Raw
1 #define USE_THE_REPOSITORY_VARIABLE
2
3 #include "git-compat-util.h"
4 #include "tree-walk.h"
5 #include "dir.h"
6 #include "gettext.h"
7 #include "hex.h"
8 #include "object-file.h"
9 #include "odb.h"
10 #include "trace2.h"
11 #include "tree.h"
12 #include "pathspec.h"
13 #include "json-writer.h"
14 #include "environment.h"
15 #include "read-cache-ll.h"
16
17 static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size, struct strbuf *err)
18 {
19 const char *path;
20 unsigned int len;
21 uint16_t mode;
22 const unsigned hashsz = desc->algo->rawsz;
23
24 if (size < hashsz + 3 || buf[size - (hashsz + 1)]) {
25 strbuf_addstr(err, _("too-short tree object"));
26 return -1;
27 }
28
29 path = parse_mode(buf, &mode);
30 if (!path) {
31 strbuf_addstr(err, _("malformed mode in tree entry"));
32 return -1;
33 }
34 if (!*path) {
35 strbuf_addstr(err, _("empty filename in tree entry"));
36 return -1;
37 }
38 len = strlen(path) + 1;
39
40 /* Initialize the descriptor entry */
41 desc->entry.path = path;
42 desc->entry.mode = (desc->flags & TREE_DESC_RAW_MODES) ? mode : canon_mode(mode);
43 desc->entry.pathlen = len - 1;
44 oidread(&desc->entry.oid, (const unsigned char *)path + len,
45 desc->algo);
46
47 return 0;
48 }
49
50 static int init_tree_desc_internal(struct tree_desc *desc,
51 const struct object_id *oid,
52 const void *buffer, unsigned long size,
53 struct strbuf *err,
54 enum tree_desc_flags flags)
55 {
56 desc->algo = (oid && oid->algo) ? &hash_algos[oid->algo] : the_hash_algo;
57 desc->buffer = buffer;
58 desc->size = size;
59 desc->flags = flags;
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 struct object_id *tree_oid,
66 const void *buffer, unsigned long size)
67 {
68 struct strbuf err = STRBUF_INIT;
69 if (init_tree_desc_internal(desc, tree_oid, buffer, size, &err, 0))
70 die("%s", err.buf);
71 strbuf_release(&err);
72 }
73
74 int init_tree_desc_gently(struct tree_desc *desc, const struct object_id *oid,
75 const void *buffer, unsigned long size,
76 enum tree_desc_flags flags)
77 {
78 struct strbuf err = STRBUF_INIT;
79 int result = init_tree_desc_internal(desc, oid, buffer, size, &err, flags);
80 if (result)
81 error("%s", err.buf);
82 strbuf_release(&err);
83 return result;
84 }
85
86 void *fill_tree_descriptor(struct repository *r,
87 struct tree_desc *desc,
88 const struct object_id *oid)
89 {
90 size_t size = 0;
91 void *buf = NULL;
92
93 if (oid) {
94 buf = odb_read_object_peeled(r->objects, oid, OBJ_TREE, &size, NULL);
95 if (!buf)
96 die(_("unable to read tree (%s)"), oid_to_hex(oid));
97 }
98 init_tree_desc(desc, oid, buf, size);
99 return buf;
100 }
101
102 static void entry_clear(struct name_entry *a)
103 {
104 memset(a, 0, sizeof(*a));
105 }
106
107 static void entry_extract(struct tree_desc *t, struct name_entry *a)
108 {
109 *a = t->entry;
110 }
111
112 static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
113 {
114 const void *buf = desc->buffer;
115 const unsigned char *end = (const unsigned char *)desc->entry.path + desc->entry.pathlen + 1 + desc->algo->rawsz;
116 unsigned long size = desc->size;
117 unsigned long len = end - (const unsigned char *)buf;
118
119 if (size < len)
120 die(_("too-short tree file"));
121 buf = end;
122 size -= len;
123 desc->buffer = buf;
124 desc->size = size;
125 if (size)
126 return decode_tree_entry(desc, buf, size, err);
127 return 0;
128 }
129
130 void update_tree_entry(struct tree_desc *desc)
131 {
132 struct strbuf err = STRBUF_INIT;
133 if (update_tree_entry_internal(desc, &err))
134 die("%s", err.buf);
135 strbuf_release(&err);
136 }
137
138 int update_tree_entry_gently(struct tree_desc *desc)
139 {
140 struct strbuf err = STRBUF_INIT;
141 if (update_tree_entry_internal(desc, &err)) {
142 error("%s", err.buf);
143 strbuf_release(&err);
144 /* Stop processing this tree after error */
145 desc->size = 0;
146 return -1;
147 }
148 strbuf_release(&err);
149 return 0;
150 }
151
152 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
153 {
154 if (!desc->size)
155 return 0;
156
157 *entry = desc->entry;
158 update_tree_entry(desc);
159 return 1;
160 }
161
162 int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
163 {
164 if (!desc->size)
165 return 0;
166
167 *entry = desc->entry;
168 if (update_tree_entry_gently(desc))
169 return 0;
170 return 1;
171 }
172
173 static int traverse_trees_atexit_registered;
174 static int traverse_trees_count;
175 static int traverse_trees_cur_depth;
176 static int traverse_trees_max_depth;
177
178 static void trace2_traverse_trees_statistics_atexit(void)
179 {
180 struct json_writer jw = JSON_WRITER_INIT;
181
182 jw_object_begin(&jw, 0);
183 jw_object_intmax(&jw, "traverse_trees_count", traverse_trees_count);
184 jw_object_intmax(&jw, "traverse_trees_max_depth", traverse_trees_max_depth);
185 jw_end(&jw);
186
187 trace2_data_json("traverse_trees", the_repository, "statistics", &jw);
188
189 jw_release(&jw);
190 }
191
192 void setup_traverse_info(struct traverse_info *info, const char *base)
193 {
194 size_t pathlen = strlen(base);
195 static struct traverse_info dummy;
196
197 memset(info, 0, sizeof(*info));
198 if (pathlen && base[pathlen-1] == '/')
199 pathlen--;
200 info->pathlen = pathlen ? pathlen + 1 : 0;
201 info->name = base;
202 info->namelen = pathlen;
203 if (pathlen)
204 info->prev = &dummy;
205
206 if (trace2_is_enabled() && !traverse_trees_atexit_registered) {
207 atexit(trace2_traverse_trees_statistics_atexit);
208 traverse_trees_atexit_registered = 1;
209 }
210 }
211
212 char *make_traverse_path(char *path, size_t pathlen,
213 const struct traverse_info *info,
214 const char *name, size_t namelen)
215 {
216 /* Always points to the end of the name we're about to add */
217 size_t pos = st_add(info->pathlen, namelen);
218
219 if (pos >= pathlen)
220 BUG("too small buffer passed to make_traverse_path");
221
222 path[pos] = 0;
223 for (;;) {
224 if (pos < namelen)
225 BUG("traverse_info pathlen does not match strings");
226 pos -= namelen;
227 memcpy(path + pos, name, namelen);
228
229 if (!pos)
230 break;
231 path[--pos] = '/';
232
233 if (!info)
234 BUG("traverse_info ran out of list items");
235 name = info->name;
236 namelen = info->namelen;
237 info = info->prev;
238 }
239 return path;
240 }
241
242 void strbuf_make_traverse_path(struct strbuf *out,
243 const struct traverse_info *info,
244 const char *name, size_t namelen)
245 {
246 size_t len = traverse_path_len(info, namelen);
247
248 strbuf_grow(out, len);
249 make_traverse_path(out->buf + out->len, out->alloc - out->len,
250 info, name, namelen);
251 strbuf_setlen(out, out->len + len);
252 }
253
254 struct tree_desc_skip {
255 struct tree_desc_skip *prev;
256 const void *ptr;
257 };
258
259 struct tree_desc_x {
260 struct tree_desc d;
261 struct tree_desc_skip *skip;
262 };
263
264 static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
265 {
266 /*
267 * The caller wants to pick *a* from a tree or nothing.
268 * We are looking at *b* in a tree.
269 *
270 * (0) If a and b are the same name, we are trivially happy.
271 *
272 * There are three possibilities where *a* could be hiding
273 * behind *b*.
274 *
275 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
276 * matter what.
277 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
278 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
279 *
280 * Otherwise we know *a* won't appear in the tree without
281 * scanning further.
282 */
283
284 int cmp = name_compare(a, a_len, b, b_len);
285
286 /* Most common case first -- reading sync'd trees */
287 if (!cmp)
288 return cmp;
289
290 if (0 < cmp) {
291 /* a comes after b; it does not matter if it is case (3)
292 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
293 return 1;
294 */
295 return 1; /* keep looking */
296 }
297
298 /* b comes after a; are we looking at case (2)? */
299 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
300 return 1; /* keep looking */
301
302 return -1; /* a cannot appear in the tree */
303 }
304
305 /*
306 * From the extended tree_desc, extract the first name entry, while
307 * paying attention to the candidate "first" name. Most importantly,
308 * when looking for an entry, if there are entries that sorts earlier
309 * in the tree object representation than that name, skip them and
310 * process the named entry first. We will remember that we haven't
311 * processed the first entry yet, and in the later call skip the
312 * entry we processed early when update_extended_entry() is called.
313 *
314 * E.g. if the underlying tree object has these entries:
315 *
316 * blob "t-1"
317 * blob "t-2"
318 * tree "t"
319 * blob "t=1"
320 *
321 * and the "first" asks for "t", remember that we still need to
322 * process "t-1" and "t-2" but extract "t". After processing the
323 * entry "t" from this call, the caller will let us know by calling
324 * update_extended_entry() that we can remember "t" has been processed
325 * already.
326 */
327
328 static void extended_entry_extract(struct tree_desc_x *t,
329 struct name_entry *a,
330 const char *first,
331 int first_len)
332 {
333 const char *path;
334 int len;
335 struct tree_desc probe;
336 struct tree_desc_skip *skip;
337
338 /*
339 * Extract the first entry from the tree_desc, but skip the
340 * ones that we already returned in earlier rounds.
341 */
342 while (1) {
343 if (!t->d.size) {
344 entry_clear(a);
345 break; /* not found */
346 }
347 entry_extract(&t->d, a);
348 for (skip = t->skip; skip; skip = skip->prev)
349 if (a->path == skip->ptr)
350 break; /* found */
351 if (!skip)
352 break;
353 /* We have processed this entry already. */
354 update_tree_entry(&t->d);
355 }
356
357 if (!first || !a->path)
358 return;
359
360 /*
361 * The caller wants "first" from this tree, or nothing.
362 */
363 path = a->path;
364 len = tree_entry_len(a);
365 switch (check_entry_match(first, first_len, path, len)) {
366 case -1:
367 entry_clear(a);
368 case 0:
369 return;
370 default:
371 break;
372 }
373
374 /*
375 * We need to look-ahead -- we suspect that a subtree whose
376 * name is "first" may be hiding behind the current entry "path".
377 */
378 probe = t->d;
379 while (probe.size) {
380 entry_extract(&probe, a);
381 path = a->path;
382 len = tree_entry_len(a);
383 switch (check_entry_match(first, first_len, path, len)) {
384 case -1:
385 entry_clear(a);
386 case 0:
387 return;
388 default:
389 update_tree_entry(&probe);
390 break;
391 }
392 /* keep looking */
393 }
394 entry_clear(a);
395 }
396
397 static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
398 {
399 if (t->d.entry.path == a->path) {
400 update_tree_entry(&t->d);
401 } else {
402 /* we have returned this entry early */
403 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
404 skip->ptr = a->path;
405 skip->prev = t->skip;
406 t->skip = skip;
407 }
408 }
409
410 static void free_extended_entry(struct tree_desc_x *t)
411 {
412 struct tree_desc_skip *p, *s;
413
414 for (s = t->skip; s; s = p) {
415 p = s->prev;
416 free(s);
417 }
418 }
419
420 static inline int prune_traversal(struct index_state *istate,
421 struct name_entry *e,
422 struct traverse_info *info,
423 struct strbuf *base,
424 int still_interesting)
425 {
426 if (!info->pathspec || still_interesting == 2)
427 return 2;
428 if (still_interesting < 0)
429 return still_interesting;
430 return tree_entry_interesting(istate, e, base,
431 info->pathspec);
432 }
433
434 int traverse_trees(struct index_state *istate,
435 int n, struct tree_desc *t,
436 struct traverse_info *info)
437 {
438 int ret = 0;
439 struct name_entry *entry;
440 int i;
441 struct tree_desc_x *tx;
442 struct strbuf base = STRBUF_INIT;
443 int interesting = 1;
444 char *traverse_path;
445 struct repository *r = istate ? istate->repo : the_repository;
446
447 if (traverse_trees_cur_depth > r->settings.max_allowed_tree_depth)
448 return error("exceeded maximum allowed tree depth");
449
450 traverse_trees_count++;
451 traverse_trees_cur_depth++;
452
453 if (traverse_trees_cur_depth > traverse_trees_max_depth)
454 traverse_trees_max_depth = traverse_trees_cur_depth;
455
456 ALLOC_ARRAY(entry, n);
457 ALLOC_ARRAY(tx, n);
458
459 for (i = 0; i < n; i++) {
460 tx[i].d = t[i];
461 tx[i].skip = NULL;
462 }
463
464 if (info->prev) {
465 strbuf_make_traverse_path(&base, info->prev,
466 info->name, info->namelen);
467 strbuf_addch(&base, '/');
468 traverse_path = xstrndup(base.buf, base.len);
469 } else {
470 traverse_path = xstrndup(info->name, info->pathlen);
471 }
472 info->traverse_path = traverse_path;
473 for (;;) {
474 int trees_used;
475 unsigned long mask, dirmask;
476 const char *first = NULL;
477 int first_len = 0;
478 struct name_entry *e = NULL;
479 int len;
480
481 for (i = 0; i < n; i++) {
482 e = entry + i;
483 extended_entry_extract(tx + i, e, NULL, 0);
484 }
485
486 /*
487 * A tree may have "t-2" at the current location even
488 * though it may have "t" that is a subtree behind it,
489 * and another tree may return "t". We want to grab
490 * all "t" from all trees to match in such a case.
491 */
492 for (i = 0; i < n; i++) {
493 e = entry + i;
494 if (!e->path)
495 continue;
496 len = tree_entry_len(e);
497 if (!first) {
498 first = e->path;
499 first_len = len;
500 continue;
501 }
502 if (name_compare(e->path, len, first, first_len) < 0) {
503 first = e->path;
504 first_len = len;
505 }
506 }
507
508 if (first) {
509 for (i = 0; i < n; i++) {
510 e = entry + i;
511 extended_entry_extract(tx + i, e, first, first_len);
512 /* Cull the ones that are not the earliest */
513 if (!e->path)
514 continue;
515 len = tree_entry_len(e);
516 if (name_compare(e->path, len, first, first_len))
517 entry_clear(e);
518 }
519 }
520
521 /* Now we have in entry[i] the earliest name from the trees */
522 mask = 0;
523 dirmask = 0;
524 for (i = 0; i < n; i++) {
525 if (!entry[i].path)
526 continue;
527 mask |= 1ul << i;
528 if (S_ISDIR(entry[i].mode))
529 dirmask |= 1ul << i;
530 e = &entry[i];
531 }
532 if (!mask)
533 break;
534 interesting = prune_traversal(istate, e, info, &base, interesting);
535 if (interesting < 0)
536 break;
537 if (interesting) {
538 trees_used = info->fn(n, mask, dirmask, entry, info);
539 if (trees_used < 0) {
540 ret = trees_used;
541 if (!info->show_all_errors)
542 break;
543 }
544 mask &= trees_used;
545 }
546 for (i = 0; i < n; i++)
547 if (mask & (1ul << i))
548 update_extended_entry(tx + i, entry + i);
549 }
550 for (i = 0; i < n; i++)
551 free_extended_entry(tx + i);
552 free(tx);
553 free(entry);
554 free(traverse_path);
555 info->traverse_path = NULL;
556 strbuf_release(&base);
557
558 traverse_trees_cur_depth--;
559 return ret;
560 }
561
562 struct dir_state {
563 void *tree;
564 unsigned long size;
565 struct object_id oid;
566 };
567
568 static int find_tree_entry(struct repository *r, struct tree_desc *t,
569 const char *name, struct object_id *result,
570 unsigned short *mode)
571 {
572 int namelen = strlen(name);
573 while (t->size) {
574 const char *entry;
575 struct object_id oid;
576 int entrylen, cmp;
577
578 oidcpy(&oid, tree_entry_extract(t, &entry, mode));
579 entrylen = tree_entry_len(&t->entry);
580 update_tree_entry(t);
581 if (entrylen > namelen)
582 continue;
583 cmp = memcmp(name, entry, entrylen);
584 if (cmp > 0)
585 continue;
586 if (cmp < 0)
587 break;
588 if (entrylen == namelen) {
589 oidcpy(result, &oid);
590 return 0;
591 }
592 if (name[entrylen] != '/')
593 continue;
594 if (!S_ISDIR(*mode))
595 break;
596 if (++entrylen == namelen) {
597 oidcpy(result, &oid);
598 return 0;
599 }
600 return get_tree_entry(r, &oid, name + entrylen, result, mode);
601 }
602 return -1;
603 }
604
605 int get_tree_entry(struct repository *r,
606 const struct object_id *tree_oid,
607 const char *name,
608 struct object_id *oid,
609 unsigned short *mode)
610 {
611 int retval;
612 void *tree;
613 size_t size;
614 struct object_id root;
615
616 tree = odb_read_object_peeled(r->objects, tree_oid, OBJ_TREE, &size, &root);
617 if (!tree)
618 return -1;
619
620 if (name[0] == '\0') {
621 oidcpy(oid, &root);
622 free(tree);
623 return 0;
624 }
625
626 if (!size) {
627 retval = -1;
628 } else {
629 struct tree_desc t;
630 init_tree_desc(&t, tree_oid, tree, size);
631 retval = find_tree_entry(r, &t, name, oid, mode);
632 }
633 free(tree);
634 return retval;
635 }
636
637 /*
638 * This is Linux's built-in max for the number of symlinks to follow.
639 * That limit, of course, does not affect git, but it's a reasonable
640 * choice.
641 */
642 #define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
643
644 /**
645 * Find a tree entry by following symlinks in tree_sha (which is
646 * assumed to be the root of the repository). In the event that a
647 * symlink points outside the repository (e.g. a link to /foo or a
648 * root-level link to ../foo), the portion of the link which is
649 * outside the repository will be returned in result_path, and *mode
650 * will be set to 0. It is assumed that result_path is uninitialized.
651 * If there are no symlinks, or the end result of the symlink chain
652 * points to an object inside the repository, result will be filled in
653 * with the sha1 of the found object, and *mode will hold the mode of
654 * the object.
655 *
656 * See the code for enum get_oid_result for a description of
657 * the return values.
658 */
659 enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r,
660 struct object_id *tree_oid, const char *name,
661 struct object_id *result, struct strbuf *result_path,
662 unsigned short *mode)
663 {
664 int retval = MISSING_OBJECT;
665 struct dir_state *parents = NULL;
666 size_t parents_alloc = 0;
667 size_t i, parents_nr = 0;
668 struct object_id current_tree_oid;
669 struct strbuf namebuf = STRBUF_INIT;
670 struct tree_desc t;
671 int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
672
673 init_tree_desc(&t, NULL, NULL, 0UL);
674 strbuf_addstr(&namebuf, name);
675 oidcpy(&current_tree_oid, tree_oid);
676
677 while (1) {
678 int find_result;
679 char *first_slash;
680 char *remainder = NULL;
681
682 if (!t.buffer) {
683 void *tree;
684 struct object_id root;
685 size_t size;
686 tree = odb_read_object_peeled(r->objects, &current_tree_oid,
687 OBJ_TREE, &size, &root);
688 if (!tree)
689 goto done;
690
691 ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
692 parents[parents_nr].tree = tree;
693 parents[parents_nr].size = size;
694 oidcpy(&parents[parents_nr].oid, &root);
695 parents_nr++;
696
697 if (namebuf.buf[0] == '\0') {
698 oidcpy(result, &root);
699 retval = FOUND;
700 goto done;
701 }
702
703 if (!size)
704 goto done;
705
706 /* descend */
707 init_tree_desc(&t, &current_tree_oid, tree, size);
708 }
709
710 /* Handle symlinks to e.g. a//b by removing leading slashes */
711 while (namebuf.buf[0] == '/') {
712 strbuf_remove(&namebuf, 0, 1);
713 }
714
715 /* Split namebuf into a first component and a remainder */
716 if ((first_slash = strchr(namebuf.buf, '/'))) {
717 *first_slash = 0;
718 remainder = first_slash + 1;
719 }
720
721 if (!strcmp(namebuf.buf, "..")) {
722 struct dir_state *parent;
723 /*
724 * We could end up with .. in the namebuf if it
725 * appears in a symlink.
726 */
727
728 if (parents_nr == 1) {
729 if (remainder)
730 *first_slash = '/';
731 strbuf_add(result_path, namebuf.buf,
732 namebuf.len);
733 *mode = 0;
734 retval = FOUND;
735 goto done;
736 }
737 parent = &parents[parents_nr - 1];
738 free(parent->tree);
739 parents_nr--;
740 parent = &parents[parents_nr - 1];
741 init_tree_desc(&t, &parent->oid, parent->tree, parent->size);
742 strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
743 continue;
744 }
745
746 /* We could end up here via a symlink to dir/.. */
747 if (namebuf.buf[0] == '\0') {
748 oidcpy(result, &parents[parents_nr - 1].oid);
749 retval = FOUND;
750 goto done;
751 }
752
753 /* Look up the first (or only) path component in the tree. */
754 find_result = find_tree_entry(r, &t, namebuf.buf,
755 &current_tree_oid, mode);
756 if (find_result) {
757 goto done;
758 }
759
760 if (S_ISDIR(*mode)) {
761 if (!remainder) {
762 oidcpy(result, &current_tree_oid);
763 retval = FOUND;
764 goto done;
765 }
766 /* Descend the tree */
767 t.buffer = NULL;
768 strbuf_remove(&namebuf, 0,
769 1 + first_slash - namebuf.buf);
770 } else if (S_ISREG(*mode)) {
771 if (!remainder) {
772 oidcpy(result, &current_tree_oid);
773 retval = FOUND;
774 } else {
775 retval = NOT_DIR;
776 }
777 goto done;
778 } else if (S_ISLNK(*mode)) {
779 /* Follow a symlink */
780 unsigned long link_len;
781 size_t link_len_st = 0;
782 size_t len;
783 char *contents, *contents_start;
784 struct dir_state *parent;
785 enum object_type type;
786
787 if (follows_remaining-- == 0) {
788 /* Too many symlinks followed */
789 retval = SYMLINK_LOOP;
790 goto done;
791 }
792
793 /*
794 * At this point, we have followed at a least
795 * one symlink, so on error we need to report this.
796 */
797 retval = DANGLING_SYMLINK;
798
799 contents = odb_read_object(r->objects,
800 &current_tree_oid, &type,
801 &link_len_st);
802 link_len = cast_size_t_to_ulong(link_len_st);
803
804 if (!contents)
805 goto done;
806
807 if (contents[0] == '/') {
808 strbuf_addstr(result_path, contents);
809 free(contents);
810 *mode = 0;
811 retval = FOUND;
812 goto done;
813 }
814
815 if (remainder)
816 len = first_slash - namebuf.buf;
817 else
818 len = namebuf.len;
819
820 contents_start = contents;
821
822 parent = &parents[parents_nr - 1];
823 init_tree_desc(&t, &parent->oid, parent->tree, parent->size);
824 strbuf_splice(&namebuf, 0, len,
825 contents_start, link_len);
826 if (remainder)
827 namebuf.buf[link_len] = '/';
828 free(contents);
829 }
830 }
831 done:
832 for (i = 0; i < parents_nr; i++)
833 free(parents[i].tree);
834 free(parents);
835
836 strbuf_release(&namebuf);
837 return retval;
838 }
839
840 static int match_entry(const struct pathspec_item *item,
841 const struct name_entry *entry, int pathlen,
842 const char *match, int matchlen,
843 enum interesting *never_interesting)
844 {
845 int m = -1; /* signals that we haven't called strncmp() */
846
847 if (item->magic & PATHSPEC_ICASE)
848 /*
849 * "Never interesting" trick requires exact
850 * matching. We could do something clever with inexact
851 * matching, but it's trickier (and not to forget that
852 * strcasecmp is locale-dependent, at least in
853 * glibc). Just disable it for now. It can't be worse
854 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
855 * pattern.
856 */
857 *never_interesting = entry_not_interesting;
858 else if (*never_interesting != entry_not_interesting) {
859 /*
860 * We have not seen any match that sorts later
861 * than the current path.
862 */
863
864 /*
865 * Does match sort strictly earlier than path
866 * with their common parts?
867 */
868 m = strncmp(match, entry->path,
869 (matchlen < pathlen) ? matchlen : pathlen);
870 if (m < 0)
871 return 0;
872
873 /*
874 * If we come here even once, that means there is at
875 * least one pathspec that would sort equal to or
876 * later than the path we are currently looking at.
877 * In other words, if we have never reached this point
878 * after iterating all pathspecs, it means all
879 * pathspecs are either outside of base, or inside the
880 * base but sorts strictly earlier than the current
881 * one. In either case, they will never match the
882 * subsequent entries. In such a case, we initialized
883 * the variable to -1 and that is what will be
884 * returned, allowing the caller to terminate early.
885 */
886 *never_interesting = entry_not_interesting;
887 }
888
889 if (pathlen > matchlen)
890 return 0;
891
892 if (matchlen > pathlen) {
893 if (match[pathlen] != '/')
894 return 0;
895 /*
896 * Reject non-directories as partial pathnames, except
897 * when match is a submodule with a trailing slash and
898 * nothing else (to handle 'submod/' and 'submod'
899 * uniformly).
900 */
901 if (!S_ISDIR(entry->mode) &&
902 (!S_ISGITLINK(entry->mode) || matchlen > pathlen + 1))
903 return 0;
904 }
905
906 if (m == -1)
907 /*
908 * we cheated and did not do strncmp(), so we do
909 * that here.
910 */
911 m = ps_strncmp(item, match, entry->path, pathlen);
912
913 /*
914 * If common part matched earlier then it is a hit,
915 * because we rejected the case where path is not a
916 * leading directory and is shorter than match.
917 */
918 if (!m)
919 /*
920 * match_entry does not check if the prefix part is
921 * matched case-sensitively. If the entry is a
922 * directory and part of prefix, it'll be rematched
923 * eventually by basecmp with special treatment for
924 * the prefix.
925 */
926 return 1;
927
928 return 0;
929 }
930
931 /* :(icase)-aware string compare */
932 static int basecmp(const struct pathspec_item *item,
933 const char *base, const char *match, int len)
934 {
935 if (item->magic & PATHSPEC_ICASE) {
936 int ret, n = len > item->prefix ? item->prefix : len;
937 ret = strncmp(base, match, n);
938 if (ret)
939 return ret;
940 base += n;
941 match += n;
942 len -= n;
943 }
944 return ps_strncmp(item, base, match, len);
945 }
946
947 static int match_dir_prefix(const struct pathspec_item *item,
948 const char *base,
949 const char *match, int matchlen)
950 {
951 if (basecmp(item, base, match, matchlen))
952 return 0;
953
954 /*
955 * If the base is a subdirectory of a path which
956 * was specified, all of them are interesting.
957 */
958 if (!matchlen ||
959 base[matchlen] == '/' ||
960 match[matchlen - 1] == '/')
961 return 1;
962
963 /* Just a random prefix match */
964 return 0;
965 }
966
967 /*
968 * Perform matching on the leading non-wildcard part of
969 * pathspec. item->nowildcard_len must be greater than zero. Return
970 * non-zero if base is matched.
971 */
972 static int match_wildcard_base(const struct pathspec_item *item,
973 const char *base, int baselen,
974 int *matched)
975 {
976 const char *match = item->match;
977 /* the wildcard part is not considered in this function */
978 int matchlen = item->nowildcard_len;
979
980 if (baselen) {
981 int dirlen;
982 /*
983 * Return early if base is longer than the
984 * non-wildcard part but it does not match.
985 */
986 if (baselen >= matchlen) {
987 *matched = matchlen;
988 return !basecmp(item, base, match, matchlen);
989 }
990
991 dirlen = matchlen;
992 while (dirlen && match[dirlen - 1] != '/')
993 dirlen--;
994
995 /*
996 * Return early if base is shorter than the
997 * non-wildcard part but it does not match. Note that
998 * base ends with '/' so we are sure it really matches
999 * directory
1000 */
1001 if (basecmp(item, base, match, baselen))
1002 return 0;
1003 *matched = baselen;
1004 } else
1005 *matched = 0;
1006 /*
1007 * we could have checked entry against the non-wildcard part
1008 * that is not in base and does similar never_interesting
1009 * optimization as in match_entry. For now just be happy with
1010 * base comparison.
1011 */
1012 return entry_interesting;
1013 }
1014
1015 /*
1016 * Is a tree entry interesting given the pathspec we have?
1017 *
1018 * Pre-condition: either baselen == 0 (i.e. empty path)
1019 * or base[baselen-1] == '/' (i.e. with trailing slash).
1020 */
1021 static enum interesting do_match(struct index_state *istate,
1022 const struct name_entry *entry,
1023 struct strbuf *base,
1024 const struct pathspec *ps,
1025 int exclude)
1026 {
1027 int i;
1028 int pathlen, baselen = base->len;
1029 enum interesting never_interesting = ps->has_wildcard ?
1030 entry_not_interesting : all_entries_not_interesting;
1031
1032 GUARD_PATHSPEC(ps,
1033 PATHSPEC_FROMTOP |
1034 PATHSPEC_MAXDEPTH |
1035 PATHSPEC_LITERAL |
1036 PATHSPEC_GLOB |
1037 PATHSPEC_ICASE |
1038 PATHSPEC_EXCLUDE |
1039 PATHSPEC_ATTR);
1040
1041 if (!ps->nr) {
1042 if (!ps->recursive ||
1043 !(ps->magic & PATHSPEC_MAXDEPTH) ||
1044 ps->max_depth == -1)
1045 return all_entries_interesting;
1046 return within_depth(base->buf, baselen,
1047 !!S_ISDIR(entry->mode),
1048 ps->max_depth) ?
1049 entry_interesting : entry_not_interesting;
1050 }
1051
1052 pathlen = tree_entry_len(entry);
1053
1054 for (i = ps->nr - 1; i >= 0; i--) {
1055 const struct pathspec_item *item = ps->items+i;
1056 const char *match = item->match;
1057 const char *base_str = base->buf;
1058 int matchlen = item->len, matched = 0;
1059
1060 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
1061 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
1062 continue;
1063
1064 if (baselen >= matchlen) {
1065 /* If it doesn't match, move along... */
1066 if (!match_dir_prefix(item, base_str, match, matchlen))
1067 goto match_wildcards;
1068
1069 if (!ps->recursive ||
1070 !(ps->magic & PATHSPEC_MAXDEPTH) ||
1071 ps->max_depth == -1) {
1072 if (!item->attr_match_nr)
1073 return all_entries_interesting;
1074 else
1075 goto interesting;
1076 }
1077
1078 if (within_depth(base_str + matchlen + 1,
1079 baselen - matchlen - 1,
1080 !!S_ISDIR(entry->mode),
1081 ps->max_depth))
1082 goto interesting;
1083 else
1084 return entry_not_interesting;
1085 }
1086
1087 /* Either there must be no base, or the base must match. */
1088 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
1089 if (match_entry(item, entry, pathlen,
1090 match + baselen, matchlen - baselen,
1091 &never_interesting))
1092 goto interesting;
1093
1094 if (item->nowildcard_len < item->len) {
1095 if (!git_fnmatch(item, match + baselen, entry->path,
1096 item->nowildcard_len - baselen))
1097 goto interesting;
1098
1099 /*
1100 * Match all directories. We'll try to
1101 * match files later on.
1102 */
1103 if (ps->recursive && S_ISDIR(entry->mode))
1104 return entry_interesting;
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 &&
1114 S_ISGITLINK(entry->mode) &&
1115 !ps_strncmp(item, match + baselen,
1116 entry->path,
1117 item->nowildcard_len - baselen))
1118 goto interesting;
1119 }
1120
1121 continue;
1122 }
1123
1124 match_wildcards:
1125 if (item->nowildcard_len == item->len)
1126 continue;
1127
1128 if (item->nowildcard_len &&
1129 !match_wildcard_base(item, base_str, baselen, &matched))
1130 continue;
1131
1132 /*
1133 * Concatenate base and entry->path into one and do
1134 * fnmatch() on it.
1135 *
1136 * While we could avoid concatenation in certain cases
1137 * [1], which saves a memcpy and potentially a
1138 * realloc, it turns out not worth it. Measurement on
1139 * linux-2.6 does not show any clear improvements,
1140 * partly because of the nowildcard_len optimization
1141 * in git_fnmatch(). Avoid micro-optimizations here.
1142 *
1143 * [1] if match_wildcard_base() says the base
1144 * directory is already matched, we only need to match
1145 * the rest, which is shorter so _in theory_ faster.
1146 */
1147
1148 strbuf_add(base, entry->path, pathlen);
1149
1150 if (!git_fnmatch(item, match, base->buf,
1151 item->nowildcard_len)) {
1152 strbuf_setlen(base, baselen);
1153 goto interesting;
1154 }
1155
1156 /*
1157 * When matching against submodules with
1158 * wildcard characters, ensure that the entry
1159 * at least matches up to the first wild
1160 * character. More accurate matching can then
1161 * be performed in the submodule itself.
1162 */
1163 if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
1164 !ps_strncmp(item, match, base->buf,
1165 item->nowildcard_len)) {
1166 strbuf_setlen(base, baselen);
1167 goto interesting;
1168 }
1169
1170 strbuf_setlen(base, baselen);
1171
1172 /*
1173 * Match all directories. We'll try to match files
1174 * later on.
1175 * max_depth is ignored but we may consider support it
1176 * in future, see
1177 * https://lore.kernel.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
1178 */
1179 if (ps->recursive && S_ISDIR(entry->mode))
1180 return entry_interesting;
1181 continue;
1182 interesting:
1183 if (item->attr_match_nr) {
1184 int ret;
1185
1186 /*
1187 * Must not return all_entries_not_interesting
1188 * prematurely. We do not know if all entries do not
1189 * match some attributes with current attr API.
1190 */
1191 never_interesting = entry_not_interesting;
1192
1193 /*
1194 * Consider all directories interesting (because some
1195 * of those files inside may match some attributes
1196 * even though the parent dir does not)
1197 *
1198 * FIXME: attributes _can_ match directories and we
1199 * can probably return all_entries_interesting or
1200 * all_entries_not_interesting here if matched.
1201 */
1202 if (S_ISDIR(entry->mode))
1203 return entry_interesting;
1204
1205 strbuf_add(base, entry->path, pathlen);
1206 ret = match_pathspec_attrs(istate, base->buf,
1207 base->len, item);
1208 strbuf_setlen(base, baselen);
1209 if (!ret)
1210 continue;
1211 }
1212 return entry_interesting;
1213 }
1214 return never_interesting; /* No matches */
1215 }
1216
1217 /*
1218 * Is a tree entry interesting given the pathspec we have?
1219 *
1220 * Pre-condition: either baselen == 0 (i.e. empty path)
1221 * or base[baselen-1] == '/' (i.e. with trailing slash).
1222 */
1223 enum interesting tree_entry_interesting(struct index_state *istate,
1224 const struct name_entry *entry,
1225 struct strbuf *base,
1226 const struct pathspec *ps)
1227 {
1228 enum interesting positive, negative;
1229 positive = do_match(istate, entry, base, ps, 0);
1230
1231 /*
1232 * case | entry | positive | negative | result
1233 * -----+-------+----------+----------+-------
1234 * 1 | file | -1 | -1..2 | -1
1235 * 2 | file | 0 | -1..2 | 0
1236 * 3 | file | 1 | -1 | 1
1237 * 4 | file | 1 | 0 | 1
1238 * 5 | file | 1 | 1 | 0
1239 * 6 | file | 1 | 2 | 0
1240 * 7 | file | 2 | -1 | 2
1241 * 8 | file | 2 | 0 | 1
1242 * 9 | file | 2 | 1 | 0
1243 * 10 | file | 2 | 2 | -1
1244 * -----+-------+----------+----------+-------
1245 * 11 | dir | -1 | -1..2 | -1
1246 * 12 | dir | 0 | -1..2 | 0
1247 * 13 | dir | 1 | -1 | 1
1248 * 14 | dir | 1 | 0 | 1
1249 * 15 | dir | 1 | 1 | 1 (*)
1250 * 16 | dir | 1 | 2 | 0
1251 * 17 | dir | 2 | -1 | 2
1252 * 18 | dir | 2 | 0 | 1
1253 * 19 | dir | 2 | 1 | 1 (*)
1254 * 20 | dir | 2 | 2 | -1
1255 *
1256 * (*) An exclude pattern interested in a directory does not
1257 * necessarily mean it will exclude all of the directory. In
1258 * wildcard case, it can't decide until looking at individual
1259 * files inside. So don't write such directories off yet.
1260 */
1261
1262 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
1263 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
1264 return positive;
1265
1266 negative = do_match(istate, entry, base, ps, 1);
1267
1268 /* #8, #18 */
1269 if (positive == all_entries_interesting &&
1270 negative == entry_not_interesting)
1271 return entry_interesting;
1272
1273 /* #3, #4, #7, #13, #14, #17 */
1274 if (negative <= entry_not_interesting)
1275 return positive;
1276
1277 /* #15, #19 */
1278 if (S_ISDIR(entry->mode) &&
1279 positive >= entry_interesting &&
1280 negative == entry_interesting)
1281 return entry_interesting;
1282
1283 if ((positive == entry_interesting &&
1284 negative >= entry_interesting) || /* #5, #6, #16 */
1285 (positive == all_entries_interesting &&
1286 negative == entry_interesting)) /* #9 */
1287 return entry_not_interesting;
1288
1289 return all_entries_not_interesting; /* #10, #20 */
1290 }