Andrew's git / gitweb.git / grep.c
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grep.con commit Merge branch 'db/maint-missing-origin' (9d5b05c)
   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        switch (p->token) {
  76        case GREP_PATTERN: /* atom */
  77        case GREP_PATTERN_HEAD:
  78        case GREP_PATTERN_BODY:
  79                x = xcalloc(1, sizeof (struct grep_expr));
  80                x->node = GREP_NODE_ATOM;
  81                x->u.atom = p;
  82                *list = p->next;
  83                return x;
  84        case GREP_OPEN_PAREN:
  85                *list = p->next;
  86                x = compile_pattern_or(list);
  87                if (!x)
  88                        return NULL;
  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        switch (p->token) {
 105        case GREP_NOT:
 106                if (!p->next)
 107                        die("--not not followed by pattern expression");
 108                *list = p->next;
 109                x = xcalloc(1, sizeof (struct grep_expr));
 110                x->node = GREP_NODE_NOT;
 111                x->u.unary = compile_pattern_not(list);
 112                if (!x->u.unary)
 113                        die("--not followed by non pattern expression");
 114                return x;
 115        default:
 116                return compile_pattern_atom(list);
 117        }
 118}
 119
 120static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 121{
 122        struct grep_pat *p;
 123        struct grep_expr *x, *y, *z;
 124
 125        x = compile_pattern_not(list);
 126        p = *list;
 127        if (p && p->token == GREP_AND) {
 128                if (!p->next)
 129                        die("--and not followed by pattern expression");
 130                *list = p->next;
 131                y = compile_pattern_and(list);
 132                if (!y)
 133                        die("--and not followed by pattern expression");
 134                z = xcalloc(1, sizeof (struct grep_expr));
 135                z->node = GREP_NODE_AND;
 136                z->u.binary.left = x;
 137                z->u.binary.right = y;
 138                return z;
 139        }
 140        return x;
 141}
 142
 143static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 144{
 145        struct grep_pat *p;
 146        struct grep_expr *x, *y, *z;
 147
 148        x = compile_pattern_and(list);
 149        p = *list;
 150        if (x && p && p->token != GREP_CLOSE_PAREN) {
 151                y = compile_pattern_or(list);
 152                if (!y)
 153                        die("not a pattern expression %s", p->pattern);
 154                z = xcalloc(1, sizeof (struct grep_expr));
 155                z->node = GREP_NODE_OR;
 156                z->u.binary.left = x;
 157                z->u.binary.right = y;
 158                return z;
 159        }
 160        return x;
 161}
 162
 163static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 164{
 165        return compile_pattern_or(list);
 166}
 167
 168void compile_grep_patterns(struct grep_opt *opt)
 169{
 170        struct grep_pat *p;
 171
 172        if (opt->all_match)
 173                opt->extended = 1;
 174
 175        for (p = opt->pattern_list; p; p = p->next) {
 176                switch (p->token) {
 177                case GREP_PATTERN: /* atom */
 178                case GREP_PATTERN_HEAD:
 179                case GREP_PATTERN_BODY:
 180                        compile_regexp(p, opt);
 181                        break;
 182                default:
 183                        opt->extended = 1;
 184                        break;
 185                }
 186        }
 187
 188        if (!opt->extended)
 189                return;
 190
 191        /* Then bundle them up in an expression.
 192         * A classic recursive descent parser would do.
 193         */
 194        p = opt->pattern_list;
 195        opt->pattern_expression = compile_pattern_expr(&p);
 196        if (p)
 197                die("incomplete pattern expression: %s", p->pattern);
 198}
 199
 200static void free_pattern_expr(struct grep_expr *x)
 201{
 202        switch (x->node) {
 203        case GREP_NODE_ATOM:
 204                break;
 205        case GREP_NODE_NOT:
 206                free_pattern_expr(x->u.unary);
 207                break;
 208        case GREP_NODE_AND:
 209        case GREP_NODE_OR:
 210                free_pattern_expr(x->u.binary.left);
 211                free_pattern_expr(x->u.binary.right);
 212                break;
 213        }
 214        free(x);
 215}
 216
 217void free_grep_patterns(struct grep_opt *opt)
 218{
 219        struct grep_pat *p, *n;
 220
 221        for (p = opt->pattern_list; p; p = n) {
 222                n = p->next;
 223                switch (p->token) {
 224                case GREP_PATTERN: /* atom */
 225                case GREP_PATTERN_HEAD:
 226                case GREP_PATTERN_BODY:
 227                        regfree(&p->regexp);
 228                        break;
 229                default:
 230                        break;
 231                }
 232                free(p);
 233        }
 234
 235        if (!opt->extended)
 236                return;
 237        free_pattern_expr(opt->pattern_expression);
 238}
 239
 240static char *end_of_line(char *cp, unsigned long *left)
 241{
 242        unsigned long l = *left;
 243        while (l && *cp != '\n') {
 244                l--;
 245                cp++;
 246        }
 247        *left = l;
 248        return cp;
 249}
 250
 251static int word_char(char ch)
 252{
 253        return isalnum(ch) || ch == '_';
 254}
 255
 256static void show_name(struct grep_opt *opt, const char *name)
 257{
 258        printf("%s%c", name, opt->null_following_name ? '\0' : '\n');
 259}
 260
 261static int fixmatch(const char *pattern, char *line, regmatch_t *match)
 262{
 263        char *hit = strstr(line, pattern);
 264        if (!hit) {
 265                match->rm_so = match->rm_eo = -1;
 266                return REG_NOMATCH;
 267        }
 268        else {
 269                match->rm_so = hit - line;
 270                match->rm_eo = match->rm_so + strlen(pattern);
 271                return 0;
 272        }
 273}
 274
 275static int strip_timestamp(char *bol, char **eol_p)
 276{
 277        char *eol = *eol_p;
 278        int ch;
 279
 280        while (bol < --eol) {
 281                if (*eol != '>')
 282                        continue;
 283                *eol_p = ++eol;
 284                ch = *eol;
 285                *eol = '\0';
 286                return ch;
 287        }
 288        return 0;
 289}
 290
 291static struct {
 292        const char *field;
 293        size_t len;
 294} header_field[] = {
 295        { "author ", 7 },
 296        { "committer ", 10 },
 297};
 298
 299static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 300                             enum grep_context ctx,
 301                             regmatch_t *pmatch, int eflags)
 302{
 303        int hit = 0;
 304        int saved_ch = 0;
 305
 306        if ((p->token != GREP_PATTERN) &&
 307            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 308                return 0;
 309
 310        if (p->token == GREP_PATTERN_HEAD) {
 311                const char *field;
 312                size_t len;
 313                assert(p->field < ARRAY_SIZE(header_field));
 314                field = header_field[p->field].field;
 315                len = header_field[p->field].len;
 316                if (strncmp(bol, field, len))
 317                        return 0;
 318                bol += len;
 319                saved_ch = strip_timestamp(bol, &eol);
 320        }
 321
 322 again:
 323        if (p->fixed)
 324                hit = !fixmatch(p->pattern, bol, pmatch);
 325        else
 326                hit = !regexec(&p->regexp, bol, 1, pmatch, eflags);
 327
 328        if (hit && p->word_regexp) {
 329                if ((pmatch[0].rm_so < 0) ||
 330                    (eol - bol) <= pmatch[0].rm_so ||
 331                    (pmatch[0].rm_eo < 0) ||
 332                    (eol - bol) < pmatch[0].rm_eo)
 333                        die("regexp returned nonsense");
 334
 335                /* Match beginning must be either beginning of the
 336                 * line, or at word boundary (i.e. the last char must
 337                 * not be a word char).  Similarly, match end must be
 338                 * either end of the line, or at word boundary
 339                 * (i.e. the next char must not be a word char).
 340                 */
 341                if ( ((pmatch[0].rm_so == 0) ||
 342                      !word_char(bol[pmatch[0].rm_so-1])) &&
 343                     ((pmatch[0].rm_eo == (eol-bol)) ||
 344                      !word_char(bol[pmatch[0].rm_eo])) )
 345                        ;
 346                else
 347                        hit = 0;
 348
 349                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 350                        /* There could be more than one match on the
 351                         * line, and the first match might not be
 352                         * strict word match.  But later ones could be!
 353                         * Forward to the next possible start, i.e. the
 354                         * next position following a non-word char.
 355                         */
 356                        bol = pmatch[0].rm_so + bol + 1;
 357                        while (word_char(bol[-1]) && bol < eol)
 358                                bol++;
 359                        if (bol < eol)
 360                                goto again;
 361                }
 362        }
 363        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 364                *eol = saved_ch;
 365        return hit;
 366}
 367
 368static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 369                           enum grep_context ctx, int collect_hits)
 370{
 371        int h = 0;
 372        regmatch_t match;
 373
 374        switch (x->node) {
 375        case GREP_NODE_ATOM:
 376                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 377                break;
 378        case GREP_NODE_NOT:
 379                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 380                break;
 381        case GREP_NODE_AND:
 382                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 383                        return 0;
 384                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 385                break;
 386        case GREP_NODE_OR:
 387                if (!collect_hits)
 388                        return (match_expr_eval(x->u.binary.left,
 389                                                bol, eol, ctx, 0) ||
 390                                match_expr_eval(x->u.binary.right,
 391                                                bol, eol, ctx, 0));
 392                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 393                x->u.binary.left->hit |= h;
 394                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
 395                break;
 396        default:
 397                die("Unexpected node type (internal error) %d", x->node);
 398        }
 399        if (collect_hits)
 400                x->hit |= h;
 401        return h;
 402}
 403
 404static int match_expr(struct grep_opt *opt, char *bol, char *eol,
 405                      enum grep_context ctx, int collect_hits)
 406{
 407        struct grep_expr *x = opt->pattern_expression;
 408        return match_expr_eval(x, bol, eol, ctx, collect_hits);
 409}
 410
 411static int match_line(struct grep_opt *opt, char *bol, char *eol,
 412                      enum grep_context ctx, int collect_hits)
 413{
 414        struct grep_pat *p;
 415        regmatch_t match;
 416
 417        if (opt->extended)
 418                return match_expr(opt, bol, eol, ctx, collect_hits);
 419
 420        /* we do not call with collect_hits without being extended */
 421        for (p = opt->pattern_list; p; p = p->next) {
 422                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
 423                        return 1;
 424        }
 425        return 0;
 426}
 427
 428static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
 429                              enum grep_context ctx,
 430                              regmatch_t *pmatch, int eflags)
 431{
 432        regmatch_t match;
 433
 434        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
 435                return 0;
 436        if (match.rm_so < 0 || match.rm_eo < 0)
 437                return 0;
 438        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
 439                if (match.rm_so > pmatch->rm_so)
 440                        return 1;
 441                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
 442                        return 1;
 443        }
 444        pmatch->rm_so = match.rm_so;
 445        pmatch->rm_eo = match.rm_eo;
 446        return 1;
 447}
 448
 449static int next_match(struct grep_opt *opt, char *bol, char *eol,
 450                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
 451{
 452        struct grep_pat *p;
 453        int hit = 0;
 454
 455        pmatch->rm_so = pmatch->rm_eo = -1;
 456        if (bol < eol) {
 457                for (p = opt->pattern_list; p; p = p->next) {
 458                        switch (p->token) {
 459                        case GREP_PATTERN: /* atom */
 460                        case GREP_PATTERN_HEAD:
 461                        case GREP_PATTERN_BODY:
 462                                hit |= match_next_pattern(p, bol, eol, ctx,
 463                                                          pmatch, eflags);
 464                                break;
 465                        default:
 466                                break;
 467                        }
 468                }
 469        }
 470        return hit;
 471}
 472
 473static void show_line(struct grep_opt *opt, char *bol, char *eol,
 474                      const char *name, unsigned lno, char sign)
 475{
 476        int rest = eol - bol;
 477
 478        if (opt->null_following_name)
 479                sign = '\0';
 480        if (opt->pathname)
 481                printf("%s%c", name, sign);
 482        if (opt->linenum)
 483                printf("%d%c", lno, sign);
 484        if (opt->color) {
 485                regmatch_t match;
 486                enum grep_context ctx = GREP_CONTEXT_BODY;
 487                int ch = *eol;
 488                int eflags = 0;
 489
 490                *eol = '\0';
 491                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
 492                        printf("%.*s%s%.*s%s",
 493                               (int)match.rm_so, bol,
 494                               opt->color_match,
 495                               (int)(match.rm_eo - match.rm_so), bol + match.rm_so,
 496                               GIT_COLOR_RESET);
 497                        bol += match.rm_eo;
 498                        rest -= match.rm_eo;
 499                        eflags = REG_NOTBOL;
 500                }
 501                *eol = ch;
 502        }
 503        printf("%.*s\n", rest, bol);
 504}
 505
 506static int grep_buffer_1(struct grep_opt *opt, const char *name,
 507                         char *buf, unsigned long size, int collect_hits)
 508{
 509        char *bol = buf;
 510        unsigned long left = size;
 511        unsigned lno = 1;
 512        struct pre_context_line {
 513                char *bol;
 514                char *eol;
 515        } *prev = NULL, *pcl;
 516        unsigned last_hit = 0;
 517        unsigned last_shown = 0;
 518        int binary_match_only = 0;
 519        const char *hunk_mark = "";
 520        unsigned count = 0;
 521        enum grep_context ctx = GREP_CONTEXT_HEAD;
 522
 523        if (buffer_is_binary(buf, size)) {
 524                switch (opt->binary) {
 525                case GREP_BINARY_DEFAULT:
 526                        binary_match_only = 1;
 527                        break;
 528                case GREP_BINARY_NOMATCH:
 529                        return 0; /* Assume unmatch */
 530                        break;
 531                default:
 532                        break;
 533                }
 534        }
 535
 536        if (opt->pre_context)
 537                prev = xcalloc(opt->pre_context, sizeof(*prev));
 538        if (opt->pre_context || opt->post_context)
 539                hunk_mark = "--\n";
 540
 541        while (left) {
 542                char *eol, ch;
 543                int hit;
 544
 545                eol = end_of_line(bol, &left);
 546                ch = *eol;
 547                *eol = 0;
 548
 549                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
 550                        ctx = GREP_CONTEXT_BODY;
 551
 552                hit = match_line(opt, bol, eol, ctx, collect_hits);
 553                *eol = ch;
 554
 555                if (collect_hits)
 556                        goto next_line;
 557
 558                /* "grep -v -e foo -e bla" should list lines
 559                 * that do not have either, so inversion should
 560                 * be done outside.
 561                 */
 562                if (opt->invert)
 563                        hit = !hit;
 564                if (opt->unmatch_name_only) {
 565                        if (hit)
 566                                return 0;
 567                        goto next_line;
 568                }
 569                if (hit) {
 570                        count++;
 571                        if (opt->status_only)
 572                                return 1;
 573                        if (binary_match_only) {
 574                                printf("Binary file %s matches\n", name);
 575                                return 1;
 576                        }
 577                        if (opt->name_only) {
 578                                show_name(opt, name);
 579                                return 1;
 580                        }
 581                        /* Hit at this line.  If we haven't shown the
 582                         * pre-context lines, we would need to show them.
 583                         * When asked to do "count", this still show
 584                         * the context which is nonsense, but the user
 585                         * deserves to get that ;-).
 586                         */
 587                        if (opt->pre_context) {
 588                                unsigned from;
 589                                if (opt->pre_context < lno)
 590                                        from = lno - opt->pre_context;
 591                                else
 592                                        from = 1;
 593                                if (from <= last_shown)
 594                                        from = last_shown + 1;
 595                                if (last_shown && from != last_shown + 1)
 596                                        fputs(hunk_mark, stdout);
 597                                while (from < lno) {
 598                                        pcl = &prev[lno-from-1];
 599                                        show_line(opt, pcl->bol, pcl->eol,
 600                                                  name, from, '-');
 601                                        from++;
 602                                }
 603                                last_shown = lno-1;
 604                        }
 605                        if (last_shown && lno != last_shown + 1)
 606                                fputs(hunk_mark, stdout);
 607                        if (!opt->count)
 608                                show_line(opt, bol, eol, name, lno, ':');
 609                        last_shown = last_hit = lno;
 610                }
 611                else if (last_hit &&
 612                         lno <= last_hit + opt->post_context) {
 613                        /* If the last hit is within the post context,
 614                         * we need to show this line.
 615                         */
 616                        if (last_shown && lno != last_shown + 1)
 617                                fputs(hunk_mark, stdout);
 618                        show_line(opt, bol, eol, name, lno, '-');
 619                        last_shown = lno;
 620                }
 621                if (opt->pre_context) {
 622                        memmove(prev+1, prev,
 623                                (opt->pre_context-1) * sizeof(*prev));
 624                        prev->bol = bol;
 625                        prev->eol = eol;
 626                }
 627
 628        next_line:
 629                bol = eol + 1;
 630                if (!left)
 631                        break;
 632                left--;
 633                lno++;
 634        }
 635
 636        free(prev);
 637        if (collect_hits)
 638                return 0;
 639
 640        if (opt->status_only)
 641                return 0;
 642        if (opt->unmatch_name_only) {
 643                /* We did not see any hit, so we want to show this */
 644                show_name(opt, name);
 645                return 1;
 646        }
 647
 648        /* NEEDSWORK:
 649         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
 650         * which feels mostly useless but sometimes useful.  Maybe
 651         * make it another option?  For now suppress them.
 652         */
 653        if (opt->count && count)
 654                printf("%s%c%u\n", name,
 655                       opt->null_following_name ? '\0' : ':', count);
 656        return !!last_hit;
 657}
 658
 659static void clr_hit_marker(struct grep_expr *x)
 660{
 661        /* All-hit markers are meaningful only at the very top level
 662         * OR node.
 663         */
 664        while (1) {
 665                x->hit = 0;
 666                if (x->node != GREP_NODE_OR)
 667                        return;
 668                x->u.binary.left->hit = 0;
 669                x = x->u.binary.right;
 670        }
 671}
 672
 673static int chk_hit_marker(struct grep_expr *x)
 674{
 675        /* Top level nodes have hit markers.  See if they all are hits */
 676        while (1) {
 677                if (x->node != GREP_NODE_OR)
 678                        return x->hit;
 679                if (!x->u.binary.left->hit)
 680                        return 0;
 681                x = x->u.binary.right;
 682        }
 683}
 684
 685int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
 686{
 687        /*
 688         * we do not have to do the two-pass grep when we do not check
 689         * buffer-wide "all-match".
 690         */
 691        if (!opt->all_match)
 692                return grep_buffer_1(opt, name, buf, size, 0);
 693
 694        /* Otherwise the toplevel "or" terms hit a bit differently.
 695         * We first clear hit markers from them.
 696         */
 697        clr_hit_marker(opt->pattern_expression);
 698        grep_buffer_1(opt, name, buf, size, 1);
 699
 700        if (!chk_hit_marker(opt->pattern_expression))
 701                return 0;
 702
 703        return grep_buffer_1(opt, name, buf, size, 0);
 704}