builtin-describe.c - jrn/git - Git at Google

 #include "cache.h"
 #include "commit.h"
 #include "tag.h"
 #include "refs.h"
 #include "builtin.h"
 #include "exec_cmd.h"
 #include "parse-options.h"
 #include "diff.h"

 #define SEEN		(1u<<0)
 #define MAX_TAGS	(FLAG_BITS - 1)

 static const char * const describe_usage[] = {
 	"git describe [options] <committish>*",
 	"git describe [options] --dirty",
 	NULL
 };

 static int debug;	/* Display lots of verbose info */
 static int all;	/* Any valid ref can be used */
 static int tags;	/* Allow lightweight tags */
 static int longformat;
 static int abbrev = DEFAULT_ABBREV;
 static int max_candidates = 10;
 static int found_names;
 static const char *pattern;
 static int always;
 static const char *dirty;

 /* diff-index command arguments to check if working tree is dirty. */
 static const char *diff_index_args[] = {
 	"diff-index", "--quiet", "HEAD", "--", NULL
 };


 struct commit_name {
 	struct tag *tag;
 	int prio; /* annotated tag = 2, tag = 1, head = 0 */
 	unsigned char sha1[20];
 	char path[FLEX_ARRAY]; /* more */
 };
 static const char *prio_names[] = {
 	"head", "lightweight", "annotated",
 };

 static void add_to_known_names(const char *path,
 			       struct commit *commit,
 			       int prio,
 			       const unsigned char *sha1)
 {
 	struct commit_name *e = commit->util;
 	if (!e || e->prio < prio) {
 		size_t len = strlen(path)+1;
 		free(e);
 		e = xmalloc(sizeof(struct commit_name) + len);
 		e->tag = NULL;
 		e->prio = prio;
 		hashcpy(e->sha1, sha1);
 		memcpy(e->path, path, len);
 		commit->util = e;
 	}
 	found_names = 1;
 }

 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	int might_be_tag = !prefixcmp(path, "refs/tags/");
 	struct commit *commit;
 	struct object *object;
 	unsigned char peeled[20];
 	int is_tag, prio;

 	if (!all && !might_be_tag)
 		return 0;

 	if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
 		commit = lookup_commit_reference_gently(peeled, 1);
 		if (!commit)
 			return 0;
 		is_tag = !!hashcmp(sha1, commit->object.sha1);
 	} else {
 		commit = lookup_commit_reference_gently(sha1, 1);
 		object = parse_object(sha1);
 		if (!commit || !object)
 			return 0;
 		is_tag = object->type == OBJ_TAG;
 	}

 	/* If --all, then any refs are used.
 	 * If --tags, then any tags are used.
 	 * Otherwise only annotated tags are used.
 	 */
 	if (might_be_tag) {
 		if (is_tag)
 			prio = 2;
 		else
 			prio = 1;

 		if (pattern && fnmatch(pattern, path + 10, 0))
 			prio = 0;
 	}
 	else
 		prio = 0;

 	if (!all) {
 		if (!prio)
 			return 0;
 	}
 	add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
 	return 0;
 }

 struct possible_tag {
 	struct commit_name *name;
 	int depth;
 	int found_order;
 	unsigned flag_within;
 };

 static int compare_pt(const void *a_, const void *b_)
 {
 	struct possible_tag *a = (struct possible_tag *)a_;
 	struct possible_tag *b = (struct possible_tag *)b_;
 	if (a->depth != b->depth)
 		return a->depth - b->depth;
 	if (a->found_order != b->found_order)
 		return a->found_order - b->found_order;
 	return 0;
 }

 static unsigned long finish_depth_computation(
 	struct commit_list **list,
 	struct possible_tag *best)
 {
 	unsigned long seen_commits = 0;
 	while (*list) {
 		struct commit *c = pop_commit(list);
 		struct commit_list *parents = c->parents;
 		seen_commits++;
 		if (c->object.flags & best->flag_within) {
 			struct commit_list *a = *list;
 			while (a) {
 				struct commit *i = a->item;
 				if (!(i->object.flags & best->flag_within))
 					break;
 				a = a->next;
 			}
 			if (!a)
 				break;
 		} else
 			best->depth++;
 		while (parents) {
 			struct commit *p = parents->item;
 			parse_commit(p);
 			if (!(p->object.flags & SEEN))
 				insert_by_date(p, list);
 			p->object.flags |= c->object.flags;
 			parents = parents->next;
 		}
 	}
 	return seen_commits;
 }

 static void display_name(struct commit_name *n)
 {
 	if (n->prio == 2 && !n->tag) {
 		n->tag = lookup_tag(n->sha1);
 		if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
 			die("annotated tag %s not available", n->path);
 		if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 			warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
 	}

 	if (n->tag)
 		printf("%s", n->tag->tag);
 	else
 		printf("%s", n->path);
 }

 static void show_suffix(int depth, const unsigned char *sha1)
 {
 	printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 }

 static void describe(const char *arg, int last_one)
 {
 	unsigned char sha1[20];
 	struct commit *cmit, *gave_up_on = NULL;
 	struct commit_list *list;
 	struct commit_name *n;
 	struct possible_tag all_matches[MAX_TAGS];
 	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 	unsigned long seen_commits = 0;
 	unsigned int unannotated_cnt = 0;

 	if (get_sha1(arg, sha1))
 		die("Not a valid object name %s", arg);
 	cmit = lookup_commit_reference(sha1);
 	if (!cmit)
 		die("%s is not a valid '%s' object", arg, commit_type);

 	n = cmit->util;
 	if (n && (tags || all || n->prio == 2)) {
 		/*
 		 * Exact match to an existing ref.
 		 */
 		display_name(n);
 		if (longformat)
 			show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 		if (dirty)
 			printf("%s", dirty);
 		printf("\n");
 		return;
 	}

 	if (!max_candidates)
 		die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 	if (debug)
 		fprintf(stderr, "searching to describe %s\n", arg);

 	list = NULL;
 	cmit->object.flags = SEEN;
 	commit_list_insert(cmit, &list);
 	while (list) {
 		struct commit *c = pop_commit(&list);
 		struct commit_list *parents = c->parents;
 		seen_commits++;
 		n = c->util;
 		if (n) {
 			if (!tags && !all && n->prio < 2) {
 				unannotated_cnt++;
 			} else if (match_cnt < max_candidates) {
 				struct possible_tag *t = &all_matches[match_cnt++];
 				t->name = n;
 				t->depth = seen_commits - 1;
 				t->flag_within = 1u << match_cnt;
 				t->found_order = match_cnt;
 				c->object.flags |= t->flag_within;
 				if (n->prio == 2)
 					annotated_cnt++;
 			}
 			else {
 				gave_up_on = c;
 				break;
 			}
 		}
 		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 			struct possible_tag *t = &all_matches[cur_match];
 			if (!(c->object.flags & t->flag_within))
 				t->depth++;
 		}
 		if (annotated_cnt && !list) {
 			if (debug)
 				fprintf(stderr, "finished search at %s\n",
 					sha1_to_hex(c->object.sha1));
 			break;
 		}
 		while (parents) {
 			struct commit *p = parents->item;
 			parse_commit(p);
 			if (!(p->object.flags & SEEN))
 				insert_by_date(p, &list);
 			p->object.flags |= c->object.flags;
 			parents = parents->next;
 		}
 	}

 	if (!match_cnt) {
 		const unsigned char *sha1 = cmit->object.sha1;
 		if (always) {
 			printf("%s", find_unique_abbrev(sha1, abbrev));
 			if (dirty)
 				printf("%s", dirty);
 			printf("\n");
 			return;
 		}
 		if (unannotated_cnt)
 			die("No annotated tags can describe '%s'.\n"
 			    "However, there were unannotated tags: try --tags.",
 			    sha1_to_hex(sha1));
 		else
 			die("No tags can describe '%s'.\n"
 			    "Try --always, or create some tags.",
 			    sha1_to_hex(sha1));
 	}

 	qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);

 	if (gave_up_on) {
 		insert_by_date(gave_up_on, &list);
 		seen_commits--;
 	}
 	seen_commits += finish_depth_computation(&list, &all_matches[0]);
 	free_commit_list(list);

 	if (debug) {
 		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 			struct possible_tag *t = &all_matches[cur_match];
 			fprintf(stderr, " %-11s %8d %s\n",
 				prio_names[t->name->prio],
 				t->depth, t->name->path);
 		}
 		fprintf(stderr, "traversed %lu commits\n", seen_commits);
 		if (gave_up_on) {
 			fprintf(stderr,
 				"more than %i tags found; listed %i most recent\n"
 				"gave up search at %s\n",
 				max_candidates, max_candidates,
 				sha1_to_hex(gave_up_on->object.sha1));
 		}
 	}

 	display_name(all_matches[0].name);
 	if (abbrev)
 		show_suffix(all_matches[0].depth, cmit->object.sha1);
 	if (dirty)
 		printf("%s", dirty);
 	printf("\n");

 	if (!last_one)
 		clear_commit_marks(cmit, -1);
 }

 int cmd_describe(int argc, const char **argv, const char *prefix)
 {
 	int contains = 0;
 	struct option options[] = {
 		OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 		OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 		OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 		OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 		OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
 		OPT__ABBREV(&abbrev),
 		OPT_SET_INT(0, "exact-match", &max_candidates,
 			    "only output exact matches", 0),
 		OPT_INTEGER(0, "candidates", &max_candidates,
 			    "consider <n> most recent tags (default: 10)"),
 		OPT_STRING(0, "match",       &pattern, "pattern",
 			   "only consider tags matching <pattern>"),
 		OPT_BOOLEAN(0, "always",     &always,
 			   "show abbreviated commit object as fallback"),
 		{OPTION_STRING, 0, "dirty",  &dirty, "mark",
 			   "append <mark> on dirty working tree (default: \"-dirty\")",
 		 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 		OPT_END(),
 	};

 	argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 	if (max_candidates < 0)
 		max_candidates = 0;
 	else if (max_candidates > MAX_TAGS)
 		max_candidates = MAX_TAGS;

 	save_commit_buffer = 0;

 	if (longformat && abbrev == 0)
 		die("--long is incompatible with --abbrev=0");

 	if (contains) {
 		const char **args = xmalloc((7 + argc) * sizeof(char *));
 		int i = 0;
 		args[i++] = "name-rev";
 		args[i++] = "--name-only";
 		args[i++] = "--no-undefined";
 		if (always)
 			args[i++] = "--always";
 		if (!all) {
 			args[i++] = "--tags";
 			if (pattern) {
 				char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 				sprintf(s, "--refs=refs/tags/%s", pattern);
 				args[i++] = s;
 			}
 		}
 		memcpy(args + i, argv, argc * sizeof(char *));
 		args[i + argc] = NULL;
 		return cmd_name_rev(i + argc, args, prefix);
 	}

 	for_each_ref(get_name, NULL);
 	if (!found_names && !always)
 		die("No names found, cannot describe anything.");

 	if (argc == 0) {
 		if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
 			dirty = NULL;
 		describe("HEAD", 1);
 	} else if (dirty) {
 		die("--dirty is incompatible with committishes");
 	} else {
 		while (argc-- > 0) {
 			describe(*argv++, argc == 0);
 		}
 	}
 	return 0;
 }
	#include "cache.h"
	#include "commit.h"
	#include "tag.h"
	#include "refs.h"
	#include "builtin.h"
	#include "exec_cmd.h"
	#include "parse-options.h"
	#include "diff.h"

	#define SEEN (1u<<0)
	#define MAX_TAGS (FLAG_BITS - 1)

	static const char * const describe_usage[] = {
	"git describe [options] <committish>*",
	"git describe [options] --dirty",
	NULL
	};

	static int debug; /* Display lots of verbose info */
	static int all; /* Any valid ref can be used */
	static int tags; /* Allow lightweight tags */
	static int longformat;
	static int abbrev = DEFAULT_ABBREV;
	static int max_candidates = 10;
	static int found_names;
	static const char *pattern;
	static int always;
	static const char *dirty;

	/* diff-index command arguments to check if working tree is dirty. */
	static const char *diff_index_args[] = {
	"diff-index", "--quiet", "HEAD", "--", NULL
	};


	struct commit_name {
	struct tag *tag;
	int prio; /* annotated tag = 2, tag = 1, head = 0 */
	unsigned char sha1[20];
	char path[FLEX_ARRAY]; /* more */
	};
	static const char *prio_names[] = {
	"head", "lightweight", "annotated",
	};

	static void add_to_known_names(const char *path,
	struct commit *commit,
	int prio,
	const unsigned char *sha1)
	{
	struct commit_name *e = commit->util;
	if (!e \|\| e->prio < prio) {
	size_t len = strlen(path)+1;
	free(e);
	e = xmalloc(sizeof(struct commit_name) + len);
	e->tag = NULL;
	e->prio = prio;
	hashcpy(e->sha1, sha1);
	memcpy(e->path, path, len);
	commit->util = e;
	}
	found_names = 1;
	}

	static int get_name(const char path, const unsigned char sha1, int flag, void *cb_data)
	{
	int might_be_tag = !prefixcmp(path, "refs/tags/");
	struct commit *commit;
	struct object *object;
	unsigned char peeled[20];
	int is_tag, prio;

	if (!all && !might_be_tag)
	return 0;

	if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
	commit = lookup_commit_reference_gently(peeled, 1);
	if (!commit)
	return 0;
	is_tag = !!hashcmp(sha1, commit->object.sha1);
	} else {
	commit = lookup_commit_reference_gently(sha1, 1);
	object = parse_object(sha1);
	if (!commit \|\| !object)
	return 0;
	is_tag = object->type == OBJ_TAG;
	}

	/* If --all, then any refs are used.
	* If --tags, then any tags are used.
	* Otherwise only annotated tags are used.
	*/
	if (might_be_tag) {
	if (is_tag)
	prio = 2;
	else
	prio = 1;

	if (pattern && fnmatch(pattern, path + 10, 0))
	prio = 0;
	}
	else
	prio = 0;

	if (!all) {
	if (!prio)
	return 0;
	}
	add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
	return 0;
	}

	struct possible_tag {
	struct commit_name *name;
	int depth;
	int found_order;
	unsigned flag_within;
	};

	static int compare_pt(const void a_, const void b_)
	{
	struct possible_tag a = (struct possible_tag )a_;
	struct possible_tag b = (struct possible_tag )b_;
	if (a->depth != b->depth)
	return a->depth - b->depth;
	if (a->found_order != b->found_order)
	return a->found_order - b->found_order;
	return 0;
	}

	static unsigned long finish_depth_computation(
	struct commit_list **list,
	struct possible_tag *best)
	{
	unsigned long seen_commits = 0;
	while (*list) {
	struct commit *c = pop_commit(list);
	struct commit_list *parents = c->parents;
	seen_commits++;
	if (c->object.flags & best->flag_within) {
	struct commit_list a = list;
	while (a) {
	struct commit *i = a->item;
	if (!(i->object.flags & best->flag_within))
	break;
	a = a->next;
	}
	if (!a)
	break;
	} else
	best->depth++;
	while (parents) {
	struct commit *p = parents->item;
	parse_commit(p);
	if (!(p->object.flags & SEEN))
	insert_by_date(p, list);
	p->object.flags \|= c->object.flags;
	parents = parents->next;
	}
	}
	return seen_commits;
	}

	static void display_name(struct commit_name *n)
	{
	if (n->prio == 2 && !n->tag) {
	n->tag = lookup_tag(n->sha1);
	if (!n->tag \|\| parse_tag(n->tag) \|\| !n->tag->tag)
	die("annotated tag %s not available", n->path);
	if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
	warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
	}

	if (n->tag)
	printf("%s", n->tag->tag);
	else
	printf("%s", n->path);
	}

	static void show_suffix(int depth, const unsigned char *sha1)
	{
	printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
	}

	static void describe(const char *arg, int last_one)
	{
	unsigned char sha1[20];
	struct commit cmit, gave_up_on = NULL;
	struct commit_list *list;
	struct commit_name *n;
	struct possible_tag all_matches[MAX_TAGS];
	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
	unsigned long seen_commits = 0;
	unsigned int unannotated_cnt = 0;

	if (get_sha1(arg, sha1))
	die("Not a valid object name %s", arg);
	cmit = lookup_commit_reference(sha1);
	if (!cmit)
	die("%s is not a valid '%s' object", arg, commit_type);

	n = cmit->util;
	if (n && (tags \|\| all \|\| n->prio == 2)) {
	/*
	* Exact match to an existing ref.
	*/
	display_name(n);
	if (longformat)
	show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
	if (dirty)
	printf("%s", dirty);
	printf("\n");
	return;
	}

	if (!max_candidates)
	die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
	if (debug)
	fprintf(stderr, "searching to describe %s\n", arg);

	list = NULL;
	cmit->object.flags = SEEN;
	commit_list_insert(cmit, &list);
	while (list) {
	struct commit *c = pop_commit(&list);
	struct commit_list *parents = c->parents;
	seen_commits++;
	n = c->util;
	if (n) {
	if (!tags && !all && n->prio < 2) {
	unannotated_cnt++;
	} else if (match_cnt < max_candidates) {
	struct possible_tag *t = &all_matches[match_cnt++];
	t->name = n;
	t->depth = seen_commits - 1;
	t->flag_within = 1u << match_cnt;
	t->found_order = match_cnt;
	c->object.flags \|= t->flag_within;
	if (n->prio == 2)
	annotated_cnt++;
	}
	else {
	gave_up_on = c;
	break;
	}
	}
	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	struct possible_tag *t = &all_matches[cur_match];
	if (!(c->object.flags & t->flag_within))
	t->depth++;
	}
	if (annotated_cnt && !list) {
	if (debug)
	fprintf(stderr, "finished search at %s\n",
	sha1_to_hex(c->object.sha1));
	break;
	}
	while (parents) {
	struct commit *p = parents->item;
	parse_commit(p);
	if (!(p->object.flags & SEEN))
	insert_by_date(p, &list);
	p->object.flags \|= c->object.flags;
	parents = parents->next;
	}
	}

	if (!match_cnt) {
	const unsigned char *sha1 = cmit->object.sha1;
	if (always) {
	printf("%s", find_unique_abbrev(sha1, abbrev));
	if (dirty)
	printf("%s", dirty);
	printf("\n");
	return;
	}
	if (unannotated_cnt)
	die("No annotated tags can describe '%s'.\n"
	"However, there were unannotated tags: try --tags.",
	sha1_to_hex(sha1));
	else
	die("No tags can describe '%s'.\n"
	"Try --always, or create some tags.",
	sha1_to_hex(sha1));
	}

	qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);

	if (gave_up_on) {
	insert_by_date(gave_up_on, &list);
	seen_commits--;
	}
	seen_commits += finish_depth_computation(&list, &all_matches[0]);
	free_commit_list(list);

	if (debug) {
	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	struct possible_tag *t = &all_matches[cur_match];
	fprintf(stderr, " %-11s %8d %s\n",
	prio_names[t->name->prio],
	t->depth, t->name->path);
	}
	fprintf(stderr, "traversed %lu commits\n", seen_commits);
	if (gave_up_on) {
	fprintf(stderr,
	"more than %i tags found; listed %i most recent\n"
	"gave up search at %s\n",
	max_candidates, max_candidates,
	sha1_to_hex(gave_up_on->object.sha1));
	}
	}

	display_name(all_matches[0].name);
	if (abbrev)
	show_suffix(all_matches[0].depth, cmit->object.sha1);
	if (dirty)
	printf("%s", dirty);
	printf("\n");

	if (!last_one)
	clear_commit_marks(cmit, -1);
	}

	int cmd_describe(int argc, const char *argv, const char prefix)
	{
	int contains = 0;
	struct option options[] = {
	OPT_BOOLEAN(0, "contains", &contains, "find the tag that comes after the commit"),
	OPT_BOOLEAN(0, "debug", &debug, "debug search strategy on stderr"),
	OPT_BOOLEAN(0, "all", &all, "use any ref in .git/refs"),
	OPT_BOOLEAN(0, "tags", &tags, "use any tag in .git/refs/tags"),
	OPT_BOOLEAN(0, "long", &longformat, "always use long format"),
	OPT__ABBREV(&abbrev),
	OPT_SET_INT(0, "exact-match", &max_candidates,
	"only output exact matches", 0),
	OPT_INTEGER(0, "candidates", &max_candidates,
	"consider <n> most recent tags (default: 10)"),
	OPT_STRING(0, "match", &pattern, "pattern",
	"only consider tags matching <pattern>"),
	OPT_BOOLEAN(0, "always", &always,
	"show abbreviated commit object as fallback"),
	{OPTION_STRING, 0, "dirty", &dirty, "mark",
	"append <mark> on dirty working tree (default: \"-dirty\")",
	PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
	OPT_END(),
	};

	argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
	if (max_candidates < 0)
	max_candidates = 0;
	else if (max_candidates > MAX_TAGS)
	max_candidates = MAX_TAGS;

	save_commit_buffer = 0;

	if (longformat && abbrev == 0)
	die("--long is incompatible with --abbrev=0");

	if (contains) {
	const char *args = xmalloc((7 + argc) sizeof(char *));
	int i = 0;
	args[i++] = "name-rev";
	args[i++] = "--name-only";
	args[i++] = "--no-undefined";
	if (always)
	args[i++] = "--always";
	if (!all) {
	args[i++] = "--tags";
	if (pattern) {
	char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
	sprintf(s, "--refs=refs/tags/%s", pattern);
	args[i++] = s;
	}
	}
	memcpy(args + i, argv, argc * sizeof(char *));
	args[i + argc] = NULL;
	return cmd_name_rev(i + argc, args, prefix);
	}

	for_each_ref(get_name, NULL);
	if (!found_names && !always)
	die("No names found, cannot describe anything.");

	if (argc == 0) {
	if (dirty && !cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1, diff_index_args, prefix))
	dirty = NULL;
	describe("HEAD", 1);
	} else if (dirty) {
	die("--dirty is incompatible with committishes");
	} else {
	while (argc-- > 0) {
	describe(*argv++, argc == 0);
	}
	}
	return 0;
	}