Andrew's git / gitweb.git / grep.c
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grep.con commit grep: add support for the PCRE v1 JIT API (fbaceaa)
   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                break;
 183
 184        case GREP_PATTERN_TYPE_ERE:
 185                opt->fixed = 0;
 186                opt->pcre1 = 0;
 187                opt->regflags |= REG_EXTENDED;
 188                break;
 189
 190        case GREP_PATTERN_TYPE_FIXED:
 191                opt->fixed = 1;
 192                opt->pcre1 = 0;
 193                break;
 194
 195        case GREP_PATTERN_TYPE_PCRE:
 196                opt->fixed = 0;
 197                opt->pcre1 = 1;
 198                break;
 199        }
 200}
 201
 202void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 203{
 204        if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 205                grep_set_pattern_type_option(pattern_type, opt);
 206        else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 207                grep_set_pattern_type_option(opt->pattern_type_option, opt);
 208        else if (opt->extended_regexp_option)
 209                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 210}
 211
 212static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 213                                        const char *origin, int no,
 214                                        enum grep_pat_token t,
 215                                        enum grep_header_field field)
 216{
 217        struct grep_pat *p = xcalloc(1, sizeof(*p));
 218        p->pattern = xmemdupz(pat, patlen);
 219        p->patternlen = patlen;
 220        p->origin = origin;
 221        p->no = no;
 222        p->token = t;
 223        p->field = field;
 224        return p;
 225}
 226
 227static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 228{
 229        **tail = p;
 230        *tail = &p->next;
 231        p->next = NULL;
 232
 233        switch (p->token) {
 234        case GREP_PATTERN: /* atom */
 235        case GREP_PATTERN_HEAD:
 236        case GREP_PATTERN_BODY:
 237                for (;;) {
 238                        struct grep_pat *new_pat;
 239                        size_t len = 0;
 240                        char *cp = p->pattern + p->patternlen, *nl = NULL;
 241                        while (++len <= p->patternlen) {
 242                                if (*(--cp) == '\n') {
 243                                        nl = cp;
 244                                        break;
 245                                }
 246                        }
 247                        if (!nl)
 248                                break;
 249                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 250                                                  p->no, p->token, p->field);
 251                        new_pat->next = p->next;
 252                        if (!p->next)
 253                                *tail = &new_pat->next;
 254                        p->next = new_pat;
 255                        *nl = '\0';
 256                        p->patternlen -= len;
 257                }
 258                break;
 259        default:
 260                break;
 261        }
 262}
 263
 264void append_header_grep_pattern(struct grep_opt *opt,
 265                                enum grep_header_field field, const char *pat)
 266{
 267        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 268                                             GREP_PATTERN_HEAD, field);
 269        if (field == GREP_HEADER_REFLOG)
 270                opt->use_reflog_filter = 1;
 271        do_append_grep_pat(&opt->header_tail, p);
 272}
 273
 274void append_grep_pattern(struct grep_opt *opt, const char *pat,
 275                         const char *origin, int no, enum grep_pat_token t)
 276{
 277        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 278}
 279
 280void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 281                     const char *origin, int no, enum grep_pat_token t)
 282{
 283        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 284        do_append_grep_pat(&opt->pattern_tail, p);
 285}
 286
 287struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 288{
 289        struct grep_pat *pat;
 290        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 291        *ret = *opt;
 292
 293        ret->pattern_list = NULL;
 294        ret->pattern_tail = &ret->pattern_list;
 295
 296        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 297        {
 298                if(pat->token == GREP_PATTERN_HEAD)
 299                        append_header_grep_pattern(ret, pat->field,
 300                                                   pat->pattern);
 301                else
 302                        append_grep_pat(ret, pat->pattern, pat->patternlen,
 303                                        pat->origin, pat->no, pat->token);
 304        }
 305
 306        return ret;
 307}
 308
 309static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 310                const char *error)
 311{
 312        char where[1024];
 313
 314        if (p->no)
 315                xsnprintf(where, sizeof(where), "In '%s' at %d, ", p->origin, p->no);
 316        else if (p->origin)
 317                xsnprintf(where, sizeof(where), "%s, ", p->origin);
 318        else
 319                where[0] = 0;
 320
 321        die("%s'%s': %s", where, p->pattern, error);
 322}
 323
 324static int is_fixed(const char *s, size_t len)
 325{
 326        size_t i;
 327
 328        for (i = 0; i < len; i++) {
 329                if (is_regex_special(s[i]))
 330                        return 0;
 331        }
 332
 333        return 1;
 334}
 335
 336static int has_null(const char *s, size_t len)
 337{
 338        /*
 339         * regcomp cannot accept patterns with NULs so when using it
 340         * we consider any pattern containing a NUL fixed.
 341         */
 342        if (memchr(s, 0, len))
 343                return 1;
 344
 345        return 0;
 346}
 347
 348#ifdef USE_LIBPCRE1
 349static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 350{
 351        const char *error;
 352        int erroffset;
 353        int options = PCRE_MULTILINE;
 354
 355        if (opt->ignore_case) {
 356                if (has_non_ascii(p->pattern))
 357                        p->pcre1_tables = pcre_maketables();
 358                options |= PCRE_CASELESS;
 359        }
 360        if (is_utf8_locale() && has_non_ascii(p->pattern))
 361                options |= PCRE_UTF8;
 362
 363        p->pcre1_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 364                                      p->pcre1_tables);
 365        if (!p->pcre1_regexp)
 366                compile_regexp_failed(p, error);
 367
 368        p->pcre1_extra_info = pcre_study(p->pcre1_regexp, PCRE_STUDY_JIT_COMPILE, &error);
 369        if (!p->pcre1_extra_info && error)
 370                die("%s", error);
 371
 372#ifdef PCRE_CONFIG_JIT
 373        pcre_config(PCRE_CONFIG_JIT, &p->pcre1_jit_on);
 374        if (p->pcre1_jit_on == 1) {
 375                p->pcre1_jit_stack = pcre_jit_stack_alloc(1, 1024 * 1024);
 376                if (!p->pcre1_jit_stack)
 377                        die("Couldn't allocate PCRE JIT stack");
 378                pcre_assign_jit_stack(p->pcre1_extra_info, NULL, p->pcre1_jit_stack);
 379        } else if (p->pcre1_jit_on != 0) {
 380                die("BUG: The pcre1_jit_on variable should be 0 or 1, not %d",
 381                    p->pcre1_jit_on);
 382        }
 383#endif
 384}
 385
 386static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 387                regmatch_t *match, int eflags)
 388{
 389        int ovector[30], ret, flags = 0;
 390
 391        if (eflags & REG_NOTBOL)
 392                flags |= PCRE_NOTBOL;
 393
 394#ifdef PCRE_CONFIG_JIT
 395        if (p->pcre1_jit_on) {
 396                ret = pcre_jit_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
 397                                    eol - line, 0, flags, ovector,
 398                                    ARRAY_SIZE(ovector), p->pcre1_jit_stack);
 399        } else
 400#endif
 401        {
 402                ret = pcre_exec(p->pcre1_regexp, p->pcre1_extra_info, line,
 403                                eol - line, 0, flags, ovector,
 404                                ARRAY_SIZE(ovector));
 405        }
 406
 407        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 408                die("pcre_exec failed with error code %d", ret);
 409        if (ret > 0) {
 410                ret = 0;
 411                match->rm_so = ovector[0];
 412                match->rm_eo = ovector[1];
 413        }
 414
 415        return ret;
 416}
 417
 418static void free_pcre1_regexp(struct grep_pat *p)
 419{
 420        pcre_free(p->pcre1_regexp);
 421#ifdef PCRE_CONFIG_JIT
 422        if (p->pcre1_jit_on) {
 423                pcre_free_study(p->pcre1_extra_info);
 424                pcre_jit_stack_free(p->pcre1_jit_stack);
 425        } else
 426#endif
 427        {
 428                pcre_free(p->pcre1_extra_info);
 429        }
 430        pcre_free((void *)p->pcre1_tables);
 431}
 432#else /* !USE_LIBPCRE1 */
 433static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 434{
 435        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 436}
 437
 438static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 439                regmatch_t *match, int eflags)
 440{
 441        return 1;
 442}
 443
 444static void free_pcre1_regexp(struct grep_pat *p)
 445{
 446}
 447#endif /* !USE_LIBPCRE1 */
 448
 449static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 450{
 451        struct strbuf sb = STRBUF_INIT;
 452        int err;
 453        int regflags = opt->regflags;
 454
 455        basic_regex_quote_buf(&sb, p->pattern);
 456        if (opt->ignore_case)
 457                regflags |= REG_ICASE;
 458        err = regcomp(&p->regexp, sb.buf, regflags);
 459        if (opt->debug)
 460                fprintf(stderr, "fixed %s\n", sb.buf);
 461        strbuf_release(&sb);
 462        if (err) {
 463                char errbuf[1024];
 464                regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 465                regfree(&p->regexp);
 466                compile_regexp_failed(p, errbuf);
 467        }
 468}
 469
 470static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 471{
 472        int icase, ascii_only;
 473        int err;
 474
 475        p->word_regexp = opt->word_regexp;
 476        p->ignore_case = opt->ignore_case;
 477        icase          = opt->regflags & REG_ICASE || p->ignore_case;
 478        ascii_only     = !has_non_ascii(p->pattern);
 479
 480        /*
 481         * Even when -F (fixed) asks us to do a non-regexp search, we
 482         * may not be able to correctly case-fold when -i
 483         * (ignore-case) is asked (in which case, we'll synthesize a
 484         * regexp to match the pattern that matches regexp special
 485         * characters literally, while ignoring case differences).  On
 486         * the other hand, even without -F, if the pattern does not
 487         * have any regexp special characters and there is no need for
 488         * case-folding search, we can internally turn it into a
 489         * simple string match using kws.  p->fixed tells us if we
 490         * want to use kws.
 491         */
 492        if (opt->fixed ||
 493            has_null(p->pattern, p->patternlen) ||
 494            is_fixed(p->pattern, p->patternlen))
 495                p->fixed = !icase || ascii_only;
 496        else
 497                p->fixed = 0;
 498
 499        if (p->fixed) {
 500                p->kws = kwsalloc(icase ? tolower_trans_tbl : NULL);
 501                kwsincr(p->kws, p->pattern, p->patternlen);
 502                kwsprep(p->kws);
 503                return;
 504        } else if (opt->fixed) {
 505                /*
 506                 * We come here when the pattern has the non-ascii
 507                 * characters we cannot case-fold, and asked to
 508                 * ignore-case.
 509                 */
 510                compile_fixed_regexp(p, opt);
 511                return;
 512        }
 513
 514        if (opt->pcre1) {
 515                compile_pcre1_regexp(p, opt);
 516                return;
 517        }
 518
 519        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 520        if (err) {
 521                char errbuf[1024];
 522                regerror(err, &p->regexp, errbuf, 1024);
 523                regfree(&p->regexp);
 524                compile_regexp_failed(p, errbuf);
 525        }
 526}
 527
 528static struct grep_expr *compile_pattern_or(struct grep_pat **);
 529static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 530{
 531        struct grep_pat *p;
 532        struct grep_expr *x;
 533
 534        p = *list;
 535        if (!p)
 536                return NULL;
 537        switch (p->token) {
 538        case GREP_PATTERN: /* atom */
 539        case GREP_PATTERN_HEAD:
 540        case GREP_PATTERN_BODY:
 541                x = xcalloc(1, sizeof (struct grep_expr));
 542                x->node = GREP_NODE_ATOM;
 543                x->u.atom = p;
 544                *list = p->next;
 545                return x;
 546        case GREP_OPEN_PAREN:
 547                *list = p->next;
 548                x = compile_pattern_or(list);
 549                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 550                        die("unmatched parenthesis");
 551                *list = (*list)->next;
 552                return x;
 553        default:
 554                return NULL;
 555        }
 556}
 557
 558static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 559{
 560        struct grep_pat *p;
 561        struct grep_expr *x;
 562
 563        p = *list;
 564        if (!p)
 565                return NULL;
 566        switch (p->token) {
 567        case GREP_NOT:
 568                if (!p->next)
 569                        die("--not not followed by pattern expression");
 570                *list = p->next;
 571                x = xcalloc(1, sizeof (struct grep_expr));
 572                x->node = GREP_NODE_NOT;
 573                x->u.unary = compile_pattern_not(list);
 574                if (!x->u.unary)
 575                        die("--not followed by non pattern expression");
 576                return x;
 577        default:
 578                return compile_pattern_atom(list);
 579        }
 580}
 581
 582static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 583{
 584        struct grep_pat *p;
 585        struct grep_expr *x, *y, *z;
 586
 587        x = compile_pattern_not(list);
 588        p = *list;
 589        if (p && p->token == GREP_AND) {
 590                if (!p->next)
 591                        die("--and not followed by pattern expression");
 592                *list = p->next;
 593                y = compile_pattern_and(list);
 594                if (!y)
 595                        die("--and not followed by pattern expression");
 596                z = xcalloc(1, sizeof (struct grep_expr));
 597                z->node = GREP_NODE_AND;
 598                z->u.binary.left = x;
 599                z->u.binary.right = y;
 600                return z;
 601        }
 602        return x;
 603}
 604
 605static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 606{
 607        struct grep_pat *p;
 608        struct grep_expr *x, *y, *z;
 609
 610        x = compile_pattern_and(list);
 611        p = *list;
 612        if (x && p && p->token != GREP_CLOSE_PAREN) {
 613                y = compile_pattern_or(list);
 614                if (!y)
 615                        die("not a pattern expression %s", p->pattern);
 616                z = xcalloc(1, sizeof (struct grep_expr));
 617                z->node = GREP_NODE_OR;
 618                z->u.binary.left = x;
 619                z->u.binary.right = y;
 620                return z;
 621        }
 622        return x;
 623}
 624
 625static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 626{
 627        return compile_pattern_or(list);
 628}
 629
 630static void indent(int in)
 631{
 632        while (in-- > 0)
 633                fputc(' ', stderr);
 634}
 635
 636static void dump_grep_pat(struct grep_pat *p)
 637{
 638        switch (p->token) {
 639        case GREP_AND: fprintf(stderr, "*and*"); break;
 640        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 641        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 642        case GREP_NOT: fprintf(stderr, "*not*"); break;
 643        case GREP_OR: fprintf(stderr, "*or*"); break;
 644
 645        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 646        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 647        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 648        }
 649
 650        switch (p->token) {
 651        default: break;
 652        case GREP_PATTERN_HEAD:
 653                fprintf(stderr, "<head %d>", p->field); break;
 654        case GREP_PATTERN_BODY:
 655                fprintf(stderr, "<body>"); break;
 656        }
 657        switch (p->token) {
 658        default: break;
 659        case GREP_PATTERN_HEAD:
 660        case GREP_PATTERN_BODY:
 661        case GREP_PATTERN:
 662                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 663                break;
 664        }
 665        fputc('\n', stderr);
 666}
 667
 668static void dump_grep_expression_1(struct grep_expr *x, int in)
 669{
 670        indent(in);
 671        switch (x->node) {
 672        case GREP_NODE_TRUE:
 673                fprintf(stderr, "true\n");
 674                break;
 675        case GREP_NODE_ATOM:
 676                dump_grep_pat(x->u.atom);
 677                break;
 678        case GREP_NODE_NOT:
 679                fprintf(stderr, "(not\n");
 680                dump_grep_expression_1(x->u.unary, in+1);
 681                indent(in);
 682                fprintf(stderr, ")\n");
 683                break;
 684        case GREP_NODE_AND:
 685                fprintf(stderr, "(and\n");
 686                dump_grep_expression_1(x->u.binary.left, in+1);
 687                dump_grep_expression_1(x->u.binary.right, in+1);
 688                indent(in);
 689                fprintf(stderr, ")\n");
 690                break;
 691        case GREP_NODE_OR:
 692                fprintf(stderr, "(or\n");
 693                dump_grep_expression_1(x->u.binary.left, in+1);
 694                dump_grep_expression_1(x->u.binary.right, in+1);
 695                indent(in);
 696                fprintf(stderr, ")\n");
 697                break;
 698        }
 699}
 700
 701static void dump_grep_expression(struct grep_opt *opt)
 702{
 703        struct grep_expr *x = opt->pattern_expression;
 704
 705        if (opt->all_match)
 706                fprintf(stderr, "[all-match]\n");
 707        dump_grep_expression_1(x, 0);
 708        fflush(NULL);
 709}
 710
 711static struct grep_expr *grep_true_expr(void)
 712{
 713        struct grep_expr *z = xcalloc(1, sizeof(*z));
 714        z->node = GREP_NODE_TRUE;
 715        return z;
 716}
 717
 718static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 719{
 720        struct grep_expr *z = xcalloc(1, sizeof(*z));
 721        z->node = GREP_NODE_OR;
 722        z->u.binary.left = left;
 723        z->u.binary.right = right;
 724        return z;
 725}
 726
 727static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 728{
 729        struct grep_pat *p;
 730        struct grep_expr *header_expr;
 731        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 732        enum grep_header_field fld;
 733
 734        if (!opt->header_list)
 735                return NULL;
 736
 737        for (p = opt->header_list; p; p = p->next) {
 738                if (p->token != GREP_PATTERN_HEAD)
 739                        die("BUG: a non-header pattern in grep header list.");
 740                if (p->field < GREP_HEADER_FIELD_MIN ||
 741                    GREP_HEADER_FIELD_MAX <= p->field)
 742                        die("BUG: unknown header field %d", p->field);
 743                compile_regexp(p, opt);
 744        }
 745
 746        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 747                header_group[fld] = NULL;
 748
 749        for (p = opt->header_list; p; p = p->next) {
 750                struct grep_expr *h;
 751                struct grep_pat *pp = p;
 752
 753                h = compile_pattern_atom(&pp);
 754                if (!h || pp != p->next)
 755                        die("BUG: malformed header expr");
 756                if (!header_group[p->field]) {
 757                        header_group[p->field] = h;
 758                        continue;
 759                }
 760                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 761        }
 762
 763        header_expr = NULL;
 764
 765        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 766                if (!header_group[fld])
 767                        continue;
 768                if (!header_expr)
 769                        header_expr = grep_true_expr();
 770                header_expr = grep_or_expr(header_group[fld], header_expr);
 771        }
 772        return header_expr;
 773}
 774
 775static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 776{
 777        struct grep_expr *z = x;
 778
 779        while (x) {
 780                assert(x->node == GREP_NODE_OR);
 781                if (x->u.binary.right &&
 782                    x->u.binary.right->node == GREP_NODE_TRUE) {
 783                        x->u.binary.right = y;
 784                        break;
 785                }
 786                x = x->u.binary.right;
 787        }
 788        return z;
 789}
 790
 791static void compile_grep_patterns_real(struct grep_opt *opt)
 792{
 793        struct grep_pat *p;
 794        struct grep_expr *header_expr = prep_header_patterns(opt);
 795
 796        for (p = opt->pattern_list; p; p = p->next) {
 797                switch (p->token) {
 798                case GREP_PATTERN: /* atom */
 799                case GREP_PATTERN_HEAD:
 800                case GREP_PATTERN_BODY:
 801                        compile_regexp(p, opt);
 802                        break;
 803                default:
 804                        opt->extended = 1;
 805                        break;
 806                }
 807        }
 808
 809        if (opt->all_match || header_expr)
 810                opt->extended = 1;
 811        else if (!opt->extended && !opt->debug)
 812                return;
 813
 814        p = opt->pattern_list;
 815        if (p)
 816                opt->pattern_expression = compile_pattern_expr(&p);
 817        if (p)
 818                die("incomplete pattern expression: %s", p->pattern);
 819
 820        if (!header_expr)
 821                return;
 822
 823        if (!opt->pattern_expression)
 824                opt->pattern_expression = header_expr;
 825        else if (opt->all_match)
 826                opt->pattern_expression = grep_splice_or(header_expr,
 827                                                         opt->pattern_expression);
 828        else
 829                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 830                                                       header_expr);
 831        opt->all_match = 1;
 832}
 833
 834void compile_grep_patterns(struct grep_opt *opt)
 835{
 836        compile_grep_patterns_real(opt);
 837        if (opt->debug)
 838                dump_grep_expression(opt);
 839}
 840
 841static void free_pattern_expr(struct grep_expr *x)
 842{
 843        switch (x->node) {
 844        case GREP_NODE_TRUE:
 845        case GREP_NODE_ATOM:
 846                break;
 847        case GREP_NODE_NOT:
 848                free_pattern_expr(x->u.unary);
 849                break;
 850        case GREP_NODE_AND:
 851        case GREP_NODE_OR:
 852                free_pattern_expr(x->u.binary.left);
 853                free_pattern_expr(x->u.binary.right);
 854                break;
 855        }
 856        free(x);
 857}
 858
 859void free_grep_patterns(struct grep_opt *opt)
 860{
 861        struct grep_pat *p, *n;
 862
 863        for (p = opt->pattern_list; p; p = n) {
 864                n = p->next;
 865                switch (p->token) {
 866                case GREP_PATTERN: /* atom */
 867                case GREP_PATTERN_HEAD:
 868                case GREP_PATTERN_BODY:
 869                        if (p->kws)
 870                                kwsfree(p->kws);
 871                        else if (p->pcre1_regexp)
 872                                free_pcre1_regexp(p);
 873                        else
 874                                regfree(&p->regexp);
 875                        free(p->pattern);
 876                        break;
 877                default:
 878                        break;
 879                }
 880                free(p);
 881        }
 882
 883        if (!opt->extended)
 884                return;
 885        free_pattern_expr(opt->pattern_expression);
 886}
 887
 888static char *end_of_line(char *cp, unsigned long *left)
 889{
 890        unsigned long l = *left;
 891        while (l && *cp != '\n') {
 892                l--;
 893                cp++;
 894        }
 895        *left = l;
 896        return cp;
 897}
 898
 899static int word_char(char ch)
 900{
 901        return isalnum(ch) || ch == '_';
 902}
 903
 904static void output_color(struct grep_opt *opt, const void *data, size_t size,
 905                         const char *color)
 906{
 907        if (want_color(opt->color) && color && color[0]) {
 908                opt->output(opt, color, strlen(color));
 909                opt->output(opt, data, size);
 910                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 911        } else
 912                opt->output(opt, data, size);
 913}
 914
 915static void output_sep(struct grep_opt *opt, char sign)
 916{
 917        if (opt->null_following_name)
 918                opt->output(opt, "\0", 1);
 919        else
 920                output_color(opt, &sign, 1, opt->color_sep);
 921}
 922
 923static void show_name(struct grep_opt *opt, const char *name)
 924{
 925        output_color(opt, name, strlen(name), opt->color_filename);
 926        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 927}
 928
 929static int fixmatch(struct grep_pat *p, char *line, char *eol,
 930                    regmatch_t *match)
 931{
 932        struct kwsmatch kwsm;
 933        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 934        if (offset == -1) {
 935                match->rm_so = match->rm_eo = -1;
 936                return REG_NOMATCH;
 937        } else {
 938                match->rm_so = offset;
 939                match->rm_eo = match->rm_so + kwsm.size[0];
 940                return 0;
 941        }
 942}
 943
 944static int patmatch(struct grep_pat *p, char *line, char *eol,
 945                    regmatch_t *match, int eflags)
 946{
 947        int hit;
 948
 949        if (p->fixed)
 950                hit = !fixmatch(p, line, eol, match);
 951        else if (p->pcre1_regexp)
 952                hit = !pcre1match(p, line, eol, match, eflags);
 953        else
 954                hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
 955                                   eflags);
 956
 957        return hit;
 958}
 959
 960static int strip_timestamp(char *bol, char **eol_p)
 961{
 962        char *eol = *eol_p;
 963        int ch;
 964
 965        while (bol < --eol) {
 966                if (*eol != '>')
 967                        continue;
 968                *eol_p = ++eol;
 969                ch = *eol;
 970                *eol = '\0';
 971                return ch;
 972        }
 973        return 0;
 974}
 975
 976static struct {
 977        const char *field;
 978        size_t len;
 979} header_field[] = {
 980        { "author ", 7 },
 981        { "committer ", 10 },
 982        { "reflog ", 7 },
 983};
 984
 985static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 986                             enum grep_context ctx,
 987                             regmatch_t *pmatch, int eflags)
 988{
 989        int hit = 0;
 990        int saved_ch = 0;
 991        const char *start = bol;
 992
 993        if ((p->token != GREP_PATTERN) &&
 994            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 995                return 0;
 996
 997        if (p->token == GREP_PATTERN_HEAD) {
 998                const char *field;
 999                size_t len;
1000                assert(p->field < ARRAY_SIZE(header_field));
1001                field = header_field[p->field].field;
1002                len = header_field[p->field].len;
1003                if (strncmp(bol, field, len))
1004                        return 0;
1005                bol += len;
1006                switch (p->field) {
1007                case GREP_HEADER_AUTHOR:
1008                case GREP_HEADER_COMMITTER:
1009                        saved_ch = strip_timestamp(bol, &eol);
1010                        break;
1011                default:
1012                        break;
1013                }
1014        }
1015
1016 again:
1017        hit = patmatch(p, bol, eol, pmatch, eflags);
1018
1019        if (hit && p->word_regexp) {
1020                if ((pmatch[0].rm_so < 0) ||
1021                    (eol - bol) < pmatch[0].rm_so ||
1022                    (pmatch[0].rm_eo < 0) ||
1023                    (eol - bol) < pmatch[0].rm_eo)
1024                        die("regexp returned nonsense");
1025
1026                /* Match beginning must be either beginning of the
1027                 * line, or at word boundary (i.e. the last char must
1028                 * not be a word char).  Similarly, match end must be
1029                 * either end of the line, or at word boundary
1030                 * (i.e. the next char must not be a word char).
1031                 */
1032                if ( ((pmatch[0].rm_so == 0) ||
1033                      !word_char(bol[pmatch[0].rm_so-1])) &&
1034                     ((pmatch[0].rm_eo == (eol-bol)) ||
1035                      !word_char(bol[pmatch[0].rm_eo])) )
1036                        ;
1037                else
1038                        hit = 0;
1039
1040                /* Words consist of at least one character. */
1041                if (pmatch->rm_so == pmatch->rm_eo)
1042                        hit = 0;
1043
1044                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1045                        /* There could be more than one match on the
1046                         * line, and the first match might not be
1047                         * strict word match.  But later ones could be!
1048                         * Forward to the next possible start, i.e. the
1049                         * next position following a non-word char.
1050                         */
1051                        bol = pmatch[0].rm_so + bol + 1;
1052                        while (word_char(bol[-1]) && bol < eol)
1053                                bol++;
1054                        eflags |= REG_NOTBOL;
1055                        if (bol < eol)
1056                                goto again;
1057                }
1058        }
1059        if (p->token == GREP_PATTERN_HEAD && saved_ch)
1060                *eol = saved_ch;
1061        if (hit) {
1062                pmatch[0].rm_so += bol - start;
1063                pmatch[0].rm_eo += bol - start;
1064        }
1065        return hit;
1066}
1067
1068static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1069                           enum grep_context ctx, int collect_hits)
1070{
1071        int h = 0;
1072        regmatch_t match;
1073
1074        if (!x)
1075                die("Not a valid grep expression");
1076        switch (x->node) {
1077        case GREP_NODE_TRUE:
1078                h = 1;
1079                break;
1080        case GREP_NODE_ATOM:
1081                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1082                break;
1083        case GREP_NODE_NOT:
1084                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1085                break;
1086        case GREP_NODE_AND:
1087                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1088                        return 0;
1089                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1090                break;
1091        case GREP_NODE_OR:
1092                if (!collect_hits)
1093                        return (match_expr_eval(x->u.binary.left,
1094                                                bol, eol, ctx, 0) ||
1095                                match_expr_eval(x->u.binary.right,
1096                                                bol, eol, ctx, 0));
1097                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1098                x->u.binary.left->hit |= h;
1099                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1100                break;
1101        default:
1102                die("Unexpected node type (internal error) %d", x->node);
1103        }
1104        if (collect_hits)
1105                x->hit |= h;
1106        return h;
1107}
1108
1109static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1110                      enum grep_context ctx, int collect_hits)
1111{
1112        struct grep_expr *x = opt->pattern_expression;
1113        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1114}
1115
1116static int match_line(struct grep_opt *opt, char *bol, char *eol,
1117                      enum grep_context ctx, int collect_hits)
1118{
1119        struct grep_pat *p;
1120        regmatch_t match;
1121
1122        if (opt->extended)
1123                return match_expr(opt, bol, eol, ctx, collect_hits);
1124
1125        /* we do not call with collect_hits without being extended */
1126        for (p = opt->pattern_list; p; p = p->next) {
1127                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1128                        return 1;
1129        }
1130        return 0;
1131}
1132
1133static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1134                              enum grep_context ctx,
1135                              regmatch_t *pmatch, int eflags)
1136{
1137        regmatch_t match;
1138
1139        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1140                return 0;
1141        if (match.rm_so < 0 || match.rm_eo < 0)
1142                return 0;
1143        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1144                if (match.rm_so > pmatch->rm_so)
1145                        return 1;
1146                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1147                        return 1;
1148        }
1149        pmatch->rm_so = match.rm_so;
1150        pmatch->rm_eo = match.rm_eo;
1151        return 1;
1152}
1153
1154static int next_match(struct grep_opt *opt, char *bol, char *eol,
1155                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1156{
1157        struct grep_pat *p;
1158        int hit = 0;
1159
1160        pmatch->rm_so = pmatch->rm_eo = -1;
1161        if (bol < eol) {
1162                for (p = opt->pattern_list; p; p = p->next) {
1163                        switch (p->token) {
1164                        case GREP_PATTERN: /* atom */
1165                        case GREP_PATTERN_HEAD:
1166                        case GREP_PATTERN_BODY:
1167                                hit |= match_next_pattern(p, bol, eol, ctx,
1168                                                          pmatch, eflags);
1169                                break;
1170                        default:
1171                                break;
1172                        }
1173                }
1174        }
1175        return hit;
1176}
1177
1178static void show_line(struct grep_opt *opt, char *bol, char *eol,
1179                      const char *name, unsigned lno, char sign)
1180{
1181        int rest = eol - bol;
1182        const char *match_color, *line_color = NULL;
1183
1184        if (opt->file_break && opt->last_shown == 0) {
1185                if (opt->show_hunk_mark)
1186                        opt->output(opt, "\n", 1);
1187        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1188                if (opt->last_shown == 0) {
1189                        if (opt->show_hunk_mark) {
1190                                output_color(opt, "--", 2, opt->color_sep);
1191                                opt->output(opt, "\n", 1);
1192                        }
1193                } else if (lno > opt->last_shown + 1) {
1194                        output_color(opt, "--", 2, opt->color_sep);
1195                        opt->output(opt, "\n", 1);
1196                }
1197        }
1198        if (opt->heading && opt->last_shown == 0) {
1199                output_color(opt, name, strlen(name), opt->color_filename);
1200                opt->output(opt, "\n", 1);
1201        }
1202        opt->last_shown = lno;
1203
1204        if (!opt->heading && opt->pathname) {
1205                output_color(opt, name, strlen(name), opt->color_filename);
1206                output_sep(opt, sign);
1207        }
1208        if (opt->linenum) {
1209                char buf[32];
1210                xsnprintf(buf, sizeof(buf), "%d", lno);
1211                output_color(opt, buf, strlen(buf), opt->color_lineno);
1212                output_sep(opt, sign);
1213        }
1214        if (opt->color) {
1215                regmatch_t match;
1216                enum grep_context ctx = GREP_CONTEXT_BODY;
1217                int ch = *eol;
1218                int eflags = 0;
1219
1220                if (sign == ':')
1221                        match_color = opt->color_match_selected;
1222                else
1223                        match_color = opt->color_match_context;
1224                if (sign == ':')
1225                        line_color = opt->color_selected;
1226                else if (sign == '-')
1227                        line_color = opt->color_context;
1228                else if (sign == '=')
1229                        line_color = opt->color_function;
1230                *eol = '\0';
1231                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1232                        if (match.rm_so == match.rm_eo)
1233                                break;
1234
1235                        output_color(opt, bol, match.rm_so, line_color);
1236                        output_color(opt, bol + match.rm_so,
1237                                     match.rm_eo - match.rm_so, match_color);
1238                        bol += match.rm_eo;
1239                        rest -= match.rm_eo;
1240                        eflags = REG_NOTBOL;
1241                }
1242                *eol = ch;
1243        }
1244        output_color(opt, bol, rest, line_color);
1245        opt->output(opt, "\n", 1);
1246}
1247
1248#ifndef NO_PTHREADS
1249int grep_use_locks;
1250
1251/*
1252 * This lock protects access to the gitattributes machinery, which is
1253 * not thread-safe.
1254 */
1255pthread_mutex_t grep_attr_mutex;
1256
1257static inline void grep_attr_lock(void)
1258{
1259        if (grep_use_locks)
1260                pthread_mutex_lock(&grep_attr_mutex);
1261}
1262
1263static inline void grep_attr_unlock(void)
1264{
1265        if (grep_use_locks)
1266                pthread_mutex_unlock(&grep_attr_mutex);
1267}
1268
1269/*
1270 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1271 */
1272pthread_mutex_t grep_read_mutex;
1273
1274#else
1275#define grep_attr_lock()
1276#define grep_attr_unlock()
1277#endif
1278
1279static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1280{
1281        xdemitconf_t *xecfg = opt->priv;
1282        if (xecfg && !xecfg->find_func) {
1283                grep_source_load_driver(gs);
1284                if (gs->driver->funcname.pattern) {
1285                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1286                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1287                } else {
1288                        xecfg = opt->priv = NULL;
1289                }
1290        }
1291
1292        if (xecfg) {
1293                char buf[1];
1294                return xecfg->find_func(bol, eol - bol, buf, 1,
1295                                        xecfg->find_func_priv) >= 0;
1296        }
1297
1298        if (bol == eol)
1299                return 0;
1300        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1301                return 1;
1302        return 0;
1303}
1304
1305static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1306                               char *bol, unsigned lno)
1307{
1308        while (bol > gs->buf) {
1309                char *eol = --bol;
1310
1311                while (bol > gs->buf && bol[-1] != '\n')
1312                        bol--;
1313                lno--;
1314
1315                if (lno <= opt->last_shown)
1316                        break;
1317
1318                if (match_funcname(opt, gs, bol, eol)) {
1319                        show_line(opt, bol, eol, gs->name, lno, '=');
1320                        break;
1321                }
1322        }
1323}
1324
1325static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1326                             char *bol, char *end, unsigned lno)
1327{
1328        unsigned cur = lno, from = 1, funcname_lno = 0;
1329        int funcname_needed = !!opt->funcname;
1330
1331        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1332                funcname_needed = 2;
1333
1334        if (opt->pre_context < lno)
1335                from = lno - opt->pre_context;
1336        if (from <= opt->last_shown)
1337                from = opt->last_shown + 1;
1338
1339        /* Rewind. */
1340        while (bol > gs->buf &&
1341               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1342                char *eol = --bol;
1343
1344                while (bol > gs->buf && bol[-1] != '\n')
1345                        bol--;
1346                cur--;
1347                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1348                        funcname_lno = cur;
1349                        funcname_needed = 0;
1350                }
1351        }
1352
1353        /* We need to look even further back to find a function signature. */
1354        if (opt->funcname && funcname_needed)
1355                show_funcname_line(opt, gs, bol, cur);
1356
1357        /* Back forward. */
1358        while (cur < lno) {
1359                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1360
1361                while (*eol != '\n')
1362                        eol++;
1363                show_line(opt, bol, eol, gs->name, cur, sign);
1364                bol = eol + 1;
1365                cur++;
1366        }
1367}
1368
1369static int should_lookahead(struct grep_opt *opt)
1370{
1371        struct grep_pat *p;
1372
1373        if (opt->extended)
1374                return 0; /* punt for too complex stuff */
1375        if (opt->invert)
1376                return 0;
1377        for (p = opt->pattern_list; p; p = p->next) {
1378                if (p->token != GREP_PATTERN)
1379                        return 0; /* punt for "header only" and stuff */
1380        }
1381        return 1;
1382}
1383
1384static int look_ahead(struct grep_opt *opt,
1385                      unsigned long *left_p,
1386                      unsigned *lno_p,
1387                      char **bol_p)
1388{
1389        unsigned lno = *lno_p;
1390        char *bol = *bol_p;
1391        struct grep_pat *p;
1392        char *sp, *last_bol;
1393        regoff_t earliest = -1;
1394
1395        for (p = opt->pattern_list; p; p = p->next) {
1396                int hit;
1397                regmatch_t m;
1398
1399                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1400                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1401                        continue;
1402                if (earliest < 0 || m.rm_so < earliest)
1403                        earliest = m.rm_so;
1404        }
1405
1406        if (earliest < 0) {
1407                *bol_p = bol + *left_p;
1408                *left_p = 0;
1409                return 1;
1410        }
1411        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1412                ; /* find the beginning of the line */
1413        last_bol = sp;
1414
1415        for (sp = bol; sp < last_bol; sp++) {
1416                if (*sp == '\n')
1417                        lno++;
1418        }
1419        *left_p -= last_bol - bol;
1420        *bol_p = last_bol;
1421        *lno_p = lno;
1422        return 0;
1423}
1424
1425static int fill_textconv_grep(struct userdiff_driver *driver,
1426                              struct grep_source *gs)
1427{
1428        struct diff_filespec *df;
1429        char *buf;
1430        size_t size;
1431
1432        if (!driver || !driver->textconv)
1433                return grep_source_load(gs);
1434
1435        /*
1436         * The textconv interface is intimately tied to diff_filespecs, so we
1437         * have to pretend to be one. If we could unify the grep_source
1438         * and diff_filespec structs, this mess could just go away.
1439         */
1440        df = alloc_filespec(gs->path);
1441        switch (gs->type) {
1442        case GREP_SOURCE_SHA1:
1443                fill_filespec(df, gs->identifier, 1, 0100644);
1444                break;
1445        case GREP_SOURCE_FILE:
1446                fill_filespec(df, null_sha1, 0, 0100644);
1447                break;
1448        default:
1449                die("BUG: attempt to textconv something without a path?");
1450        }
1451
1452        /*
1453         * fill_textconv is not remotely thread-safe; it may load objects
1454         * behind the scenes, and it modifies the global diff tempfile
1455         * structure.
1456         */
1457        grep_read_lock();
1458        size = fill_textconv(driver, df, &buf);
1459        grep_read_unlock();
1460        free_filespec(df);
1461
1462        /*
1463         * The normal fill_textconv usage by the diff machinery would just keep
1464         * the textconv'd buf separate from the diff_filespec. But much of the
1465         * grep code passes around a grep_source and assumes that its "buf"
1466         * pointer is the beginning of the thing we are searching. So let's
1467         * install our textconv'd version into the grep_source, taking care not
1468         * to leak any existing buffer.
1469         */
1470        grep_source_clear_data(gs);
1471        gs->buf = buf;
1472        gs->size = size;
1473
1474        return 0;
1475}
1476
1477static int is_empty_line(const char *bol, const char *eol)
1478{
1479        while (bol < eol && isspace(*bol))
1480                bol++;
1481        return bol == eol;
1482}
1483
1484static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1485{
1486        char *bol;
1487        char *peek_bol = NULL;
1488        unsigned long left;
1489        unsigned lno = 1;
1490        unsigned last_hit = 0;
1491        int binary_match_only = 0;
1492        unsigned count = 0;
1493        int try_lookahead = 0;
1494        int show_function = 0;
1495        struct userdiff_driver *textconv = NULL;
1496        enum grep_context ctx = GREP_CONTEXT_HEAD;
1497        xdemitconf_t xecfg;
1498
1499        if (!opt->output)
1500                opt->output = std_output;
1501
1502        if (opt->pre_context || opt->post_context || opt->file_break ||
1503            opt->funcbody) {
1504                /* Show hunk marks, except for the first file. */
1505                if (opt->last_shown)
1506                        opt->show_hunk_mark = 1;
1507                /*
1508                 * If we're using threads then we can't easily identify
1509                 * the first file.  Always put hunk marks in that case
1510                 * and skip the very first one later in work_done().
1511                 */
1512                if (opt->output != std_output)
1513                        opt->show_hunk_mark = 1;
1514        }
1515        opt->last_shown = 0;
1516
1517        if (opt->allow_textconv) {
1518                grep_source_load_driver(gs);
1519                /*
1520                 * We might set up the shared textconv cache data here, which
1521                 * is not thread-safe.
1522                 */
1523                grep_attr_lock();
1524                textconv = userdiff_get_textconv(gs->driver);
1525                grep_attr_unlock();
1526        }
1527
1528        /*
1529         * We know the result of a textconv is text, so we only have to care
1530         * about binary handling if we are not using it.
1531         */
1532        if (!textconv) {
1533                switch (opt->binary) {
1534                case GREP_BINARY_DEFAULT:
1535                        if (grep_source_is_binary(gs))
1536                                binary_match_only = 1;
1537                        break;
1538                case GREP_BINARY_NOMATCH:
1539                        if (grep_source_is_binary(gs))
1540                                return 0; /* Assume unmatch */
1541                        break;
1542                case GREP_BINARY_TEXT:
1543                        break;
1544                default:
1545                        die("BUG: unknown binary handling mode");
1546                }
1547        }
1548
1549        memset(&xecfg, 0, sizeof(xecfg));
1550        opt->priv = &xecfg;
1551
1552        try_lookahead = should_lookahead(opt);
1553
1554        if (fill_textconv_grep(textconv, gs) < 0)
1555                return 0;
1556
1557        bol = gs->buf;
1558        left = gs->size;
1559        while (left) {
1560                char *eol, ch;
1561                int hit;
1562
1563                /*
1564                 * look_ahead() skips quickly to the line that possibly
1565                 * has the next hit; don't call it if we need to do
1566                 * something more than just skipping the current line
1567                 * in response to an unmatch for the current line.  E.g.
1568                 * inside a post-context window, we will show the current
1569                 * line as a context around the previous hit when it
1570                 * doesn't hit.
1571                 */
1572                if (try_lookahead
1573                    && !(last_hit
1574                         && (show_function ||
1575                             lno <= last_hit + opt->post_context))
1576                    && look_ahead(opt, &left, &lno, &bol))
1577                        break;
1578                eol = end_of_line(bol, &left);
1579                ch = *eol;
1580                *eol = 0;
1581
1582                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1583                        ctx = GREP_CONTEXT_BODY;
1584
1585                hit = match_line(opt, bol, eol, ctx, collect_hits);
1586                *eol = ch;
1587
1588                if (collect_hits)
1589                        goto next_line;
1590
1591                /* "grep -v -e foo -e bla" should list lines
1592                 * that do not have either, so inversion should
1593                 * be done outside.
1594                 */
1595                if (opt->invert)
1596                        hit = !hit;
1597                if (opt->unmatch_name_only) {
1598                        if (hit)
1599                                return 0;
1600                        goto next_line;
1601                }
1602                if (hit) {
1603                        count++;
1604                        if (opt->status_only)
1605                                return 1;
1606                        if (opt->name_only) {
1607                                show_name(opt, gs->name);
1608                                return 1;
1609                        }
1610                        if (opt->count)
1611                                goto next_line;
1612                        if (binary_match_only) {
1613                                opt->output(opt, "Binary file ", 12);
1614                                output_color(opt, gs->name, strlen(gs->name),
1615                                             opt->color_filename);
1616                                opt->output(opt, " matches\n", 9);
1617                                return 1;
1618                        }
1619                        /* Hit at this line.  If we haven't shown the
1620                         * pre-context lines, we would need to show them.
1621                         */
1622                        if (opt->pre_context || opt->funcbody)
1623                                show_pre_context(opt, gs, bol, eol, lno);
1624                        else if (opt->funcname)
1625                                show_funcname_line(opt, gs, bol, lno);
1626                        show_line(opt, bol, eol, gs->name, lno, ':');
1627                        last_hit = lno;
1628                        if (opt->funcbody)
1629                                show_function = 1;
1630                        goto next_line;
1631                }
1632                if (show_function && (!peek_bol || peek_bol < bol)) {
1633                        unsigned long peek_left = left;
1634                        char *peek_eol = eol;
1635
1636                        /*
1637                         * Trailing empty lines are not interesting.
1638                         * Peek past them to see if they belong to the
1639                         * body of the current function.
1640                         */
1641                        peek_bol = bol;
1642                        while (is_empty_line(peek_bol, peek_eol)) {
1643                                peek_bol = peek_eol + 1;
1644                                peek_eol = end_of_line(peek_bol, &peek_left);
1645                        }
1646
1647                        if (match_funcname(opt, gs, peek_bol, peek_eol))
1648                                show_function = 0;
1649                }
1650                if (show_function ||
1651                    (last_hit && lno <= last_hit + opt->post_context)) {
1652                        /* If the last hit is within the post context,
1653                         * we need to show this line.
1654                         */
1655                        show_line(opt, bol, eol, gs->name, lno, '-');
1656                }
1657
1658        next_line:
1659                bol = eol + 1;
1660                if (!left)
1661                        break;
1662                left--;
1663                lno++;
1664        }
1665
1666        if (collect_hits)
1667                return 0;
1668
1669        if (opt->status_only)
1670                return 0;
1671        if (opt->unmatch_name_only) {
1672                /* We did not see any hit, so we want to show this */
1673                show_name(opt, gs->name);
1674                return 1;
1675        }
1676
1677        xdiff_clear_find_func(&xecfg);
1678        opt->priv = NULL;
1679
1680        /* NEEDSWORK:
1681         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1682         * which feels mostly useless but sometimes useful.  Maybe
1683         * make it another option?  For now suppress them.
1684         */
1685        if (opt->count && count) {
1686                char buf[32];
1687                if (opt->pathname) {
1688                        output_color(opt, gs->name, strlen(gs->name),
1689                                     opt->color_filename);
1690                        output_sep(opt, ':');
1691                }
1692                xsnprintf(buf, sizeof(buf), "%u\n", count);
1693                opt->output(opt, buf, strlen(buf));
1694                return 1;
1695        }
1696        return !!last_hit;
1697}
1698
1699static void clr_hit_marker(struct grep_expr *x)
1700{
1701        /* All-hit markers are meaningful only at the very top level
1702         * OR node.
1703         */
1704        while (1) {
1705                x->hit = 0;
1706                if (x->node != GREP_NODE_OR)
1707                        return;
1708                x->u.binary.left->hit = 0;
1709                x = x->u.binary.right;
1710        }
1711}
1712
1713static int chk_hit_marker(struct grep_expr *x)
1714{
1715        /* Top level nodes have hit markers.  See if they all are hits */
1716        while (1) {
1717                if (x->node != GREP_NODE_OR)
1718                        return x->hit;
1719                if (!x->u.binary.left->hit)
1720                        return 0;
1721                x = x->u.binary.right;
1722        }
1723}
1724
1725int grep_source(struct grep_opt *opt, struct grep_source *gs)
1726{
1727        /*
1728         * we do not have to do the two-pass grep when we do not check
1729         * buffer-wide "all-match".
1730         */
1731        if (!opt->all_match)
1732                return grep_source_1(opt, gs, 0);
1733
1734        /* Otherwise the toplevel "or" terms hit a bit differently.
1735         * We first clear hit markers from them.
1736         */
1737        clr_hit_marker(opt->pattern_expression);
1738        grep_source_1(opt, gs, 1);
1739
1740        if (!chk_hit_marker(opt->pattern_expression))
1741                return 0;
1742
1743        return grep_source_1(opt, gs, 0);
1744}
1745
1746int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1747{
1748        struct grep_source gs;
1749        int r;
1750
1751        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1752        gs.buf = buf;
1753        gs.size = size;
1754
1755        r = grep_source(opt, &gs);
1756
1757        grep_source_clear(&gs);
1758        return r;
1759}
1760
1761void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1762                      const char *name, const char *path,
1763                      const void *identifier)
1764{
1765        gs->type = type;
1766        gs->name = xstrdup_or_null(name);
1767        gs->path = xstrdup_or_null(path);
1768        gs->buf = NULL;
1769        gs->size = 0;
1770        gs->driver = NULL;
1771
1772        switch (type) {
1773        case GREP_SOURCE_FILE:
1774                gs->identifier = xstrdup(identifier);
1775                break;
1776        case GREP_SOURCE_SUBMODULE:
1777                if (!identifier) {
1778                        gs->identifier = NULL;
1779                        break;
1780                }
1781                /*
1782                 * FALL THROUGH
1783                 * If the identifier is non-NULL (in the submodule case) it
1784                 * will be a SHA1 that needs to be copied.
1785                 */
1786        case GREP_SOURCE_SHA1:
1787                gs->identifier = xmalloc(20);
1788                hashcpy(gs->identifier, identifier);
1789                break;
1790        case GREP_SOURCE_BUF:
1791                gs->identifier = NULL;
1792                break;
1793        }
1794}
1795
1796void grep_source_clear(struct grep_source *gs)
1797{
1798        free(gs->name);
1799        gs->name = NULL;
1800        free(gs->path);
1801        gs->path = NULL;
1802        free(gs->identifier);
1803        gs->identifier = NULL;
1804        grep_source_clear_data(gs);
1805}
1806
1807void grep_source_clear_data(struct grep_source *gs)
1808{
1809        switch (gs->type) {
1810        case GREP_SOURCE_FILE:
1811        case GREP_SOURCE_SHA1:
1812        case GREP_SOURCE_SUBMODULE:
1813                free(gs->buf);
1814                gs->buf = NULL;
1815                gs->size = 0;
1816                break;
1817        case GREP_SOURCE_BUF:
1818                /* leave user-provided buf intact */
1819                break;
1820        }
1821}
1822
1823static int grep_source_load_sha1(struct grep_source *gs)
1824{
1825        enum object_type type;
1826
1827        grep_read_lock();
1828        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1829        grep_read_unlock();
1830
1831        if (!gs->buf)
1832                return error(_("'%s': unable to read %s"),
1833                             gs->name,
1834                             sha1_to_hex(gs->identifier));
1835        return 0;
1836}
1837
1838static int grep_source_load_file(struct grep_source *gs)
1839{
1840        const char *filename = gs->identifier;
1841        struct stat st;
1842        char *data;
1843        size_t size;
1844        int i;
1845
1846        if (lstat(filename, &st) < 0) {
1847        err_ret:
1848                if (errno != ENOENT)
1849                        error_errno(_("failed to stat '%s'"), filename);
1850                return -1;
1851        }
1852        if (!S_ISREG(st.st_mode))
1853                return -1;
1854        size = xsize_t(st.st_size);
1855        i = open(filename, O_RDONLY);
1856        if (i < 0)
1857                goto err_ret;
1858        data = xmallocz(size);
1859        if (st.st_size != read_in_full(i, data, size)) {
1860                error_errno(_("'%s': short read"), filename);
1861                close(i);
1862                free(data);
1863                return -1;
1864        }
1865        close(i);
1866
1867        gs->buf = data;
1868        gs->size = size;
1869        return 0;
1870}
1871
1872static int grep_source_load(struct grep_source *gs)
1873{
1874        if (gs->buf)
1875                return 0;
1876
1877        switch (gs->type) {
1878        case GREP_SOURCE_FILE:
1879                return grep_source_load_file(gs);
1880        case GREP_SOURCE_SHA1:
1881                return grep_source_load_sha1(gs);
1882        case GREP_SOURCE_BUF:
1883                return gs->buf ? 0 : -1;
1884        case GREP_SOURCE_SUBMODULE:
1885                break;
1886        }
1887        die("BUG: invalid grep_source type to load");
1888}
1889
1890void grep_source_load_driver(struct grep_source *gs)
1891{
1892        if (gs->driver)
1893                return;
1894
1895        grep_attr_lock();
1896        if (gs->path)
1897                gs->driver = userdiff_find_by_path(gs->path);
1898        if (!gs->driver)
1899                gs->driver = userdiff_find_by_name("default");
1900        grep_attr_unlock();
1901}
1902
1903static int grep_source_is_binary(struct grep_source *gs)
1904{
1905        grep_source_load_driver(gs);
1906        if (gs->driver->binary != -1)
1907                return gs->driver->binary;
1908
1909        if (!grep_source_load(gs))
1910                return buffer_is_binary(gs->buf, gs->size);
1911
1912        return 0;
1913}