-/* Symbol table manager for Bison,
- Copyright 1984, 1989, 2000 Free Software Foundation, Inc.
+/* Symbol table manager for Bison.
+
+ 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 "symtab.h"
-#include "gram.h"
+#include <hash.h>
+#include <quotearg.h>
-bucket *firstsymbol;
-static bucket *lastsymbol;
-static bucket **symtab;
-
-static int
-hash (const char *key)
-{
- const char *cp;
- int k;
+#include "complain.h"
+#include "gram.h"
+#include "symtab.h"
- cp = key;
- k = 0;
- while (*cp)
- k = ((k << 1) ^ (*cp++)) & 0x3fff;
+/*------------------------.
+| Distinguished symbols. |
+`------------------------*/
- return k % TABSIZE;
-}
+symbol *errtoken = NULL;
+symbol *undeftoken = NULL;
+symbol *endtoken = NULL;
+symbol *accept = NULL;
+symbol *startsymbol = NULL;
+location startsymbol_location;
-/*--------------------------------------------------------------.
-| 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 *
+symbol_new (uniqstr tag, location loc)
{
- bucket *res = XMALLOC (bucket, 1);
+ symbol *res = MALLOC (res, 1);
+
+ uniqstr_assert (tag);
+ res->tag = tag;
+ res->location = loc;
- res->link = symtab[hashval];
- res->next = NULL;
- res->tag = xstrdup (tag);
res->type_name = NULL;
- res->value = 0;
+ res->destructor = NULL;
+ res->printer = NULL;
+
+ res->number = NUMBER_UNDEFINED;
res->prec = 0;
- res->assoc = right_assoc;
- res->user_token_number = 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 with SYM. Does nothing if passed 0 |
+| as TYPE_NAME. |
+`-----------------------------------------------------------------*/
+
void
-tabinit (void)
+symbol_type_set (symbol *sym, uniqstr type_name, location loc)
{
- symtab = XCALLOC (bucket *, TABSIZE);
+ if (type_name)
+ {
+ if (sym->type_name)
+ complain_at (loc, _("type redeclaration for %s"), sym->tag);
+ uniqstr_assert (type_name);
+ sym->type_name = type_name;
+ }
+}
- firstsymbol = NULL;
- lastsymbol = NULL;
+
+/*------------------------------------------------------------------.
+| Set the DESTRUCTOR associated with SYM. Do nothing if passed 0. |
+`------------------------------------------------------------------*/
+
+void
+symbol_destructor_set (symbol *sym, char *destructor, location loc)
+{
+ if (destructor)
+ {
+ if (sym->destructor)
+ complain_at (loc, _("%s redeclaration for %s"),
+ "%destructor", sym->tag);
+ sym->destructor = destructor;
+ sym->destructor_location = loc;
+ }
}
-/*----------------------------------------------------------------.
-| Find the symbol named KEY, and return it. If it does not exist |
-| yet, create it. |
-`----------------------------------------------------------------*/
+/*---------------------------------------------------------------.
+| Set the PRINTER associated with SYM. Do nothing if passed 0. |
+`---------------------------------------------------------------*/
+
+void
+symbol_printer_set (symbol *sym, char *printer, location loc)
+{
+ if (printer)
+ {
+ if (sym->printer)
+ complain_at (loc, _("%s redeclaration for %s"),
+ "%printer", sym->tag);
+ sym->printer = printer;
+ sym->printer_location = loc;
+ }
+}
+
+
+/*-----------------------------------------------------------------.
+| Set the PRECEDENCE associated with SYM. Does nothing if invoked |
+| with UNDEF_ASSOC as ASSOC. |
+`-----------------------------------------------------------------*/
+
+void
+symbol_precedence_set (symbol *sym, int prec, assoc a, location loc)
+{
+ if (a != undef_assoc)
+ {
+ if (sym->prec != 0)
+ complain_at (loc, _("redefining precedence of %s"), sym->tag);
+ sym->prec = prec;
+ sym->assoc = a;
+ }
+
+ /* Only terminals have a precedence. */
+ symbol_class_set (sym, token_sym, loc);
+}
+
+
+/*------------------------------------.
+| Set the CLASS associated with SYM. |
+`------------------------------------*/
+
+void
+symbol_class_set (symbol *sym, symbol_class class, location loc)
+{
+ if (sym->class != unknown_sym && sym->class != class)
+ complain_at (loc, _("symbol %s redefined"), sym->tag);
+
+ if (class == nterm_sym && sym->class != nterm_sym)
+ sym->number = nvars++;
+ else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
+ sym->number = ntokens++;
+
+ sym->class = class;
+}
+
+
+/*------------------------------------------------.
+| Set the USER_TOKEN_NUMBER associated with SYM. |
+`------------------------------------------------*/
-bucket *
-getsym (const char *key)
+void
+symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
{
- int hashval;
- bucket *bp;
- int found;
+ if (sym->class != token_sym)
+ abort ();
- hashval = hash (key);
- bp = symtab[hashval];
+ if (sym->user_token_number != USER_NUMBER_UNDEFINED
+ && sym->user_token_number != user_token_number)
+ complain_at (loc, _("redefining user token number of %s"), sym->tag);
- found = 0;
- while (bp != NULL && found == 0)
+ sym->user_token_number = user_token_number;
+ /* User defined $end token? */
+ if (user_token_number == 0)
{
- if (strcmp (key, bp->tag) == 0)
- found = 1;
- else
- bp = bp->link;
+ endtoken = sym;
+ endtoken->number = 0;
+ /* It is always mapped to 0, so it was already counted in
+ NTOKENS. */
+ --ntokens;
}
+}
+
- if (found == 0)
+/*----------------------------------------------------------.
+| If SYM is not defined, report an error, and consider it a |
+| nonterminal. |
+`----------------------------------------------------------*/
+
+static inline bool
+symbol_check_defined (symbol *sym)
+{
+ if (sym->class == unknown_sym)
{
- bp = bucket_new (key, hashval);
+ complain_at
+ (sym->location,
+ _("symbol %s is used, but is not defined as a token and has no rules"),
+ sym->tag);
+ sym->class = nterm_sym;
+ sym->number = nvars++;
+ }
- if (firstsymbol == NULL)
+ return true;
+}
+
+static bool
+symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
+{
+ return symbol_check_defined (sym);
+}
+
+
+/*------------------------------------------------------------------.
+| Declare the new symbol SYM. Make it an alias of SYMVAL, and type |
+| SYMVAL with SYM's type. |
+`------------------------------------------------------------------*/
+
+void
+symbol_make_alias (symbol *sym, symbol *symval, location loc)
+{
+ if (symval->alias)
+ warn_at (loc, _("symbol `%s' used more than once as a literal string"),
+ symval->tag);
+ else if (sym->alias)
+ warn_at (loc, _("symbol `%s' given more than one literal string"),
+ sym->tag);
+ else
+ {
+ symval->class = token_sym;
+ symval->user_token_number = sym->user_token_number;
+ sym->user_token_number = USER_NUMBER_ALIAS;
+ symval->alias = sym;
+ sym->alias = symval;
+ /* sym and symval combined are only one symbol. */
+ nsyms--;
+ ntokens--;
+ if (ntokens != sym->number && ntokens != symval->number)
+ abort ();
+ sym->number = symval->number =
+ (symval->number < sym->number) ? symval->number : sym->number;
+ symbol_type_set (symval, sym->type_name, loc);
+ }
+}
+
+
+/*---------------------------------------------------------.
+| Check that THIS, and its alias, have same precedence and |
+| associativity. |
+`---------------------------------------------------------*/
+
+static inline bool
+symbol_check_alias_consistency (symbol *this)
+{
+ /* Check only those who _are_ the aliases. */
+ if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)
+ {
+ if (this->prec != this->alias->prec)
{
- firstsymbol = bp;
- lastsymbol = bp;
+ 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;
}
- else
+
+ if (this->assoc != this->alias->assoc)
{
- lastsymbol->next = 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;
}
+ }
+ return true;
+}
+
+static bool
+symbol_check_alias_consistency_processor (void *this,
+ void *null ATTRIBUTE_UNUSED)
+{
+ return symbol_check_alias_consistency (this);
+}
+
- symtab[hashval] = bp;
+/*-------------------------------------------------------------------.
+| Assign a symbol number, and write the definition of the token name |
+| into FDEFINES. Put in SYMBOLS. |
+`-------------------------------------------------------------------*/
+
+static inline bool
+symbol_pack (symbol *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)
+ {
+ if (this == endtoken || this->alias == endtoken)
+ this->number = this->alias->number = 0;
+ else
+ {
+ if (this->alias->number == NUMBER_UNDEFINED)
+ abort ();
+ 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 */
+ {
+ if (this->number == NUMBER_UNDEFINED)
+ abort ();
}
- return bp;
+ symbols[this->number] = this;
+ return true;
}
+static bool
+symbol_pack_processor (void *this, void *null ATTRIBUTE_UNUSED)
+{
+ return symbol_pack (this);
+}
+
+
+
+
+/*--------------------------------------------------.
+| Put THIS in TOKEN_TRANSLATIONS if it is a token. |
+`--------------------------------------------------*/
+
+static inline bool
+symbol_translation (symbol *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;
+}
+
+static bool
+symbol_translation_processor (void *this, void *null ATTRIBUTE_UNUSED)
+{
+ return symbol_translation (this);
+}
+
+
+/*----------------------.
+| A symbol hash table. |
+`----------------------*/
+
+/* Initial capacity of symbols hash table. */
+#define HT_INITIAL_CAPACITY 257
+
+static struct hash_table *symbol_table = NULL;
+
+static inline bool
+hash_compare_symbol (const symbol *m1, const symbol *m2)
+{
+ /* Since tags are unique, we can compare the pointers themselves. */
+ return UNIQSTR_EQ (m1->tag, m2->tag);
+}
+
+static bool
+hash_symbol_comparator (void const *m1, void const *m2)
+{
+ return hash_compare_symbol (m1, m2);
+}
+
+static inline unsigned int
+hash_symbol (const symbol *m, unsigned int tablesize)
+{
+ /* Since tags are unique, we can hash the pointer itself. */
+ return ((uintptr_t) m->tag) % tablesize;
+}
+
+static unsigned int
+hash_symbol_hasher (void const *m, unsigned int tablesize)
+{
+ return hash_symbol (m, tablesize);
+}
+
+
+/*-------------------------------.
+| Create the symbol hash table. |
+`-------------------------------*/
void
-free_symtab (void)
+symbols_new (void)
{
+ symbol_table = hash_initialize (HT_INITIAL_CAPACITY,
+ NULL,
+ hash_symbol_hasher,
+ hash_symbol_comparator,
+ free);
+}
+
+
+/*----------------------------------------------------------------.
+| Find the symbol named KEY, and return it. If it does not exist |
+| yet, create it. |
+`----------------------------------------------------------------*/
+
+symbol *
+symbol_get (const char *key, location loc)
+{
+ symbol probe;
+ symbol *entry;
+
+ /* Keep the symbol in a printable form. */
+ key = uniqstr_new (quotearg_style (escape_quoting_style, key));
+ probe.tag = key;
+ entry = hash_lookup (symbol_table, &probe);
+
+ if (!entry)
+ {
+ /* First insertion in the hash. */
+ entry = symbol_new (key, loc);
+ hash_insert (symbol_table, entry);
+ }
+ return entry;
+}
+
+
+/*------------------------------------------------------------------.
+| Generate a dummy nonterminal, whose name cannot conflict with the |
+| user's names. |
+`------------------------------------------------------------------*/
+
+symbol *
+dummy_symbol_get (location loc)
+{
+ /* Incremented for each generated symbol. */
+ static int dummy_count = 0;
+ static char buf[256];
+
+ symbol *sym;
+
+ sprintf (buf, "@%d", ++dummy_count);
+ sym = symbol_get (buf, loc);
+ 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. |
+`---------------------------------------------------------------*/
+
+static void
+symbols_do (Hash_processor processor, void *processor_data)
+{
+ hash_do_for_each (symbol_table, 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_processor, NULL);
+}
+
+/*------------------------------------------------------------------.
+| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
+| number. |
+`------------------------------------------------------------------*/
+
+static void
+symbols_token_translations_init (void)
+{
+ bool 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 *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 *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;
+ }
+
+ CALLOC (token_translations, 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_processor, NULL);
+}
+
+
+/*----------------------------------------------------------------.
+| Assign symbol numbers, and write definition of token names into |
+| FDEFINES. Set up vectors SYMBOL_TABLE, TAGS of symbols. |
+`----------------------------------------------------------------*/
+
+void
+symbols_pack (void)
+{
+ CALLOC (symbols, nsyms);
+
+ symbols_do (symbol_check_alias_consistency_processor, NULL);
+ symbols_do (symbol_pack_processor, 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);
}
projects / bison.git / blobdiff