/* Symbol table manager for Bison,
- Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
-This file is part of Bison, the GNU Compiler Compiler.
+ This file is part of Bison, the GNU Compiler Compiler.
-Bison is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+ Bison is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
-Bison is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+ Bison is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
-You should have received a copy of the GNU General Public License
-along with Bison; see the file COPYING. If not, write to
-the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+ You should have received a copy of the GNU General Public License
+ along with Bison; see the file COPYING. If not, write to
+ the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
#include "system.h"
-#include "alloc.h"
+#include "quotearg.h"
+#include "hash.h"
+#include "complain.h"
#include "symtab.h"
#include "gram.h"
+/*------------------------.
+| Distinguished symbols. |
+`------------------------*/
-bucket *firstsymbol;
-static bucket *lastsymbol;
-static bucket **symtab;
+symbol_t *errtoken = NULL;
+symbol_t *undeftoken = NULL;
+symbol_t *endtoken = NULL;
+symbol_t *accept = NULL;
+symbol_t *startsymbol = NULL;
+location_t startsymbol_location;
-static int
-hash (const char *key)
+/*---------------------------------.
+| Create a new symbol, named TAG. |
+`---------------------------------*/
+
+static symbol_t *
+symbol_new (const char *tag, location_t location)
+{
+ symbol_t *res = XMALLOC (symbol_t, 1);
+
+ res->tag = xstrdup (tag);
+ res->location = location;
+
+ res->type_name = NULL;
+ res->destructor = NULL;
+ res->printer = NULL;
+
+ res->number = NUMBER_UNDEFINED;
+ res->prec = 0;
+ res->assoc = undef_assoc;
+ res->user_token_number = USER_NUMBER_UNDEFINED;
+
+ res->alias = NULL;
+ res->class = unknown_sym;
+
+ nsyms++;
+ return res;
+}
+
+
+/*------------------------------------------------------------------.
+| Set the TYPE_NAME associated to SYMBOL. Does nothing if passed 0 |
+| as TYPE_NAME. |
+`------------------------------------------------------------------*/
+
+void
+symbol_type_set (symbol_t *symbol, char *type_name, location_t location)
+{
+ if (type_name)
+ {
+ if (symbol->type_name)
+ complain_at (location,
+ _("type redeclaration for %s"), symbol->tag);
+ symbol->type_name = type_name;
+ }
+}
+
+
+/*-------------------------------------------------------------------.
+| Set the DESTRUCTOR associated to SYMBOL. Do nothing if passed 0. |
+`-------------------------------------------------------------------*/
+
+void
+symbol_destructor_set (symbol_t *symbol, char *destructor, location_t location)
+{
+ if (destructor)
+ {
+ if (symbol->destructor)
+ complain_at (location,
+ _("%s redeclaration for %s"),
+ "%destructor", symbol->tag);
+ symbol->destructor = destructor;
+ symbol->destructor_location = location;
+ }
+}
+
+
+/*----------------------------------------------------------------.
+| Set the PRINTER associated to SYMBOL. Do nothing if passed 0. |
+`----------------------------------------------------------------*/
+
+void
+symbol_printer_set (symbol_t *symbol, char *printer, location_t location)
{
- register const char *cp;
- register int k;
+ if (printer)
+ {
+ if (symbol->printer)
+ complain_at (location,
+ _("%s redeclaration for %s"),
+ "%printer", symbol->tag);
+ symbol->printer = printer;
+ symbol->printer_location = location;
+ }
+}
+
- cp = key;
- k = 0;
- while (*cp)
- k = ((k << 1) ^ (*cp++)) & 0x3fff;
+/*------------------------------------------------------------------.
+| Set the PRECEDENCE associated to SYMBOL. Does nothing if invoked |
+| with UNDEF_ASSOC as ASSOC. |
+`------------------------------------------------------------------*/
+
+void
+symbol_precedence_set (symbol_t *symbol,
+ int prec, assoc_t assoc, location_t location)
+{
+ if (assoc != undef_assoc)
+ {
+ if (symbol->prec != 0)
+ complain_at (location,
+ _("redefining precedence of %s"),
+ symbol->tag);
+ symbol->prec = prec;
+ symbol->assoc = assoc;
+ }
- return k % TABSIZE;
+ /* Only terminals have a precedence. */
+ symbol_class_set (symbol, token_sym, location);
}
+/*-------------------------------------.
+| Set the CLASS associated to SYMBOL. |
+`-------------------------------------*/
-static char *
-copys (const char *s)
+void
+symbol_class_set (symbol_t *symbol, symbol_class class, location_t location)
{
- register int i;
- register const char *cp;
- register char *result;
+ if (symbol->class != unknown_sym && symbol->class != class)
+ complain_at (location, _("symbol %s redefined"), symbol->tag);
- i = 1;
- for (cp = s; *cp; cp++)
- i++;
+ if (class == nterm_sym && symbol->class != nterm_sym)
+ symbol->number = nvars++;
+ else if (class == token_sym && symbol->number == NUMBER_UNDEFINED)
+ symbol->number = ntokens++;
- result = xmalloc((unsigned int)i);
- strcpy(result, s);
- return result;
+ symbol->class = class;
}
+/*-------------------------------------------------.
+| Set the USER_TOKEN_NUMBER associated to SYMBOL. |
+`-------------------------------------------------*/
+
void
-tabinit (void)
+symbol_user_token_number_set (symbol_t *symbol,
+ int user_token_number, location_t location)
{
-/* register int i; JF unused */
+ assert (symbol->class == token_sym);
- symtab = NEW2(TABSIZE, bucket *);
+ if (symbol->user_token_number != USER_NUMBER_UNDEFINED
+ && symbol->user_token_number != user_token_number)
+ complain_at (location, _("redefining user token number of %s"),
+ symbol->tag);
- firstsymbol = NULL;
- lastsymbol = NULL;
+ symbol->user_token_number = user_token_number;
+ /* User defined $end token? */
+ if (user_token_number == 0)
+ {
+ endtoken = symbol;
+ endtoken->number = 0;
+ /* It is always mapped to 0, so it was already counted in
+ NTOKENS. */
+ --ntokens;
+ }
}
-bucket *
-getsym (const char *key)
+/*------------.
+| Free THIS. |
+`------------*/
+
+static void
+symbol_free (symbol_t *this)
{
- register int hashval;
- register bucket *bp;
- register int found;
+ free (this->tag);
+ free (this);
+}
- hashval = hash(key);
- bp = symtab[hashval];
- found = 0;
- while (bp != NULL && found == 0)
+/*-----------------------------------------------------------.
+| If THIS is not defined, report an error, and consider it a |
+| nonterminal. |
+`-----------------------------------------------------------*/
+
+static bool
+symbol_check_defined (symbol_t *this)
+{
+ if (this->class == unknown_sym)
{
- if (strcmp(key, bp->tag) == 0)
- found = 1;
- else
- bp = bp->link;
+ complain_at
+ (this->location,
+ _("symbol %s is used, but is not defined as a token and has no rules"),
+ this->tag);
+ this->class = nterm_sym;
+ this->number = nvars++;
}
- if (found == 0)
+ return true;
+}
+
+
+/*-------------------------------------------------------------------.
+| Declare the new SYMBOL. Make it an alias of SYMVAL, and type them |
+| with TYPENAME. |
+`-------------------------------------------------------------------*/
+
+void
+symbol_make_alias (symbol_t *symbol, symbol_t *symval, location_t loc)
+{
+ if (symval->alias)
+ warn_at (loc, _("symbol `%s' used more than once as a literal string"),
+ symval->tag);
+ else if (symbol->alias)
+ warn_at (loc, _("symbol `%s' given more than one literal string"),
+ symbol->tag);
+ else
{
- nsyms++;
+ symval->class = token_sym;
+ symval->user_token_number = symbol->user_token_number;
+ symbol->user_token_number = USER_NUMBER_ALIAS;
+ symval->alias = symbol;
+ symbol->alias = symval;
+ /* symbol and symval combined are only one symbol */
+ nsyms--;
+ ntokens--;
+ assert (ntokens == symbol->number || ntokens == symval->number);
+ symbol->number = symval->number =
+ (symval->number < symbol->number) ? symval->number : symbol->number;
+ }
+}
+
- bp = NEW(bucket);
- bp->link = symtab[hashval];
- bp->next = NULL;
- bp->tag = copys(key);
- bp->class = SUNKNOWN;
+/*---------------------------------------------------------.
+| Check that THIS, and its alias, have same precedence and |
+| associativity. |
+`---------------------------------------------------------*/
- if (firstsymbol == NULL)
+static bool
+symbol_check_alias_consistence (symbol_t *this)
+{
+ /* Check only those who _are_ the aliases. */
+ if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)
+ {
+ if (this->prec != this->alias->prec)
+ {
+ if (this->prec != 0 && this->alias->prec != 0)
+ complain_at (this->alias->location,
+ _("conflicting precedences for %s and %s"),
+ this->tag, this->alias->tag);
+ if (this->prec != 0)
+ this->alias->prec = this->prec;
+ else
+ this->prec = this->alias->prec;
+ }
+
+ if (this->assoc != this->alias->assoc)
{
- firstsymbol = bp;
- lastsymbol = bp;
+ if (this->assoc != undef_assoc && this->alias->assoc != undef_assoc)
+ complain_at (this->alias->location,
+ _("conflicting associativities for %s (%s) and %s (%s)"),
+ this->tag, assoc_to_string (this->assoc),
+ this->alias->tag, assoc_to_string (this->alias->assoc));
+ if (this->assoc != undef_assoc)
+ this->alias->assoc = this->assoc;
+ else
+ this->assoc = this->alias->assoc;
}
- else
+ }
+ return true;
+}
+
+
+/*-------------------------------------------------------------------.
+| Assign a symbol number, and write the definition of the token name |
+| into FDEFINES. Put in SYMBOLS. |
+`-------------------------------------------------------------------*/
+
+static bool
+symbol_pack (symbol_t *this)
+{
+ if (this->class == nterm_sym)
+ {
+ this->number += ntokens;
+ }
+ else if (this->alias)
+ {
+ /* This symbol and its alias are a single token defn.
+ Allocate a tokno, and assign to both check agreement of
+ prec and assoc fields and make both the same */
+ if (this->number == NUMBER_UNDEFINED)
{
- lastsymbol->next = bp;
- lastsymbol = bp;
+ if (this == endtoken || this->alias == endtoken)
+ this->number = this->alias->number = 0;
+ else
+ {
+ assert (this->alias->number != NUMBER_UNDEFINED);
+ this->number = this->alias->number;
+ }
}
+ /* Do not do processing below for USER_NUMBER_ALIASes. */
+ if (this->user_token_number == USER_NUMBER_ALIAS)
+ return true;
+ }
+ else /* this->class == token_sym */
+ {
+ assert (this->number != NUMBER_UNDEFINED);
+ }
+
+ symbols[this->number] = this;
+ return true;
+}
+
+
+
+
+/*--------------------------------------------------.
+| Put THIS in TOKEN_TRANSLATIONS if it is a token. |
+`--------------------------------------------------*/
+
+static bool
+symbol_translation (symbol_t *this)
+{
+ /* Non-terminal? */
+ if (this->class == token_sym
+ && this->user_token_number != USER_NUMBER_ALIAS)
+ {
+ /* A token which translation has already been set? */
+ if (token_translations[this->user_token_number] != undeftoken->number)
+ complain_at (this->location,
+ _("tokens %s and %s both assigned number %d"),
+ symbols[token_translations[this->user_token_number]]->tag,
+ this->tag, this->user_token_number);
+
+ token_translations[this->user_token_number] = this->number;
+ }
+
+ return true;
+}
+
+
+/*----------------------.
+| A symbol hash table. |
+`----------------------*/
+
+/* Initial capacity of symbols hash table. */
+#define HT_INITIAL_CAPACITY 257
+
+static struct hash_table *symbol_table = NULL;
+
+static bool
+hash_compare_symbol_t (const symbol_t *m1, const symbol_t *m2)
+{
+ return strcmp (m1->tag, m2->tag) == 0;
+}
- symtab[hashval] = bp;
+static unsigned int
+hash_symbol_t (const symbol_t *m, unsigned int tablesize)
+{
+ return hash_string (m->tag, tablesize);
+}
+
+
+/*-------------------------------.
+| Create the symbol hash table. |
+`-------------------------------*/
+
+void
+symbols_new (void)
+{
+ symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
+ NULL,
+ (Hash_hasher) hash_symbol_t,
+ (Hash_comparator) hash_compare_symbol_t,
+ (Hash_data_freer) symbol_free);
+}
+
+
+/*----------------------------------------------------------------.
+| Find the symbol named KEY, and return it. If it does not exist |
+| yet, create it. |
+`----------------------------------------------------------------*/
+
+symbol_t *
+symbol_get (const char *key, location_t location)
+{
+ symbol_t probe;
+ symbol_t *entry;
+
+ /* Keep the symbol in a printable form. */
+ key = quotearg_style (escape_quoting_style, key);
+ *(char const **) &probe.tag = key;
+ entry = hash_lookup (symbol_table, &probe);
+
+ if (!entry)
+ {
+ /* First insertion in the hash. */
+ entry = symbol_new (key, location);
+ hash_insert (symbol_table, entry);
}
+ return entry;
+}
+
+
+/*------------------------------------------------------------------.
+| Generate a dummy nonterminal, whose name cannot conflict with the |
+| user's names. |
+`------------------------------------------------------------------*/
- return bp;
+symbol_t *
+dummy_symbol_get (location_t location)
+{
+ /* Incremented for each generated symbol. */
+ static int dummy_count = 0;
+ static char buf[256];
+
+ symbol_t *sym;
+
+ sprintf (buf, "@%d", ++dummy_count);
+ sym = symbol_get (buf, location);
+ sym->class = nterm_sym;
+ sym->number = nvars++;
+ return sym;
+}
+
+
+/*-------------------.
+| Free the symbols. |
+`-------------------*/
+
+void
+symbols_free (void)
+{
+ hash_free (symbol_table);
+ free (symbols);
}
+/*---------------------------------------------------------------.
+| Look for undefined symbols, report an error, and consider them |
+| terminals. |
+`---------------------------------------------------------------*/
+
void
-free_symtab (void)
+symbols_do (symbol_processor processor, void *processor_data)
+{
+ hash_do_for_each (symbol_table,
+ (Hash_processor) processor,
+ processor_data);
+}
+
+
+/*--------------------------------------------------------------.
+| Check that all the symbols are defined. Report any undefined |
+| symbols and consider them nonterminals. |
+`--------------------------------------------------------------*/
+
+void
+symbols_check_defined (void)
+{
+ symbols_do (symbol_check_defined, NULL);
+}
+
+/*------------------------------------------------------------------.
+| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
+| number. |
+`------------------------------------------------------------------*/
+
+static void
+symbols_token_translations_init (void)
{
- register int i;
- register bucket *bp,*bptmp;/* JF don't use ptr after free */
+ bool num_256_available_p = true;
+ int i;
- for (i = 0; i < TABSIZE; i++)
+ /* Find the highest user token number, and whether 256, the POSIX
+ preferred user token number for the error token, is used. */
+ max_user_token_number = 0;
+ for (i = 0; i < ntokens; ++i)
{
- bp = symtab[i];
- while (bp)
+ symbol_t *this = symbols[i];
+ if (this->user_token_number != USER_NUMBER_UNDEFINED)
{
- bptmp = bp->link;
-#if 0 /* This causes crashes because one string can appear more than once. */
- if (bp->type_name)
- FREE(bp->type_name);
-#endif
- FREE(bp);
- bp = bptmp;
+ if (this->user_token_number > max_user_token_number)
+ max_user_token_number = this->user_token_number;
+ if (this->user_token_number == 256)
+ num_256_available_p = false;
}
}
- FREE(symtab);
+
+ /* If 256 is not used, assign it to error, to follow POSIX. */
+ if (num_256_available_p
+ && errtoken->user_token_number == USER_NUMBER_UNDEFINED)
+ errtoken->user_token_number = 256;
+
+ /* Set the missing user numbers. */
+ if (max_user_token_number < 256)
+ max_user_token_number = 256;
+
+ for (i = 0; i < ntokens; ++i)
+ {
+ symbol_t *this = symbols[i];
+ if (this->user_token_number == USER_NUMBER_UNDEFINED)
+ this->user_token_number = ++max_user_token_number;
+ if (this->user_token_number > max_user_token_number)
+ max_user_token_number = this->user_token_number;
+ }
+
+ token_translations = XCALLOC (symbol_number_t, max_user_token_number + 1);
+
+ /* Initialize all entries for literal tokens to 2, the internal
+ token number for $undefined, which represents all invalid inputs.
+ */
+ for (i = 0; i < max_user_token_number + 1; i++)
+ token_translations[i] = undeftoken->number;
+ symbols_do (symbol_translation, NULL);
+}
+
+
+/*----------------------------------------------------------------.
+| Assign symbol numbers, and write definition of token names into |
+| FDEFINES. Set up vectors SYMBOL_TABLE, TAGS of symbols. |
+`----------------------------------------------------------------*/
+
+void
+symbols_pack (void)
+{
+ symbols = XCALLOC (symbol_t *, nsyms);
+
+ symbols_do (symbol_check_alias_consistence, NULL);
+ symbols_do (symbol_pack, NULL);
+
+ symbols_token_translations_init ();
+
+ if (startsymbol->class == unknown_sym)
+ fatal_at (startsymbol_location,
+ _("the start symbol %s is undefined"),
+ startsymbol->tag);
+ else if (startsymbol->class == token_sym)
+ fatal_at (startsymbol_location,
+ _("the start symbol %s is a token"),
+ startsymbol->tag);
}
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