Andrew's git - gitweb.git/blob

250462e0c0dd09c1047273dd8f0470bcb2db2ccd
   1#include "cache.h"
   2#include "grep.h"
   3#include "userdiff.h"
   4#include "xdiff-interface.h"
   5
   6void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
   7{
   8        struct grep_pat *p = xcalloc(1, sizeof(*p));
   9        p->pattern = pat;
  10        p->patternlen = strlen(pat);
  11        p->origin = "header";
  12        p->no = 0;
  13        p->token = GREP_PATTERN_HEAD;
  14        p->field = field;
  15        *opt->header_tail = p;
  16        opt->header_tail = &p->next;
  17        p->next = NULL;
  18}
  19
  20void append_grep_pattern(struct grep_opt *opt, const char *pat,
  21                         const char *origin, int no, enum grep_pat_token t)
  22{
  23        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
  24}
  25
  26void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
  27                     const char *origin, int no, enum grep_pat_token t)
  28{
  29        struct grep_pat *p = xcalloc(1, sizeof(*p));
  30        p->pattern = pat;
  31        p->patternlen = patlen;
  32        p->origin = origin;
  33        p->no = no;
  34        p->token = t;
  35        *opt->pattern_tail = p;
  36        opt->pattern_tail = &p->next;
  37        p->next = NULL;
  38}
  39
  40struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
  41{
  42        struct grep_pat *pat;
  43        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
  44        *ret = *opt;
  45
  46        ret->pattern_list = NULL;
  47        ret->pattern_tail = &ret->pattern_list;
  48
  49        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
  50        {
  51                if(pat->token == GREP_PATTERN_HEAD)
  52                        append_header_grep_pattern(ret, pat->field,
  53                                                   pat->pattern);
  54                else
  55                        append_grep_pat(ret, pat->pattern, pat->patternlen,
  56                                        pat->origin, pat->no, pat->token);
  57        }
  58
  59        return ret;
  60}
  61
  62static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
  63{
  64        int err;
  65
  66        p->word_regexp = opt->word_regexp;
  67        p->ignore_case = opt->ignore_case;
  68        p->fixed = opt->fixed;
  69
  70        if (p->fixed)
  71                return;
  72
  73        err = regcomp(&p->regexp, p->pattern, opt->regflags);
  74        if (err) {
  75                char errbuf[1024];
  76                char where[1024];
  77                if (p->no)
  78                        sprintf(where, "In '%s' at %d, ",
  79                                p->origin, p->no);
  80                else if (p->origin)
  81                        sprintf(where, "%s, ", p->origin);
  82                else
  83                        where[0] = 0;
  84                regerror(err, &p->regexp, errbuf, 1024);
  85                regfree(&p->regexp);
  86                die("%s'%s': %s", where, p->pattern, errbuf);
  87        }
  88}
  89
  90static struct grep_expr *compile_pattern_or(struct grep_pat **);
  91static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
  92{
  93        struct grep_pat *p;
  94        struct grep_expr *x;
  95
  96        p = *list;
  97        if (!p)
  98                return NULL;
  99        switch (p->token) {
 100        case GREP_PATTERN: /* atom */
 101        case GREP_PATTERN_HEAD:
 102        case GREP_PATTERN_BODY:
 103                x = xcalloc(1, sizeof (struct grep_expr));
 104                x->node = GREP_NODE_ATOM;
 105                x->u.atom = p;
 106                *list = p->next;
 107                return x;
 108        case GREP_OPEN_PAREN:
 109                *list = p->next;
 110                x = compile_pattern_or(list);
 111                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 112                        die("unmatched parenthesis");
 113                *list = (*list)->next;
 114                return x;
 115        default:
 116                return NULL;
 117        }
 118}
 119
 120static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 121{
 122        struct grep_pat *p;
 123        struct grep_expr *x;
 124
 125        p = *list;
 126        if (!p)
 127                return NULL;
 128        switch (p->token) {
 129        case GREP_NOT:
 130                if (!p->next)
 131                        die("--not not followed by pattern expression");
 132                *list = p->next;
 133                x = xcalloc(1, sizeof (struct grep_expr));
 134                x->node = GREP_NODE_NOT;
 135                x->u.unary = compile_pattern_not(list);
 136                if (!x->u.unary)
 137                        die("--not followed by non pattern expression");
 138                return x;
 139        default:
 140                return compile_pattern_atom(list);
 141        }
 142}
 143
 144static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 145{
 146        struct grep_pat *p;
 147        struct grep_expr *x, *y, *z;
 148
 149        x = compile_pattern_not(list);
 150        p = *list;
 151        if (p && p->token == GREP_AND) {
 152                if (!p->next)
 153                        die("--and not followed by pattern expression");
 154                *list = p->next;
 155                y = compile_pattern_and(list);
 156                if (!y)
 157                        die("--and not followed by pattern expression");
 158                z = xcalloc(1, sizeof (struct grep_expr));
 159                z->node = GREP_NODE_AND;
 160                z->u.binary.left = x;
 161                z->u.binary.right = y;
 162                return z;
 163        }
 164        return x;
 165}
 166
 167static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 168{
 169        struct grep_pat *p;
 170        struct grep_expr *x, *y, *z;
 171
 172        x = compile_pattern_and(list);
 173        p = *list;
 174        if (x && p && p->token != GREP_CLOSE_PAREN) {
 175                y = compile_pattern_or(list);
 176                if (!y)
 177                        die("not a pattern expression %s", p->pattern);
 178                z = xcalloc(1, sizeof (struct grep_expr));
 179                z->node = GREP_NODE_OR;
 180                z->u.binary.left = x;
 181                z->u.binary.right = y;
 182                return z;
 183        }
 184        return x;
 185}
 186
 187static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 188{
 189        return compile_pattern_or(list);
 190}
 191
 192static struct grep_expr *grep_true_expr(void)
 193{
 194        struct grep_expr *z = xcalloc(1, sizeof(*z));
 195        z->node = GREP_NODE_TRUE;
 196        return z;
 197}
 198
 199static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 200{
 201        struct grep_expr *z = xcalloc(1, sizeof(*z));
 202        z->node = GREP_NODE_OR;
 203        z->u.binary.left = left;
 204        z->u.binary.right = right;
 205        return z;
 206}
 207
 208static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 209{
 210        struct grep_pat *p;
 211        struct grep_expr *header_expr;
 212        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 213        enum grep_header_field fld;
 214
 215        if (!opt->header_list)
 216                return NULL;
 217        p = opt->header_list;
 218        for (p = opt->header_list; p; p = p->next) {
 219                if (p->token != GREP_PATTERN_HEAD)
 220                        die("bug: a non-header pattern in grep header list.");
 221                if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
 222                        die("bug: unknown header field %d", p->field);
 223                compile_regexp(p, opt);
 224        }
 225
 226        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 227                header_group[fld] = NULL;
 228
 229        for (p = opt->header_list; p; p = p->next) {
 230                struct grep_expr *h;
 231                struct grep_pat *pp = p;
 232
 233                h = compile_pattern_atom(&pp);
 234                if (!h || pp != p->next)
 235                        die("bug: malformed header expr");
 236                if (!header_group[p->field]) {
 237                        header_group[p->field] = h;
 238                        continue;
 239                }
 240                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 241        }
 242
 243        header_expr = NULL;
 244
 245        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 246                if (!header_group[fld])
 247                        continue;
 248                if (!header_expr)
 249                        header_expr = grep_true_expr();
 250                header_expr = grep_or_expr(header_group[fld], header_expr);
 251        }
 252        return header_expr;
 253}
 254
 255void compile_grep_patterns(struct grep_opt *opt)
 256{
 257        struct grep_pat *p;
 258        struct grep_expr *header_expr = prep_header_patterns(opt);
 259
 260        for (p = opt->pattern_list; p; p = p->next) {
 261                switch (p->token) {
 262                case GREP_PATTERN: /* atom */
 263                case GREP_PATTERN_HEAD:
 264                case GREP_PATTERN_BODY:
 265                        compile_regexp(p, opt);
 266                        break;
 267                default:
 268                        opt->extended = 1;
 269                        break;
 270                }
 271        }
 272
 273        if (opt->all_match || header_expr)
 274                opt->extended = 1;
 275        else if (!opt->extended)
 276                return;
 277
 278        p = opt->pattern_list;
 279        if (p)
 280                opt->pattern_expression = compile_pattern_expr(&p);
 281        if (p)
 282                die("incomplete pattern expression: %s", p->pattern);
 283
 284        if (!header_expr)
 285                return;
 286
 287        if (!opt->pattern_expression)
 288                opt->pattern_expression = header_expr;
 289        else
 290                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 291                                                       header_expr);
 292        opt->all_match = 1;
 293}
 294
 295static void free_pattern_expr(struct grep_expr *x)
 296{
 297        switch (x->node) {
 298        case GREP_NODE_TRUE:
 299        case GREP_NODE_ATOM:
 300                break;
 301        case GREP_NODE_NOT:
 302                free_pattern_expr(x->u.unary);
 303                break;
 304        case GREP_NODE_AND:
 305        case GREP_NODE_OR:
 306                free_pattern_expr(x->u.binary.left);
 307                free_pattern_expr(x->u.binary.right);
 308                break;
 309        }
 310        free(x);
 311}
 312
 313void free_grep_patterns(struct grep_opt *opt)
 314{
 315        struct grep_pat *p, *n;
 316
 317        for (p = opt->pattern_list; p; p = n) {
 318                n = p->next;
 319                switch (p->token) {
 320                case GREP_PATTERN: /* atom */
 321                case GREP_PATTERN_HEAD:
 322                case GREP_PATTERN_BODY:
 323                        regfree(&p->regexp);
 324                        break;
 325                default:
 326                        break;
 327                }
 328                free(p);
 329        }
 330
 331        if (!opt->extended)
 332                return;
 333        free_pattern_expr(opt->pattern_expression);
 334}
 335
 336static char *end_of_line(char *cp, unsigned long *left)
 337{
 338        unsigned long l = *left;
 339        while (l && *cp != '\n') {
 340                l--;
 341                cp++;
 342        }
 343        *left = l;
 344        return cp;
 345}
 346
 347static int word_char(char ch)
 348{
 349        return isalnum(ch) || ch == '_';
 350}
 351
 352static void output_color(struct grep_opt *opt, const void *data, size_t size,
 353                         const char *color)
 354{
 355        if (opt->color && color && color[0]) {
 356                opt->output(opt, color, strlen(color));
 357                opt->output(opt, data, size);
 358                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 359        } else
 360                opt->output(opt, data, size);
 361}
 362
 363static void output_sep(struct grep_opt *opt, char sign)
 364{
 365        if (opt->null_following_name)
 366                opt->output(opt, "\0", 1);
 367        else
 368                output_color(opt, &sign, 1, opt->color_sep);
 369}
 370
 371static void show_name(struct grep_opt *opt, const char *name)
 372{
 373        output_color(opt, name, strlen(name), opt->color_filename);
 374        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 375}
 376
 377static int fixmatch(struct grep_pat *p, char *line, char *eol,
 378                    regmatch_t *match)
 379{
 380        char *hit;
 381
 382        if (p->ignore_case) {
 383                char *s = line;
 384                do {
 385                        hit = strcasestr(s, p->pattern);
 386                        if (hit)
 387                                break;
 388                        s += strlen(s) + 1;
 389                } while (s < eol);
 390        } else
 391                hit = memmem(line, eol - line, p->pattern, p->patternlen);
 392
 393        if (!hit) {
 394                match->rm_so = match->rm_eo = -1;
 395                return REG_NOMATCH;
 396        }
 397        else {
 398                match->rm_so = hit - line;
 399                match->rm_eo = match->rm_so + p->patternlen;
 400                return 0;
 401        }
 402}
 403
 404static int regmatch(const regex_t *preg, char *line, char *eol,
 405                    regmatch_t *match, int eflags)
 406{
 407#ifdef REG_STARTEND
 408        match->rm_so = 0;
 409        match->rm_eo = eol - line;
 410        eflags |= REG_STARTEND;
 411#endif
 412        return regexec(preg, line, 1, match, eflags);
 413}
 414
 415static int patmatch(struct grep_pat *p, char *line, char *eol,
 416                    regmatch_t *match, int eflags)
 417{
 418        int hit;
 419
 420        if (p->fixed)
 421                hit = !fixmatch(p, line, eol, match);
 422        else
 423                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 424
 425        return hit;
 426}
 427
 428static int strip_timestamp(char *bol, char **eol_p)
 429{
 430        char *eol = *eol_p;
 431        int ch;
 432
 433        while (bol < --eol) {
 434                if (*eol != '>')
 435                        continue;
 436                *eol_p = ++eol;
 437                ch = *eol;
 438                *eol = '\0';
 439                return ch;
 440        }
 441        return 0;
 442}
 443
 444static struct {
 445        const char *field;
 446        size_t len;
 447} header_field[] = {
 448        { "author ", 7 },
 449        { "committer ", 10 },
 450};
 451
 452static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 453                             enum grep_context ctx,
 454                             regmatch_t *pmatch, int eflags)
 455{
 456        int hit = 0;
 457        int saved_ch = 0;
 458        const char *start = bol;
 459
 460        if ((p->token != GREP_PATTERN) &&
 461            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 462                return 0;
 463
 464        if (p->token == GREP_PATTERN_HEAD) {
 465                const char *field;
 466                size_t len;
 467                assert(p->field < ARRAY_SIZE(header_field));
 468                field = header_field[p->field].field;
 469                len = header_field[p->field].len;
 470                if (strncmp(bol, field, len))
 471                        return 0;
 472                bol += len;
 473                saved_ch = strip_timestamp(bol, &eol);
 474        }
 475
 476 again:
 477        hit = patmatch(p, bol, eol, pmatch, eflags);
 478
 479        if (hit && p->word_regexp) {
 480                if ((pmatch[0].rm_so < 0) ||
 481                    (eol - bol) < pmatch[0].rm_so ||
 482                    (pmatch[0].rm_eo < 0) ||
 483                    (eol - bol) < pmatch[0].rm_eo)
 484                        die("regexp returned nonsense");
 485
 486                /* Match beginning must be either beginning of the
 487                 * line, or at word boundary (i.e. the last char must
 488                 * not be a word char).  Similarly, match end must be
 489                 * either end of the line, or at word boundary
 490                 * (i.e. the next char must not be a word char).
 491                 */
 492                if ( ((pmatch[0].rm_so == 0) ||
 493                      !word_char(bol[pmatch[0].rm_so-1])) &&
 494                     ((pmatch[0].rm_eo == (eol-bol)) ||
 495                      !word_char(bol[pmatch[0].rm_eo])) )
 496                        ;
 497                else
 498                        hit = 0;
 499
 500                /* Words consist of at least one character. */
 501                if (pmatch->rm_so == pmatch->rm_eo)
 502                        hit = 0;
 503
 504                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 505                        /* There could be more than one match on the
 506                         * line, and the first match might not be
 507                         * strict word match.  But later ones could be!
 508                         * Forward to the next possible start, i.e. the
 509                         * next position following a non-word char.
 510                         */
 511                        bol = pmatch[0].rm_so + bol + 1;
 512                        while (word_char(bol[-1]) && bol < eol)
 513                                bol++;
 514                        eflags |= REG_NOTBOL;
 515                        if (bol < eol)
 516                                goto again;
 517                }
 518        }
 519        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 520                *eol = saved_ch;
 521        if (hit) {
 522                pmatch[0].rm_so += bol - start;
 523                pmatch[0].rm_eo += bol - start;
 524        }
 525        return hit;
 526}
 527
 528static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 529                           enum grep_context ctx, int collect_hits)
 530{
 531        int h = 0;
 532        regmatch_t match;
 533
 534        if (!x)
 535                die("Not a valid grep expression");
 536        switch (x->node) {
 537        case GREP_NODE_TRUE:
 538                h = 1;
 539                break;
 540        case GREP_NODE_ATOM:
 541                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 542                break;
 543        case GREP_NODE_NOT:
 544                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 545                break;
 546        case GREP_NODE_AND:
 547                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 548                        return 0;
 549                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 550                break;
 551        case GREP_NODE_OR:
 552                if (!collect_hits)
 553                        return (match_expr_eval(x->u.binary.left,
 554                                                bol, eol, ctx, 0) ||
 555                                match_expr_eval(x->u.binary.right,
 556                                                bol, eol, ctx, 0));
 557                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 558                x->u.binary.left->hit |= h;
 559                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 560                break;
 561        default:
 562                die("Unexpected node type (internal error) %d", x->node);
 563        }
 564        if (collect_hits)
 565                x->hit |= h;
 566        return h;
 567}
 568
 569static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 570                      enum grep_context ctx, int collect_hits)
 571{
 572        struct grep_expr *x = opt->pattern_expression;
 573        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 574}
 575
 576static int match_line(struct grep_opt *opt, char *bol, char *eol,
 577                      enum grep_context ctx, int collect_hits)
 578{
 579        struct grep_pat *p;
 580        regmatch_t match;
 581
 582        if (opt->extended)
 583                return match_expr(opt, bol, eol, ctx, collect_hits);
 584
 585        /* we do not call with collect_hits without being extended */
 586        for (p = opt->pattern_list; p; p = p->next) {
 587                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 588                        return 1;
 589        }
 590        return 0;
 591}
 592
 593static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 594                              enum grep_context ctx,
 595                              regmatch_t *pmatch, int eflags)
 596{
 597        regmatch_t match;
 598
 599        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 600                return 0;
 601        if (match.rm_so < 0 || match.rm_eo < 0)
 602                return 0;
 603        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 604                if (match.rm_so > pmatch->rm_so)
 605                        return 1;
 606                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 607                        return 1;
 608        }
 609        pmatch->rm_so = match.rm_so;
 610        pmatch->rm_eo = match.rm_eo;
 611        return 1;
 612}
 613
 614static int next_match(struct grep_opt *opt, char *bol, char *eol,
 615                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 616{
 617        struct grep_pat *p;
 618        int hit = 0;
 619
 620        pmatch->rm_so = pmatch->rm_eo = -1;
 621        if (bol < eol) {
 622                for (p = opt->pattern_list; p; p = p->next) {
 623                        switch (p->token) {
 624                        case GREP_PATTERN: /* atom */
 625                        case GREP_PATTERN_HEAD:
 626                        case GREP_PATTERN_BODY:
 627                                hit |= match_next_pattern(p, bol, eol, ctx,
 628                                                          pmatch, eflags);
 629                                break;
 630                        default:
 631                                break;
 632                        }
 633                }
 634        }
 635        return hit;
 636}
 637
 638static void show_line(struct grep_opt *opt, char *bol, char *eol,
 639                      const char *name, unsigned lno, char sign)
 640{
 641        int rest = eol - bol;
 642        char *line_color = NULL;
 643
 644        if (opt->pre_context || opt->post_context) {
 645                if (opt->last_shown == 0) {
 646                        if (opt->show_hunk_mark) {
 647                                output_color(opt, "--", 2, opt->color_sep);
 648                                opt->output(opt, "\n", 1);
 649                        }
 650                } else if (lno > opt->last_shown + 1) {
 651                        output_color(opt, "--", 2, opt->color_sep);
 652                        opt->output(opt, "\n", 1);
 653                }
 654        }
 655        opt->last_shown = lno;
 656
 657        if (opt->pathname) {
 658                output_color(opt, name, strlen(name), opt->color_filename);
 659                output_sep(opt, sign);
 660        }
 661        if (opt->linenum) {
 662                char buf[32];
 663                snprintf(buf, sizeof(buf), "%d", lno);
 664                output_color(opt, buf, strlen(buf), opt->color_lineno);
 665                output_sep(opt, sign);
 666        }
 667        if (opt->color) {
 668                regmatch_t match;
 669                enum grep_context ctx = GREP_CONTEXT_BODY;
 670                int ch = *eol;
 671                int eflags = 0;
 672
 673                if (sign == ':')
 674                        line_color = opt->color_selected;
 675                else if (sign == '-')
 676                        line_color = opt->color_context;
 677                else if (sign == '=')
 678                        line_color = opt->color_function;
 679                *eol = '\0';
 680                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 681                        if (match.rm_so == match.rm_eo)
 682                                break;
 683
 684                        output_color(opt, bol, match.rm_so, line_color);
 685                        output_color(opt, bol + match.rm_so,
 686                                     match.rm_eo - match.rm_so,
 687                                     opt->color_match);
 688                        bol += match.rm_eo;
 689                        rest -= match.rm_eo;
 690                        eflags = REG_NOTBOL;
 691                }
 692                *eol = ch;
 693        }
 694        output_color(opt, bol, rest, line_color);
 695        opt->output(opt, "\n", 1);
 696}
 697
 698static int match_funcname(struct grep_opt *opt, char *bol, char *eol)
 699{
 700        xdemitconf_t *xecfg = opt->priv;
 701        if (xecfg && xecfg->find_func) {
 702                char buf[1];
 703                return xecfg->find_func(bol, eol - bol, buf, 1,
 704                                        xecfg->find_func_priv) >= 0;
 705        }
 706
 707        if (bol == eol)
 708                return 0;
 709        if (isalpha(*bol) || *bol == '_' || *bol == '$')
 710                return 1;
 711        return 0;
 712}
 713
 714static void show_funcname_line(struct grep_opt *opt, const char *name,
 715                               char *buf, char *bol, unsigned lno)
 716{
 717        while (bol > buf) {
 718                char *eol = --bol;
 719
 720                while (bol > buf && bol[-1] != '\n')
 721                        bol--;
 722                lno--;
 723
 724                if (lno <= opt->last_shown)
 725                        break;
 726
 727                if (match_funcname(opt, bol, eol)) {
 728                        show_line(opt, bol, eol, name, lno, '=');
 729                        break;
 730                }
 731        }
 732}
 733
 734static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
 735                             char *bol, unsigned lno)
 736{
 737        unsigned cur = lno, from = 1, funcname_lno = 0;
 738        int funcname_needed = opt->funcname;
 739
 740        if (opt->pre_context < lno)
 741                from = lno - opt->pre_context;
 742        if (from <= opt->last_shown)
 743                from = opt->last_shown + 1;
 744
 745        /* Rewind. */
 746        while (bol > buf && cur > from) {
 747                char *eol = --bol;
 748
 749                while (bol > buf && bol[-1] != '\n')
 750                        bol--;
 751                cur--;
 752                if (funcname_needed && match_funcname(opt, bol, eol)) {
 753                        funcname_lno = cur;
 754                        funcname_needed = 0;
 755                }
 756        }
 757
 758        /* We need to look even further back to find a function signature. */
 759        if (opt->funcname && funcname_needed)
 760                show_funcname_line(opt, name, buf, bol, cur);
 761
 762        /* Back forward. */
 763        while (cur < lno) {
 764                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
 765
 766                while (*eol != '\n')
 767                        eol++;
 768                show_line(opt, bol, eol, name, cur, sign);
 769                bol = eol + 1;
 770                cur++;
 771        }
 772}
 773
 774static int should_lookahead(struct grep_opt *opt)
 775{
 776        struct grep_pat *p;
 777
 778        if (opt->extended)
 779                return 0; /* punt for too complex stuff */
 780        if (opt->invert)
 781                return 0;
 782        for (p = opt->pattern_list; p; p = p->next) {
 783                if (p->token != GREP_PATTERN)
 784                        return 0; /* punt for "header only" and stuff */
 785        }
 786        return 1;
 787}
 788
 789static int look_ahead(struct grep_opt *opt,
 790                      unsigned long *left_p,
 791                      unsigned *lno_p,
 792                      char **bol_p)
 793{
 794        unsigned lno = *lno_p;
 795        char *bol = *bol_p;
 796        struct grep_pat *p;
 797        char *sp, *last_bol;
 798        regoff_t earliest = -1;
 799
 800        for (p = opt->pattern_list; p; p = p->next) {
 801                int hit;
 802                regmatch_t m;
 803
 804                hit = patmatch(p, bol, bol + *left_p, &m, 0);
 805                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
 806                        continue;
 807                if (earliest < 0 || m.rm_so < earliest)
 808                        earliest = m.rm_so;
 809        }
 810
 811        if (earliest < 0) {
 812                *bol_p = bol + *left_p;
 813                *left_p = 0;
 814                return 1;
 815        }
 816        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
 817                ; /* find the beginning of the line */
 818        last_bol = sp;
 819
 820        for (sp = bol; sp < last_bol; sp++) {
 821                if (*sp == '\n')
 822                        lno++;
 823        }
 824        *left_p -= last_bol - bol;
 825        *bol_p = last_bol;
 826        *lno_p = lno;
 827        return 0;
 828}
 829
 830int grep_threads_ok(const struct grep_opt *opt)
 831{
 832        /* If this condition is true, then we may use the attribute
 833         * machinery in grep_buffer_1. The attribute code is not
 834         * thread safe, so we disable the use of threads.
 835         */
 836        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 837            !opt->name_only)
 838                return 0;
 839
 840        return 1;
 841}
 842
 843static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 844{
 845        fwrite(buf, size, 1, stdout);
 846}
 847
 848static int grep_buffer_1(struct grep_opt *opt, const char *name,
 849                         char *buf, unsigned long size, int collect_hits)
 850{
 851        char *bol = buf;
 852        unsigned long left = size;
 853        unsigned lno = 1;
 854        unsigned last_hit = 0;
 855        int binary_match_only = 0;
 856        unsigned count = 0;
 857        int try_lookahead = 0;
 858        enum grep_context ctx = GREP_CONTEXT_HEAD;
 859        xdemitconf_t xecfg;
 860
 861        if (!opt->output)
 862                opt->output = std_output;
 863
 864        if (opt->last_shown && (opt->pre_context || opt->post_context) &&
 865            opt->output == std_output)
 866                opt->show_hunk_mark = 1;
 867        opt->last_shown = 0;
 868
 869        switch (opt->binary) {
 870        case GREP_BINARY_DEFAULT:
 871                if (buffer_is_binary(buf, size))
 872                        binary_match_only = 1;
 873                break;
 874        case GREP_BINARY_NOMATCH:
 875                if (buffer_is_binary(buf, size))
 876                        return 0; /* Assume unmatch */
 877                break;
 878        case GREP_BINARY_TEXT:
 879                break;
 880        default:
 881                die("bug: unknown binary handling mode");
 882        }
 883
 884        memset(&xecfg, 0, sizeof(xecfg));
 885        if (opt->funcname && !opt->unmatch_name_only && !opt->status_only &&
 886            !opt->name_only && !binary_match_only && !collect_hits) {
 887                struct userdiff_driver *drv = userdiff_find_by_path(name);
 888                if (drv && drv->funcname.pattern) {
 889                        const struct userdiff_funcname *pe = &drv->funcname;
 890                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 891                        opt->priv = &xecfg;
 892                }
 893        }
 894        try_lookahead = should_lookahead(opt);
 895
 896        while (left) {
 897                char *eol, ch;
 898                int hit;
 899
 900                /*
 901                 * look_ahead() skips quickly to the line that possibly
 902                 * has the next hit; don't call it if we need to do
 903                 * something more than just skipping the current line
 904                 * in response to an unmatch for the current line.  E.g.
 905                 * inside a post-context window, we will show the current
 906                 * line as a context around the previous hit when it
 907                 * doesn't hit.
 908                 */
 909                if (try_lookahead
 910                    && !(last_hit
 911                         && lno <= last_hit + opt->post_context)
 912                    && look_ahead(opt, &left, &lno, &bol))
 913                        break;
 914                eol = end_of_line(bol, &left);
 915                ch = *eol;
 916                *eol = 0;
 917
 918                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
 919                        ctx = GREP_CONTEXT_BODY;
 920
 921                hit = match_line(opt, bol, eol, ctx, collect_hits);
 922                *eol = ch;
 923
 924                if (collect_hits)
 925                        goto next_line;
 926
 927                /* "grep -v -e foo -e bla" should list lines
 928                 * that do not have either, so inversion should
 929                 * be done outside.
 930                 */
 931                if (opt->invert)
 932                        hit = !hit;
 933                if (opt->unmatch_name_only) {
 934                        if (hit)
 935                                return 0;
 936                        goto next_line;
 937                }
 938                if (hit) {
 939                        count++;
 940                        if (opt->status_only)
 941                                return 1;
 942                        if (opt->name_only) {
 943                                show_name(opt, name);
 944                                return 1;
 945                        }
 946                        if (opt->count)
 947                                goto next_line;
 948                        if (binary_match_only) {
 949                                opt->output(opt, "Binary file ", 12);
 950                                output_color(opt, name, strlen(name),
 951                                             opt->color_filename);
 952                                opt->output(opt, " matches\n", 9);
 953                                return 1;
 954                        }
 955                        /* Hit at this line.  If we haven't shown the
 956                         * pre-context lines, we would need to show them.
 957                         */
 958                        if (opt->pre_context)
 959                                show_pre_context(opt, name, buf, bol, lno);
 960                        else if (opt->funcname)
 961                                show_funcname_line(opt, name, buf, bol, lno);
 962                        show_line(opt, bol, eol, name, lno, ':');
 963                        last_hit = lno;
 964                }
 965                else if (last_hit &&
 966                         lno <= last_hit + opt->post_context) {
 967                        /* If the last hit is within the post context,
 968                         * we need to show this line.
 969                         */
 970                        show_line(opt, bol, eol, name, lno, '-');
 971                }
 972
 973        next_line:
 974                bol = eol + 1;
 975                if (!left)
 976                        break;
 977                left--;
 978                lno++;
 979        }
 980
 981        if (collect_hits)
 982                return 0;
 983
 984        if (opt->status_only)
 985                return 0;
 986        if (opt->unmatch_name_only) {
 987                /* We did not see any hit, so we want to show this */
 988                show_name(opt, name);
 989                return 1;
 990        }
 991
 992        xdiff_clear_find_func(&xecfg);
 993        opt->priv = NULL;
 994
 995        /* NEEDSWORK:
 996         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 997         * which feels mostly useless but sometimes useful.  Maybe
 998         * make it another option?  For now suppress them.
 999         */
1000        if (opt->count && count) {
1001                char buf[32];
1002                output_color(opt, name, strlen(name), opt->color_filename);
1003                output_sep(opt, ':');
1004                snprintf(buf, sizeof(buf), "%u\n", count);
1005                opt->output(opt, buf, strlen(buf));
1006                return 1;
1007        }
1008        return !!last_hit;
1009}
1010
1011static void clr_hit_marker(struct grep_expr *x)
1012{
1013        /* All-hit markers are meaningful only at the very top level
1014         * OR node.
1015         */
1016        while (1) {
1017                x->hit = 0;
1018                if (x->node != GREP_NODE_OR)
1019                        return;
1020                x->u.binary.left->hit = 0;
1021                x = x->u.binary.right;
1022        }
1023}
1024
1025static int chk_hit_marker(struct grep_expr *x)
1026{
1027        /* Top level nodes have hit markers.  See if they all are hits */
1028        while (1) {
1029                if (x->node != GREP_NODE_OR)
1030                        return x->hit;
1031                if (!x->u.binary.left->hit)
1032                        return 0;
1033                x = x->u.binary.right;
1034        }
1035}
1036
1037int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
1038{
1039        /*
1040         * we do not have to do the two-pass grep when we do not check
1041         * buffer-wide "all-match".
1042         */
1043        if (!opt->all_match)
1044                return grep_buffer_1(opt, name, buf, size, 0);
1045
1046        /* Otherwise the toplevel "or" terms hit a bit differently.
1047         * We first clear hit markers from them.
1048         */
1049        clr_hit_marker(opt->pattern_expression);
1050        grep_buffer_1(opt, name, buf, size, 1);
1051
1052        if (!chk_hit_marker(opt->pattern_expression))
1053                return 0;
1054
1055        return grep_buffer_1(opt, name, buf, size, 0);
1056}