Merge branch 'np/progress'
[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 warn () {
12         echo "$*" >&2
13 }
14
15 map()
16 {
17         # if it was not rewritten, take the original
18         if test -r "$workdir/../map/$1"
19         then
20                 cat "$workdir/../map/$1"
21         else
22                 echo "$1"
23         fi
24 }
25
26 # if you run 'skip_commit "$@"' in a commit filter, it will print
27 # the (mapped) parents, effectively skipping the commit.
28
29 skip_commit()
30 {
31         shift;
32         while [ -n "$1" ];
33         do
34                 shift;
35                 map "$1";
36                 shift;
37         done;
38 }
39
40 # override die(): this version puts in an extra line break, so that
41 # the progress is still visible
42
43 die()
44 {
45         echo >&2
46         echo "$*" >&2
47         exit 1
48 }
49
50 # When piped a commit, output a script to set the ident of either
51 # "author" or "committer
52
53 set_ident () {
54         lid="$(echo "$1" | tr "A-Z" "a-z")"
55         uid="$(echo "$1" | tr "a-z" "A-Z")"
56         pick_id_script='
57                 /^'$lid' /{
58                         s/'\''/'\''\\'\'\''/g
59                         h
60                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
61                         s/'\''/'\''\'\'\''/g
62                         s/.*/export GIT_'$uid'_NAME='\''&'\''/p
63
64                         g
65                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
66                         s/'\''/'\''\'\'\''/g
67                         s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
68
69                         g
70                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
71                         s/'\''/'\''\'\'\''/g
72                         s/.*/export GIT_'$uid'_DATE='\''&'\''/p
73
74                         q
75                 }
76         '
77
78         LANG=C LC_ALL=C sed -ne "$pick_id_script"
79         # Ensure non-empty id name.
80         echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
81 }
82
83 # This script can be sourced by the commit filter to get the functions
84 test "a$SOURCE_FUNCTIONS" = a1 && return
85 this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
86 export this_script
87
88 USAGE="[--env-filter <command>] [--tree-filter <command>] \
89 [--index-filter <command>] [--parent-filter <command>] \
90 [--msg-filter <command>] [--commit-filter <command>] \
91 [--tag-name-filter <command>] [--subdirectory-filter <directory>] \
92 [--original <namespace>] [-d <directory>] [-f | --force] \
93 [<rev-list options>...]"
94
95 . git-sh-setup
96
97 git diff-files --quiet &&
98         git diff-index --cached --quiet HEAD ||
99         die "Cannot rewrite branch(es) with a dirty working directory."
100
101 tempdir=.git-rewrite
102 filter_env=
103 filter_tree=
104 filter_index=
105 filter_parent=
106 filter_msg=cat
107 filter_commit='git commit-tree "$@"'
108 filter_tag_name=
109 filter_subdir=
110 orig_namespace=refs/original/
111 force=
112 while :
113 do
114         test $# = 0 && usage
115         case "$1" in
116         --)
117                 shift
118                 break
119                 ;;
120         --force|-f)
121                 shift
122                 force=t
123                 continue
124                 ;;
125         -*)
126                 ;;
127         *)
128                 break;
129         esac
130
131         # all switches take one argument
132         ARG="$1"
133         case "$#" in 1) usage ;; esac
134         shift
135         OPTARG="$1"
136         shift
137
138         case "$ARG" in
139         -d)
140                 tempdir="$OPTARG"
141                 ;;
142         --env-filter)
143                 filter_env="$OPTARG"
144                 ;;
145         --tree-filter)
146                 filter_tree="$OPTARG"
147                 ;;
148         --index-filter)
149                 filter_index="$OPTARG"
150                 ;;
151         --parent-filter)
152                 filter_parent="$OPTARG"
153                 ;;
154         --msg-filter)
155                 filter_msg="$OPTARG"
156                 ;;
157         --commit-filter)
158                 filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
159                 ;;
160         --tag-name-filter)
161                 filter_tag_name="$OPTARG"
162                 ;;
163         --subdirectory-filter)
164                 filter_subdir="$OPTARG"
165                 ;;
166         --original)
167                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
168                 ;;
169         *)
170                 usage
171                 ;;
172         esac
173 done
174
175 case "$force" in
176 t)
177         rm -rf "$tempdir"
178 ;;
179 '')
180         test -d "$tempdir" &&
181                 die "$tempdir already exists, please remove it"
182 esac
183 mkdir -p "$tempdir/t" &&
184 tempdir="$(cd "$tempdir"; pwd)" &&
185 cd "$tempdir/t" &&
186 workdir="$(pwd)" ||
187 die ""
188
189 # Make sure refs/original is empty
190 git for-each-ref > "$tempdir"/backup-refs
191 while read sha1 type name
192 do
193         case "$force,$name" in
194         ,$orig_namespace*)
195                 die "Namespace $orig_namespace not empty"
196         ;;
197         t,$orig_namespace*)
198                 git update-ref -d "$name" $sha1
199         ;;
200         esac
201 done < "$tempdir"/backup-refs
202
203 ORIG_GIT_DIR="$GIT_DIR"
204 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
205 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
206 export GIT_DIR GIT_WORK_TREE=.
207
208 # These refs should be updated if their heads were rewritten
209
210 git rev-parse --revs-only --symbolic "$@" |
211 while read ref
212 do
213         # normalize ref
214         case "$ref" in
215         HEAD)
216                 ref="$(git symbolic-ref "$ref")"
217         ;;
218         refs/*)
219         ;;
220         *)
221                 ref="$(git for-each-ref --format='%(refname)' |
222                         grep /"$ref")"
223         esac
224
225         git check-ref-format "$ref" && echo "$ref"
226 done > "$tempdir"/heads
227
228 test -s "$tempdir"/heads ||
229         die "Which ref do you want to rewrite?"
230
231 export GIT_INDEX_FILE="$(pwd)/../index"
232 git read-tree || die "Could not seed the index"
233
234 ret=0
235
236 # map old->new commit ids for rewriting parents
237 mkdir ../map || die "Could not create map/ directory"
238
239 case "$filter_subdir" in
240 "")
241         git rev-list --reverse --topo-order --default HEAD \
242                 --parents "$@"
243         ;;
244 *)
245         git rev-list --reverse --topo-order --default HEAD \
246                 --parents --full-history "$@" -- "$filter_subdir"
247 esac > ../revs || die "Could not get the commits"
248 commits=$(wc -l <../revs | tr -d " ")
249
250 test $commits -eq 0 && die "Found nothing to rewrite"
251
252 # Rewrite the commits
253
254 i=0
255 while read commit parents; do
256         i=$(($i+1))
257         printf "\rRewrite $commit ($i/$commits)"
258
259         case "$filter_subdir" in
260         "")
261                 git read-tree -i -m $commit
262                 ;;
263         *)
264                 git read-tree -i -m $commit:"$filter_subdir"
265         esac || die "Could not initialize the index"
266
267         export GIT_COMMIT=$commit
268         git cat-file commit "$commit" >../commit ||
269                 die "Cannot read commit $commit"
270
271         eval "$(set_ident AUTHOR <../commit)" ||
272                 die "setting author failed for commit $commit"
273         eval "$(set_ident COMMITTER <../commit)" ||
274                 die "setting committer failed for commit $commit"
275         eval "$filter_env" < /dev/null ||
276                 die "env filter failed: $filter_env"
277
278         if [ "$filter_tree" ]; then
279                 git checkout-index -f -u -a ||
280                         die "Could not checkout the index"
281                 # files that $commit removed are now still in the working tree;
282                 # remove them, else they would be added again
283                 git ls-files -z --others | xargs -0 rm -f
284                 eval "$filter_tree" < /dev/null ||
285                         die "tree filter failed: $filter_tree"
286
287                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
288                         xargs -0 git update-index --add --replace --remove
289                 git ls-files -z --others | \
290                         xargs -0 git update-index --add --replace --remove
291         fi
292
293         eval "$filter_index" < /dev/null ||
294                 die "index filter failed: $filter_index"
295
296         parentstr=
297         for parent in $parents; do
298                 for reparent in $(map "$parent"); do
299                         parentstr="$parentstr -p $reparent"
300                 done
301         done
302         if [ "$filter_parent" ]; then
303                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
304                                 die "parent filter failed: $filter_parent"
305         fi
306
307         sed -e '1,/^$/d' <../commit | \
308                 eval "$filter_msg" > ../message ||
309                         die "msg filter failed: $filter_msg"
310         sh -c "$filter_commit" "git commit-tree" \
311                 $(git write-tree) $parentstr < ../message > ../map/$commit
312 done <../revs
313
314 # In case of a subdirectory filter, it is possible that a specified head
315 # is not in the set of rewritten commits, because it was pruned by the
316 # revision walker.  Fix it by mapping these heads to the next rewritten
317 # ancestor(s), i.e. the boundaries in the set of rewritten commits.
318
319 # NEEDSWORK: we should sort the unmapped refs topologically first
320 while read ref
321 do
322         sha1=$(git rev-parse "$ref"^0)
323         test -f "$workdir"/../map/$sha1 && continue
324         # Assign the boundarie(s) in the set of rewritten commits
325         # as the replacement commit(s).
326         # (This would look a bit nicer if --not --stdin worked.)
327         for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
328                 git rev-list $ref --boundary --stdin |
329                 sed -n "s/^-//p")
330         do
331                 map $p >> "$workdir"/../map/$sha1
332         done
333 done < "$tempdir"/heads
334
335 # Finally update the refs
336
337 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
338 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
339 count=0
340 echo
341 while read ref
342 do
343         # avoid rewriting a ref twice
344         test -f "$orig_namespace$ref" && continue
345
346         sha1=$(git rev-parse "$ref"^0)
347         rewritten=$(map $sha1)
348
349         test $sha1 = "$rewritten" &&
350                 warn "WARNING: Ref '$ref' is unchanged" &&
351                 continue
352
353         case "$rewritten" in
354         '')
355                 echo "Ref '$ref' was deleted"
356                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
357                         die "Could not delete $ref"
358         ;;
359         $_x40)
360                 echo "Ref '$ref' was rewritten"
361                 git update-ref -m "filter-branch: rewrite" \
362                                 "$ref" $rewritten $sha1 ||
363                         die "Could not rewrite $ref"
364         ;;
365         *)
366                 # NEEDSWORK: possibly add -Werror, making this an error
367                 warn "WARNING: '$ref' was rewritten into multiple commits:"
368                 warn "$rewritten"
369                 warn "WARNING: Ref '$ref' points to the first one now."
370                 rewritten=$(echo "$rewritten" | head -n 1)
371                 git update-ref -m "filter-branch: rewrite to first" \
372                                 "$ref" $rewritten $sha1 ||
373                         die "Could not rewrite $ref"
374         ;;
375         esac
376         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
377         count=$(($count+1))
378 done < "$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/$sha1")"
401                 export GIT_COMMIT="$sha1"
402                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
403                         die "tag name filter failed: $filter_tag_name"
404
405                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
406
407                 if [ "$type" = "tag" ]; then
408                         # Warn that we are not rewriting the tag object itself.
409                         warn "unreferencing tag object $sha1t"
410                 fi
411
412                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
413                         die "Could not write tag $new_ref"
414         done
415 fi
416
417 cd ../..
418 rm -rf "$tempdir"
419 echo
420 test $count -gt 0 && echo "These refs were rewritten:"
421 git show-ref | grep ^"$orig_namespace"
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