c3affb6caa45d1fe037a4ddfa0456cdd991e5859
   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
 332static int fixmatch(const char *pattern, char *line, char *eol,
 333                    int ignore_case, regmatch_t *match)
 334{
 335        char *hit;
 336
 337        if (ignore_case)
 338                hit = strcasestr(line, pattern);
 339        else
 340                hit = memmem(line, eol - line, pattern, strlen(pattern));
 341
 342        if (!hit) {
 343                match->rm_so = match->rm_eo = -1;
 344                return REG_NOMATCH;
 345        }
 346        else {
 347                match->rm_so = hit - line;
 348                match->rm_eo = match->rm_so + strlen(pattern);
 349                return 0;
 350        }
 351}
 352
 353static int strip_timestamp(char *bol, char **eol_p)
 354{
 355        char *eol = *eol_p;
 356        int ch;
 357
 358        while (bol < --eol) {
 359                if (*eol != '>')
 360                        continue;
 361                *eol_p = ++eol;
 362                ch = *eol;
 363                *eol = '\0';
 364                return ch;
 365        }
 366        return 0;
 367}
 368
 369static struct {
 370        const char *field;
 371        size_t len;
 372} header_field[] = {
 373        { "author ", 7 },
 374        { "committer ", 10 },
 375};
 376
 377static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 378                             enum grep_context ctx,
 379                             regmatch_t *pmatch, int eflags)
 380{
 381        int hit = 0;
 382        int saved_ch = 0;
 383        const char *start = bol;
 384
 385        if ((p->token != GREP_PATTERN) &&
 386            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 387                return 0;
 388
 389        if (p->token == GREP_PATTERN_HEAD) {
 390                const char *field;
 391                size_t len;
 392                assert(p->field < ARRAY_SIZE(header_field));
 393                field = header_field[p->field].field;
 394                len = header_field[p->field].len;
 395                if (strncmp(bol, field, len))
 396                        return 0;
 397                bol += len;
 398                saved_ch = strip_timestamp(bol, &eol);
 399        }
 400
 401 again:
 402        if (p->fixed)
 403                hit = !fixmatch(p->pattern, bol, eol, p->ignore_case, pmatch);
 404        else
 405                hit = !regexec(&p->regexp, bol, 1, pmatch, eflags);
 406
 407        if (hit && p->word_regexp) {
 408                if ((pmatch[0].rm_so < 0) ||
 409                    (eol - bol) < pmatch[0].rm_so ||
 410                    (pmatch[0].rm_eo < 0) ||
 411                    (eol - bol) < pmatch[0].rm_eo)
 412                        die("regexp returned nonsense");
 413
 414                /* Match beginning must be either beginning of the
 415                 * line, or at word boundary (i.e. the last char must
 416                 * not be a word char).  Similarly, match end must be
 417                 * either end of the line, or at word boundary
 418                 * (i.e. the next char must not be a word char).
 419                 */
 420                if ( ((pmatch[0].rm_so == 0) ||
 421                      !word_char(bol[pmatch[0].rm_so-1])) &&
 422                     ((pmatch[0].rm_eo == (eol-bol)) ||
 423                      !word_char(bol[pmatch[0].rm_eo])) )
 424                        ;
 425                else
 426                        hit = 0;
 427
 428                /* Words consist of at least one character. */
 429                if (pmatch->rm_so == pmatch->rm_eo)
 430                        hit = 0;
 431
 432                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 433                        /* There could be more than one match on the
 434                         * line, and the first match might not be
 435                         * strict word match.  But later ones could be!
 436                         * Forward to the next possible start, i.e. the
 437                         * next position following a non-word char.
 438                         */
 439                        bol = pmatch[0].rm_so + bol + 1;
 440                        while (word_char(bol[-1]) && bol < eol)
 441                                bol++;
 442                        eflags |= REG_NOTBOL;
 443                        if (bol < eol)
 444                                goto again;
 445                }
 446        }
 447        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 448                *eol = saved_ch;
 449        if (hit) {
 450                pmatch[0].rm_so += bol - start;
 451                pmatch[0].rm_eo += bol - start;
 452        }
 453        return hit;
 454}
 455
 456static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 457                           enum grep_context ctx, int collect_hits)
 458{
 459        int h = 0;
 460        regmatch_t match;
 461
 462        if (!x)
 463                die("Not a valid grep expression");
 464        switch (x->node) {
 465        case GREP_NODE_ATOM:
 466                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 467                break;
 468        case GREP_NODE_NOT:
 469                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 470                break;
 471        case GREP_NODE_AND:
 472                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 473                        return 0;
 474                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 475                break;
 476        case GREP_NODE_OR:
 477                if (!collect_hits)
 478                        return (match_expr_eval(x->u.binary.left,
 479                                                bol, eol, ctx, 0) ||
 480                                match_expr_eval(x->u.binary.right,
 481                                                bol, eol, ctx, 0));
 482                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 483                x->u.binary.left->hit |= h;
 484                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 485                break;
 486        default:
 487                die("Unexpected node type (internal error) %d", x->node);
 488        }
 489        if (collect_hits)
 490                x->hit |= h;
 491        return h;
 492}
 493
 494static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 495                      enum grep_context ctx, int collect_hits)
 496{
 497        struct grep_expr *x = opt->pattern_expression;
 498        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 499}
 500
 501static int match_line(struct grep_opt *opt, char *bol, char *eol,
 502                      enum grep_context ctx, int collect_hits)
 503{
 504        struct grep_pat *p;
 505        regmatch_t match;
 506
 507        if (opt->extended)
 508                return match_expr(opt, bol, eol, ctx, collect_hits);
 509
 510        /* we do not call with collect_hits without being extended */
 511        for (p = opt->pattern_list; p; p = p->next) {
 512                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 513                        return 1;
 514        }
 515        return 0;
 516}
 517
 518static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 519                              enum grep_context ctx,
 520                              regmatch_t *pmatch, int eflags)
 521{
 522        regmatch_t match;
 523
 524        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 525                return 0;
 526        if (match.rm_so < 0 || match.rm_eo < 0)
 527                return 0;
 528        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 529                if (match.rm_so > pmatch->rm_so)
 530                        return 1;
 531                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 532                        return 1;
 533        }
 534        pmatch->rm_so = match.rm_so;
 535        pmatch->rm_eo = match.rm_eo;
 536        return 1;
 537}
 538
 539static int next_match(struct grep_opt *opt, char *bol, char *eol,
 540                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 541{
 542        struct grep_pat *p;
 543        int hit = 0;
 544
 545        pmatch->rm_so = pmatch->rm_eo = -1;
 546        if (bol < eol) {
 547                for (p = opt->pattern_list; p; p = p->next) {
 548                        switch (p->token) {
 549                        case GREP_PATTERN: /* atom */
 550                        case GREP_PATTERN_HEAD:
 551                        case GREP_PATTERN_BODY:
 552                                hit |= match_next_pattern(p, bol, eol, ctx,
 553                                                          pmatch, eflags);
 554                                break;
 555                        default:
 556                                break;
 557                        }
 558                }
 559        }
 560        return hit;
 561}
 562
 563static void show_line(struct grep_opt *opt, char *bol, char *eol,
 564                      const char *name, unsigned lno, char sign)
 565{
 566        int rest = eol - bol;
 567        char *line_color = NULL;
 568
 569        if (opt->pre_context || opt->post_context) {
 570                if (opt->last_shown == 0) {
 571                        if (opt->show_hunk_mark) {
 572                                output_color(opt, "--", 2, opt->color_sep);
 573                                opt->output(opt, "\n", 1);
 574                        }
 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, bol + *left_p,
 731                                        p->ignore_case, &m);
 732                } else {
 733#ifdef REG_STARTEND
 734                        m.rm_so = 0;
 735                        m.rm_eo = *left_p;
 736                        hit = !regexec(&p->regexp, bol, 1, &m, REG_STARTEND);
 737#else
 738                        hit = !regexec(&p->regexp, bol, 1, &m, 0);
 739#endif
 740                }
 741                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
 742                        continue;
 743                if (earliest < 0 || m.rm_so < earliest)
 744                        earliest = m.rm_so;
 745        }
 746
 747        if (earliest < 0) {
 748                *bol_p = bol + *left_p;
 749                *left_p = 0;
 750                return 1;
 751        }
 752        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
 753                ; /* find the beginning of the line */
 754        last_bol = sp;
 755
 756        for (sp = bol; sp < last_bol; sp++) {
 757                if (*sp == '\n')
 758                        lno++;
 759        }
 760        *left_p -= last_bol - bol;
 761        *bol_p = last_bol;
 762        *lno_p = lno;
 763        return 0;
 764}
 765
 766int grep_threads_ok(const struct grep_opt *opt)
 767{
 768        /* If this condition is true, then we may use the attribute
 769         * machinery in grep_buffer_1. The attribute code is not
 770         * thread safe, so we disable the use of threads.
 771         */
 772        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 773            !opt->name_only)
 774                return 0;
 775
 776        return 1;
 777}
 778
 779static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 780{
 781        fwrite(buf, size, 1, stdout);
 782}
 783
 784static int grep_buffer_1(struct grep_opt *opt, const char *name,
 785                         char *buf, unsigned long size, int collect_hits)
 786{
 787        char *bol = buf;
 788        unsigned long left = size;
 789        unsigned lno = 1;
 790        unsigned last_hit = 0;
 791        int binary_match_only = 0;
 792        unsigned count = 0;
 793        int try_lookahead = 0;
 794        enum grep_context ctx = GREP_CONTEXT_HEAD;
 795        xdemitconf_t xecfg;
 796
 797        if (!opt->output)
 798                opt->output = std_output;
 799
 800        if (opt->last_shown && (opt->pre_context || opt->post_context) &&
 801            opt->output == std_output)
 802                opt->show_hunk_mark = 1;
 803        opt->last_shown = 0;
 804
 805        switch (opt->binary) {
 806        case GREP_BINARY_DEFAULT:
 807                if (buffer_is_binary(buf, size))
 808                        binary_match_only = 1;
 809                break;
 810        case GREP_BINARY_NOMATCH:
 811                if (buffer_is_binary(buf, size))
 812                        return 0; /* Assume unmatch */
 813                break;
 814        case GREP_BINARY_TEXT:
 815                break;
 816        default:
 817                die("bug: unknown binary handling mode");
 818        }
 819
 820        memset(&xecfg, 0, sizeof(xecfg));
 821        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 822            !opt->name_only && !binary_match_only && !collect_hits) {
 823                struct userdiff_driver *drv = userdiff_find_by_path(name);
 824                if (drv && drv->funcname.pattern) {
 825                        const struct userdiff_funcname *pe = &drv->funcname;
 826                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 827                        opt->priv = &xecfg;
 828                }
 829        }
 830        try_lookahead = should_lookahead(opt);
 831
 832        while (left) {
 833                char *eol, ch;
 834                int hit;
 835
 836                /*
 837                 * look_ahead() skips quicly to the line that possibly
 838                 * has the next hit; don't call it if we need to do
 839                 * something more than just skipping the current line
 840                 * in response to an unmatch for the current line.  E.g.
 841                 * inside a post-context window, we will show the current
 842                 * line as a context around the previous hit when it
 843                 * doesn't hit.
 844                 */
 845                if (try_lookahead
 846                    && !(last_hit
 847                         && lno <= last_hit + opt->post_context)
 848                    && look_ahead(opt, &left, &lno, &bol))
 849                        break;
 850                eol = end_of_line(bol, &left);
 851                ch = *eol;
 852                *eol = 0;
 853
 854                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
 855                        ctx = GREP_CONTEXT_BODY;
 856
 857                hit = match_line(opt, bol, eol, ctx, collect_hits);
 858                *eol = ch;
 859
 860                if (collect_hits)
 861                        goto next_line;
 862
 863                /* "grep -v -e foo -e bla" should list lines
 864                 * that do not have either, so inversion should
 865                 * be done outside.
 866                 */
 867                if (opt->invert)
 868                        hit = !hit;
 869                if (opt->unmatch_name_only) {
 870                        if (hit)
 871                                return 0;
 872                        goto next_line;
 873                }
 874                if (hit) {
 875                        count++;
 876                        if (opt->status_only)
 877                                return 1;
 878                        if (opt->name_only) {
 879                                show_name(opt, name);
 880                                return 1;
 881                        }
 882                        if (opt->count)
 883                                goto next_line;
 884                        if (binary_match_only) {
 885                                opt->output(opt, "Binary file ", 12);
 886                                output_color(opt, name, strlen(name),
 887                                             opt->color_filename);
 888                                opt->output(opt, " matches\n", 9);
 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                         */
 894                        if (opt->pre_context)
 895                                show_pre_context(opt, name, buf, bol, lno);
 896                        else if (opt->funcname)
 897                                show_funcname_line(opt, name, buf, bol, lno);
 898                        show_line(opt, bol, eol, name, lno, ':');
 899                        last_hit = lno;
 900                }
 901                else if (last_hit &&
 902                         lno <= last_hit + opt->post_context) {
 903                        /* If the last hit is within the post context,
 904                         * we need to show this line.
 905                         */
 906                        show_line(opt, bol, eol, name, lno, '-');
 907                }
 908
 909        next_line:
 910                bol = eol + 1;
 911                if (!left)
 912                        break;
 913                left--;
 914                lno++;
 915        }
 916
 917        if (collect_hits)
 918                return 0;
 919
 920        if (opt->status_only)
 921                return 0;
 922        if (opt->unmatch_name_only) {
 923                /* We did not see any hit, so we want to show this */
 924                show_name(opt, name);
 925                return 1;
 926        }
 927
 928        xdiff_clear_find_func(&xecfg);
 929        opt->priv = NULL;
 930
 931        /* NEEDSWORK:
 932         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 933         * which feels mostly useless but sometimes useful.  Maybe
 934         * make it another option?  For now suppress them.
 935         */
 936        if (opt->count && count) {
 937                char buf[32];
 938                output_color(opt, name, strlen(name), opt->color_filename);
 939                output_sep(opt, ':');
 940                snprintf(buf, sizeof(buf), "%u\n", count);
 941                opt->output(opt, buf, strlen(buf));
 942                return 1;
 943        }
 944        return !!last_hit;
 945}
 946
 947static void clr_hit_marker(struct grep_expr *x)
 948{
 949        /* All-hit markers are meaningful only at the very top level
 950         * OR node.
 951         */
 952        while (1) {
 953                x->hit = 0;
 954                if (x->node != GREP_NODE_OR)
 955                        return;
 956                x->u.binary.left->hit = 0;
 957                x = x->u.binary.right;
 958        }
 959}
 960
 961static int chk_hit_marker(struct grep_expr *x)
 962{
 963        /* Top level nodes have hit markers.  See if they all are hits */
 964        while (1) {
 965                if (x->node != GREP_NODE_OR)
 966                        return x->hit;
 967                if (!x->u.binary.left->hit)
 968                        return 0;
 969                x = x->u.binary.right;
 970        }
 971}
 972
 973int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
 974{
 975        /*
 976         * we do not have to do the two-pass grep when we do not check
 977         * buffer-wide "all-match".
 978         */
 979        if (!opt->all_match)
 980                return grep_buffer_1(opt, name, buf, size, 0);
 981
 982        /* Otherwise the toplevel "or" terms hit a bit differently.
 983         * We first clear hit markers from them.
 984         */
 985        clr_hit_marker(opt->pattern_expression);
 986        grep_buffer_1(opt, name, buf, size, 1);
 987
 988        if (!chk_hit_marker(opt->pattern_expression))
 989                return 0;
 990
 991        return grep_buffer_1(opt, name, buf, size, 0);
 992}