This rewrites `git merge-octopus' from shell to C. As for the two last
conversions, this port removes calls to external processes to avoid
reading and writing the index over and over again.
- Calls to `read-tree -u -m (--aggressive)?' are replaced by calls to
unpack_trees().
- The call to `write-tree' is replaced by a call to write_tree().
- The call to `diff-index ...' is replaced by a call to
repo_index_has_changes().
- The call to `merge-index', needed to invoke `git merge-one-file', is
replaced by a call to merge_all_index().
The index is read in cmd_merge_octopus(), and is written back by
merge_strategies_octopus(), for the same reason as merge-resolve.
Here too, merge_strategies_octopus() takes two commit lists and a string
to reduce friction when try_merge_strategies() will be modified to call
it directly. It also locks the index at the start of the merge, and
releases it at the end.
Signed-off-by: Alban Gruin <alban.gruin@xxxxxxxxx>
---
Makefile | 2 +-
builtin.h | 1 +
builtin/merge-octopus.c | 63 +++++++++++++++
git-merge-octopus.sh | 112 --------------------------
git.c | 1 +
merge-strategies.c | 171 ++++++++++++++++++++++++++++++++++++++++
merge-strategies.h | 3 +
7 files changed, 240 insertions(+), 113 deletions(-)
create mode 100644 builtin/merge-octopus.c
delete mode 100755 git-merge-octopus.sh
diff --git a/Makefile b/Makefile
index 0c18acb979..9fe1e72f6e 100644
--- a/Makefile
+++ b/Makefile
@@ -630,7 +630,6 @@ unexport CDPATH
SCRIPT_SH += git-bisect.sh
SCRIPT_SH += git-difftool--helper.sh
SCRIPT_SH += git-filter-branch.sh
-SCRIPT_SH += git-merge-octopus.sh
SCRIPT_SH += git-mergetool.sh
SCRIPT_SH += git-quiltimport.sh
SCRIPT_SH += git-request-pull.sh
@@ -1184,6 +1183,7 @@ BUILTIN_OBJS += builtin/mailsplit.o
BUILTIN_OBJS += builtin/merge-base.o
BUILTIN_OBJS += builtin/merge-file.o
BUILTIN_OBJS += builtin/merge-index.o
+BUILTIN_OBJS += builtin/merge-octopus.o
BUILTIN_OBJS += builtin/merge-one-file.o
BUILTIN_OBJS += builtin/merge-ours.o
BUILTIN_OBJS += builtin/merge-recursive.o
diff --git a/builtin.h b/builtin.h
index 4627229944..9305dda166 100644
--- a/builtin.h
+++ b/builtin.h
@@ -180,6 +180,7 @@ int cmd_maintenance(int argc, const char **argv, const char *prefix);
int cmd_merge(int argc, const char **argv, const char *prefix);
int cmd_merge_base(int argc, const char **argv, const char *prefix);
int cmd_merge_index(int argc, const char **argv, const char *prefix);
+int cmd_merge_octopus(int argc, const char **argv, const char *prefix);
int cmd_merge_ours(int argc, const char **argv, const char *prefix);
int cmd_merge_file(int argc, const char **argv, const char *prefix);
int cmd_merge_one_file(int argc, const char **argv, const char *prefix);
diff --git a/builtin/merge-octopus.c b/builtin/merge-octopus.c
new file mode 100644
index 0000000000..ff3089bfca
--- /dev/null
+++ b/builtin/merge-octopus.c
@@ -0,0 +1,63 @@
+/*
+ * Builtin "git merge-octopus"
+ *
+ * Copyright (c) 2020 Alban Gruin
+ *
+ * Based on git-merge-octopus.sh, written by Junio C Hamano.
+ *
+ * Resolve two or more trees.
+ */
+
+#include "cache.h"
+#include "builtin.h"
+#include "commit.h"
+#include "merge-strategies.h"
+
+static const char builtin_merge_octopus_usage[] =
+ "git merge-octopus [<bases>...] -- <head> <remote1> <remote2> [<remotes>...]";
+
+int cmd_merge_octopus(int argc, const char **argv, const char *prefix)
+{
+ int i, sep_seen = 0;
+ struct commit_list *bases = NULL, *remotes = NULL;
+ struct commit_list **next_base = &bases, **next_remote = &remotes;
+ const char *head_arg = NULL;
+ struct repository *r = the_repository;
+
+ if (argc < 5)
+ usage(builtin_merge_octopus_usage);
+
+ setup_work_tree();
+ if (repo_read_index(r) < 0)
+ die("invalid index");
+
+ /*
+ * The first parameters up to -- are merge bases; the rest are
+ * heads.
+ */
+ for (i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "--") == 0)
+ sep_seen = 1;
+ else if (strcmp(argv[i], "-h") == 0)
+ usage(builtin_merge_octopus_usage);
+ else if (sep_seen && !head_arg)
+ head_arg = argv[i];
+ else {
+ struct object_id oid;
+ struct commit *commit;
+
+ if (get_oid(argv[i], &oid))
+ die("object %s not found.", argv[i]);
+
+ commit = oideq(&oid, r->hash_algo->empty_tree) ?
+ NULL : lookup_commit_or_die(&oid, argv[i]);
+
+ if (sep_seen)
+ next_remote = commit_list_append(commit, next_remote);
+ else
+ next_base = commit_list_append(commit, next_base);
+ }
+ }
+
+ return merge_strategies_octopus(r, bases, head_arg, remotes);
+}
diff --git a/git-merge-octopus.sh b/git-merge-octopus.sh
deleted file mode 100755
index 2770891960..0000000000
--- a/git-merge-octopus.sh
+++ /dev/null
@@ -1,112 +0,0 @@
-#!/bin/sh
-#
-# Copyright (c) 2005 Junio C Hamano
-#
-# Resolve two or more trees.
-#
-
-. git-sh-setup
-
-LF='
-'
-
-# The first parameters up to -- are merge bases; the rest are heads.
-bases= head= remotes= sep_seen=
-for arg
-do
- case ",$sep_seen,$head,$arg," in
- *,--,)
- sep_seen=yes
- ;;
- ,yes,,*)
- head=$arg
- ;;
- ,yes,*)
- remotes="$remotes$arg "
- ;;
- *)
- bases="$bases$arg "
- ;;
- esac
-done
-
-# Reject if this is not an octopus -- resolve should be used instead.
-case "$remotes" in
-?*' '?*)
- ;;
-*)
- exit 2 ;;
-esac
-
-# MRC is the current "merge reference commit"
-# MRT is the current "merge result tree"
-
-if ! git diff-index --quiet --cached HEAD --
-then
- gettextln "Error: Your local changes to the following files would be overwritten by merge"
- git diff-index --cached --name-only HEAD -- | sed -e 's/^/ /'
- exit 2
-fi
-MRC=$(git rev-parse --verify -q $head)
-MRT=$(git write-tree)
-NON_FF_MERGE=0
-OCTOPUS_FAILURE=0
-for SHA1 in $remotes
-do
- case "$OCTOPUS_FAILURE" in
- 1)
- # We allow only last one to have a hand-resolvable
- # conflicts. Last round failed and we still had
- # a head to merge.
- gettextln "Automated merge did not work."
- gettextln "Should not be doing an octopus."
- exit 2
- esac
-
- eval pretty_name=\${GITHEAD_$SHA1:-$SHA1}
- if test "$SHA1" = "$pretty_name"
- then
- SHA1_UP="$(echo "$SHA1" | tr a-z A-Z)"
- eval pretty_name=\${GITHEAD_$SHA1_UP:-$pretty_name}
- fi
- common=$(git merge-base --all $SHA1 $MRC) ||
- die "$(eval_gettext "Unable to find common commit with \$pretty_name")"
-
- case "$LF$common$LF" in
- *"$LF$SHA1$LF"*)
- eval_gettextln "Already up to date with \$pretty_name"
- continue
- ;;
- esac
-
- if test "$common,$NON_FF_MERGE" = "$MRC,0"
- then
- # The first head being merged was a fast-forward.
- # Advance MRC to the head being merged, and use that
- # tree as the intermediate result of the merge.
- # We still need to count this as part of the parent set.
-
- eval_gettextln "Fast-forwarding to: \$pretty_name"
- git read-tree -u -m $head $SHA1 || exit
- MRC=$SHA1 MRT=$(git write-tree)
- continue
- fi
-
- NON_FF_MERGE=1
-
- eval_gettextln "Trying simple merge with \$pretty_name"
- git read-tree -u -m --aggressive $common $MRT $SHA1 || exit 2
- next=$(git write-tree 2>/dev/null)
- if test $? -ne 0
- then
- gettextln "Simple merge did not work, trying automatic merge."
- git merge-index -o --use=merge-one-file -a ||
- OCTOPUS_FAILURE=1
- next=$(git write-tree 2>/dev/null)
- fi
-
- MRC="$MRC $SHA1"
- MRT=$next
-done
-
-exit "$OCTOPUS_FAILURE"
diff --git a/git.c b/git.c
index 09d222da88..7a5e506c64 100644
--- a/git.c
+++ b/git.c
@@ -560,6 +560,7 @@ static struct cmd_struct commands[] = {
{ "merge-base", cmd_merge_base, RUN_SETUP },
{ "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
{ "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
+ { "merge-octopus", cmd_merge_octopus, RUN_SETUP | NO_PARSEOPT },
{ "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
{ "merge-one-file", cmd_merge_one_file, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
{ "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
diff --git a/merge-strategies.c b/merge-strategies.c
index 30f225ae5f..3e8255614b 100644
--- a/merge-strategies.c
+++ b/merge-strategies.c
@@ -1,5 +1,6 @@
#include "cache.h"
#include "cache-tree.h"
+#include "commit-reach.h"
#include "dir.h"
#include "entry.h"
#include "lockfile.h"
@@ -417,3 +418,173 @@ int merge_strategies_resolve(struct repository *r,
return !!error(_("unable to write new index file"));
return !!ret;
}
+
+static int octopus_fast_forward(struct repository *r, const char *branch_name,
+ struct tree *tree_head, struct tree *current_tree)
+{
+ /*
+ * The first head being merged was a fast-forward. Advance the
+ * reference commit to the head being merged, and use that tree
+ * as the intermediate result of the merge. We still need to
+ * count this as part of the parent set.
+ */
+ struct tree_desc t[2];
+
+ printf(_("Fast-forwarding to: %s\n"), branch_name);
+
+ init_tree_desc(t, tree_head->buffer, tree_head->size);
+ if (add_tree(current_tree, t + 1))
+ return -1;
+ if (merge_trees(r, t, 2, 0))
+ return -1;
+ if (write_tree(r))
+ return -1;
+
+ return 0;
+}
+
+static int octopus_do_merge(struct repository *r, const char *branch_name,
+ struct commit_list *common, struct tree *current_tree,
+ struct tree *reference_tree)
+{
+ struct tree_desc t[MAX_UNPACK_TREES];
+ struct commit_list *i;
+ int nr = 0, ret = 0;
+
+ printf(_("Trying simple merge with %s\n"), branch_name);
+
+ for (i = common; i; i = i->next) {
+ struct tree *tree = repo_get_commit_tree(r, i->item);
+ if (add_tree(tree, t + (nr++)))
+ return -1;
+ }
+
+ if (add_tree(reference_tree, t + (nr++)))
+ return -1;
+ if (add_tree(current_tree, t + (nr++)))
+ return -1;
+ if (merge_trees(r, t, nr, 1))
+ return 2;
+
+ if (write_tree(r)) {
+ puts(_("Simple merge did not work, trying automatic merge."));
+ ret = !!merge_all_index(r->index, 1, 0, merge_one_file_func, NULL);
+ write_tree(r);
+ }
+
+ return ret;
+}
+
+int merge_strategies_octopus(struct repository *r,
+ struct commit_list *bases, const char *head_arg,
+ struct commit_list *remotes)
+{
+ int ff_merge = 1, ret = 0, nr_references = 1;
+ struct commit **reference_commits, *head_commit;
+ struct tree *reference_tree, *head_tree;
+ struct commit_list *i;
+ struct object_id head;
+ struct lock_file lock = LOCK_INIT;
+
+ /*
+ * Reject if this is not an octopus -- resolve should be used
+ * instead.
+ */
+ if (commit_list_count(remotes) < 2)
+ return 2;
+
+ /* Abort if index does not match head */
+ if (check_index_is_head(r, head_arg))
+ return 2;
+
+ get_oid(head_arg, &head);
+ head_commit = lookup_commit_reference(r, &head);
+ head_tree = repo_get_commit_tree(r, head_commit);
+
+ CALLOC_ARRAY(reference_commits, commit_list_count(remotes) + 1);
+ reference_commits[0] = head_commit;
+ reference_tree = head_tree;
+
+ repo_hold_locked_index(r, &lock, LOCK_DIE_ON_ERROR);
+
+ for (i = remotes; i && i->item; i = i->next) {
+ struct commit *c = i->item;
+ struct object_id *oid = &c->object.oid;
+ struct tree *current_tree = repo_get_commit_tree(r, c);
+ struct commit_list *common, *j;
+ char *branch_name = merge_get_better_branch_name(oid_to_hex(oid));
+ int up_to_date = 0;
+
+ common = repo_get_merge_bases_many(r, c, nr_references, reference_commits);
+ if (!common) {
+ error(_("Unable to find common commit with %s"), branch_name);
+
+ free(branch_name);
+ free_commit_list(common);
+
+ ret = 2;
+ break;
+ }
+
+ /*
+ * If `oid' is reachable from `HEAD', we're already up
+ * to date.
+ */
+ for (j = common; j; j = j->next) {
+ if (oideq(&j->item->object.oid, oid)) {
+ up_to_date = 1;
+ break;
+ }
+ }
+
+ if (up_to_date) {
+ printf(_("Already up to date with %s\n"), branch_name);
+
+ free(branch_name);
+ free_commit_list(common);
+ continue;
+ }
+
+ /*
+ * If we could fast-forward so far and `HEAD' is the
+ * single merge base with the current `remote' revision,
+ * keep fast-forwarding.
+ */
+ if (ff_merge && common && !common->next && nr_references == 1 &&
+ oideq(&common->item->object.oid,
+ &reference_commits[0]->object.oid)) {
+ ret = octopus_fast_forward(r, branch_name, head_tree, current_tree);
+ nr_references = 0;
+ } else {
+ ret = octopus_do_merge(r, branch_name, common,
+ current_tree, reference_tree);
+ ff_merge = 0;
+ }
+
+ free(branch_name);
+ free_commit_list(common);
+
+ if (ret == -1 || ret == 2)
+ break;
+ else if (ret && i->next) {
+ /*
+ * We allow only last one to have a
+ * hand-resolvable conflicts. Last round failed
+ * and we still had a head to merge.
+ */
+ puts(_("Automated merge did not work."));
+ puts(_("Should not be doing an octopus."));
+
+ ret = 2;
+ break;
+ }
+
+ reference_commits[nr_references++] = c;
+ reference_tree = lookup_tree(r, &r->index->cache_tree->oid);
+ }
+
+ free(reference_commits);
+ write_locked_index(r->index, &lock, COMMIT_LOCK);
+
+ return ret;
+}
diff --git a/merge-strategies.h b/merge-strategies.h
index bba4bf999c..8de2249ee6 100644
--- a/merge-strategies.h
+++ b/merge-strategies.h
@@ -32,5 +32,8 @@ int merge_all_index(struct index_state *istate, int oneshot, int quiet,
int merge_strategies_resolve(struct repository *r,
struct commit_list *bases, const char *head_arg,
struct commit_list *remote);
+int merge_strategies_octopus(struct repository *r,
+ struct commit_list *bases, const char *head_arg,
+ struct commit_list *remote);
#endif /* MERGE_STRATEGIES_H */
--
2.37.1.412.gcfdce49ffd
