3 # git-subtree.sh: split/join git repositories in subdirectories of this one
5 # Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
8 if test -z "$GIT_EXEC_PATH" ||
test "${PATH#"${GIT_EXEC_PATH}:"}" = "$PATH" ||
! test -f "$GIT_EXEC_PATH/git-sh-setup"
10 echo >&2 'It looks like either your git installation or your'
11 echo >&2 'git-subtree installation is broken.'
14 echo >&2 " - If \`git --exec-path\` does not print the correct path to"
15 echo >&2 " your git install directory, then set the GIT_EXEC_PATH"
16 echo >&2 " environment variable to the correct directory."
17 echo >&2 " - Make sure that your \`${0##*/}\` file is either in your"
18 echo >&2 " PATH or in your git exec path (\`$(git --exec-path)\`)."
19 echo >&2 " - You should run git-subtree as \`git ${0##*/git-}\`,"
20 echo >&2 " not as \`${0##*/}\`." >&2
25 git subtree add --prefix=<prefix> <commit>
26 git subtree add --prefix=<prefix> <repository> <ref>
27 git subtree merge --prefix=<prefix> <commit>
28 git subtree split --prefix=<prefix> [<commit>]
29 git subtree pull --prefix=<prefix> <repository> <ref>
30 git subtree push --prefix=<prefix> <repository> <refspec>
35 P,prefix= the name of the subdir to split out
36 options for 'split' (also: 'push')
37 annotate= add a prefix to commit message of new commits
38 b,branch= create a new branch from the split subtree
39 ignore-joins ignore prior --rejoin commits
40 onto= try connecting new tree to an existing one
41 rejoin merge the new branch back into HEAD
42 options for 'add' and 'merge' (also: 'pull', 'split --rejoin', and 'push --rejoin')
43 squash merge subtree changes as a single commit
44 m,message= use the given message as the commit message for the merge commit
49 # Usage: debug [MSG...]
51 if test -n "$arg_debug"
53 printf "%$(($indent * 2))s%s\n" '' "$*" >&2
57 # Usage: progress [MSG...]
59 if test -z "$GIT_QUIET"
61 if test -z "$arg_debug"
65 # Print one progress line that we keep updating (use
66 # "\r" to return to the beginning of the line, rather
67 # than "\n" to start a new line). This only really
68 # works when stderr is a terminal.
69 printf "%s\r" "$*" >&2
71 # Debug mode is on. The `debug` function is regularly
74 # Don't do the one-line-with-"\r" thing, because on a
75 # terminal the debug output would overwrite and hide the
76 # progress output. Add a "progress:" prefix to make the
77 # progress output and the debug output easy to
78 # distinguish. This ensures maximum readability whether
79 # stderr is a terminal or a file.
80 printf "progress: %s\n" "$*" >&2
85 # Usage: assert CMD...
89 die
"assertion failed: $*"
98 set_args
="$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@
" || echo exit $?)"
103 # First figure out the command and whether we use --rejoin, so
104 # that we can provide more helpful validation when we do the
105 # "real" flag parsing.
114 --annotate|
-b|
-P|
-m|
--onto)
129 case "$arg_command" in
135 allow_addmerge
=$arg_split_rejoin
138 die
"Unknown command '$arg_command'"
141 # Reset the arguments array for "real" flag parsing.
144 # Begin "real" flag parsing.
149 arg_split_ignore_joins
=
152 arg_addmerge_message
=
166 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
167 arg_split_annotate
="$1"
171 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
175 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
176 arg_split_branch
="$1"
184 test -n "$allow_addmerge" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
185 arg_addmerge_message
="$1"
192 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
197 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
201 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
204 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
207 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
208 arg_split_ignore_joins
=1
211 test -n "$allow_split" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
212 arg_split_ignore_joins
=
215 test -n "$allow_addmerge" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
216 arg_addmerge_squash
=1
219 test -n "$allow_addmerge" || die
"The '$opt' flag does not make sense with 'git subtree $arg_command'."
226 die
"Unexpected option: $opt"
232 if test -z "$arg_prefix"
234 die
"You must provide the --prefix option."
237 case "$arg_command" in
239 test -e "$arg_prefix" &&
240 die
"prefix '$arg_prefix' already exists."
243 test -e "$arg_prefix" ||
244 die
"'$arg_prefix' does not exist; use 'git subtree add'"
248 dir
="$(dirname "$arg_prefix/.
")"
250 debug
"command: {$arg_command}"
251 debug
"quiet: {$GIT_QUIET}"
256 "cmd_$arg_command" "$@"
262 cachedir
="$GIT_DIR/subtree-cache/$$"
263 rm -rf "$cachedir" ||
264 die
"Can't delete old cachedir: $cachedir"
265 mkdir
-p "$cachedir" ||
266 die
"Can't create new cachedir: $cachedir"
267 mkdir
-p "$cachedir/notree" ||
268 die
"Can't create new cachedir: $cachedir/notree"
269 debug
"Using cachedir: $cachedir" >&2
272 # Usage: cache_get [REVS...]
276 if test -r "$cachedir/$oldrev"
278 read newrev
<"$cachedir/$oldrev"
284 # Usage: cache_miss [REVS...]
288 if ! test -r "$cachedir/$oldrev"
295 # Usage: check_parents PARENTS_EXPR
298 missed
=$
(cache_miss
"$1") ||
exit $?
299 local indent
=$
(($indent + 1))
302 if ! test -r "$cachedir/notree/$miss"
304 debug
"incorrect order: $miss"
305 process_split_commit
"$miss" ""
310 # Usage: set_notree REV
313 echo "1" > "$cachedir/notree/$1"
316 # Usage: cache_set OLDREV NEWREV
321 if test "$oldrev" != "latest_old" &&
322 test "$oldrev" != "latest_new" &&
323 test -e "$cachedir/$oldrev"
325 die
"cache for $oldrev already exists!"
327 echo "$newrev" >"$cachedir/$oldrev"
330 # Usage: rev_exists REV
333 if git rev-parse
"$1" >/dev
/null
2>&1
341 # Usage: try_remove_previous REV
343 # If a commit doesn't have a parent, this might not work. But we only want
344 # to remove the parent from the rev-list, and since it doesn't exist, it won't
345 # be there anyway, so do nothing in that case.
346 try_remove_previous
() {
354 # Usage: find_latest_squash DIR
355 find_latest_squash
() {
357 debug
"Looking for latest squash ($dir)..."
358 local indent
=$
(($indent + 1))
364 git log
--grep="^git-subtree-dir: $dir/*\$" \
365 --no-show-signature --pretty=format
:'START %H%n%s%n%n%b%nEND%n' HEAD |
369 debug
"{{$sq/$main/$sub}}"
374 git-subtree-mainline
:)
378 sub
="$(git rev-parse "$b^
{commit
}")" ||
379 die
"could not rev-parse split hash $b from commit $sq"
387 # Pretend its sub was a squash.
388 sq=$
(git rev-parse
--verify "$sq^2") ||
391 debug
"Squash found: $sq $sub"
403 # Usage: find_existing_splits DIR REV
404 find_existing_splits
() {
406 debug
"Looking for prior splits..."
407 local indent
=$
(($indent + 1))
413 local grep_format
="^git-subtree-dir: $dir/*\$"
414 if test -n "$arg_split_ignore_joins"
416 grep_format
="^Add '$dir/' from commit '"
418 git log
--grep="$grep_format" \
419 --no-show-signature --pretty=format
:'START %H%n%s%n%n%b%nEND%n' "$rev" |
426 git-subtree-mainline
:)
430 sub
="$(git rev-parse "$b^
{commit
}")" ||
431 die
"could not rev-parse split hash $b from commit $sq"
434 debug
"Main is: '$main'"
435 if test -z "$main" -a -n "$sub"
437 # squash commits refer to a subtree
438 debug
" Squash: $sq from $sub"
439 cache_set
"$sq" "$sub"
441 if test -n "$main" -a -n "$sub"
443 debug
" Prior: $main -> $sub"
446 try_remove_previous
"$main"
447 try_remove_previous
"$sub"
456 # Usage: copy_commit REV TREE FLAGS_STR
459 # We're going to set some environment vars here, so
460 # do it in a subshell to get rid of them safely later
461 debug copy_commit
"{$1}" "{$2}" "{$3}"
462 git log
-1 --no-show-signature --pretty=format
:'%an%n%ae%n%aD%n%cn%n%ce%n%cD%n%B' "$1" |
465 read GIT_AUTHOR_EMAIL
467 read GIT_COMMITTER_NAME
468 read GIT_COMMITTER_EMAIL
469 read GIT_COMMITTER_DATE
470 export GIT_AUTHOR_NAME \
474 GIT_COMMITTER_EMAIL \
477 printf "%s" "$arg_split_annotate"
480 git commit-tree
"$2" $3 # reads the rest of stdin
481 ) || die
"Can't copy commit $1"
484 # Usage: add_msg DIR LATEST_OLD LATEST_NEW
490 if test -n "$arg_addmerge_message"
492 commit_message
="$arg_addmerge_message"
494 commit_message
="Add '$dir/' from commit '$latest_new'"
496 if test -n "$arg_split_rejoin"
498 # If this is from a --rejoin, then rejoin_msg has
499 # already inserted the `git-subtree-xxx:` tags
500 echo "$commit_message"
506 git-subtree-dir: $dir
507 git-subtree-mainline: $latest_old
508 git-subtree-split: $latest_new
512 # Usage: add_squashed_msg REV DIR
513 add_squashed_msg
() {
515 if test -n "$arg_addmerge_message"
517 echo "$arg_addmerge_message"
519 echo "Merge commit '$1' as '$2'"
523 # Usage: rejoin_msg DIR LATEST_OLD LATEST_NEW
529 if test -n "$arg_addmerge_message"
531 commit_message
="$arg_addmerge_message"
533 commit_message
="Split '$dir/' into commit '$latest_new'"
538 git-subtree-dir: $dir
539 git-subtree-mainline: $latest_old
540 git-subtree-split: $latest_new
544 # Usage: squash_msg DIR OLD_SUBTREE_COMMIT NEW_SUBTREE_COMMIT
550 newsub_short
=$
(git rev-parse
--short "$newsub")
554 oldsub_short
=$
(git rev-parse
--short "$oldsub")
555 echo "Squashed '$dir/' changes from $oldsub_short..$newsub_short"
557 git log
--no-show-signature --pretty=tformat
:'%h %s' "$oldsub..$newsub"
558 git log
--no-show-signature --pretty=tformat
:'REVERT: %h %s' "$newsub..$oldsub"
560 echo "Squashed '$dir/' content from commit $newsub_short"
564 echo "git-subtree-dir: $dir"
565 echo "git-subtree-split: $newsub"
568 # Usage: toptree_for_commit COMMIT
569 toptree_for_commit
() {
572 git rev-parse
--verify "$commit^{tree}" ||
exit $?
575 # Usage: subtree_for_commit COMMIT DIR
576 subtree_for_commit
() {
580 git ls-tree
"$commit" -- "$dir" |
581 while read mode
type tree name
583 assert
test "$name" = "$dir"
584 assert
test "$type" = "tree" -o "$type" = "commit"
585 test "$type" = "commit" && continue # ignore submodules
591 # Usage: tree_changed TREE [PARENTS...]
598 return 0 # weird parents, consider it changed
600 ptree
=$
(toptree_for_commit
$1) ||
exit $?
601 if test "$ptree" != "$tree"
605 return 1 # not changed
610 # Usage: new_squash_commit OLD_SQUASHED_COMMIT OLD_NONSQUASHED_COMMIT NEW_NONSQUASHED_COMMIT
611 new_squash_commit
() {
616 tree
=$
(toptree_for_commit
$newsub) ||
exit $?
619 squash_msg
"$dir" "$oldsub" "$newsub" |
620 git commit-tree
"$tree" -p "$old" ||
exit $?
622 squash_msg
"$dir" "" "$newsub" |
623 git commit-tree
"$tree" ||
exit $?
627 # Usage: copy_or_skip REV TREE NEWPARENTS
633 assert
test -n "$tree"
640 for parent
in $newparents
642 ptree
=$
(toptree_for_commit
$parent) ||
exit $?
643 test -z "$ptree" && continue
644 if test "$ptree" = "$tree"
646 # an identical parent could be used in place of this rev.
647 if test -n "$identical"
649 # if a previous identical parent was found, check whether
650 # one is already an ancestor of the other
651 mergebase
=$
(git merge-base
$identical $parent)
652 if test "$identical" = "$mergebase"
654 # current identical commit is an ancestor of parent
656 elif test "$parent" != "$mergebase"
658 # no common history; commit must be copied
662 # first identical parent detected
666 nonidentical
="$parent"
669 # sometimes both old parents map to the same newparent;
670 # eliminate duplicates
672 for gp
in $gotparents
674 if test "$gp" = "$parent"
682 gotparents
="$gotparents $parent"
687 if test -n "$identical" && test -n "$nonidentical"
689 extras
=$
(git rev-list
--count $identical..
$nonidentical)
690 if test "$extras" -ne 0
692 # we need to preserve history along the other branch
696 if test -n "$identical" && test -z "$copycommit"
700 copy_commit
"$rev" "$tree" "$p" ||
exit $?
704 # Usage: ensure_clean
707 if ! git diff-index HEAD
--exit-code --quiet 2>&1
709 die
"Working tree has modifications. Cannot add."
711 if ! git diff-index
--cached HEAD
--exit-code --quiet 2>&1
713 die
"Index has modifications. Cannot add."
717 # Usage: ensure_valid_ref_format REF
718 ensure_valid_ref_format
() {
720 git check-ref-format
"refs/heads/$1" ||
721 die
"'$1' does not look like a ref"
724 # Usage: process_split_commit REV PARENTS
725 process_split_commit
() {
730 if test $indent -eq 0
732 revcount
=$
(($revcount + 1))
734 # processing commit without normal parent information;
736 parents
=$
(git rev-parse
"$rev^@")
737 extracount
=$
(($extracount + 1))
740 progress
"$revcount/$revmax ($createcount) [$extracount]"
742 debug
"Processing commit: $rev"
743 local indent
=$
(($indent + 1))
744 exists
=$
(cache_get
"$rev") ||
exit $?
747 debug
"prior: $exists"
750 createcount
=$
(($createcount + 1))
751 debug
"parents: $parents"
752 check_parents
"$parents"
753 newparents
=$
(cache_get
$parents) ||
exit $?
754 debug
"newparents: $newparents"
756 tree
=$
(subtree_for_commit
"$rev" "$dir") ||
exit $?
757 debug
"tree is: $tree"
759 # ugly. is there no better way to tell if this is a subtree
760 # vs. a mainline commit? Does it matter?
764 if test -n "$newparents"
766 cache_set
"$rev" "$rev"
771 newrev
=$
(copy_or_skip
"$rev" "$tree" "$newparents") ||
exit $?
772 debug
"newrev is: $newrev"
773 cache_set
"$rev" "$newrev"
774 cache_set latest_new
"$newrev"
775 cache_set latest_old
"$rev"
779 # Or: cmd_add REPOSITORY REF
786 git rev-parse
-q --verify "$1^{commit}" >/dev
/null ||
787 die
"'$1' does not refer to a commit"
793 # Technically we could accept a refspec here but we're
794 # just going to turn around and add FETCH_HEAD under the
795 # specified directory. Allowing a refspec might be
796 # misleading because we won't do anything with any other
797 # branches fetched via the refspec.
798 ensure_valid_ref_format
"$2"
800 cmd_add_repository
"$@"
802 say
>&2 "error: parameters were '$*'"
803 die
"Provide either a commit or a repository and commit."
807 # Usage: cmd_add_repository REPOSITORY REFSPEC
808 cmd_add_repository
() {
810 echo "git fetch" "$@"
813 git fetch
"$@" ||
exit $?
814 cmd_add_commit FETCH_HEAD
817 # Usage: cmd_add_commit REV
819 # The rev has already been validated by cmd_add(), we just
820 # need to normalize it.
822 rev=$
(git rev-parse
--verify "$1^{commit}") ||
exit $?
824 debug
"Adding $dir as '$rev'..."
825 if test -z "$arg_split_rejoin"
827 # Only bother doing this if this is a genuine 'add',
828 # not a synthetic 'add' from '--rejoin'.
829 git read-tree
--prefix="$dir" $rev ||
exit $?
831 git checkout
-- "$dir" ||
exit $?
832 tree
=$
(git write-tree
) ||
exit $?
834 headrev
=$
(git rev-parse HEAD
) ||
exit $?
835 if test -n "$headrev" && test "$headrev" != "$rev"
842 if test -n "$arg_addmerge_squash"
844 rev=$
(new_squash_commit
"" "" "$rev") ||
exit $?
845 commit
=$
(add_squashed_msg
"$rev" "$dir" |
846 git commit-tree
"$tree" $headp -p "$rev") ||
exit $?
848 revp
=$
(peel_committish
"$rev") ||
exit $?
849 commit
=$
(add_msg
"$dir" $headrev "$rev" |
850 git commit-tree
"$tree" $headp -p "$revp") ||
exit $?
852 git
reset "$commit" ||
exit $?
854 say
>&2 "Added dir '$dir'"
857 # Usage: cmd_split [REV]
861 rev=$
(git rev-parse HEAD
)
864 rev=$
(git rev-parse
-q --verify "$1^{commit}") ||
865 die
"'$1' does not refer to a commit"
867 die
"You must provide exactly one revision. Got: '$*'"
870 if test -n "$arg_split_rejoin"
875 debug
"Splitting $dir..."
876 cache_setup ||
exit $?
878 if test -n "$arg_split_onto"
880 debug
"Reading history for --onto=$arg_split_onto..."
881 git rev-list
$arg_split_onto |
884 # the 'onto' history is already just the subdir, so
885 # any parent we find there can be used verbatim
887 cache_set
"$rev" "$rev"
891 unrevs
="$(find_existing_splits "$dir" "$rev")" ||
exit $?
893 # We can't restrict rev-list to only $dir here, because some of our
894 # parents have the $dir contents the root, and those won't match.
895 # (and rev-list --follow doesn't seem to solve this)
896 grl
='git rev-list --topo-order --reverse --parents $rev $unrevs'
897 revmax
=$
(eval "$grl" |
wc -l)
902 while read rev parents
904 process_split_commit
"$rev" "$parents"
907 latest_new
=$
(cache_get latest_new
) ||
exit $?
908 if test -z "$latest_new"
910 die
"No new revisions were found"
913 if test -n "$arg_split_rejoin"
915 debug
"Merging split branch into HEAD..."
916 latest_old
=$
(cache_get latest_old
) ||
exit $?
917 arg_addmerge_message
="$(rejoin_msg "$dir" "$latest_old" "$latest_new")" ||
exit $?
918 if test -z "$(find_latest_squash "$dir")"
920 cmd_add
"$latest_new" >&2 ||
exit $?
922 cmd_merge
"$latest_new" >&2 ||
exit $?
925 if test -n "$arg_split_branch"
927 if rev_exists
"refs/heads/$arg_split_branch"
929 if ! git merge-base
--is-ancestor "$arg_split_branch" "$latest_new"
931 die
"Branch '$arg_split_branch' is not an ancestor of commit '$latest_new'."
937 git update-ref
-m 'subtree split' \
938 "refs/heads/$arg_split_branch" "$latest_new" ||
exit $?
939 say
>&2 "$action branch '$arg_split_branch'"
945 # Usage: cmd_merge REV
948 die
"You must provide exactly one revision. Got: '$*'"
949 rev=$
(git rev-parse
-q --verify "$1^{commit}") ||
950 die
"'$1' does not refer to a commit"
953 if test -n "$arg_addmerge_squash"
955 first_split
="$(find_latest_squash "$dir")" ||
exit $?
956 if test -z "$first_split"
958 die
"Can't squash-merge: '$dir' was never added."
963 if test "$sub" = "$rev"
965 say
>&2 "Subtree is already at commit $rev."
968 new
=$
(new_squash_commit
"$old" "$sub" "$rev") ||
exit $?
969 debug
"New squash commit: $new"
973 if test -n "$arg_addmerge_message"
975 git merge
-Xsubtree="$arg_prefix" \
976 --message="$arg_addmerge_message" "$rev"
978 git merge
-Xsubtree="$arg_prefix" $rev
982 # Usage: cmd_pull REPOSITORY REMOTEREF
986 die
"You must provide <repository> <ref>"
989 ensure_valid_ref_format
"$2"
990 git fetch
"$@" ||
exit $?
994 # Usage: cmd_push REPOSITORY [+][LOCALREV:]REMOTEREF
998 die
"You must provide <repository> <refspec>"
1004 remoteref
=${refspec#*:}
1005 if test "$remoteref" = "$refspec"
1007 localrevname_presplit
=HEAD
1009 localrevname_presplit
=${refspec%%:*}
1011 ensure_valid_ref_format
"$remoteref"
1012 localrev_presplit
=$
(git rev-parse
-q --verify "$localrevname_presplit^{commit}") ||
1013 die
"'$localrevname_presplit' does not refer to a commit"
1015 echo "git push using: " "$repository" "$refspec"
1016 localrev
=$
(cmd_split
"$localrev_presplit") || die
1017 git push
"$repository" "$localrev":"refs/heads/$remoteref"
1019 die
"'$dir' must already exist. Try 'git subtree add'."