[libc++] Introduce _LIBCPP_EXTERN_VIS to fix __libcpp_debug_function link errors
Summary: On Windows tests that use `_LIBCPP_ASSERT` fail to link because the assertion handler function isn't correctly exported from the libc++ dylib. This patch fixes the dll import/export issues by introducing a new visibility macro `_LIBCPP_EXTERN_VIS` for use on external variables.
Reviewers: compnerd, smeenai, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28728
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292158 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed