Andrew's git / gitweb.git / grep.c
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grep.con commit grep: rewrite an if/else condition to avoid duplicate expression (e944d9d)
   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#include "commit.h"
   8#include "quote.h"
   9
  10static int grep_source_load(struct grep_source *gs);
  11static int grep_source_is_binary(struct grep_source *gs);
  12
  13static struct grep_opt grep_defaults;
  14
  15/*
  16 * Initialize the grep_defaults template with hardcoded defaults.
  17 * We could let the compiler do this, but without C99 initializers
  18 * the code gets unwieldy and unreadable, so...
  19 */
  20void init_grep_defaults(void)
  21{
  22        struct grep_opt *opt = &grep_defaults;
  23        static int run_once;
  24
  25        if (run_once)
  26                return;
  27        run_once++;
  28
  29        memset(opt, 0, sizeof(*opt));
  30        opt->relative = 1;
  31        opt->pathname = 1;
  32        opt->regflags = REG_NEWLINE;
  33        opt->max_depth = -1;
  34        opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  35        opt->extended_regexp_option = 0;
  36        color_set(opt->color_context, "");
  37        color_set(opt->color_filename, "");
  38        color_set(opt->color_function, "");
  39        color_set(opt->color_lineno, "");
  40        color_set(opt->color_match_context, GIT_COLOR_BOLD_RED);
  41        color_set(opt->color_match_selected, GIT_COLOR_BOLD_RED);
  42        color_set(opt->color_selected, "");
  43        color_set(opt->color_sep, GIT_COLOR_CYAN);
  44        opt->color = -1;
  45}
  46
  47static int parse_pattern_type_arg(const char *opt, const char *arg)
  48{
  49        if (!strcmp(arg, "default"))
  50                return GREP_PATTERN_TYPE_UNSPECIFIED;
  51        else if (!strcmp(arg, "basic"))
  52                return GREP_PATTERN_TYPE_BRE;
  53        else if (!strcmp(arg, "extended"))
  54                return GREP_PATTERN_TYPE_ERE;
  55        else if (!strcmp(arg, "fixed"))
  56                return GREP_PATTERN_TYPE_FIXED;
  57        else if (!strcmp(arg, "perl"))
  58                return GREP_PATTERN_TYPE_PCRE;
  59        die("bad %s argument: %s", opt, arg);
  60}
  61
  62/*
  63 * Read the configuration file once and store it in
  64 * the grep_defaults template.
  65 */
  66int grep_config(const char *var, const char *value, void *cb)
  67{
  68        struct grep_opt *opt = &grep_defaults;
  69        char *color = NULL;
  70
  71        if (userdiff_config(var, value) < 0)
  72                return -1;
  73
  74        if (!strcmp(var, "grep.extendedregexp")) {
  75                if (git_config_bool(var, value))
  76                        opt->extended_regexp_option = 1;
  77                else
  78                        opt->extended_regexp_option = 0;
  79                return 0;
  80        }
  81
  82        if (!strcmp(var, "grep.patterntype")) {
  83                opt->pattern_type_option = parse_pattern_type_arg(var, value);
  84                return 0;
  85        }
  86
  87        if (!strcmp(var, "grep.linenumber")) {
  88                opt->linenum = git_config_bool(var, value);
  89                return 0;
  90        }
  91
  92        if (!strcmp(var, "grep.fullname")) {
  93                opt->relative = !git_config_bool(var, value);
  94                return 0;
  95        }
  96
  97        if (!strcmp(var, "color.grep"))
  98                opt->color = git_config_colorbool(var, value);
  99        else if (!strcmp(var, "color.grep.context"))
 100                color = opt->color_context;
 101        else if (!strcmp(var, "color.grep.filename"))
 102                color = opt->color_filename;
 103        else if (!strcmp(var, "color.grep.function"))
 104                color = opt->color_function;
 105        else if (!strcmp(var, "color.grep.linenumber"))
 106                color = opt->color_lineno;
 107        else if (!strcmp(var, "color.grep.matchcontext"))
 108                color = opt->color_match_context;
 109        else if (!strcmp(var, "color.grep.matchselected"))
 110                color = opt->color_match_selected;
 111        else if (!strcmp(var, "color.grep.selected"))
 112                color = opt->color_selected;
 113        else if (!strcmp(var, "color.grep.separator"))
 114                color = opt->color_sep;
 115        else if (!strcmp(var, "color.grep.match")) {
 116                int rc = 0;
 117                if (!value)
 118                        return config_error_nonbool(var);
 119                rc |= color_parse(value, opt->color_match_context);
 120                rc |= color_parse(value, opt->color_match_selected);
 121                return rc;
 122        }
 123
 124        if (color) {
 125                if (!value)
 126                        return config_error_nonbool(var);
 127                return color_parse(value, color);
 128        }
 129        return 0;
 130}
 131
 132/*
 133 * Initialize one instance of grep_opt and copy the
 134 * default values from the template we read the configuration
 135 * information in an earlier call to git_config(grep_config).
 136 */
 137void grep_init(struct grep_opt *opt, const char *prefix)
 138{
 139        struct grep_opt *def = &grep_defaults;
 140
 141        memset(opt, 0, sizeof(*opt));
 142        opt->prefix = prefix;
 143        opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 144        opt->pattern_tail = &opt->pattern_list;
 145        opt->header_tail = &opt->header_list;
 146
 147        opt->color = def->color;
 148        opt->extended_regexp_option = def->extended_regexp_option;
 149        opt->pattern_type_option = def->pattern_type_option;
 150        opt->linenum = def->linenum;
 151        opt->max_depth = def->max_depth;
 152        opt->pathname = def->pathname;
 153        opt->regflags = def->regflags;
 154        opt->relative = def->relative;
 155
 156        color_set(opt->color_context, def->color_context);
 157        color_set(opt->color_filename, def->color_filename);
 158        color_set(opt->color_function, def->color_function);
 159        color_set(opt->color_lineno, def->color_lineno);
 160        color_set(opt->color_match_context, def->color_match_context);
 161        color_set(opt->color_match_selected, def->color_match_selected);
 162        color_set(opt->color_selected, def->color_selected);
 163        color_set(opt->color_sep, def->color_sep);
 164}
 165
 166void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 167{
 168        if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 169                grep_set_pattern_type_option(pattern_type, opt);
 170        else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 171                grep_set_pattern_type_option(opt->pattern_type_option, opt);
 172        else if (opt->extended_regexp_option)
 173                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 174}
 175
 176void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 177{
 178        switch (pattern_type) {
 179        case GREP_PATTERN_TYPE_UNSPECIFIED:
 180                /* fall through */
 181
 182        case GREP_PATTERN_TYPE_BRE:
 183                opt->fixed = 0;
 184                opt->pcre = 0;
 185                opt->regflags &= ~REG_EXTENDED;
 186                break;
 187
 188        case GREP_PATTERN_TYPE_ERE:
 189                opt->fixed = 0;
 190                opt->pcre = 0;
 191                opt->regflags |= REG_EXTENDED;
 192                break;
 193
 194        case GREP_PATTERN_TYPE_FIXED:
 195                opt->fixed = 1;
 196                opt->pcre = 0;
 197                opt->regflags &= ~REG_EXTENDED;
 198                break;
 199
 200        case GREP_PATTERN_TYPE_PCRE:
 201                opt->fixed = 0;
 202                opt->pcre = 1;
 203                opt->regflags &= ~REG_EXTENDED;
 204                break;
 205        }
 206}
 207
 208static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 209                                        const char *origin, int no,
 210                                        enum grep_pat_token t,
 211                                        enum grep_header_field field)
 212{
 213        struct grep_pat *p = xcalloc(1, sizeof(*p));
 214        p->pattern = xmemdupz(pat, patlen);
 215        p->patternlen = patlen;
 216        p->origin = origin;
 217        p->no = no;
 218        p->token = t;
 219        p->field = field;
 220        return p;
 221}
 222
 223static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 224{
 225        **tail = p;
 226        *tail = &p->next;
 227        p->next = NULL;
 228
 229        switch (p->token) {
 230        case GREP_PATTERN: /* atom */
 231        case GREP_PATTERN_HEAD:
 232        case GREP_PATTERN_BODY:
 233                for (;;) {
 234                        struct grep_pat *new_pat;
 235                        size_t len = 0;
 236                        char *cp = p->pattern + p->patternlen, *nl = NULL;
 237                        while (++len <= p->patternlen) {
 238                                if (*(--cp) == '\n') {
 239                                        nl = cp;
 240                                        break;
 241                                }
 242                        }
 243                        if (!nl)
 244                                break;
 245                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 246                                                  p->no, p->token, p->field);
 247                        new_pat->next = p->next;
 248                        if (!p->next)
 249                                *tail = &new_pat->next;
 250                        p->next = new_pat;
 251                        *nl = '\0';
 252                        p->patternlen -= len;
 253                }
 254                break;
 255        default:
 256                break;
 257        }
 258}
 259
 260void append_header_grep_pattern(struct grep_opt *opt,
 261                                enum grep_header_field field, const char *pat)
 262{
 263        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 264                                             GREP_PATTERN_HEAD, field);
 265        if (field == GREP_HEADER_REFLOG)
 266                opt->use_reflog_filter = 1;
 267        do_append_grep_pat(&opt->header_tail, p);
 268}
 269
 270void append_grep_pattern(struct grep_opt *opt, const char *pat,
 271                         const char *origin, int no, enum grep_pat_token t)
 272{
 273        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 274}
 275
 276void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 277                     const char *origin, int no, enum grep_pat_token t)
 278{
 279        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 280        do_append_grep_pat(&opt->pattern_tail, p);
 281}
 282
 283struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 284{
 285        struct grep_pat *pat;
 286        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 287        *ret = *opt;
 288
 289        ret->pattern_list = NULL;
 290        ret->pattern_tail = &ret->pattern_list;
 291
 292        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 293        {
 294                if(pat->token == GREP_PATTERN_HEAD)
 295                        append_header_grep_pattern(ret, pat->field,
 296                                                   pat->pattern);
 297                else
 298                        append_grep_pat(ret, pat->pattern, pat->patternlen,
 299                                        pat->origin, pat->no, pat->token);
 300        }
 301
 302        return ret;
 303}
 304
 305static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 306                const char *error)
 307{
 308        char where[1024];
 309
 310        if (p->no)
 311                xsnprintf(where, sizeof(where), "In '%s' at %d, ", p->origin, p->no);
 312        else if (p->origin)
 313                xsnprintf(where, sizeof(where), "%s, ", p->origin);
 314        else
 315                where[0] = 0;
 316
 317        die("%s'%s': %s", where, p->pattern, error);
 318}
 319
 320#ifdef USE_LIBPCRE
 321static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 322{
 323        const char *error;
 324        int erroffset;
 325        int options = PCRE_MULTILINE;
 326
 327        if (opt->ignore_case)
 328                options |= PCRE_CASELESS;
 329
 330        p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 331                        NULL);
 332        if (!p->pcre_regexp)
 333                compile_regexp_failed(p, error);
 334
 335        p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 336        if (!p->pcre_extra_info && error)
 337                die("%s", error);
 338}
 339
 340static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 341                regmatch_t *match, int eflags)
 342{
 343        int ovector[30], ret, flags = 0;
 344
 345        if (eflags & REG_NOTBOL)
 346                flags |= PCRE_NOTBOL;
 347
 348        ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 349                        0, flags, ovector, ARRAY_SIZE(ovector));
 350        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 351                die("pcre_exec failed with error code %d", ret);
 352        if (ret > 0) {
 353                ret = 0;
 354                match->rm_so = ovector[0];
 355                match->rm_eo = ovector[1];
 356        }
 357
 358        return ret;
 359}
 360
 361static void free_pcre_regexp(struct grep_pat *p)
 362{
 363        pcre_free(p->pcre_regexp);
 364        pcre_free(p->pcre_extra_info);
 365}
 366#else /* !USE_LIBPCRE */
 367static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 368{
 369        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 370}
 371
 372static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 373                regmatch_t *match, int eflags)
 374{
 375        return 1;
 376}
 377
 378static void free_pcre_regexp(struct grep_pat *p)
 379{
 380}
 381#endif /* !USE_LIBPCRE */
 382
 383static int is_fixed(const char *s, size_t len)
 384{
 385        size_t i;
 386
 387        /* regcomp cannot accept patterns with NULs so we
 388         * consider any pattern containing a NUL fixed.
 389         */
 390        if (memchr(s, 0, len))
 391                return 1;
 392
 393        for (i = 0; i < len; i++) {
 394                if (is_regex_special(s[i]))
 395                        return 0;
 396        }
 397
 398        return 1;
 399}
 400
 401static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 402{
 403        struct strbuf sb = STRBUF_INIT;
 404        int err;
 405        int regflags;
 406
 407        basic_regex_quote_buf(&sb, p->pattern);
 408        regflags = opt->regflags & ~REG_EXTENDED;
 409        if (opt->ignore_case)
 410                regflags |= REG_ICASE;
 411        err = regcomp(&p->regexp, sb.buf, regflags);
 412        if (opt->debug)
 413                fprintf(stderr, "fixed %s\n", sb.buf);
 414        strbuf_release(&sb);
 415        if (err) {
 416                char errbuf[1024];
 417                regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 418                regfree(&p->regexp);
 419                compile_regexp_failed(p, errbuf);
 420        }
 421}
 422
 423static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 424{
 425        int icase, ascii_only;
 426        int err;
 427
 428        p->word_regexp = opt->word_regexp;
 429        p->ignore_case = opt->ignore_case;
 430        icase          = opt->regflags & REG_ICASE || p->ignore_case;
 431        ascii_only     = !has_non_ascii(p->pattern);
 432
 433        /*
 434         * Even when -F (fixed) asks us to do a non-regexp search, we
 435         * may not be able to correctly case-fold when -i
 436         * (ignore-case) is asked (in which case, we'll synthesize a
 437         * regexp to match the pattern that matches regexp special
 438         * characters literally, while ignoring case differences).  On
 439         * the other hand, even without -F, if the pattern does not
 440         * have any regexp special characters and there is no need for
 441         * case-folding search, we can internally turn it into a
 442         * simple string match using kws.  p->fixed tells us if we
 443         * want to use kws.
 444         */
 445        if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 446                p->fixed = !icase || ascii_only;
 447        else
 448                p->fixed = 0;
 449
 450        if (p->fixed) {
 451                if (opt->regflags & REG_ICASE || p->ignore_case)
 452                        p->kws = kwsalloc(tolower_trans_tbl);
 453                else
 454                        p->kws = kwsalloc(NULL);
 455                kwsincr(p->kws, p->pattern, p->patternlen);
 456                kwsprep(p->kws);
 457                return;
 458        } else if (opt->fixed) {
 459                /*
 460                 * We come here when the pattern has the non-ascii
 461                 * characters we cannot case-fold, and asked to
 462                 * ignore-case.
 463                 */
 464                compile_fixed_regexp(p, opt);
 465                return;
 466        }
 467
 468        if (opt->pcre) {
 469                compile_pcre_regexp(p, opt);
 470                return;
 471        }
 472
 473        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 474        if (err) {
 475                char errbuf[1024];
 476                regerror(err, &p->regexp, errbuf, 1024);
 477                regfree(&p->regexp);
 478                compile_regexp_failed(p, errbuf);
 479        }
 480}
 481
 482static struct grep_expr *compile_pattern_or(struct grep_pat **);
 483static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 484{
 485        struct grep_pat *p;
 486        struct grep_expr *x;
 487
 488        p = *list;
 489        if (!p)
 490                return NULL;
 491        switch (p->token) {
 492        case GREP_PATTERN: /* atom */
 493        case GREP_PATTERN_HEAD:
 494        case GREP_PATTERN_BODY:
 495                x = xcalloc(1, sizeof (struct grep_expr));
 496                x->node = GREP_NODE_ATOM;
 497                x->u.atom = p;
 498                *list = p->next;
 499                return x;
 500        case GREP_OPEN_PAREN:
 501                *list = p->next;
 502                x = compile_pattern_or(list);
 503                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 504                        die("unmatched parenthesis");
 505                *list = (*list)->next;
 506                return x;
 507        default:
 508                return NULL;
 509        }
 510}
 511
 512static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 513{
 514        struct grep_pat *p;
 515        struct grep_expr *x;
 516
 517        p = *list;
 518        if (!p)
 519                return NULL;
 520        switch (p->token) {
 521        case GREP_NOT:
 522                if (!p->next)
 523                        die("--not not followed by pattern expression");
 524                *list = p->next;
 525                x = xcalloc(1, sizeof (struct grep_expr));
 526                x->node = GREP_NODE_NOT;
 527                x->u.unary = compile_pattern_not(list);
 528                if (!x->u.unary)
 529                        die("--not followed by non pattern expression");
 530                return x;
 531        default:
 532                return compile_pattern_atom(list);
 533        }
 534}
 535
 536static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 537{
 538        struct grep_pat *p;
 539        struct grep_expr *x, *y, *z;
 540
 541        x = compile_pattern_not(list);
 542        p = *list;
 543        if (p && p->token == GREP_AND) {
 544                if (!p->next)
 545                        die("--and not followed by pattern expression");
 546                *list = p->next;
 547                y = compile_pattern_and(list);
 548                if (!y)
 549                        die("--and not followed by pattern expression");
 550                z = xcalloc(1, sizeof (struct grep_expr));
 551                z->node = GREP_NODE_AND;
 552                z->u.binary.left = x;
 553                z->u.binary.right = y;
 554                return z;
 555        }
 556        return x;
 557}
 558
 559static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 560{
 561        struct grep_pat *p;
 562        struct grep_expr *x, *y, *z;
 563
 564        x = compile_pattern_and(list);
 565        p = *list;
 566        if (x && p && p->token != GREP_CLOSE_PAREN) {
 567                y = compile_pattern_or(list);
 568                if (!y)
 569                        die("not a pattern expression %s", p->pattern);
 570                z = xcalloc(1, sizeof (struct grep_expr));
 571                z->node = GREP_NODE_OR;
 572                z->u.binary.left = x;
 573                z->u.binary.right = y;
 574                return z;
 575        }
 576        return x;
 577}
 578
 579static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 580{
 581        return compile_pattern_or(list);
 582}
 583
 584static void indent(int in)
 585{
 586        while (in-- > 0)
 587                fputc(' ', stderr);
 588}
 589
 590static void dump_grep_pat(struct grep_pat *p)
 591{
 592        switch (p->token) {
 593        case GREP_AND: fprintf(stderr, "*and*"); break;
 594        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 595        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 596        case GREP_NOT: fprintf(stderr, "*not*"); break;
 597        case GREP_OR: fprintf(stderr, "*or*"); break;
 598
 599        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 600        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 601        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 602        }
 603
 604        switch (p->token) {
 605        default: break;
 606        case GREP_PATTERN_HEAD:
 607                fprintf(stderr, "<head %d>", p->field); break;
 608        case GREP_PATTERN_BODY:
 609                fprintf(stderr, "<body>"); break;
 610        }
 611        switch (p->token) {
 612        default: break;
 613        case GREP_PATTERN_HEAD:
 614        case GREP_PATTERN_BODY:
 615        case GREP_PATTERN:
 616                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 617                break;
 618        }
 619        fputc('\n', stderr);
 620}
 621
 622static void dump_grep_expression_1(struct grep_expr *x, int in)
 623{
 624        indent(in);
 625        switch (x->node) {
 626        case GREP_NODE_TRUE:
 627                fprintf(stderr, "true\n");
 628                break;
 629        case GREP_NODE_ATOM:
 630                dump_grep_pat(x->u.atom);
 631                break;
 632        case GREP_NODE_NOT:
 633                fprintf(stderr, "(not\n");
 634                dump_grep_expression_1(x->u.unary, in+1);
 635                indent(in);
 636                fprintf(stderr, ")\n");
 637                break;
 638        case GREP_NODE_AND:
 639                fprintf(stderr, "(and\n");
 640                dump_grep_expression_1(x->u.binary.left, in+1);
 641                dump_grep_expression_1(x->u.binary.right, in+1);
 642                indent(in);
 643                fprintf(stderr, ")\n");
 644                break;
 645        case GREP_NODE_OR:
 646                fprintf(stderr, "(or\n");
 647                dump_grep_expression_1(x->u.binary.left, in+1);
 648                dump_grep_expression_1(x->u.binary.right, in+1);
 649                indent(in);
 650                fprintf(stderr, ")\n");
 651                break;
 652        }
 653}
 654
 655static void dump_grep_expression(struct grep_opt *opt)
 656{
 657        struct grep_expr *x = opt->pattern_expression;
 658
 659        if (opt->all_match)
 660                fprintf(stderr, "[all-match]\n");
 661        dump_grep_expression_1(x, 0);
 662        fflush(NULL);
 663}
 664
 665static struct grep_expr *grep_true_expr(void)
 666{
 667        struct grep_expr *z = xcalloc(1, sizeof(*z));
 668        z->node = GREP_NODE_TRUE;
 669        return z;
 670}
 671
 672static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 673{
 674        struct grep_expr *z = xcalloc(1, sizeof(*z));
 675        z->node = GREP_NODE_OR;
 676        z->u.binary.left = left;
 677        z->u.binary.right = right;
 678        return z;
 679}
 680
 681static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 682{
 683        struct grep_pat *p;
 684        struct grep_expr *header_expr;
 685        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 686        enum grep_header_field fld;
 687
 688        if (!opt->header_list)
 689                return NULL;
 690
 691        for (p = opt->header_list; p; p = p->next) {
 692                if (p->token != GREP_PATTERN_HEAD)
 693                        die("bug: a non-header pattern in grep header list.");
 694                if (p->field < GREP_HEADER_FIELD_MIN ||
 695                    GREP_HEADER_FIELD_MAX <= p->field)
 696                        die("bug: unknown header field %d", p->field);
 697                compile_regexp(p, opt);
 698        }
 699
 700        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 701                header_group[fld] = NULL;
 702
 703        for (p = opt->header_list; p; p = p->next) {
 704                struct grep_expr *h;
 705                struct grep_pat *pp = p;
 706
 707                h = compile_pattern_atom(&pp);
 708                if (!h || pp != p->next)
 709                        die("bug: malformed header expr");
 710                if (!header_group[p->field]) {
 711                        header_group[p->field] = h;
 712                        continue;
 713                }
 714                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 715        }
 716
 717        header_expr = NULL;
 718
 719        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 720                if (!header_group[fld])
 721                        continue;
 722                if (!header_expr)
 723                        header_expr = grep_true_expr();
 724                header_expr = grep_or_expr(header_group[fld], header_expr);
 725        }
 726        return header_expr;
 727}
 728
 729static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 730{
 731        struct grep_expr *z = x;
 732
 733        while (x) {
 734                assert(x->node == GREP_NODE_OR);
 735                if (x->u.binary.right &&
 736                    x->u.binary.right->node == GREP_NODE_TRUE) {
 737                        x->u.binary.right = y;
 738                        break;
 739                }
 740                x = x->u.binary.right;
 741        }
 742        return z;
 743}
 744
 745static void compile_grep_patterns_real(struct grep_opt *opt)
 746{
 747        struct grep_pat *p;
 748        struct grep_expr *header_expr = prep_header_patterns(opt);
 749
 750        for (p = opt->pattern_list; p; p = p->next) {
 751                switch (p->token) {
 752                case GREP_PATTERN: /* atom */
 753                case GREP_PATTERN_HEAD:
 754                case GREP_PATTERN_BODY:
 755                        compile_regexp(p, opt);
 756                        break;
 757                default:
 758                        opt->extended = 1;
 759                        break;
 760                }
 761        }
 762
 763        if (opt->all_match || header_expr)
 764                opt->extended = 1;
 765        else if (!opt->extended && !opt->debug)
 766                return;
 767
 768        p = opt->pattern_list;
 769        if (p)
 770                opt->pattern_expression = compile_pattern_expr(&p);
 771        if (p)
 772                die("incomplete pattern expression: %s", p->pattern);
 773
 774        if (!header_expr)
 775                return;
 776
 777        if (!opt->pattern_expression)
 778                opt->pattern_expression = header_expr;
 779        else if (opt->all_match)
 780                opt->pattern_expression = grep_splice_or(header_expr,
 781                                                         opt->pattern_expression);
 782        else
 783                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 784                                                       header_expr);
 785        opt->all_match = 1;
 786}
 787
 788void compile_grep_patterns(struct grep_opt *opt)
 789{
 790        compile_grep_patterns_real(opt);
 791        if (opt->debug)
 792                dump_grep_expression(opt);
 793}
 794
 795static void free_pattern_expr(struct grep_expr *x)
 796{
 797        switch (x->node) {
 798        case GREP_NODE_TRUE:
 799        case GREP_NODE_ATOM:
 800                break;
 801        case GREP_NODE_NOT:
 802                free_pattern_expr(x->u.unary);
 803                break;
 804        case GREP_NODE_AND:
 805        case GREP_NODE_OR:
 806                free_pattern_expr(x->u.binary.left);
 807                free_pattern_expr(x->u.binary.right);
 808                break;
 809        }
 810        free(x);
 811}
 812
 813void free_grep_patterns(struct grep_opt *opt)
 814{
 815        struct grep_pat *p, *n;
 816
 817        for (p = opt->pattern_list; p; p = n) {
 818                n = p->next;
 819                switch (p->token) {
 820                case GREP_PATTERN: /* atom */
 821                case GREP_PATTERN_HEAD:
 822                case GREP_PATTERN_BODY:
 823                        if (p->kws)
 824                                kwsfree(p->kws);
 825                        else if (p->pcre_regexp)
 826                                free_pcre_regexp(p);
 827                        else
 828                                regfree(&p->regexp);
 829                        free(p->pattern);
 830                        break;
 831                default:
 832                        break;
 833                }
 834                free(p);
 835        }
 836
 837        if (!opt->extended)
 838                return;
 839        free_pattern_expr(opt->pattern_expression);
 840}
 841
 842static char *end_of_line(char *cp, unsigned long *left)
 843{
 844        unsigned long l = *left;
 845        while (l && *cp != '\n') {
 846                l--;
 847                cp++;
 848        }
 849        *left = l;
 850        return cp;
 851}
 852
 853static int word_char(char ch)
 854{
 855        return isalnum(ch) || ch == '_';
 856}
 857
 858static void output_color(struct grep_opt *opt, const void *data, size_t size,
 859                         const char *color)
 860{
 861        if (want_color(opt->color) && color && color[0]) {
 862                opt->output(opt, color, strlen(color));
 863                opt->output(opt, data, size);
 864                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 865        } else
 866                opt->output(opt, data, size);
 867}
 868
 869static void output_sep(struct grep_opt *opt, char sign)
 870{
 871        if (opt->null_following_name)
 872                opt->output(opt, "\0", 1);
 873        else
 874                output_color(opt, &sign, 1, opt->color_sep);
 875}
 876
 877static void show_name(struct grep_opt *opt, const char *name)
 878{
 879        output_color(opt, name, strlen(name), opt->color_filename);
 880        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 881}
 882
 883static int fixmatch(struct grep_pat *p, char *line, char *eol,
 884                    regmatch_t *match)
 885{
 886        struct kwsmatch kwsm;
 887        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 888        if (offset == -1) {
 889                match->rm_so = match->rm_eo = -1;
 890                return REG_NOMATCH;
 891        } else {
 892                match->rm_so = offset;
 893                match->rm_eo = match->rm_so + kwsm.size[0];
 894                return 0;
 895        }
 896}
 897
 898static int regmatch(const regex_t *preg, char *line, char *eol,
 899                    regmatch_t *match, int eflags)
 900{
 901#ifdef REG_STARTEND
 902        match->rm_so = 0;
 903        match->rm_eo = eol - line;
 904        eflags |= REG_STARTEND;
 905#endif
 906        return regexec(preg, line, 1, match, eflags);
 907}
 908
 909static int patmatch(struct grep_pat *p, char *line, char *eol,
 910                    regmatch_t *match, int eflags)
 911{
 912        int hit;
 913
 914        if (p->fixed)
 915                hit = !fixmatch(p, line, eol, match);
 916        else if (p->pcre_regexp)
 917                hit = !pcrematch(p, line, eol, match, eflags);
 918        else
 919                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 920
 921        return hit;
 922}
 923
 924static int strip_timestamp(char *bol, char **eol_p)
 925{
 926        char *eol = *eol_p;
 927        int ch;
 928
 929        while (bol < --eol) {
 930                if (*eol != '>')
 931                        continue;
 932                *eol_p = ++eol;
 933                ch = *eol;
 934                *eol = '\0';
 935                return ch;
 936        }
 937        return 0;
 938}
 939
 940static struct {
 941        const char *field;
 942        size_t len;
 943} header_field[] = {
 944        { "author ", 7 },
 945        { "committer ", 10 },
 946        { "reflog ", 7 },
 947};
 948
 949static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 950                             enum grep_context ctx,
 951                             regmatch_t *pmatch, int eflags)
 952{
 953        int hit = 0;
 954        int saved_ch = 0;
 955        const char *start = bol;
 956
 957        if ((p->token != GREP_PATTERN) &&
 958            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 959                return 0;
 960
 961        if (p->token == GREP_PATTERN_HEAD) {
 962                const char *field;
 963                size_t len;
 964                assert(p->field < ARRAY_SIZE(header_field));
 965                field = header_field[p->field].field;
 966                len = header_field[p->field].len;
 967                if (strncmp(bol, field, len))
 968                        return 0;
 969                bol += len;
 970                switch (p->field) {
 971                case GREP_HEADER_AUTHOR:
 972                case GREP_HEADER_COMMITTER:
 973                        saved_ch = strip_timestamp(bol, &eol);
 974                        break;
 975                default:
 976                        break;
 977                }
 978        }
 979
 980 again:
 981        hit = patmatch(p, bol, eol, pmatch, eflags);
 982
 983        if (hit && p->word_regexp) {
 984                if ((pmatch[0].rm_so < 0) ||
 985                    (eol - bol) < pmatch[0].rm_so ||
 986                    (pmatch[0].rm_eo < 0) ||
 987                    (eol - bol) < pmatch[0].rm_eo)
 988                        die("regexp returned nonsense");
 989
 990                /* Match beginning must be either beginning of the
 991                 * line, or at word boundary (i.e. the last char must
 992                 * not be a word char).  Similarly, match end must be
 993                 * either end of the line, or at word boundary
 994                 * (i.e. the next char must not be a word char).
 995                 */
 996                if ( ((pmatch[0].rm_so == 0) ||
 997                      !word_char(bol[pmatch[0].rm_so-1])) &&
 998                     ((pmatch[0].rm_eo == (eol-bol)) ||
 999                      !word_char(bol[pmatch[0].rm_eo])) )
1000                        ;
1001                else
1002                        hit = 0;
1003
1004                /* Words consist of at least one character. */
1005                if (pmatch->rm_so == pmatch->rm_eo)
1006                        hit = 0;
1007
1008                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1009                        /* There could be more than one match on the
1010                         * line, and the first match might not be
1011                         * strict word match.  But later ones could be!
1012                         * Forward to the next possible start, i.e. the
1013                         * next position following a non-word char.
1014                         */
1015                        bol = pmatch[0].rm_so + bol + 1;
1016                        while (word_char(bol[-1]) && bol < eol)
1017                                bol++;
1018                        eflags |= REG_NOTBOL;
1019                        if (bol < eol)
1020                                goto again;
1021                }
1022        }
1023        if (p->token == GREP_PATTERN_HEAD && saved_ch)
1024                *eol = saved_ch;
1025        if (hit) {
1026                pmatch[0].rm_so += bol - start;
1027                pmatch[0].rm_eo += bol - start;
1028        }
1029        return hit;
1030}
1031
1032static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1033                           enum grep_context ctx, int collect_hits)
1034{
1035        int h = 0;
1036        regmatch_t match;
1037
1038        if (!x)
1039                die("Not a valid grep expression");
1040        switch (x->node) {
1041        case GREP_NODE_TRUE:
1042                h = 1;
1043                break;
1044        case GREP_NODE_ATOM:
1045                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1046                break;
1047        case GREP_NODE_NOT:
1048                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1049                break;
1050        case GREP_NODE_AND:
1051                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1052                        return 0;
1053                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1054                break;
1055        case GREP_NODE_OR:
1056                if (!collect_hits)
1057                        return (match_expr_eval(x->u.binary.left,
1058                                                bol, eol, ctx, 0) ||
1059                                match_expr_eval(x->u.binary.right,
1060                                                bol, eol, ctx, 0));
1061                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1062                x->u.binary.left->hit |= h;
1063                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1064                break;
1065        default:
1066                die("Unexpected node type (internal error) %d", x->node);
1067        }
1068        if (collect_hits)
1069                x->hit |= h;
1070        return h;
1071}
1072
1073static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1074                      enum grep_context ctx, int collect_hits)
1075{
1076        struct grep_expr *x = opt->pattern_expression;
1077        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1078}
1079
1080static int match_line(struct grep_opt *opt, char *bol, char *eol,
1081                      enum grep_context ctx, int collect_hits)
1082{
1083        struct grep_pat *p;
1084        regmatch_t match;
1085
1086        if (opt->extended)
1087                return match_expr(opt, bol, eol, ctx, collect_hits);
1088
1089        /* we do not call with collect_hits without being extended */
1090        for (p = opt->pattern_list; p; p = p->next) {
1091                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1092                        return 1;
1093        }
1094        return 0;
1095}
1096
1097static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1098                              enum grep_context ctx,
1099                              regmatch_t *pmatch, int eflags)
1100{
1101        regmatch_t match;
1102
1103        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1104                return 0;
1105        if (match.rm_so < 0 || match.rm_eo < 0)
1106                return 0;
1107        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1108                if (match.rm_so > pmatch->rm_so)
1109                        return 1;
1110                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1111                        return 1;
1112        }
1113        pmatch->rm_so = match.rm_so;
1114        pmatch->rm_eo = match.rm_eo;
1115        return 1;
1116}
1117
1118static int next_match(struct grep_opt *opt, char *bol, char *eol,
1119                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1120{
1121        struct grep_pat *p;
1122        int hit = 0;
1123
1124        pmatch->rm_so = pmatch->rm_eo = -1;
1125        if (bol < eol) {
1126                for (p = opt->pattern_list; p; p = p->next) {
1127                        switch (p->token) {
1128                        case GREP_PATTERN: /* atom */
1129                        case GREP_PATTERN_HEAD:
1130                        case GREP_PATTERN_BODY:
1131                                hit |= match_next_pattern(p, bol, eol, ctx,
1132                                                          pmatch, eflags);
1133                                break;
1134                        default:
1135                                break;
1136                        }
1137                }
1138        }
1139        return hit;
1140}
1141
1142static void show_line(struct grep_opt *opt, char *bol, char *eol,
1143                      const char *name, unsigned lno, char sign)
1144{
1145        int rest = eol - bol;
1146        const char *match_color, *line_color = NULL;
1147
1148        if (opt->file_break && opt->last_shown == 0) {
1149                if (opt->show_hunk_mark)
1150                        opt->output(opt, "\n", 1);
1151        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1152                if (opt->last_shown == 0) {
1153                        if (opt->show_hunk_mark) {
1154                                output_color(opt, "--", 2, opt->color_sep);
1155                                opt->output(opt, "\n", 1);
1156                        }
1157                } else if (lno > opt->last_shown + 1) {
1158                        output_color(opt, "--", 2, opt->color_sep);
1159                        opt->output(opt, "\n", 1);
1160                }
1161        }
1162        if (opt->heading && opt->last_shown == 0) {
1163                output_color(opt, name, strlen(name), opt->color_filename);
1164                opt->output(opt, "\n", 1);
1165        }
1166        opt->last_shown = lno;
1167
1168        if (!opt->heading && opt->pathname) {
1169                output_color(opt, name, strlen(name), opt->color_filename);
1170                output_sep(opt, sign);
1171        }
1172        if (opt->linenum) {
1173                char buf[32];
1174                snprintf(buf, sizeof(buf), "%d", lno);
1175                output_color(opt, buf, strlen(buf), opt->color_lineno);
1176                output_sep(opt, sign);
1177        }
1178        if (opt->color) {
1179                regmatch_t match;
1180                enum grep_context ctx = GREP_CONTEXT_BODY;
1181                int ch = *eol;
1182                int eflags = 0;
1183
1184                if (sign == ':')
1185                        match_color = opt->color_match_selected;
1186                else
1187                        match_color = opt->color_match_context;
1188                if (sign == ':')
1189                        line_color = opt->color_selected;
1190                else if (sign == '-')
1191                        line_color = opt->color_context;
1192                else if (sign == '=')
1193                        line_color = opt->color_function;
1194                *eol = '\0';
1195                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1196                        if (match.rm_so == match.rm_eo)
1197                                break;
1198
1199                        output_color(opt, bol, match.rm_so, line_color);
1200                        output_color(opt, bol + match.rm_so,
1201                                     match.rm_eo - match.rm_so, match_color);
1202                        bol += match.rm_eo;
1203                        rest -= match.rm_eo;
1204                        eflags = REG_NOTBOL;
1205                }
1206                *eol = ch;
1207        }
1208        output_color(opt, bol, rest, line_color);
1209        opt->output(opt, "\n", 1);
1210}
1211
1212#ifndef NO_PTHREADS
1213int grep_use_locks;
1214
1215/*
1216 * This lock protects access to the gitattributes machinery, which is
1217 * not thread-safe.
1218 */
1219pthread_mutex_t grep_attr_mutex;
1220
1221static inline void grep_attr_lock(void)
1222{
1223        if (grep_use_locks)
1224                pthread_mutex_lock(&grep_attr_mutex);
1225}
1226
1227static inline void grep_attr_unlock(void)
1228{
1229        if (grep_use_locks)
1230                pthread_mutex_unlock(&grep_attr_mutex);
1231}
1232
1233/*
1234 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1235 */
1236pthread_mutex_t grep_read_mutex;
1237
1238#else
1239#define grep_attr_lock()
1240#define grep_attr_unlock()
1241#endif
1242
1243static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1244{
1245        xdemitconf_t *xecfg = opt->priv;
1246        if (xecfg && !xecfg->find_func) {
1247                grep_source_load_driver(gs);
1248                if (gs->driver->funcname.pattern) {
1249                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1250                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1251                } else {
1252                        xecfg = opt->priv = NULL;
1253                }
1254        }
1255
1256        if (xecfg) {
1257                char buf[1];
1258                return xecfg->find_func(bol, eol - bol, buf, 1,
1259                                        xecfg->find_func_priv) >= 0;
1260        }
1261
1262        if (bol == eol)
1263                return 0;
1264        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1265                return 1;
1266        return 0;
1267}
1268
1269static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1270                               char *bol, unsigned lno)
1271{
1272        while (bol > gs->buf) {
1273                char *eol = --bol;
1274
1275                while (bol > gs->buf && bol[-1] != '\n')
1276                        bol--;
1277                lno--;
1278
1279                if (lno <= opt->last_shown)
1280                        break;
1281
1282                if (match_funcname(opt, gs, bol, eol)) {
1283                        show_line(opt, bol, eol, gs->name, lno, '=');
1284                        break;
1285                }
1286        }
1287}
1288
1289static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1290                             char *bol, char *end, unsigned lno)
1291{
1292        unsigned cur = lno, from = 1, funcname_lno = 0;
1293        int funcname_needed = !!opt->funcname;
1294
1295        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1296                funcname_needed = 2;
1297
1298        if (opt->pre_context < lno)
1299                from = lno - opt->pre_context;
1300        if (from <= opt->last_shown)
1301                from = opt->last_shown + 1;
1302
1303        /* Rewind. */
1304        while (bol > gs->buf &&
1305               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1306                char *eol = --bol;
1307
1308                while (bol > gs->buf && bol[-1] != '\n')
1309                        bol--;
1310                cur--;
1311                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1312                        funcname_lno = cur;
1313                        funcname_needed = 0;
1314                }
1315        }
1316
1317        /* We need to look even further back to find a function signature. */
1318        if (opt->funcname && funcname_needed)
1319                show_funcname_line(opt, gs, bol, cur);
1320
1321        /* Back forward. */
1322        while (cur < lno) {
1323                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1324
1325                while (*eol != '\n')
1326                        eol++;
1327                show_line(opt, bol, eol, gs->name, cur, sign);
1328                bol = eol + 1;
1329                cur++;
1330        }
1331}
1332
1333static int should_lookahead(struct grep_opt *opt)
1334{
1335        struct grep_pat *p;
1336
1337        if (opt->extended)
1338                return 0; /* punt for too complex stuff */
1339        if (opt->invert)
1340                return 0;
1341        for (p = opt->pattern_list; p; p = p->next) {
1342                if (p->token != GREP_PATTERN)
1343                        return 0; /* punt for "header only" and stuff */
1344        }
1345        return 1;
1346}
1347
1348static int look_ahead(struct grep_opt *opt,
1349                      unsigned long *left_p,
1350                      unsigned *lno_p,
1351                      char **bol_p)
1352{
1353        unsigned lno = *lno_p;
1354        char *bol = *bol_p;
1355        struct grep_pat *p;
1356        char *sp, *last_bol;
1357        regoff_t earliest = -1;
1358
1359        for (p = opt->pattern_list; p; p = p->next) {
1360                int hit;
1361                regmatch_t m;
1362
1363                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1364                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1365                        continue;
1366                if (earliest < 0 || m.rm_so < earliest)
1367                        earliest = m.rm_so;
1368        }
1369
1370        if (earliest < 0) {
1371                *bol_p = bol + *left_p;
1372                *left_p = 0;
1373                return 1;
1374        }
1375        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1376                ; /* find the beginning of the line */
1377        last_bol = sp;
1378
1379        for (sp = bol; sp < last_bol; sp++) {
1380                if (*sp == '\n')
1381                        lno++;
1382        }
1383        *left_p -= last_bol - bol;
1384        *bol_p = last_bol;
1385        *lno_p = lno;
1386        return 0;
1387}
1388
1389static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1390{
1391        fwrite(buf, size, 1, stdout);
1392}
1393
1394static int fill_textconv_grep(struct userdiff_driver *driver,
1395                              struct grep_source *gs)
1396{
1397        struct diff_filespec *df;
1398        char *buf;
1399        size_t size;
1400
1401        if (!driver || !driver->textconv)
1402                return grep_source_load(gs);
1403
1404        /*
1405         * The textconv interface is intimately tied to diff_filespecs, so we
1406         * have to pretend to be one. If we could unify the grep_source
1407         * and diff_filespec structs, this mess could just go away.
1408         */
1409        df = alloc_filespec(gs->path);
1410        switch (gs->type) {
1411        case GREP_SOURCE_SHA1:
1412                fill_filespec(df, gs->identifier, 1, 0100644);
1413                break;
1414        case GREP_SOURCE_FILE:
1415                fill_filespec(df, null_sha1, 0, 0100644);
1416                break;
1417        default:
1418                die("BUG: attempt to textconv something without a path?");
1419        }
1420
1421        /*
1422         * fill_textconv is not remotely thread-safe; it may load objects
1423         * behind the scenes, and it modifies the global diff tempfile
1424         * structure.
1425         */
1426        grep_read_lock();
1427        size = fill_textconv(driver, df, &buf);
1428        grep_read_unlock();
1429        free_filespec(df);
1430
1431        /*
1432         * The normal fill_textconv usage by the diff machinery would just keep
1433         * the textconv'd buf separate from the diff_filespec. But much of the
1434         * grep code passes around a grep_source and assumes that its "buf"
1435         * pointer is the beginning of the thing we are searching. So let's
1436         * install our textconv'd version into the grep_source, taking care not
1437         * to leak any existing buffer.
1438         */
1439        grep_source_clear_data(gs);
1440        gs->buf = buf;
1441        gs->size = size;
1442
1443        return 0;
1444}
1445
1446static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1447{
1448        char *bol;
1449        unsigned long left;
1450        unsigned lno = 1;
1451        unsigned last_hit = 0;
1452        int binary_match_only = 0;
1453        unsigned count = 0;
1454        int try_lookahead = 0;
1455        int show_function = 0;
1456        struct userdiff_driver *textconv = NULL;
1457        enum grep_context ctx = GREP_CONTEXT_HEAD;
1458        xdemitconf_t xecfg;
1459
1460        if (!opt->output)
1461                opt->output = std_output;
1462
1463        if (opt->pre_context || opt->post_context || opt->file_break ||
1464            opt->funcbody) {
1465                /* Show hunk marks, except for the first file. */
1466                if (opt->last_shown)
1467                        opt->show_hunk_mark = 1;
1468                /*
1469                 * If we're using threads then we can't easily identify
1470                 * the first file.  Always put hunk marks in that case
1471                 * and skip the very first one later in work_done().
1472                 */
1473                if (opt->output != std_output)
1474                        opt->show_hunk_mark = 1;
1475        }
1476        opt->last_shown = 0;
1477
1478        if (opt->allow_textconv) {
1479                grep_source_load_driver(gs);
1480                /*
1481                 * We might set up the shared textconv cache data here, which
1482                 * is not thread-safe.
1483                 */
1484                grep_attr_lock();
1485                textconv = userdiff_get_textconv(gs->driver);
1486                grep_attr_unlock();
1487        }
1488
1489        /*
1490         * We know the result of a textconv is text, so we only have to care
1491         * about binary handling if we are not using it.
1492         */
1493        if (!textconv) {
1494                switch (opt->binary) {
1495                case GREP_BINARY_DEFAULT:
1496                        if (grep_source_is_binary(gs))
1497                                binary_match_only = 1;
1498                        break;
1499                case GREP_BINARY_NOMATCH:
1500                        if (grep_source_is_binary(gs))
1501                                return 0; /* Assume unmatch */
1502                        break;
1503                case GREP_BINARY_TEXT:
1504                        break;
1505                default:
1506                        die("bug: unknown binary handling mode");
1507                }
1508        }
1509
1510        memset(&xecfg, 0, sizeof(xecfg));
1511        opt->priv = &xecfg;
1512
1513        try_lookahead = should_lookahead(opt);
1514
1515        if (fill_textconv_grep(textconv, gs) < 0)
1516                return 0;
1517
1518        bol = gs->buf;
1519        left = gs->size;
1520        while (left) {
1521                char *eol, ch;
1522                int hit;
1523
1524                /*
1525                 * look_ahead() skips quickly to the line that possibly
1526                 * has the next hit; don't call it if we need to do
1527                 * something more than just skipping the current line
1528                 * in response to an unmatch for the current line.  E.g.
1529                 * inside a post-context window, we will show the current
1530                 * line as a context around the previous hit when it
1531                 * doesn't hit.
1532                 */
1533                if (try_lookahead
1534                    && !(last_hit
1535                         && (show_function ||
1536                             lno <= last_hit + opt->post_context))
1537                    && look_ahead(opt, &left, &lno, &bol))
1538                        break;
1539                eol = end_of_line(bol, &left);
1540                ch = *eol;
1541                *eol = 0;
1542
1543                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1544                        ctx = GREP_CONTEXT_BODY;
1545
1546                hit = match_line(opt, bol, eol, ctx, collect_hits);
1547                *eol = ch;
1548
1549                if (collect_hits)
1550                        goto next_line;
1551
1552                /* "grep -v -e foo -e bla" should list lines
1553                 * that do not have either, so inversion should
1554                 * be done outside.
1555                 */
1556                if (opt->invert)
1557                        hit = !hit;
1558                if (opt->unmatch_name_only) {
1559                        if (hit)
1560                                return 0;
1561                        goto next_line;
1562                }
1563                if (hit) {
1564                        count++;
1565                        if (opt->status_only)
1566                                return 1;
1567                        if (opt->name_only) {
1568                                show_name(opt, gs->name);
1569                                return 1;
1570                        }
1571                        if (opt->count)
1572                                goto next_line;
1573                        if (binary_match_only) {
1574                                opt->output(opt, "Binary file ", 12);
1575                                output_color(opt, gs->name, strlen(gs->name),
1576                                             opt->color_filename);
1577                                opt->output(opt, " matches\n", 9);
1578                                return 1;
1579                        }
1580                        /* Hit at this line.  If we haven't shown the
1581                         * pre-context lines, we would need to show them.
1582                         */
1583                        if (opt->pre_context || opt->funcbody)
1584                                show_pre_context(opt, gs, bol, eol, lno);
1585                        else if (opt->funcname)
1586                                show_funcname_line(opt, gs, bol, lno);
1587                        show_line(opt, bol, eol, gs->name, lno, ':');
1588                        last_hit = lno;
1589                        if (opt->funcbody)
1590                                show_function = 1;
1591                        goto next_line;
1592                }
1593                if (show_function && match_funcname(opt, gs, bol, eol))
1594                        show_function = 0;
1595                if (show_function ||
1596                    (last_hit && lno <= last_hit + opt->post_context)) {
1597                        /* If the last hit is within the post context,
1598                         * we need to show this line.
1599                         */
1600                        show_line(opt, bol, eol, gs->name, lno, '-');
1601                }
1602
1603        next_line:
1604                bol = eol + 1;
1605                if (!left)
1606                        break;
1607                left--;
1608                lno++;
1609        }
1610
1611        if (collect_hits)
1612                return 0;
1613
1614        if (opt->status_only)
1615                return 0;
1616        if (opt->unmatch_name_only) {
1617                /* We did not see any hit, so we want to show this */
1618                show_name(opt, gs->name);
1619                return 1;
1620        }
1621
1622        xdiff_clear_find_func(&xecfg);
1623        opt->priv = NULL;
1624
1625        /* NEEDSWORK:
1626         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1627         * which feels mostly useless but sometimes useful.  Maybe
1628         * make it another option?  For now suppress them.
1629         */
1630        if (opt->count && count) {
1631                char buf[32];
1632                if (opt->pathname) {
1633                        output_color(opt, gs->name, strlen(gs->name),
1634                                     opt->color_filename);
1635                        output_sep(opt, ':');
1636                }
1637                snprintf(buf, sizeof(buf), "%u\n", count);
1638                opt->output(opt, buf, strlen(buf));
1639                return 1;
1640        }
1641        return !!last_hit;
1642}
1643
1644static void clr_hit_marker(struct grep_expr *x)
1645{
1646        /* All-hit markers are meaningful only at the very top level
1647         * OR node.
1648         */
1649        while (1) {
1650                x->hit = 0;
1651                if (x->node != GREP_NODE_OR)
1652                        return;
1653                x->u.binary.left->hit = 0;
1654                x = x->u.binary.right;
1655        }
1656}
1657
1658static int chk_hit_marker(struct grep_expr *x)
1659{
1660        /* Top level nodes have hit markers.  See if they all are hits */
1661        while (1) {
1662                if (x->node != GREP_NODE_OR)
1663                        return x->hit;
1664                if (!x->u.binary.left->hit)
1665                        return 0;
1666                x = x->u.binary.right;
1667        }
1668}
1669
1670int grep_source(struct grep_opt *opt, struct grep_source *gs)
1671{
1672        /*
1673         * we do not have to do the two-pass grep when we do not check
1674         * buffer-wide "all-match".
1675         */
1676        if (!opt->all_match)
1677                return grep_source_1(opt, gs, 0);
1678
1679        /* Otherwise the toplevel "or" terms hit a bit differently.
1680         * We first clear hit markers from them.
1681         */
1682        clr_hit_marker(opt->pattern_expression);
1683        grep_source_1(opt, gs, 1);
1684
1685        if (!chk_hit_marker(opt->pattern_expression))
1686                return 0;
1687
1688        return grep_source_1(opt, gs, 0);
1689}
1690
1691int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1692{
1693        struct grep_source gs;
1694        int r;
1695
1696        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1697        gs.buf = buf;
1698        gs.size = size;
1699
1700        r = grep_source(opt, &gs);
1701
1702        grep_source_clear(&gs);
1703        return r;
1704}
1705
1706void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1707                      const char *name, const char *path,
1708                      const void *identifier)
1709{
1710        gs->type = type;
1711        gs->name = xstrdup_or_null(name);
1712        gs->path = xstrdup_or_null(path);
1713        gs->buf = NULL;
1714        gs->size = 0;
1715        gs->driver = NULL;
1716
1717        switch (type) {
1718        case GREP_SOURCE_FILE:
1719                gs->identifier = xstrdup(identifier);
1720                break;
1721        case GREP_SOURCE_SHA1:
1722                gs->identifier = xmalloc(20);
1723                hashcpy(gs->identifier, identifier);
1724                break;
1725        case GREP_SOURCE_BUF:
1726                gs->identifier = NULL;
1727        }
1728}
1729
1730void grep_source_clear(struct grep_source *gs)
1731{
1732        free(gs->name);
1733        gs->name = NULL;
1734        free(gs->path);
1735        gs->path = NULL;
1736        free(gs->identifier);
1737        gs->identifier = NULL;
1738        grep_source_clear_data(gs);
1739}
1740
1741void grep_source_clear_data(struct grep_source *gs)
1742{
1743        switch (gs->type) {
1744        case GREP_SOURCE_FILE:
1745        case GREP_SOURCE_SHA1:
1746                free(gs->buf);
1747                gs->buf = NULL;
1748                gs->size = 0;
1749                break;
1750        case GREP_SOURCE_BUF:
1751                /* leave user-provided buf intact */
1752                break;
1753        }
1754}
1755
1756static int grep_source_load_sha1(struct grep_source *gs)
1757{
1758        enum object_type type;
1759
1760        grep_read_lock();
1761        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1762        grep_read_unlock();
1763
1764        if (!gs->buf)
1765                return error(_("'%s': unable to read %s"),
1766                             gs->name,
1767                             sha1_to_hex(gs->identifier));
1768        return 0;
1769}
1770
1771static int grep_source_load_file(struct grep_source *gs)
1772{
1773        const char *filename = gs->identifier;
1774        struct stat st;
1775        char *data;
1776        size_t size;
1777        int i;
1778
1779        if (lstat(filename, &st) < 0) {
1780        err_ret:
1781                if (errno != ENOENT)
1782                        error(_("'%s': %s"), filename, strerror(errno));
1783                return -1;
1784        }
1785        if (!S_ISREG(st.st_mode))
1786                return -1;
1787        size = xsize_t(st.st_size);
1788        i = open(filename, O_RDONLY);
1789        if (i < 0)
1790                goto err_ret;
1791        data = xmalloc(size + 1);
1792        if (st.st_size != read_in_full(i, data, size)) {
1793                error(_("'%s': short read %s"), filename, strerror(errno));
1794                close(i);
1795                free(data);
1796                return -1;
1797        }
1798        close(i);
1799        data[size] = 0;
1800
1801        gs->buf = data;
1802        gs->size = size;
1803        return 0;
1804}
1805
1806static int grep_source_load(struct grep_source *gs)
1807{
1808        if (gs->buf)
1809                return 0;
1810
1811        switch (gs->type) {
1812        case GREP_SOURCE_FILE:
1813                return grep_source_load_file(gs);
1814        case GREP_SOURCE_SHA1:
1815                return grep_source_load_sha1(gs);
1816        case GREP_SOURCE_BUF:
1817                return gs->buf ? 0 : -1;
1818        }
1819        die("BUG: invalid grep_source type");
1820}
1821
1822void grep_source_load_driver(struct grep_source *gs)
1823{
1824        if (gs->driver)
1825                return;
1826
1827        grep_attr_lock();
1828        if (gs->path)
1829                gs->driver = userdiff_find_by_path(gs->path);
1830        if (!gs->driver)
1831                gs->driver = userdiff_find_by_name("default");
1832        grep_attr_unlock();
1833}
1834
1835static int grep_source_is_binary(struct grep_source *gs)
1836{
1837        grep_source_load_driver(gs);
1838        if (gs->driver->binary != -1)
1839                return gs->driver->binary;
1840
1841        if (!grep_source_load(gs))
1842                return buffer_is_binary(gs->buf, gs->size);
1843
1844        return 0;
1845}