Fix a bunch of pointer declarations (codestyle)
[git/git.git] / attr.c
1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
2 #include "cache.h"
3 #include "attr.h"
4
5 const char git_attr__true[] = "(builtin)true";
6 const char git_attr__false[] = "\0(builtin)false";
7 static const char git_attr__unknown[] = "(builtin)unknown";
8 #define ATTR__TRUE git_attr__true
9 #define ATTR__FALSE git_attr__false
10 #define ATTR__UNSET NULL
11 #define ATTR__UNKNOWN git_attr__unknown
12
13 /*
14 * The basic design decision here is that we are not going to have
15 * insanely large number of attributes.
16 *
17 * This is a randomly chosen prime.
18 */
19 #define HASHSIZE 257
20
21 #ifndef DEBUG_ATTR
22 #define DEBUG_ATTR 0
23 #endif
24
25 struct git_attr {
26 struct git_attr *next;
27 unsigned h;
28 int attr_nr;
29 char name[FLEX_ARRAY];
30 };
31 static int attr_nr;
32
33 static struct git_attr_check *check_all_attr;
34 static struct git_attr *(git_attr_hash[HASHSIZE]);
35
36 static unsigned hash_name(const char *name, int namelen)
37 {
38 unsigned val = 0;
39 unsigned char c;
40
41 while (namelen--) {
42 c = *name++;
43 val = ((val << 7) | (val >> 22)) ^ c;
44 }
45 return val;
46 }
47
48 static int invalid_attr_name(const char *name, int namelen)
49 {
50 /*
51 * Attribute name cannot begin with '-' and from
52 * [-A-Za-z0-9_.]. We'd specifically exclude '=' for now,
53 * as we might later want to allow non-binary value for
54 * attributes, e.g. "*.svg merge=special-merge-program-for-svg"
55 */
56 if (*name == '-')
57 return -1;
58 while (namelen--) {
59 char ch = *name++;
60 if (! (ch == '-' || ch == '.' || ch == '_' ||
61 ('0' <= ch && ch <= '9') ||
62 ('a' <= ch && ch <= 'z') ||
63 ('A' <= ch && ch <= 'Z')) )
64 return -1;
65 }
66 return 0;
67 }
68
69 struct git_attr *git_attr(const char *name, int len)
70 {
71 unsigned hval = hash_name(name, len);
72 unsigned pos = hval % HASHSIZE;
73 struct git_attr *a;
74
75 for (a = git_attr_hash[pos]; a; a = a->next) {
76 if (a->h == hval &&
77 !memcmp(a->name, name, len) && !a->name[len])
78 return a;
79 }
80
81 if (invalid_attr_name(name, len))
82 return NULL;
83
84 a = xmalloc(sizeof(*a) + len + 1);
85 memcpy(a->name, name, len);
86 a->name[len] = 0;
87 a->h = hval;
88 a->next = git_attr_hash[pos];
89 a->attr_nr = attr_nr++;
90 git_attr_hash[pos] = a;
91
92 check_all_attr = xrealloc(check_all_attr,
93 sizeof(*check_all_attr) * attr_nr);
94 check_all_attr[a->attr_nr].attr = a;
95 check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
96 return a;
97 }
98
99 /*
100 * .gitattributes file is one line per record, each of which is
101 *
102 * (1) glob pattern.
103 * (2) whitespace
104 * (3) whitespace separated list of attribute names, each of which
105 * could be prefixed with '-' to mean "set to false", '!' to mean
106 * "unset".
107 */
108
109 /* What does a matched pattern decide? */
110 struct attr_state {
111 struct git_attr *attr;
112 const char *setto;
113 };
114
115 struct match_attr {
116 union {
117 char *pattern;
118 struct git_attr *attr;
119 } u;
120 char is_macro;
121 unsigned num_attr;
122 struct attr_state state[FLEX_ARRAY];
123 };
124
125 static const char blank[] = " \t\r\n";
126
127 static const char *parse_attr(const char *src, int lineno, const char *cp,
128 int *num_attr, struct match_attr *res)
129 {
130 const char *ep, *equals;
131 int len;
132
133 ep = cp + strcspn(cp, blank);
134 equals = strchr(cp, '=');
135 if (equals && ep < equals)
136 equals = NULL;
137 if (equals)
138 len = equals - cp;
139 else
140 len = ep - cp;
141 if (!res) {
142 if (*cp == '-' || *cp == '!') {
143 cp++;
144 len--;
145 }
146 if (invalid_attr_name(cp, len)) {
147 fprintf(stderr,
148 "%.*s is not a valid attribute name: %s:%d\n",
149 len, cp, src, lineno);
150 return NULL;
151 }
152 } else {
153 struct attr_state *e;
154
155 e = &(res->state[*num_attr]);
156 if (*cp == '-' || *cp == '!') {
157 e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
158 cp++;
159 len--;
160 }
161 else if (!equals)
162 e->setto = ATTR__TRUE;
163 else {
164 e->setto = xmemdupz(equals + 1, ep - equals - 1);
165 }
166 e->attr = git_attr(cp, len);
167 }
168 (*num_attr)++;
169 return ep + strspn(ep, blank);
170 }
171
172 static struct match_attr *parse_attr_line(const char *line, const char *src,
173 int lineno, int macro_ok)
174 {
175 int namelen;
176 int num_attr;
177 const char *cp, *name;
178 struct match_attr *res = NULL;
179 int pass;
180 int is_macro;
181
182 cp = line + strspn(line, blank);
183 if (!*cp || *cp == '#')
184 return NULL;
185 name = cp;
186 namelen = strcspn(name, blank);
187 if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
188 !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
189 if (!macro_ok) {
190 fprintf(stderr, "%s not allowed: %s:%d\n",
191 name, src, lineno);
192 return NULL;
193 }
194 is_macro = 1;
195 name += strlen(ATTRIBUTE_MACRO_PREFIX);
196 name += strspn(name, blank);
197 namelen = strcspn(name, blank);
198 if (invalid_attr_name(name, namelen)) {
199 fprintf(stderr,
200 "%.*s is not a valid attribute name: %s:%d\n",
201 namelen, name, src, lineno);
202 return NULL;
203 }
204 }
205 else
206 is_macro = 0;
207
208 for (pass = 0; pass < 2; pass++) {
209 /* pass 0 counts and allocates, pass 1 fills */
210 num_attr = 0;
211 cp = name + namelen;
212 cp = cp + strspn(cp, blank);
213 while (*cp) {
214 cp = parse_attr(src, lineno, cp, &num_attr, res);
215 if (!cp)
216 return NULL;
217 }
218 if (pass)
219 break;
220 res = xcalloc(1,
221 sizeof(*res) +
222 sizeof(struct attr_state) * num_attr +
223 (is_macro ? 0 : namelen + 1));
224 if (is_macro)
225 res->u.attr = git_attr(name, namelen);
226 else {
227 res->u.pattern = (char *)&(res->state[num_attr]);
228 memcpy(res->u.pattern, name, namelen);
229 res->u.pattern[namelen] = 0;
230 }
231 res->is_macro = is_macro;
232 res->num_attr = num_attr;
233 }
234 return res;
235 }
236
237 /*
238 * Like info/exclude and .gitignore, the attribute information can
239 * come from many places.
240 *
241 * (1) .gitattribute file of the same directory;
242 * (2) .gitattribute file of the parent directory if (1) does not have
243 * any match; this goes recursively upwards, just like .gitignore.
244 * (3) $GIT_DIR/info/attributes, which overrides both of the above.
245 *
246 * In the same file, later entries override the earlier match, so in the
247 * global list, we would have entries from info/attributes the earliest
248 * (reading the file from top to bottom), .gitattribute of the root
249 * directory (again, reading the file from top to bottom) down to the
250 * current directory, and then scan the list backwards to find the first match.
251 * This is exactly the same as what excluded() does in dir.c to deal with
252 * .gitignore
253 */
254
255 static struct attr_stack {
256 struct attr_stack *prev;
257 char *origin;
258 unsigned num_matches;
259 unsigned alloc;
260 struct match_attr **attrs;
261 } *attr_stack;
262
263 static void free_attr_elem(struct attr_stack *e)
264 {
265 int i;
266 free(e->origin);
267 for (i = 0; i < e->num_matches; i++) {
268 struct match_attr *a = e->attrs[i];
269 int j;
270 for (j = 0; j < a->num_attr; j++) {
271 const char *setto = a->state[j].setto;
272 if (setto == ATTR__TRUE ||
273 setto == ATTR__FALSE ||
274 setto == ATTR__UNSET ||
275 setto == ATTR__UNKNOWN)
276 ;
277 else
278 free((char *) setto);
279 }
280 free(a);
281 }
282 free(e);
283 }
284
285 static const char *builtin_attr[] = {
286 "[attr]binary -diff -crlf",
287 NULL,
288 };
289
290 static void handle_attr_line(struct attr_stack *res,
291 const char *line,
292 const char *src,
293 int lineno,
294 int macro_ok)
295 {
296 struct match_attr *a;
297
298 a = parse_attr_line(line, src, lineno, macro_ok);
299 if (!a)
300 return;
301 if (res->alloc <= res->num_matches) {
302 res->alloc = alloc_nr(res->num_matches);
303 res->attrs = xrealloc(res->attrs,
304 sizeof(struct match_attr *) *
305 res->alloc);
306 }
307 res->attrs[res->num_matches++] = a;
308 }
309
310 static struct attr_stack *read_attr_from_array(const char **list)
311 {
312 struct attr_stack *res;
313 const char *line;
314 int lineno = 0;
315
316 res = xcalloc(1, sizeof(*res));
317 while ((line = *(list++)) != NULL)
318 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
319 return res;
320 }
321
322 static enum git_attr_direction direction;
323 static struct index_state *use_index;
324
325 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
326 {
327 FILE *fp = fopen(path, "r");
328 struct attr_stack *res;
329 char buf[2048];
330 int lineno = 0;
331
332 if (!fp)
333 return NULL;
334 res = xcalloc(1, sizeof(*res));
335 while (fgets(buf, sizeof(buf), fp))
336 handle_attr_line(res, buf, path, ++lineno, macro_ok);
337 fclose(fp);
338 return res;
339 }
340
341 static void *read_index_data(const char *path)
342 {
343 int pos, len;
344 unsigned long sz;
345 enum object_type type;
346 void *data;
347 struct index_state *istate = use_index ? use_index : &the_index;
348
349 len = strlen(path);
350 pos = index_name_pos(istate, path, len);
351 if (pos < 0) {
352 /*
353 * We might be in the middle of a merge, in which
354 * case we would read stage #2 (ours).
355 */
356 int i;
357 for (i = -pos - 1;
358 (pos < 0 && i < istate->cache_nr &&
359 !strcmp(istate->cache[i]->name, path));
360 i++)
361 if (ce_stage(istate->cache[i]) == 2)
362 pos = i;
363 }
364 if (pos < 0)
365 return NULL;
366 data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz);
367 if (!data || type != OBJ_BLOB) {
368 free(data);
369 return NULL;
370 }
371 return data;
372 }
373
374 static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
375 {
376 struct attr_stack *res;
377 char *buf, *sp;
378 int lineno = 0;
379
380 buf = read_index_data(path);
381 if (!buf)
382 return NULL;
383
384 res = xcalloc(1, sizeof(*res));
385 for (sp = buf; *sp; ) {
386 char *ep;
387 int more;
388 for (ep = sp; *ep && *ep != '\n'; ep++)
389 ;
390 more = (*ep == '\n');
391 *ep = '\0';
392 handle_attr_line(res, sp, path, ++lineno, macro_ok);
393 sp = ep + more;
394 }
395 free(buf);
396 return res;
397 }
398
399 static struct attr_stack *read_attr(const char *path, int macro_ok)
400 {
401 struct attr_stack *res;
402
403 if (direction == GIT_ATTR_CHECKOUT) {
404 res = read_attr_from_index(path, macro_ok);
405 if (!res)
406 res = read_attr_from_file(path, macro_ok);
407 }
408 else if (direction == GIT_ATTR_CHECKIN) {
409 res = read_attr_from_file(path, macro_ok);
410 if (!res)
411 /*
412 * There is no checked out .gitattributes file there, but
413 * we might have it in the index. We allow operation in a
414 * sparsely checked out work tree, so read from it.
415 */
416 res = read_attr_from_index(path, macro_ok);
417 }
418 else
419 res = read_attr_from_index(path, macro_ok);
420 if (!res)
421 res = xcalloc(1, sizeof(*res));
422 return res;
423 }
424
425 #if DEBUG_ATTR
426 static void debug_info(const char *what, struct attr_stack *elem)
427 {
428 fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
429 }
430 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
431 {
432 const char *value = v;
433
434 if (ATTR_TRUE(value))
435 value = "set";
436 else if (ATTR_FALSE(value))
437 value = "unset";
438 else if (ATTR_UNSET(value))
439 value = "unspecified";
440
441 fprintf(stderr, "%s: %s => %s (%s)\n",
442 what, attr->name, (char *) value, match);
443 }
444 #define debug_push(a) debug_info("push", (a))
445 #define debug_pop(a) debug_info("pop", (a))
446 #else
447 #define debug_push(a) do { ; } while (0)
448 #define debug_pop(a) do { ; } while (0)
449 #define debug_set(a,b,c,d) do { ; } while (0)
450 #endif
451
452 static void drop_attr_stack(void)
453 {
454 while (attr_stack) {
455 struct attr_stack *elem = attr_stack;
456 attr_stack = elem->prev;
457 free_attr_elem(elem);
458 }
459 }
460
461 static void bootstrap_attr_stack(void)
462 {
463 if (!attr_stack) {
464 struct attr_stack *elem;
465
466 elem = read_attr_from_array(builtin_attr);
467 elem->origin = NULL;
468 elem->prev = attr_stack;
469 attr_stack = elem;
470
471 if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
472 elem = read_attr(GITATTRIBUTES_FILE, 1);
473 elem->origin = strdup("");
474 elem->prev = attr_stack;
475 attr_stack = elem;
476 debug_push(elem);
477 }
478
479 elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
480 if (!elem)
481 elem = xcalloc(1, sizeof(*elem));
482 elem->origin = NULL;
483 elem->prev = attr_stack;
484 attr_stack = elem;
485 }
486 }
487
488 static void prepare_attr_stack(const char *path, int dirlen)
489 {
490 struct attr_stack *elem, *info;
491 int len;
492 struct strbuf pathbuf;
493
494 strbuf_init(&pathbuf, dirlen+2+strlen(GITATTRIBUTES_FILE));
495
496 /*
497 * At the bottom of the attribute stack is the built-in
498 * set of attribute definitions. Then, contents from
499 * .gitattribute files from directories closer to the
500 * root to the ones in deeper directories are pushed
501 * to the stack. Finally, at the very top of the stack
502 * we always keep the contents of $GIT_DIR/info/attributes.
503 *
504 * When checking, we use entries from near the top of the
505 * stack, preferring $GIT_DIR/info/attributes, then
506 * .gitattributes in deeper directories to shallower ones,
507 * and finally use the built-in set as the default.
508 */
509 if (!attr_stack)
510 bootstrap_attr_stack();
511
512 /*
513 * Pop the "info" one that is always at the top of the stack.
514 */
515 info = attr_stack;
516 attr_stack = info->prev;
517
518 /*
519 * Pop the ones from directories that are not the prefix of
520 * the path we are checking.
521 */
522 while (attr_stack && attr_stack->origin) {
523 int namelen = strlen(attr_stack->origin);
524
525 elem = attr_stack;
526 if (namelen <= dirlen &&
527 !strncmp(elem->origin, path, namelen))
528 break;
529
530 debug_pop(elem);
531 attr_stack = elem->prev;
532 free_attr_elem(elem);
533 }
534
535 /*
536 * Read from parent directories and push them down
537 */
538 if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
539 while (1) {
540 char *cp;
541
542 len = strlen(attr_stack->origin);
543 if (dirlen <= len)
544 break;
545 strbuf_reset(&pathbuf);
546 strbuf_add(&pathbuf, path, dirlen);
547 strbuf_addch(&pathbuf, '/');
548 cp = strchr(pathbuf.buf + len + 1, '/');
549 strcpy(cp + 1, GITATTRIBUTES_FILE);
550 elem = read_attr(pathbuf.buf, 0);
551 *cp = '\0';
552 elem->origin = strdup(pathbuf.buf);
553 elem->prev = attr_stack;
554 attr_stack = elem;
555 debug_push(elem);
556 }
557 }
558
559 /*
560 * Finally push the "info" one at the top of the stack.
561 */
562 info->prev = attr_stack;
563 attr_stack = info;
564 }
565
566 static int path_matches(const char *pathname, int pathlen,
567 const char *pattern,
568 const char *base, int baselen)
569 {
570 if (!strchr(pattern, '/')) {
571 /* match basename */
572 const char *basename = strrchr(pathname, '/');
573 basename = basename ? basename + 1 : pathname;
574 return (fnmatch(pattern, basename, 0) == 0);
575 }
576 /*
577 * match with FNM_PATHNAME; the pattern has base implicitly
578 * in front of it.
579 */
580 if (*pattern == '/')
581 pattern++;
582 if (pathlen < baselen ||
583 (baselen && pathname[baselen] != '/') ||
584 strncmp(pathname, base, baselen))
585 return 0;
586 if (baselen != 0)
587 baselen++;
588 return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0;
589 }
590
591 static int fill_one(const char *what, struct match_attr *a, int rem)
592 {
593 struct git_attr_check *check = check_all_attr;
594 int i;
595
596 for (i = 0; 0 < rem && i < a->num_attr; i++) {
597 struct git_attr *attr = a->state[i].attr;
598 const char **n = &(check[attr->attr_nr].value);
599 const char *v = a->state[i].setto;
600
601 if (*n == ATTR__UNKNOWN) {
602 debug_set(what, a->u.pattern, attr, v);
603 *n = v;
604 rem--;
605 }
606 }
607 return rem;
608 }
609
610 static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
611 {
612 int i;
613 const char *base = stk->origin ? stk->origin : "";
614
615 for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
616 struct match_attr *a = stk->attrs[i];
617 if (a->is_macro)
618 continue;
619 if (path_matches(path, pathlen,
620 a->u.pattern, base, strlen(base)))
621 rem = fill_one("fill", a, rem);
622 }
623 return rem;
624 }
625
626 static int macroexpand(struct attr_stack *stk, int rem)
627 {
628 int i;
629 struct git_attr_check *check = check_all_attr;
630
631 for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
632 struct match_attr *a = stk->attrs[i];
633 if (!a->is_macro)
634 continue;
635 if (check[a->u.attr->attr_nr].value != ATTR__TRUE)
636 continue;
637 rem = fill_one("expand", a, rem);
638 }
639 return rem;
640 }
641
642 int git_checkattr(const char *path, int num, struct git_attr_check *check)
643 {
644 struct attr_stack *stk;
645 const char *cp;
646 int dirlen, pathlen, i, rem;
647
648 bootstrap_attr_stack();
649 for (i = 0; i < attr_nr; i++)
650 check_all_attr[i].value = ATTR__UNKNOWN;
651
652 pathlen = strlen(path);
653 cp = strrchr(path, '/');
654 if (!cp)
655 dirlen = 0;
656 else
657 dirlen = cp - path;
658 prepare_attr_stack(path, dirlen);
659 rem = attr_nr;
660 for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
661 rem = fill(path, pathlen, stk, rem);
662
663 for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
664 rem = macroexpand(stk, rem);
665
666 for (i = 0; i < num; i++) {
667 const char *value = check_all_attr[check[i].attr->attr_nr].value;
668 if (value == ATTR__UNKNOWN)
669 value = ATTR__UNSET;
670 check[i].value = value;
671 }
672
673 return 0;
674 }
675
676 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
677 {
678 enum git_attr_direction old = direction;
679
680 if (is_bare_repository() && new != GIT_ATTR_INDEX)
681 die("BUG: non-INDEX attr direction in a bare repo");
682
683 direction = new;
684 if (new != old)
685 drop_attr_stack();
686 use_index = istate;
687 }