Andrew's git / gitweb.git / grep.c
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grep.con commit test-lib.sh: convert $TEST_DIRECTORY to an absolute path (85176d7)
   1#include "cache.h"
   2#include "grep.h"
   3#include "userdiff.h"
   4#include "xdiff-interface.h"
   5#include "diff.h"
   6#include "diffcore.h"
   7
   8static int grep_source_load(struct grep_source *gs);
   9static int grep_source_is_binary(struct grep_source *gs);
  10
  11static struct grep_opt grep_defaults;
  12
  13/*
  14 * Initialize the grep_defaults template with hardcoded defaults.
  15 * We could let the compiler do this, but without C99 initializers
  16 * the code gets unwieldy and unreadable, so...
  17 */
  18void init_grep_defaults(void)
  19{
  20        struct grep_opt *opt = &grep_defaults;
  21        static int run_once;
  22
  23        if (run_once)
  24                return;
  25        run_once++;
  26
  27        memset(opt, 0, sizeof(*opt));
  28        opt->relative = 1;
  29        opt->pathname = 1;
  30        opt->regflags = REG_NEWLINE;
  31        opt->max_depth = -1;
  32        opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  33        opt->extended_regexp_option = 0;
  34        strcpy(opt->color_context, "");
  35        strcpy(opt->color_filename, "");
  36        strcpy(opt->color_function, "");
  37        strcpy(opt->color_lineno, "");
  38        strcpy(opt->color_match, GIT_COLOR_BOLD_RED);
  39        strcpy(opt->color_selected, "");
  40        strcpy(opt->color_sep, GIT_COLOR_CYAN);
  41        opt->color = -1;
  42}
  43
  44static int parse_pattern_type_arg(const char *opt, const char *arg)
  45{
  46        if (!strcmp(arg, "default"))
  47                return GREP_PATTERN_TYPE_UNSPECIFIED;
  48        else if (!strcmp(arg, "basic"))
  49                return GREP_PATTERN_TYPE_BRE;
  50        else if (!strcmp(arg, "extended"))
  51                return GREP_PATTERN_TYPE_ERE;
  52        else if (!strcmp(arg, "fixed"))
  53                return GREP_PATTERN_TYPE_FIXED;
  54        else if (!strcmp(arg, "perl"))
  55                return GREP_PATTERN_TYPE_PCRE;
  56        die("bad %s argument: %s", opt, arg);
  57}
  58
  59/*
  60 * Read the configuration file once and store it in
  61 * the grep_defaults template.
  62 */
  63int grep_config(const char *var, const char *value, void *cb)
  64{
  65        struct grep_opt *opt = &grep_defaults;
  66        char *color = NULL;
  67
  68        if (userdiff_config(var, value) < 0)
  69                return -1;
  70
  71        if (!strcmp(var, "grep.extendedregexp")) {
  72                if (git_config_bool(var, value))
  73                        opt->extended_regexp_option = 1;
  74                else
  75                        opt->extended_regexp_option = 0;
  76                return 0;
  77        }
  78
  79        if (!strcmp(var, "grep.patterntype")) {
  80                opt->pattern_type_option = parse_pattern_type_arg(var, value);
  81                return 0;
  82        }
  83
  84        if (!strcmp(var, "grep.linenumber")) {
  85                opt->linenum = git_config_bool(var, value);
  86                return 0;
  87        }
  88
  89        if (!strcmp(var, "color.grep"))
  90                opt->color = git_config_colorbool(var, value);
  91        else if (!strcmp(var, "color.grep.context"))
  92                color = opt->color_context;
  93        else if (!strcmp(var, "color.grep.filename"))
  94                color = opt->color_filename;
  95        else if (!strcmp(var, "color.grep.function"))
  96                color = opt->color_function;
  97        else if (!strcmp(var, "color.grep.linenumber"))
  98                color = opt->color_lineno;
  99        else if (!strcmp(var, "color.grep.match"))
 100                color = opt->color_match;
 101        else if (!strcmp(var, "color.grep.selected"))
 102                color = opt->color_selected;
 103        else if (!strcmp(var, "color.grep.separator"))
 104                color = opt->color_sep;
 105
 106        if (color) {
 107                if (!value)
 108                        return config_error_nonbool(var);
 109                color_parse(value, var, color);
 110        }
 111        return 0;
 112}
 113
 114/*
 115 * Initialize one instance of grep_opt and copy the
 116 * default values from the template we read the configuration
 117 * information in an earlier call to git_config(grep_config).
 118 */
 119void grep_init(struct grep_opt *opt, const char *prefix)
 120{
 121        struct grep_opt *def = &grep_defaults;
 122
 123        memset(opt, 0, sizeof(*opt));
 124        opt->prefix = prefix;
 125        opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 126        opt->pattern_tail = &opt->pattern_list;
 127        opt->header_tail = &opt->header_list;
 128
 129        opt->color = def->color;
 130        opt->extended_regexp_option = def->extended_regexp_option;
 131        opt->pattern_type_option = def->pattern_type_option;
 132        opt->linenum = def->linenum;
 133        opt->max_depth = def->max_depth;
 134        opt->pathname = def->pathname;
 135        opt->regflags = def->regflags;
 136        opt->relative = def->relative;
 137
 138        strcpy(opt->color_context, def->color_context);
 139        strcpy(opt->color_filename, def->color_filename);
 140        strcpy(opt->color_function, def->color_function);
 141        strcpy(opt->color_lineno, def->color_lineno);
 142        strcpy(opt->color_match, def->color_match);
 143        strcpy(opt->color_selected, def->color_selected);
 144        strcpy(opt->color_sep, def->color_sep);
 145}
 146
 147void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 148{
 149        if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 150                grep_set_pattern_type_option(pattern_type, opt);
 151        else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 152                grep_set_pattern_type_option(opt->pattern_type_option, opt);
 153        else if (opt->extended_regexp_option)
 154                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 155}
 156
 157void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 158{
 159        switch (pattern_type) {
 160        case GREP_PATTERN_TYPE_UNSPECIFIED:
 161                /* fall through */
 162
 163        case GREP_PATTERN_TYPE_BRE:
 164                opt->fixed = 0;
 165                opt->pcre = 0;
 166                opt->regflags &= ~REG_EXTENDED;
 167                break;
 168
 169        case GREP_PATTERN_TYPE_ERE:
 170                opt->fixed = 0;
 171                opt->pcre = 0;
 172                opt->regflags |= REG_EXTENDED;
 173                break;
 174
 175        case GREP_PATTERN_TYPE_FIXED:
 176                opt->fixed = 1;
 177                opt->pcre = 0;
 178                opt->regflags &= ~REG_EXTENDED;
 179                break;
 180
 181        case GREP_PATTERN_TYPE_PCRE:
 182                opt->fixed = 0;
 183                opt->pcre = 1;
 184                opt->regflags &= ~REG_EXTENDED;
 185                break;
 186        }
 187}
 188
 189static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 190                                        const char *origin, int no,
 191                                        enum grep_pat_token t,
 192                                        enum grep_header_field field)
 193{
 194        struct grep_pat *p = xcalloc(1, sizeof(*p));
 195        p->pattern = xmemdupz(pat, patlen);
 196        p->patternlen = patlen;
 197        p->origin = origin;
 198        p->no = no;
 199        p->token = t;
 200        p->field = field;
 201        return p;
 202}
 203
 204static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 205{
 206        **tail = p;
 207        *tail = &p->next;
 208        p->next = NULL;
 209
 210        switch (p->token) {
 211        case GREP_PATTERN: /* atom */
 212        case GREP_PATTERN_HEAD:
 213        case GREP_PATTERN_BODY:
 214                for (;;) {
 215                        struct grep_pat *new_pat;
 216                        size_t len = 0;
 217                        char *cp = p->pattern + p->patternlen, *nl = NULL;
 218                        while (++len <= p->patternlen) {
 219                                if (*(--cp) == '\n') {
 220                                        nl = cp;
 221                                        break;
 222                                }
 223                        }
 224                        if (!nl)
 225                                break;
 226                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 227                                                  p->no, p->token, p->field);
 228                        new_pat->next = p->next;
 229                        if (!p->next)
 230                                *tail = &new_pat->next;
 231                        p->next = new_pat;
 232                        *nl = '\0';
 233                        p->patternlen -= len;
 234                }
 235                break;
 236        default:
 237                break;
 238        }
 239}
 240
 241void append_header_grep_pattern(struct grep_opt *opt,
 242                                enum grep_header_field field, const char *pat)
 243{
 244        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 245                                             GREP_PATTERN_HEAD, field);
 246        if (field == GREP_HEADER_REFLOG)
 247                opt->use_reflog_filter = 1;
 248        do_append_grep_pat(&opt->header_tail, p);
 249}
 250
 251void append_grep_pattern(struct grep_opt *opt, const char *pat,
 252                         const char *origin, int no, enum grep_pat_token t)
 253{
 254        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 255}
 256
 257void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 258                     const char *origin, int no, enum grep_pat_token t)
 259{
 260        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 261        do_append_grep_pat(&opt->pattern_tail, p);
 262}
 263
 264struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 265{
 266        struct grep_pat *pat;
 267        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 268        *ret = *opt;
 269
 270        ret->pattern_list = NULL;
 271        ret->pattern_tail = &ret->pattern_list;
 272
 273        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 274        {
 275                if(pat->token == GREP_PATTERN_HEAD)
 276                        append_header_grep_pattern(ret, pat->field,
 277                                                   pat->pattern);
 278                else
 279                        append_grep_pat(ret, pat->pattern, pat->patternlen,
 280                                        pat->origin, pat->no, pat->token);
 281        }
 282
 283        return ret;
 284}
 285
 286static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 287                const char *error)
 288{
 289        char where[1024];
 290
 291        if (p->no)
 292                sprintf(where, "In '%s' at %d, ", p->origin, p->no);
 293        else if (p->origin)
 294                sprintf(where, "%s, ", p->origin);
 295        else
 296                where[0] = 0;
 297
 298        die("%s'%s': %s", where, p->pattern, error);
 299}
 300
 301#ifdef USE_LIBPCRE
 302static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 303{
 304        const char *error;
 305        int erroffset;
 306        int options = PCRE_MULTILINE;
 307
 308        if (opt->ignore_case)
 309                options |= PCRE_CASELESS;
 310
 311        p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 312                        NULL);
 313        if (!p->pcre_regexp)
 314                compile_regexp_failed(p, error);
 315
 316        p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 317        if (!p->pcre_extra_info && error)
 318                die("%s", error);
 319}
 320
 321static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 322                regmatch_t *match, int eflags)
 323{
 324        int ovector[30], ret, flags = 0;
 325
 326        if (eflags & REG_NOTBOL)
 327                flags |= PCRE_NOTBOL;
 328
 329        ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 330                        0, flags, ovector, ARRAY_SIZE(ovector));
 331        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 332                die("pcre_exec failed with error code %d", ret);
 333        if (ret > 0) {
 334                ret = 0;
 335                match->rm_so = ovector[0];
 336                match->rm_eo = ovector[1];
 337        }
 338
 339        return ret;
 340}
 341
 342static void free_pcre_regexp(struct grep_pat *p)
 343{
 344        pcre_free(p->pcre_regexp);
 345        pcre_free(p->pcre_extra_info);
 346}
 347#else /* !USE_LIBPCRE */
 348static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 349{
 350        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 351}
 352
 353static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 354                regmatch_t *match, int eflags)
 355{
 356        return 1;
 357}
 358
 359static void free_pcre_regexp(struct grep_pat *p)
 360{
 361}
 362#endif /* !USE_LIBPCRE */
 363
 364static int is_fixed(const char *s, size_t len)
 365{
 366        size_t i;
 367
 368        /* regcomp cannot accept patterns with NULs so we
 369         * consider any pattern containing a NUL fixed.
 370         */
 371        if (memchr(s, 0, len))
 372                return 1;
 373
 374        for (i = 0; i < len; i++) {
 375                if (is_regex_special(s[i]))
 376                        return 0;
 377        }
 378
 379        return 1;
 380}
 381
 382static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 383{
 384        int err;
 385
 386        p->word_regexp = opt->word_regexp;
 387        p->ignore_case = opt->ignore_case;
 388
 389        if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 390                p->fixed = 1;
 391        else
 392                p->fixed = 0;
 393
 394        if (p->fixed) {
 395                if (opt->regflags & REG_ICASE || p->ignore_case)
 396                        p->kws = kwsalloc(tolower_trans_tbl);
 397                else
 398                        p->kws = kwsalloc(NULL);
 399                kwsincr(p->kws, p->pattern, p->patternlen);
 400                kwsprep(p->kws);
 401                return;
 402        }
 403
 404        if (opt->pcre) {
 405                compile_pcre_regexp(p, opt);
 406                return;
 407        }
 408
 409        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 410        if (err) {
 411                char errbuf[1024];
 412                regerror(err, &p->regexp, errbuf, 1024);
 413                regfree(&p->regexp);
 414                compile_regexp_failed(p, errbuf);
 415        }
 416}
 417
 418static struct grep_expr *compile_pattern_or(struct grep_pat **);
 419static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 420{
 421        struct grep_pat *p;
 422        struct grep_expr *x;
 423
 424        p = *list;
 425        if (!p)
 426                return NULL;
 427        switch (p->token) {
 428        case GREP_PATTERN: /* atom */
 429        case GREP_PATTERN_HEAD:
 430        case GREP_PATTERN_BODY:
 431                x = xcalloc(1, sizeof (struct grep_expr));
 432                x->node = GREP_NODE_ATOM;
 433                x->u.atom = p;
 434                *list = p->next;
 435                return x;
 436        case GREP_OPEN_PAREN:
 437                *list = p->next;
 438                x = compile_pattern_or(list);
 439                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 440                        die("unmatched parenthesis");
 441                *list = (*list)->next;
 442                return x;
 443        default:
 444                return NULL;
 445        }
 446}
 447
 448static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 449{
 450        struct grep_pat *p;
 451        struct grep_expr *x;
 452
 453        p = *list;
 454        if (!p)
 455                return NULL;
 456        switch (p->token) {
 457        case GREP_NOT:
 458                if (!p->next)
 459                        die("--not not followed by pattern expression");
 460                *list = p->next;
 461                x = xcalloc(1, sizeof (struct grep_expr));
 462                x->node = GREP_NODE_NOT;
 463                x->u.unary = compile_pattern_not(list);
 464                if (!x->u.unary)
 465                        die("--not followed by non pattern expression");
 466                return x;
 467        default:
 468                return compile_pattern_atom(list);
 469        }
 470}
 471
 472static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 473{
 474        struct grep_pat *p;
 475        struct grep_expr *x, *y, *z;
 476
 477        x = compile_pattern_not(list);
 478        p = *list;
 479        if (p && p->token == GREP_AND) {
 480                if (!p->next)
 481                        die("--and not followed by pattern expression");
 482                *list = p->next;
 483                y = compile_pattern_and(list);
 484                if (!y)
 485                        die("--and not followed by pattern expression");
 486                z = xcalloc(1, sizeof (struct grep_expr));
 487                z->node = GREP_NODE_AND;
 488                z->u.binary.left = x;
 489                z->u.binary.right = y;
 490                return z;
 491        }
 492        return x;
 493}
 494
 495static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 496{
 497        struct grep_pat *p;
 498        struct grep_expr *x, *y, *z;
 499
 500        x = compile_pattern_and(list);
 501        p = *list;
 502        if (x && p && p->token != GREP_CLOSE_PAREN) {
 503                y = compile_pattern_or(list);
 504                if (!y)
 505                        die("not a pattern expression %s", p->pattern);
 506                z = xcalloc(1, sizeof (struct grep_expr));
 507                z->node = GREP_NODE_OR;
 508                z->u.binary.left = x;
 509                z->u.binary.right = y;
 510                return z;
 511        }
 512        return x;
 513}
 514
 515static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 516{
 517        return compile_pattern_or(list);
 518}
 519
 520static void indent(int in)
 521{
 522        while (in-- > 0)
 523                fputc(' ', stderr);
 524}
 525
 526static void dump_grep_pat(struct grep_pat *p)
 527{
 528        switch (p->token) {
 529        case GREP_AND: fprintf(stderr, "*and*"); break;
 530        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 531        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 532        case GREP_NOT: fprintf(stderr, "*not*"); break;
 533        case GREP_OR: fprintf(stderr, "*or*"); break;
 534
 535        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 536        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 537        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 538        }
 539
 540        switch (p->token) {
 541        default: break;
 542        case GREP_PATTERN_HEAD:
 543                fprintf(stderr, "<head %d>", p->field); break;
 544        case GREP_PATTERN_BODY:
 545                fprintf(stderr, "<body>"); break;
 546        }
 547        switch (p->token) {
 548        default: break;
 549        case GREP_PATTERN_HEAD:
 550        case GREP_PATTERN_BODY:
 551        case GREP_PATTERN:
 552                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 553                break;
 554        }
 555        fputc('\n', stderr);
 556}
 557
 558static void dump_grep_expression_1(struct grep_expr *x, int in)
 559{
 560        indent(in);
 561        switch (x->node) {
 562        case GREP_NODE_TRUE:
 563                fprintf(stderr, "true\n");
 564                break;
 565        case GREP_NODE_ATOM:
 566                dump_grep_pat(x->u.atom);
 567                break;
 568        case GREP_NODE_NOT:
 569                fprintf(stderr, "(not\n");
 570                dump_grep_expression_1(x->u.unary, in+1);
 571                indent(in);
 572                fprintf(stderr, ")\n");
 573                break;
 574        case GREP_NODE_AND:
 575                fprintf(stderr, "(and\n");
 576                dump_grep_expression_1(x->u.binary.left, in+1);
 577                dump_grep_expression_1(x->u.binary.right, in+1);
 578                indent(in);
 579                fprintf(stderr, ")\n");
 580                break;
 581        case GREP_NODE_OR:
 582                fprintf(stderr, "(or\n");
 583                dump_grep_expression_1(x->u.binary.left, in+1);
 584                dump_grep_expression_1(x->u.binary.right, in+1);
 585                indent(in);
 586                fprintf(stderr, ")\n");
 587                break;
 588        }
 589}
 590
 591static void dump_grep_expression(struct grep_opt *opt)
 592{
 593        struct grep_expr *x = opt->pattern_expression;
 594
 595        if (opt->all_match)
 596                fprintf(stderr, "[all-match]\n");
 597        dump_grep_expression_1(x, 0);
 598        fflush(NULL);
 599}
 600
 601static struct grep_expr *grep_true_expr(void)
 602{
 603        struct grep_expr *z = xcalloc(1, sizeof(*z));
 604        z->node = GREP_NODE_TRUE;
 605        return z;
 606}
 607
 608static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 609{
 610        struct grep_expr *z = xcalloc(1, sizeof(*z));
 611        z->node = GREP_NODE_OR;
 612        z->u.binary.left = left;
 613        z->u.binary.right = right;
 614        return z;
 615}
 616
 617static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 618{
 619        struct grep_pat *p;
 620        struct grep_expr *header_expr;
 621        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 622        enum grep_header_field fld;
 623
 624        if (!opt->header_list)
 625                return NULL;
 626
 627        for (p = opt->header_list; p; p = p->next) {
 628                if (p->token != GREP_PATTERN_HEAD)
 629                        die("bug: a non-header pattern in grep header list.");
 630                if (p->field < GREP_HEADER_FIELD_MIN ||
 631                    GREP_HEADER_FIELD_MAX <= p->field)
 632                        die("bug: unknown header field %d", p->field);
 633                compile_regexp(p, opt);
 634        }
 635
 636        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 637                header_group[fld] = NULL;
 638
 639        for (p = opt->header_list; p; p = p->next) {
 640                struct grep_expr *h;
 641                struct grep_pat *pp = p;
 642
 643                h = compile_pattern_atom(&pp);
 644                if (!h || pp != p->next)
 645                        die("bug: malformed header expr");
 646                if (!header_group[p->field]) {
 647                        header_group[p->field] = h;
 648                        continue;
 649                }
 650                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 651        }
 652
 653        header_expr = NULL;
 654
 655        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 656                if (!header_group[fld])
 657                        continue;
 658                if (!header_expr)
 659                        header_expr = grep_true_expr();
 660                header_expr = grep_or_expr(header_group[fld], header_expr);
 661        }
 662        return header_expr;
 663}
 664
 665static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 666{
 667        struct grep_expr *z = x;
 668
 669        while (x) {
 670                assert(x->node == GREP_NODE_OR);
 671                if (x->u.binary.right &&
 672                    x->u.binary.right->node == GREP_NODE_TRUE) {
 673                        x->u.binary.right = y;
 674                        break;
 675                }
 676                x = x->u.binary.right;
 677        }
 678        return z;
 679}
 680
 681static void compile_grep_patterns_real(struct grep_opt *opt)
 682{
 683        struct grep_pat *p;
 684        struct grep_expr *header_expr = prep_header_patterns(opt);
 685
 686        for (p = opt->pattern_list; p; p = p->next) {
 687                switch (p->token) {
 688                case GREP_PATTERN: /* atom */
 689                case GREP_PATTERN_HEAD:
 690                case GREP_PATTERN_BODY:
 691                        compile_regexp(p, opt);
 692                        break;
 693                default:
 694                        opt->extended = 1;
 695                        break;
 696                }
 697        }
 698
 699        if (opt->all_match || header_expr)
 700                opt->extended = 1;
 701        else if (!opt->extended && !opt->debug)
 702                return;
 703
 704        p = opt->pattern_list;
 705        if (p)
 706                opt->pattern_expression = compile_pattern_expr(&p);
 707        if (p)
 708                die("incomplete pattern expression: %s", p->pattern);
 709
 710        if (!header_expr)
 711                return;
 712
 713        if (!opt->pattern_expression)
 714                opt->pattern_expression = header_expr;
 715        else if (opt->all_match)
 716                opt->pattern_expression = grep_splice_or(header_expr,
 717                                                         opt->pattern_expression);
 718        else
 719                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 720                                                       header_expr);
 721        opt->all_match = 1;
 722}
 723
 724void compile_grep_patterns(struct grep_opt *opt)
 725{
 726        compile_grep_patterns_real(opt);
 727        if (opt->debug)
 728                dump_grep_expression(opt);
 729}
 730
 731static void free_pattern_expr(struct grep_expr *x)
 732{
 733        switch (x->node) {
 734        case GREP_NODE_TRUE:
 735        case GREP_NODE_ATOM:
 736                break;
 737        case GREP_NODE_NOT:
 738                free_pattern_expr(x->u.unary);
 739                break;
 740        case GREP_NODE_AND:
 741        case GREP_NODE_OR:
 742                free_pattern_expr(x->u.binary.left);
 743                free_pattern_expr(x->u.binary.right);
 744                break;
 745        }
 746        free(x);
 747}
 748
 749void free_grep_patterns(struct grep_opt *opt)
 750{
 751        struct grep_pat *p, *n;
 752
 753        for (p = opt->pattern_list; p; p = n) {
 754                n = p->next;
 755                switch (p->token) {
 756                case GREP_PATTERN: /* atom */
 757                case GREP_PATTERN_HEAD:
 758                case GREP_PATTERN_BODY:
 759                        if (p->kws)
 760                                kwsfree(p->kws);
 761                        else if (p->pcre_regexp)
 762                                free_pcre_regexp(p);
 763                        else
 764                                regfree(&p->regexp);
 765                        free(p->pattern);
 766                        break;
 767                default:
 768                        break;
 769                }
 770                free(p);
 771        }
 772
 773        if (!opt->extended)
 774                return;
 775        free_pattern_expr(opt->pattern_expression);
 776}
 777
 778static char *end_of_line(char *cp, unsigned long *left)
 779{
 780        unsigned long l = *left;
 781        while (l && *cp != '\n') {
 782                l--;
 783                cp++;
 784        }
 785        *left = l;
 786        return cp;
 787}
 788
 789static int word_char(char ch)
 790{
 791        return isalnum(ch) || ch == '_';
 792}
 793
 794static void output_color(struct grep_opt *opt, const void *data, size_t size,
 795                         const char *color)
 796{
 797        if (want_color(opt->color) && color && color[0]) {
 798                opt->output(opt, color, strlen(color));
 799                opt->output(opt, data, size);
 800                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 801        } else
 802                opt->output(opt, data, size);
 803}
 804
 805static void output_sep(struct grep_opt *opt, char sign)
 806{
 807        if (opt->null_following_name)
 808                opt->output(opt, "\0", 1);
 809        else
 810                output_color(opt, &sign, 1, opt->color_sep);
 811}
 812
 813static void show_name(struct grep_opt *opt, const char *name)
 814{
 815        output_color(opt, name, strlen(name), opt->color_filename);
 816        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 817}
 818
 819static int fixmatch(struct grep_pat *p, char *line, char *eol,
 820                    regmatch_t *match)
 821{
 822        struct kwsmatch kwsm;
 823        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 824        if (offset == -1) {
 825                match->rm_so = match->rm_eo = -1;
 826                return REG_NOMATCH;
 827        } else {
 828                match->rm_so = offset;
 829                match->rm_eo = match->rm_so + kwsm.size[0];
 830                return 0;
 831        }
 832}
 833
 834static int regmatch(const regex_t *preg, char *line, char *eol,
 835                    regmatch_t *match, int eflags)
 836{
 837#ifdef REG_STARTEND
 838        match->rm_so = 0;
 839        match->rm_eo = eol - line;
 840        eflags |= REG_STARTEND;
 841#endif
 842        return regexec(preg, line, 1, match, eflags);
 843}
 844
 845static int patmatch(struct grep_pat *p, char *line, char *eol,
 846                    regmatch_t *match, int eflags)
 847{
 848        int hit;
 849
 850        if (p->fixed)
 851                hit = !fixmatch(p, line, eol, match);
 852        else if (p->pcre_regexp)
 853                hit = !pcrematch(p, line, eol, match, eflags);
 854        else
 855                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 856
 857        return hit;
 858}
 859
 860static int strip_timestamp(char *bol, char **eol_p)
 861{
 862        char *eol = *eol_p;
 863        int ch;
 864
 865        while (bol < --eol) {
 866                if (*eol != '>')
 867                        continue;
 868                *eol_p = ++eol;
 869                ch = *eol;
 870                *eol = '\0';
 871                return ch;
 872        }
 873        return 0;
 874}
 875
 876static struct {
 877        const char *field;
 878        size_t len;
 879} header_field[] = {
 880        { "author ", 7 },
 881        { "committer ", 10 },
 882        { "reflog ", 7 },
 883};
 884
 885static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 886                             enum grep_context ctx,
 887                             regmatch_t *pmatch, int eflags)
 888{
 889        int hit = 0;
 890        int saved_ch = 0;
 891        const char *start = bol;
 892
 893        if ((p->token != GREP_PATTERN) &&
 894            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 895                return 0;
 896
 897        if (p->token == GREP_PATTERN_HEAD) {
 898                const char *field;
 899                size_t len;
 900                assert(p->field < ARRAY_SIZE(header_field));
 901                field = header_field[p->field].field;
 902                len = header_field[p->field].len;
 903                if (strncmp(bol, field, len))
 904                        return 0;
 905                bol += len;
 906                switch (p->field) {
 907                case GREP_HEADER_AUTHOR:
 908                case GREP_HEADER_COMMITTER:
 909                        saved_ch = strip_timestamp(bol, &eol);
 910                        break;
 911                default:
 912                        break;
 913                }
 914        }
 915
 916 again:
 917        hit = patmatch(p, bol, eol, pmatch, eflags);
 918
 919        if (hit && p->word_regexp) {
 920                if ((pmatch[0].rm_so < 0) ||
 921                    (eol - bol) < pmatch[0].rm_so ||
 922                    (pmatch[0].rm_eo < 0) ||
 923                    (eol - bol) < pmatch[0].rm_eo)
 924                        die("regexp returned nonsense");
 925
 926                /* Match beginning must be either beginning of the
 927                 * line, or at word boundary (i.e. the last char must
 928                 * not be a word char).  Similarly, match end must be
 929                 * either end of the line, or at word boundary
 930                 * (i.e. the next char must not be a word char).
 931                 */
 932                if ( ((pmatch[0].rm_so == 0) ||
 933                      !word_char(bol[pmatch[0].rm_so-1])) &&
 934                     ((pmatch[0].rm_eo == (eol-bol)) ||
 935                      !word_char(bol[pmatch[0].rm_eo])) )
 936                        ;
 937                else
 938                        hit = 0;
 939
 940                /* Words consist of at least one character. */
 941                if (pmatch->rm_so == pmatch->rm_eo)
 942                        hit = 0;
 943
 944                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 945                        /* There could be more than one match on the
 946                         * line, and the first match might not be
 947                         * strict word match.  But later ones could be!
 948                         * Forward to the next possible start, i.e. the
 949                         * next position following a non-word char.
 950                         */
 951                        bol = pmatch[0].rm_so + bol + 1;
 952                        while (word_char(bol[-1]) && bol < eol)
 953                                bol++;
 954                        eflags |= REG_NOTBOL;
 955                        if (bol < eol)
 956                                goto again;
 957                }
 958        }
 959        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 960                *eol = saved_ch;
 961        if (hit) {
 962                pmatch[0].rm_so += bol - start;
 963                pmatch[0].rm_eo += bol - start;
 964        }
 965        return hit;
 966}
 967
 968static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 969                           enum grep_context ctx, int collect_hits)
 970{
 971        int h = 0;
 972        regmatch_t match;
 973
 974        if (!x)
 975                die("Not a valid grep expression");
 976        switch (x->node) {
 977        case GREP_NODE_TRUE:
 978                h = 1;
 979                break;
 980        case GREP_NODE_ATOM:
 981                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 982                break;
 983        case GREP_NODE_NOT:
 984                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
 985                break;
 986        case GREP_NODE_AND:
 987                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
 988                        return 0;
 989                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
 990                break;
 991        case GREP_NODE_OR:
 992                if (!collect_hits)
 993                        return (match_expr_eval(x->u.binary.left,
 994                                                bol, eol, ctx, 0) ||
 995                                match_expr_eval(x->u.binary.right,
 996                                                bol, eol, ctx, 0));
 997                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
 998                x->u.binary.left->hit |= h;
 999                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1000                break;
1001        default:
1002                die("Unexpected node type (internal error) %d", x->node);
1003        }
1004        if (collect_hits)
1005                x->hit |= h;
1006        return h;
1007}
1008
1009static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1010                      enum grep_context ctx, int collect_hits)
1011{
1012        struct grep_expr *x = opt->pattern_expression;
1013        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1014}
1015
1016static int match_line(struct grep_opt *opt, char *bol, char *eol,
1017                      enum grep_context ctx, int collect_hits)
1018{
1019        struct grep_pat *p;
1020        regmatch_t match;
1021
1022        if (opt->extended)
1023                return match_expr(opt, bol, eol, ctx, collect_hits);
1024
1025        /* we do not call with collect_hits without being extended */
1026        for (p = opt->pattern_list; p; p = p->next) {
1027                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1028                        return 1;
1029        }
1030        return 0;
1031}
1032
1033static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1034                              enum grep_context ctx,
1035                              regmatch_t *pmatch, int eflags)
1036{
1037        regmatch_t match;
1038
1039        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1040                return 0;
1041        if (match.rm_so < 0 || match.rm_eo < 0)
1042                return 0;
1043        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1044                if (match.rm_so > pmatch->rm_so)
1045                        return 1;
1046                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1047                        return 1;
1048        }
1049        pmatch->rm_so = match.rm_so;
1050        pmatch->rm_eo = match.rm_eo;
1051        return 1;
1052}
1053
1054static int next_match(struct grep_opt *opt, char *bol, char *eol,
1055                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1056{
1057        struct grep_pat *p;
1058        int hit = 0;
1059
1060        pmatch->rm_so = pmatch->rm_eo = -1;
1061        if (bol < eol) {
1062                for (p = opt->pattern_list; p; p = p->next) {
1063                        switch (p->token) {
1064                        case GREP_PATTERN: /* atom */
1065                        case GREP_PATTERN_HEAD:
1066                        case GREP_PATTERN_BODY:
1067                                hit |= match_next_pattern(p, bol, eol, ctx,
1068                                                          pmatch, eflags);
1069                                break;
1070                        default:
1071                                break;
1072                        }
1073                }
1074        }
1075        return hit;
1076}
1077
1078static void show_line(struct grep_opt *opt, char *bol, char *eol,
1079                      const char *name, unsigned lno, char sign)
1080{
1081        int rest = eol - bol;
1082        char *line_color = NULL;
1083
1084        if (opt->file_break && opt->last_shown == 0) {
1085                if (opt->show_hunk_mark)
1086                        opt->output(opt, "\n", 1);
1087        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1088                if (opt->last_shown == 0) {
1089                        if (opt->show_hunk_mark) {
1090                                output_color(opt, "--", 2, opt->color_sep);
1091                                opt->output(opt, "\n", 1);
1092                        }
1093                } else if (lno > opt->last_shown + 1) {
1094                        output_color(opt, "--", 2, opt->color_sep);
1095                        opt->output(opt, "\n", 1);
1096                }
1097        }
1098        if (opt->heading && opt->last_shown == 0) {
1099                output_color(opt, name, strlen(name), opt->color_filename);
1100                opt->output(opt, "\n", 1);
1101        }
1102        opt->last_shown = lno;
1103
1104        if (!opt->heading && opt->pathname) {
1105                output_color(opt, name, strlen(name), opt->color_filename);
1106                output_sep(opt, sign);
1107        }
1108        if (opt->linenum) {
1109                char buf[32];
1110                snprintf(buf, sizeof(buf), "%d", lno);
1111                output_color(opt, buf, strlen(buf), opt->color_lineno);
1112                output_sep(opt, sign);
1113        }
1114        if (opt->color) {
1115                regmatch_t match;
1116                enum grep_context ctx = GREP_CONTEXT_BODY;
1117                int ch = *eol;
1118                int eflags = 0;
1119
1120                if (sign == ':')
1121                        line_color = opt->color_selected;
1122                else if (sign == '-')
1123                        line_color = opt->color_context;
1124                else if (sign == '=')
1125                        line_color = opt->color_function;
1126                *eol = '\0';
1127                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1128                        if (match.rm_so == match.rm_eo)
1129                                break;
1130
1131                        output_color(opt, bol, match.rm_so, line_color);
1132                        output_color(opt, bol + match.rm_so,
1133                                     match.rm_eo - match.rm_so,
1134                                     opt->color_match);
1135                        bol += match.rm_eo;
1136                        rest -= match.rm_eo;
1137                        eflags = REG_NOTBOL;
1138                }
1139                *eol = ch;
1140        }
1141        output_color(opt, bol, rest, line_color);
1142        opt->output(opt, "\n", 1);
1143}
1144
1145#ifndef NO_PTHREADS
1146int grep_use_locks;
1147
1148/*
1149 * This lock protects access to the gitattributes machinery, which is
1150 * not thread-safe.
1151 */
1152pthread_mutex_t grep_attr_mutex;
1153
1154static inline void grep_attr_lock(void)
1155{
1156        if (grep_use_locks)
1157                pthread_mutex_lock(&grep_attr_mutex);
1158}
1159
1160static inline void grep_attr_unlock(void)
1161{
1162        if (grep_use_locks)
1163                pthread_mutex_unlock(&grep_attr_mutex);
1164}
1165
1166/*
1167 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1168 */
1169pthread_mutex_t grep_read_mutex;
1170
1171#else
1172#define grep_attr_lock()
1173#define grep_attr_unlock()
1174#endif
1175
1176static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1177{
1178        xdemitconf_t *xecfg = opt->priv;
1179        if (xecfg && !xecfg->find_func) {
1180                grep_source_load_driver(gs);
1181                if (gs->driver->funcname.pattern) {
1182                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1183                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1184                } else {
1185                        xecfg = opt->priv = NULL;
1186                }
1187        }
1188
1189        if (xecfg) {
1190                char buf[1];
1191                return xecfg->find_func(bol, eol - bol, buf, 1,
1192                                        xecfg->find_func_priv) >= 0;
1193        }
1194
1195        if (bol == eol)
1196                return 0;
1197        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1198                return 1;
1199        return 0;
1200}
1201
1202static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1203                               char *bol, unsigned lno)
1204{
1205        while (bol > gs->buf) {
1206                char *eol = --bol;
1207
1208                while (bol > gs->buf && bol[-1] != '\n')
1209                        bol--;
1210                lno--;
1211
1212                if (lno <= opt->last_shown)
1213                        break;
1214
1215                if (match_funcname(opt, gs, bol, eol)) {
1216                        show_line(opt, bol, eol, gs->name, lno, '=');
1217                        break;
1218                }
1219        }
1220}
1221
1222static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1223                             char *bol, char *end, unsigned lno)
1224{
1225        unsigned cur = lno, from = 1, funcname_lno = 0;
1226        int funcname_needed = !!opt->funcname;
1227
1228        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1229                funcname_needed = 2;
1230
1231        if (opt->pre_context < lno)
1232                from = lno - opt->pre_context;
1233        if (from <= opt->last_shown)
1234                from = opt->last_shown + 1;
1235
1236        /* Rewind. */
1237        while (bol > gs->buf &&
1238               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1239                char *eol = --bol;
1240
1241                while (bol > gs->buf && bol[-1] != '\n')
1242                        bol--;
1243                cur--;
1244                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1245                        funcname_lno = cur;
1246                        funcname_needed = 0;
1247                }
1248        }
1249
1250        /* We need to look even further back to find a function signature. */
1251        if (opt->funcname && funcname_needed)
1252                show_funcname_line(opt, gs, bol, cur);
1253
1254        /* Back forward. */
1255        while (cur < lno) {
1256                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1257
1258                while (*eol != '\n')
1259                        eol++;
1260                show_line(opt, bol, eol, gs->name, cur, sign);
1261                bol = eol + 1;
1262                cur++;
1263        }
1264}
1265
1266static int should_lookahead(struct grep_opt *opt)
1267{
1268        struct grep_pat *p;
1269
1270        if (opt->extended)
1271                return 0; /* punt for too complex stuff */
1272        if (opt->invert)
1273                return 0;
1274        for (p = opt->pattern_list; p; p = p->next) {
1275                if (p->token != GREP_PATTERN)
1276                        return 0; /* punt for "header only" and stuff */
1277        }
1278        return 1;
1279}
1280
1281static int look_ahead(struct grep_opt *opt,
1282                      unsigned long *left_p,
1283                      unsigned *lno_p,
1284                      char **bol_p)
1285{
1286        unsigned lno = *lno_p;
1287        char *bol = *bol_p;
1288        struct grep_pat *p;
1289        char *sp, *last_bol;
1290        regoff_t earliest = -1;
1291
1292        for (p = opt->pattern_list; p; p = p->next) {
1293                int hit;
1294                regmatch_t m;
1295
1296                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1297                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1298                        continue;
1299                if (earliest < 0 || m.rm_so < earliest)
1300                        earliest = m.rm_so;
1301        }
1302
1303        if (earliest < 0) {
1304                *bol_p = bol + *left_p;
1305                *left_p = 0;
1306                return 1;
1307        }
1308        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1309                ; /* find the beginning of the line */
1310        last_bol = sp;
1311
1312        for (sp = bol; sp < last_bol; sp++) {
1313                if (*sp == '\n')
1314                        lno++;
1315        }
1316        *left_p -= last_bol - bol;
1317        *bol_p = last_bol;
1318        *lno_p = lno;
1319        return 0;
1320}
1321
1322static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1323{
1324        fwrite(buf, size, 1, stdout);
1325}
1326
1327static int fill_textconv_grep(struct userdiff_driver *driver,
1328                              struct grep_source *gs)
1329{
1330        struct diff_filespec *df;
1331        char *buf;
1332        size_t size;
1333
1334        if (!driver || !driver->textconv)
1335                return grep_source_load(gs);
1336
1337        /*
1338         * The textconv interface is intimately tied to diff_filespecs, so we
1339         * have to pretend to be one. If we could unify the grep_source
1340         * and diff_filespec structs, this mess could just go away.
1341         */
1342        df = alloc_filespec(gs->path);
1343        switch (gs->type) {
1344        case GREP_SOURCE_SHA1:
1345                fill_filespec(df, gs->identifier, 1, 0100644);
1346                break;
1347        case GREP_SOURCE_FILE:
1348                fill_filespec(df, null_sha1, 0, 0100644);
1349                break;
1350        default:
1351                die("BUG: attempt to textconv something without a path?");
1352        }
1353
1354        /*
1355         * fill_textconv is not remotely thread-safe; it may load objects
1356         * behind the scenes, and it modifies the global diff tempfile
1357         * structure.
1358         */
1359        grep_read_lock();
1360        size = fill_textconv(driver, df, &buf);
1361        grep_read_unlock();
1362        free_filespec(df);
1363
1364        /*
1365         * The normal fill_textconv usage by the diff machinery would just keep
1366         * the textconv'd buf separate from the diff_filespec. But much of the
1367         * grep code passes around a grep_source and assumes that its "buf"
1368         * pointer is the beginning of the thing we are searching. So let's
1369         * install our textconv'd version into the grep_source, taking care not
1370         * to leak any existing buffer.
1371         */
1372        grep_source_clear_data(gs);
1373        gs->buf = buf;
1374        gs->size = size;
1375
1376        return 0;
1377}
1378
1379static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1380{
1381        char *bol;
1382        unsigned long left;
1383        unsigned lno = 1;
1384        unsigned last_hit = 0;
1385        int binary_match_only = 0;
1386        unsigned count = 0;
1387        int try_lookahead = 0;
1388        int show_function = 0;
1389        struct userdiff_driver *textconv = NULL;
1390        enum grep_context ctx = GREP_CONTEXT_HEAD;
1391        xdemitconf_t xecfg;
1392
1393        if (!opt->output)
1394                opt->output = std_output;
1395
1396        if (opt->pre_context || opt->post_context || opt->file_break ||
1397            opt->funcbody) {
1398                /* Show hunk marks, except for the first file. */
1399                if (opt->last_shown)
1400                        opt->show_hunk_mark = 1;
1401                /*
1402                 * If we're using threads then we can't easily identify
1403                 * the first file.  Always put hunk marks in that case
1404                 * and skip the very first one later in work_done().
1405                 */
1406                if (opt->output != std_output)
1407                        opt->show_hunk_mark = 1;
1408        }
1409        opt->last_shown = 0;
1410
1411        if (opt->allow_textconv) {
1412                grep_source_load_driver(gs);
1413                /*
1414                 * We might set up the shared textconv cache data here, which
1415                 * is not thread-safe.
1416                 */
1417                grep_attr_lock();
1418                textconv = userdiff_get_textconv(gs->driver);
1419                grep_attr_unlock();
1420        }
1421
1422        /*
1423         * We know the result of a textconv is text, so we only have to care
1424         * about binary handling if we are not using it.
1425         */
1426        if (!textconv) {
1427                switch (opt->binary) {
1428                case GREP_BINARY_DEFAULT:
1429                        if (grep_source_is_binary(gs))
1430                                binary_match_only = 1;
1431                        break;
1432                case GREP_BINARY_NOMATCH:
1433                        if (grep_source_is_binary(gs))
1434                                return 0; /* Assume unmatch */
1435                        break;
1436                case GREP_BINARY_TEXT:
1437                        break;
1438                default:
1439                        die("bug: unknown binary handling mode");
1440                }
1441        }
1442
1443        memset(&xecfg, 0, sizeof(xecfg));
1444        opt->priv = &xecfg;
1445
1446        try_lookahead = should_lookahead(opt);
1447
1448        if (fill_textconv_grep(textconv, gs) < 0)
1449                return 0;
1450
1451        bol = gs->buf;
1452        left = gs->size;
1453        while (left) {
1454                char *eol, ch;
1455                int hit;
1456
1457                /*
1458                 * look_ahead() skips quickly to the line that possibly
1459                 * has the next hit; don't call it if we need to do
1460                 * something more than just skipping the current line
1461                 * in response to an unmatch for the current line.  E.g.
1462                 * inside a post-context window, we will show the current
1463                 * line as a context around the previous hit when it
1464                 * doesn't hit.
1465                 */
1466                if (try_lookahead
1467                    && !(last_hit
1468                         && (show_function ||
1469                             lno <= last_hit + opt->post_context))
1470                    && look_ahead(opt, &left, &lno, &bol))
1471                        break;
1472                eol = end_of_line(bol, &left);
1473                ch = *eol;
1474                *eol = 0;
1475
1476                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1477                        ctx = GREP_CONTEXT_BODY;
1478
1479                hit = match_line(opt, bol, eol, ctx, collect_hits);
1480                *eol = ch;
1481
1482                if (collect_hits)
1483                        goto next_line;
1484
1485                /* "grep -v -e foo -e bla" should list lines
1486                 * that do not have either, so inversion should
1487                 * be done outside.
1488                 */
1489                if (opt->invert)
1490                        hit = !hit;
1491                if (opt->unmatch_name_only) {
1492                        if (hit)
1493                                return 0;
1494                        goto next_line;
1495                }
1496                if (hit) {
1497                        count++;
1498                        if (opt->status_only)
1499                                return 1;
1500                        if (opt->name_only) {
1501                                show_name(opt, gs->name);
1502                                return 1;
1503                        }
1504                        if (opt->count)
1505                                goto next_line;
1506                        if (binary_match_only) {
1507                                opt->output(opt, "Binary file ", 12);
1508                                output_color(opt, gs->name, strlen(gs->name),
1509                                             opt->color_filename);
1510                                opt->output(opt, " matches\n", 9);
1511                                return 1;
1512                        }
1513                        /* Hit at this line.  If we haven't shown the
1514                         * pre-context lines, we would need to show them.
1515                         */
1516                        if (opt->pre_context || opt->funcbody)
1517                                show_pre_context(opt, gs, bol, eol, lno);
1518                        else if (opt->funcname)
1519                                show_funcname_line(opt, gs, bol, lno);
1520                        show_line(opt, bol, eol, gs->name, lno, ':');
1521                        last_hit = lno;
1522                        if (opt->funcbody)
1523                                show_function = 1;
1524                        goto next_line;
1525                }
1526                if (show_function && match_funcname(opt, gs, bol, eol))
1527                        show_function = 0;
1528                if (show_function ||
1529                    (last_hit && lno <= last_hit + opt->post_context)) {
1530                        /* If the last hit is within the post context,
1531                         * we need to show this line.
1532                         */
1533                        show_line(opt, bol, eol, gs->name, lno, '-');
1534                }
1535
1536        next_line:
1537                bol = eol + 1;
1538                if (!left)
1539                        break;
1540                left--;
1541                lno++;
1542        }
1543
1544        if (collect_hits)
1545                return 0;
1546
1547        if (opt->status_only)
1548                return 0;
1549        if (opt->unmatch_name_only) {
1550                /* We did not see any hit, so we want to show this */
1551                show_name(opt, gs->name);
1552                return 1;
1553        }
1554
1555        xdiff_clear_find_func(&xecfg);
1556        opt->priv = NULL;
1557
1558        /* NEEDSWORK:
1559         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1560         * which feels mostly useless but sometimes useful.  Maybe
1561         * make it another option?  For now suppress them.
1562         */
1563        if (opt->count && count) {
1564                char buf[32];
1565                output_color(opt, gs->name, strlen(gs->name), opt->color_filename);
1566                output_sep(opt, ':');
1567                snprintf(buf, sizeof(buf), "%u\n", count);
1568                opt->output(opt, buf, strlen(buf));
1569                return 1;
1570        }
1571        return !!last_hit;
1572}
1573
1574static void clr_hit_marker(struct grep_expr *x)
1575{
1576        /* All-hit markers are meaningful only at the very top level
1577         * OR node.
1578         */
1579        while (1) {
1580                x->hit = 0;
1581                if (x->node != GREP_NODE_OR)
1582                        return;
1583                x->u.binary.left->hit = 0;
1584                x = x->u.binary.right;
1585        }
1586}
1587
1588static int chk_hit_marker(struct grep_expr *x)
1589{
1590        /* Top level nodes have hit markers.  See if they all are hits */
1591        while (1) {
1592                if (x->node != GREP_NODE_OR)
1593                        return x->hit;
1594                if (!x->u.binary.left->hit)
1595                        return 0;
1596                x = x->u.binary.right;
1597        }
1598}
1599
1600int grep_source(struct grep_opt *opt, struct grep_source *gs)
1601{
1602        /*
1603         * we do not have to do the two-pass grep when we do not check
1604         * buffer-wide "all-match".
1605         */
1606        if (!opt->all_match)
1607                return grep_source_1(opt, gs, 0);
1608
1609        /* Otherwise the toplevel "or" terms hit a bit differently.
1610         * We first clear hit markers from them.
1611         */
1612        clr_hit_marker(opt->pattern_expression);
1613        grep_source_1(opt, gs, 1);
1614
1615        if (!chk_hit_marker(opt->pattern_expression))
1616                return 0;
1617
1618        return grep_source_1(opt, gs, 0);
1619}
1620
1621int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1622{
1623        struct grep_source gs;
1624        int r;
1625
1626        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1627        gs.buf = buf;
1628        gs.size = size;
1629
1630        r = grep_source(opt, &gs);
1631
1632        grep_source_clear(&gs);
1633        return r;
1634}
1635
1636void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1637                      const char *name, const char *path,
1638                      const void *identifier)
1639{
1640        gs->type = type;
1641        gs->name = name ? xstrdup(name) : NULL;
1642        gs->path = path ? xstrdup(path) : NULL;
1643        gs->buf = NULL;
1644        gs->size = 0;
1645        gs->driver = NULL;
1646
1647        switch (type) {
1648        case GREP_SOURCE_FILE:
1649                gs->identifier = xstrdup(identifier);
1650                break;
1651        case GREP_SOURCE_SHA1:
1652                gs->identifier = xmalloc(20);
1653                memcpy(gs->identifier, identifier, 20);
1654                break;
1655        case GREP_SOURCE_BUF:
1656                gs->identifier = NULL;
1657        }
1658}
1659
1660void grep_source_clear(struct grep_source *gs)
1661{
1662        free(gs->name);
1663        gs->name = NULL;
1664        free(gs->path);
1665        gs->path = NULL;
1666        free(gs->identifier);
1667        gs->identifier = NULL;
1668        grep_source_clear_data(gs);
1669}
1670
1671void grep_source_clear_data(struct grep_source *gs)
1672{
1673        switch (gs->type) {
1674        case GREP_SOURCE_FILE:
1675        case GREP_SOURCE_SHA1:
1676                free(gs->buf);
1677                gs->buf = NULL;
1678                gs->size = 0;
1679                break;
1680        case GREP_SOURCE_BUF:
1681                /* leave user-provided buf intact */
1682                break;
1683        }
1684}
1685
1686static int grep_source_load_sha1(struct grep_source *gs)
1687{
1688        enum object_type type;
1689
1690        grep_read_lock();
1691        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1692        grep_read_unlock();
1693
1694        if (!gs->buf)
1695                return error(_("'%s': unable to read %s"),
1696                             gs->name,
1697                             sha1_to_hex(gs->identifier));
1698        return 0;
1699}
1700
1701static int grep_source_load_file(struct grep_source *gs)
1702{
1703        const char *filename = gs->identifier;
1704        struct stat st;
1705        char *data;
1706        size_t size;
1707        int i;
1708
1709        if (lstat(filename, &st) < 0) {
1710        err_ret:
1711                if (errno != ENOENT)
1712                        error(_("'%s': %s"), filename, strerror(errno));
1713                return -1;
1714        }
1715        if (!S_ISREG(st.st_mode))
1716                return -1;
1717        size = xsize_t(st.st_size);
1718        i = open(filename, O_RDONLY);
1719        if (i < 0)
1720                goto err_ret;
1721        data = xmalloc(size + 1);
1722        if (st.st_size != read_in_full(i, data, size)) {
1723                error(_("'%s': short read %s"), filename, strerror(errno));
1724                close(i);
1725                free(data);
1726                return -1;
1727        }
1728        close(i);
1729        data[size] = 0;
1730
1731        gs->buf = data;
1732        gs->size = size;
1733        return 0;
1734}
1735
1736static int grep_source_load(struct grep_source *gs)
1737{
1738        if (gs->buf)
1739                return 0;
1740
1741        switch (gs->type) {
1742        case GREP_SOURCE_FILE:
1743                return grep_source_load_file(gs);
1744        case GREP_SOURCE_SHA1:
1745                return grep_source_load_sha1(gs);
1746        case GREP_SOURCE_BUF:
1747                return gs->buf ? 0 : -1;
1748        }
1749        die("BUG: invalid grep_source type");
1750}
1751
1752void grep_source_load_driver(struct grep_source *gs)
1753{
1754        if (gs->driver)
1755                return;
1756
1757        grep_attr_lock();
1758        if (gs->path)
1759                gs->driver = userdiff_find_by_path(gs->path);
1760        if (!gs->driver)
1761                gs->driver = userdiff_find_by_name("default");
1762        grep_attr_unlock();
1763}
1764
1765static int grep_source_is_binary(struct grep_source *gs)
1766{
1767        grep_source_load_driver(gs);
1768        if (gs->driver->binary != -1)
1769                return gs->driver->binary;
1770
1771        if (!grep_source_load(gs))
1772                return buffer_is_binary(gs->buf, gs->size);
1773
1774        return 0;
1775}