src/symtab.c

   1 /* Symbol table manager for Bison.
   2
   3    Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2006, 2007 Free
   4    Software 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 #include <quotearg.h>
  26
  27 #include "complain.h"
  28 #include "gram.h"
  29 #include "symtab.h"
  30
  31 /*------------------------.
  32 | Distinguished symbols.  |
  33 `------------------------*/
  34
  35 symbol *errtoken = NULL;
  36 symbol *undeftoken = NULL;
  37 symbol *endtoken = NULL;
  38 symbol *accept = NULL;
  39 symbol *startsymbol = NULL;
  40 location startsymbol_location;
  41
  42 /*---------------------------------------.
  43 | Default %destructor's and %printer's.  |
  44 `---------------------------------------*/
  45
  46 static code_props default_tagged_destructor = CODE_PROPS_NONE_INIT;
  47 static code_props default_tagless_destructor = CODE_PROPS_NONE_INIT;
  48 static code_props default_tagged_printer = CODE_PROPS_NONE_INIT;
  49 static code_props default_tagless_printer = CODE_PROPS_NONE_INIT;
  50
  51 /*---------------------------------.
  52 | Create a new symbol, named TAG.  |
  53 `---------------------------------*/
  54
  55 static symbol *
  56 symbol_new (uniqstr tag, location loc)
  57 {
  58   symbol *res = xmalloc (sizeof *res);
  59
  60   uniqstr_assert (tag);
  61   res->tag = tag;
  62   res->location = loc;
  63
  64   res->type_name = NULL;
  65   code_props_none_init (&res->destructor);
  66   code_props_none_init (&res->printer);
  67
  68   res->number = NUMBER_UNDEFINED;
  69   res->prec = 0;
  70   res->assoc = undef_assoc;
  71   res->user_token_number = USER_NUMBER_UNDEFINED;
  72
  73   res->alias = NULL;
  74   res->class = unknown_sym;
  75   res->declared = false;
  76
  77   if (nsyms == SYMBOL_NUMBER_MAXIMUM)
  78     fatal (_("too many symbols in input grammar (limit is %d)"),
  79            SYMBOL_NUMBER_MAXIMUM);
  80   nsyms++;
  81   return res;
  82 }
  83
  84 /*----------------------------------------.
  85 | Create a new semantic type, named TAG.  |
  86 `----------------------------------------*/
  87
  88 static semantic_type *
  89 semantic_type_new (uniqstr tag)
  90 {
  91   semantic_type *res = xmalloc (sizeof *res);
  92
  93   uniqstr_assert (tag);
  94   res->tag = tag;
  95   code_props_none_init (&res->destructor);
  96   code_props_none_init (&res->printer);
  97
  98   return res;
  99 }
 100
 101
 102 /*-----------------.
 103 | Print a symbol.  |
 104 `-----------------*/
 105
 106 #define SYMBOL_ATTR_PRINT(Attr)                         \
 107   if (s->Attr)                                          \
 108     fprintf (f, " %s { %s }", #Attr, s->Attr)
 109
 110 #define SYMBOL_CODE_PRINT(Attr)                         \
 111   if (s->Attr.code)                                     \
 112     fprintf (f, " %s { %s }", #Attr, s->Attr.code)
 113
 114 void
 115 symbol_print (symbol *s, FILE *f)
 116 {
 117   if (s)
 118     {
 119       fprintf (f, "\"%s\"", s->tag);
 120       SYMBOL_ATTR_PRINT (type_name);
 121       SYMBOL_CODE_PRINT (destructor);
 122       SYMBOL_CODE_PRINT (printer);
 123     }
 124   else
 125     fprintf (f, "<NULL>");
 126 }
 127
 128 #undef SYMBOL_ATTR_PRINT
 129 #undef SYMBOL_CODE_PRINT
 130
 131 /*------------------------------------------------------------------.
 132 | Complain that S's WHAT is redeclared at SECOND, and was first set |
 133 | at FIRST.                                                         |
 134 `------------------------------------------------------------------*/
 135
 136 static void
 137 symbol_redeclaration (symbol *s, const char *what, location first,
 138                       location second)
 139 {
 140   complain_at (second, _("%s redeclaration for %s"), what, s->tag);
 141   complain_at (first, _("previous declaration"));
 142 }
 143
 144 static void
 145 semantic_type_redeclaration (semantic_type *s, const char *what, location first,
 146                              location second)
 147 {
 148   complain_at (second, _("%s redeclaration for <%s>"), what, s->tag);
 149   complain_at (first, _("previous declaration"));
 150 }
 151
 152
 153 /*-----------------------------------------------------------------.
 154 | Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
 155 | as TYPE_NAME.                                                    |
 156 `-----------------------------------------------------------------*/
 157
 158 void
 159 symbol_type_set (symbol *sym, uniqstr type_name, location loc)
 160 {
 161   if (type_name)
 162     {
 163       if (sym->type_name)
 164         symbol_redeclaration (sym, "%type", sym->type_location, loc);
 165       uniqstr_assert (type_name);
 166       sym->type_name = type_name;
 167       sym->type_location = loc;
 168     }
 169 }
 170
 171
 172 /*-----------------------------------------.
 173 | Set the DESTRUCTOR associated with SYM.  |
 174 `-----------------------------------------*/
 175
 176 void
 177 symbol_destructor_set (symbol *sym, code_props const *destructor)
 178 {
 179   if (sym->destructor.code)
 180     symbol_redeclaration (sym, "%destructor", sym->destructor.location,
 181                           destructor->location);
 182   sym->destructor = *destructor;
 183 }
 184
 185 /*------------------------------------------.
 186 | Set the DESTRUCTOR associated with TYPE.  |
 187 `------------------------------------------*/
 188
 189 void
 190 semantic_type_destructor_set (semantic_type *type,
 191                               code_props const *destructor)
 192 {
 193   if (type->destructor.code)
 194     semantic_type_redeclaration (type, "%destructor",
 195                                  type->destructor.location,
 196                                  destructor->location);
 197   type->destructor = *destructor;
 198 }
 199
 200 /*---------------------------------------.
 201 | Get the computed %destructor for SYM.  |
 202 `---------------------------------------*/
 203
 204 code_props const *
 205 symbol_destructor_get (symbol const *sym)
 206 {
 207   /* Per-symbol %destructor.  */
 208   if (sym->destructor.code)
 209     return &sym->destructor;
 210
 211   /* Per-type %destructor.  */
 212   if (sym->type_name)
 213     {
 214       code_props const *destructor =
 215         &semantic_type_get (sym->type_name)->destructor;
 216       if (destructor->code)
 217         return destructor;
 218     }
 219
 220   /* Apply default %destructor's only to user-defined symbols.  */
 221   if (sym->tag[0] == '$' || sym == errtoken)
 222     return &code_props_none;
 223
 224   if (sym->type_name)
 225     return &default_tagged_destructor;
 226   return &default_tagless_destructor;
 227 }
 228
 229 /*--------------------------------------.
 230 | Set the PRINTER associated with SYM.  |
 231 `--------------------------------------*/
 232
 233 void
 234 symbol_printer_set (symbol *sym, code_props const *printer)
 235 {
 236   if (sym->printer.code)
 237     symbol_redeclaration (sym, "%printer",
 238                           sym->printer.location, printer->location);
 239   sym->printer = *printer;
 240 }
 241
 242 /*---------------------------------------.
 243 | Set the PRINTER associated with TYPE.  |
 244 `---------------------------------------*/
 245
 246 void
 247 semantic_type_printer_set (semantic_type *type, code_props const *printer)
 248 {
 249   if (type->printer.code)
 250     semantic_type_redeclaration (type, "%printer",
 251                                  type->printer.location, printer->location);
 252   type->printer = *printer;
 253 }
 254
 255 /*------------------------------------.
 256 | Get the computed %printer for SYM.  |
 257 `------------------------------------*/
 258
 259 code_props const *
 260 symbol_printer_get (symbol const *sym)
 261 {
 262   /* Per-symbol %printer.  */
 263   if (sym->printer.code)
 264     return &sym->printer;
 265
 266   /* Per-type %printer.  */
 267   if (sym->type_name)
 268     {
 269       code_props const *printer = &semantic_type_get (sym->type_name)->printer;
 270       if (printer->code)
 271         return printer;
 272     }
 273
 274   /* Apply the default %printer only to user-defined symbols.  */
 275   if (sym->tag[0] == '$' || sym == errtoken)
 276     return &code_props_none;
 277
 278   if (sym->type_name)
 279     return &default_tagged_printer;
 280   return &default_tagless_printer;
 281 }
 282
 283 /*-----------------------------------------------------------------.
 284 | Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
 285 | with UNDEF_ASSOC as ASSOC.                                       |
 286 `-----------------------------------------------------------------*/
 287
 288 void
 289 symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
 290 {
 291   if (a != undef_assoc)
 292     {
 293       if (sym->prec != 0)
 294         symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
 295                               loc);
 296       sym->prec = prec;
 297       sym->assoc = a;
 298       sym->prec_location = loc;
 299     }
 300
 301   /* Only terminals have a precedence. */
 302   symbol_class_set (sym, token_sym, loc, false);
 303 }
 304
 305
 306 /*------------------------------------.
 307 | Set the CLASS associated with SYM.  |
 308 `------------------------------------*/
 309
 310 void
 311 symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
 312 {
 313   if (sym->class != unknown_sym && sym->class != class)
 314     {
 315       complain_at (loc, _("symbol %s redefined"), sym->tag);
 316       sym->declared = false;
 317     }
 318
 319   if (class == nterm_sym && sym->class != nterm_sym)
 320     sym->number = nvars++;
 321   else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
 322     sym->number = ntokens++;
 323
 324   sym->class = class;
 325
 326   if (declaring)
 327     {
 328       if (sym->declared)
 329         warn_at (loc, _("symbol %s redeclared"), sym->tag);
 330       sym->declared = true;
 331     }
 332 }
 333
 334
 335 /*------------------------------------------------.
 336 | Set the USER_TOKEN_NUMBER associated with SYM.  |
 337 `------------------------------------------------*/
 338
 339 void
 340 symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
 341 {
 342   int *user_token_numberp;
 343
 344   aver (sym->class == token_sym);
 345
 346   if (sym->user_token_number != USER_NUMBER_ALIAS)
 347     user_token_numberp = &sym->user_token_number;
 348   else
 349     user_token_numberp = &sym->alias->user_token_number;
 350   if (*user_token_numberp != USER_NUMBER_UNDEFINED
 351       && *user_token_numberp != user_token_number)
 352     complain_at (loc, _("redefining user token number of %s"), sym->tag);
 353
 354   *user_token_numberp = user_token_number;
 355   /* User defined $end token? */
 356   if (user_token_number == 0)
 357     {
 358       endtoken = sym;
 359       endtoken->number = 0;
 360       /* It is always mapped to 0, so it was already counted in
 361          NTOKENS.  */
 362       --ntokens;
 363     }
 364 }
 365
 366
 367 /*----------------------------------------------------------.
 368 | If SYM is not defined, report an error, and consider it a |
 369 | nonterminal.                                              |
 370 `----------------------------------------------------------*/
 371
 372 static inline bool
 373 symbol_check_defined (symbol *sym)
 374 {
 375   if (sym->class == unknown_sym)
 376     {
 377       complain_at
 378         (sym->location,
 379          _("symbol %s is used, but is not defined as a token and has no rules"),
 380          sym->tag);
 381       sym->class = nterm_sym;
 382       sym->number = nvars++;
 383     }
 384
 385   return true;
 386 }
 387
 388 static bool
 389 symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
 390 {
 391   return symbol_check_defined (sym);
 392 }
 393
 394
 395 /*------------------------------------------------------------------.
 396 | Declare the new symbol SYM.  Make it an alias of SYMVAL, and type |
 397 | SYMVAL with SYM's type.                                           |
 398 `------------------------------------------------------------------*/
 399
 400 void
 401 symbol_make_alias (symbol *sym, symbol *symval, location loc)
 402 {
 403   if (symval->alias)
 404     warn_at (loc, _("symbol `%s' used more than once as a literal string"),
 405              symval->tag);
 406   else if (sym->alias)
 407     warn_at (loc, _("symbol `%s' given more than one literal string"),
 408              sym->tag);
 409   else
 410     {
 411       symval->class = token_sym;
 412       symval->user_token_number = sym->user_token_number;
 413       sym->user_token_number = USER_NUMBER_ALIAS;
 414       symval->alias = sym;
 415       sym->alias = symval;
 416       symval->number = sym->number;
 417       symbol_type_set (symval, sym->type_name, loc);
 418     }
 419 }
 420
 421
 422 /*---------------------------------------------------------.
 423 | Check that THIS, and its alias, have same precedence and |
 424 | associativity.                                           |
 425 `---------------------------------------------------------*/
 426
 427 static inline void
 428 symbol_check_alias_consistency (symbol *this)
 429 {
 430   symbol *alias = this;
 431   symbol *orig  = this->alias;
 432
 433   /* Check only those that _are_ the aliases.  */
 434   if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
 435     return;
 436
 437   if (orig->type_name != alias->type_name)
 438     {
 439       if (orig->type_name)
 440         symbol_type_set (alias, orig->type_name, orig->type_location);
 441       else
 442         symbol_type_set (orig, alias->type_name, alias->type_location);
 443     }
 444
 445
 446   if (orig->destructor.code || alias->destructor.code)
 447     {
 448       if (orig->destructor.code)
 449         symbol_destructor_set (alias, &orig->destructor);
 450       else
 451         symbol_destructor_set (orig, &alias->destructor);
 452     }
 453
 454   if (orig->printer.code || alias->printer.code)
 455     {
 456       if (orig->printer.code)
 457         symbol_printer_set (alias, &orig->printer);
 458       else
 459         symbol_printer_set (orig, &alias->printer);
 460     }
 461
 462   if (alias->prec || orig->prec)
 463     {
 464       if (orig->prec)
 465         symbol_precedence_set (alias, orig->prec, orig->assoc,
 466                                orig->prec_location);
 467       else
 468         symbol_precedence_set (orig, alias->prec, alias->assoc,
 469                                alias->prec_location);
 470     }
 471 }
 472
 473 static bool
 474 symbol_check_alias_consistency_processor (void *this,
 475                                           void *null ATTRIBUTE_UNUSED)
 476 {
 477   symbol_check_alias_consistency (this);
 478   return true;
 479 }
 480
 481
 482 /*-------------------------------------------------------------------.
 483 | Assign a symbol number, and write the definition of the token name |
 484 | into FDEFINES.  Put in SYMBOLS.                                    |
 485 `-------------------------------------------------------------------*/
 486
 487 static inline bool
 488 symbol_pack (symbol *this)
 489 {
 490   if (this->class == nterm_sym)
 491     {
 492       this->number += ntokens;
 493     }
 494   else if (this->alias)
 495     {
 496       /* This symbol and its alias are a single token defn.
 497          Allocate a tokno, and assign to both check agreement of
 498          prec and assoc fields and make both the same */
 499       if (this->number == NUMBER_UNDEFINED)
 500         {
 501           if (this == endtoken || this->alias == endtoken)
 502             this->number = this->alias->number = 0;
 503           else
 504             {
 505               aver (this->alias->number != NUMBER_UNDEFINED);
 506               this->number = this->alias->number;
 507             }
 508         }
 509       /* Do not do processing below for USER_NUMBER_ALIASes.  */
 510       if (this->user_token_number == USER_NUMBER_ALIAS)
 511         return true;
 512     }
 513   else /* this->class == token_sym */
 514     aver (this->number != NUMBER_UNDEFINED);
 515
 516   symbols[this->number] = this;
 517   return true;
 518 }
 519
 520 static bool
 521 symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
 522 {
 523   return symbol_pack (this);
 524 }
 525
 526
 527
 528
 529 /*--------------------------------------------------.
 530 | Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
 531 `--------------------------------------------------*/
 532
 533 static inline bool
 534 symbol_translation (symbol *this)
 535 {
 536   /* Non-terminal? */
 537   if (this->class == token_sym
 538       && this->user_token_number != USER_NUMBER_ALIAS)
 539     {
 540       /* A token which translation has already been set? */
 541       if (token_translations[this->user_token_number] != undeftoken->number)
 542         complain_at (this->location,
 543                      _("tokens %s and %s both assigned number %d"),
 544                      symbols[token_translations[this->user_token_number]]->tag,
 545                      this->tag, this->user_token_number);
 546
 547       token_translations[this->user_token_number] = this->number;
 548     }
 549
 550   return true;
 551 }
 552
 553 static bool
 554 symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
 555 {
 556   return symbol_translation (this);
 557 }
 558
 559
 560 /*---------------------------------------.
 561 | Symbol and semantic type hash tables.  |
 562 `---------------------------------------*/
 563
 564 /* Initial capacity of symbol and semantic type hash table.  */
 565 #define HT_INITIAL_CAPACITY 257
 566
 567 static struct hash_table *symbol_table = NULL;
 568 static struct hash_table *semantic_type_table = NULL;
 569
 570 static inline bool
 571 hash_compare_symbol (const symbol *m1, const symbol *m2)
 572 {
 573   /* Since tags are unique, we can compare the pointers themselves.  */
 574   return UNIQSTR_EQ (m1->tag, m2->tag);
 575 }
 576
 577 static inline bool
 578 hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
 579 {
 580   /* Since names are unique, we can compare the pointers themselves.  */
 581   return UNIQSTR_EQ (m1->tag, m2->tag);
 582 }
 583
 584 static bool
 585 hash_symbol_comparator (void const *m1, void const *m2)
 586 {
 587   return hash_compare_symbol (m1, m2);
 588 }
 589
 590 static bool
 591 hash_semantic_type_comparator (void const *m1, void const *m2)
 592 {
 593   return hash_compare_semantic_type (m1, m2);
 594 }
 595
 596 static inline size_t
 597 hash_symbol (const symbol *m, size_t tablesize)
 598 {
 599   /* Since tags are unique, we can hash the pointer itself.  */
 600   return ((uintptr_t) m->tag) % tablesize;
 601 }
 602
 603 static inline size_t
 604 hash_semantic_type (const semantic_type *m, size_t tablesize)
 605 {
 606   /* Since names are unique, we can hash the pointer itself.  */
 607   return ((uintptr_t) m->tag) % tablesize;
 608 }
 609
 610 static size_t
 611 hash_symbol_hasher (void const *m, size_t tablesize)
 612 {
 613   return hash_symbol (m, tablesize);
 614 }
 615
 616 static size_t
 617 hash_semantic_type_hasher (void const *m, size_t tablesize)
 618 {
 619   return hash_semantic_type (m, tablesize);
 620 }
 621
 622 /*-------------------------------.
 623 | Create the symbol hash table.  |
 624 `-------------------------------*/
 625
 626 void
 627 symbols_new (void)
 628 {
 629   symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
 630                                   NULL,
 631                                   hash_symbol_hasher,
 632                                   hash_symbol_comparator,
 633                                   free);
 634   semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
 635                                          NULL,
 636                                          hash_semantic_type_hasher,
 637                                          hash_semantic_type_comparator,
 638                                          free);
 639 }
 640
 641
 642 /*----------------------------------------------------------------.
 643 | Find the symbol named KEY, and return it.  If it does not exist |
 644 | yet, create it.                                                 |
 645 `----------------------------------------------------------------*/
 646
 647 symbol *
 648 symbol_from_uniqstr (const uniqstr key, location loc)
 649 {
 650   symbol probe;
 651   symbol *entry;
 652
 653   probe.tag = key;
 654   entry = hash_lookup (symbol_table, &probe);
 655
 656   if (!entry)
 657     {
 658       /* First insertion in the hash. */
 659       entry = symbol_new (key, loc);
 660       hash_insert (symbol_table, entry);
 661     }
 662   return entry;
 663 }
 664
 665
 666 /*-----------------------------------------------------------------------.
 667 | Find the semantic type named KEY, and return it.  If it does not exist |
 668 | yet, create it.                                                        |
 669 `-----------------------------------------------------------------------*/
 670
 671 semantic_type *
 672 semantic_type_from_uniqstr (const uniqstr key)
 673 {
 674   semantic_type probe;
 675   semantic_type *entry;
 676
 677   probe.tag = key;
 678   entry = hash_lookup (semantic_type_table, &probe);
 679
 680   if (!entry)
 681     {
 682       /* First insertion in the hash. */
 683       entry = semantic_type_new (key);
 684       hash_insert (semantic_type_table, entry);
 685     }
 686   return entry;
 687 }
 688
 689
 690 /*----------------------------------------------------------------.
 691 | Find the symbol named KEY, and return it.  If it does not exist |
 692 | yet, create it.                                                 |
 693 `----------------------------------------------------------------*/
 694
 695 symbol *
 696 symbol_get (const char *key, location loc)
 697 {
 698   return symbol_from_uniqstr (uniqstr_new (key), loc);
 699 }
 700
 701
 702 /*-----------------------------------------------------------------------.
 703 | Find the semantic type named KEY, and return it.  If it does not exist |
 704 | yet, create it.                                                        |
 705 `-----------------------------------------------------------------------*/
 706
 707 semantic_type *
 708 semantic_type_get (const char *key)
 709 {
 710   return semantic_type_from_uniqstr (uniqstr_new (key));
 711 }
 712
 713
 714 /*------------------------------------------------------------------.
 715 | Generate a dummy nonterminal, whose name cannot conflict with the |
 716 | user's names.                                                     |
 717 `------------------------------------------------------------------*/
 718
 719 symbol *
 720 dummy_symbol_get (location loc)
 721 {
 722   /* Incremented for each generated symbol.  */
 723   static int dummy_count = 0;
 724   static char buf[256];
 725
 726   symbol *sym;
 727
 728   sprintf (buf, "$@%d", ++dummy_count);
 729   sym = symbol_get (buf, loc);
 730   sym->class = nterm_sym;
 731   sym->number = nvars++;
 732   return sym;
 733 }
 734
 735 bool
 736 symbol_is_dummy (const symbol *sym)
 737 {
 738   return sym->tag[0] == '@' || (sym->tag[0] == '$' && sym->tag[1] == '@');
 739 }
 740
 741 /*-------------------.
 742 | Free the symbols.  |
 743 `-------------------*/
 744
 745 void
 746 symbols_free (void)
 747 {
 748   hash_free (symbol_table);
 749   hash_free (semantic_type_table);
 750   free (symbols);
 751 }
 752
 753
 754 /*---------------------------------------------------------------.
 755 | Look for undefined symbols, report an error, and consider them |
 756 | terminals.                                                     |
 757 `---------------------------------------------------------------*/
 758
 759 static void
 760 symbols_do (Hash_processor processor, void *processor_data)
 761 {
 762   hash_do_for_each (symbol_table, processor, processor_data);
 763 }
 764
 765
 766 /*--------------------------------------------------------------.
 767 | Check that all the symbols are defined.  Report any undefined |
 768 | symbols and consider them nonterminals.                       |
 769 `--------------------------------------------------------------*/
 770
 771 void
 772 symbols_check_defined (void)
 773 {
 774   symbols_do (symbol_check_defined_processor, NULL);
 775 }
 776
 777 /*------------------------------------------------------------------.
 778 | Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
 779 | number.                                                           |
 780 `------------------------------------------------------------------*/
 781
 782 static void
 783 symbols_token_translations_init (void)
 784 {
 785   bool num_256_available_p = true;
 786   int i;
 787
 788   /* Find the highest user token number, and whether 256, the POSIX
 789      preferred user token number for the error token, is used.  */
 790   max_user_token_number = 0;
 791   for (i = 0; i < ntokens; ++i)
 792     {
 793       symbol *this = symbols[i];
 794       if (this->user_token_number != USER_NUMBER_UNDEFINED)
 795         {
 796           if (this->user_token_number > max_user_token_number)
 797             max_user_token_number = this->user_token_number;
 798           if (this->user_token_number == 256)
 799             num_256_available_p = false;
 800         }
 801     }
 802
 803   /* If 256 is not used, assign it to error, to follow POSIX.  */
 804   if (num_256_available_p
 805       && errtoken->user_token_number == USER_NUMBER_UNDEFINED)
 806     errtoken->user_token_number = 256;
 807
 808   /* Set the missing user numbers. */
 809   if (max_user_token_number < 256)
 810     max_user_token_number = 256;
 811
 812   for (i = 0; i < ntokens; ++i)
 813     {
 814       symbol *this = symbols[i];
 815       if (this->user_token_number == USER_NUMBER_UNDEFINED)
 816         this->user_token_number = ++max_user_token_number;
 817       if (this->user_token_number > max_user_token_number)
 818         max_user_token_number = this->user_token_number;
 819     }
 820
 821   token_translations = xnmalloc (max_user_token_number + 1,
 822                                  sizeof *token_translations);
 823
 824   /* Initialize all entries for literal tokens to 2, the internal
 825      token number for $undefined, which represents all invalid inputs.
 826      */
 827   for (i = 0; i < max_user_token_number + 1; i++)
 828     token_translations[i] = undeftoken->number;
 829   symbols_do (symbol_translation_processor, NULL);
 830 }
 831
 832
 833 /*----------------------------------------------------------------.
 834 | Assign symbol numbers, and write definition of token names into |
 835 | FDEFINES.  Set up vectors SYMBOL_TABLE, TAGS of symbols.        |
 836 `----------------------------------------------------------------*/
 837
 838 void
 839 symbols_pack (void)
 840 {
 841   symbols_do (symbol_check_alias_consistency_processor, NULL);
 842
 843   symbols = xcalloc (nsyms, sizeof *symbols);
 844   symbols_do (symbol_pack_processor, NULL);
 845
 846   /* Aliases leave empty slots in symbols, so remove them.  */
 847   {
 848     int writei;
 849     int readi;
 850     int nsyms_old = nsyms;
 851     for (writei = 0, readi = 0; readi < nsyms_old; readi += 1)
 852       {
 853         if (symbols[readi] == NULL)
 854           {
 855             nsyms -= 1;
 856             ntokens -= 1;
 857           }
 858         else
 859           {
 860             symbols[writei] = symbols[readi];
 861             symbols[writei]->number = writei;
 862             if (symbols[writei]->alias)
 863               symbols[writei]->alias->number = writei;
 864             writei += 1;
 865           }
 866       }
 867   }
 868   symbols = xnrealloc (symbols, nsyms, sizeof *symbols);
 869
 870   symbols_token_translations_init ();
 871
 872   if (startsymbol->class == unknown_sym)
 873     fatal_at (startsymbol_location,
 874               _("the start symbol %s is undefined"),
 875               startsymbol->tag);
 876   else if (startsymbol->class == token_sym)
 877     fatal_at (startsymbol_location,
 878               _("the start symbol %s is a token"),
 879               startsymbol->tag);
 880 }
 881
 882
 883 /*--------------------------------------------------.
 884 | Set default tagged/tagless %destructor/%printer.  |
 885 `--------------------------------------------------*/
 886
 887 void
 888 default_tagged_destructor_set (code_props const *destructor)
 889 {
 890   if (default_tagged_destructor.code)
 891     {
 892       complain_at (destructor->location,
 893                    _("redeclaration for default tagged %%destructor"));
 894       complain_at (default_tagged_destructor.location,
 895                    _("previous declaration"));
 896     }
 897   default_tagged_destructor = *destructor;
 898 }
 899
 900 void
 901 default_tagless_destructor_set (code_props const *destructor)
 902 {
 903   if (default_tagless_destructor.code)
 904     {
 905       complain_at (destructor->location,
 906                    _("redeclaration for default tagless %%destructor"));
 907       complain_at (default_tagless_destructor.location,
 908                    _("previous declaration"));
 909     }
 910   default_tagless_destructor = *destructor;
 911 }
 912
 913 void
 914 default_tagged_printer_set (code_props const *printer)
 915 {
 916   if (default_tagged_printer.code)
 917     {
 918       complain_at (printer->location,
 919                    _("redeclaration for default tagged %%printer"));
 920       complain_at (default_tagged_printer.location,
 921                    _("previous declaration"));
 922     }
 923   default_tagged_printer = *printer;
 924 }
 925
 926 void
 927 default_tagless_printer_set (code_props const *printer)
 928 {
 929   if (default_tagless_printer.code)
 930     {
 931       complain_at (printer->location,
 932                    _("redeclaration for default tagless %%printer"));
 933       complain_at (default_tagless_printer.location,
 934                    _("previous declaration"));
 935     }
 936   default_tagless_printer = *printer;
 937 }