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