lalr1.cc: don't discard non-existent lookahead on syntax error.

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index 4fabf9f89c61ff214accee1a799bc229820322aa..6174e824edeb507beb4d33f60ae74cbfbd6d7367 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -1,6 +1,6 @@
 # C++ skeleton for Bison
 
 # C++ skeleton for Bison
 

-# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009

 # Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify


@@ -18,94 +18,106 @@
 
 m4_include(b4_pkgdatadir/[c++.m4])
 
 
 m4_include(b4_pkgdatadir/[c++.m4])
 

-# How the semantic value is extracted when using variants.
-b4_variant_if([
-  # b4_symbol_value(VAL, [TYPE])
-  # ----------------------------
-  m4_define([b4_symbol_value],
-  [m4_ifval([$2],
-            [$1.as<$2>()],
-            [$1])])
-]) # b4_variant_if
-
-
-# b4_symbol_actions(FILENAME, LINENO,
-#                   SYMBOL-TAG, SYMBOL-NUM,
-#                   SYMBOL-ACTION, SYMBOL-TYPENAME)
-# -------------------------------------------------
-# Same as in C, but using references instead of pointers.
-m4_define([b4_symbol_actions],
-[m4_pushdef([b4_dollar_dollar],
-            [b4_symbol_value([yyvalue], [$6])])dnl
-m4_pushdef([b4_at_dollar], [yylocation])dnl
-      case $4: // $3
-b4_syncline([$2], [$1])
-        $5;
-b4_syncline([@oline@], [@ofile@])
-        break;
-m4_popdef([b4_at_dollar])dnl
-m4_popdef([b4_dollar_dollar])dnl
+
+# b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
+# --------------------------------------------------------------
+# Declare "parser::yy<TABLE-NAME>_" which contents is CONTENT.
+m4_define([b4_integral_parser_table_declare],
+[m4_ifval([$3], [b4_c_comment([$3], [  ])
+])dnl
+  static const b4_int_type_for([$2]) yy$1_[[]];dnl

 ])
 
 ])
 

+# b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT)
+# -------------------------------------------------------------
+# Define "parser::yy<TABLE-NAME>_" which contents is CONTENT.
+m4_define([b4_integral_parser_table_define],
+[  const b4_int_type_for([$2])
+  b4_parser_class_name::yy$1_[[]] =
+  {
+  $2
+  };dnl
+])

 
 

-# b4_symbol_action_(SYMBOL-TAG, SYMBOL-NUM, SYMBOL-TYPENAME)
-# ----------------------------------------------------------
-# Invoke b4_dollar_dollar(SYMBOL_TYPENAME) for each symbol.
-m4_define([b4_symbol_action_],
-[m4_ifval($3,
-[      case $2: // $1
-        b4_dollar_dollar($@);
-       break;
-])])

 
 

+# b4_symbol_value_template(VAL, [TYPE])
+# -------------------------------------
+# Same as b4_symbol_value, but used in a template method.  It makes
+# a difference when using variants.
+m4_copy([b4_symbol_value], [b4_symbol_value_template])

 
 

-# b4_symbol_variant(YYTYPE, YYVAL, ACTION)
-# ----------------------------------------
-# Run some ACTION ("build", or "destroy") on YYVAL of symbol type
-# YYTYPE.
-m4_define([b4_symbol_variant],
-[m4_pushdef([b4_dollar_dollar],
-            [$2.$3<$][3>()])dnl
-  switch ($1)
-    {
-m4_map([b4_symbol_action_], m4_defn([b4_type_names]))
-     default:
-       break;
-    }
-m4_popdef([b4_dollar_dollar])dnl
-])

 
 

+# b4_lhs_value([TYPE])
+# --------------------
+# Expansion of $<TYPE>$.
+m4_define([b4_lhs_value],
+          [b4_symbol_value([yylhs.value], [$1])])

 
 

-# _b4_char_sizeof_counter
-# -----------------------
-# A counter used by _b4_char_sizeof_dummy to create fresh symbols.
-m4_define([_b4_char_sizeof_counter],
-[0])

 
 

-# _b4_char_sizeof_dummy
-# ---------------------
-# At each call return a new C++ identifier.
-m4_define([_b4_char_sizeof_dummy],
-[m4_define([_b4_char_sizeof_counter], m4_incr(_b4_char_sizeof_counter))dnl
-dummy[]_b4_char_sizeof_counter])
+# b4_lhs_location()
+# -----------------
+# Expansion of @$.
+m4_define([b4_lhs_location],
+          [yylhs.location])

 
 
 
 

-# b4_char_sizeof(SYMBOL-TAG, SYMBOL-NUM, SYMBOL-TYPENAME)
-# -------------------------------------------------------
-# To be mapped on the list of type names to produce:
-#
-#    char dummy1[sizeof(type_name_1)];
-#    char dummy2[sizeof(type_name_2)];
-#
-# for defined type names.
-# $3 is doubly-quoted, do not quote it again.
-m4_define([b4_char_sizeof],
-[m4_ifval($3,
-[
-      char _b4_char_sizeof_dummy@{sizeof($3)@}; // $1])dnl
-])
+# b4_rhs_data(RULE-LENGTH, NUM)
+# -----------------------------
+# Return the data corresponding to the symbol #NUM, where the current
+# rule has RULE-LENGTH symbols on RHS.
+m4_define([b4_rhs_data],
+          [yystack_@{b4_subtract($@)@}])
+
+
+# b4_rhs_state(RULE-LENGTH, NUM)
+# ------------------------------
+# The state corresponding to the symbol #NUM, where the current
+# rule has RULE-LENGTH symbols on RHS.
+m4_define([b4_rhs_state],
+          [b4_rhs_data([$1], [$2]).state])
+
+
+# b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
+# --------------------------------------
+# Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
+# symbols on RHS.
+m4_define([b4_rhs_value],
+          [b4_symbol_value([b4_rhs_data([$1], [$2]).value], [$3])])
+
+
+# b4_rhs_location(RULE-LENGTH, NUM)
+# ---------------------------------
+# Expansion of @NUM, where the current rule has RULE-LENGTH symbols
+# on RHS.
+m4_define([b4_rhs_location],
+          [b4_rhs_data([$1], [$2]).location])
+
+
+# b4_symbol_action(SYMBOL-NUM, KIND)
+# ----------------------------------
+# Run the action KIND (destructor or printer) for SYMBOL-NUM.
+# Same as in C, but using references instead of pointers.
+m4_define([b4_symbol_action],
+[b4_symbol_if([$1], [has_$2],
+[m4_pushdef([b4_dollar_dollar],
+    [b4_symbol_value_template([yysym.value],
+                              b4_symbol_if([$1], [has_type],
+                                           [b4_symbol([$1], [type])]))])dnl
+m4_pushdef([b4_at_dollar], [yysym.location])dnl
+      b4_symbol_case_([$1])
+b4_syncline([b4_symbol([$1], [$2_line])], ["b4_symbol([$1], [$2_file])"])
+        b4_symbol([$1], [$2])
+b4_syncline([@oline@], [@ofile@])
+        break;
+
+m4_popdef([b4_at_dollar])dnl
+m4_popdef([b4_dollar_dollar])dnl
+])])

 
 
 
 

+m4_pushdef([b4_copyright_years],
+           [2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009])
+

 m4_define([b4_parser_class_name],
           [b4_percent_define_get([[parser_class_name]])])
 
 m4_define([b4_parser_class_name],
           [b4_percent_define_get([[parser_class_name]])])
 


@@ -113,17 +125,18 @@ m4_define([b4_parser_class_name],
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 

-# Backward compatibility.
+b4_locations_if(
+[# Backward compatibility.

 m4_define([b4_location_constructors])
 m4_define([b4_location_constructors])

-m4_include(b4_pkgdatadir/[location.cc])
+m4_include(b4_pkgdatadir/[location.cc])])
+m4_include(b4_pkgdatadir/[stack.hh])
+b4_variant_if([m4_include(b4_pkgdatadir/[variant.hh])])

 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert_push(0)dnl
 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert_push(0)dnl

-b4_defines_if(
-[@output(b4_spec_defines_file@)
-b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++],
-             [2002, 2003, 2004, 2005, 2006, 2007, 2008])
+@output(b4_spec_defines_file@)@
+b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++])

 dnl FIXME: This is wrong, we want computed header guards.
 [
 /* C++ LALR(1) parser skeleton written by Akim Demaille.  */
 dnl FIXME: This is wrong, we want computed header guards.
 [
 /* C++ LALR(1) parser skeleton written by Akim Demaille.  */


@@ -133,65 +146,23 @@ dnl FIXME: This is wrong, we want computed header guards.
 
 ]b4_percent_code_get([[requires]])[
 
 
 ]b4_percent_code_get([[requires]])[
 

+]b4_parse_assert_if([#include <cassert>])[
+#include <stdexcept>

 #include <string>
 #include <iostream>
 #include "stack.hh"
 
 ]b4_namespace_open[
 #include <string>
 #include <iostream>
 #include "stack.hh"
 
 ]b4_namespace_open[

-  class position;
-  class location;
-]b4_variant_if([[
-  /// 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
-  {
-    /// Instantiate a \a T in here.
-    template <typename T>
-    inline void
-    build()
-    {
-      new (buffer) T;
-    }
-
-    /// Destroy the stored \a T.
-    template <typename T>
-    inline void
-    destroy()
-    {
-      reinterpret_cast<T&>(buffer).~T();
-    }
-
-    /// Accessor to a built \a T.
-    template <typename T>
-    inline T&
-    as()
-    {
-      return reinterpret_cast<T&>(buffer);
-    }
-
-    /// Const accessor to a built \a T (for %printer).
-    template <typename T>
-    inline const T&
-    as() const
-    {
-      return reinterpret_cast<const T&>(buffer);
-    }
-
-    /// A buffer large enough to store any of the semantic values.
-    char buffer[S];
-  };
-]])[
+]b4_locations_if([  class position;
+  class location;])[
+]b4_variant_if([b4_variant_define])[

 ]b4_namespace_close[
 
 ]b4_namespace_close[
 

-#include "location.hh"
+]b4_locations_if([#include "location.hh"])[

 
 /* Enabling traces.  */
 #ifndef YYDEBUG
 
 /* Enabling traces.  */
 #ifndef YYDEBUG

-# define YYDEBUG ]b4_debug_flag[
+# define YYDEBUG ]b4_parse_trace_if([1], [0])[

 #endif
 
 /* Enabling verbose error messages.  */
 #endif
 
 /* Enabling verbose error messages.  */


@@ -199,7 +170,7 @@ dnl FIXME: This is wrong, we want computed header guards.
 # undef YYERROR_VERBOSE
 # define YYERROR_VERBOSE 1
 #else
 # undef YYERROR_VERBOSE
 # define YYERROR_VERBOSE 1
 #else

-# define YYERROR_VERBOSE ]b4_error_verbose_flag[
+# define YYERROR_VERBOSE ]b4_error_verbose_if([1], [0])[

 #endif
 
 /* Enabling the token table.  */
 #endif
 
 /* Enabling the token table.  */


@@ -207,24 +178,25 @@ dnl FIXME: This is wrong, we want computed header guards.
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 
 # define YYTOKEN_TABLE ]b4_token_table[
 #endif
 

-/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
+]b4_locations_if([dnl
+[/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].

    If N is 0, then set CURRENT to the empty location which ends
    the previous symbol: RHS[0] (always defined).  */
 
 #ifndef YYLLOC_DEFAULT
    If N is 0, then set CURRENT to the empty location which ends
    the previous symbol: RHS[0] (always defined).  */
 
 #ifndef YYLLOC_DEFAULT

-# define YYLLOC_DEFAULT(Current, Rhs, N)               \
-do {                                                   \
-  if (N)                                               \
-    {                                                  \
-      (Current).begin = (Rhs)[1].begin;                        \
-      (Current).end   = (Rhs)[N].end;                  \
-    }                                                  \
-  else                                                 \
-    {                                                  \
-      (Current).begin = (Current).end = (Rhs)[0].end;  \
-    }                                                  \
+# define YYLLOC_DEFAULT(Current, Rhs, N)                        \
+do {                                                            \
+  if (N)                                                        \
+    {                                                           \
+      (Current).begin = (Rhs)[1].location.begin;                \
+      (Current).end   = (Rhs)[N].location.end;                 \
+    }                                                           \
+  else                                                          \
+    {                                                           \
+      (Current).begin = (Current).end = (Rhs)[0].location.end; \
+    }                                                           \

 } while (false)
 } while (false)

-#endif
+#endif]])[

 
 ]b4_namespace_open[
 
 
 ]b4_namespace_open[
 


@@ -232,36 +204,7 @@ do {                                                       \
   class ]b4_parser_class_name[
   {
   public:
   class ]b4_parser_class_name[
   {
   public:

-#ifndef YYSTYPE
-]b4_variant_if(
-[    /// An auxiliary type to compute the largest semantic type.
-    union union_type
-    {]m4_map([b4_char_sizeof], m4_defn([b4_type_names]))[
-    };
-
-    /// Symbol semantic values.
-    typedef variant<sizeof(union_type)> semantic_type;],
-[    /// Symbol semantic values.
-m4_ifdef([b4_stype],
-[    union semantic_type
-    {b4_user_stype
-    };],
-[m4_if(b4_tag_seen_flag, 0,
-[[    typedef int semantic_type;]],
-[[    typedef YYSTYPE semantic_type;]])])])[
-#else
-    typedef YYSTYPE semantic_type;
-#endif
-    /// Symbol locations.
-    typedef ]b4_percent_define_get([[location_type]])[ location_type;
-    /// Tokens.
-    struct token
-    {
-      ]b4_token_enums(b4_tokens)[
-    };
-    /// Token type.
-    typedef token::yytokentype token_type;
-
+]b4_public_types_declare[

     /// Build a parser object.
     ]b4_parser_class_name[ (]b4_parse_param_decl[);
     virtual ~]b4_parser_class_name[ ();
     /// Build a parser object.
     ]b4_parser_class_name[ (]b4_parse_param_decl[);
     virtual ~]b4_parser_class_name[ ();


@@ -284,106 +227,52 @@ m4_ifdef([b4_stype],
     void set_debug_level (debug_level_type l);
 #endif
 
     void set_debug_level (debug_level_type l);
 #endif
 

-  private:
-    /// Report a syntax error.
-    /// \param loc    where the syntax error is found.
+    /// Report a syntax error.]b4_locations_if([
+    /// \param loc    where the syntax error is found.])[

     /// \param msg    a description of the syntax error.
     /// \param msg    a description of the syntax error.

-    virtual void error (const location_type& loc, const std::string& msg);
+    virtual void error (]b4_locations_if([const location_type& loc, ])[const std::string& msg);
+
+  private:
+    /// State numbers.
+    typedef int state_type;

 
     /// Generate an error message.
 
     /// Generate an error message.

-    /// \param state   the state where the error occurred.
-    /// \param tok     the lookahead token.
-    virtual std::string yysyntax_error_ (int yystate]dnl
-b4_error_verbose_if([, int tok])[);
+    /// \param yystate   the state where the error occurred.
+    /// \param yytoken   the lookahead token.
+    virtual std::string yysyntax_error_ (state_type yystate, int yytoken);

 
 

-#if YYDEBUG
-    /// \brief Report a symbol value on the debug stream.
-    /// \param yytype       The token type.
-    /// \param yyvalue      Its semantic value.
-    /// \param yylocation   Its location.
-    virtual void yy_symbol_value_print_ (int yytype,
-                                        const semantic_type& yyvalue,
-                                        const location_type& yylocation);
-    /// \brief Report a symbol on the debug stream.
-    /// \param yytype       The token type.
-    /// \param yyvalue      Its semantic value.
-    /// \param yylocation   Its location.
-    virtual void yy_symbol_print_ (int yytype,
-                                  const semantic_type& yyvalue,
-                                  const location_type& yylocation);
-#endif
+    /// Compute post-reduction state.
+    /// \param yystate   the current state
+    /// \param yylhs     the nonterminal to push on the stack
+    state_type yy_lr_goto_state_ (state_type yystate, int yylhs);

 
 

+    /// Whether the given \c yypact_ value indicates a defaulted state.
+    /// \param yyvalue   the value to check
+    static bool yy_pact_value_is_default_ (int yyvalue);

 
 

-    /// State numbers.
-    typedef int state_type;
-    /// State stack type.
-    typedef stack<state_type>    state_stack_type;
-    /// Semantic value stack type.
-    typedef stack<semantic_type> semantic_stack_type;
-    /// location stack type.
-    typedef stack<location_type> location_stack_type;
-
-    /// The state stack.
-    state_stack_type yystate_stack_;
-    /// The semantic value stack.
-    semantic_stack_type yysemantic_stack_;
-    /// The location stack.
-    location_stack_type yylocation_stack_;
+    /// Whether the given \c yytable_ value indicates a syntax error.
+    /// \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;
 
     /// Internal symbol numbers.
     typedef ]b4_int_type_for([b4_translate])[ token_number_type;

-    /* Tables.  */
-    /// For a state, the index in \a yytable_ of its portion.
-    static const ]b4_int_type_for([b4_pact])[ yypact_[];

     static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;
     static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_;

-
-    /// For a state, default rule to reduce.
-    /// Unless\a  yytable_ specifies something else to do.
-    /// Zero means the default is an error.
-    static const ]b4_int_type_for([b4_defact])[ yydefact_[];
-
-    static const ]b4_int_type_for([b4_pgoto])[ yypgoto_[];
-    static const ]b4_int_type_for([b4_defgoto])[ yydefgoto_[];
-
-    /// What to do in a state.
-    /// \a yytable_[yypact_[s]]: what to do in state \a s.
-    /// - if positive, shift that token.
-    /// - if negative, reduce the rule which number is the opposite.
-    /// - if zero, do what YYDEFACT says.
-    static const ]b4_int_type_for([b4_table])[ yytable_[];

     static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
 
     static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_;
 

-    static const ]b4_int_type_for([b4_check])[ yycheck_[];
-
-    /// For a state, its accessing symbol.
-    static const ]b4_int_type_for([b4_stos])[ yystos_[];
-
-    /// For a rule, its LHS.
-    static const ]b4_int_type_for([b4_r1])[ yyr1_[];
-    /// For a rule, its RHS length.
-    static const ]b4_int_type_for([b4_r2])[ yyr2_[];
+    /* Tables.  */
+]b4_parser_tables_declare[

 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
     /// For a symbol, its name in clear.
     static const char* const yytname_[];
 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
     /// For a symbol, its name in clear.
     static const char* const yytname_[];

-#endif
+#endif]b4_error_verbose_if([

 
 

-#if YYERROR_VERBOSE

     /// Convert the symbol name \a n to a form suitable for a diagnostic.
     /// Convert the symbol name \a n to a form suitable for a diagnostic.

-    virtual std::string yytnamerr_ (const char *n);
-#endif
+    static std::string yytnamerr_ (const char *n);])[

 
 #if YYDEBUG
 
 #if YYDEBUG

-    /// A type to store symbol numbers and -1.
-    typedef ]b4_int_type_for([b4_rhs])[ rhs_number_type;
-    /// A `-1'-separated list of the rules' RHS.
-    static const rhs_number_type yyrhs_[];
-    /// For each rule, the index of the first RHS symbol in \a yyrhs_.
-    static const ]b4_int_type_for([b4_prhs])[ yyprhs_[];
-    /// For each rule, its source line number.
-    static const ]b4_int_type_for([b4_rline])[ yyrline_[];
-    /// For each scanner token number, its symbol number.
-    static const ]b4_int_type_for([b4_toknum])[ yytoken_number_[];
+]b4_integral_parser_table_declare([rline], [b4_rline],
+     [YYRLINE[YYN] -- Source line where rule number YYN was defined.])[

     /// Report on the debug stream that the rule \a r is going to be reduced.
     virtual void yy_reduce_print_ (int r);
     /// Print the state stack on the debug stream.
     /// Report on the debug stream that the rule \a r is going to be reduced.
     virtual void yy_reduce_print_ (int r);
     /// Print the state stack on the debug stream.


@@ -395,35 +284,89 @@ b4_error_verbose_if([, int tok])[);
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.

-    token_number_type yytranslate_ (int t);
+    static inline token_number_type yytranslate_ (]b4_lex_symbol_if([token_type], [int])[ t);
+
+#if YYDEBUG
+    /// \brief Display a symbol type, value and location.
+    /// \param yyo    The output stream.
+    /// \param yysym  The symbol.
+    template <typename Exact>
+    void yy_print_ (std::ostream& yyo,
+                    const symbol_base_type<Exact>& yysym) const;
+#endif

 
     /// \brief Reclaim the memory associated to a symbol.
 
     /// \brief Reclaim the memory associated to a symbol.

-    /// \param yymsg        Why this token is reclaimed.
-    /// \param yytype       The symbol type.
-    /// \param yyvalue      Its semantic value.
-    /// \param yylocation   Its location.
-    inline void yydestruct_ (const char* yymsg,
-                            int yytype,
-                            semantic_type& yyvalue,
-                            location_type& yylocation);
+    /// \param yymsg     Why this token is reclaimed.
+    ///                  If null, print nothing.
+    /// \param s         The symbol.
+    template <typename Exact>
+    inline void yy_destroy_ (const char* yymsg,
+                             symbol_base_type<Exact>& yysym) const;
+
+  private:
+    /// Element of the stack: a state and its attributes.
+    struct stack_symbol_type : symbol_base_type<stack_symbol_type>
+    {
+      /// The parent class.
+      typedef symbol_base_type<stack_symbol_type> super_type;
+
+      /// Default constructor.
+      inline stack_symbol_type ();
+
+      /// Constructor.
+      inline stack_symbol_type (]b4_args([state_type s],
+                                         [const semantic_type& v],
+                                         b4_locations_if([const location_type& l]))[);
+
+      /// The state.
+      state_type state;
+
+      /// The type (corresponding to \a state).
+      inline int type_get_ () const;
+    };
+
+    /// Stack type.
+    typedef stack<stack_symbol_type> stack_type;
+
+    /// The stack.
+    stack_type yystack_;
+
+    /// Push a new state on the stack.
+    /// \param m    a debug message to display
+    ///             if null, no trace is output.
+    /// \param s    the symbol
+    /// \warning the contents of \a s.value is stolen.
+    inline void yypush_ (const char* m, stack_symbol_type& s);
+
+    /// Push a new look ahead token on the state on the stack.
+    /// \param m    a debug message to display
+    ///             if null, no trace is output.
+    /// \param s    the state
+    /// \param sym  the symbol (for its value and location).
+    /// \warning the contents of \a s.value is stolen.
+    inline void yypush_ (const char* m, state_type s, symbol_type& sym);

 
     /// Pop \a n symbols the three stacks.
     inline void yypop_ (unsigned int n = 1);
 
     /* Constants.  */
 
     /// Pop \a n symbols the three stacks.
     inline void yypop_ (unsigned int n = 1);
 
     /* Constants.  */

-    static const int yyeof_;
-    /* LAST_ -- Last index in TABLE_.  */
-    static const int yylast_;
-    static const int yynnts_;
-    static const int yyempty_;
-    static const int yyfinal_;
-    static const int yyterror_;
-    static const int yyerrcode_;
-    static const int yyntokens_;
-    static const unsigned int yyuser_token_number_max_;
-    static const token_number_type yyundef_token_;
+    enum
+    {
+      yyeof_ = 0,
+      yylast_ = ]b4_last[,           //< Last index in yytable_.
+      yynnts_ = ]b4_nterms_number[,  //< Number of nonterminal symbols.
+      yyempty_ = -2,
+      yyfinal_ = ]b4_final_state_number[, //< Termination state number.
+      yyterror_ = 1,
+      yyerrcode_ = 256,
+      yyntokens_ = ]b4_tokens_number[,   //< Number of tokens.
+    };
+

 ]b4_parse_param_vars[
   };
 ]b4_parse_param_vars[
   };

+
+]b4_lex_symbol_if([b4_yytranslate_define
+b4_public_types_define])[

 ]b4_namespace_close[
 
 ]b4_percent_define_flag_if([[global_tokens_and_yystype]],
 ]b4_namespace_close[
 
 ]b4_percent_define_flag_if([[global_tokens_and_yystype]],


@@ -437,10 +380,8 @@ b4_error_verbose_if([, int tok])[);
 b4_percent_code_get([[provides]])[]dnl
 
 [#endif /* ! defined PARSER_HEADER_H */]
 b4_percent_code_get([[provides]])[]dnl
 
 [#endif /* ! defined PARSER_HEADER_H */]

-])dnl
-@output(b4_parser_file_name@)
-b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++],
-             [2002, 2003, 2004, 2005, 2006, 2007, 2008])
+@output(b4_parser_file_name@)@
+b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++])

 b4_percent_code_get([[top]])[]dnl
 m4_if(b4_prefix, [yy], [],
 [
 b4_percent_code_get([[top]])[]dnl
 m4_if(b4_prefix, [yy], [],
 [


@@ -448,17 +389,16 @@ m4_if(b4_prefix, [yy], [],
 #define yylex   b4_prefix[]lex])[
 
 /* First part of user declarations.  */
 #define yylex   b4_prefix[]lex])[
 
 /* First part of user declarations.  */

-]b4_user_pre_prologue
+]b4_user_pre_prologue[

 
 

-b4_defines_if([[
-#include "@basename(]b4_spec_defines_file[@)"]])[
+#include "@basename(]b4_spec_defines_file[@)"

 
 /* User implementation prologue.  */
 ]b4_user_post_prologue
 b4_percent_code_get[]dnl
 
 [#ifndef YY_
 
 /* User implementation prologue.  */
 ]b4_user_post_prologue
 b4_percent_code_get[]dnl
 
 [#ifndef YY_

-# if YYENABLE_NLS
+# if defined YYENABLE_NLS && YYENABLE_NLS

 #  if ENABLE_NLS
 #   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */
 #   define YY_(msgid) dgettext ("bison-runtime", msgid)
 #  if ENABLE_NLS
 #   include <libintl.h> /* FIXME: INFRINGES ON USER NAME SPACE */
 #   define YY_(msgid) dgettext ("bison-runtime", msgid)


@@ -478,47 +418,46 @@ b4_percent_code_get[]dnl
 /* A pseudo ostream that takes yydebug_ into account.  */
 # define YYCDEBUG if (yydebug_) (*yycdebug_)
 
 /* A pseudo ostream that takes yydebug_ into account.  */
 # define YYCDEBUG if (yydebug_) (*yycdebug_)
 

-# define YY_SYMBOL_PRINT(Title, Type, Value, Location) \
-do {                                                   \
-  if (yydebug_)                                                \
-    {                                                  \
-      *yycdebug_ << Title << ' ';                      \
-      yy_symbol_print_ ((Type), (Value), (Location));  \
-      *yycdebug_ << std::endl;                         \
-    }                                                  \
-} while (false)
+# define YY_SYMBOL_PRINT(Title, Symbol)         \
+  do {                                          \
+    if (yydebug_)                               \
+    {                                           \
+      *yycdebug_ << Title << ' ';               \
+      yy_print_ (*yycdebug_, Symbol);           \
+      *yycdebug_ << std::endl;                  \
+    }                                           \
+  } while (false)

 
 # define YY_REDUCE_PRINT(Rule)         \
 
 # define YY_REDUCE_PRINT(Rule)         \

-do {                                   \
-  if (yydebug_)                                \
-    yy_reduce_print_ (Rule);           \
-} while (false)
+  do {                                 \
+    if (yydebug_)                       \
+      yy_reduce_print_ (Rule);         \
+  } while (false)

 
 # define YY_STACK_PRINT()              \
 
 # define YY_STACK_PRINT()              \

-do {                                   \
-  if (yydebug_)                                \
-    yystack_print_ ();                 \
-} while (false)
+  do {                                 \
+    if (yydebug_)                       \
+      yystack_print_ ();                \
+  } while (false)

 
 #else /* !YYDEBUG */
 
 # define YYCDEBUG if (false) std::cerr
 
 #else /* !YYDEBUG */
 
 # define YYCDEBUG if (false) std::cerr

-# define YY_SYMBOL_PRINT(Title, Type, Value, Location)
-# define YY_REDUCE_PRINT(Rule)
-# define YY_STACK_PRINT()
+# define YY_SYMBOL_PRINT(Title, Symbol)  static_cast<void>(0)
+# define YY_REDUCE_PRINT(Rule)           static_cast<void>(0)
+# define YY_STACK_PRINT()                static_cast<void>(0)

 
 #endif /* !YYDEBUG */
 
 
 #endif /* !YYDEBUG */
 

-#define yyerrok                (yyerrstatus_ = 0)
-#define yyclearin      (yychar = yyempty_)
+#define yyerrok         (yyerrstatus_ = 0)
+#define yyclearin       (yyempty = true)

 
 

-#define YYACCEPT       goto yyacceptlab
-#define YYABORT                goto yyabortlab
-#define YYERROR                goto yyerrorlab
+#define YYACCEPT        goto yyacceptlab
+#define YYABORT         goto yyabortlab
+#define YYERROR         goto yyerrorlab

 #define YYRECOVERING()  (!!yyerrstatus_)
 
 #define YYRECOVERING()  (!!yyerrstatus_)
 

-]b4_namespace_open[
-#if YYERROR_VERBOSE
+]b4_namespace_open[]b4_error_verbose_if([[

 
   /* Return YYSTR after stripping away unnecessary quotes and
      backslashes, so that it's suitable for yyerror.  The heuristic is
 
   /* Return YYSTR after stripping away unnecessary quotes and
      backslashes, so that it's suitable for yyerror.  The heuristic is


@@ -556,8 +495,7 @@ do {                                        \
 
     return yystr;
   }
 
     return yystr;
   }

-
-#endif
+]])[

 
   /// Build a parser object.
   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
 
   /// Build a parser object.
   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [


@@ -573,62 +511,116 @@ do {                                     \
   {
   }
 
   {
   }
 

-#if YYDEBUG
-  /*--------------------------------.
-  | Print this symbol on YYOUTPUT.  |
-  `--------------------------------*/

 
 

-  inline void
-  ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
-                          const semantic_type& yyvalue, const location_type& yylocation)
+  /*---------------.
+  | Symbol types.  |
+  `---------------*/
+
+]b4_lex_symbol_if([], [b4_public_types_define])[
+
+  // stack_symbol_type.
+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
+    : super_type ()
+    , state ()

   {
   {

-    YYUSE (yylocation);
-    YYUSE (yyvalue);
-    switch (yytype)
-      {
-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
-[       default:
-         break;
-      }

   }
 
   }
 

+  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (]b4_args(
+                 [state_type s],
+                 [const semantic_type& v],
+                 b4_locations_if([const location_type& l]))[)
+    : super_type (v]b4_locations_if([, l])[)
+    , state (s)
+  {
+  }

 
 

-  void
-  ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
-                          const semantic_type& yyvalue, const location_type& yylocation)
+  int
+  ]b4_parser_class_name[::stack_symbol_type::type_get_ () const

   {
   {

-    *yycdebug_ << (yytype < yyntokens_ ? "token" : "nterm")
-              << ' ' << yytname_[yytype] << " ("
-              << yylocation << ": ";
-    yy_symbol_value_print_ (yytype, yyvalue, yylocation);
-    *yycdebug_ << ')';
+    return yystos_[state];

   }
   }

-#endif

 
 

+
+  template <typename Exact>

   void
   void

-  ]b4_parser_class_name[::yydestruct_ (const char* yymsg,
-                          int yytype, semantic_type& yyvalue, location_type& yylocation)
+  ]b4_parser_class_name[::yy_destroy_ (const char* yymsg,
+                                       symbol_base_type<Exact>& yysym) const

   {
   {

+    int yytype = yysym.type_get ();

     YYUSE (yymsg);
     YYUSE (yymsg);

-    YYUSE (yyvalue);
-    YYUSE (yylocation);
+    if (yymsg)
+      YY_SYMBOL_PRINT (yymsg, yysym);
+
+    // User destructor.
+    switch (yytype)
+      {
+]b4_symbol_foreach([b4_symbol_destructor])dnl
+[       default:
+          break;
+      }]b4_variant_if([

 
 

-    YY_SYMBOL_PRINT (yymsg, yytype, yyvalue, yylocation);
+    // Type destructor.
+  b4_symbol_variant([[yytype]], [[yysym.value]], [[template destroy]])])[
+  }

 
 

+#if YYDEBUG
+  template <typename Exact>
+  void
+  ]b4_parser_class_name[::yy_print_ (std::ostream& yyo,
+                                     const symbol_base_type<Exact>& yysym) const
+  {
+    int yytype = yysym.type_get ();
+    yyo << (yytype < yyntokens_ ? "token" : "nterm")
+        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
+        << yysym.location << ": "])[;

     switch (yytype)
       {
     switch (yytype)
       {

-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
-       default:
+]b4_symbol_foreach([b4_symbol_printer])dnl
+[       default:

          break;
       }
          break;
       }

+    yyo << ')';
+  }
+#endif
+
+  void
+  ]b4_parser_class_name[::yypush_ (const char* m, state_type s,
+                                   symbol_type& sym)
+  {
+    if (m)
+      YY_SYMBOL_PRINT (m, sym);
+]b4_variant_if(
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                    [s],
+                    [semantic_type()],
+                    b4_locations_if([sym.location]))[));
+    ]b4_symbol_variant([[yystos_[s]]], [[yystack_[0].value]],
+                       [build], [sym.value])],
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                      [s],
+                      [sym.value],
+                      b4_locations_if([sym.location]))[));]])[
+  }
+
+  void
+  ]b4_parser_class_name[::yypush_ (const char* m, stack_symbol_type& s)
+  {
+    if (m)
+      YY_SYMBOL_PRINT (m, s);
+]b4_variant_if(
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                       [s.state],
+                       [semantic_type()],
+                       b4_locations_if([s.location]))[));
+    ]b4_symbol_variant([[yystos_[s.state]]], [[yystack_[0].value]],
+                       [build], [s.value])],
+[    yystack_.push (s);])[

   }
 
   void
   ]b4_parser_class_name[::yypop_ (unsigned int n)
   {
   }
 
   void
   ]b4_parser_class_name[::yypop_ (unsigned int n)
   {

-    yystate_stack_.pop (n);
-    yysemantic_stack_.pop (n);
-    yylocation_stack_.pop (n);
+    yystack_.pop (n);

   }
 
 #if YYDEBUG
   }
 
 #if YYDEBUG


@@ -658,63 +650,77 @@ do {                                      \
   }
 #endif
 
   }
 #endif
 

+  inline ]b4_parser_class_name[::state_type
+  ]b4_parser_class_name[::yy_lr_goto_state_ (state_type yystate, int yylhs)
+  {
+    int yyr = yypgoto_[yylhs - yyntokens_] + yystate;
+    if (0 <= yyr && yyr <= yylast_ && yycheck_[yyr] == yystate)
+      return yytable_[yyr];
+    else
+      return yydefgoto_[yylhs - yyntokens_];
+  }
+
+  inline bool
+  ]b4_parser_class_name[::yy_pact_value_is_default_ (int yyvalue)
+  {
+    return yyvalue == yypact_ninf_;
+  }
+
+  inline bool
+  ]b4_parser_class_name[::yy_table_value_is_error_ (int yyvalue)
+  {
+    return yyvalue == yytable_ninf_;
+  }
+

   int
   ]b4_parser_class_name[::parse ()
   {
   int
   ]b4_parser_class_name[::parse ()
   {

-    /// Lookahead and lookahead in internal form.
-    int yychar = yyempty_;
-    int yytoken = 0;
+    /// Whether yyla contains a lookahead.
+    bool yyempty = true;

 
     /* State.  */
     int yyn;
     int yylen = 0;
 
     /* State.  */
     int yyn;
     int yylen = 0;

-    int yystate = 0;

 
     /* Error handling.  */
     int yynerrs_ = 0;
     int yyerrstatus_ = 0;
 
 
     /* Error handling.  */
     int yynerrs_ = 0;
     int yyerrstatus_ = 0;
 

-    /// Semantic value of the lookahead.
-    semantic_type yylval;
-    /// Location of the lookahead.
-    location_type yylloc;
+    /// The lookahead symbol.
+    symbol_type yyla;]b4_locations_if([[
+

     /// The locations where the error started and ended.
     /// The locations where the error started and ended.

-    location_type yyerror_range[2];
+    stack_symbol_type yyerror_range[2];]])[

 
 

-    /// $$.
-    semantic_type yyval;
-    /// @@$.
-    location_type yyloc;
+    /// $$ and @@$.
+    stack_symbol_type yylhs;

 
 

+    /// The return value of parse().

     int yyresult;
 
     YYCDEBUG << "Starting parse" << std::endl;
 
 ]m4_ifdef([b4_initial_action], [
     int yyresult;
 
     YYCDEBUG << "Starting parse" << std::endl;
 
 ]m4_ifdef([b4_initial_action], [

-m4_pushdef([b4_at_dollar],     [yylloc])dnl
-m4_pushdef([b4_dollar_dollar], [yylval])dnl
+m4_pushdef([b4_at_dollar],     [yyla.location])dnl
+m4_pushdef([b4_dollar_dollar], [yyla.value])dnl

     /* User initialization code.  */
     b4_user_initial_action
 m4_popdef([b4_dollar_dollar])dnl
 m4_popdef([b4_at_dollar])])dnl
 
     /* User initialization code.  */
     b4_user_initial_action
 m4_popdef([b4_dollar_dollar])dnl
 m4_popdef([b4_at_dollar])])dnl
 

-  [  /* Initialize the stacks.  The initial state will be pushed in
+  [  /* Initialize the stack.  The initial state will be set in

        yynewstate, since the latter expects the semantical and the
        location values to have been already stored, initialize these
        stacks with a primary value.  */
        yynewstate, since the latter expects the semantical and the
        location values to have been already stored, initialize these
        stacks with a primary value.  */

-    yystate_stack_ = state_stack_type (0);
-    yysemantic_stack_ = semantic_stack_type (0);
-    yylocation_stack_ = location_stack_type (0);
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yylloc);
+    yystack_ = stack_type (0);
+    yypush_ (0, 0, yyla);

 
 

-    /* New state.  */
+    // A new symbol was pushed on the stack.

   yynewstate:
   yynewstate:

-    yystate_stack_.push (yystate);
-    YYCDEBUG << "Entering state " << yystate << std::endl;
+    YYCDEBUG << "Entering state " << yystack_[0].state << std::endl;

 
     /* Accept?  */
 
     /* Accept?  */

-    if (yystate == yyfinal_)
+    if (yystack_[0].state == yyfinal_)

       goto yyacceptlab;
 
     goto yybackup;
       goto yyacceptlab;
 
     goto yybackup;


@@ -723,70 +729,58 @@ m4_popdef([b4_at_dollar])])dnl
   yybackup:
 
     /* Try to take a decision without lookahead.  */
   yybackup:
 
     /* Try to take a decision without lookahead.  */

-    yyn = yypact_[yystate];
-    if (yyn == yypact_ninf_)
+    yyn = yypact_[yystack_[0].state];
+    if (yy_pact_value_is_default_ (yyn))

       goto yydefault;
 
     /* Read a lookahead token.  */
       goto yydefault;
 
     /* Read a lookahead token.  */

-    if (yychar == yyempty_)
-      {
-       YYCDEBUG << "Reading a token: ";
-       yychar = ]b4_c_function_call([yylex], [int],
-                                    [[YYSTYPE*], [&yylval]][]dnl
-b4_locations_if([, [[location*], [&yylloc]]])dnl
-m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
-      }
-
-
-    /* Convert token to internal form.  */
-    if (yychar <= yyeof_)
-      {
-       yychar = yytoken = yyeof_;
-       YYCDEBUG << "Now at end of input." << std::endl;
-      }
-    else
+    if (yyempty)

       {
       {

-       yytoken = yytranslate_ (yychar);
-       YY_SYMBOL_PRINT ("Next token is", yytoken, yylval, yylloc);
+        YYCDEBUG << "Reading a token: ";
+]b4_lex_symbol_if(
+[        yyla = b4_c_function_call([yylex], [symbol_type],
+                                   m4_ifdef([b4_lex_param], b4_lex_param));],
+[        yyla.type = yytranslate_ (b4_c_function_call([yylex], [int],
+                                    [[YYSTYPE*], [&yyla.value]][]dnl
+b4_locations_if([, [[location*], [&yyla.location]]])dnl
+m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[
+        yyempty = false;

       }
       }

+    YY_SYMBOL_PRINT ("Next token is", yyla);

 
 

-    /* If the proper action on seeing token YYTOKEN is to reduce or to
-       detect an error, take that action.  */
-    yyn += yytoken;
-    if (yyn < 0 || yylast_ < yyn || yycheck_[yyn] != yytoken)
+    /* 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)

       goto yydefault;
 
     /* Reduce or error.  */
     yyn = yytable_[yyn];
     if (yyn <= 0)
       {
       goto yydefault;
 
     /* Reduce or error.  */
     yyn = yytable_[yyn];
     if (yyn <= 0)
       {

-       if (yyn == 0 || yyn == yytable_ninf_)
-       goto yyerrlab;
+       if (yy_table_value_is_error_ (yyn))
+         goto yyerrlab;

        yyn = -yyn;
        goto yyreduce;
       }
 
        yyn = -yyn;
        goto yyreduce;
       }
 

-    /* Shift the lookahead token.  */
-    YY_SYMBOL_PRINT ("Shifting", yytoken, yylval, yylloc);
-

     /* Discard the token being shifted.  */
     /* Discard the token being shifted.  */

-    yychar = yyempty_;
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yylloc);
+    yyempty = true;

 
     /* Count tokens shifted since error; after three, turn off error
        status.  */
     if (yyerrstatus_)
       --yyerrstatus_;
 
 
     /* Count tokens shifted since error; after three, turn off error
        status.  */
     if (yyerrstatus_)
       --yyerrstatus_;
 

-    yystate = yyn;
+    /* Shift the lookahead token.  */
+    yypush_ ("Shifting", yyn, yyla);

     goto yynewstate;
 
   /*-----------------------------------------------------------.
   | yydefault -- do the default action for the current state.  |
   `-----------------------------------------------------------*/
   yydefault:
     goto yynewstate;
 
   /*-----------------------------------------------------------.
   | yydefault -- do the default action for the current state.  |
   `-----------------------------------------------------------*/
   yydefault:

-    yyn = yydefact_[yystate];
+    yyn = yydefact_[yystack_[0].state];

     if (yyn == 0)
       goto yyerrlab;
     goto yyreduce;
     if (yyn == 0)
       goto yyerrlab;
     goto yyreduce;


@@ -795,79 +789,97 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
   | yyreduce -- Do a reduction.  |
   `-----------------------------*/
   yyreduce:
   | yyreduce -- Do a reduction.  |
   `-----------------------------*/
   yyreduce:

-    yylen = yyr2_[yyn];]b4_variant_if([
+    yylen = yyr2_[yyn];
+    yylhs.state = yy_lr_goto_state_(yystack_[yylen].state, yyr1_[yyn]);]b4_variant_if([

     /* Variants are always initialized to an empty instance of the
     /* Variants are always initialized to an empty instance of the

-       correct type. The default $$=$1 rule is NOT applied when using
-       variants */
-    ]b4_symbol_variant([[yyr1_@{yyn@}]], [yyval], [build])[],[
+       correct type. The default $$=$1 action is NOT applied when using
+       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.
 
     /* If YYLEN is nonzero, implement the default value of the action:
        `$$ = $1'.  Otherwise, use the top of the stack.
 

-       Otherwise, the following line sets YYVAL to garbage.
+       Otherwise, the following line sets YYLHS.VALUE to garbage.

        This behavior is undocumented and Bison
        users should not rely upon it.  */
     if (yylen)
        This behavior is undocumented and Bison
        users should not rely upon it.  */
     if (yylen)

-      yyval = yysemantic_stack_@{yylen - 1@};
+      yylhs.value = yystack_@{yylen - 1@}.value;

     else
     else

-      yyval = yysemantic_stack_@{0@};])[
-
+      yylhs.value = yystack_@{0@}.value;])[
+]b4_locations_if([dnl
+[
+    // Compute the default @@$.

     {
     {

-      slice<location_type, location_stack_type> slice (yylocation_stack_, yylen);
-      YYLLOC_DEFAULT (yyloc, slice, yylen);
-    }
+      slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
+      YYLLOC_DEFAULT (yylhs.location, slice, yylen);
+    }]])[
+
+    // Perform the reduction.

     YY_REDUCE_PRINT (yyn);
     YY_REDUCE_PRINT (yyn);

-    switch (yyn)
+    try
+    {
+      switch (yyn)

       {
       {

-       ]b4_user_actions[
+]b4_user_actions[

        default:
           break;
       }
        default:
           break;
       }

-    YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], yyval, yyloc);
+    }
+    catch (const syntax_error& yyexc)
+    {
+      error (]b4_args(b4_locations_if([yyexc.location]),
+                      [[yyexc.what()]])[);
+      YYERROR;
+    }
+    YY_SYMBOL_PRINT ("-> $$ =", yylhs);
+]b4_variant_if([[
+    // Destroy the rhs symbols.
+    for (int i = 0; i < yylen; ++i)
+      // Destroy a variant which value may have been swapped with
+      // yylhs.value (for instance if the action was "std::swap($$,
+      // $1)").  The value of yylhs.value (hence possibly one of these
+      // rhs symbols) depends on the default contruction for this
+      // type.  In the case of pointers for instance, no
+      // initialization is done, so the value is junk.  Therefore do
+      // not try to report the value of symbols about to be destroyed
+      // in the debug trace, it's possibly junk.  Hence yymsg = 0.
+      // Besides, that keeps exactly the same traces as with the other
+      // Bison skeletons.
+      yy_destroy_ (0, yystack_[i]);]])[

 
     yypop_ (yylen);
     yylen = 0;
     YY_STACK_PRINT ();
 
     yypop_ (yylen);
     yylen = 0;
     YY_STACK_PRINT ();

-    yysemantic_stack_.push (yyval);
-    yylocation_stack_.push (yyloc);

 
     /* Shift the result of the reduction.  */
 
     /* Shift the result of the reduction.  */

-    yyn = yyr1_[yyn];
-    yystate = yypgoto_[yyn - yyntokens_] + yystate_stack_[0];
-    if (0 <= yystate && yystate <= yylast_
-       && yycheck_[yystate] == yystate_stack_[0])
-      yystate = yytable_[yystate];
-    else
-      yystate = yydefgoto_[yyn - yyntokens_];
+    yypush_ (0, yylhs);

     goto yynewstate;
 
     goto yynewstate;
 

-  /*------------------------------------.
-  | yyerrlab -- here on detecting error |
-  `------------------------------------*/
+  /*--------------------------------------.
+  | yyerrlab -- here on detecting error.  |
+  `--------------------------------------*/

   yyerrlab:
     /* If not already recovering from an error, report this error.  */
     if (!yyerrstatus_)
       {
        ++yynerrs_;
   yyerrlab:
     /* If not already recovering from an error, report this error.  */
     if (!yyerrstatus_)
       {
        ++yynerrs_;

-       error (yylloc, yysyntax_error_ (yystate]dnl
-b4_error_verbose_if([, yytoken])[));
+       error (]b4_args(b4_locations_if([yyla.location]),
+                        [[yysyntax_error_ (yystack_[0].state, yyla.type)]])[);

       }
 
       }
 

-    yyerror_range[0] = yylloc;
+]b4_locations_if([[
+    yyerror_range[0].location = yyla.location;]])[

     if (yyerrstatus_ == 3)
       {
        /* If just tried and failed to reuse lookahead token after an
     if (yyerrstatus_ == 3)
       {
        /* If just tried and failed to reuse lookahead token after an

-        error, discard it.  */
-
-       if (yychar <= yyeof_)
-         {
-         /* Return failure if at end of input.  */
-         if (yychar == yyeof_)
-           YYABORT;
-         }
-       else
-         {
-           yydestruct_ ("Error: discarding", yytoken, yylval, yylloc);
-           yychar = yyempty_;
+           error, discard it.  */
+
+        /* Return failure if at end of input.  */
+        if (yyla.type == yyeof_)
+          YYABORT;
+        else if (!yyempty)
+          {
+            yy_destroy_ ("Error: discarding", yyla);
+            yyempty = true;

          }
       }
 
          }
       }
 


@@ -885,14 +897,14 @@ b4_error_verbose_if([, yytoken])[));
        YYERROR and the label yyerrorlab therefore never appears in user
        code.  */
     if (false)
        YYERROR and the label yyerrorlab therefore never appears in user
        code.  */
     if (false)

-      goto yyerrorlab;
-
-    yyerror_range[0] = yylocation_stack_[yylen - 1];
+      goto yyerrorlab;]b4_locations_if([[
+    yyerror_range[0].location = yystack_[yylen - 1].location;]])b4_variant_if([[
+    /* $$ was initialized before running the user action.  */
+    yy_destroy_ ("Error: discarding", yylhs);]])[

     /* Do not reclaim the symbols of the rule which action triggered
        this YYERROR.  */
     yypop_ (yylen);
     yylen = 0;
     /* Do not reclaim the symbols of the rule which action triggered
        this YYERROR.  */
     yypop_ (yylen);
     yylen = 0;

-    yystate = yystate_stack_[0];

     goto yyerrlab1;
 
   /*-------------------------------------------------------------.
     goto yyerrlab1;
 
   /*-------------------------------------------------------------.


@@ -900,46 +912,39 @@ b4_error_verbose_if([, yytoken])[));
   `-------------------------------------------------------------*/
   yyerrlab1:
     yyerrstatus_ = 3;  /* Each real token shifted decrements this.  */
   `-------------------------------------------------------------*/
   yyerrlab1:
     yyerrstatus_ = 3;  /* Each real token shifted decrements this.  */

+    {
+      stack_symbol_type error_token;
+      for (;;)
+        {
+          yyn = yypact_[yystack_[0].state];
+          if (!yy_pact_value_is_default_ (yyn))
+            {
+              yyn += yyterror_;
+              if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
+                {
+                  yyn = yytable_[yyn];
+                  if (0 < yyn)
+                    break;
+                }
+            }

 
 

-    for (;;)
-      {
-       yyn = yypact_[yystate];
-       if (yyn != yypact_ninf_)
-       {
-         yyn += yyterror_;
-         if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_)
-           {
-             yyn = yytable_[yyn];
-             if (0 < yyn)
-               break;
-           }
-       }
-
-       /* Pop the current state because it cannot handle the error token.  */
-       if (yystate_stack_.size () == 1)
-       YYABORT;
-
-       yyerror_range[0] = yylocation_stack_[0];
-       yydestruct_ ("Error: popping",
-                    yystos_[yystate],
-                    yysemantic_stack_[0], yylocation_stack_[0]);
-       yypop_ ();
-       yystate = yystate_stack_[0];
-       YY_STACK_PRINT ();
-      }
-
-    yyerror_range[1] = yylloc;
-    // Using YYLLOC is tempting, but would change the location of
-    // the lookahead.  YYLOC is available though.
-    YYLLOC_DEFAULT (yyloc, (yyerror_range - 1), 2);
-    yysemantic_stack_.push (yylval);
-    yylocation_stack_.push (yyloc);
-
-    /* Shift the error token.  */
-    YY_SYMBOL_PRINT ("Shifting", yystos_[yyn],
-                    yysemantic_stack_[0], yylocation_stack_[0]);
-
-    yystate = yyn;
+          // Pop the current state because it cannot handle the error token.
+          if (yystack_.size () == 1)
+            YYABORT;
+]b4_locations_if([[
+          yyerror_range[0].location = yystack_[0].location;]])[
+          yy_destroy_ ("Error: popping", yystack_[0]);
+          yypop_ ();
+          YY_STACK_PRINT ();
+        }
+]b4_locations_if([[
+      yyerror_range[1].location = yyla.location;
+      YYLLOC_DEFAULT (error_token.location, (yyerror_range - 1), 2);]])[
+
+      /* Shift the error token.  */
+      error_token.state = yyn;
+      yypush_ ("Shifting", error_token);
+    }

     goto yynewstate;
 
     /* Accept.  */
     goto yynewstate;
 
     /* Accept.  */


@@ -953,18 +958,15 @@ b4_error_verbose_if([, yytoken])[));
     goto yyreturn;
 
   yyreturn:
     goto yyreturn;
 
   yyreturn:

-    if (yychar != yyempty_)
-      yydestruct_ ("Cleanup: discarding lookahead", yytoken, yylval, yylloc);
+    if (!yyempty)
+      yy_destroy_ ("Cleanup: discarding lookahead", yyla);

 
     /* Do not reclaim the symbols of the rule which action triggered
        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);
 
     /* Do not reclaim the symbols of the rule which action triggered
        this YYABORT or YYACCEPT.  */
     yypop_ (yylen);

-    while (yystate_stack_.size () != 1)
+    while (yystack_.size () != 1)

       {
       {

-       yydestruct_ ("Cleanup: popping",
-                     yystos_[yystate_stack_[0]],
-                     yysemantic_stack_[0],
-                     yylocation_stack_[0]);
+       yy_destroy_ ("Cleanup: popping", yystack_[0]);

        yypop_ ();
       }
 
        yypop_ ();
       }
 


@@ -973,135 +975,81 @@ b4_error_verbose_if([, yytoken])[));
 
   // Generate an error message.
   std::string
 
   // Generate an error message.
   std::string

-  ]b4_parser_class_name[::yysyntax_error_ (int yystate]dnl
-b4_error_verbose_if([, int tok])[)
+  ]b4_parser_class_name[::yysyntax_error_ (]dnl
+b4_error_verbose_if([state_type yystate, int yytoken],
+                    [int, int])[)

   {
   {

-    std::string res;
-    YYUSE (yystate);
-#if YYERROR_VERBOSE
+    std::string yyres;]b4_error_verbose_if([[

     int yyn = yypact_[yystate];
     if (yypact_ninf_ < yyn && yyn <= yylast_)
       {
        /* Start YYX at -YYN if negative to avoid negative indexes in
     int yyn = yypact_[yystate];
     if (yypact_ninf_ < yyn && yyn <= yylast_)
       {
        /* Start YYX at -YYN if negative to avoid negative indexes in

-          YYCHECK.  */
+          YYCHECK.  In other words, skip the first -YYN actions for this
+          state because they are default actions.  */

        int yyxbegin = yyn < 0 ? -yyn : 0;
 
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;
        int yyxbegin = yyn < 0 ? -yyn : 0;
 
        /* Stay within bounds of both yycheck and yytname.  */
        int yychecklim = yylast_ - yyn + 1;
        int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_;

-       int count = 0;
-       for (int x = yyxbegin; x < yyxend; ++x)
-         if (yycheck_[x + yyn] == x && x != yyterror_)
-           ++count;
-
-       // FIXME: This method of building the message is not compatible
-       // with internationalization.  It should work like yacc.c does it.
-       // That is, first build a string that looks like this:
-       // "syntax error, unexpected %s or %s or %s"
-       // Then, invoke YY_ on this string.
-       // Finally, use the string as a format to output
-       // yytname_[tok], etc.
-       // Until this gets fixed, this message appears in English only.
-       res = "syntax error, unexpected ";
-       res += yytnamerr_ (yytname_[tok]);
-       if (count < 5)
-         {
-           count = 0;
-           for (int x = yyxbegin; x < yyxend; ++x)
-             if (yycheck_[x + yyn] == x && x != yyterror_)
-               {
-                 res += (!count++) ? ", expecting " : " or ";
-                 res += yytnamerr_ (yytname_[x]);
-               }
-         }
+
+        // Number of reported tokens (one for the "unexpected", one per
+        // "expected").
+       size_t yycount = 0;
+        // Its maximum.
+        enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 };
+        // Arguments of yyformat.
+        char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
+        yyarg[yycount++] = yytname_[yytoken];
+       for (int yyx = yyxbegin; yyx < yyxend; ++yyx)
+         if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_
+             && !yy_table_value_is_error_ (yytable_[yyx + yyn]))
+          {
+            if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM)
+            {
+              yycount = 1;
+              break;
+            }
+            else
+              yyarg[yycount++] = yytname_[yyx];
+          }
+
+        char const* yyformat = 0;
+        switch (yycount)
+        {
+#define YYCASE_(N, S)                           \
+          case N:                               \
+            yyformat = S;                       \
+          break
+          YYCASE_(1, YY_("syntax error, unexpected %s"));
+          YYCASE_(2, YY_("syntax error, unexpected %s, expecting %s"));
+          YYCASE_(3, YY_("syntax error, unexpected %s, expecting %s or %s"));
+          YYCASE_(4, YY_("syntax error, unexpected %s, expecting %s or %s or %s"));
+          YYCASE_(5, YY_("syntax error, unexpected %s, expecting %s or %s or %s or %s"));
+#undef YYCASE_
+        }
+        // Argument number.
+        size_t yyi = 0;
+        for (char const* yyp = yyformat; *yyp; ++yyp)
+          if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount)
+          {
+            yyres += yytnamerr_ (yyarg[yyi++]);
+            ++yyp;
+          }
+          else
+            yyres += *yyp;

       }
     else
       }
     else

-#endif
-      res = YY_("syntax error");
-    return res;
+  ]])dnl
+[    yyres = YY_("syntax error");
+    return yyres;

   }
 
 
   }
 
 

-  /* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
-     STATE-NUM.  */

   const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) b4_parser_class_name::yypact_ninf_ = b4_pact_ninf[;
   const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) b4_parser_class_name::yypact_ninf_ = b4_pact_ninf[;

-  const ]b4_int_type_for([b4_pact])[
-  ]b4_parser_class_name[::yypact_[] =
-  {
-    ]b4_pact[
-  };
-
-  /* YYDEFACT[S] -- default rule to reduce with in state S when YYTABLE
-     doesn't specify something else to do.  Zero means the default is an
-     error.  */
-  const ]b4_int_type_for([b4_defact])[
-  ]b4_parser_class_name[::yydefact_[] =
-  {
-    ]b4_defact[
-  };

 
 

-  /* YYPGOTO[NTERM-NUM].  */
-  const ]b4_int_type_for([b4_pgoto])[
-  ]b4_parser_class_name[::yypgoto_[] =
-  {
-    ]b4_pgoto[
-  };
-
-  /* YYDEFGOTO[NTERM-NUM].  */
-  const ]b4_int_type_for([b4_defgoto])[
-  ]b4_parser_class_name[::yydefgoto_[] =
-  {
-    ]b4_defgoto[
-  };
-
-  /* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
-     positive, shift that token.  If negative, reduce the rule which
-     number is the opposite.  If zero, do what YYDEFACT says.  */

   const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class_name::yytable_ninf_ = b4_table_ninf[;
   const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class_name::yytable_ninf_ = b4_table_ninf[;

-  const ]b4_int_type_for([b4_table])[
-  ]b4_parser_class_name[::yytable_[] =
-  {
-    ]b4_table[
-  };

 
 

-  /* YYCHECK.  */
-  const ]b4_int_type_for([b4_check])[
-  ]b4_parser_class_name[::yycheck_[] =
-  {
-    ]b4_check[
-  };
-
-  /* STOS_[STATE-NUM] -- The (internal number of the) accessing
-     symbol of state STATE-NUM.  */
-  const ]b4_int_type_for([b4_stos])[
-  ]b4_parser_class_name[::yystos_[] =
-  {
-    ]b4_stos[
-  };
-
-#if YYDEBUG
-  /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal symbol number corresponding
-     to YYLEX-NUM.  */
-  const ]b4_int_type_for([b4_toknum])[
-  ]b4_parser_class_name[::yytoken_number_[] =
-  {
-    ]b4_toknum[
-  };
-#endif
-
-  /* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
-  const ]b4_int_type_for([b4_r1])[
-  ]b4_parser_class_name[::yyr1_[] =
-  {
-    ]b4_r1[
-  };
-
-  /* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
-  const ]b4_int_type_for([b4_r2])[
-  ]b4_parser_class_name[::yyr2_[] =
-  {
-    ]b4_r2[
-  };
+]b4_parser_tables_define[

 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
 
 #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE
   /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.


@@ -1109,41 +1057,23 @@ b4_error_verbose_if([, int tok])[)
   const char*
   const ]b4_parser_class_name[::yytname_[] =
   {
   const char*
   const ]b4_parser_class_name[::yytname_[] =
   {

-    ]b4_tname[
+  ]b4_tname[

   };
 #endif
 
 #if YYDEBUG
   };
 #endif
 
 #if YYDEBUG

-  /* YYRHS -- A `-1'-separated list of the rules' RHS.  */
-  const ]b4_parser_class_name[::rhs_number_type
-  ]b4_parser_class_name[::yyrhs_[] =
-  {
-    ]b4_rhs[
-  };
-
-  /* YYPRHS[YYN] -- Index of the first RHS symbol of rule number YYN in
-     YYRHS.  */
-  const ]b4_int_type_for([b4_prhs])[
-  ]b4_parser_class_name[::yyprhs_[] =
-  {
-    ]b4_prhs[
-  };
-
-  /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
-  const ]b4_int_type_for([b4_rline])[
-  ]b4_parser_class_name[::yyrline_[] =
-  {
-    ]b4_rline[
-  };
+]b4_integral_parser_table_define([rline], [b4_rline])[

 
   // Print the state stack on the debug stream.
   void
   ]b4_parser_class_name[::yystack_print_ ()
   {
     *yycdebug_ << "Stack now";
 
   // Print the state stack on the debug stream.
   void
   ]b4_parser_class_name[::yystack_print_ ()
   {
     *yycdebug_ << "Stack now";

-    for (state_stack_type::const_iterator i = yystate_stack_.begin ();
-        i != yystate_stack_.end (); ++i)
-      *yycdebug_ << ' ' << *i;
+    for (stack_type::const_iterator
+           i = yystack_.begin (),
+           i_end = yystack_.end ();
+        i != i_end; ++i)
+      *yycdebug_ << ' ' << i->state;

     *yycdebug_ << std::endl;
   }
 
     *yycdebug_ << std::endl;
   }
 


@@ -1159,141 +1089,12 @@ b4_error_verbose_if([, int tok])[)
     /* The symbols being reduced.  */
     for (int yyi = 0; yyi < yynrhs; yyi++)
       YY_SYMBOL_PRINT ("   $" << yyi + 1 << " =",
     /* The symbols being reduced.  */
     for (int yyi = 0; yyi < yynrhs; yyi++)
       YY_SYMBOL_PRINT ("   $" << yyi + 1 << " =",

-                      yyrhs_[yyprhs_[yyrule] + yyi],
-                      ]b4_rhs_value(yynrhs, yyi + 1)[,
-                      ]b4_rhs_location(yynrhs, yyi + 1)[);
+                       ]b4_rhs_data(yynrhs, yyi + 1)[);

   }
 #endif // YYDEBUG
 
   }
 #endif // YYDEBUG
 

-  /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
-  ]b4_parser_class_name[::token_number_type
-  ]b4_parser_class_name[::yytranslate_ (int t)
-  {
-    static
-    const token_number_type
-    translate_table[] =
-    {
-      ]b4_translate[
-    };
-    if ((unsigned int) t <= yyuser_token_number_max_)
-      return translate_table[t];
-    else
-      return yyundef_token_;
-  }
-
-  const int ]b4_parser_class_name[::yyeof_ = 0;
-  const int ]b4_parser_class_name[::yylast_ = ]b4_last[;
-  const int ]b4_parser_class_name[::yynnts_ = ]b4_nterms_number[;
-  const int ]b4_parser_class_name[::yyempty_ = -2;
-  const int ]b4_parser_class_name[::yyfinal_ = ]b4_final_state_number[;
-  const int ]b4_parser_class_name[::yyterror_ = 1;
-  const int ]b4_parser_class_name[::yyerrcode_ = 256;
-  const int ]b4_parser_class_name[::yyntokens_ = ]b4_tokens_number[;
-
-  const unsigned int ]b4_parser_class_name[::yyuser_token_number_max_ = ]b4_user_token_number_max[;
-  const ]b4_parser_class_name[::token_number_type ]b4_parser_class_name[::yyundef_token_ = ]b4_undef_token_number[;
-
+]b4_lex_symbol_if([], [b4_yytranslate_define])[

 ]b4_namespace_close[
 ]b4_namespace_close[

-
-]b4_epilogue
-dnl
-@output(b4_dir_prefix[]stack.hh@)
-b4_copyright([Stack handling for Bison parsers in C++],
-             [2002, 2003, 2004, 2005, 2006, 2007, 2008])[
-
-#ifndef BISON_STACK_HH
-# define BISON_STACK_HH
-
-#include <deque>
-
-]b4_namespace_open[
-  template <class T, class S = std::deque<T> >
-  class stack
-  {
-  public:
-
-    // Hide our reversed order.
-    typedef typename S::reverse_iterator iterator;
-    typedef typename S::const_reverse_iterator const_iterator;
-
-    stack () : seq_ ()
-    {
-    }
-
-    stack (unsigned int n) : seq_ (n)
-    {
-    }
-
-    inline
-    T&
-    operator [] (unsigned int i)
-    {
-      return seq_[i];
-    }
-
-    inline
-    const T&
-    operator [] (unsigned int i) const
-    {
-      return seq_[i];
-    }
-
-    inline
-    void
-    push (const T& t)
-    {
-      seq_.push_front (t);
-    }
-
-    inline
-    void
-    pop (unsigned int n = 1)
-    {
-      for (; n; --n)
-       seq_.pop_front ();
-    }
-
-    inline
-    typename S::size_type
-    size () const
-    {
-      return seq_.size ();
-    }
-
-    inline const_iterator begin () const { return seq_.rbegin (); }
-    inline const_iterator end ()   const { return seq_.rend ();   }
-
-  private:
-    /// The wrapped container.
-    S seq_;
-  };
-
-  /// Present a slice of the top of a stack.
-  template <class T, class S = stack<T> >
-  class slice
-  {
-  public:
-
-    slice (const S& stack,
-          unsigned int range) : stack_ (stack),
-                                range_ (range)
-    {
-    }
-
-    inline
-    const T&
-    operator [] (unsigned int i) const
-    {
-      return stack_[range_ - i];
-    }
-
-  private:
-
-    const S& stack_;
-    unsigned int range_;
-  };
-]b4_namespace_close[
-
-#endif // not BISON_STACK_HH[]dnl
-]
+]b4_epilogue[]dnl

 m4_divert_pop(0)
 m4_divert_pop(0)

+m4_popdef([b4_copyright_years])dnl