3 # git-subtree.sh: split/join git repositories in subdirectories of this one
5 # Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
11 git subtree add --prefix=<prefix> <commit>
12 git subtree merge --prefix=<prefix> <commit>
13 git subtree pull --prefix=<prefix> <repository> <refspec...>
14 git subtree split --prefix=<prefix> <commit...>
19 prefix= the name of the subdir to split out
21 annotate= add a prefix to commit message of new commits
22 b,branch= create a new branch from the split subtree
23 ignore-joins ignore prior --rejoin commits
24 onto= try connecting new tree to an existing one
25 rejoin merge the new branch back into HEAD
26 options for 'merge' and 'pull'
27 squash merge subtree changes as a single commit
29 eval $
(echo "$OPTS_SPEC" | git rev-parse
--parseopt -- "$@" ||
echo exit $?
)
45 if [ -n "$debug" ]; then
52 if [ -z "$quiet" ]; then
62 die
"assertion failed: " "$@"
69 while [ $# -gt 0 ]; do
75 --annotate) annotate
="$1"; shift ;;
76 --no-annotate) annotate
= ;;
77 -b) branch
="$1"; shift ;;
78 --prefix) prefix
="$1"; shift ;;
79 --no-prefix) prefix
= ;;
80 --onto) onto
="$1"; shift ;;
83 --no-rejoin) rejoin
= ;;
84 --ignore-joins) ignore_joins
=1 ;;
85 --no-ignore-joins) ignore_joins
= ;;
87 --no-squash) squash
= ;;
89 *) die
"Unexpected option: $opt" ;;
96 add|merge|pull
) default
= ;;
97 split) default
="--default HEAD" ;;
98 *) die
"Unknown command '$command'" ;;
101 if [ -z "$prefix" ]; then
102 die
"You must provide the --prefix option."
106 if [ "$command" != "pull" ]; then
107 revs
=$
(git rev-parse
$default --revs-only "$@") ||
exit $?
108 dirs="$(git rev-parse --no-revs --no-flags "$@
")" ||
exit $?
109 if [ -n "$dirs" ]; then
110 die
"Error: Use --prefix instead of bare filenames."
114 debug
"command: {$command}"
115 debug
"quiet: {$quiet}"
116 debug
"revs: {$revs}"
123 cachedir
="$GIT_DIR/subtree-cache/$$"
124 rm -rf "$cachedir" || die
"Can't delete old cachedir: $cachedir"
125 mkdir
-p "$cachedir" || die
"Can't create new cachedir: $cachedir"
126 debug
"Using cachedir: $cachedir" >&2
132 if [ -r "$cachedir/$oldrev" ]; then
133 read newrev
<"$cachedir/$oldrev"
143 if [ "$oldrev" != "latest_old" \
144 -a "$oldrev" != "latest_new" \
145 -a -e "$cachedir/$oldrev" ]; then
146 die
"cache for $oldrev already exists!"
148 echo "$newrev" >"$cachedir/$oldrev"
153 if git rev-parse
"$1" >/dev
/null
2>&1; then
160 # if a commit doesn't have a parent, this might not work. But we only want
161 # to remove the parent from the rev-list, and since it doesn't exist, it won't
162 # be there anyway, so do nothing in that case.
163 try_remove_previous
()
165 if rev_exists
"$1^"; then
172 debug
"Looking for latest squash..."
174 git log
--grep="^git-subtree-dir: $dir\$" \
175 --pretty=format
:'START %H%n%s%n%n%b%nEND%n' HEAD |
176 while read a b junk
; do
179 git-subtree-mainline
:) main
="$b" ;;
180 git-subtree-split
:) sub
="$b" ;;
182 if [ -n "$sub" ]; then
183 if [ -n "$main" ]; then
185 # Pretend its sub was a squash.
188 debug
"Squash found: $sq $sub"
200 find_existing_splits
()
202 debug
"Looking for prior splits..."
205 git log
--grep="^git-subtree-dir: $dir\$" \
206 --pretty=format
:'%s%n%n%b%nEND%n' $revs |
207 while read a b junk
; do
210 git-subtree-mainline
:) main
="$b" ;;
211 git-subtree-split
:) sub
="$b" ;;
213 if [ -n "$main" -a -n "$sub" ]; then
214 debug
" Prior: $main -> $sub"
216 try_remove_previous
"$main"
217 try_remove_previous
"$sub"
228 # We're going to set some environment vars here, so
229 # do it in a subshell to get rid of them safely later
230 debug copy_commit
"{$1}" "{$2}" "{$3}"
231 git log
-1 --pretty=format
:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" |
234 read GIT_AUTHOR_EMAIL
236 read GIT_COMMITTER_NAME
237 read GIT_COMMITTER_EMAIL
238 read GIT_COMMITTER_DATE
239 export GIT_AUTHOR_NAME \
243 GIT_COMMITTER_EMAIL \
245 (echo -n "$annotate"; cat ) |
246 git commit-tree
"$2" $3 # reads the rest of stdin
247 ) || die
"Can't copy commit $1"
256 Add '$dir/' from commit '$latest_new'
258 git-subtree-dir: $dir
259 git-subtree-mainline: $latest_old
260 git-subtree-split: $latest_new
270 Split '$dir/' into commit '$latest_new'
272 git-subtree-dir: $dir
273 git-subtree-mainline: $latest_old
274 git-subtree-split: $latest_new
283 oldsub_short
=$
(git rev-parse
--short "$oldsub")
284 newsub_short
=$
(git rev-parse
--short "$newsub")
286 Squashed '$dir/' changes from $oldsub_short..$newsub_short
290 git log
--pretty=tformat
:'%h %s' "$oldsub..$newsub"
291 git log
--pretty=tformat
:'REVERT: %h %s' "$newsub..$oldsub"
295 git-subtree-dir: $dir
296 git-subtree-split: $newsub
303 git log
-1 --pretty=format
:'%T' "$commit" -- ||
exit $?
310 git ls-tree
"$commit" -- "$dir" |
311 while read mode
type tree name
; do
312 assert
[ "$name" = "$dir" ]
322 if [ $# -ne 1 ]; then
323 return 0 # weird parents, consider it changed
325 ptree
=$
(toptree_for_commit
$1)
326 if [ "$ptree" != "$tree" ]; then
329 return 1 # not changed
339 tree
=$
(toptree_for_commit
$newsub) ||
exit $?
340 squash_msg
"$dir" "$oldsub" "$newsub" |
341 git commit-tree
"$tree" -p "$old" ||
exit $?
349 assert
[ -n "$tree" ]
355 for parent
in $newparents; do
356 ptree
=$
(toptree_for_commit
$parent) ||
exit $?
357 [ -z "$ptree" ] && continue
358 if [ "$ptree" = "$tree" ]; then
359 # an identical parent could be used in place of this rev.
362 nonidentical
="$parent"
365 # sometimes both old parents map to the same newparent;
366 # eliminate duplicates
368 for gp
in $gotparents; do
369 if [ "$gp" = "$parent" ]; then
374 if [ -n "$is_new" ]; then
375 gotparents
="$gotparents $parent"
380 if [ -n "$identical" ]; then
383 copy_commit
$rev $tree "$p" ||
exit $?
389 if ! git diff-index HEAD
--exit-code --quiet; then
390 die
"Working tree has modifications. Cannot add."
392 if ! git diff-index
--cached HEAD
--exit-code --quiet; then
393 die
"Index has modifications. Cannot add."
399 if [ -e "$dir" ]; then
400 die
"'$dir' already exists. Cannot add."
405 if [ $# -ne 1 ]; then
406 die
"You must provide exactly one revision. Got: '$revs'"
410 debug
"Adding $dir as '$rev'..."
411 git read-tree
--prefix="$dir" $rev ||
exit $?
412 git checkout
"$dir" ||
exit $?
413 tree
=$
(git write-tree
) ||
exit $?
415 headrev
=$
(git rev-parse HEAD
) ||
exit $?
416 if [ -n "$headrev" -a "$headrev" != "$rev" ]; then
421 commit
=$
(add_msg
"$dir" "$headrev" "$rev" |
422 git commit-tree
$tree $headp -p "$rev") ||
exit $?
423 git
reset "$commit" ||
exit $?
428 if [ -n "$branch" ] && rev_exists
"refs/heads/$branch"; then
429 die
"Branch '$branch' already exists."
432 debug
"Splitting $dir..."
433 cache_setup ||
exit $?
435 if [ -n "$onto" ]; then
436 debug
"Reading history for --onto=$onto..."
439 # the 'onto' history is already just the subdir, so
440 # any parent we find there can be used verbatim
446 if [ -n "$ignore_joins" ]; then
449 unrevs
="$(find_existing_splits "$dir" "$revs")"
452 # We can't restrict rev-list to only $dir here, because some of our
453 # parents have the $dir contents the root, and those won't match.
454 # (and rev-list --follow doesn't seem to solve this)
455 grl
='git rev-list --reverse --parents $revs $unrevs'
456 revmax
=$
(eval "$grl" |
wc -l)
460 while read rev parents
; do
461 revcount
=$
(($revcount + 1))
462 say
-n "$revcount/$revmax ($createcount)
"
463 debug
"Processing commit: $rev"
464 exists
=$
(cache_get
$rev)
465 if [ -n "$exists" ]; then
466 debug
" prior: $exists"
469 createcount
=$
(($createcount + 1))
470 debug
" parents: $parents"
471 newparents
=$
(cache_get
$parents)
472 debug
" newparents: $newparents"
474 tree
=$
(subtree_for_commit
$rev "$dir")
475 debug
" tree is: $tree"
477 # ugly. is there no better way to tell if this is a subtree
478 # vs. a mainline commit? Does it matter?
479 [ -z $tree ] && continue
481 newrev
=$
(copy_or_skip
"$rev" "$tree" "$newparents") ||
exit $?
482 debug
" newrev is: $newrev"
483 cache_set
$rev $newrev
484 cache_set latest_new
$newrev
485 cache_set latest_old
$rev
487 latest_new
=$
(cache_get latest_new
)
488 if [ -z "$latest_new" ]; then
489 die
"No new revisions were found"
492 if [ -n "$rejoin" ]; then
493 debug
"Merging split branch into HEAD..."
494 latest_old
=$
(cache_get latest_old
)
496 -m "$(rejoin_msg $dir $latest_old $latest_new)" \
497 $latest_new >&2 ||
exit $?
499 if [ -n "$branch" ]; then
500 git update-ref
-m 'subtree split' "refs/heads/$branch" \
501 $latest_new "" ||
exit $?
502 say
"Created branch '$branch'"
513 if [ $# -ne 1 ]; then
514 die
"You must provide exactly one revision. Got: '$revs'"
518 if [ -n "$squash" ]; then
519 first_split
="$(find_latest_squash "$dir")"
520 if [ -z "$first_split" ]; then
521 die
"Can't squash-merge: '$dir' was never added."
526 new
=$
(new_squash_commit
"$old" "$sub" "$rev") ||
exit $?
527 debug
"New squash commit: $new"
531 git merge
-s subtree
$rev
538 git pull
-s subtree
"$@"