[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;
	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] >= '1' && 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;
	100	p = commit->parents;
	101	while (p) {
	102	if (!--idx) {
	103	memcpy(result, p->item->object.sha1, 20);
	104	return 0;
	105	}
	106	p = p->next;
	107	}
	108	return -1;
	109	}
	110
5736bef1 LT	111	static int find_short_object_filename(int len, const char name, unsigned char sha1)
	112	{
	113	static char dirname[PATH_MAX];
	114	char hex[40];
	115	DIR *dir;
	116	int found;
	117
	118	snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
	119	dir = opendir(dirname);
	120	sprintf(hex, "%.2s", name);
	121	found = 0;
	122	if (dir) {
	123	struct dirent *de;
	124	while ((de = readdir(dir)) != NULL) {
	125	if (strlen(de->d_name) != 38)
	126	continue;
	127	if (memcmp(de->d_name, name + 2, len-2))
	128	continue;
	129	memcpy(hex + 2, de->d_name, 38);
	130	if (++found > 1)
	131	break;
	132	}
	133	closedir(dir);
	134	}
	135	if (found == 1)
	136	return get_sha1_hex(hex, sha1) == 0;
	137	return 0;
	138	}
	139
671fe4bb LT	140	static int match_sha(unsigned len, const unsigned char a, const unsigned char b)
	141	{
	142	do {
	143	if (a != b)
	144	return 0;
	145	a++;
	146	b++;
	147	len -= 2;
	148	} while (len > 1);
	149	if (len)
	150	if ((a ^ b) & 0xf0)
	151	return 0;
	152	return 1;
	153	}
	154
5736bef1 LT	155	static int find_short_packed_object(int len, const unsigned char match, unsigned char sha1)
5736bef1 LT	156	{
671fe4bb LT	157	struct packed_git *p;
	158
	159	prepare_packed_git();
	160	for (p = packed_git; p; p = p->next) {
	161	unsigned num = num_packed_objects(p);
	162	unsigned first = 0, last = num;
	163	while (first < last) {
	164	unsigned mid = (first + last) / 2;
	165	unsigned char now[20];
	166	int cmp;
	167
	168	nth_packed_object_sha1(p, mid, now);
	169	cmp = memcmp(match, now, 20);
	170	if (!cmp) {
	171	first = mid;
	172	break;
	173	}
	174	if (cmp > 0) {
	175	first = mid+1;
	176	continue;
	177	}
	178	last = mid;
	179	}
	180	if (first < num) {
	181	unsigned char now[20], next[20];
	182	nth_packed_object_sha1(p, first, now);
	183	if (match_sha(len, match, now)) {
	184	if (nth_packed_object_sha1(p, first+1, next) \|\| !match_sha(len, match, next)) {
	185	memcpy(sha1, now, 20);
	186	return 1;
	187	}
	188	}
	189	}
	190	}
5736bef1 LT	191	return 0;
	192	}
	193
	194	static int get_short_sha1(char name, unsigned char sha1)
	195	{
	196	int i;
	197	char canonical[40];
	198	unsigned char res[20];
	199
	200	memset(res, 0, 20);
	201	memset(canonical, 'x', 40);
	202	for (i = 0;;i++) {
	203	unsigned char c = name[i];
	204	unsigned char val;
	205	if (!c \|\| i > 40)
	206	break;
	207	if (c >= '0' && c <= '9')
	208	val = c - '0';
	209	else if (c >= 'a' && c <= 'f')
	210	val = c - 'a' + 10;
	211	else if (c >= 'A' && c <='F') {
	212	val = c - 'A' + 10;
	213	c -= 'A' - 'a';
	214	}
	215	else
	216	return -1;
	217	canonical[i] = c;
	218	if (!(i & 1))
	219	val <<= 4;
	220	res[i >> 1] \|= val;
	221	}
	222	if (i < 4)
	223	return -1;
	224	if (find_short_object_filename(i, canonical, sha1))
	225	return 0;
	226	if (find_short_packed_object(i, res, sha1))
	227	return 0;
	228	return -1;
	229	}
	230
a8be83fe LT	231	/*
a8be83fe LT	232	* This is like "get_sha1()", except it allows "sha1 expressions",
218e441d	233	* notably "xyz^" for "parent of xyz"
a8be83fe LT	234	*/
	235	static int get_extended_sha1(char name, unsigned char sha1)
	236	{
5736bef1	237	int parent, ret;
a8be83fe LT	238	int len = strlen(name);
	239
	240	parent = 1;
218e441d	241	if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
a8be83fe LT	242	parent = name[len-1] - '0';
	243	len--;
	244	}
218e441d	245	if (len > 1 && name[len-1] == '^') {
218e441d	246	name[len-1] = 0;
a8be83fe	247	ret = get_parent(name, sha1, parent);
218e441d	248	name[len-1] = '^';
a8be83fe LT	249	if (!ret)
	250	return 0;
	251	}
5736bef1 LT	252	ret = get_sha1(name, sha1);
	253	if (!ret)
	254	return 0;
	255	return get_short_sha1(name, sha1);
a8be83fe LT	256	}
a8be83fe LT	257
023d66ed LT	258	static void show_default(void)
	259	{
	260	char *s = def;
	261
	262	if (s) {
	263	unsigned char sha1[20];
	264
	265	def = NULL;
	266	if (!get_extended_sha1(s, sha1)) {
042a4ed7	267	show_rev(NORMAL, sha1);
023d66ed LT	268	return;
	269	}
	270	show_arg(s);
	271	}
	272	}
	273
960bba0d LT	274	static int show_reference(const char refname, const unsigned char sha1)
	275	{
	276	show_rev(NORMAL, sha1);
	277	return 0;
	278	}
	279
178cb243 LT	280	int main(int argc, char **argv)
178cb243 LT	281	{
023d66ed	282	int i, as_is = 0;
178cb243 LT	283	unsigned char sha1[20];
	284
	285	for (i = 1; i < argc; i++) {
	286	char *arg = argv[i];
	287	char *dotdot;
	288
	289	if (as_is) {
023d66ed	290	show_norev(arg);
178cb243 LT	291	continue;
	292	}
	293	if (*arg == '-') {
	294	if (!strcmp(arg, "--")) {
023d66ed	295	show_default();
8ebb0184 LT	296	if (revs_only)
8ebb0184 LT	297	break;
178cb243 LT	298	as_is = 1;
	299	}
	300	if (!strcmp(arg, "--default")) {
178cb243 LT	301	def = argv[i+1];
	302	i++;
	303	continue;
	304	}
8ebb0184 LT	305	if (!strcmp(arg, "--revs-only")) {
	306	revs_only = 1;
	307	continue;
	308	}
	309	if (!strcmp(arg, "--no-revs")) {
	310	no_revs = 1;
	311	continue;
	312	}
f79b65aa LT	313	if (!strcmp(arg, "--flags")) {
	314	flags_only = 1;
	315	continue;
	316	}
	317	if (!strcmp(arg, "--no-flags")) {
	318	no_flags = 1;
	319	continue;
	320	}
023d66ed LT	321	if (!strcmp(arg, "--verify")) {
	322	revs_only = 1;
	323	do_rev_argument = 0;
	324	single_rev = 1;
	325	continue;
921d865e	326	}
042a4ed7 LT	327	if (!strcmp(arg, "--not")) {
	328	show_type ^= REVERSED;
	329	continue;
	330	}
960bba0d LT	331	if (!strcmp(arg, "--all")) {
	332	for_each_ref(show_reference);
	333	continue;
	334	}
023d66ed	335	show_arg(arg);
178cb243 LT	336	continue;
178cb243 LT	337	}
178cb243 LT	338	dotdot = strstr(arg, "..");
	339	if (dotdot) {
	340	unsigned char end[20];
	341	char *n = dotdot+2;
	342	*dotdot = 0;
a8be83fe	343	if (!get_extended_sha1(arg, sha1)) {
178cb243 LT	344	if (!*n)
178cb243 LT	345	n = "HEAD";
a8be83fe	346	if (!get_extended_sha1(n, end)) {
8ebb0184 LT	347	if (no_revs)
	348	continue;
	349	def = NULL;
042a4ed7 LT	350	show_rev(NORMAL, end);
042a4ed7 LT	351	show_rev(REVERSED, sha1);
178cb243 LT	352	continue;
	353	}
	354	}
	355	*dotdot = '.';
	356	}
a8be83fe	357	if (!get_extended_sha1(arg, sha1)) {
800644c5 LT	358	if (no_revs)
	359	continue;
	360	def = NULL;
042a4ed7	361	show_rev(NORMAL, sha1);
800644c5 LT	362	continue;
800644c5 LT	363	}
a8be83fe	364	if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
800644c5 LT	365	if (no_revs)
	366	continue;
	367	def = NULL;
042a4ed7	368	show_rev(REVERSED, sha1);
800644c5 LT	369	continue;
800644c5 LT	370	}
023d66ed LT	371	show_default();
	372	show_norev(arg);
	373	}
	374	show_default();
	375	if (single_rev && output_revs != 1) {
	376	fprintf(stderr, "Needed a single revision\n");
	377	exit(1);
178cb243	378	}
178cb243 LT	379	return 0;
178cb243 LT	380	}