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 #include "commit.h"
   8 #include "quote.h"
   9
  10 static int grep_source_load(struct grep_source *gs);
  11 static int grep_source_is_binary(struct grep_source *gs);
  12
  13 static struct grep_opt grep_defaults;
  14
  15 /*
  16  * Initialize the grep_defaults template with hardcoded defaults.
  17  * We could let the compiler do this, but without C99 initializers
  18  * the code gets unwieldy and unreadable, so...
  19  */
  20 void init_grep_defaults(void)
  21 {
  22         struct grep_opt *opt = &grep_defaults;
  23         static int run_once;
  24
  25         if (run_once)
  26                 return;
  27         run_once++;
  28
  29         memset(opt, 0, sizeof(*opt));
  30         opt->relative = 1;
  31         opt->pathname = 1;
  32         opt->regflags = REG_NEWLINE;
  33         opt->max_depth = -1;
  34         opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  35         opt->extended_regexp_option = 0;
  36         color_set(opt->color_context, "");
  37         color_set(opt->color_filename, "");
  38         color_set(opt->color_function, "");
  39         color_set(opt->color_lineno, "");
  40         color_set(opt->color_match_context, GIT_COLOR_BOLD_RED);
  41         color_set(opt->color_match_selected, GIT_COLOR_BOLD_RED);
  42         color_set(opt->color_selected, "");
  43         color_set(opt->color_sep, GIT_COLOR_CYAN);
  44         opt->color = -1;
  45 }
  46
  47 static int parse_pattern_type_arg(const char *opt, const char *arg)
  48 {
  49         if (!strcmp(arg, "default"))
  50                 return GREP_PATTERN_TYPE_UNSPECIFIED;
  51         else if (!strcmp(arg, "basic"))
  52                 return GREP_PATTERN_TYPE_BRE;
  53         else if (!strcmp(arg, "extended"))
  54                 return GREP_PATTERN_TYPE_ERE;
  55         else if (!strcmp(arg, "fixed"))
  56                 return GREP_PATTERN_TYPE_FIXED;
  57         else if (!strcmp(arg, "perl"))
  58                 return GREP_PATTERN_TYPE_PCRE;
  59         die("bad %s argument: %s", opt, arg);
  60 }
  61
  62 /*
  63  * Read the configuration file once and store it in
  64  * the grep_defaults template.
  65  */
  66 int grep_config(const char *var, const char *value, void *cb)
  67 {
  68         struct grep_opt *opt = &grep_defaults;
  69         char *color = NULL;
  70
  71         if (userdiff_config(var, value) < 0)
  72                 return -1;
  73
  74         if (!strcmp(var, "grep.extendedregexp")) {
  75                 if (git_config_bool(var, value))
  76                         opt->extended_regexp_option = 1;
  77                 else
  78                         opt->extended_regexp_option = 0;
  79                 return 0;
  80         }
  81
  82         if (!strcmp(var, "grep.patterntype")) {
  83                 opt->pattern_type_option = parse_pattern_type_arg(var, value);
  84                 return 0;
  85         }
  86
  87         if (!strcmp(var, "grep.linenumber")) {
  88                 opt->linenum = git_config_bool(var, value);
  89                 return 0;
  90         }
  91
  92         if (!strcmp(var, "grep.fullname")) {
  93                 opt->relative = !git_config_bool(var, value);
  94                 return 0;
  95         }
  96
  97         if (!strcmp(var, "color.grep"))
  98                 opt->color = git_config_colorbool(var, value);
  99         else if (!strcmp(var, "color.grep.context"))
 100                 color = opt->color_context;
 101         else if (!strcmp(var, "color.grep.filename"))
 102                 color = opt->color_filename;
 103         else if (!strcmp(var, "color.grep.function"))
 104                 color = opt->color_function;
 105         else if (!strcmp(var, "color.grep.linenumber"))
 106                 color = opt->color_lineno;
 107         else if (!strcmp(var, "color.grep.matchcontext"))
 108                 color = opt->color_match_context;
 109         else if (!strcmp(var, "color.grep.matchselected"))
 110                 color = opt->color_match_selected;
 111         else if (!strcmp(var, "color.grep.selected"))
 112                 color = opt->color_selected;
 113         else if (!strcmp(var, "color.grep.separator"))
 114                 color = opt->color_sep;
 115         else if (!strcmp(var, "color.grep.match")) {
 116                 int rc = 0;
 117                 if (!value)
 118                         return config_error_nonbool(var);
 119                 rc |= color_parse(value, opt->color_match_context);
 120                 rc |= color_parse(value, opt->color_match_selected);
 121                 return rc;
 122         }
 123
 124         if (color) {
 125                 if (!value)
 126                         return config_error_nonbool(var);
 127                 return color_parse(value, color);
 128         }
 129         return 0;
 130 }
 131
 132 /*
 133  * Initialize one instance of grep_opt and copy the
 134  * default values from the template we read the configuration
 135  * information in an earlier call to git_config(grep_config).
 136  */
 137 void grep_init(struct grep_opt *opt, const char *prefix)
 138 {
 139         struct grep_opt *def = &grep_defaults;
 140
 141         memset(opt, 0, sizeof(*opt));
 142         opt->prefix = prefix;
 143         opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 144         opt->pattern_tail = &opt->pattern_list;
 145         opt->header_tail = &opt->header_list;
 146
 147         opt->color = def->color;
 148         opt->extended_regexp_option = def->extended_regexp_option;
 149         opt->pattern_type_option = def->pattern_type_option;
 150         opt->linenum = def->linenum;
 151         opt->max_depth = def->max_depth;
 152         opt->pathname = def->pathname;
 153         opt->regflags = def->regflags;
 154         opt->relative = def->relative;
 155
 156         color_set(opt->color_context, def->color_context);
 157         color_set(opt->color_filename, def->color_filename);
 158         color_set(opt->color_function, def->color_function);
 159         color_set(opt->color_lineno, def->color_lineno);
 160         color_set(opt->color_match_context, def->color_match_context);
 161         color_set(opt->color_match_selected, def->color_match_selected);
 162         color_set(opt->color_selected, def->color_selected);
 163         color_set(opt->color_sep, def->color_sep);
 164 }
 165
 166 static void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 167 {
 168         switch (pattern_type) {
 169         case GREP_PATTERN_TYPE_UNSPECIFIED:
 170                 /* fall through */
 171
 172         case GREP_PATTERN_TYPE_BRE:
 173                 opt->fixed = 0;
 174                 opt->pcre = 0;
 175                 opt->regflags &= ~REG_EXTENDED;
 176                 break;
 177
 178         case GREP_PATTERN_TYPE_ERE:
 179                 opt->fixed = 0;
 180                 opt->pcre = 0;
 181                 opt->regflags |= REG_EXTENDED;
 182                 break;
 183
 184         case GREP_PATTERN_TYPE_FIXED:
 185                 opt->fixed = 1;
 186                 opt->pcre = 0;
 187                 opt->regflags &= ~REG_EXTENDED;
 188                 break;
 189
 190         case GREP_PATTERN_TYPE_PCRE:
 191                 opt->fixed = 0;
 192                 opt->pcre = 1;
 193                 opt->regflags &= ~REG_EXTENDED;
 194                 break;
 195         }
 196 }
 197
 198 void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 199 {
 200         if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 201                 grep_set_pattern_type_option(pattern_type, opt);
 202         else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 203                 grep_set_pattern_type_option(opt->pattern_type_option, opt);
 204         else if (opt->extended_regexp_option)
 205                 grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 206 }
 207
 208 static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 209                                         const char *origin, int no,
 210                                         enum grep_pat_token t,
 211                                         enum grep_header_field field)
 212 {
 213         struct grep_pat *p = xcalloc(1, sizeof(*p));
 214         p->pattern = xmemdupz(pat, patlen);
 215         p->patternlen = patlen;
 216         p->origin = origin;
 217         p->no = no;
 218         p->token = t;
 219         p->field = field;
 220         return p;
 221 }
 222
 223 static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 224 {
 225         **tail = p;
 226         *tail = &p->next;
 227         p->next = NULL;
 228
 229         switch (p->token) {
 230         case GREP_PATTERN: /* atom */
 231         case GREP_PATTERN_HEAD:
 232         case GREP_PATTERN_BODY:
 233                 for (;;) {
 234                         struct grep_pat *new_pat;
 235                         size_t len = 0;
 236                         char *cp = p->pattern + p->patternlen, *nl = NULL;
 237                         while (++len <= p->patternlen) {
 238                                 if (*(--cp) == '\n') {
 239                                         nl = cp;
 240                                         break;
 241                                 }
 242                         }
 243                         if (!nl)
 244                                 break;
 245                         new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 246                                                   p->no, p->token, p->field);
 247                         new_pat->next = p->next;
 248                         if (!p->next)
 249                                 *tail = &new_pat->next;
 250                         p->next = new_pat;
 251                         *nl = '\0';
 252                         p->patternlen -= len;
 253                 }
 254                 break;
 255         default:
 256                 break;
 257         }
 258 }
 259
 260 void append_header_grep_pattern(struct grep_opt *opt,
 261                                 enum grep_header_field field, const char *pat)
 262 {
 263         struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 264                                              GREP_PATTERN_HEAD, field);
 265         if (field == GREP_HEADER_REFLOG)
 266                 opt->use_reflog_filter = 1;
 267         do_append_grep_pat(&opt->header_tail, p);
 268 }
 269
 270 void append_grep_pattern(struct grep_opt *opt, const char *pat,
 271                          const char *origin, int no, enum grep_pat_token t)
 272 {
 273         append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 274 }
 275
 276 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 277                      const char *origin, int no, enum grep_pat_token t)
 278 {
 279         struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 280         do_append_grep_pat(&opt->pattern_tail, p);
 281 }
 282
 283 struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 284 {
 285         struct grep_pat *pat;
 286         struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 287         *ret = *opt;
 288
 289         ret->pattern_list = NULL;
 290         ret->pattern_tail = &ret->pattern_list;
 291
 292         for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 293         {
 294                 if(pat->token == GREP_PATTERN_HEAD)
 295                         append_header_grep_pattern(ret, pat->field,
 296                                                    pat->pattern);
 297                 else
 298                         append_grep_pat(ret, pat->pattern, pat->patternlen,
 299                                         pat->origin, pat->no, pat->token);
 300         }
 301
 302         return ret;
 303 }
 304
 305 static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 306                 const char *error)
 307 {
 308         char where[1024];
 309
 310         if (p->no)
 311                 xsnprintf(where, sizeof(where), "In '%s' at %d, ", p->origin, p->no);
 312         else if (p->origin)
 313                 xsnprintf(where, sizeof(where), "%s, ", p->origin);
 314         else
 315                 where[0] = 0;
 316
 317         die("%s'%s': %s", where, p->pattern, error);
 318 }
 319
 320 #ifdef USE_LIBPCRE
 321 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 322 {
 323         const char *error;
 324         int erroffset;
 325         int options = PCRE_MULTILINE;
 326
 327         if (opt->ignore_case) {
 328                 if (has_non_ascii(p->pattern))
 329                         p->pcre_tables = pcre_maketables();
 330                 options |= PCRE_CASELESS;
 331         }
 332         if (is_utf8_locale() && has_non_ascii(p->pattern))
 333                 options |= PCRE_UTF8;
 334
 335         p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 336                                       p->pcre_tables);
 337         if (!p->pcre_regexp)
 338                 compile_regexp_failed(p, error);
 339
 340         p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 341         if (!p->pcre_extra_info && error)
 342                 die("%s", error);
 343 }
 344
 345 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 346                 regmatch_t *match, int eflags)
 347 {
 348         int ovector[30], ret, flags = 0;
 349
 350         if (eflags & REG_NOTBOL)
 351                 flags |= PCRE_NOTBOL;
 352
 353         ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 354                         0, flags, ovector, ARRAY_SIZE(ovector));
 355         if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 356                 die("pcre_exec failed with error code %d", ret);
 357         if (ret > 0) {
 358                 ret = 0;
 359                 match->rm_so = ovector[0];
 360                 match->rm_eo = ovector[1];
 361         }
 362
 363         return ret;
 364 }
 365
 366 static void free_pcre_regexp(struct grep_pat *p)
 367 {
 368         pcre_free(p->pcre_regexp);
 369         pcre_free(p->pcre_extra_info);
 370         pcre_free((void *)p->pcre_tables);
 371 }
 372 #else /* !USE_LIBPCRE */
 373 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 374 {
 375         die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 376 }
 377
 378 static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 379                 regmatch_t *match, int eflags)
 380 {
 381         return 1;
 382 }
 383
 384 static void free_pcre_regexp(struct grep_pat *p)
 385 {
 386 }
 387 #endif /* !USE_LIBPCRE */
 388
 389 static int is_fixed(const char *s, size_t len)
 390 {
 391         size_t i;
 392
 393         /* regcomp cannot accept patterns with NULs so we
 394          * consider any pattern containing a NUL fixed.
 395          */
 396         if (memchr(s, 0, len))
 397                 return 1;
 398
 399         for (i = 0; i < len; i++) {
 400                 if (is_regex_special(s[i]))
 401                         return 0;
 402         }
 403
 404         return 1;
 405 }
 406
 407 static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 408 {
 409         struct strbuf sb = STRBUF_INIT;
 410         int err;
 411         int regflags;
 412
 413         basic_regex_quote_buf(&sb, p->pattern);
 414         regflags = opt->regflags & ~REG_EXTENDED;
 415         if (opt->ignore_case)
 416                 regflags |= REG_ICASE;
 417         err = regcomp(&p->regexp, sb.buf, regflags);
 418         if (opt->debug)
 419                 fprintf(stderr, "fixed %s\n", sb.buf);
 420         strbuf_release(&sb);
 421         if (err) {
 422                 char errbuf[1024];
 423                 regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 424                 regfree(&p->regexp);
 425                 compile_regexp_failed(p, errbuf);
 426         }
 427 }
 428
 429 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 430 {
 431         int icase, ascii_only;
 432         int err;
 433
 434         p->word_regexp = opt->word_regexp;
 435         p->ignore_case = opt->ignore_case;
 436         icase          = opt->regflags & REG_ICASE || p->ignore_case;
 437         ascii_only     = !has_non_ascii(p->pattern);
 438
 439         /*
 440          * Even when -F (fixed) asks us to do a non-regexp search, we
 441          * may not be able to correctly case-fold when -i
 442          * (ignore-case) is asked (in which case, we'll synthesize a
 443          * regexp to match the pattern that matches regexp special
 444          * characters literally, while ignoring case differences).  On
 445          * the other hand, even without -F, if the pattern does not
 446          * have any regexp special characters and there is no need for
 447          * case-folding search, we can internally turn it into a
 448          * simple string match using kws.  p->fixed tells us if we
 449          * want to use kws.
 450          */
 451         if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 452                 p->fixed = !icase || ascii_only;
 453         else
 454                 p->fixed = 0;
 455
 456         if (p->fixed) {
 457                 p->kws = kwsalloc(icase ? tolower_trans_tbl : NULL);
 458                 kwsincr(p->kws, p->pattern, p->patternlen);
 459                 kwsprep(p->kws);
 460                 return;
 461         } else if (opt->fixed) {
 462                 /*
 463                  * We come here when the pattern has the non-ascii
 464                  * characters we cannot case-fold, and asked to
 465                  * ignore-case.
 466                  */
 467                 compile_fixed_regexp(p, opt);
 468                 return;
 469         }
 470
 471         if (opt->pcre) {
 472                 compile_pcre_regexp(p, opt);
 473                 return;
 474         }
 475
 476         err = regcomp(&p->regexp, p->pattern, opt->regflags);
 477         if (err) {
 478                 char errbuf[1024];
 479                 regerror(err, &p->regexp, errbuf, 1024);
 480                 regfree(&p->regexp);
 481                 compile_regexp_failed(p, errbuf);
 482         }
 483 }
 484
 485 static struct grep_expr *compile_pattern_or(struct grep_pat **);
 486 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 487 {
 488         struct grep_pat *p;
 489         struct grep_expr *x;
 490
 491         p = *list;
 492         if (!p)
 493                 return NULL;
 494         switch (p->token) {
 495         case GREP_PATTERN: /* atom */
 496         case GREP_PATTERN_HEAD:
 497         case GREP_PATTERN_BODY:
 498                 x = xcalloc(1, sizeof (struct grep_expr));
 499                 x->node = GREP_NODE_ATOM;
 500                 x->u.atom = p;
 501                 *list = p->next;
 502                 return x;
 503         case GREP_OPEN_PAREN:
 504                 *list = p->next;
 505                 x = compile_pattern_or(list);
 506                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 507                         die("unmatched parenthesis");
 508                 *list = (*list)->next;
 509                 return x;
 510         default:
 511                 return NULL;
 512         }
 513 }
 514
 515 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 516 {
 517         struct grep_pat *p;
 518         struct grep_expr *x;
 519
 520         p = *list;
 521         if (!p)
 522                 return NULL;
 523         switch (p->token) {
 524         case GREP_NOT:
 525                 if (!p->next)
 526                         die("--not not followed by pattern expression");
 527                 *list = p->next;
 528                 x = xcalloc(1, sizeof (struct grep_expr));
 529                 x->node = GREP_NODE_NOT;
 530                 x->u.unary = compile_pattern_not(list);
 531                 if (!x->u.unary)
 532                         die("--not followed by non pattern expression");
 533                 return x;
 534         default:
 535                 return compile_pattern_atom(list);
 536         }
 537 }
 538
 539 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 540 {
 541         struct grep_pat *p;
 542         struct grep_expr *x, *y, *z;
 543
 544         x = compile_pattern_not(list);
 545         p = *list;
 546         if (p && p->token == GREP_AND) {
 547                 if (!p->next)
 548                         die("--and not followed by pattern expression");
 549                 *list = p->next;
 550                 y = compile_pattern_and(list);
 551                 if (!y)
 552                         die("--and not followed by pattern expression");
 553                 z = xcalloc(1, sizeof (struct grep_expr));
 554                 z->node = GREP_NODE_AND;
 555                 z->u.binary.left = x;
 556                 z->u.binary.right = y;
 557                 return z;
 558         }
 559         return x;
 560 }
 561
 562 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 563 {
 564         struct grep_pat *p;
 565         struct grep_expr *x, *y, *z;
 566
 567         x = compile_pattern_and(list);
 568         p = *list;
 569         if (x && p && p->token != GREP_CLOSE_PAREN) {
 570                 y = compile_pattern_or(list);
 571                 if (!y)
 572                         die("not a pattern expression %s", p->pattern);
 573                 z = xcalloc(1, sizeof (struct grep_expr));
 574                 z->node = GREP_NODE_OR;
 575                 z->u.binary.left = x;
 576                 z->u.binary.right = y;
 577                 return z;
 578         }
 579         return x;
 580 }
 581
 582 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 583 {
 584         return compile_pattern_or(list);
 585 }
 586
 587 static void indent(int in)
 588 {
 589         while (in-- > 0)
 590                 fputc(' ', stderr);
 591 }
 592
 593 static void dump_grep_pat(struct grep_pat *p)
 594 {
 595         switch (p->token) {
 596         case GREP_AND: fprintf(stderr, "*and*"); break;
 597         case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 598         case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 599         case GREP_NOT: fprintf(stderr, "*not*"); break;
 600         case GREP_OR: fprintf(stderr, "*or*"); break;
 601
 602         case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 603         case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 604         case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 605         }
 606
 607         switch (p->token) {
 608         default: break;
 609         case GREP_PATTERN_HEAD:
 610                 fprintf(stderr, "<head %d>", p->field); break;
 611         case GREP_PATTERN_BODY:
 612                 fprintf(stderr, "<body>"); break;
 613         }
 614         switch (p->token) {
 615         default: break;
 616         case GREP_PATTERN_HEAD:
 617         case GREP_PATTERN_BODY:
 618         case GREP_PATTERN:
 619                 fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 620                 break;
 621         }
 622         fputc('\n', stderr);
 623 }
 624
 625 static void dump_grep_expression_1(struct grep_expr *x, int in)
 626 {
 627         indent(in);
 628         switch (x->node) {
 629         case GREP_NODE_TRUE:
 630                 fprintf(stderr, "true\n");
 631                 break;
 632         case GREP_NODE_ATOM:
 633                 dump_grep_pat(x->u.atom);
 634                 break;
 635         case GREP_NODE_NOT:
 636                 fprintf(stderr, "(not\n");
 637                 dump_grep_expression_1(x->u.unary, in+1);
 638                 indent(in);
 639                 fprintf(stderr, ")\n");
 640                 break;
 641         case GREP_NODE_AND:
 642                 fprintf(stderr, "(and\n");
 643                 dump_grep_expression_1(x->u.binary.left, in+1);
 644                 dump_grep_expression_1(x->u.binary.right, in+1);
 645                 indent(in);
 646                 fprintf(stderr, ")\n");
 647                 break;
 648         case GREP_NODE_OR:
 649                 fprintf(stderr, "(or\n");
 650                 dump_grep_expression_1(x->u.binary.left, in+1);
 651                 dump_grep_expression_1(x->u.binary.right, in+1);
 652                 indent(in);
 653                 fprintf(stderr, ")\n");
 654                 break;
 655         }
 656 }
 657
 658 static void dump_grep_expression(struct grep_opt *opt)
 659 {
 660         struct grep_expr *x = opt->pattern_expression;
 661
 662         if (opt->all_match)
 663                 fprintf(stderr, "[all-match]\n");
 664         dump_grep_expression_1(x, 0);
 665         fflush(NULL);
 666 }
 667
 668 static struct grep_expr *grep_true_expr(void)
 669 {
 670         struct grep_expr *z = xcalloc(1, sizeof(*z));
 671         z->node = GREP_NODE_TRUE;
 672         return z;
 673 }
 674
 675 static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 676 {
 677         struct grep_expr *z = xcalloc(1, sizeof(*z));
 678         z->node = GREP_NODE_OR;
 679         z->u.binary.left = left;
 680         z->u.binary.right = right;
 681         return z;
 682 }
 683
 684 static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 685 {
 686         struct grep_pat *p;
 687         struct grep_expr *header_expr;
 688         struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 689         enum grep_header_field fld;
 690
 691         if (!opt->header_list)
 692                 return NULL;
 693
 694         for (p = opt->header_list; p; p = p->next) {
 695                 if (p->token != GREP_PATTERN_HEAD)
 696                         die("BUG: a non-header pattern in grep header list.");
 697                 if (p->field < GREP_HEADER_FIELD_MIN ||
 698                     GREP_HEADER_FIELD_MAX <= p->field)
 699                         die("BUG: unknown header field %d", p->field);
 700                 compile_regexp(p, opt);
 701         }
 702
 703         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 704                 header_group[fld] = NULL;
 705
 706         for (p = opt->header_list; p; p = p->next) {
 707                 struct grep_expr *h;
 708                 struct grep_pat *pp = p;
 709
 710                 h = compile_pattern_atom(&pp);
 711                 if (!h || pp != p->next)
 712                         die("BUG: malformed header expr");
 713                 if (!header_group[p->field]) {
 714                         header_group[p->field] = h;
 715                         continue;
 716                 }
 717                 header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 718         }
 719
 720         header_expr = NULL;
 721
 722         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 723                 if (!header_group[fld])
 724                         continue;
 725                 if (!header_expr)
 726                         header_expr = grep_true_expr();
 727                 header_expr = grep_or_expr(header_group[fld], header_expr);
 728         }
 729         return header_expr;
 730 }
 731
 732 static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 733 {
 734         struct grep_expr *z = x;
 735
 736         while (x) {
 737                 assert(x->node == GREP_NODE_OR);
 738                 if (x->u.binary.right &&
 739                     x->u.binary.right->node == GREP_NODE_TRUE) {
 740                         x->u.binary.right = y;
 741                         break;
 742                 }
 743                 x = x->u.binary.right;
 744         }
 745         return z;
 746 }
 747
 748 static void compile_grep_patterns_real(struct grep_opt *opt)
 749 {
 750         struct grep_pat *p;
 751         struct grep_expr *header_expr = prep_header_patterns(opt);
 752
 753         for (p = opt->pattern_list; p; p = p->next) {
 754                 switch (p->token) {
 755                 case GREP_PATTERN: /* atom */
 756                 case GREP_PATTERN_HEAD:
 757                 case GREP_PATTERN_BODY:
 758                         compile_regexp(p, opt);
 759                         break;
 760                 default:
 761                         opt->extended = 1;
 762                         break;
 763                 }
 764         }
 765
 766         if (opt->all_match || header_expr)
 767                 opt->extended = 1;
 768         else if (!opt->extended && !opt->debug)
 769                 return;
 770
 771         p = opt->pattern_list;
 772         if (p)
 773                 opt->pattern_expression = compile_pattern_expr(&p);
 774         if (p)
 775                 die("incomplete pattern expression: %s", p->pattern);
 776
 777         if (!header_expr)
 778                 return;
 779
 780         if (!opt->pattern_expression)
 781                 opt->pattern_expression = header_expr;
 782         else if (opt->all_match)
 783                 opt->pattern_expression = grep_splice_or(header_expr,
 784                                                          opt->pattern_expression);
 785         else
 786                 opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 787                                                        header_expr);
 788         opt->all_match = 1;
 789 }
 790
 791 void compile_grep_patterns(struct grep_opt *opt)
 792 {
 793         compile_grep_patterns_real(opt);
 794         if (opt->debug)
 795                 dump_grep_expression(opt);
 796 }
 797
 798 static void free_pattern_expr(struct grep_expr *x)
 799 {
 800         switch (x->node) {
 801         case GREP_NODE_TRUE:
 802         case GREP_NODE_ATOM:
 803                 break;
 804         case GREP_NODE_NOT:
 805                 free_pattern_expr(x->u.unary);
 806                 break;
 807         case GREP_NODE_AND:
 808         case GREP_NODE_OR:
 809                 free_pattern_expr(x->u.binary.left);
 810                 free_pattern_expr(x->u.binary.right);
 811                 break;
 812         }
 813         free(x);
 814 }
 815
 816 void free_grep_patterns(struct grep_opt *opt)
 817 {
 818         struct grep_pat *p, *n;
 819
 820         for (p = opt->pattern_list; p; p = n) {
 821                 n = p->next;
 822                 switch (p->token) {
 823                 case GREP_PATTERN: /* atom */
 824                 case GREP_PATTERN_HEAD:
 825                 case GREP_PATTERN_BODY:
 826                         if (p->kws)
 827                                 kwsfree(p->kws);
 828                         else if (p->pcre_regexp)
 829                                 free_pcre_regexp(p);
 830                         else
 831                                 regfree(&p->regexp);
 832                         free(p->pattern);
 833                         break;
 834                 default:
 835                         break;
 836                 }
 837                 free(p);
 838         }
 839
 840         if (!opt->extended)
 841                 return;
 842         free_pattern_expr(opt->pattern_expression);
 843 }
 844
 845 static char *end_of_line(char *cp, unsigned long *left)
 846 {
 847         unsigned long l = *left;
 848         while (l && *cp != '\n') {
 849                 l--;
 850                 cp++;
 851         }
 852         *left = l;
 853         return cp;
 854 }
 855
 856 static int word_char(char ch)
 857 {
 858         return isalnum(ch) || ch == '_';
 859 }
 860
 861 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 862                          const char *color)
 863 {
 864         if (want_color(opt->color) && color && color[0]) {
 865                 opt->output(opt, color, strlen(color));
 866                 opt->output(opt, data, size);
 867                 opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 868         } else
 869                 opt->output(opt, data, size);
 870 }
 871
 872 static void output_sep(struct grep_opt *opt, char sign)
 873 {
 874         if (opt->null_following_name)
 875                 opt->output(opt, "\0", 1);
 876         else
 877                 output_color(opt, &sign, 1, opt->color_sep);
 878 }
 879
 880 static void show_name(struct grep_opt *opt, const char *name)
 881 {
 882         output_color(opt, name, strlen(name), opt->color_filename);
 883         opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 884 }
 885
 886 static int fixmatch(struct grep_pat *p, char *line, char *eol,
 887                     regmatch_t *match)
 888 {
 889         struct kwsmatch kwsm;
 890         size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 891         if (offset == -1) {
 892                 match->rm_so = match->rm_eo = -1;
 893                 return REG_NOMATCH;
 894         } else {
 895                 match->rm_so = offset;
 896                 match->rm_eo = match->rm_so + kwsm.size[0];
 897                 return 0;
 898         }
 899 }
 900
 901 static int patmatch(struct grep_pat *p, char *line, char *eol,
 902                     regmatch_t *match, int eflags)
 903 {
 904         int hit;
 905
 906         if (p->fixed)
 907                 hit = !fixmatch(p, line, eol, match);
 908         else if (p->pcre_regexp)
 909                 hit = !pcrematch(p, line, eol, match, eflags);
 910         else
 911                 hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
 912                                    eflags);
 913
 914         return hit;
 915 }
 916
 917 static int strip_timestamp(char *bol, char **eol_p)
 918 {
 919         char *eol = *eol_p;
 920         int ch;
 921
 922         while (bol < --eol) {
 923                 if (*eol != '>')
 924                         continue;
 925                 *eol_p = ++eol;
 926                 ch = *eol;
 927                 *eol = '\0';
 928                 return ch;
 929         }
 930         return 0;
 931 }
 932
 933 static struct {
 934         const char *field;
 935         size_t len;
 936 } header_field[] = {
 937         { "author ", 7 },
 938         { "committer ", 10 },
 939         { "reflog ", 7 },
 940 };
 941
 942 static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 943                              enum grep_context ctx,
 944                              regmatch_t *pmatch, int eflags)
 945 {
 946         int hit = 0;
 947         int saved_ch = 0;
 948         const char *start = bol;
 949
 950         if ((p->token != GREP_PATTERN) &&
 951             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 952                 return 0;
 953
 954         if (p->token == GREP_PATTERN_HEAD) {
 955                 const char *field;
 956                 size_t len;
 957                 assert(p->field < ARRAY_SIZE(header_field));
 958                 field = header_field[p->field].field;
 959                 len = header_field[p->field].len;
 960                 if (strncmp(bol, field, len))
 961                         return 0;
 962                 bol += len;
 963                 switch (p->field) {
 964                 case GREP_HEADER_AUTHOR:
 965                 case GREP_HEADER_COMMITTER:
 966                         saved_ch = strip_timestamp(bol, &eol);
 967                         break;
 968                 default:
 969                         break;
 970                 }
 971         }
 972
 973  again:
 974         hit = patmatch(p, bol, eol, pmatch, eflags);
 975
 976         if (hit && p->word_regexp) {
 977                 if ((pmatch[0].rm_so < 0) ||
 978                     (eol - bol) < pmatch[0].rm_so ||
 979                     (pmatch[0].rm_eo < 0) ||
 980                     (eol - bol) < pmatch[0].rm_eo)
 981                         die("regexp returned nonsense");
 982
 983                 /* Match beginning must be either beginning of the
 984                  * line, or at word boundary (i.e. the last char must
 985                  * not be a word char).  Similarly, match end must be
 986                  * either end of the line, or at word boundary
 987                  * (i.e. the next char must not be a word char).
 988                  */
 989                 if ( ((pmatch[0].rm_so == 0) ||
 990                       !word_char(bol[pmatch[0].rm_so-1])) &&
 991                      ((pmatch[0].rm_eo == (eol-bol)) ||
 992                       !word_char(bol[pmatch[0].rm_eo])) )
 993                         ;
 994                 else
 995                         hit = 0;
 996
 997                 /* Words consist of at least one character. */
 998                 if (pmatch->rm_so == pmatch->rm_eo)
 999                         hit = 0;
1000
1001                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1002                         /* There could be more than one match on the
1003                          * line, and the first match might not be
1004                          * strict word match.  But later ones could be!
1005                          * Forward to the next possible start, i.e. the
1006                          * next position following a non-word char.
1007                          */
1008                         bol = pmatch[0].rm_so + bol + 1;
1009                         while (word_char(bol[-1]) && bol < eol)
1010                                 bol++;
1011                         eflags |= REG_NOTBOL;
1012                         if (bol < eol)
1013                                 goto again;
1014                 }
1015         }
1016         if (p->token == GREP_PATTERN_HEAD && saved_ch)
1017                 *eol = saved_ch;
1018         if (hit) {
1019                 pmatch[0].rm_so += bol - start;
1020                 pmatch[0].rm_eo += bol - start;
1021         }
1022         return hit;
1023 }
1024
1025 static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1026                            enum grep_context ctx, int collect_hits)
1027 {
1028         int h = 0;
1029         regmatch_t match;
1030
1031         if (!x)
1032                 die("Not a valid grep expression");
1033         switch (x->node) {
1034         case GREP_NODE_TRUE:
1035                 h = 1;
1036                 break;
1037         case GREP_NODE_ATOM:
1038                 h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1039                 break;
1040         case GREP_NODE_NOT:
1041                 h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1042                 break;
1043         case GREP_NODE_AND:
1044                 if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1045                         return 0;
1046                 h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1047                 break;
1048         case GREP_NODE_OR:
1049                 if (!collect_hits)
1050                         return (match_expr_eval(x->u.binary.left,
1051                                                 bol, eol, ctx, 0) ||
1052                                 match_expr_eval(x->u.binary.right,
1053                                                 bol, eol, ctx, 0));
1054                 h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1055                 x->u.binary.left->hit |= h;
1056                 h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1057                 break;
1058         default:
1059                 die("Unexpected node type (internal error) %d", x->node);
1060         }
1061         if (collect_hits)
1062                 x->hit |= h;
1063         return h;
1064 }
1065
1066 static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1067                       enum grep_context ctx, int collect_hits)
1068 {
1069         struct grep_expr *x = opt->pattern_expression;
1070         return match_expr_eval(x, bol, eol, ctx, collect_hits);
1071 }
1072
1073 static int match_line(struct grep_opt *opt, char *bol, char *eol,
1074                       enum grep_context ctx, int collect_hits)
1075 {
1076         struct grep_pat *p;
1077         regmatch_t match;
1078
1079         if (opt->extended)
1080                 return match_expr(opt, bol, eol, ctx, collect_hits);
1081
1082         /* we do not call with collect_hits without being extended */
1083         for (p = opt->pattern_list; p; p = p->next) {
1084                 if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1085                         return 1;
1086         }
1087         return 0;
1088 }
1089
1090 static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1091                               enum grep_context ctx,
1092                               regmatch_t *pmatch, int eflags)
1093 {
1094         regmatch_t match;
1095
1096         if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1097                 return 0;
1098         if (match.rm_so < 0 || match.rm_eo < 0)
1099                 return 0;
1100         if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1101                 if (match.rm_so > pmatch->rm_so)
1102                         return 1;
1103                 if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1104                         return 1;
1105         }
1106         pmatch->rm_so = match.rm_so;
1107         pmatch->rm_eo = match.rm_eo;
1108         return 1;
1109 }
1110
1111 static int next_match(struct grep_opt *opt, char *bol, char *eol,
1112                       enum grep_context ctx, regmatch_t *pmatch, int eflags)
1113 {
1114         struct grep_pat *p;
1115         int hit = 0;
1116
1117         pmatch->rm_so = pmatch->rm_eo = -1;
1118         if (bol < eol) {
1119                 for (p = opt->pattern_list; p; p = p->next) {
1120                         switch (p->token) {
1121                         case GREP_PATTERN: /* atom */
1122                         case GREP_PATTERN_HEAD:
1123                         case GREP_PATTERN_BODY:
1124                                 hit |= match_next_pattern(p, bol, eol, ctx,
1125                                                           pmatch, eflags);
1126                                 break;
1127                         default:
1128                                 break;
1129                         }
1130                 }
1131         }
1132         return hit;
1133 }
1134
1135 static void show_line(struct grep_opt *opt, char *bol, char *eol,
1136                       const char *name, unsigned lno, char sign)
1137 {
1138         int rest = eol - bol;
1139         const char *match_color, *line_color = NULL;
1140
1141         if (opt->file_break && opt->last_shown == 0) {
1142                 if (opt->show_hunk_mark)
1143                         opt->output(opt, "\n", 1);
1144         } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1145                 if (opt->last_shown == 0) {
1146                         if (opt->show_hunk_mark) {
1147                                 output_color(opt, "--", 2, opt->color_sep);
1148                                 opt->output(opt, "\n", 1);
1149                         }
1150                 } else if (lno > opt->last_shown + 1) {
1151                         output_color(opt, "--", 2, opt->color_sep);
1152                         opt->output(opt, "\n", 1);
1153                 }
1154         }
1155         if (opt->heading && opt->last_shown == 0) {
1156                 output_color(opt, name, strlen(name), opt->color_filename);
1157                 opt->output(opt, "\n", 1);
1158         }
1159         opt->last_shown = lno;
1160
1161         if (!opt->heading && opt->pathname) {
1162                 output_color(opt, name, strlen(name), opt->color_filename);
1163                 output_sep(opt, sign);
1164         }
1165         if (opt->linenum) {
1166                 char buf[32];
1167                 snprintf(buf, sizeof(buf), "%d", lno);
1168                 output_color(opt, buf, strlen(buf), opt->color_lineno);
1169                 output_sep(opt, sign);
1170         }
1171         if (opt->color) {
1172                 regmatch_t match;
1173                 enum grep_context ctx = GREP_CONTEXT_BODY;
1174                 int ch = *eol;
1175                 int eflags = 0;
1176
1177                 if (sign == ':')
1178                         match_color = opt->color_match_selected;
1179                 else
1180                         match_color = opt->color_match_context;
1181                 if (sign == ':')
1182                         line_color = opt->color_selected;
1183                 else if (sign == '-')
1184                         line_color = opt->color_context;
1185                 else if (sign == '=')
1186                         line_color = opt->color_function;
1187                 *eol = '\0';
1188                 while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1189                         if (match.rm_so == match.rm_eo)
1190                                 break;
1191
1192                         output_color(opt, bol, match.rm_so, line_color);
1193                         output_color(opt, bol + match.rm_so,
1194                                      match.rm_eo - match.rm_so, match_color);
1195                         bol += match.rm_eo;
1196                         rest -= match.rm_eo;
1197                         eflags = REG_NOTBOL;
1198                 }
1199                 *eol = ch;
1200         }
1201         output_color(opt, bol, rest, line_color);
1202         opt->output(opt, "\n", 1);
1203 }
1204
1205 #ifndef NO_PTHREADS
1206 int grep_use_locks;
1207
1208 /*
1209  * This lock protects access to the gitattributes machinery, which is
1210  * not thread-safe.
1211  */
1212 pthread_mutex_t grep_attr_mutex;
1213
1214 static inline void grep_attr_lock(void)
1215 {
1216         if (grep_use_locks)
1217                 pthread_mutex_lock(&grep_attr_mutex);
1218 }
1219
1220 static inline void grep_attr_unlock(void)
1221 {
1222         if (grep_use_locks)
1223                 pthread_mutex_unlock(&grep_attr_mutex);
1224 }
1225
1226 /*
1227  * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1228  */
1229 pthread_mutex_t grep_read_mutex;
1230
1231 #else
1232 #define grep_attr_lock()
1233 #define grep_attr_unlock()
1234 #endif
1235
1236 static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1237 {
1238         xdemitconf_t *xecfg = opt->priv;
1239         if (xecfg && !xecfg->find_func) {
1240                 grep_source_load_driver(gs);
1241                 if (gs->driver->funcname.pattern) {
1242                         const struct userdiff_funcname *pe = &gs->driver->funcname;
1243                         xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1244                 } else {
1245                         xecfg = opt->priv = NULL;
1246                 }
1247         }
1248
1249         if (xecfg) {
1250                 char buf[1];
1251                 return xecfg->find_func(bol, eol - bol, buf, 1,
1252                                         xecfg->find_func_priv) >= 0;
1253         }
1254
1255         if (bol == eol)
1256                 return 0;
1257         if (isalpha(*bol) || *bol == '_' || *bol == '$')
1258                 return 1;
1259         return 0;
1260 }
1261
1262 static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1263                                char *bol, unsigned lno)
1264 {
1265         while (bol > gs->buf) {
1266                 char *eol = --bol;
1267
1268                 while (bol > gs->buf && bol[-1] != '\n')
1269                         bol--;
1270                 lno--;
1271
1272                 if (lno <= opt->last_shown)
1273                         break;
1274
1275                 if (match_funcname(opt, gs, bol, eol)) {
1276                         show_line(opt, bol, eol, gs->name, lno, '=');
1277                         break;
1278                 }
1279         }
1280 }
1281
1282 static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1283                              char *bol, char *end, unsigned lno)
1284 {
1285         unsigned cur = lno, from = 1, funcname_lno = 0;
1286         int funcname_needed = !!opt->funcname;
1287
1288         if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1289                 funcname_needed = 2;
1290
1291         if (opt->pre_context < lno)
1292                 from = lno - opt->pre_context;
1293         if (from <= opt->last_shown)
1294                 from = opt->last_shown + 1;
1295
1296         /* Rewind. */
1297         while (bol > gs->buf &&
1298                cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1299                 char *eol = --bol;
1300
1301                 while (bol > gs->buf && bol[-1] != '\n')
1302                         bol--;
1303                 cur--;
1304                 if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1305                         funcname_lno = cur;
1306                         funcname_needed = 0;
1307                 }
1308         }
1309
1310         /* We need to look even further back to find a function signature. */
1311         if (opt->funcname && funcname_needed)
1312                 show_funcname_line(opt, gs, bol, cur);
1313
1314         /* Back forward. */
1315         while (cur < lno) {
1316                 char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1317
1318                 while (*eol != '\n')
1319                         eol++;
1320                 show_line(opt, bol, eol, gs->name, cur, sign);
1321                 bol = eol + 1;
1322                 cur++;
1323         }
1324 }
1325
1326 static int should_lookahead(struct grep_opt *opt)
1327 {
1328         struct grep_pat *p;
1329
1330         if (opt->extended)
1331                 return 0; /* punt for too complex stuff */
1332         if (opt->invert)
1333                 return 0;
1334         for (p = opt->pattern_list; p; p = p->next) {
1335                 if (p->token != GREP_PATTERN)
1336                         return 0; /* punt for "header only" and stuff */
1337         }
1338         return 1;
1339 }
1340
1341 static int look_ahead(struct grep_opt *opt,
1342                       unsigned long *left_p,
1343                       unsigned *lno_p,
1344                       char **bol_p)
1345 {
1346         unsigned lno = *lno_p;
1347         char *bol = *bol_p;
1348         struct grep_pat *p;
1349         char *sp, *last_bol;
1350         regoff_t earliest = -1;
1351
1352         for (p = opt->pattern_list; p; p = p->next) {
1353                 int hit;
1354                 regmatch_t m;
1355
1356                 hit = patmatch(p, bol, bol + *left_p, &m, 0);
1357                 if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1358                         continue;
1359                 if (earliest < 0 || m.rm_so < earliest)
1360                         earliest = m.rm_so;
1361         }
1362
1363         if (earliest < 0) {
1364                 *bol_p = bol + *left_p;
1365                 *left_p = 0;
1366                 return 1;
1367         }
1368         for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1369                 ; /* find the beginning of the line */
1370         last_bol = sp;
1371
1372         for (sp = bol; sp < last_bol; sp++) {
1373                 if (*sp == '\n')
1374                         lno++;
1375         }
1376         *left_p -= last_bol - bol;
1377         *bol_p = last_bol;
1378         *lno_p = lno;
1379         return 0;
1380 }
1381
1382 static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1383 {
1384         fwrite(buf, size, 1, stdout);
1385 }
1386
1387 static int fill_textconv_grep(struct userdiff_driver *driver,
1388                               struct grep_source *gs)
1389 {
1390         struct diff_filespec *df;
1391         char *buf;
1392         size_t size;
1393
1394         if (!driver || !driver->textconv)
1395                 return grep_source_load(gs);
1396
1397         /*
1398          * The textconv interface is intimately tied to diff_filespecs, so we
1399          * have to pretend to be one. If we could unify the grep_source
1400          * and diff_filespec structs, this mess could just go away.
1401          */
1402         df = alloc_filespec(gs->path);
1403         switch (gs->type) {
1404         case GREP_SOURCE_SHA1:
1405                 fill_filespec(df, gs->identifier, 1, 0100644);
1406                 break;
1407         case GREP_SOURCE_FILE:
1408                 fill_filespec(df, null_sha1, 0, 0100644);
1409                 break;
1410         default:
1411                 die("BUG: attempt to textconv something without a path?");
1412         }
1413
1414         /*
1415          * fill_textconv is not remotely thread-safe; it may load objects
1416          * behind the scenes, and it modifies the global diff tempfile
1417          * structure.
1418          */
1419         grep_read_lock();
1420         size = fill_textconv(driver, df, &buf);
1421         grep_read_unlock();
1422         free_filespec(df);
1423
1424         /*
1425          * The normal fill_textconv usage by the diff machinery would just keep
1426          * the textconv'd buf separate from the diff_filespec. But much of the
1427          * grep code passes around a grep_source and assumes that its "buf"
1428          * pointer is the beginning of the thing we are searching. So let's
1429          * install our textconv'd version into the grep_source, taking care not
1430          * to leak any existing buffer.
1431          */
1432         grep_source_clear_data(gs);
1433         gs->buf = buf;
1434         gs->size = size;
1435
1436         return 0;
1437 }
1438
1439 static int is_empty_line(const char *bol, const char *eol)
1440 {
1441         while (bol < eol && isspace(*bol))
1442                 bol++;
1443         return bol == eol;
1444 }
1445
1446 static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1447 {
1448         char *bol;
1449         char *peek_bol = NULL;
1450         unsigned long left;
1451         unsigned lno = 1;
1452         unsigned last_hit = 0;
1453         int binary_match_only = 0;
1454         unsigned count = 0;
1455         int try_lookahead = 0;
1456         int show_function = 0;
1457         struct userdiff_driver *textconv = NULL;
1458         enum grep_context ctx = GREP_CONTEXT_HEAD;
1459         xdemitconf_t xecfg;
1460
1461         if (!opt->output)
1462                 opt->output = std_output;
1463
1464         if (opt->pre_context || opt->post_context || opt->file_break ||
1465             opt->funcbody) {
1466                 /* Show hunk marks, except for the first file. */
1467                 if (opt->last_shown)
1468                         opt->show_hunk_mark = 1;
1469                 /*
1470                  * If we're using threads then we can't easily identify
1471                  * the first file.  Always put hunk marks in that case
1472                  * and skip the very first one later in work_done().
1473                  */
1474                 if (opt->output != std_output)
1475                         opt->show_hunk_mark = 1;
1476         }
1477         opt->last_shown = 0;
1478
1479         if (opt->allow_textconv) {
1480                 grep_source_load_driver(gs);
1481                 /*
1482                  * We might set up the shared textconv cache data here, which
1483                  * is not thread-safe.
1484                  */
1485                 grep_attr_lock();
1486                 textconv = userdiff_get_textconv(gs->driver);
1487                 grep_attr_unlock();
1488         }
1489
1490         /*
1491          * We know the result of a textconv is text, so we only have to care
1492          * about binary handling if we are not using it.
1493          */
1494         if (!textconv) {
1495                 switch (opt->binary) {
1496                 case GREP_BINARY_DEFAULT:
1497                         if (grep_source_is_binary(gs))
1498                                 binary_match_only = 1;
1499                         break;
1500                 case GREP_BINARY_NOMATCH:
1501                         if (grep_source_is_binary(gs))
1502                                 return 0; /* Assume unmatch */
1503                         break;
1504                 case GREP_BINARY_TEXT:
1505                         break;
1506                 default:
1507                         die("BUG: unknown binary handling mode");
1508                 }
1509         }
1510
1511         memset(&xecfg, 0, sizeof(xecfg));
1512         opt->priv = &xecfg;
1513
1514         try_lookahead = should_lookahead(opt);
1515
1516         if (fill_textconv_grep(textconv, gs) < 0)
1517                 return 0;
1518
1519         bol = gs->buf;
1520         left = gs->size;
1521         while (left) {
1522                 char *eol, ch;
1523                 int hit;
1524
1525                 /*
1526                  * look_ahead() skips quickly to the line that possibly
1527                  * has the next hit; don't call it if we need to do
1528                  * something more than just skipping the current line
1529                  * in response to an unmatch for the current line.  E.g.
1530                  * inside a post-context window, we will show the current
1531                  * line as a context around the previous hit when it
1532                  * doesn't hit.
1533                  */
1534                 if (try_lookahead
1535                     && !(last_hit
1536                          && (show_function ||
1537                              lno <= last_hit + opt->post_context))
1538                     && look_ahead(opt, &left, &lno, &bol))
1539                         break;
1540                 eol = end_of_line(bol, &left);
1541                 ch = *eol;
1542                 *eol = 0;
1543
1544                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1545                         ctx = GREP_CONTEXT_BODY;
1546
1547                 hit = match_line(opt, bol, eol, ctx, collect_hits);
1548                 *eol = ch;
1549
1550                 if (collect_hits)
1551                         goto next_line;
1552
1553                 /* "grep -v -e foo -e bla" should list lines
1554                  * that do not have either, so inversion should
1555                  * be done outside.
1556                  */
1557                 if (opt->invert)
1558                         hit = !hit;
1559                 if (opt->unmatch_name_only) {
1560                         if (hit)
1561                                 return 0;
1562                         goto next_line;
1563                 }
1564                 if (hit) {
1565                         count++;
1566                         if (opt->status_only)
1567                                 return 1;
1568                         if (opt->name_only) {
1569                                 show_name(opt, gs->name);
1570                                 return 1;
1571                         }
1572                         if (opt->count)
1573                                 goto next_line;
1574                         if (binary_match_only) {
1575                                 opt->output(opt, "Binary file ", 12);
1576                                 output_color(opt, gs->name, strlen(gs->name),
1577                                              opt->color_filename);
1578                                 opt->output(opt, " matches\n", 9);
1579                                 return 1;
1580                         }
1581                         /* Hit at this line.  If we haven't shown the
1582                          * pre-context lines, we would need to show them.
1583                          */
1584                         if (opt->pre_context || opt->funcbody)
1585                                 show_pre_context(opt, gs, bol, eol, lno);
1586                         else if (opt->funcname)
1587                                 show_funcname_line(opt, gs, bol, lno);
1588                         show_line(opt, bol, eol, gs->name, lno, ':');
1589                         last_hit = lno;
1590                         if (opt->funcbody)
1591                                 show_function = 1;
1592                         goto next_line;
1593                 }
1594                 if (show_function && (!peek_bol || peek_bol < bol)) {
1595                         unsigned long peek_left = left;
1596                         char *peek_eol = eol;
1597
1598                         /*
1599                          * Trailing empty lines are not interesting.
1600                          * Peek past them to see if they belong to the
1601                          * body of the current function.
1602                          */
1603                         peek_bol = bol;
1604                         while (is_empty_line(peek_bol, peek_eol)) {
1605                                 peek_bol = peek_eol + 1;
1606                                 peek_eol = end_of_line(peek_bol, &peek_left);
1607                         }
1608
1609                         if (match_funcname(opt, gs, peek_bol, peek_eol))
1610                                 show_function = 0;
1611                 }
1612                 if (show_function ||
1613                     (last_hit && lno <= last_hit + opt->post_context)) {
1614                         /* If the last hit is within the post context,
1615                          * we need to show this line.
1616                          */
1617                         show_line(opt, bol, eol, gs->name, lno, '-');
1618                 }
1619
1620         next_line:
1621                 bol = eol + 1;
1622                 if (!left)
1623                         break;
1624                 left--;
1625                 lno++;
1626         }
1627
1628         if (collect_hits)
1629                 return 0;
1630
1631         if (opt->status_only)
1632                 return 0;
1633         if (opt->unmatch_name_only) {
1634                 /* We did not see any hit, so we want to show this */
1635                 show_name(opt, gs->name);
1636                 return 1;
1637         }
1638
1639         xdiff_clear_find_func(&xecfg);
1640         opt->priv = NULL;
1641
1642         /* NEEDSWORK:
1643          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1644          * which feels mostly useless but sometimes useful.  Maybe
1645          * make it another option?  For now suppress them.
1646          */
1647         if (opt->count && count) {
1648                 char buf[32];
1649                 if (opt->pathname) {
1650                         output_color(opt, gs->name, strlen(gs->name),
1651                                      opt->color_filename);
1652                         output_sep(opt, ':');
1653                 }
1654                 snprintf(buf, sizeof(buf), "%u\n", count);
1655                 opt->output(opt, buf, strlen(buf));
1656                 return 1;
1657         }
1658         return !!last_hit;
1659 }
1660
1661 static void clr_hit_marker(struct grep_expr *x)
1662 {
1663         /* All-hit markers are meaningful only at the very top level
1664          * OR node.
1665          */
1666         while (1) {
1667                 x->hit = 0;
1668                 if (x->node != GREP_NODE_OR)
1669                         return;
1670                 x->u.binary.left->hit = 0;
1671                 x = x->u.binary.right;
1672         }
1673 }
1674
1675 static int chk_hit_marker(struct grep_expr *x)
1676 {
1677         /* Top level nodes have hit markers.  See if they all are hits */
1678         while (1) {
1679                 if (x->node != GREP_NODE_OR)
1680                         return x->hit;
1681                 if (!x->u.binary.left->hit)
1682                         return 0;
1683                 x = x->u.binary.right;
1684         }
1685 }
1686
1687 int grep_source(struct grep_opt *opt, struct grep_source *gs)
1688 {
1689         /*
1690          * we do not have to do the two-pass grep when we do not check
1691          * buffer-wide "all-match".
1692          */
1693         if (!opt->all_match)
1694                 return grep_source_1(opt, gs, 0);
1695
1696         /* Otherwise the toplevel "or" terms hit a bit differently.
1697          * We first clear hit markers from them.
1698          */
1699         clr_hit_marker(opt->pattern_expression);
1700         grep_source_1(opt, gs, 1);
1701
1702         if (!chk_hit_marker(opt->pattern_expression))
1703                 return 0;
1704
1705         return grep_source_1(opt, gs, 0);
1706 }
1707
1708 int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1709 {
1710         struct grep_source gs;
1711         int r;
1712
1713         grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1714         gs.buf = buf;
1715         gs.size = size;
1716
1717         r = grep_source(opt, &gs);
1718
1719         grep_source_clear(&gs);
1720         return r;
1721 }
1722
1723 void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1724                       const char *name, const char *path,
1725                       const void *identifier)
1726 {
1727         gs->type = type;
1728         gs->name = xstrdup_or_null(name);
1729         gs->path = xstrdup_or_null(path);
1730         gs->buf = NULL;
1731         gs->size = 0;
1732         gs->driver = NULL;
1733
1734         switch (type) {
1735         case GREP_SOURCE_FILE:
1736                 gs->identifier = xstrdup(identifier);
1737                 break;
1738         case GREP_SOURCE_SHA1:
1739                 gs->identifier = xmalloc(20);
1740                 hashcpy(gs->identifier, identifier);
1741                 break;
1742         case GREP_SOURCE_BUF:
1743                 gs->identifier = NULL;
1744         }
1745 }
1746
1747 void grep_source_clear(struct grep_source *gs)
1748 {
1749         free(gs->name);
1750         gs->name = NULL;
1751         free(gs->path);
1752         gs->path = NULL;
1753         free(gs->identifier);
1754         gs->identifier = NULL;
1755         grep_source_clear_data(gs);
1756 }
1757
1758 void grep_source_clear_data(struct grep_source *gs)
1759 {
1760         switch (gs->type) {
1761         case GREP_SOURCE_FILE:
1762         case GREP_SOURCE_SHA1:
1763                 free(gs->buf);
1764                 gs->buf = NULL;
1765                 gs->size = 0;
1766                 break;
1767         case GREP_SOURCE_BUF:
1768                 /* leave user-provided buf intact */
1769                 break;
1770         }
1771 }
1772
1773 static int grep_source_load_sha1(struct grep_source *gs)
1774 {
1775         enum object_type type;
1776
1777         grep_read_lock();
1778         gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1779         grep_read_unlock();
1780
1781         if (!gs->buf)
1782                 return error(_("'%s': unable to read %s"),
1783                              gs->name,
1784                              sha1_to_hex(gs->identifier));
1785         return 0;
1786 }
1787
1788 static int grep_source_load_file(struct grep_source *gs)
1789 {
1790         const char *filename = gs->identifier;
1791         struct stat st;
1792         char *data;
1793         size_t size;
1794         int i;
1795
1796         if (lstat(filename, &st) < 0) {
1797         err_ret:
1798                 if (errno != ENOENT)
1799                         error_errno(_("failed to stat '%s'"), filename);
1800                 return -1;
1801         }
1802         if (!S_ISREG(st.st_mode))
1803                 return -1;
1804         size = xsize_t(st.st_size);
1805         i = open(filename, O_RDONLY);
1806         if (i < 0)
1807                 goto err_ret;
1808         data = xmallocz(size);
1809         if (st.st_size != read_in_full(i, data, size)) {
1810                 error_errno(_("'%s': short read"), filename);
1811                 close(i);
1812                 free(data);
1813                 return -1;
1814         }
1815         close(i);
1816
1817         gs->buf = data;
1818         gs->size = size;
1819         return 0;
1820 }
1821
1822 static int grep_source_load(struct grep_source *gs)
1823 {
1824         if (gs->buf)
1825                 return 0;
1826
1827         switch (gs->type) {
1828         case GREP_SOURCE_FILE:
1829                 return grep_source_load_file(gs);
1830         case GREP_SOURCE_SHA1:
1831                 return grep_source_load_sha1(gs);
1832         case GREP_SOURCE_BUF:
1833                 return gs->buf ? 0 : -1;
1834         }
1835         die("BUG: invalid grep_source type");
1836 }
1837
1838 void grep_source_load_driver(struct grep_source *gs)
1839 {
1840         if (gs->driver)
1841                 return;
1842
1843         grep_attr_lock();
1844         if (gs->path)
1845                 gs->driver = userdiff_find_by_path(gs->path);
1846         if (!gs->driver)
1847                 gs->driver = userdiff_find_by_name("default");
1848         grep_attr_unlock();
1849 }
1850
1851 static int grep_source_is_binary(struct grep_source *gs)
1852 {
1853         grep_source_load_driver(gs);
1854         if (gs->driver->binary != -1)
1855                 return gs->driver->binary;
1856
1857         if (!grep_source_load(gs))
1858                 return buffer_is_binary(gs->buf, gs->size);
1859
1860         return 0;
1861 }