]> git.saurik.com Git - bison.git/blobdiff - data/lalr1.cc
Have lalr1.cc catch with Paul Eggert's patch to fix the infinite
[bison.git] / data / lalr1.cc
index 96325b0bd014a2e831089f336f493d715d527c0c..1d7b24318d00a96430750ec97153b153ac1ed87b 100644 (file)
@@ -1,6 +1,6 @@
 m4_divert(-1)
 # C++ skeleton for Bison
-# Copyright (C) 2002 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -17,15 +17,10 @@ m4_divert(-1)
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 # 02111-1307  USA
 
-m4_include([c.m4])
-
 ## ---------------- ##
 ## Default values.  ##
 ## ---------------- ##
 
-# Stack parameters.
-m4_define_default([b4_stack_depth_init],  [200])
-
 # Default Parser class name.
 m4_define_default([b4_parser_class_name], [Parser])
 
@@ -48,7 +43,7 @@ m4_define([b4_lhs_value],
 # Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
 # symbols on RHS.
 m4_define([b4_rhs_value],
-[semantic_stack_@<:@m4_eval([$1 - $2])@:>@m4_ifval([$3], [.$3])])
+[semantic_stack_@{m4_eval([$1 - $2])@}m4_ifval([$3], [.$3])])
 
 m4_define_default([b4_location_type], [Location])
 
@@ -64,28 +59,9 @@ m4_define([b4_lhs_location],
 # Expansion of @NUM, where the current rule has RULE-LENGTH symbols
 # on RHS.
 m4_define([b4_rhs_location],
-[location_stack_@<:@m4_eval([$1 - $2])@:>@])
-
-
-m4_define_default([b4_input_suffix], [.y])
-
-m4_define_default([b4_output_parser_suffix],
-[m4_translit(b4_input_suffix, [yY], [cC])])
-
-m4_define_default([b4_output_parser_name],
-[b4_output_prefix[]b4_output_infix[]b4_output_parser_suffix[]])
+[location_stack_@{m4_eval([$1 - $2])@}])
 
 
-m4_define_default([b4_output_header_suffix],
-[m4_translit(b4_input_suffix, [yY], [hH])])
-
-m4_define_default([b4_output_header_name],
-[b4_output_prefix[]b4_output_infix[]b4_output_header_suffix[]])
-
-m4_define_default([b4_header_guard],
-                  [m4_bpatsubst(m4_toupper([BISON_]b4_output_header_name),
-                                [[^ABCDEFGHIJKLMNOPQRSTUVWXYZ]], [_])])
-
 m4_define([b4_inherit],
           [m4_ifdef([b4_root],
                    [: public b4_root
@@ -105,12 +81,50 @@ m4_define([b4_constructor],
                    [])])
 
 
+# b4_parse_param_decl
+# -------------------
+#  Constructor's extra arguments.
+m4_define([b4_parse_param_decl],
+          [m4_ifset([b4_parse_param], [, b4_c_ansi_formals(b4_parse_param)])])
+
+# b4_parse_param_cons
+# -------------------
+#  constructor's extra initialisations.
+m4_define([b4_parse_param_cons],
+          [m4_ifset([b4_parse_param],
+                   [,
+      b4_cc_constructor_calls(b4_parse_param)])])
+m4_define([b4_cc_constructor_calls],
+         [m4_map_sep([b4_cc_constructor_call], [,
+      ], [$@])])
+m4_define([b4_cc_constructor_call],
+         [$2($2)])
+
+# b4_parse_param_vars
+# -------------------
+#  Extra instance variables.
+m4_define([b4_parse_param_vars],
+          [m4_ifset([b4_parse_param],
+                   [
+    /* User arguments.  */
+b4_cc_var_decls(b4_parse_param)])])
+m4_define([b4_cc_var_decls],
+         [m4_map_sep([b4_cc_var_decl], [
+], [$@])])
+m4_define([b4_cc_var_decl],
+         [    $1;])
+
+# We do want M4 expansion after # for CPP macros.
+m4_changecom()
 m4_divert(0)dnl
-#output "b4_output_header_name"
+m4_if(b4_defines_flag, 0, [],
+[@output @output_header_name@
 b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
-             [2002])
-#ifndef b4_header_guard
-# define b4_header_guard
+             [2002, 2003])[
+/* FIXME: This is wrong, we want computed header guards.
+   I don't know why the macros are missing now. :( */
+#ifndef PARSER_HEADER_H
+# define PARSER_HEADER_H
 
 #include "stack.hh"
 #include "location.hh"
@@ -119,50 +133,49 @@ b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
 #include <iostream>
 
 /* Using locations.  */
-#define YYLSP_NEEDED b4_locations_flag
+#define YYLSP_NEEDED ]b4_locations_flag[
 
-b4_token_defines(b4_tokens)
+]b4_token_defines(b4_tokens)[
 
 /* Copy the first part of user declarations.  */
-b4_pre_prologue
+]b4_pre_prologue[
 
-/* Line __line__ of __file__.  */
-#line __oline__ "__ofile__"
+]/* Line __line__ of lalr1.cc.  */
+b4_syncline([@oline@], [@ofile@])[
 
 /* Enabling traces.  */
 #ifndef YYDEBUG
-# define YYDEBUG b4_debug
+# define YYDEBUG ]b4_debug[
 #endif
 
 /* Enabling verbose error message.  */
 #ifndef YYERROR_VERBOSE
-# define YYERROR_VERBOSE b4_error_verbose
+# define YYERROR_VERBOSE ]b4_error_verbose[
 #endif
 
 #ifndef YYSTYPE
-m4_ifdef([b4_stype],
-[#line b4_stype_line "b4_filename"
+]m4_ifdef([b4_stype],
+[b4_syncline([b4_stype_line], [b4_filename])
 typedef union b4_stype yystype;
-/* Line __line__ of __file__.  */
-#line __oline__ "__ofile__"],
-[typedef int yystype;])
+/* Line __line__ of lalr1.cc.  */
+b4_syncline([@oline@], [@ofile@])],
+[typedef int yystype;])[
 # define YYSTYPE yystype
 #endif
 
 /* Copy the second part of user declarations.  */
-b4_post_prologue
+]b4_post_prologue[
 
-/* Line __line__ of __file__.  */
-#line __oline__  "__ofile__"
+]/* Line __line__ of lalr1.cc.  */
+b4_syncline([@oline@], [@ofile@])[
 #ifndef YYLLOC_DEFAULT
 # define YYLLOC_DEFAULT(Current, Rhs, N) \
-   Current.last_line = Rhs[[N]].last_line; \
-   Current.last_column = Rhs[[N]].last_column;
+   ((Current).end = Rhs[N].end)
 #endif
 
 namespace yy
 {
-  class b4_parser_class_name;
+  class ]b4_parser_class_name[;
 
   template < typename P >
   struct Traits
@@ -170,47 +183,47 @@ namespace yy
   };
 
   template < >
-  struct Traits< b4_parser_class_name >
+  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 b4_location_type LocationType;
+    typedef ]b4_location_type[ LocationType;
   };
 }
 
 namespace yy
 {
-  class b4_parser_class_name b4_inherit
+  class ]b4_parser_class_name b4_inherit[
   {
   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;
 
 #if YYLSP_NEEDED
-    b4_parser_class_name (bool debug,
-           LocationType initlocation[]b4_param) :
-      b4_constructor[]debug_ (debug),
+    ]b4_parser_class_name[ (bool debug,
+           LocationType initlocation][]b4_param[]b4_parse_param_decl[) :
+      ]b4_constructor[][debug_ (debug),
       cdebug_ (std::cerr),
-      initlocation_ (initlocation)
+      initlocation_ (initlocation)]b4_parse_param_cons[
 #else
-    b4_parser_class_name (bool debug[]b4_param) :
-      b4_constructor[]debug_ (debug),
-      cdebug_ (std::cerr)
+    ]b4_parser_class_name[ (bool debug][]b4_param[]b4_parse_param_decl[) :
+      ]b4_constructor[][debug_ (debug),
+      cdebug_ (std::cerr)]b4_parse_param_cons[
 #endif
     {
     }
 
-    virtual ~b4_parser_class_name ()
+    virtual ~]b4_parser_class_name[ ()
     {
     }
 
@@ -228,28 +241,28 @@ namespace yy
     LocationStack location_stack_;
 
     /* Tables.  */
-    static const b4_int_type_for([b4_pact]) pact_[[]];
-    static const b4_int_type_for([b4_pact]) pact_ninf_;
-    static const b4_int_type_for([b4_defact]) defact_[[]];
-    static const b4_int_type_for([b4_pgoto]) pgoto_[[]];
-    static const b4_int_type_for([b4_defgoto]) defgoto_[[]];
-    static const b4_int_type_for([b4_table]) table_[[]];
-    static const b4_int_type_for([b4_table]) table_ninf_;
-    static const b4_int_type_for([b4_check]) check_[[]];
-    static const b4_int_type_for([b4_r1]) r1_[[]];
-    static const b4_int_type_for([b4_r2]) r2_[[]];
+    static const ]b4_int_type_for([b4_pact])[ pact_[];
+    static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ pact_ninf_;
+    static const ]b4_int_type_for([b4_defact])[ defact_[];
+    static const ]b4_int_type_for([b4_pgoto])[ pgoto_[];
+    static const ]b4_int_type_for([b4_defgoto])[ defgoto_[];
+    static const ]b4_int_type_for([b4_table])[ table_[];
+    static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ table_ninf_;
+    static const ]b4_int_type_for([b4_check])[ check_[];
+    static const ]b4_int_type_for([b4_r1])[ r1_[];
+    static const ]b4_int_type_for([b4_r2])[ r2_[];
 
 #if YYDEBUG || YYERROR_VERBOSE
-    static const char* const name_[[]];
+    static const char* const name_[];
 #endif
 
     /* More tables, for debugging.  */
 #if YYDEBUG
-    static const RhsNumberType rhs_[[]];
-    static const b4_int_type_for([b4_prhs]) prhs_[[]];
-    static const b4_int_type_for([b4_rline]) rline_[[]];
-    static const b4_int_type_for([b4_stos]) stos_[[]];
-    static const b4_int_type_for([b4_toknum]) token_number_[[]];
+    static const RhsNumberType rhs_[];
+    static const ]b4_int_type_for([b4_prhs])[ prhs_[];
+    static const ]b4_int_type_for([b4_rline])[ rline_[];
+    static const ]b4_int_type_for([b4_stos])[ stos_[];
+    static const ]b4_int_type_for([b4_toknum])[ token_number_[];
 #endif
 
     /* Even more tables.  */
@@ -265,7 +278,6 @@ namespace yy
     static const int terror_;
     static const int errcode_;
     static const int ntokens_;
-    static const int initdepth_;
     static const unsigned user_token_number_max_;
     static const TokenNumberType undef_token_;
 
@@ -289,22 +301,23 @@ namespace yy
     SemanticType value;
     LocationType location;
 
-    /* @$ and $$.  */
+    /* @@$ and $$.  */
     SemanticType yyval;
     LocationType yyloc;
 
     /* Initial location.  */
     LocationType initlocation_;
+]b4_parse_param_vars[
   };
 }
 
-#endif /* not b4_header_guard */
-dnl
-#output "b4_output_prefix[]b4_output_infix[].cc"
+#endif /* ! defined PARSER_HEADER_H */]
+])dnl
+@output @output_parser_name@
 b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
-             [2002])
+             [2002, 2003])
 
-#include "b4_output_header_name"
+m4_if(b4_defines_flag, 0, [], [#include @output_header_name@])[
 
 /* Enable debugging if requested.  */
 #if YYDEBUG
@@ -313,13 +326,21 @@ b4_copyright([C++ Skeleton parser for LALR(1) parsing with Bison],
 # define YYCDEBUG    if (0) cdebug_
 #endif /* !YYDEBUG */
 
+#define YYACCEPT       goto yyacceptlab
+#define YYABORT                goto yyabortlab
+#define YYERROR                goto yyerrorlab
+
+
 int
-yy::b4_parser_class_name::parse ()
+yy::]b4_parser_class_name[::parse ()
 {
   int nerrs = 0;
   int errstatus = 0;
 
-  /* Initialize stack.  */
+  /* 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);
   semantic_stack_ = SemanticStack (1);
   location_stack_ = LocationStack (1);
@@ -342,7 +363,7 @@ yy::b4_parser_class_name::parse ()
  yybackup:
 
   /* Try to take a decision without lookahead.  */
-  n_ = pact_[[state_]];
+  n_ = pact_[state_];
   if (n_ == pact_ninf_)
     goto yydefault;
 
@@ -367,19 +388,21 @@ yy::b4_parser_class_name::parse ()
       if (debug_)
        {
          YYCDEBUG << "Next token is " << looka_
-                << " (" << name_[[ilooka_]];
+                << " (" << name_[ilooka_];
          print_ ();
          YYCDEBUG << ')' << std::endl;
        }
 #endif
     }
 
+  /* If the proper action on seeing token YYTOKEN is to reduce or to
+     detect an error, take that action.  */
   n_ += ilooka_;
-  if (n_ < 0 || last_ < n_ || check_[[n_]] != ilooka_)
+  if (n_ < 0 || last_ < n_ || check_[n_] != ilooka_)
     goto yydefault;
 
   /* Reduce or error.  */
-  n_ = table_[[n_]];
+  n_ = table_[n_];
   if (n_ < 0)
     {
       if (n_ == table_ninf_)
@@ -398,8 +421,10 @@ yy::b4_parser_class_name::parse ()
     goto yyacceptlab;
 
   /* Shift the lookahead token.  */
+#if YYDEBUG
   YYCDEBUG << "Shifting token " << looka_
-        << " (" << name_[[ilooka_]] << "), ";
+           << " (" << name_[ilooka_] << "), ";
+#endif
 
   /* Discard the token being shifted unless it is eof.  */
   if (looka_ != eof_)
@@ -416,36 +441,50 @@ yy::b4_parser_class_name::parse ()
   state_ = n_;
   goto yynewstate;
 
-  /* Default action.  */
+/*-----------------------------------------------------------.
+| yydefault -- do the default action for the current state.  |
+`-----------------------------------------------------------*/
  yydefault:
-  n_ = defact_[[state_]];
+  n_ = defact_[state_];
   if (n_ == 0)
     goto yyerrlab;
   goto yyreduce;
 
-  /* Reduce.  */
+/*-----------------------------.
+| yyreduce -- Do a reduction.  |
+`-----------------------------*/
  yyreduce:
-  len_ = r2_[[n_]];
+  len_ = r2_[n_];
+  /* If LEN_ 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.
+     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];
+      yyloc = location_stack_[len_ - 1];
     }
   else
     {
-      yyval = semantic_stack_[[0]];
-      yyloc = location_stack_[[0]];
+      yyval = semantic_stack_[0];
+      yyloc = location_stack_[0];
     }
 
 #if YYDEBUG
   if (debug_)
     {
+      // Short files will use "unsigned char" for line numbers,
+      // in which case they will be output as character litterals
+      // by "<<".
+      unsigned yylno = rline_[n_];
       YYCDEBUG << "Reducing via rule " << n_ - 1
-            << " (line " << rline_[[n_]] << "), ";
-      for (b4_int_type_for([b4_prhs]) i = prhs_[[n_]];
-          0 <= rhs_[[i]]; ++i)
-       YYCDEBUG << name_[[rhs_[i]]] << ' ';
-      YYCDEBUG << "-> " << name_[[r1_[n_]]] << std::endl;
+               << " (line " << yylno << "), ";
+      for (]b4_int_type_for([b4_prhs])[ i = prhs_[n_];
+          0 <= rhs_[i]; ++i)
+       YYCDEBUG << name_[rhs_[i]] << ' ';
+      YYCDEBUG << "-> " << name_[r1_[n_]] << std::endl;
     }
 #endif
 
@@ -457,11 +496,11 @@ yy::b4_parser_class_name::parse ()
 
   switch (n_)
     {
-      b4_actions
+      ]b4_actions[
     }
 
-/* Line __line__ of __file__.  */
-#line __oline__ "__ofile__"
+]/* Line __line__ of lalr1.cc.  */
+b4_syncline([@oline@], [@ofile@])[
 
   state_stack_.pop (len_);
   semantic_stack_.pop (len_);
@@ -482,15 +521,17 @@ yy::b4_parser_class_name::parse ()
   location_stack_.push (yyloc);
 
   /* Shift the result of the reduction.  */
-  n_ = r1_[[n_]];
-  state_ = pgoto_[[n_ - ntokens_]] + state_stack_[[0]];
-  if (0 <= state_ && state_ <= last_ && check_[[state_]] == state_stack_[[0]])
-    state_ = table_[[state_]];
+  n_ = r1_[n_];
+  state_ = pgoto_[n_ - ntokens_] + state_stack_[0];
+  if (0 <= state_ && state_ <= last_ && check_[state_] == state_stack_[0])
+    state_ = table_[state_];
   else
-    state_ = defgoto_[[n_ - ntokens_]];
+    state_ = defgoto_[n_ - ntokens_];
   goto yynewstate;
 
-  /* Report and recover from errors.  This is very incomplete.  */
+/*------------------------------------.
+| yyerrlab -- here on detecting error |
+`------------------------------------*/
  yyerrlab:
   /* If not already recovering from an error, report this error.  */
   if (!errstatus)
@@ -498,83 +539,123 @@ yy::b4_parser_class_name::parse ()
       ++nerrs;
 
 #if YYERROR_VERBOSE
-      n_ = pact_[[state_]];
+      n_ = pact_[state_];
       if (pact_ninf_ < n_ && n_ < last_)
        {
-         message = "parse error, unexpected ";
-         message += name_[[ilooka_]];
+         message = "syntax error, unexpected ";
+         message += name_[ilooka_];
          {
            int count = 0;
-           for (int x = (n_ < 0 ? -n_ : 0); x < ntokens_ + nnts_; ++x)
-             if (check_[[x + n_]] == x && x != terror_)
+            /* Start YYX at -YYN if negative to avoid negative indexes in
+               YYCHECK.  */
+           int xbegin = n_ < 0 ? -n_ : 0;
+           /* Stay within bounds of both yycheck and yytname.  */
+           int checklim = last_ - n_;
+           int xend = checklim < ntokens_ ? checklim : ntokens_;
+           for (int x = xbegin; x < xend; ++x)
+             if (check_[x + n_] == x && x != terror_)
                ++count;
            if (count < 5)
              {
                count = 0;
-               for (int x = (n_ < 0 ? -n_ : 0); x < ntokens_ + nnts_; ++x)
-                 if (check_[[x + n_]] == x && x != terror_)
+               for (int x1 = xbegin; x1 < xend; ++x1)
+                 if (check_[x1 + n_] == x1 && x1 != terror_)
                    {
                      message += (!count++) ? ", expecting " : " or ";
-                     message += name_[[x]];
+                     message += name_[x1];
                    }
              }
          }
        }
       else
 #endif
-       message = "parse error";
+       message = "syntax error";
       error_ ();
     }
-  goto yyerrlab1;
 
-  /* Error raised explicitly by an action.  */
- yyerrlab1:
   if (errstatus == 3)
     {
       /* If just tried and failed to reuse lookahead token after an
         error, discard it.  */
 
       /* Return failure if at end of input.  */
-      if (looka_ == eof_)
-       goto yyabortlab;
-      YYCDEBUG << "Discarding token " << looka_
-            << " (" << name_[[ilooka_]] << ")." << std::endl;
-      looka_ = empty_;
+      if (looka_ <= eof_)
+        {
+          /* If at end of input, pop the error token,
+            then the rest of the stack, then return failure.  */
+         if (looka_ == eof_)
+            for (;;)
+              {
+                 state_stack_.pop ();
+                 semantic_stack_.pop ();
+                 location_stack_.pop ();
+                if (state_stack_.height () == 1)
+                  YYABORT;
+//              YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
+// FIXME: yydestruct (yystos[*yyssp], yyvsp]b4_location_if([, yylsp])[);
+              }
+        }
+      else
+        {
+#if YYDEBUG
+           YYCDEBUG << "Discarding token " << looka_
+                   << " (" << name_[ilooka_] << ")." << std::endl;
+//       yydestruct (yytoken, &yylval]b4_location_if([, &yylloc])[);
+#endif
+           looka_ = empty_;
+        }
     }
 
   /* Else will try to reuse lookahead token after shifting the error
      token.  */
+  goto yyerrlab1;
+
 
-  errstatus = 3;
+/*---------------------------------------------------.
+| yyerrorlab -- error raised explicitly by YYERROR.  |
+`---------------------------------------------------*/
+yyerrorlab:
+
+  state_stack_.pop (len_);
+  semantic_stack_.pop (len_);
+  location_stack_.pop (len_);
+  state_ = state_stack_[0];
+  goto yyerrlab1;
+
+/*-------------------------------------------------------------.
+| yyerrlab1 -- common code for both syntax error and YYERROR.  |
+`-------------------------------------------------------------*/
+yyerrlab1:
+  errstatus = 3;       /* Each real token shifted decrements this.  */
 
   for (;;)
     {
-      n_ = pact_[[state_]];
+      n_ = pact_[state_];
       if (n_ != pact_ninf_)
        {
          n_ += terror_;
-         if (0 <= n_ && n_ <= last_ && check_[[n_]] == terror_)
+         if (0 <= n_ && n_ <= last_ && check_[n_] == terror_)
            {
-             n_ = table_[[n_]];
+             n_ = table_[n_];
              if (0 < n_)
                break;
            }
        }
 
       /* Pop the current state because it cannot handle the error token.  */
-      if (!state_stack_.height ())
-       goto yyabortlab;
+      if (state_stack_.height () == 1)
+       YYABORT;
 
 #if YYDEBUG
       if (debug_)
        {
-         if (stos_[[state_]] < ntokens_)
+         if (stos_[state_] < ntokens_)
            {
              YYCDEBUG << "Error: popping token "
-                    << token_number_[[stos_[state_]]]
-                    << " (" << name_[[stos_[state_]]];
+                    << token_number_[stos_[state_]]
+                    << " (" << name_[stos_[state_]];
 # ifdef YYPRINT
-             YYPRINT (stderr, token_number_[[stos_[state_]]],
+             YYPRINT (stderr, token_number_[stos_[state_]],
                       semantic_stack_.top ());
 # endif
              YYCDEBUG << ')' << std::endl;
@@ -582,14 +663,15 @@ yy::b4_parser_class_name::parse ()
          else
            {
              YYCDEBUG << "Error: popping nonterminal ("
-                    << name_[[stos_[state_]]] << ')' << std::endl;
+                    << name_[stos_[state_]] << ')' << std::endl;
            }
        }
 #endif
 
-      state_ = (state_stack_.pop (), state_stack_[[0]]);
+      state_stack_.pop ();
       semantic_stack_.pop ();
-      location_stack_.pop ();;
+      location_stack_.pop ();
+      state_ = state_stack_[0];
 
 #if YYDEBUG
       if (debug_)
@@ -624,7 +706,7 @@ yy::b4_parser_class_name::parse ()
 }
 
 void
-yy::b4_parser_class_name::lex_ ()
+yy::]b4_parser_class_name[::lex_ ()
 {
 #if YYLSP_NEEDED
   looka_ = yylex (&value, &location);
@@ -633,154 +715,153 @@ yy::b4_parser_class_name::lex_ ()
 #endif
 }
 
-/* YYPACT[[STATE-NUM]] -- Index in YYTABLE of the portion describing
+/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
    STATE-NUM.  */
-const b4_int_type_for([b4_pact]) yy::b4_parser_class_name::pact_ninf_ = b4_pact_ninf;
-const b4_int_type_for([b4_pact])
-yy::b4_parser_class_name::pact_[[]] =
+const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) yy::b4_parser_class_name::pact_ninf_ = b4_pact_ninf[;
+const ]b4_int_type_for([b4_pact])[
+yy::]b4_parser_class_name[::pact_[] =
 {
-  b4_pact
+  ]b4_pact[
 };
 
-/* YYDEFACT[[S]] -- default rule to reduce with in state S when YYTABLE
+/* 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])
-yy::b4_parser_class_name::defact_[[]] =
+const ]b4_int_type_for([b4_defact])[
+yy::]b4_parser_class_name[::defact_[] =
 {
-  b4_defact
+  ]b4_defact[
 };
 
-/* YYPGOTO[[NTERM-NUM]].  */
-const b4_int_type_for([b4_pgoto])
-yy::b4_parser_class_name::pgoto_[[]] =
+/* YYPGOTO[NTERM-NUM].  */
+const ]b4_int_type_for([b4_pgoto])[
+yy::]b4_parser_class_name[::pgoto_[] =
 {
-  b4_pgoto
+  ]b4_pgoto[
 };
 
-/* YYDEFGOTO[[NTERM-NUM]].  */
-const b4_int_type_for([b4_defgoto])
-yy::b4_parser_class_name::defgoto_[[]] =
+/* YYDEFGOTO[NTERM-NUM].  */
+const ]b4_int_type_for([b4_defgoto])[
+yy::]b4_parser_class_name[::defgoto_[] =
 {
-  b4_defgoto
+  ]b4_defgoto[
 };
 
-/* YYTABLE[[YYPACT[STATE-NUM]]].  What to do in state STATE-NUM.  If
+/* 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_for([b4_table]) yy::b4_parser_class_name::table_ninf_ = b4_table_ninf;
-const b4_int_type_for([b4_table])
-yy::b4_parser_class_name::table_[[]] =
+const ]b4_int_type(b4_table_ninf, b4_table_ninf) yy::b4_parser_class_name::table_ninf_ = b4_table_ninf[;
+const ]b4_int_type_for([b4_table])[
+yy::]b4_parser_class_name[::table_[] =
 {
-  b4_table
+  ]b4_table[
 };
 
 /* YYCHECK.  */
-const b4_int_type_for([b4_check])
-yy::b4_parser_class_name::check_[[]] =
+const ]b4_int_type_for([b4_check])[
+yy::]b4_parser_class_name[::check_[] =
 {
-  b4_check
+  ]b4_check[
 };
 
 #if YYDEBUG
-/* STOS_[[STATE-NUM]] -- The (internal number of the) accessing
+/* STOS_[STATE-NUM] -- The (internal number of the) accessing
    symbol of state STATE-NUM.  */
-const b4_int_type_for([b4_stos])
-yy::b4_parser_class_name::stos_[[]] =
+const ]b4_int_type_for([b4_stos])[
+yy::]b4_parser_class_name[::stos_[] =
 {
-  b4_stos
+  ]b4_stos[
 };
 
-/* TOKEN_NUMBER_[[YYLEX-NUM]] -- Internal token number corresponding
+/* TOKEN_NUMBER_[YYLEX-NUM] -- Internal token number corresponding
    to YYLEX-NUM.  */
-const b4_int_type_for([b4_toknum])
-yy::b4_parser_class_name::token_number_[[]] =
+const ]b4_int_type_for([b4_toknum])[
+yy::]b4_parser_class_name[::token_number_[] =
 {
-  b4_toknum
+  ]b4_toknum[
 };
 #endif
 
-/* YYR1[[YYN]] -- Symbol number of symbol that rule YYN derives.  */
-const b4_int_type_for([b4_r1])
-yy::b4_parser_class_name::r1_[[]] =
+/* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
+const ]b4_int_type_for([b4_r1])[
+yy::]b4_parser_class_name[::r1_[] =
 {
-  b4_r1
+  ]b4_r1[
 };
 
-/* YYR2[[YYN]] -- Number of symbols composing right hand side of rule YYN.  */
-const b4_int_type_for([b4_r2])
-yy::b4_parser_class_name::r2_[[]] =
+/* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
+const ]b4_int_type_for([b4_r2])[
+yy::]b4_parser_class_name[::r2_[] =
 {
-  b4_r2
+  ]b4_r2[
 };
 
 #if YYDEBUG || YYERROR_VERBOSE
-/* YYTNAME[[SYMBOL-NUM]] -- String name of the symbol SYMBOL-NUM.
+/* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
    First, the terminals, then, starting at YYNTOKENS, nonterminals. */
 const char*
-const yy::b4_parser_class_name::name_[[]] =
+const yy::]b4_parser_class_name[::name_[] =
 {
-  b4_tname
+  ]b4_tname[
 };
 #endif
 
 #if YYDEBUG
 /* YYRHS -- A `-1'-separated list of the rules' RHS. */
-const yy::b4_parser_class_name::RhsNumberType
-yy::b4_parser_class_name::rhs_[[]] =
+const yy::]b4_parser_class_name[::RhsNumberType
+yy::]b4_parser_class_name[::rhs_[] =
 {
-  b4_rhs
+  ]b4_rhs[
 };
 
-/* YYPRHS[[YYN]] -- Index of the first RHS symbol of rule number YYN in
+/* YYPRHS[YYN] -- Index of the first RHS symbol of rule number YYN in
    YYRHS.  */
-const b4_int_type_for([b4_prhs])
-yy::b4_parser_class_name::prhs_[[]] =
+const ]b4_int_type_for([b4_prhs])[
+yy::]b4_parser_class_name[::prhs_[] =
 {
-  b4_prhs
+  ]b4_prhs[
 };
 
-/* YYRLINE[[YYN]] -- source line where rule number YYN was defined.  */
-const b4_int_type_for([b4_rline])
-yy::b4_parser_class_name::rline_[[]] =
+/* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
+const ]b4_int_type_for([b4_rline])[
+yy::]b4_parser_class_name[::rline_[] =
 {
-  b4_rline
+  ]b4_rline[
 };
 #endif
 
 /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
-yy::b4_parser_class_name::TokenNumberType
-yy::b4_parser_class_name::translate_ (int token)
+yy::]b4_parser_class_name[::TokenNumberType
+yy::]b4_parser_class_name[::translate_ (int token)
 {
   static
   const TokenNumberType
-  translate_[[]] =
+  translate_table[] =
   {
-    b4_translate
+    ]b4_translate[
   };
   if ((unsigned) token <= user_token_number_max_)
-    return translate_[[token]];
+    return translate_table[token];
   else
     return undef_token_;
 }
 
-const int yy::b4_parser_class_name::eof_ = 0;
-const int yy::b4_parser_class_name::last_ = b4_last;
-const int yy::b4_parser_class_name::nnts_ = b4_nterms_number;
-const int yy::b4_parser_class_name::empty_ = -2;
-const int yy::b4_parser_class_name::final_ = b4_final_state_number;
-const int yy::b4_parser_class_name::terror_ = 1;
-const int yy::b4_parser_class_name::errcode_ = 256;
-const int yy::b4_parser_class_name::ntokens_ = b4_tokens_number;
-const int yy::b4_parser_class_name::initdepth_ = b4_stack_depth_init;
+const int yy::]b4_parser_class_name[::eof_ = 0;
+const int yy::]b4_parser_class_name[::last_ = ]b4_last[;
+const int yy::]b4_parser_class_name[::nnts_ = ]b4_nterms_number[;
+const int yy::]b4_parser_class_name[::empty_ = -2;
+const int yy::]b4_parser_class_name[::final_ = ]b4_final_state_number[;
+const int yy::]b4_parser_class_name[::terror_ = 1;
+const int yy::]b4_parser_class_name[::errcode_ = 256;
+const int yy::]b4_parser_class_name[::ntokens_ = ]b4_tokens_number[;
 
-const unsigned yy::b4_parser_class_name::user_token_number_max_ = b4_user_token_number_max;
-const yy::b4_parser_class_name::TokenNumberType yy::b4_name::undef_token_ = b4_undef_token_number;
+const unsigned yy::]b4_parser_class_name[::user_token_number_max_ = ]b4_user_token_number_max[;
+const yy::]b4_parser_class_name[::TokenNumberType yy::]b4_parser_class_name[::undef_token_ = ]b4_undef_token_number[;
 
-b4_epilogue
+]b4_epilogue
 dnl
-#output "stack.hh"
-b4_copyright([2002])
+@output stack.hh
+b4_copyright([Stack handling for Bison C++ parsers], [2002, 2003])[
 
 #ifndef BISON_STACK_HH
 # define BISON_STACK_HH
@@ -807,16 +888,16 @@ namespace yy
 
     inline
     T&
-    operator [[]] (unsigned index)
+    operator [] (unsigned i)
     {
-      return seq_[[index]];
+      return seq_[i];
     }
 
     inline
     const T&
-    operator [[]] (unsigned index) const
+    operator [] (unsigned i) const
     {
-      return seq_[[index]];
+      return seq_[i];
     }
 
     inline
@@ -862,9 +943,9 @@ namespace yy
 
     inline
     const T&
-    operator [[]] (unsigned index) const
+    operator [] (unsigned i) const
     {
-      return stack_[[range_ - index]];
+      return stack_[range_ - i];
     }
 
   private:
@@ -874,27 +955,226 @@ namespace yy
   };
 }
 
-#endif // not BISON_STACK_HH
+#endif // not BISON_STACK_HH]
 dnl
-#output "location.hh"
-b4_copyright([2002])
+@output position.hh
+b4_copyright([Position class for Bison C++ parsers], [2002, 2003])[
+
+/**
+ ** \file position.hh
+ ** Define the Location class.
+ */
+
+#ifndef BISON_POSITION_HH
+# define BISON_POSITION_HH
+
+# include <iostream>
+# include <string>
+
+namespace yy
+{
+  /** \brief Abstract a Position. */
+  class Position
+  {
+  public:
+    /** \brief Initial column number. */
+    static const unsigned int initial_column = 0;
+    /** \brief Initial line number. */
+    static const unsigned int initial_line = 1;
+
+    /** \name Ctor & dtor.
+     ** \{ */
+  public:
+    /** \brief Construct a Position. */
+    Position () :
+      filename (),
+      line (initial_line),
+      column (initial_column)
+    {
+    }
+    /** \} */
+
+
+    /** \name Line and Column related manipulators
+     ** \{ */
+  public:
+    /** \brief (line related) Advance to the COUNT next lines. */
+    inline void lines (int count = 1)
+    {
+      column = initial_column;
+      line += count;
+    }
+
+    /** \brief (column related) Advance to the COUNT next columns. */
+    inline void columns (int count = 1)
+    {
+      int leftmost = initial_column;
+      int current  = column;
+      if (leftmost <= current + count)
+       column += count;
+      else
+       column = initial_column;
+    }
+    /** \} */
+
+  public:
+    /** \brief File name to which this position refers. */
+    std::string filename;
+    /** \brief Current line number. */
+    unsigned int line;
+    /** \brief Current column number. */
+    unsigned int column;
+  };
+
+  /** \brief Add and assign a Position. */
+  inline const Position&
+  operator+= (Position& res, const int width)
+  {
+    res.columns (width);
+    return res;
+  }
+
+  /** \brief Add two Position objects. */
+  inline const Position
+  operator+ (const Position& begin, const int width)
+  {
+    Position res = begin;
+    return res += width;
+  }
+
+  /** \brief Add and assign a Position. */
+  inline const Position&
+  operator-= (Position& res, const int width)
+  {
+    return res += -width;
+  }
+
+  /** \brief Add two Position objects. */
+  inline const Position
+  operator- (const Position& begin, const int width)
+  {
+    return begin + -width;
+  }
+
+  /** \brief Intercept output stream redirection.
+   ** \param ostr the destination output stream
+   ** \param pos a reference to the Position to redirect
+   */
+  inline std::ostream&
+  operator<< (std::ostream& ostr, const Position& pos)
+  {
+    if (!pos.filename.empty ())
+      ostr << pos.filename << ':';
+    return ostr << pos.line << '.' << pos.column;
+  }
+
+}
+#endif // not BISON_POSITION_HH]
+@output location.hh
+b4_copyright([Location class for Bison C++ parsers], [2002, 2003])[
+
+/**
+ ** \file location.hh
+ ** Define the Location class.
+ */
 
 #ifndef BISON_LOCATION_HH
 # define BISON_LOCATION_HH
 
+# include <iostream>
+# include <string>
+# include "position.hh"
+
 namespace yy
 {
-  struct Position
+
+  /** \brief Abstract a Location. */
+  class Location
   {
-    int line;
-    int column;
+    /** \name Ctor & dtor.
+     ** \{ */
+  public:
+    /** \brief Construct a Location. */
+    Location (void) :
+      begin (),
+      end ()
+    {
+    }
+    /** \} */
+
+
+    /** \name Line and Column related manipulators
+     ** \{ */
+  public:
+    /** \brief Reset initial location to final location. */
+    inline void step (void)
+    {
+      begin = end;
+    }
+
+    /** \brief Extend the current location to the COUNT next columns. */
+    inline void columns (unsigned int count = 1)
+    {
+      end += count;
+    }
+
+    /** \brief Extend the current location to the COUNT next lines. */
+    inline void lines (unsigned int count = 1)
+    {
+      end.lines (count);
+    }
+    /** \} */
+
+
+  public:
+    /** \brief Beginning of the located region. */
+    Position begin;
+    /** \brief End of the located region. */
+    Position end;
   };
 
-  struct Location
+  /** \brief Join two Location objects to create a Location. */
+  inline const Location operator+ (const Location& begin, const Location& end)
   {
-    Position first;
-    Position last;
-  };
+    Location res = begin;
+    res.end = end.end;
+    return res;
+  }
+
+  /** \brief Add two Location objects */
+  inline const Location operator+ (const Location& begin, unsigned width)
+  {
+    Location res = begin;
+    res.columns (width);
+    return res;
+  }
+
+  /** \brief Add and assign a Location */
+  inline Location &operator+= (Location& res, unsigned width)
+  {
+    res.columns (width);
+    return res;
+  }
+
+  /** \brief Intercept output stream redirection.
+   ** \param ostr the destination output stream
+   ** \param loc a reference to the Location to redirect
+   **
+   ** Avoid duplicate information.
+   */
+  inline std::ostream& operator<< (std::ostream& ostr, const Location& loc)
+  {
+    Position last = loc.end - 1;
+    ostr << loc.begin;
+    if (loc.begin.filename != last.filename)
+      ostr << '-' << last;
+    else if (loc.begin.line != last.line)
+      ostr << '-' << last.line  << '.' << last.column;
+    else if (loc.begin.column != last.column)
+      ostr << '-' << last.column;
+    return ostr;
+  }
+
 }
 
-#endif // not BISON_LOCATION_HH
+#endif // not BISON_LOCATION_HH]