''\'\'\''/g
84                         s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
85
86                         g
87                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
88                         s/'\''/'\''\'\'\''/g
89                         s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
90
91                         q
92                 }
93         '
94
95         LANG=C LC_ALL=C sed -ne "$pick_id_script"
96         # Ensure non-empty id name.
97         echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
98 }
99
100 USAGE="[--env-filter <command>] [--tree-filter <command>]
101             [--index-filter <command>] [--parent-filter <command>]
102             [--msg-filter <command>] [--commit-filter <command>]
103             [--tag-name-filter <command>] [--subdirectory-filter <directory>]
104             [--original <namespace>] [-d <directory>] [-f | --force]
105             [<rev-list options>...]"
106
107 OPTIONS_SPEC=
108 . git-sh-setup
109
110 if [ "$(is_bare_repository)" = false ]; then
111         git diff-files --ignore-submodules --quiet &&
112         git diff-index --cached --quiet HEAD -- ||
113         die "Cannot rewrite branch(es) with a dirty working directory."
114 fi
115
116 tempdir=.git-rewrite
117 filter_env=
118 filter_tree=
119 filter_index=
120 filter_parent=
121 filter_msg=cat
122 filter_commit=
123 filter_tag_name=
124 filter_subdir=
125 orig_namespace=refs/original/
126 force=
127 prune_empty=
128 remap_to_ancestor=
129 while :
130 do
131         case "$1" in
132         --)
133                 shift
134                 break
135                 ;;
136         --force|-f)
137                 shift
138                 force=t
139                 continue
140                 ;;
141         --remap-to-ancestor)
142                 # deprecated ($remap_to_ancestor is set now automatically)
143                 shift
144                 remap_to_ancestor=t
145                 continue
146                 ;;
147         --prune-empty)
148                 shift
149                 prune_empty=t
150                 continue
151                 ;;
152         -*)
153                 ;;
154         *)
155                 break;
156         esac
157
158         # all switches take one argument
159         ARG="$1"
160         case "$#" in 1) usage ;; esac
161         shift
162         OPTARG="$1"
163         shift
164
165         case "$ARG" in
166         -d)
167                 tempdir="$OPTARG"
168                 ;;
169         --env-filter)
170                 filter_env="$OPTARG"
171                 ;;
172         --tree-filter)
173                 filter_tree="$OPTARG"
174                 ;;
175         --index-filter)
176                 filter_index="$OPTARG"
177                 ;;
178         --parent-filter)
179                 filter_parent="$OPTARG"
180                 ;;
181         --msg-filter)
182                 filter_msg="$OPTARG"
183                 ;;
184         --commit-filter)
185                 filter_commit="$functions; $OPTARG"
186                 ;;
187         --tag-name-filter)
188                 filter_tag_name="$OPTARG"
189                 ;;
190         --subdirectory-filter)
191                 filter_subdir="$OPTARG"
192                 remap_to_ancestor=t
193                 ;;
194         --original)
195                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
196                 ;;
197         *)
198                 usage
199                 ;;
200         esac
201 done
202
203 case "$prune_empty,$filter_commit" in
204 ,)
205         filter_commit='git commit-tree "$@"';;
206 t,)
207         filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
208 ,*)
209         ;;
210 *)
211         die "Cannot set --prune-empty and --commit-filter at the same time"
212 esac
213
214 case "$force" in
215 t)
216         rm -rf "$tempdir"
217 ;;
218 '')
219         test -d "$tempdir" &&
220                 die "$tempdir already exists, please remove it"
221 esac
222 mkdir -p "$tempdir/t" &&
223 tempdir="$(cd "$tempdir"; pwd)" &&
224 cd "$tempdir/t" &&
225 workdir="$(pwd)" ||
226 die ""
227
228 # Remove tempdir on exit
229 trap 'cd ../..; rm -rf "$tempdir"' 0
230
231 ORIG_GIT_DIR="$GIT_DIR"
232 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
233 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
234 GIT_WORK_TREE=.
235 export GIT_DIR GIT_WORK_TREE
236
237 # Make sure refs/original is empty
238 git for-each-ref > "$tempdir"/backup-refs || exit
239 while read sha1 type name
240 do
241         case "$force,$name" in
242         ,$orig_namespace*)
243                 die "Cannot create a new backup.
244 A previous backup already exists in $orig_namespace
245 Force overwriting the backup with -f"
246         ;;
247         t,$orig_namespace*)
248                 git update-ref -d "$name" $sha1
249         ;;
250         esac
251 done < "$tempdir"/backup-refs
252
253 # The refs should be updated if their heads were rewritten
254 git rev-parse --no-flags --revs-only --symbolic-full-name \
255         --default HEAD "$@" > "$tempdir"/raw-heads || exit
256 sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
257
258 test -s "$tempdir"/heads ||
259         die "Which ref do you want to rewrite?"
260
261 GIT_INDEX_FILE="$(pwd)/../index"
262 export GIT_INDEX_FILE
263
264 # map old->new commit ids for rewriting parents
265 mkdir ../map || die "Could not create map/ directory"
266
267 # we need "--" only if there are no path arguments in $@
268 nonrevs=$(git rev-parse --no-revs "$@") || exit
269 if test -z "$nonrevs"
270 then
271         dashdash=--
272 else
273         dashdash=
274         remap_to_ancestor=t
275 fi
276
277 rev_args=$(git rev-parse --revs-only "$@")
278
279 case "$filter_subdir" in
280 "")
281         eval set -- "$(git rev-parse --sq --no-revs "$@")"
282         ;;
283 *)
284         eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
285                 "$filter_subdir")"
286         ;;
287 esac
288
289 git rev-list --reverse --topo-order --default HEAD \
290         --parents --simplify-merges $rev_args "$@" > ../revs ||
291         die "Could not get the commits"
292 commits=$(wc -l <../revs | tr -d " ")
293
294 test $commits -eq 0 && die "Found nothing to rewrite"
295
296 # Rewrite the commits
297
298 git_filter_branch__commit_count=0
299 while read commit parents; do
300         git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
301         printf "\rRewrite $commit ($git_filter_branch__commit_count/$commits)"
302
303         case "$filter_subdir" in
304         "")
305                 git read-tree -i -m $commit
306                 ;;
307         *)
308                 # The commit may not have the subdirectory at all
309                 err=$(git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
310                         if ! git rev-parse -q --verify $commit:"$filter_subdir"
311                         then
312                                 rm -f "$GIT_INDEX_FILE"
313                         else
314                                 echo >&2 "$err"
315                                 false
316                         fi
317                 }
318         esac || die "Could not initialize the index"
319
320         GIT_COMMIT=$commit
321         export GIT_COMMIT
322         git cat-file commit "$commit" >../commit ||
323                 die "Cannot read commit $commit"
324
325         eval "$(set_ident AUTHOR <../commit)" ||
326                 die "setting author failed for commit $commit"
327         eval "$(set_ident COMMITTER <../commit)" ||
328                 die "setting committer failed for commit $commit"
329         eval "$filter_env" < /dev/null ||
330                 die "env filter failed: $filter_env"
331
332         if [ "$filter_tree" ]; then
333                 git checkout-index -f -u -a ||
334                         die "Could not checkout the index"
335                 # files that $commit removed are now still in the working tree;
336                 # remove them, else they would be added again
337                 git clean -d -q -f -x
338                 eval "$filter_tree" < /dev/null ||
339                         die "tree filter failed: $filter_tree"
340
341                 (
342                         git diff-index -r --name-only --ignore-submodules $commit &&
343                         git ls-files --others
344                 ) > "$tempdir"/tree-state || exit
345                 git update-index --add --replace --remove --stdin \
346                         < "$tempdir"/tree-state || exit
347         fi
348
349         eval "$filter_index" < /dev/null ||
350                 die "index filter failed: $filter_index"
351
352         parentstr=
353         for parent in $parents; do
354                 for reparent in $(map "$parent"); do
355                         parentstr="$parentstr -p $reparent"
356                 done
357         done
358         if [ "$filter_parent" ]; then
359                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
360                                 die "parent filter failed: $filter_parent"
361         fi
362
363         sed -e '1,/^$/d' <../commit | \
364                 eval "$filter_msg" > ../message ||
365                         die "msg filter failed: $filter_msg"
366         @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
367                 $(git write-tree) $parentstr < ../message > ../map/$commit ||
368                         die "could not write rewritten commit"
369 done <../revs
370
371 # If we are filtering for paths, as in the case of a subdirectory
372 # filter, it is possible that a specified head is not in the set of
373 # rewritten commits, because it was pruned by the revision walker.
374 # Ancestor remapping fixes this by mapping these heads to the unique
375 # nearest ancestor that survived the pruning.
376
377 if test "$remap_to_ancestor" = t
378 then
379         while read ref
380         do
381                 sha1=$(git rev-parse "$ref"^0)
382                 test -f "$workdir"/../map/$sha1 && continue
383                 ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
384                 test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
385         done < "$tempdir"/heads
386 fi
387
388 # Finally update the refs
389
390 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
391 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
392 echo
393 while read ref
394 do
395         # avoid rewriting a ref twice
396         test -f "$orig_namespace$ref" && continue
397
398         sha1=$(git rev-parse "$ref"^0)
399         rewritten=$(map $sha1)
400
401         test $sha1 = "$rewritten" &&
402                 warn "WARNING: Ref '$ref' is unchanged" &&
403                 continue
404
405         case "$rewritten" in
406         '')
407                 echo "Ref '$ref' was deleted"
408                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
409                         die "Could not delete $ref"
410         ;;
411         $_x40)
412                 echo "Ref '$ref' was rewritten"
413                 if ! git update-ref -m "filter-branch: rewrite" \
414                                         "$ref" $rewritten $sha1 2>/dev/null; then
415                         if test $(git cat-file -t "$ref") = tag; then
416                                 if test -z "$filter_tag_name"; then
417                                         warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
418                                         warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
419                                 fi
420                         else
421                                 die "Could not rewrite $ref"
422                         fi
423                 fi
424         ;;
425         *)
426                 # NEEDSWORK: possibly add -Werror, making this an error
427                 warn "WARNING: '$ref' was rewritten into multiple commits:"
428                 warn "$rewritten"
429                 warn "WARNING: Ref '$ref' points to the first one now."
430                 rewritten=$(echo "$rewritten" | head -n 1)
431                 git update-ref -m "filter-branch: rewrite to first" \
432                                 "$ref" $rewritten $sha1 ||
433                         die "Could not rewrite $ref"
434         ;;
435         esac
436         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
437                  exit
438 done < "$tempdir"/heads
439
440 # TODO: This should possibly go, with the semantics that all positive given
441 #       refs are updated, and their original heads stored in refs/original/
442 # Filter tags
443
444 if [ "$filter_tag_name" ]; then
445         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
446         while read sha1 type ref; do
447                 ref="${ref#refs/tags/}"
448                 # XXX: Rewrite tagged trees as well?
449                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
450                         continue;
451                 fi
452
453                 if [ "$type" = "tag" ]; then
454                         # Dereference to a commit
455                         sha1t="$sha1"
456                         sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
457                 fi
458
459                 [ -f "../map/$sha1" ] || continue
460                 new_sha1="$(cat "../map/$sha1")"
461                 GIT_COMMIT="$sha1"
462                 export GIT_COMMIT
463                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
464                         die "tag name filter failed: $filter_tag_name"
465
466                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
467
468                 if [ "$type" = "tag" ]; then
469                         new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
470                                                 "$new_sha1" "$new_ref"
471                                 git cat-file tag "$ref" |
472                                 sed -n \
473                                     -e '1,/^$/{
474                                           /^object /d
475                                           /^type /d
476                                           /^tag /d
477                                         }' \
478                                     -e '/^-----BEGIN PGP SIGNATURE-----/q' \
479                                     -e 'p' ) |
480                                 git mktag) ||
481                                 die "Could not create new tag object for $ref"
482                         if git cat-file tag "$ref" | \
483                            sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
484                         then
485                                 warn "gpg signature stripped from tag object $sha1t"
486                         fi
487                 fi
488
489                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
490                         die "Could not write tag $new_ref"
491         done
492 fi
493
494 cd ../..
495 rm -rf "$tempdir"
496
497 trap - 0
498
499 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
500 test -z "$ORIG_GIT_DIR" || {
501         GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
502 }
503 test -z "$ORIG_GIT_WORK_TREE" || {
504         GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
505         export GIT_WORK_TREE
506 }
507 test -z "$ORIG_GIT_INDEX_FILE" || {
508         GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
509         export GIT_INDEX_FILE
510 }
511
512 if [ "$(is_bare_repository)" = false ]; then
513         git read-tree -u -m HEAD || exit
514 fi
515
516 exit 0