Description of problem:

When using clang 3.4.2 and boost, I got many "__extern_always_inline" error messages. 

Notice: These error messages won't appear when using e.g Arch Linux with clang 3.4.2 and Boost 1.55 or Debian Debian Testing with the same boost and clang version.


Version-Release number of selected component (if applicable):

Fedora 21
clang 3.4.2
Boost 1.55

How reproducible:

Here's short example code:

#include <boost/archive/binary_oarchive.hpp>
#include <boost/archive/binary_iarchive.hpp>

#include <string>
#include <fstream>

class test_me
{
public:
	friend class boost::serialization::access;
	test_me(){}

	template <typename Archive> void load(Archive &ar)
	{
	}

	void load(std::string file_name);
};

void test_me::load(std::string file_name)
{
	std::ifstream input_fs(file_name.c_str());
	boost::archive::binary_iarchive ia(input_fs);

	load(ia);
}

int main()
{
	test_me * test = new test_me();
	test->load("test.out");
	return 0;
}


Steps to Reproduce:
1. Compile the code with clang++ -Wunreachable-code -std=c++11 -O3 -lboost_serialization  test.cpp
2.
3.

Actual results:

In file included from test.cpp:2:
In file included from /usr/include/boost/archive/binary_iarchive.hpp:20:
In file included from /usr/include/boost/archive/binary_iarchive_impl.hpp:21:
In file included from /usr/include/boost/archive/basic_binary_iprimitive.hpp:33:
In file included from /usr/bin/../lib/gcc/x86_64-redhat-linux/4.9.1/../../../../include/c++/4.9.1/cstring:42:
/usr/include/string.h:82:1: error: unknown type name '__extern_always_inline'
__extern_always_inline void *

Expected results:

No error messages.

Additional info:

I can fix that manually with adding -D__extern_always_inline=inline as additional clang parameter. But the code mentioned above is working on Arch Linux + Debian Testing, so I guess it must be somethig redhat-special?

Thanks many in advance! If you need additional information please let me know!

Regards,

Stefan