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         size_t originlen;
 281         unsigned num_matches;
 282         unsigned alloc;
 283         struct match_attr **attrs;
 284 } *attr_stack;
 285
 286 static void free_attr_elem(struct attr_stack *e)
 287 {
 288         int i;
 289         free(e->origin);
 290         for (i = 0; i < e->num_matches; i++) {
 291                 struct match_attr *a = e->attrs[i];
 292                 int j;
 293                 for (j = 0; j < a->num_attr; j++) {
 294                         const char *setto = a->state[j].setto;
 295                         if (setto == ATTR__TRUE ||
 296                             setto == ATTR__FALSE ||
 297                             setto == ATTR__UNSET ||
 298                             setto == ATTR__UNKNOWN)
 299                                 ;
 300                         else
 301                                 free((char *) setto);
 302                 }
 303                 free(a);
 304         }
 305         free(e->attrs);
 306         free(e);
 307 }
 308
 309 static const char *builtin_attr[] = {
 310         "[attr]binary -diff -merge -text",
 311         NULL,
 312 };
 313
 314 static void handle_attr_line(struct attr_stack *res,
 315                              const char *line,
 316                              const char *src,
 317                              int lineno,
 318                              int macro_ok)
 319 {
 320         struct match_attr *a;
 321
 322         a = parse_attr_line(line, src, lineno, macro_ok);
 323         if (!a)
 324                 return;
 325         if (res->alloc <= res->num_matches) {
 326                 res->alloc = alloc_nr(res->num_matches);
 327                 res->attrs = xrealloc(res->attrs,
 328                                       sizeof(struct match_attr *) *
 329                                       res->alloc);
 330         }
 331         res->attrs[res->num_matches++] = a;
 332 }
 333
 334 static struct attr_stack *read_attr_from_array(const char **list)
 335 {
 336         struct attr_stack *res;
 337         const char *line;
 338         int lineno = 0;
 339
 340         res = xcalloc(1, sizeof(*res));
 341         while ((line = *(list++)) != NULL)
 342                 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
 343         return res;
 344 }
 345
 346 static enum git_attr_direction direction;
 347 static struct index_state *use_index;
 348
 349 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 350 {
 351         FILE *fp = fopen(path, "r");
 352         struct attr_stack *res;
 353         char buf[2048];
 354         int lineno = 0;
 355
 356         if (!fp) {
 357                 if (errno != ENOENT && errno != ENOTDIR)
 358                         warn_on_inaccessible(path);
 359                 return NULL;
 360         }
 361         res = xcalloc(1, sizeof(*res));
 362         while (fgets(buf, sizeof(buf), fp))
 363                 handle_attr_line(res, buf, path, ++lineno, macro_ok);
 364         fclose(fp);
 365         return res;
 366 }
 367
 368 static void *read_index_data(const char *path)
 369 {
 370         int pos, len;
 371         unsigned long sz;
 372         enum object_type type;
 373         void *data;
 374         struct index_state *istate = use_index ? use_index : &the_index;
 375
 376         len = strlen(path);
 377         pos = index_name_pos(istate, path, len);
 378         if (pos < 0) {
 379                 /*
 380                  * We might be in the middle of a merge, in which
 381                  * case we would read stage #2 (ours).
 382                  */
 383                 int i;
 384                 for (i = -pos - 1;
 385                      (pos < 0 && i < istate->cache_nr &&
 386                       !strcmp(istate->cache[i]->name, path));
 387                      i++)
 388                         if (ce_stage(istate->cache[i]) == 2)
 389                                 pos = i;
 390         }
 391         if (pos < 0)
 392                 return NULL;
 393         data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz);
 394         if (!data || type != OBJ_BLOB) {
 395                 free(data);
 396                 return NULL;
 397         }
 398         return data;
 399 }
 400
 401 static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
 402 {
 403         struct attr_stack *res;
 404         char *buf, *sp;
 405         int lineno = 0;
 406
 407         buf = read_index_data(path);
 408         if (!buf)
 409                 return NULL;
 410
 411         res = xcalloc(1, sizeof(*res));
 412         for (sp = buf; *sp; ) {
 413                 char *ep;
 414                 int more;
 415                 for (ep = sp; *ep && *ep != '\n'; ep++)
 416                         ;
 417                 more = (*ep == '\n');
 418                 *ep = '\0';
 419                 handle_attr_line(res, sp, path, ++lineno, macro_ok);
 420                 sp = ep + more;
 421         }
 422         free(buf);
 423         return res;
 424 }
 425
 426 static struct attr_stack *read_attr(const char *path, int macro_ok)
 427 {
 428         struct attr_stack *res;
 429
 430         if (direction == GIT_ATTR_CHECKOUT) {
 431                 res = read_attr_from_index(path, macro_ok);
 432                 if (!res)
 433                         res = read_attr_from_file(path, macro_ok);
 434         }
 435         else if (direction == GIT_ATTR_CHECKIN) {
 436                 res = read_attr_from_file(path, macro_ok);
 437                 if (!res)
 438                         /*
 439                          * There is no checked out .gitattributes file there, but
 440                          * we might have it in the index.  We allow operation in a
 441                          * sparsely checked out work tree, so read from it.
 442                          */
 443                         res = read_attr_from_index(path, macro_ok);
 444         }
 445         else
 446                 res = read_attr_from_index(path, macro_ok);
 447         if (!res)
 448                 res = xcalloc(1, sizeof(*res));
 449         return res;
 450 }
 451
 452 #if DEBUG_ATTR
 453 static void debug_info(const char *what, struct attr_stack *elem)
 454 {
 455         fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
 456 }
 457 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
 458 {
 459         const char *value = v;
 460
 461         if (ATTR_TRUE(value))
 462                 value = "set";
 463         else if (ATTR_FALSE(value))
 464                 value = "unset";
 465         else if (ATTR_UNSET(value))
 466                 value = "unspecified";
 467
 468         fprintf(stderr, "%s: %s => %s (%s)\n",
 469                 what, attr->name, (char *) value, match);
 470 }
 471 #define debug_push(a) debug_info("push", (a))
 472 #define debug_pop(a) debug_info("pop", (a))
 473 #else
 474 #define debug_push(a) do { ; } while (0)
 475 #define debug_pop(a) do { ; } while (0)
 476 #define debug_set(a,b,c,d) do { ; } while (0)
 477 #endif
 478
 479 static void drop_attr_stack(void)
 480 {
 481         while (attr_stack) {
 482                 struct attr_stack *elem = attr_stack;
 483                 attr_stack = elem->prev;
 484                 free_attr_elem(elem);
 485         }
 486 }
 487
 488 static const char *git_etc_gitattributes(void)
 489 {
 490         static const char *system_wide;
 491         if (!system_wide)
 492                 system_wide = system_path(ETC_GITATTRIBUTES);
 493         return system_wide;
 494 }
 495
 496 static int git_attr_system(void)
 497 {
 498         return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 499 }
 500
 501 static void bootstrap_attr_stack(void)
 502 {
 503         struct attr_stack *elem;
 504         char *xdg_attributes_file;
 505
 506         if (attr_stack)
 507                 return;
 508
 509         elem = read_attr_from_array(builtin_attr);
 510         elem->origin = NULL;
 511         elem->prev = attr_stack;
 512         attr_stack = elem;
 513
 514         if (git_attr_system()) {
 515                 elem = read_attr_from_file(git_etc_gitattributes(), 1);
 516                 if (elem) {
 517                         elem->origin = NULL;
 518                         elem->prev = attr_stack;
 519                         attr_stack = elem;
 520                 }
 521         }
 522
 523         if (!git_attributes_file) {
 524                 home_config_paths(NULL, &xdg_attributes_file, "attributes");
 525                 git_attributes_file = xdg_attributes_file;
 526         }
 527         if (git_attributes_file) {
 528                 elem = read_attr_from_file(git_attributes_file, 1);
 529                 if (elem) {
 530                         elem->origin = NULL;
 531                         elem->prev = attr_stack;
 532                         attr_stack = elem;
 533                 }
 534         }
 535
 536         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 537                 elem = read_attr(GITATTRIBUTES_FILE, 1);
 538                 elem->origin = xstrdup("");
 539                 elem->originlen = 0;
 540                 elem->prev = attr_stack;
 541                 attr_stack = elem;
 542                 debug_push(elem);
 543         }
 544
 545         elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
 546         if (!elem)
 547                 elem = xcalloc(1, sizeof(*elem));
 548         elem->origin = NULL;
 549         elem->prev = attr_stack;
 550         attr_stack = elem;
 551 }
 552
 553 static void prepare_attr_stack(const char *path)
 554 {
 555         struct attr_stack *elem, *info;
 556         int dirlen, len;
 557         const char *cp;
 558
 559         cp = strrchr(path, '/');
 560         if (!cp)
 561                 dirlen = 0;
 562         else
 563                 dirlen = cp - path;
 564
 565         /*
 566          * At the bottom of the attribute stack is the built-in
 567          * set of attribute definitions, followed by the contents
 568          * of $(prefix)/etc/gitattributes and a file specified by
 569          * core.attributesfile.  Then, contents from
 570          * .gitattribute files from directories closer to the
 571          * root to the ones in deeper directories are pushed
 572          * to the stack.  Finally, at the very top of the stack
 573          * we always keep the contents of $GIT_DIR/info/attributes.
 574          *
 575          * When checking, we use entries from near the top of the
 576          * stack, preferring $GIT_DIR/info/attributes, then
 577          * .gitattributes in deeper directories to shallower ones,
 578          * and finally use the built-in set as the default.
 579          */
 580         bootstrap_attr_stack();
 581
 582         /*
 583          * Pop the "info" one that is always at the top of the stack.
 584          */
 585         info = attr_stack;
 586         attr_stack = info->prev;
 587
 588         /*
 589          * Pop the ones from directories that are not the prefix of
 590          * the path we are checking. Break out of the loop when we see
 591          * the root one (whose origin is an empty string "") or the builtin
 592          * one (whose origin is NULL) without popping it.
 593          */
 594         while (attr_stack->origin) {
 595                 int namelen = strlen(attr_stack->origin);
 596
 597                 elem = attr_stack;
 598                 if (namelen <= dirlen &&
 599                     !strncmp(elem->origin, path, namelen) &&
 600                     (!namelen || path[namelen] == '/'))
 601                         break;
 602
 603                 debug_pop(elem);
 604                 attr_stack = elem->prev;
 605                 free_attr_elem(elem);
 606         }
 607
 608         /*
 609          * Read from parent directories and push them down
 610          */
 611         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 612                 /*
 613                  * bootstrap_attr_stack() should have added, and the
 614                  * above loop should have stopped before popping, the
 615                  * root element whose attr_stack->origin is set to an
 616                  * empty string.
 617                  */
 618                 struct strbuf pathbuf = STRBUF_INIT;
 619
 620                 assert(attr_stack->origin);
 621                 while (1) {
 622                         len = strlen(attr_stack->origin);
 623                         if (dirlen <= len)
 624                                 break;
 625                         cp = memchr(path + len + 1, '/', dirlen - len - 1);
 626                         if (!cp)
 627                                 cp = path + dirlen;
 628                         strbuf_add(&pathbuf, path, cp - path);
 629                         strbuf_addch(&pathbuf, '/');
 630                         strbuf_addstr(&pathbuf, GITATTRIBUTES_FILE);
 631                         elem = read_attr(pathbuf.buf, 0);
 632                         strbuf_setlen(&pathbuf, cp - path);
 633                         elem->origin = strbuf_detach(&pathbuf, &elem->originlen);
 634                         elem->prev = attr_stack;
 635                         attr_stack = elem;
 636                         debug_push(elem);
 637                 }
 638
 639                 strbuf_release(&pathbuf);
 640         }
 641
 642         /*
 643          * Finally push the "info" one at the top of the stack.
 644          */
 645         info->prev = attr_stack;
 646         attr_stack = info;
 647 }
 648
 649 static int path_matches(const char *pathname, int pathlen,
 650                         const char *basename,
 651                         const char *pattern,
 652                         const char *base, int baselen)
 653 {
 654         if (!strchr(pattern, '/')) {
 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, const char *basename,
 697                 struct attr_stack *stk, int rem)
 698 {
 699         int i;
 700         const char *base = stk->origin ? stk->origin : "";
 701
 702         for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
 703                 struct match_attr *a = stk->attrs[i];
 704                 if (a->is_macro)
 705                         continue;
 706                 if (path_matches(path, pathlen, basename,
 707                                  a->u.pattern, base, stk->originlen))
 708                         rem = fill_one("fill", a, rem);
 709         }
 710         return rem;
 711 }
 712
 713 static int macroexpand_one(int attr_nr, int rem)
 714 {
 715         struct attr_stack *stk;
 716         struct match_attr *a = NULL;
 717         int i;
 718
 719         if (check_all_attr[attr_nr].value != ATTR__TRUE)
 720                 return rem;
 721
 722         for (stk = attr_stack; !a && stk; stk = stk->prev)
 723                 for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
 724                         struct match_attr *ma = stk->attrs[i];
 725                         if (!ma->is_macro)
 726                                 continue;
 727                         if (ma->u.attr->attr_nr == attr_nr)
 728                                 a = ma;
 729                 }
 730
 731         if (a)
 732                 rem = fill_one("expand", a, rem);
 733
 734         return rem;
 735 }
 736
 737 /*
 738  * Collect all attributes for path into the array pointed to by
 739  * check_all_attr.
 740  */
 741 static void collect_all_attrs(const char *path)
 742 {
 743         struct attr_stack *stk;
 744         int i, pathlen, rem;
 745         const char *basename;
 746
 747         prepare_attr_stack(path);
 748         for (i = 0; i < attr_nr; i++)
 749                 check_all_attr[i].value = ATTR__UNKNOWN;
 750
 751         basename = strrchr(path, '/');
 752         basename = basename ? basename + 1 : path;
 753
 754         pathlen = strlen(path);
 755         rem = attr_nr;
 756         for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
 757                 rem = fill(path, pathlen, basename, stk, rem);
 758 }
 759
 760 int git_check_attr(const char *path, int num, struct git_attr_check *check)
 761 {
 762         int i;
 763
 764         collect_all_attrs(path);
 765
 766         for (i = 0; i < num; i++) {
 767                 const char *value = check_all_attr[check[i].attr->attr_nr].value;
 768                 if (value == ATTR__UNKNOWN)
 769                         value = ATTR__UNSET;
 770                 check[i].value = value;
 771         }
 772
 773         return 0;
 774 }
 775
 776 int git_all_attrs(const char *path, int *num, struct git_attr_check **check)
 777 {
 778         int i, count, j;
 779
 780         collect_all_attrs(path);
 781
 782         /* Count the number of attributes that are set. */
 783         count = 0;
 784         for (i = 0; i < attr_nr; i++) {
 785                 const char *value = check_all_attr[i].value;
 786                 if (value != ATTR__UNSET && value != ATTR__UNKNOWN)
 787                         ++count;
 788         }
 789         *num = count;
 790         *check = xmalloc(sizeof(**check) * count);
 791         j = 0;
 792         for (i = 0; i < attr_nr; i++) {
 793                 const char *value = check_all_attr[i].value;
 794                 if (value != ATTR__UNSET && value != ATTR__UNKNOWN) {
 795                         (*check)[j].attr = check_all_attr[i].attr;
 796                         (*check)[j].value = value;
 797                         ++j;
 798                 }
 799         }
 800
 801         return 0;
 802 }
 803
 804 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
 805 {
 806         enum git_attr_direction old = direction;
 807
 808         if (is_bare_repository() && new != GIT_ATTR_INDEX)
 809                 die("BUG: non-INDEX attr direction in a bare repo");
 810
 811         direction = new;
 812         if (new != old)
 813                 drop_attr_stack();
 814         use_index = istate;
 815 }