Andrew's git / gitweb.git / grep.c
?
grep.con commit diff: avoid redundantly clearing a flag (23b65f9)
   1#include "cache.h"
   2#include "config.h"
   3#include "grep.h"
   4#include "userdiff.h"
   5#include "xdiff-interface.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "commit.h"
   9#include "quote.h"
  10
  11static int grep_source_load(struct grep_source *gs);
  12static int grep_source_is_binary(struct grep_source *gs);
  13
  14static struct grep_opt grep_defaults;
  15
  16static void std_output(struct grep_opt *opt, const void *buf, size_t size)
  17{
  18        fwrite(buf, size, 1, stdout);
  19}
  20
  21/*
  22 * Initialize the grep_defaults template with hardcoded defaults.
  23 * We could let the compiler do this, but without C99 initializers
  24 * the code gets unwieldy and unreadable, so...
  25 */
  26void init_grep_defaults(void)
  27{
  28        struct grep_opt *opt = &grep_defaults;
  29        static int run_once;
  30
  31        if (run_once)
  32                return;
  33        run_once++;
  34
  35        memset(opt, 0, sizeof(*opt));
  36        opt->relative = 1;
  37        opt->pathname = 1;
  38        opt->regflags = REG_NEWLINE;
  39        opt->max_depth = -1;
  40        opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  41        opt->extended_regexp_option = 0;
  42        color_set(opt->color_context, "");
  43        color_set(opt->color_filename, "");
  44        color_set(opt->color_function, "");
  45        color_set(opt->color_lineno, "");
  46        color_set(opt->color_match_context, GIT_COLOR_BOLD_RED);
  47        color_set(opt->color_match_selected, GIT_COLOR_BOLD_RED);
  48        color_set(opt->color_selected, "");
  49        color_set(opt->color_sep, GIT_COLOR_CYAN);
  50        opt->color = -1;
  51        opt->output = std_output;
  52}
  53
  54static int parse_pattern_type_arg(const char *opt, const char *arg)
  55{
  56        if (!strcmp(arg, "default"))
  57                return GREP_PATTERN_TYPE_UNSPECIFIED;
  58        else if (!strcmp(arg, "basic"))
  59                return GREP_PATTERN_TYPE_BRE;
  60        else if (!strcmp(arg, "extended"))
  61                return GREP_PATTERN_TYPE_ERE;
  62        else if (!strcmp(arg, "fixed"))
  63                return GREP_PATTERN_TYPE_FIXED;
  64        else if (!strcmp(arg, "perl"))
  65                return GREP_PATTERN_TYPE_PCRE;
  66        die("bad %s argument: %s", opt, arg);
  67}
  68
  69/*
  70 * Read the configuration file once and store it in
  71 * the grep_defaults template.
  72 */
  73int grep_config(const char *var, const char *value, void *cb)
  74{
  75        struct grep_opt *opt = &grep_defaults;
  76        char *color = NULL;
  77
  78        if (userdiff_config(var, value) < 0)
  79                return -1;
  80
  81        if (!strcmp(var, "grep.extendedregexp")) {
  82                if (git_config_bool(var, value))
  83                        opt->extended_regexp_option = 1;
  84                else
  85                        opt->extended_regexp_option = 0;
  86                return 0;
  87        }
  88
  89        if (!strcmp(var, "grep.patterntype")) {
  90                opt->pattern_type_option = parse_pattern_type_arg(var, value);
  91                return 0;
  92        }
  93
  94        if (!strcmp(var, "grep.linenumber")) {
  95                opt->linenum = git_config_bool(var, value);
  96                return 0;
  97        }
  98
  99        if (!strcmp(var, "grep.fullname")) {
 100                opt->relative = !git_config_bool(var, value);
 101                return 0;
 102        }
 103
 104        if (!strcmp(var, "color.grep"))
 105                opt->color = git_config_colorbool(var, value);
 106        else if (!strcmp(var, "color.grep.context"))
 107                color = opt->color_context;
 108        else if (!strcmp(var, "color.grep.filename"))
 109                color = opt->color_filename;
 110        else if (!strcmp(var, "color.grep.function"))
 111                color = opt->color_function;
 112        else if (!strcmp(var, "color.grep.linenumber"))
 113                color = opt->color_lineno;
 114        else if (!strcmp(var, "color.grep.matchcontext"))
 115                color = opt->color_match_context;
 116        else if (!strcmp(var, "color.grep.matchselected"))
 117                color = opt->color_match_selected;
 118        else if (!strcmp(var, "color.grep.selected"))
 119                color = opt->color_selected;
 120        else if (!strcmp(var, "color.grep.separator"))
 121                color = opt->color_sep;
 122        else if (!strcmp(var, "color.grep.match")) {
 123                int rc = 0;
 124                if (!value)
 125                        return config_error_nonbool(var);
 126                rc |= color_parse(value, opt->color_match_context);
 127                rc |= color_parse(value, opt->color_match_selected);
 128                return rc;
 129        }
 130
 131        if (color) {
 132                if (!value)
 133                        return config_error_nonbool(var);
 134                return color_parse(value, color);
 135        }
 136        return 0;
 137}
 138
 139/*
 140 * Initialize one instance of grep_opt and copy the
 141 * default values from the template we read the configuration
 142 * information in an earlier call to git_config(grep_config).
 143 */
 144void grep_init(struct grep_opt *opt, const char *prefix)
 145{
 146        struct grep_opt *def = &grep_defaults;
 147
 148        memset(opt, 0, sizeof(*opt));
 149        opt->prefix = prefix;
 150        opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 151        opt->pattern_tail = &opt->pattern_list;
 152        opt->header_tail = &opt->header_list;
 153
 154        opt->color = def->color;
 155        opt->extended_regexp_option = def->extended_regexp_option;
 156        opt->pattern_type_option = def->pattern_type_option;
 157        opt->linenum = def->linenum;
 158        opt->max_depth = def->max_depth;
 159        opt->pathname = def->pathname;
 160        opt->regflags = def->regflags;
 161        opt->relative = def->relative;
 162        opt->output = def->output;
 163
 164        color_set(opt->color_context, def->color_context);
 165        color_set(opt->color_filename, def->color_filename);
 166        color_set(opt->color_function, def->color_function);
 167        color_set(opt->color_lineno, def->color_lineno);
 168        color_set(opt->color_match_context, def->color_match_context);
 169        color_set(opt->color_match_selected, def->color_match_selected);
 170        color_set(opt->color_selected, def->color_selected);
 171        color_set(opt->color_sep, def->color_sep);
 172}
 173
 174static void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 175{
 176        switch (pattern_type) {
 177        case GREP_PATTERN_TYPE_UNSPECIFIED:
 178                /* fall through */
 179
 180        case GREP_PATTERN_TYPE_BRE:
 181                opt->fixed = 0;
 182                opt->pcre1 = 0;
 183                opt->pcre2 = 0;
 184                break;
 185
 186        case GREP_PATTERN_TYPE_ERE:
 187                opt->fixed = 0;
 188                opt->pcre1 = 0;
 189                opt->pcre2 = 0;
 190                opt->regflags |= REG_EXTENDED;
 191                break;
 192
 193        case GREP_PATTERN_TYPE_FIXED:
 194                opt->fixed = 1;
 195                opt->pcre1 = 0;
 196                opt->pcre2 = 0;
 197                break;
 198
 199        case GREP_PATTERN_TYPE_PCRE:
 200                opt->fixed = 0;
 201#ifdef USE_LIBPCRE2
 202                opt->pcre1 = 0;
 203                opt->pcre2 = 1;
 204#else
 205                /*
 206                 * It's important that pcre1 always be assigned to
 207                 * even when there's no USE_LIBPCRE* defined. We still
 208                 * call the PCRE stub function, it just dies with
 209                 * "cannot use Perl-compatible regexes[...]".
 210                 */
 211                opt->pcre1 = 1;
 212                opt->pcre2 = 0;
 213#endif
 214                break;
 215        }
 216}
 217
 218void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 219{
 220        if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 221                grep_set_pattern_type_option(pattern_type, opt);
 222        else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 223                grep_set_pattern_type_option(opt->pattern_type_option, opt);
 224        else if (opt->extended_regexp_option)
 225                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 226}
 227
 228static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 229                                        const char *origin, int no,
 230                                        enum grep_pat_token t,
 231                                        enum grep_header_field field)
 232{
 233        struct grep_pat *p = xcalloc(1, sizeof(*p));
 234        p->pattern = xmemdupz(pat, patlen);
 235        p->patternlen = patlen;
 236        p->origin = origin;
 237        p->no = no;
 238        p->token = t;
 239        p->field = field;
 240        return p;
 241}
 242
 243static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 244{
 245        **tail = p;
 246        *tail = &p->next;
 247        p->next = NULL;
 248
 249        switch (p->token) {
 250        case GREP_PATTERN: /* atom */
 251        case GREP_PATTERN_HEAD:
 252        case GREP_PATTERN_BODY:
 253                for (;;) {
 254                        struct grep_pat *new_pat;
 255                        size_t len = 0;
 256                        char *cp = p->pattern + p->patternlen, *nl = NULL;
 257                        while (++len <= p->patternlen) {
 258                                if (*(--cp) == '\n') {
 259                                        nl = cp;
 260                                        break;
 261                                }
 262                        }
 263                        if (!nl)
 264                                break;
 265                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 266                                                  p->no, p->token, p->field);
 267                        new_pat->next = p->next;
 268                        if (!p->next)
 269                                *tail = &new_pat->next;
 270                        p->next = new_pat;
 271                        *nl = '\0';
 272                        p->patternlen -= len;
 273                }
 274                break;
 275        default:
 276                break;
 277        }
 278}
 279
 280void append_header_grep_pattern(struct grep_opt *opt,
 281                                enum grep_header_field field, const char *pat)
 282{
 283        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 284                                             GREP_PATTERN_HEAD, field);
 285        if (field == GREP_HEADER_REFLOG)
 286                opt->use_reflog_filter = 1;
 287        do_append_grep_pat(&opt->header_tail, p);
 288}
 289
 290void append_grep_pattern(struct grep_opt *opt, const char *pat,
 291                         const char *origin, int no, enum grep_pat_token t)
 292{
 293        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 294}
 295
 296void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 297                     const char *origin, int no, enum grep_pat_token t)
 298{
 299        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 300        do_append_grep_pat(&opt->pattern_tail, p);
 301}
 302
 303struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 304{
 305        struct grep_pat *pat;
 306        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 307        *ret = *opt;
 308
 309        ret->pattern_list = NULL;
 310        ret->pattern_tail = &ret->pattern_list;
 311
 312        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 313        {
 314                if(pat->token == GREP_PATTERN_HEAD)
 315                        append_header_grep_pattern(ret, pat->field,
 316                                                   pat->pattern);
 317                else
 318                        append_grep_pat(ret, pat->pattern, pat->patternlen,
 319                                        pat->origin, pat->no, pat->token);
 320        }
 321
 322        return ret;
 323}
 324
 325static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 326                const char *error)
 327{
 328        char where[1024];
 329
 330        if (p->no)
 331                xsnprintf(where, sizeof(where), "In '%s' at %d, ", p->origin, p->no);
 332        else if (p->origin)
 333                xsnprintf(where, sizeof(where), "%s, ", p->origin);
 334        else
 335                where[0] = 0;
 336
 337        die("%s'%s': %s", where, p->pattern, error);
 338}
 339
 340static int is_fixed(const char *s, size_t len)
 341{
 342        size_t i;
 343
 344        for (i = 0; i < len; i++) {
 345                if (is_regex_special(s[i]))
 346                        return 0;
 347        }
 348
 349        return 1;
 350}
 351
 352static int has_null(const char *s, size_t len)
 353{
 354        /*
 355         * regcomp cannot accept patterns with NULs so when using it
 356         * we consider any pattern containing a NUL fixed.
 357         */
 358        if (memchr(s, 0, len))
 359                return 1;
 360
 361        return 0;
 362}
 363
 364#ifdef USE_LIBPCRE1
 365static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 366{
 367        const char *error;
 368        int erroffset;
 369        int options = PCRE_MULTILINE;
 370
 371        if (opt->ignore_case) {
 372                if (has_non_ascii(p->pattern))
 373                        p->pcre1_tables = pcre_maketables();
 374                options |= PCRE_CASELESS;
 375        }
 376        if (is_utf8_locale() && has_non_ascii(p->pattern))
 377                options |= PCRE_UTF8;
 378
 379        p->pcre1_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 380                                      p->pcre1_tables);
 381        if (!p->pcre1_regexp)
 382                compile_regexp_failed(p, error);
 383
 384        p->pcre1_extra_info = pcre_study(p->pcre1_regexp, PCRE_STUDY_JIT_COMPILE, &error);
 385        if (!p->pcre1_extra_info && error)
 386                die("%s", error);
 387
 388#ifdef GIT_PCRE1_USE_JIT
 389        pcre_config(PCRE_CONFIG_JIT, &p->pcre1_jit_on);
 390        if (p->pcre1_jit_on == 1) {
 391                p->pcre1_jit_stack = pcre_jit_stack_alloc(1, 1024 * 1024);
 392                if (!p->pcre1_jit_stack)
 393                        die("Couldn't allocate PCRE JIT stack");
 394                pcre_assign_jit_stack(p->pcre1_extra_info, NULL, p->pcre1_jit_stack);
 395        } else if (p->pcre1_jit_on != 0) {
 396                die("BUG: The pcre1_jit_on variable should be 0 or 1, not %d",
 397                    p->pcre1_jit_on);
 398        }
 399#endif
 400}
 401
 402static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 403                regmatch_t *match, int eflags)
 404{
 405        int ovector[30], ret, flags = 0;
 406
 407        if (eflags & REG_NOTBOL)
 408                flags |= PCRE_NOTBOL;
 409
 410#ifdef GIT_PCRE1_USE_JIT
 411        if (p->pcre1_jit_on) {
 412                ret = pcre_jit_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
 413                                    eol - line, 0, flags, ovector,
 414                                    ARRAY_SIZE(ovector), p->pcre1_jit_stack);
 415        } else
 416#endif
 417        {
 418                ret = pcre_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
 419                                eol - line, 0, flags, ovector,
 420                                ARRAY_SIZE(ovector));
 421        }
 422
 423        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 424                die("pcre_exec failed with error code %d", ret);
 425        if (ret > 0) {
 426                ret = 0;
 427                match->rm_so = ovector[0];
 428                match->rm_eo = ovector[1];
 429        }
 430
 431        return ret;
 432}
 433
 434static void free_pcre1_regexp(struct grep_pat *p)
 435{
 436        pcre_free(p->pcre1_regexp);
 437#ifdef GIT_PCRE1_USE_JIT
 438        if (p->pcre1_jit_on) {
 439                pcre_free_study(p->pcre1_extra_info);
 440                pcre_jit_stack_free(p->pcre1_jit_stack);
 441        } else
 442#endif
 443        {
 444                pcre_free(p->pcre1_extra_info);
 445        }
 446        pcre_free((void *)p->pcre1_tables);
 447}
 448#else /* !USE_LIBPCRE1 */
 449static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 450{
 451        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 452}
 453
 454static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 455                regmatch_t *match, int eflags)
 456{
 457        return 1;
 458}
 459
 460static void free_pcre1_regexp(struct grep_pat *p)
 461{
 462}
 463#endif /* !USE_LIBPCRE1 */
 464
 465#ifdef USE_LIBPCRE2
 466static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)
 467{
 468        int error;
 469        PCRE2_UCHAR errbuf[256];
 470        PCRE2_SIZE erroffset;
 471        int options = PCRE2_MULTILINE;
 472        const uint8_t *character_tables = NULL;
 473        int jitret;
 474
 475        assert(opt->pcre2);
 476
 477        p->pcre2_compile_context = NULL;
 478
 479        if (opt->ignore_case) {
 480                if (has_non_ascii(p->pattern)) {
 481                        character_tables = pcre2_maketables(NULL);
 482                        p->pcre2_compile_context = pcre2_compile_context_create(NULL);
 483                        pcre2_set_character_tables(p->pcre2_compile_context, character_tables);
 484                }
 485                options |= PCRE2_CASELESS;
 486        }
 487        if (is_utf8_locale() && has_non_ascii(p->pattern))
 488                options |= PCRE2_UTF;
 489
 490        p->pcre2_pattern = pcre2_compile((PCRE2_SPTR)p->pattern,
 491                                         p->patternlen, options, &error, &erroffset,
 492                                         p->pcre2_compile_context);
 493
 494        if (p->pcre2_pattern) {
 495                p->pcre2_match_data = pcre2_match_data_create_from_pattern(p->pcre2_pattern, NULL);
 496                if (!p->pcre2_match_data)
 497                        die("Couldn't allocate PCRE2 match data");
 498        } else {
 499                pcre2_get_error_message(error, errbuf, sizeof(errbuf));
 500                compile_regexp_failed(p, (const char *)&errbuf);
 501        }
 502
 503        pcre2_config(PCRE2_CONFIG_JIT, &p->pcre2_jit_on);
 504        if (p->pcre2_jit_on == 1) {
 505                jitret = pcre2_jit_compile(p->pcre2_pattern, PCRE2_JIT_COMPLETE);
 506                if (jitret)
 507                        die("Couldn't JIT the PCRE2 pattern '%s', got '%d'\n", p->pattern, jitret);
 508                p->pcre2_jit_stack = pcre2_jit_stack_create(1, 1024 * 1024, NULL);
 509                if (!p->pcre2_jit_stack)
 510                        die("Couldn't allocate PCRE2 JIT stack");
 511                p->pcre2_match_context = pcre2_match_context_create(NULL);
 512                if (!p->pcre2_match_context)
 513                        die("Couldn't allocate PCRE2 match context");
 514                pcre2_jit_stack_assign(p->pcre2_match_context, NULL, p->pcre2_jit_stack);
 515        } else if (p->pcre2_jit_on != 0) {
 516                die("BUG: The pcre2_jit_on variable should be 0 or 1, not %d",
 517                    p->pcre1_jit_on);
 518        }
 519}
 520
 521static int pcre2match(struct grep_pat *p, const char *line, const char *eol,
 522                regmatch_t *match, int eflags)
 523{
 524        int ret, flags = 0;
 525        PCRE2_SIZE *ovector;
 526        PCRE2_UCHAR errbuf[256];
 527
 528        if (eflags & REG_NOTBOL)
 529                flags |= PCRE2_NOTBOL;
 530
 531        if (p->pcre2_jit_on)
 532                ret = pcre2_jit_match(p->pcre2_pattern, (unsigned char *)line,
 533                                      eol - line, 0, flags, p->pcre2_match_data,
 534                                      NULL);
 535        else
 536                ret = pcre2_match(p->pcre2_pattern, (unsigned char *)line,
 537                                  eol - line, 0, flags, p->pcre2_match_data,
 538                                  NULL);
 539
 540        if (ret < 0 && ret != PCRE2_ERROR_NOMATCH) {
 541                pcre2_get_error_message(ret, errbuf, sizeof(errbuf));
 542                die("%s failed with error code %d: %s",
 543                    (p->pcre2_jit_on ? "pcre2_jit_match" : "pcre2_match"), ret,
 544                    errbuf);
 545        }
 546        if (ret > 0) {
 547                ovector = pcre2_get_ovector_pointer(p->pcre2_match_data);
 548                ret = 0;
 549                match->rm_so = (int)ovector[0];
 550                match->rm_eo = (int)ovector[1];
 551        }
 552
 553        return ret;
 554}
 555
 556static void free_pcre2_pattern(struct grep_pat *p)
 557{
 558        pcre2_compile_context_free(p->pcre2_compile_context);
 559        pcre2_code_free(p->pcre2_pattern);
 560        pcre2_match_data_free(p->pcre2_match_data);
 561        pcre2_jit_stack_free(p->pcre2_jit_stack);
 562        pcre2_match_context_free(p->pcre2_match_context);
 563}
 564#else /* !USE_LIBPCRE2 */
 565static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)
 566{
 567        /*
 568         * Unreachable until USE_LIBPCRE2 becomes synonymous with
 569         * USE_LIBPCRE. See the sibling comment in
 570         * grep_set_pattern_type_option().
 571         */
 572        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 573}
 574
 575static int pcre2match(struct grep_pat *p, const char *line, const char *eol,
 576                regmatch_t *match, int eflags)
 577{
 578        return 1;
 579}
 580
 581static void free_pcre2_pattern(struct grep_pat *p)
 582{
 583}
 584#endif /* !USE_LIBPCRE2 */
 585
 586static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 587{
 588        struct strbuf sb = STRBUF_INIT;
 589        int err;
 590        int regflags = opt->regflags;
 591
 592        basic_regex_quote_buf(&sb, p->pattern);
 593        if (opt->ignore_case)
 594                regflags |= REG_ICASE;
 595        err = regcomp(&p->regexp, sb.buf, regflags);
 596        if (opt->debug)
 597                fprintf(stderr, "fixed %s\n", sb.buf);
 598        strbuf_release(&sb);
 599        if (err) {
 600                char errbuf[1024];
 601                regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 602                regfree(&p->regexp);
 603                compile_regexp_failed(p, errbuf);
 604        }
 605}
 606
 607static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 608{
 609        int icase, ascii_only;
 610        int err;
 611
 612        p->word_regexp = opt->word_regexp;
 613        p->ignore_case = opt->ignore_case;
 614        icase          = opt->regflags & REG_ICASE || p->ignore_case;
 615        ascii_only     = !has_non_ascii(p->pattern);
 616
 617        /*
 618         * Even when -F (fixed) asks us to do a non-regexp search, we
 619         * may not be able to correctly case-fold when -i
 620         * (ignore-case) is asked (in which case, we'll synthesize a
 621         * regexp to match the pattern that matches regexp special
 622         * characters literally, while ignoring case differences).  On
 623         * the other hand, even without -F, if the pattern does not
 624         * have any regexp special characters and there is no need for
 625         * case-folding search, we can internally turn it into a
 626         * simple string match using kws.  p->fixed tells us if we
 627         * want to use kws.
 628         */
 629        if (opt->fixed ||
 630            has_null(p->pattern, p->patternlen) ||
 631            is_fixed(p->pattern, p->patternlen))
 632                p->fixed = !icase || ascii_only;
 633        else
 634                p->fixed = 0;
 635
 636        if (p->fixed) {
 637                p->kws = kwsalloc(icase ? tolower_trans_tbl : NULL);
 638                kwsincr(p->kws, p->pattern, p->patternlen);
 639                kwsprep(p->kws);
 640                return;
 641        } else if (opt->fixed) {
 642                /*
 643                 * We come here when the pattern has the non-ascii
 644                 * characters we cannot case-fold, and asked to
 645                 * ignore-case.
 646                 */
 647                compile_fixed_regexp(p, opt);
 648                return;
 649        }
 650
 651        if (opt->pcre2) {
 652                compile_pcre2_pattern(p, opt);
 653                return;
 654        }
 655
 656        if (opt->pcre1) {
 657                compile_pcre1_regexp(p, opt);
 658                return;
 659        }
 660
 661        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 662        if (err) {
 663                char errbuf[1024];
 664                regerror(err, &p->regexp, errbuf, 1024);
 665                regfree(&p->regexp);
 666                compile_regexp_failed(p, errbuf);
 667        }
 668}
 669
 670static struct grep_expr *compile_pattern_or(struct grep_pat **);
 671static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 672{
 673        struct grep_pat *p;
 674        struct grep_expr *x;
 675
 676        p = *list;
 677        if (!p)
 678                return NULL;
 679        switch (p->token) {
 680        case GREP_PATTERN: /* atom */
 681        case GREP_PATTERN_HEAD:
 682        case GREP_PATTERN_BODY:
 683                x = xcalloc(1, sizeof (struct grep_expr));
 684                x->node = GREP_NODE_ATOM;
 685                x->u.atom = p;
 686                *list = p->next;
 687                return x;
 688        case GREP_OPEN_PAREN:
 689                *list = p->next;
 690                x = compile_pattern_or(list);
 691                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 692                        die("unmatched parenthesis");
 693                *list = (*list)->next;
 694                return x;
 695        default:
 696                return NULL;
 697        }
 698}
 699
 700static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 701{
 702        struct grep_pat *p;
 703        struct grep_expr *x;
 704
 705        p = *list;
 706        if (!p)
 707                return NULL;
 708        switch (p->token) {
 709        case GREP_NOT:
 710                if (!p->next)
 711                        die("--not not followed by pattern expression");
 712                *list = p->next;
 713                x = xcalloc(1, sizeof (struct grep_expr));
 714                x->node = GREP_NODE_NOT;
 715                x->u.unary = compile_pattern_not(list);
 716                if (!x->u.unary)
 717                        die("--not followed by non pattern expression");
 718                return x;
 719        default:
 720                return compile_pattern_atom(list);
 721        }
 722}
 723
 724static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 725{
 726        struct grep_pat *p;
 727        struct grep_expr *x, *y, *z;
 728
 729        x = compile_pattern_not(list);
 730        p = *list;
 731        if (p && p->token == GREP_AND) {
 732                if (!p->next)
 733                        die("--and not followed by pattern expression");
 734                *list = p->next;
 735                y = compile_pattern_and(list);
 736                if (!y)
 737                        die("--and not followed by pattern expression");
 738                z = xcalloc(1, sizeof (struct grep_expr));
 739                z->node = GREP_NODE_AND;
 740                z->u.binary.left = x;
 741                z->u.binary.right = y;
 742                return z;
 743        }
 744        return x;
 745}
 746
 747static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 748{
 749        struct grep_pat *p;
 750        struct grep_expr *x, *y, *z;
 751
 752        x = compile_pattern_and(list);
 753        p = *list;
 754        if (x && p && p->token != GREP_CLOSE_PAREN) {
 755                y = compile_pattern_or(list);
 756                if (!y)
 757                        die("not a pattern expression %s", p->pattern);
 758                z = xcalloc(1, sizeof (struct grep_expr));
 759                z->node = GREP_NODE_OR;
 760                z->u.binary.left = x;
 761                z->u.binary.right = y;
 762                return z;
 763        }
 764        return x;
 765}
 766
 767static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 768{
 769        return compile_pattern_or(list);
 770}
 771
 772static void indent(int in)
 773{
 774        while (in-- > 0)
 775                fputc(' ', stderr);
 776}
 777
 778static void dump_grep_pat(struct grep_pat *p)
 779{
 780        switch (p->token) {
 781        case GREP_AND: fprintf(stderr, "*and*"); break;
 782        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 783        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 784        case GREP_NOT: fprintf(stderr, "*not*"); break;
 785        case GREP_OR: fprintf(stderr, "*or*"); break;
 786
 787        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 788        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 789        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 790        }
 791
 792        switch (p->token) {
 793        default: break;
 794        case GREP_PATTERN_HEAD:
 795                fprintf(stderr, "<head %d>", p->field); break;
 796        case GREP_PATTERN_BODY:
 797                fprintf(stderr, "<body>"); break;
 798        }
 799        switch (p->token) {
 800        default: break;
 801        case GREP_PATTERN_HEAD:
 802        case GREP_PATTERN_BODY:
 803        case GREP_PATTERN:
 804                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 805                break;
 806        }
 807        fputc('\n', stderr);
 808}
 809
 810static void dump_grep_expression_1(struct grep_expr *x, int in)
 811{
 812        indent(in);
 813        switch (x->node) {
 814        case GREP_NODE_TRUE:
 815                fprintf(stderr, "true\n");
 816                break;
 817        case GREP_NODE_ATOM:
 818                dump_grep_pat(x->u.atom);
 819                break;
 820        case GREP_NODE_NOT:
 821                fprintf(stderr, "(not\n");
 822                dump_grep_expression_1(x->u.unary, in+1);
 823                indent(in);
 824                fprintf(stderr, ")\n");
 825                break;
 826        case GREP_NODE_AND:
 827                fprintf(stderr, "(and\n");
 828                dump_grep_expression_1(x->u.binary.left, in+1);
 829                dump_grep_expression_1(x->u.binary.right, in+1);
 830                indent(in);
 831                fprintf(stderr, ")\n");
 832                break;
 833        case GREP_NODE_OR:
 834                fprintf(stderr, "(or\n");
 835                dump_grep_expression_1(x->u.binary.left, in+1);
 836                dump_grep_expression_1(x->u.binary.right, in+1);
 837                indent(in);
 838                fprintf(stderr, ")\n");
 839                break;
 840        }
 841}
 842
 843static void dump_grep_expression(struct grep_opt *opt)
 844{
 845        struct grep_expr *x = opt->pattern_expression;
 846
 847        if (opt->all_match)
 848                fprintf(stderr, "[all-match]\n");
 849        dump_grep_expression_1(x, 0);
 850        fflush(NULL);
 851}
 852
 853static struct grep_expr *grep_true_expr(void)
 854{
 855        struct grep_expr *z = xcalloc(1, sizeof(*z));
 856        z->node = GREP_NODE_TRUE;
 857        return z;
 858}
 859
 860static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 861{
 862        struct grep_expr *z = xcalloc(1, sizeof(*z));
 863        z->node = GREP_NODE_OR;
 864        z->u.binary.left = left;
 865        z->u.binary.right = right;
 866        return z;
 867}
 868
 869static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 870{
 871        struct grep_pat *p;
 872        struct grep_expr *header_expr;
 873        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 874        enum grep_header_field fld;
 875
 876        if (!opt->header_list)
 877                return NULL;
 878
 879        for (p = opt->header_list; p; p = p->next) {
 880                if (p->token != GREP_PATTERN_HEAD)
 881                        die("BUG: a non-header pattern in grep header list.");
 882                if (p->field < GREP_HEADER_FIELD_MIN ||
 883                    GREP_HEADER_FIELD_MAX <= p->field)
 884                        die("BUG: unknown header field %d", p->field);
 885                compile_regexp(p, opt);
 886        }
 887
 888        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 889                header_group[fld] = NULL;
 890
 891        for (p = opt->header_list; p; p = p->next) {
 892                struct grep_expr *h;
 893                struct grep_pat *pp = p;
 894
 895                h = compile_pattern_atom(&pp);
 896                if (!h || pp != p->next)
 897                        die("BUG: malformed header expr");
 898                if (!header_group[p->field]) {
 899                        header_group[p->field] = h;
 900                        continue;
 901                }
 902                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 903        }
 904
 905        header_expr = NULL;
 906
 907        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 908                if (!header_group[fld])
 909                        continue;
 910                if (!header_expr)
 911                        header_expr = grep_true_expr();
 912                header_expr = grep_or_expr(header_group[fld], header_expr);
 913        }
 914        return header_expr;
 915}
 916
 917static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 918{
 919        struct grep_expr *z = x;
 920
 921        while (x) {
 922                assert(x->node == GREP_NODE_OR);
 923                if (x->u.binary.right &&
 924                    x->u.binary.right->node == GREP_NODE_TRUE) {
 925                        x->u.binary.right = y;
 926                        break;
 927                }
 928                x = x->u.binary.right;
 929        }
 930        return z;
 931}
 932
 933static void compile_grep_patterns_real(struct grep_opt *opt)
 934{
 935        struct grep_pat *p;
 936        struct grep_expr *header_expr = prep_header_patterns(opt);
 937
 938        for (p = opt->pattern_list; p; p = p->next) {
 939                switch (p->token) {
 940                case GREP_PATTERN: /* atom */
 941                case GREP_PATTERN_HEAD:
 942                case GREP_PATTERN_BODY:
 943                        compile_regexp(p, opt);
 944                        break;
 945                default:
 946                        opt->extended = 1;
 947                        break;
 948                }
 949        }
 950
 951        if (opt->all_match || header_expr)
 952                opt->extended = 1;
 953        else if (!opt->extended && !opt->debug)
 954                return;
 955
 956        p = opt->pattern_list;
 957        if (p)
 958                opt->pattern_expression = compile_pattern_expr(&p);
 959        if (p)
 960                die("incomplete pattern expression: %s", p->pattern);
 961
 962        if (!header_expr)
 963                return;
 964
 965        if (!opt->pattern_expression)
 966                opt->pattern_expression = header_expr;
 967        else if (opt->all_match)
 968                opt->pattern_expression = grep_splice_or(header_expr,
 969                                                         opt->pattern_expression);
 970        else
 971                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 972                                                       header_expr);
 973        opt->all_match = 1;
 974}
 975
 976void compile_grep_patterns(struct grep_opt *opt)
 977{
 978        compile_grep_patterns_real(opt);
 979        if (opt->debug)
 980                dump_grep_expression(opt);
 981}
 982
 983static void free_pattern_expr(struct grep_expr *x)
 984{
 985        switch (x->node) {
 986        case GREP_NODE_TRUE:
 987        case GREP_NODE_ATOM:
 988                break;
 989        case GREP_NODE_NOT:
 990                free_pattern_expr(x->u.unary);
 991                break;
 992        case GREP_NODE_AND:
 993        case GREP_NODE_OR:
 994                free_pattern_expr(x->u.binary.left);
 995                free_pattern_expr(x->u.binary.right);
 996                break;
 997        }
 998        free(x);
 999}
1000
1001void free_grep_patterns(struct grep_opt *opt)
1002{
1003        struct grep_pat *p, *n;
1004
1005        for (p = opt->pattern_list; p; p = n) {
1006                n = p->next;
1007                switch (p->token) {
1008                case GREP_PATTERN: /* atom */
1009                case GREP_PATTERN_HEAD:
1010                case GREP_PATTERN_BODY:
1011                        if (p->kws)
1012                                kwsfree(p->kws);
1013                        else if (p->pcre1_regexp)
1014                                free_pcre1_regexp(p);
1015                        else if (p->pcre2_pattern)
1016                                free_pcre2_pattern(p);
1017                        else
1018                                regfree(&p->regexp);
1019                        free(p->pattern);
1020                        break;
1021                default:
1022                        break;
1023                }
1024                free(p);
1025        }
1026
1027        if (!opt->extended)
1028                return;
1029        free_pattern_expr(opt->pattern_expression);
1030}
1031
1032static char *end_of_line(char *cp, unsigned long *left)
1033{
1034        unsigned long l = *left;
1035        while (l && *cp != '\n') {
1036                l--;
1037                cp++;
1038        }
1039        *left = l;
1040        return cp;
1041}
1042
1043static int word_char(char ch)
1044{
1045        return isalnum(ch) || ch == '_';
1046}
1047
1048static void output_color(struct grep_opt *opt, const void *data, size_t size,
1049                         const char *color)
1050{
1051        if (want_color(opt->color) && color && color[0]) {
1052                opt->output(opt, color, strlen(color));
1053                opt->output(opt, data, size);
1054                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
1055        } else
1056                opt->output(opt, data, size);
1057}
1058
1059static void output_sep(struct grep_opt *opt, char sign)
1060{
1061        if (opt->null_following_name)
1062                opt->output(opt, "\0", 1);
1063        else
1064                output_color(opt, &sign, 1, opt->color_sep);
1065}
1066
1067static void show_name(struct grep_opt *opt, const char *name)
1068{
1069        output_color(opt, name, strlen(name), opt->color_filename);
1070        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
1071}
1072
1073static int fixmatch(struct grep_pat *p, char *line, char *eol,
1074                    regmatch_t *match)
1075{
1076        struct kwsmatch kwsm;
1077        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
1078        if (offset == -1) {
1079                match->rm_so = match->rm_eo = -1;
1080                return REG_NOMATCH;
1081        } else {
1082                match->rm_so = offset;
1083                match->rm_eo = match->rm_so + kwsm.size[0];
1084                return 0;
1085        }
1086}
1087
1088static int patmatch(struct grep_pat *p, char *line, char *eol,
1089                    regmatch_t *match, int eflags)
1090{
1091        int hit;
1092
1093        if (p->fixed)
1094                hit = !fixmatch(p, line, eol, match);
1095        else if (p->pcre1_regexp)
1096                hit = !pcre1match(p, line, eol, match, eflags);
1097        else if (p->pcre2_pattern)
1098                hit = !pcre2match(p, line, eol, match, eflags);
1099        else
1100                hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
1101                                   eflags);
1102
1103        return hit;
1104}
1105
1106static int strip_timestamp(char *bol, char **eol_p)
1107{
1108        char *eol = *eol_p;
1109        int ch;
1110
1111        while (bol < --eol) {
1112                if (*eol != '>')
1113                        continue;
1114                *eol_p = ++eol;
1115                ch = *eol;
1116                *eol = '\0';
1117                return ch;
1118        }
1119        return 0;
1120}
1121
1122static struct {
1123        const char *field;
1124        size_t len;
1125} header_field[] = {
1126        { "author ", 7 },
1127        { "committer ", 10 },
1128        { "reflog ", 7 },
1129};
1130
1131static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
1132                             enum grep_context ctx,
1133                             regmatch_t *pmatch, int eflags)
1134{
1135        int hit = 0;
1136        int saved_ch = 0;
1137        const char *start = bol;
1138
1139        if ((p->token != GREP_PATTERN) &&
1140            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
1141                return 0;
1142
1143        if (p->token == GREP_PATTERN_HEAD) {
1144                const char *field;
1145                size_t len;
1146                assert(p->field < ARRAY_SIZE(header_field));
1147                field = header_field[p->field].field;
1148                len = header_field[p->field].len;
1149                if (strncmp(bol, field, len))
1150                        return 0;
1151                bol += len;
1152                switch (p->field) {
1153                case GREP_HEADER_AUTHOR:
1154                case GREP_HEADER_COMMITTER:
1155                        saved_ch = strip_timestamp(bol, &eol);
1156                        break;
1157                default:
1158                        break;
1159                }
1160        }
1161
1162 again:
1163        hit = patmatch(p, bol, eol, pmatch, eflags);
1164
1165        if (hit && p->word_regexp) {
1166                if ((pmatch[0].rm_so < 0) ||
1167                    (eol - bol) < pmatch[0].rm_so ||
1168                    (pmatch[0].rm_eo < 0) ||
1169                    (eol - bol) < pmatch[0].rm_eo)
1170                        die("regexp returned nonsense");
1171
1172                /* Match beginning must be either beginning of the
1173                 * line, or at word boundary (i.e. the last char must
1174                 * not be a word char).  Similarly, match end must be
1175                 * either end of the line, or at word boundary
1176                 * (i.e. the next char must not be a word char).
1177                 */
1178                if ( ((pmatch[0].rm_so == 0) ||
1179                      !word_char(bol[pmatch[0].rm_so-1])) &&
1180                     ((pmatch[0].rm_eo == (eol-bol)) ||
1181                      !word_char(bol[pmatch[0].rm_eo])) )
1182                        ;
1183                else
1184                        hit = 0;
1185
1186                /* Words consist of at least one character. */
1187                if (pmatch->rm_so == pmatch->rm_eo)
1188                        hit = 0;
1189
1190                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1191                        /* There could be more than one match on the
1192                         * line, and the first match might not be
1193                         * strict word match.  But later ones could be!
1194                         * Forward to the next possible start, i.e. the
1195                         * next position following a non-word char.
1196                         */
1197                        bol = pmatch[0].rm_so + bol + 1;
1198                        while (word_char(bol[-1]) && bol < eol)
1199                                bol++;
1200                        eflags |= REG_NOTBOL;
1201                        if (bol < eol)
1202                                goto again;
1203                }
1204        }
1205        if (p->token == GREP_PATTERN_HEAD && saved_ch)
1206                *eol = saved_ch;
1207        if (hit) {
1208                pmatch[0].rm_so += bol - start;
1209                pmatch[0].rm_eo += bol - start;
1210        }
1211        return hit;
1212}
1213
1214static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1215                           enum grep_context ctx, int collect_hits)
1216{
1217        int h = 0;
1218        regmatch_t match;
1219
1220        if (!x)
1221                die("Not a valid grep expression");
1222        switch (x->node) {
1223        case GREP_NODE_TRUE:
1224                h = 1;
1225                break;
1226        case GREP_NODE_ATOM:
1227                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1228                break;
1229        case GREP_NODE_NOT:
1230                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1231                break;
1232        case GREP_NODE_AND:
1233                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1234                        return 0;
1235                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1236                break;
1237        case GREP_NODE_OR:
1238                if (!collect_hits)
1239                        return (match_expr_eval(x->u.binary.left,
1240                                                bol, eol, ctx, 0) ||
1241                                match_expr_eval(x->u.binary.right,
1242                                                bol, eol, ctx, 0));
1243                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1244                x->u.binary.left->hit |= h;
1245                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1246                break;
1247        default:
1248                die("Unexpected node type (internal error) %d", x->node);
1249        }
1250        if (collect_hits)
1251                x->hit |= h;
1252        return h;
1253}
1254
1255static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1256                      enum grep_context ctx, int collect_hits)
1257{
1258        struct grep_expr *x = opt->pattern_expression;
1259        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1260}
1261
1262static int match_line(struct grep_opt *opt, char *bol, char *eol,
1263                      enum grep_context ctx, int collect_hits)
1264{
1265        struct grep_pat *p;
1266        regmatch_t match;
1267
1268        if (opt->extended)
1269                return match_expr(opt, bol, eol, ctx, collect_hits);
1270
1271        /* we do not call with collect_hits without being extended */
1272        for (p = opt->pattern_list; p; p = p->next) {
1273                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1274                        return 1;
1275        }
1276        return 0;
1277}
1278
1279static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1280                              enum grep_context ctx,
1281                              regmatch_t *pmatch, int eflags)
1282{
1283        regmatch_t match;
1284
1285        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1286                return 0;
1287        if (match.rm_so < 0 || match.rm_eo < 0)
1288                return 0;
1289        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1290                if (match.rm_so > pmatch->rm_so)
1291                        return 1;
1292                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1293                        return 1;
1294        }
1295        pmatch->rm_so = match.rm_so;
1296        pmatch->rm_eo = match.rm_eo;
1297        return 1;
1298}
1299
1300static int next_match(struct grep_opt *opt, char *bol, char *eol,
1301                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1302{
1303        struct grep_pat *p;
1304        int hit = 0;
1305
1306        pmatch->rm_so = pmatch->rm_eo = -1;
1307        if (bol < eol) {
1308                for (p = opt->pattern_list; p; p = p->next) {
1309                        switch (p->token) {
1310                        case GREP_PATTERN: /* atom */
1311                        case GREP_PATTERN_HEAD:
1312                        case GREP_PATTERN_BODY:
1313                                hit |= match_next_pattern(p, bol, eol, ctx,
1314                                                          pmatch, eflags);
1315                                break;
1316                        default:
1317                                break;
1318                        }
1319                }
1320        }
1321        return hit;
1322}
1323
1324static void show_line(struct grep_opt *opt, char *bol, char *eol,
1325                      const char *name, unsigned lno, char sign)
1326{
1327        int rest = eol - bol;
1328        const char *match_color, *line_color = NULL;
1329
1330        if (opt->file_break && opt->last_shown == 0) {
1331                if (opt->show_hunk_mark)
1332                        opt->output(opt, "\n", 1);
1333        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1334                if (opt->last_shown == 0) {
1335                        if (opt->show_hunk_mark) {
1336                                output_color(opt, "--", 2, opt->color_sep);
1337                                opt->output(opt, "\n", 1);
1338                        }
1339                } else if (lno > opt->last_shown + 1) {
1340                        output_color(opt, "--", 2, opt->color_sep);
1341                        opt->output(opt, "\n", 1);
1342                }
1343        }
1344        if (opt->heading && opt->last_shown == 0) {
1345                output_color(opt, name, strlen(name), opt->color_filename);
1346                opt->output(opt, "\n", 1);
1347        }
1348        opt->last_shown = lno;
1349
1350        if (!opt->heading && opt->pathname) {
1351                output_color(opt, name, strlen(name), opt->color_filename);
1352                output_sep(opt, sign);
1353        }
1354        if (opt->linenum) {
1355                char buf[32];
1356                xsnprintf(buf, sizeof(buf), "%d", lno);
1357                output_color(opt, buf, strlen(buf), opt->color_lineno);
1358                output_sep(opt, sign);
1359        }
1360        if (opt->color) {
1361                regmatch_t match;
1362                enum grep_context ctx = GREP_CONTEXT_BODY;
1363                int ch = *eol;
1364                int eflags = 0;
1365
1366                if (sign == ':')
1367                        match_color = opt->color_match_selected;
1368                else
1369                        match_color = opt->color_match_context;
1370                if (sign == ':')
1371                        line_color = opt->color_selected;
1372                else if (sign == '-')
1373                        line_color = opt->color_context;
1374                else if (sign == '=')
1375                        line_color = opt->color_function;
1376                *eol = '\0';
1377                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1378                        if (match.rm_so == match.rm_eo)
1379                                break;
1380
1381                        output_color(opt, bol, match.rm_so, line_color);
1382                        output_color(opt, bol + match.rm_so,
1383                                     match.rm_eo - match.rm_so, match_color);
1384                        bol += match.rm_eo;
1385                        rest -= match.rm_eo;
1386                        eflags = REG_NOTBOL;
1387                }
1388                *eol = ch;
1389        }
1390        output_color(opt, bol, rest, line_color);
1391        opt->output(opt, "\n", 1);
1392}
1393
1394#ifndef NO_PTHREADS
1395int grep_use_locks;
1396
1397/*
1398 * This lock protects access to the gitattributes machinery, which is
1399 * not thread-safe.
1400 */
1401pthread_mutex_t grep_attr_mutex;
1402
1403static inline void grep_attr_lock(void)
1404{
1405        if (grep_use_locks)
1406                pthread_mutex_lock(&grep_attr_mutex);
1407}
1408
1409static inline void grep_attr_unlock(void)
1410{
1411        if (grep_use_locks)
1412                pthread_mutex_unlock(&grep_attr_mutex);
1413}
1414
1415/*
1416 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1417 */
1418pthread_mutex_t grep_read_mutex;
1419
1420#else
1421#define grep_attr_lock()
1422#define grep_attr_unlock()
1423#endif
1424
1425static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1426{
1427        xdemitconf_t *xecfg = opt->priv;
1428        if (xecfg && !xecfg->find_func) {
1429                grep_source_load_driver(gs);
1430                if (gs->driver->funcname.pattern) {
1431                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1432                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1433                } else {
1434                        xecfg = opt->priv = NULL;
1435                }
1436        }
1437
1438        if (xecfg) {
1439                char buf[1];
1440                return xecfg->find_func(bol, eol - bol, buf, 1,
1441                                        xecfg->find_func_priv) >= 0;
1442        }
1443
1444        if (bol == eol)
1445                return 0;
1446        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1447                return 1;
1448        return 0;
1449}
1450
1451static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1452                               char *bol, unsigned lno)
1453{
1454        while (bol > gs->buf) {
1455                char *eol = --bol;
1456
1457                while (bol > gs->buf && bol[-1] != '\n')
1458                        bol--;
1459                lno--;
1460
1461                if (lno <= opt->last_shown)
1462                        break;
1463
1464                if (match_funcname(opt, gs, bol, eol)) {
1465                        show_line(opt, bol, eol, gs->name, lno, '=');
1466                        break;
1467                }
1468        }
1469}
1470
1471static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1472                             char *bol, char *end, unsigned lno)
1473{
1474        unsigned cur = lno, from = 1, funcname_lno = 0;
1475        int funcname_needed = !!opt->funcname;
1476
1477        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1478                funcname_needed = 2;
1479
1480        if (opt->pre_context < lno)
1481                from = lno - opt->pre_context;
1482        if (from <= opt->last_shown)
1483                from = opt->last_shown + 1;
1484
1485        /* Rewind. */
1486        while (bol > gs->buf &&
1487               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1488                char *eol = --bol;
1489
1490                while (bol > gs->buf && bol[-1] != '\n')
1491                        bol--;
1492                cur--;
1493                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1494                        funcname_lno = cur;
1495                        funcname_needed = 0;
1496                }
1497        }
1498
1499        /* We need to look even further back to find a function signature. */
1500        if (opt->funcname && funcname_needed)
1501                show_funcname_line(opt, gs, bol, cur);
1502
1503        /* Back forward. */
1504        while (cur < lno) {
1505                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1506
1507                while (*eol != '\n')
1508                        eol++;
1509                show_line(opt, bol, eol, gs->name, cur, sign);
1510                bol = eol + 1;
1511                cur++;
1512        }
1513}
1514
1515static int should_lookahead(struct grep_opt *opt)
1516{
1517        struct grep_pat *p;
1518
1519        if (opt->extended)
1520                return 0; /* punt for too complex stuff */
1521        if (opt->invert)
1522                return 0;
1523        for (p = opt->pattern_list; p; p = p->next) {
1524                if (p->token != GREP_PATTERN)
1525                        return 0; /* punt for "header only" and stuff */
1526        }
1527        return 1;
1528}
1529
1530static int look_ahead(struct grep_opt *opt,
1531                      unsigned long *left_p,
1532                      unsigned *lno_p,
1533                      char **bol_p)
1534{
1535        unsigned lno = *lno_p;
1536        char *bol = *bol_p;
1537        struct grep_pat *p;
1538        char *sp, *last_bol;
1539        regoff_t earliest = -1;
1540
1541        for (p = opt->pattern_list; p; p = p->next) {
1542                int hit;
1543                regmatch_t m;
1544
1545                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1546                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1547                        continue;
1548                if (earliest < 0 || m.rm_so < earliest)
1549                        earliest = m.rm_so;
1550        }
1551
1552        if (earliest < 0) {
1553                *bol_p = bol + *left_p;
1554                *left_p = 0;
1555                return 1;
1556        }
1557        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1558                ; /* find the beginning of the line */
1559        last_bol = sp;
1560
1561        for (sp = bol; sp < last_bol; sp++) {
1562                if (*sp == '\n')
1563                        lno++;
1564        }
1565        *left_p -= last_bol - bol;
1566        *bol_p = last_bol;
1567        *lno_p = lno;
1568        return 0;
1569}
1570
1571static int fill_textconv_grep(struct userdiff_driver *driver,
1572                              struct grep_source *gs)
1573{
1574        struct diff_filespec *df;
1575        char *buf;
1576        size_t size;
1577
1578        if (!driver || !driver->textconv)
1579                return grep_source_load(gs);
1580
1581        /*
1582         * The textconv interface is intimately tied to diff_filespecs, so we
1583         * have to pretend to be one. If we could unify the grep_source
1584         * and diff_filespec structs, this mess could just go away.
1585         */
1586        df = alloc_filespec(gs->path);
1587        switch (gs->type) {
1588        case GREP_SOURCE_OID:
1589                fill_filespec(df, gs->identifier, 1, 0100644);
1590                break;
1591        case GREP_SOURCE_FILE:
1592                fill_filespec(df, &null_oid, 0, 0100644);
1593                break;
1594        default:
1595                die("BUG: attempt to textconv something without a path?");
1596        }
1597
1598        /*
1599         * fill_textconv is not remotely thread-safe; it may load objects
1600         * behind the scenes, and it modifies the global diff tempfile
1601         * structure.
1602         */
1603        grep_read_lock();
1604        size = fill_textconv(driver, df, &buf);
1605        grep_read_unlock();
1606        free_filespec(df);
1607
1608        /*
1609         * The normal fill_textconv usage by the diff machinery would just keep
1610         * the textconv'd buf separate from the diff_filespec. But much of the
1611         * grep code passes around a grep_source and assumes that its "buf"
1612         * pointer is the beginning of the thing we are searching. So let's
1613         * install our textconv'd version into the grep_source, taking care not
1614         * to leak any existing buffer.
1615         */
1616        grep_source_clear_data(gs);
1617        gs->buf = buf;
1618        gs->size = size;
1619
1620        return 0;
1621}
1622
1623static int is_empty_line(const char *bol, const char *eol)
1624{
1625        while (bol < eol && isspace(*bol))
1626                bol++;
1627        return bol == eol;
1628}
1629
1630static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1631{
1632        char *bol;
1633        char *peek_bol = NULL;
1634        unsigned long left;
1635        unsigned lno = 1;
1636        unsigned last_hit = 0;
1637        int binary_match_only = 0;
1638        unsigned count = 0;
1639        int try_lookahead = 0;
1640        int show_function = 0;
1641        struct userdiff_driver *textconv = NULL;
1642        enum grep_context ctx = GREP_CONTEXT_HEAD;
1643        xdemitconf_t xecfg;
1644
1645        if (!opt->output)
1646                opt->output = std_output;
1647
1648        if (opt->pre_context || opt->post_context || opt->file_break ||
1649            opt->funcbody) {
1650                /* Show hunk marks, except for the first file. */
1651                if (opt->last_shown)
1652                        opt->show_hunk_mark = 1;
1653                /*
1654                 * If we're using threads then we can't easily identify
1655                 * the first file.  Always put hunk marks in that case
1656                 * and skip the very first one later in work_done().
1657                 */
1658                if (opt->output != std_output)
1659                        opt->show_hunk_mark = 1;
1660        }
1661        opt->last_shown = 0;
1662
1663        if (opt->allow_textconv) {
1664                grep_source_load_driver(gs);
1665                /*
1666                 * We might set up the shared textconv cache data here, which
1667                 * is not thread-safe.
1668                 */
1669                grep_attr_lock();
1670                textconv = userdiff_get_textconv(gs->driver);
1671                grep_attr_unlock();
1672        }
1673
1674        /*
1675         * We know the result of a textconv is text, so we only have to care
1676         * about binary handling if we are not using it.
1677         */
1678        if (!textconv) {
1679                switch (opt->binary) {
1680                case GREP_BINARY_DEFAULT:
1681                        if (grep_source_is_binary(gs))
1682                                binary_match_only = 1;
1683                        break;
1684                case GREP_BINARY_NOMATCH:
1685                        if (grep_source_is_binary(gs))
1686                                return 0; /* Assume unmatch */
1687                        break;
1688                case GREP_BINARY_TEXT:
1689                        break;
1690                default:
1691                        die("BUG: unknown binary handling mode");
1692                }
1693        }
1694
1695        memset(&xecfg, 0, sizeof(xecfg));
1696        opt->priv = &xecfg;
1697
1698        try_lookahead = should_lookahead(opt);
1699
1700        if (fill_textconv_grep(textconv, gs) < 0)
1701                return 0;
1702
1703        bol = gs->buf;
1704        left = gs->size;
1705        while (left) {
1706                char *eol, ch;
1707                int hit;
1708
1709                /*
1710                 * look_ahead() skips quickly to the line that possibly
1711                 * has the next hit; don't call it if we need to do
1712                 * something more than just skipping the current line
1713                 * in response to an unmatch for the current line.  E.g.
1714                 * inside a post-context window, we will show the current
1715                 * line as a context around the previous hit when it
1716                 * doesn't hit.
1717                 */
1718                if (try_lookahead
1719                    && !(last_hit
1720                         && (show_function ||
1721                             lno <= last_hit + opt->post_context))
1722                    && look_ahead(opt, &left, &lno, &bol))
1723                        break;
1724                eol = end_of_line(bol, &left);
1725                ch = *eol;
1726                *eol = 0;
1727
1728                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1729                        ctx = GREP_CONTEXT_BODY;
1730
1731                hit = match_line(opt, bol, eol, ctx, collect_hits);
1732                *eol = ch;
1733
1734                if (collect_hits)
1735                        goto next_line;
1736
1737                /* "grep -v -e foo -e bla" should list lines
1738                 * that do not have either, so inversion should
1739                 * be done outside.
1740                 */
1741                if (opt->invert)
1742                        hit = !hit;
1743                if (opt->unmatch_name_only) {
1744                        if (hit)
1745                                return 0;
1746                        goto next_line;
1747                }
1748                if (hit) {
1749                        count++;
1750                        if (opt->status_only)
1751                                return 1;
1752                        if (opt->name_only) {
1753                                show_name(opt, gs->name);
1754                                return 1;
1755                        }
1756                        if (opt->count)
1757                                goto next_line;
1758                        if (binary_match_only) {
1759                                opt->output(opt, "Binary file ", 12);
1760                                output_color(opt, gs->name, strlen(gs->name),
1761                                             opt->color_filename);
1762                                opt->output(opt, " matches\n", 9);
1763                                return 1;
1764                        }
1765                        /* Hit at this line.  If we haven't shown the
1766                         * pre-context lines, we would need to show them.
1767                         */
1768                        if (opt->pre_context || opt->funcbody)
1769                                show_pre_context(opt, gs, bol, eol, lno);
1770                        else if (opt->funcname)
1771                                show_funcname_line(opt, gs, bol, lno);
1772                        show_line(opt, bol, eol, gs->name, lno, ':');
1773                        last_hit = lno;
1774                        if (opt->funcbody)
1775                                show_function = 1;
1776                        goto next_line;
1777                }
1778                if (show_function && (!peek_bol || peek_bol < bol)) {
1779                        unsigned long peek_left = left;
1780                        char *peek_eol = eol;
1781
1782                        /*
1783                         * Trailing empty lines are not interesting.
1784                         * Peek past them to see if they belong to the
1785                         * body of the current function.
1786                         */
1787                        peek_bol = bol;
1788                        while (is_empty_line(peek_bol, peek_eol)) {
1789                                peek_bol = peek_eol + 1;
1790                                peek_eol = end_of_line(peek_bol, &peek_left);
1791                        }
1792
1793                        if (match_funcname(opt, gs, peek_bol, peek_eol))
1794                                show_function = 0;
1795                }
1796                if (show_function ||
1797                    (last_hit && lno <= last_hit + opt->post_context)) {
1798                        /* If the last hit is within the post context,
1799                         * we need to show this line.
1800                         */
1801                        show_line(opt, bol, eol, gs->name, lno, '-');
1802                }
1803
1804        next_line:
1805                bol = eol + 1;
1806                if (!left)
1807                        break;
1808                left--;
1809                lno++;
1810        }
1811
1812        if (collect_hits)
1813                return 0;
1814
1815        if (opt->status_only)
1816                return 0;
1817        if (opt->unmatch_name_only) {
1818                /* We did not see any hit, so we want to show this */
1819                show_name(opt, gs->name);
1820                return 1;
1821        }
1822
1823        xdiff_clear_find_func(&xecfg);
1824        opt->priv = NULL;
1825
1826        /* NEEDSWORK:
1827         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1828         * which feels mostly useless but sometimes useful.  Maybe
1829         * make it another option?  For now suppress them.
1830         */
1831        if (opt->count && count) {
1832                char buf[32];
1833                if (opt->pathname) {
1834                        output_color(opt, gs->name, strlen(gs->name),
1835                                     opt->color_filename);
1836                        output_sep(opt, ':');
1837                }
1838                xsnprintf(buf, sizeof(buf), "%u\n", count);
1839                opt->output(opt, buf, strlen(buf));
1840                return 1;
1841        }
1842        return !!last_hit;
1843}
1844
1845static void clr_hit_marker(struct grep_expr *x)
1846{
1847        /* All-hit markers are meaningful only at the very top level
1848         * OR node.
1849         */
1850        while (1) {
1851                x->hit = 0;
1852                if (x->node != GREP_NODE_OR)
1853                        return;
1854                x->u.binary.left->hit = 0;
1855                x = x->u.binary.right;
1856        }
1857}
1858
1859static int chk_hit_marker(struct grep_expr *x)
1860{
1861        /* Top level nodes have hit markers.  See if they all are hits */
1862        while (1) {
1863                if (x->node != GREP_NODE_OR)
1864                        return x->hit;
1865                if (!x->u.binary.left->hit)
1866                        return 0;
1867                x = x->u.binary.right;
1868        }
1869}
1870
1871int grep_source(struct grep_opt *opt, struct grep_source *gs)
1872{
1873        /*
1874         * we do not have to do the two-pass grep when we do not check
1875         * buffer-wide "all-match".
1876         */
1877        if (!opt->all_match)
1878                return grep_source_1(opt, gs, 0);
1879
1880        /* Otherwise the toplevel "or" terms hit a bit differently.
1881         * We first clear hit markers from them.
1882         */
1883        clr_hit_marker(opt->pattern_expression);
1884        grep_source_1(opt, gs, 1);
1885
1886        if (!chk_hit_marker(opt->pattern_expression))
1887                return 0;
1888
1889        return grep_source_1(opt, gs, 0);
1890}
1891
1892int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1893{
1894        struct grep_source gs;
1895        int r;
1896
1897        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1898        gs.buf = buf;
1899        gs.size = size;
1900
1901        r = grep_source(opt, &gs);
1902
1903        grep_source_clear(&gs);
1904        return r;
1905}
1906
1907void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1908                      const char *name, const char *path,
1909                      const void *identifier)
1910{
1911        gs->type = type;
1912        gs->name = xstrdup_or_null(name);
1913        gs->path = xstrdup_or_null(path);
1914        gs->buf = NULL;
1915        gs->size = 0;
1916        gs->driver = NULL;
1917
1918        switch (type) {
1919        case GREP_SOURCE_FILE:
1920                gs->identifier = xstrdup(identifier);
1921                break;
1922        case GREP_SOURCE_SUBMODULE:
1923                if (!identifier) {
1924                        gs->identifier = NULL;
1925                        break;
1926                }
1927                /*
1928                 * FALL THROUGH
1929                 * If the identifier is non-NULL (in the submodule case) it
1930                 * will be a SHA1 that needs to be copied.
1931                 */
1932        case GREP_SOURCE_OID:
1933                gs->identifier = oiddup(identifier);
1934                break;
1935        case GREP_SOURCE_BUF:
1936                gs->identifier = NULL;
1937                break;
1938        }
1939}
1940
1941void grep_source_clear(struct grep_source *gs)
1942{
1943        FREE_AND_NULL(gs->name);
1944        FREE_AND_NULL(gs->path);
1945        FREE_AND_NULL(gs->identifier);
1946        grep_source_clear_data(gs);
1947}
1948
1949void grep_source_clear_data(struct grep_source *gs)
1950{
1951        switch (gs->type) {
1952        case GREP_SOURCE_FILE:
1953        case GREP_SOURCE_OID:
1954        case GREP_SOURCE_SUBMODULE:
1955                FREE_AND_NULL(gs->buf);
1956                gs->size = 0;
1957                break;
1958        case GREP_SOURCE_BUF:
1959                /* leave user-provided buf intact */
1960                break;
1961        }
1962}
1963
1964static int grep_source_load_oid(struct grep_source *gs)
1965{
1966        enum object_type type;
1967
1968        grep_read_lock();
1969        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1970        grep_read_unlock();
1971
1972        if (!gs->buf)
1973                return error(_("'%s': unable to read %s"),
1974                             gs->name,
1975                             oid_to_hex(gs->identifier));
1976        return 0;
1977}
1978
1979static int grep_source_load_file(struct grep_source *gs)
1980{
1981        const char *filename = gs->identifier;
1982        struct stat st;
1983        char *data;
1984        size_t size;
1985        int i;
1986
1987        if (lstat(filename, &st) < 0) {
1988        err_ret:
1989                if (errno != ENOENT)
1990                        error_errno(_("failed to stat '%s'"), filename);
1991                return -1;
1992        }
1993        if (!S_ISREG(st.st_mode))
1994                return -1;
1995        size = xsize_t(st.st_size);
1996        i = open(filename, O_RDONLY);
1997        if (i < 0)
1998                goto err_ret;
1999        data = xmallocz(size);
2000        if (st.st_size != read_in_full(i, data, size)) {
2001                error_errno(_("'%s': short read"), filename);
2002                close(i);
2003                free(data);
2004                return -1;
2005        }
2006        close(i);
2007
2008        gs->buf = data;
2009        gs->size = size;
2010        return 0;
2011}
2012
2013static int grep_source_load(struct grep_source *gs)
2014{
2015        if (gs->buf)
2016                return 0;
2017
2018        switch (gs->type) {
2019        case GREP_SOURCE_FILE:
2020                return grep_source_load_file(gs);
2021        case GREP_SOURCE_OID:
2022                return grep_source_load_oid(gs);
2023        case GREP_SOURCE_BUF:
2024                return gs->buf ? 0 : -1;
2025        case GREP_SOURCE_SUBMODULE:
2026                break;
2027        }
2028        die("BUG: invalid grep_source type to load");
2029}
2030
2031void grep_source_load_driver(struct grep_source *gs)
2032{
2033        if (gs->driver)
2034                return;
2035
2036        grep_attr_lock();
2037        if (gs->path)
2038                gs->driver = userdiff_find_by_path(gs->path);
2039        if (!gs->driver)
2040                gs->driver = userdiff_find_by_name("default");
2041        grep_attr_unlock();
2042}
2043
2044static int grep_source_is_binary(struct grep_source *gs)
2045{
2046        grep_source_load_driver(gs);
2047        if (gs->driver->binary != -1)
2048                return gs->driver->binary;
2049
2050        if (!grep_source_load(gs))
2051                return buffer_is_binary(gs->buf, gs->size);
2052
2053        return 0;
2054}