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
  15 const char git_attr__true[] = "(builtin)true";
  16 const char git_attr__false[] = "\0(builtin)false";
  17 static const char git_attr__unknown[] = "(builtin)unknown";
  18 #define ATTR__TRUE git_attr__true
  19 #define ATTR__FALSE git_attr__false
  20 #define ATTR__UNSET NULL
  21 #define ATTR__UNKNOWN git_attr__unknown
  22
  23 static const char *attributes_file;
  24
  25 /* This is a randomly chosen prime. */
  26 #define HASHSIZE 257
  27
  28 #ifndef DEBUG_ATTR
  29 #define DEBUG_ATTR 0
  30 #endif
  31
  32 struct git_attr {
  33         struct git_attr *next;
  34         unsigned h;
  35         int attr_nr;
  36         char name[FLEX_ARRAY];
  37 };
  38 static int attr_nr;
  39
  40 static struct git_attr_check *check_all_attr;
  41 static struct git_attr *(git_attr_hash[HASHSIZE]);
  42
  43 static unsigned hash_name(const char *name, int namelen)
  44 {
  45         unsigned val = 0, c;
  46
  47         while (namelen--) {
  48                 c = *name++;
  49                 val = ((val << 7) | (val >> 22)) ^ c;
  50         }
  51         return val;
  52 }
  53
  54 static int invalid_attr_name(const char *name, int namelen)
  55 {
  56         /*
  57          * Attribute name cannot begin with '-' and from
  58          * [-A-Za-z0-9_.].  We'd specifically exclude '=' for now,
  59          * as we might later want to allow non-binary value for
  60          * attributes, e.g. "*.svg      merge=special-merge-program-for-svg"
  61          */
  62         if (*name == '-')
  63                 return -1;
  64         while (namelen--) {
  65                 char ch = *name++;
  66                 if (! (ch == '-' || ch == '.' || ch == '_' ||
  67                        ('0' <= ch && ch <= '9') ||
  68                        ('a' <= ch && ch <= 'z') ||
  69                        ('A' <= ch && ch <= 'Z')) )
  70                         return -1;
  71         }
  72         return 0;
  73 }
  74
  75 static struct git_attr *git_attr_internal(const char *name, int len)
  76 {
  77         unsigned hval = hash_name(name, len);
  78         unsigned pos = hval % HASHSIZE;
  79         struct git_attr *a;
  80
  81         for (a = git_attr_hash[pos]; a; a = a->next) {
  82                 if (a->h == hval &&
  83                     !memcmp(a->name, name, len) && !a->name[len])
  84                         return a;
  85         }
  86
  87         if (invalid_attr_name(name, len))
  88                 return NULL;
  89
  90         a = xmalloc(sizeof(*a) + len + 1);
  91         memcpy(a->name, name, len);
  92         a->name[len] = 0;
  93         a->h = hval;
  94         a->next = git_attr_hash[pos];
  95         a->attr_nr = attr_nr++;
  96         git_attr_hash[pos] = a;
  97
  98         check_all_attr = xrealloc(check_all_attr,
  99                                   sizeof(*check_all_attr) * attr_nr);
 100         check_all_attr[a->attr_nr].attr = a;
 101         check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
 102         return a;
 103 }
 104
 105 struct git_attr *git_attr(const char *name)
 106 {
 107         return git_attr_internal(name, strlen(name));
 108 }
 109
 110 /* What does a matched pattern decide? */
 111 struct attr_state {
 112         struct git_attr *attr;
 113         const char *setto;
 114 };
 115
 116 struct match_attr {
 117         union {
 118                 char *pattern;
 119                 struct git_attr *attr;
 120         } u;
 121         char is_macro;
 122         unsigned num_attr;
 123         struct attr_state state[FLEX_ARRAY];
 124 };
 125
 126 static const char blank[] = " \t\r\n";
 127
 128 static const char *parse_attr(const char *src, int lineno, const char *cp,
 129                               int *num_attr, struct match_attr *res)
 130 {
 131         const char *ep, *equals;
 132         int len;
 133
 134         ep = cp + strcspn(cp, blank);
 135         equals = strchr(cp, '=');
 136         if (equals && ep < equals)
 137                 equals = NULL;
 138         if (equals)
 139                 len = equals - cp;
 140         else
 141                 len = ep - cp;
 142         if (!res) {
 143                 if (*cp == '-' || *cp == '!') {
 144                         cp++;
 145                         len--;
 146                 }
 147                 if (invalid_attr_name(cp, len)) {
 148                         fprintf(stderr,
 149                                 "%.*s is not a valid attribute name: %s:%d\n",
 150                                 len, cp, src, lineno);
 151                         return NULL;
 152                 }
 153         } else {
 154                 struct attr_state *e;
 155
 156                 e = &(res->state[*num_attr]);
 157                 if (*cp == '-' || *cp == '!') {
 158                         e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 159                         cp++;
 160                         len--;
 161                 }
 162                 else if (!equals)
 163                         e->setto = ATTR__TRUE;
 164                 else {
 165                         e->setto = xmemdupz(equals + 1, ep - equals - 1);
 166                 }
 167                 e->attr = git_attr_internal(cp, len);
 168         }
 169         (*num_attr)++;
 170         return ep + strspn(ep, blank);
 171 }
 172
 173 static struct match_attr *parse_attr_line(const char *line, const char *src,
 174                                           int lineno, int macro_ok)
 175 {
 176         int namelen;
 177         int num_attr;
 178         const char *cp, *name;
 179         struct match_attr *res = NULL;
 180         int pass;
 181         int is_macro;
 182
 183         cp = line + strspn(line, blank);
 184         if (!*cp || *cp == '#')
 185                 return NULL;
 186         name = cp;
 187         namelen = strcspn(name, blank);
 188         if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 189             !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
 190                 if (!macro_ok) {
 191                         fprintf(stderr, "%s not allowed: %s:%d\n",
 192                                 name, src, lineno);
 193                         return NULL;
 194                 }
 195                 is_macro = 1;
 196                 name += strlen(ATTRIBUTE_MACRO_PREFIX);
 197                 name += strspn(name, blank);
 198                 namelen = strcspn(name, blank);
 199                 if (invalid_attr_name(name, namelen)) {
 200                         fprintf(stderr,
 201                                 "%.*s is not a valid attribute name: %s:%d\n",
 202                                 namelen, name, src, lineno);
 203                         return NULL;
 204                 }
 205         }
 206         else
 207                 is_macro = 0;
 208
 209         for (pass = 0; pass < 2; pass++) {
 210                 /* pass 0 counts and allocates, pass 1 fills */
 211                 num_attr = 0;
 212                 cp = name + namelen;
 213                 cp = cp + strspn(cp, blank);
 214                 while (*cp) {
 215                         cp = parse_attr(src, lineno, cp, &num_attr, res);
 216                         if (!cp)
 217                                 return NULL;
 218                 }
 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_internal(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
 238 /*
 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  */
 255
 256 static struct attr_stack {
 257         struct attr_stack *prev;
 258         char *origin;
 259         unsigned num_matches;
 260         unsigned alloc;
 261         struct match_attr **attrs;
 262 } *attr_stack;
 263
 264 static void free_attr_elem(struct attr_stack *e)
 265 {
 266         int i;
 267         free(e->origin);
 268         for (i = 0; i < e->num_matches; i++) {
 269                 struct match_attr *a = e->attrs[i];
 270                 int j;
 271                 for (j = 0; j < a->num_attr; j++) {
 272                         const char *setto = a->state[j].setto;
 273                         if (setto == ATTR__TRUE ||
 274                             setto == ATTR__FALSE ||
 275                             setto == ATTR__UNSET ||
 276                             setto == ATTR__UNKNOWN)
 277                                 ;
 278                         else
 279                                 free((char *) setto);
 280                 }
 281                 free(a);
 282         }
 283         free(e);
 284 }
 285
 286 static const char *builtin_attr[] = {
 287         "[attr]binary -diff -text",
 288         NULL,
 289 };
 290
 291 static void handle_attr_line(struct attr_stack *res,
 292                              const char *line,
 293                              const char *src,
 294                              int lineno,
 295                              int macro_ok)
 296 {
 297         struct match_attr *a;
 298
 299         a = parse_attr_line(line, src, lineno, macro_ok);
 300         if (!a)
 301                 return;
 302         if (res->alloc <= res->num_matches) {
 303                 res->alloc = alloc_nr(res->num_matches);
 304                 res->attrs = xrealloc(res->attrs,
 305                                       sizeof(struct match_attr *) *
 306                                       res->alloc);
 307         }
 308         res->attrs[res->num_matches++] = a;
 309 }
 310
 311 static struct attr_stack *read_attr_from_array(const char **list)
 312 {
 313         struct attr_stack *res;
 314         const char *line;
 315         int lineno = 0;
 316
 317         res = xcalloc(1, sizeof(*res));
 318         while ((line = *(list++)) != NULL)
 319                 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
 320         return res;
 321 }
 322
 323 static enum git_attr_direction direction;
 324 static struct index_state *use_index;
 325
 326 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 327 {
 328         FILE *fp = fopen(path, "r");
 329         struct attr_stack *res;
 330         char buf[2048];
 331         int lineno = 0;
 332
 333         if (!fp)
 334                 return NULL;
 335         res = xcalloc(1, sizeof(*res));
 336         while (fgets(buf, sizeof(buf), fp))
 337                 handle_attr_line(res, buf, path, ++lineno, macro_ok);
 338         fclose(fp);
 339         return res;
 340 }
 341
 342 static void *read_index_data(const char *path)
 343 {
 344         int pos, len;
 345         unsigned long sz;
 346         enum object_type type;
 347         void *data;
 348         struct index_state *istate = use_index ? use_index : &the_index;
 349
 350         len = strlen(path);
 351         pos = index_name_pos(istate, path, len);
 352         if (pos < 0) {
 353                 /*
 354                  * We might be in the middle of a merge, in which
 355                  * case we would read stage #2 (ours).
 356                  */
 357                 int i;
 358                 for (i = -pos - 1;
 359                      (pos < 0 && i < istate->cache_nr &&
 360                       !strcmp(istate->cache[i]->name, path));
 361                      i++)
 362                         if (ce_stage(istate->cache[i]) == 2)
 363                                 pos = i;
 364         }
 365         if (pos < 0)
 366                 return NULL;
 367         data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz);
 368         if (!data || type != OBJ_BLOB) {
 369                 free(data);
 370                 return NULL;
 371         }
 372         return data;
 373 }
 374
 375 static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
 376 {
 377         struct attr_stack *res;
 378         char *buf, *sp;
 379         int lineno = 0;
 380
 381         buf = read_index_data(path);
 382         if (!buf)
 383                 return NULL;
 384
 385         res = xcalloc(1, sizeof(*res));
 386         for (sp = buf; *sp; ) {
 387                 char *ep;
 388                 int more;
 389                 for (ep = sp; *ep && *ep != '\n'; ep++)
 390                         ;
 391                 more = (*ep == '\n');
 392                 *ep = '\0';
 393                 handle_attr_line(res, sp, path, ++lineno, macro_ok);
 394                 sp = ep + more;
 395         }
 396         free(buf);
 397         return res;
 398 }
 399
 400 static struct attr_stack *read_attr(const char *path, int macro_ok)
 401 {
 402         struct attr_stack *res;
 403
 404         if (direction == GIT_ATTR_CHECKOUT) {
 405                 res = read_attr_from_index(path, macro_ok);
 406                 if (!res)
 407                         res = read_attr_from_file(path, macro_ok);
 408         }
 409         else if (direction == GIT_ATTR_CHECKIN) {
 410                 res = read_attr_from_file(path, macro_ok);
 411                 if (!res)
 412                         /*
 413                          * There is no checked out .gitattributes file there, but
 414                          * we might have it in the index.  We allow operation in a
 415                          * sparsely checked out work tree, so read from it.
 416                          */
 417                         res = read_attr_from_index(path, macro_ok);
 418         }
 419         else
 420                 res = read_attr_from_index(path, macro_ok);
 421         if (!res)
 422                 res = xcalloc(1, sizeof(*res));
 423         return res;
 424 }
 425
 426 #if DEBUG_ATTR
 427 static void debug_info(const char *what, struct attr_stack *elem)
 428 {
 429         fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
 430 }
 431 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
 432 {
 433         const char *value = v;
 434
 435         if (ATTR_TRUE(value))
 436                 value = "set";
 437         else if (ATTR_FALSE(value))
 438                 value = "unset";
 439         else if (ATTR_UNSET(value))
 440                 value = "unspecified";
 441
 442         fprintf(stderr, "%s: %s => %s (%s)\n",
 443                 what, attr->name, (char *) value, match);
 444 }
 445 #define debug_push(a) debug_info("push", (a))
 446 #define debug_pop(a) debug_info("pop", (a))
 447 #else
 448 #define debug_push(a) do { ; } while (0)
 449 #define debug_pop(a) do { ; } while (0)
 450 #define debug_set(a,b,c,d) do { ; } while (0)
 451 #endif
 452
 453 static void drop_attr_stack(void)
 454 {
 455         while (attr_stack) {
 456                 struct attr_stack *elem = attr_stack;
 457                 attr_stack = elem->prev;
 458                 free_attr_elem(elem);
 459         }
 460 }
 461
 462 static const char *git_etc_gitattributes(void)
 463 {
 464         static const char *system_wide;
 465         if (!system_wide)
 466                 system_wide = system_path(ETC_GITATTRIBUTES);
 467         return system_wide;
 468 }
 469
 470 static int git_attr_system(void)
 471 {
 472         return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 473 }
 474
 475 static int git_attr_config(const char *var, const char *value, void *dummy)
 476 {
 477         if (!strcmp(var, "core.attributesfile"))
 478                 return git_config_pathname(&attributes_file, var, value);
 479
 480         return 0;
 481 }
 482
 483 static void bootstrap_attr_stack(void)
 484 {
 485         if (!attr_stack) {
 486                 struct attr_stack *elem;
 487
 488                 elem = read_attr_from_array(builtin_attr);
 489                 elem->origin = NULL;
 490                 elem->prev = attr_stack;
 491                 attr_stack = elem;
 492
 493                 if (git_attr_system()) {
 494                         elem = read_attr_from_file(git_etc_gitattributes(), 1);
 495                         if (elem) {
 496                                 elem->origin = NULL;
 497                                 elem->prev = attr_stack;
 498                                 attr_stack = elem;
 499                         }
 500                 }
 501
 502                 git_config(git_attr_config, NULL);
 503                 if (attributes_file) {
 504                         elem = read_attr_from_file(attributes_file, 1);
 505                         if (elem) {
 506                                 elem->origin = NULL;
 507                                 elem->prev = attr_stack;
 508                                 attr_stack = elem;
 509                         }
 510                 }
 511
 512                 if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 513                         elem = read_attr(GITATTRIBUTES_FILE, 1);
 514                         elem->origin = strdup("");
 515                         elem->prev = attr_stack;
 516                         attr_stack = elem;
 517                         debug_push(elem);
 518                 }
 519
 520                 elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
 521                 if (!elem)
 522                         elem = xcalloc(1, sizeof(*elem));
 523                 elem->origin = NULL;
 524                 elem->prev = attr_stack;
 525                 attr_stack = elem;
 526         }
 527 }
 528
 529 static void prepare_attr_stack(const char *path, int dirlen)
 530 {
 531         struct attr_stack *elem, *info;
 532         int len;
 533         struct strbuf pathbuf;
 534
 535         strbuf_init(&pathbuf, dirlen+2+strlen(GITATTRIBUTES_FILE));
 536
 537         /*
 538          * At the bottom of the attribute stack is the built-in
 539          * set of attribute definitions, followed by the contents
 540          * of $(prefix)/etc/gitattributes and a file specified by
 541          * core.attributesfile.  Then, contents from
 542          * .gitattribute files from directories closer to the
 543          * root to the ones in deeper directories are pushed
 544          * to the stack.  Finally, at the very top of the stack
 545          * we always keep the contents of $GIT_DIR/info/attributes.
 546          *
 547          * When checking, we use entries from near the top of the
 548          * stack, preferring $GIT_DIR/info/attributes, then
 549          * .gitattributes in deeper directories to shallower ones,
 550          * and finally use the built-in set as the default.
 551          */
 552         if (!attr_stack)
 553                 bootstrap_attr_stack();
 554
 555         /*
 556          * Pop the "info" one that is always at the top of the stack.
 557          */
 558         info = attr_stack;
 559         attr_stack = info->prev;
 560
 561         /*
 562          * Pop the ones from directories that are not the prefix of
 563          * the path we are checking.
 564          */
 565         while (attr_stack && attr_stack->origin) {
 566                 int namelen = strlen(attr_stack->origin);
 567
 568                 elem = attr_stack;
 569                 if (namelen <= dirlen &&
 570                     !strncmp(elem->origin, path, namelen))
 571                         break;
 572
 573                 debug_pop(elem);
 574                 attr_stack = elem->prev;
 575                 free_attr_elem(elem);
 576         }
 577
 578         /*
 579          * Read from parent directories and push them down
 580          */
 581         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 582                 while (1) {
 583                         char *cp;
 584
 585                         len = strlen(attr_stack->origin);
 586                         if (dirlen <= len)
 587                                 break;
 588                         strbuf_reset(&pathbuf);
 589                         strbuf_add(&pathbuf, path, dirlen);
 590                         strbuf_addch(&pathbuf, '/');
 591                         cp = strchr(pathbuf.buf + len + 1, '/');
 592                         strcpy(cp + 1, GITATTRIBUTES_FILE);
 593                         elem = read_attr(pathbuf.buf, 0);
 594                         *cp = '\0';
 595                         elem->origin = strdup(pathbuf.buf);
 596                         elem->prev = attr_stack;
 597                         attr_stack = elem;
 598                         debug_push(elem);
 599                 }
 600         }
 601
 602         strbuf_release(&pathbuf);
 603
 604         /*
 605          * Finally push the "info" one at the top of the stack.
 606          */
 607         info->prev = attr_stack;
 608         attr_stack = info;
 609 }
 610
 611 static int path_matches(const char *pathname, int pathlen,
 612                         const char *pattern,
 613                         const char *base, int baselen)
 614 {
 615         if (!strchr(pattern, '/')) {
 616                 /* match basename */
 617                 const char *basename = strrchr(pathname, '/');
 618                 basename = basename ? basename + 1 : pathname;
 619                 return (fnmatch(pattern, basename, 0) == 0);
 620         }
 621         /*
 622          * match with FNM_PATHNAME; the pattern has base implicitly
 623          * in front of it.
 624          */
 625         if (*pattern == '/')
 626                 pattern++;
 627         if (pathlen < baselen ||
 628             (baselen && pathname[baselen] != '/') ||
 629             strncmp(pathname, base, baselen))
 630                 return 0;
 631         if (baselen != 0)
 632                 baselen++;
 633         return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0;
 634 }
 635
 636 static int macroexpand_one(int attr_nr, int rem);
 637
 638 static int fill_one(const char *what, struct match_attr *a, int rem)
 639 {
 640         struct git_attr_check *check = check_all_attr;
 641         int i;
 642
 643         for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {
 644                 struct git_attr *attr = a->state[i].attr;
 645                 const char **n = &(check[attr->attr_nr].value);
 646                 const char *v = a->state[i].setto;
 647
 648                 if (*n == ATTR__UNKNOWN) {
 649                         debug_set(what,
 650                                   a->is_macro ? a->u.attr->name : a->u.pattern,
 651                                   attr, v);
 652                         *n = v;
 653                         rem--;
 654                         rem = macroexpand_one(attr->attr_nr, rem);
 655                 }
 656         }
 657         return rem;
 658 }
 659
 660 static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
 661 {
 662         int i;
 663         const char *base = stk->origin ? stk->origin : "";
 664
 665         for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
 666                 struct match_attr *a = stk->attrs[i];
 667                 if (a->is_macro)
 668                         continue;
 669                 if (path_matches(path, pathlen,
 670                                  a->u.pattern, base, strlen(base)))
 671                         rem = fill_one("fill", a, rem);
 672         }
 673         return rem;
 674 }
 675
 676 static int macroexpand_one(int attr_nr, int rem)
 677 {
 678         struct attr_stack *stk;
 679         struct match_attr *a = NULL;
 680         int i;
 681
 682         if (check_all_attr[attr_nr].value != ATTR__TRUE)
 683                 return rem;
 684
 685         for (stk = attr_stack; !a && stk; stk = stk->prev)
 686                 for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
 687                         struct match_attr *ma = stk->attrs[i];
 688                         if (!ma->is_macro)
 689                                 continue;
 690                         if (ma->u.attr->attr_nr == attr_nr)
 691                                 a = ma;
 692                 }
 693
 694         if (a)
 695                 rem = fill_one("expand", a, rem);
 696
 697         return rem;
 698 }
 699
 700 int git_checkattr(const char *path, int num, struct git_attr_check *check)
 701 {
 702         struct attr_stack *stk;
 703         const char *cp;
 704         int dirlen, pathlen, i, rem;
 705
 706         bootstrap_attr_stack();
 707         for (i = 0; i < attr_nr; i++)
 708                 check_all_attr[i].value = ATTR__UNKNOWN;
 709
 710         pathlen = strlen(path);
 711         cp = strrchr(path, '/');
 712         if (!cp)
 713                 dirlen = 0;
 714         else
 715                 dirlen = cp - path;
 716         prepare_attr_stack(path, dirlen);
 717         rem = attr_nr;
 718         for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
 719                 rem = fill(path, pathlen, stk, rem);
 720
 721         for (i = 0; i < num; i++) {
 722                 const char *value = check_all_attr[check[i].attr->attr_nr].value;
 723                 if (value == ATTR__UNKNOWN)
 724                         value = ATTR__UNSET;
 725                 check[i].value = value;
 726         }
 727
 728         return 0;
 729 }
 730
 731 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
 732 {
 733         enum git_attr_direction old = direction;
 734
 735         if (is_bare_repository() && new != GIT_ATTR_INDEX)
 736                 die("BUG: non-INDEX attr direction in a bare repo");
 737
 738         direction = new;
 739         if (new != old)
 740                 drop_attr_stack();
 741         use_index = istate;
 742 }