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[thirdparty/git.git] / tree-walk.c
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "dir.h"
4 #include "object-store.h"
5 #include "tree.h"
6 #include "pathspec.h"
7 #include "json-writer.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 oidread(&desc->entry.oid, (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, OBJ_TREE, &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 static int traverse_trees_atexit_registered;
172 static int traverse_trees_count;
173 static int traverse_trees_cur_depth;
174 static int traverse_trees_max_depth;
175
176 static void trace2_traverse_trees_statistics_atexit(void)
177 {
178 struct json_writer jw = JSON_WRITER_INIT;
179
180 jw_object_begin(&jw, 0);
181 jw_object_intmax(&jw, "traverse_trees_count", traverse_trees_count);
182 jw_object_intmax(&jw, "traverse_trees_max_depth", traverse_trees_max_depth);
183 jw_end(&jw);
184
185 trace2_data_json("traverse_trees", the_repository, "statistics", &jw);
186
187 jw_release(&jw);
188 }
189
190 void setup_traverse_info(struct traverse_info *info, const char *base)
191 {
192 size_t pathlen = strlen(base);
193 static struct traverse_info dummy;
194
195 memset(info, 0, sizeof(*info));
196 if (pathlen && base[pathlen-1] == '/')
197 pathlen--;
198 info->pathlen = pathlen ? pathlen + 1 : 0;
199 info->name = base;
200 info->namelen = pathlen;
201 if (pathlen)
202 info->prev = &dummy;
203
204 if (trace2_is_enabled() && !traverse_trees_atexit_registered) {
205 atexit(trace2_traverse_trees_statistics_atexit);
206 traverse_trees_atexit_registered = 1;
207 }
208 }
209
210 char *make_traverse_path(char *path, size_t pathlen,
211 const struct traverse_info *info,
212 const char *name, size_t namelen)
213 {
214 /* Always points to the end of the name we're about to add */
215 size_t pos = st_add(info->pathlen, namelen);
216
217 if (pos >= pathlen)
218 BUG("too small buffer passed to make_traverse_path");
219
220 path[pos] = 0;
221 for (;;) {
222 if (pos < namelen)
223 BUG("traverse_info pathlen does not match strings");
224 pos -= namelen;
225 memcpy(path + pos, name, namelen);
226
227 if (!pos)
228 break;
229 path[--pos] = '/';
230
231 if (!info)
232 BUG("traverse_info ran out of list items");
233 name = info->name;
234 namelen = info->namelen;
235 info = info->prev;
236 }
237 return path;
238 }
239
240 void strbuf_make_traverse_path(struct strbuf *out,
241 const struct traverse_info *info,
242 const char *name, size_t namelen)
243 {
244 size_t len = traverse_path_len(info, namelen);
245
246 strbuf_grow(out, len);
247 make_traverse_path(out->buf + out->len, out->alloc - out->len,
248 info, name, namelen);
249 strbuf_setlen(out, out->len + len);
250 }
251
252 struct tree_desc_skip {
253 struct tree_desc_skip *prev;
254 const void *ptr;
255 };
256
257 struct tree_desc_x {
258 struct tree_desc d;
259 struct tree_desc_skip *skip;
260 };
261
262 static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
263 {
264 /*
265 * The caller wants to pick *a* from a tree or nothing.
266 * We are looking at *b* in a tree.
267 *
268 * (0) If a and b are the same name, we are trivially happy.
269 *
270 * There are three possibilities where *a* could be hiding
271 * behind *b*.
272 *
273 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
274 * matter what.
275 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
276 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
277 *
278 * Otherwise we know *a* won't appear in the tree without
279 * scanning further.
280 */
281
282 int cmp = name_compare(a, a_len, b, b_len);
283
284 /* Most common case first -- reading sync'd trees */
285 if (!cmp)
286 return cmp;
287
288 if (0 < cmp) {
289 /* a comes after b; it does not matter if it is case (3)
290 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
291 return 1;
292 */
293 return 1; /* keep looking */
294 }
295
296 /* b comes after a; are we looking at case (2)? */
297 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
298 return 1; /* keep looking */
299
300 return -1; /* a cannot appear in the tree */
301 }
302
303 /*
304 * From the extended tree_desc, extract the first name entry, while
305 * paying attention to the candidate "first" name. Most importantly,
306 * when looking for an entry, if there are entries that sorts earlier
307 * in the tree object representation than that name, skip them and
308 * process the named entry first. We will remember that we haven't
309 * processed the first entry yet, and in the later call skip the
310 * entry we processed early when update_extended_entry() is called.
311 *
312 * E.g. if the underlying tree object has these entries:
313 *
314 * blob "t-1"
315 * blob "t-2"
316 * tree "t"
317 * blob "t=1"
318 *
319 * and the "first" asks for "t", remember that we still need to
320 * process "t-1" and "t-2" but extract "t". After processing the
321 * entry "t" from this call, the caller will let us know by calling
322 * update_extended_entry() that we can remember "t" has been processed
323 * already.
324 */
325
326 static void extended_entry_extract(struct tree_desc_x *t,
327 struct name_entry *a,
328 const char *first,
329 int first_len)
330 {
331 const char *path;
332 int len;
333 struct tree_desc probe;
334 struct tree_desc_skip *skip;
335
336 /*
337 * Extract the first entry from the tree_desc, but skip the
338 * ones that we already returned in earlier rounds.
339 */
340 while (1) {
341 if (!t->d.size) {
342 entry_clear(a);
343 break; /* not found */
344 }
345 entry_extract(&t->d, a);
346 for (skip = t->skip; skip; skip = skip->prev)
347 if (a->path == skip->ptr)
348 break; /* found */
349 if (!skip)
350 break;
351 /* We have processed this entry already. */
352 update_tree_entry(&t->d);
353 }
354
355 if (!first || !a->path)
356 return;
357
358 /*
359 * The caller wants "first" from this tree, or nothing.
360 */
361 path = a->path;
362 len = tree_entry_len(a);
363 switch (check_entry_match(first, first_len, path, len)) {
364 case -1:
365 entry_clear(a);
366 case 0:
367 return;
368 default:
369 break;
370 }
371
372 /*
373 * We need to look-ahead -- we suspect that a subtree whose
374 * name is "first" may be hiding behind the current entry "path".
375 */
376 probe = t->d;
377 while (probe.size) {
378 entry_extract(&probe, a);
379 path = a->path;
380 len = tree_entry_len(a);
381 switch (check_entry_match(first, first_len, path, len)) {
382 case -1:
383 entry_clear(a);
384 case 0:
385 return;
386 default:
387 update_tree_entry(&probe);
388 break;
389 }
390 /* keep looking */
391 }
392 entry_clear(a);
393 }
394
395 static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
396 {
397 if (t->d.entry.path == a->path) {
398 update_tree_entry(&t->d);
399 } else {
400 /* we have returned this entry early */
401 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
402 skip->ptr = a->path;
403 skip->prev = t->skip;
404 t->skip = skip;
405 }
406 }
407
408 static void free_extended_entry(struct tree_desc_x *t)
409 {
410 struct tree_desc_skip *p, *s;
411
412 for (s = t->skip; s; s = p) {
413 p = s->prev;
414 free(s);
415 }
416 }
417
418 static inline int prune_traversal(struct index_state *istate,
419 struct name_entry *e,
420 struct traverse_info *info,
421 struct strbuf *base,
422 int still_interesting)
423 {
424 if (!info->pathspec || still_interesting == 2)
425 return 2;
426 if (still_interesting < 0)
427 return still_interesting;
428 return tree_entry_interesting(istate, e, base,
429 0, info->pathspec);
430 }
431
432 int traverse_trees(struct index_state *istate,
433 int n, struct tree_desc *t,
434 struct traverse_info *info)
435 {
436 int error = 0;
437 struct name_entry entry[MAX_TRAVERSE_TREES];
438 int i;
439 struct tree_desc_x tx[ARRAY_SIZE(entry)];
440 struct strbuf base = STRBUF_INIT;
441 int interesting = 1;
442 char *traverse_path;
443
444 traverse_trees_count++;
445 traverse_trees_cur_depth++;
446
447 if (traverse_trees_cur_depth > traverse_trees_max_depth)
448 traverse_trees_max_depth = traverse_trees_cur_depth;
449
450 if (n >= ARRAY_SIZE(entry))
451 BUG("traverse_trees() called with too many trees (%d)", n);
452
453 for (i = 0; i < n; i++) {
454 tx[i].d = t[i];
455 tx[i].skip = NULL;
456 }
457
458 if (info->prev) {
459 strbuf_make_traverse_path(&base, info->prev,
460 info->name, info->namelen);
461 strbuf_addch(&base, '/');
462 traverse_path = xstrndup(base.buf, base.len);
463 } else {
464 traverse_path = xstrndup(info->name, info->pathlen);
465 }
466 info->traverse_path = traverse_path;
467 for (;;) {
468 int trees_used;
469 unsigned long mask, dirmask;
470 const char *first = NULL;
471 int first_len = 0;
472 struct name_entry *e = NULL;
473 int len;
474
475 for (i = 0; i < n; i++) {
476 e = entry + i;
477 extended_entry_extract(tx + i, e, NULL, 0);
478 }
479
480 /*
481 * A tree may have "t-2" at the current location even
482 * though it may have "t" that is a subtree behind it,
483 * and another tree may return "t". We want to grab
484 * all "t" from all trees to match in such a case.
485 */
486 for (i = 0; i < n; i++) {
487 e = entry + i;
488 if (!e->path)
489 continue;
490 len = tree_entry_len(e);
491 if (!first) {
492 first = e->path;
493 first_len = len;
494 continue;
495 }
496 if (name_compare(e->path, len, first, first_len) < 0) {
497 first = e->path;
498 first_len = len;
499 }
500 }
501
502 if (first) {
503 for (i = 0; i < n; i++) {
504 e = entry + i;
505 extended_entry_extract(tx + i, e, first, first_len);
506 /* Cull the ones that are not the earliest */
507 if (!e->path)
508 continue;
509 len = tree_entry_len(e);
510 if (name_compare(e->path, len, first, first_len))
511 entry_clear(e);
512 }
513 }
514
515 /* Now we have in entry[i] the earliest name from the trees */
516 mask = 0;
517 dirmask = 0;
518 for (i = 0; i < n; i++) {
519 if (!entry[i].path)
520 continue;
521 mask |= 1ul << i;
522 if (S_ISDIR(entry[i].mode))
523 dirmask |= 1ul << i;
524 e = &entry[i];
525 }
526 if (!mask)
527 break;
528 interesting = prune_traversal(istate, e, info, &base, interesting);
529 if (interesting < 0)
530 break;
531 if (interesting) {
532 trees_used = info->fn(n, mask, dirmask, entry, info);
533 if (trees_used < 0) {
534 error = trees_used;
535 if (!info->show_all_errors)
536 break;
537 }
538 mask &= trees_used;
539 }
540 for (i = 0; i < n; i++)
541 if (mask & (1ul << i))
542 update_extended_entry(tx + i, entry + i);
543 }
544 for (i = 0; i < n; i++)
545 free_extended_entry(tx + i);
546 free(traverse_path);
547 info->traverse_path = NULL;
548 strbuf_release(&base);
549
550 traverse_trees_cur_depth--;
551 return error;
552 }
553
554 struct dir_state {
555 void *tree;
556 unsigned long size;
557 struct object_id oid;
558 };
559
560 static int find_tree_entry(struct repository *r, struct tree_desc *t,
561 const char *name, struct object_id *result,
562 unsigned short *mode)
563 {
564 int namelen = strlen(name);
565 while (t->size) {
566 const char *entry;
567 struct object_id oid;
568 int entrylen, cmp;
569
570 oidcpy(&oid, tree_entry_extract(t, &entry, mode));
571 entrylen = tree_entry_len(&t->entry);
572 update_tree_entry(t);
573 if (entrylen > namelen)
574 continue;
575 cmp = memcmp(name, entry, entrylen);
576 if (cmp > 0)
577 continue;
578 if (cmp < 0)
579 break;
580 if (entrylen == namelen) {
581 oidcpy(result, &oid);
582 return 0;
583 }
584 if (name[entrylen] != '/')
585 continue;
586 if (!S_ISDIR(*mode))
587 break;
588 if (++entrylen == namelen) {
589 oidcpy(result, &oid);
590 return 0;
591 }
592 return get_tree_entry(r, &oid, name + entrylen, result, mode);
593 }
594 return -1;
595 }
596
597 int get_tree_entry(struct repository *r,
598 const struct object_id *tree_oid,
599 const char *name,
600 struct object_id *oid,
601 unsigned short *mode)
602 {
603 int retval;
604 void *tree;
605 unsigned long size;
606 struct object_id root;
607
608 tree = read_object_with_reference(r, tree_oid, OBJ_TREE, &size, &root);
609 if (!tree)
610 return -1;
611
612 if (name[0] == '\0') {
613 oidcpy(oid, &root);
614 free(tree);
615 return 0;
616 }
617
618 if (!size) {
619 retval = -1;
620 } else {
621 struct tree_desc t;
622 init_tree_desc(&t, tree, size);
623 retval = find_tree_entry(r, &t, name, oid, mode);
624 }
625 free(tree);
626 return retval;
627 }
628
629 /*
630 * This is Linux's built-in max for the number of symlinks to follow.
631 * That limit, of course, does not affect git, but it's a reasonable
632 * choice.
633 */
634 #define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
635
636 /**
637 * Find a tree entry by following symlinks in tree_sha (which is
638 * assumed to be the root of the repository). In the event that a
639 * symlink points outside the repository (e.g. a link to /foo or a
640 * root-level link to ../foo), the portion of the link which is
641 * outside the repository will be returned in result_path, and *mode
642 * will be set to 0. It is assumed that result_path is uninitialized.
643 * If there are no symlinks, or the end result of the symlink chain
644 * points to an object inside the repository, result will be filled in
645 * with the sha1 of the found object, and *mode will hold the mode of
646 * the object.
647 *
648 * See the code for enum get_oid_result for a description of
649 * the return values.
650 */
651 enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r,
652 struct object_id *tree_oid, const char *name,
653 struct object_id *result, struct strbuf *result_path,
654 unsigned short *mode)
655 {
656 int retval = MISSING_OBJECT;
657 struct dir_state *parents = NULL;
658 size_t parents_alloc = 0;
659 size_t i, parents_nr = 0;
660 struct object_id current_tree_oid;
661 struct strbuf namebuf = STRBUF_INIT;
662 struct tree_desc t;
663 int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
664
665 init_tree_desc(&t, NULL, 0UL);
666 strbuf_addstr(&namebuf, name);
667 oidcpy(&current_tree_oid, tree_oid);
668
669 while (1) {
670 int find_result;
671 char *first_slash;
672 char *remainder = NULL;
673
674 if (!t.buffer) {
675 void *tree;
676 struct object_id root;
677 unsigned long size;
678 tree = read_object_with_reference(r,
679 &current_tree_oid,
680 OBJ_TREE, &size,
681 &root);
682 if (!tree)
683 goto done;
684
685 ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
686 parents[parents_nr].tree = tree;
687 parents[parents_nr].size = size;
688 oidcpy(&parents[parents_nr].oid, &root);
689 parents_nr++;
690
691 if (namebuf.buf[0] == '\0') {
692 oidcpy(result, &root);
693 retval = FOUND;
694 goto done;
695 }
696
697 if (!size)
698 goto done;
699
700 /* descend */
701 init_tree_desc(&t, tree, size);
702 }
703
704 /* Handle symlinks to e.g. a//b by removing leading slashes */
705 while (namebuf.buf[0] == '/') {
706 strbuf_remove(&namebuf, 0, 1);
707 }
708
709 /* Split namebuf into a first component and a remainder */
710 if ((first_slash = strchr(namebuf.buf, '/'))) {
711 *first_slash = 0;
712 remainder = first_slash + 1;
713 }
714
715 if (!strcmp(namebuf.buf, "..")) {
716 struct dir_state *parent;
717 /*
718 * We could end up with .. in the namebuf if it
719 * appears in a symlink.
720 */
721
722 if (parents_nr == 1) {
723 if (remainder)
724 *first_slash = '/';
725 strbuf_add(result_path, namebuf.buf,
726 namebuf.len);
727 *mode = 0;
728 retval = FOUND;
729 goto done;
730 }
731 parent = &parents[parents_nr - 1];
732 free(parent->tree);
733 parents_nr--;
734 parent = &parents[parents_nr - 1];
735 init_tree_desc(&t, parent->tree, parent->size);
736 strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
737 continue;
738 }
739
740 /* We could end up here via a symlink to dir/.. */
741 if (namebuf.buf[0] == '\0') {
742 oidcpy(result, &parents[parents_nr - 1].oid);
743 retval = FOUND;
744 goto done;
745 }
746
747 /* Look up the first (or only) path component in the tree. */
748 find_result = find_tree_entry(r, &t, namebuf.buf,
749 &current_tree_oid, mode);
750 if (find_result) {
751 goto done;
752 }
753
754 if (S_ISDIR(*mode)) {
755 if (!remainder) {
756 oidcpy(result, &current_tree_oid);
757 retval = FOUND;
758 goto done;
759 }
760 /* Descend the tree */
761 t.buffer = NULL;
762 strbuf_remove(&namebuf, 0,
763 1 + first_slash - namebuf.buf);
764 } else if (S_ISREG(*mode)) {
765 if (!remainder) {
766 oidcpy(result, &current_tree_oid);
767 retval = FOUND;
768 } else {
769 retval = NOT_DIR;
770 }
771 goto done;
772 } else if (S_ISLNK(*mode)) {
773 /* Follow a symlink */
774 unsigned long link_len;
775 size_t len;
776 char *contents, *contents_start;
777 struct dir_state *parent;
778 enum object_type type;
779
780 if (follows_remaining-- == 0) {
781 /* Too many symlinks followed */
782 retval = SYMLINK_LOOP;
783 goto done;
784 }
785
786 /*
787 * At this point, we have followed at a least
788 * one symlink, so on error we need to report this.
789 */
790 retval = DANGLING_SYMLINK;
791
792 contents = repo_read_object_file(r,
793 &current_tree_oid, &type,
794 &link_len);
795
796 if (!contents)
797 goto done;
798
799 if (contents[0] == '/') {
800 strbuf_addstr(result_path, contents);
801 free(contents);
802 *mode = 0;
803 retval = FOUND;
804 goto done;
805 }
806
807 if (remainder)
808 len = first_slash - namebuf.buf;
809 else
810 len = namebuf.len;
811
812 contents_start = contents;
813
814 parent = &parents[parents_nr - 1];
815 init_tree_desc(&t, parent->tree, parent->size);
816 strbuf_splice(&namebuf, 0, len,
817 contents_start, link_len);
818 if (remainder)
819 namebuf.buf[link_len] = '/';
820 free(contents);
821 }
822 }
823 done:
824 for (i = 0; i < parents_nr; i++)
825 free(parents[i].tree);
826 free(parents);
827
828 strbuf_release(&namebuf);
829 return retval;
830 }
831
832 static int match_entry(const struct pathspec_item *item,
833 const struct name_entry *entry, int pathlen,
834 const char *match, int matchlen,
835 enum interesting *never_interesting)
836 {
837 int m = -1; /* signals that we haven't called strncmp() */
838
839 if (item->magic & PATHSPEC_ICASE)
840 /*
841 * "Never interesting" trick requires exact
842 * matching. We could do something clever with inexact
843 * matching, but it's trickier (and not to forget that
844 * strcasecmp is locale-dependent, at least in
845 * glibc). Just disable it for now. It can't be worse
846 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
847 * pattern.
848 */
849 *never_interesting = entry_not_interesting;
850 else if (*never_interesting != entry_not_interesting) {
851 /*
852 * We have not seen any match that sorts later
853 * than the current path.
854 */
855
856 /*
857 * Does match sort strictly earlier than path
858 * with their common parts?
859 */
860 m = strncmp(match, entry->path,
861 (matchlen < pathlen) ? matchlen : pathlen);
862 if (m < 0)
863 return 0;
864
865 /*
866 * If we come here even once, that means there is at
867 * least one pathspec that would sort equal to or
868 * later than the path we are currently looking at.
869 * In other words, if we have never reached this point
870 * after iterating all pathspecs, it means all
871 * pathspecs are either outside of base, or inside the
872 * base but sorts strictly earlier than the current
873 * one. In either case, they will never match the
874 * subsequent entries. In such a case, we initialized
875 * the variable to -1 and that is what will be
876 * returned, allowing the caller to terminate early.
877 */
878 *never_interesting = entry_not_interesting;
879 }
880
881 if (pathlen > matchlen)
882 return 0;
883
884 if (matchlen > pathlen) {
885 if (match[pathlen] != '/')
886 return 0;
887 /*
888 * Reject non-directories as partial pathnames, except
889 * when match is a submodule with a trailing slash and
890 * nothing else (to handle 'submod/' and 'submod'
891 * uniformly).
892 */
893 if (!S_ISDIR(entry->mode) &&
894 (!S_ISGITLINK(entry->mode) || matchlen > pathlen + 1))
895 return 0;
896 }
897
898 if (m == -1)
899 /*
900 * we cheated and did not do strncmp(), so we do
901 * that here.
902 */
903 m = ps_strncmp(item, match, entry->path, pathlen);
904
905 /*
906 * If common part matched earlier then it is a hit,
907 * because we rejected the case where path is not a
908 * leading directory and is shorter than match.
909 */
910 if (!m)
911 /*
912 * match_entry does not check if the prefix part is
913 * matched case-sensitively. If the entry is a
914 * directory and part of prefix, it'll be rematched
915 * eventually by basecmp with special treatment for
916 * the prefix.
917 */
918 return 1;
919
920 return 0;
921 }
922
923 /* :(icase)-aware string compare */
924 static int basecmp(const struct pathspec_item *item,
925 const char *base, const char *match, int len)
926 {
927 if (item->magic & PATHSPEC_ICASE) {
928 int ret, n = len > item->prefix ? item->prefix : len;
929 ret = strncmp(base, match, n);
930 if (ret)
931 return ret;
932 base += n;
933 match += n;
934 len -= n;
935 }
936 return ps_strncmp(item, base, match, len);
937 }
938
939 static int match_dir_prefix(const struct pathspec_item *item,
940 const char *base,
941 const char *match, int matchlen)
942 {
943 if (basecmp(item, base, match, matchlen))
944 return 0;
945
946 /*
947 * If the base is a subdirectory of a path which
948 * was specified, all of them are interesting.
949 */
950 if (!matchlen ||
951 base[matchlen] == '/' ||
952 match[matchlen - 1] == '/')
953 return 1;
954
955 /* Just a random prefix match */
956 return 0;
957 }
958
959 /*
960 * Perform matching on the leading non-wildcard part of
961 * pathspec. item->nowildcard_len must be greater than zero. Return
962 * non-zero if base is matched.
963 */
964 static int match_wildcard_base(const struct pathspec_item *item,
965 const char *base, int baselen,
966 int *matched)
967 {
968 const char *match = item->match;
969 /* the wildcard part is not considered in this function */
970 int matchlen = item->nowildcard_len;
971
972 if (baselen) {
973 int dirlen;
974 /*
975 * Return early if base is longer than the
976 * non-wildcard part but it does not match.
977 */
978 if (baselen >= matchlen) {
979 *matched = matchlen;
980 return !basecmp(item, base, match, matchlen);
981 }
982
983 dirlen = matchlen;
984 while (dirlen && match[dirlen - 1] != '/')
985 dirlen--;
986
987 /*
988 * Return early if base is shorter than the
989 * non-wildcard part but it does not match. Note that
990 * base ends with '/' so we are sure it really matches
991 * directory
992 */
993 if (basecmp(item, base, match, baselen))
994 return 0;
995 *matched = baselen;
996 } else
997 *matched = 0;
998 /*
999 * we could have checked entry against the non-wildcard part
1000 * that is not in base and does similar never_interesting
1001 * optimization as in match_entry. For now just be happy with
1002 * base comparison.
1003 */
1004 return entry_interesting;
1005 }
1006
1007 /*
1008 * Is a tree entry interesting given the pathspec we have?
1009 *
1010 * Pre-condition: either baselen == base_offset (i.e. empty path)
1011 * or base[baselen-1] == '/' (i.e. with trailing slash).
1012 */
1013 static enum interesting do_match(struct index_state *istate,
1014 const struct name_entry *entry,
1015 struct strbuf *base, int base_offset,
1016 const struct pathspec *ps,
1017 int exclude)
1018 {
1019 int i;
1020 int pathlen, baselen = base->len - base_offset;
1021 enum interesting never_interesting = ps->has_wildcard ?
1022 entry_not_interesting : all_entries_not_interesting;
1023
1024 GUARD_PATHSPEC(ps,
1025 PATHSPEC_FROMTOP |
1026 PATHSPEC_MAXDEPTH |
1027 PATHSPEC_LITERAL |
1028 PATHSPEC_GLOB |
1029 PATHSPEC_ICASE |
1030 PATHSPEC_EXCLUDE |
1031 PATHSPEC_ATTR);
1032
1033 if (!ps->nr) {
1034 if (!ps->recursive ||
1035 !(ps->magic & PATHSPEC_MAXDEPTH) ||
1036 ps->max_depth == -1)
1037 return all_entries_interesting;
1038 return within_depth(base->buf + base_offset, baselen,
1039 !!S_ISDIR(entry->mode),
1040 ps->max_depth) ?
1041 entry_interesting : entry_not_interesting;
1042 }
1043
1044 pathlen = tree_entry_len(entry);
1045
1046 for (i = ps->nr - 1; i >= 0; i--) {
1047 const struct pathspec_item *item = ps->items+i;
1048 const char *match = item->match;
1049 const char *base_str = base->buf + base_offset;
1050 int matchlen = item->len, matched = 0;
1051
1052 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
1053 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
1054 continue;
1055
1056 if (baselen >= matchlen) {
1057 /* If it doesn't match, move along... */
1058 if (!match_dir_prefix(item, base_str, match, matchlen))
1059 goto match_wildcards;
1060
1061 if (!ps->recursive ||
1062 !(ps->magic & PATHSPEC_MAXDEPTH) ||
1063 ps->max_depth == -1) {
1064 if (!item->attr_match_nr)
1065 return all_entries_interesting;
1066 else
1067 goto interesting;
1068 }
1069
1070 if (within_depth(base_str + matchlen + 1,
1071 baselen - matchlen - 1,
1072 !!S_ISDIR(entry->mode),
1073 ps->max_depth))
1074 goto interesting;
1075 else
1076 return entry_not_interesting;
1077 }
1078
1079 /* Either there must be no base, or the base must match. */
1080 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
1081 if (match_entry(item, entry, pathlen,
1082 match + baselen, matchlen - baselen,
1083 &never_interesting))
1084 goto interesting;
1085
1086 if (item->nowildcard_len < item->len) {
1087 if (!git_fnmatch(item, match + baselen, entry->path,
1088 item->nowildcard_len - baselen))
1089 goto interesting;
1090
1091 /*
1092 * Match all directories. We'll try to
1093 * match files later on.
1094 */
1095 if (ps->recursive && S_ISDIR(entry->mode))
1096 return entry_interesting;
1097
1098 /*
1099 * When matching against submodules with
1100 * wildcard characters, ensure that the entry
1101 * at least matches up to the first wild
1102 * character. More accurate matching can then
1103 * be performed in the submodule itself.
1104 */
1105 if (ps->recurse_submodules &&
1106 S_ISGITLINK(entry->mode) &&
1107 !ps_strncmp(item, match + baselen,
1108 entry->path,
1109 item->nowildcard_len - baselen))
1110 goto interesting;
1111 }
1112
1113 continue;
1114 }
1115
1116 match_wildcards:
1117 if (item->nowildcard_len == item->len)
1118 continue;
1119
1120 if (item->nowildcard_len &&
1121 !match_wildcard_base(item, base_str, baselen, &matched))
1122 continue;
1123
1124 /*
1125 * Concatenate base and entry->path into one and do
1126 * fnmatch() on it.
1127 *
1128 * While we could avoid concatenation in certain cases
1129 * [1], which saves a memcpy and potentially a
1130 * realloc, it turns out not worth it. Measurement on
1131 * linux-2.6 does not show any clear improvements,
1132 * partly because of the nowildcard_len optimization
1133 * in git_fnmatch(). Avoid micro-optimizations here.
1134 *
1135 * [1] if match_wildcard_base() says the base
1136 * directory is already matched, we only need to match
1137 * the rest, which is shorter so _in theory_ faster.
1138 */
1139
1140 strbuf_add(base, entry->path, pathlen);
1141
1142 if (!git_fnmatch(item, match, base->buf + base_offset,
1143 item->nowildcard_len)) {
1144 strbuf_setlen(base, base_offset + baselen);
1145 goto interesting;
1146 }
1147
1148 /*
1149 * When matching against submodules with
1150 * wildcard characters, ensure that the entry
1151 * at least matches up to the first wild
1152 * character. More accurate matching can then
1153 * be performed in the submodule itself.
1154 */
1155 if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
1156 !ps_strncmp(item, match, base->buf + base_offset,
1157 item->nowildcard_len)) {
1158 strbuf_setlen(base, base_offset + baselen);
1159 goto interesting;
1160 }
1161
1162 strbuf_setlen(base, base_offset + baselen);
1163
1164 /*
1165 * Match all directories. We'll try to match files
1166 * later on.
1167 * max_depth is ignored but we may consider support it
1168 * in future, see
1169 * https://lore.kernel.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
1170 */
1171 if (ps->recursive && S_ISDIR(entry->mode))
1172 return entry_interesting;
1173 continue;
1174 interesting:
1175 if (item->attr_match_nr) {
1176 int ret;
1177
1178 /*
1179 * Must not return all_entries_not_interesting
1180 * prematurely. We do not know if all entries do not
1181 * match some attributes with current attr API.
1182 */
1183 never_interesting = entry_not_interesting;
1184
1185 /*
1186 * Consider all directories interesting (because some
1187 * of those files inside may match some attributes
1188 * even though the parent dir does not)
1189 *
1190 * FIXME: attributes _can_ match directories and we
1191 * can probably return all_entries_interesting or
1192 * all_entries_not_interesting here if matched.
1193 */
1194 if (S_ISDIR(entry->mode))
1195 return entry_interesting;
1196
1197 strbuf_add(base, entry->path, pathlen);
1198 ret = match_pathspec_attrs(istate, base->buf + base_offset,
1199 base->len - base_offset, item);
1200 strbuf_setlen(base, base_offset + baselen);
1201 if (!ret)
1202 continue;
1203 }
1204 return entry_interesting;
1205 }
1206 return never_interesting; /* No matches */
1207 }
1208
1209 /*
1210 * Is a tree entry interesting given the pathspec we have?
1211 *
1212 * Pre-condition: either baselen == base_offset (i.e. empty path)
1213 * or base[baselen-1] == '/' (i.e. with trailing slash).
1214 */
1215 enum interesting tree_entry_interesting(struct index_state *istate,
1216 const struct name_entry *entry,
1217 struct strbuf *base, int base_offset,
1218 const struct pathspec *ps)
1219 {
1220 enum interesting positive, negative;
1221 positive = do_match(istate, entry, base, base_offset, ps, 0);
1222
1223 /*
1224 * case | entry | positive | negative | result
1225 * -----+-------+----------+----------+-------
1226 * 1 | file | -1 | -1..2 | -1
1227 * 2 | file | 0 | -1..2 | 0
1228 * 3 | file | 1 | -1 | 1
1229 * 4 | file | 1 | 0 | 1
1230 * 5 | file | 1 | 1 | 0
1231 * 6 | file | 1 | 2 | 0
1232 * 7 | file | 2 | -1 | 2
1233 * 8 | file | 2 | 0 | 1
1234 * 9 | file | 2 | 1 | 0
1235 * 10 | file | 2 | 2 | -1
1236 * -----+-------+----------+----------+-------
1237 * 11 | dir | -1 | -1..2 | -1
1238 * 12 | dir | 0 | -1..2 | 0
1239 * 13 | dir | 1 | -1 | 1
1240 * 14 | dir | 1 | 0 | 1
1241 * 15 | dir | 1 | 1 | 1 (*)
1242 * 16 | dir | 1 | 2 | 0
1243 * 17 | dir | 2 | -1 | 2
1244 * 18 | dir | 2 | 0 | 1
1245 * 19 | dir | 2 | 1 | 1 (*)
1246 * 20 | dir | 2 | 2 | -1
1247 *
1248 * (*) An exclude pattern interested in a directory does not
1249 * necessarily mean it will exclude all of the directory. In
1250 * wildcard case, it can't decide until looking at individual
1251 * files inside. So don't write such directories off yet.
1252 */
1253
1254 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
1255 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
1256 return positive;
1257
1258 negative = do_match(istate, entry, base, base_offset, ps, 1);
1259
1260 /* #8, #18 */
1261 if (positive == all_entries_interesting &&
1262 negative == entry_not_interesting)
1263 return entry_interesting;
1264
1265 /* #3, #4, #7, #13, #14, #17 */
1266 if (negative <= entry_not_interesting)
1267 return positive;
1268
1269 /* #15, #19 */
1270 if (S_ISDIR(entry->mode) &&
1271 positive >= entry_interesting &&
1272 negative == entry_interesting)
1273 return entry_interesting;
1274
1275 if ((positive == entry_interesting &&
1276 negative >= entry_interesting) || /* #5, #6, #16 */
1277 (positive == all_entries_interesting &&
1278 negative == entry_interesting)) /* #9 */
1279 return entry_not_interesting;
1280
1281 return all_entries_not_interesting; /* #10, #20 */
1282 }