sha1_name.c: teach lookup context to get_sha1_with_context()
[git/git.git] / sha1_name.c
CommitLineData
9938af6a 1#include "cache.h"
5385f52d 2#include "tag.h"
9938af6a 3#include "commit.h"
5385f52d
JH
4#include "tree.h"
5#include "blob.h"
f3ab49db 6#include "tree-walk.h"
d556fae2 7#include "refs.h"
28fb8438 8#include "remote.h"
9938af6a 9
32574b68
NTND
10static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
11
a78fafe7
JH
12typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
13
14struct disambiguate_state {
15 disambiguate_hint_fn fn;
16 void *cb_data;
17 unsigned char candidate[20];
18 unsigned candidate_exists:1;
19 unsigned candidate_checked:1;
20 unsigned candidate_ok:1;
21 unsigned disambiguate_fn_used:1;
22 unsigned ambiguous:1;
23};
24
25static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
26{
27 if (!ds->candidate_exists) {
28 /* this is the first candidate */
29 hashcpy(ds->candidate, current);
30 ds->candidate_exists = 1;
31 return;
32 } else if (!hashcmp(ds->candidate, current)) {
33 /* the same as what we already have seen */
34 return;
35 }
36
37 if (!ds->fn) {
38 /* cannot disambiguate between ds->candidate and current */
39 ds->ambiguous = 1;
40 return;
41 }
42
43 if (!ds->candidate_checked) {
44 ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
45 ds->disambiguate_fn_used = 1;
46 ds->candidate_checked = 1;
47 }
48
49 if (!ds->candidate_ok) {
50 /* discard the candidate; we know it does not satisify fn */
51 hashcpy(ds->candidate, current);
52 ds->candidate_checked = 0;
53 return;
54 }
55
56 /* if we reach this point, we know ds->candidate satisfies fn */
57 if (ds->fn(current, ds->cb_data)) {
58 /*
59 * if both current and candidate satisfy fn, we cannot
60 * disambiguate.
61 */
62 ds->candidate_ok = 0;
63 ds->ambiguous = 1;
64 }
65
66 /* otherwise, current can be discarded and candidate is still good */
67}
68
69static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
9938af6a 70{
99a19b43 71 struct alternate_object_database *alt;
9938af6a 72 char hex[40];
99a19b43
JH
73 static struct alternate_object_database *fakeent;
74
75 if (!fakeent) {
274ac009
JH
76 /*
77 * Create a "fake" alternate object database that
78 * points to our own object database, to make it
79 * easier to get a temporary working space in
80 * alt->name/alt->base while iterating over the
81 * object databases including our own.
82 */
99a19b43
JH
83 const char *objdir = get_object_directory();
84 int objdir_len = strlen(objdir);
85 int entlen = objdir_len + 43;
86 fakeent = xmalloc(sizeof(*fakeent) + entlen);
87 memcpy(fakeent->base, objdir, objdir_len);
88 fakeent->name = fakeent->base + objdir_len + 1;
89 fakeent->name[-1] = '/';
90 }
91 fakeent->next = alt_odb_list;
9938af6a 92
1703f9aa 93 sprintf(hex, "%.2s", hex_pfx);
a78fafe7 94 for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
9938af6a 95 struct dirent *de;
99a19b43 96 DIR *dir;
1703f9aa 97 sprintf(alt->name, "%.2s/", hex_pfx);
99a19b43
JH
98 dir = opendir(alt->base);
99 if (!dir)
100 continue;
a78fafe7
JH
101
102 while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
103 unsigned char sha1[20];
104
9938af6a
JH
105 if (strlen(de->d_name) != 38)
106 continue;
1703f9aa 107 if (memcmp(de->d_name, hex_pfx + 2, len - 2))
9938af6a 108 continue;
a78fafe7
JH
109 memcpy(hex + 2, de->d_name, 38);
110 if (!get_sha1_hex(hex, sha1))
111 update_candidates(ds, sha1);
9938af6a
JH
112 }
113 closedir(dir);
114 }
9938af6a
JH
115}
116
117static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
118{
119 do {
120 if (*a != *b)
121 return 0;
122 a++;
123 b++;
124 len -= 2;
125 } while (len > 1);
126 if (len)
127 if ((*a ^ *b) & 0xf0)
128 return 0;
129 return 1;
130}
131
a78fafe7 132static void unique_in_pack(int len,
1703f9aa 133 const unsigned char *bin_pfx,
a78fafe7
JH
134 struct packed_git *p,
135 struct disambiguate_state *ds)
f703e6ea
JH
136{
137 uint32_t num, last, i, first = 0;
138 const unsigned char *current = NULL;
139
140 open_pack_index(p);
141 num = p->num_objects;
142 last = num;
143 while (first < last) {
144 uint32_t mid = (first + last) / 2;
145 const unsigned char *current;
146 int cmp;
147
148 current = nth_packed_object_sha1(p, mid);
1703f9aa 149 cmp = hashcmp(bin_pfx, current);
f703e6ea
JH
150 if (!cmp) {
151 first = mid;
152 break;
153 }
154 if (cmp > 0) {
155 first = mid+1;
156 continue;
157 }
158 last = mid;
159 }
160
161 /*
162 * At this point, "first" is the location of the lowest object
1703f9aa 163 * with an object name that could match "bin_pfx". See if we have
f703e6ea
JH
164 * 0, 1 or more objects that actually match(es).
165 */
a78fafe7
JH
166 for (i = first; i < num && !ds->ambiguous; i++) {
167 current = nth_packed_object_sha1(p, i);
1703f9aa 168 if (!match_sha(len, bin_pfx, current))
f703e6ea 169 break;
a78fafe7 170 update_candidates(ds, current);
f703e6ea 171 }
f703e6ea
JH
172}
173
a78fafe7
JH
174static void find_short_packed_object(int len, const unsigned char *bin_pfx,
175 struct disambiguate_state *ds)
9938af6a
JH
176{
177 struct packed_git *p;
178
179 prepare_packed_git();
a78fafe7
JH
180 for (p = packed_git; p && !ds->ambiguous; p = p->next)
181 unique_in_pack(len, bin_pfx, p, ds);
99a19b43
JH
182}
183
013f276e
JH
184#define SHORT_NAME_NOT_FOUND (-1)
185#define SHORT_NAME_AMBIGUOUS (-2)
186
a78fafe7
JH
187static int finish_object_disambiguation(struct disambiguate_state *ds,
188 unsigned char *sha1)
99a19b43 189{
a78fafe7
JH
190 if (ds->ambiguous)
191 return SHORT_NAME_AMBIGUOUS;
99a19b43 192
a78fafe7 193 if (!ds->candidate_exists)
013f276e 194 return SHORT_NAME_NOT_FOUND;
a78fafe7
JH
195
196 if (!ds->candidate_checked)
197 /*
198 * If this is the only candidate, there is no point
199 * calling the disambiguation hint callback.
200 *
201 * On the other hand, if the current candidate
202 * replaced an earlier candidate that did _not_ pass
203 * the disambiguation hint callback, then we do have
204 * more than one objects that match the short name
205 * given, so we should make sure this one matches;
206 * otherwise, if we discovered this one and the one
207 * that we previously discarded in the reverse order,
208 * we would end up showing different results in the
209 * same repository!
210 */
211 ds->candidate_ok = (!ds->disambiguate_fn_used ||
212 ds->fn(ds->candidate, ds->cb_data));
213
214 if (!ds->candidate_ok)
c005e986 215 return SHORT_NAME_AMBIGUOUS;
a78fafe7
JH
216
217 hashcpy(sha1, ds->candidate);
9938af6a
JH
218 return 0;
219}
220
aa1dec9e
JH
221static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
222{
223 int kind = sha1_object_info(sha1, NULL);
224 return kind == OBJ_COMMIT;
225}
226
e2643617
JH
227static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
228{
229 struct object *obj;
230 int kind;
231
232 kind = sha1_object_info(sha1, NULL);
233 if (kind == OBJ_COMMIT)
234 return 1;
235 if (kind != OBJ_TAG)
236 return 0;
237
238 /* We need to do this the hard way... */
239 obj = deref_tag(lookup_object(sha1), NULL, 0);
240 if (obj && obj->type == OBJ_COMMIT)
241 return 1;
242 return 0;
243}
244
013f276e 245static int get_short_sha1(const char *name, int len, unsigned char *sha1,
37c00e55 246 unsigned flags)
9938af6a 247{
013f276e 248 int i, status;
1703f9aa
JH
249 char hex_pfx[40];
250 unsigned char bin_pfx[20];
a78fafe7 251 struct disambiguate_state ds;
37c00e55 252 int quietly = !!(flags & GET_SHA1_QUIETLY);
9938af6a 253
8a83157e 254 if (len < MINIMUM_ABBREV || len > 40)
af61c6e0 255 return -1;
1703f9aa
JH
256 hashclr(bin_pfx);
257 memset(hex_pfx, 'x', 40);
af61c6e0 258 for (i = 0; i < len ;i++) {
9938af6a
JH
259 unsigned char c = name[i];
260 unsigned char val;
9938af6a
JH
261 if (c >= '0' && c <= '9')
262 val = c - '0';
263 else if (c >= 'a' && c <= 'f')
264 val = c - 'a' + 10;
265 else if (c >= 'A' && c <='F') {
266 val = c - 'A' + 10;
267 c -= 'A' - 'a';
268 }
269 else
270 return -1;
1703f9aa 271 hex_pfx[i] = c;
9938af6a
JH
272 if (!(i & 1))
273 val <<= 4;
1703f9aa 274 bin_pfx[i >> 1] |= val;
9938af6a 275 }
99a19b43 276
a78fafe7
JH
277 prepare_alt_odb();
278
279 memset(&ds, 0, sizeof(ds));
aa1dec9e
JH
280 if (flags & GET_SHA1_COMMIT)
281 ds.fn = disambiguate_commit_only;
e2643617
JH
282 else if (flags & GET_SHA1_COMMITTISH)
283 ds.fn = disambiguate_committish_only;
aa1dec9e 284
a78fafe7
JH
285 find_short_object_filename(len, hex_pfx, &ds);
286 find_short_packed_object(len, bin_pfx, &ds);
287 status = finish_object_disambiguation(&ds, sha1);
288
013f276e 289 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
1703f9aa 290 return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
013f276e
JH
291 return status;
292}
293
294const char *find_unique_abbrev(const unsigned char *sha1, int len)
295{
b66fde9a 296 int status, exists;
013f276e 297 static char hex[41];
47dd0d59 298
b66fde9a 299 exists = has_sha1_file(sha1);
013f276e 300 memcpy(hex, sha1_to_hex(sha1), 40);
02c5cba2 301 if (len == 40 || !len)
47dd0d59 302 return hex;
013f276e
JH
303 while (len < 40) {
304 unsigned char sha1_ret[20];
37c00e55 305 status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
b66fde9a
JH
306 if (exists
307 ? !status
308 : status == SHORT_NAME_NOT_FOUND) {
ea2c69ed 309 hex[len] = 0;
013f276e
JH
310 return hex;
311 }
013f276e
JH
312 len++;
313 }
b66fde9a 314 return hex;
9938af6a
JH
315}
316
6677c466 317static int ambiguous_path(const char *path, int len)
af13cdf2
LT
318{
319 int slash = 1;
6677c466 320 int cnt;
af13cdf2 321
6677c466 322 for (cnt = 0; cnt < len; cnt++) {
af13cdf2
LT
323 switch (*path++) {
324 case '\0':
325 break;
326 case '/':
327 if (slash)
328 break;
329 slash = 1;
330 continue;
331 case '.':
332 continue;
333 default:
334 slash = 0;
335 continue;
336 }
c054d64e 337 break;
af13cdf2 338 }
6677c466 339 return slash;
af13cdf2
LT
340}
341
ae0ba8e2
JH
342static inline int upstream_mark(const char *string, int len)
343{
344 const char *suffix[] = { "@{upstream}", "@{u}" };
345 int i;
346
347 for (i = 0; i < ARRAY_SIZE(suffix); i++) {
348 int suffix_len = strlen(suffix[i]);
349 if (suffix_len <= len
350 && !memcmp(string, suffix[i], suffix_len))
351 return suffix_len;
352 }
353 return 0;
354}
355
e48ba200 356static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
d18ba221 357
e86eb666
JH
358static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
359{
eedce784 360 static const char *warn_msg = "refname '%.*s' is ambiguous.";
ed378ec7 361 char *real_ref = NULL;
ab2a1a32
JH
362 int refs_found = 0;
363 int at, reflog_len;
9938af6a 364
3c3852e3 365 if (len == 40 && !get_sha1_hex(str, sha1))
9938af6a
JH
366 return 0;
367
d18ba221 368 /* basic@{time or number or -number} format to query ref-log */
694500ed 369 reflog_len = at = 0;
f265458f 370 if (len && str[len-1] == '}') {
aa9c55b6 371 for (at = len-2; at >= 0; at--) {
ab2a1a32 372 if (str[at] == '@' && str[at+1] == '{') {
ae0ba8e2 373 if (!upstream_mark(str + at, len - at)) {
28fb8438
JS
374 reflog_len = (len-1) - (at+2);
375 len = at;
376 }
ab2a1a32
JH
377 break;
378 }
d556fae2
SP
379 }
380 }
381
af13cdf2 382 /* Accept only unambiguous ref paths. */
11cf8801 383 if (len && ambiguous_path(str, len))
af13cdf2
LT
384 return -1;
385
11cf8801 386 if (!len && reflog_len) {
d18ba221
TR
387 struct strbuf buf = STRBUF_INIT;
388 int ret;
389 /* try the @{-N} syntax for n-th checkout */
431b1969 390 ret = interpret_branch_name(str+at, &buf);
d18ba221
TR
391 if (ret > 0) {
392 /* substitute this branch name and restart */
e48ba200 393 return get_sha1_1(buf.buf, buf.len, sha1, 0);
d18ba221
TR
394 } else if (ret == 0) {
395 return -1;
396 }
11cf8801
NP
397 /* allow "@{...}" to mean the current branch reflog */
398 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
f2eba66d
NP
399 } else if (reflog_len)
400 refs_found = dwim_log(str, len, sha1, &real_ref);
401 else
11cf8801 402 refs_found = dwim_ref(str, len, sha1, &real_ref);
d556fae2
SP
403
404 if (!refs_found)
405 return -1;
406
407 if (warn_ambiguous_refs && refs_found > 1)
eedce784 408 warning(warn_msg, len, str);
d556fae2 409
ab2a1a32 410 if (reflog_len) {
ab2a1a32
JH
411 int nth, i;
412 unsigned long at_time;
16d7cc90
JH
413 unsigned long co_time;
414 int co_tz, co_cnt;
415
12a258c0
JK
416 /* a @{-N} placed anywhere except the start is an error */
417 if (str[at+2] == '-')
418 return -1;
419
fe558516 420 /* Is it asking for N-th entry, or approxidate? */
ab2a1a32
JH
421 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
422 char ch = str[at+2+i];
423 if ('0' <= ch && ch <= '9')
424 nth = nth * 10 + ch - '0';
425 else
426 nth = -1;
427 }
ea360dd0
SP
428 if (100000000 <= nth) {
429 at_time = nth;
430 nth = -1;
431 } else if (0 <= nth)
ab2a1a32 432 at_time = 0;
861f00e3 433 else {
93cfa7c7 434 int errors = 0;
861f00e3 435 char *tmp = xstrndup(str + at + 2, reflog_len);
93cfa7c7 436 at_time = approxidate_careful(tmp, &errors);
861f00e3 437 free(tmp);
a5e10acb
JH
438 if (errors)
439 return -1;
861f00e3 440 }
16d7cc90
JH
441 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
442 &co_time, &co_tz, &co_cnt)) {
443 if (at_time)
eedce784
JS
444 warning("Log for '%.*s' only goes "
445 "back to %s.", len, str,
73013afd 446 show_date(co_time, co_tz, DATE_RFC2822));
e6eedc31
JS
447 else {
448 free(real_ref);
449 die("Log for '%.*s' only has %d entries.",
450 len, str, co_cnt);
451 }
16d7cc90 452 }
d556fae2
SP
453 }
454
ed378ec7 455 free(real_ref);
d556fae2 456 return 0;
9938af6a
JH
457}
458
9938af6a
JH
459static int get_parent(const char *name, int len,
460 unsigned char *result, int idx)
461{
462 unsigned char sha1[20];
e2643617 463 int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
9938af6a
JH
464 struct commit *commit;
465 struct commit_list *p;
466
467 if (ret)
468 return ret;
469 commit = lookup_commit_reference(sha1);
470 if (!commit)
471 return -1;
472 if (parse_commit(commit))
473 return -1;
474 if (!idx) {
e702496e 475 hashcpy(result, commit->object.sha1);
9938af6a
JH
476 return 0;
477 }
478 p = commit->parents;
479 while (p) {
480 if (!--idx) {
e702496e 481 hashcpy(result, p->item->object.sha1);
9938af6a
JH
482 return 0;
483 }
484 p = p->next;
485 }
486 return -1;
487}
488
4f7599ac
JH
489static int get_nth_ancestor(const char *name, int len,
490 unsigned char *result, int generation)
491{
492 unsigned char sha1[20];
621ff675
LT
493 struct commit *commit;
494 int ret;
495
e2643617 496 ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
4f7599ac
JH
497 if (ret)
498 return ret;
621ff675
LT
499 commit = lookup_commit_reference(sha1);
500 if (!commit)
501 return -1;
4f7599ac
JH
502
503 while (generation--) {
621ff675 504 if (parse_commit(commit) || !commit->parents)
4f7599ac 505 return -1;
621ff675 506 commit = commit->parents->item;
4f7599ac 507 }
621ff675 508 hashcpy(result, commit->object.sha1);
4f7599ac
JH
509 return 0;
510}
511
81776315
JH
512struct object *peel_to_type(const char *name, int namelen,
513 struct object *o, enum object_type expected_type)
514{
515 if (name && !namelen)
516 namelen = strlen(name);
81776315
JH
517 while (1) {
518 if (!o || (!o->parsed && !parse_object(o->sha1)))
519 return NULL;
520 if (o->type == expected_type)
521 return o;
522 if (o->type == OBJ_TAG)
523 o = ((struct tag*) o)->tagged;
524 else if (o->type == OBJ_COMMIT)
525 o = &(((struct commit *) o)->tree->object);
526 else {
527 if (name)
528 error("%.*s: expected %s type, but the object "
529 "dereferences to %s type",
530 namelen, name, typename(expected_type),
531 typename(o->type));
532 return NULL;
533 }
534 }
535}
536
5385f52d
JH
537static int peel_onion(const char *name, int len, unsigned char *sha1)
538{
539 unsigned char outer[20];
540 const char *sp;
885a86ab 541 unsigned int expected_type = 0;
e2643617 542 unsigned lookup_flags = 0;
5385f52d
JH
543 struct object *o;
544
545 /*
546 * "ref^{type}" dereferences ref repeatedly until you cannot
547 * dereference anymore, or you get an object of given type,
548 * whichever comes first. "ref^{}" means just dereference
549 * tags until you get a non-tag. "ref^0" is a shorthand for
550 * "ref^{commit}". "commit^{tree}" could be used to find the
551 * top-level tree of the given commit.
552 */
553 if (len < 4 || name[len-1] != '}')
554 return -1;
555
556 for (sp = name + len - 1; name <= sp; sp--) {
557 int ch = *sp;
558 if (ch == '{' && name < sp && sp[-1] == '^')
559 break;
560 }
561 if (sp <= name)
562 return -1;
563
564 sp++; /* beginning of type name, or closing brace for empty */
565 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
1974632c 566 expected_type = OBJ_COMMIT;
5385f52d 567 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
1974632c 568 expected_type = OBJ_TREE;
5385f52d 569 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
1974632c 570 expected_type = OBJ_BLOB;
5385f52d 571 else if (sp[0] == '}')
1974632c 572 expected_type = OBJ_NONE;
32574b68
NTND
573 else if (sp[0] == '/')
574 expected_type = OBJ_COMMIT;
5385f52d
JH
575 else
576 return -1;
577
e2643617
JH
578 if (expected_type == OBJ_COMMIT)
579 lookup_flags = GET_SHA1_COMMITTISH;
580
581 if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
5385f52d
JH
582 return -1;
583
584 o = parse_object(outer);
585 if (!o)
586 return -1;
885a86ab 587 if (!expected_type) {
9534f40b 588 o = deref_tag(o, name, sp - name - 2);
6e1c6c10
JH
589 if (!o || (!o->parsed && !parse_object(o->sha1)))
590 return -1;
e702496e 591 hashcpy(sha1, o->sha1);
32574b68 592 return 0;
5385f52d 593 }
32574b68
NTND
594
595 /*
596 * At this point, the syntax look correct, so
597 * if we do not get the needed object, we should
598 * barf.
599 */
600 o = peel_to_type(name, len, o, expected_type);
601 if (!o)
81776315 602 return -1;
32574b68
NTND
603
604 hashcpy(sha1, o->sha1);
605 if (sp[0] == '/') {
606 /* "$commit^{/foo}" */
607 char *prefix;
608 int ret;
609 struct commit_list *list = NULL;
610
81776315 611 /*
4322842a
NTND
612 * $commit^{/}. Some regex implementation may reject.
613 * We don't need regex anyway. '' pattern always matches.
5385f52d 614 */
4322842a 615 if (sp[1] == '}')
81776315 616 return 0;
4322842a 617
32574b68
NTND
618 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
619 commit_list_insert((struct commit *)o, &list);
620 ret = get_sha1_oneline(prefix, sha1, list);
621 free(prefix);
622 return ret;
5385f52d
JH
623 }
624 return 0;
625}
626
7dd45e15
JH
627static int get_describe_name(const char *name, int len, unsigned char *sha1)
628{
629 const char *cp;
6269b6b6 630 unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
7dd45e15
JH
631
632 for (cp = name + len - 1; name + 2 <= cp; cp--) {
633 char ch = *cp;
634 if (hexval(ch) & ~0377) {
635 /* We must be looking at g in "SOMETHING-g"
636 * for it to be describe output.
637 */
638 if (ch == 'g' && cp[-1] == '-') {
639 cp++;
640 len -= cp - name;
6269b6b6 641 return get_short_sha1(cp, len, sha1, flags);
7dd45e15
JH
642 }
643 }
644 }
645 return -1;
646}
647
e48ba200 648static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
9938af6a 649{
0601dbe1 650 int ret, has_suffix;
4f7599ac 651 const char *cp;
9938af6a 652
621ff675
LT
653 /*
654 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
4f7599ac 655 */
0601dbe1 656 has_suffix = 0;
4f7599ac
JH
657 for (cp = name + len - 1; name <= cp; cp--) {
658 int ch = *cp;
659 if ('0' <= ch && ch <= '9')
660 continue;
0601dbe1
JH
661 if (ch == '~' || ch == '^')
662 has_suffix = ch;
4f7599ac
JH
663 break;
664 }
0601dbe1
JH
665
666 if (has_suffix) {
667 int num = 0;
4f7599ac
JH
668 int len1 = cp - name;
669 cp++;
670 while (cp < name + len)
0601dbe1 671 num = num * 10 + *cp++ - '0';
621ff675
LT
672 if (!num && len1 == len - 1)
673 num = 1;
674 if (has_suffix == '^')
0601dbe1 675 return get_parent(name, len1, sha1, num);
0601dbe1
JH
676 /* else if (has_suffix == '~') -- goes without saying */
677 return get_nth_ancestor(name, len1, sha1, num);
4f7599ac
JH
678 }
679
5385f52d
JH
680 ret = peel_onion(name, len, sha1);
681 if (!ret)
682 return 0;
683
9938af6a
JH
684 ret = get_sha1_basic(name, len, sha1);
685 if (!ret)
686 return 0;
7dd45e15
JH
687
688 /* It could be describe output that is "SOMETHING-gXXXX" */
689 ret = get_describe_name(name, len, sha1);
690 if (!ret)
691 return 0;
692
e2643617 693 return get_short_sha1(name, len, sha1, lookup_flags);
9938af6a
JH
694}
695
f7bff003
JH
696/*
697 * This interprets names like ':/Initial revision of "git"' by searching
698 * through history and returning the first commit whose message starts
3d045897 699 * the given regular expression.
f7bff003
JH
700 *
701 * For future extension, ':/!' is reserved. If you want to match a message
702 * beginning with a '!', you have to repeat the exclamation mark.
703 */
704#define ONELINE_SEEN (1u<<20)
705
28a4d940
JS
706static int handle_one_ref(const char *path,
707 const unsigned char *sha1, int flag, void *cb_data)
708{
709 struct commit_list **list = cb_data;
710 struct object *object = parse_object(sha1);
711 if (!object)
712 return 0;
affeef12 713 if (object->type == OBJ_TAG) {
28a4d940 714 object = deref_tag(object, path, strlen(path));
affeef12
MK
715 if (!object)
716 return 0;
717 }
28a4d940
JS
718 if (object->type != OBJ_COMMIT)
719 return 0;
47e44ed1 720 commit_list_insert_by_date((struct commit *)object, list);
28a4d940
JS
721 return 0;
722}
723
84baa31b
NTND
724static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
725 struct commit_list *list)
28a4d940 726{
84baa31b 727 struct commit_list *backup = NULL, *l;
28042dbc 728 int found = 0;
57895105 729 regex_t regex;
28a4d940
JS
730
731 if (prefix[0] == '!') {
732 if (prefix[1] != '!')
733 die ("Invalid search pattern: %s", prefix);
734 prefix++;
735 }
57895105
LT
736
737 if (regcomp(&regex, prefix, REG_EXTENDED))
738 die("Invalid search pattern: %s", prefix);
739
84baa31b
NTND
740 for (l = list; l; l = l->next) {
741 l->item->object.flags |= ONELINE_SEEN;
28a4d940 742 commit_list_insert(l->item, &backup);
84baa31b 743 }
ed8ad7e2 744 while (list) {
28042dbc 745 char *p, *to_free = NULL;
1358e7d6 746 struct commit *commit;
364d3e65
JS
747 enum object_type type;
748 unsigned long size;
28042dbc 749 int matches;
ed8ad7e2
JM
750
751 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
283cdbcf
MK
752 if (!parse_object(commit->object.sha1))
753 continue;
364d3e65
JS
754 if (commit->buffer)
755 p = commit->buffer;
756 else {
757 p = read_sha1_file(commit->object.sha1, &type, &size);
758 if (!p)
759 continue;
28042dbc 760 to_free = p;
364d3e65 761 }
28042dbc
JH
762
763 p = strstr(p, "\n\n");
764 matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
765 free(to_free);
766
767 if (matches) {
28a4d940 768 hashcpy(sha1, commit->object.sha1);
28042dbc 769 found = 1;
28a4d940
JS
770 break;
771 }
772 }
57895105 773 regfree(&regex);
28a4d940
JS
774 free_commit_list(list);
775 for (l = backup; l; l = l->next)
776 clear_commit_marks(l->item, ONELINE_SEEN);
28042dbc
JH
777 free_commit_list(backup);
778 return found ? 0 : -1;
28a4d940
JS
779}
780
ae5a6c36 781struct grab_nth_branch_switch_cbdata {
c2883e62 782 long cnt, alloc;
ae5a6c36
JH
783 struct strbuf *buf;
784};
785
786static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
787 const char *email, unsigned long timestamp, int tz,
788 const char *message, void *cb_data)
789{
790 struct grab_nth_branch_switch_cbdata *cb = cb_data;
a884d0cb
TR
791 const char *match = NULL, *target = NULL;
792 size_t len;
c2883e62 793 int nth;
a884d0cb
TR
794
795 if (!prefixcmp(message, "checkout: moving from ")) {
796 match = message + strlen("checkout: moving from ");
d7c03c1f 797 target = strstr(match, " to ");
ae5a6c36
JH
798 }
799
c829774c 800 if (!match || !target)
ae5a6c36
JH
801 return 0;
802
d7c03c1f 803 len = target - match;
c2883e62
JH
804 nth = cb->cnt++ % cb->alloc;
805 strbuf_reset(&cb->buf[nth]);
806 strbuf_add(&cb->buf[nth], match, len);
ae5a6c36
JH
807 return 0;
808}
809
810/*
ae0ba8e2
JH
811 * Parse @{-N} syntax, return the number of characters parsed
812 * if successful; otherwise signal an error with negative value.
ae5a6c36 813 */
ae0ba8e2 814static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
ae5a6c36 815{
c2883e62 816 long nth;
39765e59 817 int i, retval;
ae5a6c36 818 struct grab_nth_branch_switch_cbdata cb;
a884d0cb
TR
819 const char *brace;
820 char *num_end;
ae5a6c36
JH
821
822 if (name[0] != '@' || name[1] != '{' || name[2] != '-')
823 return -1;
a884d0cb
TR
824 brace = strchr(name, '}');
825 if (!brace)
826 return -1;
827 nth = strtol(name+3, &num_end, 10);
828 if (num_end != brace)
ae5a6c36 829 return -1;
c2883e62
JH
830 if (nth <= 0)
831 return -1;
832 cb.alloc = nth;
833 cb.buf = xmalloc(nth * sizeof(struct strbuf));
834 for (i = 0; i < nth; i++)
835 strbuf_init(&cb.buf[i], 20);
836 cb.cnt = 0;
39765e59 837 retval = 0;
101d15e0
JH
838 for_each_recent_reflog_ent("HEAD", grab_nth_branch_switch, 40960, &cb);
839 if (cb.cnt < nth) {
840 cb.cnt = 0;
101d15e0
JH
841 for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb);
842 }
c2883e62 843 if (cb.cnt < nth)
39765e59 844 goto release_return;
c2883e62
JH
845 i = cb.cnt % nth;
846 strbuf_reset(buf);
847 strbuf_add(buf, cb.buf[i].buf, cb.buf[i].len);
39765e59
JH
848 retval = brace-name+1;
849
850release_return:
c2883e62
JH
851 for (i = 0; i < nth; i++)
852 strbuf_release(&cb.buf[i]);
853 free(cb.buf);
a884d0cb 854
39765e59 855 return retval;
ae5a6c36
JH
856}
857
619a644d
JH
858int get_sha1_mb(const char *name, unsigned char *sha1)
859{
860 struct commit *one, *two;
861 struct commit_list *mbs;
862 unsigned char sha1_tmp[20];
863 const char *dots;
864 int st;
865
866 dots = strstr(name, "...");
867 if (!dots)
868 return get_sha1(name, sha1);
869 if (dots == name)
870 st = get_sha1("HEAD", sha1_tmp);
871 else {
872 struct strbuf sb;
873 strbuf_init(&sb, dots - name);
874 strbuf_add(&sb, name, dots - name);
875 st = get_sha1(sb.buf, sha1_tmp);
876 strbuf_release(&sb);
877 }
878 if (st)
879 return st;
880 one = lookup_commit_reference_gently(sha1_tmp, 0);
881 if (!one)
882 return -1;
883
884 if (get_sha1(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
885 return -1;
886 two = lookup_commit_reference_gently(sha1_tmp, 0);
887 if (!two)
888 return -1;
889 mbs = get_merge_bases(one, two, 1);
890 if (!mbs || mbs->next)
891 st = -1;
892 else {
893 st = 0;
894 hashcpy(sha1, mbs->item->object.sha1);
895 }
896 free_commit_list(mbs);
897 return st;
898}
899
ae0ba8e2
JH
900/*
901 * This reads short-hand syntax that not only evaluates to a commit
902 * object name, but also can act as if the end user spelled the name
903 * of the branch from the command line.
904 *
905 * - "@{-N}" finds the name of the Nth previous branch we were on, and
906 * places the name of the branch in the given buf and returns the
907 * number of characters parsed if successful.
908 *
909 * - "<branch>@{upstream}" finds the name of the other ref that
910 * <branch> is configured to merge with (missing <branch> defaults
911 * to the current branch), and places the name of the branch in the
912 * given buf and returns the number of characters parsed if
913 * successful.
914 *
915 * If the input is not of the accepted format, it returns a negative
916 * number to signal an error.
917 *
918 * If the input was ok but there are not N branch switches in the
919 * reflog, it returns 0.
920 */
921int interpret_branch_name(const char *name, struct strbuf *buf)
922{
923 char *cp;
924 struct branch *upstream;
925 int namelen = strlen(name);
926 int len = interpret_nth_prior_checkout(name, buf);
927 int tmp_len;
928
929 if (!len)
930 return len; /* syntax Ok, not enough switches */
d46a8301
JK
931 if (0 < len && len == namelen)
932 return len; /* consumed all */
933 else if (0 < len) {
934 /* we have extra data, which might need further processing */
935 struct strbuf tmp = STRBUF_INIT;
936 int used = buf->len;
937 int ret;
938
939 strbuf_add(buf, name + len, namelen - len);
940 ret = interpret_branch_name(buf->buf, &tmp);
941 /* that data was not interpreted, remove our cruft */
942 if (ret < 0) {
943 strbuf_setlen(buf, used);
944 return len;
945 }
946 strbuf_reset(buf);
947 strbuf_addbuf(buf, &tmp);
948 strbuf_release(&tmp);
949 /* tweak for size of {-N} versus expanded ref name */
950 return ret - used + len;
951 }
952
ae0ba8e2
JH
953 cp = strchr(name, '@');
954 if (!cp)
955 return -1;
956 tmp_len = upstream_mark(cp, namelen - (cp - name));
957 if (!tmp_len)
958 return -1;
959 len = cp + tmp_len - name;
960 cp = xstrndup(name, cp - name);
961 upstream = branch_get(*cp ? cp : NULL);
962 if (!upstream
963 || !upstream->merge
964 || !upstream->merge[0]->dst)
965 return error("No upstream branch found for '%s'", cp);
966 free(cp);
967 cp = shorten_unambiguous_ref(upstream->merge[0]->dst, 0);
968 strbuf_reset(buf);
969 strbuf_addstr(buf, cp);
970 free(cp);
971 return len;
972}
973
6bab74e7
JN
974int strbuf_branchname(struct strbuf *sb, const char *name)
975{
976 int len = strlen(name);
977 if (interpret_branch_name(name, sb) == len)
978 return 0;
979 strbuf_add(sb, name, len);
980 return len;
981}
982
983int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
984{
985 strbuf_branchname(sb, name);
986 if (name[0] == '-')
8d9c5010 987 return -1;
6bab74e7 988 strbuf_splice(sb, 0, 0, "refs/heads/", 11);
8d9c5010 989 return check_refname_format(sb->buf, 0);
6bab74e7
JN
990}
991
9938af6a
JH
992/*
993 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
994 * notably "xyz^" for "parent of xyz"
995 */
996int get_sha1(const char *name, unsigned char *sha1)
997{
573285e5 998 struct object_context unused;
33bd598c 999 return get_sha1_with_context(name, 0, sha1, &unused);
a0cd87a5
MK
1000}
1001
009fee47
MM
1002/* Must be called only when object_name:filename doesn't exist. */
1003static void diagnose_invalid_sha1_path(const char *prefix,
1004 const char *filename,
1005 const unsigned char *tree_sha1,
1006 const char *object_name)
1007{
1008 struct stat st;
1009 unsigned char sha1[20];
1010 unsigned mode;
1011
1012 if (!prefix)
1013 prefix = "";
1014
1015 if (!lstat(filename, &st))
1016 die("Path '%s' exists on disk, but not in '%s'.",
1017 filename, object_name);
1018 if (errno == ENOENT || errno == ENOTDIR) {
1019 char *fullname = xmalloc(strlen(filename)
1020 + strlen(prefix) + 1);
1021 strcpy(fullname, prefix);
1022 strcat(fullname, filename);
1023
1024 if (!get_tree_entry(tree_sha1, fullname,
1025 sha1, &mode)) {
1026 die("Path '%s' exists, but not '%s'.\n"
e41d718c 1027 "Did you mean '%s:%s' aka '%s:./%s'?",
009fee47
MM
1028 fullname,
1029 filename,
1030 object_name,
e41d718c
MG
1031 fullname,
1032 object_name,
1033 filename);
009fee47
MM
1034 }
1035 die("Path '%s' does not exist in '%s'",
1036 filename, object_name);
1037 }
1038}
1039
1040/* Must be called only when :stage:filename doesn't exist. */
1041static void diagnose_invalid_index_path(int stage,
1042 const char *prefix,
1043 const char *filename)
1044{
1045 struct stat st;
1046 struct cache_entry *ce;
1047 int pos;
1048 unsigned namelen = strlen(filename);
1049 unsigned fullnamelen;
1050 char *fullname;
1051
1052 if (!prefix)
1053 prefix = "";
1054
1055 /* Wrong stage number? */
1056 pos = cache_name_pos(filename, namelen);
1057 if (pos < 0)
1058 pos = -pos - 1;
77e8466f
MH
1059 if (pos < active_nr) {
1060 ce = active_cache[pos];
1061 if (ce_namelen(ce) == namelen &&
1062 !memcmp(ce->name, filename, namelen))
1063 die("Path '%s' is in the index, but not at stage %d.\n"
1064 "Did you mean ':%d:%s'?",
1065 filename, stage,
1066 ce_stage(ce), filename);
1067 }
009fee47
MM
1068
1069 /* Confusion between relative and absolute filenames? */
1070 fullnamelen = namelen + strlen(prefix);
1071 fullname = xmalloc(fullnamelen + 1);
1072 strcpy(fullname, prefix);
1073 strcat(fullname, filename);
1074 pos = cache_name_pos(fullname, fullnamelen);
1075 if (pos < 0)
1076 pos = -pos - 1;
77e8466f
MH
1077 if (pos < active_nr) {
1078 ce = active_cache[pos];
1079 if (ce_namelen(ce) == fullnamelen &&
1080 !memcmp(ce->name, fullname, fullnamelen))
1081 die("Path '%s' is in the index, but not '%s'.\n"
e41d718c 1082 "Did you mean ':%d:%s' aka ':%d:./%s'?",
77e8466f 1083 fullname, filename,
e41d718c
MG
1084 ce_stage(ce), fullname,
1085 ce_stage(ce), filename);
77e8466f 1086 }
009fee47
MM
1087
1088 if (!lstat(filename, &st))
1089 die("Path '%s' exists on disk, but not in the index.", filename);
1090 if (errno == ENOENT || errno == ENOTDIR)
1091 die("Path '%s' does not exist (neither on disk nor in the index).",
1092 filename);
1093
1094 free(fullname);
1095}
1096
1097
979f7929
NTND
1098static char *resolve_relative_path(const char *rel)
1099{
1100 if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
1101 return NULL;
1102
1103 if (!startup_info)
1104 die("BUG: startup_info struct is not initialized.");
1105
1106 if (!is_inside_work_tree())
1107 die("relative path syntax can't be used outside working tree.");
1108
1109 /* die() inside prefix_path() if resolved path is outside worktree */
1110 return prefix_path(startup_info->prefix,
1111 startup_info->prefix ? strlen(startup_info->prefix) : 0,
1112 rel);
1113}
1114
33bd598c
JH
1115static int get_sha1_with_context_1(const char *name,
1116 unsigned flags,
1117 const char *prefix,
1118 unsigned char *sha1,
1119 struct object_context *oc)
a0cd87a5
MK
1120{
1121 int ret, bracket_depth;
73b0e5af
JH
1122 int namelen = strlen(name);
1123 const char *cp;
33bd598c 1124 int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
5119602a 1125
573285e5
CP
1126 memset(oc, 0, sizeof(*oc));
1127 oc->mode = S_IFINVALID;
33bd598c 1128 ret = get_sha1_1(name, namelen, sha1, flags);
73b0e5af
JH
1129 if (!ret)
1130 return ret;
33bd598c
JH
1131 /*
1132 * sha1:path --> object name of path in ent sha1
979f7929
NTND
1133 * :path -> object name of absolute path in index
1134 * :./path -> object name of path relative to cwd in index
73b0e5af 1135 * :[0-3]:path -> object name of path in index at stage
95ad6d2d 1136 * :/foo -> recent commit matching foo
73b0e5af
JH
1137 */
1138 if (name[0] == ':') {
1139 int stage = 0;
1140 struct cache_entry *ce;
979f7929 1141 char *new_path = NULL;
73b0e5af 1142 int pos;
2e83b66c 1143 if (!only_to_die && namelen > 2 && name[1] == '/') {
84baa31b
NTND
1144 struct commit_list *list = NULL;
1145 for_each_ref(handle_one_ref, &list);
1146 return get_sha1_oneline(name + 2, sha1, list);
1147 }
73b0e5af
JH
1148 if (namelen < 3 ||
1149 name[2] != ':' ||
1150 name[1] < '0' || '3' < name[1])
1151 cp = name + 1;
1152 else {
1153 stage = name[1] - '0';
1154 cp = name + 3;
5119602a 1155 }
3d6e0f74
JH
1156 new_path = resolve_relative_path(cp);
1157 if (!new_path) {
1158 namelen = namelen - (cp - name);
1159 } else {
1160 cp = new_path;
1161 namelen = strlen(cp);
1162 }
573285e5
CP
1163
1164 strncpy(oc->path, cp,
1165 sizeof(oc->path));
1166 oc->path[sizeof(oc->path)-1] = '\0';
1167
73b0e5af
JH
1168 if (!active_cache)
1169 read_cache();
73b0e5af
JH
1170 pos = cache_name_pos(cp, namelen);
1171 if (pos < 0)
1172 pos = -pos - 1;
1173 while (pos < active_nr) {
1174 ce = active_cache[pos];
1175 if (ce_namelen(ce) != namelen ||
1176 memcmp(ce->name, cp, namelen))
1177 break;
1178 if (ce_stage(ce) == stage) {
e702496e 1179 hashcpy(sha1, ce->sha1);
90064710 1180 oc->mode = ce->ce_mode;
979f7929 1181 free(new_path);
73b0e5af
JH
1182 return 0;
1183 }
e7cef45f 1184 pos++;
73b0e5af 1185 }
2e83b66c 1186 if (only_to_die && name[1] && name[1] != '/')
009fee47 1187 diagnose_invalid_index_path(stage, prefix, cp);
979f7929 1188 free(new_path);
73b0e5af
JH
1189 return -1;
1190 }
cce91a2c
SP
1191 for (cp = name, bracket_depth = 0; *cp; cp++) {
1192 if (*cp == '{')
1193 bracket_depth++;
1194 else if (bracket_depth && *cp == '}')
1195 bracket_depth--;
1196 else if (!bracket_depth && *cp == ':')
1197 break;
1198 }
1199 if (*cp == ':') {
73b0e5af 1200 unsigned char tree_sha1[20];
009fee47 1201 char *object_name = NULL;
2e83b66c 1202 if (only_to_die) {
009fee47
MM
1203 object_name = xmalloc(cp-name+1);
1204 strncpy(object_name, name, cp-name);
1205 object_name[cp-name] = '\0';
1206 }
e48ba200 1207 if (!get_sha1_1(name, cp-name, tree_sha1, 0)) {
009fee47 1208 const char *filename = cp+1;
979f7929
NTND
1209 char *new_filename = NULL;
1210
1211 new_filename = resolve_relative_path(filename);
1212 if (new_filename)
1213 filename = new_filename;
573285e5 1214 ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
2e83b66c 1215 if (only_to_die) {
009fee47
MM
1216 diagnose_invalid_sha1_path(prefix, filename,
1217 tree_sha1, object_name);
1218 free(object_name);
1219 }
573285e5
CP
1220 hashcpy(oc->tree, tree_sha1);
1221 strncpy(oc->path, filename,
1222 sizeof(oc->path));
1223 oc->path[sizeof(oc->path)-1] = '\0';
1224
979f7929 1225 free(new_filename);
009fee47
MM
1226 return ret;
1227 } else {
2e83b66c 1228 if (only_to_die)
009fee47
MM
1229 die("Invalid object name '%s'.", object_name);
1230 }
5119602a
LT
1231 }
1232 return ret;
9938af6a 1233}
f01cc14c 1234
8c135ea2
JH
1235/*
1236 * Call this function when you know "name" given by the end user must
1237 * name an object but it doesn't; the function _may_ die with a better
1238 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1239 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1240 * you have a chance to diagnose the error further.
1241 */
1242void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
f01cc14c
JH
1243{
1244 struct object_context oc;
8c135ea2 1245 unsigned char sha1[20];
33bd598c 1246 get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
8c135ea2
JH
1247}
1248
33bd598c 1249int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
f01cc14c 1250{
33bd598c 1251 return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
f01cc14c 1252}