grep.c

   1 #include "cache.h"
   2 #include "grep.h"
   3 #include "userdiff.h"
   4 #include "xdiff-interface.h"
   5 #include "diff.h"
   6 #include "diffcore.h"
   7
   8 static int grep_source_load(struct grep_source *gs);
   9 static int grep_source_is_binary(struct grep_source *gs);
  10
  11 static struct grep_opt grep_defaults;
  12
  13 /*
  14  * Initialize the grep_defaults template with hardcoded defaults.
  15  * We could let the compiler do this, but without C99 initializers
  16  * the code gets unwieldy and unreadable, so...
  17  */
  18 void init_grep_defaults(void)
  19 {
  20         struct grep_opt *opt = &grep_defaults;
  21         static int run_once;
  22
  23         if (run_once)
  24                 return;
  25         run_once++;
  26
  27         memset(opt, 0, sizeof(*opt));
  28         opt->relative = 1;
  29         opt->pathname = 1;
  30         opt->regflags = REG_NEWLINE;
  31         opt->max_depth = -1;
  32         opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  33         opt->extended_regexp_option = 0;
  34         strcpy(opt->color_context, "");
  35         strcpy(opt->color_filename, "");
  36         strcpy(opt->color_function, "");
  37         strcpy(opt->color_lineno, "");
  38         strcpy(opt->color_match, GIT_COLOR_BOLD_RED);
  39         strcpy(opt->color_selected, "");
  40         strcpy(opt->color_sep, GIT_COLOR_CYAN);
  41         opt->color = -1;
  42 }
  43
  44 static int parse_pattern_type_arg(const char *opt, const char *arg)
  45 {
  46         if (!strcmp(arg, "default"))
  47                 return GREP_PATTERN_TYPE_UNSPECIFIED;
  48         else if (!strcmp(arg, "basic"))
  49                 return GREP_PATTERN_TYPE_BRE;
  50         else if (!strcmp(arg, "extended"))
  51                 return GREP_PATTERN_TYPE_ERE;
  52         else if (!strcmp(arg, "fixed"))
  53                 return GREP_PATTERN_TYPE_FIXED;
  54         else if (!strcmp(arg, "perl"))
  55                 return GREP_PATTERN_TYPE_PCRE;
  56         die("bad %s argument: %s", opt, arg);
  57 }
  58
  59 /*
  60  * Read the configuration file once and store it in
  61  * the grep_defaults template.
  62  */
  63 int grep_config(const char *var, const char *value, void *cb)
  64 {
  65         struct grep_opt *opt = &grep_defaults;
  66         char *color = NULL;
  67
  68         if (userdiff_config(var, value) < 0)
  69                 return -1;
  70
  71         if (!strcmp(var, "grep.extendedregexp")) {
  72                 if (git_config_bool(var, value))
  73                         opt->extended_regexp_option = 1;
  74                 else
  75                         opt->extended_regexp_option = 0;
  76                 return 0;
  77         }
  78
  79         if (!strcmp(var, "grep.patterntype")) {
  80                 opt->pattern_type_option = parse_pattern_type_arg(var, value);
  81                 return 0;
  82         }
  83
  84         if (!strcmp(var, "grep.linenumber")) {
  85                 opt->linenum = git_config_bool(var, value);
  86                 return 0;
  87         }
  88
  89         if (!strcmp(var, "color.grep"))
  90                 opt->color = git_config_colorbool(var, value);
  91         else if (!strcmp(var, "color.grep.context"))
  92                 color = opt->color_context;
  93         else if (!strcmp(var, "color.grep.filename"))
  94                 color = opt->color_filename;
  95         else if (!strcmp(var, "color.grep.function"))
  96                 color = opt->color_function;
  97         else if (!strcmp(var, "color.grep.linenumber"))
  98                 color = opt->color_lineno;
  99         else if (!strcmp(var, "color.grep.match"))
 100                 color = opt->color_match;
 101         else if (!strcmp(var, "color.grep.selected"))
 102                 color = opt->color_selected;
 103         else if (!strcmp(var, "color.grep.separator"))
 104                 color = opt->color_sep;
 105
 106         if (color) {
 107                 if (!value)
 108                         return config_error_nonbool(var);
 109                 color_parse(value, var, color);
 110         }
 111         return 0;
 112 }
 113
 114 /*
 115  * Initialize one instance of grep_opt and copy the
 116  * default values from the template we read the configuration
 117  * information in an earlier call to git_config(grep_config).
 118  */
 119 void grep_init(struct grep_opt *opt, const char *prefix)
 120 {
 121         struct grep_opt *def = &grep_defaults;
 122
 123         memset(opt, 0, sizeof(*opt));
 124         opt->prefix = prefix;
 125         opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 126         opt->pattern_tail = &opt->pattern_list;
 127         opt->header_tail = &opt->header_list;
 128
 129         opt->color = def->color;
 130         opt->extended_regexp_option = def->extended_regexp_option;
 131         opt->pattern_type_option = def->pattern_type_option;
 132         opt->linenum = def->linenum;
 133         opt->max_depth = def->max_depth;
 134         opt->pathname = def->pathname;
 135         opt->regflags = def->regflags;
 136         opt->relative = def->relative;
 137
 138         strcpy(opt->color_context, def->color_context);
 139         strcpy(opt->color_filename, def->color_filename);
 140         strcpy(opt->color_function, def->color_function);
 141         strcpy(opt->color_lineno, def->color_lineno);
 142         strcpy(opt->color_match, def->color_match);
 143         strcpy(opt->color_selected, def->color_selected);
 144         strcpy(opt->color_sep, def->color_sep);
 145 }
 146
 147 void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 148 {
 149         if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 150                 grep_set_pattern_type_option(pattern_type, opt);
 151         else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 152                 grep_set_pattern_type_option(opt->pattern_type_option, opt);
 153         else if (opt->extended_regexp_option)
 154                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 155 }
 156
 157 void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 158 {
 159         switch (pattern_type) {
 160         case GREP_PATTERN_TYPE_UNSPECIFIED:
 161                 /* fall through */
 162
 163         case GREP_PATTERN_TYPE_BRE:
 164                 opt->fixed = 0;
 165                 opt->pcre = 0;
 166                 opt->regflags &= ~REG_EXTENDED;
 167                 break;
 168
 169         case GREP_PATTERN_TYPE_ERE:
 170                 opt->fixed = 0;
 171                 opt->pcre = 0;
 172                 opt->regflags |= REG_EXTENDED;
 173                 break;
 174
 175         case GREP_PATTERN_TYPE_FIXED:
 176                 opt->fixed = 1;
 177                 opt->pcre = 0;
 178                 opt->regflags &= ~REG_EXTENDED;
 179                 break;
 180
 181         case GREP_PATTERN_TYPE_PCRE:
 182                 opt->fixed = 0;
 183                 opt->pcre = 1;
 184                 opt->regflags &= ~REG_EXTENDED;
 185                 break;
 186         }
 187 }
 188
 189 static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 190                                         const char *origin, int no,
 191                                         enum grep_pat_token t,
 192                                         enum grep_header_field field)
 193 {
 194         struct grep_pat *p = xcalloc(1, sizeof(*p));
 195         p->pattern = xmemdupz(pat, patlen);
 196         p->patternlen = patlen;
 197         p->origin = origin;
 198         p->no = no;
 199         p->token = t;
 200         p->field = field;
 201         return p;
 202 }
 203
 204 static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 205 {
 206         **tail = p;
 207         *tail = &p->next;
 208         p->next = NULL;
 209
 210         switch (p->token) {
 211         case GREP_PATTERN: /* atom */
 212         case GREP_PATTERN_HEAD:
 213         case GREP_PATTERN_BODY:
 214                 for (;;) {
 215                         struct grep_pat *new_pat;
 216                         size_t len = 0;
 217                         char *cp = p->pattern + p->patternlen, *nl = NULL;
 218                         while (++len <= p->patternlen) {
 219                                 if (*(--cp) == '\n') {
 220                                         nl = cp;
 221                                         break;
 222                                 }
 223                         }
 224                         if (!nl)
 225                                 break;
 226                         new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 227                                                   p->no, p->token, p->field);
 228                         new_pat->next = p->next;
 229                         if (!p->next)
 230                                 *tail = &new_pat->next;
 231                         p->next = new_pat;
 232                         *nl = '\0';
 233                         p->patternlen -= len;
 234                 }
 235                 break;
 236         default:
 237                 break;
 238         }
 239 }
 240
 241 void append_header_grep_pattern(struct grep_opt *opt,
 242                                 enum grep_header_field field, const char *pat)
 243 {
 244         struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 245                                              GREP_PATTERN_HEAD, field);
 246         if (field == GREP_HEADER_REFLOG)
 247                 opt->use_reflog_filter = 1;
 248         do_append_grep_pat(&opt->header_tail, p);
 249 }
 250
 251 void append_grep_pattern(struct grep_opt *opt, const char *pat,
 252                          const char *origin, int no, enum grep_pat_token t)
 253 {
 254         append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 255 }
 256
 257 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 258                      const char *origin, int no, enum grep_pat_token t)
 259 {
 260         struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 261         do_append_grep_pat(&opt->pattern_tail, p);
 262 }
 263
 264 struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 265 {
 266         struct grep_pat *pat;
 267         struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 268         *ret = *opt;
 269
 270         ret->pattern_list = NULL;
 271         ret->pattern_tail = &ret->pattern_list;
 272
 273         for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 274         {
 275                 if(pat->token == GREP_PATTERN_HEAD)
 276                         append_header_grep_pattern(ret, pat->field,
 277                                                    pat->pattern);
 278                 else
 279                         append_grep_pat(ret, pat->pattern, pat->patternlen,
 280                                         pat->origin, pat->no, pat->token);
 281         }
 282
 283         return ret;
 284 }
 285
 286 static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 287                 const char *error)
 288 {
 289         char where[1024];
 290
 291         if (p->no)
 292                 sprintf(where, "In '%s' at %d, ", p->origin, p->no);
 293         else if (p->origin)
 294                 sprintf(where, "%s, ", p->origin);
 295         else
 296                 where[0] = 0;
 297
 298         die("%s'%s': %s", where, p->pattern, error);
 299 }
 300
 301 #ifdef USE_LIBPCRE
 302 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 303 {
 304         const char *error;
 305         int erroffset;
 306         int options = PCRE_MULTILINE;
 307
 308         if (opt->ignore_case)
 309                 options |= PCRE_CASELESS;
 310
 311         p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 312                         NULL);
 313         if (!p->pcre_regexp)
 314                 compile_regexp_failed(p, error);
 315
 316         p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 317         if (!p->pcre_extra_info && error)
 318                 die("%s", error);
 319 }
 320
 321 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 322                 regmatch_t *match, int eflags)
 323 {
 324         int ovector[30], ret, flags = 0;
 325
 326         if (eflags & REG_NOTBOL)
 327                 flags |= PCRE_NOTBOL;
 328
 329         ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 330                         0, flags, ovector, ARRAY_SIZE(ovector));
 331         if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 332                 die("pcre_exec failed with error code %d", ret);
 333         if (ret > 0) {
 334                 ret = 0;
 335                 match->rm_so = ovector[0];
 336                 match->rm_eo = ovector[1];
 337         }
 338
 339         return ret;
 340 }
 341
 342 static void free_pcre_regexp(struct grep_pat *p)
 343 {
 344         pcre_free(p->pcre_regexp);
 345         pcre_free(p->pcre_extra_info);
 346 }
 347 #else /* !USE_LIBPCRE */
 348 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 349 {
 350         die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 351 }
 352
 353 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 354                 regmatch_t *match, int eflags)
 355 {
 356         return 1;
 357 }
 358
 359 static void free_pcre_regexp(struct grep_pat *p)
 360 {
 361 }
 362 #endif /* !USE_LIBPCRE */
 363
 364 static int is_fixed(const char *s, size_t len)
 365 {
 366         size_t i;
 367
 368         /* regcomp cannot accept patterns with NULs so we
 369          * consider any pattern containing a NUL fixed.
 370          */
 371         if (memchr(s, 0, len))
 372                 return 1;
 373
 374         for (i = 0; i < len; i++) {
 375                 if (is_regex_special(s[i]))
 376                         return 0;
 377         }
 378
 379         return 1;
 380 }
 381
 382 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 383 {
 384         int err;
 385
 386         p->word_regexp = opt->word_regexp;
 387         p->ignore_case = opt->ignore_case;
 388
 389         if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 390                 p->fixed = 1;
 391         else
 392                 p->fixed = 0;
 393
 394         if (p->fixed) {
 395                 if (opt->regflags & REG_ICASE || p->ignore_case)
 396                         p->kws = kwsalloc(tolower_trans_tbl);
 397                 else
 398                         p->kws = kwsalloc(NULL);
 399                 kwsincr(p->kws, p->pattern, p->patternlen);
 400                 kwsprep(p->kws);
 401                 return;
 402         }
 403
 404         if (opt->pcre) {
 405                 compile_pcre_regexp(p, opt);
 406                 return;
 407         }
 408
 409         err = regcomp(&p->regexp, p->pattern, opt->regflags);
 410         if (err) {
 411                 char errbuf[1024];
 412                 regerror(err, &p->regexp, errbuf, 1024);
 413                 regfree(&p->regexp);
 414                 compile_regexp_failed(p, errbuf);
 415         }
 416 }
 417
 418 static struct grep_expr *compile_pattern_or(struct grep_pat **);
 419 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 420 {
 421         struct grep_pat *p;
 422         struct grep_expr *x;
 423
 424         p = *list;
 425         if (!p)
 426                 return NULL;
 427         switch (p->token) {
 428         case GREP_PATTERN: /* atom */
 429         case GREP_PATTERN_HEAD:
 430         case GREP_PATTERN_BODY:
 431                 x = xcalloc(1, sizeof (struct grep_expr));
 432                 x->node = GREP_NODE_ATOM;
 433                 x->u.atom = p;
 434                 *list = p->next;
 435                 return x;
 436         case GREP_OPEN_PAREN:
 437                 *list = p->next;
 438                 x = compile_pattern_or(list);
 439                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 440                         die("unmatched parenthesis");
 441                 *list = (*list)->next;
 442                 return x;
 443         default:
 444                 return NULL;
 445         }
 446 }
 447
 448 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 449 {
 450         struct grep_pat *p;
 451         struct grep_expr *x;
 452
 453         p = *list;
 454         if (!p)
 455                 return NULL;
 456         switch (p->token) {
 457         case GREP_NOT:
 458                 if (!p->next)
 459                         die("--not not followed by pattern expression");
 460                 *list = p->next;
 461                 x = xcalloc(1, sizeof (struct grep_expr));
 462                 x->node = GREP_NODE_NOT;
 463                 x->u.unary = compile_pattern_not(list);
 464                 if (!x->u.unary)
 465                         die("--not followed by non pattern expression");
 466                 return x;
 467         default:
 468                 return compile_pattern_atom(list);
 469         }
 470 }
 471
 472 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 473 {
 474         struct grep_pat *p;
 475         struct grep_expr *x, *y, *z;
 476
 477         x = compile_pattern_not(list);
 478         p = *list;
 479         if (p && p->token == GREP_AND) {
 480                 if (!p->next)
 481                         die("--and not followed by pattern expression");
 482                 *list = p->next;
 483                 y = compile_pattern_and(list);
 484                 if (!y)
 485                         die("--and not followed by pattern expression");
 486                 z = xcalloc(1, sizeof (struct grep_expr));
 487                 z->node = GREP_NODE_AND;
 488                 z->u.binary.left = x;
 489                 z->u.binary.right = y;
 490                 return z;
 491         }
 492         return x;
 493 }
 494
 495 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 496 {
 497         struct grep_pat *p;
 498         struct grep_expr *x, *y, *z;
 499
 500         x = compile_pattern_and(list);
 501         p = *list;
 502         if (x && p && p->token != GREP_CLOSE_PAREN) {
 503                 y = compile_pattern_or(list);
 504                 if (!y)
 505                         die("not a pattern expression %s", p->pattern);
 506                 z = xcalloc(1, sizeof (struct grep_expr));
 507                 z->node = GREP_NODE_OR;
 508                 z->u.binary.left = x;
 509                 z->u.binary.right = y;
 510                 return z;
 511         }
 512         return x;
 513 }
 514
 515 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 516 {
 517         return compile_pattern_or(list);
 518 }
 519
 520 static void indent(int in)
 521 {
 522         while (in-- > 0)
 523                 fputc(' ', stderr);
 524 }
 525
 526 static void dump_grep_pat(struct grep_pat *p)
 527 {
 528         switch (p->token) {
 529         case GREP_AND: fprintf(stderr, "*and*"); break;
 530         case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 531         case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 532         case GREP_NOT: fprintf(stderr, "*not*"); break;
 533         case GREP_OR: fprintf(stderr, "*or*"); break;
 534
 535         case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 536         case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 537         case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 538         }
 539
 540         switch (p->token) {
 541         default: break;
 542         case GREP_PATTERN_HEAD:
 543                 fprintf(stderr, "<head %d>", p->field); break;
 544         case GREP_PATTERN_BODY:
 545                 fprintf(stderr, "<body>"); break;
 546         }
 547         switch (p->token) {
 548         default: break;
 549         case GREP_PATTERN_HEAD:
 550         case GREP_PATTERN_BODY:
 551         case GREP_PATTERN:
 552                 fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 553                 break;
 554         }
 555         fputc('\n', stderr);
 556 }
 557
 558 static void dump_grep_expression_1(struct grep_expr *x, int in)
 559 {
 560         indent(in);
 561         switch (x->node) {
 562         case GREP_NODE_TRUE:
 563                 fprintf(stderr, "true\n");
 564                 break;
 565         case GREP_NODE_ATOM:
 566                 dump_grep_pat(x->u.atom);
 567                 break;
 568         case GREP_NODE_NOT:
 569                 fprintf(stderr, "(not\n");
 570                 dump_grep_expression_1(x->u.unary, in+1);
 571                 indent(in);
 572                 fprintf(stderr, ")\n");
 573                 break;
 574         case GREP_NODE_AND:
 575                 fprintf(stderr, "(and\n");
 576                 dump_grep_expression_1(x->u.binary.left, in+1);
 577                 dump_grep_expression_1(x->u.binary.right, in+1);
 578                 indent(in);
 579                 fprintf(stderr, ")\n");
 580                 break;
 581         case GREP_NODE_OR:
 582                 fprintf(stderr, "(or\n");
 583                 dump_grep_expression_1(x->u.binary.left, in+1);
 584                 dump_grep_expression_1(x->u.binary.right, in+1);
 585                 indent(in);
 586                 fprintf(stderr, ")\n");
 587                 break;
 588         }
 589 }
 590
 591 static void dump_grep_expression(struct grep_opt *opt)
 592 {
 593         struct grep_expr *x = opt->pattern_expression;
 594
 595         if (opt->all_match)
 596                 fprintf(stderr, "[all-match]\n");
 597         dump_grep_expression_1(x, 0);
 598         fflush(NULL);
 599 }
 600
 601 static struct grep_expr *grep_true_expr(void)
 602 {
 603         struct grep_expr *z = xcalloc(1, sizeof(*z));
 604         z->node = GREP_NODE_TRUE;
 605         return z;
 606 }
 607
 608 static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 609 {
 610         struct grep_expr *z = xcalloc(1, sizeof(*z));
 611         z->node = GREP_NODE_OR;
 612         z->u.binary.left = left;
 613         z->u.binary.right = right;
 614         return z;
 615 }
 616
 617 static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 618 {
 619         struct grep_pat *p;
 620         struct grep_expr *header_expr;
 621         struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 622         enum grep_header_field fld;
 623
 624         if (!opt->header_list)
 625                 return NULL;
 626
 627         for (p = opt->header_list; p; p = p->next) {
 628                 if (p->token != GREP_PATTERN_HEAD)
 629                         die("bug: a non-header pattern in grep header list.");
 630                 if (p->field < GREP_HEADER_FIELD_MIN ||
 631                     GREP_HEADER_FIELD_MAX <= p->field)
 632                         die("bug: unknown header field %d", p->field);
 633                 compile_regexp(p, opt);
 634         }
 635
 636         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 637                 header_group[fld] = NULL;
 638
 639         for (p = opt->header_list; p; p = p->next) {
 640                 struct grep_expr *h;
 641                 struct grep_pat *pp = p;
 642
 643                 h = compile_pattern_atom(&pp);
 644                 if (!h || pp != p->next)
 645                         die("bug: malformed header expr");
 646                 if (!header_group[p->field]) {
 647                         header_group[p->field] = h;
 648                         continue;
 649                 }
 650                 header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 651         }
 652
 653         header_expr = NULL;
 654
 655         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 656                 if (!header_group[fld])
 657                         continue;
 658                 if (!header_expr)
 659                         header_expr = grep_true_expr();
 660                 header_expr = grep_or_expr(header_group[fld], header_expr);
 661         }
 662         return header_expr;
 663 }
 664
 665 static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 666 {
 667         struct grep_expr *z = x;
 668
 669         while (x) {
 670                 assert(x->node == GREP_NODE_OR);
 671                 if (x->u.binary.right &&
 672                     x->u.binary.right->node == GREP_NODE_TRUE) {
 673                         x->u.binary.right = y;
 674                         break;
 675                 }
 676                 x = x->u.binary.right;
 677         }
 678         return z;
 679 }
 680
 681 static void compile_grep_patterns_real(struct grep_opt *opt)
 682 {
 683         struct grep_pat *p;
 684         struct grep_expr *header_expr = prep_header_patterns(opt);
 685
 686         for (p = opt->pattern_list; p; p = p->next) {
 687                 switch (p->token) {
 688                 case GREP_PATTERN: /* atom */
 689                 case GREP_PATTERN_HEAD:
 690                 case GREP_PATTERN_BODY:
 691                         compile_regexp(p, opt);
 692                         break;
 693                 default:
 694                         opt->extended = 1;
 695                         break;
 696                 }
 697         }
 698
 699         if (opt->all_match || header_expr)
 700                 opt->extended = 1;
 701         else if (!opt->extended && !opt->debug)
 702                 return;
 703
 704         p = opt->pattern_list;
 705         if (p)
 706                 opt->pattern_expression = compile_pattern_expr(&p);
 707         if (p)
 708                 die("incomplete pattern expression: %s", p->pattern);
 709
 710         if (!header_expr)
 711                 return;
 712
 713         if (!opt->pattern_expression)
 714                 opt->pattern_expression = header_expr;
 715         else if (opt->all_match)
 716                 opt->pattern_expression = grep_splice_or(header_expr,
 717                                                          opt->pattern_expression);
 718         else
 719                 opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 720                                                        header_expr);
 721         opt->all_match = 1;
 722 }
 723
 724 void compile_grep_patterns(struct grep_opt *opt)
 725 {
 726         compile_grep_patterns_real(opt);
 727         if (opt->debug)
 728                 dump_grep_expression(opt);
 729 }
 730
 731 static void free_pattern_expr(struct grep_expr *x)
 732 {
 733         switch (x->node) {
 734         case GREP_NODE_TRUE:
 735         case GREP_NODE_ATOM:
 736                 break;
 737         case GREP_NODE_NOT:
 738                 free_pattern_expr(x->u.unary);
 739                 break;
 740         case GREP_NODE_AND:
 741         case GREP_NODE_OR:
 742                 free_pattern_expr(x->u.binary.left);
 743                 free_pattern_expr(x->u.binary.right);
 744                 break;
 745         }
 746         free(x);
 747 }
 748
 749 void free_grep_patterns(struct grep_opt *opt)
 750 {
 751         struct grep_pat *p, *n;
 752
 753         for (p = opt->pattern_list; p; p = n) {
 754                 n = p->next;
 755                 switch (p->token) {
 756                 case GREP_PATTERN: /* atom */
 757                 case GREP_PATTERN_HEAD:
 758                 case GREP_PATTERN_BODY:
 759                         if (p->kws)
 760                                 kwsfree(p->kws);
 761                         else if (p->pcre_regexp)
 762                                 free_pcre_regexp(p);
 763                         else
 764                                 regfree(&p->regexp);
 765                         free(p->pattern);
 766                         break;
 767                 default:
 768                         break;
 769                 }
 770                 free(p);
 771         }
 772
 773         if (!opt->extended)
 774                 return;
 775         free_pattern_expr(opt->pattern_expression);
 776 }
 777
 778 static char *end_of_line(char *cp, unsigned long *left)
 779 {
 780         unsigned long l = *left;
 781         while (l && *cp != '\n') {
 782                 l--;
 783                 cp++;
 784         }
 785         *left = l;
 786         return cp;
 787 }
 788
 789 static int word_char(char ch)
 790 {
 791         return isalnum(ch) || ch == '_';
 792 }
 793
 794 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 795                          const char *color)
 796 {
 797         if (want_color(opt->color) && color && color[0]) {
 798                 opt->output(opt, color, strlen(color));
 799                 opt->output(opt, data, size);
 800                 opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 801         } else
 802                 opt->output(opt, data, size);
 803 }
 804
 805 static void output_sep(struct grep_opt *opt, char sign)
 806 {
 807         if (opt->null_following_name)
 808                 opt->output(opt, "\0", 1);
 809         else
 810                 output_color(opt, &sign, 1, opt->color_sep);
 811 }
 812
 813 static void show_name(struct grep_opt *opt, const char *name)
 814 {
 815         output_color(opt, name, strlen(name), opt->color_filename);
 816         opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 817 }
 818
 819 static int fixmatch(struct grep_pat *p, char *line, char *eol,
 820                     regmatch_t *match)
 821 {
 822         struct kwsmatch kwsm;
 823         size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 824         if (offset == -1) {
 825                 match->rm_so = match->rm_eo = -1;
 826                 return REG_NOMATCH;
 827         } else {
 828                 match->rm_so = offset;
 829                 match->rm_eo = match->rm_so + kwsm.size[0];
 830                 return 0;
 831         }
 832 }
 833
 834 static int regmatch(const regex_t *preg, char *line, char *eol,
 835                     regmatch_t *match, int eflags)
 836 {
 837 #ifdef REG_STARTEND
 838         match->rm_so = 0;
 839         match->rm_eo = eol - line;
 840         eflags |= REG_STARTEND;
 841 #endif
 842         return regexec(preg, line, 1, match, eflags);
 843 }
 844
 845 static int patmatch(struct grep_pat *p, char *line, char *eol,
 846                     regmatch_t *match, int eflags)
 847 {
 848         int hit;
 849
 850         if (p->fixed)
 851                 hit = !fixmatch(p, line, eol, match);
 852         else if (p->pcre_regexp)
 853                 hit = !pcrematch(p, line, eol, match, eflags);
 854         else
 855                 hit = !regmatch(&p->regexp, line, eol, match, eflags);
 856
 857         return hit;
 858 }
 859
 860 static int strip_timestamp(char *bol, char **eol_p)
 861 {
 862         char *eol = *eol_p;
 863         int ch;
 864
 865         while (bol < --eol) {
 866                 if (*eol != '>')
 867                         continue;
 868                 *eol_p = ++eol;
 869                 ch = *eol;
 870                 *eol = '\0';
 871                 return ch;
 872         }
 873         return 0;
 874 }
 875
 876 static struct {
 877         const char *field;
 878         size_t len;
 879 } header_field[] = {
 880         { "author ", 7 },
 881         { "committer ", 10 },
 882         { "reflog ", 7 },
 883 };
 884
 885 static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 886                              enum grep_context ctx,
 887                              regmatch_t *pmatch, int eflags)
 888 {
 889         int hit = 0;
 890         int saved_ch = 0;
 891         const char *start = bol;
 892
 893         if ((p->token != GREP_PATTERN) &&
 894             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 895                 return 0;
 896
 897         if (p->token == GREP_PATTERN_HEAD) {
 898                 const char *field;
 899                 size_t len;
 900                 assert(p->field < ARRAY_SIZE(header_field));
 901                 field = header_field[p->field].field;
 902                 len = header_field[p->field].len;
 903                 if (strncmp(bol, field, len))
 904                         return 0;
 905                 bol += len;
 906                 switch (p->field) {
 907                 case GREP_HEADER_AUTHOR:
 908                 case GREP_HEADER_COMMITTER:
 909                         saved_ch = strip_timestamp(bol, &eol);
 910                         break;
 911                 default:
 912                         break;
 913                 }
 914         }
 915
 916  again:
 917         hit = patmatch(p, bol, eol, pmatch, eflags);
 918
 919         if (hit && p->word_regexp) {
 920                 if ((pmatch[0].rm_so < 0) ||
 921                     (eol - bol) < pmatch[0].rm_so ||
 922                     (pmatch[0].rm_eo < 0) ||
 923                     (eol - bol) < pmatch[0].rm_eo)
 924                         die("regexp returned nonsense");
 925
 926                 /* Match beginning must be either beginning of the
 927                  * line, or at word boundary (i.e. the last char must
 928                  * not be a word char).  Similarly, match end must be
 929                  * either end of the line, or at word boundary
 930                  * (i.e. the next char must not be a word char).
 931                  */
 932                 if ( ((pmatch[0].rm_so == 0) ||
 933                       !word_char(bol[pmatch[0].rm_so-1])) &&
 934                      ((pmatch[0].rm_eo == (eol-bol)) ||
 935                       !word_char(bol[pmatch[0].rm_eo])) )
 936                         ;
 937                 else
 938                         hit = 0;
 939
 940                 /* Words consist of at least one character. */
 941                 if (pmatch->rm_so == pmatch->rm_eo)
 942                         hit = 0;
 943
 944                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 945                         /* There could be more than one match on the
 946                          * line, and the first match might not be
 947                          * strict word match.  But later ones could be!
 948                          * Forward to the next possible start, i.e. the
 949                          * next position following a non-word char.
 950                          */
 951                         bol = pmatch[0].rm_so + bol + 1;
 952                         while (word_char(bol[-1]) && bol < eol)
 953                                 bol++;
 954                         eflags |= REG_NOTBOL;
 955                         if (bol < eol)
 956                                 goto again;
 957                 }
 958         }
 959         if (p->token == GREP_PATTERN_HEAD && saved_ch)
 960                 *eol = saved_ch;
 961         if (hit) {
 962                 pmatch[0].rm_so += bol - start;
 963                 pmatch[0].rm_eo += bol - start;
 964         }
 965         return hit;
 966 }
 967
 968 static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 969                            enum grep_context ctx, int collect_hits)
 970 {
 971         int h = 0;
 972         regmatch_t match;
 973
 974         if (!x)
 975                 die("Not a valid grep expression");
 976         switch (x->node) {
 977         case GREP_NODE_TRUE:
 978                 h = 1;
 979                 break;
 980         case GREP_NODE_ATOM:
 981                 h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 982                 break;
 983         case GREP_NODE_NOT:
 984                 h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 985                 break;
 986         case GREP_NODE_AND:
 987                 if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 988                         return 0;
 989                 h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 990                 break;
 991         case GREP_NODE_OR:
 992                 if (!collect_hits)
 993                         return (match_expr_eval(x->u.binary.left,
 994                                                 bol, eol, ctx, 0) ||
 995                                 match_expr_eval(x->u.binary.right,
 996                                                 bol, eol, ctx, 0));
 997                 h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 998                 x->u.binary.left->hit |= h;
 999                 h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1000                 break;
1001         default:
1002                 die("Unexpected node type (internal error) %d", x->node);
1003         }
1004         if (collect_hits)
1005                 x->hit |= h;
1006         return h;
1007 }
1008
1009 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1010                       enum grep_context ctx, int collect_hits)
1011 {
1012         struct grep_expr *x = opt->pattern_expression;
1013         return match_expr_eval(x, bol, eol, ctx, collect_hits);
1014 }
1015
1016 static int match_line(struct grep_opt *opt, char *bol, char *eol,
1017                       enum grep_context ctx, int collect_hits)
1018 {
1019         struct grep_pat *p;
1020         regmatch_t match;
1021
1022         if (opt->extended)
1023                 return match_expr(opt, bol, eol, ctx, collect_hits);
1024
1025         /* we do not call with collect_hits without being extended */
1026         for (p = opt->pattern_list; p; p = p->next) {
1027                 if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1028                         return 1;
1029         }
1030         return 0;
1031 }
1032
1033 static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1034                               enum grep_context ctx,
1035                               regmatch_t *pmatch, int eflags)
1036 {
1037         regmatch_t match;
1038
1039         if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1040                 return 0;
1041         if (match.rm_so < 0 || match.rm_eo < 0)
1042                 return 0;
1043         if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1044                 if (match.rm_so > pmatch->rm_so)
1045                         return 1;
1046                 if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1047                         return 1;
1048         }
1049         pmatch->rm_so = match.rm_so;
1050         pmatch->rm_eo = match.rm_eo;
1051         return 1;
1052 }
1053
1054 static int next_match(struct grep_opt *opt, char *bol, char *eol,
1055                       enum grep_context ctx, regmatch_t *pmatch, int eflags)
1056 {
1057         struct grep_pat *p;
1058         int hit = 0;
1059
1060         pmatch->rm_so = pmatch->rm_eo = -1;
1061         if (bol < eol) {
1062                 for (p = opt->pattern_list; p; p = p->next) {
1063                         switch (p->token) {
1064                         case GREP_PATTERN: /* atom */
1065                         case GREP_PATTERN_HEAD:
1066                         case GREP_PATTERN_BODY:
1067                                 hit |= match_next_pattern(p, bol, eol, ctx,
1068                                                           pmatch, eflags);
1069                                 break;
1070                         default:
1071                                 break;
1072                         }
1073                 }
1074         }
1075         return hit;
1076 }
1077
1078 static void show_line(struct grep_opt *opt, char *bol, char *eol,
1079                       const char *name, unsigned lno, char sign)
1080 {
1081         int rest = eol - bol;
1082         char *line_color = NULL;
1083
1084         if (opt->file_break && opt->last_shown == 0) {
1085                 if (opt->show_hunk_mark)
1086                         opt->output(opt, "\n", 1);
1087         } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1088                 if (opt->last_shown == 0) {
1089                         if (opt->show_hunk_mark) {
1090                                 output_color(opt, "--", 2, opt->color_sep);
1091                                 opt->output(opt, "\n", 1);
1092                         }
1093                 } else if (lno > opt->last_shown + 1) {
1094                         output_color(opt, "--", 2, opt->color_sep);
1095                         opt->output(opt, "\n", 1);
1096                 }
1097         }
1098         if (opt->heading && opt->last_shown == 0) {
1099                 output_color(opt, name, strlen(name), opt->color_filename);
1100                 opt->output(opt, "\n", 1);
1101         }
1102         opt->last_shown = lno;
1103
1104         if (!opt->heading && opt->pathname) {
1105                 output_color(opt, name, strlen(name), opt->color_filename);
1106                 output_sep(opt, sign);
1107         }
1108         if (opt->linenum) {
1109                 char buf[32];
1110                 snprintf(buf, sizeof(buf), "%d", lno);
1111                 output_color(opt, buf, strlen(buf), opt->color_lineno);
1112                 output_sep(opt, sign);
1113         }
1114         if (opt->color) {
1115                 regmatch_t match;
1116                 enum grep_context ctx = GREP_CONTEXT_BODY;
1117                 int ch = *eol;
1118                 int eflags = 0;
1119
1120                 if (sign == ':')
1121                         line_color = opt->color_selected;
1122                 else if (sign == '-')
1123                         line_color = opt->color_context;
1124                 else if (sign == '=')
1125                         line_color = opt->color_function;
1126                 *eol = '\0';
1127                 while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1128                         if (match.rm_so == match.rm_eo)
1129                                 break;
1130
1131                         output_color(opt, bol, match.rm_so, line_color);
1132                         output_color(opt, bol + match.rm_so,
1133                                      match.rm_eo - match.rm_so,
1134                                      opt->color_match);
1135                         bol += match.rm_eo;
1136                         rest -= match.rm_eo;
1137                         eflags = REG_NOTBOL;
1138                 }
1139                 *eol = ch;
1140         }
1141         output_color(opt, bol, rest, line_color);
1142         opt->output(opt, "\n", 1);
1143 }
1144
1145 #ifndef NO_PTHREADS
1146 int grep_use_locks;
1147
1148 /*
1149  * This lock protects access to the gitattributes machinery, which is
1150  * not thread-safe.
1151  */
1152 pthread_mutex_t grep_attr_mutex;
1153
1154 static inline void grep_attr_lock(void)
1155 {
1156         if (grep_use_locks)
1157                 pthread_mutex_lock(&grep_attr_mutex);
1158 }
1159
1160 static inline void grep_attr_unlock(void)
1161 {
1162         if (grep_use_locks)
1163                 pthread_mutex_unlock(&grep_attr_mutex);
1164 }
1165
1166 /*
1167  * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1168  */
1169 pthread_mutex_t grep_read_mutex;
1170
1171 #else
1172 #define grep_attr_lock()
1173 #define grep_attr_unlock()
1174 #endif
1175
1176 static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1177 {
1178         xdemitconf_t *xecfg = opt->priv;
1179         if (xecfg && !xecfg->find_func) {
1180                 grep_source_load_driver(gs);
1181                 if (gs->driver->funcname.pattern) {
1182                         const struct userdiff_funcname *pe = &gs->driver->funcname;
1183                         xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1184                 } else {
1185                         xecfg = opt->priv = NULL;
1186                 }
1187         }
1188
1189         if (xecfg) {
1190                 char buf[1];
1191                 return xecfg->find_func(bol, eol - bol, buf, 1,
1192                                         xecfg->find_func_priv) >= 0;
1193         }
1194
1195         if (bol == eol)
1196                 return 0;
1197         if (isalpha(*bol) || *bol == '_' || *bol == '$')
1198                 return 1;
1199         return 0;
1200 }
1201
1202 static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1203                                char *bol, unsigned lno)
1204 {
1205         while (bol > gs->buf) {
1206                 char *eol = --bol;
1207
1208                 while (bol > gs->buf && bol[-1] != '\n')
1209                         bol--;
1210                 lno--;
1211
1212                 if (lno <= opt->last_shown)
1213                         break;
1214
1215                 if (match_funcname(opt, gs, bol, eol)) {
1216                         show_line(opt, bol, eol, gs->name, lno, '=');
1217                         break;
1218                 }
1219         }
1220 }
1221
1222 static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1223                              char *bol, char *end, unsigned lno)
1224 {
1225         unsigned cur = lno, from = 1, funcname_lno = 0;
1226         int funcname_needed = !!opt->funcname;
1227
1228         if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1229                 funcname_needed = 2;
1230
1231         if (opt->pre_context < lno)
1232                 from = lno - opt->pre_context;
1233         if (from <= opt->last_shown)
1234                 from = opt->last_shown + 1;
1235
1236         /* Rewind. */
1237         while (bol > gs->buf &&
1238                cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1239                 char *eol = --bol;
1240
1241                 while (bol > gs->buf && bol[-1] != '\n')
1242                         bol--;
1243                 cur--;
1244                 if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1245                         funcname_lno = cur;
1246                         funcname_needed = 0;
1247                 }
1248         }
1249
1250         /* We need to look even further back to find a function signature. */
1251         if (opt->funcname && funcname_needed)
1252                 show_funcname_line(opt, gs, bol, cur);
1253
1254         /* Back forward. */
1255         while (cur < lno) {
1256                 char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1257
1258                 while (*eol != '\n')
1259                         eol++;
1260                 show_line(opt, bol, eol, gs->name, cur, sign);
1261                 bol = eol + 1;
1262                 cur++;
1263         }
1264 }
1265
1266 static int should_lookahead(struct grep_opt *opt)
1267 {
1268         struct grep_pat *p;
1269
1270         if (opt->extended)
1271                 return 0; /* punt for too complex stuff */
1272         if (opt->invert)
1273                 return 0;
1274         for (p = opt->pattern_list; p; p = p->next) {
1275                 if (p->token != GREP_PATTERN)
1276                         return 0; /* punt for "header only" and stuff */
1277         }
1278         return 1;
1279 }
1280
1281 static int look_ahead(struct grep_opt *opt,
1282                       unsigned long *left_p,
1283                       unsigned *lno_p,
1284                       char **bol_p)
1285 {
1286         unsigned lno = *lno_p;
1287         char *bol = *bol_p;
1288         struct grep_pat *p;
1289         char *sp, *last_bol;
1290         regoff_t earliest = -1;
1291
1292         for (p = opt->pattern_list; p; p = p->next) {
1293                 int hit;
1294                 regmatch_t m;
1295
1296                 hit = patmatch(p, bol, bol + *left_p, &m, 0);
1297                 if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1298                         continue;
1299                 if (earliest < 0 || m.rm_so < earliest)
1300                         earliest = m.rm_so;
1301         }
1302
1303         if (earliest < 0) {
1304                 *bol_p = bol + *left_p;
1305                 *left_p = 0;
1306                 return 1;
1307         }
1308         for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1309                 ; /* find the beginning of the line */
1310         last_bol = sp;
1311
1312         for (sp = bol; sp < last_bol; sp++) {
1313                 if (*sp == '\n')
1314                         lno++;
1315         }
1316         *left_p -= last_bol - bol;
1317         *bol_p = last_bol;
1318         *lno_p = lno;
1319         return 0;
1320 }
1321
1322 static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1323 {
1324         fwrite(buf, size, 1, stdout);
1325 }
1326
1327 static int fill_textconv_grep(struct userdiff_driver *driver,
1328                               struct grep_source *gs)
1329 {
1330         struct diff_filespec *df;
1331         char *buf;
1332         size_t size;
1333
1334         if (!driver || !driver->textconv)
1335                 return grep_source_load(gs);
1336
1337         /*
1338          * The textconv interface is intimately tied to diff_filespecs, so we
1339          * have to pretend to be one. If we could unify the grep_source
1340          * and diff_filespec structs, this mess could just go away.
1341          */
1342         df = alloc_filespec(gs->path);
1343         switch (gs->type) {
1344         case GREP_SOURCE_SHA1:
1345                 fill_filespec(df, gs->identifier, 1, 0100644);
1346                 break;
1347         case GREP_SOURCE_FILE:
1348                 fill_filespec(df, null_sha1, 0, 0100644);
1349                 break;
1350         default:
1351                 die("BUG: attempt to textconv something without a path?");
1352         }
1353
1354         /*
1355          * fill_textconv is not remotely thread-safe; it may load objects
1356          * behind the scenes, and it modifies the global diff tempfile
1357          * structure.
1358          */
1359         grep_read_lock();
1360         size = fill_textconv(driver, df, &buf);
1361         grep_read_unlock();
1362         free_filespec(df);
1363
1364         /*
1365          * The normal fill_textconv usage by the diff machinery would just keep
1366          * the textconv'd buf separate from the diff_filespec. But much of the
1367          * grep code passes around a grep_source and assumes that its "buf"
1368          * pointer is the beginning of the thing we are searching. So let's
1369          * install our textconv'd version into the grep_source, taking care not
1370          * to leak any existing buffer.
1371          */
1372         grep_source_clear_data(gs);
1373         gs->buf = buf;
1374         gs->size = size;
1375
1376         return 0;
1377 }
1378
1379 static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1380 {
1381         char *bol;
1382         unsigned long left;
1383         unsigned lno = 1;
1384         unsigned last_hit = 0;
1385         int binary_match_only = 0;
1386         unsigned count = 0;
1387         int try_lookahead = 0;
1388         int show_function = 0;
1389         struct userdiff_driver *textconv = NULL;
1390         enum grep_context ctx = GREP_CONTEXT_HEAD;
1391         xdemitconf_t xecfg;
1392
1393         if (!opt->output)
1394                 opt->output = std_output;
1395
1396         if (opt->pre_context || opt->post_context || opt->file_break ||
1397             opt->funcbody) {
1398                 /* Show hunk marks, except for the first file. */
1399                 if (opt->last_shown)
1400                         opt->show_hunk_mark = 1;
1401                 /*
1402                  * If we're using threads then we can't easily identify
1403                  * the first file.  Always put hunk marks in that case
1404                  * and skip the very first one later in work_done().
1405                  */
1406                 if (opt->output != std_output)
1407                         opt->show_hunk_mark = 1;
1408         }
1409         opt->last_shown = 0;
1410
1411         if (opt->allow_textconv) {
1412                 grep_source_load_driver(gs);
1413                 /*
1414                  * We might set up the shared textconv cache data here, which
1415                  * is not thread-safe.
1416                  */
1417                 grep_attr_lock();
1418                 textconv = userdiff_get_textconv(gs->driver);
1419                 grep_attr_unlock();
1420         }
1421
1422         /*
1423          * We know the result of a textconv is text, so we only have to care
1424          * about binary handling if we are not using it.
1425          */
1426         if (!textconv) {
1427                 switch (opt->binary) {
1428                 case GREP_BINARY_DEFAULT:
1429                         if (grep_source_is_binary(gs))
1430                                 binary_match_only = 1;
1431                         break;
1432                 case GREP_BINARY_NOMATCH:
1433                         if (grep_source_is_binary(gs))
1434                                 return 0; /* Assume unmatch */
1435                         break;
1436                 case GREP_BINARY_TEXT:
1437                         break;
1438                 default:
1439                         die("bug: unknown binary handling mode");
1440                 }
1441         }
1442
1443         memset(&xecfg, 0, sizeof(xecfg));
1444         opt->priv = &xecfg;
1445
1446         try_lookahead = should_lookahead(opt);
1447
1448         if (fill_textconv_grep(textconv, gs) < 0)
1449                 return 0;
1450
1451         bol = gs->buf;
1452         left = gs->size;
1453         while (left) {
1454                 char *eol, ch;
1455                 int hit;
1456
1457                 /*
1458                  * look_ahead() skips quickly to the line that possibly
1459                  * has the next hit; don't call it if we need to do
1460                  * something more than just skipping the current line
1461                  * in response to an unmatch for the current line.  E.g.
1462                  * inside a post-context window, we will show the current
1463                  * line as a context around the previous hit when it
1464                  * doesn't hit.
1465                  */
1466                 if (try_lookahead
1467                     && !(last_hit
1468                          && (show_function ||
1469                              lno <= last_hit + opt->post_context))
1470                     && look_ahead(opt, &left, &lno, &bol))
1471                         break;
1472                 eol = end_of_line(bol, &left);
1473                 ch = *eol;
1474                 *eol = 0;
1475
1476                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1477                         ctx = GREP_CONTEXT_BODY;
1478
1479                 hit = match_line(opt, bol, eol, ctx, collect_hits);
1480                 *eol = ch;
1481
1482                 if (collect_hits)
1483                         goto next_line;
1484
1485                 /* "grep -v -e foo -e bla" should list lines
1486                  * that do not have either, so inversion should
1487                  * be done outside.
1488                  */
1489                 if (opt->invert)
1490                         hit = !hit;
1491                 if (opt->unmatch_name_only) {
1492                         if (hit)
1493                                 return 0;
1494                         goto next_line;
1495                 }
1496                 if (hit) {
1497                         count++;
1498                         if (opt->status_only)
1499                                 return 1;
1500                         if (opt->name_only) {
1501                                 show_name(opt, gs->name);
1502                                 return 1;
1503                         }
1504                         if (opt->count)
1505                                 goto next_line;
1506                         if (binary_match_only) {
1507                                 opt->output(opt, "Binary file ", 12);
1508                                 output_color(opt, gs->name, strlen(gs->name),
1509                                              opt->color_filename);
1510                                 opt->output(opt, " matches\n", 9);
1511                                 return 1;
1512                         }
1513                         /* Hit at this line.  If we haven't shown the
1514                          * pre-context lines, we would need to show them.
1515                          */
1516                         if (opt->pre_context || opt->funcbody)
1517                                 show_pre_context(opt, gs, bol, eol, lno);
1518                         else if (opt->funcname)
1519                                 show_funcname_line(opt, gs, bol, lno);
1520                         show_line(opt, bol, eol, gs->name, lno, ':');
1521                         last_hit = lno;
1522                         if (opt->funcbody)
1523                                 show_function = 1;
1524                         goto next_line;
1525                 }
1526                 if (show_function && match_funcname(opt, gs, bol, eol))
1527                         show_function = 0;
1528                 if (show_function ||
1529                     (last_hit && lno <= last_hit + opt->post_context)) {
1530                         /* If the last hit is within the post context,
1531                          * we need to show this line.
1532                          */
1533                         show_line(opt, bol, eol, gs->name, lno, '-');
1534                 }
1535
1536         next_line:
1537                 bol = eol + 1;
1538                 if (!left)
1539                         break;
1540                 left--;
1541                 lno++;
1542         }
1543
1544         if (collect_hits)
1545                 return 0;
1546
1547         if (opt->status_only)
1548                 return 0;
1549         if (opt->unmatch_name_only) {
1550                 /* We did not see any hit, so we want to show this */
1551                 show_name(opt, gs->name);
1552                 return 1;
1553         }
1554
1555         xdiff_clear_find_func(&xecfg);
1556         opt->priv = NULL;
1557
1558         /* NEEDSWORK:
1559          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1560          * which feels mostly useless but sometimes useful.  Maybe
1561          * make it another option?  For now suppress them.
1562          */
1563         if (opt->count && count) {
1564                 char buf[32];
1565                 output_color(opt, gs->name, strlen(gs->name), opt->color_filename);
1566                 output_sep(opt, ':');
1567                 snprintf(buf, sizeof(buf), "%u\n", count);
1568                 opt->output(opt, buf, strlen(buf));
1569                 return 1;
1570         }
1571         return !!last_hit;
1572 }
1573
1574 static void clr_hit_marker(struct grep_expr *x)
1575 {
1576         /* All-hit markers are meaningful only at the very top level
1577          * OR node.
1578          */
1579         while (1) {
1580                 x->hit = 0;
1581                 if (x->node != GREP_NODE_OR)
1582                         return;
1583                 x->u.binary.left->hit = 0;
1584                 x = x->u.binary.right;
1585         }
1586 }
1587
1588 static int chk_hit_marker(struct grep_expr *x)
1589 {
1590         /* Top level nodes have hit markers.  See if they all are hits */
1591         while (1) {
1592                 if (x->node != GREP_NODE_OR)
1593                         return x->hit;
1594                 if (!x->u.binary.left->hit)
1595                         return 0;
1596                 x = x->u.binary.right;
1597         }
1598 }
1599
1600 int grep_source(struct grep_opt *opt, struct grep_source *gs)
1601 {
1602         /*
1603          * we do not have to do the two-pass grep when we do not check
1604          * buffer-wide "all-match".
1605          */
1606         if (!opt->all_match)
1607                 return grep_source_1(opt, gs, 0);
1608
1609         /* Otherwise the toplevel "or" terms hit a bit differently.
1610          * We first clear hit markers from them.
1611          */
1612         clr_hit_marker(opt->pattern_expression);
1613         grep_source_1(opt, gs, 1);
1614
1615         if (!chk_hit_marker(opt->pattern_expression))
1616                 return 0;
1617
1618         return grep_source_1(opt, gs, 0);
1619 }
1620
1621 int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1622 {
1623         struct grep_source gs;
1624         int r;
1625
1626         grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1627         gs.buf = buf;
1628         gs.size = size;
1629
1630         r = grep_source(opt, &gs);
1631
1632         grep_source_clear(&gs);
1633         return r;
1634 }
1635
1636 void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1637                       const char *name, const char *path,
1638                       const void *identifier)
1639 {
1640         gs->type = type;
1641         gs->name = name ? xstrdup(name) : NULL;
1642         gs->path = path ? xstrdup(path) : NULL;
1643         gs->buf = NULL;
1644         gs->size = 0;
1645         gs->driver = NULL;
1646
1647         switch (type) {
1648         case GREP_SOURCE_FILE:
1649                 gs->identifier = xstrdup(identifier);
1650                 break;
1651         case GREP_SOURCE_SHA1:
1652                 gs->identifier = xmalloc(20);
1653                 memcpy(gs->identifier, identifier, 20);
1654                 break;
1655         case GREP_SOURCE_BUF:
1656                 gs->identifier = NULL;
1657         }
1658 }
1659
1660 void grep_source_clear(struct grep_source *gs)
1661 {
1662         free(gs->name);
1663         gs->name = NULL;
1664         free(gs->path);
1665         gs->path = NULL;
1666         free(gs->identifier);
1667         gs->identifier = NULL;
1668         grep_source_clear_data(gs);
1669 }
1670
1671 void grep_source_clear_data(struct grep_source *gs)
1672 {
1673         switch (gs->type) {
1674         case GREP_SOURCE_FILE:
1675         case GREP_SOURCE_SHA1:
1676                 free(gs->buf);
1677                 gs->buf = NULL;
1678                 gs->size = 0;
1679                 break;
1680         case GREP_SOURCE_BUF:
1681                 /* leave user-provided buf intact */
1682                 break;
1683         }
1684 }
1685
1686 static int grep_source_load_sha1(struct grep_source *gs)
1687 {
1688         enum object_type type;
1689
1690         grep_read_lock();
1691         gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1692         grep_read_unlock();
1693
1694         if (!gs->buf)
1695                 return error(_("'%s': unable to read %s"),
1696                              gs->name,
1697                              sha1_to_hex(gs->identifier));
1698         return 0;
1699 }
1700
1701 static int grep_source_load_file(struct grep_source *gs)
1702 {
1703         const char *filename = gs->identifier;
1704         struct stat st;
1705         char *data;
1706         size_t size;
1707         int i;
1708
1709         if (lstat(filename, &st) < 0) {
1710         err_ret:
1711                 if (errno != ENOENT)
1712                         error(_("'%s': %s"), filename, strerror(errno));
1713                 return -1;
1714         }
1715         if (!S_ISREG(st.st_mode))
1716                 return -1;
1717         size = xsize_t(st.st_size);
1718         i = open(filename, O_RDONLY);
1719         if (i < 0)
1720                 goto err_ret;
1721         data = xmalloc(size + 1);
1722         if (st.st_size != read_in_full(i, data, size)) {
1723                 error(_("'%s': short read %s"), filename, strerror(errno));
1724                 close(i);
1725                 free(data);
1726                 return -1;
1727         }
1728         close(i);
1729         data[size] = 0;
1730
1731         gs->buf = data;
1732         gs->size = size;
1733         return 0;
1734 }
1735
1736 static int grep_source_load(struct grep_source *gs)
1737 {
1738         if (gs->buf)
1739                 return 0;
1740
1741         switch (gs->type) {
1742         case GREP_SOURCE_FILE:
1743                 return grep_source_load_file(gs);
1744         case GREP_SOURCE_SHA1:
1745                 return grep_source_load_sha1(gs);
1746         case GREP_SOURCE_BUF:
1747                 return gs->buf ? 0 : -1;
1748         }
1749         die("BUG: invalid grep_source type");
1750 }
1751
1752 void grep_source_load_driver(struct grep_source *gs)
1753 {
1754         if (gs->driver)
1755                 return;
1756
1757         grep_attr_lock();
1758         if (gs->path)
1759                 gs->driver = userdiff_find_by_path(gs->path);
1760         if (!gs->driver)
1761                 gs->driver = userdiff_find_by_name("default");
1762         grep_attr_unlock();
1763 }
1764
1765 static int grep_source_is_binary(struct grep_source *gs)
1766 {
1767         grep_source_load_driver(gs);
1768         if (gs->driver->binary != -1)
1769                 return gs->driver->binary;
1770
1771         if (!grep_source_load(gs))
1772                 return buffer_is_binary(gs->buf, gs->size);
1773
1774         return 0;
1775 }