]> git.saurik.com Git - bison.git/blobdiff - data/lalr1.cc
Make it easier to move the definition of yytranslate_.
[bison.git] / data / lalr1.cc
index 40cdde23e8f4c084ba23377f3f791ab7579a28a8..d6a48780fd3f7d7e543624b4555a8449830e4fcb 100644 (file)
 
 m4_include(b4_pkgdatadir/[c++.m4])
 
+
+# b4_args(ARG1, ...)
+# _b4_args(ARG1, ...)
+# -------------------
+# Join with comma, skipping empty arguments.
+# b4_args calls itself recursively until it sees the first non-empty
+# argument, then calls _b4_args which prepends each non-empty argument
+# with a comma.
+m4_define([b4_args],
+[m4_if([$#$1],
+       [1], [],
+       [m4_ifval([$1],
+                 [$1[]_$0(m4_shift($@))],
+                 [$0(m4_shift($@))])])])
+
+# _b4_args(ARGS1, ...)
+# --------------------
+m4_define([_b4_args],
+[m4_if([$#$1],
+       [1], [],
+       [m4_ifval([$1], [, $1])[]$0(m4_shift($@))])])
+
+
 # b4_table_define(TABLE-NAME, CONTENT)
 # ------------------------------------
 # Define "parser::yy<TABLE-NAME>_" which contents is CONTENT.
@@ -53,6 +76,12 @@ b4_variant_if([
 ]) # b4_variant_if
 
 
+# b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT])
+# ----------------------------------------------------------------
+m4_define([b4_lex_symbol_if],
+[b4_percent_define_ifdef([[lex_symbol]], [$1], [$2])])
+
+
 # b4_assert_if([IF-ASSERTIONS-ARE-USED], [IF-NOT])
 # ------------------------------------------------
 m4_define([b4_assert_if],
@@ -156,16 +185,97 @@ m4_define([b4_symbol_case_],
 # Run actions for the symbol NUMS that all have the same type-name.
 # Skip NUMS that have no type-name.
 m4_define([b4_type_action_],
-[b4_symbol_if([$1], [has_type_name],
+[b4_symbol_if([$1], [has_type],
 [m4_map([b4_symbol_case_], [$@])[]dnl
         b4_dollar_dollar([b4_symbol([$1], [number])],
                          [b4_symbol([$1], [tag])],
-                         [b4_symbol([$1], [type_name])]);
+                         [b4_symbol([$1], [type])]);
        break;
 
 ])])
 
 
+# b4_symbol_constructor_declaration_(SYMBOL-NUMBERS)
+# ----------------------------------------------------
+# Declare the overloaded version of make_symbol for the (common) type of
+# these SYMBOL-NUMBERS.  Use at class-level.
+m4_define([b4_symbol_constructor_declaration_],
+[    template <token_type>
+    static inline symbol_type
+    make_symbol (b4_args(b4_symbol_if([$1], [has_type],
+                                      [const b4_symbol([$1], [type])& v]),
+                         b4_locations_if([const location_type& l])));
+
+])
+
+# b4_symbol_constructor_declarations
+# ----------------------------------
+# Declare the overloaded versions of make_symbol for all the value types.
+# Use at class-level.
+m4_define([b4_symbol_constructor_declarations],
+[b4_variant_if([
+    // Declaration of make_symbol for each value type.
+m4_map([b4_symbol_constructor_declaration_], m4_defn([b4_type_names]))])])
+
+
+
+# b4_symbol_constructor_specialization_(SYMBOL-NUMBER)
+# ----------------------------------------------------
+# Declare the specialization of make_symbol for this each SYMBOL-NUMBER.
+# Specializations cannot be declared at class-level, this must be done
+# at namespace-level.
+m4_define([b4_symbol_constructor_specialization_],
+[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id],
+[  template <>
+  inline
+  b4_parser_class_name::symbol_type
+  b4_parser_class_name::make_symbol <b4_parser_class_name::token::b4_symbol([$1], [id])> (dnl
+b4_args(b4_symbol_if([$1], [has_type],
+                     [const b4_symbol([$1], [type])& v]),
+        b4_locations_if([const location_type& l])));
+])])])
+
+# b4_symbol_constructor_specializations
+# -------------------------------------
+# Declare specializations of make_symbol.
+m4_define([b4_symbol_constructor_specializations],
+[b4_variant_if([
+  // Specializations of make_symbol for each symbol type.
+m4_map([b4_symbol_constructor_specialization_],
+       m4_defn([b4_symbol_numbers]))])dnl
+])
+
+
+
+# b4_symbol_constructor_definition_(SYMBOL-NUMBER)
+# ------------------------------------------------
+# Define make_symbol for this SYMBOL-NUMBER.
+m4_define([b4_symbol_constructor_definition_],
+[b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id],
+[  template <>
+  b4_parser_class_name::symbol_type
+  b4_parser_class_name::make_symbol <b4_parser_class_name::token::b4_symbol([$1], [id])> (dnl
+b4_args(b4_symbol_if([$1], [has_type],
+                     [const b4_symbol([$1], [type])& v]),
+        b4_locations_if([const location_type& l])))
+  {
+    return symbol_type (b4_args([yytranslate_ (token::b4_symbol([$1], [id]))],
+                                b4_symbol_if([$1], [has_type], [v]),
+                                b4_locations_if([l])));
+  }
+
+])])])
+
+
+# b4_symbol_constructor_declarations
+# ----------------------------------
+# Define the overloaded versions of make_symbol for all the value types.
+m4_define([b4_symbol_constructor_definitions],
+[b4_variant_if(
+[  // Implementation of make_symbol for each symbol type.
+m4_map([b4_symbol_constructor_definition_], m4_defn([b4_symbol_numbers]))])])
+
+
 # b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS])
 # ------------------------------------------------
 # Run some ACTION ("build", or "destroy") on YYVAL of symbol type
@@ -197,7 +307,14 @@ m4_define([_b4_char_sizeof_dummy],
 dummy[]_b4_char_sizeof_counter])
 
 
-# b4_char_sizeof(SYMBOL-NUM)
+# b4_char_sizeof_(SYMBOL-NUM)
+# ---------------------------
+# A comment describing this symbol.
+m4_define([b4_char_sizeof_],
+[      // b4_symbol([$1], [tag])
+])
+
+# b4_char_sizeof(SYMBOL-NUMS)
 # --------------------------
 # To be mapped on the list of type names to produce:
 #
@@ -205,12 +322,41 @@ dummy[]_b4_char_sizeof_counter])
 #    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(b4_symbol([$1], [type_name]),
+[b4_symbol_if([$1], [has_type],
 [
-      char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type_name])])@}; // b4_symbol([$1], [tag])])dnl
-])
+m4_map([b4_char_sizeof_], [$@])dnl
+      char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@};
+])])
+
+
+# b4_yytranslate_definition
+# -------------------------
+# Define yytranslate_.  Sometimes we want it in the header file,
+# sometimes the cc file suffices.
+m4_define([b4_yytranslate_definition],
+[[  // YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.
+  ]b4_parser_class_name[::token_number_type
+  ]b4_parser_class_name[::yytranslate_ (]b4_lex_symbol_if([token_type],
+                                                          [int])[ t)
+  {
+    static
+    const token_number_type
+    translate_table[] =
+    {
+]b4_translate[
+    };
+    const unsigned int user_token_number_max_ = ]b4_user_token_number_max[;
+    const token_number_type undef_token_ = ]b4_undef_token_number[;
+
+    if (static_cast<int>(t) <= yyeof_)
+      return yyeof_;
+    else if (static_cast<unsigned int> (t) <= user_token_number_max_)
+      return translate_table[t];
+    else
+      return undef_token_;
+  }
+]])
 
 
 m4_pushdef([b4_copyright_years],
@@ -223,15 +369,15 @@ m4_define([b4_parser_class_name],
 b4_defines_if([],
               [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
 
-# Backward compatibility.
+b4_locations_if(
+[# Backward compatibility.
 m4_define([b4_location_constructors])
-m4_include(b4_pkgdatadir/[location.cc])
+m4_include(b4_pkgdatadir/[location.cc])])
 
 # We do want M4 expansion after # for CPP macros.
 m4_changecom()
 m4_divert_push(0)dnl
-b4_defines_if(
-[@output(b4_spec_defines_file@)@
+@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.
 [
@@ -248,8 +394,8 @@ dnl FIXME: This is wrong, we want computed header guards.
 #include "stack.hh"
 
 ]b4_namespace_open[
-  class position;
-  class location;
+]b4_locations_if([  class position;
+  class location;])[
 ]b4_variant_if(
 [[
   /// A char[S] buffer to store and retrieve objects.
@@ -262,11 +408,12 @@ dnl FIXME: This is wrong, we want computed header guards.
   {]b4_assert_if([
     /// Whether something is contained.
     bool built;
-
-    /// Initially uninitialized.
-    variant ()
-      : built(false)
-    {}])[
+])[
+    /// Empty construction.
+    inline
+    variant ()]b4_assert_if([
+      : built(false)])[
+    {}
 
     /// Instantiate a \a T in here.
     template <typename T>
@@ -288,6 +435,15 @@ dnl FIXME: This is wrong, we want computed header guards.
       return *new (buffer) T(t);
     }
 
+    /// Construct and fill.
+    template <typename T>
+    inline
+    variant (const T& t)]b4_assert_if([
+      : built(true)])[
+    {
+      new (buffer) T(t);
+    }
+
     /// Accessor to a built \a T.
     template <typename T>
     inline T&
@@ -340,7 +496,7 @@ dnl FIXME: This is wrong, we want computed header guards.
 ]])[
 ]b4_namespace_close[
 
-#include "location.hh"
+]b4_locations_if([#include "location.hh"])[
 
 /* Enabling traces.  */
 #ifndef YYDEBUG
@@ -360,7 +516,8 @@ dnl FIXME: This is wrong, we want computed header guards.
 # 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).  */
 
@@ -377,7 +534,7 @@ do {                                                            \
       (Current).begin = (Current).end = (Rhs)[0].location.end; \
     }                                                           \
 } while (false)
-#endif
+#endif]])[
 
 ]b4_namespace_open[
 
@@ -389,8 +546,7 @@ do {                                                            \
 ]b4_variant_if(
 [    /// An auxiliary type to compute the largest semantic type.
     union union_type
-    {]m4_map([b4_char_sizeof], m4_defn([b4_symbol_numbers]))[
-    };
+    {]m4_map([b4_char_sizeof], m4_defn([b4_type_names]))[};
 
     /// Symbol semantic values.
     typedef variant<sizeof(union_type)> semantic_type;],
@@ -404,9 +560,9 @@ m4_ifdef([b4_stype],
 [[    typedef YYSTYPE semantic_type;]])])])[
 #else
     typedef YYSTYPE semantic_type;
-#endif
+#endif]b4_locations_if([
     /// Symbol locations.
-    typedef ]b4_percent_define_get([[location_type]])[ location_type;
+    typedef b4_percent_define_get([[location_type]]) location_type;])[
     /// Tokens.
     struct token
     {
@@ -438,10 +594,10 @@ m4_ifdef([b4_stype],
 #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.
-    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);
 
     /// Generate an error message.
     /// \param state   the state where the error occurred.
@@ -487,12 +643,10 @@ m4_ifdef([b4_stype],
 #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.
-    virtual std::string yytnamerr_ (const char *n);
-#endif
+    static std::string yytnamerr_ (const char *n);])[
 
 #if YYDEBUG
     /// For each rule, its source line number.
@@ -510,7 +664,7 @@ m4_ifdef([b4_stype],
 #endif
 
     /// Convert a scanner token number \a t to a symbol number.
-    static inline token_number_type yytranslate_ (int t);
+    static token_number_type yytranslate_ (]b4_lex_symbol_if([token_type], [int])[ t);
 
     /// A complete symbol, with its type.
     template <typename Exact>
@@ -519,8 +673,11 @@ m4_ifdef([b4_stype],
       /// Default constructor.
       inline symbol_base_type ();
 
-      /// Constructor.
-      inline symbol_base_type (const semantic_type& v, const location_type& l);
+      /// Constructor.]b4_locations_if([
+      inline symbol_base_type (const location_type& l)])[;
+      inline symbol_base_type (]b4_args(
+        [const semantic_type& v],
+        b4_locations_if([const location_type& l]))[);
 
       /// Return this with its exact type.
       const Exact& self () const;
@@ -530,10 +687,10 @@ m4_ifdef([b4_stype],
       int type_get () const;
 
       /// The semantic value.
-      semantic_type value;
+      semantic_type value;]b4_locations_if([
 
       /// The location.
-      location_type location;
+      location_type location;])[
     };
 
 #if YYDEBUG
@@ -553,6 +710,7 @@ m4_ifdef([b4_stype],
     inline void yy_destroy_ (const char* yymsg,
                              symbol_base_type<Exact>& yysym) const;
 
+  public:
     /// Element of the stack: a state and its attributes.
     struct symbol_type : symbol_base_type<symbol_type>
     {
@@ -563,8 +721,12 @@ m4_ifdef([b4_stype],
       inline symbol_type ();
 
       /// Constructor.
-      inline symbol_type (int t,
-                          const semantic_type& v, const location_type& l);
+      inline symbol_type (]b4_args([int t],
+                                   [const semantic_type& v],
+                                   b4_locations_if([const location_type& l]))[);
+
+      inline symbol_type (]b4_args([int t],
+                                   b4_locations_if([const location_type& l]))[);
 
       /// The symbol type.
       int type;
@@ -573,6 +735,9 @@ m4_ifdef([b4_stype],
       inline int type_get_ () const;
     };
 
+]b4_symbol_constructor_declarations[
+
+  private:
     /// Element of the stack: a state and its attributes.
     struct stack_symbol_type : symbol_base_type<stack_symbol_type>
     {
@@ -583,8 +748,9 @@ m4_ifdef([b4_stype],
       inline stack_symbol_type ();
 
       /// Constructor.
-      inline stack_symbol_type (state_type s,
-                                const semantic_type& v, const location_type& l);
+      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;
@@ -632,7 +798,7 @@ m4_ifdef([b4_stype],
 
 ]b4_parse_param_vars[
   };
-
+]b4_symbol_constructor_specializations[
 ]b4_namespace_close[
 
 ]b4_percent_define_flag_if([[global_tokens_and_yystype]],
@@ -646,7 +812,6 @@ m4_ifdef([b4_stype],
 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++])
 b4_percent_code_get([[top]])[]dnl
@@ -656,10 +821,9 @@ m4_if(b4_prefix, [yy], [],
 #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
@@ -717,16 +881,15 @@ b4_percent_code_get[]dnl
 
 #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_)
 
-]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
@@ -764,8 +927,7 @@ b4_percent_code_get[]dnl
 
     return yystr;
   }
-
-#endif
+]])[
 
   /// Build a parser object.
   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
@@ -789,16 +951,25 @@ b4_percent_code_get[]dnl
   // symbol_base_type.
   template <typename Exact>
   ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type ()
-    : value()
-    , location()
+    : value()]b4_locations_if([
+    , location()])[
   {
-  }
+  }]b4_locations_if([[
 
   template <typename Exact>
-  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (const semantic_type& v, const location_type& l)
-    : value(v)
+  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (const location_type& l)
+    : value()
     , location(l)
   {
+  }]])[
+
+  template <typename Exact>
+  ]b4_parser_class_name[::symbol_base_type<Exact>::symbol_base_type (]b4_args(
+          [const semantic_type& v],
+          b4_locations_if([const location_type& l]))[)
+    : value(v)]b4_locations_if([
+    , location(l)])[
+  {
   }
 
   template <typename Exact>
@@ -829,9 +1000,19 @@ b4_percent_code_get[]dnl
   {
   }
 
-  ]b4_parser_class_name[::symbol_type::symbol_type (int t,
-                           const semantic_type& v, const location_type& l)
-    : super_type (v, l)
+  ]b4_parser_class_name[::symbol_type::symbol_type (]b4_args(
+                [int t],
+                b4_locations_if([const location_type& l]))[)
+    : super_type (]b4_locations_if([l])[)
+    , type (t)
+  {
+  }
+
+  ]b4_parser_class_name[::symbol_type::symbol_type (]b4_args(
+                 [int t],
+                 [const semantic_type& v],
+                 b4_locations_if([const location_type& l]))[)
+    : super_type (v]b4_locations_if([, l])[)
     , type (t)
   {
   }
@@ -842,6 +1023,8 @@ b4_percent_code_get[]dnl
     return type;
   }
 
+]b4_symbol_constructor_definitions[
+
   // stack_symbol_type.
   ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type ()
     : super_type ()
@@ -849,9 +1032,11 @@ b4_percent_code_get[]dnl
   {
   }
 
-  ]b4_parser_class_name[::stack_symbol_type::stack_symbol_type (state_type s,
-                           const semantic_type& v, const location_type& l)
-    : super_type (v, l)
+  ]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)
   {
   }
@@ -893,8 +1078,8 @@ b4_percent_code_get[]dnl
   {
     int yytype = yysym.type_get ();
     yyo << (yytype < yyntokens_ ? "token" : "nterm")
-        << ' ' << yytname_[yytype] << " ("
-        << yysym.location << ": ";
+        << ' ' << yytname_[yytype] << " ("]b4_locations_if([
+        << yysym.location << ": "])[;
     switch (yytype)
       {
 ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))[
@@ -912,10 +1097,16 @@ b4_percent_code_get[]dnl
     if (m)
       YY_SYMBOL_PRINT (m, sym);
 ]b4_variant_if(
-[[    yystack_.push (stack_symbol_type (s, semantic_type(), sym.location));
+[[    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 (s, sym.value, sym.location));])[
+[[    yystack_.push (stack_symbol_type (]b4_args(
+                      [s],
+                      [sym.value],
+                      b4_locations_if([sym.location]))[));]])[
   }
 
   void
@@ -924,7 +1115,10 @@ b4_percent_code_get[]dnl
     if (m)
       YY_SYMBOL_PRINT (m, s);
 ]b4_variant_if(
-[[    yystack_.push (stack_symbol_type (s.state, semantic_type(), s.location));
+[[    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);])[
@@ -966,8 +1160,8 @@ b4_percent_code_get[]dnl
   int
   ]b4_parser_class_name[::parse ()
   {
-    /// Coded type of the lookahead.
-    int yychar = yyempty_;
+    /// Whether yyla contains a lookahead.
+    bool yyempty = true;
 
     /* State.  */
     int yyn;
@@ -979,10 +1173,10 @@ b4_percent_code_get[]dnl
     int yyerrstatus_ = 0;
 
     /// The lookahead symbol.
-    symbol_type yyla;
+    symbol_type yyla;]b4_locations_if([[
 
     /// The locations where the error started and ended.
-    stack_symbol_type yyerror_range[2];
+    stack_symbol_type yyerror_range[2];]])[
 
     /// $$ and @@$.
     stack_symbol_type yylhs;
@@ -1028,27 +1222,19 @@ m4_popdef([b4_at_dollar])])dnl
       goto yydefault;
 
     /* Read a lookahead token.  */
-    if (yychar == yyempty_)
+    if (yyempty)
       {
-       YYCDEBUG << "Reading a token: ";
-       yychar = ]b4_c_function_call([yylex], [int],
+        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))[;
-      }
-
-
-    /* Convert token to internal form.  */
-    if (yychar <= yyeof_)
-      {
-       yychar = yyla.type = yyeof_;
-       YYCDEBUG << "Now at end of input." << std::endl;
-      }
-    else
-      {
-       yyla.type = yytranslate_ (yychar);
-       YY_SYMBOL_PRINT ("Next token is", yyla);
+m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[
+        yyempty = false;
       }
+    YY_SYMBOL_PRINT ("Next token is", yyla);
 
     /* If the proper action on seeing token YYLA.TYPE is to reduce or
        to detect an error, take that action.  */
@@ -1067,7 +1253,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       }
 
     /* Discard the token being shifted.  */
-    yychar = yyempty_;
+    yyempty = true;
 
     /* Count tokens shifted since error; after three, turn off error
        status.  */
@@ -1107,12 +1293,13 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
       yylhs.value = yystack_@{yylen - 1@}.value;
     else
       yylhs.value = yystack_@{0@}.value;])[
-
+]b4_locations_if([dnl
+[
     // Compute the default @@$.
     {
       slice<stack_symbol_type, stack_type> slice (yystack_, yylen);
       YYLLOC_DEFAULT (yylhs.location, slice, yylen);
-    }
+    }]])[
 
     // Perform the reduction.
     YY_REDUCE_PRINT (yyn);
@@ -1161,25 +1348,24 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     if (!yyerrstatus_)
       {
        ++yynerrs_;
-       error (yyla.location, yysyntax_error_ (yystate, yyla.type));
+       error (]b4_args(b4_locations_if([yyla.location]),
+                        [yysyntax_error_ (yystate, yyla.type)])[);
       }
 
-    yyerror_range[0].location = yyla.location;
+]b4_locations_if([[
+    yyerror_range[0].location = yyla.location;]])[
     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
-         {
-           yy_destroy_ ("Error: discarding", yyla);
-           yychar = yyempty_;
+           error, discard it.  */
+
+        /* Return failure if at end of input.  */
+        if (yyla.type == yyeof_)
+          YYABORT;
+        else
+          {
+            yy_destroy_ ("Error: discarding", yyla);
+            yyempty = true;
          }
       }
 
@@ -1199,7 +1385,8 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     if (false)
       goto yyerrorlab;
 
-    yyerror_range[0].location = yystack_[yylen - 1].location;
+]b4_locations_if([[
+    yyerror_range[0].location = yystack_[yylen - 1].location;]])[
     /* Do not reclaim the symbols of the rule which action triggered
        this YYERROR.  */
     yypop_ (yylen);
@@ -1231,16 +1418,16 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
           // Pop the current state because it cannot handle the error token.
           if (yystack_.size () == 1)
             YYABORT;
-
-          yyerror_range[0].location = yystack_[0].location;
+]b4_locations_if([[
+          yyerror_range[0].location = yystack_[0].location;]])[
           yy_destroy_ ("Error: popping", yystack_[0]);
           yypop_ ();
           yystate = yystack_[0].state;
           YY_STACK_PRINT ();
         }
-
+]b4_locations_if([[
       yyerror_range[1].location = yyla.location;
-      YYLLOC_DEFAULT (error_token.location, (yyerror_range - 1), 2);
+      YYLLOC_DEFAULT (error_token.location, (yyerror_range - 1), 2);]])[
 
       /* Shift the error token.  */
       error_token.state = yystate = yyn;
@@ -1259,7 +1446,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
     goto yyreturn;
 
   yyreturn:
-    if (yychar != yyempty_)
+    if (!yyempty)
       yy_destroy_ ("Cleanup: discarding lookahead", yyla);
 
     /* Do not reclaim the symbols of the rule which action triggered
@@ -1276,12 +1463,11 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[;
 
   // Generate an error message.
   std::string
-  ]b4_parser_class_name[::yysyntax_error_ (int yystate, int]dnl
-b4_error_verbose_if([ tok])[)
+  ]b4_parser_class_name[::yysyntax_error_ (]dnl
+b4_error_verbose_if([int 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_)
       {
@@ -1292,36 +1478,55 @@ b4_error_verbose_if([ tok])[)
        /* 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 "expected" tokens.
+       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_)
+          {
+            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
-#endif
-      res = YY_("syntax error");
-    return res;
+  ]])dnl
+[    yyres = YY_("syntax error");
+    return yyres;
   }
 
 
@@ -1409,25 +1614,7 @@ b4_error_verbose_if([ tok])[)
   }
 #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[
-    };
-    const unsigned int user_token_number_max_ = ]b4_user_token_number_max[;
-    const token_number_type undef_token_ = ]b4_undef_token_number[;
-
-    if (static_cast<unsigned int> (t) <= user_token_number_max_)
-      return translate_table[t];
-    else
-      return undef_token_;
-  }
-
+]b4_yytranslate_definition[
 ]b4_namespace_close[
 
 ]b4_epilogue[]dnl