[thirdparty/git.git] / sha1_name.c

#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
#include "tree-walk.h"
#include "refs.h"

static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
{
	struct alternate_object_database *alt;
	char hex[40];
	int found = 0;
	static struct alternate_object_database *fakeent;

	if (!fakeent) {
		const char *objdir = get_object_directory();
		int objdir_len = strlen(objdir);
		int entlen = objdir_len + 43;
		fakeent = xmalloc(sizeof(*fakeent) + entlen);
		memcpy(fakeent->base, objdir, objdir_len);
		fakeent->name = fakeent->base + objdir_len + 1;
		fakeent->name[-1] = '/';
	}
	fakeent->next = alt_odb_list;

	sprintf(hex, "%.2s", name);
	for (alt = fakeent; alt && found < 2; alt = alt->next) {
		struct dirent *de;
		DIR *dir;
		sprintf(alt->name, "%.2s/", name);
		dir = opendir(alt->base);
		if (!dir)
			continue;
		while ((de = readdir(dir)) != NULL) {
			if (strlen(de->d_name) != 38)
				continue;
			if (memcmp(de->d_name, name + 2, len - 2))
				continue;
			if (!found) {
				memcpy(hex + 2, de->d_name, 38);
				found++;
			}
			else if (memcmp(hex + 2, de->d_name, 38)) {
				found = 2;
				break;
			}
		}
		closedir(dir);
	}
	if (found == 1)
		return get_sha1_hex(hex, sha1) == 0;
	return found;
}

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;
	const unsigned char *found_sha1 = NULL;
	int found = 0;

	prepare_packed_git();
	for (p = packed_git; p && found < 2; p = p->next) {
		uint32_t num, last;
		uint32_t first = 0;
		open_pack_index(p);
		num = p->num_objects;
		last = num;
		while (first < last) {
			uint32_t mid = (first + last) / 2;
			const unsigned char *now;
			int cmp;

			now = nth_packed_object_sha1(p, mid);
			cmp = hashcmp(match, now);
			if (!cmp) {
				first = mid;
				break;
			}
			if (cmp > 0) {
				first = mid+1;
				continue;
			}
			last = mid;
		}
		if (first < num) {
			const unsigned char *now, *next;
		       now = nth_packed_object_sha1(p, first);
			if (match_sha(len, match, now)) {
				next = nth_packed_object_sha1(p, first+1);
			       if (!next|| !match_sha(len, match, next)) {
					/* unique within this pack */
					if (!found) {
						found_sha1 = now;
						found++;
					}
					else if (hashcmp(found_sha1, now)) {
						found = 2;
						break;
					}
				}
				else {
					/* not even unique within this pack */
					found = 2;
					break;
				}
			}
		}
	}
	if (found == 1)
		hashcpy(sha1, found_sha1);
	return found;
}

#define SHORT_NAME_NOT_FOUND (-1)
#define SHORT_NAME_AMBIGUOUS (-2)

static int find_unique_short_object(int len, char *canonical,
				    unsigned char *res, unsigned char *sha1)
{
	int has_unpacked, has_packed;
	unsigned char unpacked_sha1[20], packed_sha1[20];

	prepare_alt_odb();
	has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
	has_packed = find_short_packed_object(len, res, packed_sha1);
	if (!has_unpacked && !has_packed)
		return SHORT_NAME_NOT_FOUND;
	if (1 < has_unpacked || 1 < has_packed)
		return SHORT_NAME_AMBIGUOUS;
	if (has_unpacked != has_packed) {
		hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
		return 0;
	}
	/* Both have unique ones -- do they match? */
	if (hashcmp(packed_sha1, unpacked_sha1))
		return SHORT_NAME_AMBIGUOUS;
	hashcpy(sha1, packed_sha1);
	return 0;
}

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

	if (len < MINIMUM_ABBREV || len > 40)
		return -1;
	hashclr(res);
	memset(canonical, 'x', 40);
	for (i = 0; i < len ;i++) {
		unsigned char c = name[i];
		unsigned char val;
		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;
	}

	status = find_unique_short_object(i, canonical, res, sha1);
	if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
		return error("short SHA1 %.*s is ambiguous.", len, canonical);
	return status;
}

const char *find_unique_abbrev(const unsigned char *sha1, int len)
{
	int status, exists;
	static char hex[41];

	exists = has_sha1_file(sha1);
	memcpy(hex, sha1_to_hex(sha1), 40);
	if (len == 40 || !len)
		return hex;
	while (len < 40) {
		unsigned char sha1_ret[20];
		status = get_short_sha1(hex, len, sha1_ret, 1);
		if (exists
		    ? !status
		    : status == SHORT_NAME_NOT_FOUND) {
			hex[len] = 0;
			return hex;
		}
		len++;
	}
	return hex;
}

static int ambiguous_path(const char *path, int len)
{
	int slash = 1;
	int cnt;

	for (cnt = 0; cnt < len; cnt++) {
		switch (*path++) {
		case '\0':
			break;
		case '/':
			if (slash)
				break;
			slash = 1;
			continue;
		case '.':
			continue;
		default:
			slash = 0;
			continue;
		}
		break;
	}
	return slash;
}

int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
{
	const char **p, *r;
	int refs_found = 0;

	*ref = NULL;
	for (p = ref_rev_parse_rules; *p; p++) {
		unsigned char sha1_from_ref[20];
		unsigned char *this_result;

		this_result = refs_found ? sha1_from_ref : sha1;
		r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
		if (r) {
			if (!refs_found++)
				*ref = xstrdup(r);
			if (!warn_ambiguous_refs)
				break;
		}
	}
	return refs_found;
}

int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
{
	const char **p;
	int logs_found = 0;

	*log = NULL;
	for (p = ref_rev_parse_rules; *p; p++) {
		struct stat st;
		unsigned char hash[20];
		char path[PATH_MAX];
		const char *ref, *it;

		strcpy(path, mkpath(*p, len, str));
		ref = resolve_ref(path, hash, 0, NULL);
		if (!ref)
			continue;
		if (!stat(git_path("logs/%s", path), &st) &&
		    S_ISREG(st.st_mode))
			it = path;
		else if (strcmp(ref, path) &&
			 !stat(git_path("logs/%s", ref), &st) &&
			 S_ISREG(st.st_mode))
			it = ref;
		else
			continue;
		if (!logs_found++) {
			*log = xstrdup(it);
			hashcpy(sha1, hash);
		}
		if (!warn_ambiguous_refs)
			break;
	}
	return logs_found;
}

static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
{
	static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
	char *real_ref = NULL;
	int refs_found = 0;
	int at, reflog_len;

	if (len == 40 && !get_sha1_hex(str, sha1))
		return 0;

	/* basic@{time or number} format to query ref-log */
	reflog_len = at = 0;
	if (str[len-1] == '}') {
		for (at = 0; at < len - 1; at++) {
			if (str[at] == '@' && str[at+1] == '{') {
				reflog_len = (len-1) - (at+2);
				len = at;
				break;
			}
		}
	}

	/* Accept only unambiguous ref paths. */
	if (len && ambiguous_path(str, len))
		return -1;

	if (!len && reflog_len) {
		/* allow "@{...}" to mean the current branch reflog */
		refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
	} else if (reflog_len)
		refs_found = dwim_log(str, len, sha1, &real_ref);
	else
		refs_found = dwim_ref(str, len, sha1, &real_ref);

	if (!refs_found)
		return -1;

	if (warn_ambiguous_refs && refs_found > 1)
		fprintf(stderr, warning, len, str);

	if (reflog_len) {
		int nth, i;
		unsigned long at_time;
		unsigned long co_time;
		int co_tz, co_cnt;

		/* Is it asking for N-th entry, or approxidate? */
		for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
			char ch = str[at+2+i];
			if ('0' <= ch && ch <= '9')
				nth = nth * 10 + ch - '0';
			else
				nth = -1;
		}
		if (0 <= nth)
			at_time = 0;
		else {
			char *tmp = xstrndup(str + at + 2, reflog_len);
			at_time = approxidate(tmp);
			free(tmp);
		}
		if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
				&co_time, &co_tz, &co_cnt)) {
			if (at_time)
				fprintf(stderr,
					"warning: Log for '%.*s' only goes "
					"back to %s.\n", len, str,
					show_date(co_time, co_tz, DATE_RFC2822));
			else
				fprintf(stderr,
					"warning: Log for '%.*s' only has "
					"%d entries.\n", len, str, co_cnt);
		}
	}

	free(real_ref);
	return 0;
}

static int get_sha1_1(const char *name, int len, unsigned char *sha1);

static int get_parent(const char *name, int len,
		      unsigned char *result, int idx)
{
	unsigned char sha1[20];
	int ret = get_sha1_1(name, len, 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) {
		hashcpy(result, commit->object.sha1);
		return 0;
	}
	p = commit->parents;
	while (p) {
		if (!--idx) {
			hashcpy(result, p->item->object.sha1);
			return 0;
		}
		p = p->next;
	}
	return -1;
}

static int get_nth_ancestor(const char *name, int len,
			    unsigned char *result, int generation)
{
	unsigned char sha1[20];
	struct commit *commit;
	int ret;

	ret = get_sha1_1(name, len, sha1);
	if (ret)
		return ret;
	commit = lookup_commit_reference(sha1);
	if (!commit)
		return -1;

	while (generation--) {
		if (parse_commit(commit) || !commit->parents)
			return -1;
		commit = commit->parents->item;
	}
	hashcpy(result, commit->object.sha1);
	return 0;
}

struct object *peel_to_type(const char *name, int namelen,
			    struct object *o, enum object_type expected_type)
{
	if (name && !namelen)
		namelen = strlen(name);
	if (!o) {
		unsigned char sha1[20];
		if (get_sha1_1(name, namelen, sha1))
			return NULL;
		o = parse_object(sha1);
	}
	while (1) {
		if (!o || (!o->parsed && !parse_object(o->sha1)))
			return NULL;
		if (o->type == expected_type)
			return o;
		if (o->type == OBJ_TAG)
			o = ((struct tag*) o)->tagged;
		else if (o->type == OBJ_COMMIT)
			o = &(((struct commit *) o)->tree->object);
		else {
			if (name)
				error("%.*s: expected %s type, but the object "
				      "dereferences to %s type",
				      namelen, name, typename(expected_type),
				      typename(o->type));
			return NULL;
		}
	}
}

static int peel_onion(const char *name, int len, unsigned char *sha1)
{
	unsigned char outer[20];
	const char *sp;
	unsigned int expected_type = 0;
	struct object *o;

	/*
	 * "ref^{type}" dereferences ref repeatedly until you cannot
	 * dereference anymore, or you get an object of given type,
	 * whichever comes first.  "ref^{}" means just dereference
	 * tags until you get a non-tag.  "ref^0" is a shorthand for
	 * "ref^{commit}".  "commit^{tree}" could be used to find the
	 * top-level tree of the given commit.
	 */
	if (len < 4 || name[len-1] != '}')
		return -1;

	for (sp = name + len - 1; name <= sp; sp--) {
		int ch = *sp;
		if (ch == '{' && name < sp && sp[-1] == '^')
			break;
	}
	if (sp <= name)
		return -1;

	sp++; /* beginning of type name, or closing brace for empty */
	if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
		expected_type = OBJ_COMMIT;
	else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
		expected_type = OBJ_TREE;
	else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
		expected_type = OBJ_BLOB;
	else if (sp[0] == '}')
		expected_type = OBJ_NONE;
	else
		return -1;

	if (get_sha1_1(name, sp - name - 2, outer))
		return -1;

	o = parse_object(outer);
	if (!o)
		return -1;
	if (!expected_type) {
		o = deref_tag(o, name, sp - name - 2);
		if (!o || (!o->parsed && !parse_object(o->sha1)))
			return -1;
		hashcpy(sha1, o->sha1);
	}
	else {
		/*
		 * At this point, the syntax look correct, so
		 * if we do not get the needed object, we should
		 * barf.
		 */
		o = peel_to_type(name, len, o, expected_type);
		if (o) {
			hashcpy(sha1, o->sha1);
			return 0;
		}
		return -1;
	}
	return 0;
}

static int get_describe_name(const char *name, int len, unsigned char *sha1)
{
	const char *cp;

	for (cp = name + len - 1; name + 2 <= cp; cp--) {
		char ch = *cp;
		if (hexval(ch) & ~0377) {
			/* We must be looking at g in "SOMETHING-g"
			 * for it to be describe output.
			 */
			if (ch == 'g' && cp[-1] == '-') {
				cp++;
				len -= cp - name;
				return get_short_sha1(cp, len, sha1, 1);
			}
		}
	}
	return -1;
}

static int get_sha1_1(const char *name, int len, unsigned char *sha1)
{
	int ret, has_suffix;
	const char *cp;

	/*
	 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
	 */
	has_suffix = 0;
	for (cp = name + len - 1; name <= cp; cp--) {
		int ch = *cp;
		if ('0' <= ch && ch <= '9')
			continue;
		if (ch == '~' || ch == '^')
			has_suffix = ch;
		break;
	}

	if (has_suffix) {
		int num = 0;
		int len1 = cp - name;
		cp++;
		while (cp < name + len)
			num = num * 10 + *cp++ - '0';
		if (!num && len1 == len - 1)
			num = 1;
		if (has_suffix == '^')
			return get_parent(name, len1, sha1, num);
		/* else if (has_suffix == '~') -- goes without saying */
		return get_nth_ancestor(name, len1, sha1, num);
	}

	ret = peel_onion(name, len, sha1);
	if (!ret)
		return 0;

	ret = get_sha1_basic(name, len, sha1);
	if (!ret)
		return 0;

	/* It could be describe output that is "SOMETHING-gXXXX" */
	ret = get_describe_name(name, len, sha1);
	if (!ret)
		return 0;

	return get_short_sha1(name, len, sha1, 0);
}

static int handle_one_ref(const char *path,
		const unsigned char *sha1, int flag, void *cb_data)
{
	struct commit_list **list = cb_data;
	struct object *object = parse_object(sha1);
	if (!object)
		return 0;
	if (object->type == OBJ_TAG) {
		object = deref_tag(object, path, strlen(path));
		if (!object)
			return 0;
	}
	if (object->type != OBJ_COMMIT)
		return 0;
	insert_by_date((struct commit *)object, list);
	return 0;
}

/*
 * This interprets names like ':/Initial revision of "git"' by searching
 * through history and returning the first commit whose message starts
 * with the given string.
 *
 * For future extension, ':/!' is reserved. If you want to match a message
 * beginning with a '!', you have to repeat the exclamation mark.
 */

#define ONELINE_SEEN (1u<<20)
static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
{
	struct commit_list *list = NULL, *backup = NULL, *l;
	int retval = -1;
	char *temp_commit_buffer = NULL;

	if (prefix[0] == '!') {
		if (prefix[1] != '!')
			die ("Invalid search pattern: %s", prefix);
		prefix++;
	}
	for_each_ref(handle_one_ref, &list);
	for (l = list; l; l = l->next)
		commit_list_insert(l->item, &backup);
	while (list) {
		char *p;
		struct commit *commit;
		enum object_type type;
		unsigned long size;

		commit = pop_most_recent_commit(&list, ONELINE_SEEN);
		if (!parse_object(commit->object.sha1))
			continue;
		free(temp_commit_buffer);
		if (commit->buffer)
			p = commit->buffer;
		else {
			p = read_sha1_file(commit->object.sha1, &type, &size);
			if (!p)
				continue;
			temp_commit_buffer = p;
		}
		if (!(p = strstr(p, "\n\n")))
			continue;
		if (!prefixcmp(p + 2, prefix)) {
			hashcpy(sha1, commit->object.sha1);
			retval = 0;
			break;
		}
	}
	free(temp_commit_buffer);
	free_commit_list(list);
	for (l = backup; l; l = l->next)
		clear_commit_marks(l->item, ONELINE_SEEN);
	return retval;
}

/*
 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
 * notably "xyz^" for "parent of xyz"
 */
int get_sha1(const char *name, unsigned char *sha1)
{
	unsigned unused;
	return get_sha1_with_mode(name, sha1, &unused);
}

int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
{
	int ret, bracket_depth;
	int namelen = strlen(name);
	const char *cp;

	*mode = S_IFINVALID;
	ret = get_sha1_1(name, namelen, sha1);
	if (!ret)
		return ret;
	/* sha1:path --> object name of path in ent sha1
	 * :path -> object name of path in index
	 * :[0-3]:path -> object name of path in index at stage
	 */
	if (name[0] == ':') {
		int stage = 0;
		struct cache_entry *ce;
		int pos;
		if (namelen > 2 && name[1] == '/')
			return get_sha1_oneline(name + 2, sha1);
		if (namelen < 3 ||
		    name[2] != ':' ||
		    name[1] < '0' || '3' < name[1])
			cp = name + 1;
		else {
			stage = name[1] - '0';
			cp = name + 3;
		}
		namelen = namelen - (cp - name);
		if (!active_cache)
			read_cache();
		pos = cache_name_pos(cp, namelen);
		if (pos < 0)
			pos = -pos - 1;
		while (pos < active_nr) {
			ce = active_cache[pos];
			if (ce_namelen(ce) != namelen ||
			    memcmp(ce->name, cp, namelen))
				break;
			if (ce_stage(ce) == stage) {
				hashcpy(sha1, ce->sha1);
				*mode = ce->ce_mode;
				return 0;
			}
			pos++;
		}
		return -1;
	}
	for (cp = name, bracket_depth = 0; *cp; cp++) {
		if (*cp == '{')
			bracket_depth++;
		else if (bracket_depth && *cp == '}')
			bracket_depth--;
		else if (!bracket_depth && *cp == ':')
			break;
	}
	if (*cp == ':') {
		unsigned char tree_sha1[20];
		if (!get_sha1_1(name, cp-name, tree_sha1))
			return get_tree_entry(tree_sha1, cp+1, sha1,
					      mode);
	}
	return ret;
}
Commit	Line	Data
9938af6a	1	#include "cache.h"
5385f52d	2	#include "tag.h"
9938af6a	3	#include "commit.h"
5385f52d JH	4	#include "tree.h"
5385f52d JH	5	#include "blob.h"
f3ab49db	6	#include "tree-walk.h"
d556fae2	7	#include "refs.h"
9938af6a JH	8
	9	static int find_short_object_filename(int len, const char name, unsigned char sha1)
	10	{
99a19b43	11	struct alternate_object_database *alt;
9938af6a	12	char hex[40];
99a19b43 JH	13	int found = 0;
	14	static struct alternate_object_database *fakeent;
	15
	16	if (!fakeent) {
	17	const char *objdir = get_object_directory();
	18	int objdir_len = strlen(objdir);
	19	int entlen = objdir_len + 43;
	20	fakeent = xmalloc(sizeof(*fakeent) + entlen);
	21	memcpy(fakeent->base, objdir, objdir_len);
	22	fakeent->name = fakeent->base + objdir_len + 1;
	23	fakeent->name[-1] = '/';
	24	}
	25	fakeent->next = alt_odb_list;
9938af6a	26
9938af6a	27	sprintf(hex, "%.2s", name);
99a19b43	28	for (alt = fakeent; alt && found < 2; alt = alt->next) {
9938af6a	29	struct dirent *de;
99a19b43 JH	30	DIR *dir;
	31	sprintf(alt->name, "%.2s/", name);
	32	dir = opendir(alt->base);
	33	if (!dir)
	34	continue;
9938af6a JH	35	while ((de = readdir(dir)) != NULL) {
	36	if (strlen(de->d_name) != 38)
	37	continue;
99a19b43	38	if (memcmp(de->d_name, name + 2, len - 2))
9938af6a	39	continue;
99a19b43 JH	40	if (!found) {
	41	memcpy(hex + 2, de->d_name, 38);
	42	found++;
	43	}
	44	else if (memcmp(hex + 2, de->d_name, 38)) {
	45	found = 2;
9938af6a	46	break;
99a19b43	47	}
9938af6a JH	48	}
	49	closedir(dir);
	50	}
	51	if (found == 1)
	52	return get_sha1_hex(hex, sha1) == 0;
99a19b43	53	return found;
9938af6a JH	54	}
	55
	56	static int match_sha(unsigned len, const unsigned char a, const unsigned char b)
	57	{
	58	do {
	59	if (a != b)
	60	return 0;
	61	a++;
	62	b++;
	63	len -= 2;
	64	} while (len > 1);
	65	if (len)
	66	if ((a ^ b) & 0xf0)
	67	return 0;
	68	return 1;
	69	}
	70
	71	static int find_short_packed_object(int len, const unsigned char match, unsigned char sha1)
	72	{
	73	struct packed_git *p;
d72308e0	74	const unsigned char *found_sha1 = NULL;
99a19b43	75	int found = 0;
9938af6a JH	76
9938af6a JH	77	prepare_packed_git();
99a19b43	78	for (p = packed_git; p && found < 2; p = p->next) {
1055880e JB	79	uint32_t num, last;
	80	uint32_t first = 0;
	81	open_pack_index(p);
	82	num = p->num_objects;
	83	last = num;
9938af6a	84	while (first < last) {
326bf396	85	uint32_t mid = (first + last) / 2;
d72308e0	86	const unsigned char *now;
9938af6a JH	87	int cmp;
9938af6a JH	88
d72308e0	89	now = nth_packed_object_sha1(p, mid);
a89fccd2	90	cmp = hashcmp(match, now);
9938af6a JH	91	if (!cmp) {
	92	first = mid;
	93	break;
	94	}
	95	if (cmp > 0) {
	96	first = mid+1;
	97	continue;
	98	}
	99	last = mid;
	100	}
	101	if (first < num) {
d72308e0 NP	102	const unsigned char now, next;
d72308e0 NP	103	now = nth_packed_object_sha1(p, first);
9938af6a	104	if (match_sha(len, match, now)) {
d72308e0 NP	105	next = nth_packed_object_sha1(p, first+1);
d72308e0 NP	106	if (!next\|\| !match_sha(len, match, next)) {
0bc45890 JH	107	/* unique within this pack */
0bc45890 JH	108	if (!found) {
d72308e0	109	found_sha1 = now;
0bc45890 JH	110	found++;
0bc45890 JH	111	}
a89fccd2	112	else if (hashcmp(found_sha1, now)) {
0bc45890 JH	113	found = 2;
	114	break;
	115	}
99a19b43	116	}
0bc45890 JH	117	else {
0bc45890 JH	118	/* not even unique within this pack */
99a19b43 JH	119	found = 2;
99a19b43 JH	120	break;
9938af6a JH	121	}
	122	}
	123	}
	124	}
99a19b43	125	if (found == 1)
e702496e	126	hashcpy(sha1, found_sha1);
99a19b43 JH	127	return found;
	128	}
	129
013f276e JH	130	#define SHORT_NAME_NOT_FOUND (-1)
	131	#define SHORT_NAME_AMBIGUOUS (-2)
	132
99a19b43 JH	133	static int find_unique_short_object(int len, char *canonical,
	134	unsigned char res, unsigned char sha1)
	135	{
	136	int has_unpacked, has_packed;
	137	unsigned char unpacked_sha1[20], packed_sha1[20];
	138
693d2bc6	139	prepare_alt_odb();
99a19b43 JH	140	has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
	141	has_packed = find_short_packed_object(len, res, packed_sha1);
	142	if (!has_unpacked && !has_packed)
013f276e	143	return SHORT_NAME_NOT_FOUND;
99a19b43	144	if (1 < has_unpacked \|\| 1 < has_packed)
013f276e	145	return SHORT_NAME_AMBIGUOUS;
99a19b43	146	if (has_unpacked != has_packed) {
e702496e	147	hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
99a19b43 JH	148	return 0;
	149	}
	150	/* Both have unique ones -- do they match? */
a89fccd2	151	if (hashcmp(packed_sha1, unpacked_sha1))
e974c9ab	152	return SHORT_NAME_AMBIGUOUS;
e702496e	153	hashcpy(sha1, packed_sha1);
9938af6a JH	154	return 0;
	155	}
	156
013f276e JH	157	static int get_short_sha1(const char name, int len, unsigned char sha1,
013f276e JH	158	int quietly)
9938af6a	159	{
013f276e	160	int i, status;
9938af6a JH	161	char canonical[40];
	162	unsigned char res[20];
	163
8a83157e	164	if (len < MINIMUM_ABBREV \|\| len > 40)
af61c6e0	165	return -1;
a8e0d16d	166	hashclr(res);
9938af6a	167	memset(canonical, 'x', 40);
af61c6e0	168	for (i = 0; i < len ;i++) {
9938af6a JH	169	unsigned char c = name[i];
9938af6a JH	170	unsigned char val;
9938af6a JH	171	if (c >= '0' && c <= '9')
	172	val = c - '0';
	173	else if (c >= 'a' && c <= 'f')
	174	val = c - 'a' + 10;
	175	else if (c >= 'A' && c <='F') {
	176	val = c - 'A' + 10;
	177	c -= 'A' - 'a';
	178	}
	179	else
	180	return -1;
	181	canonical[i] = c;
	182	if (!(i & 1))
	183	val <<= 4;
	184	res[i >> 1] \|= val;
	185	}
99a19b43	186
013f276e JH	187	status = find_unique_short_object(i, canonical, res, sha1);
	188	if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
	189	return error("short SHA1 %.*s is ambiguous.", len, canonical);
	190	return status;
	191	}
	192
	193	const char find_unique_abbrev(const unsigned char sha1, int len)
	194	{
b66fde9a	195	int status, exists;
013f276e	196	static char hex[41];
47dd0d59	197
b66fde9a	198	exists = has_sha1_file(sha1);
013f276e	199	memcpy(hex, sha1_to_hex(sha1), 40);
02c5cba2	200	if (len == 40 \|\| !len)
47dd0d59	201	return hex;
013f276e JH	202	while (len < 40) {
	203	unsigned char sha1_ret[20];
	204	status = get_short_sha1(hex, len, sha1_ret, 1);
b66fde9a JH	205	if (exists
	206	? !status
	207	: status == SHORT_NAME_NOT_FOUND) {
013f276e JH	208	hex[len] = 0;
	209	return hex;
	210	}
013f276e JH	211	len++;
013f276e JH	212	}
b66fde9a	213	return hex;
9938af6a JH	214	}
9938af6a JH	215
6677c466	216	static int ambiguous_path(const char *path, int len)
af13cdf2 LT	217	{
af13cdf2 LT	218	int slash = 1;
6677c466	219	int cnt;
af13cdf2	220
6677c466	221	for (cnt = 0; cnt < len; cnt++) {
af13cdf2 LT	222	switch (*path++) {
	223	case '\0':
	224	break;
	225	case '/':
	226	if (slash)
	227	break;
	228	slash = 1;
	229	continue;
	230	case '.':
	231	continue;
	232	default:
	233	slash = 0;
	234	continue;
	235	}
c054d64e	236	break;
af13cdf2	237	}
6677c466	238	return slash;
af13cdf2 LT	239	}
af13cdf2 LT	240
e86eb666	241	int dwim_ref(const char str, int len, unsigned char sha1, char **ref)
9938af6a	242	{
e86eb666 JH	243	const char *p, r;
	244	int refs_found = 0;
	245
	246	*ref = NULL;
79803322	247	for (p = ref_rev_parse_rules; *p; p++) {
e86eb666 JH	248	unsigned char sha1_from_ref[20];
	249	unsigned char *this_result;
	250
	251	this_result = refs_found ? sha1_from_ref : sha1;
	252	r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
	253	if (r) {
	254	if (!refs_found++)
	255	*ref = xstrdup(r);
	256	if (!warn_ambiguous_refs)
	257	break;
	258	}
	259	}
	260	return refs_found;
	261	}
	262
eb3a4822	263	int dwim_log(const char str, int len, unsigned char sha1, char **log)
f2eba66d NP	264	{
	265	const char **p;
	266	int logs_found = 0;
	267
	268	*log = NULL;
79803322	269	for (p = ref_rev_parse_rules; *p; p++) {
f2eba66d	270	struct stat st;
40facde0 JH	271	unsigned char hash[20];
	272	char path[PATH_MAX];
	273	const char ref, it;
	274
	275	strcpy(path, mkpath(*p, len, str));
	276	ref = resolve_ref(path, hash, 0, NULL);
	277	if (!ref)
	278	continue;
f2eba66d	279	if (!stat(git_path("logs/%s", path), &st) &&
40facde0 JH	280	S_ISREG(st.st_mode))
	281	it = path;
	282	else if (strcmp(ref, path) &&
	283	!stat(git_path("logs/%s", ref), &st) &&
	284	S_ISREG(st.st_mode))
	285	it = ref;
	286	else
	287	continue;
	288	if (!logs_found++) {
	289	*log = xstrdup(it);
	290	hashcpy(sha1, hash);
f2eba66d	291	}
40facde0 JH	292	if (!warn_ambiguous_refs)
40facde0 JH	293	break;
f2eba66d NP	294	}
	295	return logs_found;
	296	}
	297
e86eb666 JH	298	static int get_sha1_basic(const char str, int len, unsigned char sha1)
e86eb666 JH	299	{
d556fae2	300	static const char warning = "warning: refname '%.s' is ambiguous.\n";
ed378ec7	301	char *real_ref = NULL;
ab2a1a32 JH	302	int refs_found = 0;
ab2a1a32 JH	303	int at, reflog_len;
9938af6a	304
3c3852e3	305	if (len == 40 && !get_sha1_hex(str, sha1))
9938af6a JH	306	return 0;
9938af6a JH	307
ab2a1a32	308	/* basic@{time or number} format to query ref-log */
694500ed	309	reflog_len = at = 0;
ab2a1a32	310	if (str[len-1] == '}') {
11cf8801	311	for (at = 0; at < len - 1; at++) {
ab2a1a32 JH	312	if (str[at] == '@' && str[at+1] == '{') {
	313	reflog_len = (len-1) - (at+2);
	314	len = at;
	315	break;
	316	}
d556fae2 SP	317	}
	318	}
	319
af13cdf2	320	/* Accept only unambiguous ref paths. */
11cf8801	321	if (len && ambiguous_path(str, len))
af13cdf2 LT	322	return -1;
af13cdf2 LT	323
11cf8801 NP	324	if (!len && reflog_len) {
	325	/* allow "@{...}" to mean the current branch reflog */
	326	refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
f2eba66d NP	327	} else if (reflog_len)
	328	refs_found = dwim_log(str, len, sha1, &real_ref);
	329	else
11cf8801	330	refs_found = dwim_ref(str, len, sha1, &real_ref);
d556fae2 SP	331
	332	if (!refs_found)
	333	return -1;
	334
	335	if (warn_ambiguous_refs && refs_found > 1)
	336	fprintf(stderr, warning, len, str);
	337
ab2a1a32	338	if (reflog_len) {
ab2a1a32 JH	339	int nth, i;
ab2a1a32 JH	340	unsigned long at_time;
16d7cc90 JH	341	unsigned long co_time;
	342	int co_tz, co_cnt;
	343
fe558516	344	/* Is it asking for N-th entry, or approxidate? */
ab2a1a32 JH	345	for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
	346	char ch = str[at+2+i];
	347	if ('0' <= ch && ch <= '9')
	348	nth = nth * 10 + ch - '0';
	349	else
	350	nth = -1;
	351	}
	352	if (0 <= nth)
	353	at_time = 0;
861f00e3 JK	354	else {
	355	char *tmp = xstrndup(str + at + 2, reflog_len);
	356	at_time = approxidate(tmp);
	357	free(tmp);
	358	}
16d7cc90 JH	359	if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
	360	&co_time, &co_tz, &co_cnt)) {
	361	if (at_time)
	362	fprintf(stderr,
	363	"warning: Log for '%.*s' only goes "
	364	"back to %s.\n", len, str,
73013afd	365	show_date(co_time, co_tz, DATE_RFC2822));
16d7cc90 JH	366	else
	367	fprintf(stderr,
	368	"warning: Log for '%.*s' only has "
	369	"%d entries.\n", len, str, co_cnt);
	370	}
d556fae2 SP	371	}
d556fae2 SP	372
ed378ec7	373	free(real_ref);
d556fae2	374	return 0;
9938af6a JH	375	}
	376
	377	static int get_sha1_1(const char name, int len, unsigned char sha1);
	378
	379	static int get_parent(const char *name, int len,
	380	unsigned char *result, int idx)
	381	{
	382	unsigned char sha1[20];
	383	int ret = get_sha1_1(name, len, sha1);
	384	struct commit *commit;
	385	struct commit_list *p;
	386
	387	if (ret)
	388	return ret;
	389	commit = lookup_commit_reference(sha1);
	390	if (!commit)
	391	return -1;
	392	if (parse_commit(commit))
	393	return -1;
	394	if (!idx) {
e702496e	395	hashcpy(result, commit->object.sha1);
9938af6a JH	396	return 0;
	397	}
	398	p = commit->parents;
	399	while (p) {
	400	if (!--idx) {
e702496e	401	hashcpy(result, p->item->object.sha1);
9938af6a JH	402	return 0;
	403	}
	404	p = p->next;
	405	}
	406	return -1;
	407	}
	408
4f7599ac JH	409	static int get_nth_ancestor(const char *name, int len,
	410	unsigned char *result, int generation)
	411	{
	412	unsigned char sha1[20];
621ff675 LT	413	struct commit *commit;
	414	int ret;
	415
	416	ret = get_sha1_1(name, len, sha1);
4f7599ac JH	417	if (ret)
4f7599ac JH	418	return ret;
621ff675 LT	419	commit = lookup_commit_reference(sha1);
	420	if (!commit)
	421	return -1;
4f7599ac JH	422
4f7599ac JH	423	while (generation--) {
621ff675	424	if (parse_commit(commit) \|\| !commit->parents)
4f7599ac	425	return -1;
621ff675	426	commit = commit->parents->item;
4f7599ac	427	}
621ff675	428	hashcpy(result, commit->object.sha1);
4f7599ac JH	429	return 0;
	430	}
	431
81776315 JH	432	struct object peel_to_type(const char name, int namelen,
	433	struct object *o, enum object_type expected_type)
	434	{
	435	if (name && !namelen)
	436	namelen = strlen(name);
	437	if (!o) {
	438	unsigned char sha1[20];
	439	if (get_sha1_1(name, namelen, sha1))
	440	return NULL;
	441	o = parse_object(sha1);
	442	}
	443	while (1) {
	444	if (!o \|\| (!o->parsed && !parse_object(o->sha1)))
	445	return NULL;
	446	if (o->type == expected_type)
	447	return o;
	448	if (o->type == OBJ_TAG)
	449	o = ((struct tag*) o)->tagged;
	450	else if (o->type == OBJ_COMMIT)
	451	o = &(((struct commit *) o)->tree->object);
	452	else {
	453	if (name)
	454	error("%.*s: expected %s type, but the object "
	455	"dereferences to %s type",
	456	namelen, name, typename(expected_type),
	457	typename(o->type));
	458	return NULL;
	459	}
	460	}
	461	}
	462
5385f52d JH	463	static int peel_onion(const char name, int len, unsigned char sha1)
	464	{
	465	unsigned char outer[20];
	466	const char *sp;
885a86ab	467	unsigned int expected_type = 0;
5385f52d JH	468	struct object *o;
	469
	470	/*
	471	* "ref^{type}" dereferences ref repeatedly until you cannot
	472	* dereference anymore, or you get an object of given type,
	473	* whichever comes first. "ref^{}" means just dereference
	474	* tags until you get a non-tag. "ref^0" is a shorthand for
	475	* "ref^{commit}". "commit^{tree}" could be used to find the
	476	* top-level tree of the given commit.
	477	*/
	478	if (len < 4 \|\| name[len-1] != '}')
	479	return -1;
	480
	481	for (sp = name + len - 1; name <= sp; sp--) {
	482	int ch = *sp;
	483	if (ch == '{' && name < sp && sp[-1] == '^')
	484	break;
	485	}
	486	if (sp <= name)
	487	return -1;
	488
	489	sp++; /* beginning of type name, or closing brace for empty */
	490	if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
1974632c	491	expected_type = OBJ_COMMIT;
5385f52d	492	else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
1974632c	493	expected_type = OBJ_TREE;
5385f52d	494	else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
1974632c	495	expected_type = OBJ_BLOB;
5385f52d	496	else if (sp[0] == '}')
1974632c	497	expected_type = OBJ_NONE;
5385f52d JH	498	else
	499	return -1;
	500
	501	if (get_sha1_1(name, sp - name - 2, outer))
	502	return -1;
	503
	504	o = parse_object(outer);
	505	if (!o)
	506	return -1;
885a86ab	507	if (!expected_type) {
9534f40b	508	o = deref_tag(o, name, sp - name - 2);
6e1c6c10 JH	509	if (!o \|\| (!o->parsed && !parse_object(o->sha1)))
6e1c6c10 JH	510	return -1;
e702496e	511	hashcpy(sha1, o->sha1);
5385f52d JH	512	}
5385f52d JH	513	else {
81776315 JH	514	/*
81776315 JH	515	* At this point, the syntax look correct, so
5385f52d JH	516	* if we do not get the needed object, we should
	517	* barf.
	518	*/
81776315 JH	519	o = peel_to_type(name, len, o, expected_type);
	520	if (o) {
	521	hashcpy(sha1, o->sha1);
	522	return 0;
5385f52d	523	}
81776315	524	return -1;
5385f52d JH	525	}
	526	return 0;
	527	}
	528
7dd45e15 JH	529	static int get_describe_name(const char name, int len, unsigned char sha1)
	530	{
	531	const char *cp;
	532
	533	for (cp = name + len - 1; name + 2 <= cp; cp--) {
	534	char ch = *cp;
	535	if (hexval(ch) & ~0377) {
	536	/* We must be looking at g in "SOMETHING-g"
	537	* for it to be describe output.
	538	*/
	539	if (ch == 'g' && cp[-1] == '-') {
	540	cp++;
	541	len -= cp - name;
	542	return get_short_sha1(cp, len, sha1, 1);
	543	}
	544	}
	545	}
	546	return -1;
	547	}
	548
9938af6a JH	549	static int get_sha1_1(const char name, int len, unsigned char sha1)
9938af6a JH	550	{
0601dbe1	551	int ret, has_suffix;
4f7599ac	552	const char *cp;
9938af6a	553
621ff675 LT	554	/*
621ff675 LT	555	* "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
4f7599ac	556	*/
0601dbe1	557	has_suffix = 0;
4f7599ac JH	558	for (cp = name + len - 1; name <= cp; cp--) {
	559	int ch = *cp;
	560	if ('0' <= ch && ch <= '9')
	561	continue;
0601dbe1 JH	562	if (ch == '~' \|\| ch == '^')
0601dbe1 JH	563	has_suffix = ch;
4f7599ac JH	564	break;
4f7599ac JH	565	}
0601dbe1 JH	566
	567	if (has_suffix) {
	568	int num = 0;
4f7599ac JH	569	int len1 = cp - name;
	570	cp++;
	571	while (cp < name + len)
0601dbe1	572	num = num * 10 + *cp++ - '0';
621ff675 LT	573	if (!num && len1 == len - 1)
	574	num = 1;
	575	if (has_suffix == '^')
0601dbe1	576	return get_parent(name, len1, sha1, num);
0601dbe1 JH	577	/* else if (has_suffix == '~') -- goes without saying */
0601dbe1 JH	578	return get_nth_ancestor(name, len1, sha1, num);
4f7599ac JH	579	}
4f7599ac JH	580
5385f52d JH	581	ret = peel_onion(name, len, sha1);
	582	if (!ret)
	583	return 0;
	584
9938af6a JH	585	ret = get_sha1_basic(name, len, sha1);
	586	if (!ret)
	587	return 0;
7dd45e15 JH	588
	589	/* It could be describe output that is "SOMETHING-gXXXX" */
	590	ret = get_describe_name(name, len, sha1);
	591	if (!ret)
	592	return 0;
	593
013f276e	594	return get_short_sha1(name, len, sha1, 0);
9938af6a JH	595	}
9938af6a JH	596
28a4d940 JS	597	static int handle_one_ref(const char *path,
	598	const unsigned char sha1, int flag, void cb_data)
	599	{
	600	struct commit_list **list = cb_data;
	601	struct object *object = parse_object(sha1);
	602	if (!object)
	603	return 0;
affeef12	604	if (object->type == OBJ_TAG) {
28a4d940	605	object = deref_tag(object, path, strlen(path));
affeef12 MK	606	if (!object)
	607	return 0;
	608	}
28a4d940 JS	609	if (object->type != OBJ_COMMIT)
	610	return 0;
	611	insert_by_date((struct commit *)object, list);
	612	return 0;
	613	}
	614
	615	/*
	616	* This interprets names like ':/Initial revision of "git"' by searching
	617	* through history and returning the first commit whose message starts
	618	* with the given string.
	619	*
	620	* For future extension, ':/!' is reserved. If you want to match a message
	621	* beginning with a '!', you have to repeat the exclamation mark.
	622	*/
	623
	624	#define ONELINE_SEEN (1u<<20)
1358e7d6	625	static int get_sha1_oneline(const char prefix, unsigned char sha1)
28a4d940 JS	626	{
28a4d940 JS	627	struct commit_list list = NULL, backup = NULL, *l;
1358e7d6	628	int retval = -1;
364d3e65	629	char *temp_commit_buffer = NULL;
28a4d940 JS	630
	631	if (prefix[0] == '!') {
	632	if (prefix[1] != '!')
	633	die ("Invalid search pattern: %s", prefix);
	634	prefix++;
	635	}
28a4d940 JS	636	for_each_ref(handle_one_ref, &list);
	637	for (l = list; l; l = l->next)
	638	commit_list_insert(l->item, &backup);
ed8ad7e2	639	while (list) {
28a4d940	640	char *p;
1358e7d6	641	struct commit *commit;
364d3e65 JS	642	enum object_type type;
364d3e65 JS	643	unsigned long size;
ed8ad7e2 JM	644
ed8ad7e2 JM	645	commit = pop_most_recent_commit(&list, ONELINE_SEEN);
283cdbcf MK	646	if (!parse_object(commit->object.sha1))
283cdbcf MK	647	continue;
8e0f7003	648	free(temp_commit_buffer);
364d3e65 JS	649	if (commit->buffer)
	650	p = commit->buffer;
	651	else {
	652	p = read_sha1_file(commit->object.sha1, &type, &size);
	653	if (!p)
	654	continue;
	655	temp_commit_buffer = p;
	656	}
	657	if (!(p = strstr(p, "\n\n")))
28a4d940 JS	658	continue;
	659	if (!prefixcmp(p + 2, prefix)) {
	660	hashcpy(sha1, commit->object.sha1);
1358e7d6	661	retval = 0;
28a4d940 JS	662	break;
	663	}
	664	}
8e0f7003	665	free(temp_commit_buffer);
28a4d940 JS	666	free_commit_list(list);
	667	for (l = backup; l; l = l->next)
	668	clear_commit_marks(l->item, ONELINE_SEEN);
1358e7d6	669	return retval;
28a4d940 JS	670	}
28a4d940 JS	671
9938af6a JH	672	/*
	673	* This is like "get_sha1_basic()", except it allows "sha1 expressions",
	674	* notably "xyz^" for "parent of xyz"
	675	*/
	676	int get_sha1(const char name, unsigned char sha1)
	677	{
041a7308	678	unsigned unused;
a0cd87a5 MK	679	return get_sha1_with_mode(name, sha1, &unused);
	680	}
	681
	682	int get_sha1_with_mode(const char name, unsigned char sha1, unsigned *mode)
	683	{
	684	int ret, bracket_depth;
73b0e5af JH	685	int namelen = strlen(name);
73b0e5af JH	686	const char *cp;
5119602a	687
a0cd87a5	688	*mode = S_IFINVALID;
73b0e5af JH	689	ret = get_sha1_1(name, namelen, sha1);
	690	if (!ret)
	691	return ret;
	692	/* sha1:path --> object name of path in ent sha1
	693	* :path -> object name of path in index
	694	* :[0-3]:path -> object name of path in index at stage
	695	*/
	696	if (name[0] == ':') {
	697	int stage = 0;
	698	struct cache_entry *ce;
	699	int pos;
28a4d940 JS	700	if (namelen > 2 && name[1] == '/')
28a4d940 JS	701	return get_sha1_oneline(name + 2, sha1);
73b0e5af JH	702	if (namelen < 3 \|\|
	703	name[2] != ':' \|\|
	704	name[1] < '0' \|\| '3' < name[1])
	705	cp = name + 1;
	706	else {
	707	stage = name[1] - '0';
	708	cp = name + 3;
5119602a	709	}
73b0e5af JH	710	namelen = namelen - (cp - name);
	711	if (!active_cache)
	712	read_cache();
73b0e5af JH	713	pos = cache_name_pos(cp, namelen);
	714	if (pos < 0)
	715	pos = -pos - 1;
	716	while (pos < active_nr) {
	717	ce = active_cache[pos];
	718	if (ce_namelen(ce) != namelen \|\|
	719	memcmp(ce->name, cp, namelen))
	720	break;
	721	if (ce_stage(ce) == stage) {
e702496e	722	hashcpy(sha1, ce->sha1);
7a51ed66	723	*mode = ce->ce_mode;
73b0e5af JH	724	return 0;
73b0e5af JH	725	}
e7cef45f	726	pos++;
73b0e5af JH	727	}
	728	return -1;
	729	}
cce91a2c SP	730	for (cp = name, bracket_depth = 0; *cp; cp++) {
	731	if (*cp == '{')
	732	bracket_depth++;
	733	else if (bracket_depth && *cp == '}')
	734	bracket_depth--;
	735	else if (!bracket_depth && *cp == ':')
	736	break;
	737	}
	738	if (*cp == ':') {
73b0e5af JH	739	unsigned char tree_sha1[20];
	740	if (!get_sha1_1(name, cp-name, tree_sha1))
	741	return get_tree_entry(tree_sha1, cp+1, sha1,
a0cd87a5	742	mode);
5119602a LT	743	}
5119602a LT	744	return ret;
9938af6a	745	}