attr.c

   1 /*
   2  * Handle git attributes.  See gitattributes(5) for a description of
   3  * the file syntax, and Documentation/technical/api-gitattributes.txt
   4  * for a description of the API.
   5  *
   6  * One basic design decision here is that we are not going to support
   7  * an insanely large number of attributes.
   8  */
   9
  10 #define NO_THE_INDEX_COMPATIBILITY_MACROS
  11 #include "cache.h"
  12 #include "exec_cmd.h"
  13 #include "attr.h"
  14 #include "dir.h"
  15
  16 const char git_attr__true[] = "(builtin)true";
  17 const char git_attr__false[] = "\0(builtin)false";
  18 static const char git_attr__unknown[] = "(builtin)unknown";
  19 #define ATTR__TRUE git_attr__true
  20 #define ATTR__FALSE git_attr__false
  21 #define ATTR__UNSET NULL
  22 #define ATTR__UNKNOWN git_attr__unknown
  23
  24 /* This is a randomly chosen prime. */
  25 #define HASHSIZE 257
  26
  27 #ifndef DEBUG_ATTR
  28 #define DEBUG_ATTR 0
  29 #endif
  30
  31 struct git_attr {
  32         struct git_attr *next;
  33         unsigned h;
  34         int attr_nr;
  35         char name[FLEX_ARRAY];
  36 };
  37 static int attr_nr;
  38
  39 static struct git_attr_check *check_all_attr;
  40 static struct git_attr *(git_attr_hash[HASHSIZE]);
  41
  42 char *git_attr_name(struct git_attr *attr)
  43 {
  44         return attr->name;
  45 }
  46
  47 static unsigned hash_name(const char *name, int namelen)
  48 {
  49         unsigned val = 0, c;
  50
  51         while (namelen--) {
  52                 c = *name++;
  53                 val = ((val << 7) | (val >> 22)) ^ c;
  54         }
  55         return val;
  56 }
  57
  58 static int invalid_attr_name(const char *name, int namelen)
  59 {
  60         /*
  61          * Attribute name cannot begin with '-' and must consist of
  62          * characters from [-A-Za-z0-9_.].
  63          */
  64         if (namelen <= 0 || *name == '-')
  65                 return -1;
  66         while (namelen--) {
  67                 char ch = *name++;
  68                 if (! (ch == '-' || ch == '.' || ch == '_' ||
  69                        ('0' <= ch && ch <= '9') ||
  70                        ('a' <= ch && ch <= 'z') ||
  71                        ('A' <= ch && ch <= 'Z')) )
  72                         return -1;
  73         }
  74         return 0;
  75 }
  76
  77 static struct git_attr *git_attr_internal(const char *name, int len)
  78 {
  79         unsigned hval = hash_name(name, len);
  80         unsigned pos = hval % HASHSIZE;
  81         struct git_attr *a;
  82
  83         for (a = git_attr_hash[pos]; a; a = a->next) {
  84                 if (a->h == hval &&
  85                     !memcmp(a->name, name, len) && !a->name[len])
  86                         return a;
  87         }
  88
  89         if (invalid_attr_name(name, len))
  90                 return NULL;
  91
  92         a = xmalloc(sizeof(*a) + len + 1);
  93         memcpy(a->name, name, len);
  94         a->name[len] = 0;
  95         a->h = hval;
  96         a->next = git_attr_hash[pos];
  97         a->attr_nr = attr_nr++;
  98         git_attr_hash[pos] = a;
  99
 100         check_all_attr = xrealloc(check_all_attr,
 101                                   sizeof(*check_all_attr) * attr_nr);
 102         check_all_attr[a->attr_nr].attr = a;
 103         check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
 104         return a;
 105 }
 106
 107 struct git_attr *git_attr(const char *name)
 108 {
 109         return git_attr_internal(name, strlen(name));
 110 }
 111
 112 /* What does a matched pattern decide? */
 113 struct attr_state {
 114         struct git_attr *attr;
 115         const char *setto;
 116 };
 117
 118 /*
 119  * One rule, as from a .gitattributes file.
 120  *
 121  * If is_macro is true, then u.attr is a pointer to the git_attr being
 122  * defined.
 123  *
 124  * If is_macro is false, then u.pattern points at the filename pattern
 125  * to which the rule applies.  (The memory pointed to is part of the
 126  * memory block allocated for the match_attr instance.)
 127  *
 128  * In either case, num_attr is the number of attributes affected by
 129  * this rule, and state is an array listing them.  The attributes are
 130  * listed as they appear in the file (macros unexpanded).
 131  */
 132 struct match_attr {
 133         union {
 134                 char *pattern;
 135                 struct git_attr *attr;
 136         } u;
 137         char is_macro;
 138         unsigned num_attr;
 139         struct attr_state state[FLEX_ARRAY];
 140 };
 141
 142 static const char blank[] = " \t\r\n";
 143
 144 /*
 145  * Parse a whitespace-delimited attribute state (i.e., "attr",
 146  * "-attr", "!attr", or "attr=value") from the string starting at src.
 147  * If e is not NULL, write the results to *e.  Return a pointer to the
 148  * remainder of the string (with leading whitespace removed), or NULL
 149  * if there was an error.
 150  */
 151 static const char *parse_attr(const char *src, int lineno, const char *cp,
 152                               struct attr_state *e)
 153 {
 154         const char *ep, *equals;
 155         int len;
 156
 157         ep = cp + strcspn(cp, blank);
 158         equals = strchr(cp, '=');
 159         if (equals && ep < equals)
 160                 equals = NULL;
 161         if (equals)
 162                 len = equals - cp;
 163         else
 164                 len = ep - cp;
 165         if (!e) {
 166                 if (*cp == '-' || *cp == '!') {
 167                         cp++;
 168                         len--;
 169                 }
 170                 if (invalid_attr_name(cp, len)) {
 171                         fprintf(stderr,
 172                                 "%.*s is not a valid attribute name: %s:%d\n",
 173                                 len, cp, src, lineno);
 174                         return NULL;
 175                 }
 176         } else {
 177                 if (*cp == '-' || *cp == '!') {
 178                         e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 179                         cp++;
 180                         len--;
 181                 }
 182                 else if (!equals)
 183                         e->setto = ATTR__TRUE;
 184                 else {
 185                         e->setto = xmemdupz(equals + 1, ep - equals - 1);
 186                 }
 187                 e->attr = git_attr_internal(cp, len);
 188         }
 189         return ep + strspn(ep, blank);
 190 }
 191
 192 static struct match_attr *parse_attr_line(const char *line, const char *src,
 193                                           int lineno, int macro_ok)
 194 {
 195         int namelen;
 196         int num_attr, i;
 197         const char *cp, *name, *states;
 198         struct match_attr *res = NULL;
 199         int is_macro;
 200
 201         cp = line + strspn(line, blank);
 202         if (!*cp || *cp == '#')
 203                 return NULL;
 204         name = cp;
 205         namelen = strcspn(name, blank);
 206         if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 207             !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
 208                 if (!macro_ok) {
 209                         fprintf(stderr, "%s not allowed: %s:%d\n",
 210                                 name, src, lineno);
 211                         return NULL;
 212                 }
 213                 is_macro = 1;
 214                 name += strlen(ATTRIBUTE_MACRO_PREFIX);
 215                 name += strspn(name, blank);
 216                 namelen = strcspn(name, blank);
 217                 if (invalid_attr_name(name, namelen)) {
 218                         fprintf(stderr,
 219                                 "%.*s is not a valid attribute name: %s:%d\n",
 220                                 namelen, name, src, lineno);
 221                         return NULL;
 222                 }
 223         }
 224         else
 225                 is_macro = 0;
 226
 227         states = name + namelen;
 228         states += strspn(states, blank);
 229
 230         /* First pass to count the attr_states */
 231         for (cp = states, num_attr = 0; *cp; num_attr++) {
 232                 cp = parse_attr(src, lineno, cp, NULL);
 233                 if (!cp)
 234                         return NULL;
 235         }
 236
 237         res = xcalloc(1,
 238                       sizeof(*res) +
 239                       sizeof(struct attr_state) * num_attr +
 240                       (is_macro ? 0 : namelen + 1));
 241         if (is_macro)
 242                 res->u.attr = git_attr_internal(name, namelen);
 243         else {
 244                 res->u.pattern = (char *)&(res->state[num_attr]);
 245                 memcpy(res->u.pattern, name, namelen);
 246                 res->u.pattern[namelen] = 0;
 247         }
 248         res->is_macro = is_macro;
 249         res->num_attr = num_attr;
 250
 251         /* Second pass to fill the attr_states */
 252         for (cp = states, i = 0; *cp; i++) {
 253                 cp = parse_attr(src, lineno, cp, &(res->state[i]));
 254         }
 255
 256         return res;
 257 }
 258
 259 /*
 260  * Like info/exclude and .gitignore, the attribute information can
 261  * come from many places.
 262  *
 263  * (1) .gitattribute file of the same directory;
 264  * (2) .gitattribute file of the parent directory if (1) does not have
 265  *      any match; this goes recursively upwards, just like .gitignore.
 266  * (3) $GIT_DIR/info/attributes, which overrides both of the above.
 267  *
 268  * In the same file, later entries override the earlier match, so in the
 269  * global list, we would have entries from info/attributes the earliest
 270  * (reading the file from top to bottom), .gitattribute of the root
 271  * directory (again, reading the file from top to bottom) down to the
 272  * current directory, and then scan the list backwards to find the first match.
 273  * This is exactly the same as what excluded() does in dir.c to deal with
 274  * .gitignore
 275  */
 276
 277 static struct attr_stack {
 278         struct attr_stack *prev;
 279         char *origin;
 280         unsigned num_matches;
 281         unsigned alloc;
 282         struct match_attr **attrs;
 283 } *attr_stack;
 284
 285 static void free_attr_elem(struct attr_stack *e)
 286 {
 287         int i;
 288         free(e->origin);
 289         for (i = 0; i < e->num_matches; i++) {
 290                 struct match_attr *a = e->attrs[i];
 291                 int j;
 292                 for (j = 0; j < a->num_attr; j++) {
 293                         const char *setto = a->state[j].setto;
 294                         if (setto == ATTR__TRUE ||
 295                             setto == ATTR__FALSE ||
 296                             setto == ATTR__UNSET ||
 297                             setto == ATTR__UNKNOWN)
 298                                 ;
 299                         else
 300                                 free((char *) setto);
 301                 }
 302                 free(a);
 303         }
 304         free(e->attrs);
 305         free(e);
 306 }
 307
 308 static const char *builtin_attr[] = {
 309         "[attr]binary -diff -text",
 310         NULL,
 311 };
 312
 313 static void handle_attr_line(struct attr_stack *res,
 314                              const char *line,
 315                              const char *src,
 316                              int lineno,
 317                              int macro_ok)
 318 {
 319         struct match_attr *a;
 320
 321         a = parse_attr_line(line, src, lineno, macro_ok);
 322         if (!a)
 323                 return;
 324         if (res->alloc <= res->num_matches) {
 325                 res->alloc = alloc_nr(res->num_matches);
 326                 res->attrs = xrealloc(res->attrs,
 327                                       sizeof(struct match_attr *) *
 328                                       res->alloc);
 329         }
 330         res->attrs[res->num_matches++] = a;
 331 }
 332
 333 static struct attr_stack *read_attr_from_array(const char **list)
 334 {
 335         struct attr_stack *res;
 336         const char *line;
 337         int lineno = 0;
 338
 339         res = xcalloc(1, sizeof(*res));
 340         while ((line = *(list++)) != NULL)
 341                 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
 342         return res;
 343 }
 344
 345 static enum git_attr_direction direction;
 346 static struct index_state *use_index;
 347
 348 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 349 {
 350         FILE *fp = fopen(path, "r");
 351         struct attr_stack *res;
 352         char buf[2048];
 353         int lineno = 0;
 354
 355         if (!fp) {
 356                 if (errno != ENOENT && errno != ENOTDIR)
 357                         warn_on_inaccessible(path);
 358                 return NULL;
 359         }
 360         res = xcalloc(1, sizeof(*res));
 361         while (fgets(buf, sizeof(buf), fp))
 362                 handle_attr_line(res, buf, path, ++lineno, macro_ok);
 363         fclose(fp);
 364         return res;
 365 }
 366
 367 static void *read_index_data(const char *path)
 368 {
 369         int pos, len;
 370         unsigned long sz;
 371         enum object_type type;
 372         void *data;
 373         struct index_state *istate = use_index ? use_index : &the_index;
 374
 375         len = strlen(path);
 376         pos = index_name_pos(istate, path, len);
 377         if (pos < 0) {
 378                 /*
 379                  * We might be in the middle of a merge, in which
 380                  * case we would read stage #2 (ours).
 381                  */
 382                 int i;
 383                 for (i = -pos - 1;
 384                      (pos < 0 && i < istate->cache_nr &&
 385                       !strcmp(istate->cache[i]->name, path));
 386                      i++)
 387                         if (ce_stage(istate->cache[i]) == 2)
 388                                 pos = i;
 389         }
 390         if (pos < 0)
 391                 return NULL;
 392         data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz);
 393         if (!data || type != OBJ_BLOB) {
 394                 free(data);
 395                 return NULL;
 396         }
 397         return data;
 398 }
 399
 400 static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
 401 {
 402         struct attr_stack *res;
 403         char *buf, *sp;
 404         int lineno = 0;
 405
 406         buf = read_index_data(path);
 407         if (!buf)
 408                 return NULL;
 409
 410         res = xcalloc(1, sizeof(*res));
 411         for (sp = buf; *sp; ) {
 412                 char *ep;
 413                 int more;
 414                 for (ep = sp; *ep && *ep != '\n'; ep++)
 415                         ;
 416                 more = (*ep == '\n');
 417                 *ep = '\0';
 418                 handle_attr_line(res, sp, path, ++lineno, macro_ok);
 419                 sp = ep + more;
 420         }
 421         free(buf);
 422         return res;
 423 }
 424
 425 static struct attr_stack *read_attr(const char *path, int macro_ok)
 426 {
 427         struct attr_stack *res;
 428
 429         if (direction == GIT_ATTR_CHECKOUT) {
 430                 res = read_attr_from_index(path, macro_ok);
 431                 if (!res)
 432                         res = read_attr_from_file(path, macro_ok);
 433         }
 434         else if (direction == GIT_ATTR_CHECKIN) {
 435                 res = read_attr_from_file(path, macro_ok);
 436                 if (!res)
 437                         /*
 438                          * There is no checked out .gitattributes file there, but
 439                          * we might have it in the index.  We allow operation in a
 440                          * sparsely checked out work tree, so read from it.
 441                          */
 442                         res = read_attr_from_index(path, macro_ok);
 443         }
 444         else
 445                 res = read_attr_from_index(path, macro_ok);
 446         if (!res)
 447                 res = xcalloc(1, sizeof(*res));
 448         return res;
 449 }
 450
 451 #if DEBUG_ATTR
 452 static void debug_info(const char *what, struct attr_stack *elem)
 453 {
 454         fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
 455 }
 456 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
 457 {
 458         const char *value = v;
 459
 460         if (ATTR_TRUE(value))
 461                 value = "set";
 462         else if (ATTR_FALSE(value))
 463                 value = "unset";
 464         else if (ATTR_UNSET(value))
 465                 value = "unspecified";
 466
 467         fprintf(stderr, "%s: %s => %s (%s)\n",
 468                 what, attr->name, (char *) value, match);
 469 }
 470 #define debug_push(a) debug_info("push", (a))
 471 #define debug_pop(a) debug_info("pop", (a))
 472 #else
 473 #define debug_push(a) do { ; } while (0)
 474 #define debug_pop(a) do { ; } while (0)
 475 #define debug_set(a,b,c,d) do { ; } while (0)
 476 #endif
 477
 478 static void drop_attr_stack(void)
 479 {
 480         while (attr_stack) {
 481                 struct attr_stack *elem = attr_stack;
 482                 attr_stack = elem->prev;
 483                 free_attr_elem(elem);
 484         }
 485 }
 486
 487 static const char *git_etc_gitattributes(void)
 488 {
 489         static const char *system_wide;
 490         if (!system_wide)
 491                 system_wide = system_path(ETC_GITATTRIBUTES);
 492         return system_wide;
 493 }
 494
 495 static int git_attr_system(void)
 496 {
 497         return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 498 }
 499
 500 static void bootstrap_attr_stack(void)
 501 {
 502         struct attr_stack *elem;
 503         char *xdg_attributes_file;
 504
 505         if (attr_stack)
 506                 return;
 507
 508         elem = read_attr_from_array(builtin_attr);
 509         elem->origin = NULL;
 510         elem->prev = attr_stack;
 511         attr_stack = elem;
 512
 513         if (git_attr_system()) {
 514                 elem = read_attr_from_file(git_etc_gitattributes(), 1);
 515                 if (elem) {
 516                         elem->origin = NULL;
 517                         elem->prev = attr_stack;
 518                         attr_stack = elem;
 519                 }
 520         }
 521
 522         if (!git_attributes_file) {
 523                 home_config_paths(NULL, &xdg_attributes_file, "attributes");
 524                 git_attributes_file = xdg_attributes_file;
 525         }
 526         if (git_attributes_file) {
 527                 elem = read_attr_from_file(git_attributes_file, 1);
 528                 if (elem) {
 529                         elem->origin = NULL;
 530                         elem->prev = attr_stack;
 531                         attr_stack = elem;
 532                 }
 533         }
 534
 535         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 536                 elem = read_attr(GITATTRIBUTES_FILE, 1);
 537                 elem->origin = xstrdup("");
 538                 elem->prev = attr_stack;
 539                 attr_stack = elem;
 540                 debug_push(elem);
 541         }
 542
 543         elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
 544         if (!elem)
 545                 elem = xcalloc(1, sizeof(*elem));
 546         elem->origin = NULL;
 547         elem->prev = attr_stack;
 548         attr_stack = elem;
 549 }
 550
 551 static void prepare_attr_stack(const char *path)
 552 {
 553         struct attr_stack *elem, *info;
 554         int dirlen, len;
 555         const char *cp;
 556
 557         cp = strrchr(path, '/');
 558         if (!cp)
 559                 dirlen = 0;
 560         else
 561                 dirlen = cp - path;
 562
 563         /*
 564          * At the bottom of the attribute stack is the built-in
 565          * set of attribute definitions, followed by the contents
 566          * of $(prefix)/etc/gitattributes and a file specified by
 567          * core.attributesfile.  Then, contents from
 568          * .gitattribute files from directories closer to the
 569          * root to the ones in deeper directories are pushed
 570          * to the stack.  Finally, at the very top of the stack
 571          * we always keep the contents of $GIT_DIR/info/attributes.
 572          *
 573          * When checking, we use entries from near the top of the
 574          * stack, preferring $GIT_DIR/info/attributes, then
 575          * .gitattributes in deeper directories to shallower ones,
 576          * and finally use the built-in set as the default.
 577          */
 578         bootstrap_attr_stack();
 579
 580         /*
 581          * Pop the "info" one that is always at the top of the stack.
 582          */
 583         info = attr_stack;
 584         attr_stack = info->prev;
 585
 586         /*
 587          * Pop the ones from directories that are not the prefix of
 588          * the path we are checking. Break out of the loop when we see
 589          * the root one (whose origin is an empty string "") or the builtin
 590          * one (whose origin is NULL) without popping it.
 591          */
 592         while (attr_stack->origin) {
 593                 int namelen = strlen(attr_stack->origin);
 594
 595                 elem = attr_stack;
 596                 if (namelen <= dirlen &&
 597                     !strncmp(elem->origin, path, namelen) &&
 598                     (!namelen || path[namelen] == '/'))
 599                         break;
 600
 601                 debug_pop(elem);
 602                 attr_stack = elem->prev;
 603                 free_attr_elem(elem);
 604         }
 605
 606         /*
 607          * Read from parent directories and push them down
 608          */
 609         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 610                 /*
 611                  * bootstrap_attr_stack() should have added, and the
 612                  * above loop should have stopped before popping, the
 613                  * root element whose attr_stack->origin is set to an
 614                  * empty string.
 615                  */
 616                 struct strbuf pathbuf = STRBUF_INIT;
 617
 618                 assert(attr_stack->origin);
 619                 while (1) {
 620                         len = strlen(attr_stack->origin);
 621                         if (dirlen <= len)
 622                                 break;
 623                         cp = memchr(path + len + 1, '/', dirlen - len - 1);
 624                         if (!cp)
 625                                 cp = path + dirlen;
 626                         strbuf_add(&pathbuf, path, cp - path);
 627                         strbuf_addch(&pathbuf, '/');
 628                         strbuf_addstr(&pathbuf, GITATTRIBUTES_FILE);
 629                         elem = read_attr(pathbuf.buf, 0);
 630                         strbuf_setlen(&pathbuf, cp - path);
 631                         elem->origin = strbuf_detach(&pathbuf, NULL);
 632                         elem->prev = attr_stack;
 633                         attr_stack = elem;
 634                         debug_push(elem);
 635                 }
 636
 637                 strbuf_release(&pathbuf);
 638         }
 639
 640         /*
 641          * Finally push the "info" one at the top of the stack.
 642          */
 643         info->prev = attr_stack;
 644         attr_stack = info;
 645 }
 646
 647 static int path_matches(const char *pathname, int pathlen,
 648                         const char *pattern,
 649                         const char *base, int baselen)
 650 {
 651         if (!strchr(pattern, '/')) {
 652                 /* match basename */
 653                 const char *basename = strrchr(pathname, '/');
 654                 basename = basename ? basename + 1 : pathname;
 655                 return (fnmatch_icase(pattern, basename, 0) == 0);
 656         }
 657         /*
 658          * match with FNM_PATHNAME; the pattern has base implicitly
 659          * in front of it.
 660          */
 661         if (*pattern == '/')
 662                 pattern++;
 663         if (pathlen < baselen ||
 664             (baselen && pathname[baselen] != '/') ||
 665             strncmp(pathname, base, baselen))
 666                 return 0;
 667         if (baselen != 0)
 668                 baselen++;
 669         return fnmatch_icase(pattern, pathname + baselen, FNM_PATHNAME) == 0;
 670 }
 671
 672 static int macroexpand_one(int attr_nr, int rem);
 673
 674 static int fill_one(const char *what, struct match_attr *a, int rem)
 675 {
 676         struct git_attr_check *check = check_all_attr;
 677         int i;
 678
 679         for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {
 680                 struct git_attr *attr = a->state[i].attr;
 681                 const char **n = &(check[attr->attr_nr].value);
 682                 const char *v = a->state[i].setto;
 683
 684                 if (*n == ATTR__UNKNOWN) {
 685                         debug_set(what,
 686                                   a->is_macro ? a->u.attr->name : a->u.pattern,
 687                                   attr, v);
 688                         *n = v;
 689                         rem--;
 690                         rem = macroexpand_one(attr->attr_nr, rem);
 691                 }
 692         }
 693         return rem;
 694 }
 695
 696 static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
 697 {
 698         int i;
 699         const char *base = stk->origin ? stk->origin : "";
 700
 701         for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
 702                 struct match_attr *a = stk->attrs[i];
 703                 if (a->is_macro)
 704                         continue;
 705                 if (path_matches(path, pathlen,
 706                                  a->u.pattern, base, strlen(base)))
 707                         rem = fill_one("fill", a, rem);
 708         }
 709         return rem;
 710 }
 711
 712 static int macroexpand_one(int attr_nr, int rem)
 713 {
 714         struct attr_stack *stk;
 715         struct match_attr *a = NULL;
 716         int i;
 717
 718         if (check_all_attr[attr_nr].value != ATTR__TRUE)
 719                 return rem;
 720
 721         for (stk = attr_stack; !a && stk; stk = stk->prev)
 722                 for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
 723                         struct match_attr *ma = stk->attrs[i];
 724                         if (!ma->is_macro)
 725                                 continue;
 726                         if (ma->u.attr->attr_nr == attr_nr)
 727                                 a = ma;
 728                 }
 729
 730         if (a)
 731                 rem = fill_one("expand", a, rem);
 732
 733         return rem;
 734 }
 735
 736 /*
 737  * Collect all attributes for path into the array pointed to by
 738  * check_all_attr.
 739  */
 740 static void collect_all_attrs(const char *path)
 741 {
 742         struct attr_stack *stk;
 743         int i, pathlen, rem;
 744
 745         prepare_attr_stack(path);
 746         for (i = 0; i < attr_nr; i++)
 747                 check_all_attr[i].value = ATTR__UNKNOWN;
 748
 749         pathlen = strlen(path);
 750         rem = attr_nr;
 751         for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
 752                 rem = fill(path, pathlen, stk, rem);
 753 }
 754
 755 int git_check_attr(const char *path, int num, struct git_attr_check *check)
 756 {
 757         int i;
 758
 759         collect_all_attrs(path);
 760
 761         for (i = 0; i < num; i++) {
 762                 const char *value = check_all_attr[check[i].attr->attr_nr].value;
 763                 if (value == ATTR__UNKNOWN)
 764                         value = ATTR__UNSET;
 765                 check[i].value = value;
 766         }
 767
 768         return 0;
 769 }
 770
 771 int git_all_attrs(const char *path, int *num, struct git_attr_check **check)
 772 {
 773         int i, count, j;
 774
 775         collect_all_attrs(path);
 776
 777         /* Count the number of attributes that are set. */
 778         count = 0;
 779         for (i = 0; i < attr_nr; i++) {
 780                 const char *value = check_all_attr[i].value;
 781                 if (value != ATTR__UNSET && value != ATTR__UNKNOWN)
 782                         ++count;
 783         }
 784         *num = count;
 785         *check = xmalloc(sizeof(**check) * count);
 786         j = 0;
 787         for (i = 0; i < attr_nr; i++) {
 788                 const char *value = check_all_attr[i].value;
 789                 if (value != ATTR__UNSET && value != ATTR__UNKNOWN) {
 790                         (*check)[j].attr = check_all_attr[i].attr;
 791                         (*check)[j].value = value;
 792                         ++j;
 793                 }
 794         }
 795
 796         return 0;
 797 }
 798
 799 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
 800 {
 801         enum git_attr_direction old = direction;
 802
 803         if (is_bare_repository() && new != GIT_ATTR_INDEX)
 804                 die("BUG: non-INDEX attr direction in a bare repo");
 805
 806         direction = new;
 807         if (new != old)
 808                 drop_attr_stack();
 809         use_index = istate;
 810 }