cpp_expression_grammar.hpp

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/*=============================================================================
    Boost.Wave: A Standard compliant C++ preprocessor library

    http://www.boost.org/

    Copyright (c) 2001-2008 Hartmut Kaiser. Distributed under the Boost
    Software License, Version 1.0. (See accompanying file
    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/

#if !defined(CPP_EXPRESSION_GRAMMAR_HPP_099CD1A4_A6C0_44BE_8F24_0B00F5BE5674_INCLUDED)
#define CPP_EXPRESSION_GRAMMAR_HPP_099CD1A4_A6C0_44BE_8F24_0B00F5BE5674_INCLUDED

#include <boost/wave/wave_config.hpp>

#include <boost/assert.hpp>
#include <boost/spirit/include/classic_core.hpp>
#include <boost/spirit/include/classic_closure.hpp>
#include <boost/spirit/include/classic_if.hpp>
#include <boost/spirit/include/classic_assign_actor.hpp>
#include <boost/spirit/include/classic_push_back_actor.hpp>

#include <boost/spirit/include/phoenix1_functions.hpp>
#include <boost/spirit/include/phoenix1_operators.hpp>
#include <boost/spirit/include/phoenix1_primitives.hpp>
#include <boost/spirit/include/phoenix1_statements.hpp>
#include <boost/spirit/include/phoenix1_casts.hpp>

#include <boost/wave/token_ids.hpp>

#include <boost/wave/cpp_exceptions.hpp>
#include <boost/wave/grammars/cpp_expression_grammar_gen.hpp>   
#include <boost/wave/grammars/cpp_literal_grammar_gen.hpp>  
#include <boost/wave/grammars/cpp_expression_value.hpp>
#include <boost/wave/util/pattern_parser.hpp>
#include <boost/wave/util/macro_helpers.hpp>

#if !defined(spirit_append_actor)
#define spirit_append_actor(actor) boost::spirit::classic::push_back_a(actor)
#define spirit_assign_actor(actor) boost::spirit::classic::assign_a(actor)
#endif // !defined(spirit_append_actor)

// this must occur after all of the includes and before any code appears
#ifdef BOOST_HAS_ABI_HEADERS
#include BOOST_ABI_PREFIX
#endif

///////////////////////////////////////////////////////////////////////////////
//
//  Encapsulation of the grammar for evaluation of constant preprocessor
//  expressions
//
///////////////////////////////////////////////////////////////////////////////
namespace boost {
namespace wave { 
namespace grammars {
namespace closures {

///////////////////////////////////////////////////////////////////////////////
//
//  define the closure type used throughout the C++ expression grammar
//
//      Throughout this grammar all literal tokens are stored into a 
//      closure_value variables, which converts the types appropriately, where 
//      required.
//
///////////////////////////////////////////////////////////////////////////////
    struct cpp_expr_closure 
    :   boost::spirit::classic::closure<cpp_expr_closure, closure_value> 
    {
        member1 val;
    };

}   // namespace closures

namespace impl {

///////////////////////////////////////////////////////////////////////////////
//
//  convert the given token value (integer literal) to a unsigned long
//
///////////////////////////////////////////////////////////////////////////////
    struct convert_intlit {

        template <typename ArgT>
        struct result { 
        
            typedef boost::wave::grammars::closures::closure_value type; 
        };

        template <typename TokenT>
        boost::wave::grammars::closures::closure_value 
        operator()(TokenT const &token) const
        { 
            typedef boost::wave::grammars::closures::closure_value return_type;
            bool is_unsigned = false;
            uint_literal_type ul = intlit_grammar_gen<TokenT>::evaluate(token, 
                is_unsigned);

            return is_unsigned ? 
                return_type(ul) : return_type(static_cast<int_literal_type>(ul));
        }
    };
    phoenix::function<convert_intlit> const as_intlit;

///////////////////////////////////////////////////////////////////////////////
//
//  convert the given token value (character literal) to a unsigned int
//
///////////////////////////////////////////////////////////////////////////////
    struct convert_chlit {

        template <typename ArgT>
        struct result { 
        
            typedef boost::wave::grammars::closures::closure_value type; 
        };

        template <typename TokenT>
        boost::wave::grammars::closures::closure_value 
        operator()(TokenT const &token) const
        { 
            typedef boost::wave::grammars::closures::closure_value return_type;
            value_error status = error_noerror;
            unsigned int value = chlit_grammar_gen<TokenT>::evaluate(token, status);
            return return_type(value, status);
        }
    };
    phoenix::function<convert_chlit> const as_chlit;

////////////////////////////////////////////////////////////////////////////////
//
//  Handle the ?: operator with correct type and error propagation
//
////////////////////////////////////////////////////////////////////////////////
    struct operator_questionmark {
    
        template <typename CondT, typename Arg1T, typename Arg2T>
        struct result { 
        
            typedef boost::wave::grammars::closures::closure_value type; 
        };

        template <typename CondT, typename Arg1T, typename Arg2T>
        boost::wave::grammars::closures::closure_value 
        operator()(CondT const &cond, Arg1T &val1, Arg2T const &val2) const
        { 
            return val1.handle_questionmark(cond, val2);
        }
    };
    phoenix::function<operator_questionmark> const questionmark;

///////////////////////////////////////////////////////////////////////////////
//
//  Handle type conversion conserving error conditions
//
///////////////////////////////////////////////////////////////////////////////
    struct operator_to_bool {
    
        template <typename ArgT>
        struct result { 
        
            typedef boost::wave::grammars::closures::closure_value type; 
        };

        template <typename ArgT>
        boost::wave::grammars::closures::closure_value 
        operator()(ArgT &val) const
        { 
            typedef boost::wave::grammars::closures::closure_value return_type;
            return return_type(
                boost::wave::grammars::closures::as_bool(val), val.is_valid());
        }
    };
    phoenix::function<operator_to_bool> const to_bool;
    
///////////////////////////////////////////////////////////////////////////////
//
//  Handle explicit type conversion
//
///////////////////////////////////////////////////////////////////////////////
    struct operator_as_bool {
    
        template <typename ArgT>
        struct result { 
        
            typedef bool type; 
        };

        template <typename ArgT>
        bool
        operator()(ArgT &val) const
        { 
            return boost::wave::grammars::closures::as_bool(val);
        }
    };
    phoenix::function<operator_as_bool> const as_bool;
    
///////////////////////////////////////////////////////////////////////////////
//
//  Handle closure value operators with proper error propagation
//
///////////////////////////////////////////////////////////////////////////////
#define BOOST_WAVE_BINARYOP(op, optok)                                        \
    struct operator_binary_ ## op {                                           \
                                                                              \
        template <typename Arg1T, typename Arg2T>                             \
        struct result {                                                       \
                                                                              \
            typedef boost::wave::grammars::closures::closure_value type;      \
        };                                                                    \
                                                                              \
        template <typename Arg1T, typename Arg2T>                             \
        boost::wave::grammars::closures::closure_value                        \
        operator()(Arg1T &val1, Arg2T &val2) const                            \
        {                                                                     \
            return val1 optok val2;                                           \
        }                                                                     \
    };                                                                        \
    phoenix::function<operator_binary_ ## op> const binary_ ## op             \
    /**/

    BOOST_WAVE_BINARYOP(and, &&);
    BOOST_WAVE_BINARYOP(or, ||);
    
    BOOST_WAVE_BINARYOP(bitand, &);
    BOOST_WAVE_BINARYOP(bitor, |);
    BOOST_WAVE_BINARYOP(bitxor, ^);
    
    BOOST_WAVE_BINARYOP(lesseq, <=);
    BOOST_WAVE_BINARYOP(less, <);
    BOOST_WAVE_BINARYOP(greater, >);
    BOOST_WAVE_BINARYOP(greateq, >=);
    BOOST_WAVE_BINARYOP(eq, ==);
    BOOST_WAVE_BINARYOP(ne, !=);

#undef BOOST_WAVE_BINARYOP

///////////////////////////////////////////////////////////////////////////////
#define BOOST_WAVE_UNARYOP(op, optok)                                         \
    struct operator_unary_ ## op {                                            \
                                                                              \
        template <typename ArgT>                                              \
        struct result {                                                       \
                                                                              \
            typedef boost::wave::grammars::closures::closure_value type;      \
        };                                                                    \
                                                                              \
        template <typename ArgT>                                              \
        boost::wave::grammars::closures::closure_value                        \
        operator()(ArgT &val) const                                           \
        {                                                                     \
            return optok val;                                                 \
        }                                                                     \
    };                                                                        \
    phoenix::function<operator_unary_ ## op> const unary_ ## op               \
    /**/

    BOOST_WAVE_UNARYOP(neg, !);
    
#undef BOOST_WAVE_UNARYOP

}   // namespace impl

///////////////////////////////////////////////////////////////////////////////
//  define, whether the rule's should generate some debug output
#define TRACE_CPP_EXPR_GRAMMAR \
    bool(BOOST_SPIRIT_DEBUG_FLAGS_CPP & BOOST_SPIRIT_DEBUG_FLAGS_CPP_EXPR_GRAMMAR) \
    /**/

struct expression_grammar :
    public boost::spirit::classic::grammar<
        expression_grammar, 
        closures::cpp_expr_closure::context_t
    >
{
    expression_grammar()
    {
        BOOST_SPIRIT_DEBUG_TRACE_GRAMMAR_NAME(*this, "expression_grammar", 
            TRACE_CPP_EXPR_GRAMMAR);
    }
    
    // no need for copy constructor/assignment operator
    expression_grammar(expression_grammar const&);
    expression_grammar& operator= (expression_grammar const&);