The fifth batch
[git/git.git] / sha1-name.c
1 #include "cache.h"
2 #include "config.h"
3 #include "tag.h"
4 #include "commit.h"
5 #include "tree.h"
6 #include "blob.h"
7 #include "tree-walk.h"
8 #include "refs.h"
9 #include "remote.h"
10 #include "dir.h"
11 #include "sha1-array.h"
12 #include "packfile.h"
13 #include "object-store.h"
14 #include "repository.h"
15 #include "midx.h"
16 #include "commit-reach.h"
17
18 static int get_oid_oneline(const char *, struct object_id *, struct commit_list *);
19
20 typedef int (*disambiguate_hint_fn)(const struct object_id *, void *);
21
22 struct disambiguate_state {
23 int len; /* length of prefix in hex chars */
24 char hex_pfx[GIT_MAX_HEXSZ + 1];
25 struct object_id bin_pfx;
26
27 disambiguate_hint_fn fn;
28 void *cb_data;
29 struct object_id candidate;
30 unsigned candidate_exists:1;
31 unsigned candidate_checked:1;
32 unsigned candidate_ok:1;
33 unsigned disambiguate_fn_used:1;
34 unsigned ambiguous:1;
35 unsigned always_call_fn:1;
36 };
37
38 static void update_candidates(struct disambiguate_state *ds, const struct object_id *current)
39 {
40 if (ds->always_call_fn) {
41 ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
42 return;
43 }
44 if (!ds->candidate_exists) {
45 /* this is the first candidate */
46 oidcpy(&ds->candidate, current);
47 ds->candidate_exists = 1;
48 return;
49 } else if (oideq(&ds->candidate, current)) {
50 /* the same as what we already have seen */
51 return;
52 }
53
54 if (!ds->fn) {
55 /* cannot disambiguate between ds->candidate and current */
56 ds->ambiguous = 1;
57 return;
58 }
59
60 if (!ds->candidate_checked) {
61 ds->candidate_ok = ds->fn(&ds->candidate, ds->cb_data);
62 ds->disambiguate_fn_used = 1;
63 ds->candidate_checked = 1;
64 }
65
66 if (!ds->candidate_ok) {
67 /* discard the candidate; we know it does not satisfy fn */
68 oidcpy(&ds->candidate, current);
69 ds->candidate_checked = 0;
70 return;
71 }
72
73 /* if we reach this point, we know ds->candidate satisfies fn */
74 if (ds->fn(current, ds->cb_data)) {
75 /*
76 * if both current and candidate satisfy fn, we cannot
77 * disambiguate.
78 */
79 ds->candidate_ok = 0;
80 ds->ambiguous = 1;
81 }
82
83 /* otherwise, current can be discarded and candidate is still good */
84 }
85
86 static int match_sha(unsigned, const unsigned char *, const unsigned char *);
87
88 static void find_short_object_filename(struct disambiguate_state *ds)
89 {
90 struct object_directory *odb;
91
92 for (odb = the_repository->objects->odb;
93 odb && !ds->ambiguous;
94 odb = odb->next) {
95 int pos;
96 struct oid_array *loose_objects;
97
98 loose_objects = odb_loose_cache(odb, &ds->bin_pfx);
99 pos = oid_array_lookup(loose_objects, &ds->bin_pfx);
100 if (pos < 0)
101 pos = -1 - pos;
102 while (!ds->ambiguous && pos < loose_objects->nr) {
103 const struct object_id *oid;
104 oid = loose_objects->oid + pos;
105 if (!match_sha(ds->len, ds->bin_pfx.hash, oid->hash))
106 break;
107 update_candidates(ds, oid);
108 pos++;
109 }
110 }
111 }
112
113 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
114 {
115 do {
116 if (*a != *b)
117 return 0;
118 a++;
119 b++;
120 len -= 2;
121 } while (len > 1);
122 if (len)
123 if ((*a ^ *b) & 0xf0)
124 return 0;
125 return 1;
126 }
127
128 static void unique_in_midx(struct multi_pack_index *m,
129 struct disambiguate_state *ds)
130 {
131 uint32_t num, i, first = 0;
132 const struct object_id *current = NULL;
133 num = m->num_objects;
134
135 if (!num)
136 return;
137
138 bsearch_midx(&ds->bin_pfx, m, &first);
139
140 /*
141 * At this point, "first" is the location of the lowest object
142 * with an object name that could match "bin_pfx". See if we have
143 * 0, 1 or more objects that actually match(es).
144 */
145 for (i = first; i < num && !ds->ambiguous; i++) {
146 struct object_id oid;
147 current = nth_midxed_object_oid(&oid, m, i);
148 if (!match_sha(ds->len, ds->bin_pfx.hash, current->hash))
149 break;
150 update_candidates(ds, current);
151 }
152 }
153
154 static void unique_in_pack(struct packed_git *p,
155 struct disambiguate_state *ds)
156 {
157 uint32_t num, i, first = 0;
158 const struct object_id *current = NULL;
159
160 if (open_pack_index(p) || !p->num_objects)
161 return;
162
163 num = p->num_objects;
164 bsearch_pack(&ds->bin_pfx, p, &first);
165
166 /*
167 * At this point, "first" is the location of the lowest object
168 * with an object name that could match "bin_pfx". See if we have
169 * 0, 1 or more objects that actually match(es).
170 */
171 for (i = first; i < num && !ds->ambiguous; i++) {
172 struct object_id oid;
173 current = nth_packed_object_oid(&oid, p, i);
174 if (!match_sha(ds->len, ds->bin_pfx.hash, current->hash))
175 break;
176 update_candidates(ds, current);
177 }
178 }
179
180 static void find_short_packed_object(struct disambiguate_state *ds)
181 {
182 struct multi_pack_index *m;
183 struct packed_git *p;
184
185 for (m = get_multi_pack_index(the_repository); m && !ds->ambiguous;
186 m = m->next)
187 unique_in_midx(m, ds);
188 for (p = get_packed_git(the_repository); p && !ds->ambiguous;
189 p = p->next)
190 unique_in_pack(p, ds);
191 }
192
193 static int finish_object_disambiguation(struct disambiguate_state *ds,
194 struct object_id *oid)
195 {
196 if (ds->ambiguous)
197 return SHORT_NAME_AMBIGUOUS;
198
199 if (!ds->candidate_exists)
200 return MISSING_OBJECT;
201
202 if (!ds->candidate_checked)
203 /*
204 * If this is the only candidate, there is no point
205 * calling the disambiguation hint callback.
206 *
207 * On the other hand, if the current candidate
208 * replaced an earlier candidate that did _not_ pass
209 * the disambiguation hint callback, then we do have
210 * more than one objects that match the short name
211 * given, so we should make sure this one matches;
212 * otherwise, if we discovered this one and the one
213 * that we previously discarded in the reverse order,
214 * we would end up showing different results in the
215 * same repository!
216 */
217 ds->candidate_ok = (!ds->disambiguate_fn_used ||
218 ds->fn(&ds->candidate, ds->cb_data));
219
220 if (!ds->candidate_ok)
221 return SHORT_NAME_AMBIGUOUS;
222
223 oidcpy(oid, &ds->candidate);
224 return 0;
225 }
226
227 static int disambiguate_commit_only(const struct object_id *oid, void *cb_data_unused)
228 {
229 int kind = oid_object_info(the_repository, oid, NULL);
230 return kind == OBJ_COMMIT;
231 }
232
233 static int disambiguate_committish_only(const struct object_id *oid, void *cb_data_unused)
234 {
235 struct object *obj;
236 int kind;
237
238 kind = oid_object_info(the_repository, oid, NULL);
239 if (kind == OBJ_COMMIT)
240 return 1;
241 if (kind != OBJ_TAG)
242 return 0;
243
244 /* We need to do this the hard way... */
245 obj = deref_tag(the_repository, parse_object(the_repository, oid),
246 NULL, 0);
247 if (obj && obj->type == OBJ_COMMIT)
248 return 1;
249 return 0;
250 }
251
252 static int disambiguate_tree_only(const struct object_id *oid, void *cb_data_unused)
253 {
254 int kind = oid_object_info(the_repository, oid, NULL);
255 return kind == OBJ_TREE;
256 }
257
258 static int disambiguate_treeish_only(const struct object_id *oid, void *cb_data_unused)
259 {
260 struct object *obj;
261 int kind;
262
263 kind = oid_object_info(the_repository, oid, NULL);
264 if (kind == OBJ_TREE || kind == OBJ_COMMIT)
265 return 1;
266 if (kind != OBJ_TAG)
267 return 0;
268
269 /* We need to do this the hard way... */
270 obj = deref_tag(the_repository, parse_object(the_repository, oid),
271 NULL, 0);
272 if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
273 return 1;
274 return 0;
275 }
276
277 static int disambiguate_blob_only(const struct object_id *oid, void *cb_data_unused)
278 {
279 int kind = oid_object_info(the_repository, oid, NULL);
280 return kind == OBJ_BLOB;
281 }
282
283 static disambiguate_hint_fn default_disambiguate_hint;
284
285 int set_disambiguate_hint_config(const char *var, const char *value)
286 {
287 static const struct {
288 const char *name;
289 disambiguate_hint_fn fn;
290 } hints[] = {
291 { "none", NULL },
292 { "commit", disambiguate_commit_only },
293 { "committish", disambiguate_committish_only },
294 { "tree", disambiguate_tree_only },
295 { "treeish", disambiguate_treeish_only },
296 { "blob", disambiguate_blob_only }
297 };
298 int i;
299
300 if (!value)
301 return config_error_nonbool(var);
302
303 for (i = 0; i < ARRAY_SIZE(hints); i++) {
304 if (!strcasecmp(value, hints[i].name)) {
305 default_disambiguate_hint = hints[i].fn;
306 return 0;
307 }
308 }
309
310 return error("unknown hint type for '%s': %s", var, value);
311 }
312
313 static int init_object_disambiguation(const char *name, int len,
314 struct disambiguate_state *ds)
315 {
316 int i;
317
318 if (len < MINIMUM_ABBREV || len > the_hash_algo->hexsz)
319 return -1;
320
321 memset(ds, 0, sizeof(*ds));
322
323 for (i = 0; i < len ;i++) {
324 unsigned char c = name[i];
325 unsigned char val;
326 if (c >= '0' && c <= '9')
327 val = c - '0';
328 else if (c >= 'a' && c <= 'f')
329 val = c - 'a' + 10;
330 else if (c >= 'A' && c <='F') {
331 val = c - 'A' + 10;
332 c -= 'A' - 'a';
333 }
334 else
335 return -1;
336 ds->hex_pfx[i] = c;
337 if (!(i & 1))
338 val <<= 4;
339 ds->bin_pfx.hash[i >> 1] |= val;
340 }
341
342 ds->len = len;
343 ds->hex_pfx[len] = '\0';
344 prepare_alt_odb(the_repository);
345 return 0;
346 }
347
348 static int show_ambiguous_object(const struct object_id *oid, void *data)
349 {
350 const struct disambiguate_state *ds = data;
351 struct strbuf desc = STRBUF_INIT;
352 int type;
353
354 if (ds->fn && !ds->fn(oid, ds->cb_data))
355 return 0;
356
357 type = oid_object_info(the_repository, oid, NULL);
358 if (type == OBJ_COMMIT) {
359 struct commit *commit = lookup_commit(the_repository, oid);
360 if (commit) {
361 struct pretty_print_context pp = {0};
362 pp.date_mode.type = DATE_SHORT;
363 format_commit_message(commit, " %ad - %s", &desc, &pp);
364 }
365 } else if (type == OBJ_TAG) {
366 struct tag *tag = lookup_tag(the_repository, oid);
367 if (!parse_tag(tag) && tag->tag)
368 strbuf_addf(&desc, " %s", tag->tag);
369 }
370
371 advise(" %s %s%s",
372 find_unique_abbrev(oid, DEFAULT_ABBREV),
373 type_name(type) ? type_name(type) : "unknown type",
374 desc.buf);
375
376 strbuf_release(&desc);
377 return 0;
378 }
379
380 static int collect_ambiguous(const struct object_id *oid, void *data)
381 {
382 oid_array_append(data, oid);
383 return 0;
384 }
385
386 static int sort_ambiguous(const void *a, const void *b)
387 {
388 int a_type = oid_object_info(the_repository, a, NULL);
389 int b_type = oid_object_info(the_repository, b, NULL);
390 int a_type_sort;
391 int b_type_sort;
392
393 /*
394 * Sorts by hash within the same object type, just as
395 * oid_array_for_each_unique() would do.
396 */
397 if (a_type == b_type)
398 return oidcmp(a, b);
399
400 /*
401 * Between object types show tags, then commits, and finally
402 * trees and blobs.
403 *
404 * The object_type enum is commit, tree, blob, tag, but we
405 * want tag, commit, tree blob. Cleverly (perhaps too
406 * cleverly) do that with modulus, since the enum assigns 1 to
407 * commit, so tag becomes 0.
408 */
409 a_type_sort = a_type % 4;
410 b_type_sort = b_type % 4;
411 return a_type_sort > b_type_sort ? 1 : -1;
412 }
413
414 static enum get_oid_result get_short_oid(const char *name, int len,
415 struct object_id *oid,
416 unsigned flags)
417 {
418 int status;
419 struct disambiguate_state ds;
420 int quietly = !!(flags & GET_OID_QUIETLY);
421
422 if (init_object_disambiguation(name, len, &ds) < 0)
423 return -1;
424
425 if (HAS_MULTI_BITS(flags & GET_OID_DISAMBIGUATORS))
426 BUG("multiple get_short_oid disambiguator flags");
427
428 if (flags & GET_OID_COMMIT)
429 ds.fn = disambiguate_commit_only;
430 else if (flags & GET_OID_COMMITTISH)
431 ds.fn = disambiguate_committish_only;
432 else if (flags & GET_OID_TREE)
433 ds.fn = disambiguate_tree_only;
434 else if (flags & GET_OID_TREEISH)
435 ds.fn = disambiguate_treeish_only;
436 else if (flags & GET_OID_BLOB)
437 ds.fn = disambiguate_blob_only;
438 else
439 ds.fn = default_disambiguate_hint;
440
441 find_short_object_filename(&ds);
442 find_short_packed_object(&ds);
443 status = finish_object_disambiguation(&ds, oid);
444
445 /*
446 * If we didn't find it, do the usual reprepare() slow-path,
447 * since the object may have recently been added to the repository
448 * or migrated from loose to packed.
449 */
450 if (status == MISSING_OBJECT) {
451 reprepare_packed_git(the_repository);
452 find_short_object_filename(&ds);
453 find_short_packed_object(&ds);
454 status = finish_object_disambiguation(&ds, oid);
455 }
456
457 if (!quietly && (status == SHORT_NAME_AMBIGUOUS)) {
458 struct oid_array collect = OID_ARRAY_INIT;
459
460 error(_("short SHA1 %s is ambiguous"), ds.hex_pfx);
461
462 /*
463 * We may still have ambiguity if we simply saw a series of
464 * candidates that did not satisfy our hint function. In
465 * that case, we still want to show them, so disable the hint
466 * function entirely.
467 */
468 if (!ds.ambiguous)
469 ds.fn = NULL;
470
471 advise(_("The candidates are:"));
472 for_each_abbrev(ds.hex_pfx, collect_ambiguous, &collect);
473 QSORT(collect.oid, collect.nr, sort_ambiguous);
474
475 if (oid_array_for_each(&collect, show_ambiguous_object, &ds))
476 BUG("show_ambiguous_object shouldn't return non-zero");
477 oid_array_clear(&collect);
478 }
479
480 return status;
481 }
482
483 int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
484 {
485 struct oid_array collect = OID_ARRAY_INIT;
486 struct disambiguate_state ds;
487 int ret;
488
489 if (init_object_disambiguation(prefix, strlen(prefix), &ds) < 0)
490 return -1;
491
492 ds.always_call_fn = 1;
493 ds.fn = collect_ambiguous;
494 ds.cb_data = &collect;
495 find_short_object_filename(&ds);
496 find_short_packed_object(&ds);
497
498 ret = oid_array_for_each_unique(&collect, fn, cb_data);
499 oid_array_clear(&collect);
500 return ret;
501 }
502
503 /*
504 * Return the slot of the most-significant bit set in "val". There are various
505 * ways to do this quickly with fls() or __builtin_clzl(), but speed is
506 * probably not a big deal here.
507 */
508 static unsigned msb(unsigned long val)
509 {
510 unsigned r = 0;
511 while (val >>= 1)
512 r++;
513 return r;
514 }
515
516 struct min_abbrev_data {
517 unsigned int init_len;
518 unsigned int cur_len;
519 char *hex;
520 const struct object_id *oid;
521 };
522
523 static inline char get_hex_char_from_oid(const struct object_id *oid,
524 unsigned int pos)
525 {
526 static const char hex[] = "0123456789abcdef";
527
528 if ((pos & 1) == 0)
529 return hex[oid->hash[pos >> 1] >> 4];
530 else
531 return hex[oid->hash[pos >> 1] & 0xf];
532 }
533
534 static int extend_abbrev_len(const struct object_id *oid, void *cb_data)
535 {
536 struct min_abbrev_data *mad = cb_data;
537
538 unsigned int i = mad->init_len;
539 while (mad->hex[i] && mad->hex[i] == get_hex_char_from_oid(oid, i))
540 i++;
541
542 if (i < GIT_MAX_RAWSZ && i >= mad->cur_len)
543 mad->cur_len = i + 1;
544
545 return 0;
546 }
547
548 static void find_abbrev_len_for_midx(struct multi_pack_index *m,
549 struct min_abbrev_data *mad)
550 {
551 int match = 0;
552 uint32_t num, first = 0;
553 struct object_id oid;
554 const struct object_id *mad_oid;
555
556 if (!m->num_objects)
557 return;
558
559 num = m->num_objects;
560 mad_oid = mad->oid;
561 match = bsearch_midx(mad_oid, m, &first);
562
563 /*
564 * first is now the position in the packfile where we would insert
565 * mad->hash if it does not exist (or the position of mad->hash if
566 * it does exist). Hence, we consider a maximum of two objects
567 * nearby for the abbreviation length.
568 */
569 mad->init_len = 0;
570 if (!match) {
571 if (nth_midxed_object_oid(&oid, m, first))
572 extend_abbrev_len(&oid, mad);
573 } else if (first < num - 1) {
574 if (nth_midxed_object_oid(&oid, m, first + 1))
575 extend_abbrev_len(&oid, mad);
576 }
577 if (first > 0) {
578 if (nth_midxed_object_oid(&oid, m, first - 1))
579 extend_abbrev_len(&oid, mad);
580 }
581 mad->init_len = mad->cur_len;
582 }
583
584 static void find_abbrev_len_for_pack(struct packed_git *p,
585 struct min_abbrev_data *mad)
586 {
587 int match = 0;
588 uint32_t num, first = 0;
589 struct object_id oid;
590 const struct object_id *mad_oid;
591
592 if (open_pack_index(p) || !p->num_objects)
593 return;
594
595 num = p->num_objects;
596 mad_oid = mad->oid;
597 match = bsearch_pack(mad_oid, p, &first);
598
599 /*
600 * first is now the position in the packfile where we would insert
601 * mad->hash if it does not exist (or the position of mad->hash if
602 * it does exist). Hence, we consider a maximum of two objects
603 * nearby for the abbreviation length.
604 */
605 mad->init_len = 0;
606 if (!match) {
607 if (nth_packed_object_oid(&oid, p, first))
608 extend_abbrev_len(&oid, mad);
609 } else if (first < num - 1) {
610 if (nth_packed_object_oid(&oid, p, first + 1))
611 extend_abbrev_len(&oid, mad);
612 }
613 if (first > 0) {
614 if (nth_packed_object_oid(&oid, p, first - 1))
615 extend_abbrev_len(&oid, mad);
616 }
617 mad->init_len = mad->cur_len;
618 }
619
620 static void find_abbrev_len_packed(struct min_abbrev_data *mad)
621 {
622 struct multi_pack_index *m;
623 struct packed_git *p;
624
625 for (m = get_multi_pack_index(the_repository); m; m = m->next)
626 find_abbrev_len_for_midx(m, mad);
627 for (p = get_packed_git(the_repository); p; p = p->next)
628 find_abbrev_len_for_pack(p, mad);
629 }
630
631 int find_unique_abbrev_r(char *hex, const struct object_id *oid, int len)
632 {
633 struct disambiguate_state ds;
634 struct min_abbrev_data mad;
635 struct object_id oid_ret;
636 const unsigned hexsz = the_hash_algo->hexsz;
637
638 if (len < 0) {
639 unsigned long count = approximate_object_count();
640 /*
641 * Add one because the MSB only tells us the highest bit set,
642 * not including the value of all the _other_ bits (so "15"
643 * is only one off of 2^4, but the MSB is the 3rd bit.
644 */
645 len = msb(count) + 1;
646 /*
647 * We now know we have on the order of 2^len objects, which
648 * expects a collision at 2^(len/2). But we also care about hex
649 * chars, not bits, and there are 4 bits per hex. So all
650 * together we need to divide by 2 and round up.
651 */
652 len = DIV_ROUND_UP(len, 2);
653 /*
654 * For very small repos, we stick with our regular fallback.
655 */
656 if (len < FALLBACK_DEFAULT_ABBREV)
657 len = FALLBACK_DEFAULT_ABBREV;
658 }
659
660 oid_to_hex_r(hex, oid);
661 if (len == hexsz || !len)
662 return hexsz;
663
664 mad.init_len = len;
665 mad.cur_len = len;
666 mad.hex = hex;
667 mad.oid = oid;
668
669 find_abbrev_len_packed(&mad);
670
671 if (init_object_disambiguation(hex, mad.cur_len, &ds) < 0)
672 return -1;
673
674 ds.fn = extend_abbrev_len;
675 ds.always_call_fn = 1;
676 ds.cb_data = (void *)&mad;
677
678 find_short_object_filename(&ds);
679 (void)finish_object_disambiguation(&ds, &oid_ret);
680
681 hex[mad.cur_len] = 0;
682 return mad.cur_len;
683 }
684
685 const char *find_unique_abbrev(const struct object_id *oid, int len)
686 {
687 static int bufno;
688 static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
689 char *hex = hexbuffer[bufno];
690 bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
691 find_unique_abbrev_r(hex, oid, len);
692 return hex;
693 }
694
695 static int ambiguous_path(const char *path, int len)
696 {
697 int slash = 1;
698 int cnt;
699
700 for (cnt = 0; cnt < len; cnt++) {
701 switch (*path++) {
702 case '\0':
703 break;
704 case '/':
705 if (slash)
706 break;
707 slash = 1;
708 continue;
709 case '.':
710 continue;
711 default:
712 slash = 0;
713 continue;
714 }
715 break;
716 }
717 return slash;
718 }
719
720 static inline int at_mark(const char *string, int len,
721 const char **suffix, int nr)
722 {
723 int i;
724
725 for (i = 0; i < nr; i++) {
726 int suffix_len = strlen(suffix[i]);
727 if (suffix_len <= len
728 && !strncasecmp(string, suffix[i], suffix_len))
729 return suffix_len;
730 }
731 return 0;
732 }
733
734 static inline int upstream_mark(const char *string, int len)
735 {
736 const char *suffix[] = { "@{upstream}", "@{u}" };
737 return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
738 }
739
740 static inline int push_mark(const char *string, int len)
741 {
742 const char *suffix[] = { "@{push}" };
743 return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
744 }
745
746 static enum get_oid_result get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags);
747 static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
748
749 static int get_oid_basic(const char *str, int len, struct object_id *oid,
750 unsigned int flags)
751 {
752 static const char *warn_msg = "refname '%.*s' is ambiguous.";
753 static const char *object_name_msg = N_(
754 "Git normally never creates a ref that ends with 40 hex characters\n"
755 "because it will be ignored when you just specify 40-hex. These refs\n"
756 "may be created by mistake. For example,\n"
757 "\n"
758 " git checkout -b $br $(git rev-parse ...)\n"
759 "\n"
760 "where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
761 "examine these refs and maybe delete them. Turn this message off by\n"
762 "running \"git config advice.objectNameWarning false\"");
763 struct object_id tmp_oid;
764 char *real_ref = NULL;
765 int refs_found = 0;
766 int at, reflog_len, nth_prior = 0;
767
768 if (len == the_hash_algo->hexsz && !get_oid_hex(str, oid)) {
769 if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) {
770 refs_found = dwim_ref(str, len, &tmp_oid, &real_ref);
771 if (refs_found > 0) {
772 warning(warn_msg, len, str);
773 if (advice_object_name_warning)
774 fprintf(stderr, "%s\n", _(object_name_msg));
775 }
776 free(real_ref);
777 }
778 return 0;
779 }
780
781 /* basic@{time or number or -number} format to query ref-log */
782 reflog_len = at = 0;
783 if (len && str[len-1] == '}') {
784 for (at = len-4; at >= 0; at--) {
785 if (str[at] == '@' && str[at+1] == '{') {
786 if (str[at+2] == '-') {
787 if (at != 0)
788 /* @{-N} not at start */
789 return -1;
790 nth_prior = 1;
791 continue;
792 }
793 if (!upstream_mark(str + at, len - at) &&
794 !push_mark(str + at, len - at)) {
795 reflog_len = (len-1) - (at+2);
796 len = at;
797 }
798 break;
799 }
800 }
801 }
802
803 /* Accept only unambiguous ref paths. */
804 if (len && ambiguous_path(str, len))
805 return -1;
806
807 if (nth_prior) {
808 struct strbuf buf = STRBUF_INIT;
809 int detached;
810
811 if (interpret_nth_prior_checkout(str, len, &buf) > 0) {
812 detached = (buf.len == the_hash_algo->hexsz && !get_oid_hex(buf.buf, oid));
813 strbuf_release(&buf);
814 if (detached)
815 return 0;
816 }
817 }
818
819 if (!len && reflog_len)
820 /* allow "@{...}" to mean the current branch reflog */
821 refs_found = dwim_ref("HEAD", 4, oid, &real_ref);
822 else if (reflog_len)
823 refs_found = dwim_log(str, len, oid, &real_ref);
824 else
825 refs_found = dwim_ref(str, len, oid, &real_ref);
826
827 if (!refs_found)
828 return -1;
829
830 if (warn_ambiguous_refs && !(flags & GET_OID_QUIETLY) &&
831 (refs_found > 1 ||
832 !get_short_oid(str, len, &tmp_oid, GET_OID_QUIETLY)))
833 warning(warn_msg, len, str);
834
835 if (reflog_len) {
836 int nth, i;
837 timestamp_t at_time;
838 timestamp_t co_time;
839 int co_tz, co_cnt;
840
841 /* Is it asking for N-th entry, or approxidate? */
842 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
843 char ch = str[at+2+i];
844 if ('0' <= ch && ch <= '9')
845 nth = nth * 10 + ch - '0';
846 else
847 nth = -1;
848 }
849 if (100000000 <= nth) {
850 at_time = nth;
851 nth = -1;
852 } else if (0 <= nth)
853 at_time = 0;
854 else {
855 int errors = 0;
856 char *tmp = xstrndup(str + at + 2, reflog_len);
857 at_time = approxidate_careful(tmp, &errors);
858 free(tmp);
859 if (errors) {
860 free(real_ref);
861 return -1;
862 }
863 }
864 if (read_ref_at(real_ref, flags, at_time, nth, oid, NULL,
865 &co_time, &co_tz, &co_cnt)) {
866 if (!len) {
867 if (starts_with(real_ref, "refs/heads/")) {
868 str = real_ref + 11;
869 len = strlen(real_ref + 11);
870 } else {
871 /* detached HEAD */
872 str = "HEAD";
873 len = 4;
874 }
875 }
876 if (at_time) {
877 if (!(flags & GET_OID_QUIETLY)) {
878 warning("Log for '%.*s' only goes "
879 "back to %s.", len, str,
880 show_date(co_time, co_tz, DATE_MODE(RFC2822)));
881 }
882 } else {
883 if (flags & GET_OID_QUIETLY) {
884 exit(128);
885 }
886 die("Log for '%.*s' only has %d entries.",
887 len, str, co_cnt);
888 }
889 }
890 }
891
892 free(real_ref);
893 return 0;
894 }
895
896 static enum get_oid_result get_parent(const char *name, int len,
897 struct object_id *result, int idx)
898 {
899 struct object_id oid;
900 enum get_oid_result ret = get_oid_1(name, len, &oid,
901 GET_OID_COMMITTISH);
902 struct commit *commit;
903 struct commit_list *p;
904
905 if (ret)
906 return ret;
907 commit = lookup_commit_reference(the_repository, &oid);
908 if (parse_commit(commit))
909 return MISSING_OBJECT;
910 if (!idx) {
911 oidcpy(result, &commit->object.oid);
912 return FOUND;
913 }
914 p = commit->parents;
915 while (p) {
916 if (!--idx) {
917 oidcpy(result, &p->item->object.oid);
918 return FOUND;
919 }
920 p = p->next;
921 }
922 return MISSING_OBJECT;
923 }
924
925 static enum get_oid_result get_nth_ancestor(const char *name, int len,
926 struct object_id *result,
927 int generation)
928 {
929 struct object_id oid;
930 struct commit *commit;
931 int ret;
932
933 ret = get_oid_1(name, len, &oid, GET_OID_COMMITTISH);
934 if (ret)
935 return ret;
936 commit = lookup_commit_reference(the_repository, &oid);
937 if (!commit)
938 return MISSING_OBJECT;
939
940 while (generation--) {
941 if (parse_commit(commit) || !commit->parents)
942 return MISSING_OBJECT;
943 commit = commit->parents->item;
944 }
945 oidcpy(result, &commit->object.oid);
946 return FOUND;
947 }
948
949 struct object *peel_to_type(const char *name, int namelen,
950 struct object *o, enum object_type expected_type)
951 {
952 if (name && !namelen)
953 namelen = strlen(name);
954 while (1) {
955 if (!o || (!o->parsed && !parse_object(the_repository, &o->oid)))
956 return NULL;
957 if (expected_type == OBJ_ANY || o->type == expected_type)
958 return o;
959 if (o->type == OBJ_TAG)
960 o = ((struct tag*) o)->tagged;
961 else if (o->type == OBJ_COMMIT)
962 o = &(get_commit_tree(((struct commit *)o))->object);
963 else {
964 if (name)
965 error("%.*s: expected %s type, but the object "
966 "dereferences to %s type",
967 namelen, name, type_name(expected_type),
968 type_name(o->type));
969 return NULL;
970 }
971 }
972 }
973
974 static int peel_onion(const char *name, int len, struct object_id *oid,
975 unsigned lookup_flags)
976 {
977 struct object_id outer;
978 const char *sp;
979 unsigned int expected_type = 0;
980 struct object *o;
981
982 /*
983 * "ref^{type}" dereferences ref repeatedly until you cannot
984 * dereference anymore, or you get an object of given type,
985 * whichever comes first. "ref^{}" means just dereference
986 * tags until you get a non-tag. "ref^0" is a shorthand for
987 * "ref^{commit}". "commit^{tree}" could be used to find the
988 * top-level tree of the given commit.
989 */
990 if (len < 4 || name[len-1] != '}')
991 return -1;
992
993 for (sp = name + len - 1; name <= sp; sp--) {
994 int ch = *sp;
995 if (ch == '{' && name < sp && sp[-1] == '^')
996 break;
997 }
998 if (sp <= name)
999 return -1;
1000
1001 sp++; /* beginning of type name, or closing brace for empty */
1002 if (starts_with(sp, "commit}"))
1003 expected_type = OBJ_COMMIT;
1004 else if (starts_with(sp, "tag}"))
1005 expected_type = OBJ_TAG;
1006 else if (starts_with(sp, "tree}"))
1007 expected_type = OBJ_TREE;
1008 else if (starts_with(sp, "blob}"))
1009 expected_type = OBJ_BLOB;
1010 else if (starts_with(sp, "object}"))
1011 expected_type = OBJ_ANY;
1012 else if (sp[0] == '}')
1013 expected_type = OBJ_NONE;
1014 else if (sp[0] == '/')
1015 expected_type = OBJ_COMMIT;
1016 else
1017 return -1;
1018
1019 lookup_flags &= ~GET_OID_DISAMBIGUATORS;
1020 if (expected_type == OBJ_COMMIT)
1021 lookup_flags |= GET_OID_COMMITTISH;
1022 else if (expected_type == OBJ_TREE)
1023 lookup_flags |= GET_OID_TREEISH;
1024
1025 if (get_oid_1(name, sp - name - 2, &outer, lookup_flags))
1026 return -1;
1027
1028 o = parse_object(the_repository, &outer);
1029 if (!o)
1030 return -1;
1031 if (!expected_type) {
1032 o = deref_tag(the_repository, o, name, sp - name - 2);
1033 if (!o || (!o->parsed && !parse_object(the_repository, &o->oid)))
1034 return -1;
1035 oidcpy(oid, &o->oid);
1036 return 0;
1037 }
1038
1039 /*
1040 * At this point, the syntax look correct, so
1041 * if we do not get the needed object, we should
1042 * barf.
1043 */
1044 o = peel_to_type(name, len, o, expected_type);
1045 if (!o)
1046 return -1;
1047
1048 oidcpy(oid, &o->oid);
1049 if (sp[0] == '/') {
1050 /* "$commit^{/foo}" */
1051 char *prefix;
1052 int ret;
1053 struct commit_list *list = NULL;
1054
1055 /*
1056 * $commit^{/}. Some regex implementation may reject.
1057 * We don't need regex anyway. '' pattern always matches.
1058 */
1059 if (sp[1] == '}')
1060 return 0;
1061
1062 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
1063 commit_list_insert((struct commit *)o, &list);
1064 ret = get_oid_oneline(prefix, oid, list);
1065 free(prefix);
1066 return ret;
1067 }
1068 return 0;
1069 }
1070
1071 static int get_describe_name(const char *name, int len, struct object_id *oid)
1072 {
1073 const char *cp;
1074 unsigned flags = GET_OID_QUIETLY | GET_OID_COMMIT;
1075
1076 for (cp = name + len - 1; name + 2 <= cp; cp--) {
1077 char ch = *cp;
1078 if (!isxdigit(ch)) {
1079 /* We must be looking at g in "SOMETHING-g"
1080 * for it to be describe output.
1081 */
1082 if (ch == 'g' && cp[-1] == '-') {
1083 cp++;
1084 len -= cp - name;
1085 return get_short_oid(cp, len, oid, flags);
1086 }
1087 }
1088 }
1089 return -1;
1090 }
1091
1092 static enum get_oid_result get_oid_1(const char *name, int len,
1093 struct object_id *oid,
1094 unsigned lookup_flags)
1095 {
1096 int ret, has_suffix;
1097 const char *cp;
1098
1099 /*
1100 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
1101 */
1102 has_suffix = 0;
1103 for (cp = name + len - 1; name <= cp; cp--) {
1104 int ch = *cp;
1105 if ('0' <= ch && ch <= '9')
1106 continue;
1107 if (ch == '~' || ch == '^')
1108 has_suffix = ch;
1109 break;
1110 }
1111
1112 if (has_suffix) {
1113 int num = 0;
1114 int len1 = cp - name;
1115 cp++;
1116 while (cp < name + len)
1117 num = num * 10 + *cp++ - '0';
1118 if (!num && len1 == len - 1)
1119 num = 1;
1120 if (has_suffix == '^')
1121 return get_parent(name, len1, oid, num);
1122 /* else if (has_suffix == '~') -- goes without saying */
1123 return get_nth_ancestor(name, len1, oid, num);
1124 }
1125
1126 ret = peel_onion(name, len, oid, lookup_flags);
1127 if (!ret)
1128 return FOUND;
1129
1130 ret = get_oid_basic(name, len, oid, lookup_flags);
1131 if (!ret)
1132 return FOUND;
1133
1134 /* It could be describe output that is "SOMETHING-gXXXX" */
1135 ret = get_describe_name(name, len, oid);
1136 if (!ret)
1137 return FOUND;
1138
1139 return get_short_oid(name, len, oid, lookup_flags);
1140 }
1141
1142 /*
1143 * This interprets names like ':/Initial revision of "git"' by searching
1144 * through history and returning the first commit whose message starts
1145 * the given regular expression.
1146 *
1147 * For negative-matching, prefix the pattern-part with '!-', like: ':/!-WIP'.
1148 *
1149 * For a literal '!' character at the beginning of a pattern, you have to repeat
1150 * that, like: ':/!!foo'
1151 *
1152 * For future extension, all other sequences beginning with ':/!' are reserved.
1153 */
1154
1155 /* Remember to update object flag allocation in object.h */
1156 #define ONELINE_SEEN (1u<<20)
1157
1158 static int handle_one_ref(const char *path, const struct object_id *oid,
1159 int flag, void *cb_data)
1160 {
1161 struct commit_list **list = cb_data;
1162 struct object *object = parse_object(the_repository, oid);
1163 if (!object)
1164 return 0;
1165 if (object->type == OBJ_TAG) {
1166 object = deref_tag(the_repository, object, path,
1167 strlen(path));
1168 if (!object)
1169 return 0;
1170 }
1171 if (object->type != OBJ_COMMIT)
1172 return 0;
1173 commit_list_insert((struct commit *)object, list);
1174 return 0;
1175 }
1176
1177 static int get_oid_oneline(const char *prefix, struct object_id *oid,
1178 struct commit_list *list)
1179 {
1180 struct commit_list *backup = NULL, *l;
1181 int found = 0;
1182 int negative = 0;
1183 regex_t regex;
1184
1185 if (prefix[0] == '!') {
1186 prefix++;
1187
1188 if (prefix[0] == '-') {
1189 prefix++;
1190 negative = 1;
1191 } else if (prefix[0] != '!') {
1192 return -1;
1193 }
1194 }
1195
1196 if (regcomp(&regex, prefix, REG_EXTENDED))
1197 return -1;
1198
1199 for (l = list; l; l = l->next) {
1200 l->item->object.flags |= ONELINE_SEEN;
1201 commit_list_insert(l->item, &backup);
1202 }
1203 while (list) {
1204 const char *p, *buf;
1205 struct commit *commit;
1206 int matches;
1207
1208 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
1209 if (!parse_object(the_repository, &commit->object.oid))
1210 continue;
1211 buf = get_commit_buffer(commit, NULL);
1212 p = strstr(buf, "\n\n");
1213 matches = negative ^ (p && !regexec(&regex, p + 2, 0, NULL, 0));
1214 unuse_commit_buffer(commit, buf);
1215
1216 if (matches) {
1217 oidcpy(oid, &commit->object.oid);
1218 found = 1;
1219 break;
1220 }
1221 }
1222 regfree(&regex);
1223 free_commit_list(list);
1224 for (l = backup; l; l = l->next)
1225 clear_commit_marks(l->item, ONELINE_SEEN);
1226 free_commit_list(backup);
1227 return found ? 0 : -1;
1228 }
1229
1230 struct grab_nth_branch_switch_cbdata {
1231 int remaining;
1232 struct strbuf buf;
1233 };
1234
1235 static int grab_nth_branch_switch(struct object_id *ooid, struct object_id *noid,
1236 const char *email, timestamp_t timestamp, int tz,
1237 const char *message, void *cb_data)
1238 {
1239 struct grab_nth_branch_switch_cbdata *cb = cb_data;
1240 const char *match = NULL, *target = NULL;
1241 size_t len;
1242
1243 if (skip_prefix(message, "checkout: moving from ", &match))
1244 target = strstr(match, " to ");
1245
1246 if (!match || !target)
1247 return 0;
1248 if (--(cb->remaining) == 0) {
1249 len = target - match;
1250 strbuf_reset(&cb->buf);
1251 strbuf_add(&cb->buf, match, len);
1252 return 1; /* we are done */
1253 }
1254 return 0;
1255 }
1256
1257 /*
1258 * Parse @{-N} syntax, return the number of characters parsed
1259 * if successful; otherwise signal an error with negative value.
1260 */
1261 static int interpret_nth_prior_checkout(const char *name, int namelen,
1262 struct strbuf *buf)
1263 {
1264 long nth;
1265 int retval;
1266 struct grab_nth_branch_switch_cbdata cb;
1267 const char *brace;
1268 char *num_end;
1269
1270 if (namelen < 4)
1271 return -1;
1272 if (name[0] != '@' || name[1] != '{' || name[2] != '-')
1273 return -1;
1274 brace = memchr(name, '}', namelen);
1275 if (!brace)
1276 return -1;
1277 nth = strtol(name + 3, &num_end, 10);
1278 if (num_end != brace)
1279 return -1;
1280 if (nth <= 0)
1281 return -1;
1282 cb.remaining = nth;
1283 strbuf_init(&cb.buf, 20);
1284
1285 retval = 0;
1286 if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
1287 strbuf_reset(buf);
1288 strbuf_addbuf(buf, &cb.buf);
1289 retval = brace - name + 1;
1290 }
1291
1292 strbuf_release(&cb.buf);
1293 return retval;
1294 }
1295
1296 int get_oid_mb(const char *name, struct object_id *oid)
1297 {
1298 struct commit *one, *two;
1299 struct commit_list *mbs;
1300 struct object_id oid_tmp;
1301 const char *dots;
1302 int st;
1303
1304 dots = strstr(name, "...");
1305 if (!dots)
1306 return get_oid(name, oid);
1307 if (dots == name)
1308 st = get_oid("HEAD", &oid_tmp);
1309 else {
1310 struct strbuf sb;
1311 strbuf_init(&sb, dots - name);
1312 strbuf_add(&sb, name, dots - name);
1313 st = get_oid_committish(sb.buf, &oid_tmp);
1314 strbuf_release(&sb);
1315 }
1316 if (st)
1317 return st;
1318 one = lookup_commit_reference_gently(the_repository, &oid_tmp, 0);
1319 if (!one)
1320 return -1;
1321
1322 if (get_oid_committish(dots[3] ? (dots + 3) : "HEAD", &oid_tmp))
1323 return -1;
1324 two = lookup_commit_reference_gently(the_repository, &oid_tmp, 0);
1325 if (!two)
1326 return -1;
1327 mbs = get_merge_bases(one, two);
1328 if (!mbs || mbs->next)
1329 st = -1;
1330 else {
1331 st = 0;
1332 oidcpy(oid, &mbs->item->object.oid);
1333 }
1334 free_commit_list(mbs);
1335 return st;
1336 }
1337
1338 /* parse @something syntax, when 'something' is not {.*} */
1339 static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
1340 {
1341 const char *next;
1342
1343 if (len || name[1] == '{')
1344 return -1;
1345
1346 /* make sure it's a single @, or @@{.*}, not @foo */
1347 next = memchr(name + len + 1, '@', namelen - len - 1);
1348 if (next && next[1] != '{')
1349 return -1;
1350 if (!next)
1351 next = name + namelen;
1352 if (next != name + 1)
1353 return -1;
1354
1355 strbuf_reset(buf);
1356 strbuf_add(buf, "HEAD", 4);
1357 return 1;
1358 }
1359
1360 static int reinterpret(const char *name, int namelen, int len,
1361 struct strbuf *buf, unsigned allowed)
1362 {
1363 /* we have extra data, which might need further processing */
1364 struct strbuf tmp = STRBUF_INIT;
1365 int used = buf->len;
1366 int ret;
1367
1368 strbuf_add(buf, name + len, namelen - len);
1369 ret = interpret_branch_name(buf->buf, buf->len, &tmp, allowed);
1370 /* that data was not interpreted, remove our cruft */
1371 if (ret < 0) {
1372 strbuf_setlen(buf, used);
1373 return len;
1374 }
1375 strbuf_reset(buf);
1376 strbuf_addbuf(buf, &tmp);
1377 strbuf_release(&tmp);
1378 /* tweak for size of {-N} versus expanded ref name */
1379 return ret - used + len;
1380 }
1381
1382 static void set_shortened_ref(struct strbuf *buf, const char *ref)
1383 {
1384 char *s = shorten_unambiguous_ref(ref, 0);
1385 strbuf_reset(buf);
1386 strbuf_addstr(buf, s);
1387 free(s);
1388 }
1389
1390 static int branch_interpret_allowed(const char *refname, unsigned allowed)
1391 {
1392 if (!allowed)
1393 return 1;
1394
1395 if ((allowed & INTERPRET_BRANCH_LOCAL) &&
1396 starts_with(refname, "refs/heads/"))
1397 return 1;
1398 if ((allowed & INTERPRET_BRANCH_REMOTE) &&
1399 starts_with(refname, "refs/remotes/"))
1400 return 1;
1401
1402 return 0;
1403 }
1404
1405 static int interpret_branch_mark(const char *name, int namelen,
1406 int at, struct strbuf *buf,
1407 int (*get_mark)(const char *, int),
1408 const char *(*get_data)(struct branch *,
1409 struct strbuf *),
1410 unsigned allowed)
1411 {
1412 int len;
1413 struct branch *branch;
1414 struct strbuf err = STRBUF_INIT;
1415 const char *value;
1416
1417 len = get_mark(name + at, namelen - at);
1418 if (!len)
1419 return -1;
1420
1421 if (memchr(name, ':', at))
1422 return -1;
1423
1424 if (at) {
1425 char *name_str = xmemdupz(name, at);
1426 branch = branch_get(name_str);
1427 free(name_str);
1428 } else
1429 branch = branch_get(NULL);
1430
1431 value = get_data(branch, &err);
1432 if (!value)
1433 die("%s", err.buf);
1434
1435 if (!branch_interpret_allowed(value, allowed))
1436 return -1;
1437
1438 set_shortened_ref(buf, value);
1439 return len + at;
1440 }
1441
1442 int interpret_branch_name(const char *name, int namelen, struct strbuf *buf,
1443 unsigned allowed)
1444 {
1445 char *at;
1446 const char *start;
1447 int len;
1448
1449 if (!namelen)
1450 namelen = strlen(name);
1451
1452 if (!allowed || (allowed & INTERPRET_BRANCH_LOCAL)) {
1453 len = interpret_nth_prior_checkout(name, namelen, buf);
1454 if (!len) {
1455 return len; /* syntax Ok, not enough switches */
1456 } else if (len > 0) {
1457 if (len == namelen)
1458 return len; /* consumed all */
1459 else
1460 return reinterpret(name, namelen, len, buf, allowed);
1461 }
1462 }
1463
1464 for (start = name;
1465 (at = memchr(start, '@', namelen - (start - name)));
1466 start = at + 1) {
1467
1468 if (!allowed || (allowed & INTERPRET_BRANCH_HEAD)) {
1469 len = interpret_empty_at(name, namelen, at - name, buf);
1470 if (len > 0)
1471 return reinterpret(name, namelen, len, buf,
1472 allowed);
1473 }
1474
1475 len = interpret_branch_mark(name, namelen, at - name, buf,
1476 upstream_mark, branch_get_upstream,
1477 allowed);
1478 if (len > 0)
1479 return len;
1480
1481 len = interpret_branch_mark(name, namelen, at - name, buf,
1482 push_mark, branch_get_push,
1483 allowed);
1484 if (len > 0)
1485 return len;
1486 }
1487
1488 return -1;
1489 }
1490
1491 void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed)
1492 {
1493 int len = strlen(name);
1494 int used = interpret_branch_name(name, len, sb, allowed);
1495
1496 if (used < 0)
1497 used = 0;
1498 strbuf_add(sb, name + used, len - used);
1499 }
1500
1501 int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1502 {
1503 if (startup_info->have_repository)
1504 strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL);
1505 else
1506 strbuf_addstr(sb, name);
1507
1508 /*
1509 * This splice must be done even if we end up rejecting the
1510 * name; builtin/branch.c::copy_or_rename_branch() still wants
1511 * to see what the name expanded to so that "branch -m" can be
1512 * used as a tool to correct earlier mistakes.
1513 */
1514 strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1515
1516 if (*name == '-' ||
1517 !strcmp(sb->buf, "refs/heads/HEAD"))
1518 return -1;
1519
1520 return check_refname_format(sb->buf, 0);
1521 }
1522
1523 /*
1524 * This is like "get_oid_basic()", except it allows "object ID expressions",
1525 * notably "xyz^" for "parent of xyz"
1526 */
1527 int get_oid(const char *name, struct object_id *oid)
1528 {
1529 struct object_context unused;
1530 return get_oid_with_context(the_repository, name, 0, oid, &unused);
1531 }
1532
1533
1534 /*
1535 * Many callers know that the user meant to name a commit-ish by
1536 * syntactical positions where the object name appears. Calling this
1537 * function allows the machinery to disambiguate shorter-than-unique
1538 * abbreviated object names between commit-ish and others.
1539 *
1540 * Note that this does NOT error out when the named object is not a
1541 * commit-ish. It is merely to give a hint to the disambiguation
1542 * machinery.
1543 */
1544 int get_oid_committish(const char *name, struct object_id *oid)
1545 {
1546 struct object_context unused;
1547 return get_oid_with_context(the_repository,
1548 name, GET_OID_COMMITTISH,
1549 oid, &unused);
1550 }
1551
1552 int get_oid_treeish(const char *name, struct object_id *oid)
1553 {
1554 struct object_context unused;
1555 return get_oid_with_context(the_repository,
1556 name, GET_OID_TREEISH,
1557 oid, &unused);
1558 }
1559
1560 int get_oid_commit(const char *name, struct object_id *oid)
1561 {
1562 struct object_context unused;
1563 return get_oid_with_context(the_repository,
1564 name, GET_OID_COMMIT,
1565 oid, &unused);
1566 }
1567
1568 int get_oid_tree(const char *name, struct object_id *oid)
1569 {
1570 struct object_context unused;
1571 return get_oid_with_context(the_repository,
1572 name, GET_OID_TREE,
1573 oid, &unused);
1574 }
1575
1576 int get_oid_blob(const char *name, struct object_id *oid)
1577 {
1578 struct object_context unused;
1579 return get_oid_with_context(the_repository,
1580 name, GET_OID_BLOB,
1581 oid, &unused);
1582 }
1583
1584 /* Must be called only when object_name:filename doesn't exist. */
1585 static void diagnose_invalid_oid_path(const char *prefix,
1586 const char *filename,
1587 const struct object_id *tree_oid,
1588 const char *object_name,
1589 int object_name_len)
1590 {
1591 struct object_id oid;
1592 unsigned mode;
1593
1594 if (!prefix)
1595 prefix = "";
1596
1597 if (file_exists(filename))
1598 die("Path '%s' exists on disk, but not in '%.*s'.",
1599 filename, object_name_len, object_name);
1600 if (is_missing_file_error(errno)) {
1601 char *fullname = xstrfmt("%s%s", prefix, filename);
1602
1603 if (!get_tree_entry(tree_oid, fullname, &oid, &mode)) {
1604 die("Path '%s' exists, but not '%s'.\n"
1605 "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1606 fullname,
1607 filename,
1608 object_name_len, object_name,
1609 fullname,
1610 object_name_len, object_name,
1611 filename);
1612 }
1613 die("Path '%s' does not exist in '%.*s'",
1614 filename, object_name_len, object_name);
1615 }
1616 }
1617
1618 /* Must be called only when :stage:filename doesn't exist. */
1619 static void diagnose_invalid_index_path(struct index_state *istate,
1620 int stage,
1621 const char *prefix,
1622 const char *filename)
1623 {
1624 const struct cache_entry *ce;
1625 int pos;
1626 unsigned namelen = strlen(filename);
1627 struct strbuf fullname = STRBUF_INIT;
1628
1629 if (!prefix)
1630 prefix = "";
1631
1632 /* Wrong stage number? */
1633 pos = index_name_pos(istate, filename, namelen);
1634 if (pos < 0)
1635 pos = -pos - 1;
1636 if (pos < istate->cache_nr) {
1637 ce = istate->cache[pos];
1638 if (ce_namelen(ce) == namelen &&
1639 !memcmp(ce->name, filename, namelen))
1640 die("Path '%s' is in the index, but not at stage %d.\n"
1641 "Did you mean ':%d:%s'?",
1642 filename, stage,
1643 ce_stage(ce), filename);
1644 }
1645
1646 /* Confusion between relative and absolute filenames? */
1647 strbuf_addstr(&fullname, prefix);
1648 strbuf_addstr(&fullname, filename);
1649 pos = index_name_pos(istate, fullname.buf, fullname.len);
1650 if (pos < 0)
1651 pos = -pos - 1;
1652 if (pos < istate->cache_nr) {
1653 ce = istate->cache[pos];
1654 if (ce_namelen(ce) == fullname.len &&
1655 !memcmp(ce->name, fullname.buf, fullname.len))
1656 die("Path '%s' is in the index, but not '%s'.\n"
1657 "Did you mean ':%d:%s' aka ':%d:./%s'?",
1658 fullname.buf, filename,
1659 ce_stage(ce), fullname.buf,
1660 ce_stage(ce), filename);
1661 }
1662
1663 if (file_exists(filename))
1664 die("Path '%s' exists on disk, but not in the index.", filename);
1665 if (is_missing_file_error(errno))
1666 die("Path '%s' does not exist (neither on disk nor in the index).",
1667 filename);
1668
1669 strbuf_release(&fullname);
1670 }
1671
1672
1673 static char *resolve_relative_path(const char *rel)
1674 {
1675 if (!starts_with(rel, "./") && !starts_with(rel, "../"))
1676 return NULL;
1677
1678 if (!is_inside_work_tree())
1679 die("relative path syntax can't be used outside working tree.");
1680
1681 /* die() inside prefix_path() if resolved path is outside worktree */
1682 return prefix_path(startup_info->prefix,
1683 startup_info->prefix ? strlen(startup_info->prefix) : 0,
1684 rel);
1685 }
1686
1687 static enum get_oid_result get_oid_with_context_1(struct repository *repo,
1688 const char *name,
1689 unsigned flags,
1690 const char *prefix,
1691 struct object_id *oid,
1692 struct object_context *oc)
1693 {
1694 int ret, bracket_depth;
1695 int namelen = strlen(name);
1696 const char *cp;
1697 int only_to_die = flags & GET_OID_ONLY_TO_DIE;
1698
1699 if (only_to_die)
1700 flags |= GET_OID_QUIETLY;
1701
1702 memset(oc, 0, sizeof(*oc));
1703 oc->mode = S_IFINVALID;
1704 strbuf_init(&oc->symlink_path, 0);
1705 ret = get_oid_1(name, namelen, oid, flags);
1706 if (!ret)
1707 return ret;
1708 /*
1709 * sha1:path --> object name of path in ent sha1
1710 * :path -> object name of absolute path in index
1711 * :./path -> object name of path relative to cwd in index
1712 * :[0-3]:path -> object name of path in index at stage
1713 * :/foo -> recent commit matching foo
1714 */
1715 if (name[0] == ':') {
1716 int stage = 0;
1717 const struct cache_entry *ce;
1718 char *new_path = NULL;
1719 int pos;
1720 if (!only_to_die && namelen > 2 && name[1] == '/') {
1721 struct commit_list *list = NULL;
1722
1723 for_each_ref(handle_one_ref, &list);
1724 head_ref(handle_one_ref, &list);
1725 commit_list_sort_by_date(&list);
1726 return get_oid_oneline(name + 2, oid, list);
1727 }
1728 if (namelen < 3 ||
1729 name[2] != ':' ||
1730 name[1] < '0' || '3' < name[1])
1731 cp = name + 1;
1732 else {
1733 stage = name[1] - '0';
1734 cp = name + 3;
1735 }
1736 new_path = resolve_relative_path(cp);
1737 if (!new_path) {
1738 namelen = namelen - (cp - name);
1739 } else {
1740 cp = new_path;
1741 namelen = strlen(cp);
1742 }
1743
1744 if (flags & GET_OID_RECORD_PATH)
1745 oc->path = xstrdup(cp);
1746
1747 if (!repo->index->cache)
1748 repo_read_index(the_repository);
1749 pos = index_name_pos(repo->index, cp, namelen);
1750 if (pos < 0)
1751 pos = -pos - 1;
1752 while (pos < repo->index->cache_nr) {
1753 ce = repo->index->cache[pos];
1754 if (ce_namelen(ce) != namelen ||
1755 memcmp(ce->name, cp, namelen))
1756 break;
1757 if (ce_stage(ce) == stage) {
1758 oidcpy(oid, &ce->oid);
1759 oc->mode = ce->ce_mode;
1760 free(new_path);
1761 return 0;
1762 }
1763 pos++;
1764 }
1765 if (only_to_die && name[1] && name[1] != '/')
1766 diagnose_invalid_index_path(repo->index, stage, prefix, cp);
1767 free(new_path);
1768 return -1;
1769 }
1770 for (cp = name, bracket_depth = 0; *cp; cp++) {
1771 if (*cp == '{')
1772 bracket_depth++;
1773 else if (bracket_depth && *cp == '}')
1774 bracket_depth--;
1775 else if (!bracket_depth && *cp == ':')
1776 break;
1777 }
1778 if (*cp == ':') {
1779 struct object_id tree_oid;
1780 int len = cp - name;
1781 unsigned sub_flags = flags;
1782
1783 sub_flags &= ~GET_OID_DISAMBIGUATORS;
1784 sub_flags |= GET_OID_TREEISH;
1785
1786 if (!get_oid_1(name, len, &tree_oid, sub_flags)) {
1787 const char *filename = cp+1;
1788 char *new_filename = NULL;
1789
1790 new_filename = resolve_relative_path(filename);
1791 if (new_filename)
1792 filename = new_filename;
1793 if (flags & GET_OID_FOLLOW_SYMLINKS) {
1794 ret = get_tree_entry_follow_symlinks(&tree_oid,
1795 filename, oid, &oc->symlink_path,
1796 &oc->mode);
1797 } else {
1798 ret = get_tree_entry(&tree_oid, filename, oid,
1799 &oc->mode);
1800 if (ret && only_to_die) {
1801 diagnose_invalid_oid_path(prefix,
1802 filename,
1803 &tree_oid,
1804 name, len);
1805 }
1806 }
1807 if (flags & GET_OID_RECORD_PATH)
1808 oc->path = xstrdup(filename);
1809
1810 free(new_filename);
1811 return ret;
1812 } else {
1813 if (only_to_die)
1814 die("Invalid object name '%.*s'.", len, name);
1815 }
1816 }
1817 return ret;
1818 }
1819
1820 /*
1821 * Call this function when you know "name" given by the end user must
1822 * name an object but it doesn't; the function _may_ die with a better
1823 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1824 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1825 * you have a chance to diagnose the error further.
1826 */
1827 void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1828 {
1829 struct object_context oc;
1830 struct object_id oid;
1831 get_oid_with_context_1(the_repository, name, GET_OID_ONLY_TO_DIE,
1832 prefix, &oid, &oc);
1833 }
1834
1835 enum get_oid_result get_oid_with_context(struct repository *repo,
1836 const char *str,
1837 unsigned flags,
1838 struct object_id *oid,
1839 struct object_context *oc)
1840 {
1841 if (flags & GET_OID_FOLLOW_SYMLINKS && flags & GET_OID_ONLY_TO_DIE)
1842 BUG("incompatible flags for get_sha1_with_context");
1843 return get_oid_with_context_1(repo, str, flags, NULL, oid, oc);
1844 }