Andrew's git / gitweb.git / grep.c
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grep.con commit Remove a redundant errno test in a usage of remove_path (25755e8)
   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->origin = "header";
  11        p->no = 0;
  12        p->token = GREP_PATTERN_HEAD;
  13        p->field = field;
  14        *opt->header_tail = p;
  15        opt->header_tail = &p->next;
  16        p->next = NULL;
  17}
  18
  19void append_grep_pattern(struct grep_opt *opt, const char *pat,
  20                         const char *origin, int no, enum grep_pat_token t)
  21{
  22        struct grep_pat *p = xcalloc(1, sizeof(*p));
  23        p->pattern = pat;
  24        p->origin = origin;
  25        p->no = no;
  26        p->token = t;
  27        *opt->pattern_tail = p;
  28        opt->pattern_tail = &p->next;
  29        p->next = NULL;
  30}
  31
  32struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
  33{
  34        struct grep_pat *pat;
  35        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
  36        *ret = *opt;
  37
  38        ret->pattern_list = NULL;
  39        ret->pattern_tail = &ret->pattern_list;
  40
  41        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
  42        {
  43                if(pat->token == GREP_PATTERN_HEAD)
  44                        append_header_grep_pattern(ret, pat->field,
  45                                                   pat->pattern);
  46                else
  47                        append_grep_pattern(ret, pat->pattern, pat->origin,
  48                                            pat->no, pat->token);
  49        }
  50
  51        return ret;
  52}
  53
  54static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
  55{
  56        int err;
  57
  58        p->word_regexp = opt->word_regexp;
  59        p->ignore_case = opt->ignore_case;
  60        p->fixed = opt->fixed;
  61
  62        if (p->fixed)
  63                return;
  64
  65        err = regcomp(&p->regexp, p->pattern, opt->regflags);
  66        if (err) {
  67                char errbuf[1024];
  68                char where[1024];
  69                if (p->no)
  70                        sprintf(where, "In '%s' at %d, ",
  71                                p->origin, p->no);
  72                else if (p->origin)
  73                        sprintf(where, "%s, ", p->origin);
  74                else
  75                        where[0] = 0;
  76                regerror(err, &p->regexp, errbuf, 1024);
  77                regfree(&p->regexp);
  78                die("%s'%s': %s", where, p->pattern, errbuf);
  79        }
  80}
  81
  82static struct grep_expr *compile_pattern_or(struct grep_pat **);
  83static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
  84{
  85        struct grep_pat *p;
  86        struct grep_expr *x;
  87
  88        p = *list;
  89        if (!p)
  90                return NULL;
  91        switch (p->token) {
  92        case GREP_PATTERN: /* atom */
  93        case GREP_PATTERN_HEAD:
  94        case GREP_PATTERN_BODY:
  95                x = xcalloc(1, sizeof (struct grep_expr));
  96                x->node = GREP_NODE_ATOM;
  97                x->u.atom = p;
  98                *list = p->next;
  99                return x;
 100        case GREP_OPEN_PAREN:
 101                *list = p->next;
 102                x = compile_pattern_or(list);
 103                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 104                        die("unmatched parenthesis");
 105                *list = (*list)->next;
 106                return x;
 107        default:
 108                return NULL;
 109        }
 110}
 111
 112static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 113{
 114        struct grep_pat *p;
 115        struct grep_expr *x;
 116
 117        p = *list;
 118        if (!p)
 119                return NULL;
 120        switch (p->token) {
 121        case GREP_NOT:
 122                if (!p->next)
 123                        die("--not not followed by pattern expression");
 124                *list = p->next;
 125                x = xcalloc(1, sizeof (struct grep_expr));
 126                x->node = GREP_NODE_NOT;
 127                x->u.unary = compile_pattern_not(list);
 128                if (!x->u.unary)
 129                        die("--not followed by non pattern expression");
 130                return x;
 131        default:
 132                return compile_pattern_atom(list);
 133        }
 134}
 135
 136static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 137{
 138        struct grep_pat *p;
 139        struct grep_expr *x, *y, *z;
 140
 141        x = compile_pattern_not(list);
 142        p = *list;
 143        if (p && p->token == GREP_AND) {
 144                if (!p->next)
 145                        die("--and not followed by pattern expression");
 146                *list = p->next;
 147                y = compile_pattern_and(list);
 148                if (!y)
 149                        die("--and not followed by pattern expression");
 150                z = xcalloc(1, sizeof (struct grep_expr));
 151                z->node = GREP_NODE_AND;
 152                z->u.binary.left = x;
 153                z->u.binary.right = y;
 154                return z;
 155        }
 156        return x;
 157}
 158
 159static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 160{
 161        struct grep_pat *p;
 162        struct grep_expr *x, *y, *z;
 163
 164        x = compile_pattern_and(list);
 165        p = *list;
 166        if (x && p && p->token != GREP_CLOSE_PAREN) {
 167                y = compile_pattern_or(list);
 168                if (!y)
 169                        die("not a pattern expression %s", p->pattern);
 170                z = xcalloc(1, sizeof (struct grep_expr));
 171                z->node = GREP_NODE_OR;
 172                z->u.binary.left = x;
 173                z->u.binary.right = y;
 174                return z;
 175        }
 176        return x;
 177}
 178
 179static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 180{
 181        return compile_pattern_or(list);
 182}
 183
 184void compile_grep_patterns(struct grep_opt *opt)
 185{
 186        struct grep_pat *p;
 187        struct grep_expr *header_expr = NULL;
 188
 189        if (opt->header_list) {
 190                p = opt->header_list;
 191                header_expr = compile_pattern_expr(&p);
 192                if (p)
 193                        die("incomplete pattern expression: %s", p->pattern);
 194                for (p = opt->header_list; p; p = p->next) {
 195                        switch (p->token) {
 196                        case GREP_PATTERN: /* atom */
 197                        case GREP_PATTERN_HEAD:
 198                        case GREP_PATTERN_BODY:
 199                                compile_regexp(p, opt);
 200                                break;
 201                        default:
 202                                opt->extended = 1;
 203                                break;
 204                        }
 205                }
 206        }
 207
 208        for (p = opt->pattern_list; p; p = p->next) {
 209                switch (p->token) {
 210                case GREP_PATTERN: /* atom */
 211                case GREP_PATTERN_HEAD:
 212                case GREP_PATTERN_BODY:
 213                        compile_regexp(p, opt);
 214                        break;
 215                default:
 216                        opt->extended = 1;
 217                        break;
 218                }
 219        }
 220
 221        if (opt->all_match || header_expr)
 222                opt->extended = 1;
 223        else if (!opt->extended)
 224                return;
 225
 226        /* Then bundle them up in an expression.
 227         * A classic recursive descent parser would do.
 228         */
 229        p = opt->pattern_list;
 230        if (p)
 231                opt->pattern_expression = compile_pattern_expr(&p);
 232        if (p)
 233                die("incomplete pattern expression: %s", p->pattern);
 234
 235        if (!header_expr)
 236                return;
 237
 238        if (opt->pattern_expression) {
 239                struct grep_expr *z;
 240                z = xcalloc(1, sizeof(*z));
 241                z->node = GREP_NODE_OR;
 242                z->u.binary.left = opt->pattern_expression;
 243                z->u.binary.right = header_expr;
 244                opt->pattern_expression = z;
 245        } else {
 246                opt->pattern_expression = header_expr;
 247        }
 248        opt->all_match = 1;
 249}
 250
 251static void free_pattern_expr(struct grep_expr *x)
 252{
 253        switch (x->node) {
 254        case GREP_NODE_ATOM:
 255                break;
 256        case GREP_NODE_NOT:
 257                free_pattern_expr(x->u.unary);
 258                break;
 259        case GREP_NODE_AND:
 260        case GREP_NODE_OR:
 261                free_pattern_expr(x->u.binary.left);
 262                free_pattern_expr(x->u.binary.right);
 263                break;
 264        }
 265        free(x);
 266}
 267
 268void free_grep_patterns(struct grep_opt *opt)
 269{
 270        struct grep_pat *p, *n;
 271
 272        for (p = opt->pattern_list; p; p = n) {
 273                n = p->next;
 274                switch (p->token) {
 275                case GREP_PATTERN: /* atom */
 276                case GREP_PATTERN_HEAD:
 277                case GREP_PATTERN_BODY:
 278                        regfree(&p->regexp);
 279                        break;
 280                default:
 281                        break;
 282                }
 283                free(p);
 284        }
 285
 286        if (!opt->extended)
 287                return;
 288        free_pattern_expr(opt->pattern_expression);
 289}
 290
 291static char *end_of_line(char *cp, unsigned long *left)
 292{
 293        unsigned long l = *left;
 294        while (l && *cp != '\n') {
 295                l--;
 296                cp++;
 297        }
 298        *left = l;
 299        return cp;
 300}
 301
 302static int word_char(char ch)
 303{
 304        return isalnum(ch) || ch == '_';
 305}
 306
 307static void output_color(struct grep_opt *opt, const void *data, size_t size,
 308                         const char *color)
 309{
 310        if (opt->color && color && color[0]) {
 311                opt->output(opt, color, strlen(color));
 312                opt->output(opt, data, size);
 313                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 314        } else
 315                opt->output(opt, data, size);
 316}
 317
 318static void output_sep(struct grep_opt *opt, char sign)
 319{
 320        if (opt->null_following_name)
 321                opt->output(opt, "\0", 1);
 322        else
 323                output_color(opt, &sign, 1, opt->color_sep);
 324}
 325
 326static void show_name(struct grep_opt *opt, const char *name)
 327{
 328        output_color(opt, name, strlen(name), opt->color_filename);
 329        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 330}
 331
 332
 333static int fixmatch(const char *pattern, char *line, int ignore_case, regmatch_t *match)
 334{
 335        char *hit;
 336        if (ignore_case)
 337                hit = strcasestr(line, pattern);
 338        else
 339                hit = strstr(line, pattern);
 340
 341        if (!hit) {
 342                match->rm_so = match->rm_eo = -1;
 343                return REG_NOMATCH;
 344        }
 345        else {
 346                match->rm_so = hit - line;
 347                match->rm_eo = match->rm_so + strlen(pattern);
 348                return 0;
 349        }
 350}
 351
 352static int strip_timestamp(char *bol, char **eol_p)
 353{
 354        char *eol = *eol_p;
 355        int ch;
 356
 357        while (bol < --eol) {
 358                if (*eol != '>')
 359                        continue;
 360                *eol_p = ++eol;
 361                ch = *eol;
 362                *eol = '\0';
 363                return ch;
 364        }
 365        return 0;
 366}
 367
 368static struct {
 369        const char *field;
 370        size_t len;
 371} header_field[] = {
 372        { "author ", 7 },
 373        { "committer ", 10 },
 374};
 375
 376static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 377                             enum grep_context ctx,
 378                             regmatch_t *pmatch, int eflags)
 379{
 380        int hit = 0;
 381        int saved_ch = 0;
 382        const char *start = bol;
 383
 384        if ((p->token != GREP_PATTERN) &&
 385            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 386                return 0;
 387
 388        if (p->token == GREP_PATTERN_HEAD) {
 389                const char *field;
 390                size_t len;
 391                assert(p->field < ARRAY_SIZE(header_field));
 392                field = header_field[p->field].field;
 393                len = header_field[p->field].len;
 394                if (strncmp(bol, field, len))
 395                        return 0;
 396                bol += len;
 397                saved_ch = strip_timestamp(bol, &eol);
 398        }
 399
 400 again:
 401        if (p->fixed)
 402                hit = !fixmatch(p->pattern, bol, p->ignore_case, pmatch);
 403        else
 404                hit = !regexec(&p->regexp, bol, 1, pmatch, eflags);
 405
 406        if (hit && p->word_regexp) {
 407                if ((pmatch[0].rm_so < 0) ||
 408                    (eol - bol) < pmatch[0].rm_so ||
 409                    (pmatch[0].rm_eo < 0) ||
 410                    (eol - bol) < pmatch[0].rm_eo)
 411                        die("regexp returned nonsense");
 412
 413                /* Match beginning must be either beginning of the
 414                 * line, or at word boundary (i.e. the last char must
 415                 * not be a word char).  Similarly, match end must be
 416                 * either end of the line, or at word boundary
 417                 * (i.e. the next char must not be a word char).
 418                 */
 419                if ( ((pmatch[0].rm_so == 0) ||
 420                      !word_char(bol[pmatch[0].rm_so-1])) &&
 421                     ((pmatch[0].rm_eo == (eol-bol)) ||
 422                      !word_char(bol[pmatch[0].rm_eo])) )
 423                        ;
 424                else
 425                        hit = 0;
 426
 427                /* Words consist of at least one character. */
 428                if (pmatch->rm_so == pmatch->rm_eo)
 429                        hit = 0;
 430
 431                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 432                        /* There could be more than one match on the
 433                         * line, and the first match might not be
 434                         * strict word match.  But later ones could be!
 435                         * Forward to the next possible start, i.e. the
 436                         * next position following a non-word char.
 437                         */
 438                        bol = pmatch[0].rm_so + bol + 1;
 439                        while (word_char(bol[-1]) && bol < eol)
 440                                bol++;
 441                        eflags |= REG_NOTBOL;
 442                        if (bol < eol)
 443                                goto again;
 444                }
 445        }
 446        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 447                *eol = saved_ch;
 448        if (hit) {
 449                pmatch[0].rm_so += bol - start;
 450                pmatch[0].rm_eo += bol - start;
 451        }
 452        return hit;
 453}
 454
 455static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 456                           enum grep_context ctx, int collect_hits)
 457{
 458        int h = 0;
 459        regmatch_t match;
 460
 461        if (!x)
 462                die("Not a valid grep expression");
 463        switch (x->node) {
 464        case GREP_NODE_ATOM:
 465                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 466                break;
 467        case GREP_NODE_NOT:
 468                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 469                break;
 470        case GREP_NODE_AND:
 471                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 472                        return 0;
 473                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 474                break;
 475        case GREP_NODE_OR:
 476                if (!collect_hits)
 477                        return (match_expr_eval(x->u.binary.left,
 478                                                bol, eol, ctx, 0) ||
 479                                match_expr_eval(x->u.binary.right,
 480                                                bol, eol, ctx, 0));
 481                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 482                x->u.binary.left->hit |= h;
 483                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 484                break;
 485        default:
 486                die("Unexpected node type (internal error) %d", x->node);
 487        }
 488        if (collect_hits)
 489                x->hit |= h;
 490        return h;
 491}
 492
 493static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 494                      enum grep_context ctx, int collect_hits)
 495{
 496        struct grep_expr *x = opt->pattern_expression;
 497        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 498}
 499
 500static int match_line(struct grep_opt *opt, char *bol, char *eol,
 501                      enum grep_context ctx, int collect_hits)
 502{
 503        struct grep_pat *p;
 504        regmatch_t match;
 505
 506        if (opt->extended)
 507                return match_expr(opt, bol, eol, ctx, collect_hits);
 508
 509        /* we do not call with collect_hits without being extended */
 510        for (p = opt->pattern_list; p; p = p->next) {
 511                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 512                        return 1;
 513        }
 514        return 0;
 515}
 516
 517static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 518                              enum grep_context ctx,
 519                              regmatch_t *pmatch, int eflags)
 520{
 521        regmatch_t match;
 522
 523        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 524                return 0;
 525        if (match.rm_so < 0 || match.rm_eo < 0)
 526                return 0;
 527        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 528                if (match.rm_so > pmatch->rm_so)
 529                        return 1;
 530                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 531                        return 1;
 532        }
 533        pmatch->rm_so = match.rm_so;
 534        pmatch->rm_eo = match.rm_eo;
 535        return 1;
 536}
 537
 538static int next_match(struct grep_opt *opt, char *bol, char *eol,
 539                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 540{
 541        struct grep_pat *p;
 542        int hit = 0;
 543
 544        pmatch->rm_so = pmatch->rm_eo = -1;
 545        if (bol < eol) {
 546                for (p = opt->pattern_list; p; p = p->next) {
 547                        switch (p->token) {
 548                        case GREP_PATTERN: /* atom */
 549                        case GREP_PATTERN_HEAD:
 550                        case GREP_PATTERN_BODY:
 551                                hit |= match_next_pattern(p, bol, eol, ctx,
 552                                                          pmatch, eflags);
 553                                break;
 554                        default:
 555                                break;
 556                        }
 557                }
 558        }
 559        return hit;
 560}
 561
 562static void show_line(struct grep_opt *opt, char *bol, char *eol,
 563                      const char *name, unsigned lno, char sign)
 564{
 565        int rest = eol - bol;
 566        char *line_color = NULL;
 567
 568        if (opt->pre_context || opt->post_context) {
 569                if (opt->last_shown == 0) {
 570                        if (opt->show_hunk_mark) {
 571                                output_color(opt, "--", 2, opt->color_sep);
 572                                opt->output(opt, "\n", 1);
 573                        } else
 574                                opt->show_hunk_mark = 1;
 575                } else if (lno > opt->last_shown + 1) {
 576                        output_color(opt, "--", 2, opt->color_sep);
 577                        opt->output(opt, "\n", 1);
 578                }
 579        }
 580        opt->last_shown = lno;
 581
 582        if (opt->pathname) {
 583                output_color(opt, name, strlen(name), opt->color_filename);
 584                output_sep(opt, sign);
 585        }
 586        if (opt->linenum) {
 587                char buf[32];
 588                snprintf(buf, sizeof(buf), "%d", lno);
 589                output_color(opt, buf, strlen(buf), opt->color_lineno);
 590                output_sep(opt, sign);
 591        }
 592        if (opt->color) {
 593                regmatch_t match;
 594                enum grep_context ctx = GREP_CONTEXT_BODY;
 595                int ch = *eol;
 596                int eflags = 0;
 597
 598                if (sign == ':')
 599                        line_color = opt->color_selected;
 600                else if (sign == '-')
 601                        line_color = opt->color_context;
 602                else if (sign == '=')
 603                        line_color = opt->color_function;
 604                *eol = '\0';
 605                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 606                        if (match.rm_so == match.rm_eo)
 607                                break;
 608
 609                        output_color(opt, bol, match.rm_so, line_color);
 610                        output_color(opt, bol + match.rm_so,
 611                                     match.rm_eo - match.rm_so,
 612                                     opt->color_match);
 613                        bol += match.rm_eo;
 614                        rest -= match.rm_eo;
 615                        eflags = REG_NOTBOL;
 616                }
 617                *eol = ch;
 618        }
 619        output_color(opt, bol, rest, line_color);
 620        opt->output(opt, "\n", 1);
 621}
 622
 623static int match_funcname(struct grep_opt *opt, char *bol, char *eol)
 624{
 625        xdemitconf_t *xecfg = opt->priv;
 626        if (xecfg && xecfg->find_func) {
 627                char buf[1];
 628                return xecfg->find_func(bol, eol - bol, buf, 1,
 629                                        xecfg->find_func_priv) >= 0;
 630        }
 631
 632        if (bol == eol)
 633                return 0;
 634        if (isalpha(*bol) || *bol == '_' || *bol == '$')
 635                return 1;
 636        return 0;
 637}
 638
 639static void show_funcname_line(struct grep_opt *opt, const char *name,
 640                               char *buf, char *bol, unsigned lno)
 641{
 642        while (bol > buf) {
 643                char *eol = --bol;
 644
 645                while (bol > buf && bol[-1] != '\n')
 646                        bol--;
 647                lno--;
 648
 649                if (lno <= opt->last_shown)
 650                        break;
 651
 652                if (match_funcname(opt, bol, eol)) {
 653                        show_line(opt, bol, eol, name, lno, '=');
 654                        break;
 655                }
 656        }
 657}
 658
 659static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
 660                             char *bol, unsigned lno)
 661{
 662        unsigned cur = lno, from = 1, funcname_lno = 0;
 663        int funcname_needed = opt->funcname;
 664
 665        if (opt->pre_context < lno)
 666                from = lno - opt->pre_context;
 667        if (from <= opt->last_shown)
 668                from = opt->last_shown + 1;
 669
 670        /* Rewind. */
 671        while (bol > buf && cur > from) {
 672                char *eol = --bol;
 673
 674                while (bol > buf && bol[-1] != '\n')
 675                        bol--;
 676                cur--;
 677                if (funcname_needed && match_funcname(opt, bol, eol)) {
 678                        funcname_lno = cur;
 679                        funcname_needed = 0;
 680                }
 681        }
 682
 683        /* We need to look even further back to find a function signature. */
 684        if (opt->funcname && funcname_needed)
 685                show_funcname_line(opt, name, buf, bol, cur);
 686
 687        /* Back forward. */
 688        while (cur < lno) {
 689                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
 690
 691                while (*eol != '\n')
 692                        eol++;
 693                show_line(opt, bol, eol, name, cur, sign);
 694                bol = eol + 1;
 695                cur++;
 696        }
 697}
 698
 699static int should_lookahead(struct grep_opt *opt)
 700{
 701        struct grep_pat *p;
 702
 703        if (opt->extended)
 704                return 0; /* punt for too complex stuff */
 705        if (opt->invert)
 706                return 0;
 707        for (p = opt->pattern_list; p; p = p->next) {
 708                if (p->token != GREP_PATTERN)
 709                        return 0; /* punt for "header only" and stuff */
 710        }
 711        return 1;
 712}
 713
 714static int look_ahead(struct grep_opt *opt,
 715                      unsigned long *left_p,
 716                      unsigned *lno_p,
 717                      char **bol_p)
 718{
 719        unsigned lno = *lno_p;
 720        char *bol = *bol_p;
 721        struct grep_pat *p;
 722        char *sp, *last_bol;
 723        regoff_t earliest = -1;
 724
 725        for (p = opt->pattern_list; p; p = p->next) {
 726                int hit;
 727                regmatch_t m;
 728
 729                if (p->fixed)
 730                        hit = !fixmatch(p->pattern, bol, p->ignore_case, &m);
 731                else {
 732#ifdef REG_STARTEND
 733                        m.rm_so = 0;
 734                        m.rm_eo = *left_p;
 735                        hit = !regexec(&p->regexp, bol, 1, &m, REG_STARTEND);
 736#else
 737                        hit = !regexec(&p->regexp, bol, 1, &m, 0);
 738#endif
 739                }
 740                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
 741                        continue;
 742                if (earliest < 0 || m.rm_so < earliest)
 743                        earliest = m.rm_so;
 744        }
 745
 746        if (earliest < 0) {
 747                *bol_p = bol + *left_p;
 748                *left_p = 0;
 749                return 1;
 750        }
 751        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
 752                ; /* find the beginning of the line */
 753        last_bol = sp;
 754
 755        for (sp = bol; sp < last_bol; sp++) {
 756                if (*sp == '\n')
 757                        lno++;
 758        }
 759        *left_p -= last_bol - bol;
 760        *bol_p = last_bol;
 761        *lno_p = lno;
 762        return 0;
 763}
 764
 765int grep_threads_ok(const struct grep_opt *opt)
 766{
 767        /* If this condition is true, then we may use the attribute
 768         * machinery in grep_buffer_1. The attribute code is not
 769         * thread safe, so we disable the use of threads.
 770         */
 771        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 772            !opt->name_only)
 773                return 0;
 774
 775        /* If we are showing hunk marks, we should not do it for the
 776         * first match. The synchronization problem we get for this
 777         * constraint is not yet solved, so we disable threading in
 778         * this case.
 779         */
 780        if (opt->pre_context || opt->post_context)
 781                return 0;
 782
 783        return 1;
 784}
 785
 786static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 787{
 788        fwrite(buf, size, 1, stdout);
 789}
 790
 791static int grep_buffer_1(struct grep_opt *opt, const char *name,
 792                         char *buf, unsigned long size, int collect_hits)
 793{
 794        char *bol = buf;
 795        unsigned long left = size;
 796        unsigned lno = 1;
 797        unsigned last_hit = 0;
 798        int binary_match_only = 0;
 799        unsigned count = 0;
 800        int try_lookahead = 0;
 801        enum grep_context ctx = GREP_CONTEXT_HEAD;
 802        xdemitconf_t xecfg;
 803
 804        opt->last_shown = 0;
 805
 806        if (!opt->output)
 807                opt->output = std_output;
 808
 809        if (buffer_is_binary(buf, size)) {
 810                switch (opt->binary) {
 811                case GREP_BINARY_DEFAULT:
 812                        binary_match_only = 1;
 813                        break;
 814                case GREP_BINARY_NOMATCH:
 815                        return 0; /* Assume unmatch */
 816                        break;
 817                default:
 818                        break;
 819                }
 820        }
 821
 822        memset(&xecfg, 0, sizeof(xecfg));
 823        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 824            !opt->name_only && !binary_match_only && !collect_hits) {
 825                struct userdiff_driver *drv = userdiff_find_by_path(name);
 826                if (drv && drv->funcname.pattern) {
 827                        const struct userdiff_funcname *pe = &drv->funcname;
 828                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 829                        opt->priv = &xecfg;
 830                }
 831        }
 832        try_lookahead = should_lookahead(opt);
 833
 834        while (left) {
 835                char *eol, ch;
 836                int hit;
 837
 838                /*
 839                 * look_ahead() skips quicly to the line that possibly
 840                 * has the next hit; don't call it if we need to do
 841                 * something more than just skipping the current line
 842                 * in response to an unmatch for the current line.  E.g.
 843                 * inside a post-context window, we will show the current
 844                 * line as a context around the previous hit when it
 845                 * doesn't hit.
 846                 */
 847                if (try_lookahead
 848                    && !(last_hit
 849                         && lno <= last_hit + opt->post_context)
 850                    && look_ahead(opt, &left, &lno, &bol))
 851                        break;
 852                eol = end_of_line(bol, &left);
 853                ch = *eol;
 854                *eol = 0;
 855
 856                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
 857                        ctx = GREP_CONTEXT_BODY;
 858
 859                hit = match_line(opt, bol, eol, ctx, collect_hits);
 860                *eol = ch;
 861
 862                if (collect_hits)
 863                        goto next_line;
 864
 865                /* "grep -v -e foo -e bla" should list lines
 866                 * that do not have either, so inversion should
 867                 * be done outside.
 868                 */
 869                if (opt->invert)
 870                        hit = !hit;
 871                if (opt->unmatch_name_only) {
 872                        if (hit)
 873                                return 0;
 874                        goto next_line;
 875                }
 876                if (hit) {
 877                        count++;
 878                        if (opt->status_only)
 879                                return 1;
 880                        if (binary_match_only) {
 881                                opt->output(opt, "Binary file ", 12);
 882                                output_color(opt, name, strlen(name),
 883                                             opt->color_filename);
 884                                opt->output(opt, " matches\n", 9);
 885                                return 1;
 886                        }
 887                        if (opt->name_only) {
 888                                show_name(opt, name);
 889                                return 1;
 890                        }
 891                        /* Hit at this line.  If we haven't shown the
 892                         * pre-context lines, we would need to show them.
 893                         * When asked to do "count", this still show
 894                         * the context which is nonsense, but the user
 895                         * deserves to get that ;-).
 896                         */
 897                        if (opt->pre_context)
 898                                show_pre_context(opt, name, buf, bol, lno);
 899                        else if (opt->funcname)
 900                                show_funcname_line(opt, name, buf, bol, lno);
 901                        if (!opt->count)
 902                                show_line(opt, bol, eol, name, lno, ':');
 903                        last_hit = lno;
 904                }
 905                else if (last_hit &&
 906                         lno <= last_hit + opt->post_context) {
 907                        /* If the last hit is within the post context,
 908                         * we need to show this line.
 909                         */
 910                        show_line(opt, bol, eol, name, lno, '-');
 911                }
 912
 913        next_line:
 914                bol = eol + 1;
 915                if (!left)
 916                        break;
 917                left--;
 918                lno++;
 919        }
 920
 921        if (collect_hits)
 922                return 0;
 923
 924        if (opt->status_only)
 925                return 0;
 926        if (opt->unmatch_name_only) {
 927                /* We did not see any hit, so we want to show this */
 928                show_name(opt, name);
 929                return 1;
 930        }
 931
 932        xdiff_clear_find_func(&xecfg);
 933        opt->priv = NULL;
 934
 935        /* NEEDSWORK:
 936         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 937         * which feels mostly useless but sometimes useful.  Maybe
 938         * make it another option?  For now suppress them.
 939         */
 940        if (opt->count && count) {
 941                char buf[32];
 942                output_color(opt, name, strlen(name), opt->color_filename);
 943                output_sep(opt, ':');
 944                snprintf(buf, sizeof(buf), "%u\n", count);
 945                opt->output(opt, buf, strlen(buf));
 946        }
 947        return !!last_hit;
 948}
 949
 950static void clr_hit_marker(struct grep_expr *x)
 951{
 952        /* All-hit markers are meaningful only at the very top level
 953         * OR node.
 954         */
 955        while (1) {
 956                x->hit = 0;
 957                if (x->node != GREP_NODE_OR)
 958                        return;
 959                x->u.binary.left->hit = 0;
 960                x = x->u.binary.right;
 961        }
 962}
 963
 964static int chk_hit_marker(struct grep_expr *x)
 965{
 966        /* Top level nodes have hit markers.  See if they all are hits */
 967        while (1) {
 968                if (x->node != GREP_NODE_OR)
 969                        return x->hit;
 970                if (!x->u.binary.left->hit)
 971                        return 0;
 972                x = x->u.binary.right;
 973        }
 974}
 975
 976int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
 977{
 978        /*
 979         * we do not have to do the two-pass grep when we do not check
 980         * buffer-wide "all-match".
 981         */
 982        if (!opt->all_match)
 983                return grep_buffer_1(opt, name, buf, size, 0);
 984
 985        /* Otherwise the toplevel "or" terms hit a bit differently.
 986         * We first clear hit markers from them.
 987         */
 988        clr_hit_marker(opt->pattern_expression);
 989        grep_buffer_1(opt, name, buf, size, 1);
 990
 991        if (!chk_hit_marker(opt->pattern_expression))
 992                return 0;
 993
 994        return grep_buffer_1(opt, name, buf, size, 0);
 995}