grep.c

   1 #include "cache.h"
   2 #include "grep.h"
   3 #include "userdiff.h"
   4 #include "xdiff-interface.h"
   5
   6 static int grep_source_load(struct grep_source *gs);
   7 static int grep_source_is_binary(struct grep_source *gs);
   8
   9
  10 static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
  11                                         const char *origin, int no,
  12                                         enum grep_pat_token t,
  13                                         enum grep_header_field field)
  14 {
  15         struct grep_pat *p = xcalloc(1, sizeof(*p));
  16         p->pattern = xmemdupz(pat, patlen);
  17         p->patternlen = patlen;
  18         p->origin = origin;
  19         p->no = no;
  20         p->token = t;
  21         p->field = field;
  22         return p;
  23 }
  24
  25 static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
  26 {
  27         **tail = p;
  28         *tail = &p->next;
  29         p->next = NULL;
  30
  31         switch (p->token) {
  32         case GREP_PATTERN: /* atom */
  33         case GREP_PATTERN_HEAD:
  34         case GREP_PATTERN_BODY:
  35                 for (;;) {
  36                         struct grep_pat *new_pat;
  37                         size_t len = 0;
  38                         char *cp = p->pattern + p->patternlen, *nl = NULL;
  39                         while (++len <= p->patternlen) {
  40                                 if (*(--cp) == '\n') {
  41                                         nl = cp;
  42                                         break;
  43                                 }
  44                         }
  45                         if (!nl)
  46                                 break;
  47                         new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
  48                                                   p->no, p->token, p->field);
  49                         new_pat->next = p->next;
  50                         if (!p->next)
  51                                 *tail = &new_pat->next;
  52                         p->next = new_pat;
  53                         *nl = '\0';
  54                         p->patternlen -= len;
  55                 }
  56                 break;
  57         default:
  58                 break;
  59         }
  60 }
  61
  62 void append_header_grep_pattern(struct grep_opt *opt,
  63                                 enum grep_header_field field, const char *pat)
  64 {
  65         struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
  66                                              GREP_PATTERN_HEAD, field);
  67         do_append_grep_pat(&opt->header_tail, p);
  68 }
  69
  70 void append_grep_pattern(struct grep_opt *opt, const char *pat,
  71                          const char *origin, int no, enum grep_pat_token t)
  72 {
  73         append_grep_pat(opt, pat, strlen(pat), origin, no, t);
  74 }
  75
  76 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
  77                      const char *origin, int no, enum grep_pat_token t)
  78 {
  79         struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
  80         do_append_grep_pat(&opt->pattern_tail, p);
  81 }
  82
  83 struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
  84 {
  85         struct grep_pat *pat;
  86         struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
  87         *ret = *opt;
  88
  89         ret->pattern_list = NULL;
  90         ret->pattern_tail = &ret->pattern_list;
  91
  92         for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
  93         {
  94                 if(pat->token == GREP_PATTERN_HEAD)
  95                         append_header_grep_pattern(ret, pat->field,
  96                                                    pat->pattern);
  97                 else
  98                         append_grep_pat(ret, pat->pattern, pat->patternlen,
  99                                         pat->origin, pat->no, pat->token);
 100         }
 101
 102         return ret;
 103 }
 104
 105 static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 106                 const char *error)
 107 {
 108         char where[1024];
 109
 110         if (p->no)
 111                 sprintf(where, "In '%s' at %d, ", p->origin, p->no);
 112         else if (p->origin)
 113                 sprintf(where, "%s, ", p->origin);
 114         else
 115                 where[0] = 0;
 116
 117         die("%s'%s': %s", where, p->pattern, error);
 118 }
 119
 120 #ifdef USE_LIBPCRE
 121 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 122 {
 123         const char *error;
 124         int erroffset;
 125         int options = PCRE_MULTILINE;
 126
 127         if (opt->ignore_case)
 128                 options |= PCRE_CASELESS;
 129
 130         p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 131                         NULL);
 132         if (!p->pcre_regexp)
 133                 compile_regexp_failed(p, error);
 134
 135         p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 136         if (!p->pcre_extra_info && error)
 137                 die("%s", error);
 138 }
 139
 140 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 141                 regmatch_t *match, int eflags)
 142 {
 143         int ovector[30], ret, flags = 0;
 144
 145         if (eflags & REG_NOTBOL)
 146                 flags |= PCRE_NOTBOL;
 147
 148         ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 149                         0, flags, ovector, ARRAY_SIZE(ovector));
 150         if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 151                 die("pcre_exec failed with error code %d", ret);
 152         if (ret > 0) {
 153                 ret = 0;
 154                 match->rm_so = ovector[0];
 155                 match->rm_eo = ovector[1];
 156         }
 157
 158         return ret;
 159 }
 160
 161 static void free_pcre_regexp(struct grep_pat *p)
 162 {
 163         pcre_free(p->pcre_regexp);
 164         pcre_free(p->pcre_extra_info);
 165 }
 166 #else /* !USE_LIBPCRE */
 167 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 168 {
 169         die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 170 }
 171
 172 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 173                 regmatch_t *match, int eflags)
 174 {
 175         return 1;
 176 }
 177
 178 static void free_pcre_regexp(struct grep_pat *p)
 179 {
 180 }
 181 #endif /* !USE_LIBPCRE */
 182
 183 static int is_fixed(const char *s, size_t len)
 184 {
 185         size_t i;
 186
 187         /* regcomp cannot accept patterns with NULs so we
 188          * consider any pattern containing a NUL fixed.
 189          */
 190         if (memchr(s, 0, len))
 191                 return 1;
 192
 193         for (i = 0; i < len; i++) {
 194                 if (is_regex_special(s[i]))
 195                         return 0;
 196         }
 197
 198         return 1;
 199 }
 200
 201 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 202 {
 203         int err;
 204
 205         p->word_regexp = opt->word_regexp;
 206         p->ignore_case = opt->ignore_case;
 207
 208         if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 209                 p->fixed = 1;
 210         else
 211                 p->fixed = 0;
 212
 213         if (p->fixed) {
 214                 if (opt->regflags & REG_ICASE || p->ignore_case)
 215                         p->kws = kwsalloc(tolower_trans_tbl);
 216                 else
 217                         p->kws = kwsalloc(NULL);
 218                 kwsincr(p->kws, p->pattern, p->patternlen);
 219                 kwsprep(p->kws);
 220                 return;
 221         }
 222
 223         if (opt->pcre) {
 224                 compile_pcre_regexp(p, opt);
 225                 return;
 226         }
 227
 228         err = regcomp(&p->regexp, p->pattern, opt->regflags);
 229         if (err) {
 230                 char errbuf[1024];
 231                 regerror(err, &p->regexp, errbuf, 1024);
 232                 regfree(&p->regexp);
 233                 compile_regexp_failed(p, errbuf);
 234         }
 235 }
 236
 237 static struct grep_expr *compile_pattern_or(struct grep_pat **);
 238 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 239 {
 240         struct grep_pat *p;
 241         struct grep_expr *x;
 242
 243         p = *list;
 244         if (!p)
 245                 return NULL;
 246         switch (p->token) {
 247         case GREP_PATTERN: /* atom */
 248         case GREP_PATTERN_HEAD:
 249         case GREP_PATTERN_BODY:
 250                 x = xcalloc(1, sizeof (struct grep_expr));
 251                 x->node = GREP_NODE_ATOM;
 252                 x->u.atom = p;
 253                 *list = p->next;
 254                 return x;
 255         case GREP_OPEN_PAREN:
 256                 *list = p->next;
 257                 x = compile_pattern_or(list);
 258                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 259                         die("unmatched parenthesis");
 260                 *list = (*list)->next;
 261                 return x;
 262         default:
 263                 return NULL;
 264         }
 265 }
 266
 267 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 268 {
 269         struct grep_pat *p;
 270         struct grep_expr *x;
 271
 272         p = *list;
 273         if (!p)
 274                 return NULL;
 275         switch (p->token) {
 276         case GREP_NOT:
 277                 if (!p->next)
 278                         die("--not not followed by pattern expression");
 279                 *list = p->next;
 280                 x = xcalloc(1, sizeof (struct grep_expr));
 281                 x->node = GREP_NODE_NOT;
 282                 x->u.unary = compile_pattern_not(list);
 283                 if (!x->u.unary)
 284                         die("--not followed by non pattern expression");
 285                 return x;
 286         default:
 287                 return compile_pattern_atom(list);
 288         }
 289 }
 290
 291 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 292 {
 293         struct grep_pat *p;
 294         struct grep_expr *x, *y, *z;
 295
 296         x = compile_pattern_not(list);
 297         p = *list;
 298         if (p && p->token == GREP_AND) {
 299                 if (!p->next)
 300                         die("--and not followed by pattern expression");
 301                 *list = p->next;
 302                 y = compile_pattern_and(list);
 303                 if (!y)
 304                         die("--and not followed by pattern expression");
 305                 z = xcalloc(1, sizeof (struct grep_expr));
 306                 z->node = GREP_NODE_AND;
 307                 z->u.binary.left = x;
 308                 z->u.binary.right = y;
 309                 return z;
 310         }
 311         return x;
 312 }
 313
 314 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 315 {
 316         struct grep_pat *p;
 317         struct grep_expr *x, *y, *z;
 318
 319         x = compile_pattern_and(list);
 320         p = *list;
 321         if (x && p && p->token != GREP_CLOSE_PAREN) {
 322                 y = compile_pattern_or(list);
 323                 if (!y)
 324                         die("not a pattern expression %s", p->pattern);
 325                 z = xcalloc(1, sizeof (struct grep_expr));
 326                 z->node = GREP_NODE_OR;
 327                 z->u.binary.left = x;
 328                 z->u.binary.right = y;
 329                 return z;
 330         }
 331         return x;
 332 }
 333
 334 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 335 {
 336         return compile_pattern_or(list);
 337 }
 338
 339 static void indent(int in)
 340 {
 341         while (in-- > 0)
 342                 fputc(' ', stderr);
 343 }
 344
 345 static void dump_grep_pat(struct grep_pat *p)
 346 {
 347         switch (p->token) {
 348         case GREP_AND: fprintf(stderr, "*and*"); break;
 349         case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 350         case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 351         case GREP_NOT: fprintf(stderr, "*not*"); break;
 352         case GREP_OR: fprintf(stderr, "*or*"); break;
 353
 354         case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 355         case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 356         case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 357         }
 358
 359         switch (p->token) {
 360         default: break;
 361         case GREP_PATTERN_HEAD:
 362                 fprintf(stderr, "<head %d>", p->field); break;
 363         case GREP_PATTERN_BODY:
 364                 fprintf(stderr, "<body>"); break;
 365         }
 366         switch (p->token) {
 367         default: break;
 368         case GREP_PATTERN_HEAD:
 369         case GREP_PATTERN_BODY:
 370         case GREP_PATTERN:
 371                 fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 372                 break;
 373         }
 374         fputc('\n', stderr);
 375 }
 376
 377 static void dump_grep_expression_1(struct grep_expr *x, int in)
 378 {
 379         indent(in);
 380         switch (x->node) {
 381         case GREP_NODE_TRUE:
 382                 fprintf(stderr, "true\n");
 383                 break;
 384         case GREP_NODE_ATOM:
 385                 dump_grep_pat(x->u.atom);
 386                 break;
 387         case GREP_NODE_NOT:
 388                 fprintf(stderr, "(not\n");
 389                 dump_grep_expression_1(x->u.unary, in+1);
 390                 indent(in);
 391                 fprintf(stderr, ")\n");
 392                 break;
 393         case GREP_NODE_AND:
 394                 fprintf(stderr, "(and\n");
 395                 dump_grep_expression_1(x->u.binary.left, in+1);
 396                 dump_grep_expression_1(x->u.binary.right, in+1);
 397                 indent(in);
 398                 fprintf(stderr, ")\n");
 399                 break;
 400         case GREP_NODE_OR:
 401                 fprintf(stderr, "(or\n");
 402                 dump_grep_expression_1(x->u.binary.left, in+1);
 403                 dump_grep_expression_1(x->u.binary.right, in+1);
 404                 indent(in);
 405                 fprintf(stderr, ")\n");
 406                 break;
 407         }
 408 }
 409
 410 static void dump_grep_expression(struct grep_opt *opt)
 411 {
 412         struct grep_expr *x = opt->pattern_expression;
 413
 414         if (opt->all_match)
 415                 fprintf(stderr, "[all-match]\n");
 416         dump_grep_expression_1(x, 0);
 417         fflush(NULL);
 418 }
 419
 420 static struct grep_expr *grep_true_expr(void)
 421 {
 422         struct grep_expr *z = xcalloc(1, sizeof(*z));
 423         z->node = GREP_NODE_TRUE;
 424         return z;
 425 }
 426
 427 static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 428 {
 429         struct grep_expr *z = xcalloc(1, sizeof(*z));
 430         z->node = GREP_NODE_OR;
 431         z->u.binary.left = left;
 432         z->u.binary.right = right;
 433         return z;
 434 }
 435
 436 static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 437 {
 438         struct grep_pat *p;
 439         struct grep_expr *header_expr;
 440         struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 441         enum grep_header_field fld;
 442
 443         if (!opt->header_list)
 444                 return NULL;
 445
 446         for (p = opt->header_list; p; p = p->next) {
 447                 if (p->token != GREP_PATTERN_HEAD)
 448                         die("bug: a non-header pattern in grep header list.");
 449                 if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
 450                         die("bug: unknown header field %d", p->field);
 451                 compile_regexp(p, opt);
 452         }
 453
 454         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 455                 header_group[fld] = NULL;
 456
 457         for (p = opt->header_list; p; p = p->next) {
 458                 struct grep_expr *h;
 459                 struct grep_pat *pp = p;
 460
 461                 h = compile_pattern_atom(&pp);
 462                 if (!h || pp != p->next)
 463                         die("bug: malformed header expr");
 464                 if (!header_group[p->field]) {
 465                         header_group[p->field] = h;
 466                         continue;
 467                 }
 468                 header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 469         }
 470
 471         header_expr = NULL;
 472
 473         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 474                 if (!header_group[fld])
 475                         continue;
 476                 if (!header_expr)
 477                         header_expr = grep_true_expr();
 478                 header_expr = grep_or_expr(header_group[fld], header_expr);
 479         }
 480         return header_expr;
 481 }
 482
 483 static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 484 {
 485         struct grep_expr *z = x;
 486
 487         while (x) {
 488                 assert(x->node == GREP_NODE_OR);
 489                 if (x->u.binary.right &&
 490                     x->u.binary.right->node == GREP_NODE_TRUE) {
 491                         x->u.binary.right = y;
 492                         break;
 493                 }
 494                 x = x->u.binary.right;
 495         }
 496         return z;
 497 }
 498
 499 static void compile_grep_patterns_real(struct grep_opt *opt)
 500 {
 501         struct grep_pat *p;
 502         struct grep_expr *header_expr = prep_header_patterns(opt);
 503
 504         for (p = opt->pattern_list; p; p = p->next) {
 505                 switch (p->token) {
 506                 case GREP_PATTERN: /* atom */
 507                 case GREP_PATTERN_HEAD:
 508                 case GREP_PATTERN_BODY:
 509                         compile_regexp(p, opt);
 510                         break;
 511                 default:
 512                         opt->extended = 1;
 513                         break;
 514                 }
 515         }
 516
 517         if (opt->all_match || header_expr)
 518                 opt->extended = 1;
 519         else if (!opt->extended && !opt->debug)
 520                 return;
 521
 522         p = opt->pattern_list;
 523         if (p)
 524                 opt->pattern_expression = compile_pattern_expr(&p);
 525         if (p)
 526                 die("incomplete pattern expression: %s", p->pattern);
 527
 528         if (!header_expr)
 529                 return;
 530
 531         if (!opt->pattern_expression)
 532                 opt->pattern_expression = header_expr;
 533         else if (opt->all_match)
 534                 opt->pattern_expression = grep_splice_or(header_expr,
 535                                                          opt->pattern_expression);
 536         else
 537                 opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 538                                                        header_expr);
 539         opt->all_match = 1;
 540 }
 541
 542 void compile_grep_patterns(struct grep_opt *opt)
 543 {
 544         compile_grep_patterns_real(opt);
 545         if (opt->debug)
 546                 dump_grep_expression(opt);
 547 }
 548
 549 static void free_pattern_expr(struct grep_expr *x)
 550 {
 551         switch (x->node) {
 552         case GREP_NODE_TRUE:
 553         case GREP_NODE_ATOM:
 554                 break;
 555         case GREP_NODE_NOT:
 556                 free_pattern_expr(x->u.unary);
 557                 break;
 558         case GREP_NODE_AND:
 559         case GREP_NODE_OR:
 560                 free_pattern_expr(x->u.binary.left);
 561                 free_pattern_expr(x->u.binary.right);
 562                 break;
 563         }
 564         free(x);
 565 }
 566
 567 void free_grep_patterns(struct grep_opt *opt)
 568 {
 569         struct grep_pat *p, *n;
 570
 571         for (p = opt->pattern_list; p; p = n) {
 572                 n = p->next;
 573                 switch (p->token) {
 574                 case GREP_PATTERN: /* atom */
 575                 case GREP_PATTERN_HEAD:
 576                 case GREP_PATTERN_BODY:
 577                         if (p->kws)
 578                                 kwsfree(p->kws);
 579                         else if (p->pcre_regexp)
 580                                 free_pcre_regexp(p);
 581                         else
 582                                 regfree(&p->regexp);
 583                         free(p->pattern);
 584                         break;
 585                 default:
 586                         break;
 587                 }
 588                 free(p);
 589         }
 590
 591         if (!opt->extended)
 592                 return;
 593         free_pattern_expr(opt->pattern_expression);
 594 }
 595
 596 static char *end_of_line(char *cp, unsigned long *left)
 597 {
 598         unsigned long l = *left;
 599         while (l && *cp != '\n') {
 600                 l--;
 601                 cp++;
 602         }
 603         *left = l;
 604         return cp;
 605 }
 606
 607 static int word_char(char ch)
 608 {
 609         return isalnum(ch) || ch == '_';
 610 }
 611
 612 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 613                          const char *color)
 614 {
 615         if (want_color(opt->color) && color && color[0]) {
 616                 opt->output(opt, color, strlen(color));
 617                 opt->output(opt, data, size);
 618                 opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 619         } else
 620                 opt->output(opt, data, size);
 621 }
 622
 623 static void output_sep(struct grep_opt *opt, char sign)
 624 {
 625         if (opt->null_following_name)
 626                 opt->output(opt, "\0", 1);
 627         else
 628                 output_color(opt, &sign, 1, opt->color_sep);
 629 }
 630
 631 static void show_name(struct grep_opt *opt, const char *name)
 632 {
 633         output_color(opt, name, strlen(name), opt->color_filename);
 634         opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 635 }
 636
 637 static int fixmatch(struct grep_pat *p, char *line, char *eol,
 638                     regmatch_t *match)
 639 {
 640         struct kwsmatch kwsm;
 641         size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 642         if (offset == -1) {
 643                 match->rm_so = match->rm_eo = -1;
 644                 return REG_NOMATCH;
 645         } else {
 646                 match->rm_so = offset;
 647                 match->rm_eo = match->rm_so + kwsm.size[0];
 648                 return 0;
 649         }
 650 }
 651
 652 static int regmatch(const regex_t *preg, char *line, char *eol,
 653                     regmatch_t *match, int eflags)
 654 {
 655 #ifdef REG_STARTEND
 656         match->rm_so = 0;
 657         match->rm_eo = eol - line;
 658         eflags |= REG_STARTEND;
 659 #endif
 660         return regexec(preg, line, 1, match, eflags);
 661 }
 662
 663 static int patmatch(struct grep_pat *p, char *line, char *eol,
 664                     regmatch_t *match, int eflags)
 665 {
 666         int hit;
 667
 668         if (p->fixed)
 669                 hit = !fixmatch(p, line, eol, match);
 670         else if (p->pcre_regexp)
 671                 hit = !pcrematch(p, line, eol, match, eflags);
 672         else
 673                 hit = !regmatch(&p->regexp, line, eol, match, eflags);
 674
 675         return hit;
 676 }
 677
 678 static int strip_timestamp(char *bol, char **eol_p)
 679 {
 680         char *eol = *eol_p;
 681         int ch;
 682
 683         while (bol < --eol) {
 684                 if (*eol != '>')
 685                         continue;
 686                 *eol_p = ++eol;
 687                 ch = *eol;
 688                 *eol = '\0';
 689                 return ch;
 690         }
 691         return 0;
 692 }
 693
 694 static struct {
 695         const char *field;
 696         size_t len;
 697 } header_field[] = {
 698         { "author ", 7 },
 699         { "committer ", 10 },
 700 };
 701
 702 static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 703                              enum grep_context ctx,
 704                              regmatch_t *pmatch, int eflags)
 705 {
 706         int hit = 0;
 707         int saved_ch = 0;
 708         const char *start = bol;
 709
 710         if ((p->token != GREP_PATTERN) &&
 711             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 712                 return 0;
 713
 714         if (p->token == GREP_PATTERN_HEAD) {
 715                 const char *field;
 716                 size_t len;
 717                 assert(p->field < ARRAY_SIZE(header_field));
 718                 field = header_field[p->field].field;
 719                 len = header_field[p->field].len;
 720                 if (strncmp(bol, field, len))
 721                         return 0;
 722                 bol += len;
 723                 saved_ch = strip_timestamp(bol, &eol);
 724         }
 725
 726  again:
 727         hit = patmatch(p, bol, eol, pmatch, eflags);
 728
 729         if (hit && p->word_regexp) {
 730                 if ((pmatch[0].rm_so < 0) ||
 731                     (eol - bol) < pmatch[0].rm_so ||
 732                     (pmatch[0].rm_eo < 0) ||
 733                     (eol - bol) < pmatch[0].rm_eo)
 734                         die("regexp returned nonsense");
 735
 736                 /* Match beginning must be either beginning of the
 737                  * line, or at word boundary (i.e. the last char must
 738                  * not be a word char).  Similarly, match end must be
 739                  * either end of the line, or at word boundary
 740                  * (i.e. the next char must not be a word char).
 741                  */
 742                 if ( ((pmatch[0].rm_so == 0) ||
 743                       !word_char(bol[pmatch[0].rm_so-1])) &&
 744                      ((pmatch[0].rm_eo == (eol-bol)) ||
 745                       !word_char(bol[pmatch[0].rm_eo])) )
 746                         ;
 747                 else
 748                         hit = 0;
 749
 750                 /* Words consist of at least one character. */
 751                 if (pmatch->rm_so == pmatch->rm_eo)
 752                         hit = 0;
 753
 754                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 755                         /* There could be more than one match on the
 756                          * line, and the first match might not be
 757                          * strict word match.  But later ones could be!
 758                          * Forward to the next possible start, i.e. the
 759                          * next position following a non-word char.
 760                          */
 761                         bol = pmatch[0].rm_so + bol + 1;
 762                         while (word_char(bol[-1]) && bol < eol)
 763                                 bol++;
 764                         eflags |= REG_NOTBOL;
 765                         if (bol < eol)
 766                                 goto again;
 767                 }
 768         }
 769         if (p->token == GREP_PATTERN_HEAD && saved_ch)
 770                 *eol = saved_ch;
 771         if (hit) {
 772                 pmatch[0].rm_so += bol - start;
 773                 pmatch[0].rm_eo += bol - start;
 774         }
 775         return hit;
 776 }
 777
 778 static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 779                            enum grep_context ctx, int collect_hits)
 780 {
 781         int h = 0;
 782         regmatch_t match;
 783
 784         if (!x)
 785                 die("Not a valid grep expression");
 786         switch (x->node) {
 787         case GREP_NODE_TRUE:
 788                 h = 1;
 789                 break;
 790         case GREP_NODE_ATOM:
 791                 h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 792                 break;
 793         case GREP_NODE_NOT:
 794                 h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 795                 break;
 796         case GREP_NODE_AND:
 797                 if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 798                         return 0;
 799                 h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 800                 break;
 801         case GREP_NODE_OR:
 802                 if (!collect_hits)
 803                         return (match_expr_eval(x->u.binary.left,
 804                                                 bol, eol, ctx, 0) ||
 805                                 match_expr_eval(x->u.binary.right,
 806                                                 bol, eol, ctx, 0));
 807                 h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 808                 x->u.binary.left->hit |= h;
 809                 h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 810                 break;
 811         default:
 812                 die("Unexpected node type (internal error) %d", x->node);
 813         }
 814         if (collect_hits)
 815                 x->hit |= h;
 816         return h;
 817 }
 818
 819 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 820                       enum grep_context ctx, int collect_hits)
 821 {
 822         struct grep_expr *x = opt->pattern_expression;
 823         return match_expr_eval(x, bol, eol, ctx, collect_hits);
 824 }
 825
 826 static int match_line(struct grep_opt *opt, char *bol, char *eol,
 827                       enum grep_context ctx, int collect_hits)
 828 {
 829         struct grep_pat *p;
 830         regmatch_t match;
 831
 832         if (opt->extended)
 833                 return match_expr(opt, bol, eol, ctx, collect_hits);
 834
 835         /* we do not call with collect_hits without being extended */
 836         for (p = opt->pattern_list; p; p = p->next) {
 837                 if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 838                         return 1;
 839         }
 840         return 0;
 841 }
 842
 843 static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 844                               enum grep_context ctx,
 845                               regmatch_t *pmatch, int eflags)
 846 {
 847         regmatch_t match;
 848
 849         if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 850                 return 0;
 851         if (match.rm_so < 0 || match.rm_eo < 0)
 852                 return 0;
 853         if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 854                 if (match.rm_so > pmatch->rm_so)
 855                         return 1;
 856                 if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 857                         return 1;
 858         }
 859         pmatch->rm_so = match.rm_so;
 860         pmatch->rm_eo = match.rm_eo;
 861         return 1;
 862 }
 863
 864 static int next_match(struct grep_opt *opt, char *bol, char *eol,
 865                       enum grep_context ctx, regmatch_t *pmatch, int eflags)
 866 {
 867         struct grep_pat *p;
 868         int hit = 0;
 869
 870         pmatch->rm_so = pmatch->rm_eo = -1;
 871         if (bol < eol) {
 872                 for (p = opt->pattern_list; p; p = p->next) {
 873                         switch (p->token) {
 874                         case GREP_PATTERN: /* atom */
 875                         case GREP_PATTERN_HEAD:
 876                         case GREP_PATTERN_BODY:
 877                                 hit |= match_next_pattern(p, bol, eol, ctx,
 878                                                           pmatch, eflags);
 879                                 break;
 880                         default:
 881                                 break;
 882                         }
 883                 }
 884         }
 885         return hit;
 886 }
 887
 888 static void show_line(struct grep_opt *opt, char *bol, char *eol,
 889                       const char *name, unsigned lno, char sign)
 890 {
 891         int rest = eol - bol;
 892         char *line_color = NULL;
 893
 894         if (opt->file_break && opt->last_shown == 0) {
 895                 if (opt->show_hunk_mark)
 896                         opt->output(opt, "\n", 1);
 897         } else if (opt->pre_context || opt->post_context || opt->funcbody) {
 898                 if (opt->last_shown == 0) {
 899                         if (opt->show_hunk_mark) {
 900                                 output_color(opt, "--", 2, opt->color_sep);
 901                                 opt->output(opt, "\n", 1);
 902                         }
 903                 } else if (lno > opt->last_shown + 1) {
 904                         output_color(opt, "--", 2, opt->color_sep);
 905                         opt->output(opt, "\n", 1);
 906                 }
 907         }
 908         if (opt->heading && opt->last_shown == 0) {
 909                 output_color(opt, name, strlen(name), opt->color_filename);
 910                 opt->output(opt, "\n", 1);
 911         }
 912         opt->last_shown = lno;
 913
 914         if (!opt->heading && opt->pathname) {
 915                 output_color(opt, name, strlen(name), opt->color_filename);
 916                 output_sep(opt, sign);
 917         }
 918         if (opt->linenum) {
 919                 char buf[32];
 920                 snprintf(buf, sizeof(buf), "%d", lno);
 921                 output_color(opt, buf, strlen(buf), opt->color_lineno);
 922                 output_sep(opt, sign);
 923         }
 924         if (opt->color) {
 925                 regmatch_t match;
 926                 enum grep_context ctx = GREP_CONTEXT_BODY;
 927                 int ch = *eol;
 928                 int eflags = 0;
 929
 930                 if (sign == ':')
 931                         line_color = opt->color_selected;
 932                 else if (sign == '-')
 933                         line_color = opt->color_context;
 934                 else if (sign == '=')
 935                         line_color = opt->color_function;
 936                 *eol = '\0';
 937                 while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 938                         if (match.rm_so == match.rm_eo)
 939                                 break;
 940
 941                         output_color(opt, bol, match.rm_so, line_color);
 942                         output_color(opt, bol + match.rm_so,
 943                                      match.rm_eo - match.rm_so,
 944                                      opt->color_match);
 945                         bol += match.rm_eo;
 946                         rest -= match.rm_eo;
 947                         eflags = REG_NOTBOL;
 948                 }
 949                 *eol = ch;
 950         }
 951         output_color(opt, bol, rest, line_color);
 952         opt->output(opt, "\n", 1);
 953 }
 954
 955 #ifndef NO_PTHREADS
 956 int grep_use_locks;
 957
 958 /*
 959  * This lock protects access to the gitattributes machinery, which is
 960  * not thread-safe.
 961  */
 962 pthread_mutex_t grep_attr_mutex;
 963
 964 static inline void grep_attr_lock(void)
 965 {
 966         if (grep_use_locks)
 967                 pthread_mutex_lock(&grep_attr_mutex);
 968 }
 969
 970 static inline void grep_attr_unlock(void)
 971 {
 972         if (grep_use_locks)
 973                 pthread_mutex_unlock(&grep_attr_mutex);
 974 }
 975
 976 /*
 977  * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
 978  */
 979 pthread_mutex_t grep_read_mutex;
 980
 981 #else
 982 #define grep_attr_lock()
 983 #define grep_attr_unlock()
 984 #endif
 985
 986 static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
 987 {
 988         xdemitconf_t *xecfg = opt->priv;
 989         if (xecfg && !xecfg->find_func) {
 990                 grep_source_load_driver(gs);
 991                 if (gs->driver->funcname.pattern) {
 992                         const struct userdiff_funcname *pe = &gs->driver->funcname;
 993                         xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
 994                 } else {
 995                         xecfg = opt->priv = NULL;
 996                 }
 997         }
 998
 999         if (xecfg) {
1000                 char buf[1];
1001                 return xecfg->find_func(bol, eol - bol, buf, 1,
1002                                         xecfg->find_func_priv) >= 0;
1003         }
1004
1005         if (bol == eol)
1006                 return 0;
1007         if (isalpha(*bol) || *bol == '_' || *bol == '$')
1008                 return 1;
1009         return 0;
1010 }
1011
1012 static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1013                                char *bol, unsigned lno)
1014 {
1015         while (bol > gs->buf) {
1016                 char *eol = --bol;
1017
1018                 while (bol > gs->buf && bol[-1] != '\n')
1019                         bol--;
1020                 lno--;
1021
1022                 if (lno <= opt->last_shown)
1023                         break;
1024
1025                 if (match_funcname(opt, gs, bol, eol)) {
1026                         show_line(opt, bol, eol, gs->name, lno, '=');
1027                         break;
1028                 }
1029         }
1030 }
1031
1032 static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1033                              char *bol, char *end, unsigned lno)
1034 {
1035         unsigned cur = lno, from = 1, funcname_lno = 0;
1036         int funcname_needed = !!opt->funcname;
1037
1038         if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1039                 funcname_needed = 2;
1040
1041         if (opt->pre_context < lno)
1042                 from = lno - opt->pre_context;
1043         if (from <= opt->last_shown)
1044                 from = opt->last_shown + 1;
1045
1046         /* Rewind. */
1047         while (bol > gs->buf &&
1048                cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1049                 char *eol = --bol;
1050
1051                 while (bol > gs->buf && bol[-1] != '\n')
1052                         bol--;
1053                 cur--;
1054                 if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1055                         funcname_lno = cur;
1056                         funcname_needed = 0;
1057                 }
1058         }
1059
1060         /* We need to look even further back to find a function signature. */
1061         if (opt->funcname && funcname_needed)
1062                 show_funcname_line(opt, gs, bol, cur);
1063
1064         /* Back forward. */
1065         while (cur < lno) {
1066                 char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1067
1068                 while (*eol != '\n')
1069                         eol++;
1070                 show_line(opt, bol, eol, gs->name, cur, sign);
1071                 bol = eol + 1;
1072                 cur++;
1073         }
1074 }
1075
1076 static int should_lookahead(struct grep_opt *opt)
1077 {
1078         struct grep_pat *p;
1079
1080         if (opt->extended)
1081                 return 0; /* punt for too complex stuff */
1082         if (opt->invert)
1083                 return 0;
1084         for (p = opt->pattern_list; p; p = p->next) {
1085                 if (p->token != GREP_PATTERN)
1086                         return 0; /* punt for "header only" and stuff */
1087         }
1088         return 1;
1089 }
1090
1091 static int look_ahead(struct grep_opt *opt,
1092                       unsigned long *left_p,
1093                       unsigned *lno_p,
1094                       char **bol_p)
1095 {
1096         unsigned lno = *lno_p;
1097         char *bol = *bol_p;
1098         struct grep_pat *p;
1099         char *sp, *last_bol;
1100         regoff_t earliest = -1;
1101
1102         for (p = opt->pattern_list; p; p = p->next) {
1103                 int hit;
1104                 regmatch_t m;
1105
1106                 hit = patmatch(p, bol, bol + *left_p, &m, 0);
1107                 if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1108                         continue;
1109                 if (earliest < 0 || m.rm_so < earliest)
1110                         earliest = m.rm_so;
1111         }
1112
1113         if (earliest < 0) {
1114                 *bol_p = bol + *left_p;
1115                 *left_p = 0;
1116                 return 1;
1117         }
1118         for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1119                 ; /* find the beginning of the line */
1120         last_bol = sp;
1121
1122         for (sp = bol; sp < last_bol; sp++) {
1123                 if (*sp == '\n')
1124                         lno++;
1125         }
1126         *left_p -= last_bol - bol;
1127         *bol_p = last_bol;
1128         *lno_p = lno;
1129         return 0;
1130 }
1131
1132 static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1133 {
1134         fwrite(buf, size, 1, stdout);
1135 }
1136
1137 static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1138 {
1139         char *bol;
1140         unsigned long left;
1141         unsigned lno = 1;
1142         unsigned last_hit = 0;
1143         int binary_match_only = 0;
1144         unsigned count = 0;
1145         int try_lookahead = 0;
1146         int show_function = 0;
1147         enum grep_context ctx = GREP_CONTEXT_HEAD;
1148         xdemitconf_t xecfg;
1149
1150         if (!opt->output)
1151                 opt->output = std_output;
1152
1153         if (opt->pre_context || opt->post_context || opt->file_break ||
1154             opt->funcbody) {
1155                 /* Show hunk marks, except for the first file. */
1156                 if (opt->last_shown)
1157                         opt->show_hunk_mark = 1;
1158                 /*
1159                  * If we're using threads then we can't easily identify
1160                  * the first file.  Always put hunk marks in that case
1161                  * and skip the very first one later in work_done().
1162                  */
1163                 if (opt->output != std_output)
1164                         opt->show_hunk_mark = 1;
1165         }
1166         opt->last_shown = 0;
1167
1168         switch (opt->binary) {
1169         case GREP_BINARY_DEFAULT:
1170                 if (grep_source_is_binary(gs))
1171                         binary_match_only = 1;
1172                 break;
1173         case GREP_BINARY_NOMATCH:
1174                 if (grep_source_is_binary(gs))
1175                         return 0; /* Assume unmatch */
1176                 break;
1177         case GREP_BINARY_TEXT:
1178                 break;
1179         default:
1180                 die("bug: unknown binary handling mode");
1181         }
1182
1183         memset(&xecfg, 0, sizeof(xecfg));
1184         opt->priv = &xecfg;
1185
1186         try_lookahead = should_lookahead(opt);
1187
1188         if (grep_source_load(gs) < 0)
1189                 return 0;
1190
1191         bol = gs->buf;
1192         left = gs->size;
1193         while (left) {
1194                 char *eol, ch;
1195                 int hit;
1196
1197                 /*
1198                  * look_ahead() skips quickly to the line that possibly
1199                  * has the next hit; don't call it if we need to do
1200                  * something more than just skipping the current line
1201                  * in response to an unmatch for the current line.  E.g.
1202                  * inside a post-context window, we will show the current
1203                  * line as a context around the previous hit when it
1204                  * doesn't hit.
1205                  */
1206                 if (try_lookahead
1207                     && !(last_hit
1208                          && (show_function ||
1209                              lno <= last_hit + opt->post_context))
1210                     && look_ahead(opt, &left, &lno, &bol))
1211                         break;
1212                 eol = end_of_line(bol, &left);
1213                 ch = *eol;
1214                 *eol = 0;
1215
1216                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1217                         ctx = GREP_CONTEXT_BODY;
1218
1219                 hit = match_line(opt, bol, eol, ctx, collect_hits);
1220                 *eol = ch;
1221
1222                 if (collect_hits)
1223                         goto next_line;
1224
1225                 /* "grep -v -e foo -e bla" should list lines
1226                  * that do not have either, so inversion should
1227                  * be done outside.
1228                  */
1229                 if (opt->invert)
1230                         hit = !hit;
1231                 if (opt->unmatch_name_only) {
1232                         if (hit)
1233                                 return 0;
1234                         goto next_line;
1235                 }
1236                 if (hit) {
1237                         count++;
1238                         if (opt->status_only)
1239                                 return 1;
1240                         if (opt->name_only) {
1241                                 show_name(opt, gs->name);
1242                                 return 1;
1243                         }
1244                         if (opt->count)
1245                                 goto next_line;
1246                         if (binary_match_only) {
1247                                 opt->output(opt, "Binary file ", 12);
1248                                 output_color(opt, gs->name, strlen(gs->name),
1249                                              opt->color_filename);
1250                                 opt->output(opt, " matches\n", 9);
1251                                 return 1;
1252                         }
1253                         /* Hit at this line.  If we haven't shown the
1254                          * pre-context lines, we would need to show them.
1255                          */
1256                         if (opt->pre_context || opt->funcbody)
1257                                 show_pre_context(opt, gs, bol, eol, lno);
1258                         else if (opt->funcname)
1259                                 show_funcname_line(opt, gs, bol, lno);
1260                         show_line(opt, bol, eol, gs->name, lno, ':');
1261                         last_hit = lno;
1262                         if (opt->funcbody)
1263                                 show_function = 1;
1264                         goto next_line;
1265                 }
1266                 if (show_function && match_funcname(opt, gs, bol, eol))
1267                         show_function = 0;
1268                 if (show_function ||
1269                     (last_hit && lno <= last_hit + opt->post_context)) {
1270                         /* If the last hit is within the post context,
1271                          * we need to show this line.
1272                          */
1273                         show_line(opt, bol, eol, gs->name, lno, '-');
1274                 }
1275
1276         next_line:
1277                 bol = eol + 1;
1278                 if (!left)
1279                         break;
1280                 left--;
1281                 lno++;
1282         }
1283
1284         if (collect_hits)
1285                 return 0;
1286
1287         if (opt->status_only)
1288                 return 0;
1289         if (opt->unmatch_name_only) {
1290                 /* We did not see any hit, so we want to show this */
1291                 show_name(opt, gs->name);
1292                 return 1;
1293         }
1294
1295         xdiff_clear_find_func(&xecfg);
1296         opt->priv = NULL;
1297
1298         /* NEEDSWORK:
1299          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1300          * which feels mostly useless but sometimes useful.  Maybe
1301          * make it another option?  For now suppress them.
1302          */
1303         if (opt->count && count) {
1304                 char buf[32];
1305                 output_color(opt, gs->name, strlen(gs->name), opt->color_filename);
1306                 output_sep(opt, ':');
1307                 snprintf(buf, sizeof(buf), "%u\n", count);
1308                 opt->output(opt, buf, strlen(buf));
1309                 return 1;
1310         }
1311         return !!last_hit;
1312 }
1313
1314 static void clr_hit_marker(struct grep_expr *x)
1315 {
1316         /* All-hit markers are meaningful only at the very top level
1317          * OR node.
1318          */
1319         while (1) {
1320                 x->hit = 0;
1321                 if (x->node != GREP_NODE_OR)
1322                         return;
1323                 x->u.binary.left->hit = 0;
1324                 x = x->u.binary.right;
1325         }
1326 }
1327
1328 static int chk_hit_marker(struct grep_expr *x)
1329 {
1330         /* Top level nodes have hit markers.  See if they all are hits */
1331         while (1) {
1332                 if (x->node != GREP_NODE_OR)
1333                         return x->hit;
1334                 if (!x->u.binary.left->hit)
1335                         return 0;
1336                 x = x->u.binary.right;
1337         }
1338 }
1339
1340 int grep_source(struct grep_opt *opt, struct grep_source *gs)
1341 {
1342         /*
1343          * we do not have to do the two-pass grep when we do not check
1344          * buffer-wide "all-match".
1345          */
1346         if (!opt->all_match)
1347                 return grep_source_1(opt, gs, 0);
1348
1349         /* Otherwise the toplevel "or" terms hit a bit differently.
1350          * We first clear hit markers from them.
1351          */
1352         clr_hit_marker(opt->pattern_expression);
1353         grep_source_1(opt, gs, 1);
1354
1355         if (!chk_hit_marker(opt->pattern_expression))
1356                 return 0;
1357
1358         return grep_source_1(opt, gs, 0);
1359 }
1360
1361 int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1362 {
1363         struct grep_source gs;
1364         int r;
1365
1366         grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL);
1367         gs.buf = buf;
1368         gs.size = size;
1369
1370         r = grep_source(opt, &gs);
1371
1372         grep_source_clear(&gs);
1373         return r;
1374 }
1375
1376 void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1377                       const char *name, const void *identifier)
1378 {
1379         gs->type = type;
1380         gs->name = name ? xstrdup(name) : NULL;
1381         gs->buf = NULL;
1382         gs->size = 0;
1383         gs->driver = NULL;
1384
1385         switch (type) {
1386         case GREP_SOURCE_FILE:
1387                 gs->identifier = xstrdup(identifier);
1388                 break;
1389         case GREP_SOURCE_SHA1:
1390                 gs->identifier = xmalloc(20);
1391                 memcpy(gs->identifier, identifier, 20);
1392                 break;
1393         case GREP_SOURCE_BUF:
1394                 gs->identifier = NULL;
1395         }
1396 }
1397
1398 void grep_source_clear(struct grep_source *gs)
1399 {
1400         free(gs->name);
1401         gs->name = NULL;
1402         free(gs->identifier);
1403         gs->identifier = NULL;
1404         grep_source_clear_data(gs);
1405 }
1406
1407 void grep_source_clear_data(struct grep_source *gs)
1408 {
1409         switch (gs->type) {
1410         case GREP_SOURCE_FILE:
1411         case GREP_SOURCE_SHA1:
1412                 free(gs->buf);
1413                 gs->buf = NULL;
1414                 gs->size = 0;
1415                 break;
1416         case GREP_SOURCE_BUF:
1417                 /* leave user-provided buf intact */
1418                 break;
1419         }
1420 }
1421
1422 static int grep_source_load_sha1(struct grep_source *gs)
1423 {
1424         enum object_type type;
1425
1426         grep_read_lock();
1427         gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1428         grep_read_unlock();
1429
1430         if (!gs->buf)
1431                 return error(_("'%s': unable to read %s"),
1432                              gs->name,
1433                              sha1_to_hex(gs->identifier));
1434         return 0;
1435 }
1436
1437 static int grep_source_load_file(struct grep_source *gs)
1438 {
1439         const char *filename = gs->identifier;
1440         struct stat st;
1441         char *data;
1442         size_t size;
1443         int i;
1444
1445         if (lstat(filename, &st) < 0) {
1446         err_ret:
1447                 if (errno != ENOENT)
1448                         error(_("'%s': %s"), filename, strerror(errno));
1449                 return -1;
1450         }
1451         if (!S_ISREG(st.st_mode))
1452                 return -1;
1453         size = xsize_t(st.st_size);
1454         i = open(filename, O_RDONLY);
1455         if (i < 0)
1456                 goto err_ret;
1457         data = xmalloc(size + 1);
1458         if (st.st_size != read_in_full(i, data, size)) {
1459                 error(_("'%s': short read %s"), filename, strerror(errno));
1460                 close(i);
1461                 free(data);
1462                 return -1;
1463         }
1464         close(i);
1465         data[size] = 0;
1466
1467         gs->buf = data;
1468         gs->size = size;
1469         return 0;
1470 }
1471
1472 static int grep_source_load(struct grep_source *gs)
1473 {
1474         if (gs->buf)
1475                 return 0;
1476
1477         switch (gs->type) {
1478         case GREP_SOURCE_FILE:
1479                 return grep_source_load_file(gs);
1480         case GREP_SOURCE_SHA1:
1481                 return grep_source_load_sha1(gs);
1482         case GREP_SOURCE_BUF:
1483                 return gs->buf ? 0 : -1;
1484         }
1485         die("BUG: invalid grep_source type");
1486 }
1487
1488 void grep_source_load_driver(struct grep_source *gs)
1489 {
1490         if (gs->driver)
1491                 return;
1492
1493         grep_attr_lock();
1494         gs->driver = userdiff_find_by_path(gs->name);
1495         if (!gs->driver)
1496                 gs->driver = userdiff_find_by_name("default");
1497         grep_attr_unlock();
1498 }
1499
1500 static int grep_source_is_binary(struct grep_source *gs)
1501 {
1502         grep_source_load_driver(gs);
1503         if (gs->driver->binary != -1)
1504                 return gs->driver->binary;
1505
1506         if (!grep_source_load(gs))
1507                 return buffer_is_binary(gs->buf, gs->size);
1508
1509         return 0;
1510 }