Merge branch '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 "$1";
39                 shift;
40         done;
41 }
42
43 # override die(): this version puts in an extra line break, so that
44 # the progress is still visible
45
46 die()
47 {
48         echo >&2
49         echo "$*" >&2
50         exit 1
51 }
52 EOF
53 )
54
55 eval "$functions"
56
57 # When piped a commit, output a script to set the ident of either
58 # "author" or "committer
59
60 set_ident () {
61         lid="$(echo "$1" | tr "A-Z" "a-z")"
62         uid="$(echo "$1" | tr "a-z" "A-Z")"
63         pick_id_script='
64                 /^'$lid' /{
65                         s/'\''/'\''\\'\'\''/g
66                         h
67                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
68                         s/'\''/'\''\'\'\''/g
69                         s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
70
71                         g
72                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
73                         s/'\''/'\''\'\'\''/g
74                         s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
75
76                         g
77                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
78                         s/'\''/'\''\'\'\''/g
79                         s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
80
81                         q
82                 }
83         '
84
85         LANG=C LC_ALL=C sed -ne "$pick_id_script"
86         # Ensure non-empty id name.
87         echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
88 }
89
90 USAGE="[--env-filter <command>] [--tree-filter <command>] \
91 [--index-filter <command>] [--parent-filter <command>] \
92 [--msg-filter <command>] [--commit-filter <command>] \
93 [--tag-name-filter <command>] [--subdirectory-filter <directory>] \
94 [--original <namespace>] [-d <directory>] [-f | --force] \
95 [<rev-list options>...]"
96
97 OPTIONS_SPEC=
98 . git-sh-setup
99
100 git diff-files --quiet &&
101         git diff-index --cached --quiet HEAD -- ||
102         die "Cannot rewrite branch(es) with a dirty working directory."
103
104 tempdir=.git-rewrite
105 filter_env=
106 filter_tree=
107 filter_index=
108 filter_parent=
109 filter_msg=cat
110 filter_commit='git commit-tree "$@"'
111 filter_tag_name=
112 filter_subdir=
113 orig_namespace=refs/original/
114 force=
115 while :
116 do
117         test $# = 0 && usage
118         case "$1" in
119         --)
120                 shift
121                 break
122                 ;;
123         --force|-f)
124                 shift
125                 force=t
126                 continue
127                 ;;
128         -*)
129                 ;;
130         *)
131                 break;
132         esac
133
134         # all switches take one argument
135         ARG="$1"
136         case "$#" in 1) usage ;; esac
137         shift
138         OPTARG="$1"
139         shift
140
141         case "$ARG" in
142         -d)
143                 tempdir="$OPTARG"
144                 ;;
145         --env-filter)
146                 filter_env="$OPTARG"
147                 ;;
148         --tree-filter)
149                 filter_tree="$OPTARG"
150                 ;;
151         --index-filter)
152                 filter_index="$OPTARG"
153                 ;;
154         --parent-filter)
155                 filter_parent="$OPTARG"
156                 ;;
157         --msg-filter)
158                 filter_msg="$OPTARG"
159                 ;;
160         --commit-filter)
161                 filter_commit="$functions; $OPTARG"
162                 ;;
163         --tag-name-filter)
164                 filter_tag_name="$OPTARG"
165                 ;;
166         --subdirectory-filter)
167                 filter_subdir="$OPTARG"
168                 ;;
169         --original)
170                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
171                 ;;
172         *)
173                 usage
174                 ;;
175         esac
176 done
177
178 case "$force" in
179 t)
180         rm -rf "$tempdir"
181 ;;
182 '')
183         test -d "$tempdir" &&
184                 die "$tempdir already exists, please remove it"
185 esac
186 mkdir -p "$tempdir/t" &&
187 tempdir="$(cd "$tempdir"; pwd)" &&
188 cd "$tempdir/t" &&
189 workdir="$(pwd)" ||
190 die ""
191
192 # Make sure refs/original is empty
193 git for-each-ref > "$tempdir"/backup-refs
194 while read sha1 type name
195 do
196         case "$force,$name" in
197         ,$orig_namespace*)
198                 die "Namespace $orig_namespace not empty"
199         ;;
200         t,$orig_namespace*)
201                 git update-ref -d "$name" $sha1
202         ;;
203         esac
204 done < "$tempdir"/backup-refs
205
206 ORIG_GIT_DIR="$GIT_DIR"
207 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
208 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
209 GIT_WORK_TREE=.
210 export GIT_DIR GIT_WORK_TREE
211
212 # These refs should be updated if their heads were rewritten
213
214 git rev-parse --revs-only --symbolic "$@" |
215 while read ref
216 do
217         # normalize ref
218         case "$ref" in
219         HEAD)
220                 ref="$(git symbolic-ref "$ref")"
221         ;;
222         refs/*)
223         ;;
224         *)
225                 ref="$(git for-each-ref --format='%(refname)' |
226                         grep /"$ref")"
227         esac
228
229         git check-ref-format "$ref" && echo "$ref"
230 done > "$tempdir"/heads
231
232 test -s "$tempdir"/heads ||
233         die "Which ref do you want to rewrite?"
234
235 GIT_INDEX_FILE="$(pwd)/../index"
236 export GIT_INDEX_FILE
237 git read-tree || die "Could not seed the index"
238
239 ret=0
240
241 # map old->new commit ids for rewriting parents
242 mkdir ../map || die "Could not create map/ directory"
243
244 case "$filter_subdir" in
245 "")
246         git rev-list --reverse --topo-order --default HEAD \
247                 --parents "$@"
248         ;;
249 *)
250         git rev-list --reverse --topo-order --default HEAD \
251                 --parents --full-history "$@" -- "$filter_subdir"
252 esac > ../revs || die "Could not get the commits"
253 commits=$(wc -l <../revs | tr -d " ")
254
255 test $commits -eq 0 && die "Found nothing to rewrite"
256
257 # Rewrite the commits
258
259 i=0
260 while read commit parents; do
261         i=$(($i+1))
262         printf "\rRewrite $commit ($i/$commits)"
263
264         case "$filter_subdir" in
265         "")
266                 git read-tree -i -m $commit
267                 ;;
268         *)
269                 git read-tree -i -m $commit:"$filter_subdir"
270         esac || die "Could not initialize the index"
271
272         GIT_COMMIT=$commit
273         export GIT_COMMIT
274         git cat-file commit "$commit" >../commit ||
275                 die "Cannot read commit $commit"
276
277         eval "$(set_ident AUTHOR <../commit)" ||
278                 die "setting author failed for commit $commit"
279         eval "$(set_ident COMMITTER <../commit)" ||
280                 die "setting committer failed for commit $commit"
281         eval "$filter_env" < /dev/null ||
282                 die "env filter failed: $filter_env"
283
284         if [ "$filter_tree" ]; then
285                 git checkout-index -f -u -a ||
286                         die "Could not checkout the index"
287                 # files that $commit removed are now still in the working tree;
288                 # remove them, else they would be added again
289                 git ls-files -z --others | xargs -0 rm -f
290                 eval "$filter_tree" < /dev/null ||
291                         die "tree filter failed: $filter_tree"
292
293                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
294                         xargs -0 git update-index --add --replace --remove
295                 git ls-files -z --others | \
296                         xargs -0 git update-index --add --replace --remove
297         fi
298
299         eval "$filter_index" < /dev/null ||
300                 die "index filter failed: $filter_index"
301
302         parentstr=
303         for parent in $parents; do
304                 for reparent in $(map "$parent"); do
305                         parentstr="$parentstr -p $reparent"
306                 done
307         done
308         if [ "$filter_parent" ]; then
309                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
310                                 die "parent filter failed: $filter_parent"
311         fi
312
313         sed -e '1,/^$/d' <../commit | \
314                 eval "$filter_msg" > ../message ||
315                         die "msg filter failed: $filter_msg"
316         sh -c "$filter_commit" "git commit-tree" \
317                 $(git write-tree) $parentstr < ../message > ../map/$commit
318 done <../revs
319
320 # In case of a subdirectory filter, it is possible that a specified head
321 # is not in the set of rewritten commits, because it was pruned by the
322 # revision walker.  Fix it by mapping these heads to the next rewritten
323 # ancestor(s), i.e. the boundaries in the set of rewritten commits.
324
325 # NEEDSWORK: we should sort the unmapped refs topologically first
326 while read ref
327 do
328         sha1=$(git rev-parse "$ref"^0)
329         test -f "$workdir"/../map/$sha1 && continue
330         # Assign the boundarie(s) in the set of rewritten commits
331         # as the replacement commit(s).
332         # (This would look a bit nicer if --not --stdin worked.)
333         for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
334                 git rev-list $ref --boundary --stdin |
335                 sed -n "s/^-//p")
336         do
337                 map $p >> "$workdir"/../map/$sha1
338         done
339 done < "$tempdir"/heads
340
341 # Finally update the refs
342
343 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
344 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
345 count=0
346 echo
347 while read ref
348 do
349         # avoid rewriting a ref twice
350         test -f "$orig_namespace$ref" && continue
351
352         sha1=$(git rev-parse "$ref"^0)
353         rewritten=$(map $sha1)
354
355         test $sha1 = "$rewritten" &&
356                 warn "WARNING: Ref '$ref' is unchanged" &&
357                 continue
358
359         case "$rewritten" in
360         '')
361                 echo "Ref '$ref' was deleted"
362                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
363                         die "Could not delete $ref"
364         ;;
365         $_x40)
366                 echo "Ref '$ref' was rewritten"
367                 git update-ref -m "filter-branch: rewrite" \
368                                 "$ref" $rewritten $sha1 ||
369                         die "Could not rewrite $ref"
370         ;;
371         *)
372                 # NEEDSWORK: possibly add -Werror, making this an error
373                 warn "WARNING: '$ref' was rewritten into multiple commits:"
374                 warn "$rewritten"
375                 warn "WARNING: Ref '$ref' points to the first one now."
376                 rewritten=$(echo "$rewritten" | head -n 1)
377                 git update-ref -m "filter-branch: rewrite to first" \
378                                 "$ref" $rewritten $sha1 ||
379                         die "Could not rewrite $ref"
380         ;;
381         esac
382         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
383         count=$(($count+1))
384 done < "$tempdir"/heads
385
386 # TODO: This should possibly go, with the semantics that all positive given
387 #       refs are updated, and their original heads stored in refs/original/
388 # Filter tags
389
390 if [ "$filter_tag_name" ]; then
391         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
392         while read sha1 type ref; do
393                 ref="${ref#refs/tags/}"
394                 # XXX: Rewrite tagged trees as well?
395                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
396                         continue;
397                 fi
398
399                 if [ "$type" = "tag" ]; then
400                         # Dereference to a commit
401                         sha1t="$sha1"
402                         sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
403                 fi
404
405                 [ -f "../map/$sha1" ] || continue
406                 new_sha1="$(cat "../map/$sha1")"
407                 GIT_COMMIT="$sha1"
408                 export GIT_COMMIT
409                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
410                         die "tag name filter failed: $filter_tag_name"
411
412                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
413
414                 if [ "$type" = "tag" ]; then
415                         # Warn that we are not rewriting the tag object itself.
416                         warn "unreferencing tag object $sha1t"
417                 fi
418
419                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
420                         die "Could not write tag $new_ref"
421         done
422 fi
423
424 cd ../..
425 rm -rf "$tempdir"
426 echo
427 test $count -gt 0 && echo "These refs were rewritten:"
428 git show-ref | grep ^"$orig_namespace"
429
430 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
431 test -z "$ORIG_GIT_DIR" || GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
432 test -z "$ORIG_GIT_WORK_TREE" || GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
433         export GIT_WORK_TREE
434 test -z "$ORIG_GIT_INDEX_FILE" || GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
435         export GIT_INDEX_FILE
436 git read-tree -u -m HEAD
437
438 exit $ret