Code

Typo when searching for existing splits.
[git.git] / git-subtree.sh
1 #!/bin/bash
2 #
3 # git-subtree.sh: split/join git repositories in subdirectories of this one
4 #
5 # Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
6 #
7 if [ $# -eq 0 ]; then
8     set -- -h
9 fi
10 OPTS_SPEC="\
11 git subtree add --prefix=<prefix> <commit>
12 git subtree split [options...] --prefix=<prefix> <commit...>
13 git subtree merge --prefix=<prefix> <commit>
14 git subtree pull  --prefix=<prefix> <repository> <refspec...>
15 --
16 h,help        show the help
17 q             quiet
18 prefix=       the name of the subdir to split out
19  options for 'split'
20 annotate=     add a prefix to commit message of new commits
21 onto=         try connecting new tree to an existing one
22 rejoin        merge the new branch back into HEAD
23 ignore-joins  ignore prior --rejoin commits
24 "
25 eval $(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)
26 . git-sh-setup
27 require_work_tree
29 quiet=
30 command=
31 onto=
32 rejoin=
33 ignore_joins=
34 annotate=
36 debug()
37 {
38         if [ -z "$quiet" ]; then
39                 echo "$@" >&2
40         fi
41 }
43 assert()
44 {
45         if "$@"; then
46                 :
47         else
48                 die "assertion failed: " "$@"
49         fi
50 }
53 #echo "Options: $*"
55 while [ $# -gt 0 ]; do
56         opt="$1"
57         shift
58         case "$opt" in
59                 -q) quiet=1 ;;
60                 --annotate) annotate="$1"; shift ;;
61                 --no-annotate) annotate= ;;
62                 --prefix) prefix="$1"; shift ;;
63                 --no-prefix) prefix= ;;
64                 --onto) onto="$1"; shift ;;
65                 --no-onto) onto= ;;
66                 --rejoin) rejoin=1 ;;
67                 --no-rejoin) rejoin= ;;
68                 --ignore-joins) ignore_joins=1 ;;
69                 --no-ignore-joins) ignore_joins= ;;
70                 --) break ;;
71         esac
72 done
74 command="$1"
75 shift
76 case "$command" in
77         add|merge|pull) default= ;;
78         split) default="--default HEAD" ;;
79         *) die "Unknown command '$command'" ;;
80 esac
82 if [ -z "$prefix" ]; then
83         die "You must provide the --prefix option."
84 fi
85 dir="$prefix"
87 if [ "$command" != "pull" ]; then
88         revs=$(git rev-parse $default --revs-only "$@") || exit $?
89         dirs="$(git rev-parse --no-revs --no-flags "$@")" || exit $?
90         if [ -n "$dirs" ]; then
91                 die "Error: Use --prefix instead of bare filenames."
92         fi
93 fi
95 debug "command: {$command}"
96 debug "quiet: {$quiet}"
97 debug "revs: {$revs}"
98 debug "dir: {$dir}"
99 debug "opts: {$*}"
100 debug
102 cache_setup()
104         cachedir="$GIT_DIR/subtree-cache/$$"
105         rm -rf "$cachedir" || die "Can't delete old cachedir: $cachedir"
106         mkdir -p "$cachedir" || die "Can't create new cachedir: $cachedir"
107         debug "Using cachedir: $cachedir" >&2
110 cache_get()
112         for oldrev in $*; do
113                 if [ -r "$cachedir/$oldrev" ]; then
114                         read newrev <"$cachedir/$oldrev"
115                         echo $newrev
116                 fi
117         done
120 cache_set()
122         oldrev="$1"
123         newrev="$2"
124         if [ "$oldrev" != "latest_old" \
125              -a "$oldrev" != "latest_new" \
126              -a -e "$cachedir/$oldrev" ]; then
127                 die "cache for $oldrev already exists!"
128         fi
129         echo "$newrev" >"$cachedir/$oldrev"
132 # if a commit doesn't have a parent, this might not work.  But we only want
133 # to remove the parent from the rev-list, and since it doesn't exist, it won't
134 # be there anyway, so do nothing in that case.
135 try_remove_previous()
137         if git rev-parse "$1^" >/dev/null 2>&1; then
138                 echo "^$1^"
139         fi
142 find_existing_splits()
144         debug "Looking for prior splits..."
145         dir="$1"
146         revs="$2"
147         git log --grep="^git-subtree-dir: $dir\$" \
148                 --pretty=format:'%s%n%n%b%nEND' $revs |
149         while read a b junk; do
150                 case "$a" in
151                         git-subtree-mainline:) main="$b" ;;
152                         git-subtree-split:) sub="$b" ;;
153                         *)
154                                 if [ -n "$main" -a -n "$sub" ]; then
155                                         debug "  Prior: $main -> $sub"
156                                         cache_set $main $sub
157                                         try_remove_previous "$main"
158                                         try_remove_previous "$sub"
159                                         main=
160                                         sub=
161                                 fi
162                                 ;;
163                 esac
164         done
167 copy_commit()
169         # We're doing to set some environment vars here, so
170         # do it in a subshell to get rid of them safely later
171         git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" |
172         (
173                 read GIT_AUTHOR_NAME
174                 read GIT_AUTHOR_EMAIL
175                 read GIT_AUTHOR_DATE
176                 read GIT_COMMITTER_NAME
177                 read GIT_COMMITTER_EMAIL
178                 read GIT_COMMITTER_DATE
179                 export  GIT_AUTHOR_NAME \
180                         GIT_AUTHOR_EMAIL \
181                         GIT_AUTHOR_DATE \
182                         GIT_COMMITTER_NAME \
183                         GIT_COMMITTER_EMAIL \
184                         GIT_COMMITTER_DATE
185                 (echo -n "$annotate"; cat ) |
186                 git commit-tree "$2" $3  # reads the rest of stdin
187         ) || die "Can't copy commit $1"
190 add_msg()
192         dir="$1"
193         latest_old="$2"
194         latest_new="$3"
195         cat <<-EOF
196                 Add '$dir/' from commit '$latest_new'
197                 
198                 git-subtree-dir: $dir
199                 git-subtree-mainline: $latest_old
200                 git-subtree-split: $latest_new
201         EOF
204 merge_msg()
206         dir="$1"
207         latest_old="$2"
208         latest_new="$3"
209         cat <<-EOF
210                 Split '$dir/' into commit '$latest_new'
211                 
212                 git-subtree-dir: $dir
213                 git-subtree-mainline: $latest_old
214                 git-subtree-split: $latest_new
215         EOF
218 toptree_for_commit()
220         commit="$1"
221         git log -1 --pretty=format:'%T' "$commit" -- || exit $?
224 subtree_for_commit()
226         commit="$1"
227         dir="$2"
228         git ls-tree "$commit" -- "$dir" |
229         while read mode type tree name; do
230                 assert [ "$name" = "$dir" ]
231                 echo $tree
232                 break
233         done
236 tree_changed()
238         tree=$1
239         shift
240         if [ $# -ne 1 ]; then
241                 return 0   # weird parents, consider it changed
242         else
243                 ptree=$(toptree_for_commit $1)
244                 if [ "$ptree" != "$tree" ]; then
245                         return 0   # changed
246                 else
247                         return 1   # not changed
248                 fi
249         fi
252 copy_or_skip()
254         rev="$1"
255         tree="$2"
256         newparents="$3"
257         assert [ -n "$tree" ]
259         identical=
260         p=
261         for parent in $newparents; do
262                 ptree=$(toptree_for_commit $parent) || exit $?
263                 if [ "$ptree" = "$tree" ]; then
264                         # an identical parent could be used in place of this rev.
265                         identical="$parent"
266                 fi
267                 if [ -n "$ptree" ]; then
268                         parentmatch="$parentmatch$parent"
269                         p="$p -p $parent"
270                 fi
271         done
272         
273         if [ -n "$identical" -a "$parentmatch" = "$identical" ]; then
274                 echo $identical
275         else
276                 copy_commit $rev $tree "$p" || exit $?
277         fi
280 ensure_clean()
282         if ! git diff-index HEAD --exit-code --quiet; then
283                 die "Working tree has modifications.  Cannot add."
284         fi
285         if ! git diff-index --cached HEAD --exit-code --quiet; then
286                 die "Index has modifications.  Cannot add."
287         fi
290 cmd_add()
292         if [ -e "$dir" ]; then
293                 die "'$dir' already exists.  Cannot add."
294         fi
295         ensure_clean
296         
297         set -- $revs
298         if [ $# -ne 1 ]; then
299                 die "You must provide exactly one revision.  Got: '$revs'"
300         fi
301         rev="$1"
302         
303         debug "Adding $dir as '$rev'..."
304         git read-tree --prefix="$dir" $rev || exit $?
305         git checkout "$dir" || exit $?
306         tree=$(git write-tree) || exit $?
307         
308         headrev=$(git rev-parse HEAD) || exit $?
309         if [ -n "$headrev" -a "$headrev" != "$rev" ]; then
310                 headp="-p $headrev"
311         else
312                 headp=
313         fi
314         commit=$(add_msg "$dir" "$headrev" "$rev" |
315                  git commit-tree $tree $headp -p "$rev") || exit $?
316         git reset "$commit" || exit $?
319 cmd_split()
321         debug "Splitting $dir..."
322         cache_setup || exit $?
323         
324         if [ -n "$onto" ]; then
325                 debug "Reading history for --onto=$onto..."
326                 git rev-list $onto |
327                 while read rev; do
328                         # the 'onto' history is already just the subdir, so
329                         # any parent we find there can be used verbatim
330                         debug "  cache: $rev"
331                         cache_set $rev $rev
332                 done
333         fi
334         
335         if [ -n "$ignore_joins" ]; then
336                 unrevs=
337         else
338                 unrevs="$(find_existing_splits "$dir" "$revs")"
339         fi
340         
341         # We can't restrict rev-list to only "$dir" here, because that leaves out
342         # critical information about commit parents.
343         debug "git rev-list --reverse --parents $revs $unrevs"
344         git rev-list --reverse --parents $revs $unrevs |
345         while read rev parents; do
346                 debug
347                 debug "Processing commit: $rev"
348                 exists=$(cache_get $rev)
349                 if [ -n "$exists" ]; then
350                         debug "  prior: $exists"
351                         continue
352                 fi
353                 debug "  parents: $parents"
354                 newparents=$(cache_get $parents)
355                 debug "  newparents: $newparents"
356                 
357                 tree=$(subtree_for_commit $rev "$dir")
358                 debug "  tree is: $tree"
359                 [ -z $tree ] && continue
361                 newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
362                 debug "  newrev is: $newrev"
363                 cache_set $rev $newrev
364                 cache_set latest_new $newrev
365                 cache_set latest_old $rev
366         done || exit $?
367         latest_new=$(cache_get latest_new)
368         if [ -z "$latest_new" ]; then
369                 die "No new revisions were found"
370         fi
371         
372         if [ -n "$rejoin" ]; then
373                 debug "Merging split branch into HEAD..."
374                 latest_old=$(cache_get latest_old)
375                 git merge -s ours \
376                         -m "$(merge_msg $dir $latest_old $latest_new)" \
377                         $latest_new >&2
378         fi
379         echo $latest_new
380         exit 0
383 cmd_merge()
385         ensure_clean
386         
387         set -- $revs
388         if [ $# -ne 1 ]; then
389                 die "You must provide exactly one revision.  Got: '$revs'"
390         fi
391         rev="$1"
392         
393         git merge -s subtree $rev
396 cmd_pull()
398         ensure_clean
399         set -x
400         git pull -s subtree "$@"
403 "cmd_$command" "$@"