编译错误，带有boost::spirit语法分析器

Compilation error with a boost::spirit parser

本文关键字：spirit 语法 语法分析 分析器 boost 错误 带有 编译      更新时间：2023-10-16

我有一个使用boost:：spirit制作的计算器的奇怪问题。这个计算器应该以一个字符串作为参数，表示一系列用逗号分隔的算术表达式，如"a+4*5,77，（b-c）*4"。它还允许字符串"？"，并在这种情况下返回包含-1的数组。计算器使用SymTable初始化，SymTable是一个模板类参数，用于描述任何提供[string]->int运算符（例如：映射）的类，以解析变量的值。

下面的代码适用于我的Ubuntu 10.4，包括gcc 4.6.2和gcc 4.4，以及boost 1.47和1.48。它过去也在一台带有gcc 4.5.3和boost 1.47的Cray Linux机器上工作。

#include <boost/bind.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
namespace sp = boost::spirit;
namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
namespace Damaris {
template <typename Iterator, typename SymTable>
struct Calc : qi::grammar<Iterator, std::vector<int>(), ascii::space_type>
{
        qi::rule<Iterator, std::vector<int>(), ascii::space_type> start;
        qi::rule<Iterator, int(), ascii::space_type> expr;
        qi::rule<Iterator, int(), ascii::space_type> qmark;
        qi::rule<Iterator, int(), ascii::space_type> factor;
        qi::rule<Iterator, int(), ascii::space_type> simple;
        qi::rule<Iterator, std::string(), ascii::space_type> identifier;
        qi::rule<Iterator, int(SymTable), ascii::space_type> value;
        /**
         * brief Constructor.
         * param[in] sym : table of symboles.
         */
        Calc(SymTable &sym) : Calc::base_type(start)
        {
                identifier = qi::lexeme[( qi::alpha | '_') >> *( qi::alnum | '_')];
                value   = identifier[qi::_val = qi::labels::_r1[qi::_1]];
                simple  = ('(' >> expr >> ')')
                        | qi::int_
                        | value(boost::phoenix::ref(sym));
                factor  %= (simple >> '*' >> factor)[qi::_val = qi::_1 * qi::_2]
                        |  (simple >> '/' >> factor)[qi::_val = qi::_1 / qi::_2]
                        |  (simple >> '%' >> factor)[qi::_val = qi::_1 % qi::_2]
                        |   simple;
                expr    %= (factor >> '+' >> expr)[qi::_val = qi::_1 + qi::_2]
                        |  (factor >> '-' >> expr)[qi::_val = qi::_1 - qi::_2]
                        |   factor;
                qmark   = qi::char_('?')[qi::_val = -1];
                start   = qmark
                        | (expr % ',');
        }
};
}

今天，我再次尝试在Cray机器上编译相同的代码（我想从那时起，它已经升级了），我尝试了gcc 4.6.2和gcc 4.5.2，以及boost 1.48和1.49，但我总是得到我不理解的相同编译错误：

/nics/b/home/mdorier/damaris-0.4/common/Calc.hpp:74:3:   instantiated from 'Damaris::Calc<Iterator, SymTable>::Calc(SymTable&) [with Iterator = __gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, SymTable = Damaris::ParameterSet]'
/nics/b/home/mdorier/damaris-0.4/common/MetadataManager.cpp:45:79:   instantiated from here
/nics/b/home/mdorier/deploy/include/boost/spirit/home/qi/detail/assign_to.hpp:123:13: error: invalid static_cast from type 'const boost::fusion::vector2<int, int>' to type 'int'

Calc.hpp中的第74行对应于"factor=…"行。指示的实例化行（MetadataManager.cpp:45）如下：

layoutInterp = new Calc<std::string::const_iterator,ParameterSet>(*parameters);

其中layoutInterp是Calc*类型并且参数是ParameterSet*类型。

知道这个错误是从哪里来的吗？感谢

我很确定您可能已经重新安排了规则中的内容。事实上，%=自动规则表达式赋值不起作用，因为语法分析器表达式的合成类型与int不相似。

基本上，你会改变

factor %= (simple >> '*' >> factor)[ _val = _1 * _2 ]
    |  (simple >> '/' >> factor)[ _val = _1 / _2 ]
    |  (simple >> '%' >> factor)[ _val = _1 % _2 ]
    |   simple;
expr   %= (factor >> '+' >> expr)[ _val = _1 + _2 ]
    |  (factor >> '-' >> expr)[ _val = _1 - _2 ]
    |   factor;

进入

factor  = (simple >> '*' >> factor)[ _val = _1 * _2 ]
        | (simple >> '/' >> factor)[ _val = _1 / _2 ]
        | (simple >> '%' >> factor)[ _val = _1 % _2 ]
        | (simple) [_val = _1 ];
expr    = (factor >> '+' >> expr)[ _val = _1 + _2 ]
        | (factor >> '-' >> expr)[ _val = _1 - _2 ]
        | (factor) [_val = _1 ];

我已经解决了一些小问题，并为你的帖子创建了一个SSCCE，据我所知，它是有效的：

#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/karma.hpp>
#include <boost/spirit/include/phoenix.hpp>
namespace sp = boost::spirit;
namespace qi    = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
namespace karma = boost::spirit::karma;
namespace phx   = boost::phoenix;
namespace Damaris {
    template <typename Iterator, typename SymTable>
    struct Calc : qi::grammar<Iterator, std::vector<int>(), ascii::space_type>
    {
        qi::rule<Iterator, std::vector<int>(), ascii::space_type> start;
        qi::rule<Iterator, int(), ascii::space_type> expr;
        qi::rule<Iterator, int(), ascii::space_type> qmark;
        qi::rule<Iterator, int(), ascii::space_type> factor;
        qi::rule<Iterator, int(), ascii::space_type> simple;
        qi::rule<Iterator, std::string(), ascii::space_type> identifier;
        qi::rule<Iterator, int(SymTable), ascii::space_type> value;
        Calc(SymTable &sym) : Calc::base_type(start)
        {
            using namespace qi;
            identifier = lexeme[( alpha | '_') >> *( alnum | '_')];
            value   = identifier[ _val = _r1[_1] ];
            simple  = ('(' >> expr >> ')')
                    | int_
                    | value(boost::phoenix::ref(sym));
            factor  = (simple >> '*' >> factor)[ _val = _1 * _2 ]
                    | (simple >> '/' >> factor)[ _val = _1 / _2 ]
                    | (simple >> '%' >> factor)[ _val = _1 % _2 ]
                    | (simple) [_val = _1 ];
            expr    = (factor >> '+' >> expr)[ _val = _1 + _2 ]
                    | (factor >> '-' >> expr)[ _val = _1 - _2 ]
                    | (factor) [_val = _1 ];
            qmark   = char_('?')[ _val = -1 ];
            start   = qmark 
                | (expr % ',');
            BOOST_SPIRIT_DEBUG_NODE(start);
            BOOST_SPIRIT_DEBUG_NODE(qmark);
            BOOST_SPIRIT_DEBUG_NODE(expr);
            BOOST_SPIRIT_DEBUG_NODE(factor);
            BOOST_SPIRIT_DEBUG_NODE(simple);
            BOOST_SPIRIT_DEBUG_NODE(value);
            BOOST_SPIRIT_DEBUG_NODE(identifier);
        }
    };
}
int main(int argc, const char *argv[])
{
    typedef std::map<std::string, int> SymTable;
    SymTable symbols;
    Damaris::Calc<std::string::const_iterator, SymTable> calc(symbols);
    symbols["TheAnswerToLifeUniverse"] = 100;
    symbols["Everything"] = -58;
    std::string input = "3*4+5/4, TheAnswerToLifeUniverse + Everything";
    std::string::const_iterator f(input.begin()), l(input.end());
    std::vector<int> data;
    if (qi::phrase_parse(f,l,calc,ascii::space,data))
        std::cout << "output: " << karma::format(karma::int_ % ", " << karma::eol, data);
    else
        std::cout << "problem: '" << std::string(f,l) << "'n";
    return 0;
}

输出：

output: 13, 42

1gcc 4.6.1，提升1_48

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