为什么不能在c++0x模式下使用libc++链接这个boost::program_options示例？
为什么不能在c++0x模式下使用libc++链接这个boost::program_options示例？
提问于 2011-12-10 12:13:30
为boost：：program_options编译以下示例代码：http://svn.boost.org/svn/boost/trunk/libs/program_options/example/first.cpp
...on MacOS Lion (10.7.2)，使用随MacPorts一起安装的boost-1.48.0：
$ clang++ -v
Apple clang version 3.0 (tags/Apple/clang-211.12) (based on LLVM 3.0svn)
Target: x86_64-apple-darwin11.2.0
Thread model: posix
$ clang++ -std=c++0x --stdlib=libc++ -lc++ -I/opt/local/include -L/opt/local/lib -lboost_program_options first.cpp -o first
Undefined symbols for architecture x86_64:
"boost::program_options::options_description::options_description(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, unsigned int, unsigned int)", referenced from:
_main in cc-6QQcwm.o
"boost::program_options::operator<<(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, boost::program_options::options_description const&)", referenced from:
_main in cc-6QQcwm.o
"boost::program_options::abstract_variables_map::operator[](std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) const", referenced from:
boost::program_options::variables_map::operator[](std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) const in cc-6QQcwm.o
"boost::program_options::detail::cmdline::set_additional_parser(boost::function1<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&>)", referenced from:
boost::program_options::basic_command_line_parser<char>::extra_parser(boost::function1<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&>) in cc-6QQcwm.o
"boost::program_options::detail::cmdline::cmdline(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&)", referenced from:
boost::program_options::basic_command_line_parser<char>::basic_command_line_parser(int, char const* const*) in cc-6QQcwm.o
"boost::program_options::to_internal(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > boost::program_options::to_internal<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&) in cc-6QQcwm.o
"boost::program_options::invalid_option_value::invalid_option_value(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
void boost::program_options::validate<int, char>(boost::any&, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&, int*, long) in cc-6QQcwm.o
"boost::program_options::validation_error::validation_error(boost::program_options::validation_error::kind_t, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const& boost::program_options::validators::get_single_string<char>(std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&, bool) in cc-6QQcwm.o
"boost::program_options::value_semantic_codecvt_helper<char>::parse(boost::any&, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&, bool) const", referenced from:
vtable for boost::program_options::typed_value<int, char> in cc-6QQcwm.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)与MacPorts一起安装的g++4.7编译/链接的相同代码：
$ g++-mp-4.7 -std=c++0x -I/opt/local/include -L/opt/local/lib -lboost_program_options -o first first.cpp..。工作正常。就像使用不带libc++的clang一样：
clang++ -std=c++0x -I/opt/local/include -L/opt/local/lib -lboost_program_options first.cpp -o first怎么了？为什么boost::program_options和libc++不能一起工作？
回答 1
Stack Overflow用户
回答已采纳
发布于 2011-12-10 23:59:42
您需要使用clang++ -stdlib=libc++重建boost。
libc++与gcc的libstdc++不是二进制兼容的(除了一些低级的东西，如运算符new)。例如，在gcc的libstdc++中，std::string被重新计数，而在libc++中，它使用了“短串优化”。如果您意外地在同一个程序中混合了这两个字符串(并将它们误认为相同的数据结构)，您将不可避免地遇到运行时崩溃。
这起事故就是发生在你身上的。
为了将这种运行时崩溃转变为链接时错误，libc++使用名为inline namespace的C++11语言特性来更改std::string的ABI，而不会影响std::string的应用编程接口。也就是说，对您来说，std::string看起来是一样的。但是对于链接器来说，std::string正在被破坏，就好像它在名称空间std::__1中一样。因此，链接器知道std::basic_string和std::__1::basic_string是两种不同的数据结构(前者来自gcc的libstdc++，后者来自libc++)。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/8454329
复制相关文章
相似问题