]> git.saurik.com Git - bison.git/blobdiff - data/glr.cc
variants: avoid type punning issue
[bison.git] / data / glr.cc
index 0bc1f9fa53e0958e926d3ba3921259d0ce08097e..0afceeac00c9bcadd956a61a52ae8eb264354621 100644 (file)
@@ -1,8 +1,6 @@
-                                                                    -*- C -*-
-
 # C++ GLR skeleton for Bison
 
-# Copyright (C) 2002-2012 Free Software Foundation, Inc.
+# Copyright (C) 2002-2013 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
@@ -29,7 +27,7 @@
 #
 #   The additional arguments are stored as members of the parser
 #   object, yyparser.  The C routines need to carry yyparser
-#   throughout the C parser; that easy: just let yyparser become an
+#   throughout the C parser; that's easy: make yyparser an
 #   additional parse-param.  But because the C++ skeleton needs to
 #   know the "real" original parse-param, we save them
 #   (b4_parse_param_orig).  Note that b4_parse_param is overquoted
 # The locations
 #
 #   We use location.cc just like lalr1.cc, but because glr.c stores
-#   the locations in a (C++) union, the position and location classes
+#   the locations in a union, the position and location classes
 #   must not have a constructor.  Therefore, contrary to lalr1.cc, we
 #   must not define "b4_location_constructors".  As a consequence the
 #   user must initialize the first positions (in particular the
 #   filename member).
 
-# We require a pure interface using locations.
-m4_define([b4_locations_flag], [1])
-m4_define([b4_pure_flag],      [1])
+b4_token_ctor_if([b4_variant_if([],
+  [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
+               [cannot use '%s' without '%s'],
+               [%define api.token.constructor],
+               [%define api.value.type variant]))])])
 
-# The header is mandatory.
-b4_defines_if([],
-              [b4_fatal([b4_skeleton[: using %%defines is mandatory]])])
+# We require a pure interface.
+m4_define([b4_pure_flag],      [1])
 
 m4_include(b4_pkgdatadir/[c++.m4])
-b4_percent_define_ifdef([[location_type]], [],
-                        [m4_include(b4_pkgdatadir/[location.cc])])
+b4_bison_locations_if([m4_include(b4_pkgdatadir/[location.cc])])
 
 m4_define([b4_parser_class_name],
           [b4_percent_define_get([[parser_class_name]])])
@@ -63,73 +61,109 @@ m4_define([b4_parser_class_name],
 # Save the parse parameters.
 m4_define([b4_parse_param_orig], m4_defn([b4_parse_param]))
 
+# b4_parse_param_wrap
+# -------------------
+# New ones.
+m4_ifset([b4_parse_param],
+[m4_define([b4_parse_param_wrap],
+           [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]],]
+m4_defn([b4_parse_param]))],
+[m4_define([b4_parse_param_wrap],
+           [[b4_namespace_ref::b4_parser_class_name[& yyparser], [[yyparser]]]])
+])
+
 
-# b4_yy_symbol_print_generate
-# ---------------------------
+# b4_yy_symbol_print_define
+# -------------------------
 # Bypass the default implementation to generate the "yy_symbol_print"
 # and "yy_symbol_value_print" functions.
-m4_define([b4_yy_symbol_print_generate],
+m4_define([b4_yy_symbol_print_define],
 [[
 /*--------------------.
 | Print this symbol.  |
 `--------------------*/
 
-]b4_c_ansi_function_def([yy_symbol_print],
+]b4_function_define([yy_symbol_print],
     [static void],
-    [[FILE *],               []],
-    [[int yytype],           [yytype]],
-    [[const b4_namespace_ref::b4_parser_class_name::semantic_type *yyvaluep],
-                             [yyvaluep]],
-    [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
-                             [yylocationp]],
+    [[FILE *],      []],
+    [[int yytype],  [yytype]],
+    [[const ]b4_namespace_ref::b4_parser_class_name[::semantic_type *yyvaluep],
+                    [yyvaluep]][]dnl
+b4_locations_if([,
+    [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
+                    [yylocationp]]]),
     b4_parse_param)[
 {
 ]b4_parse_param_use[]dnl
 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
 }
-]])
+]])[
 
+# Hijack the initial action to initialize the locations.
+]b4_bison_locations_if([m4_define([b4_initial_action],
+[yylloc.initialize ();]m4_ifdef([b4_initial_action], [
+m4_defn([b4_initial_action])]))])[
 
-# Declare yyerror.
-m4_append([b4_post_prologue],
-[b4_syncline([@oline@], [@ofile@])
-
-b4_c_ansi_function_decl([yyerror],
-    [static void],
-    [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
-                        [yylocationp]],
+# Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
+# and declaration of yyerror.
+]m4_append([b4_post_prologue],
+[b4_syncline([@oline@], [@ofile@])[
+]b4_yylloc_default_define[
+#define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)
+]b4_function_declare([yyerror],
+    [static void],b4_locations_if([
+    [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
+                        [yylocationp]],])
     b4_parse_param,
     [[const char* msg], [msg]])])
 
 
-# Define yyerror.
+#undef yynerrs
+#undef yychar
+#undef yylval]b4_locations_if([
+#undef yylloc])
+
+m4_if(b4_prefix, [yy], [],
+[[/* Substitute the variable and function names.  */
+#define yyparse ]b4_prefix[parse
+#define yylex   ]b4_prefix[lex
+#define yyerror ]b4_prefix[error
+#define yydebug ]b4_prefix[debug
+]]b4_pure_if([], [[
+#define yylval  ]b4_prefix[lval
+#define yychar  ]b4_prefix[char
+#define yynerrs ]b4_prefix[nerrs]b4_locations_if([[
+#define yylloc  ]b4_prefix[lloc]])]))
+
+# Hijack the epilogue to define implementations (yyerror, parser member
+# functions etc.).
 m4_append([b4_epilogue],
 [b4_syncline([@oline@], [@ofile@])[
+
 /*------------------.
 | Report an error.  |
 `------------------*/
 
-]b4_c_ansi_function_def([yyerror],
-    [static void],
-    [[const b4_namespace_ref::b4_parser_class_name::location_type *yylocationp],
-                        [yylocationp]],
+]b4_function_define([yyerror],
+    [static void],b4_locations_if([
+    [[const ]b4_namespace_ref::b4_parser_class_name[::location_type *yylocationp],
+                        [yylocationp]],])
     b4_parse_param,
     [[const char* msg], [msg]])[
 {
 ]b4_parse_param_use[]dnl
-[  yyparser.error (*yylocationp, msg);
+[  yyparser.error (]b4_locations_if([[*yylocationp, ]])[msg);
 }
 
 
 ]b4_namespace_open[
-]dnl In this section, the parse param are the original parse_params.
+]dnl In this section, the parse params are the original parse_params.
 m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 [  /// Build a parser object.
   ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [
     :])[
-#if YYDEBUG
-    ]m4_ifset([b4_parse_param], [  ], [ :])[yydebug_ (false),
-      yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
+#if ]b4_api_PREFIX[DEBUG
+    ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
 #endif]b4_parse_param_cons[
   {
   }
@@ -144,24 +178,24 @@ m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
     return ::yyparse (*this]b4_user_args[);
   }
 
-#if YYDEBUG
+#if ]b4_api_PREFIX[DEBUG
   /*--------------------.
   | Print this symbol.  |
   `--------------------*/
 
   inline void
   ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
-                           const semantic_type* yyvaluep,
-                           const location_type* yylocationp)
-  {
-    YYUSE (yylocationp);
+                           const semantic_type* yyvaluep]b4_locations_if([[,
+                           const location_type* yylocationp]])[)
+  {]b4_locations_if([[
+    YYUSE (yylocationp);]])[
     YYUSE (yyvaluep);
     std::ostream& yyoutput = debug_stream ();
     std::ostream& yyo = yyoutput;
     YYUSE (yyo);
     switch (yytype)
       {
-  ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl
+]b4_symbol_foreach([b4_symbol_printer])dnl
 [        default:
           break;
       }
@@ -170,13 +204,13 @@ m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
 
   void
   ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
-                           const semantic_type* yyvaluep,
-                           const location_type* yylocationp)
+                           const semantic_type* yyvaluep]b4_locations_if([[,
+                           const location_type* yylocationp]])[)
   {
     *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
-               << ' ' << yytname[yytype] << " ("
-               << *yylocationp << ": ";
-    yy_symbol_value_print_ (yytype, yyvaluep, yylocationp);
+               << ' ' << yytname[yytype] << " ("]b4_locations_if([[
+               << *yylocationp << ": "]])[;
+    yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
     *yycdebug_ << ')';
   }
 
@@ -196,104 +230,46 @@ m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
   ]b4_parser_class_name[::debug_level_type
   ]b4_parser_class_name[::debug_level () const
   {
-    return yydebug_;
+    return yydebug;
   }
 
   void
   ]b4_parser_class_name[::set_debug_level (debug_level_type l)
   {
-    yydebug_ = l;
+    // Actually, it is yydebug which is really used.
+    yydebug = l;
   }
 
 #endif
 ]m4_popdef([b4_parse_param])dnl
-b4_namespace_close[
-
-]])
-
-
-# Let glr.c believe that the user arguments include the parser itself.
-m4_ifset([b4_parse_param],
-[m4_pushdef([b4_parse_param],
-            m4_dquote([[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]],]
-m4_defn([b4_parse_param])))],
-[m4_pushdef([b4_parse_param],
-            [[[[b4_namespace_ref::b4_parser_class_name& yyparser], [[yyparser]]]]])
+b4_namespace_close
 ])
-m4_include(b4_pkgdatadir/[glr.c])
-m4_popdef([b4_parse_param])
-
-m4_divert_push(0)
-@output(b4_spec_defines_file@)@
-b4_copyright([Skeleton interface for Bison GLR parsers in C++],
-             [2002-2006, 2009-2012])[
-
-/* C++ GLR parser skeleton written by Akim Demaille.  */
 
-]b4_cpp_guard_open([b4_spec_defines_file])[
-
-]b4_percent_code_get([[requires]])[
+# b4_shared_declarations
+# ----------------------
+# Declaration that might either go into the header (if --defines)
+# or open coded in the parser body.
+m4_define([b4_shared_declarations],
+[m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_orig]))dnl
+b4_percent_code_get([[requires]])[
 
+#include <stdexcept>
 #include <string>
-#include <iostream>
-]b4_percent_define_ifdef([[location_type]], [],
-                         [[#include "location.hh"]])[
-
-/* Using locations.  */
-#define YYLSP_NEEDED ]b4_locations_flag[
+#include <iostream>]b4_defines_if([
+b4_bison_locations_if([[#include "location.hh"]])])[
 
-/* Enabling traces.  */
-#ifndef YYDEBUG
-# define YYDEBUG ]b4_debug_flag[
-#endif
-
-/* 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
-# define YYLLOC_DEFAULT(Current, Rhs, N)                                \
-    do                                                                  \
-      if (N)                                                            \
-        {                                                               \
-          (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
-          (Current).end    = YYRHSLOC (Rhs, N).end;                     \
-        }                                                               \
-      else                                                              \
-        {                                                               \
-          (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
-        }                                                               \
-    while (/*CONSTCOND*/ 0)
-#endif
+]b4_YYDEBUG_define[
 
 ]b4_namespace_open[
+]b4_defines_if([],
+[b4_bison_locations_if([b4_position_define
+b4_location_define])])[
+
   /// A Bison parser.
   class ]b4_parser_class_name[
   {
   public:
-    /// Symbol semantic values.
-#ifndef YYSTYPE
-]m4_ifdef([b4_stype],
-[    union semantic_type
-    {
-b4_user_stype
-    };],
-[m4_if(b4_tag_seen_flag, 0,
-[[    typedef int semantic_type;]],
-[[    typedef YYSTYPE semantic_type;]])])[
-#else
-    typedef YYSTYPE semantic_type;
-#endif
-    /// Symbol locations.
-    typedef ]b4_percent_define_get([[location_type]],
-                                   [[location]])[ location_type;
-    /// Tokens.
-    struct token
-    {
-      ]b4_token_enums(b4_tokens)[
-    };
-    /// Token type.
-    typedef token::yytokentype token_type;
+]b4_public_types_declare[
 
     /// Build a parser object.
     ]b4_parser_class_name[ (]b4_parse_param_decl[);
@@ -315,34 +291,30 @@ b4_user_stype
     /// Set the current debugging level.
     void set_debug_level (debug_level_type l);
 
-  private:
-
   public:
-    /// 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);
-  private:
+    virtual void error (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
 
-#if YYDEBUG
+# if ]b4_api_PREFIX[DEBUG
   public:
     /// \brief Report a symbol value on the debug stream.
     /// \param yytype       The token type.
-    /// \param yyvaluep     Its semantic value.
-    /// \param yylocationp  Its location.
+    /// \param yyvaluep     Its semantic value.]b4_locations_if([[
+    /// \param yylocationp  Its location.]])[
     virtual void yy_symbol_value_print_ (int yytype,
-                                         const semantic_type* yyvaluep,
-                                         const location_type* yylocationp);
+                                         const semantic_type* yyvaluep]b4_locations_if([[,
+                                         const location_type* yylocationp]])[);
     /// \brief Report a symbol on the debug stream.
     /// \param yytype       The token type.
-    /// \param yyvaluep     Its semantic value.
-    /// \param yylocationp  Its location.
+    /// \param yyvaluep     Its semantic value.]b4_locations_if([[
+    /// \param yylocationp  Its location.]])[
     virtual void yy_symbol_print_ (int yytype,
-                                   const semantic_type* yyvaluep,
-                                   const location_type* yylocationp);
+                                   const semantic_type* yyvaluep]b4_locations_if([[,
+                                   const location_type* yylocationp]])[);
   private:
-    /* Debugging.  */
-    int yydebug_;
+    // Debugging.
     std::ostream* yycdebug_;
 #endif
 
@@ -351,16 +323,34 @@ b4_user_stype
 
 ]dnl Redirections for glr.c.
 b4_percent_define_flag_if([[global_tokens_and_yystype]],
-[b4_token_defines(b4_tokens)])
+[b4_token_defines])
 [
-#ifndef YYSTYPE
-# define YYSTYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
+#ifndef ]b4_api_PREFIX[STYPE
+# define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
 #endif
-#ifndef YYLTYPE
-# define YYLTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
+#ifndef ]b4_api_PREFIX[LTYPE
+# define ]b4_api_PREFIX[LTYPE ]b4_namespace_ref[::]b4_parser_class_name[::location_type
 #endif
 
 ]b4_namespace_close[
 ]b4_percent_code_get([[provides]])[
+]m4_popdef([b4_parse_param])dnl
+])
+
+b4_defines_if(
+[b4_output_begin([b4_spec_defines_file])
+b4_copyright([Skeleton interface for Bison GLR parsers in C++],
+             [2002-2013])[
+
+// C++ GLR parser skeleton written by Akim Demaille.
+
+]b4_cpp_guard_open([b4_spec_defines_file])[
+]b4_shared_declarations[
 ]b4_cpp_guard_close([b4_spec_defines_file])[
-]m4_divert_pop(0)
+]b4_output_end()])
+
+# Let glr.c (and b4_shared_declarations) believe that the user
+# arguments include the parser itself.
+m4_pushdef([b4_parse_param], m4_defn([b4_parse_param_wrap]))
+m4_include(b4_pkgdatadir/[glr.c])
+m4_popdef([b4_parse_param])