attr.con commit Merge branch 'ab/fetch-tags-noclobber' (150f307)
   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 "config.h"
  13#include "exec-cmd.h"
  14#include "attr.h"
  15#include "dir.h"
  16#include "utf8.h"
  17#include "quote.h"
  18#include "thread-utils.h"
  19
  20const char git_attr__true[] = "(builtin)true";
  21const char git_attr__false[] = "\0(builtin)false";
  22static const char git_attr__unknown[] = "(builtin)unknown";
  23#define ATTR__TRUE git_attr__true
  24#define ATTR__FALSE git_attr__false
  25#define ATTR__UNSET NULL
  26#define ATTR__UNKNOWN git_attr__unknown
  27
  28#ifndef DEBUG_ATTR
  29#define DEBUG_ATTR 0
  30#endif
  31
  32struct git_attr {
  33        int attr_nr; /* unique attribute number */
  34        char name[FLEX_ARRAY]; /* attribute name */
  35};
  36
  37const char *git_attr_name(const struct git_attr *attr)
  38{
  39        return attr->name;
  40}
  41
  42struct attr_hashmap {
  43        struct hashmap map;
  44#ifndef NO_PTHREADS
  45        pthread_mutex_t mutex;
  46#endif
  47};
  48
  49static inline void hashmap_lock(struct attr_hashmap *map)
  50{
  51#ifndef NO_PTHREADS
  52        pthread_mutex_lock(&map->mutex);
  53#endif
  54}
  55
  56static inline void hashmap_unlock(struct attr_hashmap *map)
  57{
  58#ifndef NO_PTHREADS
  59        pthread_mutex_unlock(&map->mutex);
  60#endif
  61}
  62
  63/*
  64 * The global dictionary of all interned attributes.  This
  65 * is a singleton object which is shared between threads.
  66 * Access to this dictionary must be surrounded with a mutex.
  67 */
  68static struct attr_hashmap g_attr_hashmap;
  69
  70/* The container for objects stored in "struct attr_hashmap" */
  71struct attr_hash_entry {
  72        struct hashmap_entry ent; /* must be the first member! */
  73        const char *key; /* the key; memory should be owned by value */
  74        size_t keylen; /* length of the key */
  75        void *value; /* the stored value */
  76};
  77
  78/* attr_hashmap comparison function */
  79static int attr_hash_entry_cmp(const void *unused_cmp_data,
  80                               const void *entry,
  81                               const void *entry_or_key,
  82                               const void *unused_keydata)
  83{
  84        const struct attr_hash_entry *a = entry;
  85        const struct attr_hash_entry *b = entry_or_key;
  86        return (a->keylen != b->keylen) || strncmp(a->key, b->key, a->keylen);
  87}
  88
  89/* Initialize an 'attr_hashmap' object */
  90static void attr_hashmap_init(struct attr_hashmap *map)
  91{
  92        hashmap_init(&map->map, attr_hash_entry_cmp, NULL, 0);
  93}
  94
  95/*
  96 * Retrieve the 'value' stored in a hashmap given the provided 'key'.
  97 * If there is no matching entry, return NULL.
  98 */
  99static void *attr_hashmap_get(struct attr_hashmap *map,
 100                              const char *key, size_t keylen)
 101{
 102        struct attr_hash_entry k;
 103        struct attr_hash_entry *e;
 104
 105        if (!map->map.tablesize)
 106                attr_hashmap_init(map);
 107
 108        hashmap_entry_init(&k, memhash(key, keylen));
 109        k.key = key;
 110        k.keylen = keylen;
 111        e = hashmap_get(&map->map, &k, NULL);
 112
 113        return e ? e->value : NULL;
 114}
 115
 116/* Add 'value' to a hashmap based on the provided 'key'. */
 117static void attr_hashmap_add(struct attr_hashmap *map,
 118                             const char *key, size_t keylen,
 119                             void *value)
 120{
 121        struct attr_hash_entry *e;
 122
 123        if (!map->map.tablesize)
 124                attr_hashmap_init(map);
 125
 126        e = xmalloc(sizeof(struct attr_hash_entry));
 127        hashmap_entry_init(e, memhash(key, keylen));
 128        e->key = key;
 129        e->keylen = keylen;
 130        e->value = value;
 131
 132        hashmap_add(&map->map, e);
 133}
 134
 135struct all_attrs_item {
 136        const struct git_attr *attr;
 137        const char *value;
 138        /*
 139         * If 'macro' is non-NULL, indicates that 'attr' is a macro based on
 140         * the current attribute stack and contains a pointer to the match_attr
 141         * definition of the macro
 142         */
 143        const struct match_attr *macro;
 144};
 145
 146/*
 147 * Reallocate and reinitialize the array of all attributes (which is used in
 148 * the attribute collection process) in 'check' based on the global dictionary
 149 * of attributes.
 150 */
 151static void all_attrs_init(struct attr_hashmap *map, struct attr_check *check)
 152{
 153        int i;
 154        unsigned int size;
 155
 156        hashmap_lock(map);
 157
 158        size = hashmap_get_size(&map->map);
 159        if (size < check->all_attrs_nr)
 160                BUG("interned attributes shouldn't be deleted");
 161
 162        /*
 163         * If the number of attributes in the global dictionary has increased
 164         * (or this attr_check instance doesn't have an initialized all_attrs
 165         * field), reallocate the provided attr_check instance's all_attrs
 166         * field and fill each entry with its corresponding git_attr.
 167         */
 168        if (size != check->all_attrs_nr) {
 169                struct attr_hash_entry *e;
 170                struct hashmap_iter iter;
 171                hashmap_iter_init(&map->map, &iter);
 172
 173                REALLOC_ARRAY(check->all_attrs, size);
 174                check->all_attrs_nr = size;
 175
 176                while ((e = hashmap_iter_next(&iter))) {
 177                        const struct git_attr *a = e->value;
 178                        check->all_attrs[a->attr_nr].attr = a;
 179                }
 180        }
 181
 182        hashmap_unlock(map);
 183
 184        /*
 185         * Re-initialize every entry in check->all_attrs.
 186         * This re-initialization can live outside of the locked region since
 187         * the attribute dictionary is no longer being accessed.
 188         */
 189        for (i = 0; i < check->all_attrs_nr; i++) {
 190                check->all_attrs[i].value = ATTR__UNKNOWN;
 191                check->all_attrs[i].macro = NULL;
 192        }
 193}
 194
 195static int attr_name_valid(const char *name, size_t namelen)
 196{
 197        /*
 198         * Attribute name cannot begin with '-' and must consist of
 199         * characters from [-A-Za-z0-9_.].
 200         */
 201        if (namelen <= 0 || *name == '-')
 202                return 0;
 203        while (namelen--) {
 204                char ch = *name++;
 205                if (! (ch == '-' || ch == '.' || ch == '_' ||
 206                       ('0' <= ch && ch <= '9') ||
 207                       ('a' <= ch && ch <= 'z') ||
 208                       ('A' <= ch && ch <= 'Z')) )
 209                        return 0;
 210        }
 211        return 1;
 212}
 213
 214static void report_invalid_attr(const char *name, size_t len,
 215                                const char *src, int lineno)
 216{
 217        struct strbuf err = STRBUF_INIT;
 218        strbuf_addf(&err, _("%.*s is not a valid attribute name"),
 219                    (int) len, name);
 220        fprintf(stderr, "%s: %s:%d\n", err.buf, src, lineno);
 221        strbuf_release(&err);
 222}
 223
 224/*
 225 * Given a 'name', lookup and return the corresponding attribute in the global
 226 * dictionary.  If no entry is found, create a new attribute and store it in
 227 * the dictionary.
 228 */
 229static const struct git_attr *git_attr_internal(const char *name, int namelen)
 230{
 231        struct git_attr *a;
 232
 233        if (!attr_name_valid(name, namelen))
 234                return NULL;
 235
 236        hashmap_lock(&g_attr_hashmap);
 237
 238        a = attr_hashmap_get(&g_attr_hashmap, name, namelen);
 239
 240        if (!a) {
 241                FLEX_ALLOC_MEM(a, name, name, namelen);
 242                a->attr_nr = hashmap_get_size(&g_attr_hashmap.map);
 243
 244                attr_hashmap_add(&g_attr_hashmap, a->name, namelen, a);
 245                assert(a->attr_nr ==
 246                       (hashmap_get_size(&g_attr_hashmap.map) - 1));
 247        }
 248
 249        hashmap_unlock(&g_attr_hashmap);
 250
 251        return a;
 252}
 253
 254const struct git_attr *git_attr(const char *name)
 255{
 256        return git_attr_internal(name, strlen(name));
 257}
 258
 259/* What does a matched pattern decide? */
 260struct attr_state {
 261        const struct git_attr *attr;
 262        const char *setto;
 263};
 264
 265struct pattern {
 266        const char *pattern;
 267        int patternlen;
 268        int nowildcardlen;
 269        unsigned flags;         /* EXC_FLAG_* */
 270};
 271
 272/*
 273 * One rule, as from a .gitattributes file.
 274 *
 275 * If is_macro is true, then u.attr is a pointer to the git_attr being
 276 * defined.
 277 *
 278 * If is_macro is false, then u.pat is the filename pattern to which the
 279 * rule applies.
 280 *
 281 * In either case, num_attr is the number of attributes affected by
 282 * this rule, and state is an array listing them.  The attributes are
 283 * listed as they appear in the file (macros unexpanded).
 284 */
 285struct match_attr {
 286        union {
 287                struct pattern pat;
 288                const struct git_attr *attr;
 289        } u;
 290        char is_macro;
 291        unsigned num_attr;
 292        struct attr_state state[FLEX_ARRAY];
 293};
 294
 295static const char blank[] = " \t\r\n";
 296
 297/*
 298 * Parse a whitespace-delimited attribute state (i.e., "attr",
 299 * "-attr", "!attr", or "attr=value") from the string starting at src.
 300 * If e is not NULL, write the results to *e.  Return a pointer to the
 301 * remainder of the string (with leading whitespace removed), or NULL
 302 * if there was an error.
 303 */
 304static const char *parse_attr(const char *src, int lineno, const char *cp,
 305                              struct attr_state *e)
 306{
 307        const char *ep, *equals;
 308        int len;
 309
 310        ep = cp + strcspn(cp, blank);
 311        equals = strchr(cp, '=');
 312        if (equals && ep < equals)
 313                equals = NULL;
 314        if (equals)
 315                len = equals - cp;
 316        else
 317                len = ep - cp;
 318        if (!e) {
 319                if (*cp == '-' || *cp == '!') {
 320                        cp++;
 321                        len--;
 322                }
 323                if (!attr_name_valid(cp, len)) {
 324                        report_invalid_attr(cp, len, src, lineno);
 325                        return NULL;
 326                }
 327        } else {
 328                /*
 329                 * As this function is always called twice, once with
 330                 * e == NULL in the first pass and then e != NULL in
 331                 * the second pass, no need for attr_name_valid()
 332                 * check here.
 333                 */
 334                if (*cp == '-' || *cp == '!') {
 335                        e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 336                        cp++;
 337                        len--;
 338                }
 339                else if (!equals)
 340                        e->setto = ATTR__TRUE;
 341                else {
 342                        e->setto = xmemdupz(equals + 1, ep - equals - 1);
 343                }
 344                e->attr = git_attr_internal(cp, len);
 345        }
 346        return ep + strspn(ep, blank);
 347}
 348
 349static struct match_attr *parse_attr_line(const char *line, const char *src,
 350                                          int lineno, int macro_ok)
 351{
 352        int namelen;
 353        int num_attr, i;
 354        const char *cp, *name, *states;
 355        struct match_attr *res = NULL;
 356        int is_macro;
 357        struct strbuf pattern = STRBUF_INIT;
 358
 359        cp = line + strspn(line, blank);
 360        if (!*cp || *cp == '#')
 361                return NULL;
 362        name = cp;
 363
 364        if (*cp == '"' && !unquote_c_style(&pattern, name, &states)) {
 365                name = pattern.buf;
 366                namelen = pattern.len;
 367        } else {
 368                namelen = strcspn(name, blank);
 369                states = name + namelen;
 370        }
 371
 372        if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 373            starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
 374                if (!macro_ok) {
 375                        fprintf(stderr, "%s not allowed: %s:%d\n",
 376                                name, src, lineno);
 377                        goto fail_return;
 378                }
 379                is_macro = 1;
 380                name += strlen(ATTRIBUTE_MACRO_PREFIX);
 381                name += strspn(name, blank);
 382                namelen = strcspn(name, blank);
 383                if (!attr_name_valid(name, namelen)) {
 384                        report_invalid_attr(name, namelen, src, lineno);
 385                        goto fail_return;
 386                }
 387        }
 388        else
 389                is_macro = 0;
 390
 391        states += strspn(states, blank);
 392
 393        /* First pass to count the attr_states */
 394        for (cp = states, num_attr = 0; *cp; num_attr++) {
 395                cp = parse_attr(src, lineno, cp, NULL);
 396                if (!cp)
 397                        goto fail_return;
 398        }
 399
 400        res = xcalloc(1,
 401                      sizeof(*res) +
 402                      sizeof(struct attr_state) * num_attr +
 403                      (is_macro ? 0 : namelen + 1));
 404        if (is_macro) {
 405                res->u.attr = git_attr_internal(name, namelen);
 406        } else {
 407                char *p = (char *)&(res->state[num_attr]);
 408                memcpy(p, name, namelen);
 409                res->u.pat.pattern = p;
 410                parse_exclude_pattern(&res->u.pat.pattern,
 411                                      &res->u.pat.patternlen,
 412                                      &res->u.pat.flags,
 413                                      &res->u.pat.nowildcardlen);
 414                if (res->u.pat.flags & EXC_FLAG_NEGATIVE) {
 415                        warning(_("Negative patterns are ignored in git attributes\n"
 416                                  "Use '\\!' for literal leading exclamation."));
 417                        goto fail_return;
 418                }
 419        }
 420        res->is_macro = is_macro;
 421        res->num_attr = num_attr;
 422
 423        /* Second pass to fill the attr_states */
 424        for (cp = states, i = 0; *cp; i++) {
 425                cp = parse_attr(src, lineno, cp, &(res->state[i]));
 426        }
 427
 428        strbuf_release(&pattern);
 429        return res;
 430
 431fail_return:
 432        strbuf_release(&pattern);
 433        free(res);
 434        return NULL;
 435}
 436
 437/*
 438 * Like info/exclude and .gitignore, the attribute information can
 439 * come from many places.
 440 *
 441 * (1) .gitattribute file of the same directory;
 442 * (2) .gitattribute file of the parent directory if (1) does not have
 443 *      any match; this goes recursively upwards, just like .gitignore.
 444 * (3) $GIT_DIR/info/attributes, which overrides both of the above.
 445 *
 446 * In the same file, later entries override the earlier match, so in the
 447 * global list, we would have entries from info/attributes the earliest
 448 * (reading the file from top to bottom), .gitattribute of the root
 449 * directory (again, reading the file from top to bottom) down to the
 450 * current directory, and then scan the list backwards to find the first match.
 451 * This is exactly the same as what is_excluded() does in dir.c to deal with
 452 * .gitignore file and info/excludes file as a fallback.
 453 */
 454
 455struct attr_stack {
 456        struct attr_stack *prev;
 457        char *origin;
 458        size_t originlen;
 459        unsigned num_matches;
 460        unsigned alloc;
 461        struct match_attr **attrs;
 462};
 463
 464static void attr_stack_free(struct attr_stack *e)
 465{
 466        int i;
 467        free(e->origin);
 468        for (i = 0; i < e->num_matches; i++) {
 469                struct match_attr *a = e->attrs[i];
 470                int j;
 471                for (j = 0; j < a->num_attr; j++) {
 472                        const char *setto = a->state[j].setto;
 473                        if (setto == ATTR__TRUE ||
 474                            setto == ATTR__FALSE ||
 475                            setto == ATTR__UNSET ||
 476                            setto == ATTR__UNKNOWN)
 477                                ;
 478                        else
 479                                free((char *) setto);
 480                }
 481                free(a);
 482        }
 483        free(e->attrs);
 484        free(e);
 485}
 486
 487static void drop_attr_stack(struct attr_stack **stack)
 488{
 489        while (*stack) {
 490                struct attr_stack *elem = *stack;
 491                *stack = elem->prev;
 492                attr_stack_free(elem);
 493        }
 494}
 495
 496/* List of all attr_check structs; access should be surrounded by mutex */
 497static struct check_vector {
 498        size_t nr;
 499        size_t alloc;
 500        struct attr_check **checks;
 501#ifndef NO_PTHREADS
 502        pthread_mutex_t mutex;
 503#endif
 504} check_vector;
 505
 506static inline void vector_lock(void)
 507{
 508#ifndef NO_PTHREADS
 509        pthread_mutex_lock(&check_vector.mutex);
 510#endif
 511}
 512
 513static inline void vector_unlock(void)
 514{
 515#ifndef NO_PTHREADS
 516        pthread_mutex_unlock(&check_vector.mutex);
 517#endif
 518}
 519
 520static void check_vector_add(struct attr_check *c)
 521{
 522        vector_lock();
 523
 524        ALLOC_GROW(check_vector.checks,
 525                   check_vector.nr + 1,
 526                   check_vector.alloc);
 527        check_vector.checks[check_vector.nr++] = c;
 528
 529        vector_unlock();
 530}
 531
 532static void check_vector_remove(struct attr_check *check)
 533{
 534        int i;
 535
 536        vector_lock();
 537
 538        /* Find entry */
 539        for (i = 0; i < check_vector.nr; i++)
 540                if (check_vector.checks[i] == check)
 541                        break;
 542
 543        if (i >= check_vector.nr)
 544                BUG("no entry found");
 545
 546        /* shift entries over */
 547        for (; i < check_vector.nr - 1; i++)
 548                check_vector.checks[i] = check_vector.checks[i + 1];
 549
 550        check_vector.nr--;
 551
 552        vector_unlock();
 553}
 554
 555/* Iterate through all attr_check instances and drop their stacks */
 556static void drop_all_attr_stacks(void)
 557{
 558        int i;
 559
 560        vector_lock();
 561
 562        for (i = 0; i < check_vector.nr; i++) {
 563                drop_attr_stack(&check_vector.checks[i]->stack);
 564        }
 565
 566        vector_unlock();
 567}
 568
 569struct attr_check *attr_check_alloc(void)
 570{
 571        struct attr_check *c = xcalloc(1, sizeof(struct attr_check));
 572
 573        /* save pointer to the check struct */
 574        check_vector_add(c);
 575
 576        return c;
 577}
 578
 579struct attr_check *attr_check_initl(const char *one, ...)
 580{
 581        struct attr_check *check;
 582        int cnt;
 583        va_list params;
 584        const char *param;
 585
 586        va_start(params, one);
 587        for (cnt = 1; (param = va_arg(params, const char *)) != NULL; cnt++)
 588                ;
 589        va_end(params);
 590
 591        check = attr_check_alloc();
 592        check->nr = cnt;
 593        check->alloc = cnt;
 594        check->items = xcalloc(cnt, sizeof(struct attr_check_item));
 595
 596        check->items[0].attr = git_attr(one);
 597        va_start(params, one);
 598        for (cnt = 1; cnt < check->nr; cnt++) {
 599                const struct git_attr *attr;
 600                param = va_arg(params, const char *);
 601                if (!param)
 602                        BUG("counted %d != ended at %d",
 603                            check->nr, cnt);
 604                attr = git_attr(param);
 605                if (!attr)
 606                        BUG("%s: not a valid attribute name", param);
 607                check->items[cnt].attr = attr;
 608        }
 609        va_end(params);
 610        return check;
 611}
 612
 613struct attr_check *attr_check_dup(const struct attr_check *check)
 614{
 615        struct attr_check *ret;
 616
 617        if (!check)
 618                return NULL;
 619
 620        ret = attr_check_alloc();
 621
 622        ret->nr = check->nr;
 623        ret->alloc = check->alloc;
 624        ALLOC_ARRAY(ret->items, ret->nr);
 625        COPY_ARRAY(ret->items, check->items, ret->nr);
 626
 627        return ret;
 628}
 629
 630struct attr_check_item *attr_check_append(struct attr_check *check,
 631                                          const struct git_attr *attr)
 632{
 633        struct attr_check_item *item;
 634
 635        ALLOC_GROW(check->items, check->nr + 1, check->alloc);
 636        item = &check->items[check->nr++];
 637        item->attr = attr;
 638        return item;
 639}
 640
 641void attr_check_reset(struct attr_check *check)
 642{
 643        check->nr = 0;
 644}
 645
 646void attr_check_clear(struct attr_check *check)
 647{
 648        FREE_AND_NULL(check->items);
 649        check->alloc = 0;
 650        check->nr = 0;
 651
 652        FREE_AND_NULL(check->all_attrs);
 653        check->all_attrs_nr = 0;
 654
 655        drop_attr_stack(&check->stack);
 656}
 657
 658void attr_check_free(struct attr_check *check)
 659{
 660        if (check) {
 661                /* Remove check from the check vector */
 662                check_vector_remove(check);
 663
 664                attr_check_clear(check);
 665                free(check);
 666        }
 667}
 668
 669static const char *builtin_attr[] = {
 670        "[attr]binary -diff -merge -text",
 671        NULL,
 672};
 673
 674static void handle_attr_line(struct attr_stack *res,
 675                             const char *line,
 676                             const char *src,
 677                             int lineno,
 678                             int macro_ok)
 679{
 680        struct match_attr *a;
 681
 682        a = parse_attr_line(line, src, lineno, macro_ok);
 683        if (!a)
 684                return;
 685        ALLOC_GROW(res->attrs, res->num_matches + 1, res->alloc);
 686        res->attrs[res->num_matches++] = a;
 687}
 688
 689static struct attr_stack *read_attr_from_array(const char **list)
 690{
 691        struct attr_stack *res;
 692        const char *line;
 693        int lineno = 0;
 694
 695        res = xcalloc(1, sizeof(*res));
 696        while ((line = *(list++)) != NULL)
 697                handle_attr_line(res, line, "[builtin]", ++lineno, 1);
 698        return res;
 699}
 700
 701/*
 702 * Callers into the attribute system assume there is a single, system-wide
 703 * global state where attributes are read from and when the state is flipped by
 704 * calling git_attr_set_direction(), the stack frames that have been
 705 * constructed need to be discarded so so that subsequent calls into the
 706 * attribute system will lazily read from the right place.  Since changing
 707 * direction causes a global paradigm shift, it should not ever be called while
 708 * another thread could potentially be calling into the attribute system.
 709 */
 710static enum git_attr_direction direction;
 711
 712void git_attr_set_direction(enum git_attr_direction new_direction)
 713{
 714        if (is_bare_repository() && new_direction != GIT_ATTR_INDEX)
 715                BUG("non-INDEX attr direction in a bare repo");
 716
 717        if (new_direction != direction)
 718                drop_all_attr_stacks();
 719
 720        direction = new_direction;
 721}
 722
 723static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 724{
 725        FILE *fp = fopen_or_warn(path, "r");
 726        struct attr_stack *res;
 727        char buf[2048];
 728        int lineno = 0;
 729
 730        if (!fp)
 731                return NULL;
 732        res = xcalloc(1, sizeof(*res));
 733        while (fgets(buf, sizeof(buf), fp)) {
 734                char *bufp = buf;
 735                if (!lineno)
 736                        skip_utf8_bom(&bufp, strlen(bufp));
 737                handle_attr_line(res, bufp, path, ++lineno, macro_ok);
 738        }
 739        fclose(fp);
 740        return res;
 741}
 742
 743static struct attr_stack *read_attr_from_index(const struct index_state *istate,
 744                                               const char *path,
 745                                               int macro_ok)
 746{
 747        struct attr_stack *res;
 748        char *buf, *sp;
 749        int lineno = 0;
 750
 751        if (!istate)
 752                return NULL;
 753
 754        buf = read_blob_data_from_index(istate, path, NULL);
 755        if (!buf)
 756                return NULL;
 757
 758        res = xcalloc(1, sizeof(*res));
 759        for (sp = buf; *sp; ) {
 760                char *ep;
 761                int more;
 762
 763                ep = strchrnul(sp, '\n');
 764                more = (*ep == '\n');
 765                *ep = '\0';
 766                handle_attr_line(res, sp, path, ++lineno, macro_ok);
 767                sp = ep + more;
 768        }
 769        free(buf);
 770        return res;
 771}
 772
 773static struct attr_stack *read_attr(const struct index_state *istate,
 774                                    const char *path, int macro_ok)
 775{
 776        struct attr_stack *res = NULL;
 777
 778        if (direction == GIT_ATTR_INDEX) {
 779                res = read_attr_from_index(istate, path, macro_ok);
 780        } else if (!is_bare_repository()) {
 781                if (direction == GIT_ATTR_CHECKOUT) {
 782                        res = read_attr_from_index(istate, path, macro_ok);
 783                        if (!res)
 784                                res = read_attr_from_file(path, macro_ok);
 785                } else if (direction == GIT_ATTR_CHECKIN) {
 786                        res = read_attr_from_file(path, macro_ok);
 787                        if (!res)
 788                                /*
 789                                 * There is no checked out .gitattributes file
 790                                 * there, but we might have it in the index.
 791                                 * We allow operation in a sparsely checked out
 792                                 * work tree, so read from it.
 793                                 */
 794                                res = read_attr_from_index(istate, path, macro_ok);
 795                }
 796        }
 797
 798        if (!res)
 799                res = xcalloc(1, sizeof(*res));
 800        return res;
 801}
 802
 803#if DEBUG_ATTR
 804static void debug_info(const char *what, struct attr_stack *elem)
 805{
 806        fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
 807}
 808static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
 809{
 810        const char *value = v;
 811
 812        if (ATTR_TRUE(value))
 813                value = "set";
 814        else if (ATTR_FALSE(value))
 815                value = "unset";
 816        else if (ATTR_UNSET(value))
 817                value = "unspecified";
 818
 819        fprintf(stderr, "%s: %s => %s (%s)\n",
 820                what, attr->name, (char *) value, match);
 821}
 822#define debug_push(a) debug_info("push", (a))
 823#define debug_pop(a) debug_info("pop", (a))
 824#else
 825#define debug_push(a) do { ; } while (0)
 826#define debug_pop(a) do { ; } while (0)
 827#define debug_set(a,b,c,d) do { ; } while (0)
 828#endif /* DEBUG_ATTR */
 829
 830static const char *git_etc_gitattributes(void)
 831{
 832        static const char *system_wide;
 833        if (!system_wide)
 834                system_wide = system_path(ETC_GITATTRIBUTES);
 835        return system_wide;
 836}
 837
 838static const char *get_home_gitattributes(void)
 839{
 840        if (!git_attributes_file)
 841                git_attributes_file = xdg_config_home("attributes");
 842
 843        return git_attributes_file;
 844}
 845
 846static int git_attr_system(void)
 847{
 848        return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 849}
 850
 851static GIT_PATH_FUNC(git_path_info_attributes, INFOATTRIBUTES_FILE)
 852
 853static void push_stack(struct attr_stack **attr_stack_p,
 854                       struct attr_stack *elem, char *origin, size_t originlen)
 855{
 856        if (elem) {
 857                elem->origin = origin;
 858                if (origin)
 859                        elem->originlen = originlen;
 860                elem->prev = *attr_stack_p;
 861                *attr_stack_p = elem;
 862        }
 863}
 864
 865static void bootstrap_attr_stack(const struct index_state *istate,
 866                                 struct attr_stack **stack)
 867{
 868        struct attr_stack *e;
 869
 870        if (*stack)
 871                return;
 872
 873        /* builtin frame */
 874        e = read_attr_from_array(builtin_attr);
 875        push_stack(stack, e, NULL, 0);
 876
 877        /* system-wide frame */
 878        if (git_attr_system()) {
 879                e = read_attr_from_file(git_etc_gitattributes(), 1);
 880                push_stack(stack, e, NULL, 0);
 881        }
 882
 883        /* home directory */
 884        if (get_home_gitattributes()) {
 885                e = read_attr_from_file(get_home_gitattributes(), 1);
 886                push_stack(stack, e, NULL, 0);
 887        }
 888
 889        /* root directory */
 890        e = read_attr(istate, GITATTRIBUTES_FILE, 1);
 891        push_stack(stack, e, xstrdup(""), 0);
 892
 893        /* info frame */
 894        if (startup_info->have_repository)
 895                e = read_attr_from_file(git_path_info_attributes(), 1);
 896        else
 897                e = NULL;
 898        if (!e)
 899                e = xcalloc(1, sizeof(struct attr_stack));
 900        push_stack(stack, e, NULL, 0);
 901}
 902
 903static void prepare_attr_stack(const struct index_state *istate,
 904                               const char *path, int dirlen,
 905                               struct attr_stack **stack)
 906{
 907        struct attr_stack *info;
 908        struct strbuf pathbuf = STRBUF_INIT;
 909
 910        /*
 911         * At the bottom of the attribute stack is the built-in
 912         * set of attribute definitions, followed by the contents
 913         * of $(prefix)/etc/gitattributes and a file specified by
 914         * core.attributesfile.  Then, contents from
 915         * .gitattribute files from directories closer to the
 916         * root to the ones in deeper directories are pushed
 917         * to the stack.  Finally, at the very top of the stack
 918         * we always keep the contents of $GIT_DIR/info/attributes.
 919         *
 920         * When checking, we use entries from near the top of the
 921         * stack, preferring $GIT_DIR/info/attributes, then
 922         * .gitattributes in deeper directories to shallower ones,
 923         * and finally use the built-in set as the default.
 924         */
 925        bootstrap_attr_stack(istate, stack);
 926
 927        /*
 928         * Pop the "info" one that is always at the top of the stack.
 929         */
 930        info = *stack;
 931        *stack = info->prev;
 932
 933        /*
 934         * Pop the ones from directories that are not the prefix of
 935         * the path we are checking. Break out of the loop when we see
 936         * the root one (whose origin is an empty string "") or the builtin
 937         * one (whose origin is NULL) without popping it.
 938         */
 939        while ((*stack)->origin) {
 940                int namelen = (*stack)->originlen;
 941                struct attr_stack *elem;
 942
 943                elem = *stack;
 944                if (namelen <= dirlen &&
 945                    !strncmp(elem->origin, path, namelen) &&
 946                    (!namelen || path[namelen] == '/'))
 947                        break;
 948
 949                debug_pop(elem);
 950                *stack = elem->prev;
 951                attr_stack_free(elem);
 952        }
 953
 954        /*
 955         * bootstrap_attr_stack() should have added, and the
 956         * above loop should have stopped before popping, the
 957         * root element whose attr_stack->origin is set to an
 958         * empty string.
 959         */
 960        assert((*stack)->origin);
 961
 962        strbuf_addstr(&pathbuf, (*stack)->origin);
 963        /* Build up to the directory 'path' is in */
 964        while (pathbuf.len < dirlen) {
 965                size_t len = pathbuf.len;
 966                struct attr_stack *next;
 967                char *origin;
 968
 969                /* Skip path-separator */
 970                if (len < dirlen && is_dir_sep(path[len]))
 971                        len++;
 972                /* Find the end of the next component */
 973                while (len < dirlen && !is_dir_sep(path[len]))
 974                        len++;
 975
 976                if (pathbuf.len > 0)
 977                        strbuf_addch(&pathbuf, '/');
 978                strbuf_add(&pathbuf, path + pathbuf.len, (len - pathbuf.len));
 979                strbuf_addf(&pathbuf, "/%s", GITATTRIBUTES_FILE);
 980
 981                next = read_attr(istate, pathbuf.buf, 0);
 982
 983                /* reset the pathbuf to not include "/.gitattributes" */
 984                strbuf_setlen(&pathbuf, len);
 985
 986                origin = xstrdup(pathbuf.buf);
 987                push_stack(stack, next, origin, len);
 988        }
 989
 990        /*
 991         * Finally push the "info" one at the top of the stack.
 992         */
 993        push_stack(stack, info, NULL, 0);
 994
 995        strbuf_release(&pathbuf);
 996}
 997
 998static int path_matches(const char *pathname, int pathlen,
 999                        int basename_offset,
1000                        const struct pattern *pat,
1001                        const char *base, int baselen)
1002{
1003        const char *pattern = pat->pattern;
1004        int prefix = pat->nowildcardlen;
1005        int isdir = (pathlen && pathname[pathlen - 1] == '/');
1006
1007        if ((pat->flags & EXC_FLAG_MUSTBEDIR) && !isdir)
1008                return 0;
1009
1010        if (pat->flags & EXC_FLAG_NODIR) {
1011                return match_basename(pathname + basename_offset,
1012                                      pathlen - basename_offset - isdir,
1013                                      pattern, prefix,
1014                                      pat->patternlen, pat->flags);
1015        }
1016        return match_pathname(pathname, pathlen - isdir,
1017                              base, baselen,
1018                              pattern, prefix, pat->patternlen, pat->flags);
1019}
1020
1021static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem);
1022
1023static int fill_one(const char *what, struct all_attrs_item *all_attrs,
1024                    const struct match_attr *a, int rem)
1025{
1026        int i;
1027
1028        for (i = a->num_attr - 1; rem > 0 && i >= 0; i--) {
1029                const struct git_attr *attr = a->state[i].attr;
1030                const char **n = &(all_attrs[attr->attr_nr].value);
1031                const char *v = a->state[i].setto;
1032
1033                if (*n == ATTR__UNKNOWN) {
1034                        debug_set(what,
1035                                  a->is_macro ? a->u.attr->name : a->u.pat.pattern,
1036                                  attr, v);
1037                        *n = v;
1038                        rem--;
1039                        rem = macroexpand_one(all_attrs, attr->attr_nr, rem);
1040                }
1041        }
1042        return rem;
1043}
1044
1045static int fill(const char *path, int pathlen, int basename_offset,
1046                const struct attr_stack *stack,
1047                struct all_attrs_item *all_attrs, int rem)
1048{
1049        for (; rem > 0 && stack; stack = stack->prev) {
1050                int i;
1051                const char *base = stack->origin ? stack->origin : "";
1052
1053                for (i = stack->num_matches - 1; 0 < rem && 0 <= i; i--) {
1054                        const struct match_attr *a = stack->attrs[i];
1055                        if (a->is_macro)
1056                                continue;
1057                        if (path_matches(path, pathlen, basename_offset,
1058                                         &a->u.pat, base, stack->originlen))
1059                                rem = fill_one("fill", all_attrs, a, rem);
1060                }
1061        }
1062
1063        return rem;
1064}
1065
1066static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem)
1067{
1068        const struct all_attrs_item *item = &all_attrs[nr];
1069
1070        if (item->macro && item->value == ATTR__TRUE)
1071                return fill_one("expand", all_attrs, item->macro, rem);
1072        else
1073                return rem;
1074}
1075
1076/*
1077 * Marks the attributes which are macros based on the attribute stack.
1078 * This prevents having to search through the attribute stack each time
1079 * a macro needs to be expanded during the fill stage.
1080 */
1081static void determine_macros(struct all_attrs_item *all_attrs,
1082                             const struct attr_stack *stack)
1083{
1084        for (; stack; stack = stack->prev) {
1085                int i;
1086                for (i = stack->num_matches - 1; i >= 0; i--) {
1087                        const struct match_attr *ma = stack->attrs[i];
1088                        if (ma->is_macro) {
1089                                int n = ma->u.attr->attr_nr;
1090                                if (!all_attrs[n].macro) {
1091                                        all_attrs[n].macro = ma;
1092                                }
1093                        }
1094                }
1095        }
1096}
1097
1098/*
1099 * Collect attributes for path into the array pointed to by check->all_attrs.
1100 * If check->check_nr is non-zero, only attributes in check[] are collected.
1101 * Otherwise all attributes are collected.
1102 */
1103static void collect_some_attrs(const struct index_state *istate,
1104                               const char *path,
1105                               struct attr_check *check)
1106{
1107        int i, pathlen, rem, dirlen;
1108        const char *cp, *last_slash = NULL;
1109        int basename_offset;
1110
1111        for (cp = path; *cp; cp++) {
1112                if (*cp == '/' && cp[1])
1113                        last_slash = cp;
1114        }
1115        pathlen = cp - path;
1116        if (last_slash) {
1117                basename_offset = last_slash + 1 - path;
1118                dirlen = last_slash - path;
1119        } else {
1120                basename_offset = 0;
1121                dirlen = 0;
1122        }
1123
1124        prepare_attr_stack(istate, path, dirlen, &check->stack);
1125        all_attrs_init(&g_attr_hashmap, check);
1126        determine_macros(check->all_attrs, check->stack);
1127
1128        if (check->nr) {
1129                rem = 0;
1130                for (i = 0; i < check->nr; i++) {
1131                        int n = check->items[i].attr->attr_nr;
1132                        struct all_attrs_item *item = &check->all_attrs[n];
1133                        if (item->macro) {
1134                                item->value = ATTR__UNSET;
1135                                rem++;
1136                        }
1137                }
1138                if (rem == check->nr)
1139                        return;
1140        }
1141
1142        rem = check->all_attrs_nr;
1143        fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
1144}
1145
1146int git_check_attr(const struct index_state *istate,
1147                   const char *path,
1148                   struct attr_check *check)
1149{
1150        int i;
1151
1152        collect_some_attrs(istate, path, check);
1153
1154        for (i = 0; i < check->nr; i++) {
1155                size_t n = check->items[i].attr->attr_nr;
1156                const char *value = check->all_attrs[n].value;
1157                if (value == ATTR__UNKNOWN)
1158                        value = ATTR__UNSET;
1159                check->items[i].value = value;
1160        }
1161
1162        return 0;
1163}
1164
1165void git_all_attrs(const struct index_state *istate,
1166                   const char *path, struct attr_check *check)
1167{
1168        int i;
1169
1170        attr_check_reset(check);
1171        collect_some_attrs(istate, path, check);
1172
1173        for (i = 0; i < check->all_attrs_nr; i++) {
1174                const char *name = check->all_attrs[i].attr->name;
1175                const char *value = check->all_attrs[i].value;
1176                struct attr_check_item *item;
1177                if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
1178                        continue;
1179                item = attr_check_append(check, git_attr(name));
1180                item->value = value;
1181        }
1182}
1183
1184void attr_start(void)
1185{
1186#ifndef NO_PTHREADS
1187        pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
1188        pthread_mutex_init(&check_vector.mutex, NULL);
1189#endif
1190}