builtin/grep.c

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