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"
8static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
10{
11 struct alternate_object_database *alt;
12 char hex[40];
13 int found = 0;
14 static struct alternate_object_database *fakeent;
15 if (!fakeent) {
17 const char *objdir = get_object_directory();
18 int objdir_len = strlen(objdir);
19 int entlen = objdir_len + 43;
20 fakeent = xmalloc(sizeof(*fakeent) + entlen);
21 memcpy(fakeent->base, objdir, objdir_len);
22 fakeent->name = fakeent->base + objdir_len + 1;
23 fakeent->name[-1] = '/';
24 }
25 fakeent->next = alt_odb_list;
26 sprintf(hex, "%.2s", name);
28 for (alt = fakeent; alt && found < 2; alt = alt->next) {
29 struct dirent *de;
30 DIR *dir;
31 sprintf(alt->name, "%.2s/", name);
32 dir = opendir(alt->base);
33 if (!dir)
34 continue;
35 while ((de = readdir(dir)) != NULL) {
36 if (strlen(de->d_name) != 38)
37 continue;
38 if (memcmp(de->d_name, name + 2, len - 2))
39 continue;
40 if (!found) {
41 memcpy(hex + 2, de->d_name, 38);
42 found++;
43 }
44 else if (memcmp(hex + 2, de->d_name, 38)) {
45 found = 2;
46 break;
47 }
48 }
49 closedir(dir);
50 }
51 if (found == 1)
52 return get_sha1_hex(hex, sha1) == 0;
53 return found;
54}
55static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
57{
58 do {
59 if (*a != *b)
60 return 0;
61 a++;
62 b++;
63 len -= 2;
64 } while (len > 1);
65 if (len)
66 if ((*a ^ *b) & 0xf0)
67 return 0;
68 return 1;
69}
70static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
72{
73 struct packed_git *p;
74 const unsigned char *found_sha1 = NULL;
75 int found = 0;
76 prepare_packed_git();
78 for (p = packed_git; p && found < 2; p = p->next) {
79 uint32_t num, last;
80 uint32_t first = 0;
81 open_pack_index(p);
82 num = p->num_objects;
83 last = num;
84 while (first < last) {
85 uint32_t mid = (first + last) / 2;
86 const unsigned char *now;
87 int cmp;
88 now = nth_packed_object_sha1(p, mid);
90 cmp = hashcmp(match, now);
91 if (!cmp) {
92 first = mid;
93 break;
94 }
95 if (cmp > 0) {
96 first = mid+1;
97 continue;
98 }
99 last = mid;
100 }
101 if (first < num) {
102 const unsigned char *now, *next;
103 now = nth_packed_object_sha1(p, first);
104 if (match_sha(len, match, now)) {
105 next = nth_packed_object_sha1(p, first+1);
106 if (!next|| !match_sha(len, match, next)) {
107 /* unique within this pack */
108 if (!found) {
109 found_sha1 = now;
110 found++;
111 }
112 else if (hashcmp(found_sha1, now)) {
113 found = 2;
114 break;
115 }
116 }
117 else {
118 /* not even unique within this pack */
119 found = 2;
120 break;
121 }
122 }
123 }
124 }
125 if (found == 1)
126 hashcpy(sha1, found_sha1);
127 return found;
128}
129#define SHORT_NAME_NOT_FOUND (-1)
131#define SHORT_NAME_AMBIGUOUS (-2)
132static int find_unique_short_object(int len, char *canonical,
134 unsigned char *res, unsigned char *sha1)
135{
136 int has_unpacked, has_packed;
137 unsigned char unpacked_sha1[20], packed_sha1[20];
138 prepare_alt_odb();
140 has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
141 has_packed = find_short_packed_object(len, res, packed_sha1);
142 if (!has_unpacked && !has_packed)
143 return SHORT_NAME_NOT_FOUND;
144 if (1 < has_unpacked || 1 < has_packed)
145 return SHORT_NAME_AMBIGUOUS;
146 if (has_unpacked != has_packed) {
147 hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1));
148 return 0;
149 }
150 /* Both have unique ones -- do they match? */
151 if (hashcmp(packed_sha1, unpacked_sha1))
152 return SHORT_NAME_AMBIGUOUS;
153 hashcpy(sha1, packed_sha1);
154 return 0;
155}
156static int get_short_sha1(const char *name, int len, unsigned char *sha1,
158 int quietly)
159{
160 int i, status;
161 char canonical[40];
162 unsigned char res[20];
163 if (len < MINIMUM_ABBREV || len > 40)
165 return -1;
166 hashclr(res);
167 memset(canonical, 'x', 40);
168 for (i = 0; i < len ;i++) {
169 unsigned char c = name[i];
170 unsigned char val;
171 if (c >= '0' && c <= '9')
172 val = c - '0';
173 else if (c >= 'a' && c <= 'f')
174 val = c - 'a' + 10;
175 else if (c >= 'A' && c <='F') {
176 val = c - 'A' + 10;
177 c -= 'A' - 'a';
178 }
179 else
180 return -1;
181 canonical[i] = c;
182 if (!(i & 1))
183 val <<= 4;
184 res[i >> 1] |= val;
185 }
186 status = find_unique_short_object(i, canonical, res, sha1);
188 if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
189 return error("short SHA1 %.*s is ambiguous.", len, canonical);
190 return status;
191}
192const char *find_unique_abbrev(const unsigned char *sha1, int len)
194{
195 int status, exists;
196 static char hex[41];
197 exists = has_sha1_file(sha1);
199 memcpy(hex, sha1_to_hex(sha1), 40);
200 if (len == 40 || !len)
201 return hex;
202 while (len < 40) {
203 unsigned char sha1_ret[20];
204 status = get_short_sha1(hex, len, sha1_ret, 1);
205 if (exists
206 ? !status
207 : status == SHORT_NAME_NOT_FOUND) {
208 hex[len] = 0;
209 return hex;
210 }
211 len++;
212 }
213 return hex;
214}
215static int ambiguous_path(const char *path, int len)
217{
218 int slash = 1;
219 int cnt;
220 for (cnt = 0; cnt < len; cnt++) {
222 switch (*path++) {
223 case '\0':
224 break;
225 case '/':
226 if (slash)
227 break;
228 slash = 1;
229 continue;
230 case '.':
231 continue;
232 default:
233 slash = 0;
234 continue;
235 }
236 break;
237 }
238 return slash;
239}
240int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
242{
243 const char **p, *r;
244 int refs_found = 0;
245 *ref = NULL;
247 for (p = ref_rev_parse_rules; *p; p++) {
248 char fullref[PATH_MAX];
249 unsigned char sha1_from_ref[20];
250 unsigned char *this_result;
251 this_result = refs_found ? sha1_from_ref : sha1;
253 mksnpath(fullref, sizeof(fullref), *p, len, str);
254 r = resolve_ref(fullref, this_result, 1, NULL);
255 if (r) {
256 if (!refs_found++)
257 *ref = xstrdup(r);
258 if (!warn_ambiguous_refs)
259 break;
260 }
261 }
262 return refs_found;
263}
264int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
266{
267 const char **p;
268 int logs_found = 0;
269 *log = NULL;
271 for (p = ref_rev_parse_rules; *p; p++) {
272 struct stat st;
273 unsigned char hash[20];
274 char path[PATH_MAX];
275 const char *ref, *it;
276 mksnpath(path, sizeof(path), *p, len, str);
278 ref = resolve_ref(path, hash, 1, NULL);
279 if (!ref)
280 continue;
281 if (!stat(git_path("logs/%s", path), &st) &&
282 S_ISREG(st.st_mode))
283 it = path;
284 else if (strcmp(ref, path) &&
285 !stat(git_path("logs/%s", ref), &st) &&
286 S_ISREG(st.st_mode))
287 it = ref;
288 else
289 continue;
290 if (!logs_found++) {
291 *log = xstrdup(it);
292 hashcpy(sha1, hash);
293 }
294 if (!warn_ambiguous_refs)
295 break;
296 }
297 return logs_found;
298}
299static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
301{
302 static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
303 char *real_ref = NULL;
304 int refs_found = 0;
305 int at, reflog_len;
306 if (len == 40 && !get_sha1_hex(str, sha1))
308 return 0;
309 /* basic@{time or number} format to query ref-log */
311 reflog_len = at = 0;
312 if (str[len-1] == '}') {
313 for (at = 0; at < len - 1; at++) {
314 if (str[at] == '@' && str[at+1] == '{') {
315 reflog_len = (len-1) - (at+2);
316 len = at;
317 break;
318 }
319 }
320 }
321 /* Accept only unambiguous ref paths. */
323 if (len && ambiguous_path(str, len))
324 return -1;
325 if (!len && reflog_len) {
327 /* allow "@{...}" to mean the current branch reflog */
328 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
329 } else if (reflog_len)
330 refs_found = dwim_log(str, len, sha1, &real_ref);
331 else
332 refs_found = dwim_ref(str, len, sha1, &real_ref);
333 if (!refs_found)
335 return -1;
336 if (warn_ambiguous_refs && refs_found > 1)
338 fprintf(stderr, warning, len, str);
339 if (reflog_len) {
341 int nth, i;
342 unsigned long at_time;
343 unsigned long co_time;
344 int co_tz, co_cnt;
345 /* Is it asking for N-th entry, or approxidate? */
347 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
348 char ch = str[at+2+i];
349 if ('0' <= ch && ch <= '9')
350 nth = nth * 10 + ch - '0';
351 else
352 nth = -1;
353 }
354 if (0 <= nth)
355 at_time = 0;
356 else {
357 char *tmp = xstrndup(str + at + 2, reflog_len);
358 at_time = approxidate(tmp);
359 free(tmp);
360 }
361 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
362 &co_time, &co_tz, &co_cnt)) {
363 if (at_time)
364 fprintf(stderr,
365 "warning: Log for '%.*s' only goes "
366 "back to %s.\n", len, str,
367 show_date(co_time, co_tz, DATE_RFC2822));
368 else
369 fprintf(stderr,
370 "warning: Log for '%.*s' only has "
371 "%d entries.\n", len, str, co_cnt);
372 }
373 }
374 free(real_ref);
376 return 0;
377}
378static int get_sha1_1(const char *name, int len, unsigned char *sha1);
380static int get_parent(const char *name, int len,
382 unsigned char *result, int idx)
383{
384 unsigned char sha1[20];
385 int ret = get_sha1_1(name, len, sha1);
386 struct commit *commit;
387 struct commit_list *p;
388 if (ret)
390 return ret;
391 commit = lookup_commit_reference(sha1);
392 if (!commit)
393 return -1;
394 if (parse_commit(commit))
395 return -1;
396 if (!idx) {
397 hashcpy(result, commit->object.sha1);
398 return 0;
399 }
400 p = commit->parents;
401 while (p) {
402 if (!--idx) {
403 hashcpy(result, p->item->object.sha1);
404 return 0;
405 }
406 p = p->next;
407 }
408 return -1;
409}
410static int get_nth_ancestor(const char *name, int len,
412 unsigned char *result, int generation)
413{
414 unsigned char sha1[20];
415 struct commit *commit;
416 int ret;
417 ret = get_sha1_1(name, len, sha1);
419 if (ret)
420 return ret;
421 commit = lookup_commit_reference(sha1);
422 if (!commit)
423 return -1;
424 while (generation--) {
426 if (parse_commit(commit) || !commit->parents)
427 return -1;
428 commit = commit->parents->item;
429 }
430 hashcpy(result, commit->object.sha1);
431 return 0;
432}
433struct object *peel_to_type(const char *name, int namelen,
435 struct object *o, enum object_type expected_type)
436{
437 if (name && !namelen)
438 namelen = strlen(name);
439 if (!o) {
440 unsigned char sha1[20];
441 if (get_sha1_1(name, namelen, sha1))
442 return NULL;
443 o = parse_object(sha1);
444 }
445 while (1) {
446 if (!o || (!o->parsed && !parse_object(o->sha1)))
447 return NULL;
448 if (o->type == expected_type)
449 return o;
450 if (o->type == OBJ_TAG)
451 o = ((struct tag*) o)->tagged;
452 else if (o->type == OBJ_COMMIT)
453 o = &(((struct commit *) o)->tree->object);
454 else {
455 if (name)
456 error("%.*s: expected %s type, but the object "
457 "dereferences to %s type",
458 namelen, name, typename(expected_type),
459 typename(o->type));
460 return NULL;
461 }
462 }
463}
464static int peel_onion(const char *name, int len, unsigned char *sha1)
466{
467 unsigned char outer[20];
468 const char *sp;
469 unsigned int expected_type = 0;
470 struct object *o;
471 /*
473 * "ref^{type}" dereferences ref repeatedly until you cannot
474 * dereference anymore, or you get an object of given type,
475 * whichever comes first. "ref^{}" means just dereference
476 * tags until you get a non-tag. "ref^0" is a shorthand for
477 * "ref^{commit}". "commit^{tree}" could be used to find the
478 * top-level tree of the given commit.
479 */
480 if (len < 4 || name[len-1] != '}')
481 return -1;
482 for (sp = name + len - 1; name <= sp; sp--) {
484 int ch = *sp;
485 if (ch == '{' && name < sp && sp[-1] == '^')
486 break;
487 }
488 if (sp <= name)
489 return -1;
490 sp++; /* beginning of type name, or closing brace for empty */
492 if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
493 expected_type = OBJ_COMMIT;
494 else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
495 expected_type = OBJ_TREE;
496 else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
497 expected_type = OBJ_BLOB;
498 else if (sp[0] == '}')
499 expected_type = OBJ_NONE;
500 else
501 return -1;
502 if (get_sha1_1(name, sp - name - 2, outer))
504 return -1;
505 o = parse_object(outer);
507 if (!o)
508 return -1;
509 if (!expected_type) {
510 o = deref_tag(o, name, sp - name - 2);
511 if (!o || (!o->parsed && !parse_object(o->sha1)))
512 return -1;
513 hashcpy(sha1, o->sha1);
514 }
515 else {
516 /*
517 * At this point, the syntax look correct, so
518 * if we do not get the needed object, we should
519 * barf.
520 */
521 o = peel_to_type(name, len, o, expected_type);
522 if (o) {
523 hashcpy(sha1, o->sha1);
524 return 0;
525 }
526 return -1;
527 }
528 return 0;
529}
530static int get_describe_name(const char *name, int len, unsigned char *sha1)
532{
533 const char *cp;
534 for (cp = name + len - 1; name + 2 <= cp; cp--) {
536 char ch = *cp;
537 if (hexval(ch) & ~0377) {
538 /* We must be looking at g in "SOMETHING-g"
539 * for it to be describe output.
540 */
541 if (ch == 'g' && cp[-1] == '-') {
542 cp++;
543 len -= cp - name;
544 return get_short_sha1(cp, len, sha1, 1);
545 }
546 }
547 }
548 return -1;
549}
550static int get_sha1_1(const char *name, int len, unsigned char *sha1)
552{
553 int ret, has_suffix;
554 const char *cp;
555 /*
557 * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
558 */
559 has_suffix = 0;
560 for (cp = name + len - 1; name <= cp; cp--) {
561 int ch = *cp;
562 if ('0' <= ch && ch <= '9')
563 continue;
564 if (ch == '~' || ch == '^')
565 has_suffix = ch;
566 break;
567 }
568 if (has_suffix) {
570 int num = 0;
571 int len1 = cp - name;
572 cp++;
573 while (cp < name + len)
574 num = num * 10 + *cp++ - '0';
575 if (!num && len1 == len - 1)
576 num = 1;
577 if (has_suffix == '^')
578 return get_parent(name, len1, sha1, num);
579 /* else if (has_suffix == '~') -- goes without saying */
580 return get_nth_ancestor(name, len1, sha1, num);
581 }
582 ret = peel_onion(name, len, sha1);
584 if (!ret)
585 return 0;
586 ret = get_sha1_basic(name, len, sha1);
588 if (!ret)
589 return 0;
590 /* It could be describe output that is "SOMETHING-gXXXX" */
592 ret = get_describe_name(name, len, sha1);
593 if (!ret)
594 return 0;
595 return get_short_sha1(name, len, sha1, 0);
597}
598static int handle_one_ref(const char *path,
600 const unsigned char *sha1, int flag, void *cb_data)
601{
602 struct commit_list **list = cb_data;
603 struct object *object = parse_object(sha1);
604 if (!object)
605 return 0;
606 if (object->type == OBJ_TAG) {
607 object = deref_tag(object, path, strlen(path));
608 if (!object)
609 return 0;
610 }
611 if (object->type != OBJ_COMMIT)
612 return 0;
613 insert_by_date((struct commit *)object, list);
614 return 0;
615}
616/*
618 * This interprets names like ':/Initial revision of "git"' by searching
619 * through history and returning the first commit whose message starts
620 * with the given string.
621 *
622 * For future extension, ':/!' is reserved. If you want to match a message
623 * beginning with a '!', you have to repeat the exclamation mark.
624 */
625#define ONELINE_SEEN (1u<<20)
627static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
628{
629 struct commit_list *list = NULL, *backup = NULL, *l;
630 int retval = -1;
631 char *temp_commit_buffer = NULL;
632 if (prefix[0] == '!') {
634 if (prefix[1] != '!')
635 die ("Invalid search pattern: %s", prefix);
636 prefix++;
637 }
638 for_each_ref(handle_one_ref, &list);
639 for (l = list; l; l = l->next)
640 commit_list_insert(l->item, &backup);
641 while (list) {
642 char *p;
643 struct commit *commit;
644 enum object_type type;
645 unsigned long size;
646 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
648 if (!parse_object(commit->object.sha1))
649 continue;
650 free(temp_commit_buffer);
651 if (commit->buffer)
652 p = commit->buffer;
653 else {
654 p = read_sha1_file(commit->object.sha1, &type, &size);
655 if (!p)
656 continue;
657 temp_commit_buffer = p;
658 }
659 if (!(p = strstr(p, "\n\n")))
660 continue;
661 if (!prefixcmp(p + 2, prefix)) {
662 hashcpy(sha1, commit->object.sha1);
663 retval = 0;
664 break;
665 }
666 }
667 free(temp_commit_buffer);
668 free_commit_list(list);
669 for (l = backup; l; l = l->next)
670 clear_commit_marks(l->item, ONELINE_SEEN);
671 return retval;
672}
673/*
675 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
676 * notably "xyz^" for "parent of xyz"
677 */
678int get_sha1(const char *name, unsigned char *sha1)
679{
680 unsigned unused;
681 return get_sha1_with_mode(name, sha1, &unused);
682}
683int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode)
685{
686 int ret, bracket_depth;
687 int namelen = strlen(name);
688 const char *cp;
689 *mode = S_IFINVALID;
691 ret = get_sha1_1(name, namelen, sha1);
692 if (!ret)
693 return ret;
694 /* sha1:path --> object name of path in ent sha1
695 * :path -> object name of path in index
696 * :[0-3]:path -> object name of path in index at stage
697 */
698 if (name[0] == ':') {
699 int stage = 0;
700 struct cache_entry *ce;
701 int pos;
702 if (namelen > 2 && name[1] == '/')
703 return get_sha1_oneline(name + 2, sha1);
704 if (namelen < 3 ||
705 name[2] != ':' ||
706 name[1] < '0' || '3' < name[1])
707 cp = name + 1;
708 else {
709 stage = name[1] - '0';
710 cp = name + 3;
711 }
712 namelen = namelen - (cp - name);
713 if (!active_cache)
714 read_cache();
715 pos = cache_name_pos(cp, namelen);
716 if (pos < 0)
717 pos = -pos - 1;
718 while (pos < active_nr) {
719 ce = active_cache[pos];
720 if (ce_namelen(ce) != namelen ||
721 memcmp(ce->name, cp, namelen))
722 break;
723 if (ce_stage(ce) == stage) {
724 hashcpy(sha1, ce->sha1);
725 *mode = ce->ce_mode;
726 return 0;
727 }
728 pos++;
729 }
730 return -1;
731 }
732 for (cp = name, bracket_depth = 0; *cp; cp++) {
733 if (*cp == '{')
734 bracket_depth++;
735 else if (bracket_depth && *cp == '}')
736 bracket_depth--;
737 else if (!bracket_depth && *cp == ':')
738 break;
739 }
740 if (*cp == ':') {
741 unsigned char tree_sha1[20];
742 if (!get_sha1_1(name, cp-name, tree_sha1))
743 return get_tree_entry(tree_sha1, cp+1, sha1,
744 mode);
745 }
746 return ret;
747}