]> git.saurik.com Git - bison.git/blobdiff - data/variant.hh
skeletons: fix an error message
[bison.git] / data / variant.hh
index 1534b903d3fbfffd3bb106baa97ab9aaa50b3fa9..454f360ad6be0e598437cbcd3af8d130567da98c 100644 (file)
@@ -1,7 +1,6 @@
 # C++ skeleton for Bison
 
-# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
-# Free Software Foundation, Inc.
+# Copyright (C) 2002-2012 Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -75,35 +74,50 @@ m4_map([b4_char_sizeof_], [$@])dnl
 ])])
 
 
-# b4_variant_definition
-# ---------------------
+# b4_variant_includes
+# -------------------
+# The needed includes for variants support.
+m4_define([b4_variant_includes],
+[b4_parse_assert_if([[#include <typeinfo>]])[
+#include <cstdlib>  // abort
+#ifndef YYASSERT
+# include <cassert>
+# define YYASSERT assert
+#endif
+]])
+
+# b4_variant_define
+# -----------------
 # Define "variant".
-m4_define([b4_variant_definition],
-[[
-  /// A char[S] buffer to store and retrieve objects.
+m4_define([b4_variant_define],
+[[  /// A char[S] buffer to store and retrieve objects.
   ///
   /// Sort of a variant, but does not keep track of the nature
   /// of the stored data, since that knowledge is available
   /// via the current state.
   template <size_t S>
   struct variant
-  {]b4_assert_if([
-    /// Whether something is contained.
-    bool built;
-])[
+  {
+    /// Type of *this.
+    typedef variant<S> self_type;
+
     /// Empty construction.
     inline
-    variant ()]b4_assert_if([
-      : built (false)])[
+    variant ()]b4_parse_assert_if([
+      : built (false)
+      , tname (YY_NULL)])[
     {}
 
     /// Instantiate a \a T in here.
     template <typename T>
     inline T&
     build ()
-    {]b4_assert_if([
-      assert (!built);
-      built = true;])[
+    {]b4_parse_assert_if([
+      YYASSERT (!built);
+      YYASSERT (!tname);
+      YYASSERT (sizeof (T) <= S);
+      built = true;
+      tname = typeid (T).name ();])[
       return *new (buffer.raw) T;
     }
 
@@ -111,45 +125,57 @@ m4_define([b4_variant_definition],
     template <typename T>
     inline T&
     build (const T& t)
-    {]b4_assert_if([
-      assert(!built);
-      built = true;])[
-      return *new (buffer.raw) T(t);
+    {]b4_parse_assert_if([
+      YYASSERT (!built);
+      YYASSERT (!tname);
+      YYASSERT (sizeof (T) <= S);
+      built = true;
+      tname = typeid (T).name ();])[
+      return *new (buffer.raw) T (t);
     }
 
     /// Construct and fill.
     template <typename T>
     inline
-    variant (const T& t)]b4_assert_if([
-      : built (true)])[
+    variant (const T& t)]b4_parse_assert_if([
+      : built (true)
+      , tname (typeid (T).name ())])[
     {
-      new (buffer.raw) T(t);
+      YYASSERT (sizeof (T) <= S);
+      new (buffer.raw) T (t);
     }
 
     /// Accessor to a built \a T.
     template <typename T>
     inline T&
     as ()
-    {]b4_assert_if([
-      assert (built);])[
-      return reinterpret_cast<T&>(buffer.raw);
+    {]b4_parse_assert_if([
+      YYASSERT (built);
+      YYASSERT (tname == typeid (T).name ());
+      YYASSERT (sizeof (T) <= S);])[
+      return reinterpret_cast<T&> (buffer.raw);
     }
 
     /// Const accessor to a built \a T (for %printer).
     template <typename T>
     inline const T&
     as () const
-    {]b4_assert_if([
-      assert(built);])[
-      return reinterpret_cast<const T&>(buffer.raw);
+    {]b4_parse_assert_if([
+      YYASSERT (built);
+      YYASSERT (tname == typeid (T).name ());
+      YYASSERT (sizeof (T) <= S);])[
+      return reinterpret_cast<const T&> (buffer.raw);
     }
 
-    /// Swap the content with \a other.
+    /// Swap the content with \a other, of same type.
     template <typename T>
     inline void
     swap (variant<S>& other)
-    {
-      std::swap (as<T>(), other.as<T>());
+    {]b4_parse_assert_if([
+      YYASSERT (tname == other.tname);])[
+      std::swap (as<T>(), other.as<T>());]b4_parse_assert_if([
+      std::swap (built, other.built);
+      std::swap (tname, other.tname);])[
     }
 
     /// Assign the content of \a other to this.
@@ -163,15 +189,33 @@ m4_define([b4_variant_definition],
       other.destroy<T>();
     }
 
+    /// Copy the content of \a other to this.
+    /// Destroys \a other.
+    template <typename T>
+    inline void
+    copy (const variant<S>& other)
+    {
+      build<T> (other.as<T> ());
+    }
+
     /// Destroy the stored \a T.
     template <typename T>
     inline void
     destroy ()
     {
-      as<T>().~T();]b4_assert_if([
-      built = false;])[
+      as<T> ().~T ();]b4_parse_assert_if([
+      built = false;
+      tname = YY_NULL;])[
     }
 
+    /// Prohibit blind copies.
+    //  private:
+    self_type& operator=(const self_type&)
+    {
+      abort ();
+    }
+
+  private:
     /// A buffer large enough to store any of the semantic values.
     /// Long double is chosen as it has the strongest alignment
     /// constraints.
@@ -179,7 +223,11 @@ m4_define([b4_variant_definition],
     {
       long double align_me;
       char raw[S];
-    } buffer;
+    } buffer;]b4_parse_assert_if([
+    /// Whether something is contained.
+    bool built;
+    /// If defined, the name of the stored type.
+    const char* tname;])[
   };
 ]])
 
@@ -198,7 +246,8 @@ m4_define([b4_semantic_type_declare],
     {]b4_type_foreach([b4_char_sizeof])[};
 
     /// Symbol semantic values.
-    typedef variant<sizeof(union_type)> semantic_type;])
+    typedef variant<sizeof(union_type)> semantic_type;dnl
+])
 
 
 # How the semantic value is extracted when using variants.
@@ -217,3 +266,62 @@ m4_define([b4_symbol_value_template],
 [m4_ifval([$2],
           [$1.template as< $2 >()],
           [$1])])
+
+
+
+## ------------- ##
+## make_SYMBOL.  ##
+## ------------- ##
+
+
+# b4_symbol_constructor_declare_(SYMBOL-NUMBER)
+# ---------------------------------------------
+# Declare the overloaded version of make_symbol for the (common) type of
+# these SYMBOL-NUMBERS.  Use at class-level.
+m4_define([b4_symbol_constructor_declare_],
+[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id],
+[    static inline
+    symbol_type
+    make_[]b4_symbol_([$1], [id]) (dnl
+b4_join(b4_symbol_if([$1], [has_type],
+                     [const b4_symbol([$1], [type])& v]),
+        b4_locations_if([const location_type& l])));
+
+])])])
+
+
+# b4_symbol_constructor_declare
+# -----------------------------
+# Declare symbol constructors for all the value types.
+# Use at class-level.
+m4_define([b4_symbol_constructor_declare],
+[    // Symbol constructors declarations.
+b4_symbol_foreach([b4_symbol_constructor_declare_])])
+
+
+
+# b4_symbol_constructor_define_(SYMBOL-NUMBER)
+# --------------------------------------------
+# Define symbol constructor for this SYMBOL-NUMBER.
+m4_define([b4_symbol_constructor_define_],
+[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id],
+[  b4_parser_class_name::symbol_type
+  b4_parser_class_name::make_[]b4_symbol_([$1], [id]) (dnl
+b4_join(b4_symbol_if([$1], [has_type],
+                     [const b4_symbol([$1], [type])& v]),
+        b4_locations_if([const location_type& l])))
+  {
+    return symbol_type (b4_join([token::b4_symbol([$1], [id])],
+                                b4_symbol_if([$1], [has_type], [v]),
+                                b4_locations_if([l])));
+  }
+
+])])])
+
+
+# b4_symbol_constructor_define
+# ----------------------------
+# Define the overloaded versions of make_symbol for all the value types.
+m4_define([b4_symbol_constructor_define],
+[  // Implementation of make_symbol for each symbol type.
+b4_symbol_foreach([b4_symbol_constructor_define_])])