Andrew's git / gitweb.git / grep.c
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grep.con commit Fifth batch for 2.14 (826c064)
   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, 0, &error);
 369        if (!p->pcre1_extra_info && error)
 370                die("%s", error);
 371}
 372
 373static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 374                regmatch_t *match, int eflags)
 375{
 376        int ovector[30], ret, flags = 0;
 377
 378        if (eflags & REG_NOTBOL)
 379                flags |= PCRE_NOTBOL;
 380
 381        ret = pcre_exec(p->pcre1_regexp, p->pcre1_extra_info, line, eol - line,
 382                        0, flags, ovector, ARRAY_SIZE(ovector));
 383        if (ret < 0 && ret != PCRE_ERROR_NOMATCH)
 384                die("pcre_exec failed with error code %d", ret);
 385        if (ret > 0) {
 386                ret = 0;
 387                match->rm_so = ovector[0];
 388                match->rm_eo = ovector[1];
 389        }
 390
 391        return ret;
 392}
 393
 394static void free_pcre1_regexp(struct grep_pat *p)
 395{
 396        pcre_free(p->pcre1_regexp);
 397        pcre_free(p->pcre1_extra_info);
 398        pcre_free((void *)p->pcre1_tables);
 399}
 400#else /* !USE_LIBPCRE1 */
 401static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 402{
 403        die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 404}
 405
 406static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 407                regmatch_t *match, int eflags)
 408{
 409        return 1;
 410}
 411
 412static void free_pcre1_regexp(struct grep_pat *p)
 413{
 414}
 415#endif /* !USE_LIBPCRE1 */
 416
 417static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 418{
 419        struct strbuf sb = STRBUF_INIT;
 420        int err;
 421        int regflags = opt->regflags;
 422
 423        basic_regex_quote_buf(&sb, p->pattern);
 424        if (opt->ignore_case)
 425                regflags |= REG_ICASE;
 426        err = regcomp(&p->regexp, sb.buf, regflags);
 427        if (opt->debug)
 428                fprintf(stderr, "fixed %s\n", sb.buf);
 429        strbuf_release(&sb);
 430        if (err) {
 431                char errbuf[1024];
 432                regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 433                regfree(&p->regexp);
 434                compile_regexp_failed(p, errbuf);
 435        }
 436}
 437
 438static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 439{
 440        int icase, ascii_only;
 441        int err;
 442
 443        p->word_regexp = opt->word_regexp;
 444        p->ignore_case = opt->ignore_case;
 445        icase          = opt->regflags & REG_ICASE || p->ignore_case;
 446        ascii_only     = !has_non_ascii(p->pattern);
 447
 448        /*
 449         * Even when -F (fixed) asks us to do a non-regexp search, we
 450         * may not be able to correctly case-fold when -i
 451         * (ignore-case) is asked (in which case, we'll synthesize a
 452         * regexp to match the pattern that matches regexp special
 453         * characters literally, while ignoring case differences).  On
 454         * the other hand, even without -F, if the pattern does not
 455         * have any regexp special characters and there is no need for
 456         * case-folding search, we can internally turn it into a
 457         * simple string match using kws.  p->fixed tells us if we
 458         * want to use kws.
 459         */
 460        if (opt->fixed ||
 461            has_null(p->pattern, p->patternlen) ||
 462            is_fixed(p->pattern, p->patternlen))
 463                p->fixed = !icase || ascii_only;
 464        else
 465                p->fixed = 0;
 466
 467        if (p->fixed) {
 468                p->kws = kwsalloc(icase ? tolower_trans_tbl : NULL);
 469                kwsincr(p->kws, p->pattern, p->patternlen);
 470                kwsprep(p->kws);
 471                return;
 472        } else if (opt->fixed) {
 473                /*
 474                 * We come here when the pattern has the non-ascii
 475                 * characters we cannot case-fold, and asked to
 476                 * ignore-case.
 477                 */
 478                compile_fixed_regexp(p, opt);
 479                return;
 480        }
 481
 482        if (opt->pcre1) {
 483                compile_pcre1_regexp(p, opt);
 484                return;
 485        }
 486
 487        err = regcomp(&p->regexp, p->pattern, opt->regflags);
 488        if (err) {
 489                char errbuf[1024];
 490                regerror(err, &p->regexp, errbuf, 1024);
 491                regfree(&p->regexp);
 492                compile_regexp_failed(p, errbuf);
 493        }
 494}
 495
 496static struct grep_expr *compile_pattern_or(struct grep_pat **);
 497static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 498{
 499        struct grep_pat *p;
 500        struct grep_expr *x;
 501
 502        p = *list;
 503        if (!p)
 504                return NULL;
 505        switch (p->token) {
 506        case GREP_PATTERN: /* atom */
 507        case GREP_PATTERN_HEAD:
 508        case GREP_PATTERN_BODY:
 509                x = xcalloc(1, sizeof (struct grep_expr));
 510                x->node = GREP_NODE_ATOM;
 511                x->u.atom = p;
 512                *list = p->next;
 513                return x;
 514        case GREP_OPEN_PAREN:
 515                *list = p->next;
 516                x = compile_pattern_or(list);
 517                if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 518                        die("unmatched parenthesis");
 519                *list = (*list)->next;
 520                return x;
 521        default:
 522                return NULL;
 523        }
 524}
 525
 526static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 527{
 528        struct grep_pat *p;
 529        struct grep_expr *x;
 530
 531        p = *list;
 532        if (!p)
 533                return NULL;
 534        switch (p->token) {
 535        case GREP_NOT:
 536                if (!p->next)
 537                        die("--not not followed by pattern expression");
 538                *list = p->next;
 539                x = xcalloc(1, sizeof (struct grep_expr));
 540                x->node = GREP_NODE_NOT;
 541                x->u.unary = compile_pattern_not(list);
 542                if (!x->u.unary)
 543                        die("--not followed by non pattern expression");
 544                return x;
 545        default:
 546                return compile_pattern_atom(list);
 547        }
 548}
 549
 550static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 551{
 552        struct grep_pat *p;
 553        struct grep_expr *x, *y, *z;
 554
 555        x = compile_pattern_not(list);
 556        p = *list;
 557        if (p && p->token == GREP_AND) {
 558                if (!p->next)
 559                        die("--and not followed by pattern expression");
 560                *list = p->next;
 561                y = compile_pattern_and(list);
 562                if (!y)
 563                        die("--and not followed by pattern expression");
 564                z = xcalloc(1, sizeof (struct grep_expr));
 565                z->node = GREP_NODE_AND;
 566                z->u.binary.left = x;
 567                z->u.binary.right = y;
 568                return z;
 569        }
 570        return x;
 571}
 572
 573static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 574{
 575        struct grep_pat *p;
 576        struct grep_expr *x, *y, *z;
 577
 578        x = compile_pattern_and(list);
 579        p = *list;
 580        if (x && p && p->token != GREP_CLOSE_PAREN) {
 581                y = compile_pattern_or(list);
 582                if (!y)
 583                        die("not a pattern expression %s", p->pattern);
 584                z = xcalloc(1, sizeof (struct grep_expr));
 585                z->node = GREP_NODE_OR;
 586                z->u.binary.left = x;
 587                z->u.binary.right = y;
 588                return z;
 589        }
 590        return x;
 591}
 592
 593static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 594{
 595        return compile_pattern_or(list);
 596}
 597
 598static void indent(int in)
 599{
 600        while (in-- > 0)
 601                fputc(' ', stderr);
 602}
 603
 604static void dump_grep_pat(struct grep_pat *p)
 605{
 606        switch (p->token) {
 607        case GREP_AND: fprintf(stderr, "*and*"); break;
 608        case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
 609        case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
 610        case GREP_NOT: fprintf(stderr, "*not*"); break;
 611        case GREP_OR: fprintf(stderr, "*or*"); break;
 612
 613        case GREP_PATTERN: fprintf(stderr, "pattern"); break;
 614        case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
 615        case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
 616        }
 617
 618        switch (p->token) {
 619        default: break;
 620        case GREP_PATTERN_HEAD:
 621                fprintf(stderr, "<head %d>", p->field); break;
 622        case GREP_PATTERN_BODY:
 623                fprintf(stderr, "<body>"); break;
 624        }
 625        switch (p->token) {
 626        default: break;
 627        case GREP_PATTERN_HEAD:
 628        case GREP_PATTERN_BODY:
 629        case GREP_PATTERN:
 630                fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
 631                break;
 632        }
 633        fputc('\n', stderr);
 634}
 635
 636static void dump_grep_expression_1(struct grep_expr *x, int in)
 637{
 638        indent(in);
 639        switch (x->node) {
 640        case GREP_NODE_TRUE:
 641                fprintf(stderr, "true\n");
 642                break;
 643        case GREP_NODE_ATOM:
 644                dump_grep_pat(x->u.atom);
 645                break;
 646        case GREP_NODE_NOT:
 647                fprintf(stderr, "(not\n");
 648                dump_grep_expression_1(x->u.unary, in+1);
 649                indent(in);
 650                fprintf(stderr, ")\n");
 651                break;
 652        case GREP_NODE_AND:
 653                fprintf(stderr, "(and\n");
 654                dump_grep_expression_1(x->u.binary.left, in+1);
 655                dump_grep_expression_1(x->u.binary.right, in+1);
 656                indent(in);
 657                fprintf(stderr, ")\n");
 658                break;
 659        case GREP_NODE_OR:
 660                fprintf(stderr, "(or\n");
 661                dump_grep_expression_1(x->u.binary.left, in+1);
 662                dump_grep_expression_1(x->u.binary.right, in+1);
 663                indent(in);
 664                fprintf(stderr, ")\n");
 665                break;
 666        }
 667}
 668
 669static void dump_grep_expression(struct grep_opt *opt)
 670{
 671        struct grep_expr *x = opt->pattern_expression;
 672
 673        if (opt->all_match)
 674                fprintf(stderr, "[all-match]\n");
 675        dump_grep_expression_1(x, 0);
 676        fflush(NULL);
 677}
 678
 679static struct grep_expr *grep_true_expr(void)
 680{
 681        struct grep_expr *z = xcalloc(1, sizeof(*z));
 682        z->node = GREP_NODE_TRUE;
 683        return z;
 684}
 685
 686static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 687{
 688        struct grep_expr *z = xcalloc(1, sizeof(*z));
 689        z->node = GREP_NODE_OR;
 690        z->u.binary.left = left;
 691        z->u.binary.right = right;
 692        return z;
 693}
 694
 695static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 696{
 697        struct grep_pat *p;
 698        struct grep_expr *header_expr;
 699        struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 700        enum grep_header_field fld;
 701
 702        if (!opt->header_list)
 703                return NULL;
 704
 705        for (p = opt->header_list; p; p = p->next) {
 706                if (p->token != GREP_PATTERN_HEAD)
 707                        die("BUG: a non-header pattern in grep header list.");
 708                if (p->field < GREP_HEADER_FIELD_MIN ||
 709                    GREP_HEADER_FIELD_MAX <= p->field)
 710                        die("BUG: unknown header field %d", p->field);
 711                compile_regexp(p, opt);
 712        }
 713
 714        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 715                header_group[fld] = NULL;
 716
 717        for (p = opt->header_list; p; p = p->next) {
 718                struct grep_expr *h;
 719                struct grep_pat *pp = p;
 720
 721                h = compile_pattern_atom(&pp);
 722                if (!h || pp != p->next)
 723                        die("BUG: malformed header expr");
 724                if (!header_group[p->field]) {
 725                        header_group[p->field] = h;
 726                        continue;
 727                }
 728                header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 729        }
 730
 731        header_expr = NULL;
 732
 733        for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 734                if (!header_group[fld])
 735                        continue;
 736                if (!header_expr)
 737                        header_expr = grep_true_expr();
 738                header_expr = grep_or_expr(header_group[fld], header_expr);
 739        }
 740        return header_expr;
 741}
 742
 743static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 744{
 745        struct grep_expr *z = x;
 746
 747        while (x) {
 748                assert(x->node == GREP_NODE_OR);
 749                if (x->u.binary.right &&
 750                    x->u.binary.right->node == GREP_NODE_TRUE) {
 751                        x->u.binary.right = y;
 752                        break;
 753                }
 754                x = x->u.binary.right;
 755        }
 756        return z;
 757}
 758
 759static void compile_grep_patterns_real(struct grep_opt *opt)
 760{
 761        struct grep_pat *p;
 762        struct grep_expr *header_expr = prep_header_patterns(opt);
 763
 764        for (p = opt->pattern_list; p; p = p->next) {
 765                switch (p->token) {
 766                case GREP_PATTERN: /* atom */
 767                case GREP_PATTERN_HEAD:
 768                case GREP_PATTERN_BODY:
 769                        compile_regexp(p, opt);
 770                        break;
 771                default:
 772                        opt->extended = 1;
 773                        break;
 774                }
 775        }
 776
 777        if (opt->all_match || header_expr)
 778                opt->extended = 1;
 779        else if (!opt->extended && !opt->debug)
 780                return;
 781
 782        p = opt->pattern_list;
 783        if (p)
 784                opt->pattern_expression = compile_pattern_expr(&p);
 785        if (p)
 786                die("incomplete pattern expression: %s", p->pattern);
 787
 788        if (!header_expr)
 789                return;
 790
 791        if (!opt->pattern_expression)
 792                opt->pattern_expression = header_expr;
 793        else if (opt->all_match)
 794                opt->pattern_expression = grep_splice_or(header_expr,
 795                                                         opt->pattern_expression);
 796        else
 797                opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 798                                                       header_expr);
 799        opt->all_match = 1;
 800}
 801
 802void compile_grep_patterns(struct grep_opt *opt)
 803{
 804        compile_grep_patterns_real(opt);
 805        if (opt->debug)
 806                dump_grep_expression(opt);
 807}
 808
 809static void free_pattern_expr(struct grep_expr *x)
 810{
 811        switch (x->node) {
 812        case GREP_NODE_TRUE:
 813        case GREP_NODE_ATOM:
 814                break;
 815        case GREP_NODE_NOT:
 816                free_pattern_expr(x->u.unary);
 817                break;
 818        case GREP_NODE_AND:
 819        case GREP_NODE_OR:
 820                free_pattern_expr(x->u.binary.left);
 821                free_pattern_expr(x->u.binary.right);
 822                break;
 823        }
 824        free(x);
 825}
 826
 827void free_grep_patterns(struct grep_opt *opt)
 828{
 829        struct grep_pat *p, *n;
 830
 831        for (p = opt->pattern_list; p; p = n) {
 832                n = p->next;
 833                switch (p->token) {
 834                case GREP_PATTERN: /* atom */
 835                case GREP_PATTERN_HEAD:
 836                case GREP_PATTERN_BODY:
 837                        if (p->kws)
 838                                kwsfree(p->kws);
 839                        else if (p->pcre1_regexp)
 840                                free_pcre1_regexp(p);
 841                        else
 842                                regfree(&p->regexp);
 843                        free(p->pattern);
 844                        break;
 845                default:
 846                        break;
 847                }
 848                free(p);
 849        }
 850
 851        if (!opt->extended)
 852                return;
 853        free_pattern_expr(opt->pattern_expression);
 854}
 855
 856static char *end_of_line(char *cp, unsigned long *left)
 857{
 858        unsigned long l = *left;
 859        while (l && *cp != '\n') {
 860                l--;
 861                cp++;
 862        }
 863        *left = l;
 864        return cp;
 865}
 866
 867static int word_char(char ch)
 868{
 869        return isalnum(ch) || ch == '_';
 870}
 871
 872static void output_color(struct grep_opt *opt, const void *data, size_t size,
 873                         const char *color)
 874{
 875        if (want_color(opt->color) && color && color[0]) {
 876                opt->output(opt, color, strlen(color));
 877                opt->output(opt, data, size);
 878                opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 879        } else
 880                opt->output(opt, data, size);
 881}
 882
 883static void output_sep(struct grep_opt *opt, char sign)
 884{
 885        if (opt->null_following_name)
 886                opt->output(opt, "\0", 1);
 887        else
 888                output_color(opt, &sign, 1, opt->color_sep);
 889}
 890
 891static void show_name(struct grep_opt *opt, const char *name)
 892{
 893        output_color(opt, name, strlen(name), opt->color_filename);
 894        opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 895}
 896
 897static int fixmatch(struct grep_pat *p, char *line, char *eol,
 898                    regmatch_t *match)
 899{
 900        struct kwsmatch kwsm;
 901        size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
 902        if (offset == -1) {
 903                match->rm_so = match->rm_eo = -1;
 904                return REG_NOMATCH;
 905        } else {
 906                match->rm_so = offset;
 907                match->rm_eo = match->rm_so + kwsm.size[0];
 908                return 0;
 909        }
 910}
 911
 912static int patmatch(struct grep_pat *p, char *line, char *eol,
 913                    regmatch_t *match, int eflags)
 914{
 915        int hit;
 916
 917        if (p->fixed)
 918                hit = !fixmatch(p, line, eol, match);
 919        else if (p->pcre1_regexp)
 920                hit = !pcre1match(p, line, eol, match, eflags);
 921        else
 922                hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
 923                                   eflags);
 924
 925        return hit;
 926}
 927
 928static int strip_timestamp(char *bol, char **eol_p)
 929{
 930        char *eol = *eol_p;
 931        int ch;
 932
 933        while (bol < --eol) {
 934                if (*eol != '>')
 935                        continue;
 936                *eol_p = ++eol;
 937                ch = *eol;
 938                *eol = '\0';
 939                return ch;
 940        }
 941        return 0;
 942}
 943
 944static struct {
 945        const char *field;
 946        size_t len;
 947} header_field[] = {
 948        { "author ", 7 },
 949        { "committer ", 10 },
 950        { "reflog ", 7 },
 951};
 952
 953static int match_one_pattern(struct grep_pat *p, char *bol, char *eol,
 954                             enum grep_context ctx,
 955                             regmatch_t *pmatch, int eflags)
 956{
 957        int hit = 0;
 958        int saved_ch = 0;
 959        const char *start = bol;
 960
 961        if ((p->token != GREP_PATTERN) &&
 962            ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 963                return 0;
 964
 965        if (p->token == GREP_PATTERN_HEAD) {
 966                const char *field;
 967                size_t len;
 968                assert(p->field < ARRAY_SIZE(header_field));
 969                field = header_field[p->field].field;
 970                len = header_field[p->field].len;
 971                if (strncmp(bol, field, len))
 972                        return 0;
 973                bol += len;
 974                switch (p->field) {
 975                case GREP_HEADER_AUTHOR:
 976                case GREP_HEADER_COMMITTER:
 977                        saved_ch = strip_timestamp(bol, &eol);
 978                        break;
 979                default:
 980                        break;
 981                }
 982        }
 983
 984 again:
 985        hit = patmatch(p, bol, eol, pmatch, eflags);
 986
 987        if (hit && p->word_regexp) {
 988                if ((pmatch[0].rm_so < 0) ||
 989                    (eol - bol) < pmatch[0].rm_so ||
 990                    (pmatch[0].rm_eo < 0) ||
 991                    (eol - bol) < pmatch[0].rm_eo)
 992                        die("regexp returned nonsense");
 993
 994                /* Match beginning must be either beginning of the
 995                 * line, or at word boundary (i.e. the last char must
 996                 * not be a word char).  Similarly, match end must be
 997                 * either end of the line, or at word boundary
 998                 * (i.e. the next char must not be a word char).
 999                 */
1000                if ( ((pmatch[0].rm_so == 0) ||
1001                      !word_char(bol[pmatch[0].rm_so-1])) &&
1002                     ((pmatch[0].rm_eo == (eol-bol)) ||
1003                      !word_char(bol[pmatch[0].rm_eo])) )
1004                        ;
1005                else
1006                        hit = 0;
1007
1008                /* Words consist of at least one character. */
1009                if (pmatch->rm_so == pmatch->rm_eo)
1010                        hit = 0;
1011
1012                if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
1013                        /* There could be more than one match on the
1014                         * line, and the first match might not be
1015                         * strict word match.  But later ones could be!
1016                         * Forward to the next possible start, i.e. the
1017                         * next position following a non-word char.
1018                         */
1019                        bol = pmatch[0].rm_so + bol + 1;
1020                        while (word_char(bol[-1]) && bol < eol)
1021                                bol++;
1022                        eflags |= REG_NOTBOL;
1023                        if (bol < eol)
1024                                goto again;
1025                }
1026        }
1027        if (p->token == GREP_PATTERN_HEAD && saved_ch)
1028                *eol = saved_ch;
1029        if (hit) {
1030                pmatch[0].rm_so += bol - start;
1031                pmatch[0].rm_eo += bol - start;
1032        }
1033        return hit;
1034}
1035
1036static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
1037                           enum grep_context ctx, int collect_hits)
1038{
1039        int h = 0;
1040        regmatch_t match;
1041
1042        if (!x)
1043                die("Not a valid grep expression");
1044        switch (x->node) {
1045        case GREP_NODE_TRUE:
1046                h = 1;
1047                break;
1048        case GREP_NODE_ATOM:
1049                h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
1050                break;
1051        case GREP_NODE_NOT:
1052                h = !match_expr_eval(x->u.unary, bol, eol, ctx, 0);
1053                break;
1054        case GREP_NODE_AND:
1055                if (!match_expr_eval(x->u.binary.left, bol, eol, ctx, 0))
1056                        return 0;
1057                h = match_expr_eval(x->u.binary.right, bol, eol, ctx, 0);
1058                break;
1059        case GREP_NODE_OR:
1060                if (!collect_hits)
1061                        return (match_expr_eval(x->u.binary.left,
1062                                                bol, eol, ctx, 0) ||
1063                                match_expr_eval(x->u.binary.right,
1064                                                bol, eol, ctx, 0));
1065                h = match_expr_eval(x->u.binary.left, bol, eol, ctx, 0);
1066                x->u.binary.left->hit |= h;
1067                h |= match_expr_eval(x->u.binary.right, bol, eol, ctx, 1);
1068                break;
1069        default:
1070                die("Unexpected node type (internal error) %d", x->node);
1071        }
1072        if (collect_hits)
1073                x->hit |= h;
1074        return h;
1075}
1076
1077static int match_expr(struct grep_opt *opt, char *bol, char *eol,
1078                      enum grep_context ctx, int collect_hits)
1079{
1080        struct grep_expr *x = opt->pattern_expression;
1081        return match_expr_eval(x, bol, eol, ctx, collect_hits);
1082}
1083
1084static int match_line(struct grep_opt *opt, char *bol, char *eol,
1085                      enum grep_context ctx, int collect_hits)
1086{
1087        struct grep_pat *p;
1088        regmatch_t match;
1089
1090        if (opt->extended)
1091                return match_expr(opt, bol, eol, ctx, collect_hits);
1092
1093        /* we do not call with collect_hits without being extended */
1094        for (p = opt->pattern_list; p; p = p->next) {
1095                if (match_one_pattern(p, bol, eol, ctx, &match, 0))
1096                        return 1;
1097        }
1098        return 0;
1099}
1100
1101static int match_next_pattern(struct grep_pat *p, char *bol, char *eol,
1102                              enum grep_context ctx,
1103                              regmatch_t *pmatch, int eflags)
1104{
1105        regmatch_t match;
1106
1107        if (!match_one_pattern(p, bol, eol, ctx, &match, eflags))
1108                return 0;
1109        if (match.rm_so < 0 || match.rm_eo < 0)
1110                return 0;
1111        if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1112                if (match.rm_so > pmatch->rm_so)
1113                        return 1;
1114                if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1115                        return 1;
1116        }
1117        pmatch->rm_so = match.rm_so;
1118        pmatch->rm_eo = match.rm_eo;
1119        return 1;
1120}
1121
1122static int next_match(struct grep_opt *opt, char *bol, char *eol,
1123                      enum grep_context ctx, regmatch_t *pmatch, int eflags)
1124{
1125        struct grep_pat *p;
1126        int hit = 0;
1127
1128        pmatch->rm_so = pmatch->rm_eo = -1;
1129        if (bol < eol) {
1130                for (p = opt->pattern_list; p; p = p->next) {
1131                        switch (p->token) {
1132                        case GREP_PATTERN: /* atom */
1133                        case GREP_PATTERN_HEAD:
1134                        case GREP_PATTERN_BODY:
1135                                hit |= match_next_pattern(p, bol, eol, ctx,
1136                                                          pmatch, eflags);
1137                                break;
1138                        default:
1139                                break;
1140                        }
1141                }
1142        }
1143        return hit;
1144}
1145
1146static void show_line(struct grep_opt *opt, char *bol, char *eol,
1147                      const char *name, unsigned lno, char sign)
1148{
1149        int rest = eol - bol;
1150        const char *match_color, *line_color = NULL;
1151
1152        if (opt->file_break && opt->last_shown == 0) {
1153                if (opt->show_hunk_mark)
1154                        opt->output(opt, "\n", 1);
1155        } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1156                if (opt->last_shown == 0) {
1157                        if (opt->show_hunk_mark) {
1158                                output_color(opt, "--", 2, opt->color_sep);
1159                                opt->output(opt, "\n", 1);
1160                        }
1161                } else if (lno > opt->last_shown + 1) {
1162                        output_color(opt, "--", 2, opt->color_sep);
1163                        opt->output(opt, "\n", 1);
1164                }
1165        }
1166        if (opt->heading && opt->last_shown == 0) {
1167                output_color(opt, name, strlen(name), opt->color_filename);
1168                opt->output(opt, "\n", 1);
1169        }
1170        opt->last_shown = lno;
1171
1172        if (!opt->heading && opt->pathname) {
1173                output_color(opt, name, strlen(name), opt->color_filename);
1174                output_sep(opt, sign);
1175        }
1176        if (opt->linenum) {
1177                char buf[32];
1178                xsnprintf(buf, sizeof(buf), "%d", lno);
1179                output_color(opt, buf, strlen(buf), opt->color_lineno);
1180                output_sep(opt, sign);
1181        }
1182        if (opt->color) {
1183                regmatch_t match;
1184                enum grep_context ctx = GREP_CONTEXT_BODY;
1185                int ch = *eol;
1186                int eflags = 0;
1187
1188                if (sign == ':')
1189                        match_color = opt->color_match_selected;
1190                else
1191                        match_color = opt->color_match_context;
1192                if (sign == ':')
1193                        line_color = opt->color_selected;
1194                else if (sign == '-')
1195                        line_color = opt->color_context;
1196                else if (sign == '=')
1197                        line_color = opt->color_function;
1198                *eol = '\0';
1199                while (next_match(opt, bol, eol, ctx, &match, eflags)) {
1200                        if (match.rm_so == match.rm_eo)
1201                                break;
1202
1203                        output_color(opt, bol, match.rm_so, line_color);
1204                        output_color(opt, bol + match.rm_so,
1205                                     match.rm_eo - match.rm_so, match_color);
1206                        bol += match.rm_eo;
1207                        rest -= match.rm_eo;
1208                        eflags = REG_NOTBOL;
1209                }
1210                *eol = ch;
1211        }
1212        output_color(opt, bol, rest, line_color);
1213        opt->output(opt, "\n", 1);
1214}
1215
1216#ifndef NO_PTHREADS
1217int grep_use_locks;
1218
1219/*
1220 * This lock protects access to the gitattributes machinery, which is
1221 * not thread-safe.
1222 */
1223pthread_mutex_t grep_attr_mutex;
1224
1225static inline void grep_attr_lock(void)
1226{
1227        if (grep_use_locks)
1228                pthread_mutex_lock(&grep_attr_mutex);
1229}
1230
1231static inline void grep_attr_unlock(void)
1232{
1233        if (grep_use_locks)
1234                pthread_mutex_unlock(&grep_attr_mutex);
1235}
1236
1237/*
1238 * Same as git_attr_mutex, but protecting the thread-unsafe object db access.
1239 */
1240pthread_mutex_t grep_read_mutex;
1241
1242#else
1243#define grep_attr_lock()
1244#define grep_attr_unlock()
1245#endif
1246
1247static int match_funcname(struct grep_opt *opt, struct grep_source *gs, char *bol, char *eol)
1248{
1249        xdemitconf_t *xecfg = opt->priv;
1250        if (xecfg && !xecfg->find_func) {
1251                grep_source_load_driver(gs);
1252                if (gs->driver->funcname.pattern) {
1253                        const struct userdiff_funcname *pe = &gs->driver->funcname;
1254                        xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1255                } else {
1256                        xecfg = opt->priv = NULL;
1257                }
1258        }
1259
1260        if (xecfg) {
1261                char buf[1];
1262                return xecfg->find_func(bol, eol - bol, buf, 1,
1263                                        xecfg->find_func_priv) >= 0;
1264        }
1265
1266        if (bol == eol)
1267                return 0;
1268        if (isalpha(*bol) || *bol == '_' || *bol == '$')
1269                return 1;
1270        return 0;
1271}
1272
1273static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1274                               char *bol, unsigned lno)
1275{
1276        while (bol > gs->buf) {
1277                char *eol = --bol;
1278
1279                while (bol > gs->buf && bol[-1] != '\n')
1280                        bol--;
1281                lno--;
1282
1283                if (lno <= opt->last_shown)
1284                        break;
1285
1286                if (match_funcname(opt, gs, bol, eol)) {
1287                        show_line(opt, bol, eol, gs->name, lno, '=');
1288                        break;
1289                }
1290        }
1291}
1292
1293static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1294                             char *bol, char *end, unsigned lno)
1295{
1296        unsigned cur = lno, from = 1, funcname_lno = 0;
1297        int funcname_needed = !!opt->funcname;
1298
1299        if (opt->funcbody && !match_funcname(opt, gs, bol, end))
1300                funcname_needed = 2;
1301
1302        if (opt->pre_context < lno)
1303                from = lno - opt->pre_context;
1304        if (from <= opt->last_shown)
1305                from = opt->last_shown + 1;
1306
1307        /* Rewind. */
1308        while (bol > gs->buf &&
1309               cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
1310                char *eol = --bol;
1311
1312                while (bol > gs->buf && bol[-1] != '\n')
1313                        bol--;
1314                cur--;
1315                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1316                        funcname_lno = cur;
1317                        funcname_needed = 0;
1318                }
1319        }
1320
1321        /* We need to look even further back to find a function signature. */
1322        if (opt->funcname && funcname_needed)
1323                show_funcname_line(opt, gs, bol, cur);
1324
1325        /* Back forward. */
1326        while (cur < lno) {
1327                char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1328
1329                while (*eol != '\n')
1330                        eol++;
1331                show_line(opt, bol, eol, gs->name, cur, sign);
1332                bol = eol + 1;
1333                cur++;
1334        }
1335}
1336
1337static int should_lookahead(struct grep_opt *opt)
1338{
1339        struct grep_pat *p;
1340
1341        if (opt->extended)
1342                return 0; /* punt for too complex stuff */
1343        if (opt->invert)
1344                return 0;
1345        for (p = opt->pattern_list; p; p = p->next) {
1346                if (p->token != GREP_PATTERN)
1347                        return 0; /* punt for "header only" and stuff */
1348        }
1349        return 1;
1350}
1351
1352static int look_ahead(struct grep_opt *opt,
1353                      unsigned long *left_p,
1354                      unsigned *lno_p,
1355                      char **bol_p)
1356{
1357        unsigned lno = *lno_p;
1358        char *bol = *bol_p;
1359        struct grep_pat *p;
1360        char *sp, *last_bol;
1361        regoff_t earliest = -1;
1362
1363        for (p = opt->pattern_list; p; p = p->next) {
1364                int hit;
1365                regmatch_t m;
1366
1367                hit = patmatch(p, bol, bol + *left_p, &m, 0);
1368                if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1369                        continue;
1370                if (earliest < 0 || m.rm_so < earliest)
1371                        earliest = m.rm_so;
1372        }
1373
1374        if (earliest < 0) {
1375                *bol_p = bol + *left_p;
1376                *left_p = 0;
1377                return 1;
1378        }
1379        for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1380                ; /* find the beginning of the line */
1381        last_bol = sp;
1382
1383        for (sp = bol; sp < last_bol; sp++) {
1384                if (*sp == '\n')
1385                        lno++;
1386        }
1387        *left_p -= last_bol - bol;
1388        *bol_p = last_bol;
1389        *lno_p = lno;
1390        return 0;
1391}
1392
1393static int fill_textconv_grep(struct userdiff_driver *driver,
1394                              struct grep_source *gs)
1395{
1396        struct diff_filespec *df;
1397        char *buf;
1398        size_t size;
1399
1400        if (!driver || !driver->textconv)
1401                return grep_source_load(gs);
1402
1403        /*
1404         * The textconv interface is intimately tied to diff_filespecs, so we
1405         * have to pretend to be one. If we could unify the grep_source
1406         * and diff_filespec structs, this mess could just go away.
1407         */
1408        df = alloc_filespec(gs->path);
1409        switch (gs->type) {
1410        case GREP_SOURCE_SHA1:
1411                fill_filespec(df, gs->identifier, 1, 0100644);
1412                break;
1413        case GREP_SOURCE_FILE:
1414                fill_filespec(df, null_sha1, 0, 0100644);
1415                break;
1416        default:
1417                die("BUG: attempt to textconv something without a path?");
1418        }
1419
1420        /*
1421         * fill_textconv is not remotely thread-safe; it may load objects
1422         * behind the scenes, and it modifies the global diff tempfile
1423         * structure.
1424         */
1425        grep_read_lock();
1426        size = fill_textconv(driver, df, &buf);
1427        grep_read_unlock();
1428        free_filespec(df);
1429
1430        /*
1431         * The normal fill_textconv usage by the diff machinery would just keep
1432         * the textconv'd buf separate from the diff_filespec. But much of the
1433         * grep code passes around a grep_source and assumes that its "buf"
1434         * pointer is the beginning of the thing we are searching. So let's
1435         * install our textconv'd version into the grep_source, taking care not
1436         * to leak any existing buffer.
1437         */
1438        grep_source_clear_data(gs);
1439        gs->buf = buf;
1440        gs->size = size;
1441
1442        return 0;
1443}
1444
1445static int is_empty_line(const char *bol, const char *eol)
1446{
1447        while (bol < eol && isspace(*bol))
1448                bol++;
1449        return bol == eol;
1450}
1451
1452static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1453{
1454        char *bol;
1455        char *peek_bol = NULL;
1456        unsigned long left;
1457        unsigned lno = 1;
1458        unsigned last_hit = 0;
1459        int binary_match_only = 0;
1460        unsigned count = 0;
1461        int try_lookahead = 0;
1462        int show_function = 0;
1463        struct userdiff_driver *textconv = NULL;
1464        enum grep_context ctx = GREP_CONTEXT_HEAD;
1465        xdemitconf_t xecfg;
1466
1467        if (!opt->output)
1468                opt->output = std_output;
1469
1470        if (opt->pre_context || opt->post_context || opt->file_break ||
1471            opt->funcbody) {
1472                /* Show hunk marks, except for the first file. */
1473                if (opt->last_shown)
1474                        opt->show_hunk_mark = 1;
1475                /*
1476                 * If we're using threads then we can't easily identify
1477                 * the first file.  Always put hunk marks in that case
1478                 * and skip the very first one later in work_done().
1479                 */
1480                if (opt->output != std_output)
1481                        opt->show_hunk_mark = 1;
1482        }
1483        opt->last_shown = 0;
1484
1485        if (opt->allow_textconv) {
1486                grep_source_load_driver(gs);
1487                /*
1488                 * We might set up the shared textconv cache data here, which
1489                 * is not thread-safe.
1490                 */
1491                grep_attr_lock();
1492                textconv = userdiff_get_textconv(gs->driver);
1493                grep_attr_unlock();
1494        }
1495
1496        /*
1497         * We know the result of a textconv is text, so we only have to care
1498         * about binary handling if we are not using it.
1499         */
1500        if (!textconv) {
1501                switch (opt->binary) {
1502                case GREP_BINARY_DEFAULT:
1503                        if (grep_source_is_binary(gs))
1504                                binary_match_only = 1;
1505                        break;
1506                case GREP_BINARY_NOMATCH:
1507                        if (grep_source_is_binary(gs))
1508                                return 0; /* Assume unmatch */
1509                        break;
1510                case GREP_BINARY_TEXT:
1511                        break;
1512                default:
1513                        die("BUG: unknown binary handling mode");
1514                }
1515        }
1516
1517        memset(&xecfg, 0, sizeof(xecfg));
1518        opt->priv = &xecfg;
1519
1520        try_lookahead = should_lookahead(opt);
1521
1522        if (fill_textconv_grep(textconv, gs) < 0)
1523                return 0;
1524
1525        bol = gs->buf;
1526        left = gs->size;
1527        while (left) {
1528                char *eol, ch;
1529                int hit;
1530
1531                /*
1532                 * look_ahead() skips quickly to the line that possibly
1533                 * has the next hit; don't call it if we need to do
1534                 * something more than just skipping the current line
1535                 * in response to an unmatch for the current line.  E.g.
1536                 * inside a post-context window, we will show the current
1537                 * line as a context around the previous hit when it
1538                 * doesn't hit.
1539                 */
1540                if (try_lookahead
1541                    && !(last_hit
1542                         && (show_function ||
1543                             lno <= last_hit + opt->post_context))
1544                    && look_ahead(opt, &left, &lno, &bol))
1545                        break;
1546                eol = end_of_line(bol, &left);
1547                ch = *eol;
1548                *eol = 0;
1549
1550                if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1551                        ctx = GREP_CONTEXT_BODY;
1552
1553                hit = match_line(opt, bol, eol, ctx, collect_hits);
1554                *eol = ch;
1555
1556                if (collect_hits)
1557                        goto next_line;
1558
1559                /* "grep -v -e foo -e bla" should list lines
1560                 * that do not have either, so inversion should
1561                 * be done outside.
1562                 */
1563                if (opt->invert)
1564                        hit = !hit;
1565                if (opt->unmatch_name_only) {
1566                        if (hit)
1567                                return 0;
1568                        goto next_line;
1569                }
1570                if (hit) {
1571                        count++;
1572                        if (opt->status_only)
1573                                return 1;
1574                        if (opt->name_only) {
1575                                show_name(opt, gs->name);
1576                                return 1;
1577                        }
1578                        if (opt->count)
1579                                goto next_line;
1580                        if (binary_match_only) {
1581                                opt->output(opt, "Binary file ", 12);
1582                                output_color(opt, gs->name, strlen(gs->name),
1583                                             opt->color_filename);
1584                                opt->output(opt, " matches\n", 9);
1585                                return 1;
1586                        }
1587                        /* Hit at this line.  If we haven't shown the
1588                         * pre-context lines, we would need to show them.
1589                         */
1590                        if (opt->pre_context || opt->funcbody)
1591                                show_pre_context(opt, gs, bol, eol, lno);
1592                        else if (opt->funcname)
1593                                show_funcname_line(opt, gs, bol, lno);
1594                        show_line(opt, bol, eol, gs->name, lno, ':');
1595                        last_hit = lno;
1596                        if (opt->funcbody)
1597                                show_function = 1;
1598                        goto next_line;
1599                }
1600                if (show_function && (!peek_bol || peek_bol < bol)) {
1601                        unsigned long peek_left = left;
1602                        char *peek_eol = eol;
1603
1604                        /*
1605                         * Trailing empty lines are not interesting.
1606                         * Peek past them to see if they belong to the
1607                         * body of the current function.
1608                         */
1609                        peek_bol = bol;
1610                        while (is_empty_line(peek_bol, peek_eol)) {
1611                                peek_bol = peek_eol + 1;
1612                                peek_eol = end_of_line(peek_bol, &peek_left);
1613                        }
1614
1615                        if (match_funcname(opt, gs, peek_bol, peek_eol))
1616                                show_function = 0;
1617                }
1618                if (show_function ||
1619                    (last_hit && lno <= last_hit + opt->post_context)) {
1620                        /* If the last hit is within the post context,
1621                         * we need to show this line.
1622                         */
1623                        show_line(opt, bol, eol, gs->name, lno, '-');
1624                }
1625
1626        next_line:
1627                bol = eol + 1;
1628                if (!left)
1629                        break;
1630                left--;
1631                lno++;
1632        }
1633
1634        if (collect_hits)
1635                return 0;
1636
1637        if (opt->status_only)
1638                return 0;
1639        if (opt->unmatch_name_only) {
1640                /* We did not see any hit, so we want to show this */
1641                show_name(opt, gs->name);
1642                return 1;
1643        }
1644
1645        xdiff_clear_find_func(&xecfg);
1646        opt->priv = NULL;
1647
1648        /* NEEDSWORK:
1649         * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1650         * which feels mostly useless but sometimes useful.  Maybe
1651         * make it another option?  For now suppress them.
1652         */
1653        if (opt->count && count) {
1654                char buf[32];
1655                if (opt->pathname) {
1656                        output_color(opt, gs->name, strlen(gs->name),
1657                                     opt->color_filename);
1658                        output_sep(opt, ':');
1659                }
1660                xsnprintf(buf, sizeof(buf), "%u\n", count);
1661                opt->output(opt, buf, strlen(buf));
1662                return 1;
1663        }
1664        return !!last_hit;
1665}
1666
1667static void clr_hit_marker(struct grep_expr *x)
1668{
1669        /* All-hit markers are meaningful only at the very top level
1670         * OR node.
1671         */
1672        while (1) {
1673                x->hit = 0;
1674                if (x->node != GREP_NODE_OR)
1675                        return;
1676                x->u.binary.left->hit = 0;
1677                x = x->u.binary.right;
1678        }
1679}
1680
1681static int chk_hit_marker(struct grep_expr *x)
1682{
1683        /* Top level nodes have hit markers.  See if they all are hits */
1684        while (1) {
1685                if (x->node != GREP_NODE_OR)
1686                        return x->hit;
1687                if (!x->u.binary.left->hit)
1688                        return 0;
1689                x = x->u.binary.right;
1690        }
1691}
1692
1693int grep_source(struct grep_opt *opt, struct grep_source *gs)
1694{
1695        /*
1696         * we do not have to do the two-pass grep when we do not check
1697         * buffer-wide "all-match".
1698         */
1699        if (!opt->all_match)
1700                return grep_source_1(opt, gs, 0);
1701
1702        /* Otherwise the toplevel "or" terms hit a bit differently.
1703         * We first clear hit markers from them.
1704         */
1705        clr_hit_marker(opt->pattern_expression);
1706        grep_source_1(opt, gs, 1);
1707
1708        if (!chk_hit_marker(opt->pattern_expression))
1709                return 0;
1710
1711        return grep_source_1(opt, gs, 0);
1712}
1713
1714int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
1715{
1716        struct grep_source gs;
1717        int r;
1718
1719        grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
1720        gs.buf = buf;
1721        gs.size = size;
1722
1723        r = grep_source(opt, &gs);
1724
1725        grep_source_clear(&gs);
1726        return r;
1727}
1728
1729void grep_source_init(struct grep_source *gs, enum grep_source_type type,
1730                      const char *name, const char *path,
1731                      const void *identifier)
1732{
1733        gs->type = type;
1734        gs->name = xstrdup_or_null(name);
1735        gs->path = xstrdup_or_null(path);
1736        gs->buf = NULL;
1737        gs->size = 0;
1738        gs->driver = NULL;
1739
1740        switch (type) {
1741        case GREP_SOURCE_FILE:
1742                gs->identifier = xstrdup(identifier);
1743                break;
1744        case GREP_SOURCE_SUBMODULE:
1745                if (!identifier) {
1746                        gs->identifier = NULL;
1747                        break;
1748                }
1749                /*
1750                 * FALL THROUGH
1751                 * If the identifier is non-NULL (in the submodule case) it
1752                 * will be a SHA1 that needs to be copied.
1753                 */
1754        case GREP_SOURCE_SHA1:
1755                gs->identifier = xmalloc(20);
1756                hashcpy(gs->identifier, identifier);
1757                break;
1758        case GREP_SOURCE_BUF:
1759                gs->identifier = NULL;
1760                break;
1761        }
1762}
1763
1764void grep_source_clear(struct grep_source *gs)
1765{
1766        free(gs->name);
1767        gs->name = NULL;
1768        free(gs->path);
1769        gs->path = NULL;
1770        free(gs->identifier);
1771        gs->identifier = NULL;
1772        grep_source_clear_data(gs);
1773}
1774
1775void grep_source_clear_data(struct grep_source *gs)
1776{
1777        switch (gs->type) {
1778        case GREP_SOURCE_FILE:
1779        case GREP_SOURCE_SHA1:
1780        case GREP_SOURCE_SUBMODULE:
1781                free(gs->buf);
1782                gs->buf = NULL;
1783                gs->size = 0;
1784                break;
1785        case GREP_SOURCE_BUF:
1786                /* leave user-provided buf intact */
1787                break;
1788        }
1789}
1790
1791static int grep_source_load_sha1(struct grep_source *gs)
1792{
1793        enum object_type type;
1794
1795        grep_read_lock();
1796        gs->buf = read_sha1_file(gs->identifier, &type, &gs->size);
1797        grep_read_unlock();
1798
1799        if (!gs->buf)
1800                return error(_("'%s': unable to read %s"),
1801                             gs->name,
1802                             sha1_to_hex(gs->identifier));
1803        return 0;
1804}
1805
1806static int grep_source_load_file(struct grep_source *gs)
1807{
1808        const char *filename = gs->identifier;
1809        struct stat st;
1810        char *data;
1811        size_t size;
1812        int i;
1813
1814        if (lstat(filename, &st) < 0) {
1815        err_ret:
1816                if (errno != ENOENT)
1817                        error_errno(_("failed to stat '%s'"), filename);
1818                return -1;
1819        }
1820        if (!S_ISREG(st.st_mode))
1821                return -1;
1822        size = xsize_t(st.st_size);
1823        i = open(filename, O_RDONLY);
1824        if (i < 0)
1825                goto err_ret;
1826        data = xmallocz(size);
1827        if (st.st_size != read_in_full(i, data, size)) {
1828                error_errno(_("'%s': short read"), filename);
1829                close(i);
1830                free(data);
1831                return -1;
1832        }
1833        close(i);
1834
1835        gs->buf = data;
1836        gs->size = size;
1837        return 0;
1838}
1839
1840static int grep_source_load(struct grep_source *gs)
1841{
1842        if (gs->buf)
1843                return 0;
1844
1845        switch (gs->type) {
1846        case GREP_SOURCE_FILE:
1847                return grep_source_load_file(gs);
1848        case GREP_SOURCE_SHA1:
1849                return grep_source_load_sha1(gs);
1850        case GREP_SOURCE_BUF:
1851                return gs->buf ? 0 : -1;
1852        case GREP_SOURCE_SUBMODULE:
1853                break;
1854        }
1855        die("BUG: invalid grep_source type to load");
1856}
1857
1858void grep_source_load_driver(struct grep_source *gs)
1859{
1860        if (gs->driver)
1861                return;
1862
1863        grep_attr_lock();
1864        if (gs->path)
1865                gs->driver = userdiff_find_by_path(gs->path);
1866        if (!gs->driver)
1867                gs->driver = userdiff_find_by_name("default");
1868        grep_attr_unlock();
1869}
1870
1871static int grep_source_is_binary(struct grep_source *gs)
1872{
1873        grep_source_load_driver(gs);
1874        if (gs->driver->binary != -1)
1875                return gs->driver->binary;
1876
1877        if (!grep_source_load(gs))
1878                return buffer_is_binary(gs->buf, gs->size);
1879
1880        return 0;
1881}