Question

我是currentyl尝试使用BOOST_SPIRIT_DEFINE/DECLARE/INSTANTIATE将我的提升精神x3解析器分成不同的_def和.cpp文件，但我一直收到链接错误。 HERE是我的解析器，它是分开的。

链接器错误读取

<artificial>:(.text.startup+0xbb): undefined reference to `bool kyle::parser::impl::parse_rule<__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type>, boost::spirit::x3::unused_type const>(boost::spirit::x3::rule<kyle::parser::impl::identifier_class, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, false>, __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >&, __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> const&, boost::spirit::x3::unused_type const&)'

我做错了什么？我怎样才能使我的例子有效？

config.hpp：

#include <boost/spirit/home/x3.hpp>

namespace kyle{
namespace parser{

namespace x3 = boost::spirit::x3;

typedef std::string::const_iterator iterator_type;
typedef x3::phrase_parse_context<x3::ascii::space_type>::type context_type;

}
}

literals.cpp：

#include "literals_def.hpp"
#include "config.hpp"
#include <boost/spirit/home/x3.hpp>


namespace kyle {
namespace parser {
namespace impl {

BOOST_SPIRIT_INSTANTIATE(identifier_type, iterator_type, context_type);

}
}
}

literals_def.hpp：

#include <boost/spirit/home/x3.hpp>
#include "literals.hpp"

namespace kyle {
namespace parser {
namespace impl {

namespace x3 = boost::spirit::x3;


const identifier_type identifier = "identifier";



auto const identifier_def = x3::alpha >> *x3::alnum;

BOOST_SPIRIT_DEFINE(identifier)
}
impl::identifier_type identifier(){
    return impl::identifier;
}


}
}

literals.hpp：

#include <boost/spirit/home/x3.hpp>

namespace kyle{
namespace parser{
namespace impl {
namespace x3 = boost::spirit::x3;

struct identifier_class;

typedef x3::rule<identifier_class, std::string> identifier_type;

BOOST_SPIRIT_DECLARE(identifier_type)
}

impl::identifier_type identifier();


}
}

main.cpp：

#include "literals.hpp"
#include <iostream>

template<typename Parser>
bool test(std::string str, Parser&& p, bool full_match = true)
{
    auto in = str.begin();
    auto end = str.end();
    bool ret = boost::spirit::x3::phrase_parse(in, end, p, boost::spirit::x3::space);
    ret &= (!full_match || (in == end));
    return ret;

}

int main(){
    auto b = test("fobar", kyle::parser::identifier());
    std::cout << b << std::endl;

}

Answer 1

两点：

您将上下文定义为
```
foreign_key_constraint/3
```
但是，您尝试使用typedef x3::phrase_parse_context<x3::space_type>::type context_type;而不是x3::space来调用它。

提示位于您未包含的错误消息中：

x3::ascii::space的 /home/sehe/custom/boost/boost/spirit/home/x3/nonterminal/rule.hpp:116: undefined reference to 'bool kyle::parser::impl::parse_rule<__gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::spirit::x3::rule<kyle::parser::impl::identifier_class, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, false>, __gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >&, __gnu_cxx::__normal_iterator<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit:: char_encoding::standard

迭代器类型被推断为, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)'，而不是std::string::iterator。修复它或不要始终使用std::string::const_iterator：

<强> Live On Melpon

完整代码

为后代

config.hpp：

auto

literals.cpp：

#include <boost/spirit/home/x3.hpp> namespace kyle{ namespace parser{ namespace x3 = boost::spirit::x3; typedef std::string::const_iterator iterator_type; typedef x3::phrase_parse_context<x3::space_type>::type context_type; } }

literals_def.hpp：

#include "literals_def.hpp" #include "config.hpp" #include <boost/spirit/home/x3.hpp> namespace kyle { namespace parser { namespace impl { BOOST_SPIRIT_INSTANTIATE(identifier_type, iterator_type, context_type); } } }

literals.hpp：

#include <boost/spirit/home/x3.hpp> #include "literals.hpp" namespace kyle { namespace parser { namespace impl { namespace x3 = boost::spirit::x3; const identifier_type identifier = "identifier"; auto const identifier_def = x3::alpha >> *x3::alnum; BOOST_SPIRIT_DEFINE(identifier) } impl::identifier_type identifier(){ return impl::identifier; } } }

main.cpp：

#include <boost/spirit/home/x3.hpp> namespace kyle{ namespace parser{ namespace impl { namespace x3 = boost::spirit::x3; struct identifier_class; typedef x3::rule<identifier_class, std::string> identifier_type; BOOST_SPIRIT_DECLARE(identifier_type) } impl::identifier_type identifier(); } }

CMakeLists.txt：

#include "literals.hpp" #include <iostream> template<typename Parser> bool test(std::string const& str, Parser p, std::string& output, bool full_match = true) { auto in = str.begin(); auto end = str.end(); bool ret = boost::spirit::x3::phrase_parse(in, end, p, boost::spirit::x3::space, output); ret &= (!full_match || (in == end)); return ret; } int main(){ std::string s; auto b = test("fobar", kyle::parser::identifier(), s); std::cout << b << ": " << s << std::endl; }

Answer 2

除了回答之外，我还要补充一点：

您需要对您声明的内容和实际使用内容非常准确。 X3允许任何类型的可能类型，但链接器不允许。

这里有一个提示：当发生链接器错误时，在BOOST_SPIRIT_INSTANTIATE之后，声明如下内容：

int x = context_type{};

这将是一个错误，是的，因为context_type无法转换为int。但是，该错误也会为您提供上下文的确切类型。将它与链接器错误进行比较，您将看到错误。

使用boost spirit x3

2 个答案:

完整代码