cpp_expression_grammar.hpp

C++的一个好库。。。现在很流行

                                [
                                    shift_exp.val >>= arg1
                                ]
                        )
                ;

            add_exp
                =   multiply_exp[add_exp.val = arg1]
                    >> *(   ch_p(T_PLUS)
                            >>  multiply_exp
                                [
                                    add_exp.val += arg1
                                ]
                        |   ch_p(T_MINUS)
                            >>  multiply_exp
                                [
                                    add_exp.val -= arg1
                                ]
                        )
                ;

            multiply_exp
                =   unary_exp[multiply_exp.val = arg1]
                    >> *(   ch_p(T_STAR)
                            >>  unary_exp
                                [
                                    multiply_exp.val *= arg1
                                ]
                        |   ch_p(T_DIVIDE)
                            >>  unary_exp
                                [
                                    multiply_exp.val /= arg1
                                ]
                        |   ch_p(T_PERCENT)
                            >>  unary_exp
                                [
                                    multiply_exp.val %= arg1
                                ]
                        )
                ;

            unary_exp
                =   primary_exp[unary_exp.val = arg1]
                |   ch_p(T_PLUS) >> unary_exp
                    [
                        unary_exp.val = arg1
                    ]
                |   ch_p(T_MINUS) >> unary_exp
                    [
                        unary_exp.val = -arg1
                    ]
                |   pattern_p(T_COMPL, MainTokenMask) >> unary_exp
                    [
                        unary_exp.val = ~arg1
                    ]
                |   pattern_p(T_NOT, MainTokenMask) >> unary_exp
                    [
                        unary_exp.val = !arg1
                    ]
                ;

            primary_exp
                =   constant[primary_exp.val = arg1]
                |   ch_p(T_LEFTPAREN) 
                    >> const_exp[primary_exp.val = arg1]
                    >> ch_p(T_RIGHTPAREN)
                ;

            constant
                =   ch_p(T_INTLIT) 
                    [
                        constant.val = impl::as_intlit(arg1)
                    ]
                |   ch_p(T_CHARLIT) 
                    [
                        constant.val = impl::as_chlit(arg1)
                    ]
                ;
              
            //  here follows the same grammar, but without any embedded 
            //  calculations
            const_exp_nocalc
                =   logical_or_exp_nocalc
                    >> !(   ch_p(T_QUESTION_MARK)
                            >>  const_exp_nocalc
                            >>  ch_p(T_COLON)
                            >>  const_exp_nocalc
                        )
                ;

            logical_or_exp_nocalc 
                =   logical_and_exp_nocalc
                    >> *(   pattern_p(T_OROR, MainTokenMask)
                            >>  logical_and_exp_nocalc
                        )
                ;

            logical_and_exp_nocalc
                =   inclusive_or_exp_nocalc
                    >> *(   pattern_p(T_ANDAND, MainTokenMask)
                            >>  inclusive_or_exp_nocalc
                        )
                ;

            inclusive_or_exp_nocalc
                =   exclusive_or_exp_nocalc
                    >> *(   pattern_p(T_OR, MainTokenMask)
                            >>  exclusive_or_exp_nocalc
                        )
                ;

            exclusive_or_exp_nocalc
                =   and_exp_nocalc
                    >> *(   pattern_p(T_XOR, MainTokenMask)
                            >>  and_exp_nocalc
                        )
                ;

            and_exp_nocalc
                =   cmp_equality_nocalc
                    >> *(   pattern_p(T_AND, MainTokenMask)
                            >>  cmp_equality_nocalc
                        )
                ;

            cmp_equality_nocalc
                =   cmp_relational_nocalc
                    >> *(   ch_p(T_EQUAL)
                            >>  cmp_relational_nocalc
                        |   pattern_p(T_NOTEQUAL, MainTokenMask)
                            >>  cmp_relational_nocalc
                        )
                ;

            cmp_relational_nocalc
                =   shift_exp_nocalc
                    >> *(   ch_p(T_LESSEQUAL)
                            >>  shift_exp_nocalc
                        |   ch_p(T_GREATEREQUAL)
                            >>  shift_exp_nocalc
                        |   ch_p(T_LESS)
                            >>  shift_exp_nocalc
                        |   ch_p(T_GREATER)
                            >>  shift_exp_nocalc
                        )
                ;

            shift_exp_nocalc
                =   add_exp_nocalc
                    >> *(   ch_p(T_SHIFTLEFT)
                            >>  add_exp_nocalc
                        |   ch_p(T_SHIFTRIGHT)
                            >>  add_exp_nocalc
                        )
                ;

            add_exp_nocalc
                =   multiply_exp_nocalc
                    >> *(   ch_p(T_PLUS)
                            >>  multiply_exp_nocalc
                        |   ch_p(T_MINUS)
                            >>  multiply_exp_nocalc
                        )
                ;

            multiply_exp_nocalc
                =   unary_exp_nocalc
                    >> *(   ch_p(T_STAR)
                            >>  unary_exp_nocalc
                        |   ch_p(T_DIVIDE)
                            >>  unary_exp_nocalc
                        |   ch_p(T_PERCENT)
                            >>  unary_exp_nocalc
                        )
                ;

            unary_exp_nocalc
                =   primary_exp_nocalc
                |   ch_p(T_PLUS) >> unary_exp_nocalc
                |   ch_p(T_MINUS) >> unary_exp_nocalc
                |   pattern_p(T_COMPL, MainTokenMask) >> unary_exp_nocalc
                |   pattern_p(T_NOT, MainTokenMask) >> unary_exp_nocalc
                ;

            primary_exp_nocalc
                =   constant_nocalc
                |   ch_p(T_LEFTPAREN) 
                    >> const_exp_nocalc
                    >> ch_p(T_RIGHTPAREN)
                ;

            constant_nocalc
                =   ch_p(T_INTLIT) 
                |   ch_p(T_CHARLIT) 
                ;

            BOOST_SPIRIT_DEBUG_TRACE_RULE(pp_expression, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(const_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(logical_or_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(logical_and_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(inclusive_or_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(exclusive_or_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(and_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(cmp_equality, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(cmp_relational, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(shift_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(add_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(multiply_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(unary_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(primary_exp, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(constant, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(const_exp_subrule, TRACE_CPP_EXPR_GRAMMAR);

            BOOST_SPIRIT_DEBUG_TRACE_RULE(const_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(logical_or_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(logical_and_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(inclusive_or_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(exclusive_or_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(and_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(cmp_equality_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(cmp_relational_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(shift_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(add_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(multiply_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(unary_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(primary_exp_nocalc, TRACE_CPP_EXPR_GRAMMAR);
            BOOST_SPIRIT_DEBUG_TRACE_RULE(constant_nocalc, TRACE_CPP_EXPR_GRAMMAR);
        }

    // start rule of this grammar
        simple_rule_t const& start() const
        { return pp_expression; }
    };
};

///////////////////////////////////////////////////////////////////////////////
#undef TRACE_CPP_EXPR_GRAMMAR

///////////////////////////////////////////////////////////////////////////////
//  
//  The following function is defined here, to allow the separation of 
//  the compilation of the expression_grammar from the function using it.
//  
///////////////////////////////////////////////////////////////////////////////

#if BOOST_WAVE_SEPARATE_GRAMMAR_INSTANTIATION != 0
#define BOOST_WAVE_EXPRGRAMMAR_GEN_INLINE
#else
#define BOOST_WAVE_EXPRGRAMMAR_GEN_INLINE inline
#endif 

template <typename TokenT>
BOOST_WAVE_EXPRGRAMMAR_GEN_INLINE 
bool 
expression_grammar_gen<TokenT>::evaluate(
    typename token_sequence_type::const_iterator const &first, 
    typename token_sequence_type::const_iterator const &last, 
    typename token_type::position_type const &act_pos,
    bool if_block_status)
{
    using namespace boost::spirit;
    using namespace boost::wave;
    using namespace boost::wave::grammars::closures;
    
    using boost::wave::util::impl::as_string;
    
    typedef typename token_sequence_type::const_iterator iterator_type;
    typedef typename token_sequence_type::value_type::string_type string_type;

    parse_info<iterator_type> hit(first);
    closure_value result;             // expression result
    
    try {
        expression_grammar g;             // expression grammar
        hit = parse (first, last, g[spirit_assign_actor(result)], 
                     ch_p(T_SPACE) | ch_p(T_CCOMMENT) | ch_p(T_CPPCOMMENT));

        if (!hit.hit) {
        // expression is illformed
            if (if_block_status) {
                string_type expression = as_string<string_type>(first, last);
                if (0 == expression.size()) 
                    expression = "empty expression";
                BOOST_WAVE_THROW(preprocess_exception, ill_formed_expression, 
                    expression.c_str(), act_pos);
            }
            else {
            //  as the if_block_status is false no errors will be reported
                return false;
            }
        }
    }
    catch (wave::preprocess_exception const& e) {
    // expression is illformed
        if (if_block_status) {
            throw e;
        }
        else {
        //  as the if_block_status is false no errors will be reported
            return false;
        }
    }
        
    if (!hit.full) {
    // The token list starts with a valid expression, but there remains 
    // something. If the remainder consists out of whitespace only, the 
    // expression is still valid.
    iterator_type next = hit.stop;
    
        while (next != last) {
            switch (static_cast<unsigned int>(token_id(*next))) {
            case T_SPACE:
            case T_SPACE2:
            case T_CCOMMENT:
                break;                      // ok continue
                
            case T_NEWLINE:
            case T_EOF:
            case T_CPPCOMMENT:              // contains newline
                return bool(result);        // expression is valid
                
            default:
            // expression is illformed
                if (if_block_status) {
                    string_type expression = as_string<string_type>(first, last);
                    if (0 == expression.size()) 
                        expression = "empty expression";
                    BOOST_WAVE_THROW(preprocess_exception, ill_formed_expression, 
                        expression.c_str(), act_pos);
                }
                else {
                //  as the if_block_status is false no errors will be reported
                    return false;
                }
            }
            ++next;
        }
    }

    if (closure_value::error_noerror != result.is_valid()) {
    // division by zero occured
        string_type expression = as_string<string_type>(first, last);
        if (0 == expression.size()) 
            expression = "empty expression";
            
        if (closure_value::error_division_by_zero == result.is_valid()) {
            BOOST_WAVE_THROW(preprocess_exception, division_by_zero, 
                expression.c_str(), act_pos);
        }
        else if (closure_value::error_overflow == result.is_valid()) {
            BOOST_WAVE_THROW(preprocess_exception, integer_overflow,
                expression.c_str(), act_pos);
        }
    }
    
// token sequence is a valid expression
    return bool(result);
}

#undef BOOST_WAVE_EXPRGRAMMAR_GEN_INLINE

///////////////////////////////////////////////////////////////////////////////
}   // namespace grammars
}   // namespace wave
}   // namespace boost

#endif // !defined(CPP_EXPRESSION_GRAMMAR_HPP_099CD1A4_A6C0_44BE_8F24_0B00F5BE5674_INCLUDED)