pack-objects: Fix segfault when object count is less than thread count
[git/jnareb-git.git] / attr.c
blob741db3b468c6a6ebbcd1414e42b4ef7d6ab3cc9d
1 #include "cache.h"
2 #include "attr.h"
4 const char git_attr__true[] = "(builtin)true";
5 const char git_attr__false[] = "\0(builtin)false";
6 static 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
13 * The basic design decision here is that we are not going to have
14 * insanely large number of attributes.
16 * This is a randomly chosen prime.
18 #define HASHSIZE 257
20 #ifndef DEBUG_ATTR
21 #define DEBUG_ATTR 0
22 #endif
24 struct git_attr {
25 struct git_attr *next;
26 unsigned h;
27 int attr_nr;
28 char name[FLEX_ARRAY];
30 static int attr_nr;
32 static struct git_attr_check *check_all_attr;
33 static struct git_attr *(git_attr_hash[HASHSIZE]);
35 static unsigned hash_name(const char *name, int namelen)
37 unsigned val = 0;
38 unsigned char c;
40 while (namelen--) {
41 c = *name++;
42 val = ((val << 7) | (val >> 22)) ^ c;
44 return val;
47 static int invalid_attr_name(const char *name, int namelen)
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"
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;
65 return 0;
68 struct git_attr *git_attr(const char *name, int len)
70 unsigned hval = hash_name(name, len);
71 unsigned pos = hval % HASHSIZE;
72 struct git_attr *a;
74 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;
80 if (invalid_attr_name(name, len))
81 return NULL;
83 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;
91 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;
99 * .gitattributes file is one line per record, each of which is
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".
108 /* What does a matched pattern decide? */
109 struct attr_state {
110 struct git_attr *attr;
111 const char *setto;
114 struct 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];
124 static const char blank[] = " \t\r\n";
126 static const char *parse_attr(const char *src, int lineno, const char *cp,
127 int *num_attr, struct match_attr *res)
129 const char *ep, *equals;
130 int len;
132 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--;
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;
151 } else {
152 struct attr_state *e;
154 e = &(res->state[*num_attr]);
155 if (*cp == '-' || *cp == '!') {
156 e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
157 cp++;
158 len--;
160 else if (!equals)
161 e->setto = ATTR__TRUE;
162 else {
163 e->setto = xmemdupz(equals + 1, ep - equals - 1);
165 e->attr = git_attr(cp, len);
167 (*num_attr)++;
168 return ep + strspn(ep, blank);
171 static struct match_attr *parse_attr_line(const char *line, const char *src,
172 int lineno, int macro_ok)
174 int namelen;
175 int num_attr;
176 const char *cp, *name;
177 struct match_attr *res = NULL;
178 int pass;
179 int is_macro;
181 cp = line + strspn(line, blank);
182 if (!*cp || *cp == '#')
183 return NULL;
184 name = cp;
185 namelen = strcspn(name, blank);
186 if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
187 !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
188 if (!macro_ok) {
189 fprintf(stderr, "%s not allowed: %s:%d\n",
190 name, src, lineno);
191 return NULL;
193 is_macro = 1;
194 name += strlen(ATTRIBUTE_MACRO_PREFIX);
195 name += strspn(name, blank);
196 namelen = strcspn(name, blank);
197 if (invalid_attr_name(name, namelen)) {
198 fprintf(stderr,
199 "%.*s is not a valid attribute name: %s:%d\n",
200 namelen, name, src, lineno);
201 return NULL;
204 else
205 is_macro = 0;
207 for (pass = 0; pass < 2; pass++) {
208 /* pass 0 counts and allocates, pass 1 fills */
209 num_attr = 0;
210 cp = name + namelen;
211 cp = cp + strspn(cp, blank);
212 while (*cp) {
213 cp = parse_attr(src, lineno, cp, &num_attr, res);
214 if (!cp)
215 return NULL;
217 if (pass)
218 break;
219 res = xcalloc(1,
220 sizeof(*res) +
221 sizeof(struct attr_state) * num_attr +
222 (is_macro ? 0 : namelen + 1));
223 if (is_macro)
224 res->u.attr = git_attr(name, namelen);
225 else {
226 res->u.pattern = (char*)&(res->state[num_attr]);
227 memcpy(res->u.pattern, name, namelen);
228 res->u.pattern[namelen] = 0;
230 res->is_macro = is_macro;
231 res->num_attr = num_attr;
233 return res;
237 * Like info/exclude and .gitignore, the attribute information can
238 * come from many places.
240 * (1) .gitattribute file of the same directory;
241 * (2) .gitattribute file of the parent directory if (1) does not have
242 * any match; this goes recursively upwards, just like .gitignore.
243 * (3) $GIT_DIR/info/attributes, which overrides both of the above.
245 * In the same file, later entries override the earlier match, so in the
246 * global list, we would have entries from info/attributes the earliest
247 * (reading the file from top to bottom), .gitattribute of the root
248 * directory (again, reading the file from top to bottom) down to the
249 * current directory, and then scan the list backwards to find the first match.
250 * This is exactly the same as what excluded() does in dir.c to deal with
251 * .gitignore
254 static struct attr_stack {
255 struct attr_stack *prev;
256 char *origin;
257 unsigned num_matches;
258 unsigned alloc;
259 struct match_attr **attrs;
260 } *attr_stack;
262 static void free_attr_elem(struct attr_stack *e)
264 int i;
265 free(e->origin);
266 for (i = 0; i < e->num_matches; i++) {
267 struct match_attr *a = e->attrs[i];
268 int j;
269 for (j = 0; j < a->num_attr; j++) {
270 const char *setto = a->state[j].setto;
271 if (setto == ATTR__TRUE ||
272 setto == ATTR__FALSE ||
273 setto == ATTR__UNSET ||
274 setto == ATTR__UNKNOWN)
276 else
277 free((char*) setto);
279 free(a);
281 free(e);
284 static const char *builtin_attr[] = {
285 "[attr]binary -diff -crlf",
286 NULL,
289 static void handle_attr_line(struct attr_stack *res,
290 const char *line,
291 const char *src,
292 int lineno,
293 int macro_ok)
295 struct match_attr *a;
297 a = parse_attr_line(line, src, lineno, macro_ok);
298 if (!a)
299 return;
300 if (res->alloc <= res->num_matches) {
301 res->alloc = alloc_nr(res->num_matches);
302 res->attrs = xrealloc(res->attrs,
303 sizeof(struct match_attr *) *
304 res->alloc);
306 res->attrs[res->num_matches++] = a;
309 static struct attr_stack *read_attr_from_array(const char **list)
311 struct attr_stack *res;
312 const char *line;
313 int lineno = 0;
315 res = xcalloc(1, sizeof(*res));
316 while ((line = *(list++)) != NULL)
317 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
318 return res;
321 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
323 FILE *fp = fopen(path, "r");
324 struct attr_stack *res;
325 char buf[2048];
326 int lineno = 0;
328 if (!fp)
329 return NULL;
330 res = xcalloc(1, sizeof(*res));
331 while (fgets(buf, sizeof(buf), fp))
332 handle_attr_line(res, buf, path, ++lineno, macro_ok);
333 fclose(fp);
334 return res;
337 static void *read_index_data(const char *path)
339 int pos, len;
340 unsigned long sz;
341 enum object_type type;
342 void *data;
344 len = strlen(path);
345 pos = cache_name_pos(path, len);
346 if (pos < 0) {
348 * We might be in the middle of a merge, in which
349 * case we would read stage #2 (ours).
351 int i;
352 for (i = -pos - 1;
353 (pos < 0 && i < active_nr &&
354 !strcmp(active_cache[i]->name, path));
355 i++)
356 if (ce_stage(active_cache[i]) == 2)
357 pos = i;
359 if (pos < 0)
360 return NULL;
361 data = read_sha1_file(active_cache[pos]->sha1, &type, &sz);
362 if (!data || type != OBJ_BLOB) {
363 free(data);
364 return NULL;
366 return data;
369 static struct attr_stack *read_attr(const char *path, int macro_ok)
371 struct attr_stack *res;
372 char *buf, *sp;
373 int lineno = 0;
375 res = read_attr_from_file(path, macro_ok);
376 if (res)
377 return res;
379 res = xcalloc(1, sizeof(*res));
382 * There is no checked out .gitattributes file there, but
383 * we might have it in the index. We allow operation in a
384 * sparsely checked out work tree, so read from it.
386 buf = read_index_data(path);
387 if (!buf)
388 return res;
390 for (sp = buf; *sp; ) {
391 char *ep;
392 int more;
393 for (ep = sp; *ep && *ep != '\n'; ep++)
395 more = (*ep == '\n');
396 *ep = '\0';
397 handle_attr_line(res, sp, path, ++lineno, macro_ok);
398 sp = ep + more;
400 free(buf);
401 return res;
404 #if DEBUG_ATTR
405 static void debug_info(const char *what, struct attr_stack *elem)
407 fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
409 static void debug_set(const char *what, const char *match, struct git_attr *attr, void *v)
411 const char *value = v;
413 if (ATTR_TRUE(value))
414 value = "set";
415 else if (ATTR_FALSE(value))
416 value = "unset";
417 else if (ATTR_UNSET(value))
418 value = "unspecified";
420 fprintf(stderr, "%s: %s => %s (%s)\n",
421 what, attr->name, (char *) value, match);
423 #define debug_push(a) debug_info("push", (a))
424 #define debug_pop(a) debug_info("pop", (a))
425 #else
426 #define debug_push(a) do { ; } while (0)
427 #define debug_pop(a) do { ; } while (0)
428 #define debug_set(a,b,c,d) do { ; } while (0)
429 #endif
431 static void bootstrap_attr_stack(void)
433 if (!attr_stack) {
434 struct attr_stack *elem;
436 elem = read_attr_from_array(builtin_attr);
437 elem->origin = NULL;
438 elem->prev = attr_stack;
439 attr_stack = elem;
441 elem = read_attr(GITATTRIBUTES_FILE, 1);
442 elem->origin = strdup("");
443 elem->prev = attr_stack;
444 attr_stack = elem;
445 debug_push(elem);
447 elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
448 if (!elem)
449 elem = xcalloc(1, sizeof(*elem));
450 elem->origin = NULL;
451 elem->prev = attr_stack;
452 attr_stack = elem;
456 static void prepare_attr_stack(const char *path, int dirlen)
458 struct attr_stack *elem, *info;
459 int len;
460 char pathbuf[PATH_MAX];
463 * At the bottom of the attribute stack is the built-in
464 * set of attribute definitions. Then, contents from
465 * .gitattribute files from directories closer to the
466 * root to the ones in deeper directories are pushed
467 * to the stack. Finally, at the very top of the stack
468 * we always keep the contents of $GIT_DIR/info/attributes.
470 * When checking, we use entries from near the top of the
471 * stack, preferring $GIT_DIR/info/attributes, then
472 * .gitattributes in deeper directories to shallower ones,
473 * and finally use the built-in set as the default.
475 if (!attr_stack)
476 bootstrap_attr_stack();
479 * Pop the "info" one that is always at the top of the stack.
481 info = attr_stack;
482 attr_stack = info->prev;
485 * Pop the ones from directories that are not the prefix of
486 * the path we are checking.
488 while (attr_stack && attr_stack->origin) {
489 int namelen = strlen(attr_stack->origin);
491 elem = attr_stack;
492 if (namelen <= dirlen &&
493 !strncmp(elem->origin, path, namelen))
494 break;
496 debug_pop(elem);
497 attr_stack = elem->prev;
498 free_attr_elem(elem);
502 * Read from parent directories and push them down
504 while (1) {
505 char *cp;
507 len = strlen(attr_stack->origin);
508 if (dirlen <= len)
509 break;
510 memcpy(pathbuf, path, dirlen);
511 memcpy(pathbuf + dirlen, "/", 2);
512 cp = strchr(pathbuf + len + 1, '/');
513 strcpy(cp + 1, GITATTRIBUTES_FILE);
514 elem = read_attr(pathbuf, 0);
515 *cp = '\0';
516 elem->origin = strdup(pathbuf);
517 elem->prev = attr_stack;
518 attr_stack = elem;
519 debug_push(elem);
523 * Finally push the "info" one at the top of the stack.
525 info->prev = attr_stack;
526 attr_stack = info;
529 static int path_matches(const char *pathname, int pathlen,
530 const char *pattern,
531 const char *base, int baselen)
533 if (!strchr(pattern, '/')) {
534 /* match basename */
535 const char *basename = strrchr(pathname, '/');
536 basename = basename ? basename + 1 : pathname;
537 return (fnmatch(pattern, basename, 0) == 0);
540 * match with FNM_PATHNAME; the pattern has base implicitly
541 * in front of it.
543 if (*pattern == '/')
544 pattern++;
545 if (pathlen < baselen ||
546 (baselen && pathname[baselen - 1] != '/') ||
547 strncmp(pathname, base, baselen))
548 return 0;
549 return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0;
552 static int fill_one(const char *what, struct match_attr *a, int rem)
554 struct git_attr_check *check = check_all_attr;
555 int i;
557 for (i = 0; 0 < rem && i < a->num_attr; i++) {
558 struct git_attr *attr = a->state[i].attr;
559 const char **n = &(check[attr->attr_nr].value);
560 const char *v = a->state[i].setto;
562 if (*n == ATTR__UNKNOWN) {
563 debug_set(what, a->u.pattern, attr, v);
564 *n = v;
565 rem--;
568 return rem;
571 static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
573 int i;
574 const char *base = stk->origin ? stk->origin : "";
576 for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
577 struct match_attr *a = stk->attrs[i];
578 if (a->is_macro)
579 continue;
580 if (path_matches(path, pathlen,
581 a->u.pattern, base, strlen(base)))
582 rem = fill_one("fill", a, rem);
584 return rem;
587 static int macroexpand(struct attr_stack *stk, int rem)
589 int i;
590 struct git_attr_check *check = check_all_attr;
592 for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
593 struct match_attr *a = stk->attrs[i];
594 if (!a->is_macro)
595 continue;
596 if (check[a->u.attr->attr_nr].value != ATTR__TRUE)
597 continue;
598 rem = fill_one("expand", a, rem);
600 return rem;
603 int git_checkattr(const char *path, int num, struct git_attr_check *check)
605 struct attr_stack *stk;
606 const char *cp;
607 int dirlen, pathlen, i, rem;
609 bootstrap_attr_stack();
610 for (i = 0; i < attr_nr; i++)
611 check_all_attr[i].value = ATTR__UNKNOWN;
613 pathlen = strlen(path);
614 cp = strrchr(path, '/');
615 if (!cp)
616 dirlen = 0;
617 else
618 dirlen = cp - path;
619 prepare_attr_stack(path, dirlen);
620 rem = attr_nr;
621 for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
622 rem = fill(path, pathlen, stk, rem);
624 for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
625 rem = macroexpand(stk, rem);
627 for (i = 0; i < num; i++) {
628 const char *value = check_all_attr[check[i].attr->attr_nr].value;
629 if (value == ATTR__UNKNOWN)
630 value = ATTR__UNSET;
631 check[i].value = value;
634 return 0;