Andrew's git / gitweb.git / grep.c
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grep.con commit grep: fix NO_LIBPCRE1_JIT to fully disable JIT (2fff1e1)
   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
  15static void std_output(struct grep_opt *opt, const void *buf, size_t size)
  16{
  17        fwrite(buf, size, 1, stdout);
  18}
  19
  20/*
  21 * Initialize the grep_defaults template with hardcoded defaults.
  22 * We could let the compiler do this, but without C99 initializers
  23 * the code gets unwieldy and unreadable, so...
  24 */
  25void init_grep_defaults(void)
  26{
  27        struct grep_opt *opt = &grep_defaults;
  28        static int run_once;
  29
  30        if (run_once)
  31                return;
  32        run_once++;
  33
  34        memset(opt, 0, sizeof(*opt));
  35        opt->relative = 1;
  36        opt->pathname = 1;
  37        opt->regflags = REG_NEWLINE;
  38        opt->max_depth = -1;
  39        opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  40        opt->extended_regexp_option = 0;
  41        color_set(opt->color_context, "");
  42        color_set(opt->color_filename, "");
  43        color_set(opt->color_function, "");
  44        color_set(opt->color_lineno, "");
  45        color_set(opt->color_match_context, GIT_COLOR_BOLD_RED);
  46        color_set(opt->color_match_selected, GIT_COLOR_BOLD_RED);
  47        color_set(opt->color_selected, "");
  48        color_set(opt->color_sep, GIT_COLOR_CYAN);
  49        opt->color = -1;
  50        opt->output = std_output;
  51}
  52
  53static int parse_pattern_type_arg(const char *opt, const char *arg)
  54{
  55        if (!strcmp(arg, "default"))
  56                return GREP_PATTERN_TYPE_UNSPECIFIED;
  57        else if (!strcmp(arg, "basic"))
  58                return GREP_PATTERN_TYPE_BRE;
  59        else if (!strcmp(arg, "extended"))
  60                return GREP_PATTERN_TYPE_ERE;
  61        else if (!strcmp(arg, "fixed"))
  62                return GREP_PATTERN_TYPE_FIXED;
  63        else if (!strcmp(arg, "perl"))
  64                return GREP_PATTERN_TYPE_PCRE;
  65        die("bad %s argument: %s", opt, arg);
  66}
  67
  68/*
  69 * Read the configuration file once and store it in
  70 * the grep_defaults template.
  71 */
  72int grep_config(const char *var, const char *value, void *cb)
  73{
  74        struct grep_opt *opt = &grep_defaults;
  75        char *color = NULL;
  76
  77        if (userdiff_config(var, value) < 0)
  78                return -1;
  79
  80        if (!strcmp(var, "grep.extendedregexp")) {
  81                if (git_config_bool(var, value))
  82                        opt->extended_regexp_option = 1;
  83                else
  84                        opt->extended_regexp_option = 0;
  85                return 0;
  86        }
  87
  88        if (!strcmp(var, "grep.patterntype")) {
  89                opt->pattern_type_option = parse_pattern_type_arg(var, value);
  90                return 0;
  91        }
  92
  93        if (!strcmp(var, "grep.linenumber")) {
  94                opt->linenum = git_config_bool(var, value);
  95                return 0;
  96        }
  97
  98        if (!strcmp(var, "grep.fullname")) {
  99                opt->relative = !git_config_bool(var, value);
 100                return 0;
 101        }
 102
 103        if (!strcmp(var, "color.grep"))
 104                opt->color = git_config_colorbool(var, value);
 105        else if (!strcmp(var, "color.grep.context"))
 106                color = opt->color_context;
 107        else if (!strcmp(var, "color.grep.filename"))
 108                color = opt->color_filename;
 109        else if (!strcmp(var, "color.grep.function"))
 110                color = opt->color_function;
 111        else if (!strcmp(var, "color.grep.linenumber"))
 112                color = opt->color_lineno;
 113        else if (!strcmp(var, "color.grep.matchcontext"))
 114                color = opt->color_match_context;
 115        else if (!strcmp(var, "color.grep.matchselected"))
 116                color = opt->color_match_selected;
 117        else if (!strcmp(var, "color.grep.selected"))
 118                color = opt->color_selected;
 119        else if (!strcmp(var, "color.grep.separator"))
 120                color = opt->color_sep;
 121        else if (!strcmp(var, "color.grep.match")) {
 122                int rc = 0;
 123                if (!value)
 124                        return config_error_nonbool(var);
 125                rc |= color_parse(value, opt->color_match_context);
 126                rc |= color_parse(value, opt->color_match_selected);
 127                return rc;
 128        }
 129
 130        if (color) {
 131                if (!value)
 132                        return config_error_nonbool(var);
 133                return color_parse(value, color);
 134        }
 135        return 0;
 136}
 137
 138/*
 139 * Initialize one instance of grep_opt and copy the
 140 * default values from the template we read the configuration
 141 * information in an earlier call to git_config(grep_config).
 142 */
 143void grep_init(struct grep_opt *opt, const char *prefix)
 144{
 145        struct grep_opt *def = &grep_defaults;
 146
 147        memset(opt, 0, sizeof(*opt));
 148        opt->prefix = prefix;
 149        opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 150        opt->pattern_tail = &opt->pattern_list;
 151        opt->header_tail = &opt->header_list;
 152
 153        opt->color = def->color;
 154        opt->extended_regexp_option = def->extended_regexp_option;
 155        opt->pattern_type_option = def->pattern_type_option;
 156        opt->linenum = def->linenum;
 157        opt->max_depth = def->max_depth;
 158        opt->pathname = def->pathname;
 159        opt->regflags = def->regflags;
 160        opt->relative = def->relative;
 161        opt->output = def->output;
 162
 163        color_set(opt->color_context, def->color_context);
 164        color_set(opt->color_filename, def->color_filename);
 165        color_set(opt->color_function, def->color_function);
 166        color_set(opt->color_lineno, def->color_lineno);
 167        color_set(opt->color_match_context, def->color_match_context);
 168        color_set(opt->color_match_selected, def->color_match_selected);
 169        color_set(opt->color_selected, def->color_selected);
 170        color_set(opt->color_sep, def->color_sep);
 171}
 172
 173static void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 174{
 175        switch (pattern_type) {
 176        case GREP_PATTERN_TYPE_UNSPECIFIED:
 177                /* fall through */
 178
 179        case GREP_PATTERN_TYPE_BRE:
 180                opt->fixed = 0;
 181                opt->pcre1 = 0;
 182                opt->pcre2 = 0;
 183                break;
 184
 185        case GREP_PATTERN_TYPE_ERE:
 186                opt->fixed = 0;
 187                opt->pcre1 = 0;
 188                opt->pcre2 = 0;
 189                opt->regflags |= REG_EXTENDED;
 190                break;
 191
 192        case GREP_PATTERN_TYPE_FIXED:
 193                opt->fixed = 1;
 194                opt->pcre1 = 0;
 195                opt->pcre2 = 0;
 196                break;
 197
 198        case GREP_PATTERN_TYPE_PCRE:
 199                opt->fixed = 0;
 200#ifdef USE_LIBPCRE2
 201                opt->pcre1 = 0;
 202                opt->pcre2 = 1;
 203#else
 204                /*
 205                 * It's important that pcre1 always be assigned to
 206                 * even when there's no USE_LIBPCRE* defined. We still
 207                 * call the PCRE stub function, it just dies with
 208                 * "cannot use Perl-compatible regexes[...]".
 209                 */
 210                opt->pcre1 = 1;
 211                opt->pcre2 = 0;
 212#endif
 213                break;
 214        }
 215}
 216
 217void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 218{
 219        if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 220                grep_set_pattern_type_option(pattern_type, opt);
 221        else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 222                grep_set_pattern_type_option(opt->pattern_type_option, opt);
 223        else if (opt->extended_regexp_option)
 224                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 225}
 226
 227static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 228                                        const char *origin, int no,
 229                                        enum grep_pat_token t,
 230                                        enum grep_header_field field)
 231{
 232        struct grep_pat *p = xcalloc(1, sizeof(*p));
 233        p->pattern = xmemdupz(pat, patlen);
 234        p->patternlen = patlen;
 235        p->origin = origin;
 236        p->no = no;
 237        p->token = t;
 238        p->field = field;
 239        return p;
 240}
 241
 242static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 243{
 244        **tail = p;
 245        *tail = &p->next;
 246        p->next = NULL;
 247
 248        switch (p->token) {
 249        case GREP_PATTERN: /* atom */
 250        case GREP_PATTERN_HEAD:
 251        case GREP_PATTERN_BODY:
 252                for (;;) {
 253                        struct grep_pat *new_pat;
 254                        size_t len = 0;
 255                        char *cp = p->pattern + p->patternlen, *nl = NULL;
 256                        while (++len <= p->patternlen) {
 257                                if (*(--cp) == '\n') {
 258                                        nl = cp;
 259                                        break;
 260                                }
 261                        }
 262                        if (!nl)
 263                                break;
 264                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 265                                                  p->no, p->token, p->field);
 266                        new_pat->next = p->next;
 267                        if (!p->next)
 268                                *tail = &new_pat->next;
 269                        p->next = new_pat;
 270                        *nl = '\0';
 271                        p->patternlen -= len;
 272                }
 273                break;
 274        default:
 275                break;
 276        }
 277}
 278
 279void append_header_grep_pattern(struct grep_opt *opt,
 280                                enum grep_header_field field, const char *pat)
 281{
 282        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 283                                             GREP_PATTERN_HEAD, field);
 284        if (field == GREP_HEADER_REFLOG)
 285                opt->use_reflog_filter = 1;
 286        do_append_grep_pat(&opt->header_tail, p);
 287}
 288
 289void append_grep_pattern(struct grep_opt *opt, const char *pat,
 290                         const char *origin, int no, enum grep_pat_token t)
 291{
 292        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 293}
 294
 295void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 296                     const char *origin, int no, enum grep_pat_token t)
 297{
 298        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 299        do_append_grep_pat(&opt->pattern_tail, p);
 300}
 301
 302struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 303{
 304        struct grep_pat *pat;
 305        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 306        *ret = *opt;
 307
 308        ret->pattern_list = NULL;
 309        ret->pattern_tail = &ret->pattern_list;
 310
 311        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 312        {
 313                if(pat->token == GREP_PATTERN_HEAD)
 314                        append_header_grep_pattern(ret, pat->field,
 315                                                   pat->pattern);
 316                else
 317                        append_grep_pat(ret, pat->pattern, pat->patternlen,
 318                                        pat->origin, pat->no, pat->token);
 319        }
 320
 321        return ret;
 322}
 323
 324static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 325                const char *error)
 326{
 327        char where[1024];
 328
 329        if (p->no)
 330                xsnprintf(where, sizeof(where), "In '%s' at %d, ", p->origin, p->no);
 331        else if (p->origin)
 332                xsnprintf(where, sizeof(where), "%s, ", p->origin);
 333        else
 334                where[0] = 0;
 335
 336        die("%s'%s': %s", where, p->pattern, error);
 337}
 338
 339static int is_fixed(const char *s, size_t len)
 340{
 341        size_t i;
 342
 343        for (i = 0; i < len; i++) {
 344                if (is_regex_special(s[i]))
 345                        return 0;
 346        }
 347
 348        return 1;
 349}
 350
 351static int has_null(const char *s, size_t len)
 352{
 353        /*
 354         * regcomp cannot accept patterns with NULs so when using it
 355         * we consider any pattern containing a NUL fixed.
 356         */
 357        if (memchr(s, 0, len))
 358                return 1;
 359
 360        return 0;
 361}
 362
 363#ifdef USE_LIBPCRE1
 364static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 365{
 366        const char *error;
 367        int erroffset;
 368        int options = PCRE_MULTILINE;
 369
 370        if (opt->ignore_case) {
 371                if (has_non_ascii(p->pattern))
 372                        p->pcre1_tables = pcre_maketables();
 373                options |= PCRE_CASELESS;
 374        }
 375        if (is_utf8_locale() && has_non_ascii(p->pattern))
 376                options |= PCRE_UTF8;
 377
 378        p->pcre1_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 379                                      p->pcre1_tables);
 380        if (!p->pcre1_regexp)
 381                compile_regexp_failed(p, error);
 382
 383        p->pcre1_extra_info = pcre_study(p->pcre1_regexp, GIT_PCRE_STUDY_JIT_COMPILE, &error);
 384        if (!p->pcre1_extra_info && error)
 385                die("%s", error);
 386
 387#ifdef GIT_PCRE1_USE_JIT
 388        pcre_config(PCRE_CONFIG_JIT, &p->pcre1_jit_on);
 389        if (p->pcre1_jit_on == 1) {
 390                p->pcre1_jit_stack = pcre_jit_stack_alloc(1, 1024 * 1024);
 391                if (!p->pcre1_jit_stack)
 392                        die("Couldn't allocate PCRE JIT stack");
 393                pcre_assign_jit_stack(p->pcre1_extra_info, NULL, p->pcre1_jit_stack);
 394        } else if (p->pcre1_jit_on != 0) {
 395                die("BUG: The pcre1_jit_on variable should be 0 or 1, not %d",
 396                    p->pcre1_jit_on);
 397        }
 398#endif
 399}
 400
 401static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 402                regmatch_t *match, int eflags)
 403{
 404        int ovector[30], ret, flags = 0;
 405
 406        if (eflags & REG_NOTBOL)
 407                flags |= PCRE_NOTBOL;
 408
 409#ifdef GIT_PCRE1_USE_JIT
 410        if (p->pcre1_jit_on) {
 411                ret = pcre_jit_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
 412                                    eol - line, 0, flags, ovector,
 413                                    ARRAY_SIZE(ovector), p->pcre1_jit_stack);
 414        } else
 415#endif
 416        {
 417                ret = pcre_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
 418                                eol - line, 0, flags, ovector,
 419                                ARRAY_SIZE(ovector));
 420        }
 421
 422        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 423                die("pcre_exec failed with error code %d", ret);
 424        if (ret > 0) {
 425                ret = 0;
 426                match->rm_so = ovector[0];
 427                match->rm_eo = ovector[1];
 428        }
 429
 430        return ret;
 431}
 432
 433static void free_pcre1_regexp(struct grep_pat *p)
 434{
 435        pcre_free(p->pcre1_regexp);
 436#ifdef GIT_PCRE1_USE_JIT
 437        if (p->pcre1_jit_on) {
 438                pcre_free_study(p->pcre1_extra_info);
 439                pcre_jit_stack_free(p->pcre1_jit_stack);
 440        } else
 441#endif
 442        {
 443                pcre_free(p->pcre1_extra_info);
 444        }
 445        pcre_free((void *)p->pcre1_tables);
 446}
 447#else /* !USE_LIBPCRE1 */
 448static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 449{
 450        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 451}
 452
 453static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 454                regmatch_t *match, int eflags)
 455{
 456        return 1;
 457}
 458
 459static void free_pcre1_regexp(struct grep_pat *p)
 460{
 461}
 462#endif /* !USE_LIBPCRE1 */
 463
 464#ifdef USE_LIBPCRE2
 465static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)
 466{
 467        int error;
 468        PCRE2_UCHAR errbuf[256];
 469        PCRE2_SIZE erroffset;
 470        int options = PCRE2_MULTILINE;
 471        const uint8_t *character_tables = NULL;
 472        int jitret;
 473
 474        assert(opt->pcre2);
 475
 476        p->pcre2_compile_context = NULL;
 477
 478        if (opt->ignore_case) {
 479                if (has_non_ascii(p->pattern)) {
 480                        character_tables = pcre2_maketables(NULL);
 481                        p->pcre2_compile_context = pcre2_compile_context_create(NULL);
 482                        pcre2_set_character_tables(p->pcre2_compile_context, character_tables);
 483                }
 484                options |= PCRE2_CASELESS;
 485        }
 486        if (is_utf8_locale() && has_non_ascii(p->pattern))
 487                options |= PCRE2_UTF;
 488
 489        p->pcre2_pattern = pcre2_compile((PCRE2_SPTR)p->pattern,
 490                                         p->patternlen, options, &error, &erroffset,
 491                                         p->pcre2_compile_context);
 492
 493        if (p->pcre2_pattern) {
 494                p->pcre2_match_data = pcre2_match_data_create_from_pattern(p->pcre2_pattern, NULL);
 495                if (!p->pcre2_match_data)
 496                        die("Couldn't allocate PCRE2 match data");
 497        } else {
 498                pcre2_get_error_message(error, errbuf, sizeof(errbuf));
 499                compile_regexp_failed(p, (const char *)&errbuf);
 500        }
 501
 502        pcre2_config(PCRE2_CONFIG_JIT, &p->pcre2_jit_on);
 503        if (p->pcre2_jit_on == 1) {
 504                jitret = pcre2_jit_compile(p->pcre2_pattern, PCRE2_JIT_COMPLETE);
 505                if (jitret)
 506                        die("Couldn't JIT the PCRE2 pattern '%s', got '%d'\n", p->pattern, jitret);
 507                p->pcre2_jit_stack = pcre2_jit_stack_create(1, 1024 * 1024, NULL);
 508                if (!p->pcre2_jit_stack)
 509                        die("Couldn't allocate PCRE2 JIT stack");
 510                p->pcre2_match_context = pcre2_match_context_create(NULL);
 511                if (!p->pcre2_match_context)
 512                        die("Couldn't allocate PCRE2 match context");
 513                pcre2_jit_stack_assign(p->pcre2_match_context, NULL, p->pcre2_jit_stack);
 514        } else if (p->pcre2_jit_on != 0) {
 515                die("BUG: The pcre2_jit_on variable should be 0 or 1, not %d",
 516                    p->pcre1_jit_on);
 517        }
 518}
 519
 520static int pcre2match(struct grep_pat *p, const char *line, const char *eol,
 521                regmatch_t *match, int eflags)
 522{
 523        int ret, flags = 0;
 524        PCRE2_SIZE *ovector;
 525        PCRE2_UCHAR errbuf[256];
 526
 527        if (eflags & REG_NOTBOL)
 528                flags |= PCRE2_NOTBOL;
 529
 530        if (p->pcre2_jit_on)
 531                ret = pcre2_jit_match(p->pcre2_pattern, (unsigned char *)line,
 532                                      eol - line, 0, flags, p->pcre2_match_data,
 533                                      NULL);
 534        else
 535                ret = pcre2_match(p->pcre2_pattern, (unsigned char *)line,
 536                                  eol - line, 0, flags, p->pcre2_match_data,
 537                                  NULL);
 538
 539        if (ret < 0 && ret != PCRE2_ERROR_NOMATCH) {
 540                pcre2_get_error_message(ret, errbuf, sizeof(errbuf));
 541                die("%s failed with error code %d: %s",
 542                    (p->pcre2_jit_on ? "pcre2_jit_match" : "pcre2_match"), ret,
 543                    errbuf);
 544        }
 545        if (ret > 0) {
 546                ovector = pcre2_get_ovector_pointer(p->pcre2_match_data);
 547                ret = 0;
 548                match->rm_so = (int)ovector[0];
 549                match->rm_eo = (int)ovector[1];
 550        }
 551
 552        return ret;
 553}
 554
 555static void free_pcre2_pattern(struct grep_pat *p)
 556{
 557        pcre2_compile_context_free(p->pcre2_compile_context);
 558        pcre2_code_free(p->pcre2_pattern);
 559        pcre2_match_data_free(p->pcre2_match_data);
 560        pcre2_jit_stack_free(p->pcre2_jit_stack);
 561        pcre2_match_context_free(p->pcre2_match_context);
 562}
 563#else /* !USE_LIBPCRE2 */
 564static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)
 565{
 566        /*
 567         * Unreachable until USE_LIBPCRE2 becomes synonymous with
 568         * USE_LIBPCRE. See the sibling comment in
 569         * grep_set_pattern_type_option().
 570         */
 571        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 572}
 573
 574static int pcre2match(struct grep_pat *p, const char *line, const char *eol,
 575                regmatch_t *match, int eflags)
 576{
 577        return 1;
 578}
 579
 580static void free_pcre2_pattern(struct grep_pat *p)
 581{
 582}
 583#endif /* !USE_LIBPCRE2 */
 584
 585static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 586{
 587        struct strbuf sb = STRBUF_INIT;
 588        int err;
 589        int regflags = opt->regflags;
 590
 591        basic_regex_quote_buf(&sb, p->pattern);
 592        if (opt->ignore_case)
 593                regflags |= REG_ICASE;
 594        err = regcomp(&p->regexp, sb.buf, regflags);
 595        if (opt->debug)
 596                fprintf(stderr, "fixed %s\n", sb.buf);
 597        strbuf_release(&sb);
 598        if (err) {
 599                char errbuf[1024];
 600                regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 601                regfree(&p->regexp);
 602                compile_regexp_failed(p, errbuf);
 603        }
 604}
 605
 606static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 607{
 608        int icase, ascii_only;
 609        int err;
 610
 611        p->word_regexp = opt->word_regexp;
 612        p->ignore_case = opt->ignore_case;
 613        icase          = opt->regflags & REG_ICASE || p->ignore_case;
 614        ascii_only     = !has_non_ascii(p->pattern);
 615
 616        /*
 617         * Even when -F (fixed) asks us to do a non-regexp search, we
 618         * may not be able to correctly case-fold when -i
 619         * (ignore-case) is asked (in which case, we'll synthesize a
 620         * regexp to match the pattern that matches regexp special
 621         * characters literally, while ignoring case differences).  On
 622         * the other hand, even without -F, if the pattern does not
 623         * have any regexp special characters and there is no need for
 624         * case-folding search, we can internally turn it into a
 625         * simple string match using kws.  p->fixed tells us if we
 626         * want to use kws.
 627         */
 628        if (opt->fixed ||
 629            has_null(p->pattern, p->patternlen) ||
 630            is_fixed(p->pattern, p->patternlen))
 631                p->fixed = !icase || ascii_only;
 632        else
 633                p->fixed = 0;
 634
 635        if (p->fixed) {
 636                p->kws = kwsalloc(icase ? tolower_trans_tbl : NULL);
 637                kwsincr(p->kws, p->pattern, p->patternlen);
 638                kwsprep(p->kws);
 639                return;
 640        } else if (opt->fixed) {
 641                /*
 642                 * We come here when the pattern has the non-ascii
 643                 * characters we cannot case-fold, and asked to
 644                 * ignore-case.
 645                 */
 646                compile_fixed_regexp(p, opt);
 647                return;
 648        }
 649
 650        if (opt->pcre2) {
 651                compile_pcre2_pattern(p, opt);
 652                return;
 653        }
 654
 655        if (opt->pcre1) {
 656                compile_pcre1_regexp(p, opt);
 657                return;
 658        }
 659
 660        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 661        if (err) {
 662                char errbuf[1024];
 663                regerror(err, &p->regexp, errbuf, 1024);
 664                regfree(&p->regexp);
 665                compile_regexp_failed(p, errbuf);
 666        }
 667}
 668
 669static struct grep_expr *compile_pattern_or(struct grep_pat **);
 670static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 671{
 672        struct grep_pat *p;
 673        struct grep_expr *x;
 674
 675        p = *list;
 676        if (!p)
 677                return NULL;
 678        switch (p->token) {
 679        case GREP_PATTERN: /* atom */
 680        case GREP_PATTERN_HEAD:
 681        case GREP_PATTERN_BODY:
 682                x = xcalloc(1, sizeof (struct grep_expr));
 683                x->node = GREP_NODE_ATOM;
 684                x->u.atom = p;
 685                *list = p->next;
 686                return x;
 687        case GREP_OPEN_PAREN:
 688                *list = p->next;
 689                x = compile_pattern_or(list);
 690                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 691                        die("unmatched parenthesis");
 692                *list = (*list)->next;
 693                return x;
 694        default:
 695                return NULL;
 696        }
 697}
 698
 699static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 700{
 701        struct grep_pat *p;
 702        struct grep_expr *x;
 703
 704        p = *list;
 705        if (!p)
 706                return NULL;
 707        switch (p->token) {
 708        case GREP_NOT:
 709                if (!p->next)
 710                        die("--not not followed by pattern expression");
 711                *list = p->next;
 712                x = xcalloc(1, sizeof (struct grep_expr));
 713                x->node = GREP_NODE_NOT;
 714                x->u.unary = compile_pattern_not(list);
 715                if (!x->u.unary)
 716                        die("--not followed by non pattern expression");
 717                return x;
 718        default:
 719                return compile_pattern_atom(list);
 720        }
 721}
 722
 723static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 724{
 725        struct grep_pat *p;
 726        struct grep_expr *x, *y, *z;
 727
 728        x = compile_pattern_not(list);
 729        p = *list;
 730        if (p && p->token == GREP_AND) {
 731                if (!p->next)
 732                        die("--and not followed by pattern expression");
 733                *list = p->next;
 734                y = compile_pattern_and(list);
 735                if (!y)
 736                        die("--and not followed by pattern expression");
 737                z = xcalloc(1, sizeof (struct grep_expr));
 738                z->node = GREP_NODE_AND;
 739                z->u.binary.left = x;
 740                z->u.binary.right = y;
 741                return z;
 742        }
 743        return x;
 744}
 745
 746static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 747{
 748        struct grep_pat *p;
 749        struct grep_expr *x, *y, *z;
 750
 751        x = compile_pattern_and(list);
 752        p = *list;
 753        if (x && p && p->token != GREP_CLOSE_PAREN) {
 754                y = compile_pattern_or(list);
 755                if (!y)
 756                        die("not a pattern expression %s", p->pattern);
 757                z = xcalloc(1, sizeof (struct grep_expr));
 758                z->node = GREP_NODE_OR;
 759                z->u.binary.left = x;
 760                z->u.binary.right = y;
 761                return z;
 762        }
 763        return x;
 764}
 765
 766static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 767{
 768        return compile_pattern_or(list);
 769}
 770
 771static void indent(int in)
 772{
 773        while (in-- > 0)
 774                fputc(' ', stderr);
 775}
 776
 777static void dump_grep_pat(struct grep_pat *p)
 778{
 779        switch (p->token) {
 780        case GREP_AND: fprintf(stderr, "*and*"); break;
 781        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 782        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 783        case GREP_NOT: fprintf(stderr, "*not*"); break;
 784        case GREP_OR: fprintf(stderr, "*or*"); break;
 785
 786        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 787        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 788        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 789        }
 790
 791        switch (p->token) {
 792        default: break;
 793        case GREP_PATTERN_HEAD:
 794                fprintf(stderr, "<head %d>", p->field); break;
 795        case GREP_PATTERN_BODY:
 796                fprintf(stderr, "<body>"); break;
 797        }
 798        switch (p->token) {
 799        default: break;
 800        case GREP_PATTERN_HEAD:
 801        case GREP_PATTERN_BODY:
 802        case GREP_PATTERN:
 803                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 804                break;
 805        }
 806        fputc('\n', stderr);
 807}
 808
 809static void dump_grep_expression_1(struct grep_expr *x, int in)
 810{
 811        indent(in);
 812        switch (x->node) {
 813        case GREP_NODE_TRUE:
 814                fprintf(stderr, "true\n");
 815                break;
 816        case GREP_NODE_ATOM:
 817                dump_grep_pat(x->u.atom);
 818                break;
 819        case GREP_NODE_NOT:
 820                fprintf(stderr, "(not\n");
 821                dump_grep_expression_1(x->u.unary, in+1);
 822                indent(in);
 823                fprintf(stderr, ")\n");
 824                break;
 825        case GREP_NODE_AND:
 826                fprintf(stderr, "(and\n");
 827                dump_grep_expression_1(x->u.binary.left, in+1);
 828                dump_grep_expression_1(x->u.binary.right, in+1);
 829                indent(in);
 830                fprintf(stderr, ")\n");
 831                break;
 832        case GREP_NODE_OR:
 833                fprintf(stderr, "(or\n");
 834                dump_grep_expression_1(x->u.binary.left, in+1);
 835                dump_grep_expression_1(x->u.binary.right, in+1);
 836                indent(in);
 837                fprintf(stderr, ")\n");
 838                break;
 839        }
 840}
 841
 842static void dump_grep_expression(struct grep_opt *opt)
 843{
 844        struct grep_expr *x = opt->pattern_expression;
 845
 846        if (opt->all_match)
 847                fprintf(stderr, "[all-match]\n");
 848        dump_grep_expression_1(x, 0);
 849        fflush(NULL);
 850}
 851
 852static struct grep_expr *grep_true_expr(void)
 853{
 854        struct grep_expr *z = xcalloc(1, sizeof(*z));
 855        z->node = GREP_NODE_TRUE;
 856        return z;
 857}
 858
 859static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 860{
 861        struct grep_expr *z = xcalloc(1, sizeof(*z));
 862        z->node = GREP_NODE_OR;
 863        z->u.binary.left = left;
 864        z->u.binary.right = right;
 865        return z;
 866}
 867
 868static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 869{
 870        struct grep_pat *p;
 871        struct grep_expr *header_expr;
 872        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 873        enum grep_header_field fld;
 874
 875        if (!opt->header_list)
 876                return NULL;
 877
 878        for (p = opt->header_list; p; p = p->next) {
 879                if (p->token != GREP_PATTERN_HEAD)
 880                        die("BUG: a non-header pattern in grep header list.");
 881                if (p->field < GREP_HEADER_FIELD_MIN ||
 882                    GREP_HEADER_FIELD_MAX <= p->field)
 883                        die("BUG: unknown header field %d", p->field);
 884                compile_regexp(p, opt);
 885        }
 886
 887        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 888                header_group[fld] = NULL;
 889
 890        for (p = opt->header_list; p; p = p->next) {
 891                struct grep_expr *h;
 892                struct grep_pat *pp = p;
 893
 894                h = compile_pattern_atom(&pp);
 895                if (!h || pp != p->next)
 896                        die("BUG: malformed header expr");
 897                if (!header_group[p->field]) {
 898                        header_group[p->field] = h;
 899                        continue;
 900                }
 901                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 902        }
 903
 904        header_expr = NULL;
 905
 906        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 907                if (!header_group[fld])
 908                        continue;
 909                if (!header_expr)
 910                        header_expr = grep_true_expr();
 911                header_expr = grep_or_expr(header_group[fld], header_expr);
 912        }
 913        return header_expr;
 914}
 915
 916static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 917{
 918        struct grep_expr *z = x;
 919
 920        while (x) {
 921                assert(x->node == GREP_NODE_OR);
 922                if (x->u.binary.right &&
 923                    x->u.binary.right->node == GREP_NODE_TRUE) {
 924                        x->u.binary.right = y;
 925                        break;
 926                }
 927                x = x->u.binary.right;
 928        }
 929        return z;
 930}
 931
 932static void compile_grep_patterns_real(struct grep_opt *opt)
 933{
 934        struct grep_pat *p;
 935        struct grep_expr *header_expr = prep_header_patterns(opt);
 936
 937        for (p = opt->pattern_list; p; p = p->next) {
 938                switch (p->token) {
 939                case GREP_PATTERN: /* atom */
 940                case GREP_PATTERN_HEAD:
 941                case GREP_PATTERN_BODY:
 942                        compile_regexp(p, opt);
 943                        break;
 944                default:
 945                        opt->extended = 1;
 946                        break;
 947                }
 948        }
 949
 950        if (opt->all_match || header_expr)
 951                opt->extended = 1;
 952        else if (!opt->extended && !opt->debug)
 953                return;
 954
 955        p = opt->pattern_list;
 956        if (p)
 957                opt->pattern_expression = compile_pattern_expr(&p);
 958        if (p)
 959                die("incomplete pattern expression: %s", p->pattern);
 960
 961        if (!header_expr)
 962                return;
 963
 964        if (!opt->pattern_expression)
 965                opt->pattern_expression = header_expr;
 966        else if (opt->all_match)
 967                opt->pattern_expression = grep_splice_or(header_expr,
 968                                                         opt->pattern_expression);
 969        else
 970                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 971                                                       header_expr);
 972        opt->all_match = 1;
 973}
 974
 975void compile_grep_patterns(struct grep_opt *opt)
 976{
 977        compile_grep_patterns_real(opt);
 978        if (opt->debug)
 979                dump_grep_expression(opt);
 980}
 981
 982static void free_pattern_expr(struct grep_expr *x)
 983{
 984        switch (x->node) {
 985        case GREP_NODE_TRUE:
 986        case GREP_NODE_ATOM:
 987                break;
 988        case GREP_NODE_NOT:
 989                free_pattern_expr(x->u.unary);
 990                break;
 991        case GREP_NODE_AND:
 992        case GREP_NODE_OR:
 993                free_pattern_expr(x->u.binary.left);
 994                free_pattern_expr(x->u.binary.right);
 995                break;
 996        }
 997        free(x);
 998}
 999
1000void free_grep_patterns(struct grep_opt *opt)
1001{
1002        struct grep_pat *p, *n;
1003
1004        for (p = opt->pattern_list; p; p = n) {
1005                n = p->next;
1006                switch (p->token) {
1007                case GREP_PATTERN: /* atom */
1008                case GREP_PATTERN_HEAD:
1009                case GREP_PATTERN_BODY:
1010                        if (p->kws)
1011                                kwsfree(p->kws);
1012                        else if (p->pcre1_regexp)
1013                                free_pcre1_regexp(p);
1014                        else if (p->pcre2_pattern)
1015                                free_pcre2_pattern(p);
1016                        else
1017                                regfree(&p->regexp);
1018                        free(p->pattern);
1019                        break;
1020                default:
1021                        break;
1022                }
1023                free(p);
1024        }
1025
1026        if (!opt->extended)
1027                return;
1028        free_pattern_expr(opt->pattern_expression);
1029}
1030
1031static char *end_of_line(char *cp, unsigned long *left)
1032{
1033        unsigned long l = *left;
1034        while (l && *cp != '\n') {
1035                l--;
1036                cp++;
1037        }
1038        *left = l;
1039        return cp;
1040}
1041
1042static int word_char(char ch)
1043{
1044        return isalnum(ch) || ch == '_';
1045}
1046
1047static void output_color(struct grep_opt *opt, const void *data, size_t size,
1048                         const char *color)
1049{
1050        if (want_color(opt->color) && color && color[0]) {
1051                opt->output(opt, color, strlen(color));
1052                opt->output(opt, data, size);
1053                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
1054        } else
1055                opt->output(opt, data, size);
1056}
1057
1058static void output_sep(struct grep_opt *opt, char sign)
1059{
1060        if (opt->null_following_name)
1061                opt->output(opt, "\0", 1);
1062        else
1063                output_color(opt, &sign, 1, opt->color_sep);
1064}
1065
1066static void show_name(struct grep_opt *opt, const char *name)
1067{
1068        output_color(opt, name, strlen(name), opt->color_filename);
1069        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
1070}
1071
1072static int fixmatch(struct grep_pat *p, char *line, char *eol,
1073                    regmatch_t *match)
1074{
1075        struct kwsmatch kwsm;
1076        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
1077        if (offset == -1) {
1078                match->rm_so = match->rm_eo = -1;
1079                return REG_NOMATCH;
1080        } else {
1081                match->rm_so = offset;
1082                match->rm_eo = match->rm_so + kwsm.size[0];
1083                return 0;
1084        }
1085}
1086
1087static int patmatch(struct grep_pat *p, char *line, char *eol,
1088                    regmatch_t *match, int eflags)
1089{
1090        int hit;
1091
1092        if (p->fixed)
1093                hit = !fixmatch(p, line, eol, match);
1094        else if (p->pcre1_regexp)
1095                hit = !pcre1match(p, line, eol, match, eflags);
1096        else if (p->pcre2_pattern)
1097                hit = !pcre2match(p, line, eol, match, eflags);
1098        else
1099                hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
1100                                   eflags);
1101
1102        return hit;
1103}
1104
1105static int strip_timestamp(char *bol, char **eol_p)
1106{
1107        char *eol = *eol_p;
1108        int ch;
1109
1110        while (bol < --eol) {
1111                if (*eol != '>')
1112                        continue;
1113                *eol_p = ++eol;
1114                ch = *eol;
1115                *eol = '\0';
1116                return ch;
1117        }
1118        return 0;
1119}
1120
1121static struct {
1122        const char *field;
1123        size_t len;
1124} header_field[] = {
1125        { "author ", 7 },
1126        { "committer ", 10 },
1127        { "reflog ", 7 },
1128};
1129
1130static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
1131                             enum grep_context ctx,
1132                             regmatch_t *pmatch, int eflags)
1133{
1134        int hit = 0;
1135        int saved_ch = 0;
1136        const char *start = bol;
1137
1138        if ((p->token != GREP_PATTERN) &&
1139            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
1140                return 0;
1141
1142        if (p->token == GREP_PATTERN_HEAD) {
1143                const char *field;
1144                size_t len;
1145                assert(p->field < ARRAY_SIZE(header_field));
1146                field = header_field[p->field].field;
1147                len = header_field[p->field].len;
1148                if (strncmp(bol, field, len))
1149                        return 0;
1150                bol += len;
1151                switch (p->field) {
1152                case GREP_HEADER_AUTHOR:
1153                case GREP_HEADER_COMMITTER:
1154                        saved_ch = strip_timestamp(bol, &eol);
1155                        break;
1156                default:
1157                        break;
1158                }
1159        }
1160
1161 again:
1162        hit = patmatch(p, bol, eol, pmatch, eflags);
1163
1164        if (hit && p->word_regexp) {
1165                if ((pmatch[0].rm_so < 0) ||
1166                    (eol - bol) < pmatch[0].rm_so ||
1167                    (pmatch[0].rm_eo < 0) ||
1168                    (eol - bol) < pmatch[0].rm_eo)
1169                        die("regexp returned nonsense");
1170
1171                /* Match beginning must be either beginning of the
1172                 * line, or at word boundary (i.e. the last char must
1173                 * not be a word char).  Similarly, match end must be
1174                 * either end of the line, or at word boundary
1175                 * (i.e. the next char must not be a word char).
1176                 */
1177                if ( ((pmatch[0].rm_so == 0) ||
1178                      !word_char(bol[pmatch[0].rm_so-1])) &&
1179                     ((pmatch[0].rm_eo == (eol-bol)) ||
1180                      !word_char(bol[pmatch[0].rm_eo])) )
1181                        ;
1182                else
1183                        hit = 0;
1184
1185                /* Words consist of at least one character. */
1186                if (pmatch->rm_so == pmatch->rm_eo)
1187                        hit = 0;
1188
1189                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1190                        /* There could be more than one match on the
1191                         * line, and the first match might not be
1192                         * strict word match.  But later ones could be!
1193                         * Forward to the next possible start, i.e. the
1194                         * next position following a non-word char.
1195                         */
1196                        bol = pmatch[0].rm_so + bol + 1;
1197                        while (word_char(bol[-1]) && bol < eol)
1198                                bol++;
1199                        eflags |= REG_NOTBOL;
1200                        if (bol < eol)
1201                                goto again;
1202                }
1203        }
1204        if (p->token == GREP_PATTERN_HEAD && saved_ch)
1205                *eol = saved_ch;
1206        if (hit) {
1207                pmatch[0].rm_so += bol - start;
1208                pmatch[0].rm_eo += bol - start;
1209        }
1210        return hit;
1211}
1212
1213static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1214                           enum grep_context ctx, int collect_hits)
1215{
1216        int h = 0;
1217        regmatch_t match;
1218
1219        if (!x)
1220                die("Not a valid grep expression");
1221        switch (x->node) {
1222        case GREP_NODE_TRUE:
1223                h = 1;
1224                break;
1225        case GREP_NODE_ATOM:
1226                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1227                break;
1228        case GREP_NODE_NOT:
1229                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1230                break;
1231        case GREP_NODE_AND:
1232                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1233                        return 0;
1234                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1235                break;
1236        case GREP_NODE_OR:
1237                if (!collect_hits)
1238                        return (match_expr_eval(x->u.binary.left,
1239                                                bol, eol, ctx, 0) ||
1240                                match_expr_eval(x->u.binary.right,
1241                                                bol, eol, ctx, 0));
1242                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1243                x->u.binary.left->hit |= h;
1244                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1245                break;
1246        default:
1247                die("Unexpected node type (internal error) %d", x->node);
1248        }
1249        if (collect_hits)
1250                x->hit |= h;
1251        return h;
1252}
1253
1254static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1255                      enum grep_context ctx, int collect_hits)
1256{
1257        struct grep_expr *x = opt->pattern_expression;
1258        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1259}
1260
1261static int match_line(struct grep_opt *opt, char *bol, char *eol,
1262                      enum grep_context ctx, int collect_hits)
1263{
1264        struct grep_pat *p;
1265        regmatch_t match;
1266
1267        if (opt->extended)
1268                return match_expr(opt, bol, eol, ctx, collect_hits);
1269
1270        /* we do not call with collect_hits without being extended */
1271        for (p = opt->pattern_list; p; p = p->next) {
1272                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1273                        return 1;
1274        }
1275        return 0;
1276}
1277
1278static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1279                              enum grep_context ctx,
1280                              regmatch_t *pmatch, int eflags)
1281{
1282        regmatch_t match;
1283
1284        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1285                return 0;
1286        if (match.rm_so < 0 || match.rm_eo < 0)
1287                return 0;
1288        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1289                if (match.rm_so > pmatch->rm_so)
1290                        return 1;
1291                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1292                        return 1;
1293        }
1294        pmatch->rm_so = match.rm_so;
1295        pmatch->rm_eo = match.rm_eo;
1296        return 1;
1297}
1298
1299static int next_match(struct grep_opt *opt, char *bol, char *eol,
1300                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1301{
1302        struct grep_pat *p;
1303        int hit = 0;
1304
1305        pmatch->rm_so = pmatch->rm_eo = -1;
1306        if (bol < eol) {
1307                for (p = opt->pattern_list; p; p = p->next) {
1308                        switch (p->token) {
1309                        case GREP_PATTERN: /* atom */
1310                        case GREP_PATTERN_HEAD:
1311                        case GREP_PATTERN_BODY:
1312                                hit |= match_next_pattern(p, bol, eol, ctx,
1313                                                          pmatch, eflags);
1314                                break;
1315                        default:
1316                                break;
1317                        }
1318                }
1319        }
1320        return hit;
1321}
1322
1323static void show_line(struct grep_opt *opt, char *bol, char *eol,
1324                      const char *name, unsigned lno, char sign)
1325{
1326        int rest = eol - bol;
1327        const char *match_color, *line_color = NULL;
1328
1329        if (opt->file_break && opt->last_shown == 0) {
1330                if (opt->show_hunk_mark)
1331                        opt->output(opt, "\n", 1);
1332        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1333                if (opt->last_shown == 0) {
1334                        if (opt->show_hunk_mark) {
1335                                output_color(opt, "--", 2, opt->color_sep);
1336                                opt->output(opt, "\n", 1);
1337                        }
1338                } else if (lno > opt->last_shown + 1) {
1339                        output_color(opt, "--", 2, opt->color_sep);
1340                        opt->output(opt, "\n", 1);
1341                }
1342        }
1343        if (opt->heading && opt->last_shown == 0) {
1344                output_color(opt, name, strlen(name), opt->color_filename);
1345                opt->output(opt, "\n", 1);
1346        }
1347        opt->last_shown = lno;
1348
1349        if (!opt->heading && opt->pathname) {
1350                output_color(opt, name, strlen(name), opt->color_filename);
1351                output_sep(opt, sign);
1352        }
1353        if (opt->linenum) {
1354                char buf[32];
1355                xsnprintf(buf, sizeof(buf), "%d", lno);
1356                output_color(opt, buf, strlen(buf), opt->color_lineno);
1357                output_sep(opt, sign);
1358        }
1359        if (opt->color) {
1360                regmatch_t match;
1361                enum grep_context ctx = GREP_CONTEXT_BODY;
1362                int ch = *eol;
1363                int eflags = 0;
1364
1365                if (sign == ':')
1366                        match_color = opt->color_match_selected;
1367                else
1368                        match_color = opt->color_match_context;
1369                if (sign == ':')
1370                        line_color = opt->color_selected;
1371                else if (sign == '-')
1372                        line_color = opt->color_context;
1373                else if (sign == '=')
1374                        line_color = opt->color_function;
1375                *eol = '\0';
1376                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1377                        if (match.rm_so == match.rm_eo)
1378                                break;
1379
1380                        output_color(opt, bol, match.rm_so, line_color);
1381                        output_color(opt, bol + match.rm_so,
1382                                     match.rm_eo - match.rm_so, match_color);
1383                        bol += match.rm_eo;
1384                        rest -= match.rm_eo;
1385                        eflags = REG_NOTBOL;
1386                }
1387                *eol = ch;
1388        }
1389        output_color(opt, bol, rest, line_color);
1390        opt->output(opt, "\n", 1);
1391}
1392
1393#ifndef NO_PTHREADS
1394int grep_use_locks;
1395
1396/*
1397 * This lock protects access to the gitattributes machinery, which is
1398 * not thread-safe.
1399 */
1400pthread_mutex_t grep_attr_mutex;
1401
1402static inline void grep_attr_lock(void)
1403{
1404        if (grep_use_locks)
1405                pthread_mutex_lock(&grep_attr_mutex);
1406}
1407
1408static inline void grep_attr_unlock(void)
1409{
1410        if (grep_use_locks)
1411                pthread_mutex_unlock(&grep_attr_mutex);
1412}
1413
1414/*
1415 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1416 */
1417pthread_mutex_t grep_read_mutex;
1418
1419#else
1420#define grep_attr_lock()
1421#define grep_attr_unlock()
1422#endif
1423
1424static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1425{
1426        xdemitconf_t *xecfg = opt->priv;
1427        if (xecfg && !xecfg->find_func) {
1428                grep_source_load_driver(gs);
1429                if (gs->driver->funcname.pattern) {
1430                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1431                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1432                } else {
1433                        xecfg = opt->priv = NULL;
1434                }
1435        }
1436
1437        if (xecfg) {
1438                char buf[1];
1439                return xecfg->find_func(bol, eol - bol, buf, 1,
1440                                        xecfg->find_func_priv) >= 0;
1441        }
1442
1443        if (bol == eol)
1444                return 0;
1445        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1446                return 1;
1447        return 0;
1448}
1449
1450static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1451                               char *bol, unsigned lno)
1452{
1453        while (bol > gs->buf) {
1454                char *eol = --bol;
1455
1456                while (bol > gs->buf && bol[-1] != '\n')
1457                        bol--;
1458                lno--;
1459
1460                if (lno <= opt->last_shown)
1461                        break;
1462
1463                if (match_funcname(opt, gs, bol, eol)) {
1464                        show_line(opt, bol, eol, gs->name, lno, '=');
1465                        break;
1466                }
1467        }
1468}
1469
1470static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1471                             char *bol, char *end, unsigned lno)
1472{
1473        unsigned cur = lno, from = 1, funcname_lno = 0;
1474        int funcname_needed = !!opt->funcname;
1475
1476        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1477                funcname_needed = 2;
1478
1479        if (opt->pre_context < lno)
1480                from = lno - opt->pre_context;
1481        if (from <= opt->last_shown)
1482                from = opt->last_shown + 1;
1483
1484        /* Rewind. */
1485        while (bol > gs->buf &&
1486               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1487                char *eol = --bol;
1488
1489                while (bol > gs->buf && bol[-1] != '\n')
1490                        bol--;
1491                cur--;
1492                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1493                        funcname_lno = cur;
1494                        funcname_needed = 0;
1495                }
1496        }
1497
1498        /* We need to look even further back to find a function signature. */
1499        if (opt->funcname && funcname_needed)
1500                show_funcname_line(opt, gs, bol, cur);
1501
1502        /* Back forward. */
1503        while (cur < lno) {
1504                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1505
1506                while (*eol != '\n')
1507                        eol++;
1508                show_line(opt, bol, eol, gs->name, cur, sign);
1509                bol = eol + 1;
1510                cur++;
1511        }
1512}
1513
1514static int should_lookahead(struct grep_opt *opt)
1515{
1516        struct grep_pat *p;
1517
1518        if (opt->extended)
1519                return 0; /* punt for too complex stuff */
1520        if (opt->invert)
1521                return 0;
1522        for (p = opt->pattern_list; p; p = p->next) {
1523                if (p->token != GREP_PATTERN)
1524                        return 0; /* punt for "header only" and stuff */
1525        }
1526        return 1;
1527}
1528
1529static int look_ahead(struct grep_opt *opt,
1530                      unsigned long *left_p,
1531                      unsigned *lno_p,
1532                      char **bol_p)
1533{
1534        unsigned lno = *lno_p;
1535        char *bol = *bol_p;
1536        struct grep_pat *p;
1537        char *sp, *last_bol;
1538        regoff_t earliest = -1;
1539
1540        for (p = opt->pattern_list; p; p = p->next) {
1541                int hit;
1542                regmatch_t m;
1543
1544                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1545                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1546                        continue;
1547                if (earliest < 0 || m.rm_so < earliest)
1548                        earliest = m.rm_so;
1549        }
1550
1551        if (earliest < 0) {
1552                *bol_p = bol + *left_p;
1553                *left_p = 0;
1554                return 1;
1555        }
1556        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1557                ; /* find the beginning of the line */
1558        last_bol = sp;
1559
1560        for (sp = bol; sp < last_bol; sp++) {
1561                if (*sp == '\n')
1562                        lno++;
1563        }
1564        *left_p -= last_bol - bol;
1565        *bol_p = last_bol;
1566        *lno_p = lno;
1567        return 0;
1568}
1569
1570static int fill_textconv_grep(struct userdiff_driver *driver,
1571                              struct grep_source *gs)
1572{
1573        struct diff_filespec *df;
1574        char *buf;
1575        size_t size;
1576
1577        if (!driver || !driver->textconv)
1578                return grep_source_load(gs);
1579
1580        /*
1581         * The textconv interface is intimately tied to diff_filespecs, so we
1582         * have to pretend to be one. If we could unify the grep_source
1583         * and diff_filespec structs, this mess could just go away.
1584         */
1585        df = alloc_filespec(gs->path);
1586        switch (gs->type) {
1587        case GREP_SOURCE_SHA1:
1588                fill_filespec(df, gs->identifier, 1, 0100644);
1589                break;
1590        case GREP_SOURCE_FILE:
1591                fill_filespec(df, null_sha1, 0, 0100644);
1592                break;
1593        default:
1594                die("BUG: attempt to textconv something without a path?");
1595        }
1596
1597        /*
1598         * fill_textconv is not remotely thread-safe; it may load objects
1599         * behind the scenes, and it modifies the global diff tempfile
1600         * structure.
1601         */
1602        grep_read_lock();
1603        size = fill_textconv(driver, df, &buf);
1604        grep_read_unlock();
1605        free_filespec(df);
1606
1607        /*
1608         * The normal fill_textconv usage by the diff machinery would just keep
1609         * the textconv'd buf separate from the diff_filespec. But much of the
1610         * grep code passes around a grep_source and assumes that its "buf"
1611         * pointer is the beginning of the thing we are searching. So let's
1612         * install our textconv'd version into the grep_source, taking care not
1613         * to leak any existing buffer.
1614         */
1615        grep_source_clear_data(gs);
1616        gs->buf = buf;
1617        gs->size = size;
1618
1619        return 0;
1620}
1621
1622static int is_empty_line(const char *bol, const char *eol)
1623{
1624        while (bol < eol && isspace(*bol))
1625                bol++;
1626        return bol == eol;
1627}
1628
1629static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1630{
1631        char *bol;
1632        char *peek_bol = NULL;
1633        unsigned long left;
1634        unsigned lno = 1;
1635        unsigned last_hit = 0;
1636        int binary_match_only = 0;
1637        unsigned count = 0;
1638        int try_lookahead = 0;
1639        int show_function = 0;
1640        struct userdiff_driver *textconv = NULL;
1641        enum grep_context ctx = GREP_CONTEXT_HEAD;
1642        xdemitconf_t xecfg;
1643
1644        if (!opt->output)
1645                opt->output = std_output;
1646
1647        if (opt->pre_context || opt->post_context || opt->file_break ||
1648            opt->funcbody) {
1649                /* Show hunk marks, except for the first file. */
1650                if (opt->last_shown)
1651                        opt->show_hunk_mark = 1;
1652                /*
1653                 * If we're using threads then we can't easily identify
1654                 * the first file.  Always put hunk marks in that case
1655                 * and skip the very first one later in work_done().
1656                 */
1657                if (opt->output != std_output)
1658                        opt->show_hunk_mark = 1;
1659        }
1660        opt->last_shown = 0;
1661
1662        if (opt->allow_textconv) {
1663                grep_source_load_driver(gs);
1664                /*
1665                 * We might set up the shared textconv cache data here, which
1666                 * is not thread-safe.
1667                 */
1668                grep_attr_lock();
1669                textconv = userdiff_get_textconv(gs->driver);
1670                grep_attr_unlock();
1671        }
1672
1673        /*
1674         * We know the result of a textconv is text, so we only have to care
1675         * about binary handling if we are not using it.
1676         */
1677        if (!textconv) {
1678                switch (opt->binary) {
1679                case GREP_BINARY_DEFAULT:
1680                        if (grep_source_is_binary(gs))
1681                                binary_match_only = 1;
1682                        break;
1683                case GREP_BINARY_NOMATCH:
1684                        if (grep_source_is_binary(gs))
1685                                return 0; /* Assume unmatch */
1686                        break;
1687                case GREP_BINARY_TEXT:
1688                        break;
1689                default:
1690                        die("BUG: unknown binary handling mode");
1691                }
1692        }
1693
1694        memset(&xecfg, 0, sizeof(xecfg));
1695        opt->priv = &xecfg;
1696
1697        try_lookahead = should_lookahead(opt);
1698
1699        if (fill_textconv_grep(textconv, gs) < 0)
1700                return 0;
1701
1702        bol = gs->buf;
1703        left = gs->size;
1704        while (left) {
1705                char *eol, ch;
1706                int hit;
1707
1708                /*
1709                 * look_ahead() skips quickly to the line that possibly
1710                 * has the next hit; don't call it if we need to do
1711                 * something more than just skipping the current line
1712                 * in response to an unmatch for the current line.  E.g.
1713                 * inside a post-context window, we will show the current
1714                 * line as a context around the previous hit when it
1715                 * doesn't hit.
1716                 */
1717                if (try_lookahead
1718                    && !(last_hit
1719                         && (show_function ||
1720                             lno <= last_hit + opt->post_context))
1721                    && look_ahead(opt, &left, &lno, &bol))
1722                        break;
1723                eol = end_of_line(bol, &left);
1724                ch = *eol;
1725                *eol = 0;
1726
1727                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1728                        ctx = GREP_CONTEXT_BODY;
1729
1730                hit = match_line(opt, bol, eol, ctx, collect_hits);
1731                *eol = ch;
1732
1733                if (collect_hits)
1734                        goto next_line;
1735
1736                /* "grep -v -e foo -e bla" should list lines
1737                 * that do not have either, so inversion should
1738                 * be done outside.
1739                 */
1740                if (opt->invert)
1741                        hit = !hit;
1742                if (opt->unmatch_name_only) {
1743                        if (hit)
1744                                return 0;
1745                        goto next_line;
1746                }
1747                if (hit) {
1748                        count++;
1749                        if (opt->status_only)
1750                                return 1;
1751                        if (opt->name_only) {
1752                                show_name(opt, gs->name);
1753                                return 1;
1754                        }
1755                        if (opt->count)
1756                                goto next_line;
1757                        if (binary_match_only) {
1758                                opt->output(opt, "Binary file ", 12);
1759                                output_color(opt, gs->name, strlen(gs->name),
1760                                             opt->color_filename);
1761                                opt->output(opt, " matches\n", 9);
1762                                return 1;
1763                        }
1764                        /* Hit at this line.  If we haven't shown the
1765                         * pre-context lines, we would need to show them.
1766                         */
1767                        if (opt->pre_context || opt->funcbody)
1768                                show_pre_context(opt, gs, bol, eol, lno);
1769                        else if (opt->funcname)
1770                                show_funcname_line(opt, gs, bol, lno);
1771                        show_line(opt, bol, eol, gs->name, lno, ':');
1772                        last_hit = lno;
1773                        if (opt->funcbody)
1774                                show_function = 1;
1775                        goto next_line;
1776                }
1777                if (show_function && (!peek_bol || peek_bol < bol)) {
1778                        unsigned long peek_left = left;
1779                        char *peek_eol = eol;
1780
1781                        /*
1782                         * Trailing empty lines are not interesting.
1783                         * Peek past them to see if they belong to the
1784                         * body of the current function.
1785                         */
1786                        peek_bol = bol;
1787                        while (is_empty_line(peek_bol, peek_eol)) {
1788                                peek_bol = peek_eol + 1;
1789                                peek_eol = end_of_line(peek_bol, &peek_left);
1790                        }
1791
1792                        if (match_funcname(opt, gs, peek_bol, peek_eol))
1793                                show_function = 0;
1794                }
1795                if (show_function ||
1796                    (last_hit && lno <= last_hit + opt->post_context)) {
1797                        /* If the last hit is within the post context,
1798                         * we need to show this line.
1799                         */
1800                        show_line(opt, bol, eol, gs->name, lno, '-');
1801                }
1802
1803        next_line:
1804                bol = eol + 1;
1805                if (!left)
1806                        break;
1807                left--;
1808                lno++;
1809        }
1810
1811        if (collect_hits)
1812                return 0;
1813
1814        if (opt->status_only)
1815                return 0;
1816        if (opt->unmatch_name_only) {
1817                /* We did not see any hit, so we want to show this */
1818                show_name(opt, gs->name);
1819                return 1;
1820        }
1821
1822        xdiff_clear_find_func(&xecfg);
1823        opt->priv = NULL;
1824
1825        /* NEEDSWORK:
1826         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1827         * which feels mostly useless but sometimes useful.  Maybe
1828         * make it another option?  For now suppress them.
1829         */
1830        if (opt->count && count) {
1831                char buf[32];
1832                if (opt->pathname) {
1833                        output_color(opt, gs->name, strlen(gs->name),
1834                                     opt->color_filename);
1835                        output_sep(opt, ':');
1836                }
1837                xsnprintf(buf, sizeof(buf), "%u\n", count);
1838                opt->output(opt, buf, strlen(buf));
1839                return 1;
1840        }
1841        return !!last_hit;
1842}
1843
1844static void clr_hit_marker(struct grep_expr *x)
1845{
1846        /* All-hit markers are meaningful only at the very top level
1847         * OR node.
1848         */
1849        while (1) {
1850                x->hit = 0;
1851                if (x->node != GREP_NODE_OR)
1852                        return;
1853                x->u.binary.left->hit = 0;
1854                x = x->u.binary.right;
1855        }
1856}
1857
1858static int chk_hit_marker(struct grep_expr *x)
1859{
1860        /* Top level nodes have hit markers.  See if they all are hits */
1861        while (1) {
1862                if (x->node != GREP_NODE_OR)
1863                        return x->hit;
1864                if (!x->u.binary.left->hit)
1865                        return 0;
1866                x = x->u.binary.right;
1867        }
1868}
1869
1870int grep_source(struct grep_opt *opt, struct grep_source *gs)
1871{
1872        /*
1873         * we do not have to do the two-pass grep when we do not check
1874         * buffer-wide "all-match".
1875         */
1876        if (!opt->all_match)
1877                return grep_source_1(opt, gs, 0);
1878
1879        /* Otherwise the toplevel "or" terms hit a bit differently.
1880         * We first clear hit markers from them.
1881         */
1882        clr_hit_marker(opt->pattern_expression);
1883        grep_source_1(opt, gs, 1);
1884
1885        if (!chk_hit_marker(opt->pattern_expression))
1886                return 0;
1887
1888        return grep_source_1(opt, gs, 0);
1889}
1890
1891int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1892{
1893        struct grep_source gs;
1894        int r;
1895
1896        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1897        gs.buf = buf;
1898        gs.size = size;
1899
1900        r = grep_source(opt, &gs);
1901
1902        grep_source_clear(&gs);
1903        return r;
1904}
1905
1906void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1907                      const char *name, const char *path,
1908                      const void *identifier)
1909{
1910        gs->type = type;
1911        gs->name = xstrdup_or_null(name);
1912        gs->path = xstrdup_or_null(path);
1913        gs->buf = NULL;
1914        gs->size = 0;
1915        gs->driver = NULL;
1916
1917        switch (type) {
1918        case GREP_SOURCE_FILE:
1919                gs->identifier = xstrdup(identifier);
1920                break;
1921        case GREP_SOURCE_SUBMODULE:
1922                if (!identifier) {
1923                        gs->identifier = NULL;
1924                        break;
1925                }
1926                /*
1927                 * FALL THROUGH
1928                 * If the identifier is non-NULL (in the submodule case) it
1929                 * will be a SHA1 that needs to be copied.
1930                 */
1931        case GREP_SOURCE_SHA1:
1932                gs->identifier = xmalloc(20);
1933                hashcpy(gs->identifier, 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(gs->name);
1944        gs->name = NULL;
1945        free(gs->path);
1946        gs->path = NULL;
1947        free(gs->identifier);
1948        gs->identifier = NULL;
1949        grep_source_clear_data(gs);
1950}
1951
1952void grep_source_clear_data(struct grep_source *gs)
1953{
1954        switch (gs->type) {
1955        case GREP_SOURCE_FILE:
1956        case GREP_SOURCE_SHA1:
1957        case GREP_SOURCE_SUBMODULE:
1958                free(gs->buf);
1959                gs->buf = NULL;
1960                gs->size = 0;
1961                break;
1962        case GREP_SOURCE_BUF:
1963                /* leave user-provided buf intact */
1964                break;
1965        }
1966}
1967
1968static int grep_source_load_sha1(struct grep_source *gs)
1969{
1970        enum object_type type;
1971
1972        grep_read_lock();
1973        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1974        grep_read_unlock();
1975
1976        if (!gs->buf)
1977                return error(_("'%s': unable to read %s"),
1978                             gs->name,
1979                             sha1_to_hex(gs->identifier));
1980        return 0;
1981}
1982
1983static int grep_source_load_file(struct grep_source *gs)
1984{
1985        const char *filename = gs->identifier;
1986        struct stat st;
1987        char *data;
1988        size_t size;
1989        int i;
1990
1991        if (lstat(filename, &st) < 0) {
1992        err_ret:
1993                if (errno != ENOENT)
1994                        error_errno(_("failed to stat '%s'"), filename);
1995                return -1;
1996        }
1997        if (!S_ISREG(st.st_mode))
1998                return -1;
1999        size = xsize_t(st.st_size);
2000        i = open(filename, O_RDONLY);
2001        if (i < 0)
2002                goto err_ret;
2003        data = xmallocz(size);
2004        if (st.st_size != read_in_full(i, data, size)) {
2005                error_errno(_("'%s': short read"), filename);
2006                close(i);
2007                free(data);
2008                return -1;
2009        }
2010        close(i);
2011
2012        gs->buf = data;
2013        gs->size = size;
2014        return 0;
2015}
2016
2017static int grep_source_load(struct grep_source *gs)
2018{
2019        if (gs->buf)
2020                return 0;
2021
2022        switch (gs->type) {
2023        case GREP_SOURCE_FILE:
2024                return grep_source_load_file(gs);
2025        case GREP_SOURCE_SHA1:
2026                return grep_source_load_sha1(gs);
2027        case GREP_SOURCE_BUF:
2028                return gs->buf ? 0 : -1;
2029        case GREP_SOURCE_SUBMODULE:
2030                break;
2031        }
2032        die("BUG: invalid grep_source type to load");
2033}
2034
2035void grep_source_load_driver(struct grep_source *gs)
2036{
2037        if (gs->driver)
2038                return;
2039
2040        grep_attr_lock();
2041        if (gs->path)
2042                gs->driver = userdiff_find_by_path(gs->path);
2043        if (!gs->driver)
2044                gs->driver = userdiff_find_by_name("default");
2045        grep_attr_unlock();
2046}
2047
2048static int grep_source_is_binary(struct grep_source *gs)
2049{
2050        grep_source_load_driver(gs);
2051        if (gs->driver->binary != -1)
2052                return gs->driver->binary;
2053
2054        if (!grep_source_load(gs))
2055                return buffer_is_binary(gs->buf, gs->size);
2056
2057        return 0;
2058}