Andrew's git / gitweb.git / builtin/grep.c
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builtin / grep.con commit Merge branch 'jc/diff-filter-negation' (01a2a03)
   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        N_("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 char *path, 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, path, 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_cmd_config(const char *var, const char *value, void *cb)
 265{
 266        int st = grep_config(var, value, cb);
 267        if (git_color_default_config(var, value, cb) < 0)
 268                st = -1;
 269        return st;
 270}
 271
 272static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 273{
 274        void *data;
 275
 276        grep_read_lock();
 277        data = read_sha1_file(sha1, type, size);
 278        grep_read_unlock();
 279        return data;
 280}
 281
 282static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 283                     const char *filename, int tree_name_len,
 284                     const char *path)
 285{
 286        struct strbuf pathbuf = STRBUF_INIT;
 287
 288        if (opt->relative && opt->prefix_length) {
 289                quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
 290                strbuf_insert(&pathbuf, 0, filename, tree_name_len);
 291        } else {
 292                strbuf_addstr(&pathbuf, filename);
 293        }
 294
 295#ifndef NO_PTHREADS
 296        if (use_threads) {
 297                add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 298                strbuf_release(&pathbuf);
 299                return 0;
 300        } else
 301#endif
 302        {
 303                struct grep_source gs;
 304                int hit;
 305
 306                grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
 307                strbuf_release(&pathbuf);
 308                hit = grep_source(opt, &gs);
 309
 310                grep_source_clear(&gs);
 311                return hit;
 312        }
 313}
 314
 315static int grep_file(struct grep_opt *opt, const char *filename)
 316{
 317        struct strbuf buf = STRBUF_INIT;
 318
 319        if (opt->relative && opt->prefix_length)
 320                quote_path_relative(filename, opt->prefix, &buf);
 321        else
 322                strbuf_addstr(&buf, filename);
 323
 324#ifndef NO_PTHREADS
 325        if (use_threads) {
 326                add_work(opt, GREP_SOURCE_FILE, buf.buf, filename, filename);
 327                strbuf_release(&buf);
 328                return 0;
 329        } else
 330#endif
 331        {
 332                struct grep_source gs;
 333                int hit;
 334
 335                grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
 336                strbuf_release(&buf);
 337                hit = grep_source(opt, &gs);
 338
 339                grep_source_clear(&gs);
 340                return hit;
 341        }
 342}
 343
 344static void append_path(struct grep_opt *opt, const void *data, size_t len)
 345{
 346        struct string_list *path_list = opt->output_priv;
 347
 348        if (len == 1 && *(const char *)data == '\0')
 349                return;
 350        string_list_append(path_list, xstrndup(data, len));
 351}
 352
 353static void run_pager(struct grep_opt *opt, const char *prefix)
 354{
 355        struct string_list *path_list = opt->output_priv;
 356        const char **argv = xmalloc(sizeof(const char *) * (path_list->nr + 1));
 357        int i, status;
 358
 359        for (i = 0; i < path_list->nr; i++)
 360                argv[i] = path_list->items[i].string;
 361        argv[path_list->nr] = NULL;
 362
 363        if (prefix && chdir(prefix))
 364                die(_("Failed to chdir: %s"), prefix);
 365        status = run_command_v_opt(argv, RUN_USING_SHELL);
 366        if (status)
 367                exit(status);
 368        free(argv);
 369}
 370
 371static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int cached)
 372{
 373        int hit = 0;
 374        int nr;
 375        read_cache();
 376
 377        for (nr = 0; nr < active_nr; nr++) {
 378                const struct cache_entry *ce = active_cache[nr];
 379                if (!S_ISREG(ce->ce_mode))
 380                        continue;
 381                if (!match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL))
 382                        continue;
 383                /*
 384                 * If CE_VALID is on, we assume worktree file and its cache entry
 385                 * are identical, even if worktree file has been modified, so use
 386                 * cache version instead
 387                 */
 388                if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 389                        if (ce_stage(ce))
 390                                continue;
 391                        hit |= grep_sha1(opt, ce->sha1, ce->name, 0, ce->name);
 392                }
 393                else
 394                        hit |= grep_file(opt, ce->name);
 395                if (ce_stage(ce)) {
 396                        do {
 397                                nr++;
 398                        } while (nr < active_nr &&
 399                                 !strcmp(ce->name, active_cache[nr]->name));
 400                        nr--; /* compensate for loop control */
 401                }
 402                if (hit && opt->status_only)
 403                        break;
 404        }
 405        return hit;
 406}
 407
 408static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 409                     struct tree_desc *tree, struct strbuf *base, int tn_len,
 410                     int check_attr)
 411{
 412        int hit = 0;
 413        enum interesting match = entry_not_interesting;
 414        struct name_entry entry;
 415        int old_baselen = base->len;
 416
 417        while (tree_entry(tree, &entry)) {
 418                int te_len = tree_entry_len(&entry);
 419
 420                if (match != all_entries_interesting) {
 421                        match = tree_entry_interesting(&entry, base, tn_len, pathspec);
 422                        if (match == all_entries_not_interesting)
 423                                break;
 424                        if (match == entry_not_interesting)
 425                                continue;
 426                }
 427
 428                strbuf_add(base, entry.path, te_len);
 429
 430                if (S_ISREG(entry.mode)) {
 431                        hit |= grep_sha1(opt, entry.sha1, base->buf, tn_len,
 432                                         check_attr ? base->buf + tn_len : NULL);
 433                }
 434                else if (S_ISDIR(entry.mode)) {
 435                        enum object_type type;
 436                        struct tree_desc sub;
 437                        void *data;
 438                        unsigned long size;
 439
 440                        data = lock_and_read_sha1_file(entry.sha1, &type, &size);
 441                        if (!data)
 442                                die(_("unable to read tree (%s)"),
 443                                    sha1_to_hex(entry.sha1));
 444
 445                        strbuf_addch(base, '/');
 446                        init_tree_desc(&sub, data, size);
 447                        hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
 448                                         check_attr);
 449                        free(data);
 450                }
 451                strbuf_setlen(base, old_baselen);
 452
 453                if (hit && opt->status_only)
 454                        break;
 455        }
 456        return hit;
 457}
 458
 459static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 460                       struct object *obj, const char *name)
 461{
 462        if (obj->type == OBJ_BLOB)
 463                return grep_sha1(opt, obj->sha1, name, 0, NULL);
 464        if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 465                struct tree_desc tree;
 466                void *data;
 467                unsigned long size;
 468                struct strbuf base;
 469                int hit, len;
 470
 471                grep_read_lock();
 472                data = read_object_with_reference(obj->sha1, tree_type,
 473                                                  &size, NULL);
 474                grep_read_unlock();
 475
 476                if (!data)
 477                        die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));
 478
 479                len = name ? strlen(name) : 0;
 480                strbuf_init(&base, PATH_MAX + len + 1);
 481                if (len) {
 482                        strbuf_add(&base, name, len);
 483                        strbuf_addch(&base, ':');
 484                }
 485                init_tree_desc(&tree, data, size);
 486                hit = grep_tree(opt, pathspec, &tree, &base, base.len,
 487                                obj->type == OBJ_COMMIT);
 488                strbuf_release(&base);
 489                free(data);
 490                return hit;
 491        }
 492        die(_("unable to grep from object of type %s"), typename(obj->type));
 493}
 494
 495static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 496                        const struct object_array *list)
 497{
 498        unsigned int i;
 499        int hit = 0;
 500        const unsigned int nr = list->nr;
 501
 502        for (i = 0; i < nr; i++) {
 503                struct object *real_obj;
 504                real_obj = deref_tag(list->objects[i].item, NULL, 0);
 505                if (grep_object(opt, pathspec, real_obj, list->objects[i].name)) {
 506                        hit = 1;
 507                        if (opt->status_only)
 508                                break;
 509                }
 510        }
 511        return hit;
 512}
 513
 514static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 515                          int exc_std)
 516{
 517        struct dir_struct dir;
 518        int i, hit = 0;
 519
 520        memset(&dir, 0, sizeof(dir));
 521        if (exc_std)
 522                setup_standard_excludes(&dir);
 523
 524        fill_directory(&dir, pathspec->raw);
 525        for (i = 0; i < dir.nr; i++) {
 526                const char *name = dir.entries[i]->name;
 527                int namelen = strlen(name);
 528                if (!match_pathspec_depth(pathspec, name, namelen, 0, NULL))
 529                        continue;
 530                hit |= grep_file(opt, dir.entries[i]->name);
 531                if (hit && opt->status_only)
 532                        break;
 533        }
 534        return hit;
 535}
 536
 537static int context_callback(const struct option *opt, const char *arg,
 538                            int unset)
 539{
 540        struct grep_opt *grep_opt = opt->value;
 541        int value;
 542        const char *endp;
 543
 544        if (unset) {
 545                grep_opt->pre_context = grep_opt->post_context = 0;
 546                return 0;
 547        }
 548        value = strtol(arg, (char **)&endp, 10);
 549        if (*endp) {
 550                return error(_("switch `%c' expects a numerical value"),
 551                             opt->short_name);
 552        }
 553        grep_opt->pre_context = grep_opt->post_context = value;
 554        return 0;
 555}
 556
 557static int file_callback(const struct option *opt, const char *arg, int unset)
 558{
 559        struct grep_opt *grep_opt = opt->value;
 560        int from_stdin = !strcmp(arg, "-");
 561        FILE *patterns;
 562        int lno = 0;
 563        struct strbuf sb = STRBUF_INIT;
 564
 565        patterns = from_stdin ? stdin : fopen(arg, "r");
 566        if (!patterns)
 567                die_errno(_("cannot open '%s'"), arg);
 568        while (strbuf_getline(&sb, patterns, '\n') == 0) {
 569                /* ignore empty line like grep does */
 570                if (sb.len == 0)
 571                        continue;
 572
 573                append_grep_pat(grep_opt, sb.buf, sb.len, arg, ++lno,
 574                                GREP_PATTERN);
 575        }
 576        if (!from_stdin)
 577                fclose(patterns);
 578        strbuf_release(&sb);
 579        return 0;
 580}
 581
 582static int not_callback(const struct option *opt, const char *arg, int unset)
 583{
 584        struct grep_opt *grep_opt = opt->value;
 585        append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 586        return 0;
 587}
 588
 589static int and_callback(const struct option *opt, const char *arg, int unset)
 590{
 591        struct grep_opt *grep_opt = opt->value;
 592        append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 593        return 0;
 594}
 595
 596static int open_callback(const struct option *opt, const char *arg, int unset)
 597{
 598        struct grep_opt *grep_opt = opt->value;
 599        append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 600        return 0;
 601}
 602
 603static int close_callback(const struct option *opt, const char *arg, int unset)
 604{
 605        struct grep_opt *grep_opt = opt->value;
 606        append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 607        return 0;
 608}
 609
 610static int pattern_callback(const struct option *opt, const char *arg,
 611                            int unset)
 612{
 613        struct grep_opt *grep_opt = opt->value;
 614        append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 615        return 0;
 616}
 617
 618static int help_callback(const struct option *opt, const char *arg, int unset)
 619{
 620        return -1;
 621}
 622
 623int cmd_grep(int argc, const char **argv, const char *prefix)
 624{
 625        int hit = 0;
 626        int cached = 0, untracked = 0, opt_exclude = -1;
 627        int seen_dashdash = 0;
 628        int external_grep_allowed__ignored;
 629        const char *show_in_pager = NULL, *default_pager = "dummy";
 630        struct grep_opt opt;
 631        struct object_array list = OBJECT_ARRAY_INIT;
 632        const char **paths = NULL;
 633        struct pathspec pathspec;
 634        struct string_list path_list = STRING_LIST_INIT_NODUP;
 635        int i;
 636        int dummy;
 637        int use_index = 1;
 638        int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
 639
 640        struct option options[] = {
 641                OPT_BOOL(0, "cached", &cached,
 642                        N_("search in index instead of in the work tree")),
 643                OPT_NEGBIT(0, "no-index", &use_index,
 644                         N_("find in contents not managed by git"), 1),
 645                OPT_BOOL(0, "untracked", &untracked,
 646                        N_("search in both tracked and untracked files")),
 647                OPT_SET_INT(0, "exclude-standard", &opt_exclude,
 648                            N_("search also in ignored files"), 1),
 649                OPT_GROUP(""),
 650                OPT_BOOL('v', "invert-match", &opt.invert,
 651                        N_("show non-matching lines")),
 652                OPT_BOOL('i', "ignore-case", &opt.ignore_case,
 653                        N_("case insensitive matching")),
 654                OPT_BOOL('w', "word-regexp", &opt.word_regexp,
 655                        N_("match patterns only at word boundaries")),
 656                OPT_SET_INT('a', "text", &opt.binary,
 657                        N_("process binary files as text"), GREP_BINARY_TEXT),
 658                OPT_SET_INT('I', NULL, &opt.binary,
 659                        N_("don't match patterns in binary files"),
 660                        GREP_BINARY_NOMATCH),
 661                { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, N_("depth"),
 662                        N_("descend at most <depth> levels"), PARSE_OPT_NONEG,
 663                        NULL, 1 },
 664                OPT_GROUP(""),
 665                OPT_SET_INT('E', "extended-regexp", &pattern_type_arg,
 666                            N_("use extended POSIX regular expressions"),
 667                            GREP_PATTERN_TYPE_ERE),
 668                OPT_SET_INT('G', "basic-regexp", &pattern_type_arg,
 669                            N_("use basic POSIX regular expressions (default)"),
 670                            GREP_PATTERN_TYPE_BRE),
 671                OPT_SET_INT('F', "fixed-strings", &pattern_type_arg,
 672                            N_("interpret patterns as fixed strings"),
 673                            GREP_PATTERN_TYPE_FIXED),
 674                OPT_SET_INT('P', "perl-regexp", &pattern_type_arg,
 675                            N_("use Perl-compatible regular expressions"),
 676                            GREP_PATTERN_TYPE_PCRE),
 677                OPT_GROUP(""),
 678                OPT_BOOL('n', "line-number", &opt.linenum, N_("show line numbers")),
 679                OPT_NEGBIT('h', NULL, &opt.pathname, N_("don't show filenames"), 1),
 680                OPT_BIT('H', NULL, &opt.pathname, N_("show filenames"), 1),
 681                OPT_NEGBIT(0, "full-name", &opt.relative,
 682                        N_("show filenames relative to top directory"), 1),
 683                OPT_BOOL('l', "files-with-matches", &opt.name_only,
 684                        N_("show only filenames instead of matching lines")),
 685                OPT_BOOL(0, "name-only", &opt.name_only,
 686                        N_("synonym for --files-with-matches")),
 687                OPT_BOOL('L', "files-without-match",
 688                        &opt.unmatch_name_only,
 689                        N_("show only the names of files without match")),
 690                OPT_BOOL('z', "null", &opt.null_following_name,
 691                        N_("print NUL after filenames")),
 692                OPT_BOOL('c', "count", &opt.count,
 693                        N_("show the number of matches instead of matching lines")),
 694                OPT__COLOR(&opt.color, N_("highlight matches")),
 695                OPT_BOOL(0, "break", &opt.file_break,
 696                        N_("print empty line between matches from different files")),
 697                OPT_BOOL(0, "heading", &opt.heading,
 698                        N_("show filename only once above matches from same file")),
 699                OPT_GROUP(""),
 700                OPT_CALLBACK('C', "context", &opt, N_("n"),
 701                        N_("show <n> context lines before and after matches"),
 702                        context_callback),
 703                OPT_INTEGER('B', "before-context", &opt.pre_context,
 704                        N_("show <n> context lines before matches")),
 705                OPT_INTEGER('A', "after-context", &opt.post_context,
 706                        N_("show <n> context lines after matches")),
 707                OPT_NUMBER_CALLBACK(&opt, N_("shortcut for -C NUM"),
 708                        context_callback),
 709                OPT_BOOL('p', "show-function", &opt.funcname,
 710                        N_("show a line with the function name before matches")),
 711                OPT_BOOL('W', "function-context", &opt.funcbody,
 712                        N_("show the surrounding function")),
 713                OPT_GROUP(""),
 714                OPT_CALLBACK('f', NULL, &opt, N_("file"),
 715                        N_("read patterns from file"), file_callback),
 716                { OPTION_CALLBACK, 'e', NULL, &opt, N_("pattern"),
 717                        N_("match <pattern>"), PARSE_OPT_NONEG, pattern_callback },
 718                { OPTION_CALLBACK, 0, "and", &opt, NULL,
 719                  N_("combine patterns specified with -e"),
 720                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 721                OPT_BOOL(0, "or", &dummy, ""),
 722                { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 723                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 724                { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 725                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 726                  open_callback },
 727                { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 728                  PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 729                  close_callback },
 730                OPT__QUIET(&opt.status_only,
 731                           N_("indicate hit with exit status without output")),
 732                OPT_BOOL(0, "all-match", &opt.all_match,
 733                        N_("show only matches from files that match all patterns")),
 734                { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
 735                  N_("show parse tree for grep expression"),
 736                  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
 737                OPT_GROUP(""),
 738                { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
 739                        N_("pager"), N_("show matching files in the pager"),
 740                        PARSE_OPT_OPTARG, NULL, (intptr_t)default_pager },
 741                OPT_BOOL(0, "ext-grep", &external_grep_allowed__ignored,
 742                         N_("allow calling of grep(1) (ignored by this build)")),
 743                { OPTION_CALLBACK, 0, "help-all", &options, NULL, N_("show usage"),
 744                  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 745                OPT_END()
 746        };
 747
 748        /*
 749         * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 750         * to show usage information and exit.
 751         */
 752        if (argc == 2 && !strcmp(argv[1], "-h"))
 753                usage_with_options(grep_usage, options);
 754
 755        init_grep_defaults();
 756        git_config(grep_cmd_config, NULL);
 757        grep_init(&opt, prefix);
 758
 759        /*
 760         * If there is no -- then the paths must exist in the working
 761         * tree.  If there is no explicit pattern specified with -e or
 762         * -f, we take the first unrecognized non option to be the
 763         * pattern, but then what follows it must be zero or more
 764         * valid refs up to the -- (if exists), and then existing
 765         * paths.  If there is an explicit pattern, then the first
 766         * unrecognized non option is the beginning of the refs list
 767         * that continues up to the -- (if exists), and then paths.
 768         */
 769        argc = parse_options(argc, argv, prefix, options, grep_usage,
 770                             PARSE_OPT_KEEP_DASHDASH |
 771                             PARSE_OPT_STOP_AT_NON_OPTION |
 772                             PARSE_OPT_NO_INTERNAL_HELP);
 773        grep_commit_pattern_type(pattern_type_arg, &opt);
 774
 775        if (use_index && !startup_info->have_repository)
 776                /* die the same way as if we did it at the beginning */
 777                setup_git_directory();
 778
 779        /*
 780         * skip a -- separator; we know it cannot be
 781         * separating revisions from pathnames if
 782         * we haven't even had any patterns yet
 783         */
 784        if (argc > 0 && !opt.pattern_list && !strcmp(argv[0], "--")) {
 785                argv++;
 786                argc--;
 787        }
 788
 789        /* First unrecognized non-option token */
 790        if (argc > 0 && !opt.pattern_list) {
 791                append_grep_pattern(&opt, argv[0], "command line", 0,
 792                                    GREP_PATTERN);
 793                argv++;
 794                argc--;
 795        }
 796
 797        if (show_in_pager == default_pager)
 798                show_in_pager = git_pager(1);
 799        if (show_in_pager) {
 800                opt.color = 0;
 801                opt.name_only = 1;
 802                opt.null_following_name = 1;
 803                opt.output_priv = &path_list;
 804                opt.output = append_path;
 805                string_list_append(&path_list, show_in_pager);
 806                use_threads = 0;
 807        }
 808
 809        if (!opt.pattern_list)
 810                die(_("no pattern given."));
 811        if (!opt.fixed && opt.ignore_case)
 812                opt.regflags |= REG_ICASE;
 813
 814        compile_grep_patterns(&opt);
 815
 816        /* Check revs and then paths */
 817        for (i = 0; i < argc; i++) {
 818                const char *arg = argv[i];
 819                unsigned char sha1[20];
 820                /* Is it a rev? */
 821                if (!get_sha1(arg, sha1)) {
 822                        struct object *object = parse_object_or_die(sha1, arg);
 823                        if (!seen_dashdash)
 824                                verify_non_filename(prefix, arg);
 825                        add_object_array(object, arg, &list);
 826                        continue;
 827                }
 828                if (!strcmp(arg, "--")) {
 829                        i++;
 830                        seen_dashdash = 1;
 831                }
 832                break;
 833        }
 834
 835#ifndef NO_PTHREADS
 836        if (list.nr || cached || online_cpus() == 1)
 837                use_threads = 0;
 838#else
 839        use_threads = 0;
 840#endif
 841
 842#ifndef NO_PTHREADS
 843        if (use_threads) {
 844                if (!(opt.name_only || opt.unmatch_name_only || opt.count)
 845                    && (opt.pre_context || opt.post_context ||
 846                        opt.file_break || opt.funcbody))
 847                        skip_first_line = 1;
 848                start_threads(&opt);
 849        }
 850#endif
 851
 852        /* The rest are paths */
 853        if (!seen_dashdash) {
 854                int j;
 855                for (j = i; j < argc; j++)
 856                        verify_filename(prefix, argv[j], j == i);
 857        }
 858
 859        paths = get_pathspec(prefix, argv + i);
 860        init_pathspec(&pathspec, paths);
 861        pathspec.max_depth = opt.max_depth;
 862        pathspec.recursive = 1;
 863
 864        if (show_in_pager && (cached || list.nr))
 865                die(_("--open-files-in-pager only works on the worktree"));
 866
 867        if (show_in_pager && opt.pattern_list && !opt.pattern_list->next) {
 868                const char *pager = path_list.items[0].string;
 869                int len = strlen(pager);
 870
 871                if (len > 4 && is_dir_sep(pager[len - 5]))
 872                        pager += len - 4;
 873
 874                if (!strcmp("less", pager) || !strcmp("vi", pager)) {
 875                        struct strbuf buf = STRBUF_INIT;
 876                        strbuf_addf(&buf, "+/%s%s",
 877                                        strcmp("less", pager) ? "" : "*",
 878                                        opt.pattern_list->pattern);
 879                        string_list_append(&path_list, buf.buf);
 880                        strbuf_detach(&buf, NULL);
 881                }
 882        }
 883
 884        if (!show_in_pager)
 885                setup_pager();
 886
 887        if (!use_index && (untracked || cached))
 888                die(_("--cached or --untracked cannot be used with --no-index."));
 889
 890        if (!use_index || untracked) {
 891                int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 892                if (list.nr)
 893                        die(_("--no-index or --untracked cannot be used with revs."));
 894                hit = grep_directory(&opt, &pathspec, use_exclude);
 895        } else if (0 <= opt_exclude) {
 896                die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 897        } else if (!list.nr) {
 898                if (!cached)
 899                        setup_work_tree();
 900
 901                hit = grep_cache(&opt, &pathspec, cached);
 902        } else {
 903                if (cached)
 904                        die(_("both --cached and trees are given."));
 905                hit = grep_objects(&opt, &pathspec, &list);
 906        }
 907
 908        if (use_threads)
 909                hit |= wait_all();
 910        if (hit && show_in_pager)
 911                run_pager(&opt, prefix);
 912        free_grep_patterns(&opt);
 913        return !hit;
 914}