promisor-remote: skip move_to_tail when no-op
[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);
ea82b2a0 51 desc->entry.pathlen = len - 1;
52 hashcpy(desc->entry.oid.hash, (const unsigned char *)path + len);
8354fa3d
DT
53
54 return 0;
4651ece8
LT
55}
56
8354fa3d 57static int init_tree_desc_internal(struct tree_desc *desc, const void *buffer, unsigned long size, struct strbuf *err)
6fda5e51
LT
58{
59 desc->buffer = buffer;
60 desc->size = size;
4651ece8 61 if (size)
8354fa3d
DT
62 return decode_tree_entry(desc, buffer, size, err);
63 return 0;
64}
65
66void 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
74int 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;
6fda5e51
LT
82}
83
5c377d3d 84void *fill_tree_descriptor(struct tree_desc *desc, const struct object_id *oid)
1b0c7174
JH
85{
86 unsigned long size = 0;
87 void *buf = NULL;
88
5c377d3d 89 if (oid) {
02f0547e 90 buf = read_object_with_reference(oid, tree_type, &size, NULL);
1b0c7174 91 if (!buf)
5c377d3d 92 die("unable to read tree %s", oid_to_hex(oid));
1b0c7174 93 }
6fda5e51 94 init_tree_desc(desc, buf, size);
1b0c7174
JH
95 return buf;
96}
97
1b0c7174
JH
98static void entry_clear(struct name_entry *a)
99{
100 memset(a, 0, sizeof(*a));
101}
102
103static void entry_extract(struct tree_desc *t, struct name_entry *a)
104{
4651ece8 105 *a = t->entry;
1b0c7174
JH
106}
107
8354fa3d 108static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
1b0c7174 109{
6fda5e51 110 const void *buf = desc->buffer;
ea82b2a0 111 const unsigned char *end = (const unsigned char *)desc->entry.path + desc->entry.pathlen + 1 + the_hash_algo->rawsz;
1b0c7174 112 unsigned long size = desc->size;
4651ece8 113 unsigned long len = end - (const unsigned char *)buf;
1b0c7174
JH
114
115 if (size < len)
2edffef2 116 die(_("too-short tree file"));
4651ece8
LT
117 buf = end;
118 size -= len;
119 desc->buffer = buf;
120 desc->size = size;
121 if (size)
8354fa3d
DT
122 return decode_tree_entry(desc, buf, size, err);
123 return 0;
124}
125
126void update_tree_entry(struct tree_desc *desc)
127{
128 struct strbuf err = STRBUF_INIT;
129 if (update_tree_entry_internal(desc, &err))
130 die("%s", err.buf);
131 strbuf_release(&err);
132}
133
134int update_tree_entry_gently(struct tree_desc *desc)
135{
136 struct strbuf err = STRBUF_INIT;
137 if (update_tree_entry_internal(desc, &err)) {
138 error("%s", err.buf);
139 strbuf_release(&err);
140 /* Stop processing this tree after error */
141 desc->size = 0;
142 return -1;
143 }
144 strbuf_release(&err);
145 return 0;
1b0c7174
JH
146}
147
4c068a98
LT
148int tree_entry(struct tree_desc *desc, struct name_entry *entry)
149{
4651ece8 150 if (!desc->size)
4c068a98
LT
151 return 0;
152
4651ece8
LT
153 *entry = desc->entry;
154 update_tree_entry(desc);
4c068a98
LT
155 return 1;
156}
157
8354fa3d
DT
158int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
159{
160 if (!desc->size)
161 return 0;
162
163 *entry = desc->entry;
164 if (update_tree_entry_gently(desc))
165 return 0;
166 return 1;
167}
168
40d934df
LT
169void setup_traverse_info(struct traverse_info *info, const char *base)
170{
171 int pathlen = strlen(base);
bcbe5a51 172 static struct traverse_info dummy;
40d934df
LT
173
174 memset(info, 0, sizeof(*info));
175 if (pathlen && base[pathlen-1] == '/')
176 pathlen--;
177 info->pathlen = pathlen ? pathlen + 1 : 0;
178 info->name.path = base;
ea82b2a0 179 info->name.pathlen = pathlen;
180 if (pathlen) {
181 hashcpy(info->name.oid.hash, (const unsigned char *)base + pathlen + 1);
bcbe5a51 182 info->prev = &dummy;
ea82b2a0 183 }
40d934df
LT
184}
185
186char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
187{
0de16337 188 int len = tree_entry_len(n);
40d934df
LT
189 int pathlen = info->pathlen;
190
191 path[pathlen + len] = 0;
192 for (;;) {
193 memcpy(path + pathlen, n->path, len);
194 if (!pathlen)
195 break;
196 path[--pathlen] = '/';
197 n = &info->name;
0de16337 198 len = tree_entry_len(n);
40d934df
LT
199 info = info->prev;
200 pathlen -= len;
201 }
202 return path;
203}
204
1ee26571
JH
205struct tree_desc_skip {
206 struct tree_desc_skip *prev;
207 const void *ptr;
208};
209
210struct tree_desc_x {
211 struct tree_desc d;
212 struct tree_desc_skip *skip;
213};
214
1ee26571
JH
215static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
216{
217 /*
218 * The caller wants to pick *a* from a tree or nothing.
219 * We are looking at *b* in a tree.
220 *
221 * (0) If a and b are the same name, we are trivially happy.
222 *
223 * There are three possibilities where *a* could be hiding
224 * behind *b*.
225 *
226 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
227 * matter what.
228 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
229 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
230 *
231 * Otherwise we know *a* won't appear in the tree without
232 * scanning further.
233 */
234
235 int cmp = name_compare(a, a_len, b, b_len);
236
237 /* Most common case first -- reading sync'd trees */
238 if (!cmp)
239 return cmp;
240
241 if (0 < cmp) {
242 /* a comes after b; it does not matter if it is case (3)
243 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
244 return 1;
245 */
246 return 1; /* keep looking */
247 }
248
249 /* b comes after a; are we looking at case (2)? */
250 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
251 return 1; /* keep looking */
252
253 return -1; /* a cannot appear in the tree */
254}
255
256/*
257 * From the extended tree_desc, extract the first name entry, while
258 * paying attention to the candidate "first" name. Most importantly,
259 * when looking for an entry, if there are entries that sorts earlier
260 * in the tree object representation than that name, skip them and
261 * process the named entry first. We will remember that we haven't
262 * processed the first entry yet, and in the later call skip the
263 * entry we processed early when update_extended_entry() is called.
264 *
265 * E.g. if the underlying tree object has these entries:
266 *
267 * blob "t-1"
268 * blob "t-2"
269 * tree "t"
270 * blob "t=1"
271 *
272 * and the "first" asks for "t", remember that we still need to
273 * process "t-1" and "t-2" but extract "t". After processing the
274 * entry "t" from this call, the caller will let us know by calling
275 * update_extended_entry() that we can remember "t" has been processed
276 * already.
277 */
278
279static void extended_entry_extract(struct tree_desc_x *t,
280 struct name_entry *a,
281 const char *first,
282 int first_len)
283{
284 const char *path;
285 int len;
286 struct tree_desc probe;
287 struct tree_desc_skip *skip;
288
289 /*
290 * Extract the first entry from the tree_desc, but skip the
291 * ones that we already returned in earlier rounds.
292 */
293 while (1) {
294 if (!t->d.size) {
295 entry_clear(a);
296 break; /* not found */
297 }
298 entry_extract(&t->d, a);
299 for (skip = t->skip; skip; skip = skip->prev)
300 if (a->path == skip->ptr)
301 break; /* found */
302 if (!skip)
303 break;
304 /* We have processed this entry already. */
305 update_tree_entry(&t->d);
306 }
307
308 if (!first || !a->path)
309 return;
310
311 /*
312 * The caller wants "first" from this tree, or nothing.
313 */
314 path = a->path;
0de16337 315 len = tree_entry_len(a);
1ee26571
JH
316 switch (check_entry_match(first, first_len, path, len)) {
317 case -1:
318 entry_clear(a);
319 case 0:
320 return;
321 default:
322 break;
323 }
324
325 /*
326 * We need to look-ahead -- we suspect that a subtree whose
327 * name is "first" may be hiding behind the current entry "path".
328 */
329 probe = t->d;
330 while (probe.size) {
331 entry_extract(&probe, a);
332 path = a->path;
0de16337 333 len = tree_entry_len(a);
1ee26571
JH
334 switch (check_entry_match(first, first_len, path, len)) {
335 case -1:
336 entry_clear(a);
337 case 0:
338 return;
339 default:
340 update_tree_entry(&probe);
341 break;
342 }
343 /* keep looking */
344 }
345 entry_clear(a);
346}
347
348static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
349{
350 if (t->d.entry.path == a->path) {
351 update_tree_entry(&t->d);
352 } else {
353 /* we have returned this entry early */
354 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
355 skip->ptr = a->path;
356 skip->prev = t->skip;
357 t->skip = skip;
358 }
359}
360
361static void free_extended_entry(struct tree_desc_x *t)
362{
363 struct tree_desc_skip *p, *s;
364
365 for (s = t->skip; s; s = p) {
366 p = s->prev;
367 free(s);
368 }
369}
370
67022e02
NTND
371static inline int prune_traversal(struct index_state *istate,
372 struct name_entry *e,
2842c0f9
JH
373 struct traverse_info *info,
374 struct strbuf *base,
375 int still_interesting)
376{
377 if (!info->pathspec || still_interesting == 2)
378 return 2;
379 if (still_interesting < 0)
380 return still_interesting;
67022e02
NTND
381 return tree_entry_interesting(istate, e, base,
382 0, info->pathspec);
2842c0f9
JH
383}
384
67022e02
NTND
385int traverse_trees(struct index_state *istate,
386 int n, struct tree_desc *t,
387 struct traverse_info *info)
1b0c7174 388{
e6c111b4 389 int error = 0;
1b0c7174 390 struct name_entry *entry = xmalloc(n*sizeof(*entry));
1ee26571
JH
391 int i;
392 struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
2842c0f9
JH
393 struct strbuf base = STRBUF_INIT;
394 int interesting = 1;
d9c2bd56 395 char *traverse_path;
1ee26571
JH
396
397 for (i = 0; i < n; i++)
398 tx[i].d = t[i];
1b0c7174 399
2842c0f9
JH
400 if (info->prev) {
401 strbuf_grow(&base, info->pathlen);
402 make_traverse_path(base.buf, info->prev, &info->name);
403 base.buf[info->pathlen-1] = '/';
404 strbuf_setlen(&base, info->pathlen);
d9c2bd56
DT
405 traverse_path = xstrndup(base.buf, info->pathlen);
406 } else {
407 traverse_path = xstrndup(info->name.path, info->pathlen);
2842c0f9 408 }
d9c2bd56 409 info->traverse_path = traverse_path;
1b0c7174 410 for (;;) {
a04f8196 411 int trees_used;
1ee26571
JH
412 unsigned long mask, dirmask;
413 const char *first = NULL;
414 int first_len = 0;
27c0f768 415 struct name_entry *e = NULL;
1ee26571
JH
416 int len;
417
418 for (i = 0; i < n; i++) {
419 e = entry + i;
420 extended_entry_extract(tx + i, e, NULL, 0);
421 }
1b0c7174 422
1ee26571
JH
423 /*
424 * A tree may have "t-2" at the current location even
425 * though it may have "t" that is a subtree behind it,
426 * and another tree may return "t". We want to grab
427 * all "t" from all trees to match in such a case.
428 */
1b0c7174 429 for (i = 0; i < n; i++) {
1ee26571
JH
430 e = entry + i;
431 if (!e->path)
1b0c7174 432 continue;
0de16337 433 len = tree_entry_len(e);
1ee26571
JH
434 if (!first) {
435 first = e->path;
436 first_len = len;
437 continue;
438 }
439 if (name_compare(e->path, len, first, first_len) < 0) {
440 first = e->path;
441 first_len = len;
442 }
443 }
444
445 if (first) {
446 for (i = 0; i < n; i++) {
447 e = entry + i;
448 extended_entry_extract(tx + i, e, first, first_len);
449 /* Cull the ones that are not the earliest */
450 if (!e->path)
1b0c7174 451 continue;
0de16337 452 len = tree_entry_len(e);
1ee26571
JH
453 if (name_compare(e->path, len, first, first_len))
454 entry_clear(e);
1b0c7174 455 }
1ee26571
JH
456 }
457
458 /* Now we have in entry[i] the earliest name from the trees */
459 mask = 0;
460 dirmask = 0;
461 for (i = 0; i < n; i++) {
462 if (!entry[i].path)
463 continue;
1b0c7174 464 mask |= 1ul << i;
91e4f036
LT
465 if (S_ISDIR(entry[i].mode))
466 dirmask |= 1ul << i;
2842c0f9 467 e = &entry[i];
1b0c7174
JH
468 }
469 if (!mask)
470 break;
67022e02 471 interesting = prune_traversal(istate, e, info, &base, interesting);
2842c0f9
JH
472 if (interesting < 0)
473 break;
474 if (interesting) {
a04f8196
SB
475 trees_used = info->fn(n, mask, dirmask, entry, info);
476 if (trees_used < 0) {
477 error = trees_used;
2842c0f9
JH
478 if (!info->show_all_errors)
479 break;
480 }
a04f8196 481 mask &= trees_used;
e6c111b4 482 }
1ee26571 483 for (i = 0; i < n; i++)
5803c6f8 484 if (mask & (1ul << i))
1ee26571 485 update_extended_entry(tx + i, entry + i);
1b0c7174
JH
486 }
487 free(entry);
1ee26571
JH
488 for (i = 0; i < n; i++)
489 free_extended_entry(tx + i);
490 free(tx);
d9c2bd56
DT
491 free(traverse_path);
492 info->traverse_path = NULL;
2842c0f9 493 strbuf_release(&base);
e6c111b4 494 return error;
1b0c7174
JH
495}
496
275721c2
DT
497struct dir_state {
498 void *tree;
499 unsigned long size;
3b683bcf 500 struct object_id oid;
275721c2
DT
501};
502
5ec1e728 503static int find_tree_entry(struct tree_desc *t, const char *name, struct object_id *result, unsigned short *mode)
4dcff634
JH
504{
505 int namelen = strlen(name);
506 while (t->size) {
507 const char *entry;
0a3faa45 508 struct object_id oid;
4dcff634
JH
509 int entrylen, cmp;
510
0a3faa45 511 oidcpy(&oid, tree_entry_extract(t, &entry, mode));
0de16337 512 entrylen = tree_entry_len(&t->entry);
4dcff634 513 update_tree_entry(t);
4dcff634
JH
514 if (entrylen > namelen)
515 continue;
516 cmp = memcmp(name, entry, entrylen);
517 if (cmp > 0)
518 continue;
519 if (cmp < 0)
520 break;
521 if (entrylen == namelen) {
0a3faa45 522 oidcpy(result, &oid);
4dcff634
JH
523 return 0;
524 }
525 if (name[entrylen] != '/')
526 continue;
527 if (!S_ISDIR(*mode))
528 break;
529 if (++entrylen == namelen) {
0a3faa45 530 oidcpy(result, &oid);
4dcff634
JH
531 return 0;
532 }
0a3faa45 533 return get_tree_entry(&oid, name + entrylen, result, mode);
4dcff634
JH
534 }
535 return -1;
536}
537
5ec1e728 538int get_tree_entry(const struct object_id *tree_oid, const char *name, struct object_id *oid, unsigned short *mode)
4dcff634
JH
539{
540 int retval;
541 void *tree;
6fda5e51 542 unsigned long size;
916bc35b 543 struct object_id root;
4dcff634 544
02f0547e 545 tree = read_object_with_reference(tree_oid, tree_type, &size, &root);
4dcff634
JH
546 if (!tree)
547 return -1;
d93b7d1c
JK
548
549 if (name[0] == '\0') {
916bc35b 550 oidcpy(oid, &root);
ef006503 551 free(tree);
d93b7d1c
JK
552 return 0;
553 }
554
5fb8c05f
JH
555 if (!size) {
556 retval = -1;
557 } else {
558 struct tree_desc t;
559 init_tree_desc(&t, tree, size);
916bc35b 560 retval = find_tree_entry(&t, name, oid, mode);
5fb8c05f 561 }
4dcff634
JH
562 free(tree);
563 return retval;
564}
2c389fc8 565
275721c2
DT
566/*
567 * This is Linux's built-in max for the number of symlinks to follow.
568 * That limit, of course, does not affect git, but it's a reasonable
569 * choice.
570 */
571#define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
572
573/**
574 * Find a tree entry by following symlinks in tree_sha (which is
575 * assumed to be the root of the repository). In the event that a
576 * symlink points outside the repository (e.g. a link to /foo or a
577 * root-level link to ../foo), the portion of the link which is
578 * outside the repository will be returned in result_path, and *mode
579 * will be set to 0. It is assumed that result_path is uninitialized.
580 * If there are no symlinks, or the end result of the symlink chain
581 * points to an object inside the repository, result will be filled in
582 * with the sha1 of the found object, and *mode will hold the mode of
583 * the object.
584 *
d1dd94b3 585 * See the code for enum get_oid_result for a description of
275721c2
DT
586 * the return values.
587 */
5ec1e728 588enum get_oid_result get_tree_entry_follow_symlinks(struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned short *mode)
275721c2
DT
589{
590 int retval = MISSING_OBJECT;
591 struct dir_state *parents = NULL;
592 size_t parents_alloc = 0;
071bcaab 593 size_t i, parents_nr = 0;
0d4a8b5b 594 struct object_id current_tree_oid;
275721c2
DT
595 struct strbuf namebuf = STRBUF_INIT;
596 struct tree_desc t;
597 int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
275721c2
DT
598
599 init_tree_desc(&t, NULL, 0UL);
275721c2 600 strbuf_addstr(&namebuf, name);
3b683bcf 601 oidcpy(&current_tree_oid, tree_oid);
275721c2
DT
602
603 while (1) {
604 int find_result;
605 char *first_slash;
606 char *remainder = NULL;
607
608 if (!t.buffer) {
609 void *tree;
0d4a8b5b 610 struct object_id root;
275721c2 611 unsigned long size;
02f0547e 612 tree = read_object_with_reference(&current_tree_oid,
275721c2 613 tree_type, &size,
02f0547e 614 &root);
275721c2
DT
615 if (!tree)
616 goto done;
617
618 ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
619 parents[parents_nr].tree = tree;
620 parents[parents_nr].size = size;
3b683bcf 621 oidcpy(&parents[parents_nr].oid, &root);
275721c2
DT
622 parents_nr++;
623
624 if (namebuf.buf[0] == '\0') {
3b683bcf 625 oidcpy(result, &root);
275721c2
DT
626 retval = FOUND;
627 goto done;
628 }
629
630 if (!size)
631 goto done;
632
633 /* descend */
634 init_tree_desc(&t, tree, size);
635 }
636
637 /* Handle symlinks to e.g. a//b by removing leading slashes */
638 while (namebuf.buf[0] == '/') {
639 strbuf_remove(&namebuf, 0, 1);
640 }
641
642 /* Split namebuf into a first component and a remainder */
643 if ((first_slash = strchr(namebuf.buf, '/'))) {
644 *first_slash = 0;
645 remainder = first_slash + 1;
646 }
647
648 if (!strcmp(namebuf.buf, "..")) {
649 struct dir_state *parent;
650 /*
651 * We could end up with .. in the namebuf if it
652 * appears in a symlink.
653 */
654
655 if (parents_nr == 1) {
656 if (remainder)
657 *first_slash = '/';
658 strbuf_add(result_path, namebuf.buf,
659 namebuf.len);
660 *mode = 0;
661 retval = FOUND;
662 goto done;
663 }
664 parent = &parents[parents_nr - 1];
665 free(parent->tree);
666 parents_nr--;
667 parent = &parents[parents_nr - 1];
668 init_tree_desc(&t, parent->tree, parent->size);
669 strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
670 continue;
671 }
672
673 /* We could end up here via a symlink to dir/.. */
674 if (namebuf.buf[0] == '\0') {
3b683bcf 675 oidcpy(result, &parents[parents_nr - 1].oid);
275721c2
DT
676 retval = FOUND;
677 goto done;
678 }
679
680 /* Look up the first (or only) path component in the tree. */
681 find_result = find_tree_entry(&t, namebuf.buf,
916bc35b 682 &current_tree_oid, mode);
275721c2
DT
683 if (find_result) {
684 goto done;
685 }
686
687 if (S_ISDIR(*mode)) {
688 if (!remainder) {
3b683bcf 689 oidcpy(result, &current_tree_oid);
275721c2
DT
690 retval = FOUND;
691 goto done;
692 }
693 /* Descend the tree */
694 t.buffer = NULL;
695 strbuf_remove(&namebuf, 0,
696 1 + first_slash - namebuf.buf);
697 } else if (S_ISREG(*mode)) {
698 if (!remainder) {
3b683bcf 699 oidcpy(result, &current_tree_oid);
275721c2
DT
700 retval = FOUND;
701 } else {
702 retval = NOT_DIR;
703 }
704 goto done;
705 } else if (S_ISLNK(*mode)) {
706 /* Follow a symlink */
707 unsigned long link_len;
708 size_t len;
709 char *contents, *contents_start;
710 struct dir_state *parent;
711 enum object_type type;
712
713 if (follows_remaining-- == 0) {
714 /* Too many symlinks followed */
715 retval = SYMLINK_LOOP;
716 goto done;
717 }
718
719 /*
720 * At this point, we have followed at a least
721 * one symlink, so on error we need to report this.
722 */
723 retval = DANGLING_SYMLINK;
724
b4f5aca4 725 contents = read_object_file(&current_tree_oid, &type,
726 &link_len);
275721c2
DT
727
728 if (!contents)
729 goto done;
730
731 if (contents[0] == '/') {
732 strbuf_addstr(result_path, contents);
733 free(contents);
734 *mode = 0;
735 retval = FOUND;
736 goto done;
737 }
738
739 if (remainder)
740 len = first_slash - namebuf.buf;
741 else
742 len = namebuf.len;
743
744 contents_start = contents;
745
746 parent = &parents[parents_nr - 1];
747 init_tree_desc(&t, parent->tree, parent->size);
748 strbuf_splice(&namebuf, 0, len,
749 contents_start, link_len);
750 if (remainder)
751 namebuf.buf[link_len] = '/';
752 free(contents);
753 }
754 }
755done:
756 for (i = 0; i < parents_nr; i++)
757 free(parents[i].tree);
758 free(parents);
759
760 strbuf_release(&namebuf);
761 return retval;
762}
763
93d93537
NTND
764static int match_entry(const struct pathspec_item *item,
765 const struct name_entry *entry, int pathlen,
58c4d666 766 const char *match, int matchlen,
c3a47ca9 767 enum interesting *never_interesting)
58c4d666
NTND
768{
769 int m = -1; /* signals that we haven't called strncmp() */
770
93d93537
NTND
771 if (item->magic & PATHSPEC_ICASE)
772 /*
773 * "Never interesting" trick requires exact
774 * matching. We could do something clever with inexact
775 * matching, but it's trickier (and not to forget that
776 * strcasecmp is locale-dependent, at least in
777 * glibc). Just disable it for now. It can't be worse
778 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
779 * pattern.
780 */
781 *never_interesting = entry_not_interesting;
782 else if (*never_interesting != entry_not_interesting) {
58c4d666
NTND
783 /*
784 * We have not seen any match that sorts later
785 * than the current path.
786 */
787
788 /*
789 * Does match sort strictly earlier than path
790 * with their common parts?
791 */
792 m = strncmp(match, entry->path,
793 (matchlen < pathlen) ? matchlen : pathlen);
794 if (m < 0)
795 return 0;
796
797 /*
798 * If we come here even once, that means there is at
799 * least one pathspec that would sort equal to or
800 * later than the path we are currently looking at.
801 * In other words, if we have never reached this point
802 * after iterating all pathspecs, it means all
803 * pathspecs are either outside of base, or inside the
804 * base but sorts strictly earlier than the current
805 * one. In either case, they will never match the
806 * subsequent entries. In such a case, we initialized
807 * the variable to -1 and that is what will be
808 * returned, allowing the caller to terminate early.
809 */
c3a47ca9 810 *never_interesting = entry_not_interesting;
58c4d666
NTND
811 }
812
813 if (pathlen > matchlen)
814 return 0;
815
816 if (matchlen > pathlen) {
817 if (match[pathlen] != '/')
818 return 0;
74b4f7f2 819 if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode))
58c4d666
NTND
820 return 0;
821 }
822
823 if (m == -1)
824 /*
825 * we cheated and did not do strncmp(), so we do
826 * that here.
827 */
93d93537 828 m = ps_strncmp(item, match, entry->path, pathlen);
58c4d666
NTND
829
830 /*
831 * If common part matched earlier then it is a hit,
832 * because we rejected the case where path is not a
833 * leading directory and is shorter than match.
834 */
835 if (!m)
93d93537
NTND
836 /*
837 * match_entry does not check if the prefix part is
838 * matched case-sensitively. If the entry is a
839 * directory and part of prefix, it'll be rematched
840 * eventually by basecmp with special treatment for
841 * the prefix.
842 */
58c4d666
NTND
843 return 1;
844
845 return 0;
846}
847
93d93537
NTND
848/* :(icase)-aware string compare */
849static int basecmp(const struct pathspec_item *item,
850 const char *base, const char *match, int len)
851{
852 if (item->magic & PATHSPEC_ICASE) {
853 int ret, n = len > item->prefix ? item->prefix : len;
854 ret = strncmp(base, match, n);
855 if (ret)
856 return ret;
857 base += n;
858 match += n;
859 len -= n;
860 }
861 return ps_strncmp(item, base, match, len);
862}
863
864static int match_dir_prefix(const struct pathspec_item *item,
865 const char *base,
58c4d666
NTND
866 const char *match, int matchlen)
867{
93d93537 868 if (basecmp(item, base, match, matchlen))
58c4d666
NTND
869 return 0;
870
871 /*
872 * If the base is a subdirectory of a path which
873 * was specified, all of them are interesting.
874 */
875 if (!matchlen ||
876 base[matchlen] == '/' ||
877 match[matchlen - 1] == '/')
878 return 1;
879
880 /* Just a random prefix match */
881 return 0;
882}
883
c904cd89
NTND
884/*
885 * Perform matching on the leading non-wildcard part of
886 * pathspec. item->nowildcard_len must be greater than zero. Return
887 * non-zero if base is matched.
888 */
889static int match_wildcard_base(const struct pathspec_item *item,
890 const char *base, int baselen,
891 int *matched)
892{
893 const char *match = item->match;
894 /* the wildcard part is not considered in this function */
895 int matchlen = item->nowildcard_len;
896
897 if (baselen) {
898 int dirlen;
899 /*
900 * Return early if base is longer than the
901 * non-wildcard part but it does not match.
902 */
903 if (baselen >= matchlen) {
904 *matched = matchlen;
93d93537 905 return !basecmp(item, base, match, matchlen);
c904cd89
NTND
906 }
907
908 dirlen = matchlen;
909 while (dirlen && match[dirlen - 1] != '/')
910 dirlen--;
911
912 /*
913 * Return early if base is shorter than the
914 * non-wildcard part but it does not match. Note that
915 * base ends with '/' so we are sure it really matches
916 * directory
917 */
93d93537 918 if (basecmp(item, base, match, baselen))
c904cd89
NTND
919 return 0;
920 *matched = baselen;
921 } else
922 *matched = 0;
923 /*
924 * we could have checked entry against the non-wildcard part
925 * that is not in base and does similar never_interesting
926 * optimization as in match_entry. For now just be happy with
927 * base comparison.
928 */
929 return entry_interesting;
930}
931
2c389fc8
NTND
932/*
933 * Is a tree entry interesting given the pathspec we have?
934 *
1376e507
NTND
935 * Pre-condition: either baselen == base_offset (i.e. empty path)
936 * or base[baselen-1] == '/' (i.e. with trailing slash).
2c389fc8 937 */
67022e02
NTND
938static enum interesting do_match(struct index_state *istate,
939 const struct name_entry *entry,
ef79b1f8
NTND
940 struct strbuf *base, int base_offset,
941 const struct pathspec *ps,
942 int exclude)
2c389fc8
NTND
943{
944 int i;
1376e507 945 int pathlen, baselen = base->len - base_offset;
c3a47ca9 946 enum interesting never_interesting = ps->has_wildcard ?
d688cf07 947 entry_not_interesting : all_entries_not_interesting;
2c389fc8 948
5c6933d2
NTND
949 GUARD_PATHSPEC(ps,
950 PATHSPEC_FROMTOP |
951 PATHSPEC_MAXDEPTH |
bd30c2e4 952 PATHSPEC_LITERAL |
93d93537 953 PATHSPEC_GLOB |
ef79b1f8 954 PATHSPEC_ICASE |
5a0b97b3
NTND
955 PATHSPEC_EXCLUDE |
956 PATHSPEC_ATTR);
8f4f8f45 957
bc96cc87 958 if (!ps->nr) {
6330a171
NTND
959 if (!ps->recursive ||
960 !(ps->magic & PATHSPEC_MAXDEPTH) ||
961 ps->max_depth == -1)
d688cf07
NTND
962 return all_entries_interesting;
963 return within_depth(base->buf + base_offset, baselen,
964 !!S_ISDIR(entry->mode),
965 ps->max_depth) ?
966 entry_interesting : entry_not_interesting;
bc96cc87 967 }
2c389fc8 968
0de16337 969 pathlen = tree_entry_len(entry);
2c389fc8 970
1376e507 971 for (i = ps->nr - 1; i >= 0; i--) {
2c389fc8
NTND
972 const struct pathspec_item *item = ps->items+i;
973 const char *match = item->match;
1376e507 974 const char *base_str = base->buf + base_offset;
c904cd89 975 int matchlen = item->len, matched = 0;
2c389fc8 976
ef79b1f8
NTND
977 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
978 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
979 continue;
980
2c389fc8
NTND
981 if (baselen >= matchlen) {
982 /* If it doesn't match, move along... */
93d93537 983 if (!match_dir_prefix(item, base_str, match, matchlen))
d38f2809 984 goto match_wildcards;
bc96cc87 985
6330a171
NTND
986 if (!ps->recursive ||
987 !(ps->magic & PATHSPEC_MAXDEPTH) ||
5a0b97b3
NTND
988 ps->max_depth == -1) {
989 if (!item->attr_match_nr)
990 return all_entries_interesting;
991 else
992 goto interesting;
993 }
994
995 if (within_depth(base_str + matchlen + 1,
996 baselen - matchlen - 1,
997 !!S_ISDIR(entry->mode),
998 ps->max_depth))
999 goto interesting;
1000 else
1001 return entry_not_interesting;
2c389fc8
NTND
1002 }
1003
1b740923 1004 /* Either there must be no base, or the base must match. */
93d93537
NTND
1005 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
1006 if (match_entry(item, entry, pathlen,
58c4d666
NTND
1007 match + baselen, matchlen - baselen,
1008 &never_interesting))
5a0b97b3 1009 goto interesting;
f1a2ddbb 1010
170260ae 1011 if (item->nowildcard_len < item->len) {
bd30c2e4 1012 if (!git_fnmatch(item, match + baselen, entry->path,
8c6abbcd 1013 item->nowildcard_len - baselen))
5a0b97b3 1014 goto interesting;
f1a2ddbb
NTND
1015
1016 /*
1017 * Match all directories. We'll try to
1018 * match files later on.
1019 */
1020 if (ps->recursive && S_ISDIR(entry->mode))
d688cf07 1021 return entry_interesting;
74ed4371
BW
1022
1023 /*
1024 * When matching against submodules with
1025 * wildcard characters, ensure that the entry
1026 * at least matches up to the first wild
1027 * character. More accurate matching can then
1028 * be performed in the submodule itself.
1029 */
eef3df5a
BW
1030 if (ps->recurse_submodules &&
1031 S_ISGITLINK(entry->mode) &&
74ed4371
BW
1032 !ps_strncmp(item, match + baselen,
1033 entry->path,
1034 item->nowildcard_len - baselen))
5a0b97b3 1035 goto interesting;
f1a2ddbb
NTND
1036 }
1037
1038 continue;
2c389fc8 1039 }
d38f2809
NTND
1040
1041match_wildcards:
170260ae 1042 if (item->nowildcard_len == item->len)
d38f2809
NTND
1043 continue;
1044
c904cd89
NTND
1045 if (item->nowildcard_len &&
1046 !match_wildcard_base(item, base_str, baselen, &matched))
e4ddb057 1047 continue;
c904cd89 1048
d38f2809
NTND
1049 /*
1050 * Concatenate base and entry->path into one and do
1051 * fnmatch() on it.
c904cd89
NTND
1052 *
1053 * While we could avoid concatenation in certain cases
1054 * [1], which saves a memcpy and potentially a
1055 * realloc, it turns out not worth it. Measurement on
1056 * linux-2.6 does not show any clear improvements,
1057 * partly because of the nowildcard_len optimization
1058 * in git_fnmatch(). Avoid micro-optimizations here.
1059 *
1060 * [1] if match_wildcard_base() says the base
1061 * directory is already matched, we only need to match
1062 * the rest, which is shorter so _in theory_ faster.
d38f2809
NTND
1063 */
1064
1065 strbuf_add(base, entry->path, pathlen);
1066
bd30c2e4 1067 if (!git_fnmatch(item, match, base->buf + base_offset,
8c6abbcd 1068 item->nowildcard_len)) {
1376e507 1069 strbuf_setlen(base, base_offset + baselen);
5a0b97b3 1070 goto interesting;
d38f2809 1071 }
74ed4371
BW
1072
1073 /*
1074 * When matching against submodules with
1075 * wildcard characters, ensure that the entry
1076 * at least matches up to the first wild
1077 * character. More accurate matching can then
1078 * be performed in the submodule itself.
1079 */
eef3df5a 1080 if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
74ed4371
BW
1081 !ps_strncmp(item, match, base->buf + base_offset,
1082 item->nowildcard_len)) {
1083 strbuf_setlen(base, base_offset + baselen);
5a0b97b3 1084 goto interesting;
74ed4371
BW
1085 }
1086
1376e507 1087 strbuf_setlen(base, base_offset + baselen);
d38f2809
NTND
1088
1089 /*
1090 * Match all directories. We'll try to match files
1091 * later on.
8c69c1f9
NTND
1092 * max_depth is ignored but we may consider support it
1093 * in future, see
5840eb9d 1094 * https://public-inbox.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
d38f2809
NTND
1095 */
1096 if (ps->recursive && S_ISDIR(entry->mode))
d688cf07 1097 return entry_interesting;
5a0b97b3
NTND
1098 continue;
1099interesting:
1100 if (item->attr_match_nr) {
1101 int ret;
1102
1103 /*
1104 * Must not return all_entries_not_interesting
1105 * prematurely. We do not know if all entries do not
1106 * match some attributes with current attr API.
1107 */
1108 never_interesting = entry_not_interesting;
1109
1110 /*
1111 * Consider all directories interesting (because some
1112 * of those files inside may match some attributes
1113 * even though the parent dir does not)
1114 *
1115 * FIXME: attributes _can_ match directories and we
1116 * can probably return all_entries_interesting or
1117 * all_entries_not_interesting here if matched.
1118 */
1119 if (S_ISDIR(entry->mode))
1120 return entry_interesting;
1121
1122 strbuf_add(base, entry->path, pathlen);
1123 ret = match_pathspec_attrs(istate, base->buf + base_offset,
1124 base->len - base_offset, item);
1125 strbuf_setlen(base, base_offset + baselen);
1126 if (!ret)
1127 continue;
1128 }
1129 return entry_interesting;
2c389fc8
NTND
1130 }
1131 return never_interesting; /* No matches */
1132}
ef79b1f8
NTND
1133
1134/*
1135 * Is a tree entry interesting given the pathspec we have?
1136 *
1137 * Pre-condition: either baselen == base_offset (i.e. empty path)
1138 * or base[baselen-1] == '/' (i.e. with trailing slash).
1139 */
67022e02
NTND
1140enum interesting tree_entry_interesting(struct index_state *istate,
1141 const struct name_entry *entry,
ef79b1f8
NTND
1142 struct strbuf *base, int base_offset,
1143 const struct pathspec *ps)
1144{
1145 enum interesting positive, negative;
67022e02 1146 positive = do_match(istate, entry, base, base_offset, ps, 0);
ef79b1f8
NTND
1147
1148 /*
1149 * case | entry | positive | negative | result
1150 * -----+-------+----------+----------+-------
1151 * 1 | file | -1 | -1..2 | -1
1152 * 2 | file | 0 | -1..2 | 0
1153 * 3 | file | 1 | -1 | 1
1154 * 4 | file | 1 | 0 | 1
1155 * 5 | file | 1 | 1 | 0
1156 * 6 | file | 1 | 2 | 0
1157 * 7 | file | 2 | -1 | 2
b7845ceb 1158 * 8 | file | 2 | 0 | 1
ef79b1f8
NTND
1159 * 9 | file | 2 | 1 | 0
1160 * 10 | file | 2 | 2 | -1
1161 * -----+-------+----------+----------+-------
1162 * 11 | dir | -1 | -1..2 | -1
1163 * 12 | dir | 0 | -1..2 | 0
1164 * 13 | dir | 1 | -1 | 1
1165 * 14 | dir | 1 | 0 | 1
1166 * 15 | dir | 1 | 1 | 1 (*)
1167 * 16 | dir | 1 | 2 | 0
1168 * 17 | dir | 2 | -1 | 2
b7845ceb 1169 * 18 | dir | 2 | 0 | 1
ef79b1f8
NTND
1170 * 19 | dir | 2 | 1 | 1 (*)
1171 * 20 | dir | 2 | 2 | -1
1172 *
1173 * (*) An exclude pattern interested in a directory does not
1174 * necessarily mean it will exclude all of the directory. In
1175 * wildcard case, it can't decide until looking at individual
1176 * files inside. So don't write such directories off yet.
1177 */
1178
1179 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
1180 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
1181 return positive;
1182
67022e02 1183 negative = do_match(istate, entry, base, base_offset, ps, 1);
ef79b1f8 1184
b7845ceb
NTND
1185 /* #8, #18 */
1186 if (positive == all_entries_interesting &&
1187 negative == entry_not_interesting)
1188 return entry_interesting;
1189
1190 /* #3, #4, #7, #13, #14, #17 */
ef79b1f8
NTND
1191 if (negative <= entry_not_interesting)
1192 return positive;
1193
1194 /* #15, #19 */
1195 if (S_ISDIR(entry->mode) &&
1196 positive >= entry_interesting &&
1197 negative == entry_interesting)
1198 return entry_interesting;
1199
1200 if ((positive == entry_interesting &&
1201 negative >= entry_interesting) || /* #5, #6, #16 */
1202 (positive == all_entries_interesting &&
1203 negative == entry_interesting)) /* #9 */
1204 return entry_not_interesting;
1205
1206 return all_entries_not_interesting; /* #10, #20 */
1207}