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 <regex.h>
  14 #include <fnmatch.h>
  15 #include <sys/wait.h>
  16
  17 /*
  18  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  19  * pathname wildcards are allowed.
  20  */
  21 static int pathspec_matches(const char **paths, const char *name)
  22 {
  23         int namelen, i;
  24         if (!paths || !*paths)
  25                 return 1;
  26         namelen = strlen(name);
  27         for (i = 0; paths[i]; i++) {
  28                 const char *match = paths[i];
  29                 int matchlen = strlen(match);
  30                 const char *cp, *meta;
  31
  32                 if ((matchlen <= namelen) &&
  33                     !strncmp(name, match, matchlen) &&
  34                     (match[matchlen-1] == '/' ||
  35                      name[matchlen] == '\0' || name[matchlen] == '/'))
  36                         return 1;
  37                 if (!fnmatch(match, name, 0))
  38                         return 1;
  39                 if (name[namelen-1] != '/')
  40                         continue;
  41
  42                 /* We are being asked if the directory ("name") is worth
  43                  * descending into.
  44                  *
  45                  * Find the longest leading directory name that does
  46                  * not have metacharacter in the pathspec; the name
  47                  * we are looking at must overlap with that directory.
  48                  */
  49                 for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
  50                         char ch = *cp;
  51                         if (ch == '*' || ch == '[' || ch == '?') {
  52                                 meta = cp;
  53                                 break;
  54                         }
  55                 }
  56                 if (!meta)
  57                         meta = cp; /* fully literal */
  58
  59                 if (namelen <= meta - match) {
  60                         /* Looking at "Documentation/" and
  61                          * the pattern says "Documentation/howto/", or
  62                          * "Documentation/diff*.txt".  The name we
  63                          * have should match prefix.
  64                          */
  65                         if (!memcmp(match, name, namelen))
  66                                 return 1;
  67                         continue;
  68                 }
  69
  70                 if (meta - match < namelen) {
  71                         /* Looking at "Documentation/howto/" and
  72                          * the pattern says "Documentation/h*";
  73                          * match up to "Do.../h"; this avoids descending
  74                          * into "Documentation/technical/".
  75                          */
  76                         if (!memcmp(match, name, meta - match))
  77                                 return 1;
  78                         continue;
  79                 }
  80         }
  81         return 0;
  82 }
  83
  84 struct grep_pat {
  85         struct grep_pat *next;
  86         const char *origin;
  87         int no;
  88         const char *pattern;
  89         regex_t regexp;
  90 };
  91
  92 struct grep_opt {
  93         struct grep_pat *pattern_list;
  94         struct grep_pat **pattern_tail;
  95         regex_t regexp;
  96         unsigned linenum:1;
  97         unsigned invert:1;
  98         unsigned name_only:1;
  99         unsigned unmatch_name_only:1;
 100         unsigned count:1;
 101         unsigned word_regexp:1;
 102         unsigned fixed:1;
 103 #define GREP_BINARY_DEFAULT     0
 104 #define GREP_BINARY_NOMATCH     1
 105 #define GREP_BINARY_TEXT        2
 106         unsigned binary:2;
 107         int regflags;
 108         unsigned pre_context;
 109         unsigned post_context;
 110 };
 111
 112 static void add_pattern(struct grep_opt *opt, const char *pat,
 113                         const char *origin, int no)
 114 {
 115         struct grep_pat *p = xcalloc(1, sizeof(*p));
 116         p->pattern = pat;
 117         p->origin = origin;
 118         p->no = no;
 119         *opt->pattern_tail = p;
 120         opt->pattern_tail = &p->next;
 121         p->next = NULL;
 122 }
 123
 124 static void compile_patterns(struct grep_opt *opt)
 125 {
 126         struct grep_pat *p;
 127         for (p = opt->pattern_list; p; p = p->next) {
 128                 int err = regcomp(&p->regexp, p->pattern, opt->regflags);
 129                 if (err) {
 130                         char errbuf[1024];
 131                         char where[1024];
 132                         if (p->no)
 133                                 sprintf(where, "In '%s' at %d, ",
 134                                         p->origin, p->no);
 135                         else if (p->origin)
 136                                 sprintf(where, "%s, ", p->origin);
 137                         else
 138                                 where[0] = 0;
 139                         regerror(err, &p->regexp, errbuf, 1024);
 140                         regfree(&p->regexp);
 141                         die("%s'%s': %s", where, p->pattern, errbuf);
 142                 }
 143         }
 144 }
 145
 146 static char *end_of_line(char *cp, unsigned long *left)
 147 {
 148         unsigned long l = *left;
 149         while (l && *cp != '\n') {
 150                 l--;
 151                 cp++;
 152         }
 153         *left = l;
 154         return cp;
 155 }
 156
 157 static int word_char(char ch)
 158 {
 159         return isalnum(ch) || ch == '_';
 160 }
 161
 162 static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
 163                       const char *name, unsigned lno, char sign)
 164 {
 165         printf("%s%c", name, sign);
 166         if (opt->linenum)
 167                 printf("%d%c", lno, sign);
 168         printf("%.*s\n", (int)(eol-bol), bol);
 169 }
 170
 171 /*
 172  * NEEDSWORK: share code with diff.c
 173  */
 174 #define FIRST_FEW_BYTES 8000
 175 static int buffer_is_binary(const char *ptr, unsigned long size)
 176 {
 177         if (FIRST_FEW_BYTES < size)
 178                 size = FIRST_FEW_BYTES;
 179         if (memchr(ptr, 0, size))
 180                 return 1;
 181         return 0;
 182 }
 183
 184 static int fixmatch(const char *pattern, char *line, regmatch_t *match)
 185 {
 186         char *hit = strstr(line, pattern);
 187         if (!hit) {
 188                 match->rm_so = match->rm_eo = -1;
 189                 return REG_NOMATCH;
 190         }
 191         else {
 192                 match->rm_so = hit - line;
 193                 match->rm_eo = match->rm_so + strlen(pattern);
 194                 return 0;
 195         }
 196 }
 197
 198 static int grep_buffer(struct grep_opt *opt, const char *name,
 199                        char *buf, unsigned long size)
 200 {
 201         char *bol = buf;
 202         unsigned long left = size;
 203         unsigned lno = 1;
 204         struct pre_context_line {
 205                 char *bol;
 206                 char *eol;
 207         } *prev = NULL, *pcl;
 208         unsigned last_hit = 0;
 209         unsigned last_shown = 0;
 210         int binary_match_only = 0;
 211         const char *hunk_mark = "";
 212         unsigned count = 0;
 213
 214         if (buffer_is_binary(buf, size)) {
 215                 switch (opt->binary) {
 216                 case GREP_BINARY_DEFAULT:
 217                         binary_match_only = 1;
 218                         break;
 219                 case GREP_BINARY_NOMATCH:
 220                         return 0; /* Assume unmatch */
 221                         break;
 222                 default:
 223                         break;
 224                 }
 225         }
 226
 227         if (opt->pre_context)
 228                 prev = xcalloc(opt->pre_context, sizeof(*prev));
 229         if (opt->pre_context || opt->post_context)
 230                 hunk_mark = "--\n";
 231
 232         while (left) {
 233                 regmatch_t pmatch[10];
 234                 char *eol, ch;
 235                 int hit = 0;
 236                 struct grep_pat *p;
 237
 238                 eol = end_of_line(bol, &left);
 239                 ch = *eol;
 240                 *eol = 0;
 241
 242                 for (p = opt->pattern_list; p; p = p->next) {
 243                         if (!opt->fixed) {
 244                                 regex_t *exp = &p->regexp;
 245                                 hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
 246                                                pmatch, 0);
 247                         }
 248                         else {
 249                                 hit = !fixmatch(p->pattern, bol, pmatch);
 250                         }
 251
 252                         if (hit && opt->word_regexp) {
 253                                 /* Match beginning must be either
 254                                  * beginning of the line, or at word
 255                                  * boundary (i.e. the last char must
 256                                  * not be alnum or underscore).
 257                                  */
 258                                 if ((pmatch[0].rm_so < 0) ||
 259                                     (eol - bol) <= pmatch[0].rm_so ||
 260                                     (pmatch[0].rm_eo < 0) ||
 261                                     (eol - bol) < pmatch[0].rm_eo)
 262                                         die("regexp returned nonsense");
 263                                 if (pmatch[0].rm_so != 0 &&
 264                                     word_char(bol[pmatch[0].rm_so-1]))
 265                                         hit = 0;
 266                                 if (pmatch[0].rm_eo != (eol-bol) &&
 267                                     word_char(bol[pmatch[0].rm_eo]))
 268                                         hit = 0;
 269                         }
 270                         if (hit)
 271                                 break;
 272                 }
 273                 /* "grep -v -e foo -e bla" should list lines
 274                  * that do not have either, so inversion should
 275                  * be done outside.
 276                  */
 277                 if (opt->invert)
 278                         hit = !hit;
 279                 if (opt->unmatch_name_only) {
 280                         if (hit)
 281                                 return 0;
 282                         goto next_line;
 283                 }
 284                 if (hit) {
 285                         count++;
 286                         if (binary_match_only) {
 287                                 printf("Binary file %s matches\n", name);
 288                                 return 1;
 289                         }
 290                         if (opt->name_only) {
 291                                 printf("%s\n", name);
 292                                 return 1;
 293                         }
 294                         /* Hit at this line.  If we haven't shown the
 295                          * pre-context lines, we would need to show them.
 296                          * When asked to do "count", this still show
 297                          * the context which is nonsense, but the user
 298                          * deserves to get that ;-).
 299                          */
 300                         if (opt->pre_context) {
 301                                 unsigned from;
 302                                 if (opt->pre_context < lno)
 303                                         from = lno - opt->pre_context;
 304                                 else
 305                                         from = 1;
 306                                 if (from <= last_shown)
 307                                         from = last_shown + 1;
 308                                 if (last_shown && from != last_shown + 1)
 309                                         printf(hunk_mark);
 310                                 while (from < lno) {
 311                                         pcl = &prev[lno-from-1];
 312                                         show_line(opt, pcl->bol, pcl->eol,
 313                                                   name, from, '-');
 314                                         from++;
 315                                 }
 316                                 last_shown = lno-1;
 317                         }
 318                         if (last_shown && lno != last_shown + 1)
 319                                 printf(hunk_mark);
 320                         if (!opt->count)
 321                                 show_line(opt, bol, eol, name, lno, ':');
 322                         last_shown = last_hit = lno;
 323                 }
 324                 else if (last_hit &&
 325                          lno <= last_hit + opt->post_context) {
 326                         /* If the last hit is within the post context,
 327                          * we need to show this line.
 328                          */
 329                         if (last_shown && lno != last_shown + 1)
 330                                 printf(hunk_mark);
 331                         show_line(opt, bol, eol, name, lno, '-');
 332                         last_shown = lno;
 333                 }
 334                 if (opt->pre_context) {
 335                         memmove(prev+1, prev,
 336                                 (opt->pre_context-1) * sizeof(*prev));
 337                         prev->bol = bol;
 338                         prev->eol = eol;
 339                 }
 340
 341         next_line:
 342                 *eol = ch;
 343                 bol = eol + 1;
 344                 if (!left)
 345                         break;
 346                 left--;
 347                 lno++;
 348         }
 349
 350         if (opt->unmatch_name_only) {
 351                 /* We did not see any hit, so we want to show this */
 352                 printf("%s\n", name);
 353                 return 1;
 354         }
 355
 356         /* NEEDSWORK:
 357          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 358          * which feels mostly useless but sometimes useful.  Maybe
 359          * make it another option?  For now suppress them.
 360          */
 361         if (opt->count && count)
 362                 printf("%s:%u\n", name, count);
 363         return !!last_hit;
 364 }
 365
 366 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name)
 367 {
 368         unsigned long size;
 369         char *data;
 370         char type[20];
 371         int hit;
 372         data = read_sha1_file(sha1, type, &size);
 373         if (!data) {
 374                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 375                 return 0;
 376         }
 377         hit = grep_buffer(opt, name, data, size);
 378         free(data);
 379         return hit;
 380 }
 381
 382 static int grep_file(struct grep_opt *opt, const char *filename)
 383 {
 384         struct stat st;
 385         int i;
 386         char *data;
 387         if (lstat(filename, &st) < 0) {
 388         err_ret:
 389                 if (errno != ENOENT)
 390                         error("'%s': %s", filename, strerror(errno));
 391                 return 0;
 392         }
 393         if (!st.st_size)
 394                 return 0; /* empty file -- no grep hit */
 395         if (!S_ISREG(st.st_mode))
 396                 return 0;
 397         i = open(filename, O_RDONLY);
 398         if (i < 0)
 399                 goto err_ret;
 400         data = xmalloc(st.st_size + 1);
 401         if (st.st_size != xread(i, data, st.st_size)) {
 402                 error("'%s': short read %s", filename, strerror(errno));
 403                 close(i);
 404                 free(data);
 405                 return 0;
 406         }
 407         close(i);
 408         i = grep_buffer(opt, filename, data, st.st_size);
 409         free(data);
 410         return i;
 411 }
 412
 413 static int exec_grep(int argc, const char **argv)
 414 {
 415         pid_t pid;
 416         int status;
 417
 418         argv[argc] = NULL;
 419         pid = fork();
 420         if (pid < 0)
 421                 return pid;
 422         if (!pid) {
 423                 execvp("grep", (char **) argv);
 424                 exit(255);
 425         }
 426         while (waitpid(pid, &status, 0) < 0) {
 427                 if (errno == EINTR)
 428                         continue;
 429                 return -1;
 430         }
 431         if (WIFEXITED(status)) {
 432                 if (!WEXITSTATUS(status))
 433                         return 1;
 434                 return 0;
 435         }
 436         return -1;
 437 }
 438
 439 #define MAXARGS 1000
 440
 441 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 442 {
 443         int i, nr, argc, hit;
 444         const char *argv[MAXARGS+1];
 445         struct grep_pat *p;
 446
 447         nr = 0;
 448         argv[nr++] = "grep";
 449         if (opt->word_regexp)
 450                 argv[nr++] = "-w";
 451         if (opt->name_only)
 452                 argv[nr++] = "-l";
 453         for (p = opt->pattern_list; p; p = p->next) {
 454                 argv[nr++] = "-e";
 455                 argv[nr++] = p->pattern;
 456         }
 457         argv[nr++] = "--";
 458
 459         hit = 0;
 460         argc = nr;
 461         for (i = 0; i < active_nr; i++) {
 462                 struct cache_entry *ce = active_cache[i];
 463                 if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
 464                         continue;
 465                 if (!pathspec_matches(paths, ce->name))
 466                         continue;
 467                 argv[argc++] = ce->name;
 468                 if (argc < MAXARGS)
 469                         continue;
 470                 hit += exec_grep(argc, argv);
 471                 argc = nr;
 472         }
 473         if (argc > nr)
 474                 hit += exec_grep(argc, argv);
 475         return 0;
 476 }
 477
 478 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 479 {
 480         int hit = 0;
 481         int nr;
 482         read_cache();
 483
 484 #ifdef __unix__
 485         /*
 486          * Use the external "grep" command for the case where
 487          * we grep through the checked-out files. It tends to
 488          * be a lot more optimized
 489          */
 490         if (!cached) {
 491                 hit = external_grep(opt, paths, cached);
 492                 if (hit >= 0)
 493                         return hit;
 494         }
 495 #endif
 496
 497         for (nr = 0; nr < active_nr; nr++) {
 498                 struct cache_entry *ce = active_cache[nr];
 499                 if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
 500                         continue;
 501                 if (!pathspec_matches(paths, ce->name))
 502                         continue;
 503                 if (cached)
 504                         hit |= grep_sha1(opt, ce->sha1, ce->name);
 505                 else
 506                         hit |= grep_file(opt, ce->name);
 507         }
 508         return hit;
 509 }
 510
 511 static int grep_tree(struct grep_opt *opt, const char **paths,
 512                      struct tree_desc *tree,
 513                      const char *tree_name, const char *base)
 514 {
 515         unsigned mode;
 516         int len;
 517         int hit = 0;
 518         const char *path;
 519         const unsigned char *sha1;
 520         char *down;
 521         char *path_buf = xmalloc(PATH_MAX + strlen(tree_name) + 100);
 522
 523         if (tree_name[0]) {
 524                 int offset = sprintf(path_buf, "%s:", tree_name);
 525                 down = path_buf + offset;
 526                 strcat(down, base);
 527         }
 528         else {
 529                 down = path_buf;
 530                 strcpy(down, base);
 531         }
 532         len = strlen(path_buf);
 533
 534         while (tree->size) {
 535                 int pathlen;
 536                 sha1 = tree_entry_extract(tree, &path, &mode);
 537                 pathlen = strlen(path);
 538                 strcpy(path_buf + len, path);
 539
 540                 if (S_ISDIR(mode))
 541                         /* Match "abc/" against pathspec to
 542                          * decide if we want to descend into "abc"
 543                          * directory.
 544                          */
 545                         strcpy(path_buf + len + pathlen, "/");
 546
 547                 if (!pathspec_matches(paths, down))
 548                         ;
 549                 else if (S_ISREG(mode))
 550                         hit |= grep_sha1(opt, sha1, path_buf);
 551                 else if (S_ISDIR(mode)) {
 552                         char type[20];
 553                         struct tree_desc sub;
 554                         void *data;
 555                         data = read_sha1_file(sha1, type, &sub.size);
 556                         if (!data)
 557                                 die("unable to read tree (%s)",
 558                                     sha1_to_hex(sha1));
 559                         sub.buf = data;
 560                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
 561                         free(data);
 562                 }
 563                 update_tree_entry(tree);
 564         }
 565         return hit;
 566 }
 567
 568 static int grep_object(struct grep_opt *opt, const char **paths,
 569                        struct object *obj, const char *name)
 570 {
 571         if (!strcmp(obj->type, blob_type))
 572                 return grep_sha1(opt, obj->sha1, name);
 573         if (!strcmp(obj->type, commit_type) ||
 574             !strcmp(obj->type, tree_type)) {
 575                 struct tree_desc tree;
 576                 void *data;
 577                 int hit;
 578                 data = read_object_with_reference(obj->sha1, tree_type,
 579                                                   &tree.size, NULL);
 580                 if (!data)
 581                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 582                 tree.buf = data;
 583                 hit = grep_tree(opt, paths, &tree, name, "");
 584                 free(data);
 585                 return hit;
 586         }
 587         die("unable to grep from object of type %s", obj->type);
 588 }
 589
 590 static const char builtin_grep_usage[] =
 591 "git-grep <option>* <rev>* [-e] <pattern> [<path>...]";
 592
 593 int cmd_grep(int argc, const char **argv, char **envp)
 594 {
 595         int hit = 0;
 596         int cached = 0;
 597         int seen_dashdash = 0;
 598         struct grep_opt opt;
 599         struct object_list *list, **tail, *object_list = NULL;
 600         const char *prefix = setup_git_directory();
 601         const char **paths = NULL;
 602         int i;
 603
 604         memset(&opt, 0, sizeof(opt));
 605         opt.pattern_tail = &opt.pattern_list;
 606         opt.regflags = REG_NEWLINE;
 607
 608         /*
 609          * If there is no -- then the paths must exist in the working
 610          * tree.  If there is no explicit pattern specified with -e or
 611          * -f, we take the first unrecognized non option to be the
 612          * pattern, but then what follows it must be zero or more
 613          * valid refs up to the -- (if exists), and then existing
 614          * paths.  If there is an explicit pattern, then the first
 615          * unrecocnized non option is the beginning of the refs list
 616          * that continues up to the -- (if exists), and then paths.
 617          */
 618
 619         tail = &object_list;
 620         while (1 < argc) {
 621                 const char *arg = argv[1];
 622                 argc--; argv++;
 623                 if (!strcmp("--cached", arg)) {
 624                         cached = 1;
 625                         continue;
 626                 }
 627                 if (!strcmp("-a", arg) ||
 628                     !strcmp("--text", arg)) {
 629                         opt.binary = GREP_BINARY_TEXT;
 630                         continue;
 631                 }
 632                 if (!strcmp("-i", arg) ||
 633                     !strcmp("--ignore-case", arg)) {
 634                         opt.regflags |= REG_ICASE;
 635                         continue;
 636                 }
 637                 if (!strcmp("-I", arg)) {
 638                         opt.binary = GREP_BINARY_NOMATCH;
 639                         continue;
 640                 }
 641                 if (!strcmp("-v", arg) ||
 642                     !strcmp("--invert-match", arg)) {
 643                         opt.invert = 1;
 644                         continue;
 645                 }
 646                 if (!strcmp("-E", arg) ||
 647                     !strcmp("--extended-regexp", arg)) {
 648                         opt.regflags |= REG_EXTENDED;
 649                         continue;
 650                 }
 651                 if (!strcmp("-F", arg) ||
 652                     !strcmp("--fixed-strings", arg)) {
 653                         opt.fixed = 1;
 654                         continue;
 655                 }
 656                 if (!strcmp("-G", arg) ||
 657                     !strcmp("--basic-regexp", arg)) {
 658                         opt.regflags &= ~REG_EXTENDED;
 659                         continue;
 660                 }
 661                 if (!strcmp("-n", arg)) {
 662                         opt.linenum = 1;
 663                         continue;
 664                 }
 665                 if (!strcmp("-H", arg)) {
 666                         /* We always show the pathname, so this
 667                          * is a noop.
 668                          */
 669                         continue;
 670                 }
 671                 if (!strcmp("-l", arg) ||
 672                     !strcmp("--files-with-matches", arg)) {
 673                         opt.name_only = 1;
 674                         continue;
 675                 }
 676                 if (!strcmp("-L", arg) ||
 677                     !strcmp("--files-without-match", arg)) {
 678                         opt.unmatch_name_only = 1;
 679                         continue;
 680                 }
 681                 if (!strcmp("-c", arg) ||
 682                     !strcmp("--count", arg)) {
 683                         opt.count = 1;
 684                         continue;
 685                 }
 686                 if (!strcmp("-w", arg) ||
 687                     !strcmp("--word-regexp", arg)) {
 688                         opt.word_regexp = 1;
 689                         continue;
 690                 }
 691                 if (!strncmp("-A", arg, 2) ||
 692                     !strncmp("-B", arg, 2) ||
 693                     !strncmp("-C", arg, 2) ||
 694                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
 695                         unsigned num;
 696                         const char *scan;
 697                         switch (arg[1]) {
 698                         case 'A': case 'B': case 'C':
 699                                 if (!arg[2]) {
 700                                         if (argc <= 1)
 701                                                 usage(builtin_grep_usage);
 702                                         scan = *++argv;
 703                                         argc--;
 704                                 }
 705                                 else
 706                                         scan = arg + 2;
 707                                 break;
 708                         default:
 709                                 scan = arg + 1;
 710                                 break;
 711                         }
 712                         if (sscanf(scan, "%u", &num) != 1)
 713                                 usage(builtin_grep_usage);
 714                         switch (arg[1]) {
 715                         case 'A':
 716                                 opt.post_context = num;
 717                                 break;
 718                         default:
 719                         case 'C':
 720                                 opt.post_context = num;
 721                         case 'B':
 722                                 opt.pre_context = num;
 723                                 break;
 724                         }
 725                         continue;
 726                 }
 727                 if (!strcmp("-f", arg)) {
 728                         FILE *patterns;
 729                         int lno = 0;
 730                         char buf[1024];
 731                         if (argc <= 1)
 732                                 usage(builtin_grep_usage);
 733                         patterns = fopen(argv[1], "r");
 734                         if (!patterns)
 735                                 die("'%s': %s", argv[1], strerror(errno));
 736                         while (fgets(buf, sizeof(buf), patterns)) {
 737                                 int len = strlen(buf);
 738                                 if (buf[len-1] == '\n')
 739                                         buf[len-1] = 0;
 740                                 /* ignore empty line like grep does */
 741                                 if (!buf[0])
 742                                         continue;
 743                                 add_pattern(&opt, strdup(buf), argv[1], ++lno);
 744                         }
 745                         fclose(patterns);
 746                         argv++;
 747                         argc--;
 748                         continue;
 749                 }
 750                 if (!strcmp("-e", arg)) {
 751                         if (1 < argc) {
 752                                 add_pattern(&opt, argv[1], "-e option", 0);
 753                                 argv++;
 754                                 argc--;
 755                                 continue;
 756                         }
 757                         usage(builtin_grep_usage);
 758                 }
 759                 if (!strcmp("--", arg))
 760                         break;
 761                 if (*arg == '-')
 762                         usage(builtin_grep_usage);
 763
 764                 /* First unrecognized non-option token */
 765                 if (!opt.pattern_list) {
 766                         add_pattern(&opt, arg, "command line", 0);
 767                         break;
 768                 }
 769                 else {
 770                         /* We are looking at the first path or rev;
 771                          * it is found at argv[1] after leaving the
 772                          * loop.
 773                          */
 774                         argc++; argv--;
 775                         break;
 776                 }
 777         }
 778
 779         if (!opt.pattern_list)
 780                 die("no pattern given.");
 781         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 782                 die("cannot mix --fixed-strings and regexp");
 783         if (!opt.fixed)
 784                 compile_patterns(&opt);
 785
 786         /* Check revs and then paths */
 787         for (i = 1; i < argc; i++) {
 788                 const char *arg = argv[i];
 789                 unsigned char sha1[20];
 790                 /* Is it a rev? */
 791                 if (!get_sha1(arg, sha1)) {
 792                         struct object *object = parse_object(sha1);
 793                         struct object_list *elem;
 794                         if (!object)
 795                                 die("bad object %s", arg);
 796                         elem = object_list_insert(object, tail);
 797                         elem->name = arg;
 798                         tail = &elem->next;
 799                         continue;
 800                 }
 801                 if (!strcmp(arg, "--")) {
 802                         i++;
 803                         seen_dashdash = 1;
 804                 }
 805                 break;
 806         }
 807
 808         /* The rest are paths */
 809         if (!seen_dashdash) {
 810                 int j;
 811                 for (j = i; j < argc; j++)
 812                         verify_filename(prefix, argv[j]);
 813         }
 814
 815         if (i < argc)
 816                 paths = get_pathspec(prefix, argv + i);
 817         else if (prefix) {
 818                 paths = xcalloc(2, sizeof(const char *));
 819                 paths[0] = prefix;
 820                 paths[1] = NULL;
 821         }
 822
 823         if (!object_list)
 824                 return !grep_cache(&opt, paths, cached);
 825
 826         if (cached)
 827                 die("both --cached and trees are given.");
 828
 829         for (list = object_list; list; list = list->next) {
 830                 struct object *real_obj;
 831                 real_obj = deref_tag(list->item, NULL, 0);
 832                 if (grep_object(&opt, paths, real_obj, list->name))
 833                         hit = 1;
 834         }
 835         return !hit;
 836 }