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
346int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
347{
348 char hex_pfx[40];
349 unsigned char bin_pfx[20];
350 struct disambiguate_state ds;
351 int len = strlen(prefix);
352
353 if (len < MINIMUM_ABBREV || len > 40)
354 return -1;
355 if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
356 return -1;
357
358 prepare_alt_odb();
359
360 memset(&ds, 0, sizeof(ds));
361 ds.always_call_fn = 1;
362 ds.cb_data = cb_data;
363 ds.fn = fn;
364
365 find_short_object_filename(len, hex_pfx, &ds);
366 find_short_packed_object(len, bin_pfx, &ds);
367 return ds.ambiguous;
368}
369
370const char *find_unique_abbrev(const unsigned char *sha1, int len)
371{
372 int status, exists;
373 static char hex[41];
374
375 exists = has_sha1_file(sha1);
376 memcpy(hex, sha1_to_hex(sha1), 40);
377 if (len == 40 || !len)
378 return hex;
379 while (len < 40) {
380 unsigned char sha1_ret[20];
381 status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
382 if (exists
383 ? !status
384 : status == SHORT_NAME_NOT_FOUND) {
385 hex[len] = 0;
386 return hex;
387 }
388 len++;
389 }
390 return hex;
391}
392
393static int ambiguous_path(const char *path, int len)
394{
395 int slash = 1;
396 int cnt;
397
398 for (cnt = 0; cnt < len; cnt++) {
399 switch (*path++) {
400 case '\0':
401 break;
402 case '/':
403 if (slash)
404 break;
405 slash = 1;
406 continue;
407 case '.':
408 continue;
409 default:
410 slash = 0;
411 continue;
412 }
413 break;
414 }
415 return slash;
416}
417
418static inline int upstream_mark(const char *string, int len)
419{
420 const char *suffix[] = { "@{upstream}", "@{u}" };
421 int i;
422
423 for (i = 0; i < ARRAY_SIZE(suffix); i++) {
424 int suffix_len = strlen(suffix[i]);
425 if (suffix_len <= len
426 && !memcmp(string, suffix[i], suffix_len))
427 return suffix_len;
428 }
429 return 0;
430}
431
432static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
433static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
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 static const char *object_name_msg = N_(
439 "Git normally never creates a ref that ends with 40 hex characters\n"
440 "because it will be ignored when you just specify 40-hex. These refs\n"
441 "may be created by mistake. For example,\n"
442 "\n"
443 " git checkout -b $br $(git rev-parse ...)\n"
444 "\n"
445 "where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
446 "examine these refs and maybe delete them. Turn this message off by\n"
447 "running \"git config advice.objectNameWarning false\"");
448 unsigned char tmp_sha1[20];
449 char *real_ref = NULL;
450 int refs_found = 0;
451 int at, reflog_len, nth_prior = 0;
452
453 if (len == 40 && !get_sha1_hex(str, sha1)) {
454 if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) {
455 refs_found = dwim_ref(str, len, tmp_sha1, &real_ref);
456 if (refs_found > 0) {
457 warning(warn_msg, len, str);
458 if (advice_object_name_warning)
459 fprintf(stderr, "%s\n", _(object_name_msg));
460 }
461 free(real_ref);
462 }
463 return 0;
464 }
465
466 /* basic@{time or number or -number} format to query ref-log */
467 reflog_len = at = 0;
468 if (len && str[len-1] == '}') {
469 for (at = len-4; at >= 0; at--) {
470 if (str[at] == '@' && str[at+1] == '{') {
471 if (str[at+2] == '-') {
472 if (at != 0)
473 /* @{-N} not at start */
474 return -1;
475 nth_prior = 1;
476 continue;
477 }
478 if (!upstream_mark(str + at, len - at)) {
479 reflog_len = (len-1) - (at+2);
480 len = at;
481 }
482 break;
483 }
484 }
485 }
486
487 /* Accept only unambiguous ref paths. */
488 if (len && ambiguous_path(str, len))
489 return -1;
490
491 if (nth_prior) {
492 struct strbuf buf = STRBUF_INIT;
493 int detached;
494
495 if (interpret_nth_prior_checkout(str, len, &buf) > 0) {
496 detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
497 strbuf_release(&buf);
498 if (detached)
499 return 0;
500 }
501 }
502
503 if (!len && reflog_len)
504 /* allow "@{...}" to mean the current branch reflog */
505 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
506 else if (reflog_len)
507 refs_found = dwim_log(str, len, sha1, &real_ref);
508 else
509 refs_found = dwim_ref(str, len, sha1, &real_ref);
510
511 if (!refs_found)
512 return -1;
513
514 if (warn_ambiguous_refs &&
515 (refs_found > 1 ||
516 !get_short_sha1(str, len, tmp_sha1, GET_SHA1_QUIETLY)))
517 warning(warn_msg, len, str);
518
519 if (reflog_len) {
520 int nth, i;
521 unsigned long at_time;
522 unsigned long co_time;
523 int co_tz, co_cnt;
524
525 /* Is it asking for N-th entry, or approxidate? */
526 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
527 char ch = str[at+2+i];
528 if ('0' <= ch && ch <= '9')
529 nth = nth * 10 + ch - '0';
530 else
531 nth = -1;
532 }
533 if (100000000 <= nth) {
534 at_time = nth;
535 nth = -1;
536 } else if (0 <= nth)
537 at_time = 0;
538 else {
539 int errors = 0;
540 char *tmp = xstrndup(str + at + 2, reflog_len);
541 at_time = approxidate_careful(tmp, &errors);
542 free(tmp);
543 if (errors)
544 return -1;
545 }
546 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
547 &co_time, &co_tz, &co_cnt)) {
548 if (!len) {
549 if (starts_with(real_ref, "refs/heads/")) {
550 str = real_ref + 11;
551 len = strlen(real_ref + 11);
552 } else {
553 /* detached HEAD */
554 str = "HEAD";
555 len = 4;
556 }
557 }
558 if (at_time)
559 warning("Log for '%.*s' only goes "
560 "back to %s.", len, str,
561 show_date(co_time, co_tz, DATE_RFC2822));
562 else {
563 die("Log for '%.*s' only has %d entries.",
564 len, str, co_cnt);
565 }
566 }
567 }
568
569 free(real_ref);
570 return 0;
571}
572
573static int get_parent(const char *name, int len,
574 unsigned char *result, int idx)
575{
576 unsigned char sha1[20];
577 int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
578 struct commit *commit;
579 struct commit_list *p;
580
581 if (ret)
582 return ret;
583 commit = lookup_commit_reference(sha1);
584 if (parse_commit(commit))
585 return -1;
586 if (!idx) {
587 hashcpy(result, commit->object.sha1);
588 return 0;
589 }
590 p = commit->parents;
591 while (p) {
592 if (!--idx) {
593 hashcpy(result, p->item->object.sha1);
594 return 0;
595 }
596 p = p->next;
597 }
598 return -1;
599}
600
601static int get_nth_ancestor(const char *name, int len,
602 unsigned char *result, int generation)
603{
604 unsigned char sha1[20];
605 struct commit *commit;
606 int ret;
607
608 ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
609 if (ret)
610 return ret;
611 commit = lookup_commit_reference(sha1);
612 if (!commit)
613 return -1;
614
615 while (generation--) {
616 if (parse_commit(commit) || !commit->parents)
617 return -1;
618 commit = commit->parents->item;
619 }
620 hashcpy(result, commit->object.sha1);
621 return 0;
622}
623
624struct object *peel_to_type(const char *name, int namelen,
625 struct object *o, enum object_type expected_type)
626{
627 if (name && !namelen)
628 namelen = strlen(name);
629 while (1) {
630 if (!o || (!o->parsed && !parse_object(o->sha1)))
631 return NULL;
632 if (expected_type == OBJ_ANY || o->type == expected_type)
633 return o;
634 if (o->type == OBJ_TAG)
635 o = ((struct tag*) o)->tagged;
636 else if (o->type == OBJ_COMMIT)
637 o = &(((struct commit *) o)->tree->object);
638 else {
639 if (name)
640 error("%.*s: expected %s type, but the object "
641 "dereferences to %s type",
642 namelen, name, typename(expected_type),
643 typename(o->type));
644 return NULL;
645 }
646 }
647}
648
649static int peel_onion(const char *name, int len, unsigned char *sha1)
650{
651 unsigned char outer[20];
652 const char *sp;
653 unsigned int expected_type = 0;
654 unsigned lookup_flags = 0;
655 struct object *o;
656
657 /*
658 * "ref^{type}" dereferences ref repeatedly until you cannot
659 * dereference anymore, or you get an object of given type,
660 * whichever comes first. "ref^{}" means just dereference
661 * tags until you get a non-tag. "ref^0" is a shorthand for
662 * "ref^{commit}". "commit^{tree}" could be used to find the
663 * top-level tree of the given commit.
664 */
665 if (len < 4 || name[len-1] != '}')
666 return -1;
667
668 for (sp = name + len - 1; name <= sp; sp--) {
669 int ch = *sp;
670 if (ch == '{' && name < sp && sp[-1] == '^')
671 break;
672 }
673 if (sp <= name)
674 return -1;
675
676 sp++; /* beginning of type name, or closing brace for empty */
677 if (starts_with(sp, "commit}"))
678 expected_type = OBJ_COMMIT;
679 else if (starts_with(sp, "tag}"))
680 expected_type = OBJ_TAG;
681 else if (starts_with(sp, "tree}"))
682 expected_type = OBJ_TREE;
683 else if (starts_with(sp, "blob}"))
684 expected_type = OBJ_BLOB;
685 else if (starts_with(sp, "object}"))
686 expected_type = OBJ_ANY;
687 else if (sp[0] == '}')
688 expected_type = OBJ_NONE;
689 else if (sp[0] == '/')
690 expected_type = OBJ_COMMIT;
691 else
692 return -1;
693
694 if (expected_type == OBJ_COMMIT)
695 lookup_flags = GET_SHA1_COMMITTISH;
696 else if (expected_type == OBJ_TREE)
697 lookup_flags = GET_SHA1_TREEISH;
698
699 if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
700 return -1;
701
702 o = parse_object(outer);
703 if (!o)
704 return -1;
705 if (!expected_type) {
706 o = deref_tag(o, name, sp - name - 2);
707 if (!o || (!o->parsed && !parse_object(o->sha1)))
708 return -1;
709 hashcpy(sha1, o->sha1);
710 return 0;
711 }
712
713 /*
714 * At this point, the syntax look correct, so
715 * if we do not get the needed object, we should
716 * barf.
717 */
718 o = peel_to_type(name, len, o, expected_type);
719 if (!o)
720 return -1;
721
722 hashcpy(sha1, o->sha1);
723 if (sp[0] == '/') {
724 /* "$commit^{/foo}" */
725 char *prefix;
726 int ret;
727 struct commit_list *list = NULL;
728
729 /*
730 * $commit^{/}. Some regex implementation may reject.
731 * We don't need regex anyway. '' pattern always matches.
732 */
733 if (sp[1] == '}')
734 return 0;
735
736 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
737 commit_list_insert((struct commit *)o, &list);
738 ret = get_sha1_oneline(prefix, sha1, list);
739 free(prefix);
740 return ret;
741 }
742 return 0;
743}
744
745static int get_describe_name(const char *name, int len, unsigned char *sha1)
746{
747 const char *cp;
748 unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
749
750 for (cp = name + len - 1; name + 2 <= cp; cp--) {
751 char ch = *cp;
752 if (hexval(ch) & ~0377) {
753 /* We must be looking at g in "SOMETHING-g"
754 * for it to be describe output.
755 */
756 if (ch == 'g' && cp[-1] == '-') {
757 cp++;
758 len -= cp - name;
759 return get_short_sha1(cp, len, sha1, flags);
760 }
761 }
762 }
763 return -1;
764}
765
766static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
767{
768 int ret, has_suffix;
769 const char *cp;
770
771 /*
772 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
773 */
774 has_suffix = 0;
775 for (cp = name + len - 1; name <= cp; cp--) {
776 int ch = *cp;
777 if ('0' <= ch && ch <= '9')
778 continue;
779 if (ch == '~' || ch == '^')
780 has_suffix = ch;
781 break;
782 }
783
784 if (has_suffix) {
785 int num = 0;
786 int len1 = cp - name;
787 cp++;
788 while (cp < name + len)
789 num = num * 10 + *cp++ - '0';
790 if (!num && len1 == len - 1)
791 num = 1;
792 if (has_suffix == '^')
793 return get_parent(name, len1, sha1, num);
794 /* else if (has_suffix == '~') -- goes without saying */
795 return get_nth_ancestor(name, len1, sha1, num);
796 }
797
798 ret = peel_onion(name, len, sha1);
799 if (!ret)
800 return 0;
801
802 ret = get_sha1_basic(name, len, sha1);
803 if (!ret)
804 return 0;
805
806 /* It could be describe output that is "SOMETHING-gXXXX" */
807 ret = get_describe_name(name, len, sha1);
808 if (!ret)
809 return 0;
810
811 return get_short_sha1(name, len, sha1, lookup_flags);
812}
813
814/*
815 * This interprets names like ':/Initial revision of "git"' by searching
816 * through history and returning the first commit whose message starts
817 * the given regular expression.
818 *
819 * For future extension, ':/!' is reserved. If you want to match a message
820 * beginning with a '!', you have to repeat the exclamation mark.
821 */
822
823/* Remember to update object flag allocation in object.h */
824#define ONELINE_SEEN (1u<<20)
825
826static int handle_one_ref(const char *path,
827 const unsigned char *sha1, int flag, void *cb_data)
828{
829 struct commit_list **list = cb_data;
830 struct object *object = parse_object(sha1);
831 if (!object)
832 return 0;
833 if (object->type == OBJ_TAG) {
834 object = deref_tag(object, path, strlen(path));
835 if (!object)
836 return 0;
837 }
838 if (object->type != OBJ_COMMIT)
839 return 0;
840 commit_list_insert_by_date((struct commit *)object, list);
841 return 0;
842}
843
844static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
845 struct commit_list *list)
846{
847 struct commit_list *backup = NULL, *l;
848 int found = 0;
849 regex_t regex;
850
851 if (prefix[0] == '!') {
852 if (prefix[1] != '!')
853 die ("Invalid search pattern: %s", prefix);
854 prefix++;
855 }
856
857 if (regcomp(®ex, prefix, REG_EXTENDED))
858 die("Invalid search pattern: %s", prefix);
859
860 for (l = list; l; l = l->next) {
861 l->item->object.flags |= ONELINE_SEEN;
862 commit_list_insert(l->item, &backup);
863 }
864 while (list) {
865 const char *p, *buf;
866 struct commit *commit;
867 int matches;
868
869 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
870 if (!parse_object(commit->object.sha1))
871 continue;
872 buf = get_commit_buffer(commit, NULL);
873 p = strstr(buf, "\n\n");
874 matches = p && !regexec(®ex, p + 2, 0, NULL, 0);
875 unuse_commit_buffer(commit, buf);
876
877 if (matches) {
878 hashcpy(sha1, commit->object.sha1);
879 found = 1;
880 break;
881 }
882 }
883 regfree(®ex);
884 free_commit_list(list);
885 for (l = backup; l; l = l->next)
886 clear_commit_marks(l->item, ONELINE_SEEN);
887 free_commit_list(backup);
888 return found ? 0 : -1;
889}
890
891struct grab_nth_branch_switch_cbdata {
892 int remaining;
893 struct strbuf buf;
894};
895
896static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
897 const char *email, unsigned long timestamp, int tz,
898 const char *message, void *cb_data)
899{
900 struct grab_nth_branch_switch_cbdata *cb = cb_data;
901 const char *match = NULL, *target = NULL;
902 size_t len;
903
904 if (skip_prefix(message, "checkout: moving from ", &match))
905 target = strstr(match, " to ");
906
907 if (!match || !target)
908 return 0;
909 if (--(cb->remaining) == 0) {
910 len = target - match;
911 strbuf_reset(&cb->buf);
912 strbuf_add(&cb->buf, match, len);
913 return 1; /* we are done */
914 }
915 return 0;
916}
917
918/*
919 * Parse @{-N} syntax, return the number of characters parsed
920 * if successful; otherwise signal an error with negative value.
921 */
922static int interpret_nth_prior_checkout(const char *name, int namelen,
923 struct strbuf *buf)
924{
925 long nth;
926 int retval;
927 struct grab_nth_branch_switch_cbdata cb;
928 const char *brace;
929 char *num_end;
930
931 if (namelen < 4)
932 return -1;
933 if (name[0] != '@' || name[1] != '{' || name[2] != '-')
934 return -1;
935 brace = memchr(name, '}', namelen);
936 if (!brace)
937 return -1;
938 nth = strtol(name + 3, &num_end, 10);
939 if (num_end != brace)
940 return -1;
941 if (nth <= 0)
942 return -1;
943 cb.remaining = nth;
944 strbuf_init(&cb.buf, 20);
945
946 retval = 0;
947 if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
948 strbuf_reset(buf);
949 strbuf_add(buf, cb.buf.buf, cb.buf.len);
950 retval = brace - name + 1;
951 }
952
953 strbuf_release(&cb.buf);
954 return retval;
955}
956
957int get_sha1_mb(const char *name, unsigned char *sha1)
958{
959 struct commit *one, *two;
960 struct commit_list *mbs;
961 unsigned char sha1_tmp[20];
962 const char *dots;
963 int st;
964
965 dots = strstr(name, "...");
966 if (!dots)
967 return get_sha1(name, sha1);
968 if (dots == name)
969 st = get_sha1("HEAD", sha1_tmp);
970 else {
971 struct strbuf sb;
972 strbuf_init(&sb, dots - name);
973 strbuf_add(&sb, name, dots - name);
974 st = get_sha1_committish(sb.buf, sha1_tmp);
975 strbuf_release(&sb);
976 }
977 if (st)
978 return st;
979 one = lookup_commit_reference_gently(sha1_tmp, 0);
980 if (!one)
981 return -1;
982
983 if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
984 return -1;
985 two = lookup_commit_reference_gently(sha1_tmp, 0);
986 if (!two)
987 return -1;
988 mbs = get_merge_bases(one, two, 1);
989 if (!mbs || mbs->next)
990 st = -1;
991 else {
992 st = 0;
993 hashcpy(sha1, mbs->item->object.sha1);
994 }
995 free_commit_list(mbs);
996 return st;
997}
998
999/* parse @something syntax, when 'something' is not {.*} */
1000static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
1001{
1002 const char *next;
1003
1004 if (len || name[1] == '{')
1005 return -1;
1006
1007 /* make sure it's a single @, or @@{.*}, not @foo */
1008 next = memchr(name + len + 1, '@', namelen - len - 1);
1009 if (next && next[1] != '{')
1010 return -1;
1011 if (!next)
1012 next = name + namelen;
1013 if (next != name + 1)
1014 return -1;
1015
1016 strbuf_reset(buf);
1017 strbuf_add(buf, "HEAD", 4);
1018 return 1;
1019}
1020
1021static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
1022{
1023 /* we have extra data, which might need further processing */
1024 struct strbuf tmp = STRBUF_INIT;
1025 int used = buf->len;
1026 int ret;
1027
1028 strbuf_add(buf, name + len, namelen - len);
1029 ret = interpret_branch_name(buf->buf, buf->len, &tmp);
1030 /* that data was not interpreted, remove our cruft */
1031 if (ret < 0) {
1032 strbuf_setlen(buf, used);
1033 return len;
1034 }
1035 strbuf_reset(buf);
1036 strbuf_addbuf(buf, &tmp);
1037 strbuf_release(&tmp);
1038 /* tweak for size of {-N} versus expanded ref name */
1039 return ret - used + len;
1040}
1041
1042static void set_shortened_ref(struct strbuf *buf, const char *ref)
1043{
1044 char *s = shorten_unambiguous_ref(ref, 0);
1045 strbuf_reset(buf);
1046 strbuf_addstr(buf, s);
1047 free(s);
1048}
1049
1050static const char *get_upstream_branch(const char *branch_buf, int len)
1051{
1052 char *branch = xstrndup(branch_buf, len);
1053 struct branch *upstream = branch_get(*branch ? branch : NULL);
1054
1055 /*
1056 * Upstream can be NULL only if branch refers to HEAD and HEAD
1057 * points to something different than a branch.
1058 */
1059 if (!upstream)
1060 die(_("HEAD does not point to a branch"));
1061 if (!upstream->merge || !upstream->merge[0]->dst) {
1062 if (!ref_exists(upstream->refname))
1063 die(_("No such branch: '%s'"), branch);
1064 if (!upstream->merge) {
1065 die(_("No upstream configured for branch '%s'"),
1066 upstream->name);
1067 }
1068 die(
1069 _("Upstream branch '%s' not stored as a remote-tracking branch"),
1070 upstream->merge[0]->src);
1071 }
1072 free(branch);
1073
1074 return upstream->merge[0]->dst;
1075}
1076
1077static int interpret_upstream_mark(const char *name, int namelen,
1078 int at, struct strbuf *buf)
1079{
1080 int len;
1081
1082 len = upstream_mark(name + at, namelen - at);
1083 if (!len)
1084 return -1;
1085
1086 if (memchr(name, ':', at))
1087 return -1;
1088
1089 set_shortened_ref(buf, get_upstream_branch(name, at));
1090 return len + at;
1091}
1092
1093/*
1094 * This reads short-hand syntax that not only evaluates to a commit
1095 * object name, but also can act as if the end user spelled the name
1096 * of the branch from the command line.
1097 *
1098 * - "@{-N}" finds the name of the Nth previous branch we were on, and
1099 * places the name of the branch in the given buf and returns the
1100 * number of characters parsed if successful.
1101 *
1102 * - "<branch>@{upstream}" finds the name of the other ref that
1103 * <branch> is configured to merge with (missing <branch> defaults
1104 * to the current branch), and places the name of the branch in the
1105 * given buf and returns the number of characters parsed if
1106 * successful.
1107 *
1108 * If the input is not of the accepted format, it returns a negative
1109 * number to signal an error.
1110 *
1111 * If the input was ok but there are not N branch switches in the
1112 * reflog, it returns 0.
1113 */
1114int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
1115{
1116 char *at;
1117 const char *start;
1118 int len = interpret_nth_prior_checkout(name, namelen, buf);
1119
1120 if (!namelen)
1121 namelen = strlen(name);
1122
1123 if (!len) {
1124 return len; /* syntax Ok, not enough switches */
1125 } else if (len > 0) {
1126 if (len == namelen)
1127 return len; /* consumed all */
1128 else
1129 return reinterpret(name, namelen, len, buf);
1130 }
1131
1132 for (start = name;
1133 (at = memchr(start, '@', namelen - (start - name)));
1134 start = at + 1) {
1135
1136 len = interpret_empty_at(name, namelen, at - name, buf);
1137 if (len > 0)
1138 return reinterpret(name, namelen, len, buf);
1139
1140 len = interpret_upstream_mark(name, namelen, at - name, buf);
1141 if (len > 0)
1142 return len;
1143 }
1144
1145 return -1;
1146}
1147
1148int strbuf_branchname(struct strbuf *sb, const char *name)
1149{
1150 int len = strlen(name);
1151 int used = interpret_branch_name(name, len, sb);
1152
1153 if (used == len)
1154 return 0;
1155 if (used < 0)
1156 used = 0;
1157 strbuf_add(sb, name + used, len - used);
1158 return len;
1159}
1160
1161int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1162{
1163 strbuf_branchname(sb, name);
1164 if (name[0] == '-')
1165 return -1;
1166 strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1167 return check_refname_format(sb->buf, 0);
1168}
1169
1170/*
1171 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
1172 * notably "xyz^" for "parent of xyz"
1173 */
1174int get_sha1(const char *name, unsigned char *sha1)
1175{
1176 struct object_context unused;
1177 return get_sha1_with_context(name, 0, sha1, &unused);
1178}
1179
1180/*
1181 * Many callers know that the user meant to name a commit-ish by
1182 * syntactical positions where the object name appears. Calling this
1183 * function allows the machinery to disambiguate shorter-than-unique
1184 * abbreviated object names between commit-ish and others.
1185 *
1186 * Note that this does NOT error out when the named object is not a
1187 * commit-ish. It is merely to give a hint to the disambiguation
1188 * machinery.
1189 */
1190int get_sha1_committish(const char *name, unsigned char *sha1)
1191{
1192 struct object_context unused;
1193 return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
1194 sha1, &unused);
1195}
1196
1197int get_sha1_treeish(const char *name, unsigned char *sha1)
1198{
1199 struct object_context unused;
1200 return get_sha1_with_context(name, GET_SHA1_TREEISH,
1201 sha1, &unused);
1202}
1203
1204int get_sha1_commit(const char *name, unsigned char *sha1)
1205{
1206 struct object_context unused;
1207 return get_sha1_with_context(name, GET_SHA1_COMMIT,
1208 sha1, &unused);
1209}
1210
1211int get_sha1_tree(const char *name, unsigned char *sha1)
1212{
1213 struct object_context unused;
1214 return get_sha1_with_context(name, GET_SHA1_TREE,
1215 sha1, &unused);
1216}
1217
1218int get_sha1_blob(const char *name, unsigned char *sha1)
1219{
1220 struct object_context unused;
1221 return get_sha1_with_context(name, GET_SHA1_BLOB,
1222 sha1, &unused);
1223}
1224
1225/* Must be called only when object_name:filename doesn't exist. */
1226static void diagnose_invalid_sha1_path(const char *prefix,
1227 const char *filename,
1228 const unsigned char *tree_sha1,
1229 const char *object_name,
1230 int object_name_len)
1231{
1232 struct stat st;
1233 unsigned char sha1[20];
1234 unsigned mode;
1235
1236 if (!prefix)
1237 prefix = "";
1238
1239 if (!lstat(filename, &st))
1240 die("Path '%s' exists on disk, but not in '%.*s'.",
1241 filename, object_name_len, object_name);
1242 if (errno == ENOENT || errno == ENOTDIR) {
1243 char *fullname = xstrfmt("%s%s", prefix, filename);
1244
1245 if (!get_tree_entry(tree_sha1, fullname,
1246 sha1, &mode)) {
1247 die("Path '%s' exists, but not '%s'.\n"
1248 "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1249 fullname,
1250 filename,
1251 object_name_len, object_name,
1252 fullname,
1253 object_name_len, object_name,
1254 filename);
1255 }
1256 die("Path '%s' does not exist in '%.*s'",
1257 filename, object_name_len, object_name);
1258 }
1259}
1260
1261/* Must be called only when :stage:filename doesn't exist. */
1262static void diagnose_invalid_index_path(int stage,
1263 const char *prefix,
1264 const char *filename)
1265{
1266 struct stat st;
1267 const struct cache_entry *ce;
1268 int pos;
1269 unsigned namelen = strlen(filename);
1270 unsigned fullnamelen;
1271 char *fullname;
1272
1273 if (!prefix)
1274 prefix = "";
1275
1276 /* Wrong stage number? */
1277 pos = cache_name_pos(filename, namelen);
1278 if (pos < 0)
1279 pos = -pos - 1;
1280 if (pos < active_nr) {
1281 ce = active_cache[pos];
1282 if (ce_namelen(ce) == namelen &&
1283 !memcmp(ce->name, filename, namelen))
1284 die("Path '%s' is in the index, but not at stage %d.\n"
1285 "Did you mean ':%d:%s'?",
1286 filename, stage,
1287 ce_stage(ce), filename);
1288 }
1289
1290 /* Confusion between relative and absolute filenames? */
1291 fullnamelen = namelen + strlen(prefix);
1292 fullname = xmalloc(fullnamelen + 1);
1293 strcpy(fullname, prefix);
1294 strcat(fullname, filename);
1295 pos = cache_name_pos(fullname, fullnamelen);
1296 if (pos < 0)
1297 pos = -pos - 1;
1298 if (pos < active_nr) {
1299 ce = active_cache[pos];
1300 if (ce_namelen(ce) == fullnamelen &&
1301 !memcmp(ce->name, fullname, fullnamelen))
1302 die("Path '%s' is in the index, but not '%s'.\n"
1303 "Did you mean ':%d:%s' aka ':%d:./%s'?",
1304 fullname, filename,
1305 ce_stage(ce), fullname,
1306 ce_stage(ce), filename);
1307 }
1308
1309 if (!lstat(filename, &st))
1310 die("Path '%s' exists on disk, but not in the index.", filename);
1311 if (errno == ENOENT || errno == ENOTDIR)
1312 die("Path '%s' does not exist (neither on disk nor in the index).",
1313 filename);
1314
1315 free(fullname);
1316}
1317
1318
1319static char *resolve_relative_path(const char *rel)
1320{
1321 if (!starts_with(rel, "./") && !starts_with(rel, "../"))
1322 return NULL;
1323
1324 if (!startup_info)
1325 die("BUG: startup_info struct is not initialized.");
1326
1327 if (!is_inside_work_tree())
1328 die("relative path syntax can't be used outside working tree.");
1329
1330 /* die() inside prefix_path() if resolved path is outside worktree */
1331 return prefix_path(startup_info->prefix,
1332 startup_info->prefix ? strlen(startup_info->prefix) : 0,
1333 rel);
1334}
1335
1336static int get_sha1_with_context_1(const char *name,
1337 unsigned flags,
1338 const char *prefix,
1339 unsigned char *sha1,
1340 struct object_context *oc)
1341{
1342 int ret, bracket_depth;
1343 int namelen = strlen(name);
1344 const char *cp;
1345 int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
1346
1347 memset(oc, 0, sizeof(*oc));
1348 oc->mode = S_IFINVALID;
1349 ret = get_sha1_1(name, namelen, sha1, flags);
1350 if (!ret)
1351 return ret;
1352 /*
1353 * sha1:path --> object name of path in ent sha1
1354 * :path -> object name of absolute path in index
1355 * :./path -> object name of path relative to cwd in index
1356 * :[0-3]:path -> object name of path in index at stage
1357 * :/foo -> recent commit matching foo
1358 */
1359 if (name[0] == ':') {
1360 int stage = 0;
1361 const struct cache_entry *ce;
1362 char *new_path = NULL;
1363 int pos;
1364 if (!only_to_die && namelen > 2 && name[1] == '/') {
1365 struct commit_list *list = NULL;
1366 for_each_ref(handle_one_ref, &list);
1367 return get_sha1_oneline(name + 2, sha1, list);
1368 }
1369 if (namelen < 3 ||
1370 name[2] != ':' ||
1371 name[1] < '0' || '3' < name[1])
1372 cp = name + 1;
1373 else {
1374 stage = name[1] - '0';
1375 cp = name + 3;
1376 }
1377 new_path = resolve_relative_path(cp);
1378 if (!new_path) {
1379 namelen = namelen - (cp - name);
1380 } else {
1381 cp = new_path;
1382 namelen = strlen(cp);
1383 }
1384
1385 strncpy(oc->path, cp,
1386 sizeof(oc->path));
1387 oc->path[sizeof(oc->path)-1] = '\0';
1388
1389 if (!active_cache)
1390 read_cache();
1391 pos = cache_name_pos(cp, namelen);
1392 if (pos < 0)
1393 pos = -pos - 1;
1394 while (pos < active_nr) {
1395 ce = active_cache[pos];
1396 if (ce_namelen(ce) != namelen ||
1397 memcmp(ce->name, cp, namelen))
1398 break;
1399 if (ce_stage(ce) == stage) {
1400 hashcpy(sha1, ce->sha1);
1401 oc->mode = ce->ce_mode;
1402 free(new_path);
1403 return 0;
1404 }
1405 pos++;
1406 }
1407 if (only_to_die && name[1] && name[1] != '/')
1408 diagnose_invalid_index_path(stage, prefix, cp);
1409 free(new_path);
1410 return -1;
1411 }
1412 for (cp = name, bracket_depth = 0; *cp; cp++) {
1413 if (*cp == '{')
1414 bracket_depth++;
1415 else if (bracket_depth && *cp == '}')
1416 bracket_depth--;
1417 else if (!bracket_depth && *cp == ':')
1418 break;
1419 }
1420 if (*cp == ':') {
1421 unsigned char tree_sha1[20];
1422 int len = cp - name;
1423 if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
1424 const char *filename = cp+1;
1425 char *new_filename = NULL;
1426
1427 new_filename = resolve_relative_path(filename);
1428 if (new_filename)
1429 filename = new_filename;
1430 ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
1431 if (ret && only_to_die) {
1432 diagnose_invalid_sha1_path(prefix, filename,
1433 tree_sha1,
1434 name, len);
1435 }
1436 hashcpy(oc->tree, tree_sha1);
1437 strncpy(oc->path, filename,
1438 sizeof(oc->path));
1439 oc->path[sizeof(oc->path)-1] = '\0';
1440
1441 free(new_filename);
1442 return ret;
1443 } else {
1444 if (only_to_die)
1445 die("Invalid object name '%.*s'.", len, name);
1446 }
1447 }
1448 return ret;
1449}
1450
1451/*
1452 * Call this function when you know "name" given by the end user must
1453 * name an object but it doesn't; the function _may_ die with a better
1454 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1455 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1456 * you have a chance to diagnose the error further.
1457 */
1458void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1459{
1460 struct object_context oc;
1461 unsigned char sha1[20];
1462 get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
1463}
1464
1465int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
1466{
1467 return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
1468}