src/symtab.c

   1 /* Symbol table manager for Bison.
   2
   3    Copyright (C) 1984, 1989, 2000-2002, 2004-2012 Free Software
   4    Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22 #include "system.h"
  23
  24 #include <hash.h>
  25
  26 #include "complain.h"
  27 #include "gram.h"
  28 #include "symtab.h"
  29
  30 /*-------------------------------------------------------------------.
  31 | Symbols sorted by tag.  Allocated by the first invocation of       |
  32 | symbols_do, after which no more symbols should be created.         |
  33 `-------------------------------------------------------------------*/
  34
  35 static symbol **symbols_sorted = NULL;
  36
  37 /*------------------------.
  38 | Distinguished symbols.  |
  39 `------------------------*/
  40
  41 symbol *errtoken = NULL;
  42 symbol *undeftoken = NULL;
  43 symbol *endtoken = NULL;
  44 symbol *accept = NULL;
  45 symbol *startsymbol = NULL;
  46 location startsymbol_location;
  47
  48 /*---------------------------------------.
  49 | Default %destructor's and %printer's.  |
  50 `---------------------------------------*/
  51
  52 static code_props default_tagged_destructor = CODE_PROPS_NONE_INIT;
  53 static code_props default_tagless_destructor = CODE_PROPS_NONE_INIT;
  54 static code_props default_tagged_printer = CODE_PROPS_NONE_INIT;
  55 static code_props default_tagless_printer = CODE_PROPS_NONE_INIT;
  56
  57 /*---------------------------------.
  58 | Create a new symbol, named TAG.  |
  59 `---------------------------------*/
  60
  61 static symbol *
  62 symbol_new (uniqstr tag, location loc)
  63 {
  64   symbol *res = xmalloc (sizeof *res);
  65
  66   uniqstr_assert (tag);
  67
  68   /* If the tag is not a string (starts with a double quote), check
  69      that it is valid for Yacc. */
  70   if (tag[0] != '\"' && tag[0] != '\'' && mbschr (tag, '-'))
  71     yacc_at (loc, _("POSIX Yacc forbids dashes in symbol names: %s"),
  72              tag);
  73
  74   res->tag = tag;
  75   res->location = loc;
  76
  77   res->type_name = NULL;
  78   code_props_none_init (&res->destructor);
  79   code_props_none_init (&res->printer);
  80
  81   res->number = NUMBER_UNDEFINED;
  82   res->prec = 0;
  83   res->assoc = undef_assoc;
  84   res->user_token_number = USER_NUMBER_UNDEFINED;
  85
  86   res->alias = NULL;
  87   res->class = unknown_sym;
  88   res->declared = false;
  89
  90   if (nsyms == SYMBOL_NUMBER_MAXIMUM)
  91     fatal (_("too many symbols in input grammar (limit is %d)"),
  92            SYMBOL_NUMBER_MAXIMUM);
  93   nsyms++;
  94   return res;
  95 }
  96
  97 /*----------------------------------------.
  98 | Create a new semantic type, named TAG.  |
  99 `----------------------------------------*/
 100
 101 static semantic_type *
 102 semantic_type_new (uniqstr tag)
 103 {
 104   semantic_type *res = xmalloc (sizeof *res);
 105
 106   uniqstr_assert (tag);
 107   res->tag = tag;
 108   code_props_none_init (&res->destructor);
 109   code_props_none_init (&res->printer);
 110
 111   return res;
 112 }
 113
 114
 115 /*-----------------.
 116 | Print a symbol.  |
 117 `-----------------*/
 118
 119 #define SYMBOL_ATTR_PRINT(Attr)                         \
 120   if (s->Attr)                                          \
 121     fprintf (f, " %s { %s }", #Attr, s->Attr)
 122
 123 #define SYMBOL_CODE_PRINT(Attr)                         \
 124   if (s->Attr.code)                                     \
 125     fprintf (f, " %s { %s }", #Attr, s->Attr.code)
 126
 127 void
 128 symbol_print (symbol *s, FILE *f)
 129 {
 130   if (s)
 131     {
 132       fprintf (f, "\"%s\"", s->tag);
 133       SYMBOL_ATTR_PRINT (type_name);
 134       SYMBOL_CODE_PRINT (destructor);
 135       SYMBOL_CODE_PRINT (printer);
 136     }
 137   else
 138     fprintf (f, "<NULL>");
 139 }
 140
 141 #undef SYMBOL_ATTR_PRINT
 142 #undef SYMBOL_CODE_PRINT
 143
 144 /*------------------------------------------------------------------.
 145 | Complain that S's WHAT is redeclared at SECOND, and was first set |
 146 | at FIRST.                                                         |
 147 `------------------------------------------------------------------*/
 148
 149 static void
 150 symbol_redeclaration (symbol *s, const char *what, location first,
 151                       location second)
 152 {
 153   complain_at (second, _("%s redeclaration for %s"), what, s->tag);
 154   complain_at (first, _("previous declaration"));
 155 }
 156
 157 static void
 158 semantic_type_redeclaration (semantic_type *s, const char *what, location first,
 159                              location second)
 160 {
 161   complain_at (second, _("%s redeclaration for <%s>"), what, s->tag);
 162   complain_at (first, _("previous declaration"));
 163 }
 164
 165
 166
 167 /*-----------------------------------------------------------------.
 168 | Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
 169 | as TYPE_NAME.                                                    |
 170 `-----------------------------------------------------------------*/
 171
 172 void
 173 symbol_type_set (symbol *sym, uniqstr type_name, location loc)
 174 {
 175   if (type_name)
 176     {
 177       if (sym->type_name)
 178         symbol_redeclaration (sym, "%type", sym->type_location, loc);
 179       uniqstr_assert (type_name);
 180       sym->type_name = type_name;
 181       sym->type_location = loc;
 182     }
 183 }
 184
 185 /*-----------------------------------------.
 186 | Set the DESTRUCTOR associated with SYM.  |
 187 `-----------------------------------------*/
 188
 189 void
 190 symbol_destructor_set (symbol *sym, code_props const *destructor)
 191 {
 192   if (sym->destructor.code)
 193     symbol_redeclaration (sym, "%destructor", sym->destructor.location,
 194                           destructor->location);
 195   sym->destructor = *destructor;
 196 }
 197
 198 /*------------------------------------------.
 199 | Set the DESTRUCTOR associated with TYPE.  |
 200 `------------------------------------------*/
 201
 202 void
 203 semantic_type_destructor_set (semantic_type *type,
 204                               code_props const *destructor)
 205 {
 206   if (type->destructor.code)
 207     semantic_type_redeclaration (type, "%destructor",
 208                                  type->destructor.location,
 209                                  destructor->location);
 210   type->destructor = *destructor;
 211 }
 212
 213 /*---------------------------------------.
 214 | Get the computed %destructor for SYM.  |
 215 `---------------------------------------*/
 216
 217 code_props const *
 218 symbol_destructor_get (symbol const *sym)
 219 {
 220   /* Per-symbol %destructor.  */
 221   if (sym->destructor.code)
 222     return &sym->destructor;
 223
 224   /* Per-type %destructor.  */
 225   if (sym->type_name)
 226     {
 227       code_props const *destructor =
 228         &semantic_type_get (sym->type_name)->destructor;
 229       if (destructor->code)
 230         return destructor;
 231     }
 232
 233   /* Apply default %destructor's only to user-defined symbols.  */
 234   if (sym->tag[0] == '$' || sym == errtoken)
 235     return &code_props_none;
 236
 237   if (sym->type_name)
 238     return &default_tagged_destructor;
 239   return &default_tagless_destructor;
 240 }
 241
 242 /*--------------------------------------.
 243 | Set the PRINTER associated with SYM.  |
 244 `--------------------------------------*/
 245
 246 void
 247 symbol_printer_set (symbol *sym, code_props const *printer)
 248 {
 249   if (sym->printer.code)
 250     symbol_redeclaration (sym, "%printer",
 251                           sym->printer.location, printer->location);
 252   sym->printer = *printer;
 253 }
 254
 255 /*---------------------------------------.
 256 | Set the PRINTER associated with TYPE.  |
 257 `---------------------------------------*/
 258
 259 void
 260 semantic_type_printer_set (semantic_type *type, code_props const *printer)
 261 {
 262   if (type->printer.code)
 263     semantic_type_redeclaration (type, "%printer",
 264                                  type->printer.location, printer->location);
 265   type->printer = *printer;
 266 }
 267
 268 /*------------------------------------.
 269 | Get the computed %printer for SYM.  |
 270 `------------------------------------*/
 271
 272 code_props const *
 273 symbol_printer_get (symbol const *sym)
 274 {
 275   /* Per-symbol %printer.  */
 276   if (sym->printer.code)
 277     return &sym->printer;
 278
 279   /* Per-type %printer.  */
 280   if (sym->type_name)
 281     {
 282       code_props const *printer = &semantic_type_get (sym->type_name)->printer;
 283       if (printer->code)
 284         return printer;
 285     }
 286
 287   /* Apply the default %printer only to user-defined symbols.  */
 288   if (sym->tag[0] == '$' || sym == errtoken)
 289     return &code_props_none;
 290
 291   if (sym->type_name)
 292     return &default_tagged_printer;
 293   return &default_tagless_printer;
 294 }
 295
 296 /*-----------------------------------------------------------------.
 297 | Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
 298 | with UNDEF_ASSOC as ASSOC.                                       |
 299 `-----------------------------------------------------------------*/
 300
 301 void
 302 symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
 303 {
 304   if (a != undef_assoc)
 305     {
 306       if (sym->prec != 0)
 307         symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
 308                               loc);
 309       sym->prec = prec;
 310       sym->assoc = a;
 311       sym->prec_location = loc;
 312     }
 313
 314   /* Only terminals have a precedence. */
 315   symbol_class_set (sym, token_sym, loc, false);
 316 }
 317
 318
 319 /*------------------------------------.
 320 | Set the CLASS associated with SYM.  |
 321 `------------------------------------*/
 322
 323 void
 324 symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
 325 {
 326   if (sym->class != unknown_sym && sym->class != class)
 327     {
 328       complain_at (loc, _("symbol %s redefined"), sym->tag);
 329       sym->declared = false;
 330     }
 331
 332   if (class == nterm_sym && sym->class != nterm_sym)
 333     sym->number = nvars++;
 334   else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
 335     sym->number = ntokens++;
 336
 337   sym->class = class;
 338
 339   if (declaring)
 340     {
 341       if (sym->declared)
 342         warn_at (loc, _("symbol %s redeclared"), sym->tag);
 343       sym->declared = true;
 344     }
 345 }
 346
 347
 348 /*------------------------------------------------.
 349 | Set the USER_TOKEN_NUMBER associated with SYM.  |
 350 `------------------------------------------------*/
 351
 352 void
 353 symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
 354 {
 355   int *user_token_numberp;
 356
 357   if (sym->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
 358     user_token_numberp = &sym->user_token_number;
 359   else
 360     user_token_numberp = &sym->alias->user_token_number;
 361   if (*user_token_numberp != USER_NUMBER_UNDEFINED
 362       && *user_token_numberp != user_token_number)
 363     complain_at (loc, _("redefining user token number of %s"), sym->tag);
 364
 365   *user_token_numberp = user_token_number;
 366   /* User defined $end token? */
 367   if (user_token_number == 0)
 368     {
 369       endtoken = sym;
 370       /* It is always mapped to 0, so it was already counted in
 371          NTOKENS.  */
 372       if (endtoken->number != NUMBER_UNDEFINED)
 373         --ntokens;
 374       endtoken->number = 0;
 375     }
 376 }
 377
 378
 379 /*----------------------------------------------------------.
 380 | If SYM is not defined, report an error, and consider it a |
 381 | nonterminal.                                              |
 382 `----------------------------------------------------------*/
 383
 384 static inline bool
 385 symbol_check_defined (symbol *sym)
 386 {
 387   if (sym->class == unknown_sym)
 388     {
 389       complain_at
 390         (sym->location,
 391          _("symbol %s is used, but is not defined as a token and has no rules"),
 392          sym->tag);
 393       sym->class = nterm_sym;
 394       sym->number = nvars++;
 395     }
 396
 397   return true;
 398 }
 399
 400 static bool
 401 symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
 402 {
 403   return symbol_check_defined (sym);
 404 }
 405
 406
 407 void
 408 symbol_make_alias (symbol *sym, symbol *str, location loc)
 409 {
 410   if (str->alias)
 411     warn_at (loc, _("symbol %s used more than once as a literal string"),
 412              str->tag);
 413   else if (sym->alias)
 414     warn_at (loc, _("symbol %s given more than one literal string"),
 415              sym->tag);
 416   else
 417     {
 418       str->class = token_sym;
 419       str->user_token_number = sym->user_token_number;
 420       sym->user_token_number = USER_NUMBER_HAS_STRING_ALIAS;
 421       str->alias = sym;
 422       sym->alias = str;
 423       str->number = sym->number;
 424       symbol_type_set (str, sym->type_name, loc);
 425     }
 426 }
 427
 428
 429 /*---------------------------------------------------------.
 430 | Check that THIS, and its alias, have same precedence and |
 431 | associativity.                                           |
 432 `---------------------------------------------------------*/
 433
 434 static inline void
 435 symbol_check_alias_consistency (symbol *this)
 436 {
 437   symbol *sym = this;
 438   symbol *str = this->alias;
 439
 440   /* Check only the symbol in the symbol-string pair.  */
 441   if (!(this->alias
 442         && this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS))
 443     return;
 444
 445   if (str->type_name != sym->type_name)
 446     {
 447       if (str->type_name)
 448         symbol_type_set (sym, str->type_name, str->type_location);
 449       else
 450         symbol_type_set (str, sym->type_name, sym->type_location);
 451     }
 452
 453
 454   if (str->destructor.code || sym->destructor.code)
 455     {
 456       if (str->destructor.code)
 457         symbol_destructor_set (sym, &str->destructor);
 458       else
 459         symbol_destructor_set (str, &sym->destructor);
 460     }
 461
 462   if (str->printer.code || sym->printer.code)
 463     {
 464       if (str->printer.code)
 465         symbol_printer_set (sym, &str->printer);
 466       else
 467         symbol_printer_set (str, &sym->printer);
 468     }
 469
 470   if (sym->prec || str->prec)
 471     {
 472       if (str->prec)
 473         symbol_precedence_set (sym, str->prec, str->assoc,
 474                                str->prec_location);
 475       else
 476         symbol_precedence_set (str, sym->prec, sym->assoc,
 477                                sym->prec_location);
 478     }
 479 }
 480
 481 static bool
 482 symbol_check_alias_consistency_processor (void *this,
 483                                           void *null ATTRIBUTE_UNUSED)
 484 {
 485   symbol_check_alias_consistency (this);
 486   return true;
 487 }
 488
 489
 490 /*-------------------------------------------------------------------.
 491 | Assign a symbol number, and write the definition of the token name |
 492 | into FDEFINES.  Put in SYMBOLS.                                    |
 493 `-------------------------------------------------------------------*/
 494
 495 static inline bool
 496 symbol_pack (symbol *this)
 497 {
 498   aver (this->number != NUMBER_UNDEFINED);
 499   if (this->class == nterm_sym)
 500     this->number += ntokens;
 501   else if (this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS)
 502     return true;
 503
 504   symbols[this->number] = this;
 505   return true;
 506 }
 507
 508 static bool
 509 symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
 510 {
 511   return symbol_pack (this);
 512 }
 513
 514
 515 static void
 516 user_token_number_redeclaration (int num, symbol *first, symbol *second)
 517 {
 518   /* User token numbers are not assigned during the parsing, but in a
 519      second step, via a traversal of the symbol table sorted on tag.
 520
 521      However, error messages make more sense if we keep the first
 522      declaration first.  */
 523   if (location_cmp (first->location, second->location) > 0)
 524     {
 525       symbol* tmp = first;
 526       first = second;
 527       second = tmp;
 528     }
 529   complain_at (second->location,
 530                _("user token number %d redeclaration for %s"),
 531                num, second->tag);
 532   complain_at (first->location, _("previous declaration for %s"),
 533                first->tag);
 534 }
 535
 536 /*--------------------------------------------------.
 537 | Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
 538 `--------------------------------------------------*/
 539
 540 static inline bool
 541 symbol_translation (symbol *this)
 542 {
 543   /* Non-terminal? */
 544   if (this->class == token_sym
 545       && this->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
 546     {
 547       /* A token which translation has already been set? */
 548       if (token_translations[this->user_token_number] != undeftoken->number)
 549         user_token_number_redeclaration
 550           (this->user_token_number,
 551            symbols[token_translations[this->user_token_number]],
 552            this);
 553
 554       token_translations[this->user_token_number] = this->number;
 555     }
 556
 557   return true;
 558 }
 559
 560 static bool
 561 symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
 562 {
 563   return symbol_translation (this);
 564 }
 565
 566
 567 /*---------------------------------------.
 568 | Symbol and semantic type hash tables.  |
 569 `---------------------------------------*/
 570
 571 /* Initial capacity of symbol and semantic type hash table.  */
 572 #define HT_INITIAL_CAPACITY 257
 573
 574 static struct hash_table *symbol_table = NULL;
 575 static struct hash_table *semantic_type_table = NULL;
 576
 577 static inline bool
 578 hash_compare_symbol (const symbol *m1, const symbol *m2)
 579 {
 580   /* Since tags are unique, we can compare the pointers themselves.  */
 581   return UNIQSTR_EQ (m1->tag, m2->tag);
 582 }
 583
 584 static inline bool
 585 hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
 586 {
 587   /* Since names are unique, we can compare the pointers themselves.  */
 588   return UNIQSTR_EQ (m1->tag, m2->tag);
 589 }
 590
 591 static bool
 592 hash_symbol_comparator (void const *m1, void const *m2)
 593 {
 594   return hash_compare_symbol (m1, m2);
 595 }
 596
 597 static bool
 598 hash_semantic_type_comparator (void const *m1, void const *m2)
 599 {
 600   return hash_compare_semantic_type (m1, m2);
 601 }
 602
 603 static inline size_t
 604 hash_symbol (const symbol *m, size_t tablesize)
 605 {
 606   /* Since tags are unique, we can hash the pointer itself.  */
 607   return ((uintptr_t) m->tag) % tablesize;
 608 }
 609
 610 static inline size_t
 611 hash_semantic_type (const semantic_type *m, size_t tablesize)
 612 {
 613   /* Since names are unique, we can hash the pointer itself.  */
 614   return ((uintptr_t) m->tag) % tablesize;
 615 }
 616
 617 static size_t
 618 hash_symbol_hasher (void const *m, size_t tablesize)
 619 {
 620   return hash_symbol (m, tablesize);
 621 }
 622
 623 static size_t
 624 hash_semantic_type_hasher (void const *m, size_t tablesize)
 625 {
 626   return hash_semantic_type (m, tablesize);
 627 }
 628
 629 /*-------------------------------.
 630 | Create the symbol hash table.  |
 631 `-------------------------------*/
 632
 633 void
 634 symbols_new (void)
 635 {
 636   symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
 637                                   NULL,
 638                                   hash_symbol_hasher,
 639                                   hash_symbol_comparator,
 640                                   free);
 641   semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
 642                                          NULL,
 643                                          hash_semantic_type_hasher,
 644                                          hash_semantic_type_comparator,
 645                                          free);
 646 }
 647
 648
 649 /*----------------------------------------------------------------.
 650 | Find the symbol named KEY, and return it.  If it does not exist |
 651 | yet, create it.                                                 |
 652 `----------------------------------------------------------------*/
 653
 654 symbol *
 655 symbol_from_uniqstr (const uniqstr key, location loc)
 656 {
 657   symbol probe;
 658   symbol *entry;
 659
 660   probe.tag = key;
 661   entry = hash_lookup (symbol_table, &probe);
 662
 663   if (!entry)
 664     {
 665       /* First insertion in the hash. */
 666       aver (!symbols_sorted);
 667       entry = symbol_new (key, loc);
 668       if (!hash_insert (symbol_table, entry))
 669         xalloc_die ();
 670     }
 671   return entry;
 672 }
 673
 674
 675 /*-----------------------------------------------------------------------.
 676 | Find the semantic type named KEY, and return it.  If it does not exist |
 677 | yet, create it.                                                        |
 678 `-----------------------------------------------------------------------*/
 679
 680 semantic_type *
 681 semantic_type_from_uniqstr (const uniqstr key)
 682 {
 683   semantic_type probe;
 684   semantic_type *entry;
 685
 686   probe.tag = key;
 687   entry = hash_lookup (semantic_type_table, &probe);
 688
 689   if (!entry)
 690     {
 691       /* First insertion in the hash. */
 692       entry = semantic_type_new (key);
 693       if (!hash_insert (semantic_type_table, entry))
 694         xalloc_die ();
 695     }
 696   return entry;
 697 }
 698
 699
 700 /*----------------------------------------------------------------.
 701 | Find the symbol named KEY, and return it.  If it does not exist |
 702 | yet, create it.                                                 |
 703 `----------------------------------------------------------------*/
 704
 705 symbol *
 706 symbol_get (const char *key, location loc)
 707 {
 708   return symbol_from_uniqstr (uniqstr_new (key), loc);
 709 }
 710
 711
 712 /*-----------------------------------------------------------------------.
 713 | Find the semantic type named KEY, and return it.  If it does not exist |
 714 | yet, create it.                                                        |
 715 `-----------------------------------------------------------------------*/
 716
 717 semantic_type *
 718 semantic_type_get (const char *key)
 719 {
 720   return semantic_type_from_uniqstr (uniqstr_new (key));
 721 }
 722
 723
 724 /*------------------------------------------------------------------.
 725 | Generate a dummy nonterminal, whose name cannot conflict with the |
 726 | user's names.                                                     |
 727 `------------------------------------------------------------------*/
 728
 729 symbol *
 730 dummy_symbol_get (location loc)
 731 {
 732   /* Incremented for each generated symbol.  */
 733   static int dummy_count = 0;
 734   static char buf[256];
 735
 736   symbol *sym;
 737
 738   sprintf (buf, "$@%d", ++dummy_count);
 739   sym = symbol_get (buf, loc);
 740   sym->class = nterm_sym;
 741   sym->number = nvars++;
 742   return sym;
 743 }
 744
 745 bool
 746 symbol_is_dummy (const symbol *sym)
 747 {
 748   return sym->tag[0] == '@' || (sym->tag[0] == '$' && sym->tag[1] == '@');
 749 }
 750
 751 /*-------------------.
 752 | Free the symbols.  |
 753 `-------------------*/
 754
 755 void
 756 symbols_free (void)
 757 {
 758   hash_free (symbol_table);
 759   hash_free (semantic_type_table);
 760   free (symbols);
 761   free (symbols_sorted);
 762 }
 763
 764
 765 /*---------------------------------------------------------------.
 766 | Look for undefined symbols, report an error, and consider them |
 767 | terminals.                                                     |
 768 `---------------------------------------------------------------*/
 769
 770 static int
 771 symbols_cmp (symbol const *a, symbol const *b)
 772 {
 773   return strcmp (a->tag, b->tag);
 774 }
 775
 776 static int
 777 symbols_cmp_qsort (void const *a, void const *b)
 778 {
 779   return symbols_cmp (*(symbol * const *)a, *(symbol * const *)b);
 780 }
 781
 782 static void
 783 symbols_do (Hash_processor processor, void *processor_data)
 784 {
 785   size_t count = hash_get_n_entries (symbol_table);
 786   if (!symbols_sorted)
 787     {
 788       symbols_sorted = xnmalloc (count, sizeof *symbols_sorted);
 789       hash_get_entries (symbol_table, (void**)symbols_sorted, count);
 790       qsort (symbols_sorted, count, sizeof *symbols_sorted,
 791              symbols_cmp_qsort);
 792     }
 793   {
 794     size_t i;
 795     for (i = 0; i < count; ++i)
 796       processor (symbols_sorted[i], processor_data);
 797   }
 798 }
 799
 800 /*--------------------------------------------------------------.
 801 | Check that all the symbols are defined.  Report any undefined |
 802 | symbols and consider them nonterminals.                       |
 803 `--------------------------------------------------------------*/
 804
 805 void
 806 symbols_check_defined (void)
 807 {
 808   symbols_do (symbol_check_defined_processor, NULL);
 809 }
 810
 811 /*------------------------------------------------------------------.
 812 | Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
 813 | number.                                                           |
 814 `------------------------------------------------------------------*/
 815
 816 static void
 817 symbols_token_translations_init (void)
 818 {
 819   bool num_256_available_p = true;
 820   int i;
 821
 822   /* Find the highest user token number, and whether 256, the POSIX
 823      preferred user token number for the error token, is used.  */
 824   max_user_token_number = 0;
 825   for (i = 0; i < ntokens; ++i)
 826     {
 827       symbol *this = symbols[i];
 828       if (this->user_token_number != USER_NUMBER_UNDEFINED)
 829         {
 830           if (this->user_token_number > max_user_token_number)
 831             max_user_token_number = this->user_token_number;
 832           if (this->user_token_number == 256)
 833             num_256_available_p = false;
 834         }
 835     }
 836
 837   /* If 256 is not used, assign it to error, to follow POSIX.  */
 838   if (num_256_available_p
 839       && errtoken->user_token_number == USER_NUMBER_UNDEFINED)
 840     errtoken->user_token_number = 256;
 841
 842   /* Set the missing user numbers. */
 843   if (max_user_token_number < 256)
 844     max_user_token_number = 256;
 845
 846   for (i = 0; i < ntokens; ++i)
 847     {
 848       symbol *this = symbols[i];
 849       if (this->user_token_number == USER_NUMBER_UNDEFINED)
 850         this->user_token_number = ++max_user_token_number;
 851       if (this->user_token_number > max_user_token_number)
 852         max_user_token_number = this->user_token_number;
 853     }
 854
 855   token_translations = xnmalloc (max_user_token_number + 1,
 856                                  sizeof *token_translations);
 857
 858   /* Initialize all entries for literal tokens to 2, the internal
 859      token number for $undefined, which represents all invalid inputs.
 860      */
 861   for (i = 0; i < max_user_token_number + 1; i++)
 862     token_translations[i] = undeftoken->number;
 863   symbols_do (symbol_translation_processor, NULL);
 864 }
 865
 866
 867 /*----------------------------------------------------------------.
 868 | Assign symbol numbers, and write definition of token names into |
 869 | FDEFINES.  Set up vectors SYMBOL_TABLE, TAGS of symbols.        |
 870 `----------------------------------------------------------------*/
 871
 872 void
 873 symbols_pack (void)
 874 {
 875   symbols_do (symbol_check_alias_consistency_processor, NULL);
 876
 877   symbols = xcalloc (nsyms, sizeof *symbols);
 878   symbols_do (symbol_pack_processor, NULL);
 879
 880   /* Aliases leave empty slots in symbols, so remove them.  */
 881   {
 882     int writei;
 883     int readi;
 884     int nsyms_old = nsyms;
 885     for (writei = 0, readi = 0; readi < nsyms_old; readi += 1)
 886       {
 887         if (symbols[readi] == NULL)
 888           {
 889             nsyms -= 1;
 890             ntokens -= 1;
 891           }
 892         else
 893           {
 894             symbols[writei] = symbols[readi];
 895             symbols[writei]->number = writei;
 896             if (symbols[writei]->alias)
 897               symbols[writei]->alias->number = writei;
 898             writei += 1;
 899           }
 900       }
 901   }
 902   symbols = xnrealloc (symbols, nsyms, sizeof *symbols);
 903
 904   symbols_token_translations_init ();
 905
 906   if (startsymbol->class == unknown_sym)
 907     fatal_at (startsymbol_location,
 908               _("the start symbol %s is undefined"),
 909               startsymbol->tag);
 910   else if (startsymbol->class == token_sym)
 911     fatal_at (startsymbol_location,
 912               _("the start symbol %s is a token"),
 913               startsymbol->tag);
 914 }
 915
 916
 917 /*--------------------------------------------------.
 918 | Set default tagged/tagless %destructor/%printer.  |
 919 `--------------------------------------------------*/
 920
 921 void
 922 default_tagged_destructor_set (code_props const *destructor)
 923 {
 924   if (default_tagged_destructor.code)
 925     {
 926       complain_at (destructor->location,
 927                    _("redeclaration for default tagged %%destructor"));
 928       complain_at (default_tagged_destructor.location,
 929                    _("previous declaration"));
 930     }
 931   default_tagged_destructor = *destructor;
 932 }
 933
 934 void
 935 default_tagless_destructor_set (code_props const *destructor)
 936 {
 937   if (default_tagless_destructor.code)
 938     {
 939       complain_at (destructor->location,
 940                    _("redeclaration for default tagless %%destructor"));
 941       complain_at (default_tagless_destructor.location,
 942                    _("previous declaration"));
 943     }
 944   default_tagless_destructor = *destructor;
 945 }
 946
 947 void
 948 default_tagged_printer_set (code_props const *printer)
 949 {
 950   if (default_tagged_printer.code)
 951     {
 952       complain_at (printer->location,
 953                    _("redeclaration for default tagged %%printer"));
 954       complain_at (default_tagged_printer.location,
 955                    _("previous declaration"));
 956     }
 957   default_tagged_printer = *printer;
 958 }
 959
 960 void
 961 default_tagless_printer_set (code_props const *printer)
 962 {
 963   if (default_tagless_printer.code)
 964     {
 965       complain_at (printer->location,
 966                    _("redeclaration for default tagless %%printer"));
 967       complain_at (default_tagless_printer.location,
 968                    _("previous declaration"));
 969     }
 970   default_tagless_printer = *printer;
 971 }