FM / subtree

/usr/share/doc/git/contrib/subtree

Name	Size	Mode	Actions
t/	-	0755	rm
COPYING	18092	0644	edit dl rm
git-subtree	17485	0644	edit dl rm
git-subtree.sh	17485	0644	edit dl rm
git-subtree.txt	12693	0644	edit dl rm
INSTALL	566	0644	edit dl rm
Makefile	2464	0644	edit dl rm
README	211	0644	edit dl rm
todo	1687	0644	edit dl rm

Edit: /usr/share/doc/git/contrib/subtree/git-subtree.sh (17485B)

#!/bin/sh
#
# git-subtree.sh: split/join git repositories in subdirectories of this one
#
# Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
#
if test $# -eq 0
then
	set -- -h
fi
OPTS_SPEC="\
git subtree add   --prefix=<prefix> <commit>
git subtree add   --prefix=<prefix> <repository> <ref>
git subtree merge --prefix=<prefix> <commit>
git subtree pull  --prefix=<prefix> <repository> <ref>
git subtree push  --prefix=<prefix> <repository> <ref>
git subtree split --prefix=<prefix> <commit>
--
h,help        show the help
q             quiet
d             show debug messages
P,prefix=     the name of the subdir to split out
m,message=    use the given message as the commit message for the merge commit
 options for 'split'
annotate=     add a prefix to commit message of new commits
b,branch=     create a new branch from the split subtree
ignore-joins  ignore prior --rejoin commits
onto=         try connecting new tree to an existing one
rejoin        merge the new branch back into HEAD
 options for 'add', 'merge', and 'pull'
squash        merge subtree changes as a single commit
"
eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"

PATH=$PATH:$(git --exec-path)
. git-sh-setup

require_work_tree

quiet=
branch=
debug=
command=
onto=
rejoin=
ignore_joins=
annotate=
squash=
message=
prefix=

debug () {
	if test -n "$debug"
	then
		printf "%s\n" "$*" >&2
	fi
}

say () {
	if test -z "$quiet"
	then
		printf "%s\n" "$*" >&2
	fi
}

progress () {
	if test -z "$quiet"
	then
		printf "%s\r" "$*" >&2
	fi
}

assert () {
	if ! "$@"
	then
		die "assertion failed: " "$@"
	fi
}

ensure_single_rev () {
	if test $# -ne 1
	then
		die "You must provide exactly one revision.  Got: '$@'"
	fi
}

while test $# -gt 0
do
	opt="$1"
	shift

case "$opt" in
	-q)
		quiet=1
		;;
	-d)
		debug=1
		;;
	--annotate)
		annotate="$1"
		shift
		;;
	--no-annotate)
		annotate=
		;;
	-b)
		branch="$1"
		shift
		;;
	-P)
		prefix="${1%/}"
		shift
		;;
	-m)
		message="$1"
		shift
		;;
	--no-prefix)
		prefix=
		;;
	--onto)
		onto="$1"
		shift
		;;
	--no-onto)
		onto=
		;;
	--rejoin)
		rejoin=1
		;;
	--no-rejoin)
		rejoin=
		;;
	--ignore-joins)
		ignore_joins=1
		;;
	--no-ignore-joins)
		ignore_joins=
		;;
	--squash)
		squash=1
		;;
	--no-squash)
		squash=
		;;
	--)
		break
		;;
	*)
		die "Unexpected option: $opt"
		;;
	esac
done

command="$1"
shift

case "$command" in
add|merge|pull)
	default=
	;;
split|push)
	default="--default HEAD"
	;;
*)
	die "Unknown command '$command'"
	;;
esac

if test -z "$prefix"
then
	die "You must provide the --prefix option."
fi

case "$command" in
add)
	test -e "$prefix" &&
		die "prefix '$prefix' already exists."
	;;
*)
	test -e "$prefix" ||
		die "'$prefix' does not exist; use 'git subtree add'"
	;;
esac

dir="$(dirname "$prefix/.")"

if test "$command" != "pull" &&
		test "$command" != "add" &&
		test "$command" != "push"
then
	revs=$(git rev-parse $default --revs-only "$@") || exit $?
	dirs=$(git rev-parse --no-revs --no-flags "$@") || exit $?
	ensure_single_rev $revs
	if test -n "$dirs"
	then
		die "Error: Use --prefix instead of bare filenames."
	fi
fi

debug "command: {$command}"
debug "quiet: {$quiet}"
debug "revs: {$revs}"
debug "dir: {$dir}"
debug "opts: {$*}"
debug

cache_setup () {
	cachedir="$GIT_DIR/subtree-cache/$$"
	rm -rf "$cachedir" ||
		die "Can't delete old cachedir: $cachedir"
	mkdir -p "$cachedir" ||
		die "Can't create new cachedir: $cachedir"
	mkdir -p "$cachedir/notree" ||
		die "Can't create new cachedir: $cachedir/notree"
	debug "Using cachedir: $cachedir" >&2
}

cache_get () {
	for oldrev in "$@"
	do
		if test -r "$cachedir/$oldrev"
		then
			read newrev <"$cachedir/$oldrev"
			echo $newrev
		fi
	done
}

cache_miss () {
	for oldrev in "$@"
	do
		if ! test -r "$cachedir/$oldrev"
		then
			echo $oldrev
		fi
	done
}

check_parents () {
	missed=$(cache_miss "$1")
	local indent=$(($2 + 1))
	for miss in $missed
	do
		if ! test -r "$cachedir/notree/$miss"
		then
			debug "  incorrect order: $miss"
			process_split_commit "$miss" "" "$indent"
		fi
	done
}

set_notree () {
	echo "1" > "$cachedir/notree/$1"
}

cache_set () {
	oldrev="$1"
	newrev="$2"
	if test "$oldrev" != "latest_old" &&
		test "$oldrev" != "latest_new" &&
		test -e "$cachedir/$oldrev"
	then
		die "cache for $oldrev already exists!"
	fi
	echo "$newrev" >"$cachedir/$oldrev"
}

rev_exists () {
	if git rev-parse "$1" >/dev/null 2>&1
	then
		return 0
	else
		return 1
	fi
}

rev_is_descendant_of_branch () {
	newrev="$1"
	branch="$2"
	branch_hash=$(git rev-parse "$branch")
	match=$(git rev-list -1 "$branch_hash" "^$newrev")

if test -z "$match"
	then
		return 0
	else
		return 1
	fi
}

# if a commit doesn't have a parent, this might not work.  But we only want
# to remove the parent from the rev-list, and since it doesn't exist, it won't
# be there anyway, so do nothing in that case.
try_remove_previous () {
	if rev_exists "$1^"
	then
		echo "^$1^"
	fi
}

find_latest_squash () {
	debug "Looking for latest squash ($dir)..."
	dir="$1"
	sq=
	main=
	sub=
	git log --grep="^git-subtree-dir: $dir/*\$" \
		--no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' HEAD |
	while read a b junk
	do
		debug "$a $b $junk"
		debug "{{$sq/$main/$sub}}"
		case "$a" in
		START)
			sq="$b"
			;;
		git-subtree-mainline:)
			main="$b"
			;;
		git-subtree-split:)
			sub="$(git rev-parse "$b^0")" ||
			die "could not rev-parse split hash $b from commit $sq"
			;;
		END)
			if test -n "$sub"
			then
				if test -n "$main"
				then
					# a rejoin commit?
					# Pretend its sub was a squash.
					sq="$sub"
				fi
				debug "Squash found: $sq $sub"
				echo "$sq" "$sub"
				break
			fi
			sq=
			main=
			sub=
			;;
		esac
	done
}

find_existing_splits () {
	debug "Looking for prior splits..."
	dir="$1"
	revs="$2"
	main=
	sub=
	local grep_format="^git-subtree-dir: $dir/*\$"
	if test -n "$ignore_joins"
	then
		grep_format="^Add '$dir/' from commit '"
	fi
	git log --grep="$grep_format" \
		--no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' $revs |
	while read a b junk
	do
		case "$a" in
		START)
			sq="$b"
			;;
		git-subtree-mainline:)
			main="$b"
			;;
		git-subtree-split:)
			sub="$(git rev-parse "$b^0")" ||
			die "could not rev-parse split hash $b from commit $sq"
			;;
		END)
			debug "  Main is: '$main'"
			if test -z "$main" -a -n "$sub"
			then
				# squash commits refer to a subtree
				debug "  Squash: $sq from $sub"
				cache_set "$sq" "$sub"
			fi
			if test -n "$main" -a -n "$sub"
			then
				debug "  Prior: $main -> $sub"
				cache_set $main $sub
				cache_set $sub $sub
				try_remove_previous "$main"
				try_remove_previous "$sub"
			fi
			main=
			sub=
			;;
		esac
	done
}

copy_commit () {
	# We're going to set some environment vars here, so
	# do it in a subshell to get rid of them safely later
	debug copy_commit "{$1}" "{$2}" "{$3}"
	git log -1 --no-show-signature --pretty=format:'%an%n%ae%n%aD%n%cn%n%ce%n%cD%n%B' "$1" |
	(
		read GIT_AUTHOR_NAME
		read GIT_AUTHOR_EMAIL
		read GIT_AUTHOR_DATE
		read GIT_COMMITTER_NAME
		read GIT_COMMITTER_EMAIL
		read GIT_COMMITTER_DATE
		export  GIT_AUTHOR_NAME \
			GIT_AUTHOR_EMAIL \
			GIT_AUTHOR_DATE \
			GIT_COMMITTER_NAME \
			GIT_COMMITTER_EMAIL \
			GIT_COMMITTER_DATE
		(
			printf "%s" "$annotate"
			cat
		) |
		git commit-tree "$2" $3  # reads the rest of stdin
	) || die "Can't copy commit $1"
}

add_msg () {
	dir="$1"
	latest_old="$2"
	latest_new="$3"
	if test -n "$message"
	then
		commit_message="$message"
	else
		commit_message="Add '$dir/' from commit '$latest_new'"
	fi
	cat <<-EOF
		$commit_message

git-subtree-dir: $dir
		git-subtree-mainline: $latest_old
		git-subtree-split: $latest_new
	EOF
}

add_squashed_msg () {
	if test -n "$message"
	then
		echo "$message"
	else
		echo "Merge commit '$1' as '$2'"
	fi
}

rejoin_msg () {
	dir="$1"
	latest_old="$2"
	latest_new="$3"
	if test -n "$message"
	then
		commit_message="$message"
	else
		commit_message="Split '$dir/' into commit '$latest_new'"
	fi
	cat <<-EOF
		$commit_message

git-subtree-dir: $dir
		git-subtree-mainline: $latest_old
		git-subtree-split: $latest_new
	EOF
}

squash_msg () {
	dir="$1"
	oldsub="$2"
	newsub="$3"
	newsub_short=$(git rev-parse --short "$newsub")

if test -n "$oldsub"
	then
		oldsub_short=$(git rev-parse --short "$oldsub")
		echo "Squashed '$dir/' changes from $oldsub_short..$newsub_short"
		echo
		git log --no-show-signature --pretty=tformat:'%h %s' "$oldsub..$newsub"
		git log --no-show-signature --pretty=tformat:'REVERT: %h %s' "$newsub..$oldsub"
	else
		echo "Squashed '$dir/' content from commit $newsub_short"
	fi

echo
	echo "git-subtree-dir: $dir"
	echo "git-subtree-split: $newsub"
}

toptree_for_commit () {
	commit="$1"
	git rev-parse --verify "$commit^{tree}" || exit $?
}

subtree_for_commit () {
	commit="$1"
	dir="$2"
	git ls-tree "$commit" -- "$dir" |
	while read mode type tree name
	do
		assert test "$name" = "$dir"
		assert test "$type" = "tree" -o "$type" = "commit"
		test "$type" = "commit" && continue  # ignore submodules
		echo $tree
		break
	done
}

tree_changed () {
	tree=$1
	shift
	if test $# -ne 1
	then
		return 0   # weird parents, consider it changed
	else
		ptree=$(toptree_for_commit $1)
		if test "$ptree" != "$tree"
		then
			return 0   # changed
		else
			return 1   # not changed
		fi
	fi
}

new_squash_commit () {
	old="$1"
	oldsub="$2"
	newsub="$3"
	tree=$(toptree_for_commit $newsub) || exit $?
	if test -n "$old"
	then
		squash_msg "$dir" "$oldsub" "$newsub" |
		git commit-tree "$tree" -p "$old" || exit $?
	else
		squash_msg "$dir" "" "$newsub" |
		git commit-tree "$tree" || exit $?
	fi
}

copy_or_skip () {
	rev="$1"
	tree="$2"
	newparents="$3"
	assert test -n "$tree"

identical=
	nonidentical=
	p=
	gotparents=
	copycommit=
	for parent in $newparents
	do
		ptree=$(toptree_for_commit $parent) || exit $?
		test -z "$ptree" && continue
		if test "$ptree" = "$tree"
		then
			# an identical parent could be used in place of this rev.
			if test -n "$identical"
			then
				# if a previous identical parent was found, check whether
				# one is already an ancestor of the other
				mergebase=$(git merge-base $identical $parent)
				if test "$identical" = "$mergebase"
				then
					# current identical commit is an ancestor of parent
					identical="$parent"
				elif test "$parent" != "$mergebase"
				then
					# no common history; commit must be copied
					copycommit=1
				fi
			else
				# first identical parent detected
				identical="$parent"
			fi
		else
			nonidentical="$parent"
		fi

# sometimes both old parents map to the same newparent;
		# eliminate duplicates
		is_new=1
		for gp in $gotparents
		do
			if test "$gp" = "$parent"
			then
				is_new=
				break
			fi
		done
		if test -n "$is_new"
		then
			gotparents="$gotparents $parent"
			p="$p -p $parent"
		fi
	done

if test -n "$identical" && test -n "$nonidentical"
	then
		extras=$(git rev-list --count $identical..$nonidentical)
		if test "$extras" -ne 0
		then
			# we need to preserve history along the other branch
			copycommit=1
		fi
	fi
	if test -n "$identical" && test -z "$copycommit"
	then
		echo $identical
	else
		copy_commit "$rev" "$tree" "$p" || exit $?
	fi
}

ensure_clean () {
	if ! git diff-index HEAD --exit-code --quiet 2>&1
	then
		die "Working tree has modifications.  Cannot add."
	fi
	if ! git diff-index --cached HEAD --exit-code --quiet 2>&1
	then
		die "Index has modifications.  Cannot add."
	fi
}

ensure_valid_ref_format () {
	git check-ref-format "refs/heads/$1" ||
		die "'$1' does not look like a ref"
}

process_split_commit () {
	local rev="$1"
	local parents="$2"
	local indent=$3

if test $indent -eq 0
	then
		revcount=$(($revcount + 1))
	else
		# processing commit without normal parent information;
		# fetch from repo
		parents=$(git rev-parse "$rev^@")
		extracount=$(($extracount + 1))
	fi

progress "$revcount/$revmax ($createcount) [$extracount]"

debug "Processing commit: $rev"
	exists=$(cache_get "$rev")
	if test -n "$exists"
	then
		debug "  prior: $exists"
		return
	fi
	createcount=$(($createcount + 1))
	debug "  parents: $parents"
	check_parents "$parents" "$indent"
	newparents=$(cache_get $parents)
	debug "  newparents: $newparents"

tree=$(subtree_for_commit "$rev" "$dir")
	debug "  tree is: $tree"

# ugly.  is there no better way to tell if this is a subtree
	# vs. a mainline commit?  Does it matter?
	if test -z "$tree"
	then
		set_notree "$rev"
		if test -n "$newparents"
		then
			cache_set "$rev" "$rev"
		fi
		return
	fi

newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
	debug "  newrev is: $newrev"
	cache_set "$rev" "$newrev"
	cache_set latest_new "$newrev"
	cache_set latest_old "$rev"
}

cmd_add () {
	if test -e "$dir"
	then
		die "'$dir' already exists.  Cannot add."
	fi

ensure_clean

if test $# -eq 1
	then
		git rev-parse -q --verify "$1^{commit}" >/dev/null ||
			die "'$1' does not refer to a commit"

cmd_add_commit "$@"

elif test $# -eq 2
	then
		# Technically we could accept a refspec here but we're
		# just going to turn around and add FETCH_HEAD under the
		# specified directory.  Allowing a refspec might be
		# misleading because we won't do anything with any other
		# branches fetched via the refspec.
		ensure_valid_ref_format "$2"

cmd_add_repository "$@"
	else
		say "error: parameters were '$@'"
		die "Provide either a commit or a repository and commit."
	fi
}

cmd_add_repository () {
	echo "git fetch" "$@"
	repository=$1
	refspec=$2
	git fetch "$@" || exit $?
	revs=FETCH_HEAD
	set -- $revs
	cmd_add_commit "$@"
}

cmd_add_commit () {
	rev=$(git rev-parse $default --revs-only "$@") || exit $?
	ensure_single_rev $rev

debug "Adding $dir as '$rev'..."
	git read-tree --prefix="$dir" $rev || exit $?
	git checkout -- "$dir" || exit $?
	tree=$(git write-tree) || exit $?

headrev=$(git rev-parse HEAD) || exit $?
	if test -n "$headrev" && test "$headrev" != "$rev"
	then
		headp="-p $headrev"
	else
		headp=
	fi

if test -n "$squash"
	then
		rev=$(new_squash_commit "" "" "$rev") || exit $?
		commit=$(add_squashed_msg "$rev" "$dir" |
			git commit-tree "$tree" $headp -p "$rev") || exit $?
	else
		revp=$(peel_committish "$rev") &&
		commit=$(add_msg "$dir" $headrev "$rev" |
			git commit-tree "$tree" $headp -p "$revp") || exit $?
	fi
	git reset "$commit" || exit $?

say "Added dir '$dir'"
}

cmd_split () {
	debug "Splitting $dir..."
	cache_setup || exit $?

if test -n "$onto"
	then
		debug "Reading history for --onto=$onto..."
		git rev-list $onto |
		while read rev
		do
			# the 'onto' history is already just the subdir, so
			# any parent we find there can be used verbatim
			debug "  cache: $rev"
			cache_set "$rev" "$rev"
		done
	fi

unrevs="$(find_existing_splits "$dir" "$revs")"

# We can't restrict rev-list to only $dir here, because some of our
	# parents have the $dir contents the root, and those won't match.
	# (and rev-list --follow doesn't seem to solve this)
	grl='git rev-list --topo-order --reverse --parents $revs $unrevs'
	revmax=$(eval "$grl" | wc -l)
	revcount=0
	createcount=0
	extracount=0
	eval "$grl" |
	while read rev parents
	do
		process_split_commit "$rev" "$parents" 0
	done || exit $?

latest_new=$(cache_get latest_new)
	if test -z "$latest_new"
	then
		die "No new revisions were found"
	fi

if test -n "$rejoin"
	then
		debug "Merging split branch into HEAD..."
		latest_old=$(cache_get latest_old)
		git merge -s ours \
			--allow-unrelated-histories \
			-m "$(rejoin_msg "$dir" "$latest_old" "$latest_new")" \
			"$latest_new" >&2 || exit $?
	fi
	if test -n "$branch"
	then
		if rev_exists "refs/heads/$branch"
		then
			if ! rev_is_descendant_of_branch "$latest_new" "$branch"
			then
				die "Branch '$branch' is not an ancestor of commit '$latest_new'."
			fi
			action='Updated'
		else
			action='Created'
		fi
		git update-ref -m 'subtree split' \
			"refs/heads/$branch" "$latest_new" || exit $?
		say "$action branch '$branch'"
	fi
	echo "$latest_new"
	exit 0
}

cmd_merge () {
	rev=$(git rev-parse $default --revs-only "$@") || exit $?
	ensure_single_rev $rev
	ensure_clean

if test -n "$squash"
	then
		first_split="$(find_latest_squash "$dir")"
		if test -z "$first_split"
		then
			die "Can't squash-merge: '$dir' was never added."
		fi
		set $first_split
		old=$1
		sub=$2
		if test "$sub" = "$rev"
		then
			say "Subtree is already at commit $rev."
			exit 0
		fi
		new=$(new_squash_commit "$old" "$sub" "$rev") || exit $?
		debug "New squash commit: $new"
		rev="$new"
	fi

version=$(git version)
	if test "$version" \< "git version 1.7"
	then
		if test -n "$message"
		then
			git merge -s subtree --message="$message" "$rev"
		else
			git merge -s subtree "$rev"
		fi
	else
		if test -n "$message"
		then
			git merge -Xsubtree="$prefix" \
				--message="$message" "$rev"
		else
			git merge -Xsubtree="$prefix" $rev
		fi
	fi
}

cmd_pull () {
	if test $# -ne 2
	then
		die "You must provide <repository> <ref>"
	fi
	ensure_clean
	ensure_valid_ref_format "$2"
	git fetch "$@" || exit $?
	revs=FETCH_HEAD
	set -- $revs
	cmd_merge "$@"
}

cmd_push () {
	if test $# -ne 2
	then
		die "You must provide <repository> <ref>"
	fi
	ensure_valid_ref_format "$2"
	if test -e "$dir"
	then
		repository=$1
		refspec=$2
		echo "git push using: " "$repository" "$refspec"
		localrev=$(git subtree split --prefix="$prefix") || die
		git push "$repository" "$localrev":"refs/heads/$refspec"
	else
		die "'$dir' must already exist. Try 'git subtree add'."
	fi
}

"cmd_$command" "$@"

cmd: