api.value.type: implement proper support, check, and document

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 24156030c922f62faf882f529674e500eac1edd2..4eec878abdf9295ec477cf39b6430800803637fb 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -17,6 +17,8 @@
 
 m4_include(b4_pkgdatadir/[c++.m4])
 
+# api.value.type=variant is valid.
+m4_define([b4_value_type_setup_variant])
 
 # b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
 # --------------------------------------------------------------
@@ -42,9 +44,11 @@ m4_define([b4_integral_parser_table_define],
 # b4_symbol_value_template(VAL, [TYPE])
 # -------------------------------------
 # Same as b4_symbol_value, but used in a template method.  It makes
-# a difference when using variants.
+# a difference when using variants.  Note that b4_value_type_setup_union
+# overrides b4_symbol_value, so we must override it again.
 m4_copy([b4_symbol_value], [b4_symbol_value_template])
-
+m4_append([b4_value_type_setup_union],
+          [m4_copy_force([b4_symbol_value_union], [b4_symbol_value_template])])
 
 # b4_lhs_value([TYPE])
 # --------------------
@@ -206,8 +210,9 @@ b4_location_define])])[
 
     /// Generate an error message.
     /// \param yystate   the state where the error occurred.
-    /// \param yytoken   the lookahead token.
-    virtual std::string yysyntax_error_ (state_type yystate, int yytoken);
+    /// \param yytoken   the lookahead token type, or yyempty_.
+    virtual std::string yysyntax_error_ (state_type yystate,
+                                         symbol_number_type yytoken) const;
 
     /// Compute post-reduction state.
     /// \param yystate   the current state
@@ -222,8 +227,6 @@ b4_location_define])])[
     /// \param yyvalue   the value to check
     static bool yy_table_value_is_error_ (int yyvalue);
 
-    /// Internal symbol numbers.
-    typedef ]b4_int_type_for([b4_translate])[ token_number_type;
     static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;
     static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
 
@@ -272,23 +275,26 @@ b4_location_define])])[
       /// Default constructor.
       by_state ();
 
+      /// The symbol type as needed by the constructor.
+      typedef state_type kind_type;
+
       /// Constructor.
-      by_state (state_type s);
+      by_state (kind_type s);
 
       /// Copy constructor.
       by_state (const by_state& other);
 
+      /// Steal the symbol type from \a that.
       void move (by_state& that);
 
-      /// The state.
-      state_type state;
+      /// The (internal) type number (corresponding to \a state).
+      /// "empty" when empty.
+      symbol_number_type type_get () const;
 
-      /// The type (corresponding to \a state).
-      /// -1 when empty.
-      int type_get () const;
+      enum { empty = 0 };
 
-      /// The type used to store the symbol type.
-      typedef state_type value_type;
+      /// The state.
+      state_type state;
     };
 
     /// "Internal" symbol: element of the stack.
@@ -523,7 +529,7 @@ m4_if(b4_prefix, [yy], [],
   // by_state.
   inline
   ]b4_parser_class_name[::by_state::by_state ()
-    : state (-1)
+    : state (empty)
   {}
 
   inline
@@ -536,7 +542,7 @@ m4_if(b4_prefix, [yy], [],
   ]b4_parser_class_name[::by_state::move (by_state& that)
   {
     state = that.state;
-    that.state = -1;
+    that.state = empty;
   }
 
   inline
@@ -545,10 +551,10 @@ m4_if(b4_prefix, [yy], [],
   {}
 
   inline
-  int
+  ]b4_parser_class_name[::symbol_number_type
   ]b4_parser_class_name[::by_state::type_get () const
   {
-    return state == -1 ? -1 : yystos_[state];
+    return state == empty ? 0 : yystos_[state];
   }
 
   inline
@@ -564,7 +570,7 @@ m4_if(b4_prefix, [yy], [],
                                       [value], [move], [that.value])],
                    [[value = that.value;]])[
     // that is emptied.
-    that.type = -1;
+    that.type = empty;
   }
 
   inline
@@ -589,7 +595,7 @@ m4_if(b4_prefix, [yy], [],
       YY_SYMBOL_PRINT (yymsg, yysym);]b4_variant_if([], [
 
     // User destructor.
-    int yytype = yysym.type_get ();
+    symbol_number_type yytype = yysym.type_get ();
     switch (yytype)
       {
 ]b4_symbol_foreach([b4_symbol_destructor])dnl
@@ -606,7 +612,7 @@ m4_if(b4_prefix, [yy], [],
   {
     std::ostream& yyoutput = yyo;
     YYUSE (yyoutput);
-    int yytype = yysym.type_get ();
+    symbol_number_type yytype = yysym.type_get ();
     yyo << (yytype < yyntokens_ ? "token" : "nterm")
         << ' ' << yytname_[yytype] << " ("]b4_locations_if([
         << yysym.location << ": "])[;
@@ -777,8 +783,8 @@ b4_dollar_popdef])[]dnl
 
     /* If the proper action on seeing token YYLA.TYPE is to reduce or
        to detect an error, take that action.  */
-    yyn += yyla.type;
-    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type)
+    yyn += yyla.type_get ();
+    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yyla.type_get ())
       goto yydefault;
 
     // Reduce or error.
@@ -822,7 +828,7 @@ b4_dollar_popdef])[]dnl
        variants.  */
     b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])],[
     /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+       '$$ = $1'.  Otherwise, use the top of the stack.
 
        Otherwise, the following line sets YYLHS.VALUE to garbage.
        This behavior is undocumented and Bison
@@ -874,7 +880,7 @@ b4_dollar_popdef])[]dnl
         ++yynerrs_;
         error (]b4_join(b4_locations_if([yyla.location]),
                         [[yysyntax_error_ (yystack_[0].state,
-                                           yyempty ? yyempty_ : yyla.type)]])[);
+                                           yyempty ? yyempty_ : yyla.type_get ())]])[);
       }
 
 ]b4_locations_if([[
@@ -885,7 +891,7 @@ b4_dollar_popdef])[]dnl
            error, discard it.  */
 
         // Return failure if at end of input.
-        if (yyla.type == yyeof_)
+        if (yyla.type_get () == yyeof_)
           YYABORT;
         else if (!yyempty)
           {
@@ -1011,8 +1017,8 @@ b4_dollar_popdef])[]dnl
   // Generate an error message.
   std::string
   ]b4_parser_class_name[::yysyntax_error_ (]dnl
-b4_error_verbose_if([state_type yystate, int yytoken],
-                    [int, int])[)
+b4_error_verbose_if([state_type yystate, symbol_number_type yytoken],
+                    [state_type, symbol_number_type])[) const
   {]b4_error_verbose_if([[
     std::string yyres;
     // Number of reported tokens (one for the "unexpected", one per