dir.c: move, rename and export match_attrs()
[git/git.git] / tree-walk.c
CommitLineData
1b0c7174
JH
1#include "cache.h"
2#include "tree-walk.h"
e6c111b4 3#include "unpack-trees.h"
bc96cc87 4#include "dir.h"
cbd53a21 5#include "object-store.h"
8e440259 6#include "tree.h"
64acde94 7#include "pathspec.h"
1b0c7174 8
4651ece8
LT
9static const char *get_mode(const char *str, unsigned int *modep)
10{
11 unsigned char c;
12 unsigned int mode = 0;
13
64cc1c09
MK
14 if (*str == ' ')
15 return NULL;
16
4651ece8
LT
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
8354fa3d 26static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size, struct strbuf *err)
4651ece8
LT
27{
28 const char *path;
29 unsigned int mode, len;
83e4b757 30 const unsigned hashsz = the_hash_algo->rawsz;
4651ece8 31
83e4b757 32 if (size < hashsz + 3 || buf[size - (hashsz + 1)]) {
8354fa3d
DT
33 strbuf_addstr(err, _("too-short tree object"));
34 return -1;
35 }
64cc1c09 36
4651ece8 37 path = get_mode(buf, &mode);
8354fa3d
DT
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 }
4651ece8
LT
46 len = strlen(path) + 1;
47
48 /* Initialize the descriptor entry */
49 desc->entry.path = path;
7146e66f 50 desc->entry.mode = canon_mode(mode);
7d924c91 51 desc->entry.oid = (const struct object_id *)(path + len);
8354fa3d
DT
52
53 return 0;
4651ece8
LT
54}
55
8354fa3d 56static int init_tree_desc_internal(struct tree_desc *desc, const void *buffer, unsigned long size, struct strbuf *err)
6fda5e51
LT
57{
58 desc->buffer = buffer;
59 desc->size = size;
4651ece8 60 if (size)
8354fa3d
DT
61 return decode_tree_entry(desc, buffer, size, err);
62 return 0;
63}
64
65void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
66{
67 struct strbuf err = STRBUF_INIT;
68 if (init_tree_desc_internal(desc, buffer, size, &err))
69 die("%s", err.buf);
70 strbuf_release(&err);
71}
72
73int init_tree_desc_gently(struct tree_desc *desc, const void *buffer, unsigned long size)
74{
75 struct strbuf err = STRBUF_INIT;
76 int result = init_tree_desc_internal(desc, buffer, size, &err);
77 if (result)
78 error("%s", err.buf);
79 strbuf_release(&err);
80 return result;
6fda5e51
LT
81}
82
5c377d3d 83void *fill_tree_descriptor(struct tree_desc *desc, const struct object_id *oid)
1b0c7174
JH
84{
85 unsigned long size = 0;
86 void *buf = NULL;
87
5c377d3d 88 if (oid) {
02f0547e 89 buf = read_object_with_reference(oid, tree_type, &size, NULL);
1b0c7174 90 if (!buf)
5c377d3d 91 die("unable to read tree %s", oid_to_hex(oid));
1b0c7174 92 }
6fda5e51 93 init_tree_desc(desc, buf, size);
1b0c7174
JH
94 return buf;
95}
96
1b0c7174
JH
97static void entry_clear(struct name_entry *a)
98{
99 memset(a, 0, sizeof(*a));
100}
101
102static void entry_extract(struct tree_desc *t, struct name_entry *a)
103{
4651ece8 104 *a = t->entry;
1b0c7174
JH
105}
106
8354fa3d 107static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
1b0c7174 108{
6fda5e51 109 const void *buf = desc->buffer;
e84bc23c 110 const unsigned char *end = desc->entry.oid->hash + the_hash_algo->rawsz;
1b0c7174 111 unsigned long size = desc->size;
4651ece8 112 unsigned long len = end - (const unsigned char *)buf;
1b0c7174
JH
113
114 if (size < len)
2edffef2 115 die(_("too-short tree file"));
4651ece8
LT
116 buf = end;
117 size -= len;
118 desc->buffer = buf;
119 desc->size = size;
120 if (size)
8354fa3d
DT
121 return decode_tree_entry(desc, buf, size, err);
122 return 0;
123}
124
125void update_tree_entry(struct tree_desc *desc)
126{
127 struct strbuf err = STRBUF_INIT;
128 if (update_tree_entry_internal(desc, &err))
129 die("%s", err.buf);
130 strbuf_release(&err);
131}
132
133int update_tree_entry_gently(struct tree_desc *desc)
134{
135 struct strbuf err = STRBUF_INIT;
136 if (update_tree_entry_internal(desc, &err)) {
137 error("%s", err.buf);
138 strbuf_release(&err);
139 /* Stop processing this tree after error */
140 desc->size = 0;
141 return -1;
142 }
143 strbuf_release(&err);
144 return 0;
1b0c7174
JH
145}
146
4c068a98
LT
147int tree_entry(struct tree_desc *desc, struct name_entry *entry)
148{
4651ece8 149 if (!desc->size)
4c068a98
LT
150 return 0;
151
4651ece8
LT
152 *entry = desc->entry;
153 update_tree_entry(desc);
4c068a98
LT
154 return 1;
155}
156
8354fa3d
DT
157int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
158{
159 if (!desc->size)
160 return 0;
161
162 *entry = desc->entry;
163 if (update_tree_entry_gently(desc))
164 return 0;
165 return 1;
166}
167
40d934df
LT
168void setup_traverse_info(struct traverse_info *info, const char *base)
169{
170 int pathlen = strlen(base);
bcbe5a51 171 static struct traverse_info dummy;
40d934df
LT
172
173 memset(info, 0, sizeof(*info));
174 if (pathlen && base[pathlen-1] == '/')
175 pathlen--;
176 info->pathlen = pathlen ? pathlen + 1 : 0;
177 info->name.path = base;
7d924c91 178 info->name.oid = (void *)(base + pathlen + 1);
bcbe5a51
LT
179 if (pathlen)
180 info->prev = &dummy;
40d934df
LT
181}
182
183char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
184{
0de16337 185 int len = tree_entry_len(n);
40d934df
LT
186 int pathlen = info->pathlen;
187
188 path[pathlen + len] = 0;
189 for (;;) {
190 memcpy(path + pathlen, n->path, len);
191 if (!pathlen)
192 break;
193 path[--pathlen] = '/';
194 n = &info->name;
0de16337 195 len = tree_entry_len(n);
40d934df
LT
196 info = info->prev;
197 pathlen -= len;
198 }
199 return path;
200}
201
1ee26571
JH
202struct tree_desc_skip {
203 struct tree_desc_skip *prev;
204 const void *ptr;
205};
206
207struct tree_desc_x {
208 struct tree_desc d;
209 struct tree_desc_skip *skip;
210};
211
1ee26571
JH
212static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
213{
214 /*
215 * The caller wants to pick *a* from a tree or nothing.
216 * We are looking at *b* in a tree.
217 *
218 * (0) If a and b are the same name, we are trivially happy.
219 *
220 * There are three possibilities where *a* could be hiding
221 * behind *b*.
222 *
223 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
224 * matter what.
225 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
226 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
227 *
228 * Otherwise we know *a* won't appear in the tree without
229 * scanning further.
230 */
231
232 int cmp = name_compare(a, a_len, b, b_len);
233
234 /* Most common case first -- reading sync'd trees */
235 if (!cmp)
236 return cmp;
237
238 if (0 < cmp) {
239 /* a comes after b; it does not matter if it is case (3)
240 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
241 return 1;
242 */
243 return 1; /* keep looking */
244 }
245
246 /* b comes after a; are we looking at case (2)? */
247 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
248 return 1; /* keep looking */
249
250 return -1; /* a cannot appear in the tree */
251}
252
253/*
254 * From the extended tree_desc, extract the first name entry, while
255 * paying attention to the candidate "first" name. Most importantly,
256 * when looking for an entry, if there are entries that sorts earlier
257 * in the tree object representation than that name, skip them and
258 * process the named entry first. We will remember that we haven't
259 * processed the first entry yet, and in the later call skip the
260 * entry we processed early when update_extended_entry() is called.
261 *
262 * E.g. if the underlying tree object has these entries:
263 *
264 * blob "t-1"
265 * blob "t-2"
266 * tree "t"
267 * blob "t=1"
268 *
269 * and the "first" asks for "t", remember that we still need to
270 * process "t-1" and "t-2" but extract "t". After processing the
271 * entry "t" from this call, the caller will let us know by calling
272 * update_extended_entry() that we can remember "t" has been processed
273 * already.
274 */
275
276static void extended_entry_extract(struct tree_desc_x *t,
277 struct name_entry *a,
278 const char *first,
279 int first_len)
280{
281 const char *path;
282 int len;
283 struct tree_desc probe;
284 struct tree_desc_skip *skip;
285
286 /*
287 * Extract the first entry from the tree_desc, but skip the
288 * ones that we already returned in earlier rounds.
289 */
290 while (1) {
291 if (!t->d.size) {
292 entry_clear(a);
293 break; /* not found */
294 }
295 entry_extract(&t->d, a);
296 for (skip = t->skip; skip; skip = skip->prev)
297 if (a->path == skip->ptr)
298 break; /* found */
299 if (!skip)
300 break;
301 /* We have processed this entry already. */
302 update_tree_entry(&t->d);
303 }
304
305 if (!first || !a->path)
306 return;
307
308 /*
309 * The caller wants "first" from this tree, or nothing.
310 */
311 path = a->path;
0de16337 312 len = tree_entry_len(a);
1ee26571
JH
313 switch (check_entry_match(first, first_len, path, len)) {
314 case -1:
315 entry_clear(a);
316 case 0:
317 return;
318 default:
319 break;
320 }
321
322 /*
323 * We need to look-ahead -- we suspect that a subtree whose
324 * name is "first" may be hiding behind the current entry "path".
325 */
326 probe = t->d;
327 while (probe.size) {
328 entry_extract(&probe, a);
329 path = a->path;
0de16337 330 len = tree_entry_len(a);
1ee26571
JH
331 switch (check_entry_match(first, first_len, path, len)) {
332 case -1:
333 entry_clear(a);
334 case 0:
335 return;
336 default:
337 update_tree_entry(&probe);
338 break;
339 }
340 /* keep looking */
341 }
342 entry_clear(a);
343}
344
345static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
346{
347 if (t->d.entry.path == a->path) {
348 update_tree_entry(&t->d);
349 } else {
350 /* we have returned this entry early */
351 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
352 skip->ptr = a->path;
353 skip->prev = t->skip;
354 t->skip = skip;
355 }
356}
357
358static void free_extended_entry(struct tree_desc_x *t)
359{
360 struct tree_desc_skip *p, *s;
361
362 for (s = t->skip; s; s = p) {
363 p = s->prev;
364 free(s);
365 }
366}
367
67022e02
NTND
368static inline int prune_traversal(struct index_state *istate,
369 struct name_entry *e,
2842c0f9
JH
370 struct traverse_info *info,
371 struct strbuf *base,
372 int still_interesting)
373{
374 if (!info->pathspec || still_interesting == 2)
375 return 2;
376 if (still_interesting < 0)
377 return still_interesting;
67022e02
NTND
378 return tree_entry_interesting(istate, e, base,
379 0, info->pathspec);
2842c0f9
JH
380}
381
67022e02
NTND
382int traverse_trees(struct index_state *istate,
383 int n, struct tree_desc *t,
384 struct traverse_info *info)
1b0c7174 385{
e6c111b4 386 int error = 0;
1b0c7174 387 struct name_entry *entry = xmalloc(n*sizeof(*entry));
1ee26571
JH
388 int i;
389 struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
2842c0f9
JH
390 struct strbuf base = STRBUF_INIT;
391 int interesting = 1;
d9c2bd56 392 char *traverse_path;
1ee26571
JH
393
394 for (i = 0; i < n; i++)
395 tx[i].d = t[i];
1b0c7174 396
2842c0f9
JH
397 if (info->prev) {
398 strbuf_grow(&base, info->pathlen);
399 make_traverse_path(base.buf, info->prev, &info->name);
400 base.buf[info->pathlen-1] = '/';
401 strbuf_setlen(&base, info->pathlen);
d9c2bd56
DT
402 traverse_path = xstrndup(base.buf, info->pathlen);
403 } else {
404 traverse_path = xstrndup(info->name.path, info->pathlen);
2842c0f9 405 }
d9c2bd56 406 info->traverse_path = traverse_path;
1b0c7174 407 for (;;) {
a04f8196 408 int trees_used;
1ee26571
JH
409 unsigned long mask, dirmask;
410 const char *first = NULL;
411 int first_len = 0;
27c0f768 412 struct name_entry *e = NULL;
1ee26571
JH
413 int len;
414
415 for (i = 0; i < n; i++) {
416 e = entry + i;
417 extended_entry_extract(tx + i, e, NULL, 0);
418 }
1b0c7174 419
1ee26571
JH
420 /*
421 * A tree may have "t-2" at the current location even
422 * though it may have "t" that is a subtree behind it,
423 * and another tree may return "t". We want to grab
424 * all "t" from all trees to match in such a case.
425 */
1b0c7174 426 for (i = 0; i < n; i++) {
1ee26571
JH
427 e = entry + i;
428 if (!e->path)
1b0c7174 429 continue;
0de16337 430 len = tree_entry_len(e);
1ee26571
JH
431 if (!first) {
432 first = e->path;
433 first_len = len;
434 continue;
435 }
436 if (name_compare(e->path, len, first, first_len) < 0) {
437 first = e->path;
438 first_len = len;
439 }
440 }
441
442 if (first) {
443 for (i = 0; i < n; i++) {
444 e = entry + i;
445 extended_entry_extract(tx + i, e, first, first_len);
446 /* Cull the ones that are not the earliest */
447 if (!e->path)
1b0c7174 448 continue;
0de16337 449 len = tree_entry_len(e);
1ee26571
JH
450 if (name_compare(e->path, len, first, first_len))
451 entry_clear(e);
1b0c7174 452 }
1ee26571
JH
453 }
454
455 /* Now we have in entry[i] the earliest name from the trees */
456 mask = 0;
457 dirmask = 0;
458 for (i = 0; i < n; i++) {
459 if (!entry[i].path)
460 continue;
1b0c7174 461 mask |= 1ul << i;
91e4f036
LT
462 if (S_ISDIR(entry[i].mode))
463 dirmask |= 1ul << i;
2842c0f9 464 e = &entry[i];
1b0c7174
JH
465 }
466 if (!mask)
467 break;
67022e02 468 interesting = prune_traversal(istate, e, info, &base, interesting);
2842c0f9
JH
469 if (interesting < 0)
470 break;
471 if (interesting) {
a04f8196
SB
472 trees_used = info->fn(n, mask, dirmask, entry, info);
473 if (trees_used < 0) {
474 error = trees_used;
2842c0f9
JH
475 if (!info->show_all_errors)
476 break;
477 }
a04f8196 478 mask &= trees_used;
e6c111b4 479 }
1ee26571 480 for (i = 0; i < n; i++)
5803c6f8 481 if (mask & (1ul << i))
1ee26571 482 update_extended_entry(tx + i, entry + i);
1b0c7174
JH
483 }
484 free(entry);
1ee26571
JH
485 for (i = 0; i < n; i++)
486 free_extended_entry(tx + i);
487 free(tx);
d9c2bd56
DT
488 free(traverse_path);
489 info->traverse_path = NULL;
2842c0f9 490 strbuf_release(&base);
e6c111b4 491 return error;
1b0c7174
JH
492}
493
275721c2
DT
494struct dir_state {
495 void *tree;
496 unsigned long size;
3b683bcf 497 struct object_id oid;
275721c2
DT
498};
499
916bc35b 500static int find_tree_entry(struct tree_desc *t, const char *name, struct object_id *result, unsigned *mode)
4dcff634
JH
501{
502 int namelen = strlen(name);
503 while (t->size) {
504 const char *entry;
ce6663a9 505 const struct object_id *oid;
4dcff634
JH
506 int entrylen, cmp;
507
ce6663a9 508 oid = tree_entry_extract(t, &entry, mode);
0de16337 509 entrylen = tree_entry_len(&t->entry);
4dcff634 510 update_tree_entry(t);
4dcff634
JH
511 if (entrylen > namelen)
512 continue;
513 cmp = memcmp(name, entry, entrylen);
514 if (cmp > 0)
515 continue;
516 if (cmp < 0)
517 break;
518 if (entrylen == namelen) {
916bc35b 519 oidcpy(result, oid);
4dcff634
JH
520 return 0;
521 }
522 if (name[entrylen] != '/')
523 continue;
524 if (!S_ISDIR(*mode))
525 break;
526 if (++entrylen == namelen) {
916bc35b 527 oidcpy(result, oid);
4dcff634
JH
528 return 0;
529 }
916bc35b 530 return get_tree_entry(oid, name + entrylen, result, mode);
4dcff634
JH
531 }
532 return -1;
533}
534
916bc35b 535int get_tree_entry(const struct object_id *tree_oid, const char *name, struct object_id *oid, unsigned *mode)
4dcff634
JH
536{
537 int retval;
538 void *tree;
6fda5e51 539 unsigned long size;
916bc35b 540 struct object_id root;
4dcff634 541
02f0547e 542 tree = read_object_with_reference(tree_oid, tree_type, &size, &root);
4dcff634
JH
543 if (!tree)
544 return -1;
d93b7d1c
JK
545
546 if (name[0] == '\0') {
916bc35b 547 oidcpy(oid, &root);
ef006503 548 free(tree);
d93b7d1c
JK
549 return 0;
550 }
551
5fb8c05f
JH
552 if (!size) {
553 retval = -1;
554 } else {
555 struct tree_desc t;
556 init_tree_desc(&t, tree, size);
916bc35b 557 retval = find_tree_entry(&t, name, oid, mode);
5fb8c05f 558 }
4dcff634
JH
559 free(tree);
560 return retval;
561}
2c389fc8 562
275721c2
DT
563/*
564 * This is Linux's built-in max for the number of symlinks to follow.
565 * That limit, of course, does not affect git, but it's a reasonable
566 * choice.
567 */
568#define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
569
570/**
571 * Find a tree entry by following symlinks in tree_sha (which is
572 * assumed to be the root of the repository). In the event that a
573 * symlink points outside the repository (e.g. a link to /foo or a
574 * root-level link to ../foo), the portion of the link which is
575 * outside the repository will be returned in result_path, and *mode
576 * will be set to 0. It is assumed that result_path is uninitialized.
577 * If there are no symlinks, or the end result of the symlink chain
578 * points to an object inside the repository, result will be filled in
579 * with the sha1 of the found object, and *mode will hold the mode of
580 * the object.
581 *
582 * See the code for enum follow_symlink_result for a description of
583 * the return values.
584 */
3b683bcf 585enum follow_symlinks_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned *mode)
275721c2
DT
586{
587 int retval = MISSING_OBJECT;
588 struct dir_state *parents = NULL;
589 size_t parents_alloc = 0;
071bcaab 590 size_t i, parents_nr = 0;
0d4a8b5b 591 struct object_id current_tree_oid;
275721c2
DT
592 struct strbuf namebuf = STRBUF_INIT;
593 struct tree_desc t;
594 int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
275721c2
DT
595
596 init_tree_desc(&t, NULL, 0UL);
275721c2 597 strbuf_addstr(&namebuf, name);
3b683bcf 598 oidcpy(&current_tree_oid, tree_oid);
275721c2
DT
599
600 while (1) {
601 int find_result;
602 char *first_slash;
603 char *remainder = NULL;
604
605 if (!t.buffer) {
606 void *tree;
0d4a8b5b 607 struct object_id root;
275721c2 608 unsigned long size;
02f0547e 609 tree = read_object_with_reference(&current_tree_oid,
275721c2 610 tree_type, &size,
02f0547e 611 &root);
275721c2
DT
612 if (!tree)
613 goto done;
614
615 ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
616 parents[parents_nr].tree = tree;
617 parents[parents_nr].size = size;
3b683bcf 618 oidcpy(&parents[parents_nr].oid, &root);
275721c2
DT
619 parents_nr++;
620
621 if (namebuf.buf[0] == '\0') {
3b683bcf 622 oidcpy(result, &root);
275721c2
DT
623 retval = FOUND;
624 goto done;
625 }
626
627 if (!size)
628 goto done;
629
630 /* descend */
631 init_tree_desc(&t, tree, size);
632 }
633
634 /* Handle symlinks to e.g. a//b by removing leading slashes */
635 while (namebuf.buf[0] == '/') {
636 strbuf_remove(&namebuf, 0, 1);
637 }
638
639 /* Split namebuf into a first component and a remainder */
640 if ((first_slash = strchr(namebuf.buf, '/'))) {
641 *first_slash = 0;
642 remainder = first_slash + 1;
643 }
644
645 if (!strcmp(namebuf.buf, "..")) {
646 struct dir_state *parent;
647 /*
648 * We could end up with .. in the namebuf if it
649 * appears in a symlink.
650 */
651
652 if (parents_nr == 1) {
653 if (remainder)
654 *first_slash = '/';
655 strbuf_add(result_path, namebuf.buf,
656 namebuf.len);
657 *mode = 0;
658 retval = FOUND;
659 goto done;
660 }
661 parent = &parents[parents_nr - 1];
662 free(parent->tree);
663 parents_nr--;
664 parent = &parents[parents_nr - 1];
665 init_tree_desc(&t, parent->tree, parent->size);
666 strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
667 continue;
668 }
669
670 /* We could end up here via a symlink to dir/.. */
671 if (namebuf.buf[0] == '\0') {
3b683bcf 672 oidcpy(result, &parents[parents_nr - 1].oid);
275721c2
DT
673 retval = FOUND;
674 goto done;
675 }
676
677 /* Look up the first (or only) path component in the tree. */
678 find_result = find_tree_entry(&t, namebuf.buf,
916bc35b 679 &current_tree_oid, mode);
275721c2
DT
680 if (find_result) {
681 goto done;
682 }
683
684 if (S_ISDIR(*mode)) {
685 if (!remainder) {
3b683bcf 686 oidcpy(result, &current_tree_oid);
275721c2
DT
687 retval = FOUND;
688 goto done;
689 }
690 /* Descend the tree */
691 t.buffer = NULL;
692 strbuf_remove(&namebuf, 0,
693 1 + first_slash - namebuf.buf);
694 } else if (S_ISREG(*mode)) {
695 if (!remainder) {
3b683bcf 696 oidcpy(result, &current_tree_oid);
275721c2
DT
697 retval = FOUND;
698 } else {
699 retval = NOT_DIR;
700 }
701 goto done;
702 } else if (S_ISLNK(*mode)) {
703 /* Follow a symlink */
704 unsigned long link_len;
705 size_t len;
706 char *contents, *contents_start;
707 struct dir_state *parent;
708 enum object_type type;
709
710 if (follows_remaining-- == 0) {
711 /* Too many symlinks followed */
712 retval = SYMLINK_LOOP;
713 goto done;
714 }
715
716 /*
717 * At this point, we have followed at a least
718 * one symlink, so on error we need to report this.
719 */
720 retval = DANGLING_SYMLINK;
721
b4f5aca4 722 contents = read_object_file(&current_tree_oid, &type,
723 &link_len);
275721c2
DT
724
725 if (!contents)
726 goto done;
727
728 if (contents[0] == '/') {
729 strbuf_addstr(result_path, contents);
730 free(contents);
731 *mode = 0;
732 retval = FOUND;
733 goto done;
734 }
735
736 if (remainder)
737 len = first_slash - namebuf.buf;
738 else
739 len = namebuf.len;
740
741 contents_start = contents;
742
743 parent = &parents[parents_nr - 1];
744 init_tree_desc(&t, parent->tree, parent->size);
745 strbuf_splice(&namebuf, 0, len,
746 contents_start, link_len);
747 if (remainder)
748 namebuf.buf[link_len] = '/';
749 free(contents);
750 }
751 }
752done:
753 for (i = 0; i < parents_nr; i++)
754 free(parents[i].tree);
755 free(parents);
756
757 strbuf_release(&namebuf);
758 return retval;
759}
760
93d93537
NTND
761static int match_entry(const struct pathspec_item *item,
762 const struct name_entry *entry, int pathlen,
58c4d666 763 const char *match, int matchlen,
c3a47ca9 764 enum interesting *never_interesting)
58c4d666
NTND
765{
766 int m = -1; /* signals that we haven't called strncmp() */
767
93d93537
NTND
768 if (item->magic & PATHSPEC_ICASE)
769 /*
770 * "Never interesting" trick requires exact
771 * matching. We could do something clever with inexact
772 * matching, but it's trickier (and not to forget that
773 * strcasecmp is locale-dependent, at least in
774 * glibc). Just disable it for now. It can't be worse
775 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
776 * pattern.
777 */
778 *never_interesting = entry_not_interesting;
779 else if (*never_interesting != entry_not_interesting) {
58c4d666
NTND
780 /*
781 * We have not seen any match that sorts later
782 * than the current path.
783 */
784
785 /*
786 * Does match sort strictly earlier than path
787 * with their common parts?
788 */
789 m = strncmp(match, entry->path,
790 (matchlen < pathlen) ? matchlen : pathlen);
791 if (m < 0)
792 return 0;
793
794 /*
795 * If we come here even once, that means there is at
796 * least one pathspec that would sort equal to or
797 * later than the path we are currently looking at.
798 * In other words, if we have never reached this point
799 * after iterating all pathspecs, it means all
800 * pathspecs are either outside of base, or inside the
801 * base but sorts strictly earlier than the current
802 * one. In either case, they will never match the
803 * subsequent entries. In such a case, we initialized
804 * the variable to -1 and that is what will be
805 * returned, allowing the caller to terminate early.
806 */
c3a47ca9 807 *never_interesting = entry_not_interesting;
58c4d666
NTND
808 }
809
810 if (pathlen > matchlen)
811 return 0;
812
813 if (matchlen > pathlen) {
814 if (match[pathlen] != '/')
815 return 0;
74b4f7f2 816 if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode))
58c4d666
NTND
817 return 0;
818 }
819
820 if (m == -1)
821 /*
822 * we cheated and did not do strncmp(), so we do
823 * that here.
824 */
93d93537 825 m = ps_strncmp(item, match, entry->path, pathlen);
58c4d666
NTND
826
827 /*
828 * If common part matched earlier then it is a hit,
829 * because we rejected the case where path is not a
830 * leading directory and is shorter than match.
831 */
832 if (!m)
93d93537
NTND
833 /*
834 * match_entry does not check if the prefix part is
835 * matched case-sensitively. If the entry is a
836 * directory and part of prefix, it'll be rematched
837 * eventually by basecmp with special treatment for
838 * the prefix.
839 */
58c4d666
NTND
840 return 1;
841
842 return 0;
843}
844
93d93537
NTND
845/* :(icase)-aware string compare */
846static int basecmp(const struct pathspec_item *item,
847 const char *base, const char *match, int len)
848{
849 if (item->magic & PATHSPEC_ICASE) {
850 int ret, n = len > item->prefix ? item->prefix : len;
851 ret = strncmp(base, match, n);
852 if (ret)
853 return ret;
854 base += n;
855 match += n;
856 len -= n;
857 }
858 return ps_strncmp(item, base, match, len);
859}
860
861static int match_dir_prefix(const struct pathspec_item *item,
862 const char *base,
58c4d666
NTND
863 const char *match, int matchlen)
864{
93d93537 865 if (basecmp(item, base, match, matchlen))
58c4d666
NTND
866 return 0;
867
868 /*
869 * If the base is a subdirectory of a path which
870 * was specified, all of them are interesting.
871 */
872 if (!matchlen ||
873 base[matchlen] == '/' ||
874 match[matchlen - 1] == '/')
875 return 1;
876
877 /* Just a random prefix match */
878 return 0;
879}
880
c904cd89
NTND
881/*
882 * Perform matching on the leading non-wildcard part of
883 * pathspec. item->nowildcard_len must be greater than zero. Return
884 * non-zero if base is matched.
885 */
886static int match_wildcard_base(const struct pathspec_item *item,
887 const char *base, int baselen,
888 int *matched)
889{
890 const char *match = item->match;
891 /* the wildcard part is not considered in this function */
892 int matchlen = item->nowildcard_len;
893
894 if (baselen) {
895 int dirlen;
896 /*
897 * Return early if base is longer than the
898 * non-wildcard part but it does not match.
899 */
900 if (baselen >= matchlen) {
901 *matched = matchlen;
93d93537 902 return !basecmp(item, base, match, matchlen);
c904cd89
NTND
903 }
904
905 dirlen = matchlen;
906 while (dirlen && match[dirlen - 1] != '/')
907 dirlen--;
908
909 /*
910 * Return early if base is shorter than the
911 * non-wildcard part but it does not match. Note that
912 * base ends with '/' so we are sure it really matches
913 * directory
914 */
93d93537 915 if (basecmp(item, base, match, baselen))
c904cd89
NTND
916 return 0;
917 *matched = baselen;
918 } else
919 *matched = 0;
920 /*
921 * we could have checked entry against the non-wildcard part
922 * that is not in base and does similar never_interesting
923 * optimization as in match_entry. For now just be happy with
924 * base comparison.
925 */
926 return entry_interesting;
927}
928
2c389fc8
NTND
929/*
930 * Is a tree entry interesting given the pathspec we have?
931 *
1376e507
NTND
932 * Pre-condition: either baselen == base_offset (i.e. empty path)
933 * or base[baselen-1] == '/' (i.e. with trailing slash).
2c389fc8 934 */
67022e02
NTND
935static enum interesting do_match(struct index_state *istate,
936 const struct name_entry *entry,
ef79b1f8
NTND
937 struct strbuf *base, int base_offset,
938 const struct pathspec *ps,
939 int exclude)
2c389fc8
NTND
940{
941 int i;
1376e507 942 int pathlen, baselen = base->len - base_offset;
c3a47ca9 943 enum interesting never_interesting = ps->has_wildcard ?
d688cf07 944 entry_not_interesting : all_entries_not_interesting;
2c389fc8 945
5c6933d2
NTND
946 GUARD_PATHSPEC(ps,
947 PATHSPEC_FROMTOP |
948 PATHSPEC_MAXDEPTH |
bd30c2e4 949 PATHSPEC_LITERAL |
93d93537 950 PATHSPEC_GLOB |
ef79b1f8
NTND
951 PATHSPEC_ICASE |
952 PATHSPEC_EXCLUDE);
8f4f8f45 953
bc96cc87 954 if (!ps->nr) {
6330a171
NTND
955 if (!ps->recursive ||
956 !(ps->magic & PATHSPEC_MAXDEPTH) ||
957 ps->max_depth == -1)
d688cf07
NTND
958 return all_entries_interesting;
959 return within_depth(base->buf + base_offset, baselen,
960 !!S_ISDIR(entry->mode),
961 ps->max_depth) ?
962 entry_interesting : entry_not_interesting;
bc96cc87 963 }
2c389fc8 964
0de16337 965 pathlen = tree_entry_len(entry);
2c389fc8 966
1376e507 967 for (i = ps->nr - 1; i >= 0; i--) {
2c389fc8
NTND
968 const struct pathspec_item *item = ps->items+i;
969 const char *match = item->match;
1376e507 970 const char *base_str = base->buf + base_offset;
c904cd89 971 int matchlen = item->len, matched = 0;
2c389fc8 972
ef79b1f8
NTND
973 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
974 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
975 continue;
976
2c389fc8
NTND
977 if (baselen >= matchlen) {
978 /* If it doesn't match, move along... */
93d93537 979 if (!match_dir_prefix(item, base_str, match, matchlen))
d38f2809 980 goto match_wildcards;
bc96cc87 981
6330a171
NTND
982 if (!ps->recursive ||
983 !(ps->magic & PATHSPEC_MAXDEPTH) ||
984 ps->max_depth == -1)
d688cf07 985 return all_entries_interesting;
bc96cc87 986
d688cf07
NTND
987 return within_depth(base_str + matchlen + 1,
988 baselen - matchlen - 1,
989 !!S_ISDIR(entry->mode),
990 ps->max_depth) ?
991 entry_interesting : entry_not_interesting;
2c389fc8
NTND
992 }
993
1b740923 994 /* Either there must be no base, or the base must match. */
93d93537
NTND
995 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
996 if (match_entry(item, entry, pathlen,
58c4d666
NTND
997 match + baselen, matchlen - baselen,
998 &never_interesting))
d688cf07 999 return entry_interesting;
f1a2ddbb 1000
170260ae 1001 if (item->nowildcard_len < item->len) {
bd30c2e4 1002 if (!git_fnmatch(item, match + baselen, entry->path,
8c6abbcd 1003 item->nowildcard_len - baselen))
d688cf07 1004 return entry_interesting;
f1a2ddbb
NTND
1005
1006 /*
1007 * Match all directories. We'll try to
1008 * match files later on.
1009 */
1010 if (ps->recursive && S_ISDIR(entry->mode))
d688cf07 1011 return entry_interesting;
74ed4371
BW
1012
1013 /*
1014 * When matching against submodules with
1015 * wildcard characters, ensure that the entry
1016 * at least matches up to the first wild
1017 * character. More accurate matching can then
1018 * be performed in the submodule itself.
1019 */
eef3df5a
BW
1020 if (ps->recurse_submodules &&
1021 S_ISGITLINK(entry->mode) &&
74ed4371
BW
1022 !ps_strncmp(item, match + baselen,
1023 entry->path,
1024 item->nowildcard_len - baselen))
1025 return entry_interesting;
f1a2ddbb
NTND
1026 }
1027
1028 continue;
2c389fc8 1029 }
d38f2809
NTND
1030
1031match_wildcards:
170260ae 1032 if (item->nowildcard_len == item->len)
d38f2809
NTND
1033 continue;
1034
c904cd89
NTND
1035 if (item->nowildcard_len &&
1036 !match_wildcard_base(item, base_str, baselen, &matched))
e4ddb057 1037 continue;
c904cd89 1038
d38f2809
NTND
1039 /*
1040 * Concatenate base and entry->path into one and do
1041 * fnmatch() on it.
c904cd89
NTND
1042 *
1043 * While we could avoid concatenation in certain cases
1044 * [1], which saves a memcpy and potentially a
1045 * realloc, it turns out not worth it. Measurement on
1046 * linux-2.6 does not show any clear improvements,
1047 * partly because of the nowildcard_len optimization
1048 * in git_fnmatch(). Avoid micro-optimizations here.
1049 *
1050 * [1] if match_wildcard_base() says the base
1051 * directory is already matched, we only need to match
1052 * the rest, which is shorter so _in theory_ faster.
d38f2809
NTND
1053 */
1054
1055 strbuf_add(base, entry->path, pathlen);
1056
bd30c2e4 1057 if (!git_fnmatch(item, match, base->buf + base_offset,
8c6abbcd 1058 item->nowildcard_len)) {
1376e507 1059 strbuf_setlen(base, base_offset + baselen);
d688cf07 1060 return entry_interesting;
d38f2809 1061 }
74ed4371
BW
1062
1063 /*
1064 * When matching against submodules with
1065 * wildcard characters, ensure that the entry
1066 * at least matches up to the first wild
1067 * character. More accurate matching can then
1068 * be performed in the submodule itself.
1069 */
eef3df5a 1070 if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
74ed4371
BW
1071 !ps_strncmp(item, match, base->buf + base_offset,
1072 item->nowildcard_len)) {
1073 strbuf_setlen(base, base_offset + baselen);
1074 return entry_interesting;
1075 }
1076
1376e507 1077 strbuf_setlen(base, base_offset + baselen);
d38f2809
NTND
1078
1079 /*
1080 * Match all directories. We'll try to match files
1081 * later on.
8c69c1f9
NTND
1082 * max_depth is ignored but we may consider support it
1083 * in future, see
5840eb9d 1084 * https://public-inbox.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
d38f2809
NTND
1085 */
1086 if (ps->recursive && S_ISDIR(entry->mode))
d688cf07 1087 return entry_interesting;
2c389fc8
NTND
1088 }
1089 return never_interesting; /* No matches */
1090}
ef79b1f8
NTND
1091
1092/*
1093 * Is a tree entry interesting given the pathspec we have?
1094 *
1095 * Pre-condition: either baselen == base_offset (i.e. empty path)
1096 * or base[baselen-1] == '/' (i.e. with trailing slash).
1097 */
67022e02
NTND
1098enum interesting tree_entry_interesting(struct index_state *istate,
1099 const struct name_entry *entry,
ef79b1f8
NTND
1100 struct strbuf *base, int base_offset,
1101 const struct pathspec *ps)
1102{
1103 enum interesting positive, negative;
67022e02 1104 positive = do_match(istate, entry, base, base_offset, ps, 0);
ef79b1f8
NTND
1105
1106 /*
1107 * case | entry | positive | negative | result
1108 * -----+-------+----------+----------+-------
1109 * 1 | file | -1 | -1..2 | -1
1110 * 2 | file | 0 | -1..2 | 0
1111 * 3 | file | 1 | -1 | 1
1112 * 4 | file | 1 | 0 | 1
1113 * 5 | file | 1 | 1 | 0
1114 * 6 | file | 1 | 2 | 0
1115 * 7 | file | 2 | -1 | 2
b7845ceb 1116 * 8 | file | 2 | 0 | 1
ef79b1f8
NTND
1117 * 9 | file | 2 | 1 | 0
1118 * 10 | file | 2 | 2 | -1
1119 * -----+-------+----------+----------+-------
1120 * 11 | dir | -1 | -1..2 | -1
1121 * 12 | dir | 0 | -1..2 | 0
1122 * 13 | dir | 1 | -1 | 1
1123 * 14 | dir | 1 | 0 | 1
1124 * 15 | dir | 1 | 1 | 1 (*)
1125 * 16 | dir | 1 | 2 | 0
1126 * 17 | dir | 2 | -1 | 2
b7845ceb 1127 * 18 | dir | 2 | 0 | 1
ef79b1f8
NTND
1128 * 19 | dir | 2 | 1 | 1 (*)
1129 * 20 | dir | 2 | 2 | -1
1130 *
1131 * (*) An exclude pattern interested in a directory does not
1132 * necessarily mean it will exclude all of the directory. In
1133 * wildcard case, it can't decide until looking at individual
1134 * files inside. So don't write such directories off yet.
1135 */
1136
1137 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
1138 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
1139 return positive;
1140
67022e02 1141 negative = do_match(istate, entry, base, base_offset, ps, 1);
ef79b1f8 1142
b7845ceb
NTND
1143 /* #8, #18 */
1144 if (positive == all_entries_interesting &&
1145 negative == entry_not_interesting)
1146 return entry_interesting;
1147
1148 /* #3, #4, #7, #13, #14, #17 */
ef79b1f8
NTND
1149 if (negative <= entry_not_interesting)
1150 return positive;
1151
1152 /* #15, #19 */
1153 if (S_ISDIR(entry->mode) &&
1154 positive >= entry_interesting &&
1155 negative == entry_interesting)
1156 return entry_interesting;
1157
1158 if ((positive == entry_interesting &&
1159 negative >= entry_interesting) || /* #5, #6, #16 */
1160 (positive == all_entries_interesting &&
1161 negative == entry_interesting)) /* #9 */
1162 return entry_not_interesting;
1163
1164 return all_entries_not_interesting; /* #10, #20 */
1165}