1#include "cache.h"
2#include "tag.h"
3#include "commit.h"
4#include "tree.h"
5#include "blob.h"
6#include "tree-walk.h"
7#include "refs.h"
8#include "remote.h"
9
10static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
11
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 unsigned always_call_fn:1;
24};
25
26static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
27{
28 if (ds->always_call_fn) {
29 ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
30 return;
31 }
32 if (!ds->candidate_exists) {
33 /* this is the first candidate */
34 hashcpy(ds->candidate, current);
35 ds->candidate_exists = 1;
36 return;
37 } else if (!hashcmp(ds->candidate, current)) {
38 /* the same as what we already have seen */
39 return;
40 }
41
42 if (!ds->fn) {
43 /* cannot disambiguate between ds->candidate and current */
44 ds->ambiguous = 1;
45 return;
46 }
47
48 if (!ds->candidate_checked) {
49 ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
50 ds->disambiguate_fn_used = 1;
51 ds->candidate_checked = 1;
52 }
53
54 if (!ds->candidate_ok) {
55 /* discard the candidate; we know it does not satisify fn */
56 hashcpy(ds->candidate, current);
57 ds->candidate_checked = 0;
58 return;
59 }
60
61 /* if we reach this point, we know ds->candidate satisfies fn */
62 if (ds->fn(current, ds->cb_data)) {
63 /*
64 * if both current and candidate satisfy fn, we cannot
65 * disambiguate.
66 */
67 ds->candidate_ok = 0;
68 ds->ambiguous = 1;
69 }
70
71 /* otherwise, current can be discarded and candidate is still good */
72}
73
74static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
75{
76 struct alternate_object_database *alt;
77 char hex[40];
78 static struct alternate_object_database *fakeent;
79
80 if (!fakeent) {
81 /*
82 * Create a "fake" alternate object database that
83 * points to our own object database, to make it
84 * easier to get a temporary working space in
85 * alt->name/alt->base while iterating over the
86 * object databases including our own.
87 */
88 const char *objdir = get_object_directory();
89 int objdir_len = strlen(objdir);
90 int entlen = objdir_len + 43;
91 fakeent = xmalloc(sizeof(*fakeent) + entlen);
92 memcpy(fakeent->base, objdir, objdir_len);
93 fakeent->name = fakeent->base + objdir_len + 1;
94 fakeent->name[-1] = '/';
95 }
96 fakeent->next = alt_odb_list;
97
98 sprintf(hex, "%.2s", hex_pfx);
99 for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
100 struct dirent *de;
101 DIR *dir;
102 sprintf(alt->name, "%.2s/", hex_pfx);
103 dir = opendir(alt->base);
104 if (!dir)
105 continue;
106
107 while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
108 unsigned char sha1[20];
109
110 if (strlen(de->d_name) != 38)
111 continue;
112 if (memcmp(de->d_name, hex_pfx + 2, len - 2))
113 continue;
114 memcpy(hex + 2, de->d_name, 38);
115 if (!get_sha1_hex(hex, sha1))
116 update_candidates(ds, sha1);
117 }
118 closedir(dir);
119 }
120}
121
122static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
123{
124 do {
125 if (*a != *b)
126 return 0;
127 a++;
128 b++;
129 len -= 2;
130 } while (len > 1);
131 if (len)
132 if ((*a ^ *b) & 0xf0)
133 return 0;
134 return 1;
135}
136
137static void unique_in_pack(int len,
138 const unsigned char *bin_pfx,
139 struct packed_git *p,
140 struct disambiguate_state *ds)
141{
142 uint32_t num, last, i, first = 0;
143 const unsigned char *current = NULL;
144
145 open_pack_index(p);
146 num = p->num_objects;
147 last = num;
148 while (first < last) {
149 uint32_t mid = (first + last) / 2;
150 const unsigned char *current;
151 int cmp;
152
153 current = nth_packed_object_sha1(p, mid);
154 cmp = hashcmp(bin_pfx, current);
155 if (!cmp) {
156 first = mid;
157 break;
158 }
159 if (cmp > 0) {
160 first = mid+1;
161 continue;
162 }
163 last = mid;
164 }
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 current = nth_packed_object_sha1(p, i);
173 if (!match_sha(len, bin_pfx, current))
174 break;
175 update_candidates(ds, current);
176 }
177}
178
179static void find_short_packed_object(int len, const unsigned char *bin_pfx,
180 struct disambiguate_state *ds)
181{
182 struct packed_git *p;
183
184 prepare_packed_git();
185 for (p = packed_git; p && !ds->ambiguous; p = p->next)
186 unique_in_pack(len, bin_pfx, p, ds);
187}
188
189#define SHORT_NAME_NOT_FOUND (-1)
190#define SHORT_NAME_AMBIGUOUS (-2)
191
192static int finish_object_disambiguation(struct disambiguate_state *ds,
193 unsigned char *sha1)
194{
195 if (ds->ambiguous)
196 return SHORT_NAME_AMBIGUOUS;
197
198 if (!ds->candidate_exists)
199 return SHORT_NAME_NOT_FOUND;
200
201 if (!ds->candidate_checked)
202 /*
203 * If this is the only candidate, there is no point
204 * calling the disambiguation hint callback.
205 *
206 * On the other hand, if the current candidate
207 * replaced an earlier candidate that did _not_ pass
208 * the disambiguation hint callback, then we do have
209 * more than one objects that match the short name
210 * given, so we should make sure this one matches;
211 * otherwise, if we discovered this one and the one
212 * that we previously discarded in the reverse order,
213 * we would end up showing different results in the
214 * same repository!
215 */
216 ds->candidate_ok = (!ds->disambiguate_fn_used ||
217 ds->fn(ds->candidate, ds->cb_data));
218
219 if (!ds->candidate_ok)
220 return SHORT_NAME_AMBIGUOUS;
221
222 hashcpy(sha1, ds->candidate);
223 return 0;
224}
225
226static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
227{
228 int kind = sha1_object_info(sha1, NULL);
229 return kind == OBJ_COMMIT;
230}
231
232static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
233{
234 struct object *obj;
235 int kind;
236
237 kind = sha1_object_info(sha1, NULL);
238 if (kind == OBJ_COMMIT)
239 return 1;
240 if (kind != OBJ_TAG)
241 return 0;
242
243 /* We need to do this the hard way... */
244 obj = deref_tag(parse_object(sha1), NULL, 0);
245 if (obj && obj->type == OBJ_COMMIT)
246 return 1;
247 return 0;
248}
249
250static int disambiguate_tree_only(const unsigned char *sha1, void *cb_data_unused)
251{
252 int kind = sha1_object_info(sha1, NULL);
253 return kind == OBJ_TREE;
254}
255
256static int disambiguate_treeish_only(const unsigned char *sha1, void *cb_data_unused)
257{
258 struct object *obj;
259 int kind;
260
261 kind = sha1_object_info(sha1, NULL);
262 if (kind == OBJ_TREE || kind == OBJ_COMMIT)
263 return 1;
264 if (kind != OBJ_TAG)
265 return 0;
266
267 /* We need to do this the hard way... */
268 obj = deref_tag(lookup_object(sha1), NULL, 0);
269 if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
270 return 1;
271 return 0;
272}
273
274static int disambiguate_blob_only(const unsigned char *sha1, void *cb_data_unused)
275{
276 int kind = sha1_object_info(sha1, NULL);
277 return kind == OBJ_BLOB;
278}
279
280static int prepare_prefixes(const char *name, int len,
281 unsigned char *bin_pfx,
282 char *hex_pfx)
283{
284 int i;
285
286 hashclr(bin_pfx);
287 memset(hex_pfx, 'x', 40);
288 for (i = 0; i < len ;i++) {
289 unsigned char c = name[i];
290 unsigned char val;
291 if (c >= '0' && c <= '9')
292 val = c - '0';
293 else if (c >= 'a' && c <= 'f')
294 val = c - 'a' + 10;
295 else if (c >= 'A' && c <='F') {
296 val = c - 'A' + 10;
297 c -= 'A' - 'a';
298 }
299 else
300 return -1;
301 hex_pfx[i] = c;
302 if (!(i & 1))
303 val <<= 4;
304 bin_pfx[i >> 1] |= val;
305 }
306 return 0;
307}
308
309static int get_short_sha1(const char *name, int len, unsigned char *sha1,
310 unsigned flags)
311{
312 int status;
313 char hex_pfx[40];
314 unsigned char bin_pfx[20];
315 struct disambiguate_state ds;
316 int quietly = !!(flags & GET_SHA1_QUIETLY);
317
318 if (len < MINIMUM_ABBREV || len > 40)
319 return -1;
320 if (prepare_prefixes(name, len, bin_pfx, hex_pfx) < 0)
321 return -1;
322
323 prepare_alt_odb();
324
325 memset(&ds, 0, sizeof(ds));
326 if (flags & GET_SHA1_COMMIT)
327 ds.fn = disambiguate_commit_only;
328 else if (flags & GET_SHA1_COMMITTISH)
329 ds.fn = disambiguate_committish_only;
330 else if (flags & GET_SHA1_TREE)
331 ds.fn = disambiguate_tree_only;
332 else if (flags & GET_SHA1_TREEISH)
333 ds.fn = disambiguate_treeish_only;
334 else if (flags & GET_SHA1_BLOB)
335 ds.fn = disambiguate_blob_only;
336
337 find_short_object_filename(len, hex_pfx, &ds);
338 find_short_packed_object(len, bin_pfx, &ds);
339 status = finish_object_disambiguation(&ds, sha1);
340
341 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
342 return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
343 return status;
344}
345
346
347int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
348{
349 char hex_pfx[40];
350 unsigned char bin_pfx[20];
351 struct disambiguate_state ds;
352 int len = strlen(prefix);
353
354 if (len < MINIMUM_ABBREV || len > 40)
355 return -1;
356 if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
357 return -1;
358
359 prepare_alt_odb();
360
361 memset(&ds, 0, sizeof(ds));
362 ds.always_call_fn = 1;
363 ds.cb_data = cb_data;
364 ds.fn = fn;
365
366 find_short_object_filename(len, hex_pfx, &ds);
367 find_short_packed_object(len, bin_pfx, &ds);
368 return ds.ambiguous;
369}
370
371const char *find_unique_abbrev(const unsigned char *sha1, int len)
372{
373 int status, exists;
374 static char hex[41];
375
376 exists = has_sha1_file(sha1);
377 memcpy(hex, sha1_to_hex(sha1), 40);
378 if (len == 40 || !len)
379 return hex;
380 while (len < 40) {
381 unsigned char sha1_ret[20];
382 status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
383 if (exists
384 ? !status
385 : status == SHORT_NAME_NOT_FOUND) {
386 hex[len] = 0;
387 return hex;
388 }
389 len++;
390 }
391 return hex;
392}
393
394static int ambiguous_path(const char *path, int len)
395{
396 int slash = 1;
397 int cnt;
398
399 for (cnt = 0; cnt < len; cnt++) {
400 switch (*path++) {
401 case '\0':
402 break;
403 case '/':
404 if (slash)
405 break;
406 slash = 1;
407 continue;
408 case '.':
409 continue;
410 default:
411 slash = 0;
412 continue;
413 }
414 break;
415 }
416 return slash;
417}
418
419static inline int upstream_mark(const char *string, int len)
420{
421 const char *suffix[] = { "@{upstream}", "@{u}" };
422 int i;
423
424 for (i = 0; i < ARRAY_SIZE(suffix); i++) {
425 int suffix_len = strlen(suffix[i]);
426 if (suffix_len <= len
427 && !memcmp(string, suffix[i], suffix_len))
428 return suffix_len;
429 }
430 return 0;
431}
432
433static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
434
435static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
436{
437 static const char *warn_msg = "refname '%.*s' is ambiguous.";
438 char *real_ref = NULL;
439 int refs_found = 0;
440 int at, reflog_len;
441
442 if (len == 40 && !get_sha1_hex(str, sha1))
443 return 0;
444
445 /* basic@{time or number or -number} format to query ref-log */
446 reflog_len = at = 0;
447 if (len && str[len-1] == '}') {
448 for (at = len-2; at >= 0; at--) {
449 if (str[at] == '@' && str[at+1] == '{') {
450 if (!upstream_mark(str + at, len - at)) {
451 reflog_len = (len-1) - (at+2);
452 len = at;
453 }
454 break;
455 }
456 }
457 }
458
459 /* Accept only unambiguous ref paths. */
460 if (len && ambiguous_path(str, len))
461 return -1;
462
463 if (!len && reflog_len) {
464 struct strbuf buf = STRBUF_INIT;
465 int ret;
466 /* try the @{-N} syntax for n-th checkout */
467 ret = interpret_branch_name(str+at, &buf);
468 if (ret > 0) {
469 /* substitute this branch name and restart */
470 return get_sha1_1(buf.buf, buf.len, sha1, 0);
471 } else if (ret == 0) {
472 return -1;
473 }
474 /* allow "@{...}" to mean the current branch reflog */
475 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
476 } else if (reflog_len)
477 refs_found = dwim_log(str, len, sha1, &real_ref);
478 else
479 refs_found = dwim_ref(str, len, sha1, &real_ref);
480
481 if (!refs_found)
482 return -1;
483
484 if (warn_ambiguous_refs && refs_found > 1)
485 warning(warn_msg, len, str);
486
487 if (reflog_len) {
488 int nth, i;
489 unsigned long at_time;
490 unsigned long co_time;
491 int co_tz, co_cnt;
492
493 /* a @{-N} placed anywhere except the start is an error */
494 if (str[at+2] == '-')
495 return -1;
496
497 /* Is it asking for N-th entry, or approxidate? */
498 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
499 char ch = str[at+2+i];
500 if ('0' <= ch && ch <= '9')
501 nth = nth * 10 + ch - '0';
502 else
503 nth = -1;
504 }
505 if (100000000 <= nth) {
506 at_time = nth;
507 nth = -1;
508 } else if (0 <= nth)
509 at_time = 0;
510 else {
511 int errors = 0;
512 char *tmp = xstrndup(str + at + 2, reflog_len);
513 at_time = approxidate_careful(tmp, &errors);
514 free(tmp);
515 if (errors)
516 return -1;
517 }
518 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
519 &co_time, &co_tz, &co_cnt)) {
520 if (!len) {
521 if (!prefixcmp(real_ref, "refs/heads/")) {
522 str = real_ref + 11;
523 len = strlen(real_ref + 11);
524 } else {
525 /* detached HEAD */
526 str = "HEAD";
527 len = 4;
528 }
529 }
530 if (at_time)
531 warning("Log for '%.*s' only goes "
532 "back to %s.", len, str,
533 show_date(co_time, co_tz, DATE_RFC2822));
534 else {
535 die("Log for '%.*s' only has %d entries.",
536 len, str, co_cnt);
537 }
538 }
539 }
540
541 free(real_ref);
542 return 0;
543}
544
545static int get_parent(const char *name, int len,
546 unsigned char *result, int idx)
547{
548 unsigned char sha1[20];
549 int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
550 struct commit *commit;
551 struct commit_list *p;
552
553 if (ret)
554 return ret;
555 commit = lookup_commit_reference(sha1);
556 if (!commit)
557 return -1;
558 if (parse_commit(commit))
559 return -1;
560 if (!idx) {
561 hashcpy(result, commit->object.sha1);
562 return 0;
563 }
564 p = commit->parents;
565 while (p) {
566 if (!--idx) {
567 hashcpy(result, p->item->object.sha1);
568 return 0;
569 }
570 p = p->next;
571 }
572 return -1;
573}
574
575static int get_nth_ancestor(const char *name, int len,
576 unsigned char *result, int generation)
577{
578 unsigned char sha1[20];
579 struct commit *commit;
580 int ret;
581
582 ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
583 if (ret)
584 return ret;
585 commit = lookup_commit_reference(sha1);
586 if (!commit)
587 return -1;
588
589 while (generation--) {
590 if (parse_commit(commit) || !commit->parents)
591 return -1;
592 commit = commit->parents->item;
593 }
594 hashcpy(result, commit->object.sha1);
595 return 0;
596}
597
598struct object *peel_to_type(const char *name, int namelen,
599 struct object *o, enum object_type expected_type)
600{
601 if (name && !namelen)
602 namelen = strlen(name);
603 while (1) {
604 if (!o || (!o->parsed && !parse_object(o->sha1)))
605 return NULL;
606 if (expected_type == OBJ_ANY || o->type == expected_type)
607 return o;
608 if (o->type == OBJ_TAG)
609 o = ((struct tag*) o)->tagged;
610 else if (o->type == OBJ_COMMIT)
611 o = &(((struct commit *) o)->tree->object);
612 else {
613 if (name)
614 error("%.*s: expected %s type, but the object "
615 "dereferences to %s type",
616 namelen, name, typename(expected_type),
617 typename(o->type));
618 return NULL;
619 }
620 }
621}
622
623static int peel_onion(const char *name, int len, unsigned char *sha1)
624{
625 unsigned char outer[20];
626 const char *sp;
627 unsigned int expected_type = 0;
628 unsigned lookup_flags = 0;
629 struct object *o;
630
631 /*
632 * "ref^{type}" dereferences ref repeatedly until you cannot
633 * dereference anymore, or you get an object of given type,
634 * whichever comes first. "ref^{}" means just dereference
635 * tags until you get a non-tag. "ref^0" is a shorthand for
636 * "ref^{commit}". "commit^{tree}" could be used to find the
637 * top-level tree of the given commit.
638 */
639 if (len < 4 || name[len-1] != '}')
640 return -1;
641
642 for (sp = name + len - 1; name <= sp; sp--) {
643 int ch = *sp;
644 if (ch == '{' && name < sp && sp[-1] == '^')
645 break;
646 }
647 if (sp <= name)
648 return -1;
649
650 sp++; /* beginning of type name, or closing brace for empty */
651 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
652 expected_type = OBJ_COMMIT;
653 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
654 expected_type = OBJ_TREE;
655 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
656 expected_type = OBJ_BLOB;
657 else if (!prefixcmp(sp, "object}"))
658 expected_type = OBJ_ANY;
659 else if (sp[0] == '}')
660 expected_type = OBJ_NONE;
661 else if (sp[0] == '/')
662 expected_type = OBJ_COMMIT;
663 else
664 return -1;
665
666 if (expected_type == OBJ_COMMIT)
667 lookup_flags = GET_SHA1_COMMITTISH;
668 else if (expected_type == OBJ_TREE)
669 lookup_flags = GET_SHA1_TREEISH;
670
671 if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
672 return -1;
673
674 o = parse_object(outer);
675 if (!o)
676 return -1;
677 if (!expected_type) {
678 o = deref_tag(o, name, sp - name - 2);
679 if (!o || (!o->parsed && !parse_object(o->sha1)))
680 return -1;
681 hashcpy(sha1, o->sha1);
682 return 0;
683 }
684
685 /*
686 * At this point, the syntax look correct, so
687 * if we do not get the needed object, we should
688 * barf.
689 */
690 o = peel_to_type(name, len, o, expected_type);
691 if (!o)
692 return -1;
693
694 hashcpy(sha1, o->sha1);
695 if (sp[0] == '/') {
696 /* "$commit^{/foo}" */
697 char *prefix;
698 int ret;
699 struct commit_list *list = NULL;
700
701 /*
702 * $commit^{/}. Some regex implementation may reject.
703 * We don't need regex anyway. '' pattern always matches.
704 */
705 if (sp[1] == '}')
706 return 0;
707
708 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
709 commit_list_insert((struct commit *)o, &list);
710 ret = get_sha1_oneline(prefix, sha1, list);
711 free(prefix);
712 return ret;
713 }
714 return 0;
715}
716
717static int get_describe_name(const char *name, int len, unsigned char *sha1)
718{
719 const char *cp;
720 unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
721
722 for (cp = name + len - 1; name + 2 <= cp; cp--) {
723 char ch = *cp;
724 if (hexval(ch) & ~0377) {
725 /* We must be looking at g in "SOMETHING-g"
726 * for it to be describe output.
727 */
728 if (ch == 'g' && cp[-1] == '-') {
729 cp++;
730 len -= cp - name;
731 return get_short_sha1(cp, len, sha1, flags);
732 }
733 }
734 }
735 return -1;
736}
737
738static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
739{
740 int ret, has_suffix;
741 const char *cp;
742
743 /*
744 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
745 */
746 has_suffix = 0;
747 for (cp = name + len - 1; name <= cp; cp--) {
748 int ch = *cp;
749 if ('0' <= ch && ch <= '9')
750 continue;
751 if (ch == '~' || ch == '^')
752 has_suffix = ch;
753 break;
754 }
755
756 if (has_suffix) {
757 int num = 0;
758 int len1 = cp - name;
759 cp++;
760 while (cp < name + len)
761 num = num * 10 + *cp++ - '0';
762 if (!num && len1 == len - 1)
763 num = 1;
764 if (has_suffix == '^')
765 return get_parent(name, len1, sha1, num);
766 /* else if (has_suffix == '~') -- goes without saying */
767 return get_nth_ancestor(name, len1, sha1, num);
768 }
769
770 ret = peel_onion(name, len, sha1);
771 if (!ret)
772 return 0;
773
774 ret = get_sha1_basic(name, len, sha1);
775 if (!ret)
776 return 0;
777
778 /* It could be describe output that is "SOMETHING-gXXXX" */
779 ret = get_describe_name(name, len, sha1);
780 if (!ret)
781 return 0;
782
783 return get_short_sha1(name, len, sha1, lookup_flags);
784}
785
786/*
787 * This interprets names like ':/Initial revision of "git"' by searching
788 * through history and returning the first commit whose message starts
789 * the given regular expression.
790 *
791 * For future extension, ':/!' is reserved. If you want to match a message
792 * beginning with a '!', you have to repeat the exclamation mark.
793 */
794#define ONELINE_SEEN (1u<<20)
795
796static int handle_one_ref(const char *path,
797 const unsigned char *sha1, int flag, void *cb_data)
798{
799 struct commit_list **list = cb_data;
800 struct object *object = parse_object(sha1);
801 if (!object)
802 return 0;
803 if (object->type == OBJ_TAG) {
804 object = deref_tag(object, path, strlen(path));
805 if (!object)
806 return 0;
807 }
808 if (object->type != OBJ_COMMIT)
809 return 0;
810 commit_list_insert_by_date((struct commit *)object, list);
811 return 0;
812}
813
814static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
815 struct commit_list *list)
816{
817 struct commit_list *backup = NULL, *l;
818 int found = 0;
819 regex_t regex;
820
821 if (prefix[0] == '!') {
822 if (prefix[1] != '!')
823 die ("Invalid search pattern: %s", prefix);
824 prefix++;
825 }
826
827 if (regcomp(®ex, prefix, REG_EXTENDED))
828 die("Invalid search pattern: %s", prefix);
829
830 for (l = list; l; l = l->next) {
831 l->item->object.flags |= ONELINE_SEEN;
832 commit_list_insert(l->item, &backup);
833 }
834 while (list) {
835 char *p, *to_free = NULL;
836 struct commit *commit;
837 enum object_type type;
838 unsigned long size;
839 int matches;
840
841 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
842 if (!parse_object(commit->object.sha1))
843 continue;
844 if (commit->buffer)
845 p = commit->buffer;
846 else {
847 p = read_sha1_file(commit->object.sha1, &type, &size);
848 if (!p)
849 continue;
850 to_free = p;
851 }
852
853 p = strstr(p, "\n\n");
854 matches = p && !regexec(®ex, p + 2, 0, NULL, 0);
855 free(to_free);
856
857 if (matches) {
858 hashcpy(sha1, commit->object.sha1);
859 found = 1;
860 break;
861 }
862 }
863 regfree(®ex);
864 free_commit_list(list);
865 for (l = backup; l; l = l->next)
866 clear_commit_marks(l->item, ONELINE_SEEN);
867 free_commit_list(backup);
868 return found ? 0 : -1;
869}
870
871struct grab_nth_branch_switch_cbdata {
872 int remaining;
873 struct strbuf buf;
874};
875
876static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
877 const char *email, unsigned long timestamp, int tz,
878 const char *message, void *cb_data)
879{
880 struct grab_nth_branch_switch_cbdata *cb = cb_data;
881 const char *match = NULL, *target = NULL;
882 size_t len;
883
884 if (!prefixcmp(message, "checkout: moving from ")) {
885 match = message + strlen("checkout: moving from ");
886 target = strstr(match, " to ");
887 }
888
889 if (!match || !target)
890 return 0;
891 if (--(cb->remaining) == 0) {
892 len = target - match;
893 strbuf_reset(&cb->buf);
894 strbuf_add(&cb->buf, match, len);
895 return 1; /* we are done */
896 }
897 return 0;
898}
899
900/*
901 * Parse @{-N} syntax, return the number of characters parsed
902 * if successful; otherwise signal an error with negative value.
903 */
904static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
905{
906 long nth;
907 int retval;
908 struct grab_nth_branch_switch_cbdata cb;
909 const char *brace;
910 char *num_end;
911
912 if (name[0] != '@' || name[1] != '{' || name[2] != '-')
913 return -1;
914 brace = strchr(name, '}');
915 if (!brace)
916 return -1;
917 nth = strtol(name + 3, &num_end, 10);
918 if (num_end != brace)
919 return -1;
920 if (nth <= 0)
921 return -1;
922 cb.remaining = nth;
923 strbuf_init(&cb.buf, 20);
924
925 retval = 0;
926 if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
927 strbuf_reset(buf);
928 strbuf_add(buf, cb.buf.buf, cb.buf.len);
929 retval = brace - name + 1;
930 }
931
932 strbuf_release(&cb.buf);
933 return retval;
934}
935
936int get_sha1_mb(const char *name, unsigned char *sha1)
937{
938 struct commit *one, *two;
939 struct commit_list *mbs;
940 unsigned char sha1_tmp[20];
941 const char *dots;
942 int st;
943
944 dots = strstr(name, "...");
945 if (!dots)
946 return get_sha1(name, sha1);
947 if (dots == name)
948 st = get_sha1("HEAD", sha1_tmp);
949 else {
950 struct strbuf sb;
951 strbuf_init(&sb, dots - name);
952 strbuf_add(&sb, name, dots - name);
953 st = get_sha1_committish(sb.buf, sha1_tmp);
954 strbuf_release(&sb);
955 }
956 if (st)
957 return st;
958 one = lookup_commit_reference_gently(sha1_tmp, 0);
959 if (!one)
960 return -1;
961
962 if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
963 return -1;
964 two = lookup_commit_reference_gently(sha1_tmp, 0);
965 if (!two)
966 return -1;
967 mbs = get_merge_bases(one, two, 1);
968 if (!mbs || mbs->next)
969 st = -1;
970 else {
971 st = 0;
972 hashcpy(sha1, mbs->item->object.sha1);
973 }
974 free_commit_list(mbs);
975 return st;
976}
977
978/*
979 * This reads short-hand syntax that not only evaluates to a commit
980 * object name, but also can act as if the end user spelled the name
981 * of the branch from the command line.
982 *
983 * - "@{-N}" finds the name of the Nth previous branch we were on, and
984 * places the name of the branch in the given buf and returns the
985 * number of characters parsed if successful.
986 *
987 * - "<branch>@{upstream}" finds the name of the other ref that
988 * <branch> is configured to merge with (missing <branch> defaults
989 * to the current branch), and places the name of the branch in the
990 * given buf and returns the number of characters parsed if
991 * successful.
992 *
993 * If the input is not of the accepted format, it returns a negative
994 * number to signal an error.
995 *
996 * If the input was ok but there are not N branch switches in the
997 * reflog, it returns 0.
998 */
999int interpret_branch_name(const char *name, struct strbuf *buf)
1000{
1001 char *cp;
1002 struct branch *upstream;
1003 int namelen = strlen(name);
1004 int len = interpret_nth_prior_checkout(name, buf);
1005 int tmp_len;
1006
1007 if (!len)
1008 return len; /* syntax Ok, not enough switches */
1009 if (0 < len && len == namelen)
1010 return len; /* consumed all */
1011 else if (0 < len) {
1012 /* we have extra data, which might need further processing */
1013 struct strbuf tmp = STRBUF_INIT;
1014 int used = buf->len;
1015 int ret;
1016
1017 strbuf_add(buf, name + len, namelen - len);
1018 ret = interpret_branch_name(buf->buf, &tmp);
1019 /* that data was not interpreted, remove our cruft */
1020 if (ret < 0) {
1021 strbuf_setlen(buf, used);
1022 return len;
1023 }
1024 strbuf_reset(buf);
1025 strbuf_addbuf(buf, &tmp);
1026 strbuf_release(&tmp);
1027 /* tweak for size of {-N} versus expanded ref name */
1028 return ret - used + len;
1029 }
1030
1031 cp = strchr(name, '@');
1032 if (!cp)
1033 return -1;
1034 tmp_len = upstream_mark(cp, namelen - (cp - name));
1035 if (!tmp_len)
1036 return -1;
1037 len = cp + tmp_len - name;
1038 cp = xstrndup(name, cp - name);
1039 upstream = branch_get(*cp ? cp : NULL);
1040 /*
1041 * Upstream can be NULL only if cp refers to HEAD and HEAD
1042 * points to something different than a branch.
1043 */
1044 if (!upstream)
1045 die(_("HEAD does not point to a branch"));
1046 if (!upstream->merge || !upstream->merge[0]->dst) {
1047 if (!ref_exists(upstream->refname))
1048 die(_("No such branch: '%s'"), cp);
1049 if (!upstream->merge) {
1050 die(_("No upstream configured for branch '%s'"),
1051 upstream->name);
1052 }
1053 die(
1054 _("Upstream branch '%s' not stored as a remote-tracking branch"),
1055 upstream->merge[0]->src);
1056 }
1057 free(cp);
1058 cp = shorten_unambiguous_ref(upstream->merge[0]->dst, 0);
1059 strbuf_reset(buf);
1060 strbuf_addstr(buf, cp);
1061 free(cp);
1062 return len;
1063}
1064
1065int strbuf_branchname(struct strbuf *sb, const char *name)
1066{
1067 int len = strlen(name);
1068 int used = interpret_branch_name(name, sb);
1069
1070 if (used == len)
1071 return 0;
1072 if (used < 0)
1073 used = 0;
1074 strbuf_add(sb, name + used, len - used);
1075 return len;
1076}
1077
1078int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1079{
1080 strbuf_branchname(sb, name);
1081 if (name[0] == '-')
1082 return -1;
1083 strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1084 return check_refname_format(sb->buf, 0);
1085}
1086
1087/*
1088 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
1089 * notably "xyz^" for "parent of xyz"
1090 */
1091int get_sha1(const char *name, unsigned char *sha1)
1092{
1093 struct object_context unused;
1094 return get_sha1_with_context(name, 0, sha1, &unused);
1095}
1096
1097/*
1098 * Many callers know that the user meant to name a committish by
1099 * syntactical positions where the object name appears. Calling this
1100 * function allows the machinery to disambiguate shorter-than-unique
1101 * abbreviated object names between committish and others.
1102 *
1103 * Note that this does NOT error out when the named object is not a
1104 * committish. It is merely to give a hint to the disambiguation
1105 * machinery.
1106 */
1107int get_sha1_committish(const char *name, unsigned char *sha1)
1108{
1109 struct object_context unused;
1110 return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
1111 sha1, &unused);
1112}
1113
1114int get_sha1_treeish(const char *name, unsigned char *sha1)
1115{
1116 struct object_context unused;
1117 return get_sha1_with_context(name, GET_SHA1_TREEISH,
1118 sha1, &unused);
1119}
1120
1121int get_sha1_commit(const char *name, unsigned char *sha1)
1122{
1123 struct object_context unused;
1124 return get_sha1_with_context(name, GET_SHA1_COMMIT,
1125 sha1, &unused);
1126}
1127
1128int get_sha1_tree(const char *name, unsigned char *sha1)
1129{
1130 struct object_context unused;
1131 return get_sha1_with_context(name, GET_SHA1_TREE,
1132 sha1, &unused);
1133}
1134
1135int get_sha1_blob(const char *name, unsigned char *sha1)
1136{
1137 struct object_context unused;
1138 return get_sha1_with_context(name, GET_SHA1_BLOB,
1139 sha1, &unused);
1140}
1141
1142/* Must be called only when object_name:filename doesn't exist. */
1143static void diagnose_invalid_sha1_path(const char *prefix,
1144 const char *filename,
1145 const unsigned char *tree_sha1,
1146 const char *object_name,
1147 int object_name_len)
1148{
1149 struct stat st;
1150 unsigned char sha1[20];
1151 unsigned mode;
1152
1153 if (!prefix)
1154 prefix = "";
1155
1156 if (!lstat(filename, &st))
1157 die("Path '%s' exists on disk, but not in '%.*s'.",
1158 filename, object_name_len, object_name);
1159 if (errno == ENOENT || errno == ENOTDIR) {
1160 char *fullname = xmalloc(strlen(filename)
1161 + strlen(prefix) + 1);
1162 strcpy(fullname, prefix);
1163 strcat(fullname, filename);
1164
1165 if (!get_tree_entry(tree_sha1, fullname,
1166 sha1, &mode)) {
1167 die("Path '%s' exists, but not '%s'.\n"
1168 "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1169 fullname,
1170 filename,
1171 object_name_len, object_name,
1172 fullname,
1173 object_name_len, object_name,
1174 filename);
1175 }
1176 die("Path '%s' does not exist in '%.*s'",
1177 filename, object_name_len, object_name);
1178 }
1179}
1180
1181/* Must be called only when :stage:filename doesn't exist. */
1182static void diagnose_invalid_index_path(int stage,
1183 const char *prefix,
1184 const char *filename)
1185{
1186 struct stat st;
1187 struct cache_entry *ce;
1188 int pos;
1189 unsigned namelen = strlen(filename);
1190 unsigned fullnamelen;
1191 char *fullname;
1192
1193 if (!prefix)
1194 prefix = "";
1195
1196 /* Wrong stage number? */
1197 pos = cache_name_pos(filename, namelen);
1198 if (pos < 0)
1199 pos = -pos - 1;
1200 if (pos < active_nr) {
1201 ce = active_cache[pos];
1202 if (ce_namelen(ce) == namelen &&
1203 !memcmp(ce->name, filename, namelen))
1204 die("Path '%s' is in the index, but not at stage %d.\n"
1205 "Did you mean ':%d:%s'?",
1206 filename, stage,
1207 ce_stage(ce), filename);
1208 }
1209
1210 /* Confusion between relative and absolute filenames? */
1211 fullnamelen = namelen + strlen(prefix);
1212 fullname = xmalloc(fullnamelen + 1);
1213 strcpy(fullname, prefix);
1214 strcat(fullname, filename);
1215 pos = cache_name_pos(fullname, fullnamelen);
1216 if (pos < 0)
1217 pos = -pos - 1;
1218 if (pos < active_nr) {
1219 ce = active_cache[pos];
1220 if (ce_namelen(ce) == fullnamelen &&
1221 !memcmp(ce->name, fullname, fullnamelen))
1222 die("Path '%s' is in the index, but not '%s'.\n"
1223 "Did you mean ':%d:%s' aka ':%d:./%s'?",
1224 fullname, filename,
1225 ce_stage(ce), fullname,
1226 ce_stage(ce), filename);
1227 }
1228
1229 if (!lstat(filename, &st))
1230 die("Path '%s' exists on disk, but not in the index.", filename);
1231 if (errno == ENOENT || errno == ENOTDIR)
1232 die("Path '%s' does not exist (neither on disk nor in the index).",
1233 filename);
1234
1235 free(fullname);
1236}
1237
1238
1239static char *resolve_relative_path(const char *rel)
1240{
1241 if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
1242 return NULL;
1243
1244 if (!startup_info)
1245 die("BUG: startup_info struct is not initialized.");
1246
1247 if (!is_inside_work_tree())
1248 die("relative path syntax can't be used outside working tree.");
1249
1250 /* die() inside prefix_path() if resolved path is outside worktree */
1251 return prefix_path(startup_info->prefix,
1252 startup_info->prefix ? strlen(startup_info->prefix) : 0,
1253 rel);
1254}
1255
1256static int get_sha1_with_context_1(const char *name,
1257 unsigned flags,
1258 const char *prefix,
1259 unsigned char *sha1,
1260 struct object_context *oc)
1261{
1262 int ret, bracket_depth;
1263 int namelen = strlen(name);
1264 const char *cp;
1265 int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
1266
1267 memset(oc, 0, sizeof(*oc));
1268 oc->mode = S_IFINVALID;
1269 ret = get_sha1_1(name, namelen, sha1, flags);
1270 if (!ret)
1271 return ret;
1272 /*
1273 * sha1:path --> object name of path in ent sha1
1274 * :path -> object name of absolute path in index
1275 * :./path -> object name of path relative to cwd in index
1276 * :[0-3]:path -> object name of path in index at stage
1277 * :/foo -> recent commit matching foo
1278 */
1279 if (name[0] == ':') {
1280 int stage = 0;
1281 struct cache_entry *ce;
1282 char *new_path = NULL;
1283 int pos;
1284 if (!only_to_die && namelen > 2 && name[1] == '/') {
1285 struct commit_list *list = NULL;
1286 for_each_ref(handle_one_ref, &list);
1287 return get_sha1_oneline(name + 2, sha1, list);
1288 }
1289 if (namelen < 3 ||
1290 name[2] != ':' ||
1291 name[1] < '0' || '3' < name[1])
1292 cp = name + 1;
1293 else {
1294 stage = name[1] - '0';
1295 cp = name + 3;
1296 }
1297 new_path = resolve_relative_path(cp);
1298 if (!new_path) {
1299 namelen = namelen - (cp - name);
1300 } else {
1301 cp = new_path;
1302 namelen = strlen(cp);
1303 }
1304
1305 strncpy(oc->path, cp,
1306 sizeof(oc->path));
1307 oc->path[sizeof(oc->path)-1] = '\0';
1308
1309 if (!active_cache)
1310 read_cache();
1311 pos = cache_name_pos(cp, namelen);
1312 if (pos < 0)
1313 pos = -pos - 1;
1314 while (pos < active_nr) {
1315 ce = active_cache[pos];
1316 if (ce_namelen(ce) != namelen ||
1317 memcmp(ce->name, cp, namelen))
1318 break;
1319 if (ce_stage(ce) == stage) {
1320 hashcpy(sha1, ce->sha1);
1321 oc->mode = ce->ce_mode;
1322 free(new_path);
1323 return 0;
1324 }
1325 pos++;
1326 }
1327 if (only_to_die && name[1] && name[1] != '/')
1328 diagnose_invalid_index_path(stage, prefix, cp);
1329 free(new_path);
1330 return -1;
1331 }
1332 for (cp = name, bracket_depth = 0; *cp; cp++) {
1333 if (*cp == '{')
1334 bracket_depth++;
1335 else if (bracket_depth && *cp == '}')
1336 bracket_depth--;
1337 else if (!bracket_depth && *cp == ':')
1338 break;
1339 }
1340 if (*cp == ':') {
1341 unsigned char tree_sha1[20];
1342 int len = cp - name;
1343 if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
1344 const char *filename = cp+1;
1345 char *new_filename = NULL;
1346
1347 new_filename = resolve_relative_path(filename);
1348 if (new_filename)
1349 filename = new_filename;
1350 ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
1351 if (ret && only_to_die) {
1352 diagnose_invalid_sha1_path(prefix, filename,
1353 tree_sha1,
1354 name, len);
1355 }
1356 hashcpy(oc->tree, tree_sha1);
1357 strncpy(oc->path, filename,
1358 sizeof(oc->path));
1359 oc->path[sizeof(oc->path)-1] = '\0';
1360
1361 free(new_filename);
1362 return ret;
1363 } else {
1364 if (only_to_die)
1365 die("Invalid object name '%.*s'.", len, name);
1366 }
1367 }
1368 return ret;
1369}
1370
1371/*
1372 * Call this function when you know "name" given by the end user must
1373 * name an object but it doesn't; the function _may_ die with a better
1374 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1375 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1376 * you have a chance to diagnose the error further.
1377 */
1378void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1379{
1380 struct object_context oc;
1381 unsigned char sha1[20];
1382 get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
1383}
1384
1385int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
1386{
1387 return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
1388}