[libcxx-commits] [libcxx] 2d8f23f - [libc++] Explicitly mark basic_string<...>::npos with default

[Martin Storsjö via libcxx-commits]

On Wed, 15 Jan 2020, Eric Fiselier via libcxx-commits wrote:

>
> Author: Eric Fiselier
> Date: 2020-01-15T17:02:17-05:00
> New Revision: 2d8f23f571635c1fb983b40c4c2548716a5b65b6
>
> URL: https://github.com/llvm/llvm-project/commit/2d8f23f571635c1fb983b40c4c2548716a5b65b6
> DIFF: https://github.com/llvm/llvm-project/commit/2d8f23f571635c1fb983b40c4c2548716a5b65b6.diff
>
> LOG: [libc++] Explicitly mark basic_string<...>::npos with default
> visibility.

This breaks shared builds for windows (both with clang-cl and in mingw 
mode):

In file included from ..\src\thread.cpp:12:
In file included from ..\include\thread:92:
In file included from ..\include\system_error:149:
..\include\string(4241,59): error: redeclaration of 'std::__1::basic_string::npos' cannot add 'dllexport' attribute
                basic_string<_CharT, _Traits, _Allocator>::npos;
                                                           ^
..\include\string(788,28): note: previous declaration is here
     static const size_type npos = -1;
                            ^

(Relatedly, is there any buildbot set up for libcxx on windows?)

// Martin