diff options
Diffstat (limited to 'builtin/merge-base.c')
| -rw-r--r-- | builtin/merge-base.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/builtin/merge-base.c b/builtin/merge-base.c new file mode 100644 index 0000000000..0ecde8da30 --- /dev/null +++ b/builtin/merge-base.c @@ -0,0 +1,259 @@ +#include "builtin.h" +#include "cache.h" +#include "commit.h" +#include "refs.h" +#include "diff.h" +#include "revision.h" +#include "parse-options.h" + +static int show_merge_base(struct commit **rev, int rev_nr, int show_all) +{ + struct commit_list *result; + + result = get_merge_bases_many(rev[0], rev_nr - 1, rev + 1, 0); + + if (!result) + return 1; + + while (result) { + printf("%s\n", sha1_to_hex(result->item->object.sha1)); + if (!show_all) + return 0; + result = result->next; + } + + return 0; +} + +static const char * const merge_base_usage[] = { + N_("git merge-base [-a|--all] <commit> <commit>..."), + N_("git merge-base [-a|--all] --octopus <commit>..."), + N_("git merge-base --independent <commit>..."), + N_("git merge-base --is-ancestor <commit> <commit>"), + N_("git merge-base --fork-point <ref> [<commit>]"), + NULL +}; + +static struct commit *get_commit_reference(const char *arg) +{ + unsigned char revkey[20]; + struct commit *r; + + if (get_sha1(arg, revkey)) + die("Not a valid object name %s", arg); + r = lookup_commit_reference(revkey); + if (!r) + die("Not a valid commit name %s", arg); + + return r; +} + +static int handle_independent(int count, const char **args) +{ + struct commit_list *revs = NULL; + struct commit_list *result; + int i; + + for (i = count - 1; i >= 0; i--) + commit_list_insert(get_commit_reference(args[i]), &revs); + + result = reduce_heads(revs); + if (!result) + return 1; + + while (result) { + printf("%s\n", sha1_to_hex(result->item->object.sha1)); + result = result->next; + } + return 0; +} + +static int handle_octopus(int count, const char **args, int show_all) +{ + struct commit_list *revs = NULL; + struct commit_list *result; + int i; + + for (i = count - 1; i >= 0; i--) + commit_list_insert(get_commit_reference(args[i]), &revs); + + result = reduce_heads(get_octopus_merge_bases(revs)); + + if (!result) + return 1; + + while (result) { + printf("%s\n", sha1_to_hex(result->item->object.sha1)); + if (!show_all) + return 0; + result = result->next; + } + + return 0; +} + +static int handle_is_ancestor(int argc, const char **argv) +{ + struct commit *one, *two; + + if (argc != 2) + die("--is-ancestor takes exactly two commits"); + one = get_commit_reference(argv[0]); + two = get_commit_reference(argv[1]); + if (in_merge_bases(one, two)) + return 0; + else + return 1; +} + +struct rev_collect { + struct commit **commit; + int nr; + int alloc; + unsigned int initial : 1; +}; + +static void add_one_commit(unsigned char *sha1, struct rev_collect *revs) +{ + struct commit *commit; + + if (is_null_sha1(sha1)) + return; + + commit = lookup_commit(sha1); + if (!commit || + (commit->object.flags & TMP_MARK) || + parse_commit(commit)) + return; + + ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc); + revs->commit[revs->nr++] = commit; + commit->object.flags |= TMP_MARK; +} + +static int collect_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1, + const char *ident, unsigned long timestamp, + int tz, const char *message, void *cbdata) +{ + struct rev_collect *revs = cbdata; + + if (revs->initial) { + revs->initial = 0; + add_one_commit(osha1, revs); + } + add_one_commit(nsha1, revs); + return 0; +} + +static int handle_fork_point(int argc, const char **argv) +{ + unsigned char sha1[20]; + char *refname; + const char *commitname; + struct rev_collect revs; + struct commit *derived; + struct commit_list *bases; + int i, ret = 0; + + switch (dwim_ref(argv[0], strlen(argv[0]), sha1, &refname)) { + case 0: + die("No such ref: '%s'", argv[0]); + case 1: + break; /* good */ + default: + die("Ambiguous refname: '%s'", argv[0]); + } + + commitname = (argc == 2) ? argv[1] : "HEAD"; + if (get_sha1(commitname, sha1)) + die("Not a valid object name: '%s'", commitname); + + derived = lookup_commit_reference(sha1); + memset(&revs, 0, sizeof(revs)); + revs.initial = 1; + for_each_reflog_ent(refname, collect_one_reflog_ent, &revs); + + for (i = 0; i < revs.nr; i++) + revs.commit[i]->object.flags &= ~TMP_MARK; + + bases = get_merge_bases_many(derived, revs.nr, revs.commit, 0); + + /* + * There should be one and only one merge base, when we found + * a common ancestor among reflog entries. + */ + if (!bases || bases->next) { + ret = 1; + goto cleanup_return; + } + + /* And the found one must be one of the reflog entries */ + for (i = 0; i < revs.nr; i++) + if (&bases->item->object == &revs.commit[i]->object) + break; /* found */ + if (revs.nr <= i) { + ret = 1; /* not found */ + goto cleanup_return; + } + + printf("%s\n", sha1_to_hex(bases->item->object.sha1)); + +cleanup_return: + free_commit_list(bases); + return ret; +} + +int cmd_merge_base(int argc, const char **argv, const char *prefix) +{ + struct commit **rev; + int rev_nr = 0; + int show_all = 0; + int cmdmode = 0; + + struct option options[] = { + OPT_BOOL('a', "all", &show_all, N_("output all common ancestors")), + OPT_CMDMODE(0, "octopus", &cmdmode, + N_("find ancestors for a single n-way merge"), 'o'), + OPT_CMDMODE(0, "independent", &cmdmode, + N_("list revs not reachable from others"), 'r'), + OPT_CMDMODE(0, "is-ancestor", &cmdmode, + N_("is the first one ancestor of the other?"), 'a'), + OPT_CMDMODE(0, "fork-point", &cmdmode, + N_("find where <commit> forked from reflog of <ref>"), 'f'), + OPT_END() + }; + + git_config(git_default_config, NULL); + argc = parse_options(argc, argv, prefix, options, merge_base_usage, 0); + + if (cmdmode == 'a') { + if (argc < 2) + usage_with_options(merge_base_usage, options); + if (show_all) + die("--is-ancestor cannot be used with --all"); + return handle_is_ancestor(argc, argv); + } + + if (cmdmode == 'r' && show_all) + die("--independent cannot be used with --all"); + + if (cmdmode == 'o') + return handle_octopus(argc, argv, show_all); + + if (cmdmode == 'r') + return handle_independent(argc, argv); + + if (cmdmode == 'f') { + if (argc < 1 || 2 < argc) + usage_with_options(merge_base_usage, options); + return handle_fork_point(argc, argv); + } + + if (argc < 2) + usage_with_options(merge_base_usage, options); + + rev = xmalloc(argc * sizeof(*rev)); + while (argc-- > 0) + rev[rev_nr++] = get_commit_reference(*argv++); + return show_merge_base(rev, rev_nr, show_all); +} |