Merge branch 'jk/doc-diff-options'
[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         elif test $# = 1 && test "$1" = 4b825dc642cb6eb9a060e54bf8d69288fbee4904; then
50                 :
51         else
52                 git commit-tree "$@"
53         fi
54 }
55 # override die(): this version puts in an extra line break, so that
56 # the progress is still visible
57
58 die()
59 {
60         echo >&2
61         echo "$*" >&2
62         exit 1
63 }
64 EOF
65 )
66
67 eval "$functions"
68
69 finish_ident() {
70         # Ensure non-empty id name.
71         echo "case \"\$GIT_$1_NAME\" in \"\") GIT_$1_NAME=\"\${GIT_$1_EMAIL%%@*}\" && export GIT_$1_NAME;; esac"
72         # And make sure everything is exported.
73         echo "export GIT_$1_NAME"
74         echo "export GIT_$1_EMAIL"
75         echo "export GIT_$1_DATE"
76 }
77
78 set_ident () {
79         parse_ident_from_commit author AUTHOR committer COMMITTER
80         finish_ident AUTHOR
81         finish_ident COMMITTER
82 }
83
84 USAGE="[--setup <command>] [--subdirectory-filter <directory>] [--env-filter <command>]
85         [--tree-filter <command>] [--index-filter <command>]
86         [--parent-filter <command>] [--msg-filter <command>]
87         [--commit-filter <command>] [--tag-name-filter <command>]
88         [--original <namespace>]
89         [-d <directory>] [-f | --force] [--state-branch <branch>]
90         [--] [<rev-list options>...]"
91
92 OPTIONS_SPEC=
93 . git-sh-setup
94
95 if [ "$(is_bare_repository)" = false ]; then
96         require_clean_work_tree 'rewrite branches'
97 fi
98
99 tempdir=.git-rewrite
100 filter_setup=
101 filter_env=
102 filter_tree=
103 filter_index=
104 filter_parent=
105 filter_msg=cat
106 filter_commit=
107 filter_tag_name=
108 filter_subdir=
109 state_branch=
110 orig_namespace=refs/original/
111 force=
112 prune_empty=
113 remap_to_ancestor=
114 while :
115 do
116         case "$1" in
117         --)
118                 shift
119                 break
120                 ;;
121         --force|-f)
122                 shift
123                 force=t
124                 continue
125                 ;;
126         --remap-to-ancestor)
127                 # deprecated ($remap_to_ancestor is set now automatically)
128                 shift
129                 remap_to_ancestor=t
130                 continue
131                 ;;
132         --prune-empty)
133                 shift
134                 prune_empty=t
135                 continue
136                 ;;
137         -*)
138                 ;;
139         *)
140                 break;
141         esac
142
143         # all switches take one argument
144         ARG="$1"
145         case "$#" in 1) usage ;; esac
146         shift
147         OPTARG="$1"
148         shift
149
150         case "$ARG" in
151         -d)
152                 tempdir="$OPTARG"
153                 ;;
154         --setup)
155                 filter_setup="$OPTARG"
156                 ;;
157         --subdirectory-filter)
158                 filter_subdir="$OPTARG"
159                 remap_to_ancestor=t
160                 ;;
161         --env-filter)
162                 filter_env="$OPTARG"
163                 ;;
164         --tree-filter)
165                 filter_tree="$OPTARG"
166                 ;;
167         --index-filter)
168                 filter_index="$OPTARG"
169                 ;;
170         --parent-filter)
171                 filter_parent="$OPTARG"
172                 ;;
173         --msg-filter)
174                 filter_msg="$OPTARG"
175                 ;;
176         --commit-filter)
177                 filter_commit="$functions; $OPTARG"
178                 ;;
179         --tag-name-filter)
180                 filter_tag_name="$OPTARG"
181                 ;;
182         --original)
183                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
184                 ;;
185         --state-branch)
186                 state_branch="$OPTARG"
187                 ;;
188         *)
189                 usage
190                 ;;
191         esac
192 done
193
194 case "$prune_empty,$filter_commit" in
195 ,)
196         filter_commit='git commit-tree "$@"';;
197 t,)
198         filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
199 ,*)
200         ;;
201 *)
202         die "Cannot set --prune-empty and --commit-filter at the same time"
203 esac
204
205 case "$force" in
206 t)
207         rm -rf "$tempdir"
208 ;;
209 '')
210         test -d "$tempdir" &&
211                 die "$tempdir already exists, please remove it"
212 esac
213 orig_dir=$(pwd)
214 mkdir -p "$tempdir/t" &&
215 tempdir="$(cd "$tempdir"; pwd)" &&
216 cd "$tempdir/t" &&
217 workdir="$(pwd)" ||
218 die ""
219
220 # Remove tempdir on exit
221 trap 'cd "$orig_dir"; rm -rf "$tempdir"' 0
222
223 ORIG_GIT_DIR="$GIT_DIR"
224 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
225 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
226 ORIG_GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME"
227 ORIG_GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL"
228 ORIG_GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE"
229 ORIG_GIT_COMMITTER_NAME="$GIT_COMMITTER_NAME"
230 ORIG_GIT_COMMITTER_EMAIL="$GIT_COMMITTER_EMAIL"
231 ORIG_GIT_COMMITTER_DATE="$GIT_COMMITTER_DATE"
232
233 GIT_WORK_TREE=.
234 export GIT_DIR GIT_WORK_TREE
235
236 # Make sure refs/original is empty
237 git for-each-ref > "$tempdir"/backup-refs || exit
238 while read sha1 type name
239 do
240         case "$force,$name" in
241         ,$orig_namespace*)
242                 die "Cannot create a new backup.
243 A previous backup already exists in $orig_namespace
244 Force overwriting the backup with -f"
245         ;;
246         t,$orig_namespace*)
247                 git update-ref -d "$name" $sha1
248         ;;
249         esac
250 done < "$tempdir"/backup-refs
251
252 # The refs should be updated if their heads were rewritten
253 git rev-parse --no-flags --revs-only --symbolic-full-name \
254         --default HEAD "$@" > "$tempdir"/raw-heads || exit
255 sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
256
257 test -s "$tempdir"/heads ||
258         die "You must specify a ref to rewrite."
259
260 GIT_INDEX_FILE="$(pwd)/../index"
261 export GIT_INDEX_FILE
262
263 # map old->new commit ids for rewriting parents
264 mkdir ../map || die "Could not create map/ directory"
265
266 if test -n "$state_branch"
267 then
268         state_commit=$(git rev-parse --no-flags --revs-only "$state_branch")
269         if test -n "$state_commit"
270         then
271                 echo "Populating map from $state_branch ($state_commit)" 1>&2
272                 perl -e'open(MAP, "-|", "git show $ARGV[0]:filter.map") or die;
273                         while (<MAP>) {
274                                 m/(.*):(.*)/ or die;
275                                 open F, ">../map/$1" or die;
276                                 print F "$2" or die;
277                                 close(F) or die;
278                         }
279                         close(MAP) or die;' "$state_commit" \
280                                 || die "Unable to load state from $state_branch:filter.map"
281         else
282                 echo "Branch $state_branch does not exist. Will create" 1>&2
283         fi
284 fi
285
286 # we need "--" only if there are no path arguments in $@
287 nonrevs=$(git rev-parse --no-revs "$@") || exit
288 if test -z "$nonrevs"
289 then
290         dashdash=--
291 else
292         dashdash=
293         remap_to_ancestor=t
294 fi
295
296 git rev-parse --revs-only "$@" >../parse
297
298 case "$filter_subdir" in
299 "")
300         eval set -- "$(git rev-parse --sq --no-revs "$@")"
301         ;;
302 *)
303         eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
304                 "$filter_subdir")"
305         ;;
306 esac
307
308 git rev-list --reverse --topo-order --default HEAD \
309         --parents --simplify-merges --stdin "$@" <../parse >../revs ||
310         die "Could not get the commits"
311 commits=$(wc -l <../revs | tr -d " ")
312
313 test $commits -eq 0 && die "Found nothing to rewrite"
314
315 # Rewrite the commits
316 report_progress ()
317 {
318         if test -n "$progress" &&
319                 test $git_filter_branch__commit_count -gt $next_sample_at
320         then
321                 count=$git_filter_branch__commit_count
322
323                 now=$(date +%s)
324                 elapsed=$(($now - $start_timestamp))
325                 remaining=$(( ($commits - $count) * $elapsed / $count ))
326                 if test $elapsed -gt 0
327                 then
328                         next_sample_at=$(( ($elapsed + 1) * $count / $elapsed ))
329                 else
330                         next_sample_at=$(($next_sample_at + 1))
331                 fi
332                 progress=" ($elapsed seconds passed, remaining $remaining predicted)"
333         fi
334         printf "\rRewrite $commit ($count/$commits)$progress    "
335 }
336
337 git_filter_branch__commit_count=0
338
339 progress= start_timestamp=
340 if date '+%s' 2>/dev/null | grep -q '^[0-9][0-9]*$'
341 then
342         next_sample_at=0
343         progress="dummy to ensure this is not empty"
344         start_timestamp=$(date '+%s')
345 fi
346
347 if test -n "$filter_index" ||
348    test -n "$filter_tree" ||
349    test -n "$filter_subdir"
350 then
351         need_index=t
352 else
353         need_index=
354 fi
355
356 eval "$filter_setup" < /dev/null ||
357         die "filter setup failed: $filter_setup"
358
359 while read commit parents; do
360         git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
361
362         report_progress
363
364         case "$filter_subdir" in
365         "")
366                 if test -n "$need_index"
367                 then
368                         GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
369                 fi
370                 ;;
371         *)
372                 # The commit may not have the subdirectory at all
373                 err=$(GIT_ALLOW_NULL_SHA1=1 \
374                       git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
375                         if ! git rev-parse -q --verify $commit:"$filter_subdir"
376                         then
377                                 rm -f "$GIT_INDEX_FILE"
378                         else
379                                 echo >&2 "$err"
380                                 false
381                         fi
382                 }
383         esac || die "Could not initialize the index"
384
385         GIT_COMMIT=$commit
386         export GIT_COMMIT
387         git cat-file commit "$commit" >../commit ||
388                 die "Cannot read commit $commit"
389
390         eval "$(set_ident <../commit)" ||
391                 die "setting author/committer failed for commit $commit"
392         eval "$filter_env" < /dev/null ||
393                 die "env filter failed: $filter_env"
394
395         if [ "$filter_tree" ]; then
396                 git checkout-index -f -u -a ||
397                         die "Could not checkout the index"
398                 # files that $commit removed are now still in the working tree;
399                 # remove them, else they would be added again
400                 git clean -d -q -f -x
401                 eval "$filter_tree" < /dev/null ||
402                         die "tree filter failed: $filter_tree"
403
404                 (
405                         git diff-index -r --name-only --ignore-submodules $commit -- &&
406                         git ls-files --others
407                 ) > "$tempdir"/tree-state || exit
408                 git update-index --add --replace --remove --stdin \
409                         < "$tempdir"/tree-state || exit
410         fi
411
412         eval "$filter_index" < /dev/null ||
413                 die "index filter failed: $filter_index"
414
415         parentstr=
416         for parent in $parents; do
417                 for reparent in $(map "$parent"); do
418                         case "$parentstr " in
419                         *" -p $reparent "*)
420                                 ;;
421                         *)
422                                 parentstr="$parentstr -p $reparent"
423                                 ;;
424                         esac
425                 done
426         done
427         if [ "$filter_parent" ]; then
428                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
429                                 die "parent filter failed: $filter_parent"
430         fi
431
432         {
433                 while IFS='' read -r header_line && test -n "$header_line"
434                 do
435                         # skip header lines...
436                         :;
437                 done
438                 # and output the actual commit message
439                 cat
440         } <../commit |
441                 eval "$filter_msg" > ../message ||
442                         die "msg filter failed: $filter_msg"
443
444         if test -n "$need_index"
445         then
446                 tree=$(git write-tree)
447         else
448                 tree=$(git rev-parse "$commit^{tree}")
449         fi
450         workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
451                 "$tree" $parentstr < ../message > ../map/$commit ||
452                         die "could not write rewritten commit"
453 done <../revs
454
455 # If we are filtering for paths, as in the case of a subdirectory
456 # filter, it is possible that a specified head is not in the set of
457 # rewritten commits, because it was pruned by the revision walker.
458 # Ancestor remapping fixes this by mapping these heads to the unique
459 # nearest ancestor that survived the pruning.
460
461 if test "$remap_to_ancestor" = t
462 then
463         while read ref
464         do
465                 sha1=$(git rev-parse "$ref"^0)
466                 test -f "$workdir"/../map/$sha1 && continue
467                 ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
468                 test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
469         done < "$tempdir"/heads
470 fi
471
472 # Finally update the refs
473
474 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
475 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
476 echo
477 while read ref
478 do
479         # avoid rewriting a ref twice
480         test -f "$orig_namespace$ref" && continue
481
482         sha1=$(git rev-parse "$ref"^0)
483         rewritten=$(map $sha1)
484
485         test $sha1 = "$rewritten" &&
486                 warn "WARNING: Ref '$ref' is unchanged" &&
487                 continue
488
489         case "$rewritten" in
490         '')
491                 echo "Ref '$ref' was deleted"
492                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
493                         die "Could not delete $ref"
494         ;;
495         $_x40)
496                 echo "Ref '$ref' was rewritten"
497                 if ! git update-ref -m "filter-branch: rewrite" \
498                                         "$ref" $rewritten $sha1 2>/dev/null; then
499                         if test $(git cat-file -t "$ref") = tag; then
500                                 if test -z "$filter_tag_name"; then
501                                         warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
502                                         warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
503                                 fi
504                         else
505                                 die "Could not rewrite $ref"
506                         fi
507                 fi
508         ;;
509         *)
510                 # NEEDSWORK: possibly add -Werror, making this an error
511                 warn "WARNING: '$ref' was rewritten into multiple commits:"
512                 warn "$rewritten"
513                 warn "WARNING: Ref '$ref' points to the first one now."
514                 rewritten=$(echo "$rewritten" | head -n 1)
515                 git update-ref -m "filter-branch: rewrite to first" \
516                                 "$ref" $rewritten $sha1 ||
517                         die "Could not rewrite $ref"
518         ;;
519         esac
520         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
521                  exit
522 done < "$tempdir"/heads
523
524 # TODO: This should possibly go, with the semantics that all positive given
525 #       refs are updated, and their original heads stored in refs/original/
526 # Filter tags
527
528 if [ "$filter_tag_name" ]; then
529         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
530         while read sha1 type ref; do
531                 ref="${ref#refs/tags/}"
532                 # XXX: Rewrite tagged trees as well?
533                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
534                         continue;
535                 fi
536
537                 if [ "$type" = "tag" ]; then
538                         # Dereference to a commit
539                         sha1t="$sha1"
540                         sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
541                 fi
542
543                 [ -f "../map/$sha1" ] || continue
544                 new_sha1="$(cat "../map/$sha1")"
545                 GIT_COMMIT="$sha1"
546                 export GIT_COMMIT
547                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
548                         die "tag name filter failed: $filter_tag_name"
549
550                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
551
552                 if [ "$type" = "tag" ]; then
553                         new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
554                                                 "$new_sha1" "$new_ref"
555                                 git cat-file tag "$ref" |
556                                 sed -n \
557                                     -e '1,/^$/{
558                                           /^object /d
559                                           /^type /d
560                                           /^tag /d
561                                         }' \
562                                     -e '/^-----BEGIN PGP SIGNATURE-----/q' \
563                                     -e 'p' ) |
564                                 git hash-object -t tag -w --stdin) ||
565                                 die "Could not create new tag object for $ref"
566                         if git cat-file tag "$ref" | \
567                            sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
568                         then
569                                 warn "gpg signature stripped from tag object $sha1t"
570                         fi
571                 fi
572
573                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
574                         die "Could not write tag $new_ref"
575         done
576 fi
577
578 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
579 unset GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
580 unset GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_DATE
581 test -z "$ORIG_GIT_DIR" || {
582         GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
583 }
584 test -z "$ORIG_GIT_WORK_TREE" || {
585         GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
586         export GIT_WORK_TREE
587 }
588 test -z "$ORIG_GIT_INDEX_FILE" || {
589         GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
590         export GIT_INDEX_FILE
591 }
592 test -z "$ORIG_GIT_AUTHOR_NAME" || {
593         GIT_AUTHOR_NAME="$ORIG_GIT_AUTHOR_NAME" &&
594         export GIT_AUTHOR_NAME
595 }
596 test -z "$ORIG_GIT_AUTHOR_EMAIL" || {
597         GIT_AUTHOR_EMAIL="$ORIG_GIT_AUTHOR_EMAIL" &&
598         export GIT_AUTHOR_EMAIL
599 }
600 test -z "$ORIG_GIT_AUTHOR_DATE" || {
601         GIT_AUTHOR_DATE="$ORIG_GIT_AUTHOR_DATE" &&
602         export GIT_AUTHOR_DATE
603 }
604 test -z "$ORIG_GIT_COMMITTER_NAME" || {
605         GIT_COMMITTER_NAME="$ORIG_GIT_COMMITTER_NAME" &&
606         export GIT_COMMITTER_NAME
607 }
608 test -z "$ORIG_GIT_COMMITTER_EMAIL" || {
609         GIT_COMMITTER_EMAIL="$ORIG_GIT_COMMITTER_EMAIL" &&
610         export GIT_COMMITTER_EMAIL
611 }
612 test -z "$ORIG_GIT_COMMITTER_DATE" || {
613         GIT_COMMITTER_DATE="$ORIG_GIT_COMMITTER_DATE" &&
614         export GIT_COMMITTER_DATE
615 }
616
617 if test -n "$state_branch"
618 then
619         echo "Saving rewrite state to $state_branch" 1>&2
620         state_blob=$(
621                 perl -e'opendir D, "../map" or die;
622                         open H, "|-", "git hash-object -w --stdin" or die;
623                         foreach (sort readdir(D)) {
624                                 next if m/^\.\.?$/;
625                                 open F, "<../map/$_" or die;
626                                 chomp($f = <F>);
627                                 print H "$_:$f\n" or die;
628                         }
629                         close(H) or die;' || die "Unable to save state")
630         state_tree=$(/bin/echo -e "100644 blob $state_blob\tfilter.map" | git mktree)
631         if test -n "$state_commit"
632         then
633                 state_commit=$(/bin/echo "Sync" | git commit-tree "$state_tree" -p "$state_commit")
634         else
635                 state_commit=$(/bin/echo "Sync" | git commit-tree "$state_tree" )
636         fi
637         git update-ref "$state_branch" "$state_commit"
638 fi
639
640 cd "$orig_dir"
641 rm -rf "$tempdir"
642
643 trap - 0
644
645 if [ "$(is_bare_repository)" = false ]; then
646         git read-tree -u -m HEAD || exit
647 fi
648
649 exit 0