grep.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "grep.h"
   4 #include "object-store.h"
   5 #include "userdiff.h"
   6 #include "xdiff-interface.h"
   7 #include "diff.h"
   8 #include "diffcore.h"
   9 #include "commit.h"
  10 #include "quote.h"
  11 #include "help.h"
  12
  13 static int grep_source_load(struct grep_source *gs);
  14 static int grep_source_is_binary(struct grep_source *gs,
  15                                  struct index_state *istate);
  16
  17 static void std_output(struct grep_opt *opt, const void *buf, size_t size)
  18 {
  19         fwrite(buf, size, 1, stdout);
  20 }
  21
  22 static const char *color_grep_slots[] = {
  23         [GREP_COLOR_CONTEXT]        = "context",
  24         [GREP_COLOR_FILENAME]       = "filename",
  25         [GREP_COLOR_FUNCTION]       = "function",
  26         [GREP_COLOR_LINENO]         = "lineNumber",
  27         [GREP_COLOR_COLUMNNO]       = "column",
  28         [GREP_COLOR_MATCH_CONTEXT]  = "matchContext",
  29         [GREP_COLOR_MATCH_SELECTED] = "matchSelected",
  30         [GREP_COLOR_SELECTED]       = "selected",
  31         [GREP_COLOR_SEP]            = "separator",
  32 };
  33
  34 static int parse_pattern_type_arg(const char *opt, const char *arg)
  35 {
  36         if (!strcmp(arg, "default"))
  37                 return GREP_PATTERN_TYPE_UNSPECIFIED;
  38         else if (!strcmp(arg, "basic"))
  39                 return GREP_PATTERN_TYPE_BRE;
  40         else if (!strcmp(arg, "extended"))
  41                 return GREP_PATTERN_TYPE_ERE;
  42         else if (!strcmp(arg, "fixed"))
  43                 return GREP_PATTERN_TYPE_FIXED;
  44         else if (!strcmp(arg, "perl"))
  45                 return GREP_PATTERN_TYPE_PCRE;
  46         die("bad %s argument: %s", opt, arg);
  47 }
  48
  49 define_list_config_array_extra(color_grep_slots, {"match"});
  50
  51 /*
  52  * Read the configuration file once and store it in
  53  * the grep_defaults template.
  54  */
  55 int grep_config(const char *var, const char *value, void *cb)
  56 {
  57         struct grep_opt *opt = cb;
  58         const char *slot;
  59
  60         if (userdiff_config(var, value) < 0)
  61                 return -1;
  62
  63         if (!strcmp(var, "grep.extendedregexp")) {
  64                 opt->extended_regexp_option = git_config_bool(var, value);
  65                 return 0;
  66         }
  67
  68         if (!strcmp(var, "grep.patterntype")) {
  69                 opt->pattern_type_option = parse_pattern_type_arg(var, value);
  70                 return 0;
  71         }
  72
  73         if (!strcmp(var, "grep.linenumber")) {
  74                 opt->linenum = git_config_bool(var, value);
  75                 return 0;
  76         }
  77         if (!strcmp(var, "grep.column")) {
  78                 opt->columnnum = git_config_bool(var, value);
  79                 return 0;
  80         }
  81
  82         if (!strcmp(var, "grep.fullname")) {
  83                 opt->relative = !git_config_bool(var, value);
  84                 return 0;
  85         }
  86
  87         if (!strcmp(var, "color.grep"))
  88                 opt->color = git_config_colorbool(var, value);
  89         if (!strcmp(var, "color.grep.match")) {
  90                 if (grep_config("color.grep.matchcontext", value, cb) < 0)
  91                         return -1;
  92                 if (grep_config("color.grep.matchselected", value, cb) < 0)
  93                         return -1;
  94         } else if (skip_prefix(var, "color.grep.", &slot)) {
  95                 int i = LOOKUP_CONFIG(color_grep_slots, slot);
  96                 char *color;
  97
  98                 if (i < 0)
  99                         return -1;
 100                 color = opt->colors[i];
 101                 if (!value)
 102                         return config_error_nonbool(var);
 103                 return color_parse(value, color);
 104         }
 105         return 0;
 106 }
 107
 108 void grep_init(struct grep_opt *opt, struct repository *repo)
 109 {
 110         struct grep_opt blank = GREP_OPT_INIT;
 111         memcpy(opt, &blank, sizeof(*opt));
 112
 113         opt->repo = repo;
 114         opt->pattern_tail = &opt->pattern_list;
 115         opt->header_tail = &opt->header_list;
 116 }
 117
 118 static struct grep_pat *create_grep_pat(const char *pat, size_t patlen,
 119                                         const char *origin, int no,
 120                                         enum grep_pat_token t,
 121                                         enum grep_header_field field)
 122 {
 123         struct grep_pat *p = xcalloc(1, sizeof(*p));
 124         p->pattern = xmemdupz(pat, patlen);
 125         p->patternlen = patlen;
 126         p->origin = origin;
 127         p->no = no;
 128         p->token = t;
 129         p->field = field;
 130         return p;
 131 }
 132
 133 static void do_append_grep_pat(struct grep_pat ***tail, struct grep_pat *p)
 134 {
 135         **tail = p;
 136         *tail = &p->next;
 137         p->next = NULL;
 138
 139         switch (p->token) {
 140         case GREP_PATTERN: /* atom */
 141         case GREP_PATTERN_HEAD:
 142         case GREP_PATTERN_BODY:
 143                 for (;;) {
 144                         struct grep_pat *new_pat;
 145                         size_t len = 0;
 146                         char *cp = p->pattern + p->patternlen, *nl = NULL;
 147                         while (++len <= p->patternlen) {
 148                                 if (*(--cp) == '\n') {
 149                                         nl = cp;
 150                                         break;
 151                                 }
 152                         }
 153                         if (!nl)
 154                                 break;
 155                         new_pat = create_grep_pat(nl + 1, len - 1, p->origin,
 156                                                   p->no, p->token, p->field);
 157                         new_pat->next = p->next;
 158                         if (!p->next)
 159                                 *tail = &new_pat->next;
 160                         p->next = new_pat;
 161                         *nl = '\0';
 162                         p->patternlen -= len;
 163                 }
 164                 break;
 165         default:
 166                 break;
 167         }
 168 }
 169
 170 void append_header_grep_pattern(struct grep_opt *opt,
 171                                 enum grep_header_field field, const char *pat)
 172 {
 173         struct grep_pat *p = create_grep_pat(pat, strlen(pat), "header", 0,
 174                                              GREP_PATTERN_HEAD, field);
 175         if (field == GREP_HEADER_REFLOG)
 176                 opt->use_reflog_filter = 1;
 177         do_append_grep_pat(&opt->header_tail, p);
 178 }
 179
 180 void append_grep_pattern(struct grep_opt *opt, const char *pat,
 181                          const char *origin, int no, enum grep_pat_token t)
 182 {
 183         append_grep_pat(opt, pat, strlen(pat), origin, no, t);
 184 }
 185
 186 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen,
 187                      const char *origin, int no, enum grep_pat_token t)
 188 {
 189         struct grep_pat *p = create_grep_pat(pat, patlen, origin, no, t, 0);
 190         do_append_grep_pat(&opt->pattern_tail, p);
 191 }
 192
 193 struct grep_opt *grep_opt_dup(const struct grep_opt *opt)
 194 {
 195         struct grep_pat *pat;
 196         struct grep_opt *ret = xmalloc(sizeof(struct grep_opt));
 197         *ret = *opt;
 198
 199         ret->pattern_list = NULL;
 200         ret->pattern_tail = &ret->pattern_list;
 201
 202         for(pat = opt->pattern_list; pat != NULL; pat = pat->next)
 203         {
 204                 if(pat->token == GREP_PATTERN_HEAD)
 205                         append_header_grep_pattern(ret, pat->field,
 206                                                    pat->pattern);
 207                 else
 208                         append_grep_pat(ret, pat->pattern, pat->patternlen,
 209                                         pat->origin, pat->no, pat->token);
 210         }
 211
 212         return ret;
 213 }
 214
 215 static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 216                 const char *error)
 217 {
 218         char where[1024];
 219
 220         if (p->no)
 221                 xsnprintf(where, sizeof(where), "In '%s' at %d, ", p->origin, p->no);
 222         else if (p->origin)
 223                 xsnprintf(where, sizeof(where), "%s, ", p->origin);
 224         else
 225                 where[0] = 0;
 226
 227         die("%s'%s': %s", where, p->pattern, error);
 228 }
 229
 230 static int is_fixed(const char *s, size_t len)
 231 {
 232         size_t i;
 233
 234         for (i = 0; i < len; i++) {
 235                 if (is_regex_special(s[i]))
 236                         return 0;
 237         }
 238
 239         return 1;
 240 }
 241
 242 #ifdef USE_LIBPCRE2
 243 #define GREP_PCRE2_DEBUG_MALLOC 0
 244
 245 static void *pcre2_malloc(PCRE2_SIZE size, MAYBE_UNUSED void *memory_data)
 246 {
 247         void *pointer = malloc(size);
 248 #if GREP_PCRE2_DEBUG_MALLOC
 249         static int count = 1;
 250         fprintf(stderr, "PCRE2:%p -> #%02d: alloc(%lu)\n", pointer, count++, size);
 251 #endif
 252         return pointer;
 253 }
 254
 255 static void pcre2_free(void *pointer, MAYBE_UNUSED void *memory_data)
 256 {
 257 #if GREP_PCRE2_DEBUG_MALLOC
 258         static int count = 1;
 259         if (pointer)
 260                 fprintf(stderr, "PCRE2:%p -> #%02d: free()\n", pointer, count++);
 261 #endif
 262         free(pointer);
 263 }
 264
 265 static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)
 266 {
 267         int error;
 268         PCRE2_UCHAR errbuf[256];
 269         PCRE2_SIZE erroffset;
 270         int options = PCRE2_MULTILINE;
 271         int jitret;
 272         int patinforet;
 273         size_t jitsizearg;
 274         int literal = !opt->ignore_case && (p->fixed || p->is_fixed);
 275
 276         /*
 277          * Call pcre2_general_context_create() before calling any
 278          * other pcre2_*(). It sets up our malloc()/free() functions
 279          * with which everything else is allocated.
 280          */
 281         p->pcre2_general_context = pcre2_general_context_create(
 282                 pcre2_malloc, pcre2_free, NULL);
 283         if (!p->pcre2_general_context)
 284                 die("Couldn't allocate PCRE2 general context");
 285
 286         if (opt->ignore_case) {
 287                 if (!opt->ignore_locale && has_non_ascii(p->pattern)) {
 288                         p->pcre2_tables = pcre2_maketables(p->pcre2_general_context);
 289                         p->pcre2_compile_context = pcre2_compile_context_create(p->pcre2_general_context);
 290                         pcre2_set_character_tables(p->pcre2_compile_context,
 291                                                         p->pcre2_tables);
 292                 }
 293                 options |= PCRE2_CASELESS;
 294         }
 295         if (!opt->ignore_locale && is_utf8_locale() && !literal)
 296                 options |= (PCRE2_UTF | PCRE2_UCP | PCRE2_MATCH_INVALID_UTF);
 297
 298 #ifndef GIT_PCRE2_VERSION_10_35_OR_HIGHER
 299         /*
 300          * Work around a JIT bug related to invalid Unicode character handling
 301          * fixed in 10.35:
 302          * https://github.com/PCRE2Project/pcre2/commit/c21bd977547d
 303          */
 304         options &= ~PCRE2_UCP;
 305 #endif
 306
 307 #ifndef GIT_PCRE2_VERSION_10_36_OR_HIGHER
 308         /* Work around https://bugs.exim.org/show_bug.cgi?id=2642 fixed in 10.36 */
 309         if (PCRE2_MATCH_INVALID_UTF && options & (PCRE2_UTF | PCRE2_CASELESS))
 310                 options |= PCRE2_NO_START_OPTIMIZE;
 311 #endif
 312
 313         p->pcre2_pattern = pcre2_compile((PCRE2_SPTR)p->pattern,
 314                                          p->patternlen, options, &error, &erroffset,
 315                                          p->pcre2_compile_context);
 316
 317         if (p->pcre2_pattern) {
 318                 p->pcre2_match_data = pcre2_match_data_create_from_pattern(p->pcre2_pattern, p->pcre2_general_context);
 319                 if (!p->pcre2_match_data)
 320                         die("Couldn't allocate PCRE2 match data");
 321         } else {
 322                 pcre2_get_error_message(error, errbuf, sizeof(errbuf));
 323                 compile_regexp_failed(p, (const char *)&errbuf);
 324         }
 325
 326         pcre2_config(PCRE2_CONFIG_JIT, &p->pcre2_jit_on);
 327         if (p->pcre2_jit_on) {
 328                 jitret = pcre2_jit_compile(p->pcre2_pattern, PCRE2_JIT_COMPLETE);
 329                 if (jitret)
 330                         die("Couldn't JIT the PCRE2 pattern '%s', got '%d'\n", p->pattern, jitret);
 331
 332                 /*
 333                  * The pcre2_config(PCRE2_CONFIG_JIT, ...) call just
 334                  * tells us whether the library itself supports JIT,
 335                  * but to see whether we're going to be actually using
 336                  * JIT we need to extract PCRE2_INFO_JITSIZE from the
 337                  * pattern *after* we do pcre2_jit_compile() above.
 338                  *
 339                  * This is because if the pattern contains the
 340                  * (*NO_JIT) verb (see pcre2syntax(3))
 341                  * pcre2_jit_compile() will exit early with 0. If we
 342                  * then proceed to call pcre2_jit_match() further down
 343                  * the line instead of pcre2_match() we'll either
 344                  * segfault (pre PCRE 10.31) or run into a fatal error
 345                  * (post PCRE2 10.31)
 346                  */
 347                 patinforet = pcre2_pattern_info(p->pcre2_pattern, PCRE2_INFO_JITSIZE, &jitsizearg);
 348                 if (patinforet)
 349                         BUG("pcre2_pattern_info() failed: %d", patinforet);
 350                 if (jitsizearg == 0) {
 351                         p->pcre2_jit_on = 0;
 352                         return;
 353                 }
 354         }
 355 }
 356
 357 static int pcre2match(struct grep_pat *p, const char *line, const char *eol,
 358                 regmatch_t *match, int eflags)
 359 {
 360         int ret, flags = 0;
 361         PCRE2_SIZE *ovector;
 362         PCRE2_UCHAR errbuf[256];
 363
 364         if (eflags & REG_NOTBOL)
 365                 flags |= PCRE2_NOTBOL;
 366
 367         if (p->pcre2_jit_on)
 368                 ret = pcre2_jit_match(p->pcre2_pattern, (unsigned char *)line,
 369                                       eol - line, 0, flags, p->pcre2_match_data,
 370                                       NULL);
 371         else
 372                 ret = pcre2_match(p->pcre2_pattern, (unsigned char *)line,
 373                                   eol - line, 0, flags, p->pcre2_match_data,
 374                                   NULL);
 375
 376         if (ret < 0 && ret != PCRE2_ERROR_NOMATCH) {
 377                 pcre2_get_error_message(ret, errbuf, sizeof(errbuf));
 378                 die("%s failed with error code %d: %s",
 379                     (p->pcre2_jit_on ? "pcre2_jit_match" : "pcre2_match"), ret,
 380                     errbuf);
 381         }
 382         if (ret > 0) {
 383                 ovector = pcre2_get_ovector_pointer(p->pcre2_match_data);
 384                 ret = 0;
 385                 match->rm_so = (int)ovector[0];
 386                 match->rm_eo = (int)ovector[1];
 387         }
 388
 389         return ret;
 390 }
 391
 392 static void free_pcre2_pattern(struct grep_pat *p)
 393 {
 394         pcre2_compile_context_free(p->pcre2_compile_context);
 395         pcre2_code_free(p->pcre2_pattern);
 396         pcre2_match_data_free(p->pcre2_match_data);
 397 #ifdef GIT_PCRE2_VERSION_10_34_OR_HIGHER
 398         pcre2_maketables_free(p->pcre2_general_context, p->pcre2_tables);
 399 #else
 400         free((void *)p->pcre2_tables);
 401 #endif
 402         pcre2_general_context_free(p->pcre2_general_context);
 403 }
 404 #else /* !USE_LIBPCRE2 */
 405 static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)
 406 {
 407         die("cannot use Perl-compatible regexes when not compiled with USE_LIBPCRE");
 408 }
 409
 410 static int pcre2match(struct grep_pat *p, const char *line, const char *eol,
 411                 regmatch_t *match, int eflags)
 412 {
 413         return 1;
 414 }
 415
 416 static void free_pcre2_pattern(struct grep_pat *p)
 417 {
 418 }
 419
 420 static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
 421 {
 422         struct strbuf sb = STRBUF_INIT;
 423         int err;
 424         int regflags = 0;
 425
 426         basic_regex_quote_buf(&sb, p->pattern);
 427         if (opt->ignore_case)
 428                 regflags |= REG_ICASE;
 429         err = regcomp(&p->regexp, sb.buf, regflags);
 430         strbuf_release(&sb);
 431         if (err) {
 432                 char errbuf[1024];
 433                 regerror(err, &p->regexp, errbuf, sizeof(errbuf));
 434                 compile_regexp_failed(p, errbuf);
 435         }
 436 }
 437 #endif /* !USE_LIBPCRE2 */
 438
 439 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 440 {
 441         int err;
 442         int regflags = REG_NEWLINE;
 443
 444         if (opt->pattern_type_option == GREP_PATTERN_TYPE_UNSPECIFIED)
 445                 opt->pattern_type_option = (opt->extended_regexp_option
 446                                             ? GREP_PATTERN_TYPE_ERE
 447                                             : GREP_PATTERN_TYPE_BRE);
 448
 449         p->word_regexp = opt->word_regexp;
 450         p->ignore_case = opt->ignore_case;
 451         p->fixed = opt->pattern_type_option == GREP_PATTERN_TYPE_FIXED;
 452
 453         if (opt->pattern_type_option != GREP_PATTERN_TYPE_PCRE &&
 454             memchr(p->pattern, 0, p->patternlen))
 455                 die(_("given pattern contains NULL byte (via -f <file>). This is only supported with -P under PCRE v2"));
 456
 457         p->is_fixed = is_fixed(p->pattern, p->patternlen);
 458 #ifdef USE_LIBPCRE2
 459        if (!p->fixed && !p->is_fixed) {
 460                const char *no_jit = "(*NO_JIT)";
 461                const int no_jit_len = strlen(no_jit);
 462                if (starts_with(p->pattern, no_jit) &&
 463                    is_fixed(p->pattern + no_jit_len,
 464                             p->patternlen - no_jit_len))
 465                        p->is_fixed = 1;
 466        }
 467 #endif
 468         if (p->fixed || p->is_fixed) {
 469 #ifdef USE_LIBPCRE2
 470                 if (p->is_fixed) {
 471                         compile_pcre2_pattern(p, opt);
 472                 } else {
 473                         /*
 474                          * E.g. t7811-grep-open.sh relies on the
 475                          * pattern being restored.
 476                          */
 477                         char *old_pattern = p->pattern;
 478                         size_t old_patternlen = p->patternlen;
 479                         struct strbuf sb = STRBUF_INIT;
 480
 481                         /*
 482                          * There is the PCRE2_LITERAL flag, but it's
 483                          * only in PCRE v2 10.30 and later. Needing to
 484                          * ifdef our way around that and dealing with
 485                          * it + PCRE2_MULTILINE being an error is more
 486                          * complex than just quoting this ourselves.
 487                         */
 488                         strbuf_add(&sb, "\\Q", 2);
 489                         strbuf_add(&sb, p->pattern, p->patternlen);
 490                         strbuf_add(&sb, "\\E", 2);
 491
 492                         p->pattern = sb.buf;
 493                         p->patternlen = sb.len;
 494                         compile_pcre2_pattern(p, opt);
 495                         p->pattern = old_pattern;
 496                         p->patternlen = old_patternlen;
 497                         strbuf_release(&sb);
 498                 }
 499 #else /* !USE_LIBPCRE2 */
 500                 compile_fixed_regexp(p, opt);
 501 #endif /* !USE_LIBPCRE2 */
 502                 return;
 503         }
 504
 505         if (opt->pattern_type_option == GREP_PATTERN_TYPE_PCRE) {
 506                 compile_pcre2_pattern(p, opt);
 507                 return;
 508         }
 509
 510         if (p->ignore_case)
 511                 regflags |= REG_ICASE;
 512         if (opt->pattern_type_option == GREP_PATTERN_TYPE_ERE)
 513                 regflags |= REG_EXTENDED;
 514         err = regcomp(&p->regexp, p->pattern, regflags);
 515         if (err) {
 516                 char errbuf[1024];
 517                 regerror(err, &p->regexp, errbuf, 1024);
 518                 compile_regexp_failed(p, errbuf);
 519         }
 520 }
 521
 522 static struct grep_expr *grep_not_expr(struct grep_expr *expr)
 523 {
 524         struct grep_expr *z = xcalloc(1, sizeof(*z));
 525         z->node = GREP_NODE_NOT;
 526         z->u.unary = expr;
 527         return z;
 528 }
 529
 530 static struct grep_expr *grep_binexp(enum grep_expr_node kind,
 531                                      struct grep_expr *left,
 532                                      struct grep_expr *right)
 533 {
 534         struct grep_expr *z = xcalloc(1, sizeof(*z));
 535         z->node = kind;
 536         z->u.binary.left = left;
 537         z->u.binary.right = right;
 538         return z;
 539 }
 540
 541 static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
 542 {
 543         return grep_binexp(GREP_NODE_OR, left, right);
 544 }
 545
 546 static struct grep_expr *grep_and_expr(struct grep_expr *left, struct grep_expr *right)
 547 {
 548         return grep_binexp(GREP_NODE_AND, left, right);
 549 }
 550
 551 static struct grep_expr *compile_pattern_or(struct grep_pat **);
 552 static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
 553 {
 554         struct grep_pat *p;
 555         struct grep_expr *x;
 556
 557         p = *list;
 558         if (!p)
 559                 return NULL;
 560         switch (p->token) {
 561         case GREP_PATTERN: /* atom */
 562         case GREP_PATTERN_HEAD:
 563         case GREP_PATTERN_BODY:
 564                 CALLOC_ARRAY(x, 1);
 565                 x->node = GREP_NODE_ATOM;
 566                 x->u.atom = p;
 567                 *list = p->next;
 568                 return x;
 569         case GREP_OPEN_PAREN:
 570                 *list = p->next;
 571                 x = compile_pattern_or(list);
 572                 if (!*list || (*list)->token != GREP_CLOSE_PAREN)
 573                         die("unmatched parenthesis");
 574                 *list = (*list)->next;
 575                 return x;
 576         default:
 577                 return NULL;
 578         }
 579 }
 580
 581 static struct grep_expr *compile_pattern_not(struct grep_pat **list)
 582 {
 583         struct grep_pat *p;
 584         struct grep_expr *x;
 585
 586         p = *list;
 587         if (!p)
 588                 return NULL;
 589         switch (p->token) {
 590         case GREP_NOT:
 591                 if (!p->next)
 592                         die("--not not followed by pattern expression");
 593                 *list = p->next;
 594                 x = compile_pattern_not(list);
 595                 if (!x)
 596                         die("--not followed by non pattern expression");
 597                 return grep_not_expr(x);
 598         default:
 599                 return compile_pattern_atom(list);
 600         }
 601 }
 602
 603 static struct grep_expr *compile_pattern_and(struct grep_pat **list)
 604 {
 605         struct grep_pat *p;
 606         struct grep_expr *x, *y;
 607
 608         x = compile_pattern_not(list);
 609         p = *list;
 610         if (p && p->token == GREP_AND) {
 611                 if (!x)
 612                         die("--and not preceded by pattern expression");
 613                 if (!p->next)
 614                         die("--and not followed by pattern expression");
 615                 *list = p->next;
 616                 y = compile_pattern_and(list);
 617                 if (!y)
 618                         die("--and not followed by pattern expression");
 619                 return grep_and_expr(x, y);
 620         }
 621         return x;
 622 }
 623
 624 static struct grep_expr *compile_pattern_or(struct grep_pat **list)
 625 {
 626         struct grep_pat *p;
 627         struct grep_expr *x, *y;
 628
 629         x = compile_pattern_and(list);
 630         p = *list;
 631         if (x && p && p->token != GREP_CLOSE_PAREN) {
 632                 y = compile_pattern_or(list);
 633                 if (!y)
 634                         die("not a pattern expression %s", p->pattern);
 635                 return grep_or_expr(x, y);
 636         }
 637         return x;
 638 }
 639
 640 static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
 641 {
 642         return compile_pattern_or(list);
 643 }
 644
 645 static struct grep_expr *grep_true_expr(void)
 646 {
 647         struct grep_expr *z = xcalloc(1, sizeof(*z));
 648         z->node = GREP_NODE_TRUE;
 649         return z;
 650 }
 651
 652 static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
 653 {
 654         struct grep_pat *p;
 655         struct grep_expr *header_expr;
 656         struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
 657         enum grep_header_field fld;
 658
 659         if (!opt->header_list)
 660                 return NULL;
 661
 662         for (p = opt->header_list; p; p = p->next) {
 663                 if (p->token != GREP_PATTERN_HEAD)
 664                         BUG("a non-header pattern in grep header list.");
 665                 if (p->field < GREP_HEADER_FIELD_MIN ||
 666                     GREP_HEADER_FIELD_MAX <= p->field)
 667                         BUG("unknown header field %d", p->field);
 668                 compile_regexp(p, opt);
 669         }
 670
 671         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
 672                 header_group[fld] = NULL;
 673
 674         for (p = opt->header_list; p; p = p->next) {
 675                 struct grep_expr *h;
 676                 struct grep_pat *pp = p;
 677
 678                 h = compile_pattern_atom(&pp);
 679                 if (!h || pp != p->next)
 680                         BUG("malformed header expr");
 681                 if (!header_group[p->field]) {
 682                         header_group[p->field] = h;
 683                         continue;
 684                 }
 685                 header_group[p->field] = grep_or_expr(h, header_group[p->field]);
 686         }
 687
 688         header_expr = NULL;
 689
 690         for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
 691                 if (!header_group[fld])
 692                         continue;
 693                 if (!header_expr)
 694                         header_expr = grep_true_expr();
 695                 header_expr = grep_or_expr(header_group[fld], header_expr);
 696         }
 697         return header_expr;
 698 }
 699
 700 static struct grep_expr *grep_splice_or(struct grep_expr *x, struct grep_expr *y)
 701 {
 702         struct grep_expr *z = x;
 703
 704         while (x) {
 705                 assert(x->node == GREP_NODE_OR);
 706                 if (x->u.binary.right &&
 707                     x->u.binary.right->node == GREP_NODE_TRUE) {
 708                         x->u.binary.right = y;
 709                         break;
 710                 }
 711                 x = x->u.binary.right;
 712         }
 713         return z;
 714 }
 715
 716 void compile_grep_patterns(struct grep_opt *opt)
 717 {
 718         struct grep_pat *p;
 719         struct grep_expr *header_expr = prep_header_patterns(opt);
 720         int extended = 0;
 721
 722         for (p = opt->pattern_list; p; p = p->next) {
 723                 switch (p->token) {
 724                 case GREP_PATTERN: /* atom */
 725                 case GREP_PATTERN_HEAD:
 726                 case GREP_PATTERN_BODY:
 727                         compile_regexp(p, opt);
 728                         break;
 729                 default:
 730                         extended = 1;
 731                         break;
 732                 }
 733         }
 734
 735         if (opt->all_match || opt->no_body_match || header_expr)
 736                 extended = 1;
 737         else if (!extended)
 738                 return;
 739
 740         p = opt->pattern_list;
 741         if (p)
 742                 opt->pattern_expression = compile_pattern_expr(&p);
 743         if (p)
 744                 die("incomplete pattern expression: %s", p->pattern);
 745
 746         if (opt->no_body_match && opt->pattern_expression)
 747                 opt->pattern_expression = grep_not_expr(opt->pattern_expression);
 748
 749         if (!header_expr)
 750                 return;
 751
 752         if (!opt->pattern_expression)
 753                 opt->pattern_expression = header_expr;
 754         else if (opt->all_match)
 755                 opt->pattern_expression = grep_splice_or(header_expr,
 756                                                          opt->pattern_expression);
 757         else
 758                 opt->pattern_expression = grep_or_expr(opt->pattern_expression,
 759                                                        header_expr);
 760         opt->all_match = 1;
 761 }
 762
 763 static void free_pattern_expr(struct grep_expr *x)
 764 {
 765         switch (x->node) {
 766         case GREP_NODE_TRUE:
 767         case GREP_NODE_ATOM:
 768                 break;
 769         case GREP_NODE_NOT:
 770                 free_pattern_expr(x->u.unary);
 771                 break;
 772         case GREP_NODE_AND:
 773         case GREP_NODE_OR:
 774                 free_pattern_expr(x->u.binary.left);
 775                 free_pattern_expr(x->u.binary.right);
 776                 break;
 777         }
 778         free(x);
 779 }
 780
 781 void free_grep_patterns(struct grep_opt *opt)
 782 {
 783         struct grep_pat *p, *n;
 784
 785         for (p = opt->pattern_list; p; p = n) {
 786                 n = p->next;
 787                 switch (p->token) {
 788                 case GREP_PATTERN: /* atom */
 789                 case GREP_PATTERN_HEAD:
 790                 case GREP_PATTERN_BODY:
 791                         if (p->pcre2_pattern)
 792                                 free_pcre2_pattern(p);
 793                         else
 794                                 regfree(&p->regexp);
 795                         free(p->pattern);
 796                         break;
 797                 default:
 798                         break;
 799                 }
 800                 free(p);
 801         }
 802
 803         if (!opt->pattern_expression)
 804                 return;
 805         free_pattern_expr(opt->pattern_expression);
 806 }
 807
 808 static const char *end_of_line(const char *cp, unsigned long *left)
 809 {
 810         unsigned long l = *left;
 811         while (l && *cp != '\n') {
 812                 l--;
 813                 cp++;
 814         }
 815         *left = l;
 816         return cp;
 817 }
 818
 819 static int word_char(char ch)
 820 {
 821         return isalnum(ch) || ch == '_';
 822 }
 823
 824 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 825                          const char *color)
 826 {
 827         if (want_color(opt->color) && color && color[0]) {
 828                 opt->output(opt, color, strlen(color));
 829                 opt->output(opt, data, size);
 830                 opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
 831         } else
 832                 opt->output(opt, data, size);
 833 }
 834
 835 static void output_sep(struct grep_opt *opt, char sign)
 836 {
 837         if (opt->null_following_name)
 838                 opt->output(opt, "\0", 1);
 839         else
 840                 output_color(opt, &sign, 1, opt->colors[GREP_COLOR_SEP]);
 841 }
 842
 843 static void show_name(struct grep_opt *opt, const char *name)
 844 {
 845         output_color(opt, name, strlen(name), opt->colors[GREP_COLOR_FILENAME]);
 846         opt->output(opt, opt->null_following_name ? "\0" : "\n", 1);
 847 }
 848
 849 static int patmatch(struct grep_pat *p,
 850                     const char *line, const char *eol,
 851                     regmatch_t *match, int eflags)
 852 {
 853         int hit;
 854
 855         if (p->pcre2_pattern)
 856                 hit = !pcre2match(p, line, eol, match, eflags);
 857         else
 858                 hit = !regexec_buf(&p->regexp, line, eol - line, 1, match,
 859                                    eflags);
 860
 861         return hit;
 862 }
 863
 864 static void strip_timestamp(const char *bol, const char **eol_p)
 865 {
 866         const char *eol = *eol_p;
 867
 868         while (bol < --eol) {
 869                 if (*eol != '>')
 870                         continue;
 871                 *eol_p = ++eol;
 872                 break;
 873         }
 874 }
 875
 876 static struct {
 877         const char *field;
 878         size_t len;
 879 } header_field[] = {
 880         { "author ", 7 },
 881         { "committer ", 10 },
 882         { "reflog ", 7 },
 883 };
 884
 885 static int headerless_match_one_pattern(struct grep_pat *p,
 886                                         const char *bol, const char *eol,
 887                                         enum grep_context ctx,
 888                                         regmatch_t *pmatch, int eflags)
 889 {
 890         int hit = 0;
 891         const char *start = bol;
 892
 893         if ((p->token != GREP_PATTERN) &&
 894             ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
 895                 return 0;
 896
 897  again:
 898         hit = patmatch(p, bol, eol, pmatch, eflags);
 899
 900         if (hit && p->word_regexp) {
 901                 if ((pmatch[0].rm_so < 0) ||
 902                     (eol - bol) < pmatch[0].rm_so ||
 903                     (pmatch[0].rm_eo < 0) ||
 904                     (eol - bol) < pmatch[0].rm_eo)
 905                         die("regexp returned nonsense");
 906
 907                 /* Match beginning must be either beginning of the
 908                  * line, or at word boundary (i.e. the last char must
 909                  * not be a word char).  Similarly, match end must be
 910                  * either end of the line, or at word boundary
 911                  * (i.e. the next char must not be a word char).
 912                  */
 913                 if ( ((pmatch[0].rm_so == 0) ||
 914                       !word_char(bol[pmatch[0].rm_so-1])) &&
 915                      ((pmatch[0].rm_eo == (eol-bol)) ||
 916                       !word_char(bol[pmatch[0].rm_eo])) )
 917                         ;
 918                 else
 919                         hit = 0;
 920
 921                 /* Words consist of at least one character. */
 922                 if (pmatch->rm_so == pmatch->rm_eo)
 923                         hit = 0;
 924
 925                 if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
 926                         /* There could be more than one match on the
 927                          * line, and the first match might not be
 928                          * strict word match.  But later ones could be!
 929                          * Forward to the next possible start, i.e. the
 930                          * next position following a non-word char.
 931                          */
 932                         bol = pmatch[0].rm_so + bol + 1;
 933                         while (word_char(bol[-1]) && bol < eol)
 934                                 bol++;
 935                         eflags |= REG_NOTBOL;
 936                         if (bol < eol)
 937                                 goto again;
 938                 }
 939         }
 940         if (hit) {
 941                 pmatch[0].rm_so += bol - start;
 942                 pmatch[0].rm_eo += bol - start;
 943         }
 944         return hit;
 945 }
 946
 947 static int match_one_pattern(struct grep_pat *p,
 948                              const char *bol, const char *eol,
 949                              enum grep_context ctx, regmatch_t *pmatch,
 950                              int eflags)
 951 {
 952         const char *field;
 953         size_t len;
 954
 955         if (p->token == GREP_PATTERN_HEAD) {
 956                 assert(p->field < ARRAY_SIZE(header_field));
 957                 field = header_field[p->field].field;
 958                 len = header_field[p->field].len;
 959                 if (strncmp(bol, field, len))
 960                         return 0;
 961                 bol += len;
 962
 963                 switch (p->field) {
 964                 case GREP_HEADER_AUTHOR:
 965                 case GREP_HEADER_COMMITTER:
 966                         strip_timestamp(bol, &eol);
 967                         break;
 968                 default:
 969                         break;
 970                 }
 971         }
 972
 973         return headerless_match_one_pattern(p, bol, eol, ctx, pmatch, eflags);
 974 }
 975
 976
 977 static int match_expr_eval(struct grep_opt *opt, struct grep_expr *x,
 978                            const char *bol, const char *eol,
 979                            enum grep_context ctx, ssize_t *col,
 980                            ssize_t *icol, int collect_hits)
 981 {
 982         int h = 0;
 983
 984         switch (x->node) {
 985         case GREP_NODE_TRUE:
 986                 h = 1;
 987                 break;
 988         case GREP_NODE_ATOM:
 989                 {
 990                         regmatch_t tmp;
 991                         h = match_one_pattern(x->u.atom, bol, eol, ctx,
 992                                               &tmp, 0);
 993                         if (h && (*col < 0 || tmp.rm_so < *col))
 994                                 *col = tmp.rm_so;
 995                 }
 996                 if (x->u.atom->token == GREP_PATTERN_BODY)
 997                         opt->body_hit |= h;
 998                 break;
 999         case GREP_NODE_NOT:
1000                 /*
1001                  * Upon visiting a GREP_NODE_NOT, col and icol become swapped.
1002                  */
1003                 h = !match_expr_eval(opt, x->u.unary, bol, eol, ctx, icol, col,
1004                                      0);
1005                 break;
1006         case GREP_NODE_AND:
1007                 h = match_expr_eval(opt, x->u.binary.left, bol, eol, ctx, col,
1008                                     icol, 0);
1009                 if (h || opt->columnnum) {
1010                         /*
1011                          * Don't short-circuit AND when given --column, since a
1012                          * NOT earlier in the tree may turn this into an OR. In
1013                          * this case, see the below comment.
1014                          */
1015                         h &= match_expr_eval(opt, x->u.binary.right, bol, eol,
1016                                              ctx, col, icol, 0);
1017                 }
1018                 break;
1019         case GREP_NODE_OR:
1020                 if (!(collect_hits || opt->columnnum)) {
1021                         /*
1022                          * Don't short-circuit OR when given --column (or
1023                          * collecting hits) to ensure we don't skip a later
1024                          * child that would produce an earlier match.
1025                          */
1026                         return (match_expr_eval(opt, x->u.binary.left, bol, eol,
1027                                                 ctx, col, icol, 0) ||
1028                                 match_expr_eval(opt, x->u.binary.right, bol,
1029                                                 eol, ctx, col, icol, 0));
1030                 }
1031                 h = match_expr_eval(opt, x->u.binary.left, bol, eol, ctx, col,
1032                                     icol, 0);
1033                 if (collect_hits)
1034                         x->u.binary.left->hit |= h;
1035                 h |= match_expr_eval(opt, x->u.binary.right, bol, eol, ctx, col,
1036                                      icol, collect_hits);
1037                 break;
1038         default:
1039                 die("Unexpected node type (internal error) %d", x->node);
1040         }
1041         if (collect_hits)
1042                 x->hit |= h;
1043         return h;
1044 }
1045
1046 static int match_expr(struct grep_opt *opt,
1047                       const char *bol, const char *eol,
1048                       enum grep_context ctx, ssize_t *col,
1049                       ssize_t *icol, int collect_hits)
1050 {
1051         struct grep_expr *x = opt->pattern_expression;
1052         return match_expr_eval(opt, x, bol, eol, ctx, col, icol, collect_hits);
1053 }
1054
1055 static int match_line(struct grep_opt *opt,
1056                       const char *bol, const char *eol,
1057                       ssize_t *col, ssize_t *icol,
1058                       enum grep_context ctx, int collect_hits)
1059 {
1060         struct grep_pat *p;
1061         int hit = 0;
1062
1063         if (opt->pattern_expression)
1064                 return match_expr(opt, bol, eol, ctx, col, icol,
1065                                   collect_hits);
1066
1067         /* we do not call with collect_hits without being extended */
1068         for (p = opt->pattern_list; p; p = p->next) {
1069                 regmatch_t tmp;
1070                 if (match_one_pattern(p, bol, eol, ctx, &tmp, 0)) {
1071                         hit |= 1;
1072                         if (!opt->columnnum) {
1073                                 /*
1074                                  * Without --column, any single match on a line
1075                                  * is enough to know that it needs to be
1076                                  * printed. With --column, scan _all_ patterns
1077                                  * to find the earliest.
1078                                  */
1079                                 break;
1080                         }
1081                         if (*col < 0 || tmp.rm_so < *col)
1082                                 *col = tmp.rm_so;
1083                 }
1084         }
1085         return hit;
1086 }
1087
1088 static int match_next_pattern(struct grep_pat *p,
1089                               const char *bol, const char *eol,
1090                               enum grep_context ctx,
1091                               regmatch_t *pmatch, int eflags)
1092 {
1093         regmatch_t match;
1094
1095         if (!headerless_match_one_pattern(p, bol, eol, ctx, &match, eflags))
1096                 return 0;
1097         if (match.rm_so < 0 || match.rm_eo < 0)
1098                 return 0;
1099         if (pmatch->rm_so >= 0 && pmatch->rm_eo >= 0) {
1100                 if (match.rm_so > pmatch->rm_so)
1101                         return 1;
1102                 if (match.rm_so == pmatch->rm_so && match.rm_eo < pmatch->rm_eo)
1103                         return 1;
1104         }
1105         pmatch->rm_so = match.rm_so;
1106         pmatch->rm_eo = match.rm_eo;
1107         return 1;
1108 }
1109
1110 int grep_next_match(struct grep_opt *opt,
1111                     const char *bol, const char *eol,
1112                     enum grep_context ctx, regmatch_t *pmatch,
1113                     enum grep_header_field field, int eflags)
1114 {
1115         struct grep_pat *p;
1116         int hit = 0;
1117
1118         pmatch->rm_so = pmatch->rm_eo = -1;
1119         if (bol < eol) {
1120                 for (p = ((ctx == GREP_CONTEXT_HEAD)
1121                            ? opt->header_list : opt->pattern_list);
1122                           p; p = p->next) {
1123                         switch (p->token) {
1124                         case GREP_PATTERN_HEAD:
1125                                 if ((field != GREP_HEADER_FIELD_MAX) &&
1126                                     (p->field != field))
1127                                         continue;
1128                                 /* fall thru */
1129                         case GREP_PATTERN: /* atom */
1130                         case GREP_PATTERN_BODY:
1131                                 hit |= match_next_pattern(p, bol, eol, ctx,
1132                                                           pmatch, eflags);
1133                                 break;
1134                         default:
1135                                 break;
1136                         }
1137                 }
1138         }
1139         return hit;
1140 }
1141
1142 static void show_line_header(struct grep_opt *opt, const char *name,
1143                              unsigned lno, ssize_t cno, char sign)
1144 {
1145         if (opt->heading && opt->last_shown == 0) {
1146                 output_color(opt, name, strlen(name), opt->colors[GREP_COLOR_FILENAME]);
1147                 opt->output(opt, "\n", 1);
1148         }
1149         opt->last_shown = lno;
1150
1151         if (!opt->heading && opt->pathname) {
1152                 output_color(opt, name, strlen(name), opt->colors[GREP_COLOR_FILENAME]);
1153                 output_sep(opt, sign);
1154         }
1155         if (opt->linenum) {
1156                 char buf[32];
1157                 xsnprintf(buf, sizeof(buf), "%d", lno);
1158                 output_color(opt, buf, strlen(buf), opt->colors[GREP_COLOR_LINENO]);
1159                 output_sep(opt, sign);
1160         }
1161         /*
1162          * Treat 'cno' as the 1-indexed offset from the start of a non-context
1163          * line to its first match. Otherwise, 'cno' is 0 indicating that we are
1164          * being called with a context line.
1165          */
1166         if (opt->columnnum && cno) {
1167                 char buf[32];
1168                 xsnprintf(buf, sizeof(buf), "%"PRIuMAX, (uintmax_t)cno);
1169                 output_color(opt, buf, strlen(buf), opt->colors[GREP_COLOR_COLUMNNO]);
1170                 output_sep(opt, sign);
1171         }
1172 }
1173
1174 static void show_line(struct grep_opt *opt,
1175                       const char *bol, const char *eol,
1176                       const char *name, unsigned lno, ssize_t cno, char sign)
1177 {
1178         int rest = eol - bol;
1179         const char *match_color = NULL;
1180         const char *line_color = NULL;
1181
1182         if (opt->file_break && opt->last_shown == 0) {
1183                 if (opt->show_hunk_mark)
1184                         opt->output(opt, "\n", 1);
1185         } else if (opt->pre_context || opt->post_context || opt->funcbody) {
1186                 if (opt->last_shown == 0) {
1187                         if (opt->show_hunk_mark) {
1188                                 output_color(opt, "--", 2, opt->colors[GREP_COLOR_SEP]);
1189                                 opt->output(opt, "\n", 1);
1190                         }
1191                 } else if (lno > opt->last_shown + 1) {
1192                         output_color(opt, "--", 2, opt->colors[GREP_COLOR_SEP]);
1193                         opt->output(opt, "\n", 1);
1194                 }
1195         }
1196         if (!opt->only_matching) {
1197                 /*
1198                  * In case the line we're being called with contains more than
1199                  * one match, leave printing each header to the loop below.
1200                  */
1201                 show_line_header(opt, name, lno, cno, sign);
1202         }
1203         if (opt->color || opt->only_matching) {
1204                 regmatch_t match;
1205                 enum grep_context ctx = GREP_CONTEXT_BODY;
1206                 int eflags = 0;
1207
1208                 if (opt->color) {
1209                         if (sign == ':')
1210                                 match_color = opt->colors[GREP_COLOR_MATCH_SELECTED];
1211                         else
1212                                 match_color = opt->colors[GREP_COLOR_MATCH_CONTEXT];
1213                         if (sign == ':')
1214                                 line_color = opt->colors[GREP_COLOR_SELECTED];
1215                         else if (sign == '-')
1216                                 line_color = opt->colors[GREP_COLOR_CONTEXT];
1217                         else if (sign == '=')
1218                                 line_color = opt->colors[GREP_COLOR_FUNCTION];
1219                 }
1220                 while (grep_next_match(opt, bol, eol, ctx, &match,
1221                                        GREP_HEADER_FIELD_MAX, eflags)) {
1222                         if (match.rm_so == match.rm_eo)
1223                                 break;
1224
1225                         if (opt->only_matching)
1226                                 show_line_header(opt, name, lno, cno, sign);
1227                         else
1228                                 output_color(opt, bol, match.rm_so, line_color);
1229                         output_color(opt, bol + match.rm_so,
1230                                      match.rm_eo - match.rm_so, match_color);
1231                         if (opt->only_matching)
1232                                 opt->output(opt, "\n", 1);
1233                         bol += match.rm_eo;
1234                         cno += match.rm_eo;
1235                         rest -= match.rm_eo;
1236                         eflags = REG_NOTBOL;
1237                 }
1238         }
1239         if (!opt->only_matching) {
1240                 output_color(opt, bol, rest, line_color);
1241                 opt->output(opt, "\n", 1);
1242         }
1243 }
1244
1245 int grep_use_locks;
1246
1247 /*
1248  * This lock protects access to the gitattributes machinery, which is
1249  * not thread-safe.
1250  */
1251 pthread_mutex_t grep_attr_mutex;
1252
1253 static inline void grep_attr_lock(void)
1254 {
1255         if (grep_use_locks)
1256                 pthread_mutex_lock(&grep_attr_mutex);
1257 }
1258
1259 static inline void grep_attr_unlock(void)
1260 {
1261         if (grep_use_locks)
1262                 pthread_mutex_unlock(&grep_attr_mutex);
1263 }
1264
1265 static int match_funcname(struct grep_opt *opt, struct grep_source *gs,
1266                           const char *bol, const char *eol)
1267 {
1268         xdemitconf_t *xecfg = opt->priv;
1269         if (xecfg && !xecfg->find_func) {
1270                 grep_source_load_driver(gs, opt->repo->index);
1271                 if (gs->driver->funcname.pattern) {
1272                         const struct userdiff_funcname *pe = &gs->driver->funcname;
1273                         xdiff_set_find_func(xecfg, pe->pattern, pe->cflags);
1274                 } else {
1275                         xecfg = opt->priv = NULL;
1276                 }
1277         }
1278
1279         if (xecfg) {
1280                 char buf[1];
1281                 return xecfg->find_func(bol, eol - bol, buf, 1,
1282                                         xecfg->find_func_priv) >= 0;
1283         }
1284
1285         if (bol == eol)
1286                 return 0;
1287         if (isalpha(*bol) || *bol == '_' || *bol == '$')
1288                 return 1;
1289         return 0;
1290 }
1291
1292 static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
1293                                const char *bol, unsigned lno)
1294 {
1295         while (bol > gs->buf) {
1296                 const char *eol = --bol;
1297
1298                 while (bol > gs->buf && bol[-1] != '\n')
1299                         bol--;
1300                 lno--;
1301
1302                 if (lno <= opt->last_shown)
1303                         break;
1304
1305                 if (match_funcname(opt, gs, bol, eol)) {
1306                         show_line(opt, bol, eol, gs->name, lno, 0, '=');
1307                         break;
1308                 }
1309         }
1310 }
1311
1312 static int is_empty_line(const char *bol, const char *eol);
1313
1314 static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
1315                              const char *bol, const char *end, unsigned lno)
1316 {
1317         unsigned cur = lno, from = 1, funcname_lno = 0, orig_from;
1318         int funcname_needed = !!opt->funcname, comment_needed = 0;
1319
1320         if (opt->pre_context < lno)
1321                 from = lno - opt->pre_context;
1322         if (from <= opt->last_shown)
1323                 from = opt->last_shown + 1;
1324         orig_from = from;
1325         if (opt->funcbody) {
1326                 if (match_funcname(opt, gs, bol, end))
1327                         comment_needed = 1;
1328                 else
1329                         funcname_needed = 1;
1330                 from = opt->last_shown + 1;
1331         }
1332
1333         /* Rewind. */
1334         while (bol > gs->buf && cur > from) {
1335                 const char *next_bol = bol;
1336                 const char *eol = --bol;
1337
1338                 while (bol > gs->buf && bol[-1] != '\n')
1339                         bol--;
1340                 cur--;
1341                 if (comment_needed && (is_empty_line(bol, eol) ||
1342                                        match_funcname(opt, gs, bol, eol))) {
1343                         comment_needed = 0;
1344                         from = orig_from;
1345                         if (cur < from) {
1346                                 cur++;
1347                                 bol = next_bol;
1348                                 break;
1349                         }
1350                 }
1351                 if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
1352                         funcname_lno = cur;
1353                         funcname_needed = 0;
1354                         if (opt->funcbody)
1355                                 comment_needed = 1;
1356                         else
1357                                 from = orig_from;
1358                 }
1359         }
1360
1361         /* We need to look even further back to find a function signature. */
1362         if (opt->funcname && funcname_needed)
1363                 show_funcname_line(opt, gs, bol, cur);
1364
1365         /* Back forward. */
1366         while (cur < lno) {
1367                 const char *eol = bol, sign = (cur == funcname_lno) ? '=' : '-';
1368
1369                 while (*eol != '\n')
1370                         eol++;
1371                 show_line(opt, bol, eol, gs->name, cur, 0, sign);
1372                 bol = eol + 1;
1373                 cur++;
1374         }
1375 }
1376
1377 static int should_lookahead(struct grep_opt *opt)
1378 {
1379         struct grep_pat *p;
1380
1381         if (opt->pattern_expression)
1382                 return 0; /* punt for too complex stuff */
1383         if (opt->invert)
1384                 return 0;
1385         for (p = opt->pattern_list; p; p = p->next) {
1386                 if (p->token != GREP_PATTERN)
1387                         return 0; /* punt for "header only" and stuff */
1388         }
1389         return 1;
1390 }
1391
1392 static int look_ahead(struct grep_opt *opt,
1393                       unsigned long *left_p,
1394                       unsigned *lno_p,
1395                       const char **bol_p)
1396 {
1397         unsigned lno = *lno_p;
1398         const char *bol = *bol_p;
1399         struct grep_pat *p;
1400         const char *sp, *last_bol;
1401         regoff_t earliest = -1;
1402
1403         for (p = opt->pattern_list; p; p = p->next) {
1404                 int hit;
1405                 regmatch_t m;
1406
1407                 hit = patmatch(p, bol, bol + *left_p, &m, 0);
1408                 if (!hit || m.rm_so < 0 || m.rm_eo < 0)
1409                         continue;
1410                 if (earliest < 0 || m.rm_so < earliest)
1411                         earliest = m.rm_so;
1412         }
1413
1414         if (earliest < 0) {
1415                 *bol_p = bol + *left_p;
1416                 *left_p = 0;
1417                 return 1;
1418         }
1419         for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
1420                 ; /* find the beginning of the line */
1421         last_bol = sp;
1422
1423         for (sp = bol; sp < last_bol; sp++) {
1424                 if (*sp == '\n')
1425                         lno++;
1426         }
1427         *left_p -= last_bol - bol;
1428         *bol_p = last_bol;
1429         *lno_p = lno;
1430         return 0;
1431 }
1432
1433 static int fill_textconv_grep(struct repository *r,
1434                               struct userdiff_driver *driver,
1435                               struct grep_source *gs)
1436 {
1437         struct diff_filespec *df;
1438         char *buf;
1439         size_t size;
1440
1441         if (!driver || !driver->textconv)
1442                 return grep_source_load(gs);
1443
1444         /*
1445          * The textconv interface is intimately tied to diff_filespecs, so we
1446          * have to pretend to be one. If we could unify the grep_source
1447          * and diff_filespec structs, this mess could just go away.
1448          */
1449         df = alloc_filespec(gs->path);
1450         switch (gs->type) {
1451         case GREP_SOURCE_OID:
1452                 fill_filespec(df, gs->identifier, 1, 0100644);
1453                 break;
1454         case GREP_SOURCE_FILE:
1455                 fill_filespec(df, null_oid(), 0, 0100644);
1456                 break;
1457         default:
1458                 BUG("attempt to textconv something without a path?");
1459         }
1460
1461         /*
1462          * fill_textconv is not remotely thread-safe; it modifies the global
1463          * diff tempfile structure, writes to the_repo's odb and might
1464          * internally call thread-unsafe functions such as the
1465          * prepare_packed_git() lazy-initializator. Because of the last two, we
1466          * must ensure mutual exclusion between this call and the object reading
1467          * API, thus we use obj_read_lock() here.
1468          *
1469          * TODO: allowing text conversion to run in parallel with object
1470          * reading operations might increase performance in the multithreaded
1471          * non-worktreee git-grep with --textconv.
1472          */
1473         obj_read_lock();
1474         size = fill_textconv(r, driver, df, &buf);
1475         obj_read_unlock();
1476         free_filespec(df);
1477
1478         /*
1479          * The normal fill_textconv usage by the diff machinery would just keep
1480          * the textconv'd buf separate from the diff_filespec. But much of the
1481          * grep code passes around a grep_source and assumes that its "buf"
1482          * pointer is the beginning of the thing we are searching. So let's
1483          * install our textconv'd version into the grep_source, taking care not
1484          * to leak any existing buffer.
1485          */
1486         grep_source_clear_data(gs);
1487         gs->buf = buf;
1488         gs->size = size;
1489
1490         return 0;
1491 }
1492
1493 static int is_empty_line(const char *bol, const char *eol)
1494 {
1495         while (bol < eol && isspace(*bol))
1496                 bol++;
1497         return bol == eol;
1498 }
1499
1500 static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int collect_hits)
1501 {
1502         const char *bol;
1503         const char *peek_bol = NULL;
1504         unsigned long left;
1505         unsigned lno = 1;
1506         unsigned last_hit = 0;
1507         int binary_match_only = 0;
1508         unsigned count = 0;
1509         int try_lookahead = 0;
1510         int show_function = 0;
1511         struct userdiff_driver *textconv = NULL;
1512         enum grep_context ctx = GREP_CONTEXT_HEAD;
1513         xdemitconf_t xecfg;
1514
1515         if (!opt->status_only && gs->name == NULL)
1516                 BUG("grep call which could print a name requires "
1517                     "grep_source.name be non-NULL");
1518
1519         if (!opt->output)
1520                 opt->output = std_output;
1521
1522         if (opt->pre_context || opt->post_context || opt->file_break ||
1523             opt->funcbody) {
1524                 /* Show hunk marks, except for the first file. */
1525                 if (opt->last_shown)
1526                         opt->show_hunk_mark = 1;
1527                 /*
1528                  * If we're using threads then we can't easily identify
1529                  * the first file.  Always put hunk marks in that case
1530                  * and skip the very first one later in work_done().
1531                  */
1532                 if (opt->output != std_output)
1533                         opt->show_hunk_mark = 1;
1534         }
1535         opt->last_shown = 0;
1536
1537         if (opt->allow_textconv) {
1538                 grep_source_load_driver(gs, opt->repo->index);
1539                 /*
1540                  * We might set up the shared textconv cache data here, which
1541                  * is not thread-safe. Also, get_oid_with_context() and
1542                  * parse_object() might be internally called. As they are not
1543                  * currently thread-safe and might be racy with object reading,
1544                  * obj_read_lock() must be called.
1545                  */
1546                 grep_attr_lock();
1547                 obj_read_lock();
1548                 textconv = userdiff_get_textconv(opt->repo, gs->driver);
1549                 obj_read_unlock();
1550                 grep_attr_unlock();
1551         }
1552
1553         /*
1554          * We know the result of a textconv is text, so we only have to care
1555          * about binary handling if we are not using it.
1556          */
1557         if (!textconv) {
1558                 switch (opt->binary) {
1559                 case GREP_BINARY_DEFAULT:
1560                         if (grep_source_is_binary(gs, opt->repo->index))
1561                                 binary_match_only = 1;
1562                         break;
1563                 case GREP_BINARY_NOMATCH:
1564                         if (grep_source_is_binary(gs, opt->repo->index))
1565                                 return 0; /* Assume unmatch */
1566                         break;
1567                 case GREP_BINARY_TEXT:
1568                         break;
1569                 default:
1570                         BUG("unknown binary handling mode");
1571                 }
1572         }
1573
1574         memset(&xecfg, 0, sizeof(xecfg));
1575         opt->priv = &xecfg;
1576
1577         try_lookahead = should_lookahead(opt);
1578
1579         if (fill_textconv_grep(opt->repo, textconv, gs) < 0)
1580                 return 0;
1581
1582         bol = gs->buf;
1583         left = gs->size;
1584         while (left) {
1585                 const char *eol;
1586                 int hit;
1587                 ssize_t cno;
1588                 ssize_t col = -1, icol = -1;
1589
1590                 /*
1591                  * look_ahead() skips quickly to the line that possibly
1592                  * has the next hit; don't call it if we need to do
1593                  * something more than just skipping the current line
1594                  * in response to an unmatch for the current line.  E.g.
1595                  * inside a post-context window, we will show the current
1596                  * line as a context around the previous hit when it
1597                  * doesn't hit.
1598                  */
1599                 if (try_lookahead
1600                     && !(last_hit
1601                          && (show_function ||
1602                              lno <= last_hit + opt->post_context))
1603                     && look_ahead(opt, &left, &lno, &bol))
1604                         break;
1605                 eol = end_of_line(bol, &left);
1606
1607                 if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
1608                         ctx = GREP_CONTEXT_BODY;
1609
1610                 hit = match_line(opt, bol, eol, &col, &icol, ctx, collect_hits);
1611
1612                 if (collect_hits)
1613                         goto next_line;
1614
1615                 /* "grep -v -e foo -e bla" should list lines
1616                  * that do not have either, so inversion should
1617                  * be done outside.
1618                  */
1619                 if (opt->invert)
1620                         hit = !hit;
1621                 if (opt->unmatch_name_only) {
1622                         if (hit)
1623                                 return 0;
1624                         goto next_line;
1625                 }
1626                 if (hit && (opt->max_count < 0 || count < opt->max_count)) {
1627                         count++;
1628                         if (opt->status_only)
1629                                 return 1;
1630                         if (opt->name_only) {
1631                                 show_name(opt, gs->name);
1632                                 return 1;
1633                         }
1634                         if (opt->count)
1635                                 goto next_line;
1636                         if (binary_match_only) {
1637                                 opt->output(opt, "Binary file ", 12);
1638                                 output_color(opt, gs->name, strlen(gs->name),
1639                                              opt->colors[GREP_COLOR_FILENAME]);
1640                                 opt->output(opt, " matches\n", 9);
1641                                 return 1;
1642                         }
1643                         /* Hit at this line.  If we haven't shown the
1644                          * pre-context lines, we would need to show them.
1645                          */
1646                         if (opt->pre_context || opt->funcbody)
1647                                 show_pre_context(opt, gs, bol, eol, lno);
1648                         else if (opt->funcname)
1649                                 show_funcname_line(opt, gs, bol, lno);
1650                         cno = opt->invert ? icol : col;
1651                         if (cno < 0) {
1652                                 /*
1653                                  * A negative cno indicates that there was no
1654                                  * match on the line. We are thus inverted and
1655                                  * being asked to show all lines that _don't_
1656                                  * match a given expression. Therefore, set cno
1657                                  * to 0 to suggest the whole line matches.
1658                                  */
1659                                 cno = 0;
1660                         }
1661                         show_line(opt, bol, eol, gs->name, lno, cno + 1, ':');
1662                         last_hit = lno;
1663                         if (opt->funcbody)
1664                                 show_function = 1;
1665                         goto next_line;
1666                 }
1667                 if (show_function && (!peek_bol || peek_bol < bol)) {
1668                         unsigned long peek_left = left;
1669                         const char *peek_eol = eol;
1670
1671                         /*
1672                          * Trailing empty lines are not interesting.
1673                          * Peek past them to see if they belong to the
1674                          * body of the current function.
1675                          */
1676                         peek_bol = bol;
1677                         while (is_empty_line(peek_bol, peek_eol)) {
1678                                 peek_bol = peek_eol + 1;
1679                                 peek_eol = end_of_line(peek_bol, &peek_left);
1680                         }
1681
1682                         if (match_funcname(opt, gs, peek_bol, peek_eol))
1683                                 show_function = 0;
1684                 }
1685                 if (show_function ||
1686                     (last_hit && lno <= last_hit + opt->post_context)) {
1687                         /* If the last hit is within the post context,
1688                          * we need to show this line.
1689                          */
1690                         show_line(opt, bol, eol, gs->name, lno, col + 1, '-');
1691                 }
1692
1693         next_line:
1694                 bol = eol + 1;
1695                 if (!left)
1696                         break;
1697                 left--;
1698                 lno++;
1699         }
1700
1701         if (collect_hits)
1702                 return 0;
1703
1704         if (opt->status_only)
1705                 return opt->unmatch_name_only;
1706         if (opt->unmatch_name_only) {
1707                 /* We did not see any hit, so we want to show this */
1708                 show_name(opt, gs->name);
1709                 return 1;
1710         }
1711
1712         xdiff_clear_find_func(&xecfg);
1713         opt->priv = NULL;
1714
1715         /* NEEDSWORK:
1716          * The real "grep -c foo *.c" gives many "bar.c:0" lines,
1717          * which feels mostly useless but sometimes useful.  Maybe
1718          * make it another option?  For now suppress them.
1719          */
1720         if (opt->count && count) {
1721                 char buf[32];
1722                 if (opt->pathname) {
1723                         output_color(opt, gs->name, strlen(gs->name),
1724                                      opt->colors[GREP_COLOR_FILENAME]);
1725                         output_sep(opt, ':');
1726                 }
1727                 xsnprintf(buf, sizeof(buf), "%u\n", count);
1728                 opt->output(opt, buf, strlen(buf));
1729                 return 1;
1730         }
1731         return !!last_hit;
1732 }
1733
1734 static void clr_hit_marker(struct grep_expr *x)
1735 {
1736         /* All-hit markers are meaningful only at the very top level
1737          * OR node.
1738          */
1739         while (1) {
1740                 x->hit = 0;
1741                 if (x->node != GREP_NODE_OR)
1742                         return;
1743                 x->u.binary.left->hit = 0;
1744                 x = x->u.binary.right;
1745         }
1746 }
1747
1748 static int chk_hit_marker(struct grep_expr *x)
1749 {
1750         /* Top level nodes have hit markers.  See if they all are hits */
1751         while (1) {
1752                 if (x->node != GREP_NODE_OR)
1753                         return x->hit;
1754                 if (!x->u.binary.left->hit)
1755                         return 0;
1756                 x = x->u.binary.right;
1757         }
1758 }
1759
1760 int grep_source(struct grep_opt *opt, struct grep_source *gs)
1761 {
1762         /*
1763          * we do not have to do the two-pass grep when we do not check
1764          * buffer-wide "all-match".
1765          */
1766         if (!opt->all_match && !opt->no_body_match)
1767                 return grep_source_1(opt, gs, 0);
1768
1769         /* Otherwise the toplevel "or" terms hit a bit differently.
1770          * We first clear hit markers from them.
1771          */
1772         clr_hit_marker(opt->pattern_expression);
1773         opt->body_hit = 0;
1774         grep_source_1(opt, gs, 1);
1775
1776         if (opt->all_match && !chk_hit_marker(opt->pattern_expression))
1777                 return 0;
1778         if (opt->no_body_match && opt->body_hit)
1779                 return 0;
1780
1781         return grep_source_1(opt, gs, 0);
1782 }
1783
1784 static void grep_source_init_buf(struct grep_source *gs,
1785                                  const char *buf,
1786                                  unsigned long size)
1787 {
1788         gs->type = GREP_SOURCE_BUF;
1789         gs->name = NULL;
1790         gs->path = NULL;
1791         gs->buf = buf;
1792         gs->size = size;
1793         gs->driver = NULL;
1794         gs->identifier = NULL;
1795 }
1796
1797 int grep_buffer(struct grep_opt *opt, const char *buf, unsigned long size)
1798 {
1799         struct grep_source gs;
1800         int r;
1801
1802         grep_source_init_buf(&gs, buf, size);
1803
1804         r = grep_source(opt, &gs);
1805
1806         grep_source_clear(&gs);
1807         return r;
1808 }
1809
1810 void grep_source_init_file(struct grep_source *gs, const char *name,
1811                            const char *path)
1812 {
1813         gs->type = GREP_SOURCE_FILE;
1814         gs->name = xstrdup_or_null(name);
1815         gs->path = xstrdup_or_null(path);
1816         gs->buf = NULL;
1817         gs->size = 0;
1818         gs->driver = NULL;
1819         gs->identifier = xstrdup(path);
1820 }
1821
1822 void grep_source_init_oid(struct grep_source *gs, const char *name,
1823                           const char *path, const struct object_id *oid,
1824                           struct repository *repo)
1825 {
1826         gs->type = GREP_SOURCE_OID;
1827         gs->name = xstrdup_or_null(name);
1828         gs->path = xstrdup_or_null(path);
1829         gs->buf = NULL;
1830         gs->size = 0;
1831         gs->driver = NULL;
1832         gs->identifier = oiddup(oid);
1833         gs->repo = repo;
1834 }
1835
1836 void grep_source_clear(struct grep_source *gs)
1837 {
1838         FREE_AND_NULL(gs->name);
1839         FREE_AND_NULL(gs->path);
1840         FREE_AND_NULL(gs->identifier);
1841         grep_source_clear_data(gs);
1842 }
1843
1844 void grep_source_clear_data(struct grep_source *gs)
1845 {
1846         switch (gs->type) {
1847         case GREP_SOURCE_FILE:
1848         case GREP_SOURCE_OID:
1849                 /* these types own the buffer */
1850                 free((char *)gs->buf);
1851                 gs->buf = NULL;
1852                 gs->size = 0;
1853                 break;
1854         case GREP_SOURCE_BUF:
1855                 /* leave user-provided buf intact */
1856                 break;
1857         }
1858 }
1859
1860 static int grep_source_load_oid(struct grep_source *gs)
1861 {
1862         enum object_type type;
1863
1864         gs->buf = repo_read_object_file(gs->repo, gs->identifier, &type,
1865                                         &gs->size);
1866         if (!gs->buf)
1867                 return error(_("'%s': unable to read %s"),
1868                              gs->name,
1869                              oid_to_hex(gs->identifier));
1870         return 0;
1871 }
1872
1873 static int grep_source_load_file(struct grep_source *gs)
1874 {
1875         const char *filename = gs->identifier;
1876         struct stat st;
1877         char *data;
1878         size_t size;
1879         int i;
1880
1881         if (lstat(filename, &st) < 0) {
1882         err_ret:
1883                 if (errno != ENOENT)
1884                         error_errno(_("failed to stat '%s'"), filename);
1885                 return -1;
1886         }
1887         if (!S_ISREG(st.st_mode))
1888                 return -1;
1889         size = xsize_t(st.st_size);
1890         i = open(filename, O_RDONLY);
1891         if (i < 0)
1892                 goto err_ret;
1893         data = xmallocz(size);
1894         if (st.st_size != read_in_full(i, data, size)) {
1895                 error_errno(_("'%s': short read"), filename);
1896                 close(i);
1897                 free(data);
1898                 return -1;
1899         }
1900         close(i);
1901
1902         gs->buf = data;
1903         gs->size = size;
1904         return 0;
1905 }
1906
1907 static int grep_source_load(struct grep_source *gs)
1908 {
1909         if (gs->buf)
1910                 return 0;
1911
1912         switch (gs->type) {
1913         case GREP_SOURCE_FILE:
1914                 return grep_source_load_file(gs);
1915         case GREP_SOURCE_OID:
1916                 return grep_source_load_oid(gs);
1917         case GREP_SOURCE_BUF:
1918                 return gs->buf ? 0 : -1;
1919         }
1920         BUG("invalid grep_source type to load");
1921 }
1922
1923 void grep_source_load_driver(struct grep_source *gs,
1924                              struct index_state *istate)
1925 {
1926         if (gs->driver)
1927                 return;
1928
1929         grep_attr_lock();
1930         if (gs->path)
1931                 gs->driver = userdiff_find_by_path(istate, gs->path);
1932         if (!gs->driver)
1933                 gs->driver = userdiff_find_by_name("default");
1934         grep_attr_unlock();
1935 }
1936
1937 static int grep_source_is_binary(struct grep_source *gs,
1938                                  struct index_state *istate)
1939 {
1940         grep_source_load_driver(gs, istate);
1941         if (gs->driver->binary != -1)
1942                 return gs->driver->binary;
1943
1944         if (!grep_source_load(gs))
1945                 return buffer_is_binary(gs->buf, gs->size);
1946
1947         return 0;
1948 }