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