2004-11-23 Akim Demaille <akim@epita.fr>

[bison.git] / data / lalr1.cc

diff --git a/data/lalr1.cc b/data/lalr1.cc
index fdd8c2598b282ce9395aecab39234d08c18f4ee0..817b3833b333d35868508cb33b2624ad8ce4c640 100644 (file)
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -83,13 +83,22 @@ m4_define([b4_constructor],
 
 # b4_parse_param_decl
 # -------------------
 
 # b4_parse_param_decl
 # -------------------

-#  Constructor's extra arguments.
+# Extra formal arguments of the constructor.
+# Change the parameter names from "foo" into "foo_yyarg", so that
+# there is no collision bw the user chosen attribute name, and the
+# argument name in the constructor.

 m4_define([b4_parse_param_decl],
 m4_define([b4_parse_param_decl],

-          [m4_ifset([b4_parse_param], [, b4_c_ansi_formals(b4_parse_param)])])
+[m4_ifset([b4_parse_param],
+          [, m4_map_sep([b4_parse_param_decl_1], [, ], [b4_parse_param])])])
+
+m4_define([b4_parse_param_decl_1],
+[$1_yyarg])
+
+

 
 # b4_parse_param_cons
 # -------------------
 
 # b4_parse_param_cons
 # -------------------

-#  constructor's extra initialisations.
+# Extra initialisations of the constructor.

 m4_define([b4_parse_param_cons],
           [m4_ifset([b4_parse_param],
                    [,
 m4_define([b4_parse_param_cons],
           [m4_ifset([b4_parse_param],
                    [,


@@ -98,11 +107,11 @@ m4_define([b4_cc_constructor_calls],
          [m4_map_sep([b4_cc_constructor_call], [,
       ], [$@])])
 m4_define([b4_cc_constructor_call],
          [m4_map_sep([b4_cc_constructor_call], [,
       ], [$@])])
 m4_define([b4_cc_constructor_call],

-         [$2($2)])
+         [$2 ($2_yyarg)])

 
 # b4_parse_param_vars
 # -------------------
 
 # b4_parse_param_vars
 # -------------------

-#  Extra instance variables.
+# Extra instance variables.

 m4_define([b4_parse_param_vars],
           [m4_ifset([b4_parse_param],
                    [
 m4_define([b4_parse_param_vars],
           [m4_ifset([b4_parse_param],
                    [


@@ -114,13 +123,7 @@ m4_define([b4_cc_var_decls],
 m4_define([b4_cc_var_decl],
          [    $1;])
 
 m4_define([b4_cc_var_decl],
          [    $1;])
 

-# b4_cxx_destruct_def(IGNORED-ARGUMENTS)
-# --------------------------------------
-# Declare the destruct_ method.
-m4_define([b4_cxx_destruct_def],
-[void
-yy::b4_parser_class_name::destruct_ (int yytype, SemanticType *yyvaluep, LocationType *yylocationp)[]dnl
-])
+

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


@@ -161,14 +164,16 @@ b4_syncline([@oline@], [@ofile@])[
 # define YYERROR_VERBOSE ]b4_error_verbose[
 #endif
 
 # define YYERROR_VERBOSE ]b4_error_verbose[
 #endif
 

-#ifndef YYSTYPE
+#if ! defined (YYSTYPE) && ! defined (YYSTYPE_IS_DECLARED)

 ]m4_ifdef([b4_stype],
 [b4_syncline([b4_stype_line], [b4_filename])
 ]m4_ifdef([b4_stype],
 [b4_syncline([b4_stype_line], [b4_filename])

-typedef union b4_stype yystype;
+union YYSTYPE b4_stype;

 /* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])],
 /* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])],

-[typedef int yystype;])[
-# define YYSTYPE yystype
+[typedef int YYSTYPE;])[
+# define yystype YYSTYPE /* obsolescent; will be withdrawn */
+# define YYSTYPE_IS_DECLARED 1
+# define YYSTYPE_IS_TRIVIAL 1

 #endif
 
 /* Copy the second part of user declarations.  */
 #endif
 
 /* Copy the second part of user declarations.  */


@@ -176,27 +181,41 @@ b4_syncline([@oline@], [@ofile@])],
 
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[
 
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[

+/* 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
 #ifndef YYLLOC_DEFAULT

-# define YYLLOC_DEFAULT(Current, Rhs, N) \
-   ((Current).end = Rhs[N].end)
+# 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;  \
+    }                                                  \
+} while (0)

 #endif
 
 namespace yy
 {
   class ]b4_parser_class_name[;
 
 #endif
 
 namespace yy
 {
   class ]b4_parser_class_name[;
 

-  template < typename P >
+  template <typename P>

   struct Traits
   {
   };
 
   struct Traits
   {
   };
 

-  template < >
-  struct Traits< ]b4_parser_class_name[ >
+  template <>
+  struct Traits<]b4_parser_class_name[>

   {
     typedef ]b4_int_type_for([b4_translate])[ TokenNumberType;
     typedef ]b4_int_type_for([b4_rhs])[       RhsNumberType;
   {
     typedef ]b4_int_type_for([b4_translate])[ TokenNumberType;
     typedef ]b4_int_type_for([b4_rhs])[       RhsNumberType;

-    typedef int      StateType;
-    typedef yystype  SemanticType;
+    typedef int StateType;
+    typedef YYSTYPE SemanticType;

     typedef ]b4_location_type[ LocationType;
   };
 }
     typedef ]b4_location_type[ LocationType;
   };
 }


@@ -207,28 +226,31 @@ namespace yy
   {
   public:
 
   {
   public:
 

-    typedef Traits< ]b4_parser_class_name[ >::TokenNumberType TokenNumberType;
-    typedef Traits< ]b4_parser_class_name[ >::RhsNumberType   RhsNumberType;
-    typedef Traits< ]b4_parser_class_name[ >::StateType       StateType;
-    typedef Traits< ]b4_parser_class_name[ >::SemanticType    SemanticType;
-    typedef Traits< ]b4_parser_class_name[ >::LocationType    LocationType;
+    typedef Traits<]b4_parser_class_name[>::TokenNumberType TokenNumberType;
+    typedef Traits<]b4_parser_class_name[>::RhsNumberType   RhsNumberType;
+    typedef Traits<]b4_parser_class_name[>::StateType       StateType;
+    typedef Traits<]b4_parser_class_name[>::SemanticType    SemanticType;
+    typedef Traits<]b4_parser_class_name[>::LocationType    LocationType;

 
 

-    typedef Stack< StateType >    StateStack;
-    typedef Stack< SemanticType > SemanticStack;
-    typedef Stack< LocationType > LocationStack;
+    typedef Stack<StateType>    StateStack;
+    typedef Stack<SemanticType> SemanticStack;
+    typedef Stack<LocationType> LocationStack;

 
 

-#if YYLSP_NEEDED
-    ]b4_parser_class_name[ (bool debug,
-           LocationType initlocation][]b4_param[]b4_parse_param_decl[) :
-      ]b4_constructor[][debug_ (debug),
-      cdebug_ (std::cerr),
-      initlocation_ (initlocation)]b4_parse_param_cons[
-#else

     ]b4_parser_class_name[ (bool debug][]b4_param[]b4_parse_param_decl[) :
       ]b4_constructor[][debug_ (debug),
     ]b4_parser_class_name[ (bool debug][]b4_param[]b4_parse_param_decl[) :
       ]b4_constructor[][debug_ (debug),

-      cdebug_ (std::cerr)]b4_parse_param_cons[
-#endif
+      yycdebug_ (&std::cerr)]b4_parse_param_cons[
+    {
+    }
+
+    ]b4_parser_class_name[ (bool debug,
+           LocationType][]b4_param[]b4_parse_param_decl[) :
+      ]b4_constructor[][debug_ (debug),
+      yycdebug_ (&std::cerr)]b4_parse_param_cons[

     {
     {

+      *yycdebug_ << __FILE__ << ':' << __LINE__
+                << ": this constructor is provided by backward compatibility"
+                << ", but will be removed in the near future."
+                << std::endl;

     }
 
     virtual ~]b4_parser_class_name[ ()
     }
 
     virtual ~]b4_parser_class_name[ ()


@@ -237,12 +259,22 @@ namespace yy
 
     virtual int parse ();
 
 
     virtual int parse ();
 

+    /// Return the current debugging stream.
+    std::ostream& debug_stream () const;
+    /// Set the current debugging stream.
+    void set_debug_stream (std::ostream &);
+

   private:
 
     virtual void lex_ ();
     virtual void error_ ();
   private:
 
     virtual void lex_ ();
     virtual void error_ ();

-    virtual void print_ ();

     virtual void report_syntax_error_ ();
     virtual void report_syntax_error_ ();

+#if YYDEBUG
+    virtual void symprint_ (int yytype,
+                           const SemanticType* yyvaluep,
+                           const LocationType* yylocationp);
+#endif /* ! YYDEBUG */
+

 
     /* Stacks.  */
     StateStack    state_stack_;
 
     /* Stacks.  */
     StateStack    state_stack_;


@@ -277,9 +309,13 @@ namespace yy
 #endif
 
     /* Even more tables.  */
 #endif
 
     /* Even more tables.  */

-    static inline TokenNumberType translate_ (int token);
-    static inline void destruct_ (int yytype, SemanticType *yyvaluep,
-                                 LocationType *yylocationp);
+    inline TokenNumberType translate_ (int token);
+    inline void destruct_ (const char* yymsg,
+                           int yytype,
+                           SemanticType* yyvaluep, LocationType* yylocationp);
+
+    /// Pop \a n symbols the three stacks.
+    inline void pop (unsigned int n = 1);

 
     /* Constants.  */
     static const int eof_;
 
     /* Constants.  */
     static const int eof_;


@@ -305,7 +341,7 @@ namespace yy
 
     /* Debugging.  */
     int debug_;
 
     /* Debugging.  */
     int debug_;

-    std::ostream &cdebug_;
+    std::ostream* yycdebug_;

 
     /* Look-ahead and look-ahead in internal form.  */
     int looka_;
 
     /* Look-ahead and look-ahead in internal form.  */
     int looka_;


@@ -314,18 +350,17 @@ namespace yy
     /* Message.  */
     std::string message;
 
     /* Message.  */
     std::string message;
 

-    /* Semantic value and location of look-ahead token.  */
+    /// Semantic value of the look-ahead.

     SemanticType value;
     SemanticType value;

+    /// Location of the look-ahead.

     LocationType location;
     LocationType location;

-    /* Beginning of the last erroneous token popped off.  */
-    Position error_start_;
+    /// The locations where the error started and ended.
+    Location error_range_[2];

 
 

-    /* @@$ and $$.  */
+    /// $$.

     SemanticType yyval;
     SemanticType yyval;

+    /// @@$.

     LocationType yyloc;
     LocationType yyloc;

-
-    /* Initial location.  */
-    LocationType initlocation_;

 ]b4_parse_param_vars[
   };
 }
 ]b4_parse_param_vars[
   };
 }


@@ -338,61 +373,156 @@ b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
 
 m4_if(b4_defines_flag, 0, [], [#include @output_header_name@])[
 
 
 m4_if(b4_defines_flag, 0, [], [#include @output_header_name@])[
 

+/* A pseudo ostream that takes debug_ into account. */
+# define YYCDEBUG                                                      \
+  for (bool yydebugcond_ = debug_; yydebugcond_; yydebugcond_ = false) \
+    (*yycdebug_)
+

 /* Enable debugging if requested.  */
 #if YYDEBUG
 /* Enable debugging if requested.  */
 #if YYDEBUG

-# define YYCDEBUG    if (debug_) cdebug_
+
+# define YY_SYMBOL_PRINT(Title, Type, Value, Location) \
+do {                                                   \
+  if (debug_)                                          \
+    {                                                  \
+      *yycdebug_ << (Title) << ' ';                    \
+      symprint_ ((Type), (Value), (Location));         \
+      *yycdebug_ << std::endl;                         \
+    }                                                  \
+} while (0)
+

 # define YY_REDUCE_PRINT(Rule)         \
 do {                                   \
   if (debug_)                          \
     reduce_print_ (Rule);              \
 } while (0)
 # define YY_REDUCE_PRINT(Rule)         \
 do {                                   \
   if (debug_)                          \
     reduce_print_ (Rule);              \
 } while (0)

+

 # define YY_STACK_PRINT()              \
 do {                                   \
   if (debug_)                          \
     stack_print_ ();                   \
 } while (0)
 # define YY_STACK_PRINT()              \
 do {                                   \
   if (debug_)                          \
     stack_print_ ();                   \
 } while (0)

+

 #else /* !YYDEBUG */
 #else /* !YYDEBUG */

-# define YYCDEBUG    if (0) cdebug_
+
+# define YY_SYMBOL_PRINT(Title, Type, Value, Location)

 # define YY_REDUCE_PRINT(Rule)
 # define YY_STACK_PRINT()
 # define YY_REDUCE_PRINT(Rule)
 # define YY_STACK_PRINT()

+

 #endif /* !YYDEBUG */
 
 #define YYACCEPT       goto yyacceptlab
 #define YYABORT                goto yyabortlab
 #define YYERROR                goto yyerrorlab
 
 #endif /* !YYDEBUG */
 
 #define YYACCEPT       goto yyacceptlab
 #define YYABORT                goto yyabortlab
 #define YYERROR                goto yyerrorlab
 

-]b4_yydestruct_generate([b4_cxx_destruct_def])[
+#if YYDEBUG
+/*--------------------------------.
+| Print this symbol on YYOUTPUT.  |
+`--------------------------------*/
+
+void
+yy::]b4_parser_class_name[::symprint_ (int yytype,
+                         const SemanticType* yyvaluep, const LocationType* yylocationp)
+{
+  /* Pacify ``unused variable'' warnings.  */
+  (void) yyvaluep;
+  (void) yylocationp;
+  /* Backward compatibility, but should be removed eventually. */
+  std::ostream& cdebug_ = *yycdebug_;
+  (void) cdebug_;
+
+  *yycdebug_ << (yytype < ntokens_ ? "token" : "nterm")
+            << ' ' << name_[yytype] << " ("
+             << *yylocationp << ": ";
+  switch (yytype)
+    {
+]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
+[      default:
+        break;
+    }
+  *yycdebug_ << ')';
+}
+#endif /* ! YYDEBUG */
+
+void
+yy::]b4_parser_class_name[::destruct_ (const char* yymsg,
+                         int yytype, SemanticType* yyvaluep, LocationType* yylocationp)
+{
+  /* Pacify ``unused variable'' warnings.  */
+  (void) yyvaluep;
+  (void) yylocationp;
+
+  YY_SYMBOL_PRINT (yymsg, yytype, yyvaluep, yylocationp);
+
+  switch (yytype)
+    {
+]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[
+      default:
+        break;
+    }
+}
+
+void
+yy::]b4_parser_class_name[::pop (unsigned int n)
+{
+  state_stack_.pop (n);
+  semantic_stack_.pop (n);
+  location_stack_.pop (n);
+}
+
+std::ostream&
+yy::]b4_parser_class_name[::debug_stream () const
+{
+  return *yycdebug_;
+}
+
+void
+yy::]b4_parser_class_name[::set_debug_stream (std::ostream& o)
+{
+  yycdebug_ = &o;
+}
+

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

+  YYCDEBUG << "Starting parse" << std::endl;
+

   nerrs_ = 0;
   errstatus_ = 0;
 
   nerrs_ = 0;
   errstatus_ = 0;
 

-  /* Initialize the stacks.  The initial state will be pushed in
+  /* Start.  */
+  state_ = 0;
+  looka_ = empty_;
+
+]m4_ifdef([b4_initial_action], [
+m4_pushdef([b4_at_dollar],     [location])dnl
+m4_pushdef([b4_dollar_dollar], [value])dnl
+  /* User initialization code. */
+  b4_initial_action
+m4_popdef([b4_dollar_dollar])dnl
+m4_popdef([b4_at_dollar])dnl
+/* Line __line__ of yacc.c.  */
+b4_syncline([@oline@], [@ofile@])])dnl
+
+[  /* Initialize the stacks.  The initial state will be pushed in

      yynewstate, since the latter expects the semantical and the
      location values to have been already stored, initialize these
      stacks with a primary value.  */
   state_stack_ = StateStack (0);
      yynewstate, since the latter expects the semantical and the
      location values to have been already stored, initialize these
      stacks with a primary value.  */
   state_stack_ = StateStack (0);

-  semantic_stack_ = SemanticStack (1);
-  location_stack_ = LocationStack (1);
-
-  /* Start.  */
-  state_ = 0;
-  looka_ = empty_;
-#if YYLSP_NEEDED
-  location = initlocation_;
-#endif
-  YYCDEBUG << "Starting parse" << std::endl;
+  semantic_stack_ = SemanticStack (0);
+  location_stack_ = LocationStack (0);
+  semantic_stack_.push (value);
+  location_stack_.push (location);

 
   /* New state.  */
 
   /* New state.  */

- yynewstate:
+yynewstate:

   state_stack_.push (state_);
   YYCDEBUG << "Entering state " << state_ << std::endl;
   goto yybackup;
 
   /* Backup.  */
   state_stack_.push (state_);
   YYCDEBUG << "Entering state " << state_ << std::endl;
   goto yybackup;
 
   /* Backup.  */

- yybackup:
+yybackup:

 
   /* Try to take a decision without look-ahead.  */
   n_ = pact_[state_];
 
   /* Try to take a decision without look-ahead.  */
   n_ = pact_[state_];


@@ -407,27 +537,18 @@ yy::]b4_parser_class_name[::parse ()
     }
 
   /* Convert token to internal form.  */
     }
 
   /* Convert token to internal form.  */

-  if (looka_ <= 0)
+  if (looka_ <= eof_)

     {
     {

-      looka_ = eof_;
-      ilooka_ = 0;
+      looka_ = ilooka_ = eof_;

       YYCDEBUG << "Now at end of input." << std::endl;
     }
   else
     {
       ilooka_ = translate_ (looka_);
       YYCDEBUG << "Now at end of input." << std::endl;
     }
   else
     {
       ilooka_ = translate_ (looka_);

-#if YYDEBUG
-      if (debug_)
-       {
-         YYCDEBUG << "Next token is " << looka_
-                << " (" << name_[ilooka_];
-         print_ ();
-         YYCDEBUG << ')' << std::endl;
-       }
-#endif
+      YY_SYMBOL_PRINT ("Next token is", ilooka_, &value, &location);

     }
 
     }
 

-  /* If the proper action on seeing token YYTOKEN is to reduce or to
+  /* If the proper action on seeing token ILOOKA_ is to reduce or to

      detect an error, take that action.  */
   n_ += ilooka_;
   if (n_ < 0 || last_ < n_ || check_[n_] != ilooka_)
      detect an error, take that action.  */
   n_ += ilooka_;
   if (n_ < 0 || last_ < n_ || check_[n_] != ilooka_)


@@ -453,10 +574,7 @@ yy::]b4_parser_class_name[::parse ()
     goto yyacceptlab;
 
   /* Shift the look-ahead token.  */
     goto yyacceptlab;
 
   /* Shift the look-ahead token.  */

-#if YYDEBUG
-  YYCDEBUG << "Shifting token " << looka_
-           << " (" << name_[ilooka_] << "), ";
-#endif
+  YY_SYMBOL_PRINT ("Shifting", ilooka_, &value, &location);

 
   /* Discard the token being shifted unless it is eof.  */
   if (looka_ != eof_)
 
   /* Discard the token being shifted unless it is eof.  */
   if (looka_ != eof_)


@@ -476,7 +594,7 @@ yy::]b4_parser_class_name[::parse ()
 /*-----------------------------------------------------------.
 | yydefault -- do the default action for the current state.  |
 `-----------------------------------------------------------*/
 /*-----------------------------------------------------------.
 | yydefault -- do the default action for the current state.  |
 `-----------------------------------------------------------*/

- yydefault:
+yydefault:

   n_ = defact_[state_];
   if (n_ == 0)
     goto yyerrlab;
   n_ = defact_[state_];
   if (n_ == 0)
     goto yyerrlab;


@@ -485,7 +603,7 @@ yy::]b4_parser_class_name[::parse ()
 /*-----------------------------.
 | yyreduce -- Do a reduction.  |
 `-----------------------------*/
 /*-----------------------------.
 | yyreduce -- Do a reduction.  |
 `-----------------------------*/

- yyreduce:
+yyreduce:

   len_ = r2_[n_];
   /* If LEN_ is nonzero, implement the default value of the action:
      `$$ = $1'.  Otherwise, use the top of the stack.
   len_ = r2_[n_];
   /* If LEN_ is nonzero, implement the default value of the action:
      `$$ = $1'.  Otherwise, use the top of the stack.


@@ -494,21 +612,14 @@ yy::]b4_parser_class_name[::parse ()
      This behavior is undocumented and Bison
      users should not rely upon it.  */
   if (len_)
      This behavior is undocumented and Bison
      users should not rely upon it.  */
   if (len_)

-    {
-      yyval = semantic_stack_[len_ - 1];
-      yyloc = location_stack_[len_ - 1];
-    }
+    yyval = semantic_stack_[len_ - 1];

   else
   else

-    {
-      yyval = semantic_stack_[0];
-      yyloc = location_stack_[0];
-    }
+    yyval = semantic_stack_[0];

 
 

-  if (len_)
-    {
-      Slice< LocationType, LocationStack > slice (location_stack_, len_);
-      YYLLOC_DEFAULT (yyloc, slice, len_);
-    }
+  {
+    Slice<LocationType, LocationStack> slice (location_stack_, len_);
+    YYLLOC_DEFAULT (yyloc, slice, len_);
+  }

   YY_REDUCE_PRINT (n_);
   switch (n_)
     {
   YY_REDUCE_PRINT (n_);
   switch (n_)
     {


@@ -518,9 +629,7 @@ yy::]b4_parser_class_name[::parse ()
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[
 
 ]/* Line __line__ of lalr1.cc.  */
 b4_syncline([@oline@], [@ofile@])[
 

-  state_stack_.pop (len_);
-  semantic_stack_.pop (len_);
-  location_stack_.pop (len_);
+  pop (len_);

 
   YY_STACK_PRINT ();
 
 
   YY_STACK_PRINT ();
 


@@ -539,11 +648,11 @@ b4_syncline([@oline@], [@ofile@])[
 /*------------------------------------.
 | yyerrlab -- here on detecting error |
 `------------------------------------*/
 /*------------------------------------.
 | yyerrlab -- here on detecting error |
 `------------------------------------*/

- yyerrlab:
+yyerrlab:

   /* If not already recovering from an error, report this error.  */
   report_syntax_error_ ();
 
   /* If not already recovering from an error, report this error.  */
   report_syntax_error_ ();
 

-  error_start_ = location.begin;
+  error_range_[0] = location;

   if (errstatus_ == 3)
     {
       /* If just tried and failed to reuse look-ahead token after an
   if (errstatus_ == 3)
     {
       /* If just tried and failed to reuse look-ahead token after an


@@ -557,25 +666,19 @@ b4_syncline([@oline@], [@ofile@])[
          if (looka_ == eof_)
             for (;;)
               {
          if (looka_ == eof_)
             for (;;)
               {

-                 error_start_ = location_stack_[0].begin;
-                 state_stack_.pop ();
-                 semantic_stack_.pop ();
-                 location_stack_.pop ();
+                 error_range_[0] = location_stack_[0];
+                 pop ();

                 if (state_stack_.height () == 1)
                   YYABORT;
                 if (state_stack_.height () == 1)
                   YYABORT;

-//              YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
-                 destruct_ (stos_[state_stack_[0]],
+                 destruct_ ("Error: popping",
+                            stos_[state_stack_[0]],

                             &semantic_stack_[0],
                             &location_stack_[0]);
               }
         }
       else
         {
                             &semantic_stack_[0],
                             &location_stack_[0]);
               }
         }
       else
         {

-#if YYDEBUG
-          YYCDEBUG << "Discarding token " << looka_
-                  << " (" << name_[ilooka_] << ")." << std::endl;
-#endif
-          destruct_ (ilooka_, &value, &location);
+          destruct_ ("Error: discarding", ilooka_, &value, &location);

           looka_ = empty_;
         }
     }
           looka_ = empty_;
         }
     }


@@ -597,10 +700,8 @@ yyerrorlab:
      goto yyerrorlab;
 #endif
 
      goto yyerrorlab;
 #endif
 

-  state_stack_.pop (len_);
-  semantic_stack_.pop (len_);
-  error_start_ = location_stack_[len_ - 1].begin;
-  location_stack_.pop (len_);
+  error_range_[0] = location_stack_[len_ - 1];
+  pop (len_);

   state_ = state_stack_[0];
   goto yyerrlab1;
 
   state_ = state_stack_[0];
   goto yyerrlab1;
 


@@ -628,33 +729,10 @@ yyerrlab1:
       if (state_stack_.height () == 1)
        YYABORT;
 
       if (state_stack_.height () == 1)
        YYABORT;
 

-#if YYDEBUG
-      if (debug_)
-       {
-         if (stos_[state_] < ntokens_)
-           {
-             YYCDEBUG << "Error: popping token "
-                    << token_number_[stos_[state_]]
-                    << " (" << name_[stos_[state_]];
-# ifdef YYPRINT
-             YYPRINT (stderr, token_number_[stos_[state_]],
-                      semantic_stack_.top ());
-# endif
-             YYCDEBUG << ')' << std::endl;
-           }
-         else
-           {
-             YYCDEBUG << "Error: popping nonterminal ("
-                    << name_[stos_[state_]] << ')' << std::endl;
-           }
-       }
-#endif
-      destruct_ (stos_[state_], &semantic_stack_[0], &location_stack_[0]);
-      error_start_ = location_stack_[0].begin;
-
-      state_stack_.pop ();
-      semantic_stack_.pop ();
-      location_stack_.pop ();
+      error_range_[0] = location_stack_[0];
+      destruct_ ("Error: popping",
+                 stos_[state_], &semantic_stack_[0], &location_stack_[0]);
+      pop ();

       state_ = state_stack_[0];
       YY_STACK_PRINT ();
     }
       state_ = state_stack_[0];
       YY_STACK_PRINT ();
     }


@@ -662,25 +740,29 @@ yyerrlab1:
   if (n_ == final_)
     goto yyacceptlab;
 
   if (n_ == final_)
     goto yyacceptlab;
 

-  YYCDEBUG << "Shifting error token, ";
+  error_range_[1] = location;
+  // Using LOCATION is tempting, but would change the location of
+  // the look-ahead.  YYLOC is available though.
+  YYLLOC_DEFAULT (yyloc, error_range_ - 1, 2);
+  semantic_stack_.push (value);
+  location_stack_.push (yyloc);

 
 

-  {
-    Location errloc;
-    errloc.begin = error_start_;
-    errloc.end = location.end;
-    semantic_stack_.push (value);
-    location_stack_.push (errloc);
-  }
+  /* Shift the error token. */
+  YY_SYMBOL_PRINT ("Shifting", stos_[n_],
+                  &semantic_stack_[0], &location_stack_[0]);

 
   state_ = n_;
   goto yynewstate;
 
   /* Accept.  */
 
   state_ = n_;
   goto yynewstate;
 
   /* Accept.  */

- yyacceptlab:
+yyacceptlab:

   return 0;
 
   /* Abort.  */
   return 0;
 
   /* Abort.  */

- yyabortlab:
+yyabortlab:
+  /* Free the lookahead. */
+  destruct_ ("Error: discarding lookahead", ilooka_, &value, &location);
+  looka_ = empty_;

   return 1;
 }
 
   return 1;
 }
 


@@ -817,7 +899,7 @@ yy::]b4_parser_class_name[::r2_[] =
 
 #if YYDEBUG || YYERROR_VERBOSE
 /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
 
 #if YYDEBUG || YYERROR_VERBOSE
 /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.

-   First, the terminals, then, starting at YYNTOKENS, nonterminals. */
+   First, the terminals, then, starting at NTOKENS_, nonterminals. */

 const char*
 const yy::]b4_parser_class_name[::name_[] =
 {
 const char*
 const yy::]b4_parser_class_name[::name_[] =
 {


@@ -853,11 +935,11 @@ yy::]b4_parser_class_name[::rline_[] =
 void
 yy::]b4_parser_class_name[::stack_print_ ()
 {
 void
 yy::]b4_parser_class_name[::stack_print_ ()
 {

-  cdebug_ << "state stack now";
-  for (StateStack::ConstIterator i = state_stack_.begin ();
+  *yycdebug_ << "Stack now";
+  for (StateStack::const_iterator i = state_stack_.begin ();

        i != state_stack_.end (); ++i)
        i != state_stack_.end (); ++i)

-    cdebug_ << ' ' << *i;
-  cdebug_ << std::endl;
+    *yycdebug_ << ' ' << *i;
+  *yycdebug_ << std::endl;

 }
 
 /** Report that the YYRULE is going to be reduced.  */
 }
 
 /** Report that the YYRULE is going to be reduced.  */


@@ -867,11 +949,12 @@ yy::]b4_parser_class_name[::reduce_print_ (int yyrule)
 {
   unsigned int yylno = rline_[yyrule];
   /* Print the symbols being reduced, and their result.  */
 {
   unsigned int yylno = rline_[yyrule];
   /* Print the symbols being reduced, and their result.  */

-  cdebug_ << "Reducing via rule " << n_ - 1 << " (line " << yylno << "), ";
+    *yycdebug_ << "Reducing stack by rule " << n_ - 1
+               << " (line " << yylno << "), ";

   for (]b4_int_type_for([b4_prhs])[ i = prhs_[n_];
        0 <= rhs_[i]; ++i)
   for (]b4_int_type_for([b4_prhs])[ i = prhs_[n_];
        0 <= rhs_[i]; ++i)

-    cdebug_ << name_[rhs_[i]] << ' ';
-  cdebug_ << "-> " << name_[r1_[n_]] << std::endl;
+    *yycdebug_ << name_[rhs_[i]] << ' ';
+  *yycdebug_ << "-> " << name_[r1_[n_]] << std::endl;

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


@@ -915,13 +998,14 @@ b4_copyright([Stack handling for Bison C++ parsers], [2002, 2003, 2004])[
 
 namespace yy
 {
 
 namespace yy
 {

-  template < class T, class S = std::deque< T > >
+  template <class T, class S = std::deque<T> >

   class Stack
   {
   public:
 
   class Stack
   {
   public:
 

-    typedef typename S::iterator Iterator;
-    typedef typename S::const_iterator ConstIterator;
+    // Hide our reversed order.
+    typedef typename S::reverse_iterator iterator;
+    typedef typename S::const_reverse_iterator const_iterator;

 
     Stack () : seq_ ()
     {
 
     Stack () : seq_ ()
     {


@@ -967,15 +1051,15 @@ namespace yy
       return seq_.size ();
     }
 
       return seq_.size ();
     }
 

-    inline ConstIterator begin () const { return seq_.begin (); }
-    inline ConstIterator end () const { return seq_.end (); }
+    inline const_iterator begin () const { return seq_.rbegin (); }
+    inline const_iterator end () const { return seq_.rend (); }

 
   private:
 
     S seq_;
   };
 
 
   private:
 
     S seq_;
   };
 

-  template < class T, class S = Stack< T > >
+  template <class T, class S = Stack<T> >

   class Slice
   {
   public:
   class Slice
   {
   public:


@@ -1195,7 +1279,7 @@ namespace yy
   }
 
   /** \brief Add and assign a Location */
   }
 
   /** \brief Add and assign a Location */

-  inline Location &operator+= (Location& res, unsigned int width)
+  inline Location& operator+= (Location& res, unsigned int width)

   {
     res.columns (width);
     return res;
   {
     res.columns (width);
     return res;