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 satisfy 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);
434static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf);
435
436static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
437{
438 static const char *warn_msg = "refname '%.*s' is ambiguous.";
439 static const char *object_name_msg = N_(
440 "Git normally never creates a ref that ends with 40 hex characters\n"
441 "because it will be ignored when you just specify 40-hex. These refs\n"
442 "may be created by mistake. For example,\n"
443 "\n"
444 " git checkout -b $br $(git rev-parse ...)\n"
445 "\n"
446 "where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
447 "examine these refs and maybe delete them. Turn this message off by\n"
448 "running \"git config advice.objectNameWarning false\"");
449 unsigned char tmp_sha1[20];
450 char *real_ref = NULL;
451 int refs_found = 0;
452 int at, reflog_len, nth_prior = 0;
453
454 if (len == 40 && !get_sha1_hex(str, sha1)) {
455 if (warn_on_object_refname_ambiguity) {
456 refs_found = dwim_ref(str, len, tmp_sha1, &real_ref);
457 if (refs_found > 0 && warn_ambiguous_refs) {
458 warning(warn_msg, len, str);
459 if (advice_object_name_warning)
460 fprintf(stderr, "%s\n", _(object_name_msg));
461 }
462 free(real_ref);
463 }
464 return 0;
465 }
466
467 /* basic@{time or number or -number} format to query ref-log */
468 reflog_len = at = 0;
469 if (len && str[len-1] == '}') {
470 for (at = len-4; at >= 0; at--) {
471 if (str[at] == '@' && str[at+1] == '{') {
472 if (str[at+2] == '-') {
473 if (at != 0)
474 /* @{-N} not at start */
475 return -1;
476 nth_prior = 1;
477 continue;
478 }
479 if (!upstream_mark(str + at, len - at)) {
480 reflog_len = (len-1) - (at+2);
481 len = at;
482 }
483 break;
484 }
485 }
486 }
487
488 /* Accept only unambiguous ref paths. */
489 if (len && ambiguous_path(str, len))
490 return -1;
491
492 if (nth_prior) {
493 struct strbuf buf = STRBUF_INIT;
494 int detached;
495
496 if (interpret_nth_prior_checkout(str, &buf) > 0) {
497 detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
498 strbuf_release(&buf);
499 if (detached)
500 return 0;
501 }
502 }
503
504 if (!len && reflog_len)
505 /* allow "@{...}" to mean the current branch reflog */
506 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
507 else if (reflog_len)
508 refs_found = dwim_log(str, len, sha1, &real_ref);
509 else
510 refs_found = dwim_ref(str, len, sha1, &real_ref);
511
512 if (!refs_found)
513 return -1;
514
515 if (warn_ambiguous_refs &&
516 (refs_found > 1 ||
517 !get_short_sha1(str, len, tmp_sha1, GET_SHA1_QUIETLY)))
518 warning(warn_msg, len, str);
519
520 if (reflog_len) {
521 int nth, i;
522 unsigned long at_time;
523 unsigned long co_time;
524 int co_tz, co_cnt;
525
526 /* Is it asking for N-th entry, or approxidate? */
527 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
528 char ch = str[at+2+i];
529 if ('0' <= ch && ch <= '9')
530 nth = nth * 10 + ch - '0';
531 else
532 nth = -1;
533 }
534 if (100000000 <= nth) {
535 at_time = nth;
536 nth = -1;
537 } else if (0 <= nth)
538 at_time = 0;
539 else {
540 int errors = 0;
541 char *tmp = xstrndup(str + at + 2, reflog_len);
542 at_time = approxidate_careful(tmp, &errors);
543 free(tmp);
544 if (errors)
545 return -1;
546 }
547 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
548 &co_time, &co_tz, &co_cnt)) {
549 if (!len) {
550 if (!prefixcmp(real_ref, "refs/heads/")) {
551 str = real_ref + 11;
552 len = strlen(real_ref + 11);
553 } else {
554 /* detached HEAD */
555 str = "HEAD";
556 len = 4;
557 }
558 }
559 if (at_time)
560 warning("Log for '%.*s' only goes "
561 "back to %s.", len, str,
562 show_date(co_time, co_tz, DATE_RFC2822));
563 else {
564 die("Log for '%.*s' only has %d entries.",
565 len, str, co_cnt);
566 }
567 }
568 }
569
570 free(real_ref);
571 return 0;
572}
573
574static int get_parent(const char *name, int len,
575 unsigned char *result, int idx)
576{
577 unsigned char sha1[20];
578 int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
579 struct commit *commit;
580 struct commit_list *p;
581
582 if (ret)
583 return ret;
584 commit = lookup_commit_reference(sha1);
585 if (!commit)
586 return -1;
587 if (parse_commit(commit))
588 return -1;
589 if (!idx) {
590 hashcpy(result, commit->object.sha1);
591 return 0;
592 }
593 p = commit->parents;
594 while (p) {
595 if (!--idx) {
596 hashcpy(result, p->item->object.sha1);
597 return 0;
598 }
599 p = p->next;
600 }
601 return -1;
602}
603
604static int get_nth_ancestor(const char *name, int len,
605 unsigned char *result, int generation)
606{
607 unsigned char sha1[20];
608 struct commit *commit;
609 int ret;
610
611 ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
612 if (ret)
613 return ret;
614 commit = lookup_commit_reference(sha1);
615 if (!commit)
616 return -1;
617
618 while (generation--) {
619 if (parse_commit(commit) || !commit->parents)
620 return -1;
621 commit = commit->parents->item;
622 }
623 hashcpy(result, commit->object.sha1);
624 return 0;
625}
626
627struct object *peel_to_type(const char *name, int namelen,
628 struct object *o, enum object_type expected_type)
629{
630 if (name && !namelen)
631 namelen = strlen(name);
632 while (1) {
633 if (!o || (!o->parsed && !parse_object(o->sha1)))
634 return NULL;
635 if (expected_type == OBJ_ANY || o->type == expected_type)
636 return o;
637 if (o->type == OBJ_TAG)
638 o = ((struct tag*) o)->tagged;
639 else if (o->type == OBJ_COMMIT)
640 o = &(((struct commit *) o)->tree->object);
641 else {
642 if (name)
643 error("%.*s: expected %s type, but the object "
644 "dereferences to %s type",
645 namelen, name, typename(expected_type),
646 typename(o->type));
647 return NULL;
648 }
649 }
650}
651
652static int peel_onion(const char *name, int len, unsigned char *sha1)
653{
654 unsigned char outer[20];
655 const char *sp;
656 unsigned int expected_type = 0;
657 unsigned lookup_flags = 0;
658 struct object *o;
659
660 /*
661 * "ref^{type}" dereferences ref repeatedly until you cannot
662 * dereference anymore, or you get an object of given type,
663 * whichever comes first. "ref^{}" means just dereference
664 * tags until you get a non-tag. "ref^0" is a shorthand for
665 * "ref^{commit}". "commit^{tree}" could be used to find the
666 * top-level tree of the given commit.
667 */
668 if (len < 4 || name[len-1] != '}')
669 return -1;
670
671 for (sp = name + len - 1; name <= sp; sp--) {
672 int ch = *sp;
673 if (ch == '{' && name < sp && sp[-1] == '^')
674 break;
675 }
676 if (sp <= name)
677 return -1;
678
679 sp++; /* beginning of type name, or closing brace for empty */
680 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
681 expected_type = OBJ_COMMIT;
682 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
683 expected_type = OBJ_TREE;
684 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
685 expected_type = OBJ_BLOB;
686 else if (!prefixcmp(sp, "object}"))
687 expected_type = OBJ_ANY;
688 else if (sp[0] == '}')
689 expected_type = OBJ_NONE;
690 else if (sp[0] == '/')
691 expected_type = OBJ_COMMIT;
692 else
693 return -1;
694
695 if (expected_type == OBJ_COMMIT)
696 lookup_flags = GET_SHA1_COMMITTISH;
697 else if (expected_type == OBJ_TREE)
698 lookup_flags = GET_SHA1_TREEISH;
699
700 if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
701 return -1;
702
703 o = parse_object(outer);
704 if (!o)
705 return -1;
706 if (!expected_type) {
707 o = deref_tag(o, name, sp - name - 2);
708 if (!o || (!o->parsed && !parse_object(o->sha1)))
709 return -1;
710 hashcpy(sha1, o->sha1);
711 return 0;
712 }
713
714 /*
715 * At this point, the syntax look correct, so
716 * if we do not get the needed object, we should
717 * barf.
718 */
719 o = peel_to_type(name, len, o, expected_type);
720 if (!o)
721 return -1;
722
723 hashcpy(sha1, o->sha1);
724 if (sp[0] == '/') {
725 /* "$commit^{/foo}" */
726 char *prefix;
727 int ret;
728 struct commit_list *list = NULL;
729
730 /*
731 * $commit^{/}. Some regex implementation may reject.
732 * We don't need regex anyway. '' pattern always matches.
733 */
734 if (sp[1] == '}')
735 return 0;
736
737 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
738 commit_list_insert((struct commit *)o, &list);
739 ret = get_sha1_oneline(prefix, sha1, list);
740 free(prefix);
741 return ret;
742 }
743 return 0;
744}
745
746static int get_describe_name(const char *name, int len, unsigned char *sha1)
747{
748 const char *cp;
749 unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
750
751 for (cp = name + len - 1; name + 2 <= cp; cp--) {
752 char ch = *cp;
753 if (hexval(ch) & ~0377) {
754 /* We must be looking at g in "SOMETHING-g"
755 * for it to be describe output.
756 */
757 if (ch == 'g' && cp[-1] == '-') {
758 cp++;
759 len -= cp - name;
760 return get_short_sha1(cp, len, sha1, flags);
761 }
762 }
763 }
764 return -1;
765}
766
767static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
768{
769 int ret, has_suffix;
770 const char *cp;
771
772 /*
773 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
774 */
775 has_suffix = 0;
776 for (cp = name + len - 1; name <= cp; cp--) {
777 int ch = *cp;
778 if ('0' <= ch && ch <= '9')
779 continue;
780 if (ch == '~' || ch == '^')
781 has_suffix = ch;
782 break;
783 }
784
785 if (has_suffix) {
786 int num = 0;
787 int len1 = cp - name;
788 cp++;
789 while (cp < name + len)
790 num = num * 10 + *cp++ - '0';
791 if (!num && len1 == len - 1)
792 num = 1;
793 if (has_suffix == '^')
794 return get_parent(name, len1, sha1, num);
795 /* else if (has_suffix == '~') -- goes without saying */
796 return get_nth_ancestor(name, len1, sha1, num);
797 }
798
799 ret = peel_onion(name, len, sha1);
800 if (!ret)
801 return 0;
802
803 ret = get_sha1_basic(name, len, sha1);
804 if (!ret)
805 return 0;
806
807 /* It could be describe output that is "SOMETHING-gXXXX" */
808 ret = get_describe_name(name, len, sha1);
809 if (!ret)
810 return 0;
811
812 return get_short_sha1(name, len, sha1, lookup_flags);
813}
814
815/*
816 * This interprets names like ':/Initial revision of "git"' by searching
817 * through history and returning the first commit whose message starts
818 * the given regular expression.
819 *
820 * For future extension, ':/!' is reserved. If you want to match a message
821 * beginning with a '!', you have to repeat the exclamation mark.
822 */
823#define ONELINE_SEEN (1u<<20)
824
825static int handle_one_ref(const char *path,
826 const unsigned char *sha1, int flag, void *cb_data)
827{
828 struct commit_list **list = cb_data;
829 struct object *object = parse_object(sha1);
830 if (!object)
831 return 0;
832 if (object->type == OBJ_TAG) {
833 object = deref_tag(object, path, strlen(path));
834 if (!object)
835 return 0;
836 }
837 if (object->type != OBJ_COMMIT)
838 return 0;
839 commit_list_insert_by_date((struct commit *)object, list);
840 return 0;
841}
842
843static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
844 struct commit_list *list)
845{
846 struct commit_list *backup = NULL, *l;
847 int found = 0;
848 regex_t regex;
849
850 if (prefix[0] == '!') {
851 if (prefix[1] != '!')
852 die ("Invalid search pattern: %s", prefix);
853 prefix++;
854 }
855
856 if (regcomp(®ex, prefix, REG_EXTENDED))
857 die("Invalid search pattern: %s", prefix);
858
859 for (l = list; l; l = l->next) {
860 l->item->object.flags |= ONELINE_SEEN;
861 commit_list_insert(l->item, &backup);
862 }
863 while (list) {
864 char *p, *to_free = NULL;
865 struct commit *commit;
866 enum object_type type;
867 unsigned long size;
868 int matches;
869
870 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
871 if (!parse_object(commit->object.sha1))
872 continue;
873 if (commit->buffer)
874 p = commit->buffer;
875 else {
876 p = read_sha1_file(commit->object.sha1, &type, &size);
877 if (!p)
878 continue;
879 to_free = p;
880 }
881
882 p = strstr(p, "\n\n");
883 matches = p && !regexec(®ex, p + 2, 0, NULL, 0);
884 free(to_free);
885
886 if (matches) {
887 hashcpy(sha1, commit->object.sha1);
888 found = 1;
889 break;
890 }
891 }
892 regfree(®ex);
893 free_commit_list(list);
894 for (l = backup; l; l = l->next)
895 clear_commit_marks(l->item, ONELINE_SEEN);
896 free_commit_list(backup);
897 return found ? 0 : -1;
898}
899
900struct grab_nth_branch_switch_cbdata {
901 int remaining;
902 struct strbuf buf;
903};
904
905static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
906 const char *email, unsigned long timestamp, int tz,
907 const char *message, void *cb_data)
908{
909 struct grab_nth_branch_switch_cbdata *cb = cb_data;
910 const char *match = NULL, *target = NULL;
911 size_t len;
912
913 if (!prefixcmp(message, "checkout: moving from ")) {
914 match = message + strlen("checkout: moving from ");
915 target = strstr(match, " to ");
916 }
917
918 if (!match || !target)
919 return 0;
920 if (--(cb->remaining) == 0) {
921 len = target - match;
922 strbuf_reset(&cb->buf);
923 strbuf_add(&cb->buf, match, len);
924 return 1; /* we are done */
925 }
926 return 0;
927}
928
929/*
930 * Parse @{-N} syntax, return the number of characters parsed
931 * if successful; otherwise signal an error with negative value.
932 */
933static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
934{
935 long nth;
936 int retval;
937 struct grab_nth_branch_switch_cbdata cb;
938 const char *brace;
939 char *num_end;
940
941 if (name[0] != '@' || name[1] != '{' || name[2] != '-')
942 return -1;
943 brace = strchr(name, '}');
944 if (!brace)
945 return -1;
946 nth = strtol(name + 3, &num_end, 10);
947 if (num_end != brace)
948 return -1;
949 if (nth <= 0)
950 return -1;
951 cb.remaining = nth;
952 strbuf_init(&cb.buf, 20);
953
954 retval = 0;
955 if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
956 strbuf_reset(buf);
957 strbuf_add(buf, cb.buf.buf, cb.buf.len);
958 retval = brace - name + 1;
959 }
960
961 strbuf_release(&cb.buf);
962 return retval;
963}
964
965int get_sha1_mb(const char *name, unsigned char *sha1)
966{
967 struct commit *one, *two;
968 struct commit_list *mbs;
969 unsigned char sha1_tmp[20];
970 const char *dots;
971 int st;
972
973 dots = strstr(name, "...");
974 if (!dots)
975 return get_sha1(name, sha1);
976 if (dots == name)
977 st = get_sha1("HEAD", sha1_tmp);
978 else {
979 struct strbuf sb;
980 strbuf_init(&sb, dots - name);
981 strbuf_add(&sb, name, dots - name);
982 st = get_sha1_committish(sb.buf, sha1_tmp);
983 strbuf_release(&sb);
984 }
985 if (st)
986 return st;
987 one = lookup_commit_reference_gently(sha1_tmp, 0);
988 if (!one)
989 return -1;
990
991 if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
992 return -1;
993 two = lookup_commit_reference_gently(sha1_tmp, 0);
994 if (!two)
995 return -1;
996 mbs = get_merge_bases(one, two, 1);
997 if (!mbs || mbs->next)
998 st = -1;
999 else {
1000 st = 0;
1001 hashcpy(sha1, mbs->item->object.sha1);
1002 }
1003 free_commit_list(mbs);
1004 return st;
1005}
1006
1007/* parse @something syntax, when 'something' is not {.*} */
1008static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
1009{
1010 if (len || name[1] == '{')
1011 return -1;
1012
1013 strbuf_reset(buf);
1014 strbuf_add(buf, "HEAD", 4);
1015 return 1;
1016}
1017
1018static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
1019{
1020 /* we have extra data, which might need further processing */
1021 struct strbuf tmp = STRBUF_INIT;
1022 int used = buf->len;
1023 int ret;
1024
1025 strbuf_add(buf, name + len, namelen - len);
1026 ret = interpret_branch_name(buf->buf, &tmp);
1027 /* that data was not interpreted, remove our cruft */
1028 if (ret < 0) {
1029 strbuf_setlen(buf, used);
1030 return len;
1031 }
1032 strbuf_reset(buf);
1033 strbuf_addbuf(buf, &tmp);
1034 strbuf_release(&tmp);
1035 /* tweak for size of {-N} versus expanded ref name */
1036 return ret - used + len;
1037}
1038
1039/*
1040 * This reads short-hand syntax that not only evaluates to a commit
1041 * object name, but also can act as if the end user spelled the name
1042 * of the branch from the command line.
1043 *
1044 * - "@{-N}" finds the name of the Nth previous branch we were on, and
1045 * places the name of the branch in the given buf and returns the
1046 * number of characters parsed if successful.
1047 *
1048 * - "<branch>@{upstream}" finds the name of the other ref that
1049 * <branch> is configured to merge with (missing <branch> defaults
1050 * to the current branch), and places the name of the branch in the
1051 * given buf and returns the number of characters parsed if
1052 * successful.
1053 *
1054 * If the input is not of the accepted format, it returns a negative
1055 * number to signal an error.
1056 *
1057 * If the input was ok but there are not N branch switches in the
1058 * reflog, it returns 0.
1059 */
1060int interpret_branch_name(const char *name, struct strbuf *buf)
1061{
1062 char *cp;
1063 struct branch *upstream;
1064 int namelen = strlen(name);
1065 int len = interpret_nth_prior_checkout(name, buf);
1066 int tmp_len;
1067
1068 if (!len) {
1069 return len; /* syntax Ok, not enough switches */
1070 } else if (len > 0) {
1071 if (len == namelen)
1072 return len; /* consumed all */
1073 else
1074 return reinterpret(name, namelen, len, buf);
1075 }
1076
1077 cp = strchr(name, '@');
1078 if (!cp)
1079 return -1;
1080
1081 len = interpret_empty_at(name, namelen, cp - name, buf);
1082 if (len > 0)
1083 return reinterpret(name, namelen, len, buf);
1084
1085 tmp_len = upstream_mark(cp, namelen - (cp - name));
1086 if (!tmp_len)
1087 return -1;
1088
1089 len = cp + tmp_len - name;
1090 cp = xstrndup(name, cp - name);
1091 upstream = branch_get(*cp ? cp : NULL);
1092 /*
1093 * Upstream can be NULL only if cp refers to HEAD and HEAD
1094 * points to something different than a branch.
1095 */
1096 if (!upstream)
1097 die(_("HEAD does not point to a branch"));
1098 if (!upstream->merge || !upstream->merge[0]->dst) {
1099 if (!ref_exists(upstream->refname))
1100 die(_("No such branch: '%s'"), cp);
1101 if (!upstream->merge) {
1102 die(_("No upstream configured for branch '%s'"),
1103 upstream->name);
1104 }
1105 die(
1106 _("Upstream branch '%s' not stored as a remote-tracking branch"),
1107 upstream->merge[0]->src);
1108 }
1109 free(cp);
1110 cp = shorten_unambiguous_ref(upstream->merge[0]->dst, 0);
1111 strbuf_reset(buf);
1112 strbuf_addstr(buf, cp);
1113 free(cp);
1114 return len;
1115}
1116
1117int strbuf_branchname(struct strbuf *sb, const char *name)
1118{
1119 int len = strlen(name);
1120 int used = interpret_branch_name(name, sb);
1121
1122 if (used == len)
1123 return 0;
1124 if (used < 0)
1125 used = 0;
1126 strbuf_add(sb, name + used, len - used);
1127 return len;
1128}
1129
1130int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1131{
1132 strbuf_branchname(sb, name);
1133 if (name[0] == '-')
1134 return -1;
1135 strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1136 return check_refname_format(sb->buf, 0);
1137}
1138
1139/*
1140 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
1141 * notably "xyz^" for "parent of xyz"
1142 */
1143int get_sha1(const char *name, unsigned char *sha1)
1144{
1145 struct object_context unused;
1146 return get_sha1_with_context(name, 0, sha1, &unused);
1147}
1148
1149/*
1150 * Many callers know that the user meant to name a committish by
1151 * syntactical positions where the object name appears. Calling this
1152 * function allows the machinery to disambiguate shorter-than-unique
1153 * abbreviated object names between committish and others.
1154 *
1155 * Note that this does NOT error out when the named object is not a
1156 * committish. It is merely to give a hint to the disambiguation
1157 * machinery.
1158 */
1159int get_sha1_committish(const char *name, unsigned char *sha1)
1160{
1161 struct object_context unused;
1162 return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
1163 sha1, &unused);
1164}
1165
1166int get_sha1_treeish(const char *name, unsigned char *sha1)
1167{
1168 struct object_context unused;
1169 return get_sha1_with_context(name, GET_SHA1_TREEISH,
1170 sha1, &unused);
1171}
1172
1173int get_sha1_commit(const char *name, unsigned char *sha1)
1174{
1175 struct object_context unused;
1176 return get_sha1_with_context(name, GET_SHA1_COMMIT,
1177 sha1, &unused);
1178}
1179
1180int get_sha1_tree(const char *name, unsigned char *sha1)
1181{
1182 struct object_context unused;
1183 return get_sha1_with_context(name, GET_SHA1_TREE,
1184 sha1, &unused);
1185}
1186
1187int get_sha1_blob(const char *name, unsigned char *sha1)
1188{
1189 struct object_context unused;
1190 return get_sha1_with_context(name, GET_SHA1_BLOB,
1191 sha1, &unused);
1192}
1193
1194/* Must be called only when object_name:filename doesn't exist. */
1195static void diagnose_invalid_sha1_path(const char *prefix,
1196 const char *filename,
1197 const unsigned char *tree_sha1,
1198 const char *object_name,
1199 int object_name_len)
1200{
1201 struct stat st;
1202 unsigned char sha1[20];
1203 unsigned mode;
1204
1205 if (!prefix)
1206 prefix = "";
1207
1208 if (!lstat(filename, &st))
1209 die("Path '%s' exists on disk, but not in '%.*s'.",
1210 filename, object_name_len, object_name);
1211 if (errno == ENOENT || errno == ENOTDIR) {
1212 char *fullname = xmalloc(strlen(filename)
1213 + strlen(prefix) + 1);
1214 strcpy(fullname, prefix);
1215 strcat(fullname, filename);
1216
1217 if (!get_tree_entry(tree_sha1, fullname,
1218 sha1, &mode)) {
1219 die("Path '%s' exists, but not '%s'.\n"
1220 "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1221 fullname,
1222 filename,
1223 object_name_len, object_name,
1224 fullname,
1225 object_name_len, object_name,
1226 filename);
1227 }
1228 die("Path '%s' does not exist in '%.*s'",
1229 filename, object_name_len, object_name);
1230 }
1231}
1232
1233/* Must be called only when :stage:filename doesn't exist. */
1234static void diagnose_invalid_index_path(int stage,
1235 const char *prefix,
1236 const char *filename)
1237{
1238 struct stat st;
1239 const struct cache_entry *ce;
1240 int pos;
1241 unsigned namelen = strlen(filename);
1242 unsigned fullnamelen;
1243 char *fullname;
1244
1245 if (!prefix)
1246 prefix = "";
1247
1248 /* Wrong stage number? */
1249 pos = cache_name_pos(filename, namelen);
1250 if (pos < 0)
1251 pos = -pos - 1;
1252 if (pos < active_nr) {
1253 ce = active_cache[pos];
1254 if (ce_namelen(ce) == namelen &&
1255 !memcmp(ce->name, filename, namelen))
1256 die("Path '%s' is in the index, but not at stage %d.\n"
1257 "Did you mean ':%d:%s'?",
1258 filename, stage,
1259 ce_stage(ce), filename);
1260 }
1261
1262 /* Confusion between relative and absolute filenames? */
1263 fullnamelen = namelen + strlen(prefix);
1264 fullname = xmalloc(fullnamelen + 1);
1265 strcpy(fullname, prefix);
1266 strcat(fullname, filename);
1267 pos = cache_name_pos(fullname, fullnamelen);
1268 if (pos < 0)
1269 pos = -pos - 1;
1270 if (pos < active_nr) {
1271 ce = active_cache[pos];
1272 if (ce_namelen(ce) == fullnamelen &&
1273 !memcmp(ce->name, fullname, fullnamelen))
1274 die("Path '%s' is in the index, but not '%s'.\n"
1275 "Did you mean ':%d:%s' aka ':%d:./%s'?",
1276 fullname, filename,
1277 ce_stage(ce), fullname,
1278 ce_stage(ce), filename);
1279 }
1280
1281 if (!lstat(filename, &st))
1282 die("Path '%s' exists on disk, but not in the index.", filename);
1283 if (errno == ENOENT || errno == ENOTDIR)
1284 die("Path '%s' does not exist (neither on disk nor in the index).",
1285 filename);
1286
1287 free(fullname);
1288}
1289
1290
1291static char *resolve_relative_path(const char *rel)
1292{
1293 if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
1294 return NULL;
1295
1296 if (!startup_info)
1297 die("BUG: startup_info struct is not initialized.");
1298
1299 if (!is_inside_work_tree())
1300 die("relative path syntax can't be used outside working tree.");
1301
1302 /* die() inside prefix_path() if resolved path is outside worktree */
1303 return prefix_path(startup_info->prefix,
1304 startup_info->prefix ? strlen(startup_info->prefix) : 0,
1305 rel);
1306}
1307
1308static int get_sha1_with_context_1(const char *name,
1309 unsigned flags,
1310 const char *prefix,
1311 unsigned char *sha1,
1312 struct object_context *oc)
1313{
1314 int ret, bracket_depth;
1315 int namelen = strlen(name);
1316 const char *cp;
1317 int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
1318
1319 memset(oc, 0, sizeof(*oc));
1320 oc->mode = S_IFINVALID;
1321 ret = get_sha1_1(name, namelen, sha1, flags);
1322 if (!ret)
1323 return ret;
1324 /*
1325 * sha1:path --> object name of path in ent sha1
1326 * :path -> object name of absolute path in index
1327 * :./path -> object name of path relative to cwd in index
1328 * :[0-3]:path -> object name of path in index at stage
1329 * :/foo -> recent commit matching foo
1330 */
1331 if (name[0] == ':') {
1332 int stage = 0;
1333 const struct cache_entry *ce;
1334 char *new_path = NULL;
1335 int pos;
1336 if (!only_to_die && namelen > 2 && name[1] == '/') {
1337 struct commit_list *list = NULL;
1338 for_each_ref(handle_one_ref, &list);
1339 return get_sha1_oneline(name + 2, sha1, list);
1340 }
1341 if (namelen < 3 ||
1342 name[2] != ':' ||
1343 name[1] < '0' || '3' < name[1])
1344 cp = name + 1;
1345 else {
1346 stage = name[1] - '0';
1347 cp = name + 3;
1348 }
1349 new_path = resolve_relative_path(cp);
1350 if (!new_path) {
1351 namelen = namelen - (cp - name);
1352 } else {
1353 cp = new_path;
1354 namelen = strlen(cp);
1355 }
1356
1357 strncpy(oc->path, cp,
1358 sizeof(oc->path));
1359 oc->path[sizeof(oc->path)-1] = '\0';
1360
1361 if (!active_cache)
1362 read_cache();
1363 pos = cache_name_pos(cp, namelen);
1364 if (pos < 0)
1365 pos = -pos - 1;
1366 while (pos < active_nr) {
1367 ce = active_cache[pos];
1368 if (ce_namelen(ce) != namelen ||
1369 memcmp(ce->name, cp, namelen))
1370 break;
1371 if (ce_stage(ce) == stage) {
1372 hashcpy(sha1, ce->sha1);
1373 oc->mode = ce->ce_mode;
1374 free(new_path);
1375 return 0;
1376 }
1377 pos++;
1378 }
1379 if (only_to_die && name[1] && name[1] != '/')
1380 diagnose_invalid_index_path(stage, prefix, cp);
1381 free(new_path);
1382 return -1;
1383 }
1384 for (cp = name, bracket_depth = 0; *cp; cp++) {
1385 if (*cp == '{')
1386 bracket_depth++;
1387 else if (bracket_depth && *cp == '}')
1388 bracket_depth--;
1389 else if (!bracket_depth && *cp == ':')
1390 break;
1391 }
1392 if (*cp == ':') {
1393 unsigned char tree_sha1[20];
1394 int len = cp - name;
1395 if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
1396 const char *filename = cp+1;
1397 char *new_filename = NULL;
1398
1399 new_filename = resolve_relative_path(filename);
1400 if (new_filename)
1401 filename = new_filename;
1402 ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
1403 if (ret && only_to_die) {
1404 diagnose_invalid_sha1_path(prefix, filename,
1405 tree_sha1,
1406 name, len);
1407 }
1408 hashcpy(oc->tree, tree_sha1);
1409 strncpy(oc->path, filename,
1410 sizeof(oc->path));
1411 oc->path[sizeof(oc->path)-1] = '\0';
1412
1413 free(new_filename);
1414 return ret;
1415 } else {
1416 if (only_to_die)
1417 die("Invalid object name '%.*s'.", len, name);
1418 }
1419 }
1420 return ret;
1421}
1422
1423/*
1424 * Call this function when you know "name" given by the end user must
1425 * name an object but it doesn't; the function _may_ die with a better
1426 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1427 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1428 * you have a chance to diagnose the error further.
1429 */
1430void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1431{
1432 struct object_context oc;
1433 unsigned char sha1[20];
1434 get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
1435}
1436
1437int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
1438{
1439 return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
1440}