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[2.6.209.233]) by smtp.googlemail.com with ESMTPSA id g138sm10083697wme.39.2020.11.13.04.10.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Nov 2020 04:10:56 -0800 (PST) From: Alban Gruin To: git@vger.kernel.org Cc: Junio C Hamano , Phillip Wood , Alban Gruin Subject: [PATCH v4 08/12] merge-octopus: rewrite in C Date: Fri, 13 Nov 2020 12:04:24 +0100 Message-Id: <20201113110428.21265-9-alban.gruin@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201113110428.21265-1-alban.gruin@gmail.com> References: <20201005122646.27994-1-alban.gruin@gmail.com> <20201113110428.21265-1-alban.gruin@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org 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(). - 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 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 --- 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..ca8f9f345d --- /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. + */ + +#define USE_THE_INDEX_COMPATIBILITY_MACROS +#include "cache.h" +#include "builtin.h" +#include "commit.h" +#include "merge-strategies.h" + +static const char builtin_merge_octopus_usage[] = + "git merge-octopus [...] -- [...]"; + +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 (read_cache() < 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 = 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 2b34ea0b76..2ae27f4a80 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 "lockfile.h" #include "merge-strategies.h" @@ -370,3 +371,206 @@ 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_index(r->index, 0, 0, merge_one_file_func, 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 4f996261b4..05232a5a89 100644 --- a/merge-strategies.h +++ b/merge-strategies.h @@ -36,5 +36,8 @@ 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 */