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-rw-r--r--builtin/replay.c446
1 files changed, 446 insertions, 0 deletions
diff --git a/builtin/replay.c b/builtin/replay.c
new file mode 100644
index 0000000..6bc4b47
--- /dev/null
+++ b/builtin/replay.c
@@ -0,0 +1,446 @@
+/*
+ * "git replay" builtin command
+ */
+
+#define USE_THE_INDEX_VARIABLE
+#include "git-compat-util.h"
+
+#include "builtin.h"
+#include "environment.h"
+#include "hex.h"
+#include "lockfile.h"
+#include "merge-ort.h"
+#include "object-name.h"
+#include "parse-options.h"
+#include "refs.h"
+#include "revision.h"
+#include "strmap.h"
+#include <oidset.h>
+#include <tree.h>
+
+static const char *short_commit_name(struct commit *commit)
+{
+ return repo_find_unique_abbrev(the_repository, &commit->object.oid,
+ DEFAULT_ABBREV);
+}
+
+static struct commit *peel_committish(const char *name)
+{
+ struct object *obj;
+ struct object_id oid;
+
+ if (repo_get_oid(the_repository, name, &oid))
+ return NULL;
+ obj = parse_object(the_repository, &oid);
+ return (struct commit *)repo_peel_to_type(the_repository, name, 0, obj,
+ OBJ_COMMIT);
+}
+
+static char *get_author(const char *message)
+{
+ size_t len;
+ const char *a;
+
+ a = find_commit_header(message, "author", &len);
+ if (a)
+ return xmemdupz(a, len);
+
+ return NULL;
+}
+
+static struct commit *create_commit(struct tree *tree,
+ struct commit *based_on,
+ struct commit *parent)
+{
+ struct object_id ret;
+ struct object *obj;
+ struct commit_list *parents = NULL;
+ char *author;
+ char *sign_commit = NULL; /* FIXME: cli users might want to sign again */
+ struct commit_extra_header *extra;
+ struct strbuf msg = STRBUF_INIT;
+ const char *out_enc = get_commit_output_encoding();
+ const char *message = repo_logmsg_reencode(the_repository, based_on,
+ NULL, out_enc);
+ const char *orig_message = NULL;
+ const char *exclude_gpgsig[] = { "gpgsig", NULL };
+
+ commit_list_insert(parent, &parents);
+ extra = read_commit_extra_headers(based_on, exclude_gpgsig);
+ find_commit_subject(message, &orig_message);
+ strbuf_addstr(&msg, orig_message);
+ author = get_author(message);
+ reset_ident_date();
+ if (commit_tree_extended(msg.buf, msg.len, &tree->object.oid, parents,
+ &ret, author, NULL, sign_commit, extra)) {
+ error(_("failed to write commit object"));
+ return NULL;
+ }
+ free(author);
+ strbuf_release(&msg);
+
+ obj = parse_object(the_repository, &ret);
+ return (struct commit *)obj;
+}
+
+struct ref_info {
+ struct commit *onto;
+ struct strset positive_refs;
+ struct strset negative_refs;
+ int positive_refexprs;
+ int negative_refexprs;
+};
+
+static void get_ref_information(struct rev_cmdline_info *cmd_info,
+ struct ref_info *ref_info)
+{
+ int i;
+
+ ref_info->onto = NULL;
+ strset_init(&ref_info->positive_refs);
+ strset_init(&ref_info->negative_refs);
+ ref_info->positive_refexprs = 0;
+ ref_info->negative_refexprs = 0;
+
+ /*
+ * When the user specifies e.g.
+ * git replay origin/main..mybranch
+ * git replay ^origin/next mybranch1 mybranch2
+ * we want to be able to determine where to replay the commits. In
+ * these examples, the branches are probably based on an old version
+ * of either origin/main or origin/next, so we want to replay on the
+ * newest version of that branch. In contrast we would want to error
+ * out if they ran
+ * git replay ^origin/master ^origin/next mybranch
+ * git replay mybranch~2..mybranch
+ * the first of those because there's no unique base to choose, and
+ * the second because they'd likely just be replaying commits on top
+ * of the same commit and not making any difference.
+ */
+ for (i = 0; i < cmd_info->nr; i++) {
+ struct rev_cmdline_entry *e = cmd_info->rev + i;
+ struct object_id oid;
+ const char *refexpr = e->name;
+ char *fullname = NULL;
+ int can_uniquely_dwim = 1;
+
+ if (*refexpr == '^')
+ refexpr++;
+ if (repo_dwim_ref(the_repository, refexpr, strlen(refexpr), &oid, &fullname, 0) != 1)
+ can_uniquely_dwim = 0;
+
+ if (e->flags & BOTTOM) {
+ if (can_uniquely_dwim)
+ strset_add(&ref_info->negative_refs, fullname);
+ if (!ref_info->negative_refexprs)
+ ref_info->onto = lookup_commit_reference_gently(the_repository,
+ &e->item->oid, 1);
+ ref_info->negative_refexprs++;
+ } else {
+ if (can_uniquely_dwim)
+ strset_add(&ref_info->positive_refs, fullname);
+ ref_info->positive_refexprs++;
+ }
+
+ free(fullname);
+ }
+}
+
+static void determine_replay_mode(struct rev_cmdline_info *cmd_info,
+ const char *onto_name,
+ const char **advance_name,
+ struct commit **onto,
+ struct strset **update_refs)
+{
+ struct ref_info rinfo;
+
+ get_ref_information(cmd_info, &rinfo);
+ if (!rinfo.positive_refexprs)
+ die(_("need some commits to replay"));
+ if (onto_name && *advance_name)
+ die(_("--onto and --advance are incompatible"));
+ else if (onto_name) {
+ *onto = peel_committish(onto_name);
+ if (rinfo.positive_refexprs <
+ strset_get_size(&rinfo.positive_refs))
+ die(_("all positive revisions given must be references"));
+ } else if (*advance_name) {
+ struct object_id oid;
+ char *fullname = NULL;
+
+ *onto = peel_committish(*advance_name);
+ if (repo_dwim_ref(the_repository, *advance_name, strlen(*advance_name),
+ &oid, &fullname, 0) == 1) {
+ *advance_name = fullname;
+ } else {
+ die(_("argument to --advance must be a reference"));
+ }
+ if (rinfo.positive_refexprs > 1)
+ die(_("cannot advance target with multiple sources because ordering would be ill-defined"));
+ } else {
+ int positive_refs_complete = (
+ rinfo.positive_refexprs ==
+ strset_get_size(&rinfo.positive_refs));
+ int negative_refs_complete = (
+ rinfo.negative_refexprs ==
+ strset_get_size(&rinfo.negative_refs));
+ /*
+ * We need either positive_refs_complete or
+ * negative_refs_complete, but not both.
+ */
+ if (rinfo.negative_refexprs > 0 &&
+ positive_refs_complete == negative_refs_complete)
+ die(_("cannot implicitly determine whether this is an --advance or --onto operation"));
+ if (negative_refs_complete) {
+ struct hashmap_iter iter;
+ struct strmap_entry *entry;
+
+ if (rinfo.negative_refexprs == 0)
+ die(_("all positive revisions given must be references"));
+ else if (rinfo.negative_refexprs > 1)
+ die(_("cannot implicitly determine whether this is an --advance or --onto operation"));
+ else if (rinfo.positive_refexprs > 1)
+ die(_("cannot advance target with multiple source branches because ordering would be ill-defined"));
+
+ /* Only one entry, but we have to loop to get it */
+ strset_for_each_entry(&rinfo.negative_refs,
+ &iter, entry) {
+ *advance_name = entry->key;
+ }
+ } else { /* positive_refs_complete */
+ if (rinfo.negative_refexprs > 1)
+ die(_("cannot implicitly determine correct base for --onto"));
+ if (rinfo.negative_refexprs == 1)
+ *onto = rinfo.onto;
+ }
+ }
+ if (!*advance_name) {
+ *update_refs = xcalloc(1, sizeof(**update_refs));
+ **update_refs = rinfo.positive_refs;
+ memset(&rinfo.positive_refs, 0, sizeof(**update_refs));
+ }
+ strset_clear(&rinfo.negative_refs);
+ strset_clear(&rinfo.positive_refs);
+}
+
+static struct commit *mapped_commit(kh_oid_map_t *replayed_commits,
+ struct commit *commit,
+ struct commit *fallback)
+{
+ khint_t pos = kh_get_oid_map(replayed_commits, commit->object.oid);
+ if (pos == kh_end(replayed_commits))
+ return fallback;
+ return kh_value(replayed_commits, pos);
+}
+
+static struct commit *pick_regular_commit(struct commit *pickme,
+ kh_oid_map_t *replayed_commits,
+ struct commit *onto,
+ struct merge_options *merge_opt,
+ struct merge_result *result)
+{
+ struct commit *base, *replayed_base;
+ struct tree *pickme_tree, *base_tree;
+
+ base = pickme->parents->item;
+ replayed_base = mapped_commit(replayed_commits, base, onto);
+
+ result->tree = repo_get_commit_tree(the_repository, replayed_base);
+ pickme_tree = repo_get_commit_tree(the_repository, pickme);
+ base_tree = repo_get_commit_tree(the_repository, base);
+
+ merge_opt->branch1 = short_commit_name(replayed_base);
+ merge_opt->branch2 = short_commit_name(pickme);
+ merge_opt->ancestor = xstrfmt("parent of %s", merge_opt->branch2);
+
+ merge_incore_nonrecursive(merge_opt,
+ base_tree,
+ result->tree,
+ pickme_tree,
+ result);
+
+ free((char*)merge_opt->ancestor);
+ merge_opt->ancestor = NULL;
+ if (!result->clean)
+ return NULL;
+ return create_commit(result->tree, pickme, replayed_base);
+}
+
+int cmd_replay(int argc, const char **argv, const char *prefix)
+{
+ const char *advance_name = NULL;
+ struct commit *onto = NULL;
+ const char *onto_name = NULL;
+ int contained = 0;
+
+ struct rev_info revs;
+ struct commit *last_commit = NULL;
+ struct commit *commit;
+ struct merge_options merge_opt;
+ struct merge_result result;
+ struct strset *update_refs = NULL;
+ kh_oid_map_t *replayed_commits;
+ int ret = 0;
+
+ const char * const replay_usage[] = {
+ N_("(EXPERIMENTAL!) git replay "
+ "([--contained] --onto <newbase> | --advance <branch>) "
+ "<revision-range>..."),
+ NULL
+ };
+ struct option replay_options[] = {
+ OPT_STRING(0, "advance", &advance_name,
+ N_("branch"),
+ N_("make replay advance given branch")),
+ OPT_STRING(0, "onto", &onto_name,
+ N_("revision"),
+ N_("replay onto given commit")),
+ OPT_BOOL(0, "contained", &contained,
+ N_("advance all branches contained in revision-range")),
+ OPT_END()
+ };
+
+ argc = parse_options(argc, argv, prefix, replay_options, replay_usage,
+ PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN_OPT);
+
+ if (!onto_name && !advance_name) {
+ error(_("option --onto or --advance is mandatory"));
+ usage_with_options(replay_usage, replay_options);
+ }
+
+ if (advance_name && contained)
+ die(_("options '%s' and '%s' cannot be used together"),
+ "--advance", "--contained");
+
+ repo_init_revisions(the_repository, &revs, prefix);
+
+ /*
+ * Set desired values for rev walking options here. If they
+ * are changed by some user specified option in setup_revisions()
+ * below, we will detect that below and then warn.
+ *
+ * TODO: In the future we might want to either die(), or allow
+ * some options changing these values if we think they could
+ * be useful.
+ */
+ revs.reverse = 1;
+ revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
+ revs.topo_order = 1;
+ revs.simplify_history = 0;
+
+ argc = setup_revisions(argc, argv, &revs, NULL);
+ if (argc > 1) {
+ ret = error(_("unrecognized argument: %s"), argv[1]);
+ goto cleanup;
+ }
+
+ /*
+ * Detect and warn if we override some user specified rev
+ * walking options.
+ */
+ if (revs.reverse != 1) {
+ warning(_("some rev walking options will be overridden as "
+ "'%s' bit in 'struct rev_info' will be forced"),
+ "reverse");
+ revs.reverse = 1;
+ }
+ if (revs.sort_order != REV_SORT_IN_GRAPH_ORDER) {
+ warning(_("some rev walking options will be overridden as "
+ "'%s' bit in 'struct rev_info' will be forced"),
+ "sort_order");
+ revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
+ }
+ if (revs.topo_order != 1) {
+ warning(_("some rev walking options will be overridden as "
+ "'%s' bit in 'struct rev_info' will be forced"),
+ "topo_order");
+ revs.topo_order = 1;
+ }
+ if (revs.simplify_history != 0) {
+ warning(_("some rev walking options will be overridden as "
+ "'%s' bit in 'struct rev_info' will be forced"),
+ "simplify_history");
+ revs.simplify_history = 0;
+ }
+
+ determine_replay_mode(&revs.cmdline, onto_name, &advance_name,
+ &onto, &update_refs);
+
+ if (!onto) /* FIXME: Should handle replaying down to root commit */
+ die("Replaying down to root commit is not supported yet!");
+
+ if (prepare_revision_walk(&revs) < 0) {
+ ret = error(_("error preparing revisions"));
+ goto cleanup;
+ }
+
+ init_merge_options(&merge_opt, the_repository);
+ memset(&result, 0, sizeof(result));
+ merge_opt.show_rename_progress = 0;
+ last_commit = onto;
+ replayed_commits = kh_init_oid_map();
+ while ((commit = get_revision(&revs))) {
+ const struct name_decoration *decoration;
+ khint_t pos;
+ int hr;
+
+ if (!commit->parents)
+ die(_("replaying down to root commit is not supported yet!"));
+ if (commit->parents->next)
+ die(_("replaying merge commits is not supported yet!"));
+
+ last_commit = pick_regular_commit(commit, replayed_commits, onto,
+ &merge_opt, &result);
+ if (!last_commit)
+ break;
+
+ /* Record commit -> last_commit mapping */
+ pos = kh_put_oid_map(replayed_commits, commit->object.oid, &hr);
+ if (hr == 0)
+ BUG("Duplicate rewritten commit: %s\n",
+ oid_to_hex(&commit->object.oid));
+ kh_value(replayed_commits, pos) = last_commit;
+
+ /* Update any necessary branches */
+ if (advance_name)
+ continue;
+ decoration = get_name_decoration(&commit->object);
+ if (!decoration)
+ continue;
+ while (decoration) {
+ if (decoration->type == DECORATION_REF_LOCAL &&
+ (contained || strset_contains(update_refs,
+ decoration->name))) {
+ printf("update %s %s %s\n",
+ decoration->name,
+ oid_to_hex(&last_commit->object.oid),
+ oid_to_hex(&commit->object.oid));
+ }
+ decoration = decoration->next;
+ }
+ }
+
+ /* In --advance mode, advance the target ref */
+ if (result.clean == 1 && advance_name) {
+ printf("update %s %s %s\n",
+ advance_name,
+ oid_to_hex(&last_commit->object.oid),
+ oid_to_hex(&onto->object.oid));
+ }
+
+ merge_finalize(&merge_opt, &result);
+ kh_destroy_oid_map(replayed_commits);
+ if (update_refs) {
+ strset_clear(update_refs);
+ free(update_refs);
+ }
+ ret = result.clean;
+
+cleanup:
+ release_revisions(&revs);
+
+ /* Return */
+ if (ret < 0)
+ exit(128);
+ return ret ? 0 : 1;
+}