| Current File : //usr/share/bison/glr.cc |
# C++ GLR skeleton for Bison
# Copyright (C) 2002-2015 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 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, 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])
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. |
`--------------------*/
]b4_function_define([yy_symbol_print],
[static void],
[[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])]))])[
# 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@])[
/*------------------.
| Report an error. |
`------------------*/
]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 (]b4_locations_if([[*yylocationp, ]])[msg);
}
]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[
{
}
]b4_parser_class_name::~b4_parser_class_name[ ()
{
}
int
]b4_parser_class_name[::parse ()
{
return ::yyparse (*this]b4_user_args[);
}
#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);
std::ostream& yyoutput = debug_stream ();
std::ostream& yyo = yyoutput;
YYUSE (yyo);
]b4_symbol_actions([printer])[
}
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_ << ')';
}
std::ostream&
]b4_parser_class_name[::debug_stream () const
{
return *yycdebug_;
}
void
]b4_parser_class_name[::set_debug_stream (std::ostream& o)
{
yycdebug_ = &o;
}
]b4_parser_class_name[::debug_level_type
]b4_parser_class_name[::debug_level () const
{
return yydebug;
}
void
]b4_parser_class_name[::set_debug_level (debug_level_type l)
{
// Actually, it is yydebug which is really used.
yydebug = l;
}
#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"]])])[
]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:
]b4_public_types_declare[
/// Build a parser object.
]b4_parser_class_name[ (]b4_parse_param_decl[);
virtual ~]b4_parser_class_name[ ();
/// Parse.
/// \returns 0 iff parsing succeeded.
virtual int parse ();
/// The current debugging stream.
std::ostream& debug_stream () const;
/// Set the current debugging stream.
void set_debug_stream (std::ostream &);
/// Type for debugging levels.
typedef int debug_level_type;
/// The current debugging level.
debug_level_type debug_level () const;
/// Set the current debugging level.
void set_debug_level (debug_level_type l);
public:
/// 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 (]b4_locations_if([[const location_type& loc, ]])[const std::string& msg);
# 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.]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:
// Debugging.
std::ostream* yycdebug_;
#endif
]b4_parse_param_vars[
};
]dnl Redirections for glr.c.
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
])
b4_defines_if(
[b4_output_begin([b4_spec_defines_file])
b4_copyright([Skeleton interface for Bison GLR parsers in C++],
[2002-2015])[
// 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])