builtin / grep.con commit fetch-pack: avoid repeatedly re-scanning pack directory (b495697)
   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
  21static char const * const grep_usage[] = {
  22        "git grep [options] [-e] <pattern> [<rev>...] [[--] <path>...]",
  23        NULL
  24};
  25
  26static int use_threads = 1;
  27
  28#ifndef NO_PTHREADS
  29#define THREADS 8
  30static pthread_t threads[THREADS];
  31
  32/* We use one producer thread and THREADS consumer
  33 * threads. The producer adds struct work_items to 'todo' and the
  34 * consumers pick work items from the same array.
  35 */
  36struct work_item {
  37        struct grep_source source;
  38        char done;
  39        struct strbuf out;
  40};
  41
  42/* In the range [todo_done, todo_start) in 'todo' we have work_items
  43 * that have been or are processed by a consumer thread. We haven't
  44 * written the result for these to stdout yet.
  45 *
  46 * The work_items in [todo_start, todo_end) are waiting to be picked
  47 * up by a consumer thread.
  48 *
  49 * The ranges are modulo TODO_SIZE.
  50 */
  51#define TODO_SIZE 128
  52static struct work_item todo[TODO_SIZE];
  53static int todo_start;
  54static int todo_end;
  55static int todo_done;
  56
  57/* Has all work items been added? */
  58static int all_work_added;
  59
  60/* This lock protects all the variables above. */
  61static pthread_mutex_t grep_mutex;
  62
  63static inline void grep_lock(void)
  64{
  65        if (use_threads)
  66                pthread_mutex_lock(&grep_mutex);
  67}
  68
  69static inline void grep_unlock(void)
  70{
  71        if (use_threads)
  72                pthread_mutex_unlock(&grep_mutex);
  73}
  74
  75/* Signalled when a new work_item is added to todo. */
  76static pthread_cond_t cond_add;
  77
  78/* Signalled when the result from one work_item is written to
  79 * stdout.
  80 */
  81static pthread_cond_t cond_write;
  82
  83/* Signalled when we are finished with everything. */
  84static pthread_cond_t cond_result;
  85
  86static int skip_first_line;
  87
  88static void add_work(struct grep_opt *opt, enum grep_source_type type,
  89                     const char *name, const void *id)
  90{
  91        grep_lock();
  92
  93        while ((todo_end+1) % ARRAY_SIZE(todo) == todo_done) {
  94                pthread_cond_wait(&cond_write, &grep_mutex);
  95        }
  96
  97        grep_source_init(&todo[todo_end].source, type, name, id);
  98        if (opt->binary != GREP_BINARY_TEXT)
  99                grep_source_load_driver(&todo[todo_end].source);
 100        todo[todo_end].done = 0;
 101        strbuf_reset(&todo[todo_end].out);
 102        todo_end = (todo_end + 1) % ARRAY_SIZE(todo);
 103
 104        pthread_cond_signal(&cond_add);
 105        grep_unlock();
 106}
 107
 108static struct work_item *get_work(void)
 109{
 110        struct work_item *ret;
 111
 112        grep_lock();
 113        while (todo_start == todo_end && !all_work_added) {
 114                pthread_cond_wait(&cond_add, &grep_mutex);
 115        }
 116
 117        if (todo_start == todo_end && all_work_added) {
 118                ret = NULL;
 119        } else {
 120                ret = &todo[todo_start];
 121                todo_start = (todo_start + 1) % ARRAY_SIZE(todo);
 122        }
 123        grep_unlock();
 124        return ret;
 125}
 126
 127static void work_done(struct work_item *w)
 128{
 129        int old_done;
 130
 131        grep_lock();
 132        w->done = 1;
 133        old_done = todo_done;
 134        for(; todo[todo_done].done && todo_done != todo_start;
 135            todo_done = (todo_done+1) % ARRAY_SIZE(todo)) {
 136                w = &todo[todo_done];
 137                if (w->out.len) {
 138                        const char *p = w->out.buf;
 139                        size_t len = w->out.len;
 140
 141                        /* Skip the leading hunk mark of the first file. */
 142                        if (skip_first_line) {
 143                                while (len) {
 144                                        len--;
 145                                        if (*p++ == '\n')
 146                                                break;
 147                                }
 148                                skip_first_line = 0;
 149                        }
 150
 151                        write_or_die(1, p, len);
 152                }
 153                grep_source_clear(&w->source);
 154        }
 155
 156        if (old_done != todo_done)
 157                pthread_cond_signal(&cond_write);
 158
 159        if (all_work_added && todo_done == todo_end)
 160                pthread_cond_signal(&cond_result);
 161
 162        grep_unlock();
 163}
 164
 165static void *run(void *arg)
 166{
 167        int hit = 0;
 168        struct grep_opt *opt = arg;
 169
 170        while (1) {
 171                struct work_item *w = get_work();
 172                if (!w)
 173                        break;
 174
 175                opt->output_priv = w;
 176                hit |= grep_source(opt, &w->source);
 177                grep_source_clear_data(&w->source);
 178                work_done(w);
 179        }
 180        free_grep_patterns(arg);
 181        free(arg);
 182
 183        return (void*) (intptr_t) hit;
 184}
 185
 186static void strbuf_out(struct grep_opt *opt, const void *buf, size_t size)
 187{
 188        struct work_item *w = opt->output_priv;
 189        strbuf_add(&w->out, buf, size);
 190}
 191
 192static void start_threads(struct grep_opt *opt)
 193{
 194        int i;
 195
 196        pthread_mutex_init(&grep_mutex, NULL);
 197        pthread_mutex_init(&grep_read_mutex, NULL);
 198        pthread_mutex_init(&grep_attr_mutex, NULL);
 199        pthread_cond_init(&cond_add, NULL);
 200        pthread_cond_init(&cond_write, NULL);
 201        pthread_cond_init(&cond_result, NULL);
 202        grep_use_locks = 1;
 203
 204        for (i = 0; i < ARRAY_SIZE(todo); i++) {
 205                strbuf_init(&todo[i].out, 0);
 206        }
 207
 208        for (i = 0; i < ARRAY_SIZE(threads); i++) {
 209                int err;
 210                struct grep_opt *o = grep_opt_dup(opt);
 211                o->output = strbuf_out;
 212                o->debug = 0;
 213                compile_grep_patterns(o);
 214                err = pthread_create(&threads[i], NULL, run, o);
 215
 216                if (err)
 217                        die(_("grep: failed to create thread: %s"),
 218                            strerror(err));
 219        }
 220}
 221
 222static int wait_all(void)
 223{
 224        int hit = 0;
 225        int i;
 226
 227        grep_lock();
 228        all_work_added = 1;
 229
 230        /* Wait until all work is done. */
 231        while (todo_done != todo_end)
 232                pthread_cond_wait(&cond_result, &grep_mutex);
 233
 234        /* Wake up all the consumer threads so they can see that there
 235         * is no more work to do.
 236         */
 237        pthread_cond_broadcast(&cond_add);
 238        grep_unlock();
 239
 240        for (i = 0; i < ARRAY_SIZE(threads); i++) {
 241                void *h;
 242                pthread_join(threads[i], &h);
 243                hit |= (int) (intptr_t) h;
 244        }
 245
 246        pthread_mutex_destroy(&grep_mutex);
 247        pthread_mutex_destroy(&grep_read_mutex);
 248        pthread_mutex_destroy(&grep_attr_mutex);
 249        pthread_cond_destroy(&cond_add);
 250        pthread_cond_destroy(&cond_write);
 251        pthread_cond_destroy(&cond_result);
 252        grep_use_locks = 0;
 253
 254        return hit;
 255}
 256#else /* !NO_PTHREADS */
 257
 258static int wait_all(void)
 259{
 260        return 0;
 261}
 262#endif
 263
 264static int grep_config(const char *var, const char *value, void *cb)
 265{
 266        struct grep_opt *opt = cb;
 267        char *color = NULL;
 268
 269        if (userdiff_config(var, value) < 0)
 270                return -1;
 271
 272        if (!strcmp(var, "grep.extendedregexp")) {
 273                if (git_config_bool(var, value))
 274                        opt->regflags |= REG_EXTENDED;
 275                else
 276                        opt->regflags &= ~REG_EXTENDED;
 277                return 0;
 278        }
 279
 280        if (!strcmp(var, "grep.linenumber")) {
 281                opt->linenum = git_config_bool(var, value);
 282                return 0;
 283        }
 284
 285        if (!strcmp(var, "color.grep"))
 286                opt->color = git_config_colorbool(var, value);
 287        else if (!strcmp(var, "color.grep.context"))
 288                color = opt->color_context;
 289        else if (!strcmp(var, "color.grep.filename"))
 290                color = opt->color_filename;
 291        else if (!strcmp(var, "color.grep.function"))
 292                color = opt->color_function;
 293        else if (!strcmp(var, "color.grep.linenumber"))
 294                color = opt->color_lineno;
 295        else if (!strcmp(var, "color.grep.match"))
 296                color = opt->color_match;
 297        else if (!strcmp(var, "color.grep.selected"))
 298                color = opt->color_selected;
 299        else if (!strcmp(var, "color.grep.separator"))
 300                color = opt->color_sep;
 301        else
 302                return git_color_default_config(var, value, cb);
 303        if (color) {
 304                if (!value)
 305                        return config_error_nonbool(var);
 306                color_parse(value, var, color);
 307        }
 308        return 0;
 309}
 310
 311static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 312{
 313        void *data;
 314
 315        grep_read_lock();
 316        data = read_sha1_file(sha1, type, size);
 317        grep_read_unlock();
 318        return data;
 319}
 320
 321static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 322                     const char *filename, int tree_name_len)
 323{
 324        struct strbuf pathbuf = STRBUF_INIT;
 325
 326        if (opt->relative && opt->prefix_length) {
 327                quote_path_relative(filename + tree_name_len, -1, &pathbuf,
 328                                    opt->prefix);
 329                strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 330        } else {
 331                strbuf_addstr(&pathbuf, filename);
 332        }
 333
 334#ifndef NO_PTHREADS
 335        if (use_threads) {
 336                add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 337                strbuf_release(&pathbuf);
 338                return 0;
 339        } else
 340#endif
 341        {
 342                struct grep_source gs;
 343                int hit;
 344
 345                grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, sha1);
 346                strbuf_release(&pathbuf);
 347                hit = grep_source(opt, &gs);
 348
 349                grep_source_clear(&gs);
 350                return hit;
 351        }
 352}
 353
 354static int grep_file(struct grep_opt *opt, const char *filename)
 355{
 356        struct strbuf buf = STRBUF_INIT;
 357
 358        if (opt->relative && opt->prefix_length)
 359                quote_path_relative(filename, -1, &buf, opt->prefix);
 360        else
 361                strbuf_addstr(&buf, filename);
 362
 363#ifndef NO_PTHREADS
 364        if (use_threads) {
 365                add_work(opt, GREP_SOURCE_FILE, buf.buf, filename);
 366                strbuf_release(&buf);
 367                return 0;
 368        } else
 369#endif
 370        {
 371                struct grep_source gs;
 372                int hit;
 373
 374                grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename);
 375                strbuf_release(&buf);
 376                hit = grep_source(opt, &gs);
 377
 378                grep_source_clear(&gs);
 379                return hit;
 380        }
 381}
 382
 383static void append_path(struct grep_opt *opt, const void *data, size_t len)
 384{
 385        struct string_list *path_list = opt->output_priv;
 386
 387        if (len == 1 && *(const char *)data == '\0')
 388                return;
 389        string_list_append(path_list, xstrndup(data, len));
 390}
 391
 392static void run_pager(struct grep_opt *opt, const char *prefix)
 393{
 394        struct string_list *path_list = opt->output_priv;
 395        const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 396        int i, status;
 397
 398        for (i = 0; i < path_list->nr; i++)
 399                argv[i] = path_list->items[i].string;
 400        argv[path_list->nr] = NULL;
 401
 402        if (prefix && chdir(prefix))
 403                die(_("Failed to chdir: %s"), prefix);
 404        status = run_command_v_opt(argv, RUN_USING_SHELL);
 405        if (status)
 406                exit(status);
 407        free(argv);
 408}
 409
 410static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 411{
 412        int hit = 0;
 413        int nr;
 414        read_cache();
 415
 416        for (nr = 0; nr < active_nr; nr++) {
 417                struct cache_entry *ce = active_cache[nr];
 418                if (!S_ISREG(ce->ce_mode))
 419                        continue;
 420                if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 421                        continue;
 422                /*
 423                 * If CE_VALID is on, we assume worktree file and its cache entry
 424                 * are identical, even if worktree file has been modified, so use
 425                 * cache version instead
 426                 */
 427                if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 428                        if (ce_stage(ce))
 429                                continue;
 430                        hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 431                }
 432                else
 433                        hit |= grep_file(opt, ce->name);
 434                if (ce_stage(ce)) {
 435                        do {
 436                                nr++;
 437                        } while (nr < active_nr &&
 438                                 !strcmp(ce->name, active_cache[nr]->name));
 439                        nr--; /* compensate for loop control */
 440                }
 441                if (hit && opt->status_only)
 442                        break;
 443        }
 444        return hit;
 445}
 446
 447static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 448                     struct tree_desc *tree, struct strbuf *base, int tn_len)
 449{
 450        int hit = 0;
 451        enum interesting match = entry_not_interesting;
 452        struct name_entry entry;
 453        int old_baselen = base->len;
 454
 455        while (tree_entry(tree, &entry)) {
 456                int te_len = tree_entry_len(&entry);
 457
 458                if (match != all_entries_interesting) {
 459                        match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 460                        if (match == all_entries_not_interesting)
 461                                break;
 462                        if (match == entry_not_interesting)
 463                                continue;
 464                }
 465
 466                strbuf_add(base, entry.path, te_len);
 467
 468                if (S_ISREG(entry.mode)) {
 469                        hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len);
 470                }
 471                else if (S_ISDIR(entry.mode)) {
 472                        enum object_type type;
 473                        struct tree_desc sub;
 474                        void *data;
 475                        unsigned long size;
 476
 477                        data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 478                        if (!data)
 479                                die(_("unable to read tree (%s)"),
 480                                    sha1_to_hex(entry.sha1));
 481
 482                        strbuf_addch(base, '/');
 483                        init_tree_desc(&sub, data, size);
 484                        hit |= grep_tree(opt, pathspec, &sub, base, tn_len);
 485                        free(data);
 486                }
 487                strbuf_setlen(base, old_baselen);
 488
 489                if (hit && opt->status_only)
 490                        break;
 491        }
 492        return hit;
 493}
 494
 495static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 496                       struct object *obj, const char *name)
 497{
 498        if (obj->type == OBJ_BLOB)
 499                return grep_sha1(opt, obj->sha1, name, 0);
 500        if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 501                struct tree_desc tree;
 502                void *data;
 503                unsigned long size;
 504                struct strbuf base;
 505                int hit, len;
 506
 507                grep_read_lock();
 508                data = read_object_with_reference(obj->sha1, tree_type,
 509                                                  &size, NULL);
 510                grep_read_unlock();
 511
 512                if (!data)
 513                        die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 514
 515                len = name ? strlen(name) : 0;
 516                strbuf_init(&base, PATH_MAX + len + 1);
 517                if (len) {
 518                        strbuf_add(&base, name, len);
 519                        strbuf_addch(&base, ':');
 520                }
 521                init_tree_desc(&tree, data, size);
 522                hit = grep_tree(opt, pathspec, &tree, &base, base.len);
 523                strbuf_release(&base);
 524                free(data);
 525                return hit;
 526        }
 527        die(_("unable to grep from object of type %s"), typename(obj->type));
 528}
 529
 530static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 531                        const struct object_array *list)
 532{
 533        unsigned int i;
 534        int hit = 0;
 535        const unsigned int nr = list->nr;
 536
 537        for (i = 0; i < nr; i++) {
 538                struct object *real_obj;
 539                real_obj = deref_tag(list->objects[i].item, NULL, 0);
 540                if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 541                        hit = 1;
 542                        if (opt->status_only)
 543                                break;
 544                }
 545        }
 546        return hit;
 547}
 548
 549static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 550                          int exc_std)
 551{
 552        struct dir_struct dir;
 553        int i, hit = 0;
 554
 555        memset(&dir, 0, sizeof(dir));
 556        if (exc_std)
 557                setup_standard_excludes(&dir);
 558
 559        fill_directory(&dir, pathspec->raw);
 560        for (i = 0; i < dir.nr; i++) {
 561                const char *name = dir.entries[i]->name;
 562                int namelen = strlen(name);
 563                if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 564                        continue;
 565                hit |= grep_file(opt, dir.entries[i]->name);
 566                if (hit && opt->status_only)
 567                        break;
 568        }
 569        return hit;
 570}
 571
 572static int context_callback(const struct option *opt, const char *arg,
 573                            int unset)
 574{
 575        struct grep_opt *grep_opt = opt->value;
 576        int value;
 577        const char *endp;
 578
 579        if (unset) {
 580                grep_opt->pre_context = grep_opt->post_context = 0;
 581                return 0;
 582        }
 583        value = strtol(arg, (char **)&endp, 10);
 584        if (*endp) {
 585                return error(_("switch `%c' expects a numerical value"),
 586                             opt->short_name);
 587        }
 588        grep_opt->pre_context = grep_opt->post_context = value;
 589        return 0;
 590}
 591
 592static int file_callback(const struct option *opt, const char *arg, int unset)
 593{
 594        struct grep_opt *grep_opt = opt->value;
 595        int from_stdin = !strcmp(arg, "-");
 596        FILE *patterns;
 597        int lno = 0;
 598        struct strbuf sb = STRBUF_INIT;
 599
 600        patterns = from_stdin ? stdin : fopen(arg, "r");
 601        if (!patterns)
 602                die_errno(_("cannot open '%s'"), arg);
 603        while (strbuf_getline(&sb, patterns, '\n') == 0) {
 604                /* ignore empty line like grep does */
 605                if (sb.len == 0)
 606                        continue;
 607
 608                append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 609                                GREP_PATTERN);
 610        }
 611        if (!from_stdin)
 612                fclose(patterns);
 613        strbuf_release(&sb);
 614        return 0;
 615}
 616
 617static int not_callback(const struct option *opt, const char *arg, int unset)
 618{
 619        struct grep_opt *grep_opt = opt->value;
 620        append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 621        return 0;
 622}
 623
 624static int and_callback(const struct option *opt, const char *arg, int unset)
 625{
 626        struct grep_opt *grep_opt = opt->value;
 627        append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 628        return 0;
 629}
 630
 631static int open_callback(const struct option *opt, const char *arg, int unset)
 632{
 633        struct grep_opt *grep_opt = opt->value;
 634        append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 635        return 0;
 636}
 637
 638static int close_callback(const struct option *opt, const char *arg, int unset)
 639{
 640        struct grep_opt *grep_opt = opt->value;
 641        append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 642        return 0;
 643}
 644
 645static int pattern_callback(const struct option *opt, const char *arg,
 646                            int unset)
 647{
 648        struct grep_opt *grep_opt = opt->value;
 649        append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 650        return 0;
 651}
 652
 653static int help_callback(const struct option *opt, const char *arg, int unset)
 654{
 655        return -1;
 656}
 657
 658int cmd_grep(int argc, const char **argv, const char *prefix)
 659{
 660        int hit = 0;
 661        int cached = 0, untracked = 0, opt_exclude = -1;
 662        int seen_dashdash = 0;
 663        int external_grep_allowed__ignored;
 664        const char *show_in_pager = NULL, *default_pager = "dummy";
 665        struct grep_opt opt;
 666        struct object_array list = OBJECT_ARRAY_INIT;
 667        const char **paths = NULL;
 668        struct pathspec pathspec;
 669        struct string_list path_list = STRING_LIST_INIT_NODUP;
 670        int i;
 671        int dummy;
 672        int use_index = 1;
 673        enum {
 674                pattern_type_unspecified = 0,
 675                pattern_type_bre,
 676                pattern_type_ere,
 677                pattern_type_fixed,
 678                pattern_type_pcre,
 679        };
 680        int pattern_type = pattern_type_unspecified;
 681
 682        struct option options[] = {
 683                OPT_BOOLEAN(0, "cached", &cached,
 684                        "search in index instead of in the work tree"),
 685                OPT_NEGBIT(0, "no-index", &use_index,
 686                         "finds in contents not managed by git", 1),
 687                OPT_BOOLEAN(0, "untracked", &untracked,
 688                        "search in both tracked and untracked files"),
 689                OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 690                            "search also in ignored files", 1),
 691                OPT_GROUP(""),
 692                OPT_BOOLEAN('v', "invert-match", &opt.invert,
 693                        "show non-matching lines"),
 694                OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 695                        "case insensitive matching"),
 696                OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 697                        "match patterns only at word boundaries"),
 698                OPT_SET_INT('a', "text", &opt.binary,
 699                        "process binary files as text", GREP_BINARY_TEXT),
 700                OPT_SET_INT('I', NULL, &opt.binary,
 701                        "don't match patterns in binary files",
 702                        GREP_BINARY_NOMATCH),
 703                { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 704                        "descend at most <depth> levels", PARSE_OPT_NONEG,
 705                        NULL, 1 },
 706                OPT_GROUP(""),
 707                OPT_SET_INT('E', "extended-regexp", &pattern_type,
 708                            "use extended POSIX regular expressions",
 709                            pattern_type_ere),
 710                OPT_SET_INT('G', "basic-regexp", &pattern_type,
 711                            "use basic POSIX regular expressions (default)",
 712                            pattern_type_bre),
 713                OPT_SET_INT('F', "fixed-strings", &pattern_type,
 714                            "interpret patterns as fixed strings",
 715                            pattern_type_fixed),
 716                OPT_SET_INT('P', "perl-regexp", &pattern_type,
 717                            "use Perl-compatible regular expressions",
 718                            pattern_type_pcre),
 719                OPT_GROUP(""),
 720                OPT_BOOLEAN('n', "line-number", &opt.linenum, "show line numbers"),
 721                OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 722                OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 723                OPT_NEGBIT(0, "full-name", &opt.relative,
 724                        "show filenames relative to top directory", 1),
 725                OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 726                        "show only filenames instead of matching lines"),
 727                OPT_BOOLEAN(0, "name-only", &opt.name_only,
 728                        "synonym for --files-with-matches"),
 729                OPT_BOOLEAN('L', "files-without-match",
 730                        &opt.unmatch_name_only,
 731                        "show only the names of files without match"),
 732                OPT_BOOLEAN('z', "null", &opt.null_following_name,
 733                        "print NUL after filenames"),
 734                OPT_BOOLEAN('c', "count", &opt.count,
 735                        "show the number of matches instead of matching lines"),
 736                OPT__COLOR(&opt.color, "highlight matches"),
 737                OPT_BOOLEAN(0, "break", &opt.file_break,
 738                        "print empty line between matches from different files"),
 739                OPT_BOOLEAN(0, "heading", &opt.heading,
 740                        "show filename only once above matches from same file"),
 741                OPT_GROUP(""),
 742                OPT_CALLBACK('C', "context", &opt, "n",
 743                        "show <n> context lines before and after matches",
 744                        context_callback),
 745                OPT_INTEGER('B', "before-context", &opt.pre_context,
 746                        "show <n> context lines before matches"),
 747                OPT_INTEGER('A', "after-context", &opt.post_context,
 748                        "show <n> context lines after matches"),
 749                OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 750                        context_callback),
 751                OPT_BOOLEAN('p', "show-function", &opt.funcname,
 752                        "show a line with the function name before matches"),
 753                OPT_BOOLEAN('W', "function-context", &opt.funcbody,
 754                        "show the surrounding function"),
 755                OPT_GROUP(""),
 756                OPT_CALLBACK('f', NULL, &opt, "file",
 757                        "read patterns from file", file_callback),
 758                { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 759                        "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 760                { OPTION_CALLBACK, 0, "and", &opt, NULL,
 761                  "combine patterns specified with -e",
 762                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 763                OPT_BOOLEAN(0, "or", &dummy, ""),
 764                { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 765                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 766                { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 767                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 768                  open_callback },
 769                { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 770                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 771                  close_callback },
 772                OPT__QUIET(&opt.status_only,
 773                           "indicate hit with exit status without output"),
 774                OPT_BOOLEAN(0, "all-match", &opt.all_match,
 775                        "show only matches from files that match all patterns"),
 776                { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 777                  "show parse tree for grep expression",
 778                  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 779                OPT_GROUP(""),
 780                { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 781                        "pager", "show matching files in the pager",
 782                        PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 783                OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
 784                            "allow calling of grep(1) (ignored by this build)"),
 785                { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 786                  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 787                OPT_END()
 788        };
 789
 790        /*
 791         * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 792         * to show usage information and exit.
 793         */
 794        if (argc == 2 && !strcmp(argv[1], "-h"))
 795                usage_with_options(grep_usage, options);
 796
 797        memset(&opt, 0, sizeof(opt));
 798        opt.prefix = prefix;
 799        opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 800        opt.relative = 1;
 801        opt.pathname = 1;
 802        opt.pattern_tail = &opt.pattern_list;
 803        opt.header_tail = &opt.header_list;
 804        opt.regflags = REG_NEWLINE;
 805        opt.max_depth = -1;
 806
 807        strcpy(opt.color_context, "");
 808        strcpy(opt.color_filename, "");
 809        strcpy(opt.color_function, "");
 810        strcpy(opt.color_lineno, "");
 811        strcpy(opt.color_match, GIT_COLOR_BOLD_RED);
 812        strcpy(opt.color_selected, "");
 813        strcpy(opt.color_sep, GIT_COLOR_CYAN);
 814        opt.color = -1;
 815        git_config(grep_config, &opt);
 816
 817        /*
 818         * If there is no -- then the paths must exist in the working
 819         * tree.  If there is no explicit pattern specified with -e or
 820         * -f, we take the first unrecognized non option to be the
 821         * pattern, but then what follows it must be zero or more
 822         * valid refs up to the -- (if exists), and then existing
 823         * paths.  If there is an explicit pattern, then the first
 824         * unrecognized non option is the beginning of the refs list
 825         * that continues up to the -- (if exists), and then paths.
 826         */
 827        argc = parse_options(argc, argv, prefix, options, grep_usage,
 828                             PARSE_OPT_KEEP_DASHDASH |
 829                             PARSE_OPT_STOP_AT_NON_OPTION |
 830                             PARSE_OPT_NO_INTERNAL_HELP);
 831        switch (pattern_type) {
 832        case pattern_type_fixed:
 833                opt.fixed = 1;
 834                opt.pcre = 0;
 835                break;
 836        case pattern_type_bre:
 837                opt.fixed = 0;
 838                opt.pcre = 0;
 839                opt.regflags &= ~REG_EXTENDED;
 840                break;
 841        case pattern_type_ere:
 842                opt.fixed = 0;
 843                opt.pcre = 0;
 844                opt.regflags |= REG_EXTENDED;
 845                break;
 846        case pattern_type_pcre:
 847                opt.fixed = 0;
 848                opt.pcre = 1;
 849                break;
 850        default:
 851                break; /* nothing */
 852        }
 853
 854        if (use_index && !startup_info->have_repository)
 855                /* die the same way as if we did it at the beginning */
 856                setup_git_directory();
 857
 858        /*
 859         * skip a -- separator; we know it cannot be
 860         * separating revisions from pathnames if
 861         * we haven't even had any patterns yet
 862         */
 863        if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 864                argv++;
 865                argc--;
 866        }
 867
 868        /* First unrecognized non-option token */
 869        if (argc > 0 && !opt.pattern_list) {
 870                append_grep_pattern(&opt, argv[0], "command line", 0,
 871                                    GREP_PATTERN);
 872                argv++;
 873                argc--;
 874        }
 875
 876        if (show_in_pager == default_pager)
 877                show_in_pager = git_pager(1);
 878        if (show_in_pager) {
 879                opt.color = 0;
 880                opt.name_only = 1;
 881                opt.null_following_name = 1;
 882                opt.output_priv = &path_list;
 883                opt.output = append_path;
 884                string_list_append(&path_list, show_in_pager);
 885                use_threads = 0;
 886        }
 887
 888        if (!opt.pattern_list)
 889                die(_("no pattern given."));
 890        if (!opt.fixed && opt.ignore_case)
 891                opt.regflags |= REG_ICASE;
 892
 893        compile_grep_patterns(&opt);
 894
 895        /* Check revs and then paths */
 896        for (i = 0; i < argc; i++) {
 897                const char *arg = argv[i];
 898                unsigned char sha1[20];
 899                /* Is it a rev? */
 900                if (!get_sha1(arg, sha1)) {
 901                        struct object *object = parse_object(sha1);
 902                        if (!object)
 903                                die(_("bad object %s"), arg);
 904                        add_object_array(object, arg, &list);
 905                        continue;
 906                }
 907                if (!strcmp(arg, "--")) {
 908                        i++;
 909                        seen_dashdash = 1;
 910                }
 911                break;
 912        }
 913
 914#ifndef NO_PTHREADS
 915        if (list.nr || cached || online_cpus() == 1)
 916                use_threads = 0;
 917#else
 918        use_threads = 0;
 919#endif
 920
 921#ifndef NO_PTHREADS
 922        if (use_threads) {
 923                if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 924                    && (opt.pre_context || opt.post_context ||
 925                        opt.file_break || opt.funcbody))
 926                        skip_first_line = 1;
 927                start_threads(&opt);
 928        }
 929#endif
 930
 931        /* The rest are paths */
 932        if (!seen_dashdash) {
 933                int j;
 934                for (j = i; j < argc; j++)
 935                        verify_filename(prefix, argv[j], j == i);
 936        }
 937
 938        paths = get_pathspec(prefix, argv + i);
 939        init_pathspec(&pathspec, paths);
 940        pathspec.max_depth = opt.max_depth;
 941        pathspec.recursive = 1;
 942
 943        if (show_in_pager && (cached || list.nr))
 944                die(_("--open-files-in-pager only works on the worktree"));
 945
 946        if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 947                const char *pager = path_list.items[0].string;
 948                int len = strlen(pager);
 949
 950                if (len > 4 && is_dir_sep(pager[len - 5]))
 951                        pager += len - 4;
 952
 953                if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 954                        struct strbuf buf = STRBUF_INIT;
 955                        strbuf_addf(&buf, "+/%s%s",
 956                                        strcmp("less", pager) ? "" : "*",
 957                                        opt.pattern_list->pattern);
 958                        string_list_append(&path_list, buf.buf);
 959                        strbuf_detach(&buf, NULL);
 960                }
 961        }
 962
 963        if (!show_in_pager)
 964                setup_pager();
 965
 966        if (!use_index && (untracked || cached))
 967                die(_("--cached or --untracked cannot be used with --no-index."));
 968
 969        if (!use_index || untracked) {
 970                int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 971                if (list.nr)
 972                        die(_("--no-index or --untracked cannot be used with revs."));
 973                hit = grep_directory(&opt, &pathspec, use_exclude);
 974        } else if (0 <= opt_exclude) {
 975                die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 976        } else if (!list.nr) {
 977                if (!cached)
 978                        setup_work_tree();
 979
 980                hit = grep_cache(&opt, &pathspec, cached);
 981        } else {
 982                if (cached)
 983                        die(_("both --cached and trees are given."));
 984                hit = grep_objects(&opt, &pathspec, &list);
 985        }
 986
 987        if (use_threads)
 988                hit |= wait_all();
 989        if (hit && show_in_pager)
 990                run_pager(&opt, prefix);
 991        free_grep_patterns(&opt);
 992        return !hit;
 993}