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