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 #include "utf8.h"
  16
  17 const char git_attr__true[] = "(builtin)true";
  18 const char git_attr__false[] = "\0(builtin)false";
  19 static const char git_attr__unknown[] = "(builtin)unknown";
  20 #define ATTR__TRUE git_attr__true
  21 #define ATTR__FALSE git_attr__false
  22 #define ATTR__UNSET NULL
  23 #define ATTR__UNKNOWN git_attr__unknown
  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         int maybe_macro;
  37         int maybe_real;
  38         char name[FLEX_ARRAY];
  39 };
  40 static int attr_nr;
  41 static int cannot_trust_maybe_real;
  42
  43 static struct git_attr_check *check_all_attr;
  44 static struct git_attr *(git_attr_hash[HASHSIZE]);
  45
  46 char *git_attr_name(struct git_attr *attr)
  47 {
  48         return attr->name;
  49 }
  50
  51 static unsigned hash_name(const char *name, int namelen)
  52 {
  53         unsigned val = 0, c;
  54
  55         while (namelen--) {
  56                 c = *name++;
  57                 val = ((val << 7) | (val >> 22)) ^ c;
  58         }
  59         return val;
  60 }
  61
  62 static int invalid_attr_name(const char *name, int namelen)
  63 {
  64         /*
  65          * Attribute name cannot begin with '-' and must consist of
  66          * characters from [-A-Za-z0-9_.].
  67          */
  68         if (namelen <= 0 || *name == '-')
  69                 return -1;
  70         while (namelen--) {
  71                 char ch = *name++;
  72                 if (! (ch == '-' || ch == '.' || ch == '_' ||
  73                        ('0' <= ch && ch <= '9') ||
  74                        ('a' <= ch && ch <= 'z') ||
  75                        ('A' <= ch && ch <= 'Z')) )
  76                         return -1;
  77         }
  78         return 0;
  79 }
  80
  81 static struct git_attr *git_attr_internal(const char *name, int len)
  82 {
  83         unsigned hval = hash_name(name, len);
  84         unsigned pos = hval % HASHSIZE;
  85         struct git_attr *a;
  86
  87         for (a = git_attr_hash[pos]; a; a = a->next) {
  88                 if (a->h == hval &&
  89                     !memcmp(a->name, name, len) && !a->name[len])
  90                         return a;
  91         }
  92
  93         if (invalid_attr_name(name, len))
  94                 return NULL;
  95
  96         a = xmalloc(sizeof(*a) + len + 1);
  97         memcpy(a->name, name, len);
  98         a->name[len] = 0;
  99         a->h = hval;
 100         a->next = git_attr_hash[pos];
 101         a->attr_nr = attr_nr++;
 102         a->maybe_macro = 0;
 103         a->maybe_real = 0;
 104         git_attr_hash[pos] = a;
 105
 106         REALLOC_ARRAY(check_all_attr, attr_nr);
 107         check_all_attr[a->attr_nr].attr = a;
 108         check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
 109         return a;
 110 }
 111
 112 struct git_attr *git_attr(const char *name)
 113 {
 114         return git_attr_internal(name, strlen(name));
 115 }
 116
 117 /* What does a matched pattern decide? */
 118 struct attr_state {
 119         struct git_attr *attr;
 120         const char *setto;
 121 };
 122
 123 struct pattern {
 124         const char *pattern;
 125         int patternlen;
 126         int nowildcardlen;
 127         int flags;              /* EXC_FLAG_* */
 128 };
 129
 130 /*
 131  * One rule, as from a .gitattributes file.
 132  *
 133  * If is_macro is true, then u.attr is a pointer to the git_attr being
 134  * defined.
 135  *
 136  * If is_macro is false, then u.pattern points at the filename pattern
 137  * to which the rule applies.  (The memory pointed to is part of the
 138  * memory block allocated for the match_attr instance.)
 139  *
 140  * In either case, num_attr is the number of attributes affected by
 141  * this rule, and state is an array listing them.  The attributes are
 142  * listed as they appear in the file (macros unexpanded).
 143  */
 144 struct match_attr {
 145         union {
 146                 struct pattern pat;
 147                 struct git_attr *attr;
 148         } u;
 149         char is_macro;
 150         unsigned num_attr;
 151         struct attr_state state[FLEX_ARRAY];
 152 };
 153
 154 static const char blank[] = " \t\r\n";
 155
 156 /*
 157  * Parse a whitespace-delimited attribute state (i.e., "attr",
 158  * "-attr", "!attr", or "attr=value") from the string starting at src.
 159  * If e is not NULL, write the results to *e.  Return a pointer to the
 160  * remainder of the string (with leading whitespace removed), or NULL
 161  * if there was an error.
 162  */
 163 static const char *parse_attr(const char *src, int lineno, const char *cp,
 164                               struct attr_state *e)
 165 {
 166         const char *ep, *equals;
 167         int len;
 168
 169         ep = cp + strcspn(cp, blank);
 170         equals = strchr(cp, '=');
 171         if (equals && ep < equals)
 172                 equals = NULL;
 173         if (equals)
 174                 len = equals - cp;
 175         else
 176                 len = ep - cp;
 177         if (!e) {
 178                 if (*cp == '-' || *cp == '!') {
 179                         cp++;
 180                         len--;
 181                 }
 182                 if (invalid_attr_name(cp, len)) {
 183                         fprintf(stderr,
 184                                 "%.*s is not a valid attribute name: %s:%d\n",
 185                                 len, cp, src, lineno);
 186                         return NULL;
 187                 }
 188         } else {
 189                 if (*cp == '-' || *cp == '!') {
 190                         e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 191                         cp++;
 192                         len--;
 193                 }
 194                 else if (!equals)
 195                         e->setto = ATTR__TRUE;
 196                 else {
 197                         e->setto = xmemdupz(equals + 1, ep - equals - 1);
 198                 }
 199                 e->attr = git_attr_internal(cp, len);
 200         }
 201         return ep + strspn(ep, blank);
 202 }
 203
 204 static struct match_attr *parse_attr_line(const char *line, const char *src,
 205                                           int lineno, int macro_ok)
 206 {
 207         int namelen;
 208         int num_attr, i;
 209         const char *cp, *name, *states;
 210         struct match_attr *res = NULL;
 211         int is_macro;
 212
 213         cp = line + strspn(line, blank);
 214         if (!*cp || *cp == '#')
 215                 return NULL;
 216         name = cp;
 217         namelen = strcspn(name, blank);
 218         if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 219             starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
 220                 if (!macro_ok) {
 221                         fprintf(stderr, "%s not allowed: %s:%d\n",
 222                                 name, src, lineno);
 223                         return NULL;
 224                 }
 225                 is_macro = 1;
 226                 name += strlen(ATTRIBUTE_MACRO_PREFIX);
 227                 name += strspn(name, blank);
 228                 namelen = strcspn(name, blank);
 229                 if (invalid_attr_name(name, namelen)) {
 230                         fprintf(stderr,
 231                                 "%.*s is not a valid attribute name: %s:%d\n",
 232                                 namelen, name, src, lineno);
 233                         return NULL;
 234                 }
 235         }
 236         else
 237                 is_macro = 0;
 238
 239         states = name + namelen;
 240         states += strspn(states, blank);
 241
 242         /* First pass to count the attr_states */
 243         for (cp = states, num_attr = 0; *cp; num_attr++) {
 244                 cp = parse_attr(src, lineno, cp, NULL);
 245                 if (!cp)
 246                         return NULL;
 247         }
 248
 249         res = xcalloc(1,
 250                       sizeof(*res) +
 251                       sizeof(struct attr_state) * num_attr +
 252                       (is_macro ? 0 : namelen + 1));
 253         if (is_macro) {
 254                 res->u.attr = git_attr_internal(name, namelen);
 255                 res->u.attr->maybe_macro = 1;
 256         } else {
 257                 char *p = (char *)&(res->state[num_attr]);
 258                 memcpy(p, name, namelen);
 259                 res->u.pat.pattern = p;
 260                 parse_exclude_pattern(&res->u.pat.pattern,
 261                                       &res->u.pat.patternlen,
 262                                       &res->u.pat.flags,
 263                                       &res->u.pat.nowildcardlen);
 264                 if (res->u.pat.flags & EXC_FLAG_NEGATIVE) {
 265                         warning(_("Negative patterns are ignored in git attributes\n"
 266                                   "Use '\\!' for literal leading exclamation."));
 267                         return NULL;
 268                 }
 269         }
 270         res->is_macro = is_macro;
 271         res->num_attr = num_attr;
 272
 273         /* Second pass to fill the attr_states */
 274         for (cp = states, i = 0; *cp; i++) {
 275                 cp = parse_attr(src, lineno, cp, &(res->state[i]));
 276                 if (!is_macro)
 277                         res->state[i].attr->maybe_real = 1;
 278                 if (res->state[i].attr->maybe_macro)
 279                         cannot_trust_maybe_real = 1;
 280         }
 281
 282         return res;
 283 }
 284
 285 /*
 286  * Like info/exclude and .gitignore, the attribute information can
 287  * come from many places.
 288  *
 289  * (1) .gitattribute file of the same directory;
 290  * (2) .gitattribute file of the parent directory if (1) does not have
 291  *      any match; this goes recursively upwards, just like .gitignore.
 292  * (3) $GIT_DIR/info/attributes, which overrides both of the above.
 293  *
 294  * In the same file, later entries override the earlier match, so in the
 295  * global list, we would have entries from info/attributes the earliest
 296  * (reading the file from top to bottom), .gitattribute of the root
 297  * directory (again, reading the file from top to bottom) down to the
 298  * current directory, and then scan the list backwards to find the first match.
 299  * This is exactly the same as what is_excluded() does in dir.c to deal with
 300  * .gitignore
 301  */
 302
 303 static struct attr_stack {
 304         struct attr_stack *prev;
 305         char *origin;
 306         size_t originlen;
 307         unsigned num_matches;
 308         unsigned alloc;
 309         struct match_attr **attrs;
 310 } *attr_stack;
 311
 312 static void free_attr_elem(struct attr_stack *e)
 313 {
 314         int i;
 315         free(e->origin);
 316         for (i = 0; i < e->num_matches; i++) {
 317                 struct match_attr *a = e->attrs[i];
 318                 int j;
 319                 for (j = 0; j < a->num_attr; j++) {
 320                         const char *setto = a->state[j].setto;
 321                         if (setto == ATTR__TRUE ||
 322                             setto == ATTR__FALSE ||
 323                             setto == ATTR__UNSET ||
 324                             setto == ATTR__UNKNOWN)
 325                                 ;
 326                         else
 327                                 free((char *) setto);
 328                 }
 329                 free(a);
 330         }
 331         free(e->attrs);
 332         free(e);
 333 }
 334
 335 static const char *builtin_attr[] = {
 336         "[attr]binary -diff -merge -text",
 337         NULL,
 338 };
 339
 340 static void handle_attr_line(struct attr_stack *res,
 341                              const char *line,
 342                              const char *src,
 343                              int lineno,
 344                              int macro_ok)
 345 {
 346         struct match_attr *a;
 347
 348         a = parse_attr_line(line, src, lineno, macro_ok);
 349         if (!a)
 350                 return;
 351         ALLOC_GROW(res->attrs, res->num_matches + 1, res->alloc);
 352         res->attrs[res->num_matches++] = a;
 353 }
 354
 355 static struct attr_stack *read_attr_from_array(const char **list)
 356 {
 357         struct attr_stack *res;
 358         const char *line;
 359         int lineno = 0;
 360
 361         res = xcalloc(1, sizeof(*res));
 362         while ((line = *(list++)) != NULL)
 363                 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
 364         return res;
 365 }
 366
 367 static enum git_attr_direction direction;
 368 static struct index_state *use_index;
 369
 370 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 371 {
 372         FILE *fp = fopen(path, "r");
 373         struct attr_stack *res;
 374         char buf[2048];
 375         int lineno = 0;
 376
 377         if (!fp) {
 378                 if (errno != ENOENT && errno != ENOTDIR)
 379                         warn_on_inaccessible(path);
 380                 return NULL;
 381         }
 382         res = xcalloc(1, sizeof(*res));
 383         while (fgets(buf, sizeof(buf), fp)) {
 384                 char *bufp = buf;
 385                 if (!lineno)
 386                         skip_utf8_bom(&bufp, strlen(bufp));
 387                 handle_attr_line(res, bufp, path, ++lineno, macro_ok);
 388         }
 389         fclose(fp);
 390         return res;
 391 }
 392
 393 static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
 394 {
 395         struct attr_stack *res;
 396         char *buf, *sp;
 397         int lineno = 0;
 398
 399         buf = read_blob_data_from_index(use_index ? use_index : &the_index, path, NULL);
 400         if (!buf)
 401                 return NULL;
 402
 403         res = xcalloc(1, sizeof(*res));
 404         for (sp = buf; *sp; ) {
 405                 char *ep;
 406                 int more;
 407                 for (ep = sp; *ep && *ep != '\n'; ep++)
 408                         ;
 409                 more = (*ep == '\n');
 410                 *ep = '\0';
 411                 handle_attr_line(res, sp, path, ++lineno, macro_ok);
 412                 sp = ep + more;
 413         }
 414         free(buf);
 415         return res;
 416 }
 417
 418 static struct attr_stack *read_attr(const char *path, int macro_ok)
 419 {
 420         struct attr_stack *res;
 421
 422         if (direction == GIT_ATTR_CHECKOUT) {
 423                 res = read_attr_from_index(path, macro_ok);
 424                 if (!res)
 425                         res = read_attr_from_file(path, macro_ok);
 426         }
 427         else if (direction == GIT_ATTR_CHECKIN) {
 428                 res = read_attr_from_file(path, macro_ok);
 429                 if (!res)
 430                         /*
 431                          * There is no checked out .gitattributes file there, but
 432                          * we might have it in the index.  We allow operation in a
 433                          * sparsely checked out work tree, so read from it.
 434                          */
 435                         res = read_attr_from_index(path, macro_ok);
 436         }
 437         else
 438                 res = read_attr_from_index(path, macro_ok);
 439         if (!res)
 440                 res = xcalloc(1, sizeof(*res));
 441         return res;
 442 }
 443
 444 #if DEBUG_ATTR
 445 static void debug_info(const char *what, struct attr_stack *elem)
 446 {
 447         fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
 448 }
 449 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
 450 {
 451         const char *value = v;
 452
 453         if (ATTR_TRUE(value))
 454                 value = "set";
 455         else if (ATTR_FALSE(value))
 456                 value = "unset";
 457         else if (ATTR_UNSET(value))
 458                 value = "unspecified";
 459
 460         fprintf(stderr, "%s: %s => %s (%s)\n",
 461                 what, attr->name, (char *) value, match);
 462 }
 463 #define debug_push(a) debug_info("push", (a))
 464 #define debug_pop(a) debug_info("pop", (a))
 465 #else
 466 #define debug_push(a) do { ; } while (0)
 467 #define debug_pop(a) do { ; } while (0)
 468 #define debug_set(a,b,c,d) do { ; } while (0)
 469 #endif
 470
 471 static void drop_attr_stack(void)
 472 {
 473         while (attr_stack) {
 474                 struct attr_stack *elem = attr_stack;
 475                 attr_stack = elem->prev;
 476                 free_attr_elem(elem);
 477         }
 478 }
 479
 480 static const char *git_etc_gitattributes(void)
 481 {
 482         static const char *system_wide;
 483         if (!system_wide)
 484                 system_wide = system_path(ETC_GITATTRIBUTES);
 485         return system_wide;
 486 }
 487
 488 static int git_attr_system(void)
 489 {
 490         return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 491 }
 492
 493 static void bootstrap_attr_stack(void)
 494 {
 495         struct attr_stack *elem;
 496         char *xdg_attributes_file;
 497
 498         if (attr_stack)
 499                 return;
 500
 501         elem = read_attr_from_array(builtin_attr);
 502         elem->origin = NULL;
 503         elem->prev = attr_stack;
 504         attr_stack = elem;
 505
 506         if (git_attr_system()) {
 507                 elem = read_attr_from_file(git_etc_gitattributes(), 1);
 508                 if (elem) {
 509                         elem->origin = NULL;
 510                         elem->prev = attr_stack;
 511                         attr_stack = elem;
 512                 }
 513         }
 514
 515         if (!git_attributes_file) {
 516                 home_config_paths(NULL, &xdg_attributes_file, "attributes");
 517                 git_attributes_file = xdg_attributes_file;
 518         }
 519         if (git_attributes_file) {
 520                 elem = read_attr_from_file(git_attributes_file, 1);
 521                 if (elem) {
 522                         elem->origin = NULL;
 523                         elem->prev = attr_stack;
 524                         attr_stack = elem;
 525                 }
 526         }
 527
 528         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 529                 elem = read_attr(GITATTRIBUTES_FILE, 1);
 530                 elem->origin = xstrdup("");
 531                 elem->originlen = 0;
 532                 elem->prev = attr_stack;
 533                 attr_stack = elem;
 534                 debug_push(elem);
 535         }
 536
 537         elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
 538         if (!elem)
 539                 elem = xcalloc(1, sizeof(*elem));
 540         elem->origin = NULL;
 541         elem->prev = attr_stack;
 542         attr_stack = elem;
 543 }
 544
 545 static void prepare_attr_stack(const char *path, int dirlen)
 546 {
 547         struct attr_stack *elem, *info;
 548         int len;
 549         const char *cp;
 550
 551         /*
 552          * At the bottom of the attribute stack is the built-in
 553          * set of attribute definitions, followed by the contents
 554          * of $(prefix)/etc/gitattributes and a file specified by
 555          * core.attributesfile.  Then, contents from
 556          * .gitattribute files from directories closer to the
 557          * root to the ones in deeper directories are pushed
 558          * to the stack.  Finally, at the very top of the stack
 559          * we always keep the contents of $GIT_DIR/info/attributes.
 560          *
 561          * When checking, we use entries from near the top of the
 562          * stack, preferring $GIT_DIR/info/attributes, then
 563          * .gitattributes in deeper directories to shallower ones,
 564          * and finally use the built-in set as the default.
 565          */
 566         bootstrap_attr_stack();
 567
 568         /*
 569          * Pop the "info" one that is always at the top of the stack.
 570          */
 571         info = attr_stack;
 572         attr_stack = info->prev;
 573
 574         /*
 575          * Pop the ones from directories that are not the prefix of
 576          * the path we are checking. Break out of the loop when we see
 577          * the root one (whose origin is an empty string "") or the builtin
 578          * one (whose origin is NULL) without popping it.
 579          */
 580         while (attr_stack->origin) {
 581                 int namelen = strlen(attr_stack->origin);
 582
 583                 elem = attr_stack;
 584                 if (namelen <= dirlen &&
 585                     !strncmp(elem->origin, path, namelen) &&
 586                     (!namelen || path[namelen] == '/'))
 587                         break;
 588
 589                 debug_pop(elem);
 590                 attr_stack = elem->prev;
 591                 free_attr_elem(elem);
 592         }
 593
 594         /*
 595          * Read from parent directories and push them down
 596          */
 597         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 598                 /*
 599                  * bootstrap_attr_stack() should have added, and the
 600                  * above loop should have stopped before popping, the
 601                  * root element whose attr_stack->origin is set to an
 602                  * empty string.
 603                  */
 604                 struct strbuf pathbuf = STRBUF_INIT;
 605
 606                 assert(attr_stack->origin);
 607                 while (1) {
 608                         len = strlen(attr_stack->origin);
 609                         if (dirlen <= len)
 610                                 break;
 611                         cp = memchr(path + len + 1, '/', dirlen - len - 1);
 612                         if (!cp)
 613                                 cp = path + dirlen;
 614                         strbuf_add(&pathbuf, path, cp - path);
 615                         strbuf_addch(&pathbuf, '/');
 616                         strbuf_addstr(&pathbuf, GITATTRIBUTES_FILE);
 617                         elem = read_attr(pathbuf.buf, 0);
 618                         strbuf_setlen(&pathbuf, cp - path);
 619                         elem->origin = strbuf_detach(&pathbuf, &elem->originlen);
 620                         elem->prev = attr_stack;
 621                         attr_stack = elem;
 622                         debug_push(elem);
 623                 }
 624
 625                 strbuf_release(&pathbuf);
 626         }
 627
 628         /*
 629          * Finally push the "info" one at the top of the stack.
 630          */
 631         info->prev = attr_stack;
 632         attr_stack = info;
 633 }
 634
 635 static int path_matches(const char *pathname, int pathlen,
 636                         int basename_offset,
 637                         const struct pattern *pat,
 638                         const char *base, int baselen)
 639 {
 640         const char *pattern = pat->pattern;
 641         int prefix = pat->nowildcardlen;
 642         int isdir = (pathlen && pathname[pathlen - 1] == '/');
 643
 644         if ((pat->flags & EXC_FLAG_MUSTBEDIR) && !isdir)
 645                 return 0;
 646
 647         if (pat->flags & EXC_FLAG_NODIR) {
 648                 return match_basename(pathname + basename_offset,
 649                                       pathlen - basename_offset - isdir,
 650                                       pattern, prefix,
 651                                       pat->patternlen, pat->flags);
 652         }
 653         return match_pathname(pathname, pathlen - isdir,
 654                               base, baselen,
 655                               pattern, prefix, pat->patternlen, pat->flags);
 656 }
 657
 658 static int macroexpand_one(int attr_nr, int rem);
 659
 660 static int fill_one(const char *what, struct match_attr *a, int rem)
 661 {
 662         struct git_attr_check *check = check_all_attr;
 663         int i;
 664
 665         for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {
 666                 struct git_attr *attr = a->state[i].attr;
 667                 const char **n = &(check[attr->attr_nr].value);
 668                 const char *v = a->state[i].setto;
 669
 670                 if (*n == ATTR__UNKNOWN) {
 671                         debug_set(what,
 672                                   a->is_macro ? a->u.attr->name : a->u.pat.pattern,
 673                                   attr, v);
 674                         *n = v;
 675                         rem--;
 676                         rem = macroexpand_one(attr->attr_nr, rem);
 677                 }
 678         }
 679         return rem;
 680 }
 681
 682 static int fill(const char *path, int pathlen, int basename_offset,
 683                 struct attr_stack *stk, int rem)
 684 {
 685         int i;
 686         const char *base = stk->origin ? stk->origin : "";
 687
 688         for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
 689                 struct match_attr *a = stk->attrs[i];
 690                 if (a->is_macro)
 691                         continue;
 692                 if (path_matches(path, pathlen, basename_offset,
 693                                  &a->u.pat, base, stk->originlen))
 694                         rem = fill_one("fill", a, rem);
 695         }
 696         return rem;
 697 }
 698
 699 static int macroexpand_one(int nr, int rem)
 700 {
 701         struct attr_stack *stk;
 702         struct match_attr *a = NULL;
 703         int i;
 704
 705         if (check_all_attr[nr].value != ATTR__TRUE ||
 706             !check_all_attr[nr].attr->maybe_macro)
 707                 return rem;
 708
 709         for (stk = attr_stack; !a && stk; stk = stk->prev)
 710                 for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
 711                         struct match_attr *ma = stk->attrs[i];
 712                         if (!ma->is_macro)
 713                                 continue;
 714                         if (ma->u.attr->attr_nr == nr)
 715                                 a = ma;
 716                 }
 717
 718         if (a)
 719                 rem = fill_one("expand", a, rem);
 720
 721         return rem;
 722 }
 723
 724 /*
 725  * Collect attributes for path into the array pointed to by
 726  * check_all_attr. If num is non-zero, only attributes in check[] are
 727  * collected. Otherwise all attributes are collected.
 728  */
 729 static void collect_some_attrs(const char *path, int num,
 730                                struct git_attr_check *check)
 731
 732 {
 733         struct attr_stack *stk;
 734         int i, pathlen, rem, dirlen;
 735         const char *cp, *last_slash = NULL;
 736         int basename_offset;
 737
 738         for (cp = path; *cp; cp++) {
 739                 if (*cp == '/' && cp[1])
 740                         last_slash = cp;
 741         }
 742         pathlen = cp - path;
 743         if (last_slash) {
 744                 basename_offset = last_slash + 1 - path;
 745                 dirlen = last_slash - path;
 746         } else {
 747                 basename_offset = 0;
 748                 dirlen = 0;
 749         }
 750
 751         prepare_attr_stack(path, dirlen);
 752         for (i = 0; i < attr_nr; i++)
 753                 check_all_attr[i].value = ATTR__UNKNOWN;
 754         if (num && !cannot_trust_maybe_real) {
 755                 rem = 0;
 756                 for (i = 0; i < num; i++) {
 757                         if (!check[i].attr->maybe_real) {
 758                                 struct git_attr_check *c;
 759                                 c = check_all_attr + check[i].attr->attr_nr;
 760                                 c->value = ATTR__UNSET;
 761                                 rem++;
 762                         }
 763                 }
 764                 if (rem == num)
 765                         return;
 766         }
 767
 768         rem = attr_nr;
 769         for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
 770                 rem = fill(path, pathlen, basename_offset, stk, rem);
 771 }
 772
 773 int git_check_attr(const char *path, int num, struct git_attr_check *check)
 774 {
 775         int i;
 776
 777         collect_some_attrs(path, num, check);
 778
 779         for (i = 0; i < num; i++) {
 780                 const char *value = check_all_attr[check[i].attr->attr_nr].value;
 781                 if (value == ATTR__UNKNOWN)
 782                         value = ATTR__UNSET;
 783                 check[i].value = value;
 784         }
 785
 786         return 0;
 787 }
 788
 789 int git_all_attrs(const char *path, int *num, struct git_attr_check **check)
 790 {
 791         int i, count, j;
 792
 793         collect_some_attrs(path, 0, NULL);
 794
 795         /* Count the number of attributes that are set. */
 796         count = 0;
 797         for (i = 0; i < attr_nr; i++) {
 798                 const char *value = check_all_attr[i].value;
 799                 if (value != ATTR__UNSET && value != ATTR__UNKNOWN)
 800                         ++count;
 801         }
 802         *num = count;
 803         *check = xmalloc(sizeof(**check) * count);
 804         j = 0;
 805         for (i = 0; i < attr_nr; i++) {
 806                 const char *value = check_all_attr[i].value;
 807                 if (value != ATTR__UNSET && value != ATTR__UNKNOWN) {
 808                         (*check)[j].attr = check_all_attr[i].attr;
 809                         (*check)[j].value = value;
 810                         ++j;
 811                 }
 812         }
 813
 814         return 0;
 815 }
 816
 817 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
 818 {
 819         enum git_attr_direction old = direction;
 820
 821         if (is_bare_repository() && new != GIT_ATTR_INDEX)
 822                 die("BUG: non-INDEX attr direction in a bare repo");
 823
 824         direction = new;
 825         if (new != old)
 826                 drop_attr_stack();
 827         use_index = istate;
 828 }