diff options
Diffstat (limited to 'contrib/subtree/git-subtree.sh')
| -rwxr-xr-x | contrib/subtree/git-subtree.sh | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh new file mode 100755 index 0000000000..920c664bb7 --- /dev/null +++ b/contrib/subtree/git-subtree.sh @@ -0,0 +1,712 @@ +#!/bin/bash +# +# git-subtree.sh: split/join git repositories in subdirectories of this one +# +# Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com> +# +if [ $# -eq 0 ]; then + set -- -h +fi +OPTS_SPEC="\ +git subtree add --prefix=<prefix> <commit> +git subtree merge --prefix=<prefix> <commit> +git subtree pull --prefix=<prefix> <repository> <refspec...> +git subtree push --prefix=<prefix> <repository> <refspec...> +git subtree split --prefix=<prefix> <commit...> +-- +h,help show the help +q quiet +d show debug messages +P,prefix= the name of the subdir to split out +m,message= use the given message as the commit message for the merge commit + options for 'split' +annotate= add a prefix to commit message of new commits +b,branch= create a new branch from the split subtree +ignore-joins ignore prior --rejoin commits +onto= try connecting new tree to an existing one +rejoin merge the new branch back into HEAD + options for 'add', 'merge', 'pull' and 'push' +squash merge subtree changes as a single commit +" +eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)" + +PATH=$PATH:$(git --exec-path) +. git-sh-setup + +require_work_tree + +quiet= +branch= +debug= +command= +onto= +rejoin= +ignore_joins= +annotate= +squash= +message= + +debug() +{ + if [ -n "$debug" ]; then + echo "$@" >&2 + fi +} + +say() +{ + if [ -z "$quiet" ]; then + echo "$@" >&2 + fi +} + +assert() +{ + if "$@"; then + : + else + die "assertion failed: " "$@" + fi +} + + +#echo "Options: $*" + +while [ $# -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 '$command'" ;; +esac + +if [ -z "$prefix" ]; then + die "You must provide the --prefix option." +fi + +case "$command" in + add) [ -e "$prefix" ] && + die "prefix '$prefix' already exists." ;; + *) [ -e "$prefix" ] || + die "'$prefix' does not exist; use 'git subtree add'" ;; +esac + +dir="$(dirname "$prefix/.")" + +if [ "$command" != "pull" -a "$command" != "add" -a "$command" != "push" ]; then + revs=$(git rev-parse $default --revs-only "$@") || exit $? + dirs="$(git rev-parse --no-revs --no-flags "$@")" || exit $? + if [ -n "$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 $*; do + if [ -r "$cachedir/$oldrev" ]; then + read newrev <"$cachedir/$oldrev" + echo $newrev + fi + done +} + +cache_miss() +{ + for oldrev in $*; do + if [ ! -r "$cachedir/$oldrev" ]; then + echo $oldrev + fi + done +} + +check_parents() +{ + missed=$(cache_miss $*) + for miss in $missed; do + if [ ! -r "$cachedir/notree/$miss" ]; then + debug " incorrect order: $miss" + fi + done +} + +set_notree() +{ + echo "1" > "$cachedir/notree/$1" +} + +cache_set() +{ + oldrev="$1" + newrev="$2" + if [ "$oldrev" != "latest_old" \ + -a "$oldrev" != "latest_new" \ + -a -e "$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 [ -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: $dir/*\$" \ + --pretty=format:'START %H%n%s%n%n%b%nEND%n' HEAD | + while read a b junk; do + debug "$a $b $junk" + debug "{{$sq/$main/$sub}}" + case "$a" in + START) sq="$b" ;; + git-subtree-mainline:) main="$b" ;; + git-subtree-split:) sub="$b" ;; + END) + if [ -n "$sub" ]; then + if [ -n "$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= + git log --grep="^git-subtree-dir: $dir/*\$" \ + --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="$b" ;; + END) + debug " Main is: '$main'" + if [ -z "$main" -a -n "$sub" ]; then + # squash commits refer to a subtree + debug " Squash: $sq from $sub" + cache_set "$sq" "$sub" + fi + if [ -n "$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 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" | + ( + read GIT_AUTHOR_NAME + read GIT_AUTHOR_EMAIL + read GIT_AUTHOR_DATE + read GIT_COMMITTER_NAME + read GIT_COMMITTER_EMAIL + read GIT_COMMITTER_DATE + export GIT_AUTHOR_NAME \ + GIT_AUTHOR_EMAIL \ + GIT_AUTHOR_DATE \ + GIT_COMMITTER_NAME \ + GIT_COMMITTER_EMAIL \ + GIT_COMMITTER_DATE + (echo -n "$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="$3" + if [ -n "$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: $latest_new + EOF +} + +add_squashed_msg() +{ + if [ -n "$message" ]; then + echo "$message" + else + echo "Merge commit '$1' as '$2'" + fi +} + +rejoin_msg() +{ + dir="$1" + latest_old="$2" + latest_new="$3" + if [ -n "$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 "$newsub") + + if [ -n "$oldsub" ]; then + oldsub_short=$(git rev-parse --short "$oldsub") + echo "Squashed '$dir/' changes from $oldsub_short..$newsub_short" + echo + git log --pretty=tformat:'%h %s' "$oldsub..$newsub" + git log --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="$1" + git log -1 --pretty=format:'%T' "$commit" -- || exit $? +} + +subtree_for_commit() +{ + commit="$1" + dir="$2" + git ls-tree "$commit" -- "$dir" | + while read mode type tree name; do + assert [ "$name" = "$dir" ] + assert [ "$type" = "tree" -o "$type" = "commit" ] + [ "$type" = "commit" ] && continue # ignore submodules + echo $tree + break + done +} + +tree_changed() +{ + tree=$1 + shift + if [ $# -ne 1 ]; then + return 0 # weird parents, consider it changed + else + ptree=$(toptree_for_commit $1) + if [ "$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 $? + if [ -n "$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="$3" + assert [ -n "$tree" ] + + identical= + nonidentical= + p= + gotparents= + for parent in $newparents; do + ptree=$(toptree_for_commit $parent) || exit $? + [ -z "$ptree" ] && continue + if [ "$ptree" = "$tree" ]; then + # an identical parent could be used in place of this rev. + identical="$parent" + else + nonidentical="$parent" + fi + + # sometimes both old parents map to the same newparent; + # eliminate duplicates + is_new=1 + for gp in $gotparents; do + if [ "$gp" = "$parent" ]; then + is_new= + break + fi + done + if [ -n "$is_new" ]; then + gotparents="$gotparents $parent" + p="$p -p $parent" + fi + done + + if [ -n "$identical" ]; then + echo $identical + else + copy_commit $rev $tree "$p" || exit $? + fi +} + +ensure_clean() +{ + if ! git diff-index HEAD --exit-code --quiet 2>&1; then + die "Working tree has modifications. Cannot add." + fi + if ! git diff-index --cached HEAD --exit-code --quiet 2>&1; then + die "Index has modifications. Cannot add." + fi +} + +cmd_add() +{ + if [ -e "$dir" ]; then + die "'$dir' already exists. Cannot add." + fi + + ensure_clean + + if [ $# -eq 1 ]; then + "cmd_add_commit" "$@" + elif [ $# -eq 2 ]; then + "cmd_add_repository" "$@" + else + say "error: parameters were '$@'" + die "Provide either a refspec or a repository and refspec." + fi +} + +cmd_add_repository() +{ + echo "git fetch" "$@" + repository=$1 + refspec=$2 + git fetch "$@" || exit $? + revs=FETCH_HEAD + set -- $revs + cmd_add_commit "$@" +} + +cmd_add_commit() +{ + revs=$(git rev-parse $default --revs-only "$@") || exit $? + set -- $revs + rev="$1" + + 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 $? + if [ -n "$headrev" -a "$headrev" != "$rev" ]; then + headp="-p $headrev" + else + headp= + fi + + if [ -n "$squash" ]; then + rev=$(new_squash_commit "" "" "$rev") || exit $? + commit=$(add_squashed_msg "$rev" "$dir" | + git commit-tree $tree $headp -p "$rev") || exit $? + else + commit=$(add_msg "$dir" "$headrev" "$rev" | + git commit-tree $tree $headp -p "$rev") || exit $? + fi + git reset "$commit" || exit $? + + say "Added dir '$dir'" +} + +cmd_split() +{ + debug "Splitting $dir..." + cache_setup || exit $? + + if [ -n "$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 $rev + done + fi + + if [ -n "$ignore_joins" ]; then + unrevs= + else + unrevs="$(find_existing_splits "$dir" "$revs")" + fi + + # 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 "$grl" | wc -l) + revcount=0 + createcount=0 + eval "$grl" | + while read rev parents; do + revcount=$(($revcount + 1)) + say -n "$revcount/$revmax ($createcount)
" + debug "Processing commit: $rev" + exists=$(cache_get $rev) + if [ -n "$exists" ]; then + debug " prior: $exists" + continue + fi + createcount=$(($createcount + 1)) + debug " parents: $parents" + newparents=$(cache_get $parents) + debug " newparents: $newparents" + + tree=$(subtree_for_commit $rev "$dir") + debug " tree is: $tree" + + check_parents $parents + + # ugly. is there no better way to tell if this is a subtree + # vs. a mainline commit? Does it matter? + if [ -z $tree ]; then + set_notree $rev + if [ -n "$newparents" ]; then + cache_set $rev $rev + fi + continue + fi + + newrev=$(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 + done || exit $? + latest_new=$(cache_get latest_new) + if [ -z "$latest_new" ]; then + die "No new revisions were found" + fi + + if [ -n "$rejoin" ]; then + debug "Merging split branch into HEAD..." + latest_old=$(cache_get latest_old) + git merge -s ours \ + -m "$(rejoin_msg $dir $latest_old $latest_new)" \ + $latest_new >&2 || exit $? + fi + if [ -n "$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 $latest_new + exit 0 +} + +cmd_merge() +{ + revs=$(git rev-parse $default --revs-only "$@") || exit $? + ensure_clean + + set -- $revs + if [ $# -ne 1 ]; then + die "You must provide exactly one revision. Got: '$revs'" + fi + rev="$1" + + if [ -n "$squash" ]; then + first_split="$(find_latest_squash "$dir")" + if [ -z "$first_split" ]; then + die "Can't squash-merge: '$dir' was never added." + fi + set $first_split + old=$1 + sub=$2 + if [ "$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=$(git version) + if [ "$version" \< "git version 1.7" ]; then + if [ -n "$message" ]; then + git merge -s subtree --message="$message" $rev + else + git merge -s subtree $rev + fi + else + if [ -n "$message" ]; then + git merge -Xsubtree="$prefix" --message="$message" $rev + else + git merge -Xsubtree="$prefix" $rev + fi + fi +} + +cmd_pull() +{ + ensure_clean + git fetch "$@" || exit $? + revs=FETCH_HEAD + set -- $revs + cmd_merge "$@" +} + +cmd_push() +{ + if [ $# -ne 2 ]; then + die "You must provide <repository> <refspec>" + fi + if [ -e "$dir" ]; then + repository=$1 + refspec=$2 + echo "git push using: " $repository $refspec + git push $repository $(git subtree split --prefix=$prefix):refs/heads/$refspec + else + die "'$dir' must already exist. Try 'git subtree add'." + fi +} + +"cmd_$command" "$@" |