Andrew's git / gitweb.git / grep.c
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grep.con commit gettext: add is_utf8_locale() (e8c1672)
   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                if (has_non_ascii(p->pattern))
 329                        p->pcre_tables = pcre_maketables();
 330                options |= PCRE_CASELESS;
 331        }
 332
 333        p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 334                                      p->pcre_tables);
 335        if (!p->pcre_regexp)
 336                compile_regexp_failed(p, error);
 337
 338        p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 339        if (!p->pcre_extra_info && error)
 340                die("%s", error);
 341}
 342
 343static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 344                regmatch_t *match, int eflags)
 345{
 346        int ovector[30], ret, flags = 0;
 347
 348        if (eflags & REG_NOTBOL)
 349                flags |= PCRE_NOTBOL;
 350
 351        ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 352                        0, flags, ovector, ARRAY_SIZE(ovector));
 353        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 354                die("pcre_exec failed with error code %d", ret);
 355        if (ret > 0) {
 356                ret = 0;
 357                match->rm_so = ovector[0];
 358                match->rm_eo = ovector[1];
 359        }
 360
 361        return ret;
 362}
 363
 364static void free_pcre_regexp(struct grep_pat *p)
 365{
 366        pcre_free(p->pcre_regexp);
 367        pcre_free(p->pcre_extra_info);
 368        pcre_free((void *)p->pcre_tables);
 369}
 370#else /* !USE_LIBPCRE */
 371static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 372{
 373        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 374}
 375
 376static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 377                regmatch_t *match, int eflags)
 378{
 379        return 1;
 380}
 381
 382static void free_pcre_regexp(struct grep_pat *p)
 383{
 384}
 385#endif /* !USE_LIBPCRE */
 386
 387static int is_fixed(const char *s, size_t len)
 388{
 389        size_t i;
 390
 391        /* regcomp cannot accept patterns with NULs so we
 392         * consider any pattern containing a NUL fixed.
 393         */
 394        if (memchr(s, 0, len))
 395                return 1;
 396
 397        for (i = 0; i < len; i++) {
 398                if (is_regex_special(s[i]))
 399                        return 0;
 400        }
 401
 402        return 1;
 403}
 404
 405static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 406{
 407        struct strbuf sb = STRBUF_INIT;
 408        int err;
 409        int regflags;
 410
 411        basic_regex_quote_buf(&sb, p->pattern);
 412        regflags = opt->regflags & ~REG_EXTENDED;
 413        if (opt->ignore_case)
 414                regflags |= REG_ICASE;
 415        err = regcomp(&p->regexp, sb.buf, regflags);
 416        if (opt->debug)
 417                fprintf(stderr, "fixed %s\n", sb.buf);
 418        strbuf_release(&sb);
 419        if (err) {
 420                char errbuf[1024];
 421                regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 422                regfree(&p->regexp);
 423                compile_regexp_failed(p, errbuf);
 424        }
 425}
 426
 427static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 428{
 429        int icase, ascii_only;
 430        int err;
 431
 432        p->word_regexp = opt->word_regexp;
 433        p->ignore_case = opt->ignore_case;
 434        icase          = opt->regflags & REG_ICASE || p->ignore_case;
 435        ascii_only     = !has_non_ascii(p->pattern);
 436
 437        /*
 438         * Even when -F (fixed) asks us to do a non-regexp search, we
 439         * may not be able to correctly case-fold when -i
 440         * (ignore-case) is asked (in which case, we'll synthesize a
 441         * regexp to match the pattern that matches regexp special
 442         * characters literally, while ignoring case differences).  On
 443         * the other hand, even without -F, if the pattern does not
 444         * have any regexp special characters and there is no need for
 445         * case-folding search, we can internally turn it into a
 446         * simple string match using kws.  p->fixed tells us if we
 447         * want to use kws.
 448         */
 449        if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 450                p->fixed = !icase || ascii_only;
 451        else
 452                p->fixed = 0;
 453
 454        if (p->fixed) {
 455                if (opt->regflags & REG_ICASE || p->ignore_case)
 456                        p->kws = kwsalloc(tolower_trans_tbl);
 457                else
 458                        p->kws = kwsalloc(NULL);
 459                kwsincr(p->kws, p->pattern, p->patternlen);
 460                kwsprep(p->kws);
 461                return;
 462        } else if (opt->fixed) {
 463                /*
 464                 * We come here when the pattern has the non-ascii
 465                 * characters we cannot case-fold, and asked to
 466                 * ignore-case.
 467                 */
 468                compile_fixed_regexp(p, opt);
 469                return;
 470        }
 471
 472        if (opt->pcre) {
 473                compile_pcre_regexp(p, opt);
 474                return;
 475        }
 476
 477        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 478        if (err) {
 479                char errbuf[1024];
 480                regerror(err, &p->regexp, errbuf, 1024);
 481                regfree(&p->regexp);
 482                compile_regexp_failed(p, errbuf);
 483        }
 484}
 485
 486static struct grep_expr *compile_pattern_or(struct grep_pat **);
 487static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 488{
 489        struct grep_pat *p;
 490        struct grep_expr *x;
 491
 492        p = *list;
 493        if (!p)
 494                return NULL;
 495        switch (p->token) {
 496        case GREP_PATTERN: /* atom */
 497        case GREP_PATTERN_HEAD:
 498        case GREP_PATTERN_BODY:
 499                x = xcalloc(1, sizeof (struct grep_expr));
 500                x->node = GREP_NODE_ATOM;
 501                x->u.atom = p;
 502                *list = p->next;
 503                return x;
 504        case GREP_OPEN_PAREN:
 505                *list = p->next;
 506                x = compile_pattern_or(list);
 507                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 508                        die("unmatched parenthesis");
 509                *list = (*list)->next;
 510                return x;
 511        default:
 512                return NULL;
 513        }
 514}
 515
 516static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 517{
 518        struct grep_pat *p;
 519        struct grep_expr *x;
 520
 521        p = *list;
 522        if (!p)
 523                return NULL;
 524        switch (p->token) {
 525        case GREP_NOT:
 526                if (!p->next)
 527                        die("--not not followed by pattern expression");
 528                *list = p->next;
 529                x = xcalloc(1, sizeof (struct grep_expr));
 530                x->node = GREP_NODE_NOT;
 531                x->u.unary = compile_pattern_not(list);
 532                if (!x->u.unary)
 533                        die("--not followed by non pattern expression");
 534                return x;
 535        default:
 536                return compile_pattern_atom(list);
 537        }
 538}
 539
 540static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 541{
 542        struct grep_pat *p;
 543        struct grep_expr *x, *y, *z;
 544
 545        x = compile_pattern_not(list);
 546        p = *list;
 547        if (p && p->token == GREP_AND) {
 548                if (!p->next)
 549                        die("--and not followed by pattern expression");
 550                *list = p->next;
 551                y = compile_pattern_and(list);
 552                if (!y)
 553                        die("--and not followed by pattern expression");
 554                z = xcalloc(1, sizeof (struct grep_expr));
 555                z->node = GREP_NODE_AND;
 556                z->u.binary.left = x;
 557                z->u.binary.right = y;
 558                return z;
 559        }
 560        return x;
 561}
 562
 563static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 564{
 565        struct grep_pat *p;
 566        struct grep_expr *x, *y, *z;
 567
 568        x = compile_pattern_and(list);
 569        p = *list;
 570        if (x && p && p->token != GREP_CLOSE_PAREN) {
 571                y = compile_pattern_or(list);
 572                if (!y)
 573                        die("not a pattern expression %s", p->pattern);
 574                z = xcalloc(1, sizeof (struct grep_expr));
 575                z->node = GREP_NODE_OR;
 576                z->u.binary.left = x;
 577                z->u.binary.right = y;
 578                return z;
 579        }
 580        return x;
 581}
 582
 583static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 584{
 585        return compile_pattern_or(list);
 586}
 587
 588static void indent(int in)
 589{
 590        while (in-- > 0)
 591                fputc(' ', stderr);
 592}
 593
 594static void dump_grep_pat(struct grep_pat *p)
 595{
 596        switch (p->token) {
 597        case GREP_AND: fprintf(stderr, "*and*"); break;
 598        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 599        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 600        case GREP_NOT: fprintf(stderr, "*not*"); break;
 601        case GREP_OR: fprintf(stderr, "*or*"); break;
 602
 603        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 604        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 605        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 606        }
 607
 608        switch (p->token) {
 609        default: break;
 610        case GREP_PATTERN_HEAD:
 611                fprintf(stderr, "<head %d>", p->field); break;
 612        case GREP_PATTERN_BODY:
 613                fprintf(stderr, "<body>"); break;
 614        }
 615        switch (p->token) {
 616        default: break;
 617        case GREP_PATTERN_HEAD:
 618        case GREP_PATTERN_BODY:
 619        case GREP_PATTERN:
 620                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 621                break;
 622        }
 623        fputc('\n', stderr);
 624}
 625
 626static void dump_grep_expression_1(struct grep_expr *x, int in)
 627{
 628        indent(in);
 629        switch (x->node) {
 630        case GREP_NODE_TRUE:
 631                fprintf(stderr, "true\n");
 632                break;
 633        case GREP_NODE_ATOM:
 634                dump_grep_pat(x->u.atom);
 635                break;
 636        case GREP_NODE_NOT:
 637                fprintf(stderr, "(not\n");
 638                dump_grep_expression_1(x->u.unary, in+1);
 639                indent(in);
 640                fprintf(stderr, ")\n");
 641                break;
 642        case GREP_NODE_AND:
 643                fprintf(stderr, "(and\n");
 644                dump_grep_expression_1(x->u.binary.left, in+1);
 645                dump_grep_expression_1(x->u.binary.right, in+1);
 646                indent(in);
 647                fprintf(stderr, ")\n");
 648                break;
 649        case GREP_NODE_OR:
 650                fprintf(stderr, "(or\n");
 651                dump_grep_expression_1(x->u.binary.left, in+1);
 652                dump_grep_expression_1(x->u.binary.right, in+1);
 653                indent(in);
 654                fprintf(stderr, ")\n");
 655                break;
 656        }
 657}
 658
 659static void dump_grep_expression(struct grep_opt *opt)
 660{
 661        struct grep_expr *x = opt->pattern_expression;
 662
 663        if (opt->all_match)
 664                fprintf(stderr, "[all-match]\n");
 665        dump_grep_expression_1(x, 0);
 666        fflush(NULL);
 667}
 668
 669static struct grep_expr *grep_true_expr(void)
 670{
 671        struct grep_expr *z = xcalloc(1, sizeof(*z));
 672        z->node = GREP_NODE_TRUE;
 673        return z;
 674}
 675
 676static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 677{
 678        struct grep_expr *z = xcalloc(1, sizeof(*z));
 679        z->node = GREP_NODE_OR;
 680        z->u.binary.left = left;
 681        z->u.binary.right = right;
 682        return z;
 683}
 684
 685static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 686{
 687        struct grep_pat *p;
 688        struct grep_expr *header_expr;
 689        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 690        enum grep_header_field fld;
 691
 692        if (!opt->header_list)
 693                return NULL;
 694
 695        for (p = opt->header_list; p; p = p->next) {
 696                if (p->token != GREP_PATTERN_HEAD)
 697                        die("bug: a non-header pattern in grep header list.");
 698                if (p->field < GREP_HEADER_FIELD_MIN ||
 699                    GREP_HEADER_FIELD_MAX <= p->field)
 700                        die("bug: unknown header field %d", p->field);
 701                compile_regexp(p, opt);
 702        }
 703
 704        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 705                header_group[fld] = NULL;
 706
 707        for (p = opt->header_list; p; p = p->next) {
 708                struct grep_expr *h;
 709                struct grep_pat *pp = p;
 710
 711                h = compile_pattern_atom(&pp);
 712                if (!h || pp != p->next)
 713                        die("bug: malformed header expr");
 714                if (!header_group[p->field]) {
 715                        header_group[p->field] = h;
 716                        continue;
 717                }
 718                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 719        }
 720
 721        header_expr = NULL;
 722
 723        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 724                if (!header_group[fld])
 725                        continue;
 726                if (!header_expr)
 727                        header_expr = grep_true_expr();
 728                header_expr = grep_or_expr(header_group[fld], header_expr);
 729        }
 730        return header_expr;
 731}
 732
 733static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 734{
 735        struct grep_expr *z = x;
 736
 737        while (x) {
 738                assert(x->node == GREP_NODE_OR);
 739                if (x->u.binary.right &&
 740                    x->u.binary.right->node == GREP_NODE_TRUE) {
 741                        x->u.binary.right = y;
 742                        break;
 743                }
 744                x = x->u.binary.right;
 745        }
 746        return z;
 747}
 748
 749static void compile_grep_patterns_real(struct grep_opt *opt)
 750{
 751        struct grep_pat *p;
 752        struct grep_expr *header_expr = prep_header_patterns(opt);
 753
 754        for (p = opt->pattern_list; p; p = p->next) {
 755                switch (p->token) {
 756                case GREP_PATTERN: /* atom */
 757                case GREP_PATTERN_HEAD:
 758                case GREP_PATTERN_BODY:
 759                        compile_regexp(p, opt);
 760                        break;
 761                default:
 762                        opt->extended = 1;
 763                        break;
 764                }
 765        }
 766
 767        if (opt->all_match || header_expr)
 768                opt->extended = 1;
 769        else if (!opt->extended && !opt->debug)
 770                return;
 771
 772        p = opt->pattern_list;
 773        if (p)
 774                opt->pattern_expression = compile_pattern_expr(&p);
 775        if (p)
 776                die("incomplete pattern expression: %s", p->pattern);
 777
 778        if (!header_expr)
 779                return;
 780
 781        if (!opt->pattern_expression)
 782                opt->pattern_expression = header_expr;
 783        else if (opt->all_match)
 784                opt->pattern_expression = grep_splice_or(header_expr,
 785                                                         opt->pattern_expression);
 786        else
 787                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 788                                                       header_expr);
 789        opt->all_match = 1;
 790}
 791
 792void compile_grep_patterns(struct grep_opt *opt)
 793{
 794        compile_grep_patterns_real(opt);
 795        if (opt->debug)
 796                dump_grep_expression(opt);
 797}
 798
 799static void free_pattern_expr(struct grep_expr *x)
 800{
 801        switch (x->node) {
 802        case GREP_NODE_TRUE:
 803        case GREP_NODE_ATOM:
 804                break;
 805        case GREP_NODE_NOT:
 806                free_pattern_expr(x->u.unary);
 807                break;
 808        case GREP_NODE_AND:
 809        case GREP_NODE_OR:
 810                free_pattern_expr(x->u.binary.left);
 811                free_pattern_expr(x->u.binary.right);
 812                break;
 813        }
 814        free(x);
 815}
 816
 817void free_grep_patterns(struct grep_opt *opt)
 818{
 819        struct grep_pat *p, *n;
 820
 821        for (p = opt->pattern_list; p; p = n) {
 822                n = p->next;
 823                switch (p->token) {
 824                case GREP_PATTERN: /* atom */
 825                case GREP_PATTERN_HEAD:
 826                case GREP_PATTERN_BODY:
 827                        if (p->kws)
 828                                kwsfree(p->kws);
 829                        else if (p->pcre_regexp)
 830                                free_pcre_regexp(p);
 831                        else
 832                                regfree(&p->regexp);
 833                        free(p->pattern);
 834                        break;
 835                default:
 836                        break;
 837                }
 838                free(p);
 839        }
 840
 841        if (!opt->extended)
 842                return;
 843        free_pattern_expr(opt->pattern_expression);
 844}
 845
 846static char *end_of_line(char *cp, unsigned long *left)
 847{
 848        unsigned long l = *left;
 849        while (l && *cp != '\n') {
 850                l--;
 851                cp++;
 852        }
 853        *left = l;
 854        return cp;
 855}
 856
 857static int word_char(char ch)
 858{
 859        return isalnum(ch) || ch == '_';
 860}
 861
 862static void output_color(struct grep_opt *opt, const void *data, size_t size,
 863                         const char *color)
 864{
 865        if (want_color(opt->color) && color && color[0]) {
 866                opt->output(opt, color, strlen(color));
 867                opt->output(opt, data, size);
 868                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 869        } else
 870                opt->output(opt, data, size);
 871}
 872
 873static void output_sep(struct grep_opt *opt, char sign)
 874{
 875        if (opt->null_following_name)
 876                opt->output(opt, "\0", 1);
 877        else
 878                output_color(opt, &sign, 1, opt->color_sep);
 879}
 880
 881static void show_name(struct grep_opt *opt, const char *name)
 882{
 883        output_color(opt, name, strlen(name), opt->color_filename);
 884        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 885}
 886
 887static int fixmatch(struct grep_pat *p, char *line, char *eol,
 888                    regmatch_t *match)
 889{
 890        struct kwsmatch kwsm;
 891        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 892        if (offset == -1) {
 893                match->rm_so = match->rm_eo = -1;
 894                return REG_NOMATCH;
 895        } else {
 896                match->rm_so = offset;
 897                match->rm_eo = match->rm_so + kwsm.size[0];
 898                return 0;
 899        }
 900}
 901
 902static int regmatch(const regex_t *preg, char *line, char *eol,
 903                    regmatch_t *match, int eflags)
 904{
 905#ifdef REG_STARTEND
 906        match->rm_so = 0;
 907        match->rm_eo = eol - line;
 908        eflags |= REG_STARTEND;
 909#endif
 910        return regexec(preg, line, 1, match, eflags);
 911}
 912
 913static int patmatch(struct grep_pat *p, char *line, char *eol,
 914                    regmatch_t *match, int eflags)
 915{
 916        int hit;
 917
 918        if (p->fixed)
 919                hit = !fixmatch(p, line, eol, match);
 920        else if (p->pcre_regexp)
 921                hit = !pcrematch(p, line, eol, match, eflags);
 922        else
 923                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 924
 925        return hit;
 926}
 927
 928static int strip_timestamp(char *bol, char **eol_p)
 929{
 930        char *eol = *eol_p;
 931        int ch;
 932
 933        while (bol < --eol) {
 934                if (*eol != '>')
 935                        continue;
 936                *eol_p = ++eol;
 937                ch = *eol;
 938                *eol = '\0';
 939                return ch;
 940        }
 941        return 0;
 942}
 943
 944static struct {
 945        const char *field;
 946        size_t len;
 947} header_field[] = {
 948        { "author ", 7 },
 949        { "committer ", 10 },
 950        { "reflog ", 7 },
 951};
 952
 953static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 954                             enum grep_context ctx,
 955                             regmatch_t *pmatch, int eflags)
 956{
 957        int hit = 0;
 958        int saved_ch = 0;
 959        const char *start = bol;
 960
 961        if ((p->token != GREP_PATTERN) &&
 962            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 963                return 0;
 964
 965        if (p->token == GREP_PATTERN_HEAD) {
 966                const char *field;
 967                size_t len;
 968                assert(p->field < ARRAY_SIZE(header_field));
 969                field = header_field[p->field].field;
 970                len = header_field[p->field].len;
 971                if (strncmp(bol, field, len))
 972                        return 0;
 973                bol += len;
 974                switch (p->field) {
 975                case GREP_HEADER_AUTHOR:
 976                case GREP_HEADER_COMMITTER:
 977                        saved_ch = strip_timestamp(bol, &eol);
 978                        break;
 979                default:
 980                        break;
 981                }
 982        }
 983
 984 again:
 985        hit = patmatch(p, bol, eol, pmatch, eflags);
 986
 987        if (hit && p->word_regexp) {
 988                if ((pmatch[0].rm_so < 0) ||
 989                    (eol - bol) < pmatch[0].rm_so ||
 990                    (pmatch[0].rm_eo < 0) ||
 991                    (eol - bol) < pmatch[0].rm_eo)
 992                        die("regexp returned nonsense");
 993
 994                /* Match beginning must be either beginning of the
 995                 * line, or at word boundary (i.e. the last char must
 996                 * not be a word char).  Similarly, match end must be
 997                 * either end of the line, or at word boundary
 998                 * (i.e. the next char must not be a word char).
 999                 */
1000                if ( ((pmatch[0].rm_so == 0) ||
1001                      !word_char(bol[pmatch[0].rm_so-1])) &&
1002                     ((pmatch[0].rm_eo == (eol-bol)) ||
1003                      !word_char(bol[pmatch[0].rm_eo])) )
1004                        ;
1005                else
1006                        hit = 0;
1007
1008                /* Words consist of at least one character. */
1009                if (pmatch->rm_so == pmatch->rm_eo)
1010                        hit = 0;
1011
1012                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1013                        /* There could be more than one match on the
1014                         * line, and the first match might not be
1015                         * strict word match.  But later ones could be!
1016                         * Forward to the next possible start, i.e. the
1017                         * next position following a non-word char.
1018                         */
1019                        bol = pmatch[0].rm_so + bol + 1;
1020                        while (word_char(bol[-1]) && bol < eol)
1021                                bol++;
1022                        eflags |= REG_NOTBOL;
1023                        if (bol < eol)
1024                                goto again;
1025                }
1026        }
1027        if (p->token == GREP_PATTERN_HEAD && saved_ch)
1028                *eol = saved_ch;
1029        if (hit) {
1030                pmatch[0].rm_so += bol - start;
1031                pmatch[0].rm_eo += bol - start;
1032        }
1033        return hit;
1034}
1035
1036static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1037                           enum grep_context ctx, int collect_hits)
1038{
1039        int h = 0;
1040        regmatch_t match;
1041
1042        if (!x)
1043                die("Not a valid grep expression");
1044        switch (x->node) {
1045        case GREP_NODE_TRUE:
1046                h = 1;
1047                break;
1048        case GREP_NODE_ATOM:
1049                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1050                break;
1051        case GREP_NODE_NOT:
1052                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1053                break;
1054        case GREP_NODE_AND:
1055                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1056                        return 0;
1057                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1058                break;
1059        case GREP_NODE_OR:
1060                if (!collect_hits)
1061                        return (match_expr_eval(x->u.binary.left,
1062                                                bol, eol, ctx, 0) ||
1063                                match_expr_eval(x->u.binary.right,
1064                                                bol, eol, ctx, 0));
1065                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1066                x->u.binary.left->hit |= h;
1067                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1068                break;
1069        default:
1070                die("Unexpected node type (internal error) %d", x->node);
1071        }
1072        if (collect_hits)
1073                x->hit |= h;
1074        return h;
1075}
1076
1077static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1078                      enum grep_context ctx, int collect_hits)
1079{
1080        struct grep_expr *x = opt->pattern_expression;
1081        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1082}
1083
1084static int match_line(struct grep_opt *opt, char *bol, char *eol,
1085                      enum grep_context ctx, int collect_hits)
1086{
1087        struct grep_pat *p;
1088        regmatch_t match;
1089
1090        if (opt->extended)
1091                return match_expr(opt, bol, eol, ctx, collect_hits);
1092
1093        /* we do not call with collect_hits without being extended */
1094        for (p = opt->pattern_list; p; p = p->next) {
1095                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1096                        return 1;
1097        }
1098        return 0;
1099}
1100
1101static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1102                              enum grep_context ctx,
1103                              regmatch_t *pmatch, int eflags)
1104{
1105        regmatch_t match;
1106
1107        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1108                return 0;
1109        if (match.rm_so < 0 || match.rm_eo < 0)
1110                return 0;
1111        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1112                if (match.rm_so > pmatch->rm_so)
1113                        return 1;
1114                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1115                        return 1;
1116        }
1117        pmatch->rm_so = match.rm_so;
1118        pmatch->rm_eo = match.rm_eo;
1119        return 1;
1120}
1121
1122static int next_match(struct grep_opt *opt, char *bol, char *eol,
1123                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1124{
1125        struct grep_pat *p;
1126        int hit = 0;
1127
1128        pmatch->rm_so = pmatch->rm_eo = -1;
1129        if (bol < eol) {
1130                for (p = opt->pattern_list; p; p = p->next) {
1131                        switch (p->token) {
1132                        case GREP_PATTERN: /* atom */
1133                        case GREP_PATTERN_HEAD:
1134                        case GREP_PATTERN_BODY:
1135                                hit |= match_next_pattern(p, bol, eol, ctx,
1136                                                          pmatch, eflags);
1137                                break;
1138                        default:
1139                                break;
1140                        }
1141                }
1142        }
1143        return hit;
1144}
1145
1146static void show_line(struct grep_opt *opt, char *bol, char *eol,
1147                      const char *name, unsigned lno, char sign)
1148{
1149        int rest = eol - bol;
1150        const char *match_color, *line_color = NULL;
1151
1152        if (opt->file_break && opt->last_shown == 0) {
1153                if (opt->show_hunk_mark)
1154                        opt->output(opt, "\n", 1);
1155        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1156                if (opt->last_shown == 0) {
1157                        if (opt->show_hunk_mark) {
1158                                output_color(opt, "--", 2, opt->color_sep);
1159                                opt->output(opt, "\n", 1);
1160                        }
1161                } else if (lno > opt->last_shown + 1) {
1162                        output_color(opt, "--", 2, opt->color_sep);
1163                        opt->output(opt, "\n", 1);
1164                }
1165        }
1166        if (opt->heading && opt->last_shown == 0) {
1167                output_color(opt, name, strlen(name), opt->color_filename);
1168                opt->output(opt, "\n", 1);
1169        }
1170        opt->last_shown = lno;
1171
1172        if (!opt->heading && opt->pathname) {
1173                output_color(opt, name, strlen(name), opt->color_filename);
1174                output_sep(opt, sign);
1175        }
1176        if (opt->linenum) {
1177                char buf[32];
1178                snprintf(buf, sizeof(buf), "%d", lno);
1179                output_color(opt, buf, strlen(buf), opt->color_lineno);
1180                output_sep(opt, sign);
1181        }
1182        if (opt->color) {
1183                regmatch_t match;
1184                enum grep_context ctx = GREP_CONTEXT_BODY;
1185                int ch = *eol;
1186                int eflags = 0;
1187
1188                if (sign == ':')
1189                        match_color = opt->color_match_selected;
1190                else
1191                        match_color = opt->color_match_context;
1192                if (sign == ':')
1193                        line_color = opt->color_selected;
1194                else if (sign == '-')
1195                        line_color = opt->color_context;
1196                else if (sign == '=')
1197                        line_color = opt->color_function;
1198                *eol = '\0';
1199                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1200                        if (match.rm_so == match.rm_eo)
1201                                break;
1202
1203                        output_color(opt, bol, match.rm_so, line_color);
1204                        output_color(opt, bol + match.rm_so,
1205                                     match.rm_eo - match.rm_so, match_color);
1206                        bol += match.rm_eo;
1207                        rest -= match.rm_eo;
1208                        eflags = REG_NOTBOL;
1209                }
1210                *eol = ch;
1211        }
1212        output_color(opt, bol, rest, line_color);
1213        opt->output(opt, "\n", 1);
1214}
1215
1216#ifndef NO_PTHREADS
1217int grep_use_locks;
1218
1219/*
1220 * This lock protects access to the gitattributes machinery, which is
1221 * not thread-safe.
1222 */
1223pthread_mutex_t grep_attr_mutex;
1224
1225static inline void grep_attr_lock(void)
1226{
1227        if (grep_use_locks)
1228                pthread_mutex_lock(&grep_attr_mutex);
1229}
1230
1231static inline void grep_attr_unlock(void)
1232{
1233        if (grep_use_locks)
1234                pthread_mutex_unlock(&grep_attr_mutex);
1235}
1236
1237/*
1238 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1239 */
1240pthread_mutex_t grep_read_mutex;
1241
1242#else
1243#define grep_attr_lock()
1244#define grep_attr_unlock()
1245#endif
1246
1247static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1248{
1249        xdemitconf_t *xecfg = opt->priv;
1250        if (xecfg && !xecfg->find_func) {
1251                grep_source_load_driver(gs);
1252                if (gs->driver->funcname.pattern) {
1253                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1254                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1255                } else {
1256                        xecfg = opt->priv = NULL;
1257                }
1258        }
1259
1260        if (xecfg) {
1261                char buf[1];
1262                return xecfg->find_func(bol, eol - bol, buf, 1,
1263                                        xecfg->find_func_priv) >= 0;
1264        }
1265
1266        if (bol == eol)
1267                return 0;
1268        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1269                return 1;
1270        return 0;
1271}
1272
1273static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1274                               char *bol, unsigned lno)
1275{
1276        while (bol > gs->buf) {
1277                char *eol = --bol;
1278
1279                while (bol > gs->buf && bol[-1] != '\n')
1280                        bol--;
1281                lno--;
1282
1283                if (lno <= opt->last_shown)
1284                        break;
1285
1286                if (match_funcname(opt, gs, bol, eol)) {
1287                        show_line(opt, bol, eol, gs->name, lno, '=');
1288                        break;
1289                }
1290        }
1291}
1292
1293static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1294                             char *bol, char *end, unsigned lno)
1295{
1296        unsigned cur = lno, from = 1, funcname_lno = 0;
1297        int funcname_needed = !!opt->funcname;
1298
1299        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1300                funcname_needed = 2;
1301
1302        if (opt->pre_context < lno)
1303                from = lno - opt->pre_context;
1304        if (from <= opt->last_shown)
1305                from = opt->last_shown + 1;
1306
1307        /* Rewind. */
1308        while (bol > gs->buf &&
1309               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1310                char *eol = --bol;
1311
1312                while (bol > gs->buf && bol[-1] != '\n')
1313                        bol--;
1314                cur--;
1315                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1316                        funcname_lno = cur;
1317                        funcname_needed = 0;
1318                }
1319        }
1320
1321        /* We need to look even further back to find a function signature. */
1322        if (opt->funcname && funcname_needed)
1323                show_funcname_line(opt, gs, bol, cur);
1324
1325        /* Back forward. */
1326        while (cur < lno) {
1327                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1328
1329                while (*eol != '\n')
1330                        eol++;
1331                show_line(opt, bol, eol, gs->name, cur, sign);
1332                bol = eol + 1;
1333                cur++;
1334        }
1335}
1336
1337static int should_lookahead(struct grep_opt *opt)
1338{
1339        struct grep_pat *p;
1340
1341        if (opt->extended)
1342                return 0; /* punt for too complex stuff */
1343        if (opt->invert)
1344                return 0;
1345        for (p = opt->pattern_list; p; p = p->next) {
1346                if (p->token != GREP_PATTERN)
1347                        return 0; /* punt for "header only" and stuff */
1348        }
1349        return 1;
1350}
1351
1352static int look_ahead(struct grep_opt *opt,
1353                      unsigned long *left_p,
1354                      unsigned *lno_p,
1355                      char **bol_p)
1356{
1357        unsigned lno = *lno_p;
1358        char *bol = *bol_p;
1359        struct grep_pat *p;
1360        char *sp, *last_bol;
1361        regoff_t earliest = -1;
1362
1363        for (p = opt->pattern_list; p; p = p->next) {
1364                int hit;
1365                regmatch_t m;
1366
1367                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1368                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1369                        continue;
1370                if (earliest < 0 || m.rm_so < earliest)
1371                        earliest = m.rm_so;
1372        }
1373
1374        if (earliest < 0) {
1375                *bol_p = bol + *left_p;
1376                *left_p = 0;
1377                return 1;
1378        }
1379        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1380                ; /* find the beginning of the line */
1381        last_bol = sp;
1382
1383        for (sp = bol; sp < last_bol; sp++) {
1384                if (*sp == '\n')
1385                        lno++;
1386        }
1387        *left_p -= last_bol - bol;
1388        *bol_p = last_bol;
1389        *lno_p = lno;
1390        return 0;
1391}
1392
1393static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1394{
1395        fwrite(buf, size, 1, stdout);
1396}
1397
1398static int fill_textconv_grep(struct userdiff_driver *driver,
1399                              struct grep_source *gs)
1400{
1401        struct diff_filespec *df;
1402        char *buf;
1403        size_t size;
1404
1405        if (!driver || !driver->textconv)
1406                return grep_source_load(gs);
1407
1408        /*
1409         * The textconv interface is intimately tied to diff_filespecs, so we
1410         * have to pretend to be one. If we could unify the grep_source
1411         * and diff_filespec structs, this mess could just go away.
1412         */
1413        df = alloc_filespec(gs->path);
1414        switch (gs->type) {
1415        case GREP_SOURCE_SHA1:
1416                fill_filespec(df, gs->identifier, 1, 0100644);
1417                break;
1418        case GREP_SOURCE_FILE:
1419                fill_filespec(df, null_sha1, 0, 0100644);
1420                break;
1421        default:
1422                die("BUG: attempt to textconv something without a path?");
1423        }
1424
1425        /*
1426         * fill_textconv is not remotely thread-safe; it may load objects
1427         * behind the scenes, and it modifies the global diff tempfile
1428         * structure.
1429         */
1430        grep_read_lock();
1431        size = fill_textconv(driver, df, &buf);
1432        grep_read_unlock();
1433        free_filespec(df);
1434
1435        /*
1436         * The normal fill_textconv usage by the diff machinery would just keep
1437         * the textconv'd buf separate from the diff_filespec. But much of the
1438         * grep code passes around a grep_source and assumes that its "buf"
1439         * pointer is the beginning of the thing we are searching. So let's
1440         * install our textconv'd version into the grep_source, taking care not
1441         * to leak any existing buffer.
1442         */
1443        grep_source_clear_data(gs);
1444        gs->buf = buf;
1445        gs->size = size;
1446
1447        return 0;
1448}
1449
1450static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1451{
1452        char *bol;
1453        unsigned long left;
1454        unsigned lno = 1;
1455        unsigned last_hit = 0;
1456        int binary_match_only = 0;
1457        unsigned count = 0;
1458        int try_lookahead = 0;
1459        int show_function = 0;
1460        struct userdiff_driver *textconv = NULL;
1461        enum grep_context ctx = GREP_CONTEXT_HEAD;
1462        xdemitconf_t xecfg;
1463
1464        if (!opt->output)
1465                opt->output = std_output;
1466
1467        if (opt->pre_context || opt->post_context || opt->file_break ||
1468            opt->funcbody) {
1469                /* Show hunk marks, except for the first file. */
1470                if (opt->last_shown)
1471                        opt->show_hunk_mark = 1;
1472                /*
1473                 * If we're using threads then we can't easily identify
1474                 * the first file.  Always put hunk marks in that case
1475                 * and skip the very first one later in work_done().
1476                 */
1477                if (opt->output != std_output)
1478                        opt->show_hunk_mark = 1;
1479        }
1480        opt->last_shown = 0;
1481
1482        if (opt->allow_textconv) {
1483                grep_source_load_driver(gs);
1484                /*
1485                 * We might set up the shared textconv cache data here, which
1486                 * is not thread-safe.
1487                 */
1488                grep_attr_lock();
1489                textconv = userdiff_get_textconv(gs->driver);
1490                grep_attr_unlock();
1491        }
1492
1493        /*
1494         * We know the result of a textconv is text, so we only have to care
1495         * about binary handling if we are not using it.
1496         */
1497        if (!textconv) {
1498                switch (opt->binary) {
1499                case GREP_BINARY_DEFAULT:
1500                        if (grep_source_is_binary(gs))
1501                                binary_match_only = 1;
1502                        break;
1503                case GREP_BINARY_NOMATCH:
1504                        if (grep_source_is_binary(gs))
1505                                return 0; /* Assume unmatch */
1506                        break;
1507                case GREP_BINARY_TEXT:
1508                        break;
1509                default:
1510                        die("bug: unknown binary handling mode");
1511                }
1512        }
1513
1514        memset(&xecfg, 0, sizeof(xecfg));
1515        opt->priv = &xecfg;
1516
1517        try_lookahead = should_lookahead(opt);
1518
1519        if (fill_textconv_grep(textconv, gs) < 0)
1520                return 0;
1521
1522        bol = gs->buf;
1523        left = gs->size;
1524        while (left) {
1525                char *eol, ch;
1526                int hit;
1527
1528                /*
1529                 * look_ahead() skips quickly to the line that possibly
1530                 * has the next hit; don't call it if we need to do
1531                 * something more than just skipping the current line
1532                 * in response to an unmatch for the current line.  E.g.
1533                 * inside a post-context window, we will show the current
1534                 * line as a context around the previous hit when it
1535                 * doesn't hit.
1536                 */
1537                if (try_lookahead
1538                    && !(last_hit
1539                         && (show_function ||
1540                             lno <= last_hit + opt->post_context))
1541                    && look_ahead(opt, &left, &lno, &bol))
1542                        break;
1543                eol = end_of_line(bol, &left);
1544                ch = *eol;
1545                *eol = 0;
1546
1547                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1548                        ctx = GREP_CONTEXT_BODY;
1549
1550                hit = match_line(opt, bol, eol, ctx, collect_hits);
1551                *eol = ch;
1552
1553                if (collect_hits)
1554                        goto next_line;
1555
1556                /* "grep -v -e foo -e bla" should list lines
1557                 * that do not have either, so inversion should
1558                 * be done outside.
1559                 */
1560                if (opt->invert)
1561                        hit = !hit;
1562                if (opt->unmatch_name_only) {
1563                        if (hit)
1564                                return 0;
1565                        goto next_line;
1566                }
1567                if (hit) {
1568                        count++;
1569                        if (opt->status_only)
1570                                return 1;
1571                        if (opt->name_only) {
1572                                show_name(opt, gs->name);
1573                                return 1;
1574                        }
1575                        if (opt->count)
1576                                goto next_line;
1577                        if (binary_match_only) {
1578                                opt->output(opt, "Binary file ", 12);
1579                                output_color(opt, gs->name, strlen(gs->name),
1580                                             opt->color_filename);
1581                                opt->output(opt, " matches\n", 9);
1582                                return 1;
1583                        }
1584                        /* Hit at this line.  If we haven't shown the
1585                         * pre-context lines, we would need to show them.
1586                         */
1587                        if (opt->pre_context || opt->funcbody)
1588                                show_pre_context(opt, gs, bol, eol, lno);
1589                        else if (opt->funcname)
1590                                show_funcname_line(opt, gs, bol, lno);
1591                        show_line(opt, bol, eol, gs->name, lno, ':');
1592                        last_hit = lno;
1593                        if (opt->funcbody)
1594                                show_function = 1;
1595                        goto next_line;
1596                }
1597                if (show_function && match_funcname(opt, gs, bol, eol))
1598                        show_function = 0;
1599                if (show_function ||
1600                    (last_hit && lno <= last_hit + opt->post_context)) {
1601                        /* If the last hit is within the post context,
1602                         * we need to show this line.
1603                         */
1604                        show_line(opt, bol, eol, gs->name, lno, '-');
1605                }
1606
1607        next_line:
1608                bol = eol + 1;
1609                if (!left)
1610                        break;
1611                left--;
1612                lno++;
1613        }
1614
1615        if (collect_hits)
1616                return 0;
1617
1618        if (opt->status_only)
1619                return 0;
1620        if (opt->unmatch_name_only) {
1621                /* We did not see any hit, so we want to show this */
1622                show_name(opt, gs->name);
1623                return 1;
1624        }
1625
1626        xdiff_clear_find_func(&xecfg);
1627        opt->priv = NULL;
1628
1629        /* NEEDSWORK:
1630         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1631         * which feels mostly useless but sometimes useful.  Maybe
1632         * make it another option?  For now suppress them.
1633         */
1634        if (opt->count && count) {
1635                char buf[32];
1636                if (opt->pathname) {
1637                        output_color(opt, gs->name, strlen(gs->name),
1638                                     opt->color_filename);
1639                        output_sep(opt, ':');
1640                }
1641                snprintf(buf, sizeof(buf), "%u\n", count);
1642                opt->output(opt, buf, strlen(buf));
1643                return 1;
1644        }
1645        return !!last_hit;
1646}
1647
1648static void clr_hit_marker(struct grep_expr *x)
1649{
1650        /* All-hit markers are meaningful only at the very top level
1651         * OR node.
1652         */
1653        while (1) {
1654                x->hit = 0;
1655                if (x->node != GREP_NODE_OR)
1656                        return;
1657                x->u.binary.left->hit = 0;
1658                x = x->u.binary.right;
1659        }
1660}
1661
1662static int chk_hit_marker(struct grep_expr *x)
1663{
1664        /* Top level nodes have hit markers.  See if they all are hits */
1665        while (1) {
1666                if (x->node != GREP_NODE_OR)
1667                        return x->hit;
1668                if (!x->u.binary.left->hit)
1669                        return 0;
1670                x = x->u.binary.right;
1671        }
1672}
1673
1674int grep_source(struct grep_opt *opt, struct grep_source *gs)
1675{
1676        /*
1677         * we do not have to do the two-pass grep when we do not check
1678         * buffer-wide "all-match".
1679         */
1680        if (!opt->all_match)
1681                return grep_source_1(opt, gs, 0);
1682
1683        /* Otherwise the toplevel "or" terms hit a bit differently.
1684         * We first clear hit markers from them.
1685         */
1686        clr_hit_marker(opt->pattern_expression);
1687        grep_source_1(opt, gs, 1);
1688
1689        if (!chk_hit_marker(opt->pattern_expression))
1690                return 0;
1691
1692        return grep_source_1(opt, gs, 0);
1693}
1694
1695int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1696{
1697        struct grep_source gs;
1698        int r;
1699
1700        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1701        gs.buf = buf;
1702        gs.size = size;
1703
1704        r = grep_source(opt, &gs);
1705
1706        grep_source_clear(&gs);
1707        return r;
1708}
1709
1710void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1711                      const char *name, const char *path,
1712                      const void *identifier)
1713{
1714        gs->type = type;
1715        gs->name = xstrdup_or_null(name);
1716        gs->path = xstrdup_or_null(path);
1717        gs->buf = NULL;
1718        gs->size = 0;
1719        gs->driver = NULL;
1720
1721        switch (type) {
1722        case GREP_SOURCE_FILE:
1723                gs->identifier = xstrdup(identifier);
1724                break;
1725        case GREP_SOURCE_SHA1:
1726                gs->identifier = xmalloc(20);
1727                hashcpy(gs->identifier, identifier);
1728                break;
1729        case GREP_SOURCE_BUF:
1730                gs->identifier = NULL;
1731        }
1732}
1733
1734void grep_source_clear(struct grep_source *gs)
1735{
1736        free(gs->name);
1737        gs->name = NULL;
1738        free(gs->path);
1739        gs->path = NULL;
1740        free(gs->identifier);
1741        gs->identifier = NULL;
1742        grep_source_clear_data(gs);
1743}
1744
1745void grep_source_clear_data(struct grep_source *gs)
1746{
1747        switch (gs->type) {
1748        case GREP_SOURCE_FILE:
1749        case GREP_SOURCE_SHA1:
1750                free(gs->buf);
1751                gs->buf = NULL;
1752                gs->size = 0;
1753                break;
1754        case GREP_SOURCE_BUF:
1755                /* leave user-provided buf intact */
1756                break;
1757        }
1758}
1759
1760static int grep_source_load_sha1(struct grep_source *gs)
1761{
1762        enum object_type type;
1763
1764        grep_read_lock();
1765        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1766        grep_read_unlock();
1767
1768        if (!gs->buf)
1769                return error(_("'%s': unable to read %s"),
1770                             gs->name,
1771                             sha1_to_hex(gs->identifier));
1772        return 0;
1773}
1774
1775static int grep_source_load_file(struct grep_source *gs)
1776{
1777        const char *filename = gs->identifier;
1778        struct stat st;
1779        char *data;
1780        size_t size;
1781        int i;
1782
1783        if (lstat(filename, &st) < 0) {
1784        err_ret:
1785                if (errno != ENOENT)
1786                        error(_("'%s': %s"), filename, strerror(errno));
1787                return -1;
1788        }
1789        if (!S_ISREG(st.st_mode))
1790                return -1;
1791        size = xsize_t(st.st_size);
1792        i = open(filename, O_RDONLY);
1793        if (i < 0)
1794                goto err_ret;
1795        data = xmalloc(size + 1);
1796        if (st.st_size != read_in_full(i, data, size)) {
1797                error(_("'%s': short read %s"), filename, strerror(errno));
1798                close(i);
1799                free(data);
1800                return -1;
1801        }
1802        close(i);
1803        data[size] = 0;
1804
1805        gs->buf = data;
1806        gs->size = size;
1807        return 0;
1808}
1809
1810static int grep_source_load(struct grep_source *gs)
1811{
1812        if (gs->buf)
1813                return 0;
1814
1815        switch (gs->type) {
1816        case GREP_SOURCE_FILE:
1817                return grep_source_load_file(gs);
1818        case GREP_SOURCE_SHA1:
1819                return grep_source_load_sha1(gs);
1820        case GREP_SOURCE_BUF:
1821                return gs->buf ? 0 : -1;
1822        }
1823        die("BUG: invalid grep_source type");
1824}
1825
1826void grep_source_load_driver(struct grep_source *gs)
1827{
1828        if (gs->driver)
1829                return;
1830
1831        grep_attr_lock();
1832        if (gs->path)
1833                gs->driver = userdiff_find_by_path(gs->path);
1834        if (!gs->driver)
1835                gs->driver = userdiff_find_by_name("default");
1836        grep_attr_unlock();
1837}
1838
1839static int grep_source_is_binary(struct grep_source *gs)
1840{
1841        grep_source_load_driver(gs);
1842        if (gs->driver->binary != -1)
1843                return gs->driver->binary;
1844
1845        if (!grep_source_load(gs))
1846                return buffer_is_binary(gs->buf, gs->size);
1847
1848        return 0;
1849}