Andrew's git / gitweb.git / builtin/grep.c
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builtin / grep.con commit commit: teach --amend to carry forward extra headers (ed7a42a)
   1/*
   2 * Builtin "git grep"
   3 *
   4 * Copyright (c) 2006 Junio C Hamano
   5 */
   6#include "cache.h"
   7#include "blob.h"
   8#include "tree.h"
   9#include "commit.h"
  10#include "tag.h"
  11#include "tree-walk.h"
  12#include "builtin.h"
  13#include "parse-options.h"
  14#include "string-list.h"
  15#include "run-command.h"
  16#include "userdiff.h"
  17#include "grep.h"
  18#include "quote.h"
  19#include "dir.h"
  20#include "thread-utils.h"
  21
  22static char const * const grep_usage[] = {
  23        "git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]",
  24        NULL
  25};
  26
  27static int use_threads = 1;
  28
  29#ifndef NO_PTHREADS
  30#define THREADS 8
  31static pthread_t threads[THREADS];
  32
  33static void *load_sha1(const unsigned char *sha1, unsigned long *size,
  34                       const char *name);
  35static void *load_file(const char *filename, size_t *sz);
  36
  37enum work_type {WORK_SHA1, WORK_FILE};
  38
  39/* We use one producer thread and THREADS consumer
  40 * threads. The producer adds struct work_items to 'todo' and the
  41 * consumers pick work items from the same array.
  42 */
  43struct work_item {
  44        enum work_type type;
  45        char *name;
  46
  47        /* if type == WORK_SHA1, then 'identifier' is a SHA1,
  48         * otherwise type == WORK_FILE, and 'identifier' is a NUL
  49         * terminated filename.
  50         */
  51        void *identifier;
  52        char done;
  53        struct strbuf out;
  54};
  55
  56/* In the range [todo_done, todo_start) in 'todo' we have work_items
  57 * that have been or are processed by a consumer thread. We haven't
  58 * written the result for these to stdout yet.
  59 *
  60 * The work_items in [todo_start, todo_end) are waiting to be picked
  61 * up by a consumer thread.
  62 *
  63 * The ranges are modulo TODO_SIZE.
  64 */
  65#define TODO_SIZE 128
  66static struct work_item todo[TODO_SIZE];
  67static int todo_start;
  68static int todo_end;
  69static int todo_done;
  70
  71/* Has all work items been added? */
  72static int all_work_added;
  73
  74/* This lock protects all the variables above. */
  75static pthread_mutex_t grep_mutex;
  76
  77/* Used to serialize calls to read_sha1_file. */
  78static pthread_mutex_t read_sha1_mutex;
  79
  80#define grep_lock() pthread_mutex_lock(&grep_mutex)
  81#define grep_unlock() pthread_mutex_unlock(&grep_mutex)
  82#define read_sha1_lock() pthread_mutex_lock(&read_sha1_mutex)
  83#define read_sha1_unlock() pthread_mutex_unlock(&read_sha1_mutex)
  84
  85/* Signalled when a new work_item is added to todo. */
  86static pthread_cond_t cond_add;
  87
  88/* Signalled when the result from one work_item is written to
  89 * stdout.
  90 */
  91static pthread_cond_t cond_write;
  92
  93/* Signalled when we are finished with everything. */
  94static pthread_cond_t cond_result;
  95
  96static int skip_first_line;
  97
  98static void add_work(enum work_type type, char *name, void *id)
  99{
 100        grep_lock();
 101
 102        while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
 103                pthread_cond_wait(&cond_write, &grep_mutex);
 104        }
 105
 106        todo[todo_end].type = type;
 107        todo[todo_end].name = name;
 108        todo[todo_end].identifier = id;
 109        todo[todo_end].done = 0;
 110        strbuf_reset(&todo[todo_end].out);
 111        todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 112
 113        pthread_cond_signal(&cond_add);
 114        grep_unlock();
 115}
 116
 117static struct work_item *get_work(void)
 118{
 119        struct work_item *ret;
 120
 121        grep_lock();
 122        while (todo_start == todo_end && !all_work_added) {
 123                pthread_cond_wait(&cond_add, &grep_mutex);
 124        }
 125
 126        if (todo_start == todo_end && all_work_added) {
 127                ret = NULL;
 128        } else {
 129                ret = &todo[todo_start];
 130                todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 131        }
 132        grep_unlock();
 133        return ret;
 134}
 135
 136static void grep_sha1_async(struct grep_opt *opt, char *name,
 137                            const unsigned char *sha1)
 138{
 139        unsigned char *s;
 140        s = xmalloc(20);
 141        memcpy(s, sha1, 20);
 142        add_work(WORK_SHA1, name, s);
 143}
 144
 145static void grep_file_async(struct grep_opt *opt, char *name,
 146                            const char *filename)
 147{
 148        add_work(WORK_FILE, name, xstrdup(filename));
 149}
 150
 151static void work_done(struct work_item *w)
 152{
 153        int old_done;
 154
 155        grep_lock();
 156        w->done = 1;
 157        old_done = todo_done;
 158        for(; todo[todo_done].done && todo_done != todo_start;
 159            todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 160                w = &todo[todo_done];
 161                if (w->out.len) {
 162                        const char *p = w->out.buf;
 163                        size_t len = w->out.len;
 164
 165                        /* Skip the leading hunk mark of the first file. */
 166                        if (skip_first_line) {
 167                                while (len) {
 168                                        len--;
 169                                        if (*p++ == '\n')
 170                                                break;
 171                                }
 172                                skip_first_line = 0;
 173                        }
 174
 175                        write_or_die(1, p, len);
 176                }
 177                free(w->name);
 178                free(w->identifier);
 179        }
 180
 181        if (old_done != todo_done)
 182                pthread_cond_signal(&cond_write);
 183
 184        if (all_work_added && todo_done == todo_end)
 185                pthread_cond_signal(&cond_result);
 186
 187        grep_unlock();
 188}
 189
 190static void *run(void *arg)
 191{
 192        int hit = 0;
 193        struct grep_opt *opt = arg;
 194
 195        while (1) {
 196                struct work_item *w = get_work();
 197                if (!w)
 198                        break;
 199
 200                opt->output_priv = w;
 201                if (w->type == WORK_SHA1) {
 202                        unsigned long sz;
 203                        void* data = load_sha1(w->identifier, &sz, w->name);
 204
 205                        if (data) {
 206                                hit |= grep_buffer(opt, w->name, data, sz);
 207                                free(data);
 208                        }
 209                } else if (w->type == WORK_FILE) {
 210                        size_t sz;
 211                        void* data = load_file(w->identifier, &sz);
 212                        if (data) {
 213                                hit |= grep_buffer(opt, w->name, data, sz);
 214                                free(data);
 215                        }
 216                } else {
 217                        assert(0);
 218                }
 219
 220                work_done(w);
 221        }
 222        free_grep_patterns(arg);
 223        free(arg);
 224
 225        return (void*) (intptr_t) hit;
 226}
 227
 228static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 229{
 230        struct work_item *w = opt->output_priv;
 231        strbuf_add(&w->out, buf, size);
 232}
 233
 234static void start_threads(struct grep_opt *opt)
 235{
 236        int i;
 237
 238        pthread_mutex_init(&grep_mutex, NULL);
 239        pthread_mutex_init(&read_sha1_mutex, NULL);
 240        pthread_cond_init(&cond_add, NULL);
 241        pthread_cond_init(&cond_write, NULL);
 242        pthread_cond_init(&cond_result, NULL);
 243
 244        for (i = 0; i < ARRAY_SIZE(todo); i++) {
 245                strbuf_init(&todo[i].out, 0);
 246        }
 247
 248        for (i = 0; i < ARRAY_SIZE(threads); i++) {
 249                int err;
 250                struct grep_opt *o = grep_opt_dup(opt);
 251                o->output = strbuf_out;
 252                compile_grep_patterns(o);
 253                err = pthread_create(&threads[i], NULL, run, o);
 254
 255                if (err)
 256                        die(_("grep: failed to create thread: %s"),
 257                            strerror(err));
 258        }
 259}
 260
 261static int wait_all(void)
 262{
 263        int hit = 0;
 264        int i;
 265
 266        grep_lock();
 267        all_work_added = 1;
 268
 269        /* Wait until all work is done. */
 270        while (todo_done != todo_end)
 271                pthread_cond_wait(&cond_result, &grep_mutex);
 272
 273        /* Wake up all the consumer threads so they can see that there
 274         * is no more work to do.
 275         */
 276        pthread_cond_broadcast(&cond_add);
 277        grep_unlock();
 278
 279        for (i = 0; i < ARRAY_SIZE(threads); i++) {
 280                void *h;
 281                pthread_join(threads[i], &h);
 282                hit |= (int) (intptr_t) h;
 283        }
 284
 285        pthread_mutex_destroy(&grep_mutex);
 286        pthread_mutex_destroy(&read_sha1_mutex);
 287        pthread_cond_destroy(&cond_add);
 288        pthread_cond_destroy(&cond_write);
 289        pthread_cond_destroy(&cond_result);
 290
 291        return hit;
 292}
 293#else /* !NO_PTHREADS */
 294#define read_sha1_lock()
 295#define read_sha1_unlock()
 296
 297static int wait_all(void)
 298{
 299        return 0;
 300}
 301#endif
 302
 303static int grep_config(const char *var, const char *value, void *cb)
 304{
 305        struct grep_opt *opt = cb;
 306        char *color = NULL;
 307
 308        switch (userdiff_config(var, value)) {
 309        case 0: break;
 310        case -1: return -1;
 311        default: return 0;
 312        }
 313
 314        if (!strcmp(var, "grep.extendedregexp")) {
 315                if (git_config_bool(var, value))
 316                        opt->regflags |= REG_EXTENDED;
 317                else
 318                        opt->regflags &= ~REG_EXTENDED;
 319                return 0;
 320        }
 321
 322        if (!strcmp(var, "grep.linenumber")) {
 323                opt->linenum = git_config_bool(var, value);
 324                return 0;
 325        }
 326
 327        if (!strcmp(var, "color.grep"))
 328                opt->color = git_config_colorbool(var, value);
 329        else if (!strcmp(var, "color.grep.context"))
 330                color = opt->color_context;
 331        else if (!strcmp(var, "color.grep.filename"))
 332                color = opt->color_filename;
 333        else if (!strcmp(var, "color.grep.function"))
 334                color = opt->color_function;
 335        else if (!strcmp(var, "color.grep.linenumber"))
 336                color = opt->color_lineno;
 337        else if (!strcmp(var, "color.grep.match"))
 338                color = opt->color_match;
 339        else if (!strcmp(var, "color.grep.selected"))
 340                color = opt->color_selected;
 341        else if (!strcmp(var, "color.grep.separator"))
 342                color = opt->color_sep;
 343        else
 344                return git_color_default_config(var, value, cb);
 345        if (color) {
 346                if (!value)
 347                        return config_error_nonbool(var);
 348                color_parse(value, var, color);
 349        }
 350        return 0;
 351}
 352
 353static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 354{
 355        void *data;
 356
 357        if (use_threads) {
 358                read_sha1_lock();
 359                data = read_sha1_file(sha1, type, size);
 360                read_sha1_unlock();
 361        } else {
 362                data = read_sha1_file(sha1, type, size);
 363        }
 364        return data;
 365}
 366
 367static void *load_sha1(const unsigned char *sha1, unsigned long *size,
 368                       const char *name)
 369{
 370        enum object_type type;
 371        void *data = lock_and_read_sha1_file(sha1, &type, size);
 372
 373        if (!data)
 374                error(_("'%s': unable to read %s"), name, sha1_to_hex(sha1));
 375
 376        return data;
 377}
 378
 379static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 380                     const char *filename, int tree_name_len)
 381{
 382        struct strbuf pathbuf = STRBUF_INIT;
 383        char *name;
 384
 385        if (opt->relative && opt->prefix_length) {
 386                quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 387                                    opt->prefix);
 388                strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 389        } else {
 390                strbuf_addstr(&pathbuf, filename);
 391        }
 392
 393        name = strbuf_detach(&pathbuf, NULL);
 394
 395#ifndef NO_PTHREADS
 396        if (use_threads) {
 397                grep_sha1_async(opt, name, sha1);
 398                return 0;
 399        } else
 400#endif
 401        {
 402                int hit;
 403                unsigned long sz;
 404                void *data = load_sha1(sha1, &sz, name);
 405                if (!data)
 406                        hit = 0;
 407                else
 408                        hit = grep_buffer(opt, name, data, sz);
 409
 410                free(data);
 411                free(name);
 412                return hit;
 413        }
 414}
 415
 416static void *load_file(const char *filename, size_t *sz)
 417{
 418        struct stat st;
 419        char *data;
 420        int i;
 421
 422        if (lstat(filename, &st) < 0) {
 423        err_ret:
 424                if (errno != ENOENT)
 425                        error(_("'%s': %s"), filename, strerror(errno));
 426                return NULL;
 427        }
 428        if (!S_ISREG(st.st_mode))
 429                return NULL;
 430        *sz = xsize_t(st.st_size);
 431        i = open(filename, O_RDONLY);
 432        if (i < 0)
 433                goto err_ret;
 434        data = xmalloc(*sz + 1);
 435        if (st.st_size != read_in_full(i, data, *sz)) {
 436                error(_("'%s': short read %s"), filename, strerror(errno));
 437                close(i);
 438                free(data);
 439                return NULL;
 440        }
 441        close(i);
 442        data[*sz] = 0;
 443        return data;
 444}
 445
 446static int grep_file(struct grep_opt *opt, const char *filename)
 447{
 448        struct strbuf buf = STRBUF_INIT;
 449        char *name;
 450
 451        if (opt->relative && opt->prefix_length)
 452                quote_path_relative(filename, -1, &buf, opt->prefix);
 453        else
 454                strbuf_addstr(&buf, filename);
 455        name = strbuf_detach(&buf, NULL);
 456
 457#ifndef NO_PTHREADS
 458        if (use_threads) {
 459                grep_file_async(opt, name, filename);
 460                return 0;
 461        } else
 462#endif
 463        {
 464                int hit;
 465                size_t sz;
 466                void *data = load_file(filename, &sz);
 467                if (!data)
 468                        hit = 0;
 469                else
 470                        hit = grep_buffer(opt, name, data, sz);
 471
 472                free(data);
 473                free(name);
 474                return hit;
 475        }
 476}
 477
 478static void append_path(struct grep_opt *opt, const void *data, size_t len)
 479{
 480        struct string_list *path_list = opt->output_priv;
 481
 482        if (len == 1 && *(const char *)data == '\0')
 483                return;
 484        string_list_append(path_list, xstrndup(data, len));
 485}
 486
 487static void run_pager(struct grep_opt *opt, const char *prefix)
 488{
 489        struct string_list *path_list = opt->output_priv;
 490        const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 491        int i, status;
 492
 493        for (i = 0; i < path_list->nr; i++)
 494                argv[i] = path_list->items[i].string;
 495        argv[path_list->nr] = NULL;
 496
 497        if (prefix && chdir(prefix))
 498                die(_("Failed to chdir: %s"), prefix);
 499        status = run_command_v_opt(argv, RUN_USING_SHELL);
 500        if (status)
 501                exit(status);
 502        free(argv);
 503}
 504
 505static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 506{
 507        int hit = 0;
 508        int nr;
 509        read_cache();
 510
 511        for (nr = 0; nr < active_nr; nr++) {
 512                struct cache_entry *ce = active_cache[nr];
 513                if (!S_ISREG(ce->ce_mode))
 514                        continue;
 515                if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 516                        continue;
 517                /*
 518                 * If CE_VALID is on, we assume worktree file and its cache entry
 519                 * are identical, even if worktree file has been modified, so use
 520                 * cache version instead
 521                 */
 522                if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 523                        if (ce_stage(ce))
 524                                continue;
 525                        hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 526                }
 527                else
 528                        hit |= grep_file(opt, ce->name);
 529                if (ce_stage(ce)) {
 530                        do {
 531                                nr++;
 532                        } while (nr < active_nr &&
 533                                 !strcmp(ce->name, active_cache[nr]->name));
 534                        nr--; /* compensate for loop control */
 535                }
 536                if (hit && opt->status_only)
 537                        break;
 538        }
 539        return hit;
 540}
 541
 542static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 543                     struct tree_desc *tree, struct strbuf *base, int tn_len)
 544{
 545        int hit = 0, match = 0;
 546        struct name_entry entry;
 547        int old_baselen = base->len;
 548
 549        while (tree_entry(tree, &entry)) {
 550                int te_len = tree_entry_len(entry.path, entry.sha1);
 551
 552                if (match != 2) {
 553                        match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 554                        if (match < 0)
 555                                break;
 556                        if (match == 0)
 557                                continue;
 558                }
 559
 560                strbuf_add(base, entry.path, te_len);
 561
 562                if (S_ISREG(entry.mode)) {
 563                        hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 564                }
 565                else if (S_ISDIR(entry.mode)) {
 566                        enum object_type type;
 567                        struct tree_desc sub;
 568                        void *data;
 569                        unsigned long size;
 570
 571                        data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 572                        if (!data)
 573                                die(_("unable to read tree (%s)"),
 574                                    sha1_to_hex(entry.sha1));
 575
 576                        strbuf_addch(base, '/');
 577                        init_tree_desc(&sub, data, size);
 578                        hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 579                        free(data);
 580                }
 581                strbuf_setlen(base, old_baselen);
 582
 583                if (hit && opt->status_only)
 584                        break;
 585        }
 586        return hit;
 587}
 588
 589static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 590                       struct object *obj, const char *name)
 591{
 592        if (obj->type == OBJ_BLOB)
 593                return grep_sha1(opt, obj->sha1, name, 0);
 594        if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 595                struct tree_desc tree;
 596                void *data;
 597                unsigned long size;
 598                struct strbuf base;
 599                int hit, len;
 600
 601                read_sha1_lock();
 602                data = read_object_with_reference(obj->sha1, tree_type,
 603                                                  &size, NULL);
 604                read_sha1_unlock();
 605
 606                if (!data)
 607                        die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 608
 609                len = name ? strlen(name) : 0;
 610                strbuf_init(&base, PATH_MAX + len + 1);
 611                if (len) {
 612                        strbuf_add(&base, name, len);
 613                        strbuf_addch(&base, ':');
 614                }
 615                init_tree_desc(&tree, data, size);
 616                hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 617                strbuf_release(&base);
 618                free(data);
 619                return hit;
 620        }
 621        die(_("unable to grep from object of type %s"), typename(obj->type));
 622}
 623
 624static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 625                        const struct object_array *list)
 626{
 627        unsigned int i;
 628        int hit = 0;
 629        const unsigned int nr = list->nr;
 630
 631        for (i = 0; i < nr; i++) {
 632                struct object *real_obj;
 633                real_obj = deref_tag(list->objects[i].item, NULL, 0);
 634                if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 635                        hit = 1;
 636                        if (opt->status_only)
 637                                break;
 638                }
 639        }
 640        return hit;
 641}
 642
 643static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 644                          int exc_std)
 645{
 646        struct dir_struct dir;
 647        int i, hit = 0;
 648
 649        memset(&dir, 0, sizeof(dir));
 650        if (exc_std)
 651                setup_standard_excludes(&dir);
 652
 653        fill_directory(&dir, pathspec->raw);
 654        for (i = 0; i < dir.nr; i++) {
 655                const char *name = dir.entries[i]->name;
 656                int namelen = strlen(name);
 657                if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 658                        continue;
 659                hit |= grep_file(opt, dir.entries[i]->name);
 660                if (hit && opt->status_only)
 661                        break;
 662        }
 663        return hit;
 664}
 665
 666static int context_callback(const struct option *opt, const char *arg,
 667                            int unset)
 668{
 669        struct grep_opt *grep_opt = opt->value;
 670        int value;
 671        const char *endp;
 672
 673        if (unset) {
 674                grep_opt->pre_context = grep_opt->post_context = 0;
 675                return 0;
 676        }
 677        value = strtol(arg, (char **)&endp, 10);
 678        if (*endp) {
 679                return error(_("switch `%c' expects a numerical value"),
 680                             opt->short_name);
 681        }
 682        grep_opt->pre_context = grep_opt->post_context = value;
 683        return 0;
 684}
 685
 686static int file_callback(const struct option *opt, const char *arg, int unset)
 687{
 688        struct grep_opt *grep_opt = opt->value;
 689        int from_stdin = !strcmp(arg, "-");
 690        FILE *patterns;
 691        int lno = 0;
 692        struct strbuf sb = STRBUF_INIT;
 693
 694        patterns = from_stdin ? stdin : fopen(arg, "r");
 695        if (!patterns)
 696                die_errno(_("cannot open '%s'"), arg);
 697        while (strbuf_getline(&sb, patterns, '\n') == 0) {
 698                char *s;
 699                size_t len;
 700
 701                /* ignore empty line like grep does */
 702                if (sb.len == 0)
 703                        continue;
 704
 705                s = strbuf_detach(&sb, &len);
 706                append_grep_pat(grep_opt, s, len, arg, ++lno, GREP_PATTERN);
 707        }
 708        if (!from_stdin)
 709                fclose(patterns);
 710        strbuf_release(&sb);
 711        return 0;
 712}
 713
 714static int not_callback(const struct option *opt, const char *arg, int unset)
 715{
 716        struct grep_opt *grep_opt = opt->value;
 717        append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 718        return 0;
 719}
 720
 721static int and_callback(const struct option *opt, const char *arg, int unset)
 722{
 723        struct grep_opt *grep_opt = opt->value;
 724        append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 725        return 0;
 726}
 727
 728static int open_callback(const struct option *opt, const char *arg, int unset)
 729{
 730        struct grep_opt *grep_opt = opt->value;
 731        append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 732        return 0;
 733}
 734
 735static int close_callback(const struct option *opt, const char *arg, int unset)
 736{
 737        struct grep_opt *grep_opt = opt->value;
 738        append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 739        return 0;
 740}
 741
 742static int pattern_callback(const struct option *opt, const char *arg,
 743                            int unset)
 744{
 745        struct grep_opt *grep_opt = opt->value;
 746        append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 747        return 0;
 748}
 749
 750static int help_callback(const struct option *opt, const char *arg, int unset)
 751{
 752        return -1;
 753}
 754
 755int cmd_grep(int argc, const char **argv, const char *prefix)
 756{
 757        int hit = 0;
 758        int cached = 0, untracked = 0, opt_exclude = -1;
 759        int seen_dashdash = 0;
 760        int external_grep_allowed__ignored;
 761        const char *show_in_pager = NULL, *default_pager = "dummy";
 762        struct grep_opt opt;
 763        struct object_array list = OBJECT_ARRAY_INIT;
 764        const char **paths = NULL;
 765        struct pathspec pathspec;
 766        struct string_list path_list = STRING_LIST_INIT_NODUP;
 767        int i;
 768        int dummy;
 769        int use_index = 1;
 770        enum {
 771                pattern_type_unspecified = 0,
 772                pattern_type_bre,
 773                pattern_type_ere,
 774                pattern_type_fixed,
 775                pattern_type_pcre,
 776        };
 777        int pattern_type = pattern_type_unspecified;
 778
 779        struct option options[] = {
 780                OPT_BOOLEAN(0, "cached", &cached,
 781                        "search in index instead of in the work tree"),
 782                { OPTION_BOOLEAN, 0, "index", &use_index, NULL,
 783                        "finds in contents not managed by git",
 784                        PARSE_OPT_NOARG | PARSE_OPT_NEGHELP },
 785                OPT_BOOLEAN(0, "untracked", &untracked,
 786                        "search in both tracked and untracked files"),
 787                OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 788                            "search also in ignored files", 1),
 789                OPT_GROUP(""),
 790                OPT_BOOLEAN('v', "invert-match", &opt.invert,
 791                        "show non-matching lines"),
 792                OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 793                        "case insensitive matching"),
 794                OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 795                        "match patterns only at word boundaries"),
 796                OPT_SET_INT('a', "text", &opt.binary,
 797                        "process binary files as text", GREP_BINARY_TEXT),
 798                OPT_SET_INT('I', NULL, &opt.binary,
 799                        "don't match patterns in binary files",
 800                        GREP_BINARY_NOMATCH),
 801                { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 802                        "descend at most <depth> levels", PARSE_OPT_NONEG,
 803                        NULL, 1 },
 804                OPT_GROUP(""),
 805                OPT_SET_INT('E', "extended-regexp", &pattern_type,
 806                            "use extended POSIX regular expressions",
 807                            pattern_type_ere),
 808                OPT_SET_INT('G', "basic-regexp", &pattern_type,
 809                            "use basic POSIX regular expressions (default)",
 810                            pattern_type_bre),
 811                OPT_SET_INT('F', "fixed-strings", &pattern_type,
 812                            "interpret patterns as fixed strings",
 813                            pattern_type_fixed),
 814                OPT_SET_INT('P', "perl-regexp", &pattern_type,
 815                            "use Perl-compatible regular expressions",
 816                            pattern_type_pcre),
 817                OPT_GROUP(""),
 818                OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
 819                OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 820                OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 821                OPT_NEGBIT(0, "full-name", &opt.relative,
 822                        "show filenames relative to top directory", 1),
 823                OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 824                        "show only filenames instead of matching lines"),
 825                OPT_BOOLEAN(0, "name-only", &opt.name_only,
 826                        "synonym for --files-with-matches"),
 827                OPT_BOOLEAN('L', "files-without-match",
 828                        &opt.unmatch_name_only,
 829                        "show only the names of files without match"),
 830                OPT_BOOLEAN('z', "null", &opt.null_following_name,
 831                        "print NUL after filenames"),
 832                OPT_BOOLEAN('c', "count", &opt.count,
 833                        "show the number of matches instead of matching lines"),
 834                OPT__COLOR(&opt.color, "highlight matches"),
 835                OPT_BOOLEAN(0, "break", &opt.file_break,
 836                        "print empty line between matches from different files"),
 837                OPT_BOOLEAN(0, "heading", &opt.heading,
 838                        "show filename only once above matches from same file"),
 839                OPT_GROUP(""),
 840                OPT_CALLBACK('C', "context", &opt, "n",
 841                        "show <n> context lines before and after matches",
 842                        context_callback),
 843                OPT_INTEGER('B', "before-context", &opt.pre_context,
 844                        "show <n> context lines before matches"),
 845                OPT_INTEGER('A', "after-context", &opt.post_context,
 846                        "show <n> context lines after matches"),
 847                OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 848                        context_callback),
 849                OPT_BOOLEAN('p', "show-function", &opt.funcname,
 850                        "show a line with the function name before matches"),
 851                OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 852                        "show the surrounding function"),
 853                OPT_GROUP(""),
 854                OPT_CALLBACK('f', NULL, &opt, "file",
 855                        "read patterns from file", file_callback),
 856                { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 857                        "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 858                { OPTION_CALLBACK, 0, "and", &opt, NULL,
 859                  "combine patterns specified with -e",
 860                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 861                OPT_BOOLEAN(0, "or", &dummy, ""),
 862                { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 863                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 864                { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 865                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 866                  open_callback },
 867                { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 868                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 869                  close_callback },
 870                OPT__QUIET(&opt.status_only,
 871                           "indicate hit with exit status without output"),
 872                OPT_BOOLEAN(0, "all-match", &opt.all_match,
 873                        "show only matches from files that match all patterns"),
 874                OPT_GROUP(""),
 875                { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 876                        "pager", "show matching files in the pager",
 877                        PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 878                OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 879                            "allow calling of grep(1) (ignored by this build)"),
 880                { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 881                  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 882                OPT_END()
 883        };
 884
 885        /*
 886         * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 887         * to show usage information and exit.
 888         */
 889        if (argc == 2 && !strcmp(argv[1], "-h"))
 890                usage_with_options(grep_usage, options);
 891
 892        memset(&opt, 0, sizeof(opt));
 893        opt.prefix = prefix;
 894        opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 895        opt.relative = 1;
 896        opt.pathname = 1;
 897        opt.pattern_tail = &opt.pattern_list;
 898        opt.header_tail = &opt.header_list;
 899        opt.regflags = REG_NEWLINE;
 900        opt.max_depth = -1;
 901
 902        strcpy(opt.color_context, "");
 903        strcpy(opt.color_filename, "");
 904        strcpy(opt.color_function, "");
 905        strcpy(opt.color_lineno, "");
 906        strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
 907        strcpy(opt.color_selected, "");
 908        strcpy(opt.color_sep, GIT_COLOR_CYAN);
 909        opt.color = -1;
 910        git_config(grep_config, &opt);
 911
 912        /*
 913         * If there is no -- then the paths must exist in the working
 914         * tree.  If there is no explicit pattern specified with -e or
 915         * -f, we take the first unrecognized non option to be the
 916         * pattern, but then what follows it must be zero or more
 917         * valid refs up to the -- (if exists), and then existing
 918         * paths.  If there is an explicit pattern, then the first
 919         * unrecognized non option is the beginning of the refs list
 920         * that continues up to the -- (if exists), and then paths.
 921         */
 922        argc = parse_options(argc, argv, prefix, options, grep_usage,
 923                             PARSE_OPT_KEEP_DASHDASH |
 924                             PARSE_OPT_STOP_AT_NON_OPTION |
 925                             PARSE_OPT_NO_INTERNAL_HELP);
 926        switch (pattern_type) {
 927        case pattern_type_fixed:
 928                opt.fixed = 1;
 929                opt.pcre = 0;
 930                break;
 931        case pattern_type_bre:
 932                opt.fixed = 0;
 933                opt.pcre = 0;
 934                opt.regflags &= ~REG_EXTENDED;
 935                break;
 936        case pattern_type_ere:
 937                opt.fixed = 0;
 938                opt.pcre = 0;
 939                opt.regflags |= REG_EXTENDED;
 940                break;
 941        case pattern_type_pcre:
 942                opt.fixed = 0;
 943                opt.pcre = 1;
 944                break;
 945        default:
 946                break; /* nothing */
 947        }
 948
 949        if (use_index && !startup_info->have_repository)
 950                /* die the same way as if we did it at the beginning */
 951                setup_git_directory();
 952
 953        /*
 954         * skip a -- separator; we know it cannot be
 955         * separating revisions from pathnames if
 956         * we haven't even had any patterns yet
 957         */
 958        if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 959                argv++;
 960                argc--;
 961        }
 962
 963        /* First unrecognized non-option token */
 964        if (argc > 0 && !opt.pattern_list) {
 965                append_grep_pattern(&opt, argv[0], "command line", 0,
 966                                    GREP_PATTERN);
 967                argv++;
 968                argc--;
 969        }
 970
 971        if (show_in_pager == default_pager)
 972                show_in_pager = git_pager(1);
 973        if (show_in_pager) {
 974                opt.color = 0;
 975                opt.name_only = 1;
 976                opt.null_following_name = 1;
 977                opt.output_priv = &path_list;
 978                opt.output = append_path;
 979                string_list_append(&path_list, show_in_pager);
 980                use_threads = 0;
 981        }
 982
 983        if (!opt.pattern_list)
 984                die(_("no pattern given."));
 985        if (!opt.fixed && opt.ignore_case)
 986                opt.regflags |= REG_ICASE;
 987
 988#ifndef NO_PTHREADS
 989        if (online_cpus() == 1 || !grep_threads_ok(&opt))
 990                use_threads = 0;
 991
 992        if (use_threads) {
 993                if (opt.pre_context || opt.post_context || opt.file_break ||
 994                    opt.funcbody)
 995                        skip_first_line = 1;
 996                start_threads(&opt);
 997        }
 998#else
 999        use_threads = 0;
1000#endif
1001
1002        compile_grep_patterns(&opt);
1003
1004        /* Check revs and then paths */
1005        for (i = 0; i < argc; i++) {
1006                const char *arg = argv[i];
1007                unsigned char sha1[20];
1008                /* Is it a rev? */
1009                if (!get_sha1(arg, sha1)) {
1010                        struct object *object = parse_object(sha1);
1011                        if (!object)
1012                                die(_("bad object %s"), arg);
1013                        add_object_array(object, arg, &list);
1014                        continue;
1015                }
1016                if (!strcmp(arg, "--")) {
1017                        i++;
1018                        seen_dashdash = 1;
1019                }
1020                break;
1021        }
1022
1023        /* The rest are paths */
1024        if (!seen_dashdash) {
1025                int j;
1026                for (j = i; j < argc; j++)
1027                        verify_filename(prefix, argv[j]);
1028        }
1029
1030        paths = get_pathspec(prefix, argv + i);
1031        init_pathspec(&pathspec, paths);
1032        pathspec.max_depth = opt.max_depth;
1033        pathspec.recursive = 1;
1034
1035        if (show_in_pager && (cached || list.nr))
1036                die(_("--open-files-in-pager only works on the worktree"));
1037
1038        if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
1039                const char *pager = path_list.items[0].string;
1040                int len = strlen(pager);
1041
1042                if (len > 4 && is_dir_sep(pager[len - 5]))
1043                        pager += len - 4;
1044
1045                if (!strcmp("less", pager) || !strcmp("vi", pager)) {
1046                        struct strbuf buf = STRBUF_INIT;
1047                        strbuf_addf(&buf, "+/%s%s",
1048                                        strcmp("less", pager) ? "" : "*",
1049                                        opt.pattern_list->pattern);
1050                        string_list_append(&path_list, buf.buf);
1051                        strbuf_detach(&buf, NULL);
1052                }
1053        }
1054
1055        if (!show_in_pager)
1056                setup_pager();
1057
1058        if (!use_index && (untracked || cached))
1059                die(_("--cached or --untracked cannot be used with --no-index."));
1060
1061        if (!use_index || untracked) {
1062                int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
1063                if (list.nr)
1064                        die(_("--no-index or --untracked cannot be used with revs."));
1065                hit = grep_directory(&opt, &pathspec, use_exclude);
1066        } else if (0 <= opt_exclude) {
1067                die(_("--[no-]exclude-standard cannot be used for tracked contents."));
1068        } else if (!list.nr) {
1069                if (!cached)
1070                        setup_work_tree();
1071
1072                hit = grep_cache(&opt, &pathspec, cached);
1073        } else {
1074                if (cached)
1075                        die(_("both --cached and trees are given."));
1076                hit = grep_objects(&opt, &pathspec, &list);
1077        }
1078
1079        if (use_threads)
1080                hit |= wait_all();
1081        if (hit && show_in_pager)
1082                run_pager(&opt, prefix);
1083        free_grep_patterns(&opt);
1084        return !hit;
1085}