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_index_as_tree().
- The call to `diff-index ...' is replaced by a call to
repo_index_has_changes(), and is moved from cmd_merge_octopus() to
merge_octopus().
- The call to `merge-index', needed to invoke `git merge-one-file', is
replaced by a call to merge_all().
The index is read in cmd_merge_octopus(), and is wrote back by
merge_strategies_octopus().
Here to, merge_strategies_octopus() takes two commit lists and a string
to reduce frictions when try_merge_strategies() will be modified to call
it directly.
Signed-off-by: Alban Gruin <alban.gruin@xxxxxxxxx>
---
Makefile | 2 +-
builtin.h | 1 +
builtin/merge-octopus.c | 69 ++++++++++++++
git-merge-octopus.sh | 112 ----------------------
git.c | 1 +
merge-strategies.c | 204 ++++++++++++++++++++++++++++++++++++++++
merge-strategies.h | 3 +
7 files changed, 279 insertions(+), 113 deletions(-)
create mode 100644 builtin/merge-octopus.c
delete mode 100755 git-merge-octopus.sh
diff --git a/Makefile b/Makefile
index 3cc6b192f1..2b2bdffafe 100644
--- a/Makefile
+++ b/Makefile
@@ -600,7 +600,6 @@ 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
@@ -1093,6 +1092,7 @@ 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 35e91c16d0..50225404a0 100644
--- a/builtin.h
+++ b/builtin.h
@@ -176,6 +176,7 @@ 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..abf0981fe8
--- /dev/null
+++ b/builtin/merge-octopus.c
@@ -0,0 +1,69 @@
+/*
+ * 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;
+
+ if (argc < 5)
+ usage(builtin_merge_octopus_usage);
+
+ setup_work_tree();
+ if (repo_read_index(the_repository) < 0)
+ die("corrupted cache");
+
+ /*
+ * 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;
+
+ get_oid(argv[i], &oid);
+
+ if (!oideq(&oid, the_hash_algo->empty_tree)) {
+ struct commit *commit;
+ commit = 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);
+ }
+ }
+ }
+
+ /*
+ * Reject if this is not an octopus -- resolve should be used
+ * instead.
+ */
+ if (commit_list_count(remotes) < 2)
+ return 2;
+
+ return merge_strategies_octopus(the_repository, bases, head_arg, remotes);
+}
diff --git a/git-merge-octopus.sh b/git-merge-octopus.sh
deleted file mode 100755
index 7d19d37951..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 $? -ne 0
- then
- gettextln "Simple merge did not work, trying automatic merge."
- git merge-index -o git-merge-one-file -a ||
- OCTOPUS_FAILURE=1
- next=$(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 64a1a1de41..d51fb5d2bf 100644
--- a/git.c
+++ b/git.c
@@ -539,6 +539,7 @@ 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 6b4b3d03a6..37c662094e 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 "ll-merge.h"
#include "lockfile.h"
@@ -407,3 +408,206 @@ int merge_strategies_resolve(struct repository *r,
rollback_lock_file(&lock);
return 2;
}
+
+static int fast_forward(struct repository *r, const struct object_id *oids,
+ int nr, int aggressive)
+{
+ int i;
+ struct tree_desc t[MAX_UNPACK_TREES];
+ struct unpack_trees_options opts;
+ struct lock_file lock = LOCK_INIT;
+
+ repo_read_index_preload(r, NULL, 0);
+ if (refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL))
+ return -1;
+
+ repo_hold_locked_index(r, &lock, LOCK_DIE_ON_ERROR);
+
+ memset(&opts, 0, sizeof(opts));
+ opts.head_idx = 1;
+ opts.src_index = r->index;
+ opts.dst_index = r->index;
+ opts.merge = 1;
+ opts.update = 1;
+ opts.aggressive = aggressive;
+
+ for (i = 0; i < nr; i++) {
+ struct tree *tree;
+ tree = parse_tree_indirect(oids + i);
+ if (parse_tree(tree))
+ return -1;
+ init_tree_desc(t + i, tree->buffer, tree->size);
+ }
+
+ if (nr == 1)
+ opts.fn = oneway_merge;
+ else if (nr == 2) {
+ opts.fn = twoway_merge;
+ opts.initial_checkout = is_index_unborn(r->index);
+ } else if (nr >= 3) {
+ opts.fn = threeway_merge;
+ opts.head_idx = nr - 1;
+ }
+
+ if (unpack_trees(nr, t, &opts))
+ return -1;
+
+ if (write_locked_index(r->index, &lock, COMMIT_LOCK))
+ return error(_("unable to write new index file"));
+
+ return 0;
+}
+
+static int write_tree(struct repository *r, struct tree **reference_tree)
+{
+ struct object_id oid;
+ int ret;
+
+ ret = write_index_as_tree(&oid, r->index, r->index_file, 0, NULL);
+ if (!ret)
+ *reference_tree = lookup_tree(r, &oid);
+
+ return ret;
+}
+
+int merge_strategies_octopus(struct repository *r,
+ struct commit_list *bases, const char *head_arg,
+ struct commit_list *remotes)
+{
+ int non_ff_merge = 0, ret = 0, references = 1;
+ struct commit **reference_commit;
+ struct tree *reference_tree;
+ struct commit_list *j;
+ struct object_id head;
+ struct strbuf sb = STRBUF_INIT;
+
+ get_oid(head_arg, &head);
+
+ reference_commit = xcalloc(commit_list_count(remotes) + 1, sizeof(struct commit *));
+ reference_commit[0] = lookup_commit_reference(r, &head);
+ reference_tree = repo_get_commit_tree(r, reference_commit[0]);
+
+ if (repo_index_has_changes(r, reference_tree, &sb)) {
+ error(_("Your local changes to the following files "
+ "would be overwritten by merge:\n %s"),
+ sb.buf);
+ strbuf_release(&sb);
+ ret = 2;
+ goto out;
+ }
+
+ for (j = remotes; j && j->item; j = j->next) {
+ struct commit *c = j->item;
+ struct object_id *oid = &c->object.oid;
+ struct commit_list *common, *k;
+ char *branch_name;
+ int can_ff = 1;
+
+ if (ret) {
+ /*
+ * 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;
+ goto out;
+ }
+
+ branch_name = merge_get_better_branch_name(oid_to_hex(oid));
+ common = get_merge_bases_many(c, references, reference_commit);
+
+ if (!common)
+ die(_("Unable to find common commit with %s"), branch_name);
+
+ for (k = common; k && !oideq(&k->item->object.oid, oid); k = k->next);
+
+ if (k) {
+ printf(_("Already up to date with %s\n"), branch_name);
+ free(branch_name);
+ free_commit_list(common);
+ continue;
+ }
+
+ if (!non_ff_merge) {
+ int i;
+
+ for (i = 0, k = common; k && i < references && can_ff; k = k->next, i++) {
+ can_ff = oideq(&k->item->object.oid,
+ &reference_commit[i]->object.oid);
+ }
+ }
+
+ if (!non_ff_merge && can_ff) {
+ /*
+ * 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 object_id oids[2];
+ printf(_("Fast-forwarding to: %s\n"), branch_name);
+
+ oidcpy(oids, &head);
+ oidcpy(oids + 1, oid);
+
+ ret = fast_forward(r, oids, 2, 0);
+ if (ret) {
+ free(branch_name);
+ free_commit_list(common);
+ goto out;
+ }
+
+ references = 0;
+ write_tree(r, &reference_tree);
+ } else {
+ int i = 0;
+ struct tree *next = NULL;
+ struct object_id oids[MAX_UNPACK_TREES];
+
+ non_ff_merge = 1;
+ printf(_("Trying simple merge with %s\n"), branch_name);
+
+ for (k = common; k; k = k->next)
+ oidcpy(oids + (i++), &k->item->object.oid);
+
+ oidcpy(oids + (i++), &reference_tree->object.oid);
+ oidcpy(oids + (i++), oid);
+
+ if (fast_forward(r, oids, i, 1)) {
+ ret = 2;
+
+ free(branch_name);
+ free_commit_list(common);
+
+ goto out;
+ }
+
+ if (write_tree(r, &next)) {
+ struct lock_file lock = LOCK_INIT;
+
+ puts(_("Simple merge did not work, trying automatic merge."));
+ repo_hold_locked_index(r, &lock, LOCK_DIE_ON_ERROR);
+ ret = !!merge_all(r->index, 0, 0, merge_one_file_cb, r);
+ write_locked_index(r->index, &lock, COMMIT_LOCK);
+
+ write_tree(r, &next);
+ }
+
+ reference_tree = next;
+ }
+
+ reference_commit[references++] = c;
+
+ free(branch_name);
+ free_commit_list(common);
+ }
+
+out:
+ free(reference_commit);
+ return ret;
+}
diff --git a/merge-strategies.h b/merge-strategies.h
index 778f8ce9d6..938411a04e 100644
--- a/merge-strategies.h
+++ b/merge-strategies.h
@@ -37,5 +37,8 @@ int merge_all(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 */
--
2.28.0.662.ge304723957
