diff options
Diffstat (limited to 'builtin/replay.c')
| -rw-r--r-- | builtin/replay.c | 446 |
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; +} |