src/symtab.c

   1 /* Symbol table manager for Bison.
   2
   3    Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2006, 2007,
   4    2008-2009 Free 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 | Get the CLASS associated with SYM. |
 173 `-----------------------------------*/
 174
 175 const char *
 176 symbol_class_get_string (symbol *sym)
 177 {
 178   if (sym->class)
 179     {
 180       if (sym->class == token_sym)
 181         return "terminal";
 182       else if (sym->class == nterm_sym)
 183         return "nonterminal";
 184     }
 185   return "unknown";
 186 }
 187
 188
 189 /*-----------------------------------------.
 190 | Set the DESTRUCTOR associated with SYM.  |
 191 `-----------------------------------------*/
 192
 193 void
 194 symbol_destructor_set (symbol *sym, code_props const *destructor)
 195 {
 196   if (sym->destructor.code)
 197     symbol_redeclaration (sym, "%destructor", sym->destructor.location,
 198                           destructor->location);
 199   sym->destructor = *destructor;
 200 }
 201
 202 /*------------------------------------------.
 203 | Set the DESTRUCTOR associated with TYPE.  |
 204 `------------------------------------------*/
 205
 206 void
 207 semantic_type_destructor_set (semantic_type *type,
 208                               code_props const *destructor)
 209 {
 210   if (type->destructor.code)
 211     semantic_type_redeclaration (type, "%destructor",
 212                                  type->destructor.location,
 213                                  destructor->location);
 214   type->destructor = *destructor;
 215 }
 216
 217 /*---------------------------------------.
 218 | Get the computed %destructor for SYM.  |
 219 `---------------------------------------*/
 220
 221 code_props const *
 222 symbol_destructor_get (symbol const *sym)
 223 {
 224   /* Per-symbol %destructor.  */
 225   if (sym->destructor.code)
 226     return &sym->destructor;
 227
 228   /* Per-type %destructor.  */
 229   if (sym->type_name)
 230     {
 231       code_props const *destructor =
 232         &semantic_type_get (sym->type_name)->destructor;
 233       if (destructor->code)
 234         return destructor;
 235     }
 236
 237   /* Apply default %destructor's only to user-defined symbols.  */
 238   if (sym->tag[0] == '$' || sym == errtoken)
 239     return &code_props_none;
 240
 241   if (sym->type_name)
 242     return &default_tagged_destructor;
 243   return &default_tagless_destructor;
 244 }
 245
 246 /*--------------------------------------.
 247 | Set the PRINTER associated with SYM.  |
 248 `--------------------------------------*/
 249
 250 void
 251 symbol_printer_set (symbol *sym, code_props const *printer)
 252 {
 253   if (sym->printer.code)
 254     symbol_redeclaration (sym, "%printer",
 255                           sym->printer.location, printer->location);
 256   sym->printer = *printer;
 257 }
 258
 259 /*---------------------------------------.
 260 | Set the PRINTER associated with TYPE.  |
 261 `---------------------------------------*/
 262
 263 void
 264 semantic_type_printer_set (semantic_type *type, code_props const *printer)
 265 {
 266   if (type->printer.code)
 267     semantic_type_redeclaration (type, "%printer",
 268                                  type->printer.location, printer->location);
 269   type->printer = *printer;
 270 }
 271
 272 /*------------------------------------.
 273 | Get the computed %printer for SYM.  |
 274 `------------------------------------*/
 275
 276 code_props const *
 277 symbol_printer_get (symbol const *sym)
 278 {
 279   /* Per-symbol %printer.  */
 280   if (sym->printer.code)
 281     return &sym->printer;
 282
 283   /* Per-type %printer.  */
 284   if (sym->type_name)
 285     {
 286       code_props const *printer = &semantic_type_get (sym->type_name)->printer;
 287       if (printer->code)
 288         return printer;
 289     }
 290
 291   /* Apply the default %printer only to user-defined symbols.  */
 292   if (sym->tag[0] == '$' || sym == errtoken)
 293     return &code_props_none;
 294
 295   if (sym->type_name)
 296     return &default_tagged_printer;
 297   return &default_tagless_printer;
 298 }
 299
 300 /*-----------------------------------------------------------------.
 301 | Set the PRECEDENCE associated with SYM.  Does nothing if invoked |
 302 | with UNDEF_ASSOC as ASSOC.                                       |
 303 `-----------------------------------------------------------------*/
 304
 305 void
 306 symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
 307 {
 308   if (a != undef_assoc)
 309     {
 310       if (sym->prec != 0)
 311         symbol_redeclaration (sym, assoc_to_string (a), sym->prec_location,
 312                               loc);
 313       sym->prec = prec;
 314       sym->assoc = a;
 315       sym->prec_location = loc;
 316     }
 317
 318   /* Only terminals have a precedence. */
 319   symbol_class_set (sym, token_sym, loc, false);
 320 }
 321
 322
 323 /*------------------------------------.
 324 | Set the CLASS associated with SYM.  |
 325 `------------------------------------*/
 326
 327 void
 328 symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
 329 {
 330   if (sym->class != unknown_sym && sym->class != class)
 331     {
 332       complain_at (loc, _("symbol %s redefined"), sym->tag);
 333       sym->declared = false;
 334     }
 335
 336   if (class == nterm_sym && sym->class != nterm_sym)
 337     sym->number = nvars++;
 338   else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
 339     sym->number = ntokens++;
 340
 341   sym->class = class;
 342
 343   if (declaring)
 344     {
 345       if (sym->declared)
 346         warn_at (loc, _("symbol %s redeclared"), sym->tag);
 347       sym->declared = true;
 348     }
 349 }
 350
 351
 352 /*------------------------------------------------.
 353 | Set the USER_TOKEN_NUMBER associated with SYM.  |
 354 `------------------------------------------------*/
 355
 356 void
 357 symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
 358 {
 359   int *user_token_numberp;
 360
 361   if (sym->user_token_number != USER_NUMBER_ALIAS)
 362     user_token_numberp = &sym->user_token_number;
 363   else
 364     user_token_numberp = &sym->alias->user_token_number;
 365   if (*user_token_numberp != USER_NUMBER_UNDEFINED
 366       && *user_token_numberp != user_token_number)
 367     complain_at (loc, _("redefining user token number of %s"), sym->tag);
 368
 369   *user_token_numberp = user_token_number;
 370   /* User defined $end token? */
 371   if (user_token_number == 0)
 372     {
 373       endtoken = sym;
 374       endtoken->number = 0;
 375       /* It is always mapped to 0, so it was already counted in
 376          NTOKENS.  */
 377       --ntokens;
 378     }
 379 }
 380
 381
 382 /*----------------------------------------------------------.
 383 | If SYM is not defined, report an error, and consider it a |
 384 | nonterminal.                                              |
 385 `----------------------------------------------------------*/
 386
 387 static inline bool
 388 symbol_check_defined (symbol *sym)
 389 {
 390   if (sym->class == unknown_sym)
 391     {
 392       complain_at
 393         (sym->location,
 394          _("symbol %s is used, but is not defined as a token and has no rules"),
 395          sym->tag);
 396       sym->class = nterm_sym;
 397       sym->number = nvars++;
 398     }
 399
 400   return true;
 401 }
 402
 403 static bool
 404 symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
 405 {
 406   return symbol_check_defined (sym);
 407 }
 408
 409
 410 /*------------------------------------------------------------------.
 411 | Declare the new symbol SYM.  Make it an alias of SYMVAL, and type |
 412 | SYMVAL with SYM's type.                                           |
 413 `------------------------------------------------------------------*/
 414
 415 void
 416 symbol_make_alias (symbol *sym, symbol *symval, location loc)
 417 {
 418   if (symval->alias)
 419     warn_at (loc, _("symbol `%s' used more than once as a literal string"),
 420              symval->tag);
 421   else if (sym->alias)
 422     warn_at (loc, _("symbol `%s' given more than one literal string"),
 423              sym->tag);
 424   else
 425     {
 426       symval->class = token_sym;
 427       symval->user_token_number = sym->user_token_number;
 428       sym->user_token_number = USER_NUMBER_ALIAS;
 429       symval->alias = sym;
 430       sym->alias = symval;
 431       symval->number = sym->number;
 432       symbol_type_set (symval, sym->type_name, loc);
 433     }
 434 }
 435
 436
 437 /*---------------------------------------------------------.
 438 | Check that THIS, and its alias, have same precedence and |
 439 | associativity.                                           |
 440 `---------------------------------------------------------*/
 441
 442 static inline void
 443 symbol_check_alias_consistency (symbol *this)
 444 {
 445   symbol *alias = this;
 446   symbol *orig  = this->alias;
 447
 448   /* Check only those that _are_ the aliases.  */
 449   if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
 450     return;
 451
 452   if (orig->type_name != alias->type_name)
 453     {
 454       if (orig->type_name)
 455         symbol_type_set (alias, orig->type_name, orig->type_location);
 456       else
 457         symbol_type_set (orig, alias->type_name, alias->type_location);
 458     }
 459
 460
 461   if (orig->destructor.code || alias->destructor.code)
 462     {
 463       if (orig->destructor.code)
 464         symbol_destructor_set (alias, &orig->destructor);
 465       else
 466         symbol_destructor_set (orig, &alias->destructor);
 467     }
 468
 469   if (orig->printer.code || alias->printer.code)
 470     {
 471       if (orig->printer.code)
 472         symbol_printer_set (alias, &orig->printer);
 473       else
 474         symbol_printer_set (orig, &alias->printer);
 475     }
 476
 477   if (alias->prec || orig->prec)
 478     {
 479       if (orig->prec)
 480         symbol_precedence_set (alias, orig->prec, orig->assoc,
 481                                orig->prec_location);
 482       else
 483         symbol_precedence_set (orig, alias->prec, alias->assoc,
 484                                alias->prec_location);
 485     }
 486 }
 487
 488 static bool
 489 symbol_check_alias_consistency_processor (void *this,
 490                                           void *null ATTRIBUTE_UNUSED)
 491 {
 492   symbol_check_alias_consistency (this);
 493   return true;
 494 }
 495
 496
 497 /*-------------------------------------------------------------------.
 498 | Assign a symbol number, and write the definition of the token name |
 499 | into FDEFINES.  Put in SYMBOLS.                                    |
 500 `-------------------------------------------------------------------*/
 501
 502 static inline bool
 503 symbol_pack (symbol *this)
 504 {
 505   if (this->class == nterm_sym)
 506     {
 507       this->number += ntokens;
 508     }
 509   else if (this->alias)
 510     {
 511       /* This symbol and its alias are a single token defn.
 512          Allocate a tokno, and assign to both check agreement of
 513          prec and assoc fields and make both the same */
 514       if (this->number == NUMBER_UNDEFINED)
 515         {
 516           if (this == endtoken || this->alias == endtoken)
 517             this->number = this->alias->number = 0;
 518           else
 519             {
 520               aver (this->alias->number != NUMBER_UNDEFINED);
 521               this->number = this->alias->number;
 522             }
 523         }
 524       /* Do not do processing below for USER_NUMBER_ALIASes.  */
 525       if (this->user_token_number == USER_NUMBER_ALIAS)
 526         return true;
 527     }
 528   else /* this->class == token_sym */
 529     aver (this->number != NUMBER_UNDEFINED);
 530
 531   symbols[this->number] = this;
 532   return true;
 533 }
 534
 535 static bool
 536 symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
 537 {
 538   return symbol_pack (this);
 539 }
 540
 541
 542
 543
 544 /*--------------------------------------------------.
 545 | Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
 546 `--------------------------------------------------*/
 547
 548 static inline bool
 549 symbol_translation (symbol *this)
 550 {
 551   /* Non-terminal? */
 552   if (this->class == token_sym
 553       && this->user_token_number != USER_NUMBER_ALIAS)
 554     {
 555       /* A token which translation has already been set? */
 556       if (token_translations[this->user_token_number] != undeftoken->number)
 557         complain_at (this->location,
 558                      _("tokens %s and %s both assigned number %d"),
 559                      symbols[token_translations[this->user_token_number]]->tag,
 560                      this->tag, this->user_token_number);
 561
 562       token_translations[this->user_token_number] = this->number;
 563     }
 564
 565   return true;
 566 }
 567
 568 static bool
 569 symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
 570 {
 571   return symbol_translation (this);
 572 }
 573
 574
 575 /*---------------------------------------.
 576 | Symbol and semantic type hash tables.  |
 577 `---------------------------------------*/
 578
 579 /* Initial capacity of symbol and semantic type hash table.  */
 580 #define HT_INITIAL_CAPACITY 257
 581
 582 static struct hash_table *symbol_table = NULL;
 583 static struct hash_table *semantic_type_table = NULL;
 584
 585 static inline bool
 586 hash_compare_symbol (const symbol *m1, const symbol *m2)
 587 {
 588   /* Since tags are unique, we can compare the pointers themselves.  */
 589   return UNIQSTR_EQ (m1->tag, m2->tag);
 590 }
 591
 592 static inline bool
 593 hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
 594 {
 595   /* Since names are unique, we can compare the pointers themselves.  */
 596   return UNIQSTR_EQ (m1->tag, m2->tag);
 597 }
 598
 599 static bool
 600 hash_symbol_comparator (void const *m1, void const *m2)
 601 {
 602   return hash_compare_symbol (m1, m2);
 603 }
 604
 605 static bool
 606 hash_semantic_type_comparator (void const *m1, void const *m2)
 607 {
 608   return hash_compare_semantic_type (m1, m2);
 609 }
 610
 611 static inline size_t
 612 hash_symbol (const symbol *m, size_t tablesize)
 613 {
 614   /* Since tags are unique, we can hash the pointer itself.  */
 615   return ((uintptr_t) m->tag) % tablesize;
 616 }
 617
 618 static inline size_t
 619 hash_semantic_type (const semantic_type *m, size_t tablesize)
 620 {
 621   /* Since names are unique, we can hash the pointer itself.  */
 622   return ((uintptr_t) m->tag) % tablesize;
 623 }
 624
 625 static size_t
 626 hash_symbol_hasher (void const *m, size_t tablesize)
 627 {
 628   return hash_symbol (m, tablesize);
 629 }
 630
 631 static size_t
 632 hash_semantic_type_hasher (void const *m, size_t tablesize)
 633 {
 634   return hash_semantic_type (m, tablesize);
 635 }
 636
 637 /*-------------------------------.
 638 | Create the symbol hash table.  |
 639 `-------------------------------*/
 640
 641 void
 642 symbols_new (void)
 643 {
 644   symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
 645                                   NULL,
 646                                   hash_symbol_hasher,
 647                                   hash_symbol_comparator,
 648                                   free);
 649   semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
 650                                          NULL,
 651                                          hash_semantic_type_hasher,
 652                                          hash_semantic_type_comparator,
 653                                          free);
 654 }
 655
 656
 657 /*----------------------------------------------------------------.
 658 | Find the symbol named KEY, and return it.  If it does not exist |
 659 | yet, create it.                                                 |
 660 `----------------------------------------------------------------*/
 661
 662 symbol *
 663 symbol_from_uniqstr (const uniqstr key, location loc)
 664 {
 665   symbol probe;
 666   symbol *entry;
 667
 668   probe.tag = key;
 669   entry = hash_lookup (symbol_table, &probe);
 670
 671   if (!entry)
 672     {
 673       /* First insertion in the hash. */
 674       entry = symbol_new (key, loc);
 675       if (!hash_insert (symbol_table, entry))
 676         xalloc_die ();
 677     }
 678   return entry;
 679 }
 680
 681
 682 /*-----------------------------------------------------------------------.
 683 | Find the semantic type named KEY, and return it.  If it does not exist |
 684 | yet, create it.                                                        |
 685 `-----------------------------------------------------------------------*/
 686
 687 semantic_type *
 688 semantic_type_from_uniqstr (const uniqstr key)
 689 {
 690   semantic_type probe;
 691   semantic_type *entry;
 692
 693   probe.tag = key;
 694   entry = hash_lookup (semantic_type_table, &probe);
 695
 696   if (!entry)
 697     {
 698       /* First insertion in the hash. */
 699       entry = semantic_type_new (key);
 700       if (!hash_insert (semantic_type_table, entry))
 701         xalloc_die ();
 702     }
 703   return entry;
 704 }
 705
 706
 707 /*----------------------------------------------------------------.
 708 | Find the symbol named KEY, and return it.  If it does not exist |
 709 | yet, create it.                                                 |
 710 `----------------------------------------------------------------*/
 711
 712 symbol *
 713 symbol_get (const char *key, location loc)
 714 {
 715   return symbol_from_uniqstr (uniqstr_new (key), loc);
 716 }
 717
 718
 719 /*-----------------------------------------------------------------------.
 720 | Find the semantic type named KEY, and return it.  If it does not exist |
 721 | yet, create it.                                                        |
 722 `-----------------------------------------------------------------------*/
 723
 724 semantic_type *
 725 semantic_type_get (const char *key)
 726 {
 727   return semantic_type_from_uniqstr (uniqstr_new (key));
 728 }
 729
 730
 731 /*------------------------------------------------------------------.
 732 | Generate a dummy nonterminal, whose name cannot conflict with the |
 733 | user's names.                                                     |
 734 `------------------------------------------------------------------*/
 735
 736 symbol *
 737 dummy_symbol_get (location loc)
 738 {
 739   /* Incremented for each generated symbol.  */
 740   static int dummy_count = 0;
 741   static char buf[256];
 742
 743   symbol *sym;
 744
 745   sprintf (buf, "$@%d", ++dummy_count);
 746   sym = symbol_get (buf, loc);
 747   sym->class = nterm_sym;
 748   sym->number = nvars++;
 749   return sym;
 750 }
 751
 752 bool
 753 symbol_is_dummy (const symbol *sym)
 754 {
 755   return sym->tag[0] == '@' || (sym->tag[0] == '$' && sym->tag[1] == '@');
 756 }
 757
 758 /*-------------------.
 759 | Free the symbols.  |
 760 `-------------------*/
 761
 762 void
 763 symbols_free (void)
 764 {
 765   hash_free (symbol_table);
 766   hash_free (semantic_type_table);
 767   free (symbols);
 768 }
 769
 770
 771 /*---------------------------------------------------------------.
 772 | Look for undefined symbols, report an error, and consider them |
 773 | terminals.                                                     |
 774 `---------------------------------------------------------------*/
 775
 776 static void
 777 symbols_do (Hash_processor processor, void *processor_data)
 778 {
 779   hash_do_for_each (symbol_table, processor, processor_data);
 780 }
 781
 782
 783 /*--------------------------------------------------------------.
 784 | Check that all the symbols are defined.  Report any undefined |
 785 | symbols and consider them nonterminals.                       |
 786 `--------------------------------------------------------------*/
 787
 788 void
 789 symbols_check_defined (void)
 790 {
 791   symbols_do (symbol_check_defined_processor, NULL);
 792 }
 793
 794 /*------------------------------------------------------------------.
 795 | Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
 796 | number.                                                           |
 797 `------------------------------------------------------------------*/
 798
 799 static void
 800 symbols_token_translations_init (void)
 801 {
 802   bool num_256_available_p = true;
 803   int i;
 804
 805   /* Find the highest user token number, and whether 256, the POSIX
 806      preferred user token number for the error token, is used.  */
 807   max_user_token_number = 0;
 808   for (i = 0; i < ntokens; ++i)
 809     {
 810       symbol *this = symbols[i];
 811       if (this->user_token_number != USER_NUMBER_UNDEFINED)
 812         {
 813           if (this->user_token_number > max_user_token_number)
 814             max_user_token_number = this->user_token_number;
 815           if (this->user_token_number == 256)
 816             num_256_available_p = false;
 817         }
 818     }
 819
 820   /* If 256 is not used, assign it to error, to follow POSIX.  */
 821   if (num_256_available_p
 822       && errtoken->user_token_number == USER_NUMBER_UNDEFINED)
 823     errtoken->user_token_number = 256;
 824
 825   /* Set the missing user numbers. */
 826   if (max_user_token_number < 256)
 827     max_user_token_number = 256;
 828
 829   for (i = 0; i < ntokens; ++i)
 830     {
 831       symbol *this = symbols[i];
 832       if (this->user_token_number == USER_NUMBER_UNDEFINED)
 833         this->user_token_number = ++max_user_token_number;
 834       if (this->user_token_number > max_user_token_number)
 835         max_user_token_number = this->user_token_number;
 836     }
 837
 838   token_translations = xnmalloc (max_user_token_number + 1,
 839                                  sizeof *token_translations);
 840
 841   /* Initialize all entries for literal tokens to 2, the internal
 842      token number for $undefined, which represents all invalid inputs.
 843      */
 844   for (i = 0; i < max_user_token_number + 1; i++)
 845     token_translations[i] = undeftoken->number;
 846   symbols_do (symbol_translation_processor, NULL);
 847 }
 848
 849
 850 /*----------------------------------------------------------------.
 851 | Assign symbol numbers, and write definition of token names into |
 852 | FDEFINES.  Set up vectors SYMBOL_TABLE, TAGS of symbols.        |
 853 `----------------------------------------------------------------*/
 854
 855 void
 856 symbols_pack (void)
 857 {
 858   symbols_do (symbol_check_alias_consistency_processor, NULL);
 859
 860   symbols = xcalloc (nsyms, sizeof *symbols);
 861   symbols_do (symbol_pack_processor, NULL);
 862
 863   /* Aliases leave empty slots in symbols, so remove them.  */
 864   {
 865     int writei;
 866     int readi;
 867     int nsyms_old = nsyms;
 868     for (writei = 0, readi = 0; readi < nsyms_old; readi += 1)
 869       {
 870         if (symbols[readi] == NULL)
 871           {
 872             nsyms -= 1;
 873             ntokens -= 1;
 874           }
 875         else
 876           {
 877             symbols[writei] = symbols[readi];
 878             symbols[writei]->number = writei;
 879             if (symbols[writei]->alias)
 880               symbols[writei]->alias->number = writei;
 881             writei += 1;
 882           }
 883       }
 884   }
 885   symbols = xnrealloc (symbols, nsyms, sizeof *symbols);
 886
 887   symbols_token_translations_init ();
 888
 889   if (startsymbol->class == unknown_sym)
 890     fatal_at (startsymbol_location,
 891               _("the start symbol %s is undefined"),
 892               startsymbol->tag);
 893   else if (startsymbol->class == token_sym)
 894     fatal_at (startsymbol_location,
 895               _("the start symbol %s is a token"),
 896               startsymbol->tag);
 897 }
 898
 899
 900 /*--------------------------------------------------.
 901 | Set default tagged/tagless %destructor/%printer.  |
 902 `--------------------------------------------------*/
 903
 904 void
 905 default_tagged_destructor_set (code_props const *destructor)
 906 {
 907   if (default_tagged_destructor.code)
 908     {
 909       complain_at (destructor->location,
 910                    _("redeclaration for default tagged %%destructor"));
 911       complain_at (default_tagged_destructor.location,
 912                    _("previous declaration"));
 913     }
 914   default_tagged_destructor = *destructor;
 915 }
 916
 917 void
 918 default_tagless_destructor_set (code_props const *destructor)
 919 {
 920   if (default_tagless_destructor.code)
 921     {
 922       complain_at (destructor->location,
 923                    _("redeclaration for default tagless %%destructor"));
 924       complain_at (default_tagless_destructor.location,
 925                    _("previous declaration"));
 926     }
 927   default_tagless_destructor = *destructor;
 928 }
 929
 930 void
 931 default_tagged_printer_set (code_props const *printer)
 932 {
 933   if (default_tagged_printer.code)
 934     {
 935       complain_at (printer->location,
 936                    _("redeclaration for default tagged %%printer"));
 937       complain_at (default_tagged_printer.location,
 938                    _("previous declaration"));
 939     }
 940   default_tagged_printer = *printer;
 941 }
 942
 943 void
 944 default_tagless_printer_set (code_props const *printer)
 945 {
 946   if (default_tagless_printer.code)
 947     {
 948       complain_at (printer->location,
 949                    _("redeclaration for default tagless %%printer"));
 950       complain_at (default_tagless_printer.location,
 951                    _("previous declaration"));
 952     }
 953   default_tagless_printer = *printer;
 954 }