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         if (field == GREP_HEADER_REFLOG)
  68                 opt->use_reflog_filter = 1;
  69         do_append_grep_pat(&opt->header_tail, p);
  70 }
  71
  72 void append_grep_pattern(struct grep_opt *opt, const char *pat,
  73                          const char *origin, int no, enum grep_pat_token t)
  74 {
  75         append_grep_pat(opt, pat, strlen(pat), origin, no, t);
  76 }
  77
  78 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
  79                      const char *origin, int no, enum grep_pat_token t)
  80 {
  81         struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
  82         do_append_grep_pat(&opt->pattern_tail, p);
  83 }
  84
  85 struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
  86 {
  87         struct grep_pat *pat;
  88         struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
  89         *ret = *opt;
  90
  91         ret->pattern_list = NULL;
  92         ret->pattern_tail = &ret->pattern_list;
  93
  94         for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
  95         {
  96                 if(pat->token == GREP_PATTERN_HEAD)
  97                         append_header_grep_pattern(ret, pat->field,
  98                                                    pat->pattern);
  99                 else
 100                         append_grep_pat(ret, pat->pattern, pat->patternlen,
 101                                         pat->origin, pat->no, pat->token);
 102         }
 103
 104         return ret;
 105 }
 106
 107 static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 108                 const char *error)
 109 {
 110         char where[1024];
 111
 112         if (p->no)
 113                 sprintf(where, "In '%s' at %d, ", p->origin, p->no);
 114         else if (p->origin)
 115                 sprintf(where, "%s, ", p->origin);
 116         else
 117                 where[0] = 0;
 118
 119         die("%s'%s': %s", where, p->pattern, error);
 120 }
 121
 122 #ifdef USE_LIBPCRE
 123 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 124 {
 125         const char *error;
 126         int erroffset;
 127         int options = PCRE_MULTILINE;
 128
 129         if (opt->ignore_case)
 130                 options |= PCRE_CASELESS;
 131
 132         p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 133                         NULL);
 134         if (!p->pcre_regexp)
 135                 compile_regexp_failed(p, error);
 136
 137         p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 138         if (!p->pcre_extra_info && error)
 139                 die("%s", error);
 140 }
 141
 142 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 143                 regmatch_t *match, int eflags)
 144 {
 145         int ovector[30], ret, flags = 0;
 146
 147         if (eflags & REG_NOTBOL)
 148                 flags |= PCRE_NOTBOL;
 149
 150         ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 151                         0, flags, ovector, ARRAY_SIZE(ovector));
 152         if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 153                 die("pcre_exec failed with error code %d", ret);
 154         if (ret > 0) {
 155                 ret = 0;
 156                 match->rm_so = ovector[0];
 157                 match->rm_eo = ovector[1];
 158         }
 159
 160         return ret;
 161 }
 162
 163 static void free_pcre_regexp(struct grep_pat *p)
 164 {
 165         pcre_free(p->pcre_regexp);
 166         pcre_free(p->pcre_extra_info);
 167 }
 168 #else /* !USE_LIBPCRE */
 169 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 170 {
 171         die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 172 }
 173
 174 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 175                 regmatch_t *match, int eflags)
 176 {
 177         return 1;
 178 }
 179
 180 static void free_pcre_regexp(struct grep_pat *p)
 181 {
 182 }
 183 #endif /* !USE_LIBPCRE */
 184
 185 static int is_fixed(const char *s, size_t len)
 186 {
 187         size_t i;
 188
 189         /* regcomp cannot accept patterns with NULs so we
 190          * consider any pattern containing a NUL fixed.
 191          */
 192         if (memchr(s, 0, len))
 193                 return 1;
 194
 195         for (i = 0; i < len; i++) {
 196                 if (is_regex_special(s[i]))
 197                         return 0;
 198         }
 199
 200         return 1;
 201 }
 202
 203 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 204 {
 205         int err;
 206
 207         p->word_regexp = opt->word_regexp;
 208         p->ignore_case = opt->ignore_case;
 209
 210         if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 211                 p->fixed = 1;
 212         else
 213                 p->fixed = 0;
 214
 215         if (p->fixed) {
 216                 if (opt->regflags & REG_ICASE || p->ignore_case)
 217                         p->kws = kwsalloc(tolower_trans_tbl);
 218                 else
 219                         p->kws = kwsalloc(NULL);
 220                 kwsincr(p->kws, p->pattern, p->patternlen);
 221                 kwsprep(p->kws);
 222                 return;
 223         }
 224
 225         if (opt->pcre) {
 226                 compile_pcre_regexp(p, opt);
 227                 return;
 228         }
 229
 230         err = regcomp(&p->regexp, p->pattern, opt->regflags);
 231         if (err) {
 232                 char errbuf[1024];
 233                 regerror(err, &p->regexp, errbuf, 1024);
 234                 regfree(&p->regexp);
 235                 compile_regexp_failed(p, errbuf);
 236         }
 237 }
 238
 239 static struct grep_expr *compile_pattern_or(struct grep_pat **);
 240 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 241 {
 242         struct grep_pat *p;
 243         struct grep_expr *x;
 244
 245         p = *list;
 246         if (!p)
 247                 return NULL;
 248         switch (p->token) {
 249         case GREP_PATTERN: /* atom */
 250         case GREP_PATTERN_HEAD:
 251         case GREP_PATTERN_BODY:
 252                 x = xcalloc(1, sizeof (struct grep_expr));
 253                 x->node = GREP_NODE_ATOM;
 254                 x->u.atom = p;
 255                 *list = p->next;
 256                 return x;
 257         case GREP_OPEN_PAREN:
 258                 *list = p->next;
 259                 x = compile_pattern_or(list);
 260                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 261                         die("unmatched parenthesis");
 262                 *list = (*list)->next;
 263                 return x;
 264         default:
 265                 return NULL;
 266         }
 267 }
 268
 269 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 270 {
 271         struct grep_pat *p;
 272         struct grep_expr *x;
 273
 274         p = *list;
 275         if (!p)
 276                 return NULL;
 277         switch (p->token) {
 278         case GREP_NOT:
 279                 if (!p->next)
 280                         die("--not not followed by pattern expression");
 281                 *list = p->next;
 282                 x = xcalloc(1, sizeof (struct grep_expr));
 283                 x->node = GREP_NODE_NOT;
 284                 x->u.unary = compile_pattern_not(list);
 285                 if (!x->u.unary)
 286                         die("--not followed by non pattern expression");
 287                 return x;
 288         default:
 289                 return compile_pattern_atom(list);
 290         }
 291 }
 292
 293 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 294 {
 295         struct grep_pat *p;
 296         struct grep_expr *x, *y, *z;
 297
 298         x = compile_pattern_not(list);
 299         p = *list;
 300         if (p && p->token == GREP_AND) {
 301                 if (!p->next)
 302                         die("--and not followed by pattern expression");
 303                 *list = p->next;
 304                 y = compile_pattern_and(list);
 305                 if (!y)
 306                         die("--and not followed by pattern expression");
 307                 z = xcalloc(1, sizeof (struct grep_expr));
 308                 z->node = GREP_NODE_AND;
 309                 z->u.binary.left = x;
 310                 z->u.binary.right = y;
 311                 return z;
 312         }
 313         return x;
 314 }
 315
 316 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 317 {
 318         struct grep_pat *p;
 319         struct grep_expr *x, *y, *z;
 320
 321         x = compile_pattern_and(list);
 322         p = *list;
 323         if (x && p && p->token != GREP_CLOSE_PAREN) {
 324                 y = compile_pattern_or(list);
 325                 if (!y)
 326                         die("not a pattern expression %s", p->pattern);
 327                 z = xcalloc(1, sizeof (struct grep_expr));
 328                 z->node = GREP_NODE_OR;
 329                 z->u.binary.left = x;
 330                 z->u.binary.right = y;
 331                 return z;
 332         }
 333         return x;
 334 }
 335
 336 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 337 {
 338         return compile_pattern_or(list);
 339 }
 340
 341 static void indent(int in)
 342 {
 343         while (in-- > 0)
 344                 fputc(' ', stderr);
 345 }
 346
 347 static void dump_grep_pat(struct grep_pat *p)
 348 {
 349         switch (p->token) {
 350         case GREP_AND: fprintf(stderr, "*and*"); break;
 351         case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 352         case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 353         case GREP_NOT: fprintf(stderr, "*not*"); break;
 354         case GREP_OR: fprintf(stderr, "*or*"); break;
 355
 356         case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 357         case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 358         case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 359         }
 360
 361         switch (p->token) {
 362         default: break;
 363         case GREP_PATTERN_HEAD:
 364                 fprintf(stderr, "<head %d>", p->field); break;
 365         case GREP_PATTERN_BODY:
 366                 fprintf(stderr, "<body>"); break;
 367         }
 368         switch (p->token) {
 369         default: break;
 370         case GREP_PATTERN_HEAD:
 371         case GREP_PATTERN_BODY:
 372         case GREP_PATTERN:
 373                 fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 374                 break;
 375         }
 376         fputc('\n', stderr);
 377 }
 378
 379 static void dump_grep_expression_1(struct grep_expr *x, int in)
 380 {
 381         indent(in);
 382         switch (x->node) {
 383         case GREP_NODE_TRUE:
 384                 fprintf(stderr, "true\n");
 385                 break;
 386         case GREP_NODE_ATOM:
 387                 dump_grep_pat(x->u.atom);
 388                 break;
 389         case GREP_NODE_NOT:
 390                 fprintf(stderr, "(not\n");
 391                 dump_grep_expression_1(x->u.unary, in+1);
 392                 indent(in);
 393                 fprintf(stderr, ")\n");
 394                 break;
 395         case GREP_NODE_AND:
 396                 fprintf(stderr, "(and\n");
 397                 dump_grep_expression_1(x->u.binary.left, in+1);
 398                 dump_grep_expression_1(x->u.binary.right, in+1);
 399                 indent(in);
 400                 fprintf(stderr, ")\n");
 401                 break;
 402         case GREP_NODE_OR:
 403                 fprintf(stderr, "(or\n");
 404                 dump_grep_expression_1(x->u.binary.left, in+1);
 405                 dump_grep_expression_1(x->u.binary.right, in+1);
 406                 indent(in);
 407                 fprintf(stderr, ")\n");
 408                 break;
 409         }
 410 }
 411
 412 static void dump_grep_expression(struct grep_opt *opt)
 413 {
 414         struct grep_expr *x = opt->pattern_expression;
 415
 416         if (opt->all_match)
 417                 fprintf(stderr, "[all-match]\n");
 418         dump_grep_expression_1(x, 0);
 419         fflush(NULL);
 420 }
 421
 422 static struct grep_expr *grep_true_expr(void)
 423 {
 424         struct grep_expr *z = xcalloc(1, sizeof(*z));
 425         z->node = GREP_NODE_TRUE;
 426         return z;
 427 }
 428
 429 static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 430 {
 431         struct grep_expr *z = xcalloc(1, sizeof(*z));
 432         z->node = GREP_NODE_OR;
 433         z->u.binary.left = left;
 434         z->u.binary.right = right;
 435         return z;
 436 }
 437
 438 static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 439 {
 440         struct grep_pat *p;
 441         struct grep_expr *header_expr;
 442         struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 443         enum grep_header_field fld;
 444
 445         if (!opt->header_list)
 446                 return NULL;
 447
 448         for (p = opt->header_list; p; p = p->next) {
 449                 if (p->token != GREP_PATTERN_HEAD)
 450                         die("bug: a non-header pattern in grep header list.");
 451                 if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
 452                         die("bug: unknown header field %d", p->field);
 453                 compile_regexp(p, opt);
 454         }
 455
 456         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 457                 header_group[fld] = NULL;
 458
 459         for (p = opt->header_list; p; p = p->next) {
 460                 struct grep_expr *h;
 461                 struct grep_pat *pp = p;
 462
 463                 h = compile_pattern_atom(&pp);
 464                 if (!h || pp != p->next)
 465                         die("bug: malformed header expr");
 466                 if (!header_group[p->field]) {
 467                         header_group[p->field] = h;
 468                         continue;
 469                 }
 470                 header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 471         }
 472
 473         header_expr = NULL;
 474
 475         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 476                 if (!header_group[fld])
 477                         continue;
 478                 if (!header_expr)
 479                         header_expr = grep_true_expr();
 480                 header_expr = grep_or_expr(header_group[fld], header_expr);
 481         }
 482         return header_expr;
 483 }
 484
 485 static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 486 {
 487         struct grep_expr *z = x;
 488
 489         while (x) {
 490                 assert(x->node == GREP_NODE_OR);
 491                 if (x->u.binary.right &&
 492                     x->u.binary.right->node == GREP_NODE_TRUE) {
 493                         x->u.binary.right = y;
 494                         break;
 495                 }
 496                 x = x->u.binary.right;
 497         }
 498         return z;
 499 }
 500
 501 static void compile_grep_patterns_real(struct grep_opt *opt)
 502 {
 503         struct grep_pat *p;
 504         struct grep_expr *header_expr = prep_header_patterns(opt);
 505
 506         for (p = opt->pattern_list; p; p = p->next) {
 507                 switch (p->token) {
 508                 case GREP_PATTERN: /* atom */
 509                 case GREP_PATTERN_HEAD:
 510                 case GREP_PATTERN_BODY:
 511                         compile_regexp(p, opt);
 512                         break;
 513                 default:
 514                         opt->extended = 1;
 515                         break;
 516                 }
 517         }
 518
 519         if (opt->all_match || header_expr)
 520                 opt->extended = 1;
 521         else if (!opt->extended && !opt->debug)
 522                 return;
 523
 524         p = opt->pattern_list;
 525         if (p)
 526                 opt->pattern_expression = compile_pattern_expr(&p);
 527         if (p)
 528                 die("incomplete pattern expression: %s", p->pattern);
 529
 530         if (!header_expr)
 531                 return;
 532
 533         if (!opt->pattern_expression)
 534                 opt->pattern_expression = header_expr;
 535         else if (opt->all_match)
 536                 opt->pattern_expression = grep_splice_or(header_expr,
 537                                                          opt->pattern_expression);
 538         else
 539                 opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 540                                                        header_expr);
 541         opt->all_match = 1;
 542 }
 543
 544 void compile_grep_patterns(struct grep_opt *opt)
 545 {
 546         compile_grep_patterns_real(opt);
 547         if (opt->debug)
 548                 dump_grep_expression(opt);
 549 }
 550
 551 static void free_pattern_expr(struct grep_expr *x)
 552 {
 553         switch (x->node) {
 554         case GREP_NODE_TRUE:
 555         case GREP_NODE_ATOM:
 556                 break;
 557         case GREP_NODE_NOT:
 558                 free_pattern_expr(x->u.unary);
 559                 break;
 560         case GREP_NODE_AND:
 561         case GREP_NODE_OR:
 562                 free_pattern_expr(x->u.binary.left);
 563                 free_pattern_expr(x->u.binary.right);
 564                 break;
 565         }
 566         free(x);
 567 }
 568
 569 void free_grep_patterns(struct grep_opt *opt)
 570 {
 571         struct grep_pat *p, *n;
 572
 573         for (p = opt->pattern_list; p; p = n) {
 574                 n = p->next;
 575                 switch (p->token) {
 576                 case GREP_PATTERN: /* atom */
 577                 case GREP_PATTERN_HEAD:
 578                 case GREP_PATTERN_BODY:
 579                         if (p->kws)
 580                                 kwsfree(p->kws);
 581                         else if (p->pcre_regexp)
 582                                 free_pcre_regexp(p);
 583                         else
 584                                 regfree(&p->regexp);
 585                         free(p->pattern);
 586                         break;
 587                 default:
 588                         break;
 589                 }
 590                 free(p);
 591         }
 592
 593         if (!opt->extended)
 594                 return;
 595         free_pattern_expr(opt->pattern_expression);
 596 }
 597
 598 static char *end_of_line(char *cp, unsigned long *left)
 599 {
 600         unsigned long l = *left;
 601         while (l && *cp != '\n') {
 602                 l--;
 603                 cp++;
 604         }
 605         *left = l;
 606         return cp;
 607 }
 608
 609 static int word_char(char ch)
 610 {
 611         return isalnum(ch) || ch == '_';
 612 }
 613
 614 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 615                          const char *color)
 616 {
 617         if (want_color(opt->color) && color && color[0]) {
 618                 opt->output(opt, color, strlen(color));
 619                 opt->output(opt, data, size);
 620                 opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 621         } else
 622                 opt->output(opt, data, size);
 623 }
 624
 625 static void output_sep(struct grep_opt *opt, char sign)
 626 {
 627         if (opt->null_following_name)
 628                 opt->output(opt, "\0", 1);
 629         else
 630                 output_color(opt, &sign, 1, opt->color_sep);
 631 }
 632
 633 static void show_name(struct grep_opt *opt, const char *name)
 634 {
 635         output_color(opt, name, strlen(name), opt->color_filename);
 636         opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 637 }
 638
 639 static int fixmatch(struct grep_pat *p, char *line, char *eol,
 640                     regmatch_t *match)
 641 {
 642         struct kwsmatch kwsm;
 643         size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 644         if (offset == -1) {
 645                 match->rm_so = match->rm_eo = -1;
 646                 return REG_NOMATCH;
 647         } else {
 648                 match->rm_so = offset;
 649                 match->rm_eo = match->rm_so + kwsm.size[0];
 650                 return 0;
 651         }
 652 }
 653
 654 static int regmatch(const regex_t *preg, char *line, char *eol,
 655                     regmatch_t *match, int eflags)
 656 {
 657 #ifdef REG_STARTEND
 658         match->rm_so = 0;
 659         match->rm_eo = eol - line;
 660         eflags |= REG_STARTEND;
 661 #endif
 662         return regexec(preg, line, 1, match, eflags);
 663 }
 664
 665 static int patmatch(struct grep_pat *p, char *line, char *eol,
 666                     regmatch_t *match, int eflags)
 667 {
 668         int hit;
 669
 670         if (p->fixed)
 671                 hit = !fixmatch(p, line, eol, match);
 672         else if (p->pcre_regexp)
 673                 hit = !pcrematch(p, line, eol, match, eflags);
 674         else
 675                 hit = !regmatch(&p->regexp, line, eol, match, eflags);
 676
 677         return hit;
 678 }
 679
 680 static int strip_timestamp(char *bol, char **eol_p)
 681 {
 682         char *eol = *eol_p;
 683         int ch;
 684
 685         while (bol < --eol) {
 686                 if (*eol != '>')
 687                         continue;
 688                 *eol_p = ++eol;
 689                 ch = *eol;
 690                 *eol = '\0';
 691                 return ch;
 692         }
 693         return 0;
 694 }
 695
 696 static struct {
 697         const char *field;
 698         size_t len;
 699 } header_field[] = {
 700         { "author ", 7 },
 701         { "committer ", 10 },
 702         { "reflog ", 7 },
 703 };
 704
 705 static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 706                              enum grep_context ctx,
 707                              regmatch_t *pmatch, int eflags)
 708 {
 709         int hit = 0;
 710         int saved_ch = 0;
 711         const char *start = bol;
 712
 713         if ((p->token != GREP_PATTERN) &&
 714             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 715                 return 0;
 716
 717         if (p->token == GREP_PATTERN_HEAD) {
 718                 const char *field;
 719                 size_t len;
 720                 assert(p->field < ARRAY_SIZE(header_field));
 721                 field = header_field[p->field].field;
 722                 len = header_field[p->field].len;
 723                 if (strncmp(bol, field, len))
 724                         return 0;
 725                 bol += len;
 726                 switch (p->field) {
 727                 case GREP_HEADER_AUTHOR:
 728                 case GREP_HEADER_COMMITTER:
 729                         saved_ch = strip_timestamp(bol, &eol);
 730                         break;
 731                 default:
 732                         break;
 733                 }
 734         }
 735
 736  again:
 737         hit = patmatch(p, bol, eol, pmatch, eflags);
 738
 739         if (hit && p->word_regexp) {
 740                 if ((pmatch[0].rm_so < 0) ||
 741                     (eol - bol) < pmatch[0].rm_so ||
 742                     (pmatch[0].rm_eo < 0) ||
 743                     (eol - bol) < pmatch[0].rm_eo)
 744                         die("regexp returned nonsense");
 745
 746                 /* Match beginning must be either beginning of the
 747                  * line, or at word boundary (i.e. the last char must
 748                  * not be a word char).  Similarly, match end must be
 749                  * either end of the line, or at word boundary
 750                  * (i.e. the next char must not be a word char).
 751                  */
 752                 if ( ((pmatch[0].rm_so == 0) ||
 753                       !word_char(bol[pmatch[0].rm_so-1])) &&
 754                      ((pmatch[0].rm_eo == (eol-bol)) ||
 755                       !word_char(bol[pmatch[0].rm_eo])) )
 756                         ;
 757                 else
 758                         hit = 0;
 759
 760                 /* Words consist of at least one character. */
 761                 if (pmatch->rm_so == pmatch->rm_eo)
 762                         hit = 0;
 763
 764                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 765                         /* There could be more than one match on the
 766                          * line, and the first match might not be
 767                          * strict word match.  But later ones could be!
 768                          * Forward to the next possible start, i.e. the
 769                          * next position following a non-word char.
 770                          */
 771                         bol = pmatch[0].rm_so + bol + 1;
 772                         while (word_char(bol[-1]) && bol < eol)
 773                                 bol++;
 774                         eflags |= REG_NOTBOL;
 775                         if (bol < eol)
 776                                 goto again;
 777                 }
 778         }
 779         if (p->token == GREP_PATTERN_HEAD && saved_ch)
 780                 *eol = saved_ch;
 781         if (hit) {
 782                 pmatch[0].rm_so += bol - start;
 783                 pmatch[0].rm_eo += bol - start;
 784         }
 785         return hit;
 786 }
 787
 788 static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 789                            enum grep_context ctx, int collect_hits)
 790 {
 791         int h = 0;
 792         regmatch_t match;
 793
 794         if (!x)
 795                 die("Not a valid grep expression");
 796         switch (x->node) {
 797         case GREP_NODE_TRUE:
 798                 h = 1;
 799                 break;
 800         case GREP_NODE_ATOM:
 801                 h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 802                 break;
 803         case GREP_NODE_NOT:
 804                 h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 805                 break;
 806         case GREP_NODE_AND:
 807                 if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 808                         return 0;
 809                 h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 810                 break;
 811         case GREP_NODE_OR:
 812                 if (!collect_hits)
 813                         return (match_expr_eval(x->u.binary.left,
 814                                                 bol, eol, ctx, 0) ||
 815                                 match_expr_eval(x->u.binary.right,
 816                                                 bol, eol, ctx, 0));
 817                 h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 818                 x->u.binary.left->hit |= h;
 819                 h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 820                 break;
 821         default:
 822                 die("Unexpected node type (internal error) %d", x->node);
 823         }
 824         if (collect_hits)
 825                 x->hit |= h;
 826         return h;
 827 }
 828
 829 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 830                       enum grep_context ctx, int collect_hits)
 831 {
 832         struct grep_expr *x = opt->pattern_expression;
 833         return match_expr_eval(x, bol, eol, ctx, collect_hits);
 834 }
 835
 836 static int match_line(struct grep_opt *opt, char *bol, char *eol,
 837                       enum grep_context ctx, int collect_hits)
 838 {
 839         struct grep_pat *p;
 840         regmatch_t match;
 841
 842         if (opt->extended)
 843                 return match_expr(opt, bol, eol, ctx, collect_hits);
 844
 845         /* we do not call with collect_hits without being extended */
 846         for (p = opt->pattern_list; p; p = p->next) {
 847                 if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 848                         return 1;
 849         }
 850         return 0;
 851 }
 852
 853 static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 854                               enum grep_context ctx,
 855                               regmatch_t *pmatch, int eflags)
 856 {
 857         regmatch_t match;
 858
 859         if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 860                 return 0;
 861         if (match.rm_so < 0 || match.rm_eo < 0)
 862                 return 0;
 863         if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 864                 if (match.rm_so > pmatch->rm_so)
 865                         return 1;
 866                 if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 867                         return 1;
 868         }
 869         pmatch->rm_so = match.rm_so;
 870         pmatch->rm_eo = match.rm_eo;
 871         return 1;
 872 }
 873
 874 static int next_match(struct grep_opt *opt, char *bol, char *eol,
 875                       enum grep_context ctx, regmatch_t *pmatch, int eflags)
 876 {
 877         struct grep_pat *p;
 878         int hit = 0;
 879
 880         pmatch->rm_so = pmatch->rm_eo = -1;
 881         if (bol < eol) {
 882                 for (p = opt->pattern_list; p; p = p->next) {
 883                         switch (p->token) {
 884                         case GREP_PATTERN: /* atom */
 885                         case GREP_PATTERN_HEAD:
 886                         case GREP_PATTERN_BODY:
 887                                 hit |= match_next_pattern(p, bol, eol, ctx,
 888                                                           pmatch, eflags);
 889                                 break;
 890                         default:
 891                                 break;
 892                         }
 893                 }
 894         }
 895         return hit;
 896 }
 897
 898 static void show_line(struct grep_opt *opt, char *bol, char *eol,
 899                       const char *name, unsigned lno, char sign)
 900 {
 901         int rest = eol - bol;
 902         char *line_color = NULL;
 903
 904         if (opt->file_break && opt->last_shown == 0) {
 905                 if (opt->show_hunk_mark)
 906                         opt->output(opt, "\n", 1);
 907         } else if (opt->pre_context || opt->post_context || opt->funcbody) {
 908                 if (opt->last_shown == 0) {
 909                         if (opt->show_hunk_mark) {
 910                                 output_color(opt, "--", 2, opt->color_sep);
 911                                 opt->output(opt, "\n", 1);
 912                         }
 913                 } else if (lno > opt->last_shown + 1) {
 914                         output_color(opt, "--", 2, opt->color_sep);
 915                         opt->output(opt, "\n", 1);
 916                 }
 917         }
 918         if (opt->heading && opt->last_shown == 0) {
 919                 output_color(opt, name, strlen(name), opt->color_filename);
 920                 opt->output(opt, "\n", 1);
 921         }
 922         opt->last_shown = lno;
 923
 924         if (!opt->heading && opt->pathname) {
 925                 output_color(opt, name, strlen(name), opt->color_filename);
 926                 output_sep(opt, sign);
 927         }
 928         if (opt->linenum) {
 929                 char buf[32];
 930                 snprintf(buf, sizeof(buf), "%d", lno);
 931                 output_color(opt, buf, strlen(buf), opt->color_lineno);
 932                 output_sep(opt, sign);
 933         }
 934         if (opt->color) {
 935                 regmatch_t match;
 936                 enum grep_context ctx = GREP_CONTEXT_BODY;
 937                 int ch = *eol;
 938                 int eflags = 0;
 939
 940                 if (sign == ':')
 941                         line_color = opt->color_selected;
 942                 else if (sign == '-')
 943                         line_color = opt->color_context;
 944                 else if (sign == '=')
 945                         line_color = opt->color_function;
 946                 *eol = '\0';
 947                 while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 948                         if (match.rm_so == match.rm_eo)
 949                                 break;
 950
 951                         output_color(opt, bol, match.rm_so, line_color);
 952                         output_color(opt, bol + match.rm_so,
 953                                      match.rm_eo - match.rm_so,
 954                                      opt->color_match);
 955                         bol += match.rm_eo;
 956                         rest -= match.rm_eo;
 957                         eflags = REG_NOTBOL;
 958                 }
 959                 *eol = ch;
 960         }
 961         output_color(opt, bol, rest, line_color);
 962         opt->output(opt, "\n", 1);
 963 }
 964
 965 #ifndef NO_PTHREADS
 966 int grep_use_locks;
 967
 968 /*
 969  * This lock protects access to the gitattributes machinery, which is
 970  * not thread-safe.
 971  */
 972 pthread_mutex_t grep_attr_mutex;
 973
 974 static inline void grep_attr_lock(void)
 975 {
 976         if (grep_use_locks)
 977                 pthread_mutex_lock(&grep_attr_mutex);
 978 }
 979
 980 static inline void grep_attr_unlock(void)
 981 {
 982         if (grep_use_locks)
 983                 pthread_mutex_unlock(&grep_attr_mutex);
 984 }
 985
 986 /*
 987  * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
 988  */
 989 pthread_mutex_t grep_read_mutex;
 990
 991 #else
 992 #define grep_attr_lock()
 993 #define grep_attr_unlock()
 994 #endif
 995
 996 static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
 997 {
 998         xdemitconf_t *xecfg = opt->priv;
 999         if (xecfg && !xecfg->find_func) {
1000                 grep_source_load_driver(gs);
1001                 if (gs->driver->funcname.pattern) {
1002                         const struct userdiff_funcname *pe = &gs->driver->funcname;
1003                         xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1004                 } else {
1005                         xecfg = opt->priv = NULL;
1006                 }
1007         }
1008
1009         if (xecfg) {
1010                 char buf[1];
1011                 return xecfg->find_func(bol, eol - bol, buf, 1,
1012                                         xecfg->find_func_priv) >= 0;
1013         }
1014
1015         if (bol == eol)
1016                 return 0;
1017         if (isalpha(*bol) || *bol == '_' || *bol == '$')
1018                 return 1;
1019         return 0;
1020 }
1021
1022 static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1023                                char *bol, unsigned lno)
1024 {
1025         while (bol > gs->buf) {
1026                 char *eol = --bol;
1027
1028                 while (bol > gs->buf && bol[-1] != '\n')
1029                         bol--;
1030                 lno--;
1031
1032                 if (lno <= opt->last_shown)
1033                         break;
1034
1035                 if (match_funcname(opt, gs, bol, eol)) {
1036                         show_line(opt, bol, eol, gs->name, lno, '=');
1037                         break;
1038                 }
1039         }
1040 }
1041
1042 static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1043                              char *bol, char *end, unsigned lno)
1044 {
1045         unsigned cur = lno, from = 1, funcname_lno = 0;
1046         int funcname_needed = !!opt->funcname;
1047
1048         if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1049                 funcname_needed = 2;
1050
1051         if (opt->pre_context < lno)
1052                 from = lno - opt->pre_context;
1053         if (from <= opt->last_shown)
1054                 from = opt->last_shown + 1;
1055
1056         /* Rewind. */
1057         while (bol > gs->buf &&
1058                cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1059                 char *eol = --bol;
1060
1061                 while (bol > gs->buf && bol[-1] != '\n')
1062                         bol--;
1063                 cur--;
1064                 if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1065                         funcname_lno = cur;
1066                         funcname_needed = 0;
1067                 }
1068         }
1069
1070         /* We need to look even further back to find a function signature. */
1071         if (opt->funcname && funcname_needed)
1072                 show_funcname_line(opt, gs, bol, cur);
1073
1074         /* Back forward. */
1075         while (cur < lno) {
1076                 char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1077
1078                 while (*eol != '\n')
1079                         eol++;
1080                 show_line(opt, bol, eol, gs->name, cur, sign);
1081                 bol = eol + 1;
1082                 cur++;
1083         }
1084 }
1085
1086 static int should_lookahead(struct grep_opt *opt)
1087 {
1088         struct grep_pat *p;
1089
1090         if (opt->extended)
1091                 return 0; /* punt for too complex stuff */
1092         if (opt->invert)
1093                 return 0;
1094         for (p = opt->pattern_list; p; p = p->next) {
1095                 if (p->token != GREP_PATTERN)
1096                         return 0; /* punt for "header only" and stuff */
1097         }
1098         return 1;
1099 }
1100
1101 static int look_ahead(struct grep_opt *opt,
1102                       unsigned long *left_p,
1103                       unsigned *lno_p,
1104                       char **bol_p)
1105 {
1106         unsigned lno = *lno_p;
1107         char *bol = *bol_p;
1108         struct grep_pat *p;
1109         char *sp, *last_bol;
1110         regoff_t earliest = -1;
1111
1112         for (p = opt->pattern_list; p; p = p->next) {
1113                 int hit;
1114                 regmatch_t m;
1115
1116                 hit = patmatch(p, bol, bol + *left_p, &m, 0);
1117                 if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1118                         continue;
1119                 if (earliest < 0 || m.rm_so < earliest)
1120                         earliest = m.rm_so;
1121         }
1122
1123         if (earliest < 0) {
1124                 *bol_p = bol + *left_p;
1125                 *left_p = 0;
1126                 return 1;
1127         }
1128         for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1129                 ; /* find the beginning of the line */
1130         last_bol = sp;
1131
1132         for (sp = bol; sp < last_bol; sp++) {
1133                 if (*sp == '\n')
1134                         lno++;
1135         }
1136         *left_p -= last_bol - bol;
1137         *bol_p = last_bol;
1138         *lno_p = lno;
1139         return 0;
1140 }
1141
1142 static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1143 {
1144         fwrite(buf, size, 1, stdout);
1145 }
1146
1147 static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1148 {
1149         char *bol;
1150         unsigned long left;
1151         unsigned lno = 1;
1152         unsigned last_hit = 0;
1153         int binary_match_only = 0;
1154         unsigned count = 0;
1155         int try_lookahead = 0;
1156         int show_function = 0;
1157         enum grep_context ctx = GREP_CONTEXT_HEAD;
1158         xdemitconf_t xecfg;
1159
1160         if (!opt->output)
1161                 opt->output = std_output;
1162
1163         if (opt->pre_context || opt->post_context || opt->file_break ||
1164             opt->funcbody) {
1165                 /* Show hunk marks, except for the first file. */
1166                 if (opt->last_shown)
1167                         opt->show_hunk_mark = 1;
1168                 /*
1169                  * If we're using threads then we can't easily identify
1170                  * the first file.  Always put hunk marks in that case
1171                  * and skip the very first one later in work_done().
1172                  */
1173                 if (opt->output != std_output)
1174                         opt->show_hunk_mark = 1;
1175         }
1176         opt->last_shown = 0;
1177
1178         switch (opt->binary) {
1179         case GREP_BINARY_DEFAULT:
1180                 if (grep_source_is_binary(gs))
1181                         binary_match_only = 1;
1182                 break;
1183         case GREP_BINARY_NOMATCH:
1184                 if (grep_source_is_binary(gs))
1185                         return 0; /* Assume unmatch */
1186                 break;
1187         case GREP_BINARY_TEXT:
1188                 break;
1189         default:
1190                 die("bug: unknown binary handling mode");
1191         }
1192
1193         memset(&xecfg, 0, sizeof(xecfg));
1194         opt->priv = &xecfg;
1195
1196         try_lookahead = should_lookahead(opt);
1197
1198         if (grep_source_load(gs) < 0)
1199                 return 0;
1200
1201         bol = gs->buf;
1202         left = gs->size;
1203         while (left) {
1204                 char *eol, ch;
1205                 int hit;
1206
1207                 /*
1208                  * look_ahead() skips quickly to the line that possibly
1209                  * has the next hit; don't call it if we need to do
1210                  * something more than just skipping the current line
1211                  * in response to an unmatch for the current line.  E.g.
1212                  * inside a post-context window, we will show the current
1213                  * line as a context around the previous hit when it
1214                  * doesn't hit.
1215                  */
1216                 if (try_lookahead
1217                     && !(last_hit
1218                          && (show_function ||
1219                              lno <= last_hit + opt->post_context))
1220                     && look_ahead(opt, &left, &lno, &bol))
1221                         break;
1222                 eol = end_of_line(bol, &left);
1223                 ch = *eol;
1224                 *eol = 0;
1225
1226                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1227                         ctx = GREP_CONTEXT_BODY;
1228
1229                 hit = match_line(opt, bol, eol, ctx, collect_hits);
1230                 *eol = ch;
1231
1232                 if (collect_hits)
1233                         goto next_line;
1234
1235                 /* "grep -v -e foo -e bla" should list lines
1236                  * that do not have either, so inversion should
1237                  * be done outside.
1238                  */
1239                 if (opt->invert)
1240                         hit = !hit;
1241                 if (opt->unmatch_name_only) {
1242                         if (hit)
1243                                 return 0;
1244                         goto next_line;
1245                 }
1246                 if (hit) {
1247                         count++;
1248                         if (opt->status_only)
1249                                 return 1;
1250                         if (opt->name_only) {
1251                                 show_name(opt, gs->name);
1252                                 return 1;
1253                         }
1254                         if (opt->count)
1255                                 goto next_line;
1256                         if (binary_match_only) {
1257                                 opt->output(opt, "Binary file ", 12);
1258                                 output_color(opt, gs->name, strlen(gs->name),
1259                                              opt->color_filename);
1260                                 opt->output(opt, " matches\n", 9);
1261                                 return 1;
1262                         }
1263                         /* Hit at this line.  If we haven't shown the
1264                          * pre-context lines, we would need to show them.
1265                          */
1266                         if (opt->pre_context || opt->funcbody)
1267                                 show_pre_context(opt, gs, bol, eol, lno);
1268                         else if (opt->funcname)
1269                                 show_funcname_line(opt, gs, bol, lno);
1270                         show_line(opt, bol, eol, gs->name, lno, ':');
1271                         last_hit = lno;
1272                         if (opt->funcbody)
1273                                 show_function = 1;
1274                         goto next_line;
1275                 }
1276                 if (show_function && match_funcname(opt, gs, bol, eol))
1277                         show_function = 0;
1278                 if (show_function ||
1279                     (last_hit && lno <= last_hit + opt->post_context)) {
1280                         /* If the last hit is within the post context,
1281                          * we need to show this line.
1282                          */
1283                         show_line(opt, bol, eol, gs->name, lno, '-');
1284                 }
1285
1286         next_line:
1287                 bol = eol + 1;
1288                 if (!left)
1289                         break;
1290                 left--;
1291                 lno++;
1292         }
1293
1294         if (collect_hits)
1295                 return 0;
1296
1297         if (opt->status_only)
1298                 return 0;
1299         if (opt->unmatch_name_only) {
1300                 /* We did not see any hit, so we want to show this */
1301                 show_name(opt, gs->name);
1302                 return 1;
1303         }
1304
1305         xdiff_clear_find_func(&xecfg);
1306         opt->priv = NULL;
1307
1308         /* NEEDSWORK:
1309          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1310          * which feels mostly useless but sometimes useful.  Maybe
1311          * make it another option?  For now suppress them.
1312          */
1313         if (opt->count && count) {
1314                 char buf[32];
1315                 output_color(opt, gs->name, strlen(gs->name), opt->color_filename);
1316                 output_sep(opt, ':');
1317                 snprintf(buf, sizeof(buf), "%u\n", count);
1318                 opt->output(opt, buf, strlen(buf));
1319                 return 1;
1320         }
1321         return !!last_hit;
1322 }
1323
1324 static void clr_hit_marker(struct grep_expr *x)
1325 {
1326         /* All-hit markers are meaningful only at the very top level
1327          * OR node.
1328          */
1329         while (1) {
1330                 x->hit = 0;
1331                 if (x->node != GREP_NODE_OR)
1332                         return;
1333                 x->u.binary.left->hit = 0;
1334                 x = x->u.binary.right;
1335         }
1336 }
1337
1338 static int chk_hit_marker(struct grep_expr *x)
1339 {
1340         /* Top level nodes have hit markers.  See if they all are hits */
1341         while (1) {
1342                 if (x->node != GREP_NODE_OR)
1343                         return x->hit;
1344                 if (!x->u.binary.left->hit)
1345                         return 0;
1346                 x = x->u.binary.right;
1347         }
1348 }
1349
1350 int grep_source(struct grep_opt *opt, struct grep_source *gs)
1351 {
1352         /*
1353          * we do not have to do the two-pass grep when we do not check
1354          * buffer-wide "all-match".
1355          */
1356         if (!opt->all_match)
1357                 return grep_source_1(opt, gs, 0);
1358
1359         /* Otherwise the toplevel "or" terms hit a bit differently.
1360          * We first clear hit markers from them.
1361          */
1362         clr_hit_marker(opt->pattern_expression);
1363         grep_source_1(opt, gs, 1);
1364
1365         if (!chk_hit_marker(opt->pattern_expression))
1366                 return 0;
1367
1368         return grep_source_1(opt, gs, 0);
1369 }
1370
1371 int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1372 {
1373         struct grep_source gs;
1374         int r;
1375
1376         grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL);
1377         gs.buf = buf;
1378         gs.size = size;
1379
1380         r = grep_source(opt, &gs);
1381
1382         grep_source_clear(&gs);
1383         return r;
1384 }
1385
1386 void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1387                       const char *name, const void *identifier)
1388 {
1389         gs->type = type;
1390         gs->name = name ? xstrdup(name) : NULL;
1391         gs->buf = NULL;
1392         gs->size = 0;
1393         gs->driver = NULL;
1394
1395         switch (type) {
1396         case GREP_SOURCE_FILE:
1397                 gs->identifier = xstrdup(identifier);
1398                 break;
1399         case GREP_SOURCE_SHA1:
1400                 gs->identifier = xmalloc(20);
1401                 memcpy(gs->identifier, identifier, 20);
1402                 break;
1403         case GREP_SOURCE_BUF:
1404                 gs->identifier = NULL;
1405         }
1406 }
1407
1408 void grep_source_clear(struct grep_source *gs)
1409 {
1410         free(gs->name);
1411         gs->name = NULL;
1412         free(gs->identifier);
1413         gs->identifier = NULL;
1414         grep_source_clear_data(gs);
1415 }
1416
1417 void grep_source_clear_data(struct grep_source *gs)
1418 {
1419         switch (gs->type) {
1420         case GREP_SOURCE_FILE:
1421         case GREP_SOURCE_SHA1:
1422                 free(gs->buf);
1423                 gs->buf = NULL;
1424                 gs->size = 0;
1425                 break;
1426         case GREP_SOURCE_BUF:
1427                 /* leave user-provided buf intact */
1428                 break;
1429         }
1430 }
1431
1432 static int grep_source_load_sha1(struct grep_source *gs)
1433 {
1434         enum object_type type;
1435
1436         grep_read_lock();
1437         gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1438         grep_read_unlock();
1439
1440         if (!gs->buf)
1441                 return error(_("'%s': unable to read %s"),
1442                              gs->name,
1443                              sha1_to_hex(gs->identifier));
1444         return 0;
1445 }
1446
1447 static int grep_source_load_file(struct grep_source *gs)
1448 {
1449         const char *filename = gs->identifier;
1450         struct stat st;
1451         char *data;
1452         size_t size;
1453         int i;
1454
1455         if (lstat(filename, &st) < 0) {
1456         err_ret:
1457                 if (errno != ENOENT)
1458                         error(_("'%s': %s"), filename, strerror(errno));
1459                 return -1;
1460         }
1461         if (!S_ISREG(st.st_mode))
1462                 return -1;
1463         size = xsize_t(st.st_size);
1464         i = open(filename, O_RDONLY);
1465         if (i < 0)
1466                 goto err_ret;
1467         data = xmalloc(size + 1);
1468         if (st.st_size != read_in_full(i, data, size)) {
1469                 error(_("'%s': short read %s"), filename, strerror(errno));
1470                 close(i);
1471                 free(data);
1472                 return -1;
1473         }
1474         close(i);
1475         data[size] = 0;
1476
1477         gs->buf = data;
1478         gs->size = size;
1479         return 0;
1480 }
1481
1482 static int grep_source_load(struct grep_source *gs)
1483 {
1484         if (gs->buf)
1485                 return 0;
1486
1487         switch (gs->type) {
1488         case GREP_SOURCE_FILE:
1489                 return grep_source_load_file(gs);
1490         case GREP_SOURCE_SHA1:
1491                 return grep_source_load_sha1(gs);
1492         case GREP_SOURCE_BUF:
1493                 return gs->buf ? 0 : -1;
1494         }
1495         die("BUG: invalid grep_source type");
1496 }
1497
1498 void grep_source_load_driver(struct grep_source *gs)
1499 {
1500         if (gs->driver)
1501                 return;
1502
1503         grep_attr_lock();
1504         gs->driver = userdiff_find_by_path(gs->name);
1505         if (!gs->driver)
1506                 gs->driver = userdiff_find_by_name("default");
1507         grep_attr_unlock();
1508 }
1509
1510 static int grep_source_is_binary(struct grep_source *gs)
1511 {
1512         grep_source_load_driver(gs);
1513         if (gs->driver->binary != -1)
1514                 return gs->driver->binary;
1515
1516         if (!grep_source_load(gs))
1517                 return buffer_is_binary(gs->buf, gs->size);
1518
1519         return 0;
1520 }