[thirdparty/git.git] / rev-parse.c

/*
 * rev-parse.c
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"
#include "commit.h"
#include "refs.h"

static char *def = NULL;
static int no_revs = 0;
static int single_rev = 0;
static int revs_only = 0;
static int do_rev_argument = 1;
static int output_revs = 0;
static int flags_only = 0;
static int no_flags = 0;

#define NORMAL 0
#define REVERSED 1
static int show_type = NORMAL;

static int get_extended_sha1(char *name, unsigned char *sha1);

/*
 * Some arguments are relevant "revision" arguments,
 * others are about output format or other details.
 * This sorts it all out.
 */
static int is_rev_argument(const char *arg)
{
	static const char *rev_args[] = {
		"--max-count=",
		"--max-age=",
		"--min-age=",
		"--merge-order",
		NULL
	};
	const char **p = rev_args;

	for (;;) {
		const char *str = *p++;
		int len;
		if (!str)
			return 0;
		len = strlen(str);
		if (!strncmp(arg, str, len))
			return 1;
	}
}

static void show_rev(int type, const unsigned char *sha1)
{
	if (no_revs)
		return;
	output_revs++;
	printf("%s%s\n", type == show_type ? "" : "^", sha1_to_hex(sha1));
}

static void show_rev_arg(char *rev)
{
	if (no_revs)
		return;
	puts(rev);
}

static void show_norev(char *norev)
{
	if (flags_only)
		return;
	if (revs_only)
		return;
	puts(norev);
}

static void show_arg(char *arg)
{
	if (no_flags)
		return;
	if (do_rev_argument && is_rev_argument(arg))
		show_rev_arg(arg);
	else
		show_norev(arg);
}

static int get_parent(char *name, unsigned char *result, int idx)
{
	unsigned char sha1[20];
	int ret = get_extended_sha1(name, sha1);
	struct commit *commit;
	struct commit_list *p;

	if (ret)
		return ret;
	commit = lookup_commit_reference(sha1);
	if (!commit)
		return -1;
	if (parse_commit(commit))
		return -1;
	if (!idx) {
		memcpy(result, commit->object.sha1, 20);
		return 0;
	}
	p = commit->parents;
	while (p) {
		if (!--idx) {
			memcpy(result, p->item->object.sha1, 20);
			return 0;
		}
		p = p->next;
	}
	return -1;
}

static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
{
	static char dirname[PATH_MAX];
	char hex[40];
	DIR *dir;
	int found;

	snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
	dir = opendir(dirname);
	sprintf(hex, "%.2s", name);
	found = 0;
	if (dir) {
		struct dirent *de;
		while ((de = readdir(dir)) != NULL) {
			if (strlen(de->d_name) != 38)
				continue;
			if (memcmp(de->d_name, name + 2, len-2))
				continue;
			memcpy(hex + 2, de->d_name, 38);
			if (++found > 1)
				break;
		}
		closedir(dir);
	}
	if (found == 1)
		return get_sha1_hex(hex, sha1) == 0;
	return 0;
}

static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
{
	do {
		if (*a != *b)
			return 0;
		a++;
		b++;
		len -= 2;
	} while (len > 1);
	if (len)
		if ((*a ^ *b) & 0xf0)
			return 0;
	return 1;
}

static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
{
	struct packed_git *p;

	prepare_packed_git();
	for (p = packed_git; p; p = p->next) {
		unsigned num = num_packed_objects(p);
		unsigned first = 0, last = num;
		while (first < last) {
			unsigned mid = (first + last) / 2;
			unsigned char now[20];
			int cmp;

			nth_packed_object_sha1(p, mid, now);
			cmp = memcmp(match, now, 20);
			if (!cmp) {
				first = mid;
				break;
			}
			if (cmp > 0) {
				first = mid+1;
				continue;
			}
			last = mid;
		}
		if (first < num) {
			unsigned char now[20], next[20];
			nth_packed_object_sha1(p, first, now);
			if (match_sha(len, match, now)) {
				if (nth_packed_object_sha1(p, first+1, next) || !match_sha(len, match, next)) {
					memcpy(sha1, now, 20);
					return 1;
				}
			}
		}	
	}
	return 0;
}

static int get_short_sha1(char *name, unsigned char *sha1)
{
	int i;
	char canonical[40];
	unsigned char res[20];

	memset(res, 0, 20);
	memset(canonical, 'x', 40);
	for (i = 0;;i++) {
		unsigned char c = name[i];
		unsigned char val;
		if (!c || i > 40)
			break;
		if (c >= '0' && c <= '9')
			val = c - '0';
		else if (c >= 'a' && c <= 'f')
			val = c - 'a' + 10;
		else if (c >= 'A' && c <='F') {
			val = c - 'A' + 10;
			c -= 'A' - 'a';
		}
		else
			return -1;
		canonical[i] = c;
		if (!(i & 1))
			val <<= 4;
		res[i >> 1] |= val;
	}
	if (i < 4)
		return -1;
	if (find_short_object_filename(i, canonical, sha1))
		return 0;
	if (find_short_packed_object(i, res, sha1))
		return 0;
	return -1;
}

/*
 * This is like "get_sha1()", except it allows "sha1 expressions",
 * notably "xyz^" for "parent of xyz"
 */
static int get_extended_sha1(char *name, unsigned char *sha1)
{
	int parent, ret;
	int len = strlen(name);

	parent = 1;
	if (len > 2 && name[len-1] >= '0' && name[len-1] <= '9') {
		parent = name[len-1] - '0';
		len--;
	}
	if (len > 1 && name[len-1] == '^') {
		name[len-1] = 0;
		ret = get_parent(name, sha1, parent);
		name[len-1] = '^';
		if (!ret)
			return 0;
	}
	ret = get_sha1(name, sha1);
	if (!ret)
		return 0;
	return get_short_sha1(name, sha1);
}

static void show_default(void)
{
	char *s = def;

	if (s) {
		unsigned char sha1[20];

		def = NULL;
		if (!get_extended_sha1(s, sha1)) {
			show_rev(NORMAL, sha1);
			return;
		}
		show_arg(s);
	}
}

static int show_reference(const char *refname, const unsigned char *sha1)
{
	show_rev(NORMAL, sha1);
	return 0;
}

int main(int argc, char **argv)
{
	int i, as_is = 0;
	unsigned char sha1[20];

	for (i = 1; i < argc; i++) {
		char *arg = argv[i];
		char *dotdot;
	
		if (as_is) {
			show_norev(arg);
			continue;
		}
		if (*arg == '-') {
			if (!strcmp(arg, "--")) {
				show_default();
				if (revs_only)
					break;
				as_is = 1;
			}
			if (!strcmp(arg, "--default")) {
				def = argv[i+1];
				i++;
				continue;
			}
			if (!strcmp(arg, "--revs-only")) {
				revs_only = 1;
				continue;
			}
			if (!strcmp(arg, "--no-revs")) {
				no_revs = 1;
				continue;
			}
			if (!strcmp(arg, "--flags")) {
				flags_only = 1;
				continue;
			}
			if (!strcmp(arg, "--no-flags")) {
				no_flags = 1;
				continue;
			}
			if (!strcmp(arg, "--verify")) {
				revs_only = 1;
				do_rev_argument = 0;
				single_rev = 1;
				continue;
			}
			if (!strcmp(arg, "--not")) {
				show_type ^= REVERSED;
				continue;
			}
			if (!strcmp(arg, "--all")) {
				for_each_ref(show_reference);
				continue;
			}
			show_arg(arg);
			continue;
		}
		dotdot = strstr(arg, "..");
		if (dotdot) {
			unsigned char end[20];
			char *n = dotdot+2;
			*dotdot = 0;
			if (!get_extended_sha1(arg, sha1)) {
				if (!*n)
					n = "HEAD";
				if (!get_extended_sha1(n, end)) {
					if (no_revs)
						continue;
					def = NULL;
					show_rev(NORMAL, end);
					show_rev(REVERSED, sha1);
					continue;
				}
			}
			*dotdot = '.';
		}
		if (!get_extended_sha1(arg, sha1)) {
			if (no_revs)
				continue;
			def = NULL;
			show_rev(NORMAL, sha1);
			continue;
		}
		if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
			if (no_revs)
				continue;
			def = NULL;
			show_rev(REVERSED, sha1);
			continue;
		}
		show_default();
		show_norev(arg);
	}
	show_default();
	if (single_rev && output_revs != 1) {
		fprintf(stderr, "Needed a single revision\n");
		exit(1);
	}
	return 0;
}
Commit	Line	Data
178cb243 LT	1	/*
	2	* rev-parse.c
	3	*
	4	* Copyright (C) Linus Torvalds, 2005
	5	*/
	6	#include "cache.h"
a8be83fe	7	#include "commit.h"
960bba0d	8	#include "refs.h"
a8be83fe	9
023d66ed LT	10	static char *def = NULL;
	11	static int no_revs = 0;
	12	static int single_rev = 0;
	13	static int revs_only = 0;
	14	static int do_rev_argument = 1;
	15	static int output_revs = 0;
f79b65aa LT	16	static int flags_only = 0;
f79b65aa LT	17	static int no_flags = 0;
023d66ed	18
042a4ed7 LT	19	#define NORMAL 0
	20	#define REVERSED 1
	21	static int show_type = NORMAL;
	22
a8be83fe	23	static int get_extended_sha1(char name, unsigned char sha1);
178cb243	24
921d865e LT	25	/*
	26	* Some arguments are relevant "revision" arguments,
	27	* others are about output format or other details.
	28	* This sorts it all out.
	29	*/
	30	static int is_rev_argument(const char *arg)
	31	{
	32	static const char *rev_args[] = {
	33	"--max-count=",
	34	"--max-age=",
	35	"--min-age=",
	36	"--merge-order",
	37	NULL
	38	};
	39	const char **p = rev_args;
	40
	41	for (;;) {
	42	const char str = p++;
	43	int len;
	44	if (!str)
	45	return 0;
	46	len = strlen(str);
	47	if (!strncmp(arg, str, len))
	48	return 1;
	49	}
	50	}
	51
960bba0d	52	static void show_rev(int type, const unsigned char *sha1)
023d66ed LT	53	{
	54	if (no_revs)
	55	return;
	56	output_revs++;
042a4ed7	57	printf("%s%s\n", type == show_type ? "" : "^", sha1_to_hex(sha1));
023d66ed LT	58	}
	59
	60	static void show_rev_arg(char *rev)
	61	{
	62	if (no_revs)
	63	return;
	64	puts(rev);
	65	}
	66
	67	static void show_norev(char *norev)
	68	{
f79b65aa LT	69	if (flags_only)
f79b65aa LT	70	return;
023d66ed LT	71	if (revs_only)
	72	return;
	73	puts(norev);
	74	}
	75
	76	static void show_arg(char *arg)
	77	{
f79b65aa LT	78	if (no_flags)
f79b65aa LT	79	return;
023d66ed LT	80	if (do_rev_argument && is_rev_argument(arg))
	81	show_rev_arg(arg);
	82	else
	83	show_norev(arg);
	84	}
	85
a8be83fe LT	86	static int get_parent(char name, unsigned char result, int idx)
	87	{
	88	unsigned char sha1[20];
	89	int ret = get_extended_sha1(name, sha1);
	90	struct commit *commit;
	91	struct commit_list *p;
	92
	93	if (ret)
	94	return ret;
	95	commit = lookup_commit_reference(sha1);
	96	if (!commit)
	97	return -1;
	98	if (parse_commit(commit))
	99	return -1;
79162bb8 LT	100	if (!idx) {
	101	memcpy(result, commit->object.sha1, 20);
	102	return 0;
	103	}
a8be83fe LT	104	p = commit->parents;
	105	while (p) {
	106	if (!--idx) {
	107	memcpy(result, p->item->object.sha1, 20);
	108	return 0;
	109	}
	110	p = p->next;
	111	}
	112	return -1;
	113	}
	114
5736bef1 LT	115	static int find_short_object_filename(int len, const char name, unsigned char sha1)
	116	{
	117	static char dirname[PATH_MAX];
	118	char hex[40];
	119	DIR *dir;
	120	int found;
	121
	122	snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
	123	dir = opendir(dirname);
	124	sprintf(hex, "%.2s", name);
	125	found = 0;
	126	if (dir) {
	127	struct dirent *de;
	128	while ((de = readdir(dir)) != NULL) {
	129	if (strlen(de->d_name) != 38)
	130	continue;
	131	if (memcmp(de->d_name, name + 2, len-2))
	132	continue;
	133	memcpy(hex + 2, de->d_name, 38);
	134	if (++found > 1)
	135	break;
	136	}
	137	closedir(dir);
	138	}
	139	if (found == 1)
	140	return get_sha1_hex(hex, sha1) == 0;
	141	return 0;
	142	}
	143
671fe4bb LT	144	static int match_sha(unsigned len, const unsigned char a, const unsigned char b)
	145	{
	146	do {
	147	if (a != b)
	148	return 0;
	149	a++;
	150	b++;
	151	len -= 2;
	152	} while (len > 1);
	153	if (len)
	154	if ((a ^ b) & 0xf0)
	155	return 0;
	156	return 1;
	157	}
	158
5736bef1 LT	159	static int find_short_packed_object(int len, const unsigned char match, unsigned char sha1)
5736bef1 LT	160	{
671fe4bb LT	161	struct packed_git *p;
	162
	163	prepare_packed_git();
	164	for (p = packed_git; p; p = p->next) {
	165	unsigned num = num_packed_objects(p);
	166	unsigned first = 0, last = num;
	167	while (first < last) {
	168	unsigned mid = (first + last) / 2;
	169	unsigned char now[20];
	170	int cmp;
	171
	172	nth_packed_object_sha1(p, mid, now);
	173	cmp = memcmp(match, now, 20);
	174	if (!cmp) {
	175	first = mid;
	176	break;
	177	}
	178	if (cmp > 0) {
	179	first = mid+1;
	180	continue;
	181	}
	182	last = mid;
	183	}
	184	if (first < num) {
	185	unsigned char now[20], next[20];
	186	nth_packed_object_sha1(p, first, now);
	187	if (match_sha(len, match, now)) {
	188	if (nth_packed_object_sha1(p, first+1, next) \|\| !match_sha(len, match, next)) {
	189	memcpy(sha1, now, 20);
	190	return 1;
	191	}
	192	}
	193	}
	194	}
5736bef1 LT	195	return 0;
	196	}
	197
	198	static int get_short_sha1(char name, unsigned char sha1)
	199	{
	200	int i;
	201	char canonical[40];
	202	unsigned char res[20];
	203
	204	memset(res, 0, 20);
	205	memset(canonical, 'x', 40);
	206	for (i = 0;;i++) {
	207	unsigned char c = name[i];
	208	unsigned char val;
	209	if (!c \|\| i > 40)
	210	break;
	211	if (c >= '0' && c <= '9')
	212	val = c - '0';
	213	else if (c >= 'a' && c <= 'f')
	214	val = c - 'a' + 10;
	215	else if (c >= 'A' && c <='F') {
	216	val = c - 'A' + 10;
	217	c -= 'A' - 'a';
	218	}
	219	else
	220	return -1;
	221	canonical[i] = c;
	222	if (!(i & 1))
	223	val <<= 4;
	224	res[i >> 1] \|= val;
	225	}
	226	if (i < 4)
	227	return -1;
	228	if (find_short_object_filename(i, canonical, sha1))
	229	return 0;
	230	if (find_short_packed_object(i, res, sha1))
	231	return 0;
	232	return -1;
	233	}
	234
a8be83fe LT	235	/*
a8be83fe LT	236	* This is like "get_sha1()", except it allows "sha1 expressions",
218e441d	237	* notably "xyz^" for "parent of xyz"
a8be83fe LT	238	*/
	239	static int get_extended_sha1(char name, unsigned char sha1)
	240	{
5736bef1	241	int parent, ret;
a8be83fe LT	242	int len = strlen(name);
	243
	244	parent = 1;
79162bb8	245	if (len > 2 && name[len-1] >= '0' && name[len-1] <= '9') {
a8be83fe LT	246	parent = name[len-1] - '0';
	247	len--;
	248	}
218e441d	249	if (len > 1 && name[len-1] == '^') {
218e441d	250	name[len-1] = 0;
a8be83fe	251	ret = get_parent(name, sha1, parent);
218e441d	252	name[len-1] = '^';
a8be83fe LT	253	if (!ret)
	254	return 0;
	255	}
5736bef1 LT	256	ret = get_sha1(name, sha1);
	257	if (!ret)
	258	return 0;
	259	return get_short_sha1(name, sha1);
a8be83fe LT	260	}
a8be83fe LT	261
023d66ed LT	262	static void show_default(void)
	263	{
	264	char *s = def;
	265
	266	if (s) {
	267	unsigned char sha1[20];
	268
	269	def = NULL;
	270	if (!get_extended_sha1(s, sha1)) {
042a4ed7	271	show_rev(NORMAL, sha1);
023d66ed LT	272	return;
	273	}
	274	show_arg(s);
	275	}
	276	}
	277
960bba0d LT	278	static int show_reference(const char refname, const unsigned char sha1)
	279	{
	280	show_rev(NORMAL, sha1);
	281	return 0;
	282	}
	283
178cb243 LT	284	int main(int argc, char **argv)
178cb243 LT	285	{
023d66ed	286	int i, as_is = 0;
178cb243 LT	287	unsigned char sha1[20];
	288
	289	for (i = 1; i < argc; i++) {
	290	char *arg = argv[i];
	291	char *dotdot;
	292
	293	if (as_is) {
023d66ed	294	show_norev(arg);
178cb243 LT	295	continue;
	296	}
	297	if (*arg == '-') {
	298	if (!strcmp(arg, "--")) {
023d66ed	299	show_default();
8ebb0184 LT	300	if (revs_only)
8ebb0184 LT	301	break;
178cb243 LT	302	as_is = 1;
	303	}
	304	if (!strcmp(arg, "--default")) {
178cb243 LT	305	def = argv[i+1];
	306	i++;
	307	continue;
	308	}
8ebb0184 LT	309	if (!strcmp(arg, "--revs-only")) {
	310	revs_only = 1;
	311	continue;
	312	}
	313	if (!strcmp(arg, "--no-revs")) {
	314	no_revs = 1;
	315	continue;
	316	}
f79b65aa LT	317	if (!strcmp(arg, "--flags")) {
	318	flags_only = 1;
	319	continue;
	320	}
	321	if (!strcmp(arg, "--no-flags")) {
	322	no_flags = 1;
	323	continue;
	324	}
023d66ed LT	325	if (!strcmp(arg, "--verify")) {
	326	revs_only = 1;
	327	do_rev_argument = 0;
	328	single_rev = 1;
	329	continue;
921d865e	330	}
042a4ed7 LT	331	if (!strcmp(arg, "--not")) {
	332	show_type ^= REVERSED;
	333	continue;
	334	}
960bba0d LT	335	if (!strcmp(arg, "--all")) {
	336	for_each_ref(show_reference);
	337	continue;
	338	}
023d66ed	339	show_arg(arg);
178cb243 LT	340	continue;
178cb243 LT	341	}
178cb243 LT	342	dotdot = strstr(arg, "..");
	343	if (dotdot) {
	344	unsigned char end[20];
	345	char *n = dotdot+2;
	346	*dotdot = 0;
a8be83fe	347	if (!get_extended_sha1(arg, sha1)) {
178cb243 LT	348	if (!*n)
178cb243 LT	349	n = "HEAD";
a8be83fe	350	if (!get_extended_sha1(n, end)) {
8ebb0184 LT	351	if (no_revs)
	352	continue;
	353	def = NULL;
042a4ed7 LT	354	show_rev(NORMAL, end);
042a4ed7 LT	355	show_rev(REVERSED, sha1);
178cb243 LT	356	continue;
	357	}
	358	}
	359	*dotdot = '.';
	360	}
a8be83fe	361	if (!get_extended_sha1(arg, sha1)) {
800644c5 LT	362	if (no_revs)
	363	continue;
	364	def = NULL;
042a4ed7	365	show_rev(NORMAL, sha1);
800644c5 LT	366	continue;
800644c5 LT	367	}
a8be83fe	368	if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
800644c5 LT	369	if (no_revs)
	370	continue;
	371	def = NULL;
042a4ed7	372	show_rev(REVERSED, sha1);
800644c5 LT	373	continue;
800644c5 LT	374	}
023d66ed LT	375	show_default();
	376	show_norev(arg);
	377	}
	378	show_default();
	379	if (single_rev && output_revs != 1) {
	380	fprintf(stderr, "Needed a single revision\n");
	381	exit(1);
178cb243	382	}
178cb243 LT	383	return 0;
178cb243 LT	384	}