Andrew's git / gitweb.git / grep.c
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grep.con commit grep: support newline separated pattern list (526a858)
   1#include "cache.h"
   2#include "grep.h"
   3#include "userdiff.h"
   4#include "xdiff-interface.h"
   5
   6static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
   7                                        const char *origin, int no,
   8                                        enum grep_pat_token t,
   9                                        enum grep_header_field field)
  10{
  11        struct grep_pat *p = xcalloc(1, sizeof(*p));
  12        p->pattern = xmemdupz(pat, patlen);
  13        p->patternlen = patlen;
  14        p->origin = origin;
  15        p->no = no;
  16        p->token = t;
  17        p->field = field;
  18        return p;
  19}
  20
  21static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
  22{
  23        **tail = p;
  24        *tail = &p->next;
  25        p->next = NULL;
  26
  27        switch (p->token) {
  28        case GREP_PATTERN: /* atom */
  29        case GREP_PATTERN_HEAD:
  30        case GREP_PATTERN_BODY:
  31                for (;;) {
  32                        struct grep_pat *new_pat;
  33                        size_t len = 0;
  34                        char *cp = p->pattern + p->patternlen, *nl = NULL;
  35                        while (++len <= p->patternlen) {
  36                                if (*(--cp) == '\n') {
  37                                        nl = cp;
  38                                        break;
  39                                }
  40                        }
  41                        if (!nl)
  42                                break;
  43                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
  44                                                  p->no, p->token, p->field);
  45                        new_pat->next = p->next;
  46                        if (!p->next)
  47                                *tail = &new_pat->next;
  48                        p->next = new_pat;
  49                        *nl = '\0';
  50                        p->patternlen -= len;
  51                }
  52                break;
  53        default:
  54                break;
  55        }
  56}
  57
  58void append_header_grep_pattern(struct grep_opt *opt,
  59                                enum grep_header_field field, const char *pat)
  60{
  61        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
  62                                             GREP_PATTERN_HEAD, field);
  63        do_append_grep_pat(&opt->header_tail, p);
  64}
  65
  66void append_grep_pattern(struct grep_opt *opt, const char *pat,
  67                         const char *origin, int no, enum grep_pat_token t)
  68{
  69        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
  70}
  71
  72void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
  73                     const char *origin, int no, enum grep_pat_token t)
  74{
  75        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
  76        do_append_grep_pat(&opt->pattern_tail, p);
  77}
  78
  79struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
  80{
  81        struct grep_pat *pat;
  82        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
  83        *ret = *opt;
  84
  85        ret->pattern_list = NULL;
  86        ret->pattern_tail = &ret->pattern_list;
  87
  88        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
  89        {
  90                if(pat->token == GREP_PATTERN_HEAD)
  91                        append_header_grep_pattern(ret, pat->field,
  92                                                   pat->pattern);
  93                else
  94                        append_grep_pat(ret, pat->pattern, pat->patternlen,
  95                                        pat->origin, pat->no, pat->token);
  96        }
  97
  98        return ret;
  99}
 100
 101static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 102                const char *error)
 103{
 104        char where[1024];
 105
 106        if (p->no)
 107                sprintf(where, "In '%s' at %d, ", p->origin, p->no);
 108        else if (p->origin)
 109                sprintf(where, "%s, ", p->origin);
 110        else
 111                where[0] = 0;
 112
 113        die("%s'%s': %s", where, p->pattern, error);
 114}
 115
 116#ifdef USE_LIBPCRE
 117static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 118{
 119        const char *error;
 120        int erroffset;
 121        int options = 0;
 122
 123        if (opt->ignore_case)
 124                options |= PCRE_CASELESS;
 125
 126        p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 127                        NULL);
 128        if (!p->pcre_regexp)
 129                compile_regexp_failed(p, error);
 130
 131        p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 132        if (!p->pcre_extra_info && error)
 133                die("%s", error);
 134}
 135
 136static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 137                regmatch_t *match, int eflags)
 138{
 139        int ovector[30], ret, flags = 0;
 140
 141        if (eflags & REG_NOTBOL)
 142                flags |= PCRE_NOTBOL;
 143
 144        ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 145                        0, flags, ovector, ARRAY_SIZE(ovector));
 146        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 147                die("pcre_exec failed with error code %d", ret);
 148        if (ret > 0) {
 149                ret = 0;
 150                match->rm_so = ovector[0];
 151                match->rm_eo = ovector[1];
 152        }
 153
 154        return ret;
 155}
 156
 157static void free_pcre_regexp(struct grep_pat *p)
 158{
 159        pcre_free(p->pcre_regexp);
 160        pcre_free(p->pcre_extra_info);
 161}
 162#else /* !USE_LIBPCRE */
 163static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 164{
 165        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 166}
 167
 168static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 169                regmatch_t *match, int eflags)
 170{
 171        return 1;
 172}
 173
 174static void free_pcre_regexp(struct grep_pat *p)
 175{
 176}
 177#endif /* !USE_LIBPCRE */
 178
 179static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 180{
 181        int err;
 182
 183        p->word_regexp = opt->word_regexp;
 184        p->ignore_case = opt->ignore_case;
 185        p->fixed = opt->fixed;
 186
 187        if (p->fixed)
 188                return;
 189
 190        if (opt->pcre) {
 191                compile_pcre_regexp(p, opt);
 192                return;
 193        }
 194
 195        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 196        if (err) {
 197                char errbuf[1024];
 198                regerror(err, &p->regexp, errbuf, 1024);
 199                regfree(&p->regexp);
 200                compile_regexp_failed(p, errbuf);
 201        }
 202}
 203
 204static struct grep_expr *compile_pattern_or(struct grep_pat **);
 205static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 206{
 207        struct grep_pat *p;
 208        struct grep_expr *x;
 209
 210        p = *list;
 211        if (!p)
 212                return NULL;
 213        switch (p->token) {
 214        case GREP_PATTERN: /* atom */
 215        case GREP_PATTERN_HEAD:
 216        case GREP_PATTERN_BODY:
 217                x = xcalloc(1, sizeof (struct grep_expr));
 218                x->node = GREP_NODE_ATOM;
 219                x->u.atom = p;
 220                *list = p->next;
 221                return x;
 222        case GREP_OPEN_PAREN:
 223                *list = p->next;
 224                x = compile_pattern_or(list);
 225                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 226                        die("unmatched parenthesis");
 227                *list = (*list)->next;
 228                return x;
 229        default:
 230                return NULL;
 231        }
 232}
 233
 234static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 235{
 236        struct grep_pat *p;
 237        struct grep_expr *x;
 238
 239        p = *list;
 240        if (!p)
 241                return NULL;
 242        switch (p->token) {
 243        case GREP_NOT:
 244                if (!p->next)
 245                        die("--not not followed by pattern expression");
 246                *list = p->next;
 247                x = xcalloc(1, sizeof (struct grep_expr));
 248                x->node = GREP_NODE_NOT;
 249                x->u.unary = compile_pattern_not(list);
 250                if (!x->u.unary)
 251                        die("--not followed by non pattern expression");
 252                return x;
 253        default:
 254                return compile_pattern_atom(list);
 255        }
 256}
 257
 258static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 259{
 260        struct grep_pat *p;
 261        struct grep_expr *x, *y, *z;
 262
 263        x = compile_pattern_not(list);
 264        p = *list;
 265        if (p && p->token == GREP_AND) {
 266                if (!p->next)
 267                        die("--and not followed by pattern expression");
 268                *list = p->next;
 269                y = compile_pattern_and(list);
 270                if (!y)
 271                        die("--and not followed by pattern expression");
 272                z = xcalloc(1, sizeof (struct grep_expr));
 273                z->node = GREP_NODE_AND;
 274                z->u.binary.left = x;
 275                z->u.binary.right = y;
 276                return z;
 277        }
 278        return x;
 279}
 280
 281static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 282{
 283        struct grep_pat *p;
 284        struct grep_expr *x, *y, *z;
 285
 286        x = compile_pattern_and(list);
 287        p = *list;
 288        if (x && p && p->token != GREP_CLOSE_PAREN) {
 289                y = compile_pattern_or(list);
 290                if (!y)
 291                        die("not a pattern expression %s", p->pattern);
 292                z = xcalloc(1, sizeof (struct grep_expr));
 293                z->node = GREP_NODE_OR;
 294                z->u.binary.left = x;
 295                z->u.binary.right = y;
 296                return z;
 297        }
 298        return x;
 299}
 300
 301static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 302{
 303        return compile_pattern_or(list);
 304}
 305
 306static struct grep_expr *grep_true_expr(void)
 307{
 308        struct grep_expr *z = xcalloc(1, sizeof(*z));
 309        z->node = GREP_NODE_TRUE;
 310        return z;
 311}
 312
 313static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 314{
 315        struct grep_expr *z = xcalloc(1, sizeof(*z));
 316        z->node = GREP_NODE_OR;
 317        z->u.binary.left = left;
 318        z->u.binary.right = right;
 319        return z;
 320}
 321
 322static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 323{
 324        struct grep_pat *p;
 325        struct grep_expr *header_expr;
 326        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 327        enum grep_header_field fld;
 328
 329        if (!opt->header_list)
 330                return NULL;
 331        p = opt->header_list;
 332        for (p = opt->header_list; p; p = p->next) {
 333                if (p->token != GREP_PATTERN_HEAD)
 334                        die("bug: a non-header pattern in grep header list.");
 335                if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
 336                        die("bug: unknown header field %d", p->field);
 337                compile_regexp(p, opt);
 338        }
 339
 340        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 341                header_group[fld] = NULL;
 342
 343        for (p = opt->header_list; p; p = p->next) {
 344                struct grep_expr *h;
 345                struct grep_pat *pp = p;
 346
 347                h = compile_pattern_atom(&pp);
 348                if (!h || pp != p->next)
 349                        die("bug: malformed header expr");
 350                if (!header_group[p->field]) {
 351                        header_group[p->field] = h;
 352                        continue;
 353                }
 354                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 355        }
 356
 357        header_expr = NULL;
 358
 359        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 360                if (!header_group[fld])
 361                        continue;
 362                if (!header_expr)
 363                        header_expr = grep_true_expr();
 364                header_expr = grep_or_expr(header_group[fld], header_expr);
 365        }
 366        return header_expr;
 367}
 368
 369void compile_grep_patterns(struct grep_opt *opt)
 370{
 371        struct grep_pat *p;
 372        struct grep_expr *header_expr = prep_header_patterns(opt);
 373
 374        for (p = opt->pattern_list; p; p = p->next) {
 375                switch (p->token) {
 376                case GREP_PATTERN: /* atom */
 377                case GREP_PATTERN_HEAD:
 378                case GREP_PATTERN_BODY:
 379                        compile_regexp(p, opt);
 380                        break;
 381                default:
 382                        opt->extended = 1;
 383                        break;
 384                }
 385        }
 386
 387        if (opt->all_match || header_expr)
 388                opt->extended = 1;
 389        else if (!opt->extended)
 390                return;
 391
 392        p = opt->pattern_list;
 393        if (p)
 394                opt->pattern_expression = compile_pattern_expr(&p);
 395        if (p)
 396                die("incomplete pattern expression: %s", p->pattern);
 397
 398        if (!header_expr)
 399                return;
 400
 401        if (!opt->pattern_expression)
 402                opt->pattern_expression = header_expr;
 403        else
 404                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 405                                                       header_expr);
 406        opt->all_match = 1;
 407}
 408
 409static void free_pattern_expr(struct grep_expr *x)
 410{
 411        switch (x->node) {
 412        case GREP_NODE_TRUE:
 413        case GREP_NODE_ATOM:
 414                break;
 415        case GREP_NODE_NOT:
 416                free_pattern_expr(x->u.unary);
 417                break;
 418        case GREP_NODE_AND:
 419        case GREP_NODE_OR:
 420                free_pattern_expr(x->u.binary.left);
 421                free_pattern_expr(x->u.binary.right);
 422                break;
 423        }
 424        free(x);
 425}
 426
 427void free_grep_patterns(struct grep_opt *opt)
 428{
 429        struct grep_pat *p, *n;
 430
 431        for (p = opt->pattern_list; p; p = n) {
 432                n = p->next;
 433                switch (p->token) {
 434                case GREP_PATTERN: /* atom */
 435                case GREP_PATTERN_HEAD:
 436                case GREP_PATTERN_BODY:
 437                        if (p->pcre_regexp)
 438                                free_pcre_regexp(p);
 439                        else
 440                                regfree(&p->regexp);
 441                        free(p->pattern);
 442                        break;
 443                default:
 444                        break;
 445                }
 446                free(p);
 447        }
 448
 449        if (!opt->extended)
 450                return;
 451        free_pattern_expr(opt->pattern_expression);
 452}
 453
 454static char *end_of_line(char *cp, unsigned long *left)
 455{
 456        unsigned long l = *left;
 457        while (l && *cp != '\n') {
 458                l--;
 459                cp++;
 460        }
 461        *left = l;
 462        return cp;
 463}
 464
 465static int word_char(char ch)
 466{
 467        return isalnum(ch) || ch == '_';
 468}
 469
 470static void output_color(struct grep_opt *opt, const void *data, size_t size,
 471                         const char *color)
 472{
 473        if (opt->color && color && color[0]) {
 474                opt->output(opt, color, strlen(color));
 475                opt->output(opt, data, size);
 476                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 477        } else
 478                opt->output(opt, data, size);
 479}
 480
 481static void output_sep(struct grep_opt *opt, char sign)
 482{
 483        if (opt->null_following_name)
 484                opt->output(opt, "\0", 1);
 485        else
 486                output_color(opt, &sign, 1, opt->color_sep);
 487}
 488
 489static void show_name(struct grep_opt *opt, const char *name)
 490{
 491        output_color(opt, name, strlen(name), opt->color_filename);
 492        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 493}
 494
 495static int fixmatch(struct grep_pat *p, char *line, char *eol,
 496                    regmatch_t *match)
 497{
 498        char *hit;
 499
 500        if (p->ignore_case) {
 501                char *s = line;
 502                do {
 503                        hit = strcasestr(s, p->pattern);
 504                        if (hit)
 505                                break;
 506                        s += strlen(s) + 1;
 507                } while (s < eol);
 508        } else
 509                hit = memmem(line, eol - line, p->pattern, p->patternlen);
 510
 511        if (!hit) {
 512                match->rm_so = match->rm_eo = -1;
 513                return REG_NOMATCH;
 514        }
 515        else {
 516                match->rm_so = hit - line;
 517                match->rm_eo = match->rm_so + p->patternlen;
 518                return 0;
 519        }
 520}
 521
 522static int regmatch(const regex_t *preg, char *line, char *eol,
 523                    regmatch_t *match, int eflags)
 524{
 525#ifdef REG_STARTEND
 526        match->rm_so = 0;
 527        match->rm_eo = eol - line;
 528        eflags |= REG_STARTEND;
 529#endif
 530        return regexec(preg, line, 1, match, eflags);
 531}
 532
 533static int patmatch(struct grep_pat *p, char *line, char *eol,
 534                    regmatch_t *match, int eflags)
 535{
 536        int hit;
 537
 538        if (p->fixed)
 539                hit = !fixmatch(p, line, eol, match);
 540        else if (p->pcre_regexp)
 541                hit = !pcrematch(p, line, eol, match, eflags);
 542        else
 543                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 544
 545        return hit;
 546}
 547
 548static int strip_timestamp(char *bol, char **eol_p)
 549{
 550        char *eol = *eol_p;
 551        int ch;
 552
 553        while (bol < --eol) {
 554                if (*eol != '>')
 555                        continue;
 556                *eol_p = ++eol;
 557                ch = *eol;
 558                *eol = '\0';
 559                return ch;
 560        }
 561        return 0;
 562}
 563
 564static struct {
 565        const char *field;
 566        size_t len;
 567} header_field[] = {
 568        { "author ", 7 },
 569        { "committer ", 10 },
 570};
 571
 572static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 573                             enum grep_context ctx,
 574                             regmatch_t *pmatch, int eflags)
 575{
 576        int hit = 0;
 577        int saved_ch = 0;
 578        const char *start = bol;
 579
 580        if ((p->token != GREP_PATTERN) &&
 581            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 582                return 0;
 583
 584        if (p->token == GREP_PATTERN_HEAD) {
 585                const char *field;
 586                size_t len;
 587                assert(p->field < ARRAY_SIZE(header_field));
 588                field = header_field[p->field].field;
 589                len = header_field[p->field].len;
 590                if (strncmp(bol, field, len))
 591                        return 0;
 592                bol += len;
 593                saved_ch = strip_timestamp(bol, &eol);
 594        }
 595
 596 again:
 597        hit = patmatch(p, bol, eol, pmatch, eflags);
 598
 599        if (hit && p->word_regexp) {
 600                if ((pmatch[0].rm_so < 0) ||
 601                    (eol - bol) < pmatch[0].rm_so ||
 602                    (pmatch[0].rm_eo < 0) ||
 603                    (eol - bol) < pmatch[0].rm_eo)
 604                        die("regexp returned nonsense");
 605
 606                /* Match beginning must be either beginning of the
 607                 * line, or at word boundary (i.e. the last char must
 608                 * not be a word char).  Similarly, match end must be
 609                 * either end of the line, or at word boundary
 610                 * (i.e. the next char must not be a word char).
 611                 */
 612                if ( ((pmatch[0].rm_so == 0) ||
 613                      !word_char(bol[pmatch[0].rm_so-1])) &&
 614                     ((pmatch[0].rm_eo == (eol-bol)) ||
 615                      !word_char(bol[pmatch[0].rm_eo])) )
 616                        ;
 617                else
 618                        hit = 0;
 619
 620                /* Words consist of at least one character. */
 621                if (pmatch->rm_so == pmatch->rm_eo)
 622                        hit = 0;
 623
 624                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 625                        /* There could be more than one match on the
 626                         * line, and the first match might not be
 627                         * strict word match.  But later ones could be!
 628                         * Forward to the next possible start, i.e. the
 629                         * next position following a non-word char.
 630                         */
 631                        bol = pmatch[0].rm_so + bol + 1;
 632                        while (word_char(bol[-1]) && bol < eol)
 633                                bol++;
 634                        eflags |= REG_NOTBOL;
 635                        if (bol < eol)
 636                                goto again;
 637                }
 638        }
 639        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 640                *eol = saved_ch;
 641        if (hit) {
 642                pmatch[0].rm_so += bol - start;
 643                pmatch[0].rm_eo += bol - start;
 644        }
 645        return hit;
 646}
 647
 648static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 649                           enum grep_context ctx, int collect_hits)
 650{
 651        int h = 0;
 652        regmatch_t match;
 653
 654        if (!x)
 655                die("Not a valid grep expression");
 656        switch (x->node) {
 657        case GREP_NODE_TRUE:
 658                h = 1;
 659                break;
 660        case GREP_NODE_ATOM:
 661                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 662                break;
 663        case GREP_NODE_NOT:
 664                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 665                break;
 666        case GREP_NODE_AND:
 667                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 668                        return 0;
 669                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 670                break;
 671        case GREP_NODE_OR:
 672                if (!collect_hits)
 673                        return (match_expr_eval(x->u.binary.left,
 674                                                bol, eol, ctx, 0) ||
 675                                match_expr_eval(x->u.binary.right,
 676                                                bol, eol, ctx, 0));
 677                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 678                x->u.binary.left->hit |= h;
 679                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 680                break;
 681        default:
 682                die("Unexpected node type (internal error) %d", x->node);
 683        }
 684        if (collect_hits)
 685                x->hit |= h;
 686        return h;
 687}
 688
 689static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 690                      enum grep_context ctx, int collect_hits)
 691{
 692        struct grep_expr *x = opt->pattern_expression;
 693        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 694}
 695
 696static int match_line(struct grep_opt *opt, char *bol, char *eol,
 697                      enum grep_context ctx, int collect_hits)
 698{
 699        struct grep_pat *p;
 700        regmatch_t match;
 701
 702        if (opt->extended)
 703                return match_expr(opt, bol, eol, ctx, collect_hits);
 704
 705        /* we do not call with collect_hits without being extended */
 706        for (p = opt->pattern_list; p; p = p->next) {
 707                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 708                        return 1;
 709        }
 710        return 0;
 711}
 712
 713static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 714                              enum grep_context ctx,
 715                              regmatch_t *pmatch, int eflags)
 716{
 717        regmatch_t match;
 718
 719        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 720                return 0;
 721        if (match.rm_so < 0 || match.rm_eo < 0)
 722                return 0;
 723        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 724                if (match.rm_so > pmatch->rm_so)
 725                        return 1;
 726                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 727                        return 1;
 728        }
 729        pmatch->rm_so = match.rm_so;
 730        pmatch->rm_eo = match.rm_eo;
 731        return 1;
 732}
 733
 734static int next_match(struct grep_opt *opt, char *bol, char *eol,
 735                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 736{
 737        struct grep_pat *p;
 738        int hit = 0;
 739
 740        pmatch->rm_so = pmatch->rm_eo = -1;
 741        if (bol < eol) {
 742                for (p = opt->pattern_list; p; p = p->next) {
 743                        switch (p->token) {
 744                        case GREP_PATTERN: /* atom */
 745                        case GREP_PATTERN_HEAD:
 746                        case GREP_PATTERN_BODY:
 747                                hit |= match_next_pattern(p, bol, eol, ctx,
 748                                                          pmatch, eflags);
 749                                break;
 750                        default:
 751                                break;
 752                        }
 753                }
 754        }
 755        return hit;
 756}
 757
 758static void show_line(struct grep_opt *opt, char *bol, char *eol,
 759                      const char *name, unsigned lno, char sign)
 760{
 761        int rest = eol - bol;
 762        char *line_color = NULL;
 763
 764        if (opt->pre_context || opt->post_context) {
 765                if (opt->last_shown == 0) {
 766                        if (opt->show_hunk_mark) {
 767                                output_color(opt, "--", 2, opt->color_sep);
 768                                opt->output(opt, "\n", 1);
 769                        }
 770                } else if (lno > opt->last_shown + 1) {
 771                        output_color(opt, "--", 2, opt->color_sep);
 772                        opt->output(opt, "\n", 1);
 773                }
 774        }
 775        opt->last_shown = lno;
 776
 777        if (opt->pathname) {
 778                output_color(opt, name, strlen(name), opt->color_filename);
 779                output_sep(opt, sign);
 780        }
 781        if (opt->linenum) {
 782                char buf[32];
 783                snprintf(buf, sizeof(buf), "%d", lno);
 784                output_color(opt, buf, strlen(buf), opt->color_lineno);
 785                output_sep(opt, sign);
 786        }
 787        if (opt->color) {
 788                regmatch_t match;
 789                enum grep_context ctx = GREP_CONTEXT_BODY;
 790                int ch = *eol;
 791                int eflags = 0;
 792
 793                if (sign == ':')
 794                        line_color = opt->color_selected;
 795                else if (sign == '-')
 796                        line_color = opt->color_context;
 797                else if (sign == '=')
 798                        line_color = opt->color_function;
 799                *eol = '\0';
 800                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 801                        if (match.rm_so == match.rm_eo)
 802                                break;
 803
 804                        output_color(opt, bol, match.rm_so, line_color);
 805                        output_color(opt, bol + match.rm_so,
 806                                     match.rm_eo - match.rm_so,
 807                                     opt->color_match);
 808                        bol += match.rm_eo;
 809                        rest -= match.rm_eo;
 810                        eflags = REG_NOTBOL;
 811                }
 812                *eol = ch;
 813        }
 814        output_color(opt, bol, rest, line_color);
 815        opt->output(opt, "\n", 1);
 816}
 817
 818static int match_funcname(struct grep_opt *opt, char *bol, char *eol)
 819{
 820        xdemitconf_t *xecfg = opt->priv;
 821        if (xecfg && xecfg->find_func) {
 822                char buf[1];
 823                return xecfg->find_func(bol, eol - bol, buf, 1,
 824                                        xecfg->find_func_priv) >= 0;
 825        }
 826
 827        if (bol == eol)
 828                return 0;
 829        if (isalpha(*bol) || *bol == '_' || *bol == '$')
 830                return 1;
 831        return 0;
 832}
 833
 834static void show_funcname_line(struct grep_opt *opt, const char *name,
 835                               char *buf, char *bol, unsigned lno)
 836{
 837        while (bol > buf) {
 838                char *eol = --bol;
 839
 840                while (bol > buf && bol[-1] != '\n')
 841                        bol--;
 842                lno--;
 843
 844                if (lno <= opt->last_shown)
 845                        break;
 846
 847                if (match_funcname(opt, bol, eol)) {
 848                        show_line(opt, bol, eol, name, lno, '=');
 849                        break;
 850                }
 851        }
 852}
 853
 854static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
 855                             char *bol, unsigned lno)
 856{
 857        unsigned cur = lno, from = 1, funcname_lno = 0;
 858        int funcname_needed = opt->funcname;
 859
 860        if (opt->pre_context < lno)
 861                from = lno - opt->pre_context;
 862        if (from <= opt->last_shown)
 863                from = opt->last_shown + 1;
 864
 865        /* Rewind. */
 866        while (bol > buf && cur > from) {
 867                char *eol = --bol;
 868
 869                while (bol > buf && bol[-1] != '\n')
 870                        bol--;
 871                cur--;
 872                if (funcname_needed && match_funcname(opt, bol, eol)) {
 873                        funcname_lno = cur;
 874                        funcname_needed = 0;
 875                }
 876        }
 877
 878        /* We need to look even further back to find a function signature. */
 879        if (opt->funcname && funcname_needed)
 880                show_funcname_line(opt, name, buf, bol, cur);
 881
 882        /* Back forward. */
 883        while (cur < lno) {
 884                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
 885
 886                while (*eol != '\n')
 887                        eol++;
 888                show_line(opt, bol, eol, name, cur, sign);
 889                bol = eol + 1;
 890                cur++;
 891        }
 892}
 893
 894static int should_lookahead(struct grep_opt *opt)
 895{
 896        struct grep_pat *p;
 897
 898        if (opt->extended)
 899                return 0; /* punt for too complex stuff */
 900        if (opt->invert)
 901                return 0;
 902        for (p = opt->pattern_list; p; p = p->next) {
 903                if (p->token != GREP_PATTERN)
 904                        return 0; /* punt for "header only" and stuff */
 905        }
 906        return 1;
 907}
 908
 909static int look_ahead(struct grep_opt *opt,
 910                      unsigned long *left_p,
 911                      unsigned *lno_p,
 912                      char **bol_p)
 913{
 914        unsigned lno = *lno_p;
 915        char *bol = *bol_p;
 916        struct grep_pat *p;
 917        char *sp, *last_bol;
 918        regoff_t earliest = -1;
 919
 920        for (p = opt->pattern_list; p; p = p->next) {
 921                int hit;
 922                regmatch_t m;
 923
 924                hit = patmatch(p, bol, bol + *left_p, &m, 0);
 925                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
 926                        continue;
 927                if (earliest < 0 || m.rm_so < earliest)
 928                        earliest = m.rm_so;
 929        }
 930
 931        if (earliest < 0) {
 932                *bol_p = bol + *left_p;
 933                *left_p = 0;
 934                return 1;
 935        }
 936        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
 937                ; /* find the beginning of the line */
 938        last_bol = sp;
 939
 940        for (sp = bol; sp < last_bol; sp++) {
 941                if (*sp == '\n')
 942                        lno++;
 943        }
 944        *left_p -= last_bol - bol;
 945        *bol_p = last_bol;
 946        *lno_p = lno;
 947        return 0;
 948}
 949
 950int grep_threads_ok(const struct grep_opt *opt)
 951{
 952        /* If this condition is true, then we may use the attribute
 953         * machinery in grep_buffer_1. The attribute code is not
 954         * thread safe, so we disable the use of threads.
 955         */
 956        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 957            !opt->name_only)
 958                return 0;
 959
 960        return 1;
 961}
 962
 963static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 964{
 965        fwrite(buf, size, 1, stdout);
 966}
 967
 968static int grep_buffer_1(struct grep_opt *opt, const char *name,
 969                         char *buf, unsigned long size, int collect_hits)
 970{
 971        char *bol = buf;
 972        unsigned long left = size;
 973        unsigned lno = 1;
 974        unsigned last_hit = 0;
 975        int binary_match_only = 0;
 976        unsigned count = 0;
 977        int try_lookahead = 0;
 978        enum grep_context ctx = GREP_CONTEXT_HEAD;
 979        xdemitconf_t xecfg;
 980
 981        if (!opt->output)
 982                opt->output = std_output;
 983
 984        if (opt->last_shown && (opt->pre_context || opt->post_context) &&
 985            opt->output == std_output)
 986                opt->show_hunk_mark = 1;
 987        opt->last_shown = 0;
 988
 989        switch (opt->binary) {
 990        case GREP_BINARY_DEFAULT:
 991                if (buffer_is_binary(buf, size))
 992                        binary_match_only = 1;
 993                break;
 994        case GREP_BINARY_NOMATCH:
 995                if (buffer_is_binary(buf, size))
 996                        return 0; /* Assume unmatch */
 997                break;
 998        case GREP_BINARY_TEXT:
 999                break;
1000        default:
1001                die("bug: unknown binary handling mode");
1002        }
1003
1004        memset(&xecfg, 0, sizeof(xecfg));
1005        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
1006            !opt->name_only && !binary_match_only && !collect_hits) {
1007                struct userdiff_driver *drv = userdiff_find_by_path(name);
1008                if (drv && drv->funcname.pattern) {
1009                        const struct userdiff_funcname *pe = &drv->funcname;
1010                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1011                        opt->priv = &xecfg;
1012                }
1013        }
1014        try_lookahead = should_lookahead(opt);
1015
1016        while (left) {
1017                char *eol, ch;
1018                int hit;
1019
1020                /*
1021                 * look_ahead() skips quickly to the line that possibly
1022                 * has the next hit; don't call it if we need to do
1023                 * something more than just skipping the current line
1024                 * in response to an unmatch for the current line.  E.g.
1025                 * inside a post-context window, we will show the current
1026                 * line as a context around the previous hit when it
1027                 * doesn't hit.
1028                 */
1029                if (try_lookahead
1030                    && !(last_hit
1031                         && lno <= last_hit + opt->post_context)
1032                    && look_ahead(opt, &left, &lno, &bol))
1033                        break;
1034                eol = end_of_line(bol, &left);
1035                ch = *eol;
1036                *eol = 0;
1037
1038                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1039                        ctx = GREP_CONTEXT_BODY;
1040
1041                hit = match_line(opt, bol, eol, ctx, collect_hits);
1042                *eol = ch;
1043
1044                if (collect_hits)
1045                        goto next_line;
1046
1047                /* "grep -v -e foo -e bla" should list lines
1048                 * that do not have either, so inversion should
1049                 * be done outside.
1050                 */
1051                if (opt->invert)
1052                        hit = !hit;
1053                if (opt->unmatch_name_only) {
1054                        if (hit)
1055                                return 0;
1056                        goto next_line;
1057                }
1058                if (hit) {
1059                        count++;
1060                        if (opt->status_only)
1061                                return 1;
1062                        if (opt->name_only) {
1063                                show_name(opt, name);
1064                                return 1;
1065                        }
1066                        if (opt->count)
1067                                goto next_line;
1068                        if (binary_match_only) {
1069                                opt->output(opt, "Binary file ", 12);
1070                                output_color(opt, name, strlen(name),
1071                                             opt->color_filename);
1072                                opt->output(opt, " matches\n", 9);
1073                                return 1;
1074                        }
1075                        /* Hit at this line.  If we haven't shown the
1076                         * pre-context lines, we would need to show them.
1077                         */
1078                        if (opt->pre_context)
1079                                show_pre_context(opt, name, buf, bol, lno);
1080                        else if (opt->funcname)
1081                                show_funcname_line(opt, name, buf, bol, lno);
1082                        show_line(opt, bol, eol, name, lno, ':');
1083                        last_hit = lno;
1084                }
1085                else if (last_hit &&
1086                         lno <= last_hit + opt->post_context) {
1087                        /* If the last hit is within the post context,
1088                         * we need to show this line.
1089                         */
1090                        show_line(opt, bol, eol, name, lno, '-');
1091                }
1092
1093        next_line:
1094                bol = eol + 1;
1095                if (!left)
1096                        break;
1097                left--;
1098                lno++;
1099        }
1100
1101        if (collect_hits)
1102                return 0;
1103
1104        if (opt->status_only)
1105                return 0;
1106        if (opt->unmatch_name_only) {
1107                /* We did not see any hit, so we want to show this */
1108                show_name(opt, name);
1109                return 1;
1110        }
1111
1112        xdiff_clear_find_func(&xecfg);
1113        opt->priv = NULL;
1114
1115        /* NEEDSWORK:
1116         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1117         * which feels mostly useless but sometimes useful.  Maybe
1118         * make it another option?  For now suppress them.
1119         */
1120        if (opt->count && count) {
1121                char buf[32];
1122                output_color(opt, name, strlen(name), opt->color_filename);
1123                output_sep(opt, ':');
1124                snprintf(buf, sizeof(buf), "%u\n", count);
1125                opt->output(opt, buf, strlen(buf));
1126                return 1;
1127        }
1128        return !!last_hit;
1129}
1130
1131static void clr_hit_marker(struct grep_expr *x)
1132{
1133        /* All-hit markers are meaningful only at the very top level
1134         * OR node.
1135         */
1136        while (1) {
1137                x->hit = 0;
1138                if (x->node != GREP_NODE_OR)
1139                        return;
1140                x->u.binary.left->hit = 0;
1141                x = x->u.binary.right;
1142        }
1143}
1144
1145static int chk_hit_marker(struct grep_expr *x)
1146{
1147        /* Top level nodes have hit markers.  See if they all are hits */
1148        while (1) {
1149                if (x->node != GREP_NODE_OR)
1150                        return x->hit;
1151                if (!x->u.binary.left->hit)
1152                        return 0;
1153                x = x->u.binary.right;
1154        }
1155}
1156
1157int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
1158{
1159        /*
1160         * we do not have to do the two-pass grep when we do not check
1161         * buffer-wide "all-match".
1162         */
1163        if (!opt->all_match)
1164                return grep_buffer_1(opt, name, buf, size, 0);
1165
1166        /* Otherwise the toplevel "or" terms hit a bit differently.
1167         * We first clear hit markers from them.
1168         */
1169        clr_hit_marker(opt->pattern_expression);
1170        grep_buffer_1(opt, name, buf, size, 1);
1171
1172        if (!chk_hit_marker(opt->pattern_expression))
1173                return 0;
1174
1175        return grep_buffer_1(opt, name, buf, size, 0);
1176}