1#include "cache.h"
2#include "attr.h"
3const char git_attr__true[] = "(builtin)true";
5const char git_attr__false[] = "\0(builtin)false";
6static const char git_attr__unknown[] = "(builtin)unknown";
7#define ATTR__TRUE git_attr__true
8#define ATTR__FALSE git_attr__false
9#define ATTR__UNSET NULL
10#define ATTR__UNKNOWN git_attr__unknown
11/*
13 * The basic design decision here is that we are not going to have
14 * insanely large number of attributes.
15 *
16 * This is a randomly chosen prime.
17 */
18#define HASHSIZE 257
19#ifndef DEBUG_ATTR
21#define DEBUG_ATTR 0
22#endif
23struct git_attr {
25 struct git_attr *next;
26 unsigned h;
27 int attr_nr;
28 char name[FLEX_ARRAY];
29};
30static int attr_nr;
31static struct git_attr_check *check_all_attr;
33static struct git_attr *(git_attr_hash[HASHSIZE]);
34static unsigned hash_name(const char *name, int namelen)
36{
37 unsigned val = 0;
38 unsigned char c;
39 while (namelen--) {
41 c = *name++;
42 val = ((val << 7) | (val >> 22)) ^ c;
43 }
44 return val;
45}
46static int invalid_attr_name(const char *name, int namelen)
48{
49 /*
50 * Attribute name cannot begin with '-' and from
51 * [-A-Za-z0-9_.]. We'd specifically exclude '=' for now,
52 * as we might later want to allow non-binary value for
53 * attributes, e.g. "*.svg merge=special-merge-program-for-svg"
54 */
55 if (*name == '-')
56 return -1;
57 while (namelen--) {
58 char ch = *name++;
59 if (! (ch == '-' || ch == '.' || ch == '_' ||
60 ('0' <= ch && ch <= '9') ||
61 ('a' <= ch && ch <= 'z') ||
62 ('A' <= ch && ch <= 'Z')) )
63 return -1;
64 }
65 return 0;
66}
67struct git_attr *git_attr(const char *name, int len)
69{
70 unsigned hval = hash_name(name, len);
71 unsigned pos = hval % HASHSIZE;
72 struct git_attr *a;
73 for (a = git_attr_hash[pos]; a; a = a->next) {
75 if (a->h == hval &&
76 !memcmp(a->name, name, len) && !a->name[len])
77 return a;
78 }
79 if (invalid_attr_name(name, len))
81 return NULL;
82 a = xmalloc(sizeof(*a) + len + 1);
84 memcpy(a->name, name, len);
85 a->name[len] = 0;
86 a->h = hval;
87 a->next = git_attr_hash[pos];
88 a->attr_nr = attr_nr++;
89 git_attr_hash[pos] = a;
90 check_all_attr = xrealloc(check_all_attr,
92 sizeof(*check_all_attr) * attr_nr);
93 check_all_attr[a->attr_nr].attr = a;
94 check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
95 return a;
96}
97/*
99 * .gitattributes file is one line per record, each of which is
100 *
101 * (1) glob pattern.
102 * (2) whitespace
103 * (3) whitespace separated list of attribute names, each of which
104 * could be prefixed with '-' to mean "set to false", '!' to mean
105 * "unset".
106 */
107/* What does a matched pattern decide? */
109struct attr_state {
110 struct git_attr *attr;
111 const char *setto;
112};
113struct match_attr {
115 union {
116 char *pattern;
117 struct git_attr *attr;
118 } u;
119 char is_macro;
120 unsigned num_attr;
121 struct attr_state state[FLEX_ARRAY];
122};
123static const char blank[] = " \t\r\n";
125static const char *parse_attr(const char *src, int lineno, const char *cp,
127 int *num_attr, struct match_attr *res)
128{
129 const char *ep, *equals;
130 int len;
131 ep = cp + strcspn(cp, blank);
133 equals = strchr(cp, '=');
134 if (equals && ep < equals)
135 equals = NULL;
136 if (equals)
137 len = equals - cp;
138 else
139 len = ep - cp;
140 if (!res) {
141 if (*cp == '-' || *cp == '!') {
142 cp++;
143 len--;
144 }
145 if (invalid_attr_name(cp, len)) {
146 fprintf(stderr,
147 "%.*s is not a valid attribute name: %s:%d\n",
148 len, cp, src, lineno);
149 return NULL;
150 }
151 } else {
152 struct attr_state *e;
153 e = &(res->state[*num_attr]);
155 if (*cp == '-' || *cp == '!') {
156 e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
157 cp++;
158 len--;
159 }
160 else if (!equals)
161 e->setto = ATTR__TRUE;
162 else {
163 char *value;
164 int vallen = ep - equals;
165 value = xmalloc(vallen);
166 memcpy(value, equals+1, vallen-1);
167 value[vallen-1] = 0;
168 e->setto = value;
169 }
170 e->attr = git_attr(cp, len);
171 }
172 (*num_attr)++;
173 return ep + strspn(ep, blank);
174}
175static struct match_attr *parse_attr_line(const char *line, const char *src,
177 int lineno, int macro_ok)
178{
179 int namelen;
180 int num_attr;
181 const char *cp, *name;
182 struct match_attr *res = NULL;
183 int pass;
184 int is_macro;
185 cp = line + strspn(line, blank);
187 if (!*cp || *cp == '#')
188 return NULL;
189 name = cp;
190 namelen = strcspn(name, blank);
191 if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
192 !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
193 if (!macro_ok) {
194 fprintf(stderr, "%s not allowed: %s:%d\n",
195 name, src, lineno);
196 return NULL;
197 }
198 is_macro = 1;
199 name += strlen(ATTRIBUTE_MACRO_PREFIX);
200 name += strspn(name, blank);
201 namelen = strcspn(name, blank);
202 if (invalid_attr_name(name, namelen)) {
203 fprintf(stderr,
204 "%.*s is not a valid attribute name: %s:%d\n",
205 namelen, name, src, lineno);
206 return NULL;
207 }
208 }
209 else
210 is_macro = 0;
211 for (pass = 0; pass < 2; pass++) {
213 /* pass 0 counts and allocates, pass 1 fills */
214 num_attr = 0;
215 cp = name + namelen;
216 cp = cp + strspn(cp, blank);
217 while (*cp)
218 cp = parse_attr(src, lineno, cp, &num_attr, res);
219 if (pass)
220 break;
221 res = xcalloc(1,
222 sizeof(*res) +
223 sizeof(struct attr_state) * num_attr +
224 (is_macro ? 0 : namelen + 1));
225 if (is_macro)
226 res->u.attr = git_attr(name, namelen);
227 else {
228 res->u.pattern = (char*)&(res->state[num_attr]);
229 memcpy(res->u.pattern, name, namelen);
230 res->u.pattern[namelen] = 0;
231 }
232 res->is_macro = is_macro;
233 res->num_attr = num_attr;
234 }
235 return res;
236}
237/*
239 * Like info/exclude and .gitignore, the attribute information can
240 * come from many places.
241 *
242 * (1) .gitattribute file of the same directory;
243 * (2) .gitattribute file of the parent directory if (1) does not have
244 * any match; this goes recursively upwards, just like .gitignore.
245 * (3) $GIT_DIR/info/attributes, which overrides both of the above.
246 *
247 * In the same file, later entries override the earlier match, so in the
248 * global list, we would have entries from info/attributes the earliest
249 * (reading the file from top to bottom), .gitattribute of the root
250 * directory (again, reading the file from top to bottom) down to the
251 * current directory, and then scan the list backwards to find the first match.
252 * This is exactly the same as what excluded() does in dir.c to deal with
253 * .gitignore
254 */
255static struct attr_stack {
257 struct attr_stack *prev;
258 char *origin;
259 unsigned num_matches;
260 struct match_attr **attrs;
261} *attr_stack;
262static 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}
284static const char *builtin_attr[] = {
286 "[attr]binary -diff -crlf",
287 NULL,
288};
289static struct attr_stack *read_attr_from_array(const char **list)
291{
292 struct attr_stack *res;
293 const char *line;
294 int lineno = 0;
295 res = xcalloc(1, sizeof(*res));
297 while ((line = *(list++)) != NULL) {
298 struct match_attr *a;
299 a = parse_attr_line(line, "[builtin]", ++lineno, 1);
301 if (!a)
302 continue;
303 res->attrs = xrealloc(res->attrs,
304 sizeof(struct match_attr *) * (res->num_matches + 1));
305 res->attrs[res->num_matches++] = a;
306 }
307 return res;
308}
309static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
311{
312 FILE *fp;
313 struct attr_stack *res;
314 char buf[2048];
315 int lineno = 0;
316 res = xcalloc(1, sizeof(*res));
318 fp = fopen(path, "r");
319 if (!fp)
320 return res;
321 while (fgets(buf, sizeof(buf), fp)) {
323 struct match_attr *a;
324 a = parse_attr_line(buf, path, ++lineno, macro_ok);
326 if (!a)
327 continue;
328 res->attrs = xrealloc(res->attrs,
329 sizeof(struct match_attr *) * (res->num_matches + 1));
330 res->attrs[res->num_matches++] = a;
331 }
332 fclose(fp);
333 return res;
334}
335#if DEBUG_ATTR
337static void debug_info(const char *what, struct attr_stack *elem)
338{
339 fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
340}
341static void debug_set(const char *what, const char *match, struct git_attr *attr, void *v)
342{
343 const char *value = v;
344 if (ATTR_TRUE(value))
346 value = "set";
347 else if (ATTR_FALSE(value))
348 value = "unset";
349 else if (ATTR_UNSET(value))
350 value = "unspecified";
351 fprintf(stderr, "%s: %s => %s (%s)\n",
353 what, attr->name, (char *) value, match);
354}
355#define debug_push(a) debug_info("push", (a))
356#define debug_pop(a) debug_info("pop", (a))
357#else
358#define debug_push(a) do { ; } while (0)
359#define debug_pop(a) do { ; } while (0)
360#define debug_set(a,b,c,d) do { ; } while (0)
361#endif
362static void bootstrap_attr_stack(void)
364{
365 if (!attr_stack) {
366 struct attr_stack *elem;
367 elem = read_attr_from_array(builtin_attr);
369 elem->origin = NULL;
370 elem->prev = attr_stack;
371 attr_stack = elem;
372 elem = read_attr_from_file(GITATTRIBUTES_FILE, 1);
374 elem->origin = strdup("");
375 elem->prev = attr_stack;
376 attr_stack = elem;
377 debug_push(elem);
378 elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
380 elem->origin = NULL;
381 elem->prev = attr_stack;
382 attr_stack = elem;
383 }
384}
385static void prepare_attr_stack(const char *path, int dirlen)
387{
388 struct attr_stack *elem, *info;
389 int len;
390 char pathbuf[PATH_MAX];
391 /*
393 * At the bottom of the attribute stack is the built-in
394 * set of attribute definitions. Then, contents from
395 * .gitattribute files from directories closer to the
396 * root to the ones in deeper directories are pushed
397 * to the stack. Finally, at the very top of the stack
398 * we always keep the contents of $GIT_DIR/info/attributes.
399 *
400 * When checking, we use entries from near the top of the
401 * stack, preferring $GIT_DIR/info/attributes, then
402 * .gitattributes in deeper directories to shallower ones,
403 * and finally use the built-in set as the default.
404 */
405 if (!attr_stack)
406 bootstrap_attr_stack();
407 /*
409 * Pop the "info" one that is always at the top of the stack.
410 */
411 info = attr_stack;
412 attr_stack = info->prev;
413 /*
415 * Pop the ones from directories that are not the prefix of
416 * the path we are checking.
417 */
418 while (attr_stack && attr_stack->origin) {
419 int namelen = strlen(attr_stack->origin);
420 elem = attr_stack;
422 if (namelen <= dirlen &&
423 !strncmp(elem->origin, path, namelen))
424 break;
425 debug_pop(elem);
427 attr_stack = elem->prev;
428 free_attr_elem(elem);
429 }
430 /*
432 * Read from parent directories and push them down
433 */
434 while (1) {
435 char *cp;
436 len = strlen(attr_stack->origin);
438 if (dirlen <= len)
439 break;
440 memcpy(pathbuf, path, dirlen);
441 memcpy(pathbuf + dirlen, "/", 2);
442 cp = strchr(pathbuf + len + 1, '/');
443 strcpy(cp + 1, GITATTRIBUTES_FILE);
444 elem = read_attr_from_file(pathbuf, 0);
445 *cp = '\0';
446 elem->origin = strdup(pathbuf);
447 elem->prev = attr_stack;
448 attr_stack = elem;
449 debug_push(elem);
450 }
451 /*
453 * Finally push the "info" one at the top of the stack.
454 */
455 info->prev = attr_stack;
456 attr_stack = info;
457}
458static int path_matches(const char *pathname, int pathlen,
460 const char *pattern,
461 const char *base, int baselen)
462{
463 if (!strchr(pattern, '/')) {
464 /* match basename */
465 const char *basename = strrchr(pathname, '/');
466 basename = basename ? basename + 1 : pathname;
467 return (fnmatch(pattern, basename, 0) == 0);
468 }
469 /*
470 * match with FNM_PATHNAME; the pattern has base implicitly
471 * in front of it.
472 */
473 if (*pattern == '/')
474 pattern++;
475 if (pathlen < baselen ||
476 (baselen && pathname[baselen - 1] != '/') ||
477 strncmp(pathname, base, baselen))
478 return 0;
479 return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0;
480}
481static int fill_one(const char *what, struct match_attr *a, int rem)
483{
484 struct git_attr_check *check = check_all_attr;
485 int i;
486 for (i = 0; 0 < rem && i < a->num_attr; i++) {
488 struct git_attr *attr = a->state[i].attr;
489 const char **n = &(check[attr->attr_nr].value);
490 const char *v = a->state[i].setto;
491 if (*n == ATTR__UNKNOWN) {
493 debug_set(what, a->u.pattern, attr, v);
494 *n = v;
495 rem--;
496 }
497 }
498 return rem;
499}
500static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
502{
503 int i;
504 const char *base = stk->origin ? stk->origin : "";
505 for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
507 struct match_attr *a = stk->attrs[i];
508 if (a->is_macro)
509 continue;
510 if (path_matches(path, pathlen,
511 a->u.pattern, base, strlen(base)))
512 rem = fill_one("fill", a, rem);
513 }
514 return rem;
515}
516static int macroexpand(struct attr_stack *stk, int rem)
518{
519 int i;
520 struct git_attr_check *check = check_all_attr;
521 for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
523 struct match_attr *a = stk->attrs[i];
524 if (!a->is_macro)
525 continue;
526 if (check[a->u.attr->attr_nr].value != ATTR__TRUE)
527 continue;
528 rem = fill_one("expand", a, rem);
529 }
530 return rem;
531}
532int git_checkattr(const char *path, int num, struct git_attr_check *check)
534{
535 struct attr_stack *stk;
536 const char *cp;
537 int dirlen, pathlen, i, rem;
538 bootstrap_attr_stack();
540 for (i = 0; i < attr_nr; i++)
541 check_all_attr[i].value = ATTR__UNKNOWN;
542 pathlen = strlen(path);
544 cp = strrchr(path, '/');
545 if (!cp)
546 dirlen = 0;
547 else
548 dirlen = cp - path;
549 prepare_attr_stack(path, dirlen);
550 rem = attr_nr;
551 for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
552 rem = fill(path, pathlen, stk, rem);
553 for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
555 rem = macroexpand(stk, rem);
556 for (i = 0; i < num; i++) {
558 const char *value = check_all_attr[check[i].attr->attr_nr].value;
559 if (value == ATTR__UNKNOWN)
560 value = ATTR__UNSET;
561 check[i].value = value;
562 }
563 return 0;
565}