+ if (sym->prec != 0)
+ redeclaration (sym, assoc_to_string (a), sym->prec_location, loc);
+ sym->prec = prec;
+ sym->assoc = a;
+ sym->prec_location = loc;
+ }
+
+ /* 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. |
+`------------------------------------------------*/
+
+void
+symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
+{
+ if (sym->class != token_sym)
+ abort ();
+
+ 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);
+
+ sym->user_token_number = user_token_number;
+ /* User defined $end token? */
+ if (user_token_number == 0)
+ {
+ endtoken = sym;
+ endtoken->number = 0;
+ /* It is always mapped to 0, so it was already counted in
+ NTOKENS. */
+ --ntokens;
+ }
+}
+
+
+/*----------------------------------------------------------.
+| 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)
+ {
+ 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++;
+ }
+
+ 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 void
+symbol_check_alias_consistency (symbol *this)
+{
+ symbol *alias = this;
+ symbol *orig = this->alias;
+
+ /* Check only those that _are_ the aliases. */
+ if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
+ return;
+
+ if (orig->type_name != alias->type_name)
+ {
+ if (orig->type_name)
+ symbol_type_set (alias, orig->type_name, orig->type_location);