sha1_name.con commit Merge branch 'nd/ignore-glob-doc-update' (0dbd562)
   1#include "cache.h"
   2#include "config.h"
   3#include "tag.h"
   4#include "commit.h"
   5#include "tree.h"
   6#include "blob.h"
   7#include "tree-walk.h"
   8#include "refs.h"
   9#include "remote.h"
  10#include "dir.h"
  11#include "sha1-array.h"
  12#include "packfile.h"
  13
  14static int get_oid_oneline(const char *, struct object_id *, struct commit_list *);
  15
  16typedef int (*disambiguate_hint_fn)(const struct object_id *, void *);
  17
  18struct disambiguate_state {
  19        int len; /* length of prefix in hex chars */
  20        char hex_pfx[GIT_MAX_HEXSZ + 1];
  21        struct object_id bin_pfx;
  22
  23        disambiguate_hint_fn fn;
  24        void *cb_data;
  25        struct object_id candidate;
  26        unsigned candidate_exists:1;
  27        unsigned candidate_checked:1;
  28        unsigned candidate_ok:1;
  29        unsigned disambiguate_fn_used:1;
  30        unsigned ambiguous:1;
  31        unsigned always_call_fn:1;
  32};
  33
  34static void update_candidates(struct disambiguate_state *ds, const struct object_id *current)
  35{
  36        if (ds->always_call_fn) {
  37                ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
  38                return;
  39        }
  40        if (!ds->candidate_exists) {
  41                /* this is the first candidate */
  42                oidcpy(&ds->candidate, current);
  43                ds->candidate_exists = 1;
  44                return;
  45        } else if (!oidcmp(&ds->candidate, current)) {
  46                /* the same as what we already have seen */
  47                return;
  48        }
  49
  50        if (!ds->fn) {
  51                /* cannot disambiguate between ds->candidate and current */
  52                ds->ambiguous = 1;
  53                return;
  54        }
  55
  56        if (!ds->candidate_checked) {
  57                ds->candidate_ok = ds->fn(&ds->candidate, ds->cb_data);
  58                ds->disambiguate_fn_used = 1;
  59                ds->candidate_checked = 1;
  60        }
  61
  62        if (!ds->candidate_ok) {
  63                /* discard the candidate; we know it does not satisfy fn */
  64                oidcpy(&ds->candidate, current);
  65                ds->candidate_checked = 0;
  66                return;
  67        }
  68
  69        /* if we reach this point, we know ds->candidate satisfies fn */
  70        if (ds->fn(current, ds->cb_data)) {
  71                /*
  72                 * if both current and candidate satisfy fn, we cannot
  73                 * disambiguate.
  74                 */
  75                ds->candidate_ok = 0;
  76                ds->ambiguous = 1;
  77        }
  78
  79        /* otherwise, current can be discarded and candidate is still good */
  80}
  81
  82static int append_loose_object(const struct object_id *oid, const char *path,
  83                               void *data)
  84{
  85        oid_array_append(data, oid);
  86        return 0;
  87}
  88
  89static int match_sha(unsigned, const unsigned char *, const unsigned char *);
  90
  91static void find_short_object_filename(struct disambiguate_state *ds)
  92{
  93        int subdir_nr = ds->bin_pfx.hash[0];
  94        struct alternate_object_database *alt;
  95        static struct alternate_object_database *fakeent;
  96
  97        if (!fakeent) {
  98                /*
  99                 * Create a "fake" alternate object database that
 100                 * points to our own object database, to make it
 101                 * easier to get a temporary working space in
 102                 * alt->name/alt->base while iterating over the
 103                 * object databases including our own.
 104                 */
 105                fakeent = alloc_alt_odb(get_object_directory());
 106        }
 107        fakeent->next = alt_odb_list;
 108
 109        for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
 110                int pos;
 111
 112                if (!alt->loose_objects_subdir_seen[subdir_nr]) {
 113                        struct strbuf *buf = alt_scratch_buf(alt);
 114                        for_each_file_in_obj_subdir(subdir_nr, buf,
 115                                                    append_loose_object,
 116                                                    NULL, NULL,
 117                                                    &alt->loose_objects_cache);
 118                        alt->loose_objects_subdir_seen[subdir_nr] = 1;
 119                }
 120
 121                pos = oid_array_lookup(&alt->loose_objects_cache, &ds->bin_pfx);
 122                if (pos < 0)
 123                        pos = -1 - pos;
 124                while (!ds->ambiguous && pos < alt->loose_objects_cache.nr) {
 125                        const struct object_id *oid;
 126                        oid = alt->loose_objects_cache.oid + pos;
 127                        if (!match_sha(ds->len, ds->bin_pfx.hash, oid->hash))
 128                                break;
 129                        update_candidates(ds, oid);
 130                        pos++;
 131                }
 132        }
 133}
 134
 135static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
 136{
 137        do {
 138                if (*a != *b)
 139                        return 0;
 140                a++;
 141                b++;
 142                len -= 2;
 143        } while (len > 1);
 144        if (len)
 145                if ((*a ^ *b) & 0xf0)
 146                        return 0;
 147        return 1;
 148}
 149
 150static void unique_in_pack(struct packed_git *p,
 151                           struct disambiguate_state *ds)
 152{
 153        uint32_t num, last, i, first = 0;
 154        const struct object_id *current = NULL;
 155
 156        if (open_pack_index(p) || !p->num_objects)
 157                return;
 158
 159        num = p->num_objects;
 160        last = num;
 161        while (first < last) {
 162                uint32_t mid = first + (last - first) / 2;
 163                const unsigned char *current;
 164                int cmp;
 165
 166                current = nth_packed_object_sha1(p, mid);
 167                cmp = hashcmp(ds->bin_pfx.hash, current);
 168                if (!cmp) {
 169                        first = mid;
 170                        break;
 171                }
 172                if (cmp > 0) {
 173                        first = mid+1;
 174                        continue;
 175                }
 176                last = mid;
 177        }
 178
 179        /*
 180         * At this point, "first" is the location of the lowest object
 181         * with an object name that could match "bin_pfx".  See if we have
 182         * 0, 1 or more objects that actually match(es).
 183         */
 184        for (i = first; i < num && !ds->ambiguous; i++) {
 185                struct object_id oid;
 186                current = nth_packed_object_oid(&oid, p, i);
 187                if (!match_sha(ds->len, ds->bin_pfx.hash, current->hash))
 188                        break;
 189                update_candidates(ds, current);
 190        }
 191}
 192
 193static void find_short_packed_object(struct disambiguate_state *ds)
 194{
 195        struct packed_git *p;
 196
 197        prepare_packed_git();
 198        for (p = packed_git; p && !ds->ambiguous; p = p->next)
 199                unique_in_pack(p, ds);
 200}
 201
 202#define SHORT_NAME_NOT_FOUND (-1)
 203#define SHORT_NAME_AMBIGUOUS (-2)
 204
 205static int finish_object_disambiguation(struct disambiguate_state *ds,
 206                                        struct object_id *oid)
 207{
 208        if (ds->ambiguous)
 209                return SHORT_NAME_AMBIGUOUS;
 210
 211        if (!ds->candidate_exists)
 212                return SHORT_NAME_NOT_FOUND;
 213
 214        if (!ds->candidate_checked)
 215                /*
 216                 * If this is the only candidate, there is no point
 217                 * calling the disambiguation hint callback.
 218                 *
 219                 * On the other hand, if the current candidate
 220                 * replaced an earlier candidate that did _not_ pass
 221                 * the disambiguation hint callback, then we do have
 222                 * more than one objects that match the short name
 223                 * given, so we should make sure this one matches;
 224                 * otherwise, if we discovered this one and the one
 225                 * that we previously discarded in the reverse order,
 226                 * we would end up showing different results in the
 227                 * same repository!
 228                 */
 229                ds->candidate_ok = (!ds->disambiguate_fn_used ||
 230                                    ds->fn(&ds->candidate, ds->cb_data));
 231
 232        if (!ds->candidate_ok)
 233                return SHORT_NAME_AMBIGUOUS;
 234
 235        oidcpy(oid, &ds->candidate);
 236        return 0;
 237}
 238
 239static int disambiguate_commit_only(const struct object_id *oid, void *cb_data_unused)
 240{
 241        int kind = sha1_object_info(oid->hash, NULL);
 242        return kind == OBJ_COMMIT;
 243}
 244
 245static int disambiguate_committish_only(const struct object_id *oid, void *cb_data_unused)
 246{
 247        struct object *obj;
 248        int kind;
 249
 250        kind = sha1_object_info(oid->hash, NULL);
 251        if (kind == OBJ_COMMIT)
 252                return 1;
 253        if (kind != OBJ_TAG)
 254                return 0;
 255
 256        /* We need to do this the hard way... */
 257        obj = deref_tag(parse_object(oid), NULL, 0);
 258        if (obj && obj->type == OBJ_COMMIT)
 259                return 1;
 260        return 0;
 261}
 262
 263static int disambiguate_tree_only(const struct object_id *oid, void *cb_data_unused)
 264{
 265        int kind = sha1_object_info(oid->hash, NULL);
 266        return kind == OBJ_TREE;
 267}
 268
 269static int disambiguate_treeish_only(const struct object_id *oid, void *cb_data_unused)
 270{
 271        struct object *obj;
 272        int kind;
 273
 274        kind = sha1_object_info(oid->hash, NULL);
 275        if (kind == OBJ_TREE || kind == OBJ_COMMIT)
 276                return 1;
 277        if (kind != OBJ_TAG)
 278                return 0;
 279
 280        /* We need to do this the hard way... */
 281        obj = deref_tag(parse_object(oid), NULL, 0);
 282        if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
 283                return 1;
 284        return 0;
 285}
 286
 287static int disambiguate_blob_only(const struct object_id *oid, void *cb_data_unused)
 288{
 289        int kind = sha1_object_info(oid->hash, NULL);
 290        return kind == OBJ_BLOB;
 291}
 292
 293static disambiguate_hint_fn default_disambiguate_hint;
 294
 295int set_disambiguate_hint_config(const char *var, const char *value)
 296{
 297        static const struct {
 298                const char *name;
 299                disambiguate_hint_fn fn;
 300        } hints[] = {
 301                { "none", NULL },
 302                { "commit", disambiguate_commit_only },
 303                { "committish", disambiguate_committish_only },
 304                { "tree", disambiguate_tree_only },
 305                { "treeish", disambiguate_treeish_only },
 306                { "blob", disambiguate_blob_only }
 307        };
 308        int i;
 309
 310        if (!value)
 311                return config_error_nonbool(var);
 312
 313        for (i = 0; i < ARRAY_SIZE(hints); i++) {
 314                if (!strcasecmp(value, hints[i].name)) {
 315                        default_disambiguate_hint = hints[i].fn;
 316                        return 0;
 317                }
 318        }
 319
 320        return error("unknown hint type for '%s': %s", var, value);
 321}
 322
 323static int init_object_disambiguation(const char *name, int len,
 324                                      struct disambiguate_state *ds)
 325{
 326        int i;
 327
 328        if (len < MINIMUM_ABBREV || len > GIT_SHA1_HEXSZ)
 329                return -1;
 330
 331        memset(ds, 0, sizeof(*ds));
 332
 333        for (i = 0; i < len ;i++) {
 334                unsigned char c = name[i];
 335                unsigned char val;
 336                if (c >= '0' && c <= '9')
 337                        val = c - '0';
 338                else if (c >= 'a' && c <= 'f')
 339                        val = c - 'a' + 10;
 340                else if (c >= 'A' && c <='F') {
 341                        val = c - 'A' + 10;
 342                        c -= 'A' - 'a';
 343                }
 344                else
 345                        return -1;
 346                ds->hex_pfx[i] = c;
 347                if (!(i & 1))
 348                        val <<= 4;
 349                ds->bin_pfx.hash[i >> 1] |= val;
 350        }
 351
 352        ds->len = len;
 353        ds->hex_pfx[len] = '\0';
 354        prepare_alt_odb();
 355        return 0;
 356}
 357
 358static int show_ambiguous_object(const struct object_id *oid, void *data)
 359{
 360        const struct disambiguate_state *ds = data;
 361        struct strbuf desc = STRBUF_INIT;
 362        int type;
 363
 364
 365        if (ds->fn && !ds->fn(oid, ds->cb_data))
 366                return 0;
 367
 368        type = sha1_object_info(oid->hash, NULL);
 369        if (type == OBJ_COMMIT) {
 370                struct commit *commit = lookup_commit(oid);
 371                if (commit) {
 372                        struct pretty_print_context pp = {0};
 373                        pp.date_mode.type = DATE_SHORT;
 374                        format_commit_message(commit, " %ad - %s", &desc, &pp);
 375                }
 376        } else if (type == OBJ_TAG) {
 377                struct tag *tag = lookup_tag(oid);
 378                if (!parse_tag(tag) && tag->tag)
 379                        strbuf_addf(&desc, " %s", tag->tag);
 380        }
 381
 382        advise("  %s %s%s",
 383               find_unique_abbrev(oid->hash, DEFAULT_ABBREV),
 384               typename(type) ? typename(type) : "unknown type",
 385               desc.buf);
 386
 387        strbuf_release(&desc);
 388        return 0;
 389}
 390
 391static int get_short_oid(const char *name, int len, struct object_id *oid,
 392                          unsigned flags)
 393{
 394        int status;
 395        struct disambiguate_state ds;
 396        int quietly = !!(flags & GET_OID_QUIETLY);
 397
 398        if (init_object_disambiguation(name, len, &ds) < 0)
 399                return -1;
 400
 401        if (HAS_MULTI_BITS(flags & GET_OID_DISAMBIGUATORS))
 402                die("BUG: multiple get_short_oid disambiguator flags");
 403
 404        if (flags & GET_OID_COMMIT)
 405                ds.fn = disambiguate_commit_only;
 406        else if (flags & GET_OID_COMMITTISH)
 407                ds.fn = disambiguate_committish_only;
 408        else if (flags & GET_OID_TREE)
 409                ds.fn = disambiguate_tree_only;
 410        else if (flags & GET_OID_TREEISH)
 411                ds.fn = disambiguate_treeish_only;
 412        else if (flags & GET_OID_BLOB)
 413                ds.fn = disambiguate_blob_only;
 414        else
 415                ds.fn = default_disambiguate_hint;
 416
 417        find_short_object_filename(&ds);
 418        find_short_packed_object(&ds);
 419        status = finish_object_disambiguation(&ds, oid);
 420
 421        if (!quietly && (status == SHORT_NAME_AMBIGUOUS)) {
 422                error(_("short SHA1 %s is ambiguous"), ds.hex_pfx);
 423
 424                /*
 425                 * We may still have ambiguity if we simply saw a series of
 426                 * candidates that did not satisfy our hint function. In
 427                 * that case, we still want to show them, so disable the hint
 428                 * function entirely.
 429                 */
 430                if (!ds.ambiguous)
 431                        ds.fn = NULL;
 432
 433                advise(_("The candidates are:"));
 434                for_each_abbrev(ds.hex_pfx, show_ambiguous_object, &ds);
 435        }
 436
 437        return status;
 438}
 439
 440static int collect_ambiguous(const struct object_id *oid, void *data)
 441{
 442        oid_array_append(data, oid);
 443        return 0;
 444}
 445
 446int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
 447{
 448        struct oid_array collect = OID_ARRAY_INIT;
 449        struct disambiguate_state ds;
 450        int ret;
 451
 452        if (init_object_disambiguation(prefix, strlen(prefix), &ds) < 0)
 453                return -1;
 454
 455        ds.always_call_fn = 1;
 456        ds.fn = collect_ambiguous;
 457        ds.cb_data = &collect;
 458        find_short_object_filename(&ds);
 459        find_short_packed_object(&ds);
 460
 461        ret = oid_array_for_each_unique(&collect, fn, cb_data);
 462        oid_array_clear(&collect);
 463        return ret;
 464}
 465
 466/*
 467 * Return the slot of the most-significant bit set in "val". There are various
 468 * ways to do this quickly with fls() or __builtin_clzl(), but speed is
 469 * probably not a big deal here.
 470 */
 471static unsigned msb(unsigned long val)
 472{
 473        unsigned r = 0;
 474        while (val >>= 1)
 475                r++;
 476        return r;
 477}
 478
 479struct min_abbrev_data {
 480        unsigned int init_len;
 481        unsigned int cur_len;
 482        char *hex;
 483        const unsigned char *hash;
 484};
 485
 486static inline char get_hex_char_from_oid(const struct object_id *oid,
 487                                         unsigned int pos)
 488{
 489        static const char hex[] = "0123456789abcdef";
 490
 491        if ((pos & 1) == 0)
 492                return hex[oid->hash[pos >> 1] >> 4];
 493        else
 494                return hex[oid->hash[pos >> 1] & 0xf];
 495}
 496
 497static int extend_abbrev_len(const struct object_id *oid, void *cb_data)
 498{
 499        struct min_abbrev_data *mad = cb_data;
 500
 501        unsigned int i = mad->init_len;
 502        while (mad->hex[i] && mad->hex[i] == get_hex_char_from_oid(oid, i))
 503                i++;
 504
 505        if (i < GIT_MAX_RAWSZ && i >= mad->cur_len)
 506                mad->cur_len = i + 1;
 507
 508        return 0;
 509}
 510
 511static void find_abbrev_len_for_pack(struct packed_git *p,
 512                                     struct min_abbrev_data *mad)
 513{
 514        int match = 0;
 515        uint32_t num, last, first = 0;
 516        struct object_id oid;
 517
 518        if (open_pack_index(p) || !p->num_objects)
 519                return;
 520
 521        num = p->num_objects;
 522        last = num;
 523        while (first < last) {
 524                uint32_t mid = first + (last - first) / 2;
 525                const unsigned char *current;
 526                int cmp;
 527
 528                current = nth_packed_object_sha1(p, mid);
 529                cmp = hashcmp(mad->hash, current);
 530                if (!cmp) {
 531                        match = 1;
 532                        first = mid;
 533                        break;
 534                }
 535                if (cmp > 0) {
 536                        first = mid + 1;
 537                        continue;
 538                }
 539                last = mid;
 540        }
 541
 542        /*
 543         * first is now the position in the packfile where we would insert
 544         * mad->hash if it does not exist (or the position of mad->hash if
 545         * it does exist). Hence, we consider a maximum of three objects
 546         * nearby for the abbreviation length.
 547         */
 548        mad->init_len = 0;
 549        if (!match) {
 550                nth_packed_object_oid(&oid, p, first);
 551                extend_abbrev_len(&oid, mad);
 552        } else if (first < num - 1) {
 553                nth_packed_object_oid(&oid, p, first + 1);
 554                extend_abbrev_len(&oid, mad);
 555        }
 556        if (first > 0) {
 557                nth_packed_object_oid(&oid, p, first - 1);
 558                extend_abbrev_len(&oid, mad);
 559        }
 560        mad->init_len = mad->cur_len;
 561}
 562
 563static void find_abbrev_len_packed(struct min_abbrev_data *mad)
 564{
 565        struct packed_git *p;
 566
 567        prepare_packed_git();
 568        for (p = packed_git; p; p = p->next)
 569                find_abbrev_len_for_pack(p, mad);
 570}
 571
 572int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len)
 573{
 574        struct disambiguate_state ds;
 575        struct min_abbrev_data mad;
 576        struct object_id oid_ret;
 577        if (len < 0) {
 578                unsigned long count = approximate_object_count();
 579                /*
 580                 * Add one because the MSB only tells us the highest bit set,
 581                 * not including the value of all the _other_ bits (so "15"
 582                 * is only one off of 2^4, but the MSB is the 3rd bit.
 583                 */
 584                len = msb(count) + 1;
 585                /*
 586                 * We now know we have on the order of 2^len objects, which
 587                 * expects a collision at 2^(len/2). But we also care about hex
 588                 * chars, not bits, and there are 4 bits per hex. So all
 589                 * together we need to divide by 2 and round up.
 590                 */
 591                len = DIV_ROUND_UP(len, 2);
 592                /*
 593                 * For very small repos, we stick with our regular fallback.
 594                 */
 595                if (len < FALLBACK_DEFAULT_ABBREV)
 596                        len = FALLBACK_DEFAULT_ABBREV;
 597        }
 598
 599        sha1_to_hex_r(hex, sha1);
 600        if (len == GIT_SHA1_HEXSZ || !len)
 601                return GIT_SHA1_HEXSZ;
 602
 603        mad.init_len = len;
 604        mad.cur_len = len;
 605        mad.hex = hex;
 606        mad.hash = sha1;
 607
 608        find_abbrev_len_packed(&mad);
 609
 610        if (init_object_disambiguation(hex, mad.cur_len, &ds) < 0)
 611                return -1;
 612
 613        ds.fn = extend_abbrev_len;
 614        ds.always_call_fn = 1;
 615        ds.cb_data = (void *)&mad;
 616
 617        find_short_object_filename(&ds);
 618        (void)finish_object_disambiguation(&ds, &oid_ret);
 619
 620        hex[mad.cur_len] = 0;
 621        return mad.cur_len;
 622}
 623
 624const char *find_unique_abbrev(const unsigned char *sha1, int len)
 625{
 626        static int bufno;
 627        static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
 628        char *hex = hexbuffer[bufno];
 629        bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
 630        find_unique_abbrev_r(hex, sha1, len);
 631        return hex;
 632}
 633
 634static int ambiguous_path(const char *path, int len)
 635{
 636        int slash = 1;
 637        int cnt;
 638
 639        for (cnt = 0; cnt < len; cnt++) {
 640                switch (*path++) {
 641                case '\0':
 642                        break;
 643                case '/':
 644                        if (slash)
 645                                break;
 646                        slash = 1;
 647                        continue;
 648                case '.':
 649                        continue;
 650                default:
 651                        slash = 0;
 652                        continue;
 653                }
 654                break;
 655        }
 656        return slash;
 657}
 658
 659static inline int at_mark(const char *string, int len,
 660                          const char **suffix, int nr)
 661{
 662        int i;
 663
 664        for (i = 0; i < nr; i++) {
 665                int suffix_len = strlen(suffix[i]);
 666                if (suffix_len <= len
 667                    && !strncasecmp(string, suffix[i], suffix_len))
 668                        return suffix_len;
 669        }
 670        return 0;
 671}
 672
 673static inline int upstream_mark(const char *string, int len)
 674{
 675        const char *suffix[] = { "@{upstream}", "@{u}" };
 676        return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
 677}
 678
 679static inline int push_mark(const char *string, int len)
 680{
 681        const char *suffix[] = { "@{push}" };
 682        return at_mark(string, len, suffix, ARRAY_SIZE(suffix));
 683}
 684
 685static int get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags);
 686static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
 687
 688static int get_oid_basic(const char *str, int len, struct object_id *oid,
 689                          unsigned int flags)
 690{
 691        static const char *warn_msg = "refname '%.*s' is ambiguous.";
 692        static const char *object_name_msg = N_(
 693        "Git normally never creates a ref that ends with 40 hex characters\n"
 694        "because it will be ignored when you just specify 40-hex. These refs\n"
 695        "may be created by mistake. For example,\n"
 696        "\n"
 697        "  git checkout -b $br $(git rev-parse ...)\n"
 698        "\n"
 699        "where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
 700        "examine these refs and maybe delete them. Turn this message off by\n"
 701        "running \"git config advice.objectNameWarning false\"");
 702        struct object_id tmp_oid;
 703        char *real_ref = NULL;
 704        int refs_found = 0;
 705        int at, reflog_len, nth_prior = 0;
 706
 707        if (len == GIT_SHA1_HEXSZ && !get_oid_hex(str, oid)) {
 708                if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) {
 709                        refs_found = dwim_ref(str, len, &tmp_oid, &real_ref);
 710                        if (refs_found > 0) {
 711                                warning(warn_msg, len, str);
 712                                if (advice_object_name_warning)
 713                                        fprintf(stderr, "%s\n", _(object_name_msg));
 714                        }
 715                        free(real_ref);
 716                }
 717                return 0;
 718        }
 719
 720        /* basic@{time or number or -number} format to query ref-log */
 721        reflog_len = at = 0;
 722        if (len && str[len-1] == '}') {
 723                for (at = len-4; at >= 0; at--) {
 724                        if (str[at] == '@' && str[at+1] == '{') {
 725                                if (str[at+2] == '-') {
 726                                        if (at != 0)
 727                                                /* @{-N} not at start */
 728                                                return -1;
 729                                        nth_prior = 1;
 730                                        continue;
 731                                }
 732                                if (!upstream_mark(str + at, len - at) &&
 733                                    !push_mark(str + at, len - at)) {
 734                                        reflog_len = (len-1) - (at+2);
 735                                        len = at;
 736                                }
 737                                break;
 738                        }
 739                }
 740        }
 741
 742        /* Accept only unambiguous ref paths. */
 743        if (len && ambiguous_path(str, len))
 744                return -1;
 745
 746        if (nth_prior) {
 747                struct strbuf buf = STRBUF_INIT;
 748                int detached;
 749
 750                if (interpret_nth_prior_checkout(str, len, &buf) > 0) {
 751                        detached = (buf.len == GIT_SHA1_HEXSZ && !get_oid_hex(buf.buf, oid));
 752                        strbuf_release(&buf);
 753                        if (detached)
 754                                return 0;
 755                }
 756        }
 757
 758        if (!len && reflog_len)
 759                /* allow "@{...}" to mean the current branch reflog */
 760                refs_found = dwim_ref("HEAD", 4, oid, &real_ref);
 761        else if (reflog_len)
 762                refs_found = dwim_log(str, len, oid, &real_ref);
 763        else
 764                refs_found = dwim_ref(str, len, oid, &real_ref);
 765
 766        if (!refs_found)
 767                return -1;
 768
 769        if (warn_ambiguous_refs && !(flags & GET_OID_QUIETLY) &&
 770            (refs_found > 1 ||
 771             !get_short_oid(str, len, &tmp_oid, GET_OID_QUIETLY)))
 772                warning(warn_msg, len, str);
 773
 774        if (reflog_len) {
 775                int nth, i;
 776                timestamp_t at_time;
 777                timestamp_t co_time;
 778                int co_tz, co_cnt;
 779
 780                /* Is it asking for N-th entry, or approxidate? */
 781                for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 782                        char ch = str[at+2+i];
 783                        if ('0' <= ch && ch <= '9')
 784                                nth = nth * 10 + ch - '0';
 785                        else
 786                                nth = -1;
 787                }
 788                if (100000000 <= nth) {
 789                        at_time = nth;
 790                        nth = -1;
 791                } else if (0 <= nth)
 792                        at_time = 0;
 793                else {
 794                        int errors = 0;
 795                        char *tmp = xstrndup(str + at + 2, reflog_len);
 796                        at_time = approxidate_careful(tmp, &errors);
 797                        free(tmp);
 798                        if (errors) {
 799                                free(real_ref);
 800                                return -1;
 801                        }
 802                }
 803                if (read_ref_at(real_ref, flags, at_time, nth, oid, NULL,
 804                                &co_time, &co_tz, &co_cnt)) {
 805                        if (!len) {
 806                                if (starts_with(real_ref, "refs/heads/")) {
 807                                        str = real_ref + 11;
 808                                        len = strlen(real_ref + 11);
 809                                } else {
 810                                        /* detached HEAD */
 811                                        str = "HEAD";
 812                                        len = 4;
 813                                }
 814                        }
 815                        if (at_time) {
 816                                if (!(flags & GET_OID_QUIETLY)) {
 817                                        warning("Log for '%.*s' only goes "
 818                                                "back to %s.", len, str,
 819                                                show_date(co_time, co_tz, DATE_MODE(RFC2822)));
 820                                }
 821                        } else {
 822                                if (flags & GET_OID_QUIETLY) {
 823                                        exit(128);
 824                                }
 825                                die("Log for '%.*s' only has %d entries.",
 826                                    len, str, co_cnt);
 827                        }
 828                }
 829        }
 830
 831        free(real_ref);
 832        return 0;
 833}
 834
 835static int get_parent(const char *name, int len,
 836                      struct object_id *result, int idx)
 837{
 838        struct object_id oid;
 839        int ret = get_oid_1(name, len, &oid, GET_OID_COMMITTISH);
 840        struct commit *commit;
 841        struct commit_list *p;
 842
 843        if (ret)
 844                return ret;
 845        commit = lookup_commit_reference(&oid);
 846        if (parse_commit(commit))
 847                return -1;
 848        if (!idx) {
 849                oidcpy(result, &commit->object.oid);
 850                return 0;
 851        }
 852        p = commit->parents;
 853        while (p) {
 854                if (!--idx) {
 855                        oidcpy(result, &p->item->object.oid);
 856                        return 0;
 857                }
 858                p = p->next;
 859        }
 860        return -1;
 861}
 862
 863static int get_nth_ancestor(const char *name, int len,
 864                            struct object_id *result, int generation)
 865{
 866        struct object_id oid;
 867        struct commit *commit;
 868        int ret;
 869
 870        ret = get_oid_1(name, len, &oid, GET_OID_COMMITTISH);
 871        if (ret)
 872                return ret;
 873        commit = lookup_commit_reference(&oid);
 874        if (!commit)
 875                return -1;
 876
 877        while (generation--) {
 878                if (parse_commit(commit) || !commit->parents)
 879                        return -1;
 880                commit = commit->parents->item;
 881        }
 882        oidcpy(result, &commit->object.oid);
 883        return 0;
 884}
 885
 886struct object *peel_to_type(const char *name, int namelen,
 887                            struct object *o, enum object_type expected_type)
 888{
 889        if (name && !namelen)
 890                namelen = strlen(name);
 891        while (1) {
 892                if (!o || (!o->parsed && !parse_object(&o->oid)))
 893                        return NULL;
 894                if (expected_type == OBJ_ANY || o->type == expected_type)
 895                        return o;
 896                if (o->type == OBJ_TAG)
 897                        o = ((struct tag*) o)->tagged;
 898                else if (o->type == OBJ_COMMIT)
 899                        o = &(((struct commit *) o)->tree->object);
 900                else {
 901                        if (name)
 902                                error("%.*s: expected %s type, but the object "
 903                                      "dereferences to %s type",
 904                                      namelen, name, typename(expected_type),
 905                                      typename(o->type));
 906                        return NULL;
 907                }
 908        }
 909}
 910
 911static int peel_onion(const char *name, int len, struct object_id *oid,
 912                      unsigned lookup_flags)
 913{
 914        struct object_id outer;
 915        const char *sp;
 916        unsigned int expected_type = 0;
 917        struct object *o;
 918
 919        /*
 920         * "ref^{type}" dereferences ref repeatedly until you cannot
 921         * dereference anymore, or you get an object of given type,
 922         * whichever comes first.  "ref^{}" means just dereference
 923         * tags until you get a non-tag.  "ref^0" is a shorthand for
 924         * "ref^{commit}".  "commit^{tree}" could be used to find the
 925         * top-level tree of the given commit.
 926         */
 927        if (len < 4 || name[len-1] != '}')
 928                return -1;
 929
 930        for (sp = name + len - 1; name <= sp; sp--) {
 931                int ch = *sp;
 932                if (ch == '{' && name < sp && sp[-1] == '^')
 933                        break;
 934        }
 935        if (sp <= name)
 936                return -1;
 937
 938        sp++; /* beginning of type name, or closing brace for empty */
 939        if (starts_with(sp, "commit}"))
 940                expected_type = OBJ_COMMIT;
 941        else if (starts_with(sp, "tag}"))
 942                expected_type = OBJ_TAG;
 943        else if (starts_with(sp, "tree}"))
 944                expected_type = OBJ_TREE;
 945        else if (starts_with(sp, "blob}"))
 946                expected_type = OBJ_BLOB;
 947        else if (starts_with(sp, "object}"))
 948                expected_type = OBJ_ANY;
 949        else if (sp[0] == '}')
 950                expected_type = OBJ_NONE;
 951        else if (sp[0] == '/')
 952                expected_type = OBJ_COMMIT;
 953        else
 954                return -1;
 955
 956        lookup_flags &= ~GET_OID_DISAMBIGUATORS;
 957        if (expected_type == OBJ_COMMIT)
 958                lookup_flags |= GET_OID_COMMITTISH;
 959        else if (expected_type == OBJ_TREE)
 960                lookup_flags |= GET_OID_TREEISH;
 961
 962        if (get_oid_1(name, sp - name - 2, &outer, lookup_flags))
 963                return -1;
 964
 965        o = parse_object(&outer);
 966        if (!o)
 967                return -1;
 968        if (!expected_type) {
 969                o = deref_tag(o, name, sp - name - 2);
 970                if (!o || (!o->parsed && !parse_object(&o->oid)))
 971                        return -1;
 972                oidcpy(oid, &o->oid);
 973                return 0;
 974        }
 975
 976        /*
 977         * At this point, the syntax look correct, so
 978         * if we do not get the needed object, we should
 979         * barf.
 980         */
 981        o = peel_to_type(name, len, o, expected_type);
 982        if (!o)
 983                return -1;
 984
 985        oidcpy(oid, &o->oid);
 986        if (sp[0] == '/') {
 987                /* "$commit^{/foo}" */
 988                char *prefix;
 989                int ret;
 990                struct commit_list *list = NULL;
 991
 992                /*
 993                 * $commit^{/}. Some regex implementation may reject.
 994                 * We don't need regex anyway. '' pattern always matches.
 995                 */
 996                if (sp[1] == '}')
 997                        return 0;
 998
 999                prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
1000                commit_list_insert((struct commit *)o, &list);
1001                ret = get_oid_oneline(prefix, oid, list);
1002                free(prefix);
1003                return ret;
1004        }
1005        return 0;
1006}
1007
1008static int get_describe_name(const char *name, int len, struct object_id *oid)
1009{
1010        const char *cp;
1011        unsigned flags = GET_OID_QUIETLY | GET_OID_COMMIT;
1012
1013        for (cp = name + len - 1; name + 2 <= cp; cp--) {
1014                char ch = *cp;
1015                if (!isxdigit(ch)) {
1016                        /* We must be looking at g in "SOMETHING-g"
1017                         * for it to be describe output.
1018                         */
1019                        if (ch == 'g' && cp[-1] == '-') {
1020                                cp++;
1021                                len -= cp - name;
1022                                return get_short_oid(cp, len, oid, flags);
1023                        }
1024                }
1025        }
1026        return -1;
1027}
1028
1029static int get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags)
1030{
1031        int ret, has_suffix;
1032        const char *cp;
1033
1034        /*
1035         * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
1036         */
1037        has_suffix = 0;
1038        for (cp = name + len - 1; name <= cp; cp--) {
1039                int ch = *cp;
1040                if ('0' <= ch && ch <= '9')
1041                        continue;
1042                if (ch == '~' || ch == '^')
1043                        has_suffix = ch;
1044                break;
1045        }
1046
1047        if (has_suffix) {
1048                int num = 0;
1049                int len1 = cp - name;
1050                cp++;
1051                while (cp < name + len)
1052                        num = num * 10 + *cp++ - '0';
1053                if (!num && len1 == len - 1)
1054                        num = 1;
1055                if (has_suffix == '^')
1056                        return get_parent(name, len1, oid, num);
1057                /* else if (has_suffix == '~') -- goes without saying */
1058                return get_nth_ancestor(name, len1, oid, num);
1059        }
1060
1061        ret = peel_onion(name, len, oid, lookup_flags);
1062        if (!ret)
1063                return 0;
1064
1065        ret = get_oid_basic(name, len, oid, lookup_flags);
1066        if (!ret)
1067                return 0;
1068
1069        /* It could be describe output that is "SOMETHING-gXXXX" */
1070        ret = get_describe_name(name, len, oid);
1071        if (!ret)
1072                return 0;
1073
1074        return get_short_oid(name, len, oid, lookup_flags);
1075}
1076
1077/*
1078 * This interprets names like ':/Initial revision of "git"' by searching
1079 * through history and returning the first commit whose message starts
1080 * the given regular expression.
1081 *
1082 * For negative-matching, prefix the pattern-part with '!-', like: ':/!-WIP'.
1083 *
1084 * For a literal '!' character at the beginning of a pattern, you have to repeat
1085 * that, like: ':/!!foo'
1086 *
1087 * For future extension, all other sequences beginning with ':/!' are reserved.
1088 */
1089
1090/* Remember to update object flag allocation in object.h */
1091#define ONELINE_SEEN (1u<<20)
1092
1093static int handle_one_ref(const char *path, const struct object_id *oid,
1094                          int flag, void *cb_data)
1095{
1096        struct commit_list **list = cb_data;
1097        struct object *object = parse_object(oid);
1098        if (!object)
1099                return 0;
1100        if (object->type == OBJ_TAG) {
1101                object = deref_tag(object, path, strlen(path));
1102                if (!object)
1103                        return 0;
1104        }
1105        if (object->type != OBJ_COMMIT)
1106                return 0;
1107        commit_list_insert((struct commit *)object, list);
1108        return 0;
1109}
1110
1111static int get_oid_oneline(const char *prefix, struct object_id *oid,
1112                            struct commit_list *list)
1113{
1114        struct commit_list *backup = NULL, *l;
1115        int found = 0;
1116        int negative = 0;
1117        regex_t regex;
1118
1119        if (prefix[0] == '!') {
1120                prefix++;
1121
1122                if (prefix[0] == '-') {
1123                        prefix++;
1124                        negative = 1;
1125                } else if (prefix[0] != '!') {
1126                        return -1;
1127                }
1128        }
1129
1130        if (regcomp(&regex, prefix, REG_EXTENDED))
1131                return -1;
1132
1133        for (l = list; l; l = l->next) {
1134                l->item->object.flags |= ONELINE_SEEN;
1135                commit_list_insert(l->item, &backup);
1136        }
1137        while (list) {
1138                const char *p, *buf;
1139                struct commit *commit;
1140                int matches;
1141
1142                commit = pop_most_recent_commit(&list, ONELINE_SEEN);
1143                if (!parse_object(&commit->object.oid))
1144                        continue;
1145                buf = get_commit_buffer(commit, NULL);
1146                p = strstr(buf, "\n\n");
1147                matches = negative ^ (p && !regexec(&regex, p + 2, 0, NULL, 0));
1148                unuse_commit_buffer(commit, buf);
1149
1150                if (matches) {
1151                        oidcpy(oid, &commit->object.oid);
1152                        found = 1;
1153                        break;
1154                }
1155        }
1156        regfree(&regex);
1157        free_commit_list(list);
1158        for (l = backup; l; l = l->next)
1159                clear_commit_marks(l->item, ONELINE_SEEN);
1160        free_commit_list(backup);
1161        return found ? 0 : -1;
1162}
1163
1164struct grab_nth_branch_switch_cbdata {
1165        int remaining;
1166        struct strbuf buf;
1167};
1168
1169static int grab_nth_branch_switch(struct object_id *ooid, struct object_id *noid,
1170                                  const char *email, timestamp_t timestamp, int tz,
1171                                  const char *message, void *cb_data)
1172{
1173        struct grab_nth_branch_switch_cbdata *cb = cb_data;
1174        const char *match = NULL, *target = NULL;
1175        size_t len;
1176
1177        if (skip_prefix(message, "checkout: moving from ", &match))
1178                target = strstr(match, " to ");
1179
1180        if (!match || !target)
1181                return 0;
1182        if (--(cb->remaining) == 0) {
1183                len = target - match;
1184                strbuf_reset(&cb->buf);
1185                strbuf_add(&cb->buf, match, len);
1186                return 1; /* we are done */
1187        }
1188        return 0;
1189}
1190
1191/*
1192 * Parse @{-N} syntax, return the number of characters parsed
1193 * if successful; otherwise signal an error with negative value.
1194 */
1195static int interpret_nth_prior_checkout(const char *name, int namelen,
1196                                        struct strbuf *buf)
1197{
1198        long nth;
1199        int retval;
1200        struct grab_nth_branch_switch_cbdata cb;
1201        const char *brace;
1202        char *num_end;
1203
1204        if (namelen < 4)
1205                return -1;
1206        if (name[0] != '@' || name[1] != '{' || name[2] != '-')
1207                return -1;
1208        brace = memchr(name, '}', namelen);
1209        if (!brace)
1210                return -1;
1211        nth = strtol(name + 3, &num_end, 10);
1212        if (num_end != brace)
1213                return -1;
1214        if (nth <= 0)
1215                return -1;
1216        cb.remaining = nth;
1217        strbuf_init(&cb.buf, 20);
1218
1219        retval = 0;
1220        if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
1221                strbuf_reset(buf);
1222                strbuf_addbuf(buf, &cb.buf);
1223                retval = brace - name + 1;
1224        }
1225
1226        strbuf_release(&cb.buf);
1227        return retval;
1228}
1229
1230int get_oid_mb(const char *name, struct object_id *oid)
1231{
1232        struct commit *one, *two;
1233        struct commit_list *mbs;
1234        struct object_id oid_tmp;
1235        const char *dots;
1236        int st;
1237
1238        dots = strstr(name, "...");
1239        if (!dots)
1240                return get_oid(name, oid);
1241        if (dots == name)
1242                st = get_oid("HEAD", &oid_tmp);
1243        else {
1244                struct strbuf sb;
1245                strbuf_init(&sb, dots - name);
1246                strbuf_add(&sb, name, dots - name);
1247                st = get_oid_committish(sb.buf, &oid_tmp);
1248                strbuf_release(&sb);
1249        }
1250        if (st)
1251                return st;
1252        one = lookup_commit_reference_gently(&oid_tmp, 0);
1253        if (!one)
1254                return -1;
1255
1256        if (get_oid_committish(dots[3] ? (dots + 3) : "HEAD", &oid_tmp))
1257                return -1;
1258        two = lookup_commit_reference_gently(&oid_tmp, 0);
1259        if (!two)
1260                return -1;
1261        mbs = get_merge_bases(one, two);
1262        if (!mbs || mbs->next)
1263                st = -1;
1264        else {
1265                st = 0;
1266                oidcpy(oid, &mbs->item->object.oid);
1267        }
1268        free_commit_list(mbs);
1269        return st;
1270}
1271
1272/* parse @something syntax, when 'something' is not {.*} */
1273static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
1274{
1275        const char *next;
1276
1277        if (len || name[1] == '{')
1278                return -1;
1279
1280        /* make sure it's a single @, or @@{.*}, not @foo */
1281        next = memchr(name + len + 1, '@', namelen - len - 1);
1282        if (next && next[1] != '{')
1283                return -1;
1284        if (!next)
1285                next = name + namelen;
1286        if (next != name + 1)
1287                return -1;
1288
1289        strbuf_reset(buf);
1290        strbuf_add(buf, "HEAD", 4);
1291        return 1;
1292}
1293
1294static int reinterpret(const char *name, int namelen, int len,
1295                       struct strbuf *buf, unsigned allowed)
1296{
1297        /* we have extra data, which might need further processing */
1298        struct strbuf tmp = STRBUF_INIT;
1299        int used = buf->len;
1300        int ret;
1301
1302        strbuf_add(buf, name + len, namelen - len);
1303        ret = interpret_branch_name(buf->buf, buf->len, &tmp, allowed);
1304        /* that data was not interpreted, remove our cruft */
1305        if (ret < 0) {
1306                strbuf_setlen(buf, used);
1307                return len;
1308        }
1309        strbuf_reset(buf);
1310        strbuf_addbuf(buf, &tmp);
1311        strbuf_release(&tmp);
1312        /* tweak for size of {-N} versus expanded ref name */
1313        return ret - used + len;
1314}
1315
1316static void set_shortened_ref(struct strbuf *buf, const char *ref)
1317{
1318        char *s = shorten_unambiguous_ref(ref, 0);
1319        strbuf_reset(buf);
1320        strbuf_addstr(buf, s);
1321        free(s);
1322}
1323
1324static int branch_interpret_allowed(const char *refname, unsigned allowed)
1325{
1326        if (!allowed)
1327                return 1;
1328
1329        if ((allowed & INTERPRET_BRANCH_LOCAL) &&
1330            starts_with(refname, "refs/heads/"))
1331                return 1;
1332        if ((allowed & INTERPRET_BRANCH_REMOTE) &&
1333            starts_with(refname, "refs/remotes/"))
1334                return 1;
1335
1336        return 0;
1337}
1338
1339static int interpret_branch_mark(const char *name, int namelen,
1340                                 int at, struct strbuf *buf,
1341                                 int (*get_mark)(const char *, int),
1342                                 const char *(*get_data)(struct branch *,
1343                                                         struct strbuf *),
1344                                 unsigned allowed)
1345{
1346        int len;
1347        struct branch *branch;
1348        struct strbuf err = STRBUF_INIT;
1349        const char *value;
1350
1351        len = get_mark(name + at, namelen - at);
1352        if (!len)
1353                return -1;
1354
1355        if (memchr(name, ':', at))
1356                return -1;
1357
1358        if (at) {
1359                char *name_str = xmemdupz(name, at);
1360                branch = branch_get(name_str);
1361                free(name_str);
1362        } else
1363                branch = branch_get(NULL);
1364
1365        value = get_data(branch, &err);
1366        if (!value)
1367                die("%s", err.buf);
1368
1369        if (!branch_interpret_allowed(value, allowed))
1370                return -1;
1371
1372        set_shortened_ref(buf, value);
1373        return len + at;
1374}
1375
1376int interpret_branch_name(const char *name, int namelen, struct strbuf *buf,
1377                          unsigned allowed)
1378{
1379        char *at;
1380        const char *start;
1381        int len;
1382
1383        if (!namelen)
1384                namelen = strlen(name);
1385
1386        if (!allowed || (allowed & INTERPRET_BRANCH_LOCAL)) {
1387                len = interpret_nth_prior_checkout(name, namelen, buf);
1388                if (!len) {
1389                        return len; /* syntax Ok, not enough switches */
1390                } else if (len > 0) {
1391                        if (len == namelen)
1392                                return len; /* consumed all */
1393                        else
1394                                return reinterpret(name, namelen, len, buf, allowed);
1395                }
1396        }
1397
1398        for (start = name;
1399             (at = memchr(start, '@', namelen - (start - name)));
1400             start = at + 1) {
1401
1402                if (!allowed || (allowed & INTERPRET_BRANCH_HEAD)) {
1403                        len = interpret_empty_at(name, namelen, at - name, buf);
1404                        if (len > 0)
1405                                return reinterpret(name, namelen, len, buf,
1406                                                   allowed);
1407                }
1408
1409                len = interpret_branch_mark(name, namelen, at - name, buf,
1410                                            upstream_mark, branch_get_upstream,
1411                                            allowed);
1412                if (len > 0)
1413                        return len;
1414
1415                len = interpret_branch_mark(name, namelen, at - name, buf,
1416                                            push_mark, branch_get_push,
1417                                            allowed);
1418                if (len > 0)
1419                        return len;
1420        }
1421
1422        return -1;
1423}
1424
1425void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed)
1426{
1427        int len = strlen(name);
1428        int used = interpret_branch_name(name, len, sb, allowed);
1429
1430        if (used < 0)
1431                used = 0;
1432        strbuf_add(sb, name + used, len - used);
1433}
1434
1435int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1436{
1437        if (startup_info->have_repository)
1438                strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL);
1439        else
1440                strbuf_addstr(sb, name);
1441
1442        /*
1443         * This splice must be done even if we end up rejecting the
1444         * name; builtin/branch.c::copy_or_rename_branch() still wants
1445         * to see what the name expanded to so that "branch -m" can be
1446         * used as a tool to correct earlier mistakes.
1447         */
1448        strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1449
1450        if (*name == '-' ||
1451            !strcmp(sb->buf, "refs/heads/HEAD"))
1452                return -1;
1453
1454        return check_refname_format(sb->buf, 0);
1455}
1456
1457/*
1458 * This is like "get_oid_basic()", except it allows "object ID expressions",
1459 * notably "xyz^" for "parent of xyz"
1460 */
1461int get_oid(const char *name, struct object_id *oid)
1462{
1463        struct object_context unused;
1464        return get_oid_with_context(name, 0, oid, &unused);
1465}
1466
1467
1468/*
1469 * Many callers know that the user meant to name a commit-ish by
1470 * syntactical positions where the object name appears.  Calling this
1471 * function allows the machinery to disambiguate shorter-than-unique
1472 * abbreviated object names between commit-ish and others.
1473 *
1474 * Note that this does NOT error out when the named object is not a
1475 * commit-ish. It is merely to give a hint to the disambiguation
1476 * machinery.
1477 */
1478int get_oid_committish(const char *name, struct object_id *oid)
1479{
1480        struct object_context unused;
1481        return get_oid_with_context(name, GET_OID_COMMITTISH,
1482                                    oid, &unused);
1483}
1484
1485int get_oid_treeish(const char *name, struct object_id *oid)
1486{
1487        struct object_context unused;
1488        return get_oid_with_context(name, GET_OID_TREEISH,
1489                                    oid, &unused);
1490}
1491
1492int get_oid_commit(const char *name, struct object_id *oid)
1493{
1494        struct object_context unused;
1495        return get_oid_with_context(name, GET_OID_COMMIT,
1496                                    oid, &unused);
1497}
1498
1499int get_oid_tree(const char *name, struct object_id *oid)
1500{
1501        struct object_context unused;
1502        return get_oid_with_context(name, GET_OID_TREE,
1503                                    oid, &unused);
1504}
1505
1506int get_oid_blob(const char *name, struct object_id *oid)
1507{
1508        struct object_context unused;
1509        return get_oid_with_context(name, GET_OID_BLOB,
1510                                    oid, &unused);
1511}
1512
1513/* Must be called only when object_name:filename doesn't exist. */
1514static void diagnose_invalid_oid_path(const char *prefix,
1515                                      const char *filename,
1516                                      const struct object_id *tree_oid,
1517                                      const char *object_name,
1518                                      int object_name_len)
1519{
1520        struct object_id oid;
1521        unsigned mode;
1522
1523        if (!prefix)
1524                prefix = "";
1525
1526        if (file_exists(filename))
1527                die("Path '%s' exists on disk, but not in '%.*s'.",
1528                    filename, object_name_len, object_name);
1529        if (is_missing_file_error(errno)) {
1530                char *fullname = xstrfmt("%s%s", prefix, filename);
1531
1532                if (!get_tree_entry(tree_oid->hash, fullname,
1533                                    oid.hash, &mode)) {
1534                        die("Path '%s' exists, but not '%s'.\n"
1535                            "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1536                            fullname,
1537                            filename,
1538                            object_name_len, object_name,
1539                            fullname,
1540                            object_name_len, object_name,
1541                            filename);
1542                }
1543                die("Path '%s' does not exist in '%.*s'",
1544                    filename, object_name_len, object_name);
1545        }
1546}
1547
1548/* Must be called only when :stage:filename doesn't exist. */
1549static void diagnose_invalid_index_path(int stage,
1550                                        const char *prefix,
1551                                        const char *filename)
1552{
1553        const struct cache_entry *ce;
1554        int pos;
1555        unsigned namelen = strlen(filename);
1556        struct strbuf fullname = STRBUF_INIT;
1557
1558        if (!prefix)
1559                prefix = "";
1560
1561        /* Wrong stage number? */
1562        pos = cache_name_pos(filename, namelen);
1563        if (pos < 0)
1564                pos = -pos - 1;
1565        if (pos < active_nr) {
1566                ce = active_cache[pos];
1567                if (ce_namelen(ce) == namelen &&
1568                    !memcmp(ce->name, filename, namelen))
1569                        die("Path '%s' is in the index, but not at stage %d.\n"
1570                            "Did you mean ':%d:%s'?",
1571                            filename, stage,
1572                            ce_stage(ce), filename);
1573        }
1574
1575        /* Confusion between relative and absolute filenames? */
1576        strbuf_addstr(&fullname, prefix);
1577        strbuf_addstr(&fullname, filename);
1578        pos = cache_name_pos(fullname.buf, fullname.len);
1579        if (pos < 0)
1580                pos = -pos - 1;
1581        if (pos < active_nr) {
1582                ce = active_cache[pos];
1583                if (ce_namelen(ce) == fullname.len &&
1584                    !memcmp(ce->name, fullname.buf, fullname.len))
1585                        die("Path '%s' is in the index, but not '%s'.\n"
1586                            "Did you mean ':%d:%s' aka ':%d:./%s'?",
1587                            fullname.buf, filename,
1588                            ce_stage(ce), fullname.buf,
1589                            ce_stage(ce), filename);
1590        }
1591
1592        if (file_exists(filename))
1593                die("Path '%s' exists on disk, but not in the index.", filename);
1594        if (is_missing_file_error(errno))
1595                die("Path '%s' does not exist (neither on disk nor in the index).",
1596                    filename);
1597
1598        strbuf_release(&fullname);
1599}
1600
1601
1602static char *resolve_relative_path(const char *rel)
1603{
1604        if (!starts_with(rel, "./") && !starts_with(rel, "../"))
1605                return NULL;
1606
1607        if (!is_inside_work_tree())
1608                die("relative path syntax can't be used outside working tree.");
1609
1610        /* die() inside prefix_path() if resolved path is outside worktree */
1611        return prefix_path(startup_info->prefix,
1612                           startup_info->prefix ? strlen(startup_info->prefix) : 0,
1613                           rel);
1614}
1615
1616static int get_oid_with_context_1(const char *name,
1617                                  unsigned flags,
1618                                  const char *prefix,
1619                                  struct object_id *oid,
1620                                  struct object_context *oc)
1621{
1622        int ret, bracket_depth;
1623        int namelen = strlen(name);
1624        const char *cp;
1625        int only_to_die = flags & GET_OID_ONLY_TO_DIE;
1626
1627        if (only_to_die)
1628                flags |= GET_OID_QUIETLY;
1629
1630        memset(oc, 0, sizeof(*oc));
1631        oc->mode = S_IFINVALID;
1632        strbuf_init(&oc->symlink_path, 0);
1633        ret = get_oid_1(name, namelen, oid, flags);
1634        if (!ret)
1635                return ret;
1636        /*
1637         * sha1:path --> object name of path in ent sha1
1638         * :path -> object name of absolute path in index
1639         * :./path -> object name of path relative to cwd in index
1640         * :[0-3]:path -> object name of path in index at stage
1641         * :/foo -> recent commit matching foo
1642         */
1643        if (name[0] == ':') {
1644                int stage = 0;
1645                const struct cache_entry *ce;
1646                char *new_path = NULL;
1647                int pos;
1648                if (!only_to_die && namelen > 2 && name[1] == '/') {
1649                        struct commit_list *list = NULL;
1650
1651                        for_each_ref(handle_one_ref, &list);
1652                        commit_list_sort_by_date(&list);
1653                        return get_oid_oneline(name + 2, oid, list);
1654                }
1655                if (namelen < 3 ||
1656                    name[2] != ':' ||
1657                    name[1] < '0' || '3' < name[1])
1658                        cp = name + 1;
1659                else {
1660                        stage = name[1] - '0';
1661                        cp = name + 3;
1662                }
1663                new_path = resolve_relative_path(cp);
1664                if (!new_path) {
1665                        namelen = namelen - (cp - name);
1666                } else {
1667                        cp = new_path;
1668                        namelen = strlen(cp);
1669                }
1670
1671                if (flags & GET_OID_RECORD_PATH)
1672                        oc->path = xstrdup(cp);
1673
1674                if (!active_cache)
1675                        read_cache();
1676                pos = cache_name_pos(cp, namelen);
1677                if (pos < 0)
1678                        pos = -pos - 1;
1679                while (pos < active_nr) {
1680                        ce = active_cache[pos];
1681                        if (ce_namelen(ce) != namelen ||
1682                            memcmp(ce->name, cp, namelen))
1683                                break;
1684                        if (ce_stage(ce) == stage) {
1685                                oidcpy(oid, &ce->oid);
1686                                oc->mode = ce->ce_mode;
1687                                free(new_path);
1688                                return 0;
1689                        }
1690                        pos++;
1691                }
1692                if (only_to_die && name[1] && name[1] != '/')
1693                        diagnose_invalid_index_path(stage, prefix, cp);
1694                free(new_path);
1695                return -1;
1696        }
1697        for (cp = name, bracket_depth = 0; *cp; cp++) {
1698                if (*cp == '{')
1699                        bracket_depth++;
1700                else if (bracket_depth && *cp == '}')
1701                        bracket_depth--;
1702                else if (!bracket_depth && *cp == ':')
1703                        break;
1704        }
1705        if (*cp == ':') {
1706                struct object_id tree_oid;
1707                int len = cp - name;
1708                unsigned sub_flags = flags;
1709
1710                sub_flags &= ~GET_OID_DISAMBIGUATORS;
1711                sub_flags |= GET_OID_TREEISH;
1712
1713                if (!get_oid_1(name, len, &tree_oid, sub_flags)) {
1714                        const char *filename = cp+1;
1715                        char *new_filename = NULL;
1716
1717                        new_filename = resolve_relative_path(filename);
1718                        if (new_filename)
1719                                filename = new_filename;
1720                        if (flags & GET_OID_FOLLOW_SYMLINKS) {
1721                                ret = get_tree_entry_follow_symlinks(tree_oid.hash,
1722                                        filename, oid->hash, &oc->symlink_path,
1723                                        &oc->mode);
1724                        } else {
1725                                ret = get_tree_entry(tree_oid.hash, filename,
1726                                                     oid->hash, &oc->mode);
1727                                if (ret && only_to_die) {
1728                                        diagnose_invalid_oid_path(prefix,
1729                                                                   filename,
1730                                                                   &tree_oid,
1731                                                                   name, len);
1732                                }
1733                        }
1734                        hashcpy(oc->tree, tree_oid.hash);
1735                        if (flags & GET_OID_RECORD_PATH)
1736                                oc->path = xstrdup(filename);
1737
1738                        free(new_filename);
1739                        return ret;
1740                } else {
1741                        if (only_to_die)
1742                                die("Invalid object name '%.*s'.", len, name);
1743                }
1744        }
1745        return ret;
1746}
1747
1748/*
1749 * Call this function when you know "name" given by the end user must
1750 * name an object but it doesn't; the function _may_ die with a better
1751 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1752 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1753 * you have a chance to diagnose the error further.
1754 */
1755void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1756{
1757        struct object_context oc;
1758        struct object_id oid;
1759        get_oid_with_context_1(name, GET_OID_ONLY_TO_DIE, prefix, &oid, &oc);
1760}
1761
1762int get_oid_with_context(const char *str, unsigned flags, struct object_id *oid, struct object_context *oc)
1763{
1764        if (flags & GET_OID_FOLLOW_SYMLINKS && flags & GET_OID_ONLY_TO_DIE)
1765                die("BUG: incompatible flags for get_sha1_with_context");
1766        return get_oid_with_context_1(str, flags, NULL, oid, oc);
1767}