Merge branch 'tb/commit-graph-split-strategy'
[git] / dir.c
1 /*
2  * This handles recursive filename detection with exclude
3  * files, index knowledge etc..
4  *
5  * Copyright (C) Linus Torvalds, 2005-2006
6  *               Junio Hamano, 2005-2006
7  */
8 #include "cache.h"
9 #include "config.h"
10 #include "dir.h"
11 #include "object-store.h"
12 #include "attr.h"
13 #include "refs.h"
14 #include "wildmatch.h"
15 #include "pathspec.h"
16 #include "utf8.h"
17 #include "varint.h"
18 #include "ewah/ewok.h"
19 #include "fsmonitor.h"
20 #include "submodule-config.h"
21
22 /*
23  * Tells read_directory_recursive how a file or directory should be treated.
24  * Values are ordered by significance, e.g. if a directory contains both
25  * excluded and untracked files, it is listed as untracked because
26  * path_untracked > path_excluded.
27  */
28 enum path_treatment {
29         path_none = 0,
30         path_recurse,
31         path_excluded,
32         path_untracked
33 };
34
35 /*
36  * Support data structure for our opendir/readdir/closedir wrappers
37  */
38 struct cached_dir {
39         DIR *fdir;
40         struct untracked_cache_dir *untracked;
41         int nr_files;
42         int nr_dirs;
43
44         const char *d_name;
45         int d_type;
46         const char *file;
47         struct untracked_cache_dir *ucd;
48 };
49
50 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
51         struct index_state *istate, const char *path, int len,
52         struct untracked_cache_dir *untracked,
53         int check_only, int stop_at_first_file, const struct pathspec *pathspec);
54 static int resolve_dtype(int dtype, struct index_state *istate,
55                          const char *path, int len);
56
57 int count_slashes(const char *s)
58 {
59         int cnt = 0;
60         while (*s)
61                 if (*s++ == '/')
62                         cnt++;
63         return cnt;
64 }
65
66 int fspathcmp(const char *a, const char *b)
67 {
68         return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
69 }
70
71 int fspathncmp(const char *a, const char *b, size_t count)
72 {
73         return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
74 }
75
76 int git_fnmatch(const struct pathspec_item *item,
77                 const char *pattern, const char *string,
78                 int prefix)
79 {
80         if (prefix > 0) {
81                 if (ps_strncmp(item, pattern, string, prefix))
82                         return WM_NOMATCH;
83                 pattern += prefix;
84                 string += prefix;
85         }
86         if (item->flags & PATHSPEC_ONESTAR) {
87                 int pattern_len = strlen(++pattern);
88                 int string_len = strlen(string);
89                 return string_len < pattern_len ||
90                         ps_strcmp(item, pattern,
91                                   string + string_len - pattern_len);
92         }
93         if (item->magic & PATHSPEC_GLOB)
94                 return wildmatch(pattern, string,
95                                  WM_PATHNAME |
96                                  (item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0));
97         else
98                 /* wildmatch has not learned no FNM_PATHNAME mode yet */
99                 return wildmatch(pattern, string,
100                                  item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0);
101 }
102
103 static int fnmatch_icase_mem(const char *pattern, int patternlen,
104                              const char *string, int stringlen,
105                              int flags)
106 {
107         int match_status;
108         struct strbuf pat_buf = STRBUF_INIT;
109         struct strbuf str_buf = STRBUF_INIT;
110         const char *use_pat = pattern;
111         const char *use_str = string;
112
113         if (pattern[patternlen]) {
114                 strbuf_add(&pat_buf, pattern, patternlen);
115                 use_pat = pat_buf.buf;
116         }
117         if (string[stringlen]) {
118                 strbuf_add(&str_buf, string, stringlen);
119                 use_str = str_buf.buf;
120         }
121
122         if (ignore_case)
123                 flags |= WM_CASEFOLD;
124         match_status = wildmatch(use_pat, use_str, flags);
125
126         strbuf_release(&pat_buf);
127         strbuf_release(&str_buf);
128
129         return match_status;
130 }
131
132 static size_t common_prefix_len(const struct pathspec *pathspec)
133 {
134         int n;
135         size_t max = 0;
136
137         /*
138          * ":(icase)path" is treated as a pathspec full of
139          * wildcard. In other words, only prefix is considered common
140          * prefix. If the pathspec is abc/foo abc/bar, running in
141          * subdir xyz, the common prefix is still xyz, not xyz/abc as
142          * in non-:(icase).
143          */
144         GUARD_PATHSPEC(pathspec,
145                        PATHSPEC_FROMTOP |
146                        PATHSPEC_MAXDEPTH |
147                        PATHSPEC_LITERAL |
148                        PATHSPEC_GLOB |
149                        PATHSPEC_ICASE |
150                        PATHSPEC_EXCLUDE |
151                        PATHSPEC_ATTR);
152
153         for (n = 0; n < pathspec->nr; n++) {
154                 size_t i = 0, len = 0, item_len;
155                 if (pathspec->items[n].magic & PATHSPEC_EXCLUDE)
156                         continue;
157                 if (pathspec->items[n].magic & PATHSPEC_ICASE)
158                         item_len = pathspec->items[n].prefix;
159                 else
160                         item_len = pathspec->items[n].nowildcard_len;
161                 while (i < item_len && (n == 0 || i < max)) {
162                         char c = pathspec->items[n].match[i];
163                         if (c != pathspec->items[0].match[i])
164                                 break;
165                         if (c == '/')
166                                 len = i + 1;
167                         i++;
168                 }
169                 if (n == 0 || len < max) {
170                         max = len;
171                         if (!max)
172                                 break;
173                 }
174         }
175         return max;
176 }
177
178 /*
179  * Returns a copy of the longest leading path common among all
180  * pathspecs.
181  */
182 char *common_prefix(const struct pathspec *pathspec)
183 {
184         unsigned long len = common_prefix_len(pathspec);
185
186         return len ? xmemdupz(pathspec->items[0].match, len) : NULL;
187 }
188
189 int fill_directory(struct dir_struct *dir,
190                    struct index_state *istate,
191                    const struct pathspec *pathspec)
192 {
193         const char *prefix;
194         size_t prefix_len;
195
196         /*
197          * Calculate common prefix for the pathspec, and
198          * use that to optimize the directory walk
199          */
200         prefix_len = common_prefix_len(pathspec);
201         prefix = prefix_len ? pathspec->items[0].match : "";
202
203         /* Read the directory and prune it */
204         read_directory(dir, istate, prefix, prefix_len, pathspec);
205
206         return prefix_len;
207 }
208
209 int within_depth(const char *name, int namelen,
210                         int depth, int max_depth)
211 {
212         const char *cp = name, *cpe = name + namelen;
213
214         while (cp < cpe) {
215                 if (*cp++ != '/')
216                         continue;
217                 depth++;
218                 if (depth > max_depth)
219                         return 0;
220         }
221         return 1;
222 }
223
224 /*
225  * Read the contents of the blob with the given OID into a buffer.
226  * Append a trailing LF to the end if the last line doesn't have one.
227  *
228  * Returns:
229  *    -1 when the OID is invalid or unknown or does not refer to a blob.
230  *     0 when the blob is empty.
231  *     1 along with { data, size } of the (possibly augmented) buffer
232  *       when successful.
233  *
234  * Optionally updates the given oid_stat with the given OID (when valid).
235  */
236 static int do_read_blob(const struct object_id *oid, struct oid_stat *oid_stat,
237                         size_t *size_out, char **data_out)
238 {
239         enum object_type type;
240         unsigned long sz;
241         char *data;
242
243         *size_out = 0;
244         *data_out = NULL;
245
246         data = read_object_file(oid, &type, &sz);
247         if (!data || type != OBJ_BLOB) {
248                 free(data);
249                 return -1;
250         }
251
252         if (oid_stat) {
253                 memset(&oid_stat->stat, 0, sizeof(oid_stat->stat));
254                 oidcpy(&oid_stat->oid, oid);
255         }
256
257         if (sz == 0) {
258                 free(data);
259                 return 0;
260         }
261
262         if (data[sz - 1] != '\n') {
263                 data = xrealloc(data, st_add(sz, 1));
264                 data[sz++] = '\n';
265         }
266
267         *size_out = xsize_t(sz);
268         *data_out = data;
269
270         return 1;
271 }
272
273 #define DO_MATCH_EXCLUDE   (1<<0)
274 #define DO_MATCH_DIRECTORY (1<<1)
275 #define DO_MATCH_LEADING_PATHSPEC (1<<2)
276
277 /*
278  * Does the given pathspec match the given name?  A match is found if
279  *
280  * (1) the pathspec string is leading directory of 'name' ("RECURSIVELY"), or
281  * (2) the pathspec string has a leading part matching 'name' ("LEADING"), or
282  * (3) the pathspec string is a wildcard and matches 'name' ("WILDCARD"), or
283  * (4) the pathspec string is exactly the same as 'name' ("EXACT").
284  *
285  * Return value tells which case it was (1-4), or 0 when there is no match.
286  *
287  * It may be instructive to look at a small table of concrete examples
288  * to understand the differences between 1, 2, and 4:
289  *
290  *                              Pathspecs
291  *                |    a/b    |   a/b/    |   a/b/c
292  *          ------+-----------+-----------+------------
293  *          a/b   |  EXACT    |  EXACT[1] | LEADING[2]
294  *  Names   a/b/  | RECURSIVE |   EXACT   | LEADING[2]
295  *          a/b/c | RECURSIVE | RECURSIVE |   EXACT
296  *
297  * [1] Only if DO_MATCH_DIRECTORY is passed; otherwise, this is NOT a match.
298  * [2] Only if DO_MATCH_LEADING_PATHSPEC is passed; otherwise, not a match.
299  */
300 static int match_pathspec_item(const struct index_state *istate,
301                                const struct pathspec_item *item, int prefix,
302                                const char *name, int namelen, unsigned flags)
303 {
304         /* name/namelen has prefix cut off by caller */
305         const char *match = item->match + prefix;
306         int matchlen = item->len - prefix;
307
308         /*
309          * The normal call pattern is:
310          * 1. prefix = common_prefix_len(ps);
311          * 2. prune something, or fill_directory
312          * 3. match_pathspec()
313          *
314          * 'prefix' at #1 may be shorter than the command's prefix and
315          * it's ok for #2 to match extra files. Those extras will be
316          * trimmed at #3.
317          *
318          * Suppose the pathspec is 'foo' and '../bar' running from
319          * subdir 'xyz'. The common prefix at #1 will be empty, thanks
320          * to "../". We may have xyz/foo _and_ XYZ/foo after #2. The
321          * user does not want XYZ/foo, only the "foo" part should be
322          * case-insensitive. We need to filter out XYZ/foo here. In
323          * other words, we do not trust the caller on comparing the
324          * prefix part when :(icase) is involved. We do exact
325          * comparison ourselves.
326          *
327          * Normally the caller (common_prefix_len() in fact) does
328          * _exact_ matching on name[-prefix+1..-1] and we do not need
329          * to check that part. Be defensive and check it anyway, in
330          * case common_prefix_len is changed, or a new caller is
331          * introduced that does not use common_prefix_len.
332          *
333          * If the penalty turns out too high when prefix is really
334          * long, maybe change it to
335          * strncmp(match, name, item->prefix - prefix)
336          */
337         if (item->prefix && (item->magic & PATHSPEC_ICASE) &&
338             strncmp(item->match, name - prefix, item->prefix))
339                 return 0;
340
341         if (item->attr_match_nr &&
342             !match_pathspec_attrs(istate, name, namelen, item))
343                 return 0;
344
345         /* If the match was just the prefix, we matched */
346         if (!*match)
347                 return MATCHED_RECURSIVELY;
348
349         if (matchlen <= namelen && !ps_strncmp(item, match, name, matchlen)) {
350                 if (matchlen == namelen)
351                         return MATCHED_EXACTLY;
352
353                 if (match[matchlen-1] == '/' || name[matchlen] == '/')
354                         return MATCHED_RECURSIVELY;
355         } else if ((flags & DO_MATCH_DIRECTORY) &&
356                    match[matchlen - 1] == '/' &&
357                    namelen == matchlen - 1 &&
358                    !ps_strncmp(item, match, name, namelen))
359                 return MATCHED_EXACTLY;
360
361         if (item->nowildcard_len < item->len &&
362             !git_fnmatch(item, match, name,
363                          item->nowildcard_len - prefix))
364                 return MATCHED_FNMATCH;
365
366         /* Perform checks to see if "name" is a leading string of the pathspec */
367         if (flags & DO_MATCH_LEADING_PATHSPEC) {
368                 /* name is a literal prefix of the pathspec */
369                 int offset = name[namelen-1] == '/' ? 1 : 0;
370                 if ((namelen < matchlen) &&
371                     (match[namelen-offset] == '/') &&
372                     !ps_strncmp(item, match, name, namelen))
373                         return MATCHED_RECURSIVELY_LEADING_PATHSPEC;
374
375                 /* name doesn't match up to the first wild character */
376                 if (item->nowildcard_len < item->len &&
377                     ps_strncmp(item, match, name,
378                                item->nowildcard_len - prefix))
379                         return 0;
380
381                 /*
382                  * name has no wildcard, and it didn't match as a leading
383                  * pathspec so return.
384                  */
385                 if (item->nowildcard_len == item->len)
386                         return 0;
387
388                 /*
389                  * Here is where we would perform a wildmatch to check if
390                  * "name" can be matched as a directory (or a prefix) against
391                  * the pathspec.  Since wildmatch doesn't have this capability
392                  * at the present we have to punt and say that it is a match,
393                  * potentially returning a false positive
394                  * The submodules themselves will be able to perform more
395                  * accurate matching to determine if the pathspec matches.
396                  */
397                 return MATCHED_RECURSIVELY_LEADING_PATHSPEC;
398         }
399
400         return 0;
401 }
402
403 /*
404  * Given a name and a list of pathspecs, returns the nature of the
405  * closest (i.e. most specific) match of the name to any of the
406  * pathspecs.
407  *
408  * The caller typically calls this multiple times with the same
409  * pathspec and seen[] array but with different name/namelen
410  * (e.g. entries from the index) and is interested in seeing if and
411  * how each pathspec matches all the names it calls this function
412  * with.  A mark is left in the seen[] array for each pathspec element
413  * indicating the closest type of match that element achieved, so if
414  * seen[n] remains zero after multiple invocations, that means the nth
415  * pathspec did not match any names, which could indicate that the
416  * user mistyped the nth pathspec.
417  */
418 static int do_match_pathspec(const struct index_state *istate,
419                              const struct pathspec *ps,
420                              const char *name, int namelen,
421                              int prefix, char *seen,
422                              unsigned flags)
423 {
424         int i, retval = 0, exclude = flags & DO_MATCH_EXCLUDE;
425
426         GUARD_PATHSPEC(ps,
427                        PATHSPEC_FROMTOP |
428                        PATHSPEC_MAXDEPTH |
429                        PATHSPEC_LITERAL |
430                        PATHSPEC_GLOB |
431                        PATHSPEC_ICASE |
432                        PATHSPEC_EXCLUDE |
433                        PATHSPEC_ATTR);
434
435         if (!ps->nr) {
436                 if (!ps->recursive ||
437                     !(ps->magic & PATHSPEC_MAXDEPTH) ||
438                     ps->max_depth == -1)
439                         return MATCHED_RECURSIVELY;
440
441                 if (within_depth(name, namelen, 0, ps->max_depth))
442                         return MATCHED_EXACTLY;
443                 else
444                         return 0;
445         }
446
447         name += prefix;
448         namelen -= prefix;
449
450         for (i = ps->nr - 1; i >= 0; i--) {
451                 int how;
452
453                 if ((!exclude &&   ps->items[i].magic & PATHSPEC_EXCLUDE) ||
454                     ( exclude && !(ps->items[i].magic & PATHSPEC_EXCLUDE)))
455                         continue;
456
457                 if (seen && seen[i] == MATCHED_EXACTLY)
458                         continue;
459                 /*
460                  * Make exclude patterns optional and never report
461                  * "pathspec ':(exclude)foo' matches no files"
462                  */
463                 if (seen && ps->items[i].magic & PATHSPEC_EXCLUDE)
464                         seen[i] = MATCHED_FNMATCH;
465                 how = match_pathspec_item(istate, ps->items+i, prefix, name,
466                                           namelen, flags);
467                 if (ps->recursive &&
468                     (ps->magic & PATHSPEC_MAXDEPTH) &&
469                     ps->max_depth != -1 &&
470                     how && how != MATCHED_FNMATCH) {
471                         int len = ps->items[i].len;
472                         if (name[len] == '/')
473                                 len++;
474                         if (within_depth(name+len, namelen-len, 0, ps->max_depth))
475                                 how = MATCHED_EXACTLY;
476                         else
477                                 how = 0;
478                 }
479                 if (how) {
480                         if (retval < how)
481                                 retval = how;
482                         if (seen && seen[i] < how)
483                                 seen[i] = how;
484                 }
485         }
486         return retval;
487 }
488
489 int match_pathspec(const struct index_state *istate,
490                    const struct pathspec *ps,
491                    const char *name, int namelen,
492                    int prefix, char *seen, int is_dir)
493 {
494         int positive, negative;
495         unsigned flags = is_dir ? DO_MATCH_DIRECTORY : 0;
496         positive = do_match_pathspec(istate, ps, name, namelen,
497                                      prefix, seen, flags);
498         if (!(ps->magic & PATHSPEC_EXCLUDE) || !positive)
499                 return positive;
500         negative = do_match_pathspec(istate, ps, name, namelen,
501                                      prefix, seen,
502                                      flags | DO_MATCH_EXCLUDE);
503         return negative ? 0 : positive;
504 }
505
506 /**
507  * Check if a submodule is a superset of the pathspec
508  */
509 int submodule_path_match(const struct index_state *istate,
510                          const struct pathspec *ps,
511                          const char *submodule_name,
512                          char *seen)
513 {
514         int matched = do_match_pathspec(istate, ps, submodule_name,
515                                         strlen(submodule_name),
516                                         0, seen,
517                                         DO_MATCH_DIRECTORY |
518                                         DO_MATCH_LEADING_PATHSPEC);
519         return matched;
520 }
521
522 int report_path_error(const char *ps_matched,
523                       const struct pathspec *pathspec)
524 {
525         /*
526          * Make sure all pathspec matched; otherwise it is an error.
527          */
528         int num, errors = 0;
529         for (num = 0; num < pathspec->nr; num++) {
530                 int other, found_dup;
531
532                 if (ps_matched[num])
533                         continue;
534                 /*
535                  * The caller might have fed identical pathspec
536                  * twice.  Do not barf on such a mistake.
537                  * FIXME: parse_pathspec should have eliminated
538                  * duplicate pathspec.
539                  */
540                 for (found_dup = other = 0;
541                      !found_dup && other < pathspec->nr;
542                      other++) {
543                         if (other == num || !ps_matched[other])
544                                 continue;
545                         if (!strcmp(pathspec->items[other].original,
546                                     pathspec->items[num].original))
547                                 /*
548                                  * Ok, we have a match already.
549                                  */
550                                 found_dup = 1;
551                 }
552                 if (found_dup)
553                         continue;
554
555                 error(_("pathspec '%s' did not match any file(s) known to git"),
556                       pathspec->items[num].original);
557                 errors++;
558         }
559         return errors;
560 }
561
562 /*
563  * Return the length of the "simple" part of a path match limiter.
564  */
565 int simple_length(const char *match)
566 {
567         int len = -1;
568
569         for (;;) {
570                 unsigned char c = *match++;
571                 len++;
572                 if (c == '\0' || is_glob_special(c))
573                         return len;
574         }
575 }
576
577 int no_wildcard(const char *string)
578 {
579         return string[simple_length(string)] == '\0';
580 }
581
582 void parse_path_pattern(const char **pattern,
583                            int *patternlen,
584                            unsigned *flags,
585                            int *nowildcardlen)
586 {
587         const char *p = *pattern;
588         size_t i, len;
589
590         *flags = 0;
591         if (*p == '!') {
592                 *flags |= PATTERN_FLAG_NEGATIVE;
593                 p++;
594         }
595         len = strlen(p);
596         if (len && p[len - 1] == '/') {
597                 len--;
598                 *flags |= PATTERN_FLAG_MUSTBEDIR;
599         }
600         for (i = 0; i < len; i++) {
601                 if (p[i] == '/')
602                         break;
603         }
604         if (i == len)
605                 *flags |= PATTERN_FLAG_NODIR;
606         *nowildcardlen = simple_length(p);
607         /*
608          * we should have excluded the trailing slash from 'p' too,
609          * but that's one more allocation. Instead just make sure
610          * nowildcardlen does not exceed real patternlen
611          */
612         if (*nowildcardlen > len)
613                 *nowildcardlen = len;
614         if (*p == '*' && no_wildcard(p + 1))
615                 *flags |= PATTERN_FLAG_ENDSWITH;
616         *pattern = p;
617         *patternlen = len;
618 }
619
620 int pl_hashmap_cmp(const void *unused_cmp_data,
621                    const struct hashmap_entry *a,
622                    const struct hashmap_entry *b,
623                    const void *key)
624 {
625         const struct pattern_entry *ee1 =
626                         container_of(a, struct pattern_entry, ent);
627         const struct pattern_entry *ee2 =
628                         container_of(b, struct pattern_entry, ent);
629
630         size_t min_len = ee1->patternlen <= ee2->patternlen
631                          ? ee1->patternlen
632                          : ee2->patternlen;
633
634         if (ignore_case)
635                 return strncasecmp(ee1->pattern, ee2->pattern, min_len);
636         return strncmp(ee1->pattern, ee2->pattern, min_len);
637 }
638
639 static char *dup_and_filter_pattern(const char *pattern)
640 {
641         char *set, *read;
642         size_t count  = 0;
643         char *result = xstrdup(pattern);
644
645         set = result;
646         read = result;
647
648         while (*read) {
649                 /* skip escape characters (once) */
650                 if (*read == '\\')
651                         read++;
652
653                 *set = *read;
654
655                 set++;
656                 read++;
657                 count++;
658         }
659         *set = 0;
660
661         if (count > 2 &&
662             *(set - 1) == '*' &&
663             *(set - 2) == '/')
664                 *(set - 2) = 0;
665
666         return result;
667 }
668
669 static void add_pattern_to_hashsets(struct pattern_list *pl, struct path_pattern *given)
670 {
671         struct pattern_entry *translated;
672         char *truncated;
673         char *data = NULL;
674         const char *prev, *cur, *next;
675
676         if (!pl->use_cone_patterns)
677                 return;
678
679         if (given->flags & PATTERN_FLAG_NEGATIVE &&
680             given->flags & PATTERN_FLAG_MUSTBEDIR &&
681             !strcmp(given->pattern, "/*")) {
682                 pl->full_cone = 0;
683                 return;
684         }
685
686         if (!given->flags && !strcmp(given->pattern, "/*")) {
687                 pl->full_cone = 1;
688                 return;
689         }
690
691         if (given->patternlen < 2 ||
692             *given->pattern == '*' ||
693             strstr(given->pattern, "**")) {
694                 /* Not a cone pattern. */
695                 warning(_("unrecognized pattern: '%s'"), given->pattern);
696                 goto clear_hashmaps;
697         }
698
699         prev = given->pattern;
700         cur = given->pattern + 1;
701         next = given->pattern + 2;
702
703         while (*cur) {
704                 /* Watch for glob characters '*', '\', '[', '?' */
705                 if (!is_glob_special(*cur))
706                         goto increment;
707
708                 /* But only if *prev != '\\' */
709                 if (*prev == '\\')
710                         goto increment;
711
712                 /* But allow the initial '\' */
713                 if (*cur == '\\' &&
714                     is_glob_special(*next))
715                         goto increment;
716
717                 /* But a trailing '/' then '*' is fine */
718                 if (*prev == '/' &&
719                     *cur == '*' &&
720                     *next == 0)
721                         goto increment;
722
723                 /* Not a cone pattern. */
724                 warning(_("unrecognized pattern: '%s'"), given->pattern);
725                 goto clear_hashmaps;
726
727         increment:
728                 prev++;
729                 cur++;
730                 next++;
731         }
732
733         if (given->patternlen > 2 &&
734             !strcmp(given->pattern + given->patternlen - 2, "/*")) {
735                 if (!(given->flags & PATTERN_FLAG_NEGATIVE)) {
736                         /* Not a cone pattern. */
737                         warning(_("unrecognized pattern: '%s'"), given->pattern);
738                         goto clear_hashmaps;
739                 }
740
741                 truncated = dup_and_filter_pattern(given->pattern);
742
743                 translated = xmalloc(sizeof(struct pattern_entry));
744                 translated->pattern = truncated;
745                 translated->patternlen = given->patternlen - 2;
746                 hashmap_entry_init(&translated->ent,
747                                    ignore_case ?
748                                    strihash(translated->pattern) :
749                                    strhash(translated->pattern));
750
751                 if (!hashmap_get_entry(&pl->recursive_hashmap,
752                                        translated, ent, NULL)) {
753                         /* We did not see the "parent" included */
754                         warning(_("unrecognized negative pattern: '%s'"),
755                                 given->pattern);
756                         free(truncated);
757                         free(translated);
758                         goto clear_hashmaps;
759                 }
760
761                 hashmap_add(&pl->parent_hashmap, &translated->ent);
762                 hashmap_remove(&pl->recursive_hashmap, &translated->ent, &data);
763                 free(data);
764                 return;
765         }
766
767         if (given->flags & PATTERN_FLAG_NEGATIVE) {
768                 warning(_("unrecognized negative pattern: '%s'"),
769                         given->pattern);
770                 goto clear_hashmaps;
771         }
772
773         translated = xmalloc(sizeof(struct pattern_entry));
774
775         translated->pattern = dup_and_filter_pattern(given->pattern);
776         translated->patternlen = given->patternlen;
777         hashmap_entry_init(&translated->ent,
778                            ignore_case ?
779                            strihash(translated->pattern) :
780                            strhash(translated->pattern));
781
782         hashmap_add(&pl->recursive_hashmap, &translated->ent);
783
784         if (hashmap_get_entry(&pl->parent_hashmap, translated, ent, NULL)) {
785                 /* we already included this at the parent level */
786                 warning(_("your sparse-checkout file may have issues: pattern '%s' is repeated"),
787                         given->pattern);
788                 hashmap_remove(&pl->parent_hashmap, &translated->ent, &data);
789                 free(data);
790                 free(translated);
791         }
792
793         return;
794
795 clear_hashmaps:
796         warning(_("disabling cone pattern matching"));
797         hashmap_free_entries(&pl->parent_hashmap, struct pattern_entry, ent);
798         hashmap_free_entries(&pl->recursive_hashmap, struct pattern_entry, ent);
799         pl->use_cone_patterns = 0;
800 }
801
802 static int hashmap_contains_path(struct hashmap *map,
803                                  struct strbuf *pattern)
804 {
805         struct pattern_entry p;
806
807         /* Check straight mapping */
808         p.pattern = pattern->buf;
809         p.patternlen = pattern->len;
810         hashmap_entry_init(&p.ent,
811                            ignore_case ?
812                            strihash(p.pattern) :
813                            strhash(p.pattern));
814         return !!hashmap_get_entry(map, &p, ent, NULL);
815 }
816
817 int hashmap_contains_parent(struct hashmap *map,
818                             const char *path,
819                             struct strbuf *buffer)
820 {
821         char *slash_pos;
822
823         strbuf_setlen(buffer, 0);
824
825         if (path[0] != '/')
826                 strbuf_addch(buffer, '/');
827
828         strbuf_addstr(buffer, path);
829
830         slash_pos = strrchr(buffer->buf, '/');
831
832         while (slash_pos > buffer->buf) {
833                 strbuf_setlen(buffer, slash_pos - buffer->buf);
834
835                 if (hashmap_contains_path(map, buffer))
836                         return 1;
837
838                 slash_pos = strrchr(buffer->buf, '/');
839         }
840
841         return 0;
842 }
843
844 void add_pattern(const char *string, const char *base,
845                  int baselen, struct pattern_list *pl, int srcpos)
846 {
847         struct path_pattern *pattern;
848         int patternlen;
849         unsigned flags;
850         int nowildcardlen;
851
852         parse_path_pattern(&string, &patternlen, &flags, &nowildcardlen);
853         if (flags & PATTERN_FLAG_MUSTBEDIR) {
854                 FLEXPTR_ALLOC_MEM(pattern, pattern, string, patternlen);
855         } else {
856                 pattern = xmalloc(sizeof(*pattern));
857                 pattern->pattern = string;
858         }
859         pattern->patternlen = patternlen;
860         pattern->nowildcardlen = nowildcardlen;
861         pattern->base = base;
862         pattern->baselen = baselen;
863         pattern->flags = flags;
864         pattern->srcpos = srcpos;
865         ALLOC_GROW(pl->patterns, pl->nr + 1, pl->alloc);
866         pl->patterns[pl->nr++] = pattern;
867         pattern->pl = pl;
868
869         add_pattern_to_hashsets(pl, pattern);
870 }
871
872 static int read_skip_worktree_file_from_index(const struct index_state *istate,
873                                               const char *path,
874                                               size_t *size_out, char **data_out,
875                                               struct oid_stat *oid_stat)
876 {
877         int pos, len;
878
879         len = strlen(path);
880         pos = index_name_pos(istate, path, len);
881         if (pos < 0)
882                 return -1;
883         if (!ce_skip_worktree(istate->cache[pos]))
884                 return -1;
885
886         return do_read_blob(&istate->cache[pos]->oid, oid_stat, size_out, data_out);
887 }
888
889 /*
890  * Frees memory within pl which was allocated for exclude patterns and
891  * the file buffer.  Does not free pl itself.
892  */
893 void clear_pattern_list(struct pattern_list *pl)
894 {
895         int i;
896
897         for (i = 0; i < pl->nr; i++)
898                 free(pl->patterns[i]);
899         free(pl->patterns);
900         free(pl->filebuf);
901
902         memset(pl, 0, sizeof(*pl));
903 }
904
905 static void trim_trailing_spaces(char *buf)
906 {
907         char *p, *last_space = NULL;
908
909         for (p = buf; *p; p++)
910                 switch (*p) {
911                 case ' ':
912                         if (!last_space)
913                                 last_space = p;
914                         break;
915                 case '\\':
916                         p++;
917                         if (!*p)
918                                 return;
919                         /* fallthrough */
920                 default:
921                         last_space = NULL;
922                 }
923
924         if (last_space)
925                 *last_space = '\0';
926 }
927
928 /*
929  * Given a subdirectory name and "dir" of the current directory,
930  * search the subdir in "dir" and return it, or create a new one if it
931  * does not exist in "dir".
932  *
933  * If "name" has the trailing slash, it'll be excluded in the search.
934  */
935 static struct untracked_cache_dir *lookup_untracked(struct untracked_cache *uc,
936                                                     struct untracked_cache_dir *dir,
937                                                     const char *name, int len)
938 {
939         int first, last;
940         struct untracked_cache_dir *d;
941         if (!dir)
942                 return NULL;
943         if (len && name[len - 1] == '/')
944                 len--;
945         first = 0;
946         last = dir->dirs_nr;
947         while (last > first) {
948                 int cmp, next = first + ((last - first) >> 1);
949                 d = dir->dirs[next];
950                 cmp = strncmp(name, d->name, len);
951                 if (!cmp && strlen(d->name) > len)
952                         cmp = -1;
953                 if (!cmp)
954                         return d;
955                 if (cmp < 0) {
956                         last = next;
957                         continue;
958                 }
959                 first = next+1;
960         }
961
962         uc->dir_created++;
963         FLEX_ALLOC_MEM(d, name, name, len);
964
965         ALLOC_GROW(dir->dirs, dir->dirs_nr + 1, dir->dirs_alloc);
966         MOVE_ARRAY(dir->dirs + first + 1, dir->dirs + first,
967                    dir->dirs_nr - first);
968         dir->dirs_nr++;
969         dir->dirs[first] = d;
970         return d;
971 }
972
973 static void do_invalidate_gitignore(struct untracked_cache_dir *dir)
974 {
975         int i;
976         dir->valid = 0;
977         dir->untracked_nr = 0;
978         for (i = 0; i < dir->dirs_nr; i++)
979                 do_invalidate_gitignore(dir->dirs[i]);
980 }
981
982 static void invalidate_gitignore(struct untracked_cache *uc,
983                                  struct untracked_cache_dir *dir)
984 {
985         uc->gitignore_invalidated++;
986         do_invalidate_gitignore(dir);
987 }
988
989 static void invalidate_directory(struct untracked_cache *uc,
990                                  struct untracked_cache_dir *dir)
991 {
992         int i;
993
994         /*
995          * Invalidation increment here is just roughly correct. If
996          * untracked_nr or any of dirs[].recurse is non-zero, we
997          * should increment dir_invalidated too. But that's more
998          * expensive to do.
999          */
1000         if (dir->valid)
1001                 uc->dir_invalidated++;
1002
1003         dir->valid = 0;
1004         dir->untracked_nr = 0;
1005         for (i = 0; i < dir->dirs_nr; i++)
1006                 dir->dirs[i]->recurse = 0;
1007 }
1008
1009 static int add_patterns_from_buffer(char *buf, size_t size,
1010                                     const char *base, int baselen,
1011                                     struct pattern_list *pl);
1012
1013 /*
1014  * Given a file with name "fname", read it (either from disk, or from
1015  * an index if 'istate' is non-null), parse it and store the
1016  * exclude rules in "pl".
1017  *
1018  * If "ss" is not NULL, compute SHA-1 of the exclude file and fill
1019  * stat data from disk (only valid if add_patterns returns zero). If
1020  * ss_valid is non-zero, "ss" must contain good value as input.
1021  */
1022 static int add_patterns(const char *fname, const char *base, int baselen,
1023                         struct pattern_list *pl, struct index_state *istate,
1024                         struct oid_stat *oid_stat)
1025 {
1026         struct stat st;
1027         int r;
1028         int fd;
1029         size_t size = 0;
1030         char *buf;
1031
1032         fd = open(fname, O_RDONLY);
1033         if (fd < 0 || fstat(fd, &st) < 0) {
1034                 if (fd < 0)
1035                         warn_on_fopen_errors(fname);
1036                 else
1037                         close(fd);
1038                 if (!istate)
1039                         return -1;
1040                 r = read_skip_worktree_file_from_index(istate, fname,
1041                                                        &size, &buf,
1042                                                        oid_stat);
1043                 if (r != 1)
1044                         return r;
1045         } else {
1046                 size = xsize_t(st.st_size);
1047                 if (size == 0) {
1048                         if (oid_stat) {
1049                                 fill_stat_data(&oid_stat->stat, &st);
1050                                 oidcpy(&oid_stat->oid, the_hash_algo->empty_blob);
1051                                 oid_stat->valid = 1;
1052                         }
1053                         close(fd);
1054                         return 0;
1055                 }
1056                 buf = xmallocz(size);
1057                 if (read_in_full(fd, buf, size) != size) {
1058                         free(buf);
1059                         close(fd);
1060                         return -1;
1061                 }
1062                 buf[size++] = '\n';
1063                 close(fd);
1064                 if (oid_stat) {
1065                         int pos;
1066                         if (oid_stat->valid &&
1067                             !match_stat_data_racy(istate, &oid_stat->stat, &st))
1068                                 ; /* no content change, ss->sha1 still good */
1069                         else if (istate &&
1070                                  (pos = index_name_pos(istate, fname, strlen(fname))) >= 0 &&
1071                                  !ce_stage(istate->cache[pos]) &&
1072                                  ce_uptodate(istate->cache[pos]) &&
1073                                  !would_convert_to_git(istate, fname))
1074                                 oidcpy(&oid_stat->oid,
1075                                        &istate->cache[pos]->oid);
1076                         else
1077                                 hash_object_file(the_hash_algo, buf, size,
1078                                                  "blob", &oid_stat->oid);
1079                         fill_stat_data(&oid_stat->stat, &st);
1080                         oid_stat->valid = 1;
1081                 }
1082         }
1083
1084         add_patterns_from_buffer(buf, size, base, baselen, pl);
1085         return 0;
1086 }
1087
1088 static int add_patterns_from_buffer(char *buf, size_t size,
1089                                     const char *base, int baselen,
1090                                     struct pattern_list *pl)
1091 {
1092         int i, lineno = 1;
1093         char *entry;
1094
1095         hashmap_init(&pl->recursive_hashmap, pl_hashmap_cmp, NULL, 0);
1096         hashmap_init(&pl->parent_hashmap, pl_hashmap_cmp, NULL, 0);
1097
1098         pl->filebuf = buf;
1099
1100         if (skip_utf8_bom(&buf, size))
1101                 size -= buf - pl->filebuf;
1102
1103         entry = buf;
1104
1105         for (i = 0; i < size; i++) {
1106                 if (buf[i] == '\n') {
1107                         if (entry != buf + i && entry[0] != '#') {
1108                                 buf[i - (i && buf[i-1] == '\r')] = 0;
1109                                 trim_trailing_spaces(entry);
1110                                 add_pattern(entry, base, baselen, pl, lineno);
1111                         }
1112                         lineno++;
1113                         entry = buf + i + 1;
1114                 }
1115         }
1116         return 0;
1117 }
1118
1119 int add_patterns_from_file_to_list(const char *fname, const char *base,
1120                                    int baselen, struct pattern_list *pl,
1121                                    struct index_state *istate)
1122 {
1123         return add_patterns(fname, base, baselen, pl, istate, NULL);
1124 }
1125
1126 int add_patterns_from_blob_to_list(
1127         struct object_id *oid,
1128         const char *base, int baselen,
1129         struct pattern_list *pl)
1130 {
1131         char *buf;
1132         size_t size;
1133         int r;
1134
1135         r = do_read_blob(oid, NULL, &size, &buf);
1136         if (r != 1)
1137                 return r;
1138
1139         add_patterns_from_buffer(buf, size, base, baselen, pl);
1140         return 0;
1141 }
1142
1143 struct pattern_list *add_pattern_list(struct dir_struct *dir,
1144                                       int group_type, const char *src)
1145 {
1146         struct pattern_list *pl;
1147         struct exclude_list_group *group;
1148
1149         group = &dir->exclude_list_group[group_type];
1150         ALLOC_GROW(group->pl, group->nr + 1, group->alloc);
1151         pl = &group->pl[group->nr++];
1152         memset(pl, 0, sizeof(*pl));
1153         pl->src = src;
1154         return pl;
1155 }
1156
1157 /*
1158  * Used to set up core.excludesfile and .git/info/exclude lists.
1159  */
1160 static void add_patterns_from_file_1(struct dir_struct *dir, const char *fname,
1161                                      struct oid_stat *oid_stat)
1162 {
1163         struct pattern_list *pl;
1164         /*
1165          * catch setup_standard_excludes() that's called before
1166          * dir->untracked is assigned. That function behaves
1167          * differently when dir->untracked is non-NULL.
1168          */
1169         if (!dir->untracked)
1170                 dir->unmanaged_exclude_files++;
1171         pl = add_pattern_list(dir, EXC_FILE, fname);
1172         if (add_patterns(fname, "", 0, pl, NULL, oid_stat) < 0)
1173                 die(_("cannot use %s as an exclude file"), fname);
1174 }
1175
1176 void add_patterns_from_file(struct dir_struct *dir, const char *fname)
1177 {
1178         dir->unmanaged_exclude_files++; /* see validate_untracked_cache() */
1179         add_patterns_from_file_1(dir, fname, NULL);
1180 }
1181
1182 int match_basename(const char *basename, int basenamelen,
1183                    const char *pattern, int prefix, int patternlen,
1184                    unsigned flags)
1185 {
1186         if (prefix == patternlen) {
1187                 if (patternlen == basenamelen &&
1188                     !fspathncmp(pattern, basename, basenamelen))
1189                         return 1;
1190         } else if (flags & PATTERN_FLAG_ENDSWITH) {
1191                 /* "*literal" matching against "fooliteral" */
1192                 if (patternlen - 1 <= basenamelen &&
1193                     !fspathncmp(pattern + 1,
1194                                    basename + basenamelen - (patternlen - 1),
1195                                    patternlen - 1))
1196                         return 1;
1197         } else {
1198                 if (fnmatch_icase_mem(pattern, patternlen,
1199                                       basename, basenamelen,
1200                                       0) == 0)
1201                         return 1;
1202         }
1203         return 0;
1204 }
1205
1206 int match_pathname(const char *pathname, int pathlen,
1207                    const char *base, int baselen,
1208                    const char *pattern, int prefix, int patternlen,
1209                    unsigned flags)
1210 {
1211         const char *name;
1212         int namelen;
1213
1214         /*
1215          * match with FNM_PATHNAME; the pattern has base implicitly
1216          * in front of it.
1217          */
1218         if (*pattern == '/') {
1219                 pattern++;
1220                 patternlen--;
1221                 prefix--;
1222         }
1223
1224         /*
1225          * baselen does not count the trailing slash. base[] may or
1226          * may not end with a trailing slash though.
1227          */
1228         if (pathlen < baselen + 1 ||
1229             (baselen && pathname[baselen] != '/') ||
1230             fspathncmp(pathname, base, baselen))
1231                 return 0;
1232
1233         namelen = baselen ? pathlen - baselen - 1 : pathlen;
1234         name = pathname + pathlen - namelen;
1235
1236         if (prefix) {
1237                 /*
1238                  * if the non-wildcard part is longer than the
1239                  * remaining pathname, surely it cannot match.
1240                  */
1241                 if (prefix > namelen)
1242                         return 0;
1243
1244                 if (fspathncmp(pattern, name, prefix))
1245                         return 0;
1246                 pattern += prefix;
1247                 patternlen -= prefix;
1248                 name    += prefix;
1249                 namelen -= prefix;
1250
1251                 /*
1252                  * If the whole pattern did not have a wildcard,
1253                  * then our prefix match is all we need; we
1254                  * do not need to call fnmatch at all.
1255                  */
1256                 if (!patternlen && !namelen)
1257                         return 1;
1258         }
1259
1260         return fnmatch_icase_mem(pattern, patternlen,
1261                                  name, namelen,
1262                                  WM_PATHNAME) == 0;
1263 }
1264
1265 /*
1266  * Scan the given exclude list in reverse to see whether pathname
1267  * should be ignored.  The first match (i.e. the last on the list), if
1268  * any, determines the fate.  Returns the exclude_list element which
1269  * matched, or NULL for undecided.
1270  */
1271 static struct path_pattern *last_matching_pattern_from_list(const char *pathname,
1272                                                        int pathlen,
1273                                                        const char *basename,
1274                                                        int *dtype,
1275                                                        struct pattern_list *pl,
1276                                                        struct index_state *istate)
1277 {
1278         struct path_pattern *res = NULL; /* undecided */
1279         int i;
1280
1281         if (!pl->nr)
1282                 return NULL;    /* undefined */
1283
1284         for (i = pl->nr - 1; 0 <= i; i--) {
1285                 struct path_pattern *pattern = pl->patterns[i];
1286                 const char *exclude = pattern->pattern;
1287                 int prefix = pattern->nowildcardlen;
1288
1289                 if (pattern->flags & PATTERN_FLAG_MUSTBEDIR) {
1290                         *dtype = resolve_dtype(*dtype, istate, pathname, pathlen);
1291                         if (*dtype != DT_DIR)
1292                                 continue;
1293                 }
1294
1295                 if (pattern->flags & PATTERN_FLAG_NODIR) {
1296                         if (match_basename(basename,
1297                                            pathlen - (basename - pathname),
1298                                            exclude, prefix, pattern->patternlen,
1299                                            pattern->flags)) {
1300                                 res = pattern;
1301                                 break;
1302                         }
1303                         continue;
1304                 }
1305
1306                 assert(pattern->baselen == 0 ||
1307                        pattern->base[pattern->baselen - 1] == '/');
1308                 if (match_pathname(pathname, pathlen,
1309                                    pattern->base,
1310                                    pattern->baselen ? pattern->baselen - 1 : 0,
1311                                    exclude, prefix, pattern->patternlen,
1312                                    pattern->flags)) {
1313                         res = pattern;
1314                         break;
1315                 }
1316         }
1317         return res;
1318 }
1319
1320 /*
1321  * Scan the list of patterns to determine if the ordered list
1322  * of patterns matches on 'pathname'.
1323  *
1324  * Return 1 for a match, 0 for not matched and -1 for undecided.
1325  */
1326 enum pattern_match_result path_matches_pattern_list(
1327                                 const char *pathname, int pathlen,
1328                                 const char *basename, int *dtype,
1329                                 struct pattern_list *pl,
1330                                 struct index_state *istate)
1331 {
1332         struct path_pattern *pattern;
1333         struct strbuf parent_pathname = STRBUF_INIT;
1334         int result = NOT_MATCHED;
1335         const char *slash_pos;
1336
1337         if (!pl->use_cone_patterns) {
1338                 pattern = last_matching_pattern_from_list(pathname, pathlen, basename,
1339                                                         dtype, pl, istate);
1340                 if (pattern) {
1341                         if (pattern->flags & PATTERN_FLAG_NEGATIVE)
1342                                 return NOT_MATCHED;
1343                         else
1344                                 return MATCHED;
1345                 }
1346
1347                 return UNDECIDED;
1348         }
1349
1350         if (pl->full_cone)
1351                 return MATCHED;
1352
1353         strbuf_addch(&parent_pathname, '/');
1354         strbuf_add(&parent_pathname, pathname, pathlen);
1355
1356         if (hashmap_contains_path(&pl->recursive_hashmap,
1357                                   &parent_pathname)) {
1358                 result = MATCHED_RECURSIVE;
1359                 goto done;
1360         }
1361
1362         slash_pos = strrchr(parent_pathname.buf, '/');
1363
1364         if (slash_pos == parent_pathname.buf) {
1365                 /* include every file in root */
1366                 result = MATCHED;
1367                 goto done;
1368         }
1369
1370         strbuf_setlen(&parent_pathname, slash_pos - parent_pathname.buf);
1371
1372         if (hashmap_contains_path(&pl->parent_hashmap, &parent_pathname)) {
1373                 result = MATCHED;
1374                 goto done;
1375         }
1376
1377         if (hashmap_contains_parent(&pl->recursive_hashmap,
1378                                     pathname,
1379                                     &parent_pathname))
1380                 result = MATCHED_RECURSIVE;
1381
1382 done:
1383         strbuf_release(&parent_pathname);
1384         return result;
1385 }
1386
1387 static struct path_pattern *last_matching_pattern_from_lists(
1388                 struct dir_struct *dir, struct index_state *istate,
1389                 const char *pathname, int pathlen,
1390                 const char *basename, int *dtype_p)
1391 {
1392         int i, j;
1393         struct exclude_list_group *group;
1394         struct path_pattern *pattern;
1395         for (i = EXC_CMDL; i <= EXC_FILE; i++) {
1396                 group = &dir->exclude_list_group[i];
1397                 for (j = group->nr - 1; j >= 0; j--) {
1398                         pattern = last_matching_pattern_from_list(
1399                                 pathname, pathlen, basename, dtype_p,
1400                                 &group->pl[j], istate);
1401                         if (pattern)
1402                                 return pattern;
1403                 }
1404         }
1405         return NULL;
1406 }
1407
1408 /*
1409  * Loads the per-directory exclude list for the substring of base
1410  * which has a char length of baselen.
1411  */
1412 static void prep_exclude(struct dir_struct *dir,
1413                          struct index_state *istate,
1414                          const char *base, int baselen)
1415 {
1416         struct exclude_list_group *group;
1417         struct pattern_list *pl;
1418         struct exclude_stack *stk = NULL;
1419         struct untracked_cache_dir *untracked;
1420         int current;
1421
1422         group = &dir->exclude_list_group[EXC_DIRS];
1423
1424         /*
1425          * Pop the exclude lists from the EXCL_DIRS exclude_list_group
1426          * which originate from directories not in the prefix of the
1427          * path being checked.
1428          */
1429         while ((stk = dir->exclude_stack) != NULL) {
1430                 if (stk->baselen <= baselen &&
1431                     !strncmp(dir->basebuf.buf, base, stk->baselen))
1432                         break;
1433                 pl = &group->pl[dir->exclude_stack->exclude_ix];
1434                 dir->exclude_stack = stk->prev;
1435                 dir->pattern = NULL;
1436                 free((char *)pl->src); /* see strbuf_detach() below */
1437                 clear_pattern_list(pl);
1438                 free(stk);
1439                 group->nr--;
1440         }
1441
1442         /* Skip traversing into sub directories if the parent is excluded */
1443         if (dir->pattern)
1444                 return;
1445
1446         /*
1447          * Lazy initialization. All call sites currently just
1448          * memset(dir, 0, sizeof(*dir)) before use. Changing all of
1449          * them seems lots of work for little benefit.
1450          */
1451         if (!dir->basebuf.buf)
1452                 strbuf_init(&dir->basebuf, PATH_MAX);
1453
1454         /* Read from the parent directories and push them down. */
1455         current = stk ? stk->baselen : -1;
1456         strbuf_setlen(&dir->basebuf, current < 0 ? 0 : current);
1457         if (dir->untracked)
1458                 untracked = stk ? stk->ucd : dir->untracked->root;
1459         else
1460                 untracked = NULL;
1461
1462         while (current < baselen) {
1463                 const char *cp;
1464                 struct oid_stat oid_stat;
1465
1466                 stk = xcalloc(1, sizeof(*stk));
1467                 if (current < 0) {
1468                         cp = base;
1469                         current = 0;
1470                 } else {
1471                         cp = strchr(base + current + 1, '/');
1472                         if (!cp)
1473                                 die("oops in prep_exclude");
1474                         cp++;
1475                         untracked =
1476                                 lookup_untracked(dir->untracked, untracked,
1477                                                  base + current,
1478                                                  cp - base - current);
1479                 }
1480                 stk->prev = dir->exclude_stack;
1481                 stk->baselen = cp - base;
1482                 stk->exclude_ix = group->nr;
1483                 stk->ucd = untracked;
1484                 pl = add_pattern_list(dir, EXC_DIRS, NULL);
1485                 strbuf_add(&dir->basebuf, base + current, stk->baselen - current);
1486                 assert(stk->baselen == dir->basebuf.len);
1487
1488                 /* Abort if the directory is excluded */
1489                 if (stk->baselen) {
1490                         int dt = DT_DIR;
1491                         dir->basebuf.buf[stk->baselen - 1] = 0;
1492                         dir->pattern = last_matching_pattern_from_lists(dir,
1493                                                                         istate,
1494                                 dir->basebuf.buf, stk->baselen - 1,
1495                                 dir->basebuf.buf + current, &dt);
1496                         dir->basebuf.buf[stk->baselen - 1] = '/';
1497                         if (dir->pattern &&
1498                             dir->pattern->flags & PATTERN_FLAG_NEGATIVE)
1499                                 dir->pattern = NULL;
1500                         if (dir->pattern) {
1501                                 dir->exclude_stack = stk;
1502                                 return;
1503                         }
1504                 }
1505
1506                 /* Try to read per-directory file */
1507                 oidclr(&oid_stat.oid);
1508                 oid_stat.valid = 0;
1509                 if (dir->exclude_per_dir &&
1510                     /*
1511                      * If we know that no files have been added in
1512                      * this directory (i.e. valid_cached_dir() has
1513                      * been executed and set untracked->valid) ..
1514                      */
1515                     (!untracked || !untracked->valid ||
1516                      /*
1517                       * .. and .gitignore does not exist before
1518                       * (i.e. null exclude_oid). Then we can skip
1519                       * loading .gitignore, which would result in
1520                       * ENOENT anyway.
1521                       */
1522                      !is_null_oid(&untracked->exclude_oid))) {
1523                         /*
1524                          * dir->basebuf gets reused by the traversal, but we
1525                          * need fname to remain unchanged to ensure the src
1526                          * member of each struct path_pattern correctly
1527                          * back-references its source file.  Other invocations
1528                          * of add_pattern_list provide stable strings, so we
1529                          * strbuf_detach() and free() here in the caller.
1530                          */
1531                         struct strbuf sb = STRBUF_INIT;
1532                         strbuf_addbuf(&sb, &dir->basebuf);
1533                         strbuf_addstr(&sb, dir->exclude_per_dir);
1534                         pl->src = strbuf_detach(&sb, NULL);
1535                         add_patterns(pl->src, pl->src, stk->baselen, pl, istate,
1536                                      untracked ? &oid_stat : NULL);
1537                 }
1538                 /*
1539                  * NEEDSWORK: when untracked cache is enabled, prep_exclude()
1540                  * will first be called in valid_cached_dir() then maybe many
1541                  * times more in last_matching_pattern(). When the cache is
1542                  * used, last_matching_pattern() will not be called and
1543                  * reading .gitignore content will be a waste.
1544                  *
1545                  * So when it's called by valid_cached_dir() and we can get
1546                  * .gitignore SHA-1 from the index (i.e. .gitignore is not
1547                  * modified on work tree), we could delay reading the
1548                  * .gitignore content until we absolutely need it in
1549                  * last_matching_pattern(). Be careful about ignore rule
1550                  * order, though, if you do that.
1551                  */
1552                 if (untracked &&
1553                     !oideq(&oid_stat.oid, &untracked->exclude_oid)) {
1554                         invalidate_gitignore(dir->untracked, untracked);
1555                         oidcpy(&untracked->exclude_oid, &oid_stat.oid);
1556                 }
1557                 dir->exclude_stack = stk;
1558                 current = stk->baselen;
1559         }
1560         strbuf_setlen(&dir->basebuf, baselen);
1561 }
1562
1563 /*
1564  * Loads the exclude lists for the directory containing pathname, then
1565  * scans all exclude lists to determine whether pathname is excluded.
1566  * Returns the exclude_list element which matched, or NULL for
1567  * undecided.
1568  */
1569 struct path_pattern *last_matching_pattern(struct dir_struct *dir,
1570                                       struct index_state *istate,
1571                                       const char *pathname,
1572                                       int *dtype_p)
1573 {
1574         int pathlen = strlen(pathname);
1575         const char *basename = strrchr(pathname, '/');
1576         basename = (basename) ? basename+1 : pathname;
1577
1578         prep_exclude(dir, istate, pathname, basename-pathname);
1579
1580         if (dir->pattern)
1581                 return dir->pattern;
1582
1583         return last_matching_pattern_from_lists(dir, istate, pathname, pathlen,
1584                         basename, dtype_p);
1585 }
1586
1587 /*
1588  * Loads the exclude lists for the directory containing pathname, then
1589  * scans all exclude lists to determine whether pathname is excluded.
1590  * Returns 1 if true, otherwise 0.
1591  */
1592 int is_excluded(struct dir_struct *dir, struct index_state *istate,
1593                 const char *pathname, int *dtype_p)
1594 {
1595         struct path_pattern *pattern =
1596                 last_matching_pattern(dir, istate, pathname, dtype_p);
1597         if (pattern)
1598                 return pattern->flags & PATTERN_FLAG_NEGATIVE ? 0 : 1;
1599         return 0;
1600 }
1601
1602 static struct dir_entry *dir_entry_new(const char *pathname, int len)
1603 {
1604         struct dir_entry *ent;
1605
1606         FLEX_ALLOC_MEM(ent, name, pathname, len);
1607         ent->len = len;
1608         return ent;
1609 }
1610
1611 static struct dir_entry *dir_add_name(struct dir_struct *dir,
1612                                       struct index_state *istate,
1613                                       const char *pathname, int len)
1614 {
1615         if (index_file_exists(istate, pathname, len, ignore_case))
1616                 return NULL;
1617
1618         ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
1619         return dir->entries[dir->nr++] = dir_entry_new(pathname, len);
1620 }
1621
1622 struct dir_entry *dir_add_ignored(struct dir_struct *dir,
1623                                   struct index_state *istate,
1624                                   const char *pathname, int len)
1625 {
1626         if (!index_name_is_other(istate, pathname, len))
1627                 return NULL;
1628
1629         ALLOC_GROW(dir->ignored, dir->ignored_nr+1, dir->ignored_alloc);
1630         return dir->ignored[dir->ignored_nr++] = dir_entry_new(pathname, len);
1631 }
1632
1633 enum exist_status {
1634         index_nonexistent = 0,
1635         index_directory,
1636         index_gitdir
1637 };
1638
1639 /*
1640  * Do not use the alphabetically sorted index to look up
1641  * the directory name; instead, use the case insensitive
1642  * directory hash.
1643  */
1644 static enum exist_status directory_exists_in_index_icase(struct index_state *istate,
1645                                                          const char *dirname, int len)
1646 {
1647         struct cache_entry *ce;
1648
1649         if (index_dir_exists(istate, dirname, len))
1650                 return index_directory;
1651
1652         ce = index_file_exists(istate, dirname, len, ignore_case);
1653         if (ce && S_ISGITLINK(ce->ce_mode))
1654                 return index_gitdir;
1655
1656         return index_nonexistent;
1657 }
1658
1659 /*
1660  * The index sorts alphabetically by entry name, which
1661  * means that a gitlink sorts as '\0' at the end, while
1662  * a directory (which is defined not as an entry, but as
1663  * the files it contains) will sort with the '/' at the
1664  * end.
1665  */
1666 static enum exist_status directory_exists_in_index(struct index_state *istate,
1667                                                    const char *dirname, int len)
1668 {
1669         int pos;
1670
1671         if (ignore_case)
1672                 return directory_exists_in_index_icase(istate, dirname, len);
1673
1674         pos = index_name_pos(istate, dirname, len);
1675         if (pos < 0)
1676                 pos = -pos-1;
1677         while (pos < istate->cache_nr) {
1678                 const struct cache_entry *ce = istate->cache[pos++];
1679                 unsigned char endchar;
1680
1681                 if (strncmp(ce->name, dirname, len))
1682                         break;
1683                 endchar = ce->name[len];
1684                 if (endchar > '/')
1685                         break;
1686                 if (endchar == '/')
1687                         return index_directory;
1688                 if (!endchar && S_ISGITLINK(ce->ce_mode))
1689                         return index_gitdir;
1690         }
1691         return index_nonexistent;
1692 }
1693
1694 /*
1695  * When we find a directory when traversing the filesystem, we
1696  * have three distinct cases:
1697  *
1698  *  - ignore it
1699  *  - see it as a directory
1700  *  - recurse into it
1701  *
1702  * and which one we choose depends on a combination of existing
1703  * git index contents and the flags passed into the directory
1704  * traversal routine.
1705  *
1706  * Case 1: If we *already* have entries in the index under that
1707  * directory name, we always recurse into the directory to see
1708  * all the files.
1709  *
1710  * Case 2: If we *already* have that directory name as a gitlink,
1711  * we always continue to see it as a gitlink, regardless of whether
1712  * there is an actual git directory there or not (it might not
1713  * be checked out as a subproject!)
1714  *
1715  * Case 3: if we didn't have it in the index previously, we
1716  * have a few sub-cases:
1717  *
1718  *  (a) if "show_other_directories" is true, we show it as
1719  *      just a directory, unless "hide_empty_directories" is
1720  *      also true, in which case we need to check if it contains any
1721  *      untracked and / or ignored files.
1722  *  (b) if it looks like a git directory, and we don't have
1723  *      'no_gitlinks' set we treat it as a gitlink, and show it
1724  *      as a directory.
1725  *  (c) otherwise, we recurse into it.
1726  */
1727 static enum path_treatment treat_directory(struct dir_struct *dir,
1728         struct index_state *istate,
1729         struct untracked_cache_dir *untracked,
1730         const char *dirname, int len, int baselen, int excluded,
1731         const struct pathspec *pathspec)
1732 {
1733         /*
1734          * WARNING: From this function, you can return path_recurse or you
1735          *          can call read_directory_recursive() (or neither), but
1736          *          you CAN'T DO BOTH.
1737          */
1738         enum path_treatment state;
1739         int matches_how = 0;
1740         int nested_repo = 0, check_only, stop_early;
1741         int old_ignored_nr, old_untracked_nr;
1742         /* The "len-1" is to strip the final '/' */
1743         enum exist_status status = directory_exists_in_index(istate, dirname, len-1);
1744
1745         if (status == index_directory)
1746                 return path_recurse;
1747         if (status == index_gitdir)
1748                 return path_none;
1749         if (status != index_nonexistent)
1750                 BUG("Unhandled value for directory_exists_in_index: %d\n", status);
1751
1752         /*
1753          * We don't want to descend into paths that don't match the necessary
1754          * patterns.  Clearly, if we don't have a pathspec, then we can't check
1755          * for matching patterns.  Also, if (excluded) then we know we matched
1756          * the exclusion patterns so as an optimization we can skip checking
1757          * for matching patterns.
1758          */
1759         if (pathspec && !excluded) {
1760                 matches_how = do_match_pathspec(istate, pathspec, dirname, len,
1761                                                 0 /* prefix */, NULL /* seen */,
1762                                                 DO_MATCH_LEADING_PATHSPEC);
1763                 if (!matches_how)
1764                         return path_none;
1765         }
1766
1767
1768         if ((dir->flags & DIR_SKIP_NESTED_GIT) ||
1769                 !(dir->flags & DIR_NO_GITLINKS)) {
1770                 struct strbuf sb = STRBUF_INIT;
1771                 strbuf_addstr(&sb, dirname);
1772                 nested_repo = is_nonbare_repository_dir(&sb);
1773                 strbuf_release(&sb);
1774         }
1775         if (nested_repo)
1776                 return ((dir->flags & DIR_SKIP_NESTED_GIT) ? path_none :
1777                         (excluded ? path_excluded : path_untracked));
1778
1779         if (!(dir->flags & DIR_SHOW_OTHER_DIRECTORIES)) {
1780                 if (excluded &&
1781                     (dir->flags & DIR_SHOW_IGNORED_TOO) &&
1782                     (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING)) {
1783
1784                         /*
1785                          * This is an excluded directory and we are
1786                          * showing ignored paths that match an exclude
1787                          * pattern.  (e.g. show directory as ignored
1788                          * only if it matches an exclude pattern).
1789                          * This path will either be 'path_excluded`
1790                          * (if we are showing empty directories or if
1791                          * the directory is not empty), or will be
1792                          * 'path_none' (empty directory, and we are
1793                          * not showing empty directories).
1794                          */
1795                         if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
1796                                 return path_excluded;
1797
1798                         if (read_directory_recursive(dir, istate, dirname, len,
1799                                                      untracked, 1, 1, pathspec) == path_excluded)
1800                                 return path_excluded;
1801
1802                         return path_none;
1803                 }
1804                 return path_recurse;
1805         }
1806
1807         /* This is the "show_other_directories" case */
1808
1809         /*
1810          * If we have a pathspec which could match something _below_ this
1811          * directory (e.g. when checking 'subdir/' having a pathspec like
1812          * 'subdir/some/deep/path/file' or 'subdir/widget-*.c'), then we
1813          * need to recurse.
1814          */
1815         if (matches_how == MATCHED_RECURSIVELY_LEADING_PATHSPEC)
1816                 return path_recurse;
1817
1818         /*
1819          * Other than the path_recurse case immediately above, we only need
1820          * to recurse into untracked/ignored directories if either of the
1821          * following bits is set:
1822          *   - DIR_SHOW_IGNORED_TOO (because then we need to determine if
1823          *                           there are ignored directories below)
1824          *   - DIR_HIDE_EMPTY_DIRECTORIES (because we have to determine if
1825          *                                 the directory is empty)
1826          */
1827         if (!(dir->flags & (DIR_SHOW_IGNORED_TOO | DIR_HIDE_EMPTY_DIRECTORIES)))
1828                 return excluded ? path_excluded : path_untracked;
1829
1830         /*
1831          * ...and even if DIR_SHOW_IGNORED_TOO is set, we can still avoid
1832          * recursing into ignored directories if the path is excluded and
1833          * DIR_SHOW_IGNORED_TOO_MODE_MATCHING is also set.
1834          */
1835         if (excluded &&
1836             (dir->flags & DIR_SHOW_IGNORED_TOO) &&
1837             (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING))
1838                 return path_excluded;
1839
1840         /*
1841          * If we have we don't want to know the all the paths under an
1842          * untracked or ignored directory, we still need to go into the
1843          * directory to determine if it is empty (because an empty directory
1844          * should be path_none instead of path_excluded or path_untracked).
1845          */
1846         check_only = ((dir->flags & DIR_HIDE_EMPTY_DIRECTORIES) &&
1847                       !(dir->flags & DIR_SHOW_IGNORED_TOO));
1848
1849         /*
1850          * However, there's another optimization possible as a subset of
1851          * check_only, based on the cases we have to consider:
1852          *   A) Directory matches no exclude patterns:
1853          *     * Directory is empty => path_none
1854          *     * Directory has an untracked file under it => path_untracked
1855          *     * Directory has only ignored files under it => path_excluded
1856          *   B) Directory matches an exclude pattern:
1857          *     * Directory is empty => path_none
1858          *     * Directory has an untracked file under it => path_excluded
1859          *     * Directory has only ignored files under it => path_excluded
1860          * In case A, we can exit as soon as we've found an untracked
1861          * file but otherwise have to walk all files.  In case B, though,
1862          * we can stop at the first file we find under the directory.
1863          */
1864         stop_early = check_only && excluded;
1865
1866         /*
1867          * If /every/ file within an untracked directory is ignored, then
1868          * we want to treat the directory as ignored (for e.g. status
1869          * --porcelain), without listing the individual ignored files
1870          * underneath.  To do so, we'll save the current ignored_nr, and
1871          * pop all the ones added after it if it turns out the entire
1872          * directory is ignored.  Also, when DIR_SHOW_IGNORED_TOO and
1873          * !DIR_KEEP_UNTRACKED_CONTENTS then we don't want to show
1874          * untracked paths so will need to pop all those off the last
1875          * after we traverse.
1876          */
1877         old_ignored_nr = dir->ignored_nr;
1878         old_untracked_nr = dir->nr;
1879
1880         /* Actually recurse into dirname now, we'll fixup the state later. */
1881         untracked = lookup_untracked(dir->untracked, untracked,
1882                                      dirname + baselen, len - baselen);
1883         state = read_directory_recursive(dir, istate, dirname, len, untracked,
1884                                          check_only, stop_early, pathspec);
1885
1886         /* There are a variety of reasons we may need to fixup the state... */
1887         if (state == path_excluded) {
1888                 /* state == path_excluded implies all paths under
1889                  * dirname were ignored...
1890                  *
1891                  * if running e.g. `git status --porcelain --ignored=matching`,
1892                  * then we want to see the subpaths that are ignored.
1893                  *
1894                  * if running e.g. just `git status --porcelain`, then
1895                  * we just want the directory itself to be listed as ignored
1896                  * and not the individual paths underneath.
1897                  */
1898                 int want_ignored_subpaths =
1899                         ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
1900                          (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING));
1901
1902                 if (want_ignored_subpaths) {
1903                         /*
1904                          * with --ignored=matching, we want the subpaths
1905                          * INSTEAD of the directory itself.
1906                          */
1907                         state = path_none;
1908                 } else {
1909                         int i;
1910                         for (i = old_ignored_nr + 1; i<dir->ignored_nr; ++i)
1911                                 FREE_AND_NULL(dir->ignored[i]);
1912                         dir->ignored_nr = old_ignored_nr;
1913                 }
1914         }
1915
1916         /*
1917          * We may need to ignore some of the untracked paths we found while
1918          * traversing subdirectories.
1919          */
1920         if ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
1921             !(dir->flags & DIR_KEEP_UNTRACKED_CONTENTS)) {
1922                 int i;
1923                 for (i = old_untracked_nr + 1; i<dir->nr; ++i)
1924                         FREE_AND_NULL(dir->entries[i]);
1925                 dir->nr = old_untracked_nr;
1926         }
1927
1928         /*
1929          * If there is nothing under the current directory and we are not
1930          * hiding empty directories, then we need to report on the
1931          * untracked or ignored status of the directory itself.
1932          */
1933         if (state == path_none && !(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
1934                 state = excluded ? path_excluded : path_untracked;
1935
1936         return state;
1937 }
1938
1939 /*
1940  * This is an inexact early pruning of any recursive directory
1941  * reading - if the path cannot possibly be in the pathspec,
1942  * return true, and we'll skip it early.
1943  */
1944 static int simplify_away(const char *path, int pathlen,
1945                          const struct pathspec *pathspec)
1946 {
1947         int i;
1948
1949         if (!pathspec || !pathspec->nr)
1950                 return 0;
1951
1952         GUARD_PATHSPEC(pathspec,
1953                        PATHSPEC_FROMTOP |
1954                        PATHSPEC_MAXDEPTH |
1955                        PATHSPEC_LITERAL |
1956                        PATHSPEC_GLOB |
1957                        PATHSPEC_ICASE |
1958                        PATHSPEC_EXCLUDE |
1959                        PATHSPEC_ATTR);
1960
1961         for (i = 0; i < pathspec->nr; i++) {
1962                 const struct pathspec_item *item = &pathspec->items[i];
1963                 int len = item->nowildcard_len;
1964
1965                 if (len > pathlen)
1966                         len = pathlen;
1967                 if (!ps_strncmp(item, item->match, path, len))
1968                         return 0;
1969         }
1970
1971         return 1;
1972 }
1973
1974 /*
1975  * This function tells us whether an excluded path matches a
1976  * list of "interesting" pathspecs. That is, whether a path matched
1977  * by any of the pathspecs could possibly be ignored by excluding
1978  * the specified path. This can happen if:
1979  *
1980  *   1. the path is mentioned explicitly in the pathspec
1981  *
1982  *   2. the path is a directory prefix of some element in the
1983  *      pathspec
1984  */
1985 static int exclude_matches_pathspec(const char *path, int pathlen,
1986                                     const struct pathspec *pathspec)
1987 {
1988         int i;
1989
1990         if (!pathspec || !pathspec->nr)
1991                 return 0;
1992
1993         GUARD_PATHSPEC(pathspec,
1994                        PATHSPEC_FROMTOP |
1995                        PATHSPEC_MAXDEPTH |
1996                        PATHSPEC_LITERAL |
1997                        PATHSPEC_GLOB |
1998                        PATHSPEC_ICASE |
1999                        PATHSPEC_EXCLUDE);
2000
2001         for (i = 0; i < pathspec->nr; i++) {
2002                 const struct pathspec_item *item = &pathspec->items[i];
2003                 int len = item->nowildcard_len;
2004
2005                 if (len == pathlen &&
2006                     !ps_strncmp(item, item->match, path, pathlen))
2007                         return 1;
2008                 if (len > pathlen &&
2009                     item->match[pathlen] == '/' &&
2010                     !ps_strncmp(item, item->match, path, pathlen))
2011                         return 1;
2012         }
2013         return 0;
2014 }
2015
2016 static int get_index_dtype(struct index_state *istate,
2017                            const char *path, int len)
2018 {
2019         int pos;
2020         const struct cache_entry *ce;
2021
2022         ce = index_file_exists(istate, path, len, 0);
2023         if (ce) {
2024                 if (!ce_uptodate(ce))
2025                         return DT_UNKNOWN;
2026                 if (S_ISGITLINK(ce->ce_mode))
2027                         return DT_DIR;
2028                 /*
2029                  * Nobody actually cares about the
2030                  * difference between DT_LNK and DT_REG
2031                  */
2032                 return DT_REG;
2033         }
2034
2035         /* Try to look it up as a directory */
2036         pos = index_name_pos(istate, path, len);
2037         if (pos >= 0)
2038                 return DT_UNKNOWN;
2039         pos = -pos-1;
2040         while (pos < istate->cache_nr) {
2041                 ce = istate->cache[pos++];
2042                 if (strncmp(ce->name, path, len))
2043                         break;
2044                 if (ce->name[len] > '/')
2045                         break;
2046                 if (ce->name[len] < '/')
2047                         continue;
2048                 if (!ce_uptodate(ce))
2049                         break;  /* continue? */
2050                 return DT_DIR;
2051         }
2052         return DT_UNKNOWN;
2053 }
2054
2055 static int resolve_dtype(int dtype, struct index_state *istate,
2056                          const char *path, int len)
2057 {
2058         struct stat st;
2059
2060         if (dtype != DT_UNKNOWN)
2061                 return dtype;
2062         dtype = get_index_dtype(istate, path, len);
2063         if (dtype != DT_UNKNOWN)
2064                 return dtype;
2065         if (lstat(path, &st))
2066                 return dtype;
2067         if (S_ISREG(st.st_mode))
2068                 return DT_REG;
2069         if (S_ISDIR(st.st_mode))
2070                 return DT_DIR;
2071         if (S_ISLNK(st.st_mode))
2072                 return DT_LNK;
2073         return dtype;
2074 }
2075
2076 static enum path_treatment treat_path_fast(struct dir_struct *dir,
2077                                            struct untracked_cache_dir *untracked,
2078                                            struct cached_dir *cdir,
2079                                            struct index_state *istate,
2080                                            struct strbuf *path,
2081                                            int baselen,
2082                                            const struct pathspec *pathspec)
2083 {
2084         /*
2085          * WARNING: From this function, you can return path_recurse or you
2086          *          can call read_directory_recursive() (or neither), but
2087          *          you CAN'T DO BOTH.
2088          */
2089         strbuf_setlen(path, baselen);
2090         if (!cdir->ucd) {
2091                 strbuf_addstr(path, cdir->file);
2092                 return path_untracked;
2093         }
2094         strbuf_addstr(path, cdir->ucd->name);
2095         /* treat_one_path() does this before it calls treat_directory() */
2096         strbuf_complete(path, '/');
2097         if (cdir->ucd->check_only)
2098                 /*
2099                  * check_only is set as a result of treat_directory() getting
2100                  * to its bottom. Verify again the same set of directories
2101                  * with check_only set.
2102                  */
2103                 return read_directory_recursive(dir, istate, path->buf, path->len,
2104                                                 cdir->ucd, 1, 0, pathspec);
2105         /*
2106          * We get path_recurse in the first run when
2107          * directory_exists_in_index() returns index_nonexistent. We
2108          * are sure that new changes in the index does not impact the
2109          * outcome. Return now.
2110          */
2111         return path_recurse;
2112 }
2113
2114 static enum path_treatment treat_path(struct dir_struct *dir,
2115                                       struct untracked_cache_dir *untracked,
2116                                       struct cached_dir *cdir,
2117                                       struct index_state *istate,
2118                                       struct strbuf *path,
2119                                       int baselen,
2120                                       const struct pathspec *pathspec)
2121 {
2122         int has_path_in_index, dtype, excluded;
2123
2124         if (!cdir->d_name)
2125                 return treat_path_fast(dir, untracked, cdir, istate, path,
2126                                        baselen, pathspec);
2127         if (is_dot_or_dotdot(cdir->d_name) || !fspathcmp(cdir->d_name, ".git"))
2128                 return path_none;
2129         strbuf_setlen(path, baselen);
2130         strbuf_addstr(path, cdir->d_name);
2131         if (simplify_away(path->buf, path->len, pathspec))
2132                 return path_none;
2133
2134         dtype = resolve_dtype(cdir->d_type, istate, path->buf, path->len);
2135
2136         /* Always exclude indexed files */
2137         has_path_in_index = !!index_file_exists(istate, path->buf, path->len,
2138                                                 ignore_case);
2139         if (dtype != DT_DIR && has_path_in_index)
2140                 return path_none;
2141
2142         /*
2143          * When we are looking at a directory P in the working tree,
2144          * there are three cases:
2145          *
2146          * (1) P exists in the index.  Everything inside the directory P in
2147          * the working tree needs to go when P is checked out from the
2148          * index.
2149          *
2150          * (2) P does not exist in the index, but there is P/Q in the index.
2151          * We know P will stay a directory when we check out the contents
2152          * of the index, but we do not know yet if there is a directory
2153          * P/Q in the working tree to be killed, so we need to recurse.
2154          *
2155          * (3) P does not exist in the index, and there is no P/Q in the index
2156          * to require P to be a directory, either.  Only in this case, we
2157          * know that everything inside P will not be killed without
2158          * recursing.
2159          */
2160         if ((dir->flags & DIR_COLLECT_KILLED_ONLY) &&
2161             (dtype == DT_DIR) &&
2162             !has_path_in_index &&
2163             (directory_exists_in_index(istate, path->buf, path->len) == index_nonexistent))
2164                 return path_none;
2165
2166         excluded = is_excluded(dir, istate, path->buf, &dtype);
2167
2168         /*
2169          * Excluded? If we don't explicitly want to show
2170          * ignored files, ignore it
2171          */
2172         if (excluded && !(dir->flags & (DIR_SHOW_IGNORED|DIR_SHOW_IGNORED_TOO)))
2173                 return path_excluded;
2174
2175         switch (dtype) {
2176         default:
2177                 return path_none;
2178         case DT_DIR:
2179                 /*
2180                  * WARNING: Do not ignore/amend the return value from
2181                  * treat_directory(), and especially do not change it to return
2182                  * path_recurse as that can cause exponential slowdown.
2183                  * Instead, modify treat_directory() to return the right value.
2184                  */
2185                 strbuf_addch(path, '/');
2186                 return treat_directory(dir, istate, untracked,
2187                                        path->buf, path->len,
2188                                        baselen, excluded, pathspec);
2189         case DT_REG:
2190         case DT_LNK:
2191                 if (excluded)
2192                         return path_excluded;
2193                 if (pathspec &&
2194                     !do_match_pathspec(istate, pathspec, path->buf, path->len,
2195                                        0 /* prefix */, NULL /* seen */,
2196                                        0 /* flags */))
2197                         return path_none;
2198                 return path_untracked;
2199         }
2200 }
2201
2202 static void add_untracked(struct untracked_cache_dir *dir, const char *name)
2203 {
2204         if (!dir)
2205                 return;
2206         ALLOC_GROW(dir->untracked, dir->untracked_nr + 1,
2207                    dir->untracked_alloc);
2208         dir->untracked[dir->untracked_nr++] = xstrdup(name);
2209 }
2210
2211 static int valid_cached_dir(struct dir_struct *dir,
2212                             struct untracked_cache_dir *untracked,
2213                             struct index_state *istate,
2214                             struct strbuf *path,
2215                             int check_only)
2216 {
2217         struct stat st;
2218
2219         if (!untracked)
2220                 return 0;
2221
2222         /*
2223          * With fsmonitor, we can trust the untracked cache's valid field.
2224          */
2225         refresh_fsmonitor(istate);
2226         if (!(dir->untracked->use_fsmonitor && untracked->valid)) {
2227                 if (lstat(path->len ? path->buf : ".", &st)) {
2228                         memset(&untracked->stat_data, 0, sizeof(untracked->stat_data));
2229                         return 0;
2230                 }
2231                 if (!untracked->valid ||
2232                         match_stat_data_racy(istate, &untracked->stat_data, &st)) {
2233                         fill_stat_data(&untracked->stat_data, &st);
2234                         return 0;
2235                 }
2236         }
2237
2238         if (untracked->check_only != !!check_only)
2239                 return 0;
2240
2241         /*
2242          * prep_exclude will be called eventually on this directory,
2243          * but it's called much later in last_matching_pattern(). We
2244          * need it now to determine the validity of the cache for this
2245          * path. The next calls will be nearly no-op, the way
2246          * prep_exclude() is designed.
2247          */
2248         if (path->len && path->buf[path->len - 1] != '/') {
2249                 strbuf_addch(path, '/');
2250                 prep_exclude(dir, istate, path->buf, path->len);
2251                 strbuf_setlen(path, path->len - 1);
2252         } else
2253                 prep_exclude(dir, istate, path->buf, path->len);
2254
2255         /* hopefully prep_exclude() haven't invalidated this entry... */
2256         return untracked->valid;
2257 }
2258
2259 static int open_cached_dir(struct cached_dir *cdir,
2260                            struct dir_struct *dir,
2261                            struct untracked_cache_dir *untracked,
2262                            struct index_state *istate,
2263                            struct strbuf *path,
2264                            int check_only)
2265 {
2266         const char *c_path;
2267
2268         memset(cdir, 0, sizeof(*cdir));
2269         cdir->untracked = untracked;
2270         if (valid_cached_dir(dir, untracked, istate, path, check_only))
2271                 return 0;
2272         c_path = path->len ? path->buf : ".";
2273         cdir->fdir = opendir(c_path);
2274         if (!cdir->fdir)
2275                 warning_errno(_("could not open directory '%s'"), c_path);
2276         if (dir->untracked) {
2277                 invalidate_directory(dir->untracked, untracked);
2278                 dir->untracked->dir_opened++;
2279         }
2280         if (!cdir->fdir)
2281                 return -1;
2282         return 0;
2283 }
2284
2285 static int read_cached_dir(struct cached_dir *cdir)
2286 {
2287         struct dirent *de;
2288
2289         if (cdir->fdir) {
2290                 de = readdir(cdir->fdir);
2291                 if (!de) {
2292                         cdir->d_name = NULL;
2293                         cdir->d_type = DT_UNKNOWN;
2294                         return -1;
2295                 }
2296                 cdir->d_name = de->d_name;
2297                 cdir->d_type = DTYPE(de);
2298                 return 0;
2299         }
2300         while (cdir->nr_dirs < cdir->untracked->dirs_nr) {
2301                 struct untracked_cache_dir *d = cdir->untracked->dirs[cdir->nr_dirs];
2302                 if (!d->recurse) {
2303                         cdir->nr_dirs++;
2304                         continue;
2305                 }
2306                 cdir->ucd = d;
2307                 cdir->nr_dirs++;
2308                 return 0;
2309         }
2310         cdir->ucd = NULL;
2311         if (cdir->nr_files < cdir->untracked->untracked_nr) {
2312                 struct untracked_cache_dir *d = cdir->untracked;
2313                 cdir->file = d->untracked[cdir->nr_files++];
2314                 return 0;
2315         }
2316         return -1;
2317 }
2318
2319 static void close_cached_dir(struct cached_dir *cdir)
2320 {
2321         if (cdir->fdir)
2322                 closedir(cdir->fdir);
2323         /*
2324          * We have gone through this directory and found no untracked
2325          * entries. Mark it valid.
2326          */
2327         if (cdir->untracked) {
2328                 cdir->untracked->valid = 1;
2329                 cdir->untracked->recurse = 1;
2330         }
2331 }
2332
2333 static void add_path_to_appropriate_result_list(struct dir_struct *dir,
2334         struct untracked_cache_dir *untracked,
2335         struct cached_dir *cdir,
2336         struct index_state *istate,
2337         struct strbuf *path,
2338         int baselen,
2339         const struct pathspec *pathspec,
2340         enum path_treatment state)
2341 {
2342         /* add the path to the appropriate result list */
2343         switch (state) {
2344         case path_excluded:
2345                 if (dir->flags & DIR_SHOW_IGNORED)
2346                         dir_add_name(dir, istate, path->buf, path->len);
2347                 else if ((dir->flags & DIR_SHOW_IGNORED_TOO) ||
2348                         ((dir->flags & DIR_COLLECT_IGNORED) &&
2349                         exclude_matches_pathspec(path->buf, path->len,
2350                                                  pathspec)))
2351                         dir_add_ignored(dir, istate, path->buf, path->len);
2352                 break;
2353
2354         case path_untracked:
2355                 if (dir->flags & DIR_SHOW_IGNORED)
2356                         break;
2357                 dir_add_name(dir, istate, path->buf, path->len);
2358                 if (cdir->fdir)
2359                         add_untracked(untracked, path->buf + baselen);
2360                 break;
2361
2362         default:
2363                 break;
2364         }
2365 }
2366
2367 /*
2368  * Read a directory tree. We currently ignore anything but
2369  * directories, regular files and symlinks. That's because git
2370  * doesn't handle them at all yet. Maybe that will change some
2371  * day.
2372  *
2373  * Also, we ignore the name ".git" (even if it is not a directory).
2374  * That likely will not change.
2375  *
2376  * If 'stop_at_first_file' is specified, 'path_excluded' is returned
2377  * to signal that a file was found. This is the least significant value that
2378  * indicates that a file was encountered that does not depend on the order of
2379  * whether an untracked or excluded path was encountered first.
2380  *
2381  * Returns the most significant path_treatment value encountered in the scan.
2382  * If 'stop_at_first_file' is specified, `path_excluded` is the most
2383  * significant path_treatment value that will be returned.
2384  */
2385
2386 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
2387         struct index_state *istate, const char *base, int baselen,
2388         struct untracked_cache_dir *untracked, int check_only,
2389         int stop_at_first_file, const struct pathspec *pathspec)
2390 {
2391         /*
2392          * WARNING: Do NOT recurse unless path_recurse is returned from
2393          *          treat_path().  Recursing on any other return value
2394          *          can result in exponential slowdown.
2395          */
2396         struct cached_dir cdir;
2397         enum path_treatment state, subdir_state, dir_state = path_none;
2398         struct strbuf path = STRBUF_INIT;
2399
2400         strbuf_add(&path, base, baselen);
2401
2402         if (open_cached_dir(&cdir, dir, untracked, istate, &path, check_only))
2403                 goto out;
2404
2405         if (untracked)
2406                 untracked->check_only = !!check_only;
2407
2408         while (!read_cached_dir(&cdir)) {
2409                 /* check how the file or directory should be treated */
2410                 state = treat_path(dir, untracked, &cdir, istate, &path,
2411                                    baselen, pathspec);
2412
2413                 if (state > dir_state)
2414                         dir_state = state;
2415
2416                 /* recurse into subdir if instructed by treat_path */
2417                 if (state == path_recurse) {
2418                         struct untracked_cache_dir *ud;
2419                         ud = lookup_untracked(dir->untracked, untracked,
2420                                               path.buf + baselen,
2421                                               path.len - baselen);
2422                         subdir_state =
2423                                 read_directory_recursive(dir, istate, path.buf,
2424                                                          path.len, ud,
2425                                                          check_only, stop_at_first_file, pathspec);
2426                         if (subdir_state > dir_state)
2427                                 dir_state = subdir_state;
2428
2429                         if (pathspec &&
2430                             !match_pathspec(istate, pathspec, path.buf, path.len,
2431                                             0 /* prefix */, NULL,
2432                                             0 /* do NOT special case dirs */))
2433                                 state = path_none;
2434                 }
2435
2436                 if (check_only) {
2437                         if (stop_at_first_file) {
2438                                 /*
2439                                  * If stopping at first file, then
2440                                  * signal that a file was found by
2441                                  * returning `path_excluded`. This is
2442                                  * to return a consistent value
2443                                  * regardless of whether an ignored or
2444                                  * excluded file happened to be
2445                                  * encountered 1st.
2446                                  *
2447                                  * In current usage, the
2448                                  * `stop_at_first_file` is passed when
2449                                  * an ancestor directory has matched
2450                                  * an exclude pattern, so any found
2451                                  * files will be excluded.
2452                                  */
2453                                 if (dir_state >= path_excluded) {
2454                                         dir_state = path_excluded;
2455                                         break;
2456                                 }
2457                         }
2458
2459                         /* abort early if maximum state has been reached */
2460                         if (dir_state == path_untracked) {
2461                                 if (cdir.fdir)
2462                                         add_untracked(untracked, path.buf + baselen);
2463                                 break;
2464                         }
2465                         /* skip the add_path_to_appropriate_result_list() */
2466                         continue;
2467                 }
2468
2469                 add_path_to_appropriate_result_list(dir, untracked, &cdir,
2470                                                     istate, &path, baselen,
2471                                                     pathspec, state);
2472         }
2473         close_cached_dir(&cdir);
2474  out:
2475         strbuf_release(&path);
2476
2477         return dir_state;
2478 }
2479
2480 int cmp_dir_entry(const void *p1, const void *p2)
2481 {
2482         const struct dir_entry *e1 = *(const struct dir_entry **)p1;
2483         const struct dir_entry *e2 = *(const struct dir_entry **)p2;
2484
2485         return name_compare(e1->name, e1->len, e2->name, e2->len);
2486 }
2487
2488 /* check if *out lexically strictly contains *in */
2489 int check_dir_entry_contains(const struct dir_entry *out, const struct dir_entry *in)
2490 {
2491         return (out->len < in->len) &&
2492                 (out->name[out->len - 1] == '/') &&
2493                 !memcmp(out->name, in->name, out->len);
2494 }
2495
2496 static int treat_leading_path(struct dir_struct *dir,
2497                               struct index_state *istate,
2498                               const char *path, int len,
2499                               const struct pathspec *pathspec)
2500 {
2501         struct strbuf sb = STRBUF_INIT;
2502         struct strbuf subdir = STRBUF_INIT;
2503         int prevlen, baselen;
2504         const char *cp;
2505         struct cached_dir cdir;
2506         enum path_treatment state = path_none;
2507
2508         /*
2509          * For each directory component of path, we are going to check whether
2510          * that path is relevant given the pathspec.  For example, if path is
2511          *    foo/bar/baz/
2512          * then we will ask treat_path() whether we should go into foo, then
2513          * whether we should go into bar, then whether baz is relevant.
2514          * Checking each is important because e.g. if path is
2515          *    .git/info/
2516          * then we need to check .git to know we shouldn't traverse it.
2517          * If the return from treat_path() is:
2518          *    * path_none, for any path, we return false.
2519          *    * path_recurse, for all path components, we return true
2520          *    * <anything else> for some intermediate component, we make sure
2521          *        to add that path to the relevant list but return false
2522          *        signifying that we shouldn't recurse into it.
2523          */
2524
2525         while (len && path[len - 1] == '/')
2526                 len--;
2527         if (!len)
2528                 return 1;
2529
2530         memset(&cdir, 0, sizeof(cdir));
2531         cdir.d_type = DT_DIR;
2532         baselen = 0;
2533         prevlen = 0;
2534         while (1) {
2535                 prevlen = baselen + !!baselen;
2536                 cp = path + prevlen;
2537                 cp = memchr(cp, '/', path + len - cp);
2538                 if (!cp)
2539                         baselen = len;
2540                 else
2541                         baselen = cp - path;
2542                 strbuf_reset(&sb);
2543                 strbuf_add(&sb, path, baselen);
2544                 if (!is_directory(sb.buf))
2545                         break;
2546                 strbuf_reset(&sb);
2547                 strbuf_add(&sb, path, prevlen);
2548                 strbuf_reset(&subdir);
2549                 strbuf_add(&subdir, path+prevlen, baselen-prevlen);
2550                 cdir.d_name = subdir.buf;
2551                 state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen, pathspec);
2552
2553                 if (state != path_recurse)
2554                         break; /* do not recurse into it */
2555                 if (len <= baselen)
2556                         break; /* finished checking */
2557         }
2558         add_path_to_appropriate_result_list(dir, NULL, &cdir, istate,
2559                                             &sb, baselen, pathspec,
2560                                             state);
2561
2562         strbuf_release(&subdir);
2563         strbuf_release(&sb);
2564         return state == path_recurse;
2565 }
2566
2567 static const char *get_ident_string(void)
2568 {
2569         static struct strbuf sb = STRBUF_INIT;
2570         struct utsname uts;
2571
2572         if (sb.len)
2573                 return sb.buf;
2574         if (uname(&uts) < 0)
2575                 die_errno(_("failed to get kernel name and information"));
2576         strbuf_addf(&sb, "Location %s, system %s", get_git_work_tree(),
2577                     uts.sysname);
2578         return sb.buf;
2579 }
2580
2581 static int ident_in_untracked(const struct untracked_cache *uc)
2582 {
2583         /*
2584          * Previous git versions may have saved many NUL separated
2585          * strings in the "ident" field, but it is insane to manage
2586          * many locations, so just take care of the first one.
2587          */
2588
2589         return !strcmp(uc->ident.buf, get_ident_string());
2590 }
2591
2592 static void set_untracked_ident(struct untracked_cache *uc)
2593 {
2594         strbuf_reset(&uc->ident);
2595         strbuf_addstr(&uc->ident, get_ident_string());
2596
2597         /*
2598          * This strbuf used to contain a list of NUL separated
2599          * strings, so save NUL too for backward compatibility.
2600          */
2601         strbuf_addch(&uc->ident, 0);
2602 }
2603
2604 static void new_untracked_cache(struct index_state *istate)
2605 {
2606         struct untracked_cache *uc = xcalloc(1, sizeof(*uc));
2607         strbuf_init(&uc->ident, 100);
2608         uc->exclude_per_dir = ".gitignore";
2609         /* should be the same flags used by git-status */
2610         uc->dir_flags = DIR_SHOW_OTHER_DIRECTORIES | DIR_HIDE_EMPTY_DIRECTORIES;
2611         set_untracked_ident(uc);
2612         istate->untracked = uc;
2613         istate->cache_changed |= UNTRACKED_CHANGED;
2614 }
2615
2616 void add_untracked_cache(struct index_state *istate)
2617 {
2618         if (!istate->untracked) {
2619                 new_untracked_cache(istate);
2620         } else {
2621                 if (!ident_in_untracked(istate->untracked)) {
2622                         free_untracked_cache(istate->untracked);
2623                         new_untracked_cache(istate);
2624                 }
2625         }
2626 }
2627
2628 void remove_untracked_cache(struct index_state *istate)
2629 {
2630         if (istate->untracked) {
2631                 free_untracked_cache(istate->untracked);
2632                 istate->untracked = NULL;
2633                 istate->cache_changed |= UNTRACKED_CHANGED;
2634         }
2635 }
2636
2637 static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *dir,
2638                                                       int base_len,
2639                                                       const struct pathspec *pathspec)
2640 {
2641         struct untracked_cache_dir *root;
2642         static int untracked_cache_disabled = -1;
2643
2644         if (!dir->untracked)
2645                 return NULL;
2646         if (untracked_cache_disabled < 0)
2647                 untracked_cache_disabled = git_env_bool("GIT_DISABLE_UNTRACKED_CACHE", 0);
2648         if (untracked_cache_disabled)
2649                 return NULL;
2650
2651         /*
2652          * We only support $GIT_DIR/info/exclude and core.excludesfile
2653          * as the global ignore rule files. Any other additions
2654          * (e.g. from command line) invalidate the cache. This
2655          * condition also catches running setup_standard_excludes()
2656          * before setting dir->untracked!
2657          */
2658         if (dir->unmanaged_exclude_files)
2659                 return NULL;
2660
2661         /*
2662          * Optimize for the main use case only: whole-tree git
2663          * status. More work involved in treat_leading_path() if we
2664          * use cache on just a subset of the worktree. pathspec
2665          * support could make the matter even worse.
2666          */
2667         if (base_len || (pathspec && pathspec->nr))
2668                 return NULL;
2669
2670         /* Different set of flags may produce different results */
2671         if (dir->flags != dir->untracked->dir_flags ||
2672             /*
2673              * See treat_directory(), case index_nonexistent. Without
2674              * this flag, we may need to also cache .git file content
2675              * for the resolve_gitlink_ref() call, which we don't.
2676              */
2677             !(dir->flags & DIR_SHOW_OTHER_DIRECTORIES) ||
2678             /* We don't support collecting ignore files */
2679             (dir->flags & (DIR_SHOW_IGNORED | DIR_SHOW_IGNORED_TOO |
2680                            DIR_COLLECT_IGNORED)))
2681                 return NULL;
2682
2683         /*
2684          * If we use .gitignore in the cache and now you change it to
2685          * .gitexclude, everything will go wrong.
2686          */
2687         if (dir->exclude_per_dir != dir->untracked->exclude_per_dir &&
2688             strcmp(dir->exclude_per_dir, dir->untracked->exclude_per_dir))
2689                 return NULL;
2690
2691         /*
2692          * EXC_CMDL is not considered in the cache. If people set it,
2693          * skip the cache.
2694          */
2695         if (dir->exclude_list_group[EXC_CMDL].nr)
2696                 return NULL;
2697
2698         if (!ident_in_untracked(dir->untracked)) {
2699                 warning(_("untracked cache is disabled on this system or location"));
2700                 return NULL;
2701         }
2702
2703         if (!dir->untracked->root) {
2704                 const int len = sizeof(*dir->untracked->root);
2705                 dir->untracked->root = xmalloc(len);
2706                 memset(dir->untracked->root, 0, len);
2707         }
2708
2709         /* Validate $GIT_DIR/info/exclude and core.excludesfile */
2710         root = dir->untracked->root;
2711         if (!oideq(&dir->ss_info_exclude.oid,
2712                    &dir->untracked->ss_info_exclude.oid)) {
2713                 invalidate_gitignore(dir->untracked, root);
2714                 dir->untracked->ss_info_exclude = dir->ss_info_exclude;
2715         }
2716         if (!oideq(&dir->ss_excludes_file.oid,
2717                    &dir->untracked->ss_excludes_file.oid)) {
2718                 invalidate_gitignore(dir->untracked, root);
2719                 dir->untracked->ss_excludes_file = dir->ss_excludes_file;
2720         }
2721
2722         /* Make sure this directory is not dropped out at saving phase */
2723         root->recurse = 1;
2724         return root;
2725 }
2726
2727 int read_directory(struct dir_struct *dir, struct index_state *istate,
2728                    const char *path, int len, const struct pathspec *pathspec)
2729 {
2730         struct untracked_cache_dir *untracked;
2731
2732         trace_performance_enter();
2733
2734         if (has_symlink_leading_path(path, len)) {
2735                 trace_performance_leave("read directory %.*s", len, path);
2736                 return dir->nr;
2737         }
2738
2739         untracked = validate_untracked_cache(dir, len, pathspec);
2740         if (!untracked)
2741                 /*
2742                  * make sure untracked cache code path is disabled,
2743                  * e.g. prep_exclude()
2744                  */
2745                 dir->untracked = NULL;
2746         if (!len || treat_leading_path(dir, istate, path, len, pathspec))
2747                 read_directory_recursive(dir, istate, path, len, untracked, 0, 0, pathspec);
2748         QSORT(dir->entries, dir->nr, cmp_dir_entry);
2749         QSORT(dir->ignored, dir->ignored_nr, cmp_dir_entry);
2750
2751         trace_performance_leave("read directory %.*s", len, path);
2752         if (dir->untracked) {
2753                 static int force_untracked_cache = -1;
2754                 static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);
2755
2756                 if (force_untracked_cache < 0)
2757                         force_untracked_cache =
2758                                 git_env_bool("GIT_FORCE_UNTRACKED_CACHE", 0);
2759                 trace_printf_key(&trace_untracked_stats,
2760                                  "node creation: %u\n"
2761                                  "gitignore invalidation: %u\n"
2762                                  "directory invalidation: %u\n"
2763                                  "opendir: %u\n",
2764                                  dir->untracked->dir_created,
2765                                  dir->untracked->gitignore_invalidated,
2766                                  dir->untracked->dir_invalidated,
2767                                  dir->untracked->dir_opened);
2768                 if (force_untracked_cache &&
2769                         dir->untracked == istate->untracked &&
2770                     (dir->untracked->dir_opened ||
2771                      dir->untracked->gitignore_invalidated ||
2772                      dir->untracked->dir_invalidated))
2773                         istate->cache_changed |= UNTRACKED_CHANGED;
2774                 if (dir->untracked != istate->untracked) {
2775                         FREE_AND_NULL(dir->untracked);
2776                 }
2777         }
2778         return dir->nr;
2779 }
2780
2781 int file_exists(const char *f)
2782 {
2783         struct stat sb;
2784         return lstat(f, &sb) == 0;
2785 }
2786
2787 int repo_file_exists(struct repository *repo, const char *path)
2788 {
2789         if (repo != the_repository)
2790                 BUG("do not know how to check file existence in arbitrary repo");
2791
2792         return file_exists(path);
2793 }
2794
2795 static int cmp_icase(char a, char b)
2796 {
2797         if (a == b)
2798                 return 0;
2799         if (ignore_case)
2800                 return toupper(a) - toupper(b);
2801         return a - b;
2802 }
2803
2804 /*
2805  * Given two normalized paths (a trailing slash is ok), if subdir is
2806  * outside dir, return -1.  Otherwise return the offset in subdir that
2807  * can be used as relative path to dir.
2808  */
2809 int dir_inside_of(const char *subdir, const char *dir)
2810 {
2811         int offset = 0;
2812
2813         assert(dir && subdir && *dir && *subdir);
2814
2815         while (*dir && *subdir && !cmp_icase(*dir, *subdir)) {
2816                 dir++;
2817                 subdir++;
2818                 offset++;
2819         }
2820
2821         /* hel[p]/me vs hel[l]/yeah */
2822         if (*dir && *subdir)
2823                 return -1;
2824
2825         if (!*subdir)
2826                 return !*dir ? offset : -1; /* same dir */
2827
2828         /* foo/[b]ar vs foo/[] */
2829         if (is_dir_sep(dir[-1]))
2830                 return is_dir_sep(subdir[-1]) ? offset : -1;
2831
2832         /* foo[/]bar vs foo[] */
2833         return is_dir_sep(*subdir) ? offset + 1 : -1;
2834 }
2835
2836 int is_inside_dir(const char *dir)
2837 {
2838         char *cwd;
2839         int rc;
2840
2841         if (!dir)
2842                 return 0;
2843
2844         cwd = xgetcwd();
2845         rc = (dir_inside_of(cwd, dir) >= 0);
2846         free(cwd);
2847         return rc;
2848 }
2849
2850 int is_empty_dir(const char *path)
2851 {
2852         DIR *dir = opendir(path);
2853         struct dirent *e;
2854         int ret = 1;
2855
2856         if (!dir)
2857                 return 0;
2858
2859         while ((e = readdir(dir)) != NULL)
2860                 if (!is_dot_or_dotdot(e->d_name)) {
2861                         ret = 0;
2862                         break;
2863                 }
2864
2865         closedir(dir);
2866         return ret;
2867 }
2868
2869 static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up)
2870 {
2871         DIR *dir;
2872         struct dirent *e;
2873         int ret = 0, original_len = path->len, len, kept_down = 0;
2874         int only_empty = (flag & REMOVE_DIR_EMPTY_ONLY);
2875         int keep_toplevel = (flag & REMOVE_DIR_KEEP_TOPLEVEL);
2876         struct object_id submodule_head;
2877
2878         if ((flag & REMOVE_DIR_KEEP_NESTED_GIT) &&
2879             !resolve_gitlink_ref(path->buf, "HEAD", &submodule_head)) {
2880                 /* Do not descend and nuke a nested git work tree. */
2881                 if (kept_up)
2882                         *kept_up = 1;
2883                 return 0;
2884         }
2885
2886         flag &= ~REMOVE_DIR_KEEP_TOPLEVEL;
2887         dir = opendir(path->buf);
2888         if (!dir) {
2889                 if (errno == ENOENT)
2890                         return keep_toplevel ? -1 : 0;
2891                 else if (errno == EACCES && !keep_toplevel)
2892                         /*
2893                          * An empty dir could be removable even if it
2894                          * is unreadable:
2895                          */
2896                         return rmdir(path->buf);
2897                 else
2898                         return -1;
2899         }
2900         strbuf_complete(path, '/');
2901
2902         len = path->len;
2903         while ((e = readdir(dir)) != NULL) {
2904                 struct stat st;
2905                 if (is_dot_or_dotdot(e->d_name))
2906                         continue;
2907
2908                 strbuf_setlen(path, len);
2909                 strbuf_addstr(path, e->d_name);
2910                 if (lstat(path->buf, &st)) {
2911                         if (errno == ENOENT)
2912                                 /*
2913                                  * file disappeared, which is what we
2914                                  * wanted anyway
2915                                  */
2916                                 continue;
2917                         /* fall through */
2918                 } else if (S_ISDIR(st.st_mode)) {
2919                         if (!remove_dir_recurse(path, flag, &kept_down))
2920                                 continue; /* happy */
2921                 } else if (!only_empty &&
2922                            (!unlink(path->buf) || errno == ENOENT)) {
2923                         continue; /* happy, too */
2924                 }
2925
2926                 /* path too long, stat fails, or non-directory still exists */
2927                 ret = -1;
2928                 break;
2929         }
2930         closedir(dir);
2931
2932         strbuf_setlen(path, original_len);
2933         if (!ret && !keep_toplevel && !kept_down)
2934                 ret = (!rmdir(path->buf) || errno == ENOENT) ? 0 : -1;
2935         else if (kept_up)
2936                 /*
2937                  * report the uplevel that it is not an error that we
2938                  * did not rmdir() our directory.
2939                  */
2940                 *kept_up = !ret;
2941         return ret;
2942 }
2943
2944 int remove_dir_recursively(struct strbuf *path, int flag)
2945 {
2946         return remove_dir_recurse(path, flag, NULL);
2947 }
2948
2949 static GIT_PATH_FUNC(git_path_info_exclude, "info/exclude")
2950
2951 void setup_standard_excludes(struct dir_struct *dir)
2952 {
2953         dir->exclude_per_dir = ".gitignore";
2954
2955         /* core.excludesfile defaulting to $XDG_CONFIG_HOME/git/ignore */
2956         if (!excludes_file)
2957                 excludes_file = xdg_config_home("ignore");
2958         if (excludes_file && !access_or_warn(excludes_file, R_OK, 0))
2959                 add_patterns_from_file_1(dir, excludes_file,
2960                                          dir->untracked ? &dir->ss_excludes_file : NULL);
2961
2962         /* per repository user preference */
2963         if (startup_info->have_repository) {
2964                 const char *path = git_path_info_exclude();
2965                 if (!access_or_warn(path, R_OK, 0))
2966                         add_patterns_from_file_1(dir, path,
2967                                                  dir->untracked ? &dir->ss_info_exclude : NULL);
2968         }
2969 }
2970
2971 int remove_path(const char *name)
2972 {
2973         char *slash;
2974
2975         if (unlink(name) && !is_missing_file_error(errno))
2976                 return -1;
2977
2978         slash = strrchr(name, '/');
2979         if (slash) {
2980                 char *dirs = xstrdup(name);
2981                 slash = dirs + (slash - name);
2982                 do {
2983                         *slash = '\0';
2984                 } while (rmdir(dirs) == 0 && (slash = strrchr(dirs, '/')));
2985                 free(dirs);
2986         }
2987         return 0;
2988 }
2989
2990 /*
2991  * Frees memory within dir which was allocated for exclude lists and
2992  * the exclude_stack.  Does not free dir itself.
2993  */
2994 void clear_directory(struct dir_struct *dir)
2995 {
2996         int i, j;
2997         struct exclude_list_group *group;
2998         struct pattern_list *pl;
2999         struct exclude_stack *stk;
3000
3001         for (i = EXC_CMDL; i <= EXC_FILE; i++) {
3002                 group = &dir->exclude_list_group[i];
3003                 for (j = 0; j < group->nr; j++) {
3004                         pl = &group->pl[j];
3005                         if (i == EXC_DIRS)
3006                                 free((char *)pl->src);
3007                         clear_pattern_list(pl);
3008                 }
3009                 free(group->pl);
3010         }
3011
3012         stk = dir->exclude_stack;
3013         while (stk) {
3014                 struct exclude_stack *prev = stk->prev;
3015                 free(stk);
3016                 stk = prev;
3017         }
3018         strbuf_release(&dir->basebuf);
3019 }
3020
3021 struct ondisk_untracked_cache {
3022         struct stat_data info_exclude_stat;
3023         struct stat_data excludes_file_stat;
3024         uint32_t dir_flags;
3025 };
3026
3027 #define ouc_offset(x) offsetof(struct ondisk_untracked_cache, x)
3028
3029 struct write_data {
3030         int index;         /* number of written untracked_cache_dir */
3031         struct ewah_bitmap *check_only; /* from untracked_cache_dir */
3032         struct ewah_bitmap *valid;      /* from untracked_cache_dir */
3033         struct ewah_bitmap *sha1_valid; /* set if exclude_sha1 is not null */
3034         struct strbuf out;
3035         struct strbuf sb_stat;
3036         struct strbuf sb_sha1;
3037 };
3038
3039 static void stat_data_to_disk(struct stat_data *to, const struct stat_data *from)
3040 {
3041         to->sd_ctime.sec  = htonl(from->sd_ctime.sec);
3042         to->sd_ctime.nsec = htonl(from->sd_ctime.nsec);
3043         to->sd_mtime.sec  = htonl(from->sd_mtime.sec);
3044         to->sd_mtime.nsec = htonl(from->sd_mtime.nsec);
3045         to->sd_dev        = htonl(from->sd_dev);
3046         to->sd_ino        = htonl(from->sd_ino);
3047         to->sd_uid        = htonl(from->sd_uid);
3048         to->sd_gid        = htonl(from->sd_gid);
3049         to->sd_size       = htonl(from->sd_size);
3050 }
3051
3052 static void write_one_dir(struct untracked_cache_dir *untracked,
3053                           struct write_data *wd)
3054 {
3055         struct stat_data stat_data;
3056         struct strbuf *out = &wd->out;
3057         unsigned char intbuf[16];
3058         unsigned int intlen, value;
3059         int i = wd->index++;
3060
3061         /*
3062          * untracked_nr should be reset whenever valid is clear, but
3063          * for safety..
3064          */
3065         if (!untracked->valid) {
3066                 untracked->untracked_nr = 0;
3067                 untracked->check_only = 0;
3068         }
3069
3070         if (untracked->check_only)
3071                 ewah_set(wd->check_only, i);
3072         if (untracked->valid) {
3073                 ewah_set(wd->valid, i);
3074                 stat_data_to_disk(&stat_data, &untracked->stat_data);
3075                 strbuf_add(&wd->sb_stat, &stat_data, sizeof(stat_data));
3076         }
3077         if (!is_null_oid(&untracked->exclude_oid)) {
3078                 ewah_set(wd->sha1_valid, i);
3079                 strbuf_add(&wd->sb_sha1, untracked->exclude_oid.hash,
3080                            the_hash_algo->rawsz);
3081         }
3082
3083         intlen = encode_varint(untracked->untracked_nr, intbuf);
3084         strbuf_add(out, intbuf, intlen);
3085
3086         /* skip non-recurse directories */
3087         for (i = 0, value = 0; i < untracked->dirs_nr; i++)
3088                 if (untracked->dirs[i]->recurse)
3089                         value++;
3090         intlen = encode_varint(value, intbuf);
3091         strbuf_add(out, intbuf, intlen);
3092
3093         strbuf_add(out, untracked->name, strlen(untracked->name) + 1);
3094
3095         for (i = 0; i < untracked->untracked_nr; i++)
3096                 strbuf_add(out, untracked->untracked[i],
3097                            strlen(untracked->untracked[i]) + 1);
3098
3099         for (i = 0; i < untracked->dirs_nr; i++)
3100                 if (untracked->dirs[i]->recurse)
3101                         write_one_dir(untracked->dirs[i], wd);
3102 }
3103
3104 void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked)
3105 {
3106         struct ondisk_untracked_cache *ouc;
3107         struct write_data wd;
3108         unsigned char varbuf[16];
3109         int varint_len;
3110         const unsigned hashsz = the_hash_algo->rawsz;
3111
3112         ouc = xcalloc(1, sizeof(*ouc));
3113         stat_data_to_disk(&ouc->info_exclude_stat, &untracked->ss_info_exclude.stat);
3114         stat_data_to_disk(&ouc->excludes_file_stat, &untracked->ss_excludes_file.stat);
3115         ouc->dir_flags = htonl(untracked->dir_flags);
3116
3117         varint_len = encode_varint(untracked->ident.len, varbuf);
3118         strbuf_add(out, varbuf, varint_len);
3119         strbuf_addbuf(out, &untracked->ident);
3120
3121         strbuf_add(out, ouc, sizeof(*ouc));
3122         strbuf_add(out, untracked->ss_info_exclude.oid.hash, hashsz);
3123         strbuf_add(out, untracked->ss_excludes_file.oid.hash, hashsz);
3124         strbuf_add(out, untracked->exclude_per_dir, strlen(untracked->exclude_per_dir) + 1);
3125         FREE_AND_NULL(ouc);
3126
3127         if (!untracked->root) {
3128                 varint_len = encode_varint(0, varbuf);
3129                 strbuf_add(out, varbuf, varint_len);
3130                 return;
3131         }
3132
3133         wd.index      = 0;
3134         wd.check_only = ewah_new();
3135         wd.valid      = ewah_new();
3136         wd.sha1_valid = ewah_new();
3137         strbuf_init(&wd.out, 1024);
3138         strbuf_init(&wd.sb_stat, 1024);
3139         strbuf_init(&wd.sb_sha1, 1024);
3140         write_one_dir(untracked->root, &wd);
3141
3142         varint_len = encode_varint(wd.index, varbuf);
3143         strbuf_add(out, varbuf, varint_len);
3144         strbuf_addbuf(out, &wd.out);
3145         ewah_serialize_strbuf(wd.valid, out);
3146         ewah_serialize_strbuf(wd.check_only, out);
3147         ewah_serialize_strbuf(wd.sha1_valid, out);
3148         strbuf_addbuf(out, &wd.sb_stat);
3149         strbuf_addbuf(out, &wd.sb_sha1);
3150         strbuf_addch(out, '\0'); /* safe guard for string lists */
3151
3152         ewah_free(wd.valid);
3153         ewah_free(wd.check_only);
3154         ewah_free(wd.sha1_valid);
3155         strbuf_release(&wd.out);
3156         strbuf_release(&wd.sb_stat);
3157         strbuf_release(&wd.sb_sha1);
3158 }
3159
3160 static void free_untracked(struct untracked_cache_dir *ucd)
3161 {
3162         int i;
3163         if (!ucd)
3164                 return;
3165         for (i = 0; i < ucd->dirs_nr; i++)
3166                 free_untracked(ucd->dirs[i]);
3167         for (i = 0; i < ucd->untracked_nr; i++)
3168                 free(ucd->untracked[i]);
3169         free(ucd->untracked);
3170         free(ucd->dirs);
3171         free(ucd);
3172 }
3173
3174 void free_untracked_cache(struct untracked_cache *uc)
3175 {
3176         if (uc)
3177                 free_untracked(uc->root);
3178         free(uc);
3179 }
3180
3181 struct read_data {
3182         int index;
3183         struct untracked_cache_dir **ucd;
3184         struct ewah_bitmap *check_only;
3185         struct ewah_bitmap *valid;
3186         struct ewah_bitmap *sha1_valid;
3187         const unsigned char *data;
3188         const unsigned char *end;
3189 };
3190
3191 static void stat_data_from_disk(struct stat_data *to, const unsigned char *data)
3192 {
3193         memcpy(to, data, sizeof(*to));
3194         to->sd_ctime.sec  = ntohl(to->sd_ctime.sec);
3195         to->sd_ctime.nsec = ntohl(to->sd_ctime.nsec);
3196         to->sd_mtime.sec  = ntohl(to->sd_mtime.sec);
3197         to->sd_mtime.nsec = ntohl(to->sd_mtime.nsec);
3198         to->sd_dev        = ntohl(to->sd_dev);
3199         to->sd_ino        = ntohl(to->sd_ino);
3200         to->sd_uid        = ntohl(to->sd_uid);
3201         to->sd_gid        = ntohl(to->sd_gid);
3202         to->sd_size       = ntohl(to->sd_size);
3203 }
3204
3205 static int read_one_dir(struct untracked_cache_dir **untracked_,
3206                         struct read_data *rd)
3207 {
3208         struct untracked_cache_dir ud, *untracked;
3209         const unsigned char *data = rd->data, *end = rd->end;
3210         const unsigned char *eos;
3211         unsigned int value;
3212         int i;
3213
3214         memset(&ud, 0, sizeof(ud));
3215
3216         value = decode_varint(&data);
3217         if (data > end)
3218                 return -1;
3219         ud.recurse         = 1;
3220         ud.untracked_alloc = value;
3221         ud.untracked_nr    = value;
3222         if (ud.untracked_nr)
3223                 ALLOC_ARRAY(ud.untracked, ud.untracked_nr);
3224
3225         ud.dirs_alloc = ud.dirs_nr = decode_varint(&data);
3226         if (data > end)
3227                 return -1;
3228         ALLOC_ARRAY(ud.dirs, ud.dirs_nr);
3229
3230         eos = memchr(data, '\0', end - data);
3231         if (!eos || eos == end)
3232                 return -1;
3233
3234         *untracked_ = untracked = xmalloc(st_add3(sizeof(*untracked), eos - data, 1));
3235         memcpy(untracked, &ud, sizeof(ud));
3236         memcpy(untracked->name, data, eos - data + 1);
3237         data = eos + 1;
3238
3239         for (i = 0; i < untracked->untracked_nr; i++) {
3240                 eos = memchr(data, '\0', end - data);
3241                 if (!eos || eos == end)
3242                         return -1;
3243                 untracked->untracked[i] = xmemdupz(data, eos - data);
3244                 data = eos + 1;
3245         }
3246
3247         rd->ucd[rd->index++] = untracked;
3248         rd->data = data;
3249
3250         for (i = 0; i < untracked->dirs_nr; i++) {
3251                 if (read_one_dir(untracked->dirs + i, rd) < 0)
3252                         return -1;
3253         }
3254         return 0;
3255 }
3256
3257 static void set_check_only(size_t pos, void *cb)
3258 {
3259         struct read_data *rd = cb;
3260         struct untracked_cache_dir *ud = rd->ucd[pos];
3261         ud->check_only = 1;
3262 }
3263
3264 static void read_stat(size_t pos, void *cb)
3265 {
3266         struct read_data *rd = cb;
3267         struct untracked_cache_dir *ud = rd->ucd[pos];
3268         if (rd->data + sizeof(struct stat_data) > rd->end) {
3269                 rd->data = rd->end + 1;
3270                 return;
3271         }
3272         stat_data_from_disk(&ud->stat_data, rd->data);
3273         rd->data += sizeof(struct stat_data);
3274         ud->valid = 1;
3275 }
3276
3277 static void read_oid(size_t pos, void *cb)
3278 {
3279         struct read_data *rd = cb;
3280         struct untracked_cache_dir *ud = rd->ucd[pos];
3281         if (rd->data + the_hash_algo->rawsz > rd->end) {
3282                 rd->data = rd->end + 1;
3283                 return;
3284         }
3285         hashcpy(ud->exclude_oid.hash, rd->data);
3286         rd->data += the_hash_algo->rawsz;
3287 }
3288
3289 static void load_oid_stat(struct oid_stat *oid_stat, const unsigned char *data,
3290                           const unsigned char *sha1)
3291 {
3292         stat_data_from_disk(&oid_stat->stat, data);
3293         hashcpy(oid_stat->oid.hash, sha1);
3294         oid_stat->valid = 1;
3295 }
3296
3297 struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz)
3298 {
3299         struct untracked_cache *uc;
3300         struct read_data rd;
3301         const unsigned char *next = data, *end = (const unsigned char *)data + sz;
3302         const char *ident;
3303         int ident_len;
3304         ssize_t len;
3305         const char *exclude_per_dir;
3306         const unsigned hashsz = the_hash_algo->rawsz;
3307         const unsigned offset = sizeof(struct ondisk_untracked_cache);
3308         const unsigned exclude_per_dir_offset = offset + 2 * hashsz;
3309
3310         if (sz <= 1 || end[-1] != '\0')
3311                 return NULL;
3312         end--;
3313
3314         ident_len = decode_varint(&next);
3315         if (next + ident_len > end)
3316                 return NULL;
3317         ident = (const char *)next;
3318         next += ident_len;
3319
3320         if (next + exclude_per_dir_offset + 1 > end)
3321                 return NULL;
3322
3323         uc = xcalloc(1, sizeof(*uc));
3324         strbuf_init(&uc->ident, ident_len);
3325         strbuf_add(&uc->ident, ident, ident_len);
3326         load_oid_stat(&uc->ss_info_exclude,
3327                       next + ouc_offset(info_exclude_stat),
3328                       next + offset);
3329         load_oid_stat(&uc->ss_excludes_file,
3330                       next + ouc_offset(excludes_file_stat),
3331                       next + offset + hashsz);
3332         uc->dir_flags = get_be32(next + ouc_offset(dir_flags));
3333         exclude_per_dir = (const char *)next + exclude_per_dir_offset;
3334         uc->exclude_per_dir = xstrdup(exclude_per_dir);
3335         /* NUL after exclude_per_dir is covered by sizeof(*ouc) */
3336         next += exclude_per_dir_offset + strlen(exclude_per_dir) + 1;
3337         if (next >= end)
3338                 goto done2;
3339
3340         len = decode_varint(&next);
3341         if (next > end || len == 0)
3342                 goto done2;
3343
3344         rd.valid      = ewah_new();
3345         rd.check_only = ewah_new();
3346         rd.sha1_valid = ewah_new();
3347         rd.data       = next;
3348         rd.end        = end;
3349         rd.index      = 0;
3350         ALLOC_ARRAY(rd.ucd, len);
3351
3352         if (read_one_dir(&uc->root, &rd) || rd.index != len)
3353                 goto done;
3354
3355         next = rd.data;
3356         len = ewah_read_mmap(rd.valid, next, end - next);
3357         if (len < 0)
3358                 goto done;
3359
3360         next += len;
3361         len = ewah_read_mmap(rd.check_only, next, end - next);
3362         if (len < 0)
3363                 goto done;
3364
3365         next += len;
3366         len = ewah_read_mmap(rd.sha1_valid, next, end - next);
3367         if (len < 0)
3368                 goto done;
3369
3370         ewah_each_bit(rd.check_only, set_check_only, &rd);
3371         rd.data = next + len;
3372         ewah_each_bit(rd.valid, read_stat, &rd);
3373         ewah_each_bit(rd.sha1_valid, read_oid, &rd);
3374         next = rd.data;
3375
3376 done:
3377         free(rd.ucd);
3378         ewah_free(rd.valid);
3379         ewah_free(rd.check_only);
3380         ewah_free(rd.sha1_valid);
3381 done2:
3382         if (next != end) {
3383                 free_untracked_cache(uc);
3384                 uc = NULL;
3385         }
3386         return uc;
3387 }
3388
3389 static void invalidate_one_directory(struct untracked_cache *uc,
3390                                      struct untracked_cache_dir *ucd)
3391 {
3392         uc->dir_invalidated++;
3393         ucd->valid = 0;
3394         ucd->untracked_nr = 0;
3395 }
3396
3397 /*
3398  * Normally when an entry is added or removed from a directory,
3399  * invalidating that directory is enough. No need to touch its
3400  * ancestors. When a directory is shown as "foo/bar/" in git-status
3401  * however, deleting or adding an entry may have cascading effect.
3402  *
3403  * Say the "foo/bar/file" has become untracked, we need to tell the
3404  * untracked_cache_dir of "foo" that "bar/" is not an untracked
3405  * directory any more (because "bar" is managed by foo as an untracked
3406  * "file").
3407  *
3408  * Similarly, if "foo/bar/file" moves from untracked to tracked and it
3409  * was the last untracked entry in the entire "foo", we should show
3410  * "foo/" instead. Which means we have to invalidate past "bar" up to
3411  * "foo".
3412  *
3413  * This function traverses all directories from root to leaf. If there
3414  * is a chance of one of the above cases happening, we invalidate back
3415  * to root. Otherwise we just invalidate the leaf. There may be a more
3416  * sophisticated way than checking for SHOW_OTHER_DIRECTORIES to
3417  * detect these cases and avoid unnecessary invalidation, for example,
3418  * checking for the untracked entry named "bar/" in "foo", but for now
3419  * stick to something safe and simple.
3420  */
3421 static int invalidate_one_component(struct untracked_cache *uc,
3422                                     struct untracked_cache_dir *dir,
3423                                     const char *path, int len)
3424 {
3425         const char *rest = strchr(path, '/');
3426
3427         if (rest) {
3428                 int component_len = rest - path;
3429                 struct untracked_cache_dir *d =
3430                         lookup_untracked(uc, dir, path, component_len);
3431                 int ret =
3432                         invalidate_one_component(uc, d, rest + 1,
3433                                                  len - (component_len + 1));
3434                 if (ret)
3435                         invalidate_one_directory(uc, dir);
3436                 return ret;
3437         }
3438
3439         invalidate_one_directory(uc, dir);
3440         return uc->dir_flags & DIR_SHOW_OTHER_DIRECTORIES;
3441 }
3442
3443 void untracked_cache_invalidate_path(struct index_state *istate,
3444                                      const char *path, int safe_path)
3445 {
3446         if (!istate->untracked || !istate->untracked->root)
3447                 return;
3448         if (!safe_path && !verify_path(path, 0))
3449                 return;
3450         invalidate_one_component(istate->untracked, istate->untracked->root,
3451                                  path, strlen(path));
3452 }
3453
3454 void untracked_cache_remove_from_index(struct index_state *istate,
3455                                        const char *path)
3456 {
3457         untracked_cache_invalidate_path(istate, path, 1);
3458 }
3459
3460 void untracked_cache_add_to_index(struct index_state *istate,
3461                                   const char *path)
3462 {
3463         untracked_cache_invalidate_path(istate, path, 1);
3464 }
3465
3466 static void connect_wt_gitdir_in_nested(const char *sub_worktree,
3467                                         const char *sub_gitdir)
3468 {
3469         int i;
3470         struct repository subrepo;
3471         struct strbuf sub_wt = STRBUF_INIT;
3472         struct strbuf sub_gd = STRBUF_INIT;
3473
3474         const struct submodule *sub;
3475
3476         /* If the submodule has no working tree, we can ignore it. */
3477         if (repo_init(&subrepo, sub_gitdir, sub_worktree))
3478                 return;
3479
3480         if (repo_read_index(&subrepo) < 0)
3481                 die(_("index file corrupt in repo %s"), subrepo.gitdir);
3482
3483         for (i = 0; i < subrepo.index->cache_nr; i++) {
3484                 const struct cache_entry *ce = subrepo.index->cache[i];
3485
3486                 if (!S_ISGITLINK(ce->ce_mode))
3487                         continue;
3488
3489                 while (i + 1 < subrepo.index->cache_nr &&
3490                        !strcmp(ce->name, subrepo.index->cache[i + 1]->name))
3491                         /*
3492                          * Skip entries with the same name in different stages
3493                          * to make sure an entry is returned only once.
3494                          */
3495                         i++;
3496
3497                 sub = submodule_from_path(&subrepo, &null_oid, ce->name);
3498                 if (!sub || !is_submodule_active(&subrepo, ce->name))
3499                         /* .gitmodules broken or inactive sub */
3500                         continue;
3501
3502                 strbuf_reset(&sub_wt);
3503                 strbuf_reset(&sub_gd);
3504                 strbuf_addf(&sub_wt, "%s/%s", sub_worktree, sub->path);
3505                 strbuf_addf(&sub_gd, "%s/modules/%s", sub_gitdir, sub->name);
3506
3507                 connect_work_tree_and_git_dir(sub_wt.buf, sub_gd.buf, 1);
3508         }
3509         strbuf_release(&sub_wt);
3510         strbuf_release(&sub_gd);
3511         repo_clear(&subrepo);
3512 }
3513
3514 void connect_work_tree_and_git_dir(const char *work_tree_,
3515                                    const char *git_dir_,
3516                                    int recurse_into_nested)
3517 {
3518         struct strbuf gitfile_sb = STRBUF_INIT;
3519         struct strbuf cfg_sb = STRBUF_INIT;
3520         struct strbuf rel_path = STRBUF_INIT;
3521         char *git_dir, *work_tree;
3522
3523         /* Prepare .git file */
3524         strbuf_addf(&gitfile_sb, "%s/.git", work_tree_);
3525         if (safe_create_leading_directories_const(gitfile_sb.buf))
3526                 die(_("could not create directories for %s"), gitfile_sb.buf);
3527
3528         /* Prepare config file */
3529         strbuf_addf(&cfg_sb, "%s/config", git_dir_);
3530         if (safe_create_leading_directories_const(cfg_sb.buf))
3531                 die(_("could not create directories for %s"), cfg_sb.buf);
3532
3533         git_dir = real_pathdup(git_dir_, 1);
3534         work_tree = real_pathdup(work_tree_, 1);
3535
3536         /* Write .git file */
3537         write_file(gitfile_sb.buf, "gitdir: %s",
3538                    relative_path(git_dir, work_tree, &rel_path));
3539         /* Update core.worktree setting */
3540         git_config_set_in_file(cfg_sb.buf, "core.worktree",
3541                                relative_path(work_tree, git_dir, &rel_path));
3542
3543         strbuf_release(&gitfile_sb);
3544         strbuf_release(&cfg_sb);
3545         strbuf_release(&rel_path);
3546
3547         if (recurse_into_nested)
3548                 connect_wt_gitdir_in_nested(work_tree, git_dir);
3549
3550         free(work_tree);
3551         free(git_dir);
3552 }
3553
3554 /*
3555  * Migrate the git directory of the given path from old_git_dir to new_git_dir.
3556  */
3557 void relocate_gitdir(const char *path, const char *old_git_dir, const char *new_git_dir)
3558 {
3559         if (rename(old_git_dir, new_git_dir) < 0)
3560                 die_errno(_("could not migrate git directory from '%s' to '%s'"),
3561                         old_git_dir, new_git_dir);
3562
3563         connect_work_tree_and_git_dir(path, new_git_dir, 0);
3564 }