Andrew's git / gitweb.git / grep.c
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grep.con commit for-each-ref: Do not lookup objects when they will not be used (b7dd2d2)
   1#include "cache.h"
   2#include "grep.h"
   3#include "xdiff-interface.h"
   4
   5void append_header_grep_pattern(struct grep_opt *opt, enum grep_header_field field, const char *pat)
   6{
   7        struct grep_pat *p = xcalloc(1, sizeof(*p));
   8        p->pattern = pat;
   9        p->origin = "header";
  10        p->no = 0;
  11        p->token = GREP_PATTERN_HEAD;
  12        p->field = field;
  13        *opt->pattern_tail = p;
  14        opt->pattern_tail = &p->next;
  15        p->next = NULL;
  16}
  17
  18void append_grep_pattern(struct grep_opt *opt, const char *pat,
  19                         const char *origin, int no, enum grep_pat_token t)
  20{
  21        struct grep_pat *p = xcalloc(1, sizeof(*p));
  22        p->pattern = pat;
  23        p->origin = origin;
  24        p->no = no;
  25        p->token = t;
  26        *opt->pattern_tail = p;
  27        opt->pattern_tail = &p->next;
  28        p->next = NULL;
  29}
  30
  31static int is_fixed(const char *s)
  32{
  33        while (*s && !is_regex_special(*s))
  34                s++;
  35        return !*s;
  36}
  37
  38static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
  39{
  40        int err;
  41
  42        p->word_regexp = opt->word_regexp;
  43
  44        if (opt->fixed || is_fixed(p->pattern))
  45                p->fixed = 1;
  46        if (opt->regflags & REG_ICASE)
  47                p->fixed = 0;
  48        if (p->fixed)
  49                return;
  50
  51        err = regcomp(&p->regexp, p->pattern, opt->regflags);
  52        if (err) {
  53                char errbuf[1024];
  54                char where[1024];
  55                if (p->no)
  56                        sprintf(where, "In '%s' at %d, ",
  57                                p->origin, p->no);
  58                else if (p->origin)
  59                        sprintf(where, "%s, ", p->origin);
  60                else
  61                        where[0] = 0;
  62                regerror(err, &p->regexp, errbuf, 1024);
  63                regfree(&p->regexp);
  64                die("%s'%s': %s", where, p->pattern, errbuf);
  65        }
  66}
  67
  68static struct grep_expr *compile_pattern_or(struct grep_pat **);
  69static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
  70{
  71        struct grep_pat *p;
  72        struct grep_expr *x;
  73
  74        p = *list;
  75        if (!p)
  76                return NULL;
  77        switch (p->token) {
  78        case GREP_PATTERN: /* atom */
  79        case GREP_PATTERN_HEAD:
  80        case GREP_PATTERN_BODY:
  81                x = xcalloc(1, sizeof (struct grep_expr));
  82                x->node = GREP_NODE_ATOM;
  83                x->u.atom = p;
  84                *list = p->next;
  85                return x;
  86        case GREP_OPEN_PAREN:
  87                *list = p->next;
  88                x = compile_pattern_or(list);
  89                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
  90                        die("unmatched parenthesis");
  91                *list = (*list)->next;
  92                return x;
  93        default:
  94                return NULL;
  95        }
  96}
  97
  98static struct grep_expr *compile_pattern_not(struct grep_pat **list)
  99{
 100        struct grep_pat *p;
 101        struct grep_expr *x;
 102
 103        p = *list;
 104        if (!p)
 105                return NULL;
 106        switch (p->token) {
 107        case GREP_NOT:
 108                if (!p->next)
 109                        die("--not not followed by pattern expression");
 110                *list = p->next;
 111                x = xcalloc(1, sizeof (struct grep_expr));
 112                x->node = GREP_NODE_NOT;
 113                x->u.unary = compile_pattern_not(list);
 114                if (!x->u.unary)
 115                        die("--not followed by non pattern expression");
 116                return x;
 117        default:
 118                return compile_pattern_atom(list);
 119        }
 120}
 121
 122static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 123{
 124        struct grep_pat *p;
 125        struct grep_expr *x, *y, *z;
 126
 127        x = compile_pattern_not(list);
 128        p = *list;
 129        if (p && p->token == GREP_AND) {
 130                if (!p->next)
 131                        die("--and not followed by pattern expression");
 132                *list = p->next;
 133                y = compile_pattern_and(list);
 134                if (!y)
 135                        die("--and not followed by pattern expression");
 136                z = xcalloc(1, sizeof (struct grep_expr));
 137                z->node = GREP_NODE_AND;
 138                z->u.binary.left = x;
 139                z->u.binary.right = y;
 140                return z;
 141        }
 142        return x;
 143}
 144
 145static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 146{
 147        struct grep_pat *p;
 148        struct grep_expr *x, *y, *z;
 149
 150        x = compile_pattern_and(list);
 151        p = *list;
 152        if (x && p && p->token != GREP_CLOSE_PAREN) {
 153                y = compile_pattern_or(list);
 154                if (!y)
 155                        die("not a pattern expression %s", p->pattern);
 156                z = xcalloc(1, sizeof (struct grep_expr));
 157                z->node = GREP_NODE_OR;
 158                z->u.binary.left = x;
 159                z->u.binary.right = y;
 160                return z;
 161        }
 162        return x;
 163}
 164
 165static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 166{
 167        return compile_pattern_or(list);
 168}
 169
 170void compile_grep_patterns(struct grep_opt *opt)
 171{
 172        struct grep_pat *p;
 173
 174        if (opt->all_match)
 175                opt->extended = 1;
 176
 177        for (p = opt->pattern_list; p; p = p->next) {
 178                switch (p->token) {
 179                case GREP_PATTERN: /* atom */
 180                case GREP_PATTERN_HEAD:
 181                case GREP_PATTERN_BODY:
 182                        compile_regexp(p, opt);
 183                        break;
 184                default:
 185                        opt->extended = 1;
 186                        break;
 187                }
 188        }
 189
 190        if (!opt->extended)
 191                return;
 192
 193        /* Then bundle them up in an expression.
 194         * A classic recursive descent parser would do.
 195         */
 196        p = opt->pattern_list;
 197        if (p)
 198                opt->pattern_expression = compile_pattern_expr(&p);
 199        if (p)
 200                die("incomplete pattern expression: %s", p->pattern);
 201}
 202
 203static void free_pattern_expr(struct grep_expr *x)
 204{
 205        switch (x->node) {
 206        case GREP_NODE_ATOM:
 207                break;
 208        case GREP_NODE_NOT:
 209                free_pattern_expr(x->u.unary);
 210                break;
 211        case GREP_NODE_AND:
 212        case GREP_NODE_OR:
 213                free_pattern_expr(x->u.binary.left);
 214                free_pattern_expr(x->u.binary.right);
 215                break;
 216        }
 217        free(x);
 218}
 219
 220void free_grep_patterns(struct grep_opt *opt)
 221{
 222        struct grep_pat *p, *n;
 223
 224        for (p = opt->pattern_list; p; p = n) {
 225                n = p->next;
 226                switch (p->token) {
 227                case GREP_PATTERN: /* atom */
 228                case GREP_PATTERN_HEAD:
 229                case GREP_PATTERN_BODY:
 230                        regfree(&p->regexp);
 231                        break;
 232                default:
 233                        break;
 234                }
 235                free(p);
 236        }
 237
 238        if (!opt->extended)
 239                return;
 240        free_pattern_expr(opt->pattern_expression);
 241}
 242
 243static char *end_of_line(char *cp, unsigned long *left)
 244{
 245        unsigned long l = *left;
 246        while (l && *cp != '\n') {
 247                l--;
 248                cp++;
 249        }
 250        *left = l;
 251        return cp;
 252}
 253
 254static int word_char(char ch)
 255{
 256        return isalnum(ch) || ch == '_';
 257}
 258
 259static void show_name(struct grep_opt *opt, const char *name)
 260{
 261        printf("%s%c", name, opt->null_following_name ? '\0' : '\n');
 262}
 263
 264static int fixmatch(const char *pattern, char *line, regmatch_t *match)
 265{
 266        char *hit = strstr(line, pattern);
 267        if (!hit) {
 268                match->rm_so = match->rm_eo = -1;
 269                return REG_NOMATCH;
 270        }
 271        else {
 272                match->rm_so = hit - line;
 273                match->rm_eo = match->rm_so + strlen(pattern);
 274                return 0;
 275        }
 276}
 277
 278static int strip_timestamp(char *bol, char **eol_p)
 279{
 280        char *eol = *eol_p;
 281        int ch;
 282
 283        while (bol < --eol) {
 284                if (*eol != '>')
 285                        continue;
 286                *eol_p = ++eol;
 287                ch = *eol;
 288                *eol = '\0';
 289                return ch;
 290        }
 291        return 0;
 292}
 293
 294static struct {
 295        const char *field;
 296        size_t len;
 297} header_field[] = {
 298        { "author ", 7 },
 299        { "committer ", 10 },
 300};
 301
 302static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 303                             enum grep_context ctx,
 304                             regmatch_t *pmatch, int eflags)
 305{
 306        int hit = 0;
 307        int saved_ch = 0;
 308        const char *start = bol;
 309
 310        if ((p->token != GREP_PATTERN) &&
 311            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 312                return 0;
 313
 314        if (p->token == GREP_PATTERN_HEAD) {
 315                const char *field;
 316                size_t len;
 317                assert(p->field < ARRAY_SIZE(header_field));
 318                field = header_field[p->field].field;
 319                len = header_field[p->field].len;
 320                if (strncmp(bol, field, len))
 321                        return 0;
 322                bol += len;
 323                saved_ch = strip_timestamp(bol, &eol);
 324        }
 325
 326 again:
 327        if (p->fixed)
 328                hit = !fixmatch(p->pattern, bol, pmatch);
 329        else
 330                hit = !regexec(&p->regexp, bol, 1, pmatch, eflags);
 331
 332        if (hit && p->word_regexp) {
 333                if ((pmatch[0].rm_so < 0) ||
 334                    (eol - bol) <= pmatch[0].rm_so ||
 335                    (pmatch[0].rm_eo < 0) ||
 336                    (eol - bol) < pmatch[0].rm_eo)
 337                        die("regexp returned nonsense");
 338
 339                /* Match beginning must be either beginning of the
 340                 * line, or at word boundary (i.e. the last char must
 341                 * not be a word char).  Similarly, match end must be
 342                 * either end of the line, or at word boundary
 343                 * (i.e. the next char must not be a word char).
 344                 */
 345                if ( ((pmatch[0].rm_so == 0) ||
 346                      !word_char(bol[pmatch[0].rm_so-1])) &&
 347                     ((pmatch[0].rm_eo == (eol-bol)) ||
 348                      !word_char(bol[pmatch[0].rm_eo])) )
 349                        ;
 350                else
 351                        hit = 0;
 352
 353                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 354                        /* There could be more than one match on the
 355                         * line, and the first match might not be
 356                         * strict word match.  But later ones could be!
 357                         * Forward to the next possible start, i.e. the
 358                         * next position following a non-word char.
 359                         */
 360                        bol = pmatch[0].rm_so + bol + 1;
 361                        while (word_char(bol[-1]) && bol < eol)
 362                                bol++;
 363                        if (bol < eol)
 364                                goto again;
 365                }
 366        }
 367        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 368                *eol = saved_ch;
 369        if (hit) {
 370                pmatch[0].rm_so += bol - start;
 371                pmatch[0].rm_eo += bol - start;
 372        }
 373        return hit;
 374}
 375
 376static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 377                           enum grep_context ctx, int collect_hits)
 378{
 379        int h = 0;
 380        regmatch_t match;
 381
 382        if (!x)
 383                die("Not a valid grep expression");
 384        switch (x->node) {
 385        case GREP_NODE_ATOM:
 386                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 387                break;
 388        case GREP_NODE_NOT:
 389                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 390                break;
 391        case GREP_NODE_AND:
 392                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 393                        return 0;
 394                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 395                break;
 396        case GREP_NODE_OR:
 397                if (!collect_hits)
 398                        return (match_expr_eval(x->u.binary.left,
 399                                                bol, eol, ctx, 0) ||
 400                                match_expr_eval(x->u.binary.right,
 401                                                bol, eol, ctx, 0));
 402                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 403                x->u.binary.left->hit |= h;
 404                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 405                break;
 406        default:
 407                die("Unexpected node type (internal error) %d", x->node);
 408        }
 409        if (collect_hits)
 410                x->hit |= h;
 411        return h;
 412}
 413
 414static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 415                      enum grep_context ctx, int collect_hits)
 416{
 417        struct grep_expr *x = opt->pattern_expression;
 418        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 419}
 420
 421static int match_line(struct grep_opt *opt, char *bol, char *eol,
 422                      enum grep_context ctx, int collect_hits)
 423{
 424        struct grep_pat *p;
 425        regmatch_t match;
 426
 427        if (opt->extended)
 428                return match_expr(opt, bol, eol, ctx, collect_hits);
 429
 430        /* we do not call with collect_hits without being extended */
 431        for (p = opt->pattern_list; p; p = p->next) {
 432                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 433                        return 1;
 434        }
 435        return 0;
 436}
 437
 438static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 439                              enum grep_context ctx,
 440                              regmatch_t *pmatch, int eflags)
 441{
 442        regmatch_t match;
 443
 444        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 445                return 0;
 446        if (match.rm_so < 0 || match.rm_eo < 0)
 447                return 0;
 448        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 449                if (match.rm_so > pmatch->rm_so)
 450                        return 1;
 451                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 452                        return 1;
 453        }
 454        pmatch->rm_so = match.rm_so;
 455        pmatch->rm_eo = match.rm_eo;
 456        return 1;
 457}
 458
 459static int next_match(struct grep_opt *opt, char *bol, char *eol,
 460                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 461{
 462        struct grep_pat *p;
 463        int hit = 0;
 464
 465        pmatch->rm_so = pmatch->rm_eo = -1;
 466        if (bol < eol) {
 467                for (p = opt->pattern_list; p; p = p->next) {
 468                        switch (p->token) {
 469                        case GREP_PATTERN: /* atom */
 470                        case GREP_PATTERN_HEAD:
 471                        case GREP_PATTERN_BODY:
 472                                hit |= match_next_pattern(p, bol, eol, ctx,
 473                                                          pmatch, eflags);
 474                                break;
 475                        default:
 476                                break;
 477                        }
 478                }
 479        }
 480        return hit;
 481}
 482
 483static void show_line(struct grep_opt *opt, char *bol, char *eol,
 484                      const char *name, unsigned lno, char sign)
 485{
 486        int rest = eol - bol;
 487
 488        if (opt->null_following_name)
 489                sign = '\0';
 490        if (opt->pathname)
 491                printf("%s%c", name, sign);
 492        if (opt->linenum)
 493                printf("%d%c", lno, sign);
 494        if (opt->color) {
 495                regmatch_t match;
 496                enum grep_context ctx = GREP_CONTEXT_BODY;
 497                int ch = *eol;
 498                int eflags = 0;
 499
 500                *eol = '\0';
 501                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 502                        printf("%.*s%s%.*s%s",
 503                               (int)match.rm_so, bol,
 504                               opt->color_match,
 505                               (int)(match.rm_eo - match.rm_so), bol + match.rm_so,
 506                               GIT_COLOR_RESET);
 507                        bol += match.rm_eo;
 508                        rest -= match.rm_eo;
 509                        eflags = REG_NOTBOL;
 510                }
 511                *eol = ch;
 512        }
 513        printf("%.*s\n", rest, bol);
 514}
 515
 516static int grep_buffer_1(struct grep_opt *opt, const char *name,
 517                         char *buf, unsigned long size, int collect_hits)
 518{
 519        char *bol = buf;
 520        unsigned long left = size;
 521        unsigned lno = 1;
 522        struct pre_context_line {
 523                char *bol;
 524                char *eol;
 525        } *prev = NULL, *pcl;
 526        unsigned last_hit = 0;
 527        unsigned last_shown = 0;
 528        int binary_match_only = 0;
 529        const char *hunk_mark = "";
 530        unsigned count = 0;
 531        enum grep_context ctx = GREP_CONTEXT_HEAD;
 532
 533        if (buffer_is_binary(buf, size)) {
 534                switch (opt->binary) {
 535                case GREP_BINARY_DEFAULT:
 536                        binary_match_only = 1;
 537                        break;
 538                case GREP_BINARY_NOMATCH:
 539                        return 0; /* Assume unmatch */
 540                        break;
 541                default:
 542                        break;
 543                }
 544        }
 545
 546        if (opt->pre_context)
 547                prev = xcalloc(opt->pre_context, sizeof(*prev));
 548        if (opt->pre_context || opt->post_context)
 549                hunk_mark = "--\n";
 550
 551        while (left) {
 552                char *eol, ch;
 553                int hit;
 554
 555                eol = end_of_line(bol, &left);
 556                ch = *eol;
 557                *eol = 0;
 558
 559                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
 560                        ctx = GREP_CONTEXT_BODY;
 561
 562                hit = match_line(opt, bol, eol, ctx, collect_hits);
 563                *eol = ch;
 564
 565                if (collect_hits)
 566                        goto next_line;
 567
 568                /* "grep -v -e foo -e bla" should list lines
 569                 * that do not have either, so inversion should
 570                 * be done outside.
 571                 */
 572                if (opt->invert)
 573                        hit = !hit;
 574                if (opt->unmatch_name_only) {
 575                        if (hit)
 576                                return 0;
 577                        goto next_line;
 578                }
 579                if (hit) {
 580                        count++;
 581                        if (opt->status_only)
 582                                return 1;
 583                        if (binary_match_only) {
 584                                printf("Binary file %s matches\n", name);
 585                                return 1;
 586                        }
 587                        if (opt->name_only) {
 588                                show_name(opt, name);
 589                                return 1;
 590                        }
 591                        /* Hit at this line.  If we haven't shown the
 592                         * pre-context lines, we would need to show them.
 593                         * When asked to do "count", this still show
 594                         * the context which is nonsense, but the user
 595                         * deserves to get that ;-).
 596                         */
 597                        if (opt->pre_context) {
 598                                unsigned from;
 599                                if (opt->pre_context < lno)
 600                                        from = lno - opt->pre_context;
 601                                else
 602                                        from = 1;
 603                                if (from <= last_shown)
 604                                        from = last_shown + 1;
 605                                if (last_shown && from != last_shown + 1)
 606                                        fputs(hunk_mark, stdout);
 607                                while (from < lno) {
 608                                        pcl = &prev[lno-from-1];
 609                                        show_line(opt, pcl->bol, pcl->eol,
 610                                                  name, from, '-');
 611                                        from++;
 612                                }
 613                                last_shown = lno-1;
 614                        }
 615                        if (last_shown && lno != last_shown + 1)
 616                                fputs(hunk_mark, stdout);
 617                        if (!opt->count)
 618                                show_line(opt, bol, eol, name, lno, ':');
 619                        last_shown = last_hit = lno;
 620                }
 621                else if (last_hit &&
 622                         lno <= last_hit + opt->post_context) {
 623                        /* If the last hit is within the post context,
 624                         * we need to show this line.
 625                         */
 626                        if (last_shown && lno != last_shown + 1)
 627                                fputs(hunk_mark, stdout);
 628                        show_line(opt, bol, eol, name, lno, '-');
 629                        last_shown = lno;
 630                }
 631                if (opt->pre_context) {
 632                        memmove(prev+1, prev,
 633                                (opt->pre_context-1) * sizeof(*prev));
 634                        prev->bol = bol;
 635                        prev->eol = eol;
 636                }
 637
 638        next_line:
 639                bol = eol + 1;
 640                if (!left)
 641                        break;
 642                left--;
 643                lno++;
 644        }
 645
 646        free(prev);
 647        if (collect_hits)
 648                return 0;
 649
 650        if (opt->status_only)
 651                return 0;
 652        if (opt->unmatch_name_only) {
 653                /* We did not see any hit, so we want to show this */
 654                show_name(opt, name);
 655                return 1;
 656        }
 657
 658        /* NEEDSWORK:
 659         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 660         * which feels mostly useless but sometimes useful.  Maybe
 661         * make it another option?  For now suppress them.
 662         */
 663        if (opt->count && count)
 664                printf("%s%c%u\n", name,
 665                       opt->null_following_name ? '\0' : ':', count);
 666        return !!last_hit;
 667}
 668
 669static void clr_hit_marker(struct grep_expr *x)
 670{
 671        /* All-hit markers are meaningful only at the very top level
 672         * OR node.
 673         */
 674        while (1) {
 675                x->hit = 0;
 676                if (x->node != GREP_NODE_OR)
 677                        return;
 678                x->u.binary.left->hit = 0;
 679                x = x->u.binary.right;
 680        }
 681}
 682
 683static int chk_hit_marker(struct grep_expr *x)
 684{
 685        /* Top level nodes have hit markers.  See if they all are hits */
 686        while (1) {
 687                if (x->node != GREP_NODE_OR)
 688                        return x->hit;
 689                if (!x->u.binary.left->hit)
 690                        return 0;
 691                x = x->u.binary.right;
 692        }
 693}
 694
 695int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
 696{
 697        /*
 698         * we do not have to do the two-pass grep when we do not check
 699         * buffer-wide "all-match".
 700         */
 701        if (!opt->all_match)
 702                return grep_buffer_1(opt, name, buf, size, 0);
 703
 704        /* Otherwise the toplevel "or" terms hit a bit differently.
 705         * We first clear hit markers from them.
 706         */
 707        clr_hit_marker(opt->pattern_expression);
 708        grep_buffer_1(opt, name, buf, size, 1);
 709
 710        if (!chk_hit_marker(opt->pattern_expression))
 711                return 0;
 712
 713        return grep_buffer_1(opt, name, buf, size, 0);
 714}