/* Symbol table manager for Bison,
- Copyright 1984, 1989, 2000, 2001 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.
#include "system.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 *eoftoken = NULL;
+symbol_t *axiom = NULL;
+symbol_t *startsymbol = NULL;
-static int
-hash (const char *key)
-{
- const char *cp;
- int k;
-
- cp = key;
- k = 0;
- while (*cp)
- k = ((k << 1) ^ (*cp++)) & 0x3fff;
-
- return k % TABSIZE;
-}
-
-/*--------------------------------------------------------------.
-| Create a new symbol, named TAG, which hash value is HASHVAL. |
-`--------------------------------------------------------------*/
+/*---------------------------------.
+| Create a new symbol, named TAG. |
+`---------------------------------*/
-static bucket *
-bucket_new (const char *tag, int hashval)
+static symbol_t *
+symbol_new (const char *tag)
{
- bucket *res = XMALLOC (bucket, 1);
+ symbol_t *res = XMALLOC (symbol_t, 1);
- res->link = symtab[hashval];
- res->next = NULL;
res->tag = xstrdup (tag);
res->type_name = NULL;
- res->value = -1;
+ res->number = NUMBER_UNDEFINED;
res->prec = 0;
res->assoc = right_assoc;
- res->user_token_number = SUNDEF;
+ res->user_token_number = USER_NUMBER_UNDEFINED;
res->alias = NULL;
res->class = unknown_sym;
}
+/*-----------------------------------------.
+| Set the TYPE_NAME associated to SYMBOL. |
+`-----------------------------------------*/
+
void
-tabinit (void)
+symbol_type_set (symbol_t *symbol, char *type_name)
{
- symtab = XCALLOC (bucket *, TABSIZE);
+ if (symbol->type_name)
+ complain (_("type redeclaration for %s"), symbol->tag);
+ symbol->type_name = type_name;
+}
+
- firstsymbol = NULL;
- lastsymbol = NULL;
+/*------------------------------------------.
+| Set the PRECEDENCE associated to SYMBOL. |
+`------------------------------------------*/
+
+void
+symbol_precedence_set (symbol_t *symbol,
+ int prec, associativity assoc)
+{
+ if (symbol->prec != 0)
+ complain (_("redefining precedence of %s"), symbol->tag);
+ symbol->prec = prec;
+ symbol->assoc = assoc;
}
-/*----------------------------------------------------------------.
-| Find the symbol named KEY, and return it. If it does not exist |
-| yet, create it. |
-`----------------------------------------------------------------*/
+/*-------------------------------------.
+| Set the CLASS associated to SYMBOL. |
+`-------------------------------------*/
-bucket *
-getsym (const char *key)
+void
+symbol_class_set (symbol_t *symbol, symbol_class class)
{
- int hashval;
- bucket *bp;
- int found;
+ if (symbol->class != unknown_sym && symbol->class != class)
+ complain (_("symbol %s redefined"), symbol->tag);
- hashval = hash (key);
- bp = symtab[hashval];
+ if (class == nterm_sym && symbol->class != nterm_sym)
+ symbol->number = nvars++;
+ else if (class == token_sym && symbol->number == NUMBER_UNDEFINED)
+ symbol->number = ntokens++;
- found = 0;
- while (bp != NULL && found == 0)
+ symbol->class = class;
+}
+
+
+/*-------------------------------------------------.
+| Set the USER_TOKEN_NUMBER associated to SYMBOL. |
+`-------------------------------------------------*/
+
+void
+symbol_user_token_number_set (symbol_t *symbol, int user_token_number)
+{
+ assert (symbol->class == token_sym);
+
+ if (symbol->user_token_number != USER_NUMBER_UNDEFINED
+ && symbol->user_token_number != user_token_number)
+ complain (_("redefining user token number of %s"), symbol->tag);
+
+ symbol->user_token_number = user_token_number;
+ /* User defined EOF token? */
+ if (user_token_number == 0)
{
- if (strcmp (key, bp->tag) == 0)
- found = 1;
- else
- bp = bp->link;
+ eoftoken = symbol;
+ eoftoken->number = 0;
+ /* It is always mapped to 0, so it was already counted in
+ NTOKENS. */
+ --ntokens;
}
+}
+
+
+/*------------.
+| Free THIS. |
+`------------*/
+
+static void
+symbol_free (symbol_t *this)
+{
+#if 0
+ /* This causes crashes because one string can appear more
+ than once. */
+ XFREE (this->type_name);
+#endif
+ XFREE (this->tag);
+ XFREE (this);
+}
+
+
+/*-----------------------------------------------------------.
+| If THIS is not defined, report an error, and consider it a |
+| nonterminal. |
+`-----------------------------------------------------------*/
- if (found == 0)
+static bool
+symbol_check_defined (symbol_t *this)
+{
+ if (this->class == unknown_sym)
+ {
+ complain
+ (_("symbol %s is used, but is not defined as a token and has no rules"),
+ this->tag);
+ this->class = nterm_sym;
+ this->number = nvars++;
+ }
+
+ 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, char *typename)
+{
+ if (symval->alias)
+ warn (_("symbol `%s' used more than once as a literal string"),
+ symval->tag);
+ else if (symbol->alias)
+ warn (_("symbol `%s' given more than one literal string"),
+ symbol->tag);
+ else
{
- bp = bucket_new (key, hashval);
+ symval->class = token_sym;
+ symval->type_name = typename;
+ 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;
+ }
+}
+
+
+/*---------------------------------------------------------.
+| Check that THIS, and its alias, have same precedence and |
+| associativity. |
+`---------------------------------------------------------*/
+
+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 (_("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 (firstsymbol == NULL)
+ if (this->assoc != this->alias->assoc)
{
- firstsymbol = bp;
- lastsymbol = bp;
+ if (this->assoc != 0 && this->alias->assoc != 0)
+ complain (_("conflicting assoc values for %s and %s"),
+ this->tag, this->alias->tag);
+ if (this->assoc != 0)
+ 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 == eoftoken || this->alias == eoftoken)
+ 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_ALIASs. */
+ 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;
+}
+
+
+
- symtab[hashval] = bp;
+/*--------------------------------------------------.
+| 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 (_("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 bp;
+ 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) ? FALSE : TRUE;
+}
+
+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
-free_symtab (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 *
+getsym (const char *key)
+{
+ symbol_t probe;
+ symbol_t *entry;
+
+ (const char *) probe.tag = key;
+ entry = hash_lookup (symbol_table, &probe);
+
+ if (!entry)
+ {
+ /* First insertion in the hash. */
+ entry = symbol_new (key);
+ hash_insert (symbol_table, entry);
+ }
+ return entry;
+}
+
+
+/*-------------------.
+| Free the symbols. |
+`-------------------*/
+
+void
+symbols_free (void)
+{
+ hash_free (symbol_table);
+}
+
+
+/*---------------------------------------------------------------.
+| Look for undefined symbols, report an error, and consider them |
+| terminals. |
+`---------------------------------------------------------------*/
+
+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)
+{
+ int num_256_available_p = TRUE;
int i;
- bucket *bp, *bptmp; /* JF don't use ptr after free */
- 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)
- XFREE (bp->type_name);
-#endif
- XFREE (bp->tag);
- XFREE (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;
}
}
- XFREE (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 (_("the start symbol %s is undefined"), startsymbol->tag);
+ else if (startsymbol->class == token_sym)
+ fatal (_("the start symbol %s is a token"), startsymbol->tag);
}
projects / bison.git / blobdiff