Andrew's git / gitweb.git / grep.c
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grep.con commit ident: use full dns names to generate email addresses (f8254d3)
   1#include "cache.h"
   2#include "grep.h"
   3#include "userdiff.h"
   4#include "xdiff-interface.h"
   5
   6void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
   7{
   8        struct grep_pat *p = xcalloc(1, sizeof(*p));
   9        p->pattern = pat;
  10        p->patternlen = strlen(pat);
  11        p->origin = "header";
  12        p->no = 0;
  13        p->token = GREP_PATTERN_HEAD;
  14        p->field = field;
  15        *opt->header_tail = p;
  16        opt->header_tail = &p->next;
  17        p->next = NULL;
  18}
  19
  20void append_grep_pattern(struct grep_opt *opt, const char *pat,
  21                         const char *origin, int no, enum grep_pat_token t)
  22{
  23        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
  24}
  25
  26void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
  27                     const char *origin, int no, enum grep_pat_token t)
  28{
  29        struct grep_pat *p = xcalloc(1, sizeof(*p));
  30        p->pattern = pat;
  31        p->patternlen = patlen;
  32        p->origin = origin;
  33        p->no = no;
  34        p->token = t;
  35        *opt->pattern_tail = p;
  36        opt->pattern_tail = &p->next;
  37        p->next = NULL;
  38}
  39
  40struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
  41{
  42        struct grep_pat *pat;
  43        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
  44        *ret = *opt;
  45
  46        ret->pattern_list = NULL;
  47        ret->pattern_tail = &ret->pattern_list;
  48
  49        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
  50        {
  51                if(pat->token == GREP_PATTERN_HEAD)
  52                        append_header_grep_pattern(ret, pat->field,
  53                                                   pat->pattern);
  54                else
  55                        append_grep_pat(ret, pat->pattern, pat->patternlen,
  56                                        pat->origin, pat->no, pat->token);
  57        }
  58
  59        return ret;
  60}
  61
  62static NORETURN void compile_regexp_failed(const struct grep_pat *p,
  63                const char *error)
  64{
  65        char where[1024];
  66
  67        if (p->no)
  68                sprintf(where, "In '%s' at %d, ", p->origin, p->no);
  69        else if (p->origin)
  70                sprintf(where, "%s, ", p->origin);
  71        else
  72                where[0] = 0;
  73
  74        die("%s'%s': %s", where, p->pattern, error);
  75}
  76
  77#ifdef USE_LIBPCRE
  78static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
  79{
  80        const char *error;
  81        int erroffset;
  82        int options = PCRE_MULTILINE;
  83
  84        if (opt->ignore_case)
  85                options |= PCRE_CASELESS;
  86
  87        p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
  88                        NULL);
  89        if (!p->pcre_regexp)
  90                compile_regexp_failed(p, error);
  91
  92        p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
  93        if (!p->pcre_extra_info && error)
  94                die("%s", error);
  95}
  96
  97static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
  98                regmatch_t *match, int eflags)
  99{
 100        int ovector[30], ret, flags = 0;
 101
 102        if (eflags & REG_NOTBOL)
 103                flags |= PCRE_NOTBOL;
 104
 105        ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 106                        0, flags, ovector, ARRAY_SIZE(ovector));
 107        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 108                die("pcre_exec failed with error code %d", ret);
 109        if (ret > 0) {
 110                ret = 0;
 111                match->rm_so = ovector[0];
 112                match->rm_eo = ovector[1];
 113        }
 114
 115        return ret;
 116}
 117
 118static void free_pcre_regexp(struct grep_pat *p)
 119{
 120        pcre_free(p->pcre_regexp);
 121        pcre_free(p->pcre_extra_info);
 122}
 123#else /* !USE_LIBPCRE */
 124static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 125{
 126        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 127}
 128
 129static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 130                regmatch_t *match, int eflags)
 131{
 132        return 1;
 133}
 134
 135static void free_pcre_regexp(struct grep_pat *p)
 136{
 137}
 138#endif /* !USE_LIBPCRE */
 139
 140static int is_fixed(const char *s, size_t len)
 141{
 142        size_t i;
 143
 144        /* regcomp cannot accept patterns with NULs so we
 145         * consider any pattern containing a NUL fixed.
 146         */
 147        if (memchr(s, 0, len))
 148                return 1;
 149
 150        for (i = 0; i < len; i++) {
 151                if (is_regex_special(s[i]))
 152                        return 0;
 153        }
 154
 155        return 1;
 156}
 157
 158static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 159{
 160        int err;
 161
 162        p->word_regexp = opt->word_regexp;
 163        p->ignore_case = opt->ignore_case;
 164
 165        if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 166                p->fixed = 1;
 167        else
 168                p->fixed = 0;
 169
 170        if (p->fixed) {
 171                if (opt->regflags & REG_ICASE || p->ignore_case)
 172                        p->kws = kwsalloc(tolower_trans_tbl);
 173                else
 174                        p->kws = kwsalloc(NULL);
 175                kwsincr(p->kws, p->pattern, p->patternlen);
 176                kwsprep(p->kws);
 177                return;
 178        }
 179
 180        if (opt->pcre) {
 181                compile_pcre_regexp(p, opt);
 182                return;
 183        }
 184
 185        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 186        if (err) {
 187                char errbuf[1024];
 188                regerror(err, &p->regexp, errbuf, 1024);
 189                regfree(&p->regexp);
 190                compile_regexp_failed(p, errbuf);
 191        }
 192}
 193
 194static struct grep_expr *compile_pattern_or(struct grep_pat **);
 195static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 196{
 197        struct grep_pat *p;
 198        struct grep_expr *x;
 199
 200        p = *list;
 201        if (!p)
 202                return NULL;
 203        switch (p->token) {
 204        case GREP_PATTERN: /* atom */
 205        case GREP_PATTERN_HEAD:
 206        case GREP_PATTERN_BODY:
 207                x = xcalloc(1, sizeof (struct grep_expr));
 208                x->node = GREP_NODE_ATOM;
 209                x->u.atom = p;
 210                *list = p->next;
 211                return x;
 212        case GREP_OPEN_PAREN:
 213                *list = p->next;
 214                x = compile_pattern_or(list);
 215                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 216                        die("unmatched parenthesis");
 217                *list = (*list)->next;
 218                return x;
 219        default:
 220                return NULL;
 221        }
 222}
 223
 224static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 225{
 226        struct grep_pat *p;
 227        struct grep_expr *x;
 228
 229        p = *list;
 230        if (!p)
 231                return NULL;
 232        switch (p->token) {
 233        case GREP_NOT:
 234                if (!p->next)
 235                        die("--not not followed by pattern expression");
 236                *list = p->next;
 237                x = xcalloc(1, sizeof (struct grep_expr));
 238                x->node = GREP_NODE_NOT;
 239                x->u.unary = compile_pattern_not(list);
 240                if (!x->u.unary)
 241                        die("--not followed by non pattern expression");
 242                return x;
 243        default:
 244                return compile_pattern_atom(list);
 245        }
 246}
 247
 248static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 249{
 250        struct grep_pat *p;
 251        struct grep_expr *x, *y, *z;
 252
 253        x = compile_pattern_not(list);
 254        p = *list;
 255        if (p && p->token == GREP_AND) {
 256                if (!p->next)
 257                        die("--and not followed by pattern expression");
 258                *list = p->next;
 259                y = compile_pattern_and(list);
 260                if (!y)
 261                        die("--and not followed by pattern expression");
 262                z = xcalloc(1, sizeof (struct grep_expr));
 263                z->node = GREP_NODE_AND;
 264                z->u.binary.left = x;
 265                z->u.binary.right = y;
 266                return z;
 267        }
 268        return x;
 269}
 270
 271static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 272{
 273        struct grep_pat *p;
 274        struct grep_expr *x, *y, *z;
 275
 276        x = compile_pattern_and(list);
 277        p = *list;
 278        if (x && p && p->token != GREP_CLOSE_PAREN) {
 279                y = compile_pattern_or(list);
 280                if (!y)
 281                        die("not a pattern expression %s", p->pattern);
 282                z = xcalloc(1, sizeof (struct grep_expr));
 283                z->node = GREP_NODE_OR;
 284                z->u.binary.left = x;
 285                z->u.binary.right = y;
 286                return z;
 287        }
 288        return x;
 289}
 290
 291static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 292{
 293        return compile_pattern_or(list);
 294}
 295
 296static struct grep_expr *grep_true_expr(void)
 297{
 298        struct grep_expr *z = xcalloc(1, sizeof(*z));
 299        z->node = GREP_NODE_TRUE;
 300        return z;
 301}
 302
 303static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 304{
 305        struct grep_expr *z = xcalloc(1, sizeof(*z));
 306        z->node = GREP_NODE_OR;
 307        z->u.binary.left = left;
 308        z->u.binary.right = right;
 309        return z;
 310}
 311
 312static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 313{
 314        struct grep_pat *p;
 315        struct grep_expr *header_expr;
 316        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 317        enum grep_header_field fld;
 318
 319        if (!opt->header_list)
 320                return NULL;
 321
 322        for (p = opt->header_list; p; p = p->next) {
 323                if (p->token != GREP_PATTERN_HEAD)
 324                        die("bug: a non-header pattern in grep header list.");
 325                if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
 326                        die("bug: unknown header field %d", p->field);
 327                compile_regexp(p, opt);
 328        }
 329
 330        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 331                header_group[fld] = NULL;
 332
 333        for (p = opt->header_list; p; p = p->next) {
 334                struct grep_expr *h;
 335                struct grep_pat *pp = p;
 336
 337                h = compile_pattern_atom(&pp);
 338                if (!h || pp != p->next)
 339                        die("bug: malformed header expr");
 340                if (!header_group[p->field]) {
 341                        header_group[p->field] = h;
 342                        continue;
 343                }
 344                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 345        }
 346
 347        header_expr = NULL;
 348
 349        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 350                if (!header_group[fld])
 351                        continue;
 352                if (!header_expr)
 353                        header_expr = grep_true_expr();
 354                header_expr = grep_or_expr(header_group[fld], header_expr);
 355        }
 356        return header_expr;
 357}
 358
 359void compile_grep_patterns(struct grep_opt *opt)
 360{
 361        struct grep_pat *p;
 362        struct grep_expr *header_expr = prep_header_patterns(opt);
 363
 364        for (p = opt->pattern_list; p; p = p->next) {
 365                switch (p->token) {
 366                case GREP_PATTERN: /* atom */
 367                case GREP_PATTERN_HEAD:
 368                case GREP_PATTERN_BODY:
 369                        compile_regexp(p, opt);
 370                        break;
 371                default:
 372                        opt->extended = 1;
 373                        break;
 374                }
 375        }
 376
 377        if (opt->all_match || header_expr)
 378                opt->extended = 1;
 379        else if (!opt->extended)
 380                return;
 381
 382        p = opt->pattern_list;
 383        if (p)
 384                opt->pattern_expression = compile_pattern_expr(&p);
 385        if (p)
 386                die("incomplete pattern expression: %s", p->pattern);
 387
 388        if (!header_expr)
 389                return;
 390
 391        if (!opt->pattern_expression)
 392                opt->pattern_expression = header_expr;
 393        else
 394                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 395                                                       header_expr);
 396        opt->all_match = 1;
 397}
 398
 399static void free_pattern_expr(struct grep_expr *x)
 400{
 401        switch (x->node) {
 402        case GREP_NODE_TRUE:
 403        case GREP_NODE_ATOM:
 404                break;
 405        case GREP_NODE_NOT:
 406                free_pattern_expr(x->u.unary);
 407                break;
 408        case GREP_NODE_AND:
 409        case GREP_NODE_OR:
 410                free_pattern_expr(x->u.binary.left);
 411                free_pattern_expr(x->u.binary.right);
 412                break;
 413        }
 414        free(x);
 415}
 416
 417void free_grep_patterns(struct grep_opt *opt)
 418{
 419        struct grep_pat *p, *n;
 420
 421        for (p = opt->pattern_list; p; p = n) {
 422                n = p->next;
 423                switch (p->token) {
 424                case GREP_PATTERN: /* atom */
 425                case GREP_PATTERN_HEAD:
 426                case GREP_PATTERN_BODY:
 427                        if (p->kws)
 428                                kwsfree(p->kws);
 429                        else if (p->pcre_regexp)
 430                                free_pcre_regexp(p);
 431                        else
 432                                regfree(&p->regexp);
 433                        break;
 434                default:
 435                        break;
 436                }
 437                free(p);
 438        }
 439
 440        if (!opt->extended)
 441                return;
 442        free_pattern_expr(opt->pattern_expression);
 443}
 444
 445static char *end_of_line(char *cp, unsigned long *left)
 446{
 447        unsigned long l = *left;
 448        while (l && *cp != '\n') {
 449                l--;
 450                cp++;
 451        }
 452        *left = l;
 453        return cp;
 454}
 455
 456static int word_char(char ch)
 457{
 458        return isalnum(ch) || ch == '_';
 459}
 460
 461static void output_color(struct grep_opt *opt, const void *data, size_t size,
 462                         const char *color)
 463{
 464        if (want_color(opt->color) && color && color[0]) {
 465                opt->output(opt, color, strlen(color));
 466                opt->output(opt, data, size);
 467                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 468        } else
 469                opt->output(opt, data, size);
 470}
 471
 472static void output_sep(struct grep_opt *opt, char sign)
 473{
 474        if (opt->null_following_name)
 475                opt->output(opt, "\0", 1);
 476        else
 477                output_color(opt, &sign, 1, opt->color_sep);
 478}
 479
 480static void show_name(struct grep_opt *opt, const char *name)
 481{
 482        output_color(opt, name, strlen(name), opt->color_filename);
 483        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 484}
 485
 486static int fixmatch(struct grep_pat *p, char *line, char *eol,
 487                    regmatch_t *match)
 488{
 489        struct kwsmatch kwsm;
 490        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 491        if (offset == -1) {
 492                match->rm_so = match->rm_eo = -1;
 493                return REG_NOMATCH;
 494        } else {
 495                match->rm_so = offset;
 496                match->rm_eo = match->rm_so + kwsm.size[0];
 497                return 0;
 498        }
 499}
 500
 501static int regmatch(const regex_t *preg, char *line, char *eol,
 502                    regmatch_t *match, int eflags)
 503{
 504#ifdef REG_STARTEND
 505        match->rm_so = 0;
 506        match->rm_eo = eol - line;
 507        eflags |= REG_STARTEND;
 508#endif
 509        return regexec(preg, line, 1, match, eflags);
 510}
 511
 512static int patmatch(struct grep_pat *p, char *line, char *eol,
 513                    regmatch_t *match, int eflags)
 514{
 515        int hit;
 516
 517        if (p->fixed)
 518                hit = !fixmatch(p, line, eol, match);
 519        else if (p->pcre_regexp)
 520                hit = !pcrematch(p, line, eol, match, eflags);
 521        else
 522                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 523
 524        return hit;
 525}
 526
 527static int strip_timestamp(char *bol, char **eol_p)
 528{
 529        char *eol = *eol_p;
 530        int ch;
 531
 532        while (bol < --eol) {
 533                if (*eol != '>')
 534                        continue;
 535                *eol_p = ++eol;
 536                ch = *eol;
 537                *eol = '\0';
 538                return ch;
 539        }
 540        return 0;
 541}
 542
 543static struct {
 544        const char *field;
 545        size_t len;
 546} header_field[] = {
 547        { "author ", 7 },
 548        { "committer ", 10 },
 549};
 550
 551static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 552                             enum grep_context ctx,
 553                             regmatch_t *pmatch, int eflags)
 554{
 555        int hit = 0;
 556        int saved_ch = 0;
 557        const char *start = bol;
 558
 559        if ((p->token != GREP_PATTERN) &&
 560            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 561                return 0;
 562
 563        if (p->token == GREP_PATTERN_HEAD) {
 564                const char *field;
 565                size_t len;
 566                assert(p->field < ARRAY_SIZE(header_field));
 567                field = header_field[p->field].field;
 568                len = header_field[p->field].len;
 569                if (strncmp(bol, field, len))
 570                        return 0;
 571                bol += len;
 572                saved_ch = strip_timestamp(bol, &eol);
 573        }
 574
 575 again:
 576        hit = patmatch(p, bol, eol, pmatch, eflags);
 577
 578        if (hit && p->word_regexp) {
 579                if ((pmatch[0].rm_so < 0) ||
 580                    (eol - bol) < pmatch[0].rm_so ||
 581                    (pmatch[0].rm_eo < 0) ||
 582                    (eol - bol) < pmatch[0].rm_eo)
 583                        die("regexp returned nonsense");
 584
 585                /* Match beginning must be either beginning of the
 586                 * line, or at word boundary (i.e. the last char must
 587                 * not be a word char).  Similarly, match end must be
 588                 * either end of the line, or at word boundary
 589                 * (i.e. the next char must not be a word char).
 590                 */
 591                if ( ((pmatch[0].rm_so == 0) ||
 592                      !word_char(bol[pmatch[0].rm_so-1])) &&
 593                     ((pmatch[0].rm_eo == (eol-bol)) ||
 594                      !word_char(bol[pmatch[0].rm_eo])) )
 595                        ;
 596                else
 597                        hit = 0;
 598
 599                /* Words consist of at least one character. */
 600                if (pmatch->rm_so == pmatch->rm_eo)
 601                        hit = 0;
 602
 603                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 604                        /* There could be more than one match on the
 605                         * line, and the first match might not be
 606                         * strict word match.  But later ones could be!
 607                         * Forward to the next possible start, i.e. the
 608                         * next position following a non-word char.
 609                         */
 610                        bol = pmatch[0].rm_so + bol + 1;
 611                        while (word_char(bol[-1]) && bol < eol)
 612                                bol++;
 613                        eflags |= REG_NOTBOL;
 614                        if (bol < eol)
 615                                goto again;
 616                }
 617        }
 618        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 619                *eol = saved_ch;
 620        if (hit) {
 621                pmatch[0].rm_so += bol - start;
 622                pmatch[0].rm_eo += bol - start;
 623        }
 624        return hit;
 625}
 626
 627static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 628                           enum grep_context ctx, int collect_hits)
 629{
 630        int h = 0;
 631        regmatch_t match;
 632
 633        if (!x)
 634                die("Not a valid grep expression");
 635        switch (x->node) {
 636        case GREP_NODE_TRUE:
 637                h = 1;
 638                break;
 639        case GREP_NODE_ATOM:
 640                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 641                break;
 642        case GREP_NODE_NOT:
 643                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 644                break;
 645        case GREP_NODE_AND:
 646                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 647                        return 0;
 648                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 649                break;
 650        case GREP_NODE_OR:
 651                if (!collect_hits)
 652                        return (match_expr_eval(x->u.binary.left,
 653                                                bol, eol, ctx, 0) ||
 654                                match_expr_eval(x->u.binary.right,
 655                                                bol, eol, ctx, 0));
 656                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 657                x->u.binary.left->hit |= h;
 658                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 659                break;
 660        default:
 661                die("Unexpected node type (internal error) %d", x->node);
 662        }
 663        if (collect_hits)
 664                x->hit |= h;
 665        return h;
 666}
 667
 668static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 669                      enum grep_context ctx, int collect_hits)
 670{
 671        struct grep_expr *x = opt->pattern_expression;
 672        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 673}
 674
 675static int match_line(struct grep_opt *opt, char *bol, char *eol,
 676                      enum grep_context ctx, int collect_hits)
 677{
 678        struct grep_pat *p;
 679        regmatch_t match;
 680
 681        if (opt->extended)
 682                return match_expr(opt, bol, eol, ctx, collect_hits);
 683
 684        /* we do not call with collect_hits without being extended */
 685        for (p = opt->pattern_list; p; p = p->next) {
 686                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 687                        return 1;
 688        }
 689        return 0;
 690}
 691
 692static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 693                              enum grep_context ctx,
 694                              regmatch_t *pmatch, int eflags)
 695{
 696        regmatch_t match;
 697
 698        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 699                return 0;
 700        if (match.rm_so < 0 || match.rm_eo < 0)
 701                return 0;
 702        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 703                if (match.rm_so > pmatch->rm_so)
 704                        return 1;
 705                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 706                        return 1;
 707        }
 708        pmatch->rm_so = match.rm_so;
 709        pmatch->rm_eo = match.rm_eo;
 710        return 1;
 711}
 712
 713static int next_match(struct grep_opt *opt, char *bol, char *eol,
 714                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 715{
 716        struct grep_pat *p;
 717        int hit = 0;
 718
 719        pmatch->rm_so = pmatch->rm_eo = -1;
 720        if (bol < eol) {
 721                for (p = opt->pattern_list; p; p = p->next) {
 722                        switch (p->token) {
 723                        case GREP_PATTERN: /* atom */
 724                        case GREP_PATTERN_HEAD:
 725                        case GREP_PATTERN_BODY:
 726                                hit |= match_next_pattern(p, bol, eol, ctx,
 727                                                          pmatch, eflags);
 728                                break;
 729                        default:
 730                                break;
 731                        }
 732                }
 733        }
 734        return hit;
 735}
 736
 737static void show_line(struct grep_opt *opt, char *bol, char *eol,
 738                      const char *name, unsigned lno, char sign)
 739{
 740        int rest = eol - bol;
 741        char *line_color = NULL;
 742
 743        if (opt->file_break && opt->last_shown == 0) {
 744                if (opt->show_hunk_mark)
 745                        opt->output(opt, "\n", 1);
 746        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
 747                if (opt->last_shown == 0) {
 748                        if (opt->show_hunk_mark) {
 749                                output_color(opt, "--", 2, opt->color_sep);
 750                                opt->output(opt, "\n", 1);
 751                        }
 752                } else if (lno > opt->last_shown + 1) {
 753                        output_color(opt, "--", 2, opt->color_sep);
 754                        opt->output(opt, "\n", 1);
 755                }
 756        }
 757        if (opt->heading && opt->last_shown == 0) {
 758                output_color(opt, name, strlen(name), opt->color_filename);
 759                opt->output(opt, "\n", 1);
 760        }
 761        opt->last_shown = lno;
 762
 763        if (!opt->heading && opt->pathname) {
 764                output_color(opt, name, strlen(name), opt->color_filename);
 765                output_sep(opt, sign);
 766        }
 767        if (opt->linenum) {
 768                char buf[32];
 769                snprintf(buf, sizeof(buf), "%d", lno);
 770                output_color(opt, buf, strlen(buf), opt->color_lineno);
 771                output_sep(opt, sign);
 772        }
 773        if (opt->color) {
 774                regmatch_t match;
 775                enum grep_context ctx = GREP_CONTEXT_BODY;
 776                int ch = *eol;
 777                int eflags = 0;
 778
 779                if (sign == ':')
 780                        line_color = opt->color_selected;
 781                else if (sign == '-')
 782                        line_color = opt->color_context;
 783                else if (sign == '=')
 784                        line_color = opt->color_function;
 785                *eol = '\0';
 786                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 787                        if (match.rm_so == match.rm_eo)
 788                                break;
 789
 790                        output_color(opt, bol, match.rm_so, line_color);
 791                        output_color(opt, bol + match.rm_so,
 792                                     match.rm_eo - match.rm_so,
 793                                     opt->color_match);
 794                        bol += match.rm_eo;
 795                        rest -= match.rm_eo;
 796                        eflags = REG_NOTBOL;
 797                }
 798                *eol = ch;
 799        }
 800        output_color(opt, bol, rest, line_color);
 801        opt->output(opt, "\n", 1);
 802}
 803
 804#ifndef NO_PTHREADS
 805int grep_use_locks;
 806
 807/*
 808 * This lock protects access to the gitattributes machinery, which is
 809 * not thread-safe.
 810 */
 811pthread_mutex_t grep_attr_mutex;
 812
 813static inline void grep_attr_lock(void)
 814{
 815        if (grep_use_locks)
 816                pthread_mutex_lock(&grep_attr_mutex);
 817}
 818
 819static inline void grep_attr_unlock(void)
 820{
 821        if (grep_use_locks)
 822                pthread_mutex_unlock(&grep_attr_mutex);
 823}
 824
 825/*
 826 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
 827 */
 828pthread_mutex_t grep_read_mutex;
 829
 830#else
 831#define grep_attr_lock()
 832#define grep_attr_unlock()
 833#endif
 834
 835static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
 836{
 837        xdemitconf_t *xecfg = opt->priv;
 838        if (xecfg && !xecfg->find_func) {
 839                grep_source_load_driver(gs);
 840                if (gs->driver->funcname.pattern) {
 841                        const struct userdiff_funcname *pe = &gs->driver->funcname;
 842                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
 843                } else {
 844                        xecfg = opt->priv = NULL;
 845                }
 846        }
 847
 848        if (xecfg) {
 849                char buf[1];
 850                return xecfg->find_func(bol, eol - bol, buf, 1,
 851                                        xecfg->find_func_priv) >= 0;
 852        }
 853
 854        if (bol == eol)
 855                return 0;
 856        if (isalpha(*bol) || *bol == '_' || *bol == '$')
 857                return 1;
 858        return 0;
 859}
 860
 861static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
 862                               char *bol, unsigned lno)
 863{
 864        while (bol > gs->buf) {
 865                char *eol = --bol;
 866
 867                while (bol > gs->buf && bol[-1] != '\n')
 868                        bol--;
 869                lno--;
 870
 871                if (lno <= opt->last_shown)
 872                        break;
 873
 874                if (match_funcname(opt, gs, bol, eol)) {
 875                        show_line(opt, bol, eol, gs->name, lno, '=');
 876                        break;
 877                }
 878        }
 879}
 880
 881static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
 882                             char *bol, char *end, unsigned lno)
 883{
 884        unsigned cur = lno, from = 1, funcname_lno = 0;
 885        int funcname_needed = !!opt->funcname;
 886
 887        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
 888                funcname_needed = 2;
 889
 890        if (opt->pre_context < lno)
 891                from = lno - opt->pre_context;
 892        if (from <= opt->last_shown)
 893                from = opt->last_shown + 1;
 894
 895        /* Rewind. */
 896        while (bol > gs->buf &&
 897               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
 898                char *eol = --bol;
 899
 900                while (bol > gs->buf && bol[-1] != '\n')
 901                        bol--;
 902                cur--;
 903                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
 904                        funcname_lno = cur;
 905                        funcname_needed = 0;
 906                }
 907        }
 908
 909        /* We need to look even further back to find a function signature. */
 910        if (opt->funcname && funcname_needed)
 911                show_funcname_line(opt, gs, bol, cur);
 912
 913        /* Back forward. */
 914        while (cur < lno) {
 915                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
 916
 917                while (*eol != '\n')
 918                        eol++;
 919                show_line(opt, bol, eol, gs->name, cur, sign);
 920                bol = eol + 1;
 921                cur++;
 922        }
 923}
 924
 925static int should_lookahead(struct grep_opt *opt)
 926{
 927        struct grep_pat *p;
 928
 929        if (opt->extended)
 930                return 0; /* punt for too complex stuff */
 931        if (opt->invert)
 932                return 0;
 933        for (p = opt->pattern_list; p; p = p->next) {
 934                if (p->token != GREP_PATTERN)
 935                        return 0; /* punt for "header only" and stuff */
 936        }
 937        return 1;
 938}
 939
 940static int look_ahead(struct grep_opt *opt,
 941                      unsigned long *left_p,
 942                      unsigned *lno_p,
 943                      char **bol_p)
 944{
 945        unsigned lno = *lno_p;
 946        char *bol = *bol_p;
 947        struct grep_pat *p;
 948        char *sp, *last_bol;
 949        regoff_t earliest = -1;
 950
 951        for (p = opt->pattern_list; p; p = p->next) {
 952                int hit;
 953                regmatch_t m;
 954
 955                hit = patmatch(p, bol, bol + *left_p, &m, 0);
 956                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
 957                        continue;
 958                if (earliest < 0 || m.rm_so < earliest)
 959                        earliest = m.rm_so;
 960        }
 961
 962        if (earliest < 0) {
 963                *bol_p = bol + *left_p;
 964                *left_p = 0;
 965                return 1;
 966        }
 967        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
 968                ; /* find the beginning of the line */
 969        last_bol = sp;
 970
 971        for (sp = bol; sp < last_bol; sp++) {
 972                if (*sp == '\n')
 973                        lno++;
 974        }
 975        *left_p -= last_bol - bol;
 976        *bol_p = last_bol;
 977        *lno_p = lno;
 978        return 0;
 979}
 980
 981static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 982{
 983        fwrite(buf, size, 1, stdout);
 984}
 985
 986static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
 987{
 988        char *bol;
 989        unsigned long left;
 990        unsigned lno = 1;
 991        unsigned last_hit = 0;
 992        int binary_match_only = 0;
 993        unsigned count = 0;
 994        int try_lookahead = 0;
 995        int show_function = 0;
 996        enum grep_context ctx = GREP_CONTEXT_HEAD;
 997        xdemitconf_t xecfg;
 998
 999        if (!opt->output)
1000                opt->output = std_output;
1001
1002        if (opt->pre_context || opt->post_context || opt->file_break ||
1003            opt->funcbody) {
1004                /* Show hunk marks, except for the first file. */
1005                if (opt->last_shown)
1006                        opt->show_hunk_mark = 1;
1007                /*
1008                 * If we're using threads then we can't easily identify
1009                 * the first file.  Always put hunk marks in that case
1010                 * and skip the very first one later in work_done().
1011                 */
1012                if (opt->output != std_output)
1013                        opt->show_hunk_mark = 1;
1014        }
1015        opt->last_shown = 0;
1016
1017        switch (opt->binary) {
1018        case GREP_BINARY_DEFAULT:
1019                if (grep_source_is_binary(gs))
1020                        binary_match_only = 1;
1021                break;
1022        case GREP_BINARY_NOMATCH:
1023                if (grep_source_is_binary(gs))
1024                        return 0; /* Assume unmatch */
1025                break;
1026        case GREP_BINARY_TEXT:
1027                break;
1028        default:
1029                die("bug: unknown binary handling mode");
1030        }
1031
1032        memset(&xecfg, 0, sizeof(xecfg));
1033        opt->priv = &xecfg;
1034
1035        try_lookahead = should_lookahead(opt);
1036
1037        if (grep_source_load(gs) < 0)
1038                return 0;
1039
1040        bol = gs->buf;
1041        left = gs->size;
1042        while (left) {
1043                char *eol, ch;
1044                int hit;
1045
1046                /*
1047                 * look_ahead() skips quickly to the line that possibly
1048                 * has the next hit; don't call it if we need to do
1049                 * something more than just skipping the current line
1050                 * in response to an unmatch for the current line.  E.g.
1051                 * inside a post-context window, we will show the current
1052                 * line as a context around the previous hit when it
1053                 * doesn't hit.
1054                 */
1055                if (try_lookahead
1056                    && !(last_hit
1057                         && (show_function ||
1058                             lno <= last_hit + opt->post_context))
1059                    && look_ahead(opt, &left, &lno, &bol))
1060                        break;
1061                eol = end_of_line(bol, &left);
1062                ch = *eol;
1063                *eol = 0;
1064
1065                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1066                        ctx = GREP_CONTEXT_BODY;
1067
1068                hit = match_line(opt, bol, eol, ctx, collect_hits);
1069                *eol = ch;
1070
1071                if (collect_hits)
1072                        goto next_line;
1073
1074                /* "grep -v -e foo -e bla" should list lines
1075                 * that do not have either, so inversion should
1076                 * be done outside.
1077                 */
1078                if (opt->invert)
1079                        hit = !hit;
1080                if (opt->unmatch_name_only) {
1081                        if (hit)
1082                                return 0;
1083                        goto next_line;
1084                }
1085                if (hit) {
1086                        count++;
1087                        if (opt->status_only)
1088                                return 1;
1089                        if (opt->name_only) {
1090                                show_name(opt, gs->name);
1091                                return 1;
1092                        }
1093                        if (opt->count)
1094                                goto next_line;
1095                        if (binary_match_only) {
1096                                opt->output(opt, "Binary file ", 12);
1097                                output_color(opt, gs->name, strlen(gs->name),
1098                                             opt->color_filename);
1099                                opt->output(opt, " matches\n", 9);
1100                                return 1;
1101                        }
1102                        /* Hit at this line.  If we haven't shown the
1103                         * pre-context lines, we would need to show them.
1104                         */
1105                        if (opt->pre_context || opt->funcbody)
1106                                show_pre_context(opt, gs, bol, eol, lno);
1107                        else if (opt->funcname)
1108                                show_funcname_line(opt, gs, bol, lno);
1109                        show_line(opt, bol, eol, gs->name, lno, ':');
1110                        last_hit = lno;
1111                        if (opt->funcbody)
1112                                show_function = 1;
1113                        goto next_line;
1114                }
1115                if (show_function && match_funcname(opt, gs, bol, eol))
1116                        show_function = 0;
1117                if (show_function ||
1118                    (last_hit && lno <= last_hit + opt->post_context)) {
1119                        /* If the last hit is within the post context,
1120                         * we need to show this line.
1121                         */
1122                        show_line(opt, bol, eol, gs->name, lno, '-');
1123                }
1124
1125        next_line:
1126                bol = eol + 1;
1127                if (!left)
1128                        break;
1129                left--;
1130                lno++;
1131        }
1132
1133        if (collect_hits)
1134                return 0;
1135
1136        if (opt->status_only)
1137                return 0;
1138        if (opt->unmatch_name_only) {
1139                /* We did not see any hit, so we want to show this */
1140                show_name(opt, gs->name);
1141                return 1;
1142        }
1143
1144        xdiff_clear_find_func(&xecfg);
1145        opt->priv = NULL;
1146
1147        /* NEEDSWORK:
1148         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1149         * which feels mostly useless but sometimes useful.  Maybe
1150         * make it another option?  For now suppress them.
1151         */
1152        if (opt->count && count) {
1153                char buf[32];
1154                output_color(opt, gs->name, strlen(gs->name), opt->color_filename);
1155                output_sep(opt, ':');
1156                snprintf(buf, sizeof(buf), "%u\n", count);
1157                opt->output(opt, buf, strlen(buf));
1158                return 1;
1159        }
1160        return !!last_hit;
1161}
1162
1163static void clr_hit_marker(struct grep_expr *x)
1164{
1165        /* All-hit markers are meaningful only at the very top level
1166         * OR node.
1167         */
1168        while (1) {
1169                x->hit = 0;
1170                if (x->node != GREP_NODE_OR)
1171                        return;
1172                x->u.binary.left->hit = 0;
1173                x = x->u.binary.right;
1174        }
1175}
1176
1177static int chk_hit_marker(struct grep_expr *x)
1178{
1179        /* Top level nodes have hit markers.  See if they all are hits */
1180        while (1) {
1181                if (x->node != GREP_NODE_OR)
1182                        return x->hit;
1183                if (!x->u.binary.left->hit)
1184                        return 0;
1185                x = x->u.binary.right;
1186        }
1187}
1188
1189int grep_source(struct grep_opt *opt, struct grep_source *gs)
1190{
1191        /*
1192         * we do not have to do the two-pass grep when we do not check
1193         * buffer-wide "all-match".
1194         */
1195        if (!opt->all_match)
1196                return grep_source_1(opt, gs, 0);
1197
1198        /* Otherwise the toplevel "or" terms hit a bit differently.
1199         * We first clear hit markers from them.
1200         */
1201        clr_hit_marker(opt->pattern_expression);
1202        grep_source_1(opt, gs, 1);
1203
1204        if (!chk_hit_marker(opt->pattern_expression))
1205                return 0;
1206
1207        return grep_source_1(opt, gs, 0);
1208}
1209
1210int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1211{
1212        struct grep_source gs;
1213        int r;
1214
1215        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL);
1216        gs.buf = buf;
1217        gs.size = size;
1218
1219        r = grep_source(opt, &gs);
1220
1221        grep_source_clear(&gs);
1222        return r;
1223}
1224
1225void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1226                      const char *name, const void *identifier)
1227{
1228        gs->type = type;
1229        gs->name = name ? xstrdup(name) : NULL;
1230        gs->buf = NULL;
1231        gs->size = 0;
1232        gs->driver = NULL;
1233
1234        switch (type) {
1235        case GREP_SOURCE_FILE:
1236                gs->identifier = xstrdup(identifier);
1237                break;
1238        case GREP_SOURCE_SHA1:
1239                gs->identifier = xmalloc(20);
1240                memcpy(gs->identifier, identifier, 20);
1241                break;
1242        case GREP_SOURCE_BUF:
1243                gs->identifier = NULL;
1244        }
1245}
1246
1247void grep_source_clear(struct grep_source *gs)
1248{
1249        free(gs->name);
1250        gs->name = NULL;
1251        free(gs->identifier);
1252        gs->identifier = NULL;
1253        grep_source_clear_data(gs);
1254}
1255
1256void grep_source_clear_data(struct grep_source *gs)
1257{
1258        switch (gs->type) {
1259        case GREP_SOURCE_FILE:
1260        case GREP_SOURCE_SHA1:
1261                free(gs->buf);
1262                gs->buf = NULL;
1263                gs->size = 0;
1264                break;
1265        case GREP_SOURCE_BUF:
1266                /* leave user-provided buf intact */
1267                break;
1268        }
1269}
1270
1271static int grep_source_load_sha1(struct grep_source *gs)
1272{
1273        enum object_type type;
1274
1275        grep_read_lock();
1276        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1277        grep_read_unlock();
1278
1279        if (!gs->buf)
1280                return error(_("'%s': unable to read %s"),
1281                             gs->name,
1282                             sha1_to_hex(gs->identifier));
1283        return 0;
1284}
1285
1286static int grep_source_load_file(struct grep_source *gs)
1287{
1288        const char *filename = gs->identifier;
1289        struct stat st;
1290        char *data;
1291        size_t size;
1292        int i;
1293
1294        if (lstat(filename, &st) < 0) {
1295        err_ret:
1296                if (errno != ENOENT)
1297                        error(_("'%s': %s"), filename, strerror(errno));
1298                return -1;
1299        }
1300        if (!S_ISREG(st.st_mode))
1301                return -1;
1302        size = xsize_t(st.st_size);
1303        i = open(filename, O_RDONLY);
1304        if (i < 0)
1305                goto err_ret;
1306        data = xmalloc(size + 1);
1307        if (st.st_size != read_in_full(i, data, size)) {
1308                error(_("'%s': short read %s"), filename, strerror(errno));
1309                close(i);
1310                free(data);
1311                return -1;
1312        }
1313        close(i);
1314        data[size] = 0;
1315
1316        gs->buf = data;
1317        gs->size = size;
1318        return 0;
1319}
1320
1321int grep_source_load(struct grep_source *gs)
1322{
1323        if (gs->buf)
1324                return 0;
1325
1326        switch (gs->type) {
1327        case GREP_SOURCE_FILE:
1328                return grep_source_load_file(gs);
1329        case GREP_SOURCE_SHA1:
1330                return grep_source_load_sha1(gs);
1331        case GREP_SOURCE_BUF:
1332                return gs->buf ? 0 : -1;
1333        }
1334        die("BUG: invalid grep_source type");
1335}
1336
1337void grep_source_load_driver(struct grep_source *gs)
1338{
1339        if (gs->driver)
1340                return;
1341
1342        grep_attr_lock();
1343        gs->driver = userdiff_find_by_path(gs->name);
1344        if (!gs->driver)
1345                gs->driver = userdiff_find_by_name("default");
1346        grep_attr_unlock();
1347}
1348
1349int grep_source_is_binary(struct grep_source *gs)
1350{
1351        grep_source_load_driver(gs);
1352        if (gs->driver->binary != -1)
1353                return gs->driver->binary;
1354
1355        if (!grep_source_load(gs))
1356                return buffer_is_binary(gs->buf, gs->size);
1357
1358        return 0;
1359}