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