Andrew's git / gitweb.git / grep.c
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grep.con commit diff-tree: update stale in-code comments (8ba74bf)
   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
   8static int grep_source_load(struct grep_source *gs);
   9static int grep_source_is_binary(struct grep_source *gs);
  10
  11static struct grep_opt grep_defaults;
  12
  13/*
  14 * Initialize the grep_defaults template with hardcoded defaults.
  15 * We could let the compiler do this, but without C99 initializers
  16 * the code gets unwieldy and unreadable, so...
  17 */
  18void init_grep_defaults(void)
  19{
  20        struct grep_opt *opt = &grep_defaults;
  21        static int run_once;
  22
  23        if (run_once)
  24                return;
  25        run_once++;
  26
  27        memset(opt, 0, sizeof(*opt));
  28        opt->relative = 1;
  29        opt->pathname = 1;
  30        opt->regflags = REG_NEWLINE;
  31        opt->max_depth = -1;
  32        opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
  33        opt->extended_regexp_option = 0;
  34        strcpy(opt->color_context, "");
  35        strcpy(opt->color_filename, "");
  36        strcpy(opt->color_function, "");
  37        strcpy(opt->color_lineno, "");
  38        strcpy(opt->color_match_context, GIT_COLOR_BOLD_RED);
  39        strcpy(opt->color_match_selected, GIT_COLOR_BOLD_RED);
  40        strcpy(opt->color_selected, "");
  41        strcpy(opt->color_sep, GIT_COLOR_CYAN);
  42        opt->color = -1;
  43}
  44
  45static int parse_pattern_type_arg(const char *opt, const char *arg)
  46{
  47        if (!strcmp(arg, "default"))
  48                return GREP_PATTERN_TYPE_UNSPECIFIED;
  49        else if (!strcmp(arg, "basic"))
  50                return GREP_PATTERN_TYPE_BRE;
  51        else if (!strcmp(arg, "extended"))
  52                return GREP_PATTERN_TYPE_ERE;
  53        else if (!strcmp(arg, "fixed"))
  54                return GREP_PATTERN_TYPE_FIXED;
  55        else if (!strcmp(arg, "perl"))
  56                return GREP_PATTERN_TYPE_PCRE;
  57        die("bad %s argument: %s", opt, arg);
  58}
  59
  60/*
  61 * Read the configuration file once and store it in
  62 * the grep_defaults template.
  63 */
  64int grep_config(const char *var, const char *value, void *cb)
  65{
  66        struct grep_opt *opt = &grep_defaults;
  67        char *color = NULL;
  68
  69        if (userdiff_config(var, value) < 0)
  70                return -1;
  71
  72        if (!strcmp(var, "grep.extendedregexp")) {
  73                if (git_config_bool(var, value))
  74                        opt->extended_regexp_option = 1;
  75                else
  76                        opt->extended_regexp_option = 0;
  77                return 0;
  78        }
  79
  80        if (!strcmp(var, "grep.patterntype")) {
  81                opt->pattern_type_option = parse_pattern_type_arg(var, value);
  82                return 0;
  83        }
  84
  85        if (!strcmp(var, "grep.linenumber")) {
  86                opt->linenum = git_config_bool(var, value);
  87                return 0;
  88        }
  89
  90        if (!strcmp(var, "grep.fullname")) {
  91                opt->relative = !git_config_bool(var, value);
  92                return 0;
  93        }
  94
  95        if (!strcmp(var, "color.grep"))
  96                opt->color = git_config_colorbool(var, value);
  97        else if (!strcmp(var, "color.grep.context"))
  98                color = opt->color_context;
  99        else if (!strcmp(var, "color.grep.filename"))
 100                color = opt->color_filename;
 101        else if (!strcmp(var, "color.grep.function"))
 102                color = opt->color_function;
 103        else if (!strcmp(var, "color.grep.linenumber"))
 104                color = opt->color_lineno;
 105        else if (!strcmp(var, "color.grep.matchcontext"))
 106                color = opt->color_match_context;
 107        else if (!strcmp(var, "color.grep.matchselected"))
 108                color = opt->color_match_selected;
 109        else if (!strcmp(var, "color.grep.selected"))
 110                color = opt->color_selected;
 111        else if (!strcmp(var, "color.grep.separator"))
 112                color = opt->color_sep;
 113        else if (!strcmp(var, "color.grep.match")) {
 114                int rc = 0;
 115                if (!value)
 116                        return config_error_nonbool(var);
 117                rc |= color_parse(value, opt->color_match_context);
 118                rc |= color_parse(value, opt->color_match_selected);
 119                return rc;
 120        }
 121
 122        if (color) {
 123                if (!value)
 124                        return config_error_nonbool(var);
 125                return color_parse(value, color);
 126        }
 127        return 0;
 128}
 129
 130/*
 131 * Initialize one instance of grep_opt and copy the
 132 * default values from the template we read the configuration
 133 * information in an earlier call to git_config(grep_config).
 134 */
 135void grep_init(struct grep_opt *opt, const char *prefix)
 136{
 137        struct grep_opt *def = &grep_defaults;
 138
 139        memset(opt, 0, sizeof(*opt));
 140        opt->prefix = prefix;
 141        opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 142        opt->pattern_tail = &opt->pattern_list;
 143        opt->header_tail = &opt->header_list;
 144
 145        opt->color = def->color;
 146        opt->extended_regexp_option = def->extended_regexp_option;
 147        opt->pattern_type_option = def->pattern_type_option;
 148        opt->linenum = def->linenum;
 149        opt->max_depth = def->max_depth;
 150        opt->pathname = def->pathname;
 151        opt->regflags = def->regflags;
 152        opt->relative = def->relative;
 153
 154        strcpy(opt->color_context, def->color_context);
 155        strcpy(opt->color_filename, def->color_filename);
 156        strcpy(opt->color_function, def->color_function);
 157        strcpy(opt->color_lineno, def->color_lineno);
 158        strcpy(opt->color_match_context, def->color_match_context);
 159        strcpy(opt->color_match_selected, def->color_match_selected);
 160        strcpy(opt->color_selected, def->color_selected);
 161        strcpy(opt->color_sep, def->color_sep);
 162}
 163
 164void grep_commit_pattern_type(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 165{
 166        if (pattern_type != GREP_PATTERN_TYPE_UNSPECIFIED)
 167                grep_set_pattern_type_option(pattern_type, opt);
 168        else if (opt->pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
 169                grep_set_pattern_type_option(opt->pattern_type_option, opt);
 170        else if (opt->extended_regexp_option)
 171                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, opt);
 172}
 173
 174void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
 175{
 176        switch (pattern_type) {
 177        case GREP_PATTERN_TYPE_UNSPECIFIED:
 178                /* fall through */
 179
 180        case GREP_PATTERN_TYPE_BRE:
 181                opt->fixed = 0;
 182                opt->pcre = 0;
 183                opt->regflags &= ~REG_EXTENDED;
 184                break;
 185
 186        case GREP_PATTERN_TYPE_ERE:
 187                opt->fixed = 0;
 188                opt->pcre = 0;
 189                opt->regflags |= REG_EXTENDED;
 190                break;
 191
 192        case GREP_PATTERN_TYPE_FIXED:
 193                opt->fixed = 1;
 194                opt->pcre = 0;
 195                opt->regflags &= ~REG_EXTENDED;
 196                break;
 197
 198        case GREP_PATTERN_TYPE_PCRE:
 199                opt->fixed = 0;
 200                opt->pcre = 1;
 201                opt->regflags &= ~REG_EXTENDED;
 202                break;
 203        }
 204}
 205
 206static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 207                                        const char *origin, int no,
 208                                        enum grep_pat_token t,
 209                                        enum grep_header_field field)
 210{
 211        struct grep_pat *p = xcalloc(1, sizeof(*p));
 212        p->pattern = xmemdupz(pat, patlen);
 213        p->patternlen = patlen;
 214        p->origin = origin;
 215        p->no = no;
 216        p->token = t;
 217        p->field = field;
 218        return p;
 219}
 220
 221static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 222{
 223        **tail = p;
 224        *tail = &p->next;
 225        p->next = NULL;
 226
 227        switch (p->token) {
 228        case GREP_PATTERN: /* atom */
 229        case GREP_PATTERN_HEAD:
 230        case GREP_PATTERN_BODY:
 231                for (;;) {
 232                        struct grep_pat *new_pat;
 233                        size_t len = 0;
 234                        char *cp = p->pattern + p->patternlen, *nl = NULL;
 235                        while (++len <= p->patternlen) {
 236                                if (*(--cp) == '\n') {
 237                                        nl = cp;
 238                                        break;
 239                                }
 240                        }
 241                        if (!nl)
 242                                break;
 243                        new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 244                                                  p->no, p->token, p->field);
 245                        new_pat->next = p->next;
 246                        if (!p->next)
 247                                *tail = &new_pat->next;
 248                        p->next = new_pat;
 249                        *nl = '\0';
 250                        p->patternlen -= len;
 251                }
 252                break;
 253        default:
 254                break;
 255        }
 256}
 257
 258void append_header_grep_pattern(struct grep_opt *opt,
 259                                enum grep_header_field field, const char *pat)
 260{
 261        struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 262                                             GREP_PATTERN_HEAD, field);
 263        if (field == GREP_HEADER_REFLOG)
 264                opt->use_reflog_filter = 1;
 265        do_append_grep_pat(&opt->header_tail, p);
 266}
 267
 268void append_grep_pattern(struct grep_opt *opt, const char *pat,
 269                         const char *origin, int no, enum grep_pat_token t)
 270{
 271        append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 272}
 273
 274void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 275                     const char *origin, int no, enum grep_pat_token t)
 276{
 277        struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 278        do_append_grep_pat(&opt->pattern_tail, p);
 279}
 280
 281struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 282{
 283        struct grep_pat *pat;
 284        struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 285        *ret = *opt;
 286
 287        ret->pattern_list = NULL;
 288        ret->pattern_tail = &ret->pattern_list;
 289
 290        for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 291        {
 292                if(pat->token == GREP_PATTERN_HEAD)
 293                        append_header_grep_pattern(ret, pat->field,
 294                                                   pat->pattern);
 295                else
 296                        append_grep_pat(ret, pat->pattern, pat->patternlen,
 297                                        pat->origin, pat->no, pat->token);
 298        }
 299
 300        return ret;
 301}
 302
 303static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 304                const char *error)
 305{
 306        char where[1024];
 307
 308        if (p->no)
 309                sprintf(where, "In '%s' at %d, ", p->origin, p->no);
 310        else if (p->origin)
 311                sprintf(where, "%s, ", p->origin);
 312        else
 313                where[0] = 0;
 314
 315        die("%s'%s': %s", where, p->pattern, error);
 316}
 317
 318#ifdef USE_LIBPCRE
 319static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 320{
 321        const char *error;
 322        int erroffset;
 323        int options = PCRE_MULTILINE;
 324
 325        if (opt->ignore_case)
 326                options |= PCRE_CASELESS;
 327
 328        p->pcre_regexp = pcre_compile(p->pattern, options, &error, &erroffset,
 329                        NULL);
 330        if (!p->pcre_regexp)
 331                compile_regexp_failed(p, error);
 332
 333        p->pcre_extra_info = pcre_study(p->pcre_regexp, 0, &error);
 334        if (!p->pcre_extra_info && error)
 335                die("%s", error);
 336}
 337
 338static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 339                regmatch_t *match, int eflags)
 340{
 341        int ovector[30], ret, flags = 0;
 342
 343        if (eflags & REG_NOTBOL)
 344                flags |= PCRE_NOTBOL;
 345
 346        ret = pcre_exec(p->pcre_regexp, p->pcre_extra_info, line, eol - line,
 347                        0, flags, ovector, ARRAY_SIZE(ovector));
 348        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 349                die("pcre_exec failed with error code %d", ret);
 350        if (ret > 0) {
 351                ret = 0;
 352                match->rm_so = ovector[0];
 353                match->rm_eo = ovector[1];
 354        }
 355
 356        return ret;
 357}
 358
 359static void free_pcre_regexp(struct grep_pat *p)
 360{
 361        pcre_free(p->pcre_regexp);
 362        pcre_free(p->pcre_extra_info);
 363}
 364#else /* !USE_LIBPCRE */
 365static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 366{
 367        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 368}
 369
 370static int pcrematch(struct grep_pat *p, const char *line, const char *eol,
 371                regmatch_t *match, int eflags)
 372{
 373        return 1;
 374}
 375
 376static void free_pcre_regexp(struct grep_pat *p)
 377{
 378}
 379#endif /* !USE_LIBPCRE */
 380
 381static int is_fixed(const char *s, size_t len)
 382{
 383        size_t i;
 384
 385        /* regcomp cannot accept patterns with NULs so we
 386         * consider any pattern containing a NUL fixed.
 387         */
 388        if (memchr(s, 0, len))
 389                return 1;
 390
 391        for (i = 0; i < len; i++) {
 392                if (is_regex_special(s[i]))
 393                        return 0;
 394        }
 395
 396        return 1;
 397}
 398
 399static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 400{
 401        int err;
 402
 403        p->word_regexp = opt->word_regexp;
 404        p->ignore_case = opt->ignore_case;
 405
 406        if (opt->fixed || is_fixed(p->pattern, p->patternlen))
 407                p->fixed = 1;
 408        else
 409                p->fixed = 0;
 410
 411        if (p->fixed) {
 412                if (opt->regflags & REG_ICASE || p->ignore_case)
 413                        p->kws = kwsalloc(tolower_trans_tbl);
 414                else
 415                        p->kws = kwsalloc(NULL);
 416                kwsincr(p->kws, p->pattern, p->patternlen);
 417                kwsprep(p->kws);
 418                return;
 419        }
 420
 421        if (opt->pcre) {
 422                compile_pcre_regexp(p, opt);
 423                return;
 424        }
 425
 426        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 427        if (err) {
 428                char errbuf[1024];
 429                regerror(err, &p->regexp, errbuf, 1024);
 430                regfree(&p->regexp);
 431                compile_regexp_failed(p, errbuf);
 432        }
 433}
 434
 435static struct grep_expr *compile_pattern_or(struct grep_pat **);
 436static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 437{
 438        struct grep_pat *p;
 439        struct grep_expr *x;
 440
 441        p = *list;
 442        if (!p)
 443                return NULL;
 444        switch (p->token) {
 445        case GREP_PATTERN: /* atom */
 446        case GREP_PATTERN_HEAD:
 447        case GREP_PATTERN_BODY:
 448                x = xcalloc(1, sizeof (struct grep_expr));
 449                x->node = GREP_NODE_ATOM;
 450                x->u.atom = p;
 451                *list = p->next;
 452                return x;
 453        case GREP_OPEN_PAREN:
 454                *list = p->next;
 455                x = compile_pattern_or(list);
 456                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 457                        die("unmatched parenthesis");
 458                *list = (*list)->next;
 459                return x;
 460        default:
 461                return NULL;
 462        }
 463}
 464
 465static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 466{
 467        struct grep_pat *p;
 468        struct grep_expr *x;
 469
 470        p = *list;
 471        if (!p)
 472                return NULL;
 473        switch (p->token) {
 474        case GREP_NOT:
 475                if (!p->next)
 476                        die("--not not followed by pattern expression");
 477                *list = p->next;
 478                x = xcalloc(1, sizeof (struct grep_expr));
 479                x->node = GREP_NODE_NOT;
 480                x->u.unary = compile_pattern_not(list);
 481                if (!x->u.unary)
 482                        die("--not followed by non pattern expression");
 483                return x;
 484        default:
 485                return compile_pattern_atom(list);
 486        }
 487}
 488
 489static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 490{
 491        struct grep_pat *p;
 492        struct grep_expr *x, *y, *z;
 493
 494        x = compile_pattern_not(list);
 495        p = *list;
 496        if (p && p->token == GREP_AND) {
 497                if (!p->next)
 498                        die("--and not followed by pattern expression");
 499                *list = p->next;
 500                y = compile_pattern_and(list);
 501                if (!y)
 502                        die("--and not followed by pattern expression");
 503                z = xcalloc(1, sizeof (struct grep_expr));
 504                z->node = GREP_NODE_AND;
 505                z->u.binary.left = x;
 506                z->u.binary.right = y;
 507                return z;
 508        }
 509        return x;
 510}
 511
 512static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 513{
 514        struct grep_pat *p;
 515        struct grep_expr *x, *y, *z;
 516
 517        x = compile_pattern_and(list);
 518        p = *list;
 519        if (x && p && p->token != GREP_CLOSE_PAREN) {
 520                y = compile_pattern_or(list);
 521                if (!y)
 522                        die("not a pattern expression %s", p->pattern);
 523                z = xcalloc(1, sizeof (struct grep_expr));
 524                z->node = GREP_NODE_OR;
 525                z->u.binary.left = x;
 526                z->u.binary.right = y;
 527                return z;
 528        }
 529        return x;
 530}
 531
 532static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 533{
 534        return compile_pattern_or(list);
 535}
 536
 537static void indent(int in)
 538{
 539        while (in-- > 0)
 540                fputc(' ', stderr);
 541}
 542
 543static void dump_grep_pat(struct grep_pat *p)
 544{
 545        switch (p->token) {
 546        case GREP_AND: fprintf(stderr, "*and*"); break;
 547        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 548        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 549        case GREP_NOT: fprintf(stderr, "*not*"); break;
 550        case GREP_OR: fprintf(stderr, "*or*"); break;
 551
 552        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 553        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 554        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 555        }
 556
 557        switch (p->token) {
 558        default: break;
 559        case GREP_PATTERN_HEAD:
 560                fprintf(stderr, "<head %d>", p->field); break;
 561        case GREP_PATTERN_BODY:
 562                fprintf(stderr, "<body>"); break;
 563        }
 564        switch (p->token) {
 565        default: break;
 566        case GREP_PATTERN_HEAD:
 567        case GREP_PATTERN_BODY:
 568        case GREP_PATTERN:
 569                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 570                break;
 571        }
 572        fputc('\n', stderr);
 573}
 574
 575static void dump_grep_expression_1(struct grep_expr *x, int in)
 576{
 577        indent(in);
 578        switch (x->node) {
 579        case GREP_NODE_TRUE:
 580                fprintf(stderr, "true\n");
 581                break;
 582        case GREP_NODE_ATOM:
 583                dump_grep_pat(x->u.atom);
 584                break;
 585        case GREP_NODE_NOT:
 586                fprintf(stderr, "(not\n");
 587                dump_grep_expression_1(x->u.unary, in+1);
 588                indent(in);
 589                fprintf(stderr, ")\n");
 590                break;
 591        case GREP_NODE_AND:
 592                fprintf(stderr, "(and\n");
 593                dump_grep_expression_1(x->u.binary.left, in+1);
 594                dump_grep_expression_1(x->u.binary.right, in+1);
 595                indent(in);
 596                fprintf(stderr, ")\n");
 597                break;
 598        case GREP_NODE_OR:
 599                fprintf(stderr, "(or\n");
 600                dump_grep_expression_1(x->u.binary.left, in+1);
 601                dump_grep_expression_1(x->u.binary.right, in+1);
 602                indent(in);
 603                fprintf(stderr, ")\n");
 604                break;
 605        }
 606}
 607
 608static void dump_grep_expression(struct grep_opt *opt)
 609{
 610        struct grep_expr *x = opt->pattern_expression;
 611
 612        if (opt->all_match)
 613                fprintf(stderr, "[all-match]\n");
 614        dump_grep_expression_1(x, 0);
 615        fflush(NULL);
 616}
 617
 618static struct grep_expr *grep_true_expr(void)
 619{
 620        struct grep_expr *z = xcalloc(1, sizeof(*z));
 621        z->node = GREP_NODE_TRUE;
 622        return z;
 623}
 624
 625static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 626{
 627        struct grep_expr *z = xcalloc(1, sizeof(*z));
 628        z->node = GREP_NODE_OR;
 629        z->u.binary.left = left;
 630        z->u.binary.right = right;
 631        return z;
 632}
 633
 634static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 635{
 636        struct grep_pat *p;
 637        struct grep_expr *header_expr;
 638        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 639        enum grep_header_field fld;
 640
 641        if (!opt->header_list)
 642                return NULL;
 643
 644        for (p = opt->header_list; p; p = p->next) {
 645                if (p->token != GREP_PATTERN_HEAD)
 646                        die("bug: a non-header pattern in grep header list.");
 647                if (p->field < GREP_HEADER_FIELD_MIN ||
 648                    GREP_HEADER_FIELD_MAX <= p->field)
 649                        die("bug: unknown header field %d", p->field);
 650                compile_regexp(p, opt);
 651        }
 652
 653        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 654                header_group[fld] = NULL;
 655
 656        for (p = opt->header_list; p; p = p->next) {
 657                struct grep_expr *h;
 658                struct grep_pat *pp = p;
 659
 660                h = compile_pattern_atom(&pp);
 661                if (!h || pp != p->next)
 662                        die("bug: malformed header expr");
 663                if (!header_group[p->field]) {
 664                        header_group[p->field] = h;
 665                        continue;
 666                }
 667                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 668        }
 669
 670        header_expr = NULL;
 671
 672        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 673                if (!header_group[fld])
 674                        continue;
 675                if (!header_expr)
 676                        header_expr = grep_true_expr();
 677                header_expr = grep_or_expr(header_group[fld], header_expr);
 678        }
 679        return header_expr;
 680}
 681
 682static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 683{
 684        struct grep_expr *z = x;
 685
 686        while (x) {
 687                assert(x->node == GREP_NODE_OR);
 688                if (x->u.binary.right &&
 689                    x->u.binary.right->node == GREP_NODE_TRUE) {
 690                        x->u.binary.right = y;
 691                        break;
 692                }
 693                x = x->u.binary.right;
 694        }
 695        return z;
 696}
 697
 698static void compile_grep_patterns_real(struct grep_opt *opt)
 699{
 700        struct grep_pat *p;
 701        struct grep_expr *header_expr = prep_header_patterns(opt);
 702
 703        for (p = opt->pattern_list; p; p = p->next) {
 704                switch (p->token) {
 705                case GREP_PATTERN: /* atom */
 706                case GREP_PATTERN_HEAD:
 707                case GREP_PATTERN_BODY:
 708                        compile_regexp(p, opt);
 709                        break;
 710                default:
 711                        opt->extended = 1;
 712                        break;
 713                }
 714        }
 715
 716        if (opt->all_match || header_expr)
 717                opt->extended = 1;
 718        else if (!opt->extended && !opt->debug)
 719                return;
 720
 721        p = opt->pattern_list;
 722        if (p)
 723                opt->pattern_expression = compile_pattern_expr(&p);
 724        if (p)
 725                die("incomplete pattern expression: %s", p->pattern);
 726
 727        if (!header_expr)
 728                return;
 729
 730        if (!opt->pattern_expression)
 731                opt->pattern_expression = header_expr;
 732        else if (opt->all_match)
 733                opt->pattern_expression = grep_splice_or(header_expr,
 734                                                         opt->pattern_expression);
 735        else
 736                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 737                                                       header_expr);
 738        opt->all_match = 1;
 739}
 740
 741void compile_grep_patterns(struct grep_opt *opt)
 742{
 743        compile_grep_patterns_real(opt);
 744        if (opt->debug)
 745                dump_grep_expression(opt);
 746}
 747
 748static void free_pattern_expr(struct grep_expr *x)
 749{
 750        switch (x->node) {
 751        case GREP_NODE_TRUE:
 752        case GREP_NODE_ATOM:
 753                break;
 754        case GREP_NODE_NOT:
 755                free_pattern_expr(x->u.unary);
 756                break;
 757        case GREP_NODE_AND:
 758        case GREP_NODE_OR:
 759                free_pattern_expr(x->u.binary.left);
 760                free_pattern_expr(x->u.binary.right);
 761                break;
 762        }
 763        free(x);
 764}
 765
 766void free_grep_patterns(struct grep_opt *opt)
 767{
 768        struct grep_pat *p, *n;
 769
 770        for (p = opt->pattern_list; p; p = n) {
 771                n = p->next;
 772                switch (p->token) {
 773                case GREP_PATTERN: /* atom */
 774                case GREP_PATTERN_HEAD:
 775                case GREP_PATTERN_BODY:
 776                        if (p->kws)
 777                                kwsfree(p->kws);
 778                        else if (p->pcre_regexp)
 779                                free_pcre_regexp(p);
 780                        else
 781                                regfree(&p->regexp);
 782                        free(p->pattern);
 783                        break;
 784                default:
 785                        break;
 786                }
 787                free(p);
 788        }
 789
 790        if (!opt->extended)
 791                return;
 792        free_pattern_expr(opt->pattern_expression);
 793}
 794
 795static char *end_of_line(char *cp, unsigned long *left)
 796{
 797        unsigned long l = *left;
 798        while (l && *cp != '\n') {
 799                l--;
 800                cp++;
 801        }
 802        *left = l;
 803        return cp;
 804}
 805
 806static int word_char(char ch)
 807{
 808        return isalnum(ch) || ch == '_';
 809}
 810
 811static void output_color(struct grep_opt *opt, const void *data, size_t size,
 812                         const char *color)
 813{
 814        if (want_color(opt->color) && color && color[0]) {
 815                opt->output(opt, color, strlen(color));
 816                opt->output(opt, data, size);
 817                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 818        } else
 819                opt->output(opt, data, size);
 820}
 821
 822static void output_sep(struct grep_opt *opt, char sign)
 823{
 824        if (opt->null_following_name)
 825                opt->output(opt, "\0", 1);
 826        else
 827                output_color(opt, &sign, 1, opt->color_sep);
 828}
 829
 830static void show_name(struct grep_opt *opt, const char *name)
 831{
 832        output_color(opt, name, strlen(name), opt->color_filename);
 833        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 834}
 835
 836static int fixmatch(struct grep_pat *p, char *line, char *eol,
 837                    regmatch_t *match)
 838{
 839        struct kwsmatch kwsm;
 840        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 841        if (offset == -1) {
 842                match->rm_so = match->rm_eo = -1;
 843                return REG_NOMATCH;
 844        } else {
 845                match->rm_so = offset;
 846                match->rm_eo = match->rm_so + kwsm.size[0];
 847                return 0;
 848        }
 849}
 850
 851static int regmatch(const regex_t *preg, char *line, char *eol,
 852                    regmatch_t *match, int eflags)
 853{
 854#ifdef REG_STARTEND
 855        match->rm_so = 0;
 856        match->rm_eo = eol - line;
 857        eflags |= REG_STARTEND;
 858#endif
 859        return regexec(preg, line, 1, match, eflags);
 860}
 861
 862static int patmatch(struct grep_pat *p, char *line, char *eol,
 863                    regmatch_t *match, int eflags)
 864{
 865        int hit;
 866
 867        if (p->fixed)
 868                hit = !fixmatch(p, line, eol, match);
 869        else if (p->pcre_regexp)
 870                hit = !pcrematch(p, line, eol, match, eflags);
 871        else
 872                hit = !regmatch(&p->regexp, line, eol, match, eflags);
 873
 874        return hit;
 875}
 876
 877static int strip_timestamp(char *bol, char **eol_p)
 878{
 879        char *eol = *eol_p;
 880        int ch;
 881
 882        while (bol < --eol) {
 883                if (*eol != '>')
 884                        continue;
 885                *eol_p = ++eol;
 886                ch = *eol;
 887                *eol = '\0';
 888                return ch;
 889        }
 890        return 0;
 891}
 892
 893static struct {
 894        const char *field;
 895        size_t len;
 896} header_field[] = {
 897        { "author ", 7 },
 898        { "committer ", 10 },
 899        { "reflog ", 7 },
 900};
 901
 902static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 903                             enum grep_context ctx,
 904                             regmatch_t *pmatch, int eflags)
 905{
 906        int hit = 0;
 907        int saved_ch = 0;
 908        const char *start = bol;
 909
 910        if ((p->token != GREP_PATTERN) &&
 911            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 912                return 0;
 913
 914        if (p->token == GREP_PATTERN_HEAD) {
 915                const char *field;
 916                size_t len;
 917                assert(p->field < ARRAY_SIZE(header_field));
 918                field = header_field[p->field].field;
 919                len = header_field[p->field].len;
 920                if (strncmp(bol, field, len))
 921                        return 0;
 922                bol += len;
 923                switch (p->field) {
 924                case GREP_HEADER_AUTHOR:
 925                case GREP_HEADER_COMMITTER:
 926                        saved_ch = strip_timestamp(bol, &eol);
 927                        break;
 928                default:
 929                        break;
 930                }
 931        }
 932
 933 again:
 934        hit = patmatch(p, bol, eol, pmatch, eflags);
 935
 936        if (hit && p->word_regexp) {
 937                if ((pmatch[0].rm_so < 0) ||
 938                    (eol - bol) < pmatch[0].rm_so ||
 939                    (pmatch[0].rm_eo < 0) ||
 940                    (eol - bol) < pmatch[0].rm_eo)
 941                        die("regexp returned nonsense");
 942
 943                /* Match beginning must be either beginning of the
 944                 * line, or at word boundary (i.e. the last char must
 945                 * not be a word char).  Similarly, match end must be
 946                 * either end of the line, or at word boundary
 947                 * (i.e. the next char must not be a word char).
 948                 */
 949                if ( ((pmatch[0].rm_so == 0) ||
 950                      !word_char(bol[pmatch[0].rm_so-1])) &&
 951                     ((pmatch[0].rm_eo == (eol-bol)) ||
 952                      !word_char(bol[pmatch[0].rm_eo])) )
 953                        ;
 954                else
 955                        hit = 0;
 956
 957                /* Words consist of at least one character. */
 958                if (pmatch->rm_so == pmatch->rm_eo)
 959                        hit = 0;
 960
 961                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 962                        /* There could be more than one match on the
 963                         * line, and the first match might not be
 964                         * strict word match.  But later ones could be!
 965                         * Forward to the next possible start, i.e. the
 966                         * next position following a non-word char.
 967                         */
 968                        bol = pmatch[0].rm_so + bol + 1;
 969                        while (word_char(bol[-1]) && bol < eol)
 970                                bol++;
 971                        eflags |= REG_NOTBOL;
 972                        if (bol < eol)
 973                                goto again;
 974                }
 975        }
 976        if (p->token == GREP_PATTERN_HEAD && saved_ch)
 977                *eol = saved_ch;
 978        if (hit) {
 979                pmatch[0].rm_so += bol - start;
 980                pmatch[0].rm_eo += bol - start;
 981        }
 982        return hit;
 983}
 984
 985static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
 986                           enum grep_context ctx, int collect_hits)
 987{
 988        int h = 0;
 989        regmatch_t match;
 990
 991        if (!x)
 992                die("Not a valid grep expression");
 993        switch (x->node) {
 994        case GREP_NODE_TRUE:
 995                h = 1;
 996                break;
 997        case GREP_NODE_ATOM:
 998                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
 999                break;
1000        case GREP_NODE_NOT:
1001                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1002                break;
1003        case GREP_NODE_AND:
1004                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1005                        return 0;
1006                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1007                break;
1008        case GREP_NODE_OR:
1009                if (!collect_hits)
1010                        return (match_expr_eval(x->u.binary.left,
1011                                                bol, eol, ctx, 0) ||
1012                                match_expr_eval(x->u.binary.right,
1013                                                bol, eol, ctx, 0));
1014                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1015                x->u.binary.left->hit |= h;
1016                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1017                break;
1018        default:
1019                die("Unexpected node type (internal error) %d", x->node);
1020        }
1021        if (collect_hits)
1022                x->hit |= h;
1023        return h;
1024}
1025
1026static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1027                      enum grep_context ctx, int collect_hits)
1028{
1029        struct grep_expr *x = opt->pattern_expression;
1030        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1031}
1032
1033static int match_line(struct grep_opt *opt, char *bol, char *eol,
1034                      enum grep_context ctx, int collect_hits)
1035{
1036        struct grep_pat *p;
1037        regmatch_t match;
1038
1039        if (opt->extended)
1040                return match_expr(opt, bol, eol, ctx, collect_hits);
1041
1042        /* we do not call with collect_hits without being extended */
1043        for (p = opt->pattern_list; p; p = p->next) {
1044                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1045                        return 1;
1046        }
1047        return 0;
1048}
1049
1050static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1051                              enum grep_context ctx,
1052                              regmatch_t *pmatch, int eflags)
1053{
1054        regmatch_t match;
1055
1056        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1057                return 0;
1058        if (match.rm_so < 0 || match.rm_eo < 0)
1059                return 0;
1060        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1061                if (match.rm_so > pmatch->rm_so)
1062                        return 1;
1063                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1064                        return 1;
1065        }
1066        pmatch->rm_so = match.rm_so;
1067        pmatch->rm_eo = match.rm_eo;
1068        return 1;
1069}
1070
1071static int next_match(struct grep_opt *opt, char *bol, char *eol,
1072                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1073{
1074        struct grep_pat *p;
1075        int hit = 0;
1076
1077        pmatch->rm_so = pmatch->rm_eo = -1;
1078        if (bol < eol) {
1079                for (p = opt->pattern_list; p; p = p->next) {
1080                        switch (p->token) {
1081                        case GREP_PATTERN: /* atom */
1082                        case GREP_PATTERN_HEAD:
1083                        case GREP_PATTERN_BODY:
1084                                hit |= match_next_pattern(p, bol, eol, ctx,
1085                                                          pmatch, eflags);
1086                                break;
1087                        default:
1088                                break;
1089                        }
1090                }
1091        }
1092        return hit;
1093}
1094
1095static void show_line(struct grep_opt *opt, char *bol, char *eol,
1096                      const char *name, unsigned lno, char sign)
1097{
1098        int rest = eol - bol;
1099        const char *match_color, *line_color = NULL;
1100
1101        if (opt->file_break && opt->last_shown == 0) {
1102                if (opt->show_hunk_mark)
1103                        opt->output(opt, "\n", 1);
1104        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1105                if (opt->last_shown == 0) {
1106                        if (opt->show_hunk_mark) {
1107                                output_color(opt, "--", 2, opt->color_sep);
1108                                opt->output(opt, "\n", 1);
1109                        }
1110                } else if (lno > opt->last_shown + 1) {
1111                        output_color(opt, "--", 2, opt->color_sep);
1112                        opt->output(opt, "\n", 1);
1113                }
1114        }
1115        if (opt->heading && opt->last_shown == 0) {
1116                output_color(opt, name, strlen(name), opt->color_filename);
1117                opt->output(opt, "\n", 1);
1118        }
1119        opt->last_shown = lno;
1120
1121        if (!opt->heading && opt->pathname) {
1122                output_color(opt, name, strlen(name), opt->color_filename);
1123                output_sep(opt, sign);
1124        }
1125        if (opt->linenum) {
1126                char buf[32];
1127                snprintf(buf, sizeof(buf), "%d", lno);
1128                output_color(opt, buf, strlen(buf), opt->color_lineno);
1129                output_sep(opt, sign);
1130        }
1131        if (opt->color) {
1132                regmatch_t match;
1133                enum grep_context ctx = GREP_CONTEXT_BODY;
1134                int ch = *eol;
1135                int eflags = 0;
1136
1137                if (sign == ':')
1138                        match_color = opt->color_match_selected;
1139                else
1140                        match_color = opt->color_match_context;
1141                if (sign == ':')
1142                        line_color = opt->color_selected;
1143                else if (sign == '-')
1144                        line_color = opt->color_context;
1145                else if (sign == '=')
1146                        line_color = opt->color_function;
1147                *eol = '\0';
1148                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1149                        if (match.rm_so == match.rm_eo)
1150                                break;
1151
1152                        output_color(opt, bol, match.rm_so, line_color);
1153                        output_color(opt, bol + match.rm_so,
1154                                     match.rm_eo - match.rm_so, match_color);
1155                        bol += match.rm_eo;
1156                        rest -= match.rm_eo;
1157                        eflags = REG_NOTBOL;
1158                }
1159                *eol = ch;
1160        }
1161        output_color(opt, bol, rest, line_color);
1162        opt->output(opt, "\n", 1);
1163}
1164
1165#ifndef NO_PTHREADS
1166int grep_use_locks;
1167
1168/*
1169 * This lock protects access to the gitattributes machinery, which is
1170 * not thread-safe.
1171 */
1172pthread_mutex_t grep_attr_mutex;
1173
1174static inline void grep_attr_lock(void)
1175{
1176        if (grep_use_locks)
1177                pthread_mutex_lock(&grep_attr_mutex);
1178}
1179
1180static inline void grep_attr_unlock(void)
1181{
1182        if (grep_use_locks)
1183                pthread_mutex_unlock(&grep_attr_mutex);
1184}
1185
1186/*
1187 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1188 */
1189pthread_mutex_t grep_read_mutex;
1190
1191#else
1192#define grep_attr_lock()
1193#define grep_attr_unlock()
1194#endif
1195
1196static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1197{
1198        xdemitconf_t *xecfg = opt->priv;
1199        if (xecfg && !xecfg->find_func) {
1200                grep_source_load_driver(gs);
1201                if (gs->driver->funcname.pattern) {
1202                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1203                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1204                } else {
1205                        xecfg = opt->priv = NULL;
1206                }
1207        }
1208
1209        if (xecfg) {
1210                char buf[1];
1211                return xecfg->find_func(bol, eol - bol, buf, 1,
1212                                        xecfg->find_func_priv) >= 0;
1213        }
1214
1215        if (bol == eol)
1216                return 0;
1217        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1218                return 1;
1219        return 0;
1220}
1221
1222static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1223                               char *bol, unsigned lno)
1224{
1225        while (bol > gs->buf) {
1226                char *eol = --bol;
1227
1228                while (bol > gs->buf && bol[-1] != '\n')
1229                        bol--;
1230                lno--;
1231
1232                if (lno <= opt->last_shown)
1233                        break;
1234
1235                if (match_funcname(opt, gs, bol, eol)) {
1236                        show_line(opt, bol, eol, gs->name, lno, '=');
1237                        break;
1238                }
1239        }
1240}
1241
1242static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1243                             char *bol, char *end, unsigned lno)
1244{
1245        unsigned cur = lno, from = 1, funcname_lno = 0;
1246        int funcname_needed = !!opt->funcname;
1247
1248        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1249                funcname_needed = 2;
1250
1251        if (opt->pre_context < lno)
1252                from = lno - opt->pre_context;
1253        if (from <= opt->last_shown)
1254                from = opt->last_shown + 1;
1255
1256        /* Rewind. */
1257        while (bol > gs->buf &&
1258               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1259                char *eol = --bol;
1260
1261                while (bol > gs->buf && bol[-1] != '\n')
1262                        bol--;
1263                cur--;
1264                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1265                        funcname_lno = cur;
1266                        funcname_needed = 0;
1267                }
1268        }
1269
1270        /* We need to look even further back to find a function signature. */
1271        if (opt->funcname && funcname_needed)
1272                show_funcname_line(opt, gs, bol, cur);
1273
1274        /* Back forward. */
1275        while (cur < lno) {
1276                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1277
1278                while (*eol != '\n')
1279                        eol++;
1280                show_line(opt, bol, eol, gs->name, cur, sign);
1281                bol = eol + 1;
1282                cur++;
1283        }
1284}
1285
1286static int should_lookahead(struct grep_opt *opt)
1287{
1288        struct grep_pat *p;
1289
1290        if (opt->extended)
1291                return 0; /* punt for too complex stuff */
1292        if (opt->invert)
1293                return 0;
1294        for (p = opt->pattern_list; p; p = p->next) {
1295                if (p->token != GREP_PATTERN)
1296                        return 0; /* punt for "header only" and stuff */
1297        }
1298        return 1;
1299}
1300
1301static int look_ahead(struct grep_opt *opt,
1302                      unsigned long *left_p,
1303                      unsigned *lno_p,
1304                      char **bol_p)
1305{
1306        unsigned lno = *lno_p;
1307        char *bol = *bol_p;
1308        struct grep_pat *p;
1309        char *sp, *last_bol;
1310        regoff_t earliest = -1;
1311
1312        for (p = opt->pattern_list; p; p = p->next) {
1313                int hit;
1314                regmatch_t m;
1315
1316                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1317                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1318                        continue;
1319                if (earliest < 0 || m.rm_so < earliest)
1320                        earliest = m.rm_so;
1321        }
1322
1323        if (earliest < 0) {
1324                *bol_p = bol + *left_p;
1325                *left_p = 0;
1326                return 1;
1327        }
1328        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1329                ; /* find the beginning of the line */
1330        last_bol = sp;
1331
1332        for (sp = bol; sp < last_bol; sp++) {
1333                if (*sp == '\n')
1334                        lno++;
1335        }
1336        *left_p -= last_bol - bol;
1337        *bol_p = last_bol;
1338        *lno_p = lno;
1339        return 0;
1340}
1341
1342static void std_output(struct grep_opt *opt, const void *buf, size_t size)
1343{
1344        fwrite(buf, size, 1, stdout);
1345}
1346
1347static int fill_textconv_grep(struct userdiff_driver *driver,
1348                              struct grep_source *gs)
1349{
1350        struct diff_filespec *df;
1351        char *buf;
1352        size_t size;
1353
1354        if (!driver || !driver->textconv)
1355                return grep_source_load(gs);
1356
1357        /*
1358         * The textconv interface is intimately tied to diff_filespecs, so we
1359         * have to pretend to be one. If we could unify the grep_source
1360         * and diff_filespec structs, this mess could just go away.
1361         */
1362        df = alloc_filespec(gs->path);
1363        switch (gs->type) {
1364        case GREP_SOURCE_SHA1:
1365                fill_filespec(df, gs->identifier, 1, 0100644);
1366                break;
1367        case GREP_SOURCE_FILE:
1368                fill_filespec(df, null_sha1, 0, 0100644);
1369                break;
1370        default:
1371                die("BUG: attempt to textconv something without a path?");
1372        }
1373
1374        /*
1375         * fill_textconv is not remotely thread-safe; it may load objects
1376         * behind the scenes, and it modifies the global diff tempfile
1377         * structure.
1378         */
1379        grep_read_lock();
1380        size = fill_textconv(driver, df, &buf);
1381        grep_read_unlock();
1382        free_filespec(df);
1383
1384        /*
1385         * The normal fill_textconv usage by the diff machinery would just keep
1386         * the textconv'd buf separate from the diff_filespec. But much of the
1387         * grep code passes around a grep_source and assumes that its "buf"
1388         * pointer is the beginning of the thing we are searching. So let's
1389         * install our textconv'd version into the grep_source, taking care not
1390         * to leak any existing buffer.
1391         */
1392        grep_source_clear_data(gs);
1393        gs->buf = buf;
1394        gs->size = size;
1395
1396        return 0;
1397}
1398
1399static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1400{
1401        char *bol;
1402        unsigned long left;
1403        unsigned lno = 1;
1404        unsigned last_hit = 0;
1405        int binary_match_only = 0;
1406        unsigned count = 0;
1407        int try_lookahead = 0;
1408        int show_function = 0;
1409        struct userdiff_driver *textconv = NULL;
1410        enum grep_context ctx = GREP_CONTEXT_HEAD;
1411        xdemitconf_t xecfg;
1412
1413        if (!opt->output)
1414                opt->output = std_output;
1415
1416        if (opt->pre_context || opt->post_context || opt->file_break ||
1417            opt->funcbody) {
1418                /* Show hunk marks, except for the first file. */
1419                if (opt->last_shown)
1420                        opt->show_hunk_mark = 1;
1421                /*
1422                 * If we're using threads then we can't easily identify
1423                 * the first file.  Always put hunk marks in that case
1424                 * and skip the very first one later in work_done().
1425                 */
1426                if (opt->output != std_output)
1427                        opt->show_hunk_mark = 1;
1428        }
1429        opt->last_shown = 0;
1430
1431        if (opt->allow_textconv) {
1432                grep_source_load_driver(gs);
1433                /*
1434                 * We might set up the shared textconv cache data here, which
1435                 * is not thread-safe.
1436                 */
1437                grep_attr_lock();
1438                textconv = userdiff_get_textconv(gs->driver);
1439                grep_attr_unlock();
1440        }
1441
1442        /*
1443         * We know the result of a textconv is text, so we only have to care
1444         * about binary handling if we are not using it.
1445         */
1446        if (!textconv) {
1447                switch (opt->binary) {
1448                case GREP_BINARY_DEFAULT:
1449                        if (grep_source_is_binary(gs))
1450                                binary_match_only = 1;
1451                        break;
1452                case GREP_BINARY_NOMATCH:
1453                        if (grep_source_is_binary(gs))
1454                                return 0; /* Assume unmatch */
1455                        break;
1456                case GREP_BINARY_TEXT:
1457                        break;
1458                default:
1459                        die("bug: unknown binary handling mode");
1460                }
1461        }
1462
1463        memset(&xecfg, 0, sizeof(xecfg));
1464        opt->priv = &xecfg;
1465
1466        try_lookahead = should_lookahead(opt);
1467
1468        if (fill_textconv_grep(textconv, gs) < 0)
1469                return 0;
1470
1471        bol = gs->buf;
1472        left = gs->size;
1473        while (left) {
1474                char *eol, ch;
1475                int hit;
1476
1477                /*
1478                 * look_ahead() skips quickly to the line that possibly
1479                 * has the next hit; don't call it if we need to do
1480                 * something more than just skipping the current line
1481                 * in response to an unmatch for the current line.  E.g.
1482                 * inside a post-context window, we will show the current
1483                 * line as a context around the previous hit when it
1484                 * doesn't hit.
1485                 */
1486                if (try_lookahead
1487                    && !(last_hit
1488                         && (show_function ||
1489                             lno <= last_hit + opt->post_context))
1490                    && look_ahead(opt, &left, &lno, &bol))
1491                        break;
1492                eol = end_of_line(bol, &left);
1493                ch = *eol;
1494                *eol = 0;
1495
1496                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1497                        ctx = GREP_CONTEXT_BODY;
1498
1499                hit = match_line(opt, bol, eol, ctx, collect_hits);
1500                *eol = ch;
1501
1502                if (collect_hits)
1503                        goto next_line;
1504
1505                /* "grep -v -e foo -e bla" should list lines
1506                 * that do not have either, so inversion should
1507                 * be done outside.
1508                 */
1509                if (opt->invert)
1510                        hit = !hit;
1511                if (opt->unmatch_name_only) {
1512                        if (hit)
1513                                return 0;
1514                        goto next_line;
1515                }
1516                if (hit) {
1517                        count++;
1518                        if (opt->status_only)
1519                                return 1;
1520                        if (opt->name_only) {
1521                                show_name(opt, gs->name);
1522                                return 1;
1523                        }
1524                        if (opt->count)
1525                                goto next_line;
1526                        if (binary_match_only) {
1527                                opt->output(opt, "Binary file ", 12);
1528                                output_color(opt, gs->name, strlen(gs->name),
1529                                             opt->color_filename);
1530                                opt->output(opt, " matches\n", 9);
1531                                return 1;
1532                        }
1533                        /* Hit at this line.  If we haven't shown the
1534                         * pre-context lines, we would need to show them.
1535                         */
1536                        if (opt->pre_context || opt->funcbody)
1537                                show_pre_context(opt, gs, bol, eol, lno);
1538                        else if (opt->funcname)
1539                                show_funcname_line(opt, gs, bol, lno);
1540                        show_line(opt, bol, eol, gs->name, lno, ':');
1541                        last_hit = lno;
1542                        if (opt->funcbody)
1543                                show_function = 1;
1544                        goto next_line;
1545                }
1546                if (show_function && match_funcname(opt, gs, bol, eol))
1547                        show_function = 0;
1548                if (show_function ||
1549                    (last_hit && lno <= last_hit + opt->post_context)) {
1550                        /* If the last hit is within the post context,
1551                         * we need to show this line.
1552                         */
1553                        show_line(opt, bol, eol, gs->name, lno, '-');
1554                }
1555
1556        next_line:
1557                bol = eol + 1;
1558                if (!left)
1559                        break;
1560                left--;
1561                lno++;
1562        }
1563
1564        if (collect_hits)
1565                return 0;
1566
1567        if (opt->status_only)
1568                return 0;
1569        if (opt->unmatch_name_only) {
1570                /* We did not see any hit, so we want to show this */
1571                show_name(opt, gs->name);
1572                return 1;
1573        }
1574
1575        xdiff_clear_find_func(&xecfg);
1576        opt->priv = NULL;
1577
1578        /* NEEDSWORK:
1579         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1580         * which feels mostly useless but sometimes useful.  Maybe
1581         * make it another option?  For now suppress them.
1582         */
1583        if (opt->count && count) {
1584                char buf[32];
1585                if (opt->pathname) {
1586                        output_color(opt, gs->name, strlen(gs->name),
1587                                     opt->color_filename);
1588                        output_sep(opt, ':');
1589                }
1590                snprintf(buf, sizeof(buf), "%u\n", count);
1591                opt->output(opt, buf, strlen(buf));
1592                return 1;
1593        }
1594        return !!last_hit;
1595}
1596
1597static void clr_hit_marker(struct grep_expr *x)
1598{
1599        /* All-hit markers are meaningful only at the very top level
1600         * OR node.
1601         */
1602        while (1) {
1603                x->hit = 0;
1604                if (x->node != GREP_NODE_OR)
1605                        return;
1606                x->u.binary.left->hit = 0;
1607                x = x->u.binary.right;
1608        }
1609}
1610
1611static int chk_hit_marker(struct grep_expr *x)
1612{
1613        /* Top level nodes have hit markers.  See if they all are hits */
1614        while (1) {
1615                if (x->node != GREP_NODE_OR)
1616                        return x->hit;
1617                if (!x->u.binary.left->hit)
1618                        return 0;
1619                x = x->u.binary.right;
1620        }
1621}
1622
1623int grep_source(struct grep_opt *opt, struct grep_source *gs)
1624{
1625        /*
1626         * we do not have to do the two-pass grep when we do not check
1627         * buffer-wide "all-match".
1628         */
1629        if (!opt->all_match)
1630                return grep_source_1(opt, gs, 0);
1631
1632        /* Otherwise the toplevel "or" terms hit a bit differently.
1633         * We first clear hit markers from them.
1634         */
1635        clr_hit_marker(opt->pattern_expression);
1636        grep_source_1(opt, gs, 1);
1637
1638        if (!chk_hit_marker(opt->pattern_expression))
1639                return 0;
1640
1641        return grep_source_1(opt, gs, 0);
1642}
1643
1644int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1645{
1646        struct grep_source gs;
1647        int r;
1648
1649        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1650        gs.buf = buf;
1651        gs.size = size;
1652
1653        r = grep_source(opt, &gs);
1654
1655        grep_source_clear(&gs);
1656        return r;
1657}
1658
1659void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1660                      const char *name, const char *path,
1661                      const void *identifier)
1662{
1663        gs->type = type;
1664        gs->name = xstrdup_or_null(name);
1665        gs->path = xstrdup_or_null(path);
1666        gs->buf = NULL;
1667        gs->size = 0;
1668        gs->driver = NULL;
1669
1670        switch (type) {
1671        case GREP_SOURCE_FILE:
1672                gs->identifier = xstrdup(identifier);
1673                break;
1674        case GREP_SOURCE_SHA1:
1675                gs->identifier = xmalloc(20);
1676                hashcpy(gs->identifier, identifier);
1677                break;
1678        case GREP_SOURCE_BUF:
1679                gs->identifier = NULL;
1680        }
1681}
1682
1683void grep_source_clear(struct grep_source *gs)
1684{
1685        free(gs->name);
1686        gs->name = NULL;
1687        free(gs->path);
1688        gs->path = NULL;
1689        free(gs->identifier);
1690        gs->identifier = NULL;
1691        grep_source_clear_data(gs);
1692}
1693
1694void grep_source_clear_data(struct grep_source *gs)
1695{
1696        switch (gs->type) {
1697        case GREP_SOURCE_FILE:
1698        case GREP_SOURCE_SHA1:
1699                free(gs->buf);
1700                gs->buf = NULL;
1701                gs->size = 0;
1702                break;
1703        case GREP_SOURCE_BUF:
1704                /* leave user-provided buf intact */
1705                break;
1706        }
1707}
1708
1709static int grep_source_load_sha1(struct grep_source *gs)
1710{
1711        enum object_type type;
1712
1713        grep_read_lock();
1714        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1715        grep_read_unlock();
1716
1717        if (!gs->buf)
1718                return error(_("'%s': unable to read %s"),
1719                             gs->name,
1720                             sha1_to_hex(gs->identifier));
1721        return 0;
1722}
1723
1724static int grep_source_load_file(struct grep_source *gs)
1725{
1726        const char *filename = gs->identifier;
1727        struct stat st;
1728        char *data;
1729        size_t size;
1730        int i;
1731
1732        if (lstat(filename, &st) < 0) {
1733        err_ret:
1734                if (errno != ENOENT)
1735                        error(_("'%s': %s"), filename, strerror(errno));
1736                return -1;
1737        }
1738        if (!S_ISREG(st.st_mode))
1739                return -1;
1740        size = xsize_t(st.st_size);
1741        i = open(filename, O_RDONLY);
1742        if (i < 0)
1743                goto err_ret;
1744        data = xmalloc(size + 1);
1745        if (st.st_size != read_in_full(i, data, size)) {
1746                error(_("'%s': short read %s"), filename, strerror(errno));
1747                close(i);
1748                free(data);
1749                return -1;
1750        }
1751        close(i);
1752        data[size] = 0;
1753
1754        gs->buf = data;
1755        gs->size = size;
1756        return 0;
1757}
1758
1759static int grep_source_load(struct grep_source *gs)
1760{
1761        if (gs->buf)
1762                return 0;
1763
1764        switch (gs->type) {
1765        case GREP_SOURCE_FILE:
1766                return grep_source_load_file(gs);
1767        case GREP_SOURCE_SHA1:
1768                return grep_source_load_sha1(gs);
1769        case GREP_SOURCE_BUF:
1770                return gs->buf ? 0 : -1;
1771        }
1772        die("BUG: invalid grep_source type");
1773}
1774
1775void grep_source_load_driver(struct grep_source *gs)
1776{
1777        if (gs->driver)
1778                return;
1779
1780        grep_attr_lock();
1781        if (gs->path)
1782                gs->driver = userdiff_find_by_path(gs->path);
1783        if (!gs->driver)
1784                gs->driver = userdiff_find_by_name("default");
1785        grep_attr_unlock();
1786}
1787
1788static int grep_source_is_binary(struct grep_source *gs)
1789{
1790        grep_source_load_driver(gs);
1791        if (gs->driver->binary != -1)
1792                return gs->driver->binary;
1793
1794        if (!grep_source_load(gs))
1795                return buffer_is_binary(gs->buf, gs->size);
1796
1797        return 0;
1798}