Andrew's git / gitweb.git / grep.c
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grep.con commit grep: Colorize selected, context, and function lines (00588bb)
   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->pattern_tail = p;
  15        opt->pattern_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
 188        if (opt->all_match)
 189                opt->extended = 1;
 190
 191        for (p = opt->pattern_list; p; p = p->next) {
 192                switch (p->token) {
 193                case GREP_PATTERN: /* atom */
 194                case GREP_PATTERN_HEAD:
 195                case GREP_PATTERN_BODY:
 196                        compile_regexp(p, opt);
 197                        break;
 198                default:
 199                        opt->extended = 1;
 200                        break;
 201                }
 202        }
 203
 204        if (!opt->extended)
 205                return;
 206
 207        /* Then bundle them up in an expression.
 208         * A classic recursive descent parser would do.
 209         */
 210        p = opt->pattern_list;
 211        if (p)
 212                opt->pattern_expression = compile_pattern_expr(&p);
 213        if (p)
 214                die("incomplete pattern expression: %s", p->pattern);
 215}
 216
 217static void free_pattern_expr(struct grep_expr *x)
 218{
 219        switch (x->node) {
 220        case GREP_NODE_ATOM:
 221                break;
 222        case GREP_NODE_NOT:
 223                free_pattern_expr(x->u.unary);
 224                break;
 225        case GREP_NODE_AND:
 226        case GREP_NODE_OR:
 227                free_pattern_expr(x->u.binary.left);
 228                free_pattern_expr(x->u.binary.right);
 229                break;
 230        }
 231        free(x);
 232}
 233
 234void free_grep_patterns(struct grep_opt *opt)
 235{
 236        struct grep_pat *p, *n;
 237
 238        for (p = opt->pattern_list; p; p = n) {
 239                n = p->next;
 240                switch (p->token) {
 241                case GREP_PATTERN: /* atom */
 242                case GREP_PATTERN_HEAD:
 243                case GREP_PATTERN_BODY:
 244                        regfree(&p->regexp);
 245                        break;
 246                default:
 247                        break;
 248                }
 249                free(p);
 250        }
 251
 252        if (!opt->extended)
 253                return;
 254        free_pattern_expr(opt->pattern_expression);
 255}
 256
 257static char *end_of_line(char *cp, unsigned long *left)
 258{
 259        unsigned long l = *left;
 260        while (l && *cp != '\n') {
 261                l--;
 262                cp++;
 263        }
 264        *left = l;
 265        return cp;
 266}
 267
 268static int word_char(char ch)
 269{
 270        return isalnum(ch) || ch == '_';
 271}
 272
 273static void output_color(struct grep_opt *opt, const void *data, size_t size,
 274                         const char *color)
 275{
 276        if (opt->color && color && color[0]) {
 277                opt->output(opt, color, strlen(color));
 278                opt->output(opt, data, size);
 279                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 280        } else
 281                opt->output(opt, data, size);
 282}
 283
 284static void output_sep(struct grep_opt *opt, char sign)
 285{
 286        if (opt->null_following_name)
 287                opt->output(opt, "\0", 1);
 288        else
 289                output_color(opt, &sign, 1, opt->color_sep);
 290}
 291
 292static void show_name(struct grep_opt *opt, const char *name)
 293{
 294        output_color(opt, name, strlen(name), opt->color_filename);
 295        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 296}
 297
 298
 299static int fixmatch(const char *pattern, char *line, int ignore_case, regmatch_t *match)
 300{
 301        char *hit;
 302        if (ignore_case)
 303                hit = strcasestr(line, pattern);
 304        else
 305                hit = strstr(line, pattern);
 306
 307        if (!hit) {
 308                match->rm_so = match->rm_eo = -1;
 309                return REG_NOMATCH;
 310        }
 311        else {
 312                match->rm_so = hit - line;
 313                match->rm_eo = match->rm_so + strlen(pattern);
 314                return 0;
 315        }
 316}
 317
 318static int strip_timestamp(char *bol, char **eol_p)
 319{
 320        char *eol = *eol_p;
 321        int ch;
 322
 323        while (bol < --eol) {
 324                if (*eol != '>')
 325                        continue;
 326                *eol_p = ++eol;
 327                ch = *eol;
 328                *eol = '\0';
 329                return ch;
 330        }
 331        return 0;
 332}
 333
 334static struct {
 335        const char *field;
 336        size_t len;
 337} header_field[] = {
 338        { "author ", 7 },
 339        { "committer ", 10 },
 340};
 341
 342static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 343                             enum grep_context ctx,
 344                             regmatch_t *pmatch, int eflags)
 345{
 346        int hit = 0;
 347        int saved_ch = 0;
 348        const char *start = bol;
 349
 350        if ((p->token != GREP_PATTERN) &&
 351            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 352                return 0;
 353
 354        if (p->token == GREP_PATTERN_HEAD) {
 355                const char *field;
 356                size_t len;
 357                assert(p->field < ARRAY_SIZE(header_field));
 358                field = header_field[p->field].field;
 359                len = header_field[p->field].len;
 360                if (strncmp(bol, field, len))
 361                        return 0;
 362                bol += len;
 363                saved_ch = strip_timestamp(bol, &eol);
 364        }
 365
 366 again:
 367        if (p->fixed)
 368                hit = !fixmatch(p->pattern, bol, p->ignore_case, pmatch);
 369        else
 370                hit = !regexec(&p->regexp, bol, 1, pmatch, eflags);
 371
 372        if (hit && p->word_regexp) {
 373                if ((pmatch[0].rm_so < 0) ||
 374                    (eol - bol) < pmatch[0].rm_so ||
 375                    (pmatch[0].rm_eo < 0) ||
 376                    (eol - bol) < pmatch[0].rm_eo)
 377                        die("regexp returned nonsense");
 378
 379                /* Match beginning must be either beginning of the
 380                 * line, or at word boundary (i.e. the last char must
 381                 * not be a word char).  Similarly, match end must be
 382                 * either end of the line, or at word boundary
 383                 * (i.e. the next char must not be a word char).
 384                 */
 385                if ( ((pmatch[0].rm_so == 0) ||
 386                      !word_char(bol[pmatch[0].rm_so-1])) &&
 387                     ((pmatch[0].rm_eo == (eol-bol)) ||
 388                      !word_char(bol[pmatch[0].rm_eo])) )
 389                        ;
 390                else
 391                        hit = 0;
 392
 393                /* Words consist of at least one character. */
 394                if (pmatch->rm_so == pmatch->rm_eo)
 395                        hit = 0;
 396
 397                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 398                        /* There could be more than one match on the
 399                         * line, and the first match might not be
 400                         * strict word match.  But later ones could be!
 401                         * Forward to the next possible start, i.e. the
 402                         * next position following a non-word char.
 403                         */
 404                        bol = pmatch[0].rm_so + bol + 1;
 405                        while (word_char(bol[-1]) && bol < eol)
 406                                bol++;
 407                        eflags |= REG_NOTBOL;
 408                        if (bol < eol)
 409                                goto again;
 410                }
 411        }
 412        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 413                *eol = saved_ch;
 414        if (hit) {
 415                pmatch[0].rm_so += bol - start;
 416                pmatch[0].rm_eo += bol - start;
 417        }
 418        return hit;
 419}
 420
 421static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 422                           enum grep_context ctx, int collect_hits)
 423{
 424        int h = 0;
 425        regmatch_t match;
 426
 427        if (!x)
 428                die("Not a valid grep expression");
 429        switch (x->node) {
 430        case GREP_NODE_ATOM:
 431                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 432                break;
 433        case GREP_NODE_NOT:
 434                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 435                break;
 436        case GREP_NODE_AND:
 437                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 438                        return 0;
 439                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 440                break;
 441        case GREP_NODE_OR:
 442                if (!collect_hits)
 443                        return (match_expr_eval(x->u.binary.left,
 444                                                bol, eol, ctx, 0) ||
 445                                match_expr_eval(x->u.binary.right,
 446                                                bol, eol, ctx, 0));
 447                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 448                x->u.binary.left->hit |= h;
 449                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 450                break;
 451        default:
 452                die("Unexpected node type (internal error) %d", x->node);
 453        }
 454        if (collect_hits)
 455                x->hit |= h;
 456        return h;
 457}
 458
 459static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 460                      enum grep_context ctx, int collect_hits)
 461{
 462        struct grep_expr *x = opt->pattern_expression;
 463        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 464}
 465
 466static int match_line(struct grep_opt *opt, char *bol, char *eol,
 467                      enum grep_context ctx, int collect_hits)
 468{
 469        struct grep_pat *p;
 470        regmatch_t match;
 471
 472        if (opt->extended)
 473                return match_expr(opt, bol, eol, ctx, collect_hits);
 474
 475        /* we do not call with collect_hits without being extended */
 476        for (p = opt->pattern_list; p; p = p->next) {
 477                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 478                        return 1;
 479        }
 480        return 0;
 481}
 482
 483static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 484                              enum grep_context ctx,
 485                              regmatch_t *pmatch, int eflags)
 486{
 487        regmatch_t match;
 488
 489        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 490                return 0;
 491        if (match.rm_so < 0 || match.rm_eo < 0)
 492                return 0;
 493        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 494                if (match.rm_so > pmatch->rm_so)
 495                        return 1;
 496                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 497                        return 1;
 498        }
 499        pmatch->rm_so = match.rm_so;
 500        pmatch->rm_eo = match.rm_eo;
 501        return 1;
 502}
 503
 504static int next_match(struct grep_opt *opt, char *bol, char *eol,
 505                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 506{
 507        struct grep_pat *p;
 508        int hit = 0;
 509
 510        pmatch->rm_so = pmatch->rm_eo = -1;
 511        if (bol < eol) {
 512                for (p = opt->pattern_list; p; p = p->next) {
 513                        switch (p->token) {
 514                        case GREP_PATTERN: /* atom */
 515                        case GREP_PATTERN_HEAD:
 516                        case GREP_PATTERN_BODY:
 517                                hit |= match_next_pattern(p, bol, eol, ctx,
 518                                                          pmatch, eflags);
 519                                break;
 520                        default:
 521                                break;
 522                        }
 523                }
 524        }
 525        return hit;
 526}
 527
 528static void show_line(struct grep_opt *opt, char *bol, char *eol,
 529                      const char *name, unsigned lno, char sign)
 530{
 531        int rest = eol - bol;
 532        char *line_color = NULL;
 533
 534        if (opt->pre_context || opt->post_context) {
 535                if (opt->last_shown == 0) {
 536                        if (opt->show_hunk_mark) {
 537                                output_color(opt, "--", 2, opt->color_sep);
 538                                opt->output(opt, "\n", 1);
 539                        } else
 540                                opt->show_hunk_mark = 1;
 541                } else if (lno > opt->last_shown + 1) {
 542                        output_color(opt, "--", 2, opt->color_sep);
 543                        opt->output(opt, "\n", 1);
 544                }
 545        }
 546        opt->last_shown = lno;
 547
 548        if (opt->pathname) {
 549                output_color(opt, name, strlen(name), opt->color_filename);
 550                output_sep(opt, sign);
 551        }
 552        if (opt->linenum) {
 553                char buf[32];
 554                snprintf(buf, sizeof(buf), "%d", lno);
 555                output_color(opt, buf, strlen(buf), opt->color_lineno);
 556                output_sep(opt, sign);
 557        }
 558        if (opt->color) {
 559                regmatch_t match;
 560                enum grep_context ctx = GREP_CONTEXT_BODY;
 561                int ch = *eol;
 562                int eflags = 0;
 563
 564                if (sign == ':')
 565                        line_color = opt->color_selected;
 566                else if (sign == '-')
 567                        line_color = opt->color_context;
 568                else if (sign == '=')
 569                        line_color = opt->color_function;
 570                *eol = '\0';
 571                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 572                        if (match.rm_so == match.rm_eo)
 573                                break;
 574
 575                        output_color(opt, bol, match.rm_so, line_color);
 576                        output_color(opt, bol + match.rm_so,
 577                                     match.rm_eo - match.rm_so,
 578                                     opt->color_match);
 579                        bol += match.rm_eo;
 580                        rest -= match.rm_eo;
 581                        eflags = REG_NOTBOL;
 582                }
 583                *eol = ch;
 584        }
 585        output_color(opt, bol, rest, line_color);
 586        opt->output(opt, "\n", 1);
 587}
 588
 589static int match_funcname(struct grep_opt *opt, char *bol, char *eol)
 590{
 591        xdemitconf_t *xecfg = opt->priv;
 592        if (xecfg && xecfg->find_func) {
 593                char buf[1];
 594                return xecfg->find_func(bol, eol - bol, buf, 1,
 595                                        xecfg->find_func_priv) >= 0;
 596        }
 597
 598        if (bol == eol)
 599                return 0;
 600        if (isalpha(*bol) || *bol == '_' || *bol == '$')
 601                return 1;
 602        return 0;
 603}
 604
 605static void show_funcname_line(struct grep_opt *opt, const char *name,
 606                               char *buf, char *bol, unsigned lno)
 607{
 608        while (bol > buf) {
 609                char *eol = --bol;
 610
 611                while (bol > buf && bol[-1] != '\n')
 612                        bol--;
 613                lno--;
 614
 615                if (lno <= opt->last_shown)
 616                        break;
 617
 618                if (match_funcname(opt, bol, eol)) {
 619                        show_line(opt, bol, eol, name, lno, '=');
 620                        break;
 621                }
 622        }
 623}
 624
 625static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
 626                             char *bol, unsigned lno)
 627{
 628        unsigned cur = lno, from = 1, funcname_lno = 0;
 629        int funcname_needed = opt->funcname;
 630
 631        if (opt->pre_context < lno)
 632                from = lno - opt->pre_context;
 633        if (from <= opt->last_shown)
 634                from = opt->last_shown + 1;
 635
 636        /* Rewind. */
 637        while (bol > buf && cur > from) {
 638                char *eol = --bol;
 639
 640                while (bol > buf && bol[-1] != '\n')
 641                        bol--;
 642                cur--;
 643                if (funcname_needed && match_funcname(opt, bol, eol)) {
 644                        funcname_lno = cur;
 645                        funcname_needed = 0;
 646                }
 647        }
 648
 649        /* We need to look even further back to find a function signature. */
 650        if (opt->funcname && funcname_needed)
 651                show_funcname_line(opt, name, buf, bol, cur);
 652
 653        /* Back forward. */
 654        while (cur < lno) {
 655                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
 656
 657                while (*eol != '\n')
 658                        eol++;
 659                show_line(opt, bol, eol, name, cur, sign);
 660                bol = eol + 1;
 661                cur++;
 662        }
 663}
 664
 665static int should_lookahead(struct grep_opt *opt)
 666{
 667        struct grep_pat *p;
 668
 669        if (opt->extended)
 670                return 0; /* punt for too complex stuff */
 671        if (opt->invert)
 672                return 0;
 673        for (p = opt->pattern_list; p; p = p->next) {
 674                if (p->token != GREP_PATTERN)
 675                        return 0; /* punt for "header only" and stuff */
 676        }
 677        return 1;
 678}
 679
 680static int look_ahead(struct grep_opt *opt,
 681                      unsigned long *left_p,
 682                      unsigned *lno_p,
 683                      char **bol_p)
 684{
 685        unsigned lno = *lno_p;
 686        char *bol = *bol_p;
 687        struct grep_pat *p;
 688        char *sp, *last_bol;
 689        regoff_t earliest = -1;
 690
 691        for (p = opt->pattern_list; p; p = p->next) {
 692                int hit;
 693                regmatch_t m;
 694
 695                if (p->fixed)
 696                        hit = !fixmatch(p->pattern, bol, p->ignore_case, &m);
 697                else {
 698#ifdef REG_STARTEND
 699                        m.rm_so = 0;
 700                        m.rm_eo = *left_p;
 701                        hit = !regexec(&p->regexp, bol, 1, &m, REG_STARTEND);
 702#else
 703                        hit = !regexec(&p->regexp, bol, 1, &m, 0);
 704#endif
 705                }
 706                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
 707                        continue;
 708                if (earliest < 0 || m.rm_so < earliest)
 709                        earliest = m.rm_so;
 710        }
 711
 712        if (earliest < 0) {
 713                *bol_p = bol + *left_p;
 714                *left_p = 0;
 715                return 1;
 716        }
 717        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
 718                ; /* find the beginning of the line */
 719        last_bol = sp;
 720
 721        for (sp = bol; sp < last_bol; sp++) {
 722                if (*sp == '\n')
 723                        lno++;
 724        }
 725        *left_p -= last_bol - bol;
 726        *bol_p = last_bol;
 727        *lno_p = lno;
 728        return 0;
 729}
 730
 731int grep_threads_ok(const struct grep_opt *opt)
 732{
 733        /* If this condition is true, then we may use the attribute
 734         * machinery in grep_buffer_1. The attribute code is not
 735         * thread safe, so we disable the use of threads.
 736         */
 737        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 738            !opt->name_only)
 739                return 0;
 740
 741        /* If we are showing hunk marks, we should not do it for the
 742         * first match. The synchronization problem we get for this
 743         * constraint is not yet solved, so we disable threading in
 744         * this case.
 745         */
 746        if (opt->pre_context || opt->post_context)
 747                return 0;
 748
 749        return 1;
 750}
 751
 752static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 753{
 754        fwrite(buf, size, 1, stdout);
 755}
 756
 757static int grep_buffer_1(struct grep_opt *opt, const char *name,
 758                         char *buf, unsigned long size, int collect_hits)
 759{
 760        char *bol = buf;
 761        unsigned long left = size;
 762        unsigned lno = 1;
 763        unsigned last_hit = 0;
 764        int binary_match_only = 0;
 765        unsigned count = 0;
 766        int try_lookahead = 0;
 767        enum grep_context ctx = GREP_CONTEXT_HEAD;
 768        xdemitconf_t xecfg;
 769
 770        opt->last_shown = 0;
 771
 772        if (!opt->output)
 773                opt->output = std_output;
 774
 775        if (buffer_is_binary(buf, size)) {
 776                switch (opt->binary) {
 777                case GREP_BINARY_DEFAULT:
 778                        binary_match_only = 1;
 779                        break;
 780                case GREP_BINARY_NOMATCH:
 781                        return 0; /* Assume unmatch */
 782                        break;
 783                default:
 784                        break;
 785                }
 786        }
 787
 788        memset(&xecfg, 0, sizeof(xecfg));
 789        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 790            !opt->name_only && !binary_match_only && !collect_hits) {
 791                struct userdiff_driver *drv = userdiff_find_by_path(name);
 792                if (drv && drv->funcname.pattern) {
 793                        const struct userdiff_funcname *pe = &drv->funcname;
 794                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 795                        opt->priv = &xecfg;
 796                }
 797        }
 798        try_lookahead = should_lookahead(opt);
 799
 800        while (left) {
 801                char *eol, ch;
 802                int hit;
 803
 804                /*
 805                 * look_ahead() skips quicly to the line that possibly
 806                 * has the next hit; don't call it if we need to do
 807                 * something more than just skipping the current line
 808                 * in response to an unmatch for the current line.  E.g.
 809                 * inside a post-context window, we will show the current
 810                 * line as a context around the previous hit when it
 811                 * doesn't hit.
 812                 */
 813                if (try_lookahead
 814                    && !(last_hit
 815                         && lno <= last_hit + opt->post_context)
 816                    && look_ahead(opt, &left, &lno, &bol))
 817                        break;
 818                eol = end_of_line(bol, &left);
 819                ch = *eol;
 820                *eol = 0;
 821
 822                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
 823                        ctx = GREP_CONTEXT_BODY;
 824
 825                hit = match_line(opt, bol, eol, ctx, collect_hits);
 826                *eol = ch;
 827
 828                if (collect_hits)
 829                        goto next_line;
 830
 831                /* "grep -v -e foo -e bla" should list lines
 832                 * that do not have either, so inversion should
 833                 * be done outside.
 834                 */
 835                if (opt->invert)
 836                        hit = !hit;
 837                if (opt->unmatch_name_only) {
 838                        if (hit)
 839                                return 0;
 840                        goto next_line;
 841                }
 842                if (hit) {
 843                        count++;
 844                        if (opt->status_only)
 845                                return 1;
 846                        if (binary_match_only) {
 847                                opt->output(opt, "Binary file ", 12);
 848                                output_color(opt, name, strlen(name),
 849                                             opt->color_filename);
 850                                opt->output(opt, " matches\n", 9);
 851                                return 1;
 852                        }
 853                        if (opt->name_only) {
 854                                show_name(opt, name);
 855                                return 1;
 856                        }
 857                        /* Hit at this line.  If we haven't shown the
 858                         * pre-context lines, we would need to show them.
 859                         * When asked to do "count", this still show
 860                         * the context which is nonsense, but the user
 861                         * deserves to get that ;-).
 862                         */
 863                        if (opt->pre_context)
 864                                show_pre_context(opt, name, buf, bol, lno);
 865                        else if (opt->funcname)
 866                                show_funcname_line(opt, name, buf, bol, lno);
 867                        if (!opt->count)
 868                                show_line(opt, bol, eol, name, lno, ':');
 869                        last_hit = lno;
 870                }
 871                else if (last_hit &&
 872                         lno <= last_hit + opt->post_context) {
 873                        /* If the last hit is within the post context,
 874                         * we need to show this line.
 875                         */
 876                        show_line(opt, bol, eol, name, lno, '-');
 877                }
 878
 879        next_line:
 880                bol = eol + 1;
 881                if (!left)
 882                        break;
 883                left--;
 884                lno++;
 885        }
 886
 887        if (collect_hits)
 888                return 0;
 889
 890        if (opt->status_only)
 891                return 0;
 892        if (opt->unmatch_name_only) {
 893                /* We did not see any hit, so we want to show this */
 894                show_name(opt, name);
 895                return 1;
 896        }
 897
 898        xdiff_clear_find_func(&xecfg);
 899        opt->priv = NULL;
 900
 901        /* NEEDSWORK:
 902         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 903         * which feels mostly useless but sometimes useful.  Maybe
 904         * make it another option?  For now suppress them.
 905         */
 906        if (opt->count && count) {
 907                char buf[32];
 908                output_color(opt, name, strlen(name), opt->color_filename);
 909                output_sep(opt, ':');
 910                snprintf(buf, sizeof(buf), "%u\n", count);
 911                opt->output(opt, buf, strlen(buf));
 912        }
 913        return !!last_hit;
 914}
 915
 916static void clr_hit_marker(struct grep_expr *x)
 917{
 918        /* All-hit markers are meaningful only at the very top level
 919         * OR node.
 920         */
 921        while (1) {
 922                x->hit = 0;
 923                if (x->node != GREP_NODE_OR)
 924                        return;
 925                x->u.binary.left->hit = 0;
 926                x = x->u.binary.right;
 927        }
 928}
 929
 930static int chk_hit_marker(struct grep_expr *x)
 931{
 932        /* Top level nodes have hit markers.  See if they all are hits */
 933        while (1) {
 934                if (x->node != GREP_NODE_OR)
 935                        return x->hit;
 936                if (!x->u.binary.left->hit)
 937                        return 0;
 938                x = x->u.binary.right;
 939        }
 940}
 941
 942int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
 943{
 944        /*
 945         * we do not have to do the two-pass grep when we do not check
 946         * buffer-wide "all-match".
 947         */
 948        if (!opt->all_match)
 949                return grep_buffer_1(opt, name, buf, size, 0);
 950
 951        /* Otherwise the toplevel "or" terms hit a bit differently.
 952         * We first clear hit markers from them.
 953         */
 954        clr_hit_marker(opt->pattern_expression);
 955        grep_buffer_1(opt, name, buf, size, 1);
 956
 957        if (!chk_hit_marker(opt->pattern_expression))
 958                return 0;
 959
 960        return grep_buffer_1(opt, name, buf, size, 0);
 961}