Merge branch 'bc/object-id'
[git/git.git] / tree-walk.c
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "unpack-trees.h"
4 #include "dir.h"
5 #include "object-store.h"
6 #include "tree.h"
7 #include "pathspec.h"
8
9 static const char *get_mode(const char *str, unsigned int *modep)
10 {
11 unsigned char c;
12 unsigned int mode = 0;
13
14 if (*str == ' ')
15 return NULL;
16
17 while ((c = *str++) != ' ') {
18 if (c < '0' || c > '7')
19 return NULL;
20 mode = (mode << 3) + (c - '0');
21 }
22 *modep = mode;
23 return str;
24 }
25
26 static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size, struct strbuf *err)
27 {
28 const char *path;
29 unsigned int mode, len;
30 const unsigned hashsz = the_hash_algo->rawsz;
31
32 if (size < hashsz + 3 || buf[size - (hashsz + 1)]) {
33 strbuf_addstr(err, _("too-short tree object"));
34 return -1;
35 }
36
37 path = get_mode(buf, &mode);
38 if (!path) {
39 strbuf_addstr(err, _("malformed mode in tree entry"));
40 return -1;
41 }
42 if (!*path) {
43 strbuf_addstr(err, _("empty filename in tree entry"));
44 return -1;
45 }
46 len = strlen(path) + 1;
47
48 /* Initialize the descriptor entry */
49 desc->entry.path = path;
50 desc->entry.mode = canon_mode(mode);
51 desc->entry.oid = (const struct object_id *)(path + len);
52
53 return 0;
54 }
55
56 static int init_tree_desc_internal(struct tree_desc *desc, const void *buffer, unsigned long size, struct strbuf *err)
57 {
58 desc->buffer = buffer;
59 desc->size = size;
60 if (size)
61 return decode_tree_entry(desc, buffer, size, err);
62 return 0;
63 }
64
65 void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
66 {
67 struct strbuf err = STRBUF_INIT;
68 if (init_tree_desc_internal(desc, buffer, size, &err))
69 die("%s", err.buf);
70 strbuf_release(&err);
71 }
72
73 int init_tree_desc_gently(struct tree_desc *desc, const void *buffer, unsigned long size)
74 {
75 struct strbuf err = STRBUF_INIT;
76 int result = init_tree_desc_internal(desc, buffer, size, &err);
77 if (result)
78 error("%s", err.buf);
79 strbuf_release(&err);
80 return result;
81 }
82
83 void *fill_tree_descriptor(struct tree_desc *desc, const struct object_id *oid)
84 {
85 unsigned long size = 0;
86 void *buf = NULL;
87
88 if (oid) {
89 buf = read_object_with_reference(oid, tree_type, &size, NULL);
90 if (!buf)
91 die("unable to read tree %s", oid_to_hex(oid));
92 }
93 init_tree_desc(desc, buf, size);
94 return buf;
95 }
96
97 static void entry_clear(struct name_entry *a)
98 {
99 memset(a, 0, sizeof(*a));
100 }
101
102 static void entry_extract(struct tree_desc *t, struct name_entry *a)
103 {
104 *a = t->entry;
105 }
106
107 static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
108 {
109 const void *buf = desc->buffer;
110 const unsigned char *end = desc->entry.oid->hash + the_hash_algo->rawsz;
111 unsigned long size = desc->size;
112 unsigned long len = end - (const unsigned char *)buf;
113
114 if (size < len)
115 die(_("too-short tree file"));
116 buf = end;
117 size -= len;
118 desc->buffer = buf;
119 desc->size = size;
120 if (size)
121 return decode_tree_entry(desc, buf, size, err);
122 return 0;
123 }
124
125 void update_tree_entry(struct tree_desc *desc)
126 {
127 struct strbuf err = STRBUF_INIT;
128 if (update_tree_entry_internal(desc, &err))
129 die("%s", err.buf);
130 strbuf_release(&err);
131 }
132
133 int update_tree_entry_gently(struct tree_desc *desc)
134 {
135 struct strbuf err = STRBUF_INIT;
136 if (update_tree_entry_internal(desc, &err)) {
137 error("%s", err.buf);
138 strbuf_release(&err);
139 /* Stop processing this tree after error */
140 desc->size = 0;
141 return -1;
142 }
143 strbuf_release(&err);
144 return 0;
145 }
146
147 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
148 {
149 if (!desc->size)
150 return 0;
151
152 *entry = desc->entry;
153 update_tree_entry(desc);
154 return 1;
155 }
156
157 int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
158 {
159 if (!desc->size)
160 return 0;
161
162 *entry = desc->entry;
163 if (update_tree_entry_gently(desc))
164 return 0;
165 return 1;
166 }
167
168 void setup_traverse_info(struct traverse_info *info, const char *base)
169 {
170 int pathlen = strlen(base);
171 static struct traverse_info dummy;
172
173 memset(info, 0, sizeof(*info));
174 if (pathlen && base[pathlen-1] == '/')
175 pathlen--;
176 info->pathlen = pathlen ? pathlen + 1 : 0;
177 info->name.path = base;
178 info->name.oid = (void *)(base + pathlen + 1);
179 if (pathlen)
180 info->prev = &dummy;
181 }
182
183 char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
184 {
185 int len = tree_entry_len(n);
186 int pathlen = info->pathlen;
187
188 path[pathlen + len] = 0;
189 for (;;) {
190 memcpy(path + pathlen, n->path, len);
191 if (!pathlen)
192 break;
193 path[--pathlen] = '/';
194 n = &info->name;
195 len = tree_entry_len(n);
196 info = info->prev;
197 pathlen -= len;
198 }
199 return path;
200 }
201
202 struct tree_desc_skip {
203 struct tree_desc_skip *prev;
204 const void *ptr;
205 };
206
207 struct tree_desc_x {
208 struct tree_desc d;
209 struct tree_desc_skip *skip;
210 };
211
212 static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
213 {
214 /*
215 * The caller wants to pick *a* from a tree or nothing.
216 * We are looking at *b* in a tree.
217 *
218 * (0) If a and b are the same name, we are trivially happy.
219 *
220 * There are three possibilities where *a* could be hiding
221 * behind *b*.
222 *
223 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
224 * matter what.
225 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
226 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
227 *
228 * Otherwise we know *a* won't appear in the tree without
229 * scanning further.
230 */
231
232 int cmp = name_compare(a, a_len, b, b_len);
233
234 /* Most common case first -- reading sync'd trees */
235 if (!cmp)
236 return cmp;
237
238 if (0 < cmp) {
239 /* a comes after b; it does not matter if it is case (3)
240 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
241 return 1;
242 */
243 return 1; /* keep looking */
244 }
245
246 /* b comes after a; are we looking at case (2)? */
247 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
248 return 1; /* keep looking */
249
250 return -1; /* a cannot appear in the tree */
251 }
252
253 /*
254 * From the extended tree_desc, extract the first name entry, while
255 * paying attention to the candidate "first" name. Most importantly,
256 * when looking for an entry, if there are entries that sorts earlier
257 * in the tree object representation than that name, skip them and
258 * process the named entry first. We will remember that we haven't
259 * processed the first entry yet, and in the later call skip the
260 * entry we processed early when update_extended_entry() is called.
261 *
262 * E.g. if the underlying tree object has these entries:
263 *
264 * blob "t-1"
265 * blob "t-2"
266 * tree "t"
267 * blob "t=1"
268 *
269 * and the "first" asks for "t", remember that we still need to
270 * process "t-1" and "t-2" but extract "t". After processing the
271 * entry "t" from this call, the caller will let us know by calling
272 * update_extended_entry() that we can remember "t" has been processed
273 * already.
274 */
275
276 static void extended_entry_extract(struct tree_desc_x *t,
277 struct name_entry *a,
278 const char *first,
279 int first_len)
280 {
281 const char *path;
282 int len;
283 struct tree_desc probe;
284 struct tree_desc_skip *skip;
285
286 /*
287 * Extract the first entry from the tree_desc, but skip the
288 * ones that we already returned in earlier rounds.
289 */
290 while (1) {
291 if (!t->d.size) {
292 entry_clear(a);
293 break; /* not found */
294 }
295 entry_extract(&t->d, a);
296 for (skip = t->skip; skip; skip = skip->prev)
297 if (a->path == skip->ptr)
298 break; /* found */
299 if (!skip)
300 break;
301 /* We have processed this entry already. */
302 update_tree_entry(&t->d);
303 }
304
305 if (!first || !a->path)
306 return;
307
308 /*
309 * The caller wants "first" from this tree, or nothing.
310 */
311 path = a->path;
312 len = tree_entry_len(a);
313 switch (check_entry_match(first, first_len, path, len)) {
314 case -1:
315 entry_clear(a);
316 case 0:
317 return;
318 default:
319 break;
320 }
321
322 /*
323 * We need to look-ahead -- we suspect that a subtree whose
324 * name is "first" may be hiding behind the current entry "path".
325 */
326 probe = t->d;
327 while (probe.size) {
328 entry_extract(&probe, a);
329 path = a->path;
330 len = tree_entry_len(a);
331 switch (check_entry_match(first, first_len, path, len)) {
332 case -1:
333 entry_clear(a);
334 case 0:
335 return;
336 default:
337 update_tree_entry(&probe);
338 break;
339 }
340 /* keep looking */
341 }
342 entry_clear(a);
343 }
344
345 static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
346 {
347 if (t->d.entry.path == a->path) {
348 update_tree_entry(&t->d);
349 } else {
350 /* we have returned this entry early */
351 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
352 skip->ptr = a->path;
353 skip->prev = t->skip;
354 t->skip = skip;
355 }
356 }
357
358 static void free_extended_entry(struct tree_desc_x *t)
359 {
360 struct tree_desc_skip *p, *s;
361
362 for (s = t->skip; s; s = p) {
363 p = s->prev;
364 free(s);
365 }
366 }
367
368 static inline int prune_traversal(struct name_entry *e,
369 struct traverse_info *info,
370 struct strbuf *base,
371 int still_interesting)
372 {
373 if (!info->pathspec || still_interesting == 2)
374 return 2;
375 if (still_interesting < 0)
376 return still_interesting;
377 return tree_entry_interesting(e, base, 0, info->pathspec);
378 }
379
380 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
381 {
382 int error = 0;
383 struct name_entry *entry = xmalloc(n*sizeof(*entry));
384 int i;
385 struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
386 struct strbuf base = STRBUF_INIT;
387 int interesting = 1;
388 char *traverse_path;
389
390 for (i = 0; i < n; i++)
391 tx[i].d = t[i];
392
393 if (info->prev) {
394 strbuf_grow(&base, info->pathlen);
395 make_traverse_path(base.buf, info->prev, &info->name);
396 base.buf[info->pathlen-1] = '/';
397 strbuf_setlen(&base, info->pathlen);
398 traverse_path = xstrndup(base.buf, info->pathlen);
399 } else {
400 traverse_path = xstrndup(info->name.path, info->pathlen);
401 }
402 info->traverse_path = traverse_path;
403 for (;;) {
404 int trees_used;
405 unsigned long mask, dirmask;
406 const char *first = NULL;
407 int first_len = 0;
408 struct name_entry *e = NULL;
409 int len;
410
411 for (i = 0; i < n; i++) {
412 e = entry + i;
413 extended_entry_extract(tx + i, e, NULL, 0);
414 }
415
416 /*
417 * A tree may have "t-2" at the current location even
418 * though it may have "t" that is a subtree behind it,
419 * and another tree may return "t". We want to grab
420 * all "t" from all trees to match in such a case.
421 */
422 for (i = 0; i < n; i++) {
423 e = entry + i;
424 if (!e->path)
425 continue;
426 len = tree_entry_len(e);
427 if (!first) {
428 first = e->path;
429 first_len = len;
430 continue;
431 }
432 if (name_compare(e->path, len, first, first_len) < 0) {
433 first = e->path;
434 first_len = len;
435 }
436 }
437
438 if (first) {
439 for (i = 0; i < n; i++) {
440 e = entry + i;
441 extended_entry_extract(tx + i, e, first, first_len);
442 /* Cull the ones that are not the earliest */
443 if (!e->path)
444 continue;
445 len = tree_entry_len(e);
446 if (name_compare(e->path, len, first, first_len))
447 entry_clear(e);
448 }
449 }
450
451 /* Now we have in entry[i] the earliest name from the trees */
452 mask = 0;
453 dirmask = 0;
454 for (i = 0; i < n; i++) {
455 if (!entry[i].path)
456 continue;
457 mask |= 1ul << i;
458 if (S_ISDIR(entry[i].mode))
459 dirmask |= 1ul << i;
460 e = &entry[i];
461 }
462 if (!mask)
463 break;
464 interesting = prune_traversal(e, info, &base, interesting);
465 if (interesting < 0)
466 break;
467 if (interesting) {
468 trees_used = info->fn(n, mask, dirmask, entry, info);
469 if (trees_used < 0) {
470 error = trees_used;
471 if (!info->show_all_errors)
472 break;
473 }
474 mask &= trees_used;
475 }
476 for (i = 0; i < n; i++)
477 if (mask & (1ul << i))
478 update_extended_entry(tx + i, entry + i);
479 }
480 free(entry);
481 for (i = 0; i < n; i++)
482 free_extended_entry(tx + i);
483 free(tx);
484 free(traverse_path);
485 info->traverse_path = NULL;
486 strbuf_release(&base);
487 return error;
488 }
489
490 struct dir_state {
491 void *tree;
492 unsigned long size;
493 struct object_id oid;
494 };
495
496 static int find_tree_entry(struct tree_desc *t, const char *name, struct object_id *result, unsigned *mode)
497 {
498 int namelen = strlen(name);
499 while (t->size) {
500 const char *entry;
501 const struct object_id *oid;
502 int entrylen, cmp;
503
504 oid = tree_entry_extract(t, &entry, mode);
505 entrylen = tree_entry_len(&t->entry);
506 update_tree_entry(t);
507 if (entrylen > namelen)
508 continue;
509 cmp = memcmp(name, entry, entrylen);
510 if (cmp > 0)
511 continue;
512 if (cmp < 0)
513 break;
514 if (entrylen == namelen) {
515 oidcpy(result, oid);
516 return 0;
517 }
518 if (name[entrylen] != '/')
519 continue;
520 if (!S_ISDIR(*mode))
521 break;
522 if (++entrylen == namelen) {
523 oidcpy(result, oid);
524 return 0;
525 }
526 return get_tree_entry(oid, name + entrylen, result, mode);
527 }
528 return -1;
529 }
530
531 int get_tree_entry(const struct object_id *tree_oid, const char *name, struct object_id *oid, unsigned *mode)
532 {
533 int retval;
534 void *tree;
535 unsigned long size;
536 struct object_id root;
537
538 tree = read_object_with_reference(tree_oid, tree_type, &size, &root);
539 if (!tree)
540 return -1;
541
542 if (name[0] == '\0') {
543 oidcpy(oid, &root);
544 free(tree);
545 return 0;
546 }
547
548 if (!size) {
549 retval = -1;
550 } else {
551 struct tree_desc t;
552 init_tree_desc(&t, tree, size);
553 retval = find_tree_entry(&t, name, oid, mode);
554 }
555 free(tree);
556 return retval;
557 }
558
559 /*
560 * This is Linux's built-in max for the number of symlinks to follow.
561 * That limit, of course, does not affect git, but it's a reasonable
562 * choice.
563 */
564 #define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
565
566 /**
567 * Find a tree entry by following symlinks in tree_sha (which is
568 * assumed to be the root of the repository). In the event that a
569 * symlink points outside the repository (e.g. a link to /foo or a
570 * root-level link to ../foo), the portion of the link which is
571 * outside the repository will be returned in result_path, and *mode
572 * will be set to 0. It is assumed that result_path is uninitialized.
573 * If there are no symlinks, or the end result of the symlink chain
574 * points to an object inside the repository, result will be filled in
575 * with the sha1 of the found object, and *mode will hold the mode of
576 * the object.
577 *
578 * See the code for enum follow_symlink_result for a description of
579 * the return values.
580 */
581 enum follow_symlinks_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned *mode)
582 {
583 int retval = MISSING_OBJECT;
584 struct dir_state *parents = NULL;
585 size_t parents_alloc = 0;
586 size_t i, parents_nr = 0;
587 struct object_id current_tree_oid;
588 struct strbuf namebuf = STRBUF_INIT;
589 struct tree_desc t;
590 int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
591
592 init_tree_desc(&t, NULL, 0UL);
593 strbuf_addstr(&namebuf, name);
594 oidcpy(&current_tree_oid, tree_oid);
595
596 while (1) {
597 int find_result;
598 char *first_slash;
599 char *remainder = NULL;
600
601 if (!t.buffer) {
602 void *tree;
603 struct object_id root;
604 unsigned long size;
605 tree = read_object_with_reference(&current_tree_oid,
606 tree_type, &size,
607 &root);
608 if (!tree)
609 goto done;
610
611 ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
612 parents[parents_nr].tree = tree;
613 parents[parents_nr].size = size;
614 oidcpy(&parents[parents_nr].oid, &root);
615 parents_nr++;
616
617 if (namebuf.buf[0] == '\0') {
618 oidcpy(result, &root);
619 retval = FOUND;
620 goto done;
621 }
622
623 if (!size)
624 goto done;
625
626 /* descend */
627 init_tree_desc(&t, tree, size);
628 }
629
630 /* Handle symlinks to e.g. a//b by removing leading slashes */
631 while (namebuf.buf[0] == '/') {
632 strbuf_remove(&namebuf, 0, 1);
633 }
634
635 /* Split namebuf into a first component and a remainder */
636 if ((first_slash = strchr(namebuf.buf, '/'))) {
637 *first_slash = 0;
638 remainder = first_slash + 1;
639 }
640
641 if (!strcmp(namebuf.buf, "..")) {
642 struct dir_state *parent;
643 /*
644 * We could end up with .. in the namebuf if it
645 * appears in a symlink.
646 */
647
648 if (parents_nr == 1) {
649 if (remainder)
650 *first_slash = '/';
651 strbuf_add(result_path, namebuf.buf,
652 namebuf.len);
653 *mode = 0;
654 retval = FOUND;
655 goto done;
656 }
657 parent = &parents[parents_nr - 1];
658 free(parent->tree);
659 parents_nr--;
660 parent = &parents[parents_nr - 1];
661 init_tree_desc(&t, parent->tree, parent->size);
662 strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
663 continue;
664 }
665
666 /* We could end up here via a symlink to dir/.. */
667 if (namebuf.buf[0] == '\0') {
668 oidcpy(result, &parents[parents_nr - 1].oid);
669 retval = FOUND;
670 goto done;
671 }
672
673 /* Look up the first (or only) path component in the tree. */
674 find_result = find_tree_entry(&t, namebuf.buf,
675 &current_tree_oid, mode);
676 if (find_result) {
677 goto done;
678 }
679
680 if (S_ISDIR(*mode)) {
681 if (!remainder) {
682 oidcpy(result, &current_tree_oid);
683 retval = FOUND;
684 goto done;
685 }
686 /* Descend the tree */
687 t.buffer = NULL;
688 strbuf_remove(&namebuf, 0,
689 1 + first_slash - namebuf.buf);
690 } else if (S_ISREG(*mode)) {
691 if (!remainder) {
692 oidcpy(result, &current_tree_oid);
693 retval = FOUND;
694 } else {
695 retval = NOT_DIR;
696 }
697 goto done;
698 } else if (S_ISLNK(*mode)) {
699 /* Follow a symlink */
700 unsigned long link_len;
701 size_t len;
702 char *contents, *contents_start;
703 struct dir_state *parent;
704 enum object_type type;
705
706 if (follows_remaining-- == 0) {
707 /* Too many symlinks followed */
708 retval = SYMLINK_LOOP;
709 goto done;
710 }
711
712 /*
713 * At this point, we have followed at a least
714 * one symlink, so on error we need to report this.
715 */
716 retval = DANGLING_SYMLINK;
717
718 contents = read_object_file(&current_tree_oid, &type,
719 &link_len);
720
721 if (!contents)
722 goto done;
723
724 if (contents[0] == '/') {
725 strbuf_addstr(result_path, contents);
726 free(contents);
727 *mode = 0;
728 retval = FOUND;
729 goto done;
730 }
731
732 if (remainder)
733 len = first_slash - namebuf.buf;
734 else
735 len = namebuf.len;
736
737 contents_start = contents;
738
739 parent = &parents[parents_nr - 1];
740 init_tree_desc(&t, parent->tree, parent->size);
741 strbuf_splice(&namebuf, 0, len,
742 contents_start, link_len);
743 if (remainder)
744 namebuf.buf[link_len] = '/';
745 free(contents);
746 }
747 }
748 done:
749 for (i = 0; i < parents_nr; i++)
750 free(parents[i].tree);
751 free(parents);
752
753 strbuf_release(&namebuf);
754 return retval;
755 }
756
757 static int match_entry(const struct pathspec_item *item,
758 const struct name_entry *entry, int pathlen,
759 const char *match, int matchlen,
760 enum interesting *never_interesting)
761 {
762 int m = -1; /* signals that we haven't called strncmp() */
763
764 if (item->magic & PATHSPEC_ICASE)
765 /*
766 * "Never interesting" trick requires exact
767 * matching. We could do something clever with inexact
768 * matching, but it's trickier (and not to forget that
769 * strcasecmp is locale-dependent, at least in
770 * glibc). Just disable it for now. It can't be worse
771 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
772 * pattern.
773 */
774 *never_interesting = entry_not_interesting;
775 else if (*never_interesting != entry_not_interesting) {
776 /*
777 * We have not seen any match that sorts later
778 * than the current path.
779 */
780
781 /*
782 * Does match sort strictly earlier than path
783 * with their common parts?
784 */
785 m = strncmp(match, entry->path,
786 (matchlen < pathlen) ? matchlen : pathlen);
787 if (m < 0)
788 return 0;
789
790 /*
791 * If we come here even once, that means there is at
792 * least one pathspec that would sort equal to or
793 * later than the path we are currently looking at.
794 * In other words, if we have never reached this point
795 * after iterating all pathspecs, it means all
796 * pathspecs are either outside of base, or inside the
797 * base but sorts strictly earlier than the current
798 * one. In either case, they will never match the
799 * subsequent entries. In such a case, we initialized
800 * the variable to -1 and that is what will be
801 * returned, allowing the caller to terminate early.
802 */
803 *never_interesting = entry_not_interesting;
804 }
805
806 if (pathlen > matchlen)
807 return 0;
808
809 if (matchlen > pathlen) {
810 if (match[pathlen] != '/')
811 return 0;
812 if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode))
813 return 0;
814 }
815
816 if (m == -1)
817 /*
818 * we cheated and did not do strncmp(), so we do
819 * that here.
820 */
821 m = ps_strncmp(item, match, entry->path, pathlen);
822
823 /*
824 * If common part matched earlier then it is a hit,
825 * because we rejected the case where path is not a
826 * leading directory and is shorter than match.
827 */
828 if (!m)
829 /*
830 * match_entry does not check if the prefix part is
831 * matched case-sensitively. If the entry is a
832 * directory and part of prefix, it'll be rematched
833 * eventually by basecmp with special treatment for
834 * the prefix.
835 */
836 return 1;
837
838 return 0;
839 }
840
841 /* :(icase)-aware string compare */
842 static int basecmp(const struct pathspec_item *item,
843 const char *base, const char *match, int len)
844 {
845 if (item->magic & PATHSPEC_ICASE) {
846 int ret, n = len > item->prefix ? item->prefix : len;
847 ret = strncmp(base, match, n);
848 if (ret)
849 return ret;
850 base += n;
851 match += n;
852 len -= n;
853 }
854 return ps_strncmp(item, base, match, len);
855 }
856
857 static int match_dir_prefix(const struct pathspec_item *item,
858 const char *base,
859 const char *match, int matchlen)
860 {
861 if (basecmp(item, base, match, matchlen))
862 return 0;
863
864 /*
865 * If the base is a subdirectory of a path which
866 * was specified, all of them are interesting.
867 */
868 if (!matchlen ||
869 base[matchlen] == '/' ||
870 match[matchlen - 1] == '/')
871 return 1;
872
873 /* Just a random prefix match */
874 return 0;
875 }
876
877 /*
878 * Perform matching on the leading non-wildcard part of
879 * pathspec. item->nowildcard_len must be greater than zero. Return
880 * non-zero if base is matched.
881 */
882 static int match_wildcard_base(const struct pathspec_item *item,
883 const char *base, int baselen,
884 int *matched)
885 {
886 const char *match = item->match;
887 /* the wildcard part is not considered in this function */
888 int matchlen = item->nowildcard_len;
889
890 if (baselen) {
891 int dirlen;
892 /*
893 * Return early if base is longer than the
894 * non-wildcard part but it does not match.
895 */
896 if (baselen >= matchlen) {
897 *matched = matchlen;
898 return !basecmp(item, base, match, matchlen);
899 }
900
901 dirlen = matchlen;
902 while (dirlen && match[dirlen - 1] != '/')
903 dirlen--;
904
905 /*
906 * Return early if base is shorter than the
907 * non-wildcard part but it does not match. Note that
908 * base ends with '/' so we are sure it really matches
909 * directory
910 */
911 if (basecmp(item, base, match, baselen))
912 return 0;
913 *matched = baselen;
914 } else
915 *matched = 0;
916 /*
917 * we could have checked entry against the non-wildcard part
918 * that is not in base and does similar never_interesting
919 * optimization as in match_entry. For now just be happy with
920 * base comparison.
921 */
922 return entry_interesting;
923 }
924
925 /*
926 * Is a tree entry interesting given the pathspec we have?
927 *
928 * Pre-condition: either baselen == base_offset (i.e. empty path)
929 * or base[baselen-1] == '/' (i.e. with trailing slash).
930 */
931 static enum interesting do_match(const struct name_entry *entry,
932 struct strbuf *base, int base_offset,
933 const struct pathspec *ps,
934 int exclude)
935 {
936 int i;
937 int pathlen, baselen = base->len - base_offset;
938 enum interesting never_interesting = ps->has_wildcard ?
939 entry_not_interesting : all_entries_not_interesting;
940
941 GUARD_PATHSPEC(ps,
942 PATHSPEC_FROMTOP |
943 PATHSPEC_MAXDEPTH |
944 PATHSPEC_LITERAL |
945 PATHSPEC_GLOB |
946 PATHSPEC_ICASE |
947 PATHSPEC_EXCLUDE);
948
949 if (!ps->nr) {
950 if (!ps->recursive ||
951 !(ps->magic & PATHSPEC_MAXDEPTH) ||
952 ps->max_depth == -1)
953 return all_entries_interesting;
954 return within_depth(base->buf + base_offset, baselen,
955 !!S_ISDIR(entry->mode),
956 ps->max_depth) ?
957 entry_interesting : entry_not_interesting;
958 }
959
960 pathlen = tree_entry_len(entry);
961
962 for (i = ps->nr - 1; i >= 0; i--) {
963 const struct pathspec_item *item = ps->items+i;
964 const char *match = item->match;
965 const char *base_str = base->buf + base_offset;
966 int matchlen = item->len, matched = 0;
967
968 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
969 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
970 continue;
971
972 if (baselen >= matchlen) {
973 /* If it doesn't match, move along... */
974 if (!match_dir_prefix(item, base_str, match, matchlen))
975 goto match_wildcards;
976
977 if (!ps->recursive ||
978 !(ps->magic & PATHSPEC_MAXDEPTH) ||
979 ps->max_depth == -1)
980 return all_entries_interesting;
981
982 return within_depth(base_str + matchlen + 1,
983 baselen - matchlen - 1,
984 !!S_ISDIR(entry->mode),
985 ps->max_depth) ?
986 entry_interesting : entry_not_interesting;
987 }
988
989 /* Either there must be no base, or the base must match. */
990 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
991 if (match_entry(item, entry, pathlen,
992 match + baselen, matchlen - baselen,
993 &never_interesting))
994 return entry_interesting;
995
996 if (item->nowildcard_len < item->len) {
997 if (!git_fnmatch(item, match + baselen, entry->path,
998 item->nowildcard_len - baselen))
999 return entry_interesting;
1000
1001 /*
1002 * Match all directories. We'll try to
1003 * match files later on.
1004 */
1005 if (ps->recursive && S_ISDIR(entry->mode))
1006 return entry_interesting;
1007
1008 /*
1009 * When matching against submodules with
1010 * wildcard characters, ensure that the entry
1011 * at least matches up to the first wild
1012 * character. More accurate matching can then
1013 * be performed in the submodule itself.
1014 */
1015 if (ps->recurse_submodules &&
1016 S_ISGITLINK(entry->mode) &&
1017 !ps_strncmp(item, match + baselen,
1018 entry->path,
1019 item->nowildcard_len - baselen))
1020 return entry_interesting;
1021 }
1022
1023 continue;
1024 }
1025
1026 match_wildcards:
1027 if (item->nowildcard_len == item->len)
1028 continue;
1029
1030 if (item->nowildcard_len &&
1031 !match_wildcard_base(item, base_str, baselen, &matched))
1032 continue;
1033
1034 /*
1035 * Concatenate base and entry->path into one and do
1036 * fnmatch() on it.
1037 *
1038 * While we could avoid concatenation in certain cases
1039 * [1], which saves a memcpy and potentially a
1040 * realloc, it turns out not worth it. Measurement on
1041 * linux-2.6 does not show any clear improvements,
1042 * partly because of the nowildcard_len optimization
1043 * in git_fnmatch(). Avoid micro-optimizations here.
1044 *
1045 * [1] if match_wildcard_base() says the base
1046 * directory is already matched, we only need to match
1047 * the rest, which is shorter so _in theory_ faster.
1048 */
1049
1050 strbuf_add(base, entry->path, pathlen);
1051
1052 if (!git_fnmatch(item, match, base->buf + base_offset,
1053 item->nowildcard_len)) {
1054 strbuf_setlen(base, base_offset + baselen);
1055 return entry_interesting;
1056 }
1057
1058 /*
1059 * When matching against submodules with
1060 * wildcard characters, ensure that the entry
1061 * at least matches up to the first wild
1062 * character. More accurate matching can then
1063 * be performed in the submodule itself.
1064 */
1065 if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
1066 !ps_strncmp(item, match, base->buf + base_offset,
1067 item->nowildcard_len)) {
1068 strbuf_setlen(base, base_offset + baselen);
1069 return entry_interesting;
1070 }
1071
1072 strbuf_setlen(base, base_offset + baselen);
1073
1074 /*
1075 * Match all directories. We'll try to match files
1076 * later on.
1077 * max_depth is ignored but we may consider support it
1078 * in future, see
1079 * https://public-inbox.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
1080 */
1081 if (ps->recursive && S_ISDIR(entry->mode))
1082 return entry_interesting;
1083 }
1084 return never_interesting; /* No matches */
1085 }
1086
1087 /*
1088 * Is a tree entry interesting given the pathspec we have?
1089 *
1090 * Pre-condition: either baselen == base_offset (i.e. empty path)
1091 * or base[baselen-1] == '/' (i.e. with trailing slash).
1092 */
1093 enum interesting tree_entry_interesting(const struct name_entry *entry,
1094 struct strbuf *base, int base_offset,
1095 const struct pathspec *ps)
1096 {
1097 enum interesting positive, negative;
1098 positive = do_match(entry, base, base_offset, ps, 0);
1099
1100 /*
1101 * case | entry | positive | negative | result
1102 * -----+-------+----------+----------+-------
1103 * 1 | file | -1 | -1..2 | -1
1104 * 2 | file | 0 | -1..2 | 0
1105 * 3 | file | 1 | -1 | 1
1106 * 4 | file | 1 | 0 | 1
1107 * 5 | file | 1 | 1 | 0
1108 * 6 | file | 1 | 2 | 0
1109 * 7 | file | 2 | -1 | 2
1110 * 8 | file | 2 | 0 | 2
1111 * 9 | file | 2 | 1 | 0
1112 * 10 | file | 2 | 2 | -1
1113 * -----+-------+----------+----------+-------
1114 * 11 | dir | -1 | -1..2 | -1
1115 * 12 | dir | 0 | -1..2 | 0
1116 * 13 | dir | 1 | -1 | 1
1117 * 14 | dir | 1 | 0 | 1
1118 * 15 | dir | 1 | 1 | 1 (*)
1119 * 16 | dir | 1 | 2 | 0
1120 * 17 | dir | 2 | -1 | 2
1121 * 18 | dir | 2 | 0 | 2
1122 * 19 | dir | 2 | 1 | 1 (*)
1123 * 20 | dir | 2 | 2 | -1
1124 *
1125 * (*) An exclude pattern interested in a directory does not
1126 * necessarily mean it will exclude all of the directory. In
1127 * wildcard case, it can't decide until looking at individual
1128 * files inside. So don't write such directories off yet.
1129 */
1130
1131 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
1132 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
1133 return positive;
1134
1135 negative = do_match(entry, base, base_offset, ps, 1);
1136
1137 /* #3, #4, #7, #8, #13, #14, #17, #18 */
1138 if (negative <= entry_not_interesting)
1139 return positive;
1140
1141 /* #15, #19 */
1142 if (S_ISDIR(entry->mode) &&
1143 positive >= entry_interesting &&
1144 negative == entry_interesting)
1145 return entry_interesting;
1146
1147 if ((positive == entry_interesting &&
1148 negative >= entry_interesting) || /* #5, #6, #16 */
1149 (positive == all_entries_interesting &&
1150 negative == entry_interesting)) /* #9 */
1151 return entry_not_interesting;
1152
1153 return all_entries_not_interesting; /* #10, #20 */
1154 }