news: restructure, document variants for C++
[bison.git] / data / glr.cc
index 69232f97d4944364db389cd3621238df8bd6d9d5..0164eda6b439c5ddde10e82bac75b6342f4c32c9 100644 (file)
-m4_divert(-1)                                                       -*- C -*-
-
 # C++ GLR skeleton for Bison
-# Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
 
-# This program is free software; you can redistribute it and/or modify
+# 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
-# the Free Software Foundation; either version 2 of the License, or
+# the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
-
+#
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
-
+#
 # You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-# 02110-1301  USA
-
-# We require a pure interface using locations.
-m4_define([b4_location_flag], [1])
-m4_define([b4_pure],          [1])
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+# This skeleton produces a C++ class that encapsulates a C glr parser.
+# This is in order to reduce the maintenance burden.  The glr.c
+# skeleton is clean and pure enough so that there are no real
+# problems.  The C++ interface is the same as that of lalr1.cc.  In
+# fact, glr.c can replace yacc.c without the user noticing any
+# difference, and similarly for glr.cc replacing lalr1.cc.
+#
+# The passing of parse-params
+#
+#   The additional arguments are stored as members of the parser
+#   object, yyparser.  The C routines need to carry yyparser
+#   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
+#   (and c.m4 strips one level of quotes).  This is a PITA, and
+#   explains why there are so many levels of quotes.
+#
+# The locations
+#
+#   We use location.cc just like lalr1.cc, but because glr.c stores
+#   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.
+m4_define([b4_pure_flag],      [1])
 
 m4_include(b4_pkgdatadir/[c++.m4])
-m4_include(b4_pkgdatadir/[location.cc])
-
-
-# b4_yysymprint_generate(FUNCTION-DECLARATOR)
-# -------------------------------------------
-# Generate the "yysymprint" function, which declaration is issued using
-# FUNCTION-DECLARATOR, which may be "b4_c_ansi_function_def" for ISO C
-# or "b4_c_function_def" for K&R.
-m4_define([b4_yysymprint_generate],
-[b4_c_ansi_function_decl([yyerror],
-    [static void],
-    [[yy::b4_parser_class_name::location_type *yylocationp], [yylocationp]],
-    b4_parse_param,
-    [[const char* msg], [msg]])[
-
-/*--------------------------------.
-| Print this symbol on YYOUTPUT.  |
-`--------------------------------*/
+b4_bison_locations_if([m4_include(b4_pkgdatadir/[location.cc])])
+
+m4_define([b4_parser_class_name],
+          [b4_percent_define_get([[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_define
+# -------------------------
+# Bypass the default implementation to generate the "yy_symbol_print"
+# and "yy_symbol_value_print" functions.
+m4_define([b4_yy_symbol_print_define],
+[[
+/*--------------------.
+| Print this symbol.  |
+`--------------------*/
 
-]$1([yysymprint],
+]b4_function_define([yy_symbol_print],
     [static void],
-    [[FILE *yyoutput],       [yyoutput]],
-    [[int yytype],           [yytype]],
-    [[const yy::b4_parser_class_name::semantic_type *yyvaluep],
-                             [yyvaluep]][]dnl
-b4_location_if([,
-    [[const yy::b4_parser_class_name::location_type *yylocationp],
-                             [yylocationp]]])[]dnl
-m4_ifset([b4_parse_param], [, b4_parse_param]))[
+    [[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)[
 {
-  YYUSE (yyoutput);
 ]b4_parse_param_use[]dnl
-[
-  yyparser.yysymprint_ (yytype, yyvaluep]b4_location_if([, yylocationp])[);
+[  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])]))])[
+
+# 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]])])
+
+
+#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@])[
 
-m4_prepend([b4_epilogue],
-[[
 /*------------------.
 | Report an error.  |
 `------------------*/
 
-]b4_c_ansi_function_def([yyerror],
-    [static void],
-    [[yy::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);
 }
 
 
-namespace yy
-{
-]dnl Restore the actual parser params.
-m4_popdef([b4_parse_param])dnl
-[
-  /// Build a parser object.
-  ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)
-    : yycdebug_ (&std::cerr)]b4_parse_param_cons[
+]b4_namespace_open[
+]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 ]b4_api_PREFIX[DEBUG
+    ]m4_ifset([b4_parse_param], [  ], [ :])[yycdebug_ (&std::cerr)]m4_ifset([b4_parse_param], [,])[
+#endif]b4_parse_param_cons[
   {
   }
 
@@ -99,32 +172,39 @@ m4_popdef([b4_parse_param])dnl
     return ::yyparse (*this]b4_user_args[);
   }
 
-#if YYDEBUG
-
-  /*--------------------------------.
-  | Print this symbol on YYOUTPUT.  |
-  `--------------------------------*/
-
-  void
-  ]b4_parser_class_name[::yysymprint_ (int yytype,
-                           const semantic_type* yyvaluep, const location_type* yylocationp)
-  {
-    /* Pacify ``unused variable'' warnings.  */
+#if ]b4_api_PREFIX[DEBUG
+  /*--------------------.
+  | Print this symbol.  |
+  `--------------------*/
+
+  inline void
+  ]b4_parser_class_name[::yy_symbol_value_print_ (int yytype,
+                           const semantic_type* yyvaluep]b4_locations_if([[,
+                           const location_type* yylocationp]])[)
+  {]b4_locations_if([[
+    YYUSE (yylocationp);]])[
     YYUSE (yyvaluep);
-    YYUSE (yylocationp);
-    /* Backward compatibility, but should be removed eventually.  */
-    std::ostream& cdebug_ = *yycdebug_;
-    YYUSE (cdebug_);
-
-    *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
-              << ' ' << yytname[yytype] << " ("
-               << *yylocationp << ": ";
+    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;
       }
+  }
+
+
+  void
+  ]b4_parser_class_name[::yy_symbol_print_ (int yytype,
+                           const semantic_type* yyvaluep]b4_locations_if([[,
+                           const location_type* yylocationp]])[)
+  {
+    *yycdebug_ << (yytype < YYNTOKENS ? "token" : "nterm")
+               << ' ' << yytname[yytype] << " ("]b4_locations_if([[
+               << *yylocationp << ": "]])[;
+    yy_symbol_value_print_ (yytype, yyvaluep]b4_locations_if([[, yylocationp]])[);
     *yycdebug_ << ')';
   }
 
@@ -144,126 +224,46 @@ m4_popdef([b4_parse_param])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 /* ! YYDEBUG */
-
-} // namespace yy
-
-]])
-
-# Let glr.c believe that the user arguments are only the parser itself.
-m4_pushdef([b4_parse_param],
-          [[yy::b4_parser_class_name& yyparser, yyparser],]
-           m4_defn([b4_parse_param]))
-m4_include(b4_pkgdatadir/[glr.c])
-@output @output_header_name@
-b4_copyright([C++ Skeleton parser for GLALR(1) parsing with Bison],
-             [2002, 2003, 2004, 2005])[
-
-/* C++ GLR parser skeleton written by Akim Demaille.  */
-
-#ifndef PARSER_HEADER_H
-# define PARSER_HEADER_H
-
-#include <string>
-#include <iostream>
-
-/* Using locations.  */
-#define YYLSP_NEEDED ]b4_locations_flag[
-
-namespace yy
-{
-  class position;
-  class location;
-}
-
-/* Copy the first part of user declarations.  */
-]b4_pre_prologue[
-
-]/* Line __line__ of glr.cc.  */
-b4_syncline([@oline@], [@ofile@])[
-
-#include "stack.hh"
-#include "location.hh"
-
-/* Enabling traces.  */
-#ifndef YYDEBUG
-# define YYDEBUG ]b4_debug[
 #endif
+]m4_popdef([b4_parse_param])dnl
+b4_namespace_close
+])
+
+# 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_defines_if([
+b4_bison_locations_if([[#include "location.hh"]])])[
 
-/* Enabling verbose error messages.  */
-#ifdef YYERROR_VERBOSE
-# undef YYERROR_VERBOSE
-# define YYERROR_VERBOSE 1
-#else
-# define YYERROR_VERBOSE ]b4_error_verbose[
-#endif
-
-/* Enabling the token table.  */
-#ifndef YYTOKEN_TABLE
-# define YYTOKEN_TABLE ]b4_token_table[
-#endif
-
-#if 0
-/* Copy the second part of user declarations.  */
-]b4_post_prologue[
-
-]/* Line __line__ of glr.cc.  */
-
-b4_syncline([@oline@], [@ofile@])[
-#endif
+]b4_YYDEBUG_define[
 
-/* 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 (0)
-#endif
+]b4_namespace_open[
+]b4_defines_if([],
+[b4_bison_locations_if([b4_position_define
+b4_location_define])])[
 
-namespace yy
-{
   /// A Bison parser.
   class ]b4_parser_class_name[
   {
   public:
-    /// Symbol semantic values.
-#if ! defined (YYSTYPE)
-]m4_ifdef([b4_stype],
-[b4_syncline([b4_stype_line], [b4_file_name])
-    union semantic_type b4_stype;
-/* Line __line__ of lalr1.cc.  */
-b4_syncline([@oline@], [@ofile@])],
-[    typedef int semantic_type;])[
-#else
-    typedef YYSTYPE semantic_type;
-#endif
-    /// Symbol locations.
-    typedef ]b4_location_type[ location_type;
-    /// Tokens.
-    struct token
-    {
-      ]b4_token_enums(b4_tokens)[
-    };
+]b4_public_types_declare[
 
     /// Build a parser object.
     ]b4_parser_class_name[ (]b4_parse_param_decl[);
@@ -285,47 +285,66 @@ b4_syncline([@oline@], [@ofile@])],
     /// 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.]b4_locations_if([[
+    /// \param yylocationp  Its location.]])[
+    virtual void yy_symbol_value_print_ (int yytype,
+                                         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.
-    virtual void yysymprint_ (int yytype,
-                             const semantic_type* yyvaluep,
-                             const location_type* yylocationp);
+    /// \param yyvaluep     Its semantic value.]b4_locations_if([[
+    /// \param yylocationp  Its location.]])[
+    virtual void yy_symbol_print_ (int yytype,
+                                   const semantic_type* yyvaluep]b4_locations_if([[,
+                                   const location_type* yylocationp]])[);
   private:
-#endif /* ! YYDEBUG */
-
-
-    /// \brief Reclaim the memory associated to a symbol.
-    /// \param yymsg        Why this token is reclaimed.
-    /// \param yytype       The symbol type.
-    /// \param yyvaluep     Its semantic value.
-    /// \param yylocationp  Its location.
-    inline void yydestruct_ (const char* yymsg,
-                             int yytype,
-                             semantic_type* yyvaluep,
-                             location_type* yylocationp);
-
-    /* Debugging.  */
+    // Debugging.
     std::ostream* yycdebug_;
+#endif
+
 ]b4_parse_param_vars[
   };
 
 ]dnl Redirections for glr.c.
-[#define YYSTYPE yy::]b4_parser_class_name[::semantic_type
-#define YYLTYPE yy::]b4_parser_class_name[::location_type
+b4_percent_define_flag_if([[global_tokens_and_yystype]],
+[b4_token_defines])
+[
+#ifndef ]b4_api_PREFIX[STYPE
+# define ]b4_api_PREFIX[STYPE ]b4_namespace_ref[::]b4_parser_class_name[::semantic_type
+#endif
+#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
+])
 
-#endif /* ! defined PARSER_HEADER_H */]
+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])[
+]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])