Merge branch 'tb/banned-vsprintf-namefix'
[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.pathlen = len - 1;
52 hashcpy(desc->entry.oid.hash, (const unsigned char *)path + len);
53
54 return 0;
55 }
56
57 static int init_tree_desc_internal(struct tree_desc *desc, const void *buffer, unsigned long size, struct strbuf *err)
58 {
59 desc->buffer = buffer;
60 desc->size = size;
61 if (size)
62 return decode_tree_entry(desc, buffer, size, err);
63 return 0;
64 }
65
66 void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
67 {
68 struct strbuf err = STRBUF_INIT;
69 if (init_tree_desc_internal(desc, buffer, size, &err))
70 die("%s", err.buf);
71 strbuf_release(&err);
72 }
73
74 int init_tree_desc_gently(struct tree_desc *desc, const void *buffer, unsigned long size)
75 {
76 struct strbuf err = STRBUF_INIT;
77 int result = init_tree_desc_internal(desc, buffer, size, &err);
78 if (result)
79 error("%s", err.buf);
80 strbuf_release(&err);
81 return result;
82 }
83
84 void *fill_tree_descriptor(struct repository *r,
85 struct tree_desc *desc,
86 const struct object_id *oid)
87 {
88 unsigned long size = 0;
89 void *buf = NULL;
90
91 if (oid) {
92 buf = read_object_with_reference(r, oid, tree_type, &size, NULL);
93 if (!buf)
94 die("unable to read tree %s", oid_to_hex(oid));
95 }
96 init_tree_desc(desc, buf, size);
97 return buf;
98 }
99
100 static void entry_clear(struct name_entry *a)
101 {
102 memset(a, 0, sizeof(*a));
103 }
104
105 static void entry_extract(struct tree_desc *t, struct name_entry *a)
106 {
107 *a = t->entry;
108 }
109
110 static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
111 {
112 const void *buf = desc->buffer;
113 const unsigned char *end = (const unsigned char *)desc->entry.path + desc->entry.pathlen + 1 + the_hash_algo->rawsz;
114 unsigned long size = desc->size;
115 unsigned long len = end - (const unsigned char *)buf;
116
117 if (size < len)
118 die(_("too-short tree file"));
119 buf = end;
120 size -= len;
121 desc->buffer = buf;
122 desc->size = size;
123 if (size)
124 return decode_tree_entry(desc, buf, size, err);
125 return 0;
126 }
127
128 void update_tree_entry(struct tree_desc *desc)
129 {
130 struct strbuf err = STRBUF_INIT;
131 if (update_tree_entry_internal(desc, &err))
132 die("%s", err.buf);
133 strbuf_release(&err);
134 }
135
136 int update_tree_entry_gently(struct tree_desc *desc)
137 {
138 struct strbuf err = STRBUF_INIT;
139 if (update_tree_entry_internal(desc, &err)) {
140 error("%s", err.buf);
141 strbuf_release(&err);
142 /* Stop processing this tree after error */
143 desc->size = 0;
144 return -1;
145 }
146 strbuf_release(&err);
147 return 0;
148 }
149
150 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
151 {
152 if (!desc->size)
153 return 0;
154
155 *entry = desc->entry;
156 update_tree_entry(desc);
157 return 1;
158 }
159
160 int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
161 {
162 if (!desc->size)
163 return 0;
164
165 *entry = desc->entry;
166 if (update_tree_entry_gently(desc))
167 return 0;
168 return 1;
169 }
170
171 void setup_traverse_info(struct traverse_info *info, const char *base)
172 {
173 size_t pathlen = strlen(base);
174 static struct traverse_info dummy;
175
176 memset(info, 0, sizeof(*info));
177 if (pathlen && base[pathlen-1] == '/')
178 pathlen--;
179 info->pathlen = pathlen ? pathlen + 1 : 0;
180 info->name = base;
181 info->namelen = pathlen;
182 if (pathlen)
183 info->prev = &dummy;
184 }
185
186 char *make_traverse_path(char *path, size_t pathlen,
187 const struct traverse_info *info,
188 const char *name, size_t namelen)
189 {
190 /* Always points to the end of the name we're about to add */
191 size_t pos = st_add(info->pathlen, namelen);
192
193 if (pos >= pathlen)
194 BUG("too small buffer passed to make_traverse_path");
195
196 path[pos] = 0;
197 for (;;) {
198 if (pos < namelen)
199 BUG("traverse_info pathlen does not match strings");
200 pos -= namelen;
201 memcpy(path + pos, name, namelen);
202
203 if (!pos)
204 break;
205 path[--pos] = '/';
206
207 if (!info)
208 BUG("traverse_info ran out of list items");
209 name = info->name;
210 namelen = info->namelen;
211 info = info->prev;
212 }
213 return path;
214 }
215
216 void strbuf_make_traverse_path(struct strbuf *out,
217 const struct traverse_info *info,
218 const char *name, size_t namelen)
219 {
220 size_t len = traverse_path_len(info, namelen);
221
222 strbuf_grow(out, len);
223 make_traverse_path(out->buf + out->len, out->alloc - out->len,
224 info, name, namelen);
225 strbuf_setlen(out, out->len + len);
226 }
227
228 struct tree_desc_skip {
229 struct tree_desc_skip *prev;
230 const void *ptr;
231 };
232
233 struct tree_desc_x {
234 struct tree_desc d;
235 struct tree_desc_skip *skip;
236 };
237
238 static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
239 {
240 /*
241 * The caller wants to pick *a* from a tree or nothing.
242 * We are looking at *b* in a tree.
243 *
244 * (0) If a and b are the same name, we are trivially happy.
245 *
246 * There are three possibilities where *a* could be hiding
247 * behind *b*.
248 *
249 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
250 * matter what.
251 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
252 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
253 *
254 * Otherwise we know *a* won't appear in the tree without
255 * scanning further.
256 */
257
258 int cmp = name_compare(a, a_len, b, b_len);
259
260 /* Most common case first -- reading sync'd trees */
261 if (!cmp)
262 return cmp;
263
264 if (0 < cmp) {
265 /* a comes after b; it does not matter if it is case (3)
266 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
267 return 1;
268 */
269 return 1; /* keep looking */
270 }
271
272 /* b comes after a; are we looking at case (2)? */
273 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
274 return 1; /* keep looking */
275
276 return -1; /* a cannot appear in the tree */
277 }
278
279 /*
280 * From the extended tree_desc, extract the first name entry, while
281 * paying attention to the candidate "first" name. Most importantly,
282 * when looking for an entry, if there are entries that sorts earlier
283 * in the tree object representation than that name, skip them and
284 * process the named entry first. We will remember that we haven't
285 * processed the first entry yet, and in the later call skip the
286 * entry we processed early when update_extended_entry() is called.
287 *
288 * E.g. if the underlying tree object has these entries:
289 *
290 * blob "t-1"
291 * blob "t-2"
292 * tree "t"
293 * blob "t=1"
294 *
295 * and the "first" asks for "t", remember that we still need to
296 * process "t-1" and "t-2" but extract "t". After processing the
297 * entry "t" from this call, the caller will let us know by calling
298 * update_extended_entry() that we can remember "t" has been processed
299 * already.
300 */
301
302 static void extended_entry_extract(struct tree_desc_x *t,
303 struct name_entry *a,
304 const char *first,
305 int first_len)
306 {
307 const char *path;
308 int len;
309 struct tree_desc probe;
310 struct tree_desc_skip *skip;
311
312 /*
313 * Extract the first entry from the tree_desc, but skip the
314 * ones that we already returned in earlier rounds.
315 */
316 while (1) {
317 if (!t->d.size) {
318 entry_clear(a);
319 break; /* not found */
320 }
321 entry_extract(&t->d, a);
322 for (skip = t->skip; skip; skip = skip->prev)
323 if (a->path == skip->ptr)
324 break; /* found */
325 if (!skip)
326 break;
327 /* We have processed this entry already. */
328 update_tree_entry(&t->d);
329 }
330
331 if (!first || !a->path)
332 return;
333
334 /*
335 * The caller wants "first" from this tree, or nothing.
336 */
337 path = a->path;
338 len = tree_entry_len(a);
339 switch (check_entry_match(first, first_len, path, len)) {
340 case -1:
341 entry_clear(a);
342 case 0:
343 return;
344 default:
345 break;
346 }
347
348 /*
349 * We need to look-ahead -- we suspect that a subtree whose
350 * name is "first" may be hiding behind the current entry "path".
351 */
352 probe = t->d;
353 while (probe.size) {
354 entry_extract(&probe, a);
355 path = a->path;
356 len = tree_entry_len(a);
357 switch (check_entry_match(first, first_len, path, len)) {
358 case -1:
359 entry_clear(a);
360 case 0:
361 return;
362 default:
363 update_tree_entry(&probe);
364 break;
365 }
366 /* keep looking */
367 }
368 entry_clear(a);
369 }
370
371 static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
372 {
373 if (t->d.entry.path == a->path) {
374 update_tree_entry(&t->d);
375 } else {
376 /* we have returned this entry early */
377 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
378 skip->ptr = a->path;
379 skip->prev = t->skip;
380 t->skip = skip;
381 }
382 }
383
384 static void free_extended_entry(struct tree_desc_x *t)
385 {
386 struct tree_desc_skip *p, *s;
387
388 for (s = t->skip; s; s = p) {
389 p = s->prev;
390 free(s);
391 }
392 }
393
394 static inline int prune_traversal(struct index_state *istate,
395 struct name_entry *e,
396 struct traverse_info *info,
397 struct strbuf *base,
398 int still_interesting)
399 {
400 if (!info->pathspec || still_interesting == 2)
401 return 2;
402 if (still_interesting < 0)
403 return still_interesting;
404 return tree_entry_interesting(istate, e, base,
405 0, info->pathspec);
406 }
407
408 int traverse_trees(struct index_state *istate,
409 int n, struct tree_desc *t,
410 struct traverse_info *info)
411 {
412 int error = 0;
413 struct name_entry *entry = xmalloc(n*sizeof(*entry));
414 int i;
415 struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
416 struct strbuf base = STRBUF_INIT;
417 int interesting = 1;
418 char *traverse_path;
419
420 for (i = 0; i < n; i++)
421 tx[i].d = t[i];
422
423 if (info->prev) {
424 strbuf_make_traverse_path(&base, info->prev,
425 info->name, info->namelen);
426 strbuf_addch(&base, '/');
427 traverse_path = xstrndup(base.buf, base.len);
428 } else {
429 traverse_path = xstrndup(info->name, info->pathlen);
430 }
431 info->traverse_path = traverse_path;
432 for (;;) {
433 int trees_used;
434 unsigned long mask, dirmask;
435 const char *first = NULL;
436 int first_len = 0;
437 struct name_entry *e = NULL;
438 int len;
439
440 for (i = 0; i < n; i++) {
441 e = entry + i;
442 extended_entry_extract(tx + i, e, NULL, 0);
443 }
444
445 /*
446 * A tree may have "t-2" at the current location even
447 * though it may have "t" that is a subtree behind it,
448 * and another tree may return "t". We want to grab
449 * all "t" from all trees to match in such a case.
450 */
451 for (i = 0; i < n; i++) {
452 e = entry + i;
453 if (!e->path)
454 continue;
455 len = tree_entry_len(e);
456 if (!first) {
457 first = e->path;
458 first_len = len;
459 continue;
460 }
461 if (name_compare(e->path, len, first, first_len) < 0) {
462 first = e->path;
463 first_len = len;
464 }
465 }
466
467 if (first) {
468 for (i = 0; i < n; i++) {
469 e = entry + i;
470 extended_entry_extract(tx + i, e, first, first_len);
471 /* Cull the ones that are not the earliest */
472 if (!e->path)
473 continue;
474 len = tree_entry_len(e);
475 if (name_compare(e->path, len, first, first_len))
476 entry_clear(e);
477 }
478 }
479
480 /* Now we have in entry[i] the earliest name from the trees */
481 mask = 0;
482 dirmask = 0;
483 for (i = 0; i < n; i++) {
484 if (!entry[i].path)
485 continue;
486 mask |= 1ul << i;
487 if (S_ISDIR(entry[i].mode))
488 dirmask |= 1ul << i;
489 e = &entry[i];
490 }
491 if (!mask)
492 break;
493 interesting = prune_traversal(istate, e, info, &base, interesting);
494 if (interesting < 0)
495 break;
496 if (interesting) {
497 trees_used = info->fn(n, mask, dirmask, entry, info);
498 if (trees_used < 0) {
499 error = trees_used;
500 if (!info->show_all_errors)
501 break;
502 }
503 mask &= trees_used;
504 }
505 for (i = 0; i < n; i++)
506 if (mask & (1ul << i))
507 update_extended_entry(tx + i, entry + i);
508 }
509 free(entry);
510 for (i = 0; i < n; i++)
511 free_extended_entry(tx + i);
512 free(tx);
513 free(traverse_path);
514 info->traverse_path = NULL;
515 strbuf_release(&base);
516 return error;
517 }
518
519 struct dir_state {
520 void *tree;
521 unsigned long size;
522 struct object_id oid;
523 };
524
525 static int find_tree_entry(struct repository *r, struct tree_desc *t,
526 const char *name, struct object_id *result,
527 unsigned short *mode)
528 {
529 int namelen = strlen(name);
530 while (t->size) {
531 const char *entry;
532 struct object_id oid;
533 int entrylen, cmp;
534
535 oidcpy(&oid, tree_entry_extract(t, &entry, mode));
536 entrylen = tree_entry_len(&t->entry);
537 update_tree_entry(t);
538 if (entrylen > namelen)
539 continue;
540 cmp = memcmp(name, entry, entrylen);
541 if (cmp > 0)
542 continue;
543 if (cmp < 0)
544 break;
545 if (entrylen == namelen) {
546 oidcpy(result, &oid);
547 return 0;
548 }
549 if (name[entrylen] != '/')
550 continue;
551 if (!S_ISDIR(*mode))
552 break;
553 if (++entrylen == namelen) {
554 oidcpy(result, &oid);
555 return 0;
556 }
557 return get_tree_entry(r, &oid, name + entrylen, result, mode);
558 }
559 return -1;
560 }
561
562 int get_tree_entry(struct repository *r,
563 const struct object_id *tree_oid,
564 const char *name,
565 struct object_id *oid,
566 unsigned short *mode)
567 {
568 int retval;
569 void *tree;
570 unsigned long size;
571 struct object_id root;
572
573 tree = read_object_with_reference(r, tree_oid, tree_type, &size, &root);
574 if (!tree)
575 return -1;
576
577 if (name[0] == '\0') {
578 oidcpy(oid, &root);
579 free(tree);
580 return 0;
581 }
582
583 if (!size) {
584 retval = -1;
585 } else {
586 struct tree_desc t;
587 init_tree_desc(&t, tree, size);
588 retval = find_tree_entry(r, &t, name, oid, mode);
589 }
590 free(tree);
591 return retval;
592 }
593
594 /*
595 * This is Linux's built-in max for the number of symlinks to follow.
596 * That limit, of course, does not affect git, but it's a reasonable
597 * choice.
598 */
599 #define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
600
601 /**
602 * Find a tree entry by following symlinks in tree_sha (which is
603 * assumed to be the root of the repository). In the event that a
604 * symlink points outside the repository (e.g. a link to /foo or a
605 * root-level link to ../foo), the portion of the link which is
606 * outside the repository will be returned in result_path, and *mode
607 * will be set to 0. It is assumed that result_path is uninitialized.
608 * If there are no symlinks, or the end result of the symlink chain
609 * points to an object inside the repository, result will be filled in
610 * with the sha1 of the found object, and *mode will hold the mode of
611 * the object.
612 *
613 * See the code for enum get_oid_result for a description of
614 * the return values.
615 */
616 enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r,
617 struct object_id *tree_oid, const char *name,
618 struct object_id *result, struct strbuf *result_path,
619 unsigned short *mode)
620 {
621 int retval = MISSING_OBJECT;
622 struct dir_state *parents = NULL;
623 size_t parents_alloc = 0;
624 size_t i, parents_nr = 0;
625 struct object_id current_tree_oid;
626 struct strbuf namebuf = STRBUF_INIT;
627 struct tree_desc t;
628 int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
629
630 init_tree_desc(&t, NULL, 0UL);
631 strbuf_addstr(&namebuf, name);
632 oidcpy(&current_tree_oid, tree_oid);
633
634 while (1) {
635 int find_result;
636 char *first_slash;
637 char *remainder = NULL;
638
639 if (!t.buffer) {
640 void *tree;
641 struct object_id root;
642 unsigned long size;
643 tree = read_object_with_reference(r,
644 &current_tree_oid,
645 tree_type, &size,
646 &root);
647 if (!tree)
648 goto done;
649
650 ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
651 parents[parents_nr].tree = tree;
652 parents[parents_nr].size = size;
653 oidcpy(&parents[parents_nr].oid, &root);
654 parents_nr++;
655
656 if (namebuf.buf[0] == '\0') {
657 oidcpy(result, &root);
658 retval = FOUND;
659 goto done;
660 }
661
662 if (!size)
663 goto done;
664
665 /* descend */
666 init_tree_desc(&t, tree, size);
667 }
668
669 /* Handle symlinks to e.g. a//b by removing leading slashes */
670 while (namebuf.buf[0] == '/') {
671 strbuf_remove(&namebuf, 0, 1);
672 }
673
674 /* Split namebuf into a first component and a remainder */
675 if ((first_slash = strchr(namebuf.buf, '/'))) {
676 *first_slash = 0;
677 remainder = first_slash + 1;
678 }
679
680 if (!strcmp(namebuf.buf, "..")) {
681 struct dir_state *parent;
682 /*
683 * We could end up with .. in the namebuf if it
684 * appears in a symlink.
685 */
686
687 if (parents_nr == 1) {
688 if (remainder)
689 *first_slash = '/';
690 strbuf_add(result_path, namebuf.buf,
691 namebuf.len);
692 *mode = 0;
693 retval = FOUND;
694 goto done;
695 }
696 parent = &parents[parents_nr - 1];
697 free(parent->tree);
698 parents_nr--;
699 parent = &parents[parents_nr - 1];
700 init_tree_desc(&t, parent->tree, parent->size);
701 strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
702 continue;
703 }
704
705 /* We could end up here via a symlink to dir/.. */
706 if (namebuf.buf[0] == '\0') {
707 oidcpy(result, &parents[parents_nr - 1].oid);
708 retval = FOUND;
709 goto done;
710 }
711
712 /* Look up the first (or only) path component in the tree. */
713 find_result = find_tree_entry(r, &t, namebuf.buf,
714 &current_tree_oid, mode);
715 if (find_result) {
716 goto done;
717 }
718
719 if (S_ISDIR(*mode)) {
720 if (!remainder) {
721 oidcpy(result, &current_tree_oid);
722 retval = FOUND;
723 goto done;
724 }
725 /* Descend the tree */
726 t.buffer = NULL;
727 strbuf_remove(&namebuf, 0,
728 1 + first_slash - namebuf.buf);
729 } else if (S_ISREG(*mode)) {
730 if (!remainder) {
731 oidcpy(result, &current_tree_oid);
732 retval = FOUND;
733 } else {
734 retval = NOT_DIR;
735 }
736 goto done;
737 } else if (S_ISLNK(*mode)) {
738 /* Follow a symlink */
739 unsigned long link_len;
740 size_t len;
741 char *contents, *contents_start;
742 struct dir_state *parent;
743 enum object_type type;
744
745 if (follows_remaining-- == 0) {
746 /* Too many symlinks followed */
747 retval = SYMLINK_LOOP;
748 goto done;
749 }
750
751 /*
752 * At this point, we have followed at a least
753 * one symlink, so on error we need to report this.
754 */
755 retval = DANGLING_SYMLINK;
756
757 contents = repo_read_object_file(r,
758 &current_tree_oid, &type,
759 &link_len);
760
761 if (!contents)
762 goto done;
763
764 if (contents[0] == '/') {
765 strbuf_addstr(result_path, contents);
766 free(contents);
767 *mode = 0;
768 retval = FOUND;
769 goto done;
770 }
771
772 if (remainder)
773 len = first_slash - namebuf.buf;
774 else
775 len = namebuf.len;
776
777 contents_start = contents;
778
779 parent = &parents[parents_nr - 1];
780 init_tree_desc(&t, parent->tree, parent->size);
781 strbuf_splice(&namebuf, 0, len,
782 contents_start, link_len);
783 if (remainder)
784 namebuf.buf[link_len] = '/';
785 free(contents);
786 }
787 }
788 done:
789 for (i = 0; i < parents_nr; i++)
790 free(parents[i].tree);
791 free(parents);
792
793 strbuf_release(&namebuf);
794 return retval;
795 }
796
797 static int match_entry(const struct pathspec_item *item,
798 const struct name_entry *entry, int pathlen,
799 const char *match, int matchlen,
800 enum interesting *never_interesting)
801 {
802 int m = -1; /* signals that we haven't called strncmp() */
803
804 if (item->magic & PATHSPEC_ICASE)
805 /*
806 * "Never interesting" trick requires exact
807 * matching. We could do something clever with inexact
808 * matching, but it's trickier (and not to forget that
809 * strcasecmp is locale-dependent, at least in
810 * glibc). Just disable it for now. It can't be worse
811 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
812 * pattern.
813 */
814 *never_interesting = entry_not_interesting;
815 else if (*never_interesting != entry_not_interesting) {
816 /*
817 * We have not seen any match that sorts later
818 * than the current path.
819 */
820
821 /*
822 * Does match sort strictly earlier than path
823 * with their common parts?
824 */
825 m = strncmp(match, entry->path,
826 (matchlen < pathlen) ? matchlen : pathlen);
827 if (m < 0)
828 return 0;
829
830 /*
831 * If we come here even once, that means there is at
832 * least one pathspec that would sort equal to or
833 * later than the path we are currently looking at.
834 * In other words, if we have never reached this point
835 * after iterating all pathspecs, it means all
836 * pathspecs are either outside of base, or inside the
837 * base but sorts strictly earlier than the current
838 * one. In either case, they will never match the
839 * subsequent entries. In such a case, we initialized
840 * the variable to -1 and that is what will be
841 * returned, allowing the caller to terminate early.
842 */
843 *never_interesting = entry_not_interesting;
844 }
845
846 if (pathlen > matchlen)
847 return 0;
848
849 if (matchlen > pathlen) {
850 if (match[pathlen] != '/')
851 return 0;
852 if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode))
853 return 0;
854 }
855
856 if (m == -1)
857 /*
858 * we cheated and did not do strncmp(), so we do
859 * that here.
860 */
861 m = ps_strncmp(item, match, entry->path, pathlen);
862
863 /*
864 * If common part matched earlier then it is a hit,
865 * because we rejected the case where path is not a
866 * leading directory and is shorter than match.
867 */
868 if (!m)
869 /*
870 * match_entry does not check if the prefix part is
871 * matched case-sensitively. If the entry is a
872 * directory and part of prefix, it'll be rematched
873 * eventually by basecmp with special treatment for
874 * the prefix.
875 */
876 return 1;
877
878 return 0;
879 }
880
881 /* :(icase)-aware string compare */
882 static int basecmp(const struct pathspec_item *item,
883 const char *base, const char *match, int len)
884 {
885 if (item->magic & PATHSPEC_ICASE) {
886 int ret, n = len > item->prefix ? item->prefix : len;
887 ret = strncmp(base, match, n);
888 if (ret)
889 return ret;
890 base += n;
891 match += n;
892 len -= n;
893 }
894 return ps_strncmp(item, base, match, len);
895 }
896
897 static int match_dir_prefix(const struct pathspec_item *item,
898 const char *base,
899 const char *match, int matchlen)
900 {
901 if (basecmp(item, base, match, matchlen))
902 return 0;
903
904 /*
905 * If the base is a subdirectory of a path which
906 * was specified, all of them are interesting.
907 */
908 if (!matchlen ||
909 base[matchlen] == '/' ||
910 match[matchlen - 1] == '/')
911 return 1;
912
913 /* Just a random prefix match */
914 return 0;
915 }
916
917 /*
918 * Perform matching on the leading non-wildcard part of
919 * pathspec. item->nowildcard_len must be greater than zero. Return
920 * non-zero if base is matched.
921 */
922 static int match_wildcard_base(const struct pathspec_item *item,
923 const char *base, int baselen,
924 int *matched)
925 {
926 const char *match = item->match;
927 /* the wildcard part is not considered in this function */
928 int matchlen = item->nowildcard_len;
929
930 if (baselen) {
931 int dirlen;
932 /*
933 * Return early if base is longer than the
934 * non-wildcard part but it does not match.
935 */
936 if (baselen >= matchlen) {
937 *matched = matchlen;
938 return !basecmp(item, base, match, matchlen);
939 }
940
941 dirlen = matchlen;
942 while (dirlen && match[dirlen - 1] != '/')
943 dirlen--;
944
945 /*
946 * Return early if base is shorter than the
947 * non-wildcard part but it does not match. Note that
948 * base ends with '/' so we are sure it really matches
949 * directory
950 */
951 if (basecmp(item, base, match, baselen))
952 return 0;
953 *matched = baselen;
954 } else
955 *matched = 0;
956 /*
957 * we could have checked entry against the non-wildcard part
958 * that is not in base and does similar never_interesting
959 * optimization as in match_entry. For now just be happy with
960 * base comparison.
961 */
962 return entry_interesting;
963 }
964
965 /*
966 * Is a tree entry interesting given the pathspec we have?
967 *
968 * Pre-condition: either baselen == base_offset (i.e. empty path)
969 * or base[baselen-1] == '/' (i.e. with trailing slash).
970 */
971 static enum interesting do_match(struct index_state *istate,
972 const struct name_entry *entry,
973 struct strbuf *base, int base_offset,
974 const struct pathspec *ps,
975 int exclude)
976 {
977 int i;
978 int pathlen, baselen = base->len - base_offset;
979 enum interesting never_interesting = ps->has_wildcard ?
980 entry_not_interesting : all_entries_not_interesting;
981
982 GUARD_PATHSPEC(ps,
983 PATHSPEC_FROMTOP |
984 PATHSPEC_MAXDEPTH |
985 PATHSPEC_LITERAL |
986 PATHSPEC_GLOB |
987 PATHSPEC_ICASE |
988 PATHSPEC_EXCLUDE |
989 PATHSPEC_ATTR);
990
991 if (!ps->nr) {
992 if (!ps->recursive ||
993 !(ps->magic & PATHSPEC_MAXDEPTH) ||
994 ps->max_depth == -1)
995 return all_entries_interesting;
996 return within_depth(base->buf + base_offset, baselen,
997 !!S_ISDIR(entry->mode),
998 ps->max_depth) ?
999 entry_interesting : entry_not_interesting;
1000 }
1001
1002 pathlen = tree_entry_len(entry);
1003
1004 for (i = ps->nr - 1; i >= 0; i--) {
1005 const struct pathspec_item *item = ps->items+i;
1006 const char *match = item->match;
1007 const char *base_str = base->buf + base_offset;
1008 int matchlen = item->len, matched = 0;
1009
1010 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
1011 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
1012 continue;
1013
1014 if (baselen >= matchlen) {
1015 /* If it doesn't match, move along... */
1016 if (!match_dir_prefix(item, base_str, match, matchlen))
1017 goto match_wildcards;
1018
1019 if (!ps->recursive ||
1020 !(ps->magic & PATHSPEC_MAXDEPTH) ||
1021 ps->max_depth == -1) {
1022 if (!item->attr_match_nr)
1023 return all_entries_interesting;
1024 else
1025 goto interesting;
1026 }
1027
1028 if (within_depth(base_str + matchlen + 1,
1029 baselen - matchlen - 1,
1030 !!S_ISDIR(entry->mode),
1031 ps->max_depth))
1032 goto interesting;
1033 else
1034 return entry_not_interesting;
1035 }
1036
1037 /* Either there must be no base, or the base must match. */
1038 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
1039 if (match_entry(item, entry, pathlen,
1040 match + baselen, matchlen - baselen,
1041 &never_interesting))
1042 goto interesting;
1043
1044 if (item->nowildcard_len < item->len) {
1045 if (!git_fnmatch(item, match + baselen, entry->path,
1046 item->nowildcard_len - baselen))
1047 goto interesting;
1048
1049 /*
1050 * Match all directories. We'll try to
1051 * match files later on.
1052 */
1053 if (ps->recursive && S_ISDIR(entry->mode))
1054 return entry_interesting;
1055
1056 /*
1057 * When matching against submodules with
1058 * wildcard characters, ensure that the entry
1059 * at least matches up to the first wild
1060 * character. More accurate matching can then
1061 * be performed in the submodule itself.
1062 */
1063 if (ps->recurse_submodules &&
1064 S_ISGITLINK(entry->mode) &&
1065 !ps_strncmp(item, match + baselen,
1066 entry->path,
1067 item->nowildcard_len - baselen))
1068 goto interesting;
1069 }
1070
1071 continue;
1072 }
1073
1074 match_wildcards:
1075 if (item->nowildcard_len == item->len)
1076 continue;
1077
1078 if (item->nowildcard_len &&
1079 !match_wildcard_base(item, base_str, baselen, &matched))
1080 continue;
1081
1082 /*
1083 * Concatenate base and entry->path into one and do
1084 * fnmatch() on it.
1085 *
1086 * While we could avoid concatenation in certain cases
1087 * [1], which saves a memcpy and potentially a
1088 * realloc, it turns out not worth it. Measurement on
1089 * linux-2.6 does not show any clear improvements,
1090 * partly because of the nowildcard_len optimization
1091 * in git_fnmatch(). Avoid micro-optimizations here.
1092 *
1093 * [1] if match_wildcard_base() says the base
1094 * directory is already matched, we only need to match
1095 * the rest, which is shorter so _in theory_ faster.
1096 */
1097
1098 strbuf_add(base, entry->path, pathlen);
1099
1100 if (!git_fnmatch(item, match, base->buf + base_offset,
1101 item->nowildcard_len)) {
1102 strbuf_setlen(base, base_offset + baselen);
1103 goto interesting;
1104 }
1105
1106 /*
1107 * When matching against submodules with
1108 * wildcard characters, ensure that the entry
1109 * at least matches up to the first wild
1110 * character. More accurate matching can then
1111 * be performed in the submodule itself.
1112 */
1113 if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
1114 !ps_strncmp(item, match, base->buf + base_offset,
1115 item->nowildcard_len)) {
1116 strbuf_setlen(base, base_offset + baselen);
1117 goto interesting;
1118 }
1119
1120 strbuf_setlen(base, base_offset + baselen);
1121
1122 /*
1123 * Match all directories. We'll try to match files
1124 * later on.
1125 * max_depth is ignored but we may consider support it
1126 * in future, see
1127 * https://public-inbox.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
1128 */
1129 if (ps->recursive && S_ISDIR(entry->mode))
1130 return entry_interesting;
1131 continue;
1132 interesting:
1133 if (item->attr_match_nr) {
1134 int ret;
1135
1136 /*
1137 * Must not return all_entries_not_interesting
1138 * prematurely. We do not know if all entries do not
1139 * match some attributes with current attr API.
1140 */
1141 never_interesting = entry_not_interesting;
1142
1143 /*
1144 * Consider all directories interesting (because some
1145 * of those files inside may match some attributes
1146 * even though the parent dir does not)
1147 *
1148 * FIXME: attributes _can_ match directories and we
1149 * can probably return all_entries_interesting or
1150 * all_entries_not_interesting here if matched.
1151 */
1152 if (S_ISDIR(entry->mode))
1153 return entry_interesting;
1154
1155 strbuf_add(base, entry->path, pathlen);
1156 ret = match_pathspec_attrs(istate, base->buf + base_offset,
1157 base->len - base_offset, item);
1158 strbuf_setlen(base, base_offset + baselen);
1159 if (!ret)
1160 continue;
1161 }
1162 return entry_interesting;
1163 }
1164 return never_interesting; /* No matches */
1165 }
1166
1167 /*
1168 * Is a tree entry interesting given the pathspec we have?
1169 *
1170 * Pre-condition: either baselen == base_offset (i.e. empty path)
1171 * or base[baselen-1] == '/' (i.e. with trailing slash).
1172 */
1173 enum interesting tree_entry_interesting(struct index_state *istate,
1174 const struct name_entry *entry,
1175 struct strbuf *base, int base_offset,
1176 const struct pathspec *ps)
1177 {
1178 enum interesting positive, negative;
1179 positive = do_match(istate, entry, base, base_offset, ps, 0);
1180
1181 /*
1182 * case | entry | positive | negative | result
1183 * -----+-------+----------+----------+-------
1184 * 1 | file | -1 | -1..2 | -1
1185 * 2 | file | 0 | -1..2 | 0
1186 * 3 | file | 1 | -1 | 1
1187 * 4 | file | 1 | 0 | 1
1188 * 5 | file | 1 | 1 | 0
1189 * 6 | file | 1 | 2 | 0
1190 * 7 | file | 2 | -1 | 2
1191 * 8 | file | 2 | 0 | 1
1192 * 9 | file | 2 | 1 | 0
1193 * 10 | file | 2 | 2 | -1
1194 * -----+-------+----------+----------+-------
1195 * 11 | dir | -1 | -1..2 | -1
1196 * 12 | dir | 0 | -1..2 | 0
1197 * 13 | dir | 1 | -1 | 1
1198 * 14 | dir | 1 | 0 | 1
1199 * 15 | dir | 1 | 1 | 1 (*)
1200 * 16 | dir | 1 | 2 | 0
1201 * 17 | dir | 2 | -1 | 2
1202 * 18 | dir | 2 | 0 | 1
1203 * 19 | dir | 2 | 1 | 1 (*)
1204 * 20 | dir | 2 | 2 | -1
1205 *
1206 * (*) An exclude pattern interested in a directory does not
1207 * necessarily mean it will exclude all of the directory. In
1208 * wildcard case, it can't decide until looking at individual
1209 * files inside. So don't write such directories off yet.
1210 */
1211
1212 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
1213 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
1214 return positive;
1215
1216 negative = do_match(istate, entry, base, base_offset, ps, 1);
1217
1218 /* #8, #18 */
1219 if (positive == all_entries_interesting &&
1220 negative == entry_not_interesting)
1221 return entry_interesting;
1222
1223 /* #3, #4, #7, #13, #14, #17 */
1224 if (negative <= entry_not_interesting)
1225 return positive;
1226
1227 /* #15, #19 */
1228 if (S_ISDIR(entry->mode) &&
1229 positive >= entry_interesting &&
1230 negative == entry_interesting)
1231 return entry_interesting;
1232
1233 if ((positive == entry_interesting &&
1234 negative >= entry_interesting) || /* #5, #6, #16 */
1235 (positive == all_entries_interesting &&
1236 negative == entry_interesting)) /* #9 */
1237 return entry_not_interesting;
1238
1239 return all_entries_not_interesting; /* #10, #20 */
1240 }