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
35static symbol **symbols_sorted = NULL;
36
37/*------------------------.
38| Distinguished symbols.  |
39`------------------------*/
40
41symbol *errtoken = NULL;
42symbol *undeftoken = NULL;
43symbol *endtoken = NULL;
44symbol *accept = NULL;
45symbol *startsymbol = NULL;
46location startsymbol_location;
47
48/*---------------------------------------.
49| Default %destructor's and %printer's.  |
50`---------------------------------------*/
51
52static code_props default_tagged_destructor = CODE_PROPS_NONE_INIT;
53static code_props default_tagless_destructor = CODE_PROPS_NONE_INIT;
54static code_props default_tagged_printer = CODE_PROPS_NONE_INIT;
55static code_props default_tagless_printer = CODE_PROPS_NONE_INIT;
56
57/*---------------------------------.
58| Create a new symbol, named TAG.  |
59`---------------------------------*/
60
61static symbol *
62symbol_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
101static semantic_type *
102semantic_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
127void
128symbol_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
149static void
150symbol_redeclaration (symbol *s, const char *what, location first,
151                      location second)
152{
153  unsigned i = 0;
154  complain_at_indent (second, &i, _("%s redeclaration for %s"), what, s->tag);
155  i += SUB_INDENT;
156  complain_at_indent (first, &i, _("previous declaration"));
157}
158
159static void
160semantic_type_redeclaration (semantic_type *s, const char *what, location first,
161                             location second)
162{
163  unsigned i = 0;
164  complain_at_indent (second, &i, _("%s redeclaration for <%s>"), what, s->tag);
165  i += SUB_INDENT;
166  complain_at_indent (first, &i, _("previous declaration"));
167}
168
169
170
171/*-----------------------------------------------------------------.
172| Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
173| as TYPE_NAME.                                                    |
174`-----------------------------------------------------------------*/
175
176void
177symbol_type_set (symbol *sym, uniqstr type_name, location loc)
178{
179  if (type_name)
180    {
181      if (sym->type_name)
182	symbol_redeclaration (sym, "%type", sym->type_location, loc);
183      uniqstr_assert (type_name);
184      sym->type_name = type_name;
185      sym->type_location = loc;
186    }
187}
188
189/*-----------------------------------------.
190| Set the DESTRUCTOR associated with SYM.  |
191`-----------------------------------------*/
192
193void
194symbol_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
206void
207semantic_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
221code_props const *
222symbol_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] == '$' || sym == errtoken)
239    return &code_props_none;
240
241  if (sym->type_name)
242    return &default_tagged_destructor;
243  return &default_tagless_destructor;
244}
245
246/*--------------------------------------.
247| Set the PRINTER associated with SYM.  |
248`--------------------------------------*/
249
250void
251symbol_printer_set (symbol *sym, code_props const *printer)
252{
253  if (sym->printer.code)
254    symbol_redeclaration (sym, "%printer",
255                          sym->printer.location, printer->location);
256  sym->printer = *printer;
257}
258
259/*---------------------------------------.
260| Set the PRINTER associated with TYPE.  |
261`---------------------------------------*/
262
263void
264semantic_type_printer_set (semantic_type *type, code_props const *printer)
265{
266  if (type->printer.code)
267    semantic_type_redeclaration (type, "%printer",
268                                 type->printer.location, printer->location);
269  type->printer = *printer;
270}
271
272/*------------------------------------.
273| Get the computed %printer for SYM.  |
274`------------------------------------*/
275
276code_props const *
277symbol_printer_get (symbol const *sym)
278{
279  /* Per-symbol %printer.  */
280  if (sym->printer.code)
281    return &sym->printer;
282
283  /* Per-type %printer.  */
284  if (sym->type_name)
285    {
286      code_props const *printer = &semantic_type_get (sym->type_name)->printer;
287      if (printer->code)
288        return printer;
289    }
290
291  /* Apply the default %printer only to user-defined symbols.  */
292  if (sym->tag[0] == '$' || 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
305void
306symbol_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
327void
328symbol_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
356void
357symbol_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_HAS_STRING_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      /* It is always mapped to 0, so it was already counted in
375	 NTOKENS.  */
376      if (endtoken->number != NUMBER_UNDEFINED)
377        --ntokens;
378      endtoken->number = 0;
379    }
380}
381
382
383/*----------------------------------------------------------.
384| If SYM is not defined, report an error, and consider it a |
385| nonterminal.                                              |
386`----------------------------------------------------------*/
387
388static inline bool
389symbol_check_defined (symbol *sym)
390{
391  if (sym->class == unknown_sym)
392    {
393      complain_at
394	(sym->location,
395	 _("symbol %s is used, but is not defined as a token and has no rules"),
396	 sym->tag);
397      sym->class = nterm_sym;
398      sym->number = nvars++;
399    }
400
401  return true;
402}
403
404static bool
405symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
406{
407  return symbol_check_defined (sym);
408}
409
410
411void
412symbol_make_alias (symbol *sym, symbol *str, location loc)
413{
414  if (str->alias)
415    warn_at (loc, _("symbol %s used more than once as a literal string"),
416             str->tag);
417  else if (sym->alias)
418    warn_at (loc, _("symbol %s given more than one literal string"),
419             sym->tag);
420  else
421    {
422      str->class = token_sym;
423      str->user_token_number = sym->user_token_number;
424      sym->user_token_number = USER_NUMBER_HAS_STRING_ALIAS;
425      str->alias = sym;
426      sym->alias = str;
427      str->number = sym->number;
428      symbol_type_set (str, sym->type_name, loc);
429    }
430}
431
432
433/*---------------------------------------------------------.
434| Check that THIS, and its alias, have same precedence and |
435| associativity.                                           |
436`---------------------------------------------------------*/
437
438static inline void
439symbol_check_alias_consistency (symbol *this)
440{
441  symbol *sym = this;
442  symbol *str = this->alias;
443
444  /* Check only the symbol in the symbol-string pair.  */
445  if (!(this->alias
446        && this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS))
447    return;
448
449  if (str->type_name != sym->type_name)
450    {
451      if (str->type_name)
452	symbol_type_set (sym, str->type_name, str->type_location);
453      else
454	symbol_type_set (str, sym->type_name, sym->type_location);
455    }
456
457
458  if (str->destructor.code || sym->destructor.code)
459    {
460      if (str->destructor.code)
461	symbol_destructor_set (sym, &str->destructor);
462      else
463	symbol_destructor_set (str, &sym->destructor);
464    }
465
466  if (str->printer.code || sym->printer.code)
467    {
468      if (str->printer.code)
469	symbol_printer_set (sym, &str->printer);
470      else
471	symbol_printer_set (str, &sym->printer);
472    }
473
474  if (sym->prec || str->prec)
475    {
476      if (str->prec)
477	symbol_precedence_set (sym, str->prec, str->assoc,
478			       str->prec_location);
479      else
480	symbol_precedence_set (str, sym->prec, sym->assoc,
481			       sym->prec_location);
482    }
483}
484
485static bool
486symbol_check_alias_consistency_processor (void *this,
487					  void *null ATTRIBUTE_UNUSED)
488{
489  symbol_check_alias_consistency (this);
490  return true;
491}
492
493
494/*-------------------------------------------------------------------.
495| Assign a symbol number, and write the definition of the token name |
496| into FDEFINES.  Put in SYMBOLS.                                    |
497`-------------------------------------------------------------------*/
498
499static inline bool
500symbol_pack (symbol *this)
501{
502  aver (this->number != NUMBER_UNDEFINED);
503  if (this->class == nterm_sym)
504    this->number += ntokens;
505  else if (this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS)
506    return true;
507
508  symbols[this->number] = this;
509  return true;
510}
511
512static bool
513symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
514{
515  return symbol_pack (this);
516}
517
518
519static void
520user_token_number_redeclaration (int num, symbol *first, symbol *second)
521{
522  unsigned i = 0;
523  /* User token numbers are not assigned during the parsing, but in a
524     second step, via a traversal of the symbol table sorted on tag.
525
526     However, error messages make more sense if we keep the first
527     declaration first.  */
528  if (location_cmp (first->location, second->location) > 0)
529    {
530      symbol* tmp = first;
531      first = second;
532      second = tmp;
533    }
534  complain_at_indent (second->location, &i,
535                      _("user token number %d redeclaration for %s"),
536                      num, second->tag);
537  i += SUB_INDENT;
538  complain_at_indent (first->location, &i,
539                      _("previous declaration for %s"),
540                      first->tag);
541}
542
543/*--------------------------------------------------.
544| Put THIS in TOKEN_TRANSLATIONS if it is a token.  |
545`--------------------------------------------------*/
546
547static inline bool
548symbol_translation (symbol *this)
549{
550  /* Non-terminal? */
551  if (this->class == token_sym
552      && this->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
553    {
554      /* A token which translation has already been set? */
555      if (token_translations[this->user_token_number] != undeftoken->number)
556	user_token_number_redeclaration
557          (this->user_token_number,
558           symbols[token_translations[this->user_token_number]],
559           this);
560
561      token_translations[this->user_token_number] = this->number;
562    }
563
564  return true;
565}
566
567static bool
568symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
569{
570  return symbol_translation (this);
571}
572
573
574/*---------------------------------------.
575| Symbol and semantic type hash tables.  |
576`---------------------------------------*/
577
578/* Initial capacity of symbol and semantic type hash table.  */
579#define HT_INITIAL_CAPACITY 257
580
581static struct hash_table *symbol_table = NULL;
582static struct hash_table *semantic_type_table = NULL;
583
584static inline bool
585hash_compare_symbol (const symbol *m1, const symbol *m2)
586{
587  /* Since tags are unique, we can compare the pointers themselves.  */
588  return UNIQSTR_EQ (m1->tag, m2->tag);
589}
590
591static inline bool
592hash_compare_semantic_type (const semantic_type *m1, const semantic_type *m2)
593{
594  /* Since names are unique, we can compare the pointers themselves.  */
595  return UNIQSTR_EQ (m1->tag, m2->tag);
596}
597
598static bool
599hash_symbol_comparator (void const *m1, void const *m2)
600{
601  return hash_compare_symbol (m1, m2);
602}
603
604static bool
605hash_semantic_type_comparator (void const *m1, void const *m2)
606{
607  return hash_compare_semantic_type (m1, m2);
608}
609
610static inline size_t
611hash_symbol (const symbol *m, size_t tablesize)
612{
613  /* Since tags are unique, we can hash the pointer itself.  */
614  return ((uintptr_t) m->tag) % tablesize;
615}
616
617static inline size_t
618hash_semantic_type (const semantic_type *m, size_t tablesize)
619{
620  /* Since names are unique, we can hash the pointer itself.  */
621  return ((uintptr_t) m->tag) % tablesize;
622}
623
624static size_t
625hash_symbol_hasher (void const *m, size_t tablesize)
626{
627  return hash_symbol (m, tablesize);
628}
629
630static size_t
631hash_semantic_type_hasher (void const *m, size_t tablesize)
632{
633  return hash_semantic_type (m, tablesize);
634}
635
636/*-------------------------------.
637| Create the symbol hash table.  |
638`-------------------------------*/
639
640void
641symbols_new (void)
642{
643  symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
644				  NULL,
645				  hash_symbol_hasher,
646				  hash_symbol_comparator,
647				  free);
648  semantic_type_table = hash_initialize (HT_INITIAL_CAPACITY,
649				         NULL,
650				         hash_semantic_type_hasher,
651				         hash_semantic_type_comparator,
652				         free);
653}
654
655
656/*----------------------------------------------------------------.
657| Find the symbol named KEY, and return it.  If it does not exist |
658| yet, create it.                                                 |
659`----------------------------------------------------------------*/
660
661symbol *
662symbol_from_uniqstr (const uniqstr key, location loc)
663{
664  symbol probe;
665  symbol *entry;
666
667  probe.tag = key;
668  entry = hash_lookup (symbol_table, &probe);
669
670  if (!entry)
671    {
672      /* First insertion in the hash. */
673      aver (!symbols_sorted);
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
687semantic_type *
688semantic_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
712symbol *
713symbol_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
724semantic_type *
725semantic_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
736symbol *
737dummy_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
752bool
753symbol_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
762void
763symbols_free (void)
764{
765  hash_free (symbol_table);
766  hash_free (semantic_type_table);
767  free (symbols);
768  free (symbols_sorted);
769}
770
771
772/*---------------------------------------------------------------.
773| Look for undefined symbols, report an error, and consider them |
774| terminals.                                                     |
775`---------------------------------------------------------------*/
776
777static int
778symbols_cmp (symbol const *a, symbol const *b)
779{
780  return strcmp (a->tag, b->tag);
781}
782
783static int
784symbols_cmp_qsort (void const *a, void const *b)
785{
786  return symbols_cmp (*(symbol * const *)a, *(symbol * const *)b);
787}
788
789static void
790symbols_do (Hash_processor processor, void *processor_data)
791{
792  size_t count = hash_get_n_entries (symbol_table);
793  if (!symbols_sorted)
794    {
795      symbols_sorted = xnmalloc (count, sizeof *symbols_sorted);
796      hash_get_entries (symbol_table, (void**)symbols_sorted, count);
797      qsort (symbols_sorted, count, sizeof *symbols_sorted,
798             symbols_cmp_qsort);
799    }
800  {
801    size_t i;
802    for (i = 0; i < count; ++i)
803      processor (symbols_sorted[i], processor_data);
804  }
805}
806
807/*--------------------------------------------------------------.
808| Check that all the symbols are defined.  Report any undefined |
809| symbols and consider them nonterminals.                       |
810`--------------------------------------------------------------*/
811
812void
813symbols_check_defined (void)
814{
815  symbols_do (symbol_check_defined_processor, NULL);
816}
817
818/*------------------------------------------------------------------.
819| Set TOKEN_TRANSLATIONS.  Check that no two symbols share the same |
820| number.                                                           |
821`------------------------------------------------------------------*/
822
823static void
824symbols_token_translations_init (void)
825{
826  bool num_256_available_p = true;
827  int i;
828
829  /* Find the highest user token number, and whether 256, the POSIX
830     preferred user token number for the error token, is used.  */
831  max_user_token_number = 0;
832  for (i = 0; i < ntokens; ++i)
833    {
834      symbol *this = symbols[i];
835      if (this->user_token_number != USER_NUMBER_UNDEFINED)
836	{
837	  if (this->user_token_number > max_user_token_number)
838	    max_user_token_number = this->user_token_number;
839	  if (this->user_token_number == 256)
840	    num_256_available_p = false;
841	}
842    }
843
844  /* If 256 is not used, assign it to error, to follow POSIX.  */
845  if (num_256_available_p
846      && errtoken->user_token_number == USER_NUMBER_UNDEFINED)
847    errtoken->user_token_number = 256;
848
849  /* Set the missing user numbers. */
850  if (max_user_token_number < 256)
851    max_user_token_number = 256;
852
853  for (i = 0; i < ntokens; ++i)
854    {
855      symbol *this = symbols[i];
856      if (this->user_token_number == USER_NUMBER_UNDEFINED)
857	this->user_token_number = ++max_user_token_number;
858      if (this->user_token_number > max_user_token_number)
859	max_user_token_number = this->user_token_number;
860    }
861
862  token_translations = xnmalloc (max_user_token_number + 1,
863				 sizeof *token_translations);
864
865  /* Initialize all entries for literal tokens to 2, the internal
866     token number for $undefined, which represents all invalid inputs.
867     */
868  for (i = 0; i < max_user_token_number + 1; i++)
869    token_translations[i] = undeftoken->number;
870  symbols_do (symbol_translation_processor, NULL);
871}
872
873
874/*----------------------------------------------------------------.
875| Assign symbol numbers, and write definition of token names into |
876| FDEFINES.  Set up vectors SYMBOL_TABLE, TAGS of symbols.        |
877`----------------------------------------------------------------*/
878
879void
880symbols_pack (void)
881{
882  symbols_do (symbol_check_alias_consistency_processor, NULL);
883
884  symbols = xcalloc (nsyms, sizeof *symbols);
885  symbols_do (symbol_pack_processor, NULL);
886
887  /* Aliases leave empty slots in symbols, so remove them.  */
888  {
889    int writei;
890    int readi;
891    int nsyms_old = nsyms;
892    for (writei = 0, readi = 0; readi < nsyms_old; readi += 1)
893      {
894        if (symbols[readi] == NULL)
895          {
896            nsyms -= 1;
897            ntokens -= 1;
898          }
899        else
900          {
901            symbols[writei] = symbols[readi];
902            symbols[writei]->number = writei;
903            if (symbols[writei]->alias)
904              symbols[writei]->alias->number = writei;
905            writei += 1;
906          }
907      }
908  }
909  symbols = xnrealloc (symbols, nsyms, sizeof *symbols);
910
911  symbols_token_translations_init ();
912
913  if (startsymbol->class == unknown_sym)
914    fatal_at (startsymbol_location,
915	      _("the start symbol %s is undefined"),
916	      startsymbol->tag);
917  else if (startsymbol->class == token_sym)
918    fatal_at (startsymbol_location,
919	      _("the start symbol %s is a token"),
920	      startsymbol->tag);
921}
922
923
924/*--------------------------------------------------.
925| Set default tagged/tagless %destructor/%printer.  |
926`--------------------------------------------------*/
927
928void
929default_tagged_destructor_set (code_props const *destructor)
930{
931  if (default_tagged_destructor.code)
932    {
933      unsigned i = 0;
934      complain_at_indent (destructor->location, &i,
935                          _("redeclaration for default tagged %%destructor"));
936      i += SUB_INDENT;
937      complain_at_indent (default_tagged_destructor.location, &i,
938		          _("previous declaration"));
939    }
940  default_tagged_destructor = *destructor;
941}
942
943void
944default_tagless_destructor_set (code_props const *destructor)
945{
946  if (default_tagless_destructor.code)
947    {
948      unsigned i = 0;
949      complain_at_indent (destructor->location, &i,
950                          _("redeclaration for default tagless %%destructor"));
951      i += SUB_INDENT;
952      complain_at_indent (default_tagless_destructor.location, &i,
953                          _("previous declaration"));
954    }
955  default_tagless_destructor = *destructor;
956}
957
958void
959default_tagged_printer_set (code_props const *printer)
960{
961  if (default_tagged_printer.code)
962    {
963      unsigned i = 0;
964      complain_at_indent (printer->location, &i,
965                          _("redeclaration for default tagged %%printer"));
966      i += SUB_INDENT;
967      complain_at_indent (default_tagged_printer.location, &i,
968		          _("previous declaration"));
969    }
970  default_tagged_printer = *printer;
971}
972
973void
974default_tagless_printer_set (code_props const *printer)
975{
976  if (default_tagless_printer.code)
977    {
978      unsigned i = 0;
979      complain_at_indent (printer->location, &i,
980                          _("redeclaration for default tagless %%printer"));
981      i += SUB_INDENT;
982      complain_at_indent (default_tagless_printer.location, &i,
983		          _("previous declaration"));
984    }
985  default_tagless_printer = *printer;
986}
987