1 /* Symbol table manager for Bison.
3 Copyright (C) 1984, 1989, 2000-2002, 2004-2010 Free Software
6 This file is part of Bison, the GNU Compiler Compiler.
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.
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.
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/>. */
31 /*-------------------------------------------------------------------.
32 | Symbols sorted by tag. Allocated by the first invocation of |
33 | symbols_do, after which no more symbols should be created. |
34 `-------------------------------------------------------------------*/
36 static symbol
**symbols_sorted
= NULL
;
38 /*------------------------.
39 | Distinguished symbols. |
40 `------------------------*/
42 symbol
*errtoken
= NULL
;
43 symbol
*undeftoken
= NULL
;
44 symbol
*endtoken
= NULL
;
45 symbol
*accept
= NULL
;
46 symbol
*startsymbol
= NULL
;
47 location startsymbol_location
;
49 /*---------------------------------------.
50 | Default %destructor's and %printer's. |
51 `---------------------------------------*/
53 static code_props default_tagged_destructor
= CODE_PROPS_NONE_INIT
;
54 static code_props default_tagless_destructor
= CODE_PROPS_NONE_INIT
;
55 static code_props default_tagged_printer
= CODE_PROPS_NONE_INIT
;
56 static code_props default_tagless_printer
= CODE_PROPS_NONE_INIT
;
58 /*---------------------------------.
59 | Create a new symbol, named TAG. |
60 `---------------------------------*/
63 symbol_new (uniqstr tag
, location loc
)
65 symbol
*res
= xmalloc (sizeof *res
);
69 /* If the tag is not a string (starts with a double quote), check
70 that it is valid for Yacc. */
71 if (tag
[0] != '\"' && tag
[0] != '\'' && strchr (tag
, '-'))
72 yacc_at (loc
, _("POSIX Yacc forbids dashes in symbol names: %s"),
78 res
->type_name
= NULL
;
79 code_props_none_init (&res
->destructor
);
80 code_props_none_init (&res
->printer
);
82 res
->number
= NUMBER_UNDEFINED
;
84 res
->assoc
= undef_assoc
;
85 res
->user_token_number
= USER_NUMBER_UNDEFINED
;
88 res
->class = unknown_sym
;
89 res
->declared
= false;
91 if (nsyms
== SYMBOL_NUMBER_MAXIMUM
)
92 fatal (_("too many symbols in input grammar (limit is %d)"),
93 SYMBOL_NUMBER_MAXIMUM
);
98 /*----------------------------------------.
99 | Create a new semantic type, named TAG. |
100 `----------------------------------------*/
102 static semantic_type
*
103 semantic_type_new (uniqstr tag
)
105 semantic_type
*res
= xmalloc (sizeof *res
);
107 uniqstr_assert (tag
);
109 code_props_none_init (&res
->destructor
);
110 code_props_none_init (&res
->printer
);
120 #define SYMBOL_ATTR_PRINT(Attr) \
122 fprintf (f, " %s { %s }", #Attr, s->Attr)
124 #define SYMBOL_CODE_PRINT(Attr) \
126 fprintf (f, " %s { %s }", #Attr, s->Attr.code)
129 symbol_print (symbol
*s
, FILE *f
)
133 fprintf (f
, "\"%s\"", s
->tag
);
134 SYMBOL_ATTR_PRINT (type_name
);
135 SYMBOL_CODE_PRINT (destructor
);
136 SYMBOL_CODE_PRINT (printer
);
139 fprintf (f
, "<NULL>");
142 #undef SYMBOL_ATTR_PRINT
143 #undef SYMBOL_CODE_PRINT
145 /*------------------------------------------------------------------.
146 | Complain that S's WHAT is redeclared at SECOND, and was first set |
148 `------------------------------------------------------------------*/
151 symbol_redeclaration (symbol
*s
, const char *what
, location first
,
154 complain_at (second
, _("%s redeclaration for %s"), what
, s
->tag
);
155 complain_at (first
, _("previous declaration"));
159 semantic_type_redeclaration (semantic_type
*s
, const char *what
, location first
,
162 complain_at (second
, _("%s redeclaration for <%s>"), what
, s
->tag
);
163 complain_at (first
, _("previous declaration"));
168 /*-----------------------------------------------------------------.
169 | Set the TYPE_NAME associated with SYM. Does nothing if passed 0 |
171 `-----------------------------------------------------------------*/
174 symbol_type_set (symbol
*sym
, uniqstr type_name
, location loc
)
179 symbol_redeclaration (sym
, "%type", sym
->type_location
, loc
);
180 uniqstr_assert (type_name
);
181 sym
->type_name
= type_name
;
182 sym
->type_location
= loc
;
186 /*-----------------------------------------.
187 | Set the DESTRUCTOR associated with SYM. |
188 `-----------------------------------------*/
191 symbol_destructor_set (symbol
*sym
, code_props
const *destructor
)
193 if (sym
->destructor
.code
)
194 symbol_redeclaration (sym
, "%destructor", sym
->destructor
.location
,
195 destructor
->location
);
196 sym
->destructor
= *destructor
;
199 /*------------------------------------------.
200 | Set the DESTRUCTOR associated with TYPE. |
201 `------------------------------------------*/
204 semantic_type_destructor_set (semantic_type
*type
,
205 code_props
const *destructor
)
207 if (type
->destructor
.code
)
208 semantic_type_redeclaration (type
, "%destructor",
209 type
->destructor
.location
,
210 destructor
->location
);
211 type
->destructor
= *destructor
;
214 /*---------------------------------------.
215 | Get the computed %destructor for SYM. |
216 `---------------------------------------*/
219 symbol_destructor_get (symbol
const *sym
)
221 /* Per-symbol %destructor. */
222 if (sym
->destructor
.code
)
223 return &sym
->destructor
;
225 /* Per-type %destructor. */
228 code_props
const *destructor
=
229 &semantic_type_get (sym
->type_name
)->destructor
;
230 if (destructor
->code
)
234 /* Apply default %destructor's only to user-defined symbols. */
235 if (sym
->tag
[0] == '$' || sym
== errtoken
)
236 return &code_props_none
;
239 return &default_tagged_destructor
;
240 return &default_tagless_destructor
;
243 /*--------------------------------------.
244 | Set the PRINTER associated with SYM. |
245 `--------------------------------------*/
248 symbol_printer_set (symbol
*sym
, code_props
const *printer
)
250 if (sym
->printer
.code
)
251 symbol_redeclaration (sym
, "%printer",
252 sym
->printer
.location
, printer
->location
);
253 sym
->printer
= *printer
;
256 /*---------------------------------------.
257 | Set the PRINTER associated with TYPE. |
258 `---------------------------------------*/
261 semantic_type_printer_set (semantic_type
*type
, code_props
const *printer
)
263 if (type
->printer
.code
)
264 semantic_type_redeclaration (type
, "%printer",
265 type
->printer
.location
, printer
->location
);
266 type
->printer
= *printer
;
269 /*------------------------------------.
270 | Get the computed %printer for SYM. |
271 `------------------------------------*/
274 symbol_printer_get (symbol
const *sym
)
276 /* Per-symbol %printer. */
277 if (sym
->printer
.code
)
278 return &sym
->printer
;
280 /* Per-type %printer. */
283 code_props
const *printer
= &semantic_type_get (sym
->type_name
)->printer
;
288 /* Apply the default %printer only to user-defined symbols. */
289 if (sym
->tag
[0] == '$' || sym
== errtoken
)
290 return &code_props_none
;
293 return &default_tagged_printer
;
294 return &default_tagless_printer
;
297 /*-----------------------------------------------------------------.
298 | Set the PRECEDENCE associated with SYM. Does nothing if invoked |
299 | with UNDEF_ASSOC as ASSOC. |
300 `-----------------------------------------------------------------*/
303 symbol_precedence_set (symbol
*sym
, int prec
, assoc a
, location loc
)
305 if (a
!= undef_assoc
)
308 symbol_redeclaration (sym
, assoc_to_string (a
), sym
->prec_location
,
312 sym
->prec_location
= loc
;
315 /* Only terminals have a precedence. */
316 symbol_class_set (sym
, token_sym
, loc
, false);
320 /*------------------------------------.
321 | Set the CLASS associated with SYM. |
322 `------------------------------------*/
325 symbol_class_set (symbol
*sym
, symbol_class
class, location loc
, bool declaring
)
327 if (sym
->class != unknown_sym
&& sym
->class != class)
329 complain_at (loc
, _("symbol %s redefined"), sym
->tag
);
330 sym
->declared
= false;
333 if (class == nterm_sym
&& sym
->class != nterm_sym
)
334 sym
->number
= nvars
++;
335 else if (class == token_sym
&& sym
->number
== NUMBER_UNDEFINED
)
336 sym
->number
= ntokens
++;
343 warn_at (loc
, _("symbol %s redeclared"), sym
->tag
);
344 sym
->declared
= true;
349 /*------------------------------------------------.
350 | Set the USER_TOKEN_NUMBER associated with SYM. |
351 `------------------------------------------------*/
354 symbol_user_token_number_set (symbol
*sym
, int user_token_number
, location loc
)
356 int *user_token_numberp
;
358 if (sym
->user_token_number
!= USER_NUMBER_HAS_STRING_ALIAS
)
359 user_token_numberp
= &sym
->user_token_number
;
361 user_token_numberp
= &sym
->alias
->user_token_number
;
362 if (*user_token_numberp
!= USER_NUMBER_UNDEFINED
363 && *user_token_numberp
!= user_token_number
)
364 complain_at (loc
, _("redefining user token number of %s"), sym
->tag
);
366 *user_token_numberp
= user_token_number
;
367 /* User defined $end token? */
368 if (user_token_number
== 0)
371 endtoken
->number
= 0;
372 /* It is always mapped to 0, so it was already counted in
379 /*----------------------------------------------------------.
380 | If SYM is not defined, report an error, and consider it a |
382 `----------------------------------------------------------*/
385 symbol_check_defined (symbol
*sym
)
387 if (sym
->class == unknown_sym
)
391 _("symbol %s is used, but is not defined as a token and has no rules"),
393 sym
->class = nterm_sym
;
394 sym
->number
= nvars
++;
401 symbol_check_defined_processor (void *sym
, void *null ATTRIBUTE_UNUSED
)
403 return symbol_check_defined (sym
);
408 symbol_make_alias (symbol
*sym
, symbol
*str
, location loc
)
411 warn_at (loc
, _("symbol `%s' used more than once as a literal string"),
414 warn_at (loc
, _("symbol `%s' given more than one literal string"),
418 str
->class = token_sym
;
419 str
->user_token_number
= sym
->user_token_number
;
420 sym
->user_token_number
= USER_NUMBER_HAS_STRING_ALIAS
;
423 str
->number
= sym
->number
;
424 symbol_type_set (str
, sym
->type_name
, loc
);
429 /*---------------------------------------------------------.
430 | Check that THIS, and its alias, have same precedence and |
432 `---------------------------------------------------------*/
435 symbol_check_alias_consistency (symbol
*this)
438 symbol
*str
= this->alias
;
440 /* Check only the symbol in the symbol-string pair. */
442 && this->user_token_number
== USER_NUMBER_HAS_STRING_ALIAS
))
445 if (str
->type_name
!= sym
->type_name
)
448 symbol_type_set (sym
, str
->type_name
, str
->type_location
);
450 symbol_type_set (str
, sym
->type_name
, sym
->type_location
);
454 if (str
->destructor
.code
|| sym
->destructor
.code
)
456 if (str
->destructor
.code
)
457 symbol_destructor_set (sym
, &str
->destructor
);
459 symbol_destructor_set (str
, &sym
->destructor
);
462 if (str
->printer
.code
|| sym
->printer
.code
)
464 if (str
->printer
.code
)
465 symbol_printer_set (sym
, &str
->printer
);
467 symbol_printer_set (str
, &sym
->printer
);
470 if (sym
->prec
|| str
->prec
)
473 symbol_precedence_set (sym
, str
->prec
, str
->assoc
,
476 symbol_precedence_set (str
, sym
->prec
, sym
->assoc
,
482 symbol_check_alias_consistency_processor (void *this,
483 void *null ATTRIBUTE_UNUSED
)
485 symbol_check_alias_consistency (this);
490 /*-------------------------------------------------------------------.
491 | Assign a symbol number, and write the definition of the token name |
492 | into FDEFINES. Put in SYMBOLS. |
493 `-------------------------------------------------------------------*/
496 symbol_pack (symbol
*this)
498 aver (this->number
!= NUMBER_UNDEFINED
);
499 if (this->class == nterm_sym
)
500 this->number
+= ntokens
;
501 else if (this->user_token_number
== USER_NUMBER_HAS_STRING_ALIAS
)
504 symbols
[this->number
] = this;
509 symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED
)
511 return symbol_pack (this);
516 user_token_number_redeclaration (int num
, symbol
*first
, symbol
*second
)
518 /* User token numbers are not assigned during the parsing, but in a
519 second step, via a traversal of the symbol table sorted on tag.
521 However, error messages make more sense if we keep the first
522 declaration first. */
523 if (location_cmp (first
->location
, second
->location
) > 0)
529 complain_at (second
->location
,
530 _("user token number %d redeclaration for %s"),
532 complain_at (first
->location
, _("previous declaration for %s"),
536 /*--------------------------------------------------.
537 | Put THIS in TOKEN_TRANSLATIONS if it is a token. |
538 `--------------------------------------------------*/
541 symbol_translation (symbol
*this)
544 if (this->class == token_sym
545 && this->user_token_number
!= USER_NUMBER_HAS_STRING_ALIAS
)
547 /* A token which translation has already been set? */
548 if (token_translations
[this->user_token_number
] != undeftoken
->number
)
549 user_token_number_redeclaration
550 (this->user_token_number
,
551 symbols
[token_translations
[this->user_token_number
]],
554 token_translations
[this->user_token_number
] = this->number
;
561 symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED
)
563 return symbol_translation (this);
567 /*---------------------------------------.
568 | Symbol and semantic type hash tables. |
569 `---------------------------------------*/
571 /* Initial capacity of symbol and semantic type hash table. */
572 #define HT_INITIAL_CAPACITY 257
574 static struct hash_table
*symbol_table
= NULL
;
575 static struct hash_table
*semantic_type_table
= NULL
;
578 hash_compare_symbol (const symbol
*m1
, const symbol
*m2
)
580 /* Since tags are unique, we can compare the pointers themselves. */
581 return UNIQSTR_EQ (m1
->tag
, m2
->tag
);
585 hash_compare_semantic_type (const semantic_type
*m1
, const semantic_type
*m2
)
587 /* Since names are unique, we can compare the pointers themselves. */
588 return UNIQSTR_EQ (m1
->tag
, m2
->tag
);
592 hash_symbol_comparator (void const *m1
, void const *m2
)
594 return hash_compare_symbol (m1
, m2
);
598 hash_semantic_type_comparator (void const *m1
, void const *m2
)
600 return hash_compare_semantic_type (m1
, m2
);
604 hash_symbol (const symbol
*m
, size_t tablesize
)
606 /* Since tags are unique, we can hash the pointer itself. */
607 return ((uintptr_t) m
->tag
) % tablesize
;
611 hash_semantic_type (const semantic_type
*m
, size_t tablesize
)
613 /* Since names are unique, we can hash the pointer itself. */
614 return ((uintptr_t) m
->tag
) % tablesize
;
618 hash_symbol_hasher (void const *m
, size_t tablesize
)
620 return hash_symbol (m
, tablesize
);
624 hash_semantic_type_hasher (void const *m
, size_t tablesize
)
626 return hash_semantic_type (m
, tablesize
);
629 /*-------------------------------.
630 | Create the symbol hash table. |
631 `-------------------------------*/
636 symbol_table
= hash_initialize (HT_INITIAL_CAPACITY
,
639 hash_symbol_comparator
,
641 semantic_type_table
= hash_initialize (HT_INITIAL_CAPACITY
,
643 hash_semantic_type_hasher
,
644 hash_semantic_type_comparator
,
649 /*----------------------------------------------------------------.
650 | Find the symbol named KEY, and return it. If it does not exist |
652 `----------------------------------------------------------------*/
655 symbol_from_uniqstr (const uniqstr key
, location loc
)
661 entry
= hash_lookup (symbol_table
, &probe
);
665 /* First insertion in the hash. */
666 aver (!symbols_sorted
);
667 entry
= symbol_new (key
, loc
);
668 if (!hash_insert (symbol_table
, entry
))
675 /*-----------------------------------------------------------------------.
676 | Find the semantic type named KEY, and return it. If it does not exist |
678 `-----------------------------------------------------------------------*/
681 semantic_type_from_uniqstr (const uniqstr key
)
684 semantic_type
*entry
;
687 entry
= hash_lookup (semantic_type_table
, &probe
);
691 /* First insertion in the hash. */
692 entry
= semantic_type_new (key
);
693 if (!hash_insert (semantic_type_table
, entry
))
700 /*----------------------------------------------------------------.
701 | Find the symbol named KEY, and return it. If it does not exist |
703 `----------------------------------------------------------------*/
706 symbol_get (const char *key
, location loc
)
708 return symbol_from_uniqstr (uniqstr_new (key
), loc
);
712 /*-----------------------------------------------------------------------.
713 | Find the semantic type named KEY, and return it. If it does not exist |
715 `-----------------------------------------------------------------------*/
718 semantic_type_get (const char *key
)
720 return semantic_type_from_uniqstr (uniqstr_new (key
));
724 /*------------------------------------------------------------------.
725 | Generate a dummy nonterminal, whose name cannot conflict with the |
727 `------------------------------------------------------------------*/
730 dummy_symbol_get (location loc
)
732 /* Incremented for each generated symbol. */
733 static int dummy_count
= 0;
734 static char buf
[256];
738 sprintf (buf
, "$@%d", ++dummy_count
);
739 sym
= symbol_get (buf
, loc
);
740 sym
->class = nterm_sym
;
741 sym
->number
= nvars
++;
746 symbol_is_dummy (const symbol
*sym
)
748 return sym
->tag
[0] == '@' || (sym
->tag
[0] == '$' && sym
->tag
[1] == '@');
751 /*-------------------.
752 | Free the symbols. |
753 `-------------------*/
758 hash_free (symbol_table
);
759 hash_free (semantic_type_table
);
761 free (symbols_sorted
);
765 /*---------------------------------------------------------------.
766 | Look for undefined symbols, report an error, and consider them |
768 `---------------------------------------------------------------*/
771 symbols_cmp (symbol
const *a
, symbol
const *b
)
773 return strcmp (a
->tag
, b
->tag
);
777 symbols_cmp_qsort (void const *a
, void const *b
)
779 return symbols_cmp (*(symbol
* const *)a
, *(symbol
* const *)b
);
783 symbols_do (Hash_processor processor
, void *processor_data
)
785 size_t count
= hash_get_n_entries (symbol_table
);
788 symbols_sorted
= xnmalloc (count
, sizeof *symbols_sorted
);
789 hash_get_entries (symbol_table
, (void**)symbols_sorted
, count
);
790 qsort (symbols_sorted
, count
, sizeof *symbols_sorted
,
795 for (i
= 0; i
< count
; ++i
)
796 processor (symbols_sorted
[i
], processor_data
);
800 /*--------------------------------------------------------------.
801 | Check that all the symbols are defined. Report any undefined |
802 | symbols and consider them nonterminals. |
803 `--------------------------------------------------------------*/
806 symbols_check_defined (void)
808 symbols_do (symbol_check_defined_processor
, NULL
);
811 /*------------------------------------------------------------------.
812 | Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
814 `------------------------------------------------------------------*/
817 symbols_token_translations_init (void)
819 bool num_256_available_p
= true;
822 /* Find the highest user token number, and whether 256, the POSIX
823 preferred user token number for the error token, is used. */
824 max_user_token_number
= 0;
825 for (i
= 0; i
< ntokens
; ++i
)
827 symbol
*this = symbols
[i
];
828 if (this->user_token_number
!= USER_NUMBER_UNDEFINED
)
830 if (this->user_token_number
> max_user_token_number
)
831 max_user_token_number
= this->user_token_number
;
832 if (this->user_token_number
== 256)
833 num_256_available_p
= false;
837 /* If 256 is not used, assign it to error, to follow POSIX. */
838 if (num_256_available_p
839 && errtoken
->user_token_number
== USER_NUMBER_UNDEFINED
)
840 errtoken
->user_token_number
= 256;
842 /* Set the missing user numbers. */
843 if (max_user_token_number
< 256)
844 max_user_token_number
= 256;
846 for (i
= 0; i
< ntokens
; ++i
)
848 symbol
*this = symbols
[i
];
849 if (this->user_token_number
== USER_NUMBER_UNDEFINED
)
850 this->user_token_number
= ++max_user_token_number
;
851 if (this->user_token_number
> max_user_token_number
)
852 max_user_token_number
= this->user_token_number
;
855 token_translations
= xnmalloc (max_user_token_number
+ 1,
856 sizeof *token_translations
);
858 /* Initialize all entries for literal tokens to 2, the internal
859 token number for $undefined, which represents all invalid inputs.
861 for (i
= 0; i
< max_user_token_number
+ 1; i
++)
862 token_translations
[i
] = undeftoken
->number
;
863 symbols_do (symbol_translation_processor
, NULL
);
867 /*----------------------------------------------------------------.
868 | Assign symbol numbers, and write definition of token names into |
869 | FDEFINES. Set up vectors SYMBOL_TABLE, TAGS of symbols. |
870 `----------------------------------------------------------------*/
875 symbols_do (symbol_check_alias_consistency_processor
, NULL
);
877 symbols
= xcalloc (nsyms
, sizeof *symbols
);
878 symbols_do (symbol_pack_processor
, NULL
);
880 /* Aliases leave empty slots in symbols, so remove them. */
884 int nsyms_old
= nsyms
;
885 for (writei
= 0, readi
= 0; readi
< nsyms_old
; readi
+= 1)
887 if (symbols
[readi
] == NULL
)
894 symbols
[writei
] = symbols
[readi
];
895 symbols
[writei
]->number
= writei
;
896 if (symbols
[writei
]->alias
)
897 symbols
[writei
]->alias
->number
= writei
;
902 symbols
= xnrealloc (symbols
, nsyms
, sizeof *symbols
);
904 symbols_token_translations_init ();
906 if (startsymbol
->class == unknown_sym
)
907 fatal_at (startsymbol_location
,
908 _("the start symbol %s is undefined"),
910 else if (startsymbol
->class == token_sym
)
911 fatal_at (startsymbol_location
,
912 _("the start symbol %s is a token"),
917 /*--------------------------------------------------.
918 | Set default tagged/tagless %destructor/%printer. |
919 `--------------------------------------------------*/
922 default_tagged_destructor_set (code_props
const *destructor
)
924 if (default_tagged_destructor
.code
)
926 complain_at (destructor
->location
,
927 _("redeclaration for default tagged %%destructor"));
928 complain_at (default_tagged_destructor
.location
,
929 _("previous declaration"));
931 default_tagged_destructor
= *destructor
;
935 default_tagless_destructor_set (code_props
const *destructor
)
937 if (default_tagless_destructor
.code
)
939 complain_at (destructor
->location
,
940 _("redeclaration for default tagless %%destructor"));
941 complain_at (default_tagless_destructor
.location
,
942 _("previous declaration"));
944 default_tagless_destructor
= *destructor
;
948 default_tagged_printer_set (code_props
const *printer
)
950 if (default_tagged_printer
.code
)
952 complain_at (printer
->location
,
953 _("redeclaration for default tagged %%printer"));
954 complain_at (default_tagged_printer
.location
,
955 _("previous declaration"));
957 default_tagged_printer
= *printer
;
961 default_tagless_printer_set (code_props
const *printer
)
963 if (default_tagless_printer
.code
)
965 complain_at (printer
->location
,
966 _("redeclaration for default tagless %%printer"));
967 complain_at (default_tagless_printer
.location
,
968 _("previous declaration"));
970 default_tagless_printer
= *printer
;