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