[libcxxabi] [test] Fix the mingw test config

[mstorsjo]

Summary

Don't link libc++abi separately in addition to the main -lc++; in
mingw build configs, libc++abi is always bundled into libc++
(via LIBCXX_ENABLE_STATIC_ABI_LIBRARY).

In the case of a shared linked libc++, linking a separate static
libc++abi leads to linker errors.

Define _LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS while building tests.

[mstorsjo]

Ping

[ldionne]

libcxxabi/test/configs/llvm-libc++abi-mingw.cfg.in

6

Could we instead define it just in the tests that include libcxxabi source files? I don't think there is a lot of those.

[mstorsjo]

libcxxabi/test/configs/llvm-libc++abi-mingw.cfg.in

6

There's a couple of them, and we could do that.

But secondly, we also need to define this for all tests that include cxxabi.h and call functions from there directly. cxxabi.h defaults to dllimport unless this define is set (libcxx has this machinery for customizing the defaults based on the build style etc, via the __config file etc, but libcxxabi doesn't have that). The default of dllimport doesn't work when we're statically linking libcxx+libcxxabi in the end. So even then, we need this defined in one way or another.

(I guess we could rework how the visibility attributes in cxxabi.h work too, but there's little benefit to that outside of the tests, as I don't believe regular user code ever would be including that header.)

[mstorsjo]

Removed the part which isn't needed after D148441.

[phosek]

LGTM

libcxxabi/test/configs/llvm-libc++abi-mingw.cfg.in

 # This testing configuration handles running the test suite against LLVM's libc++abi
 # using either a DLL or a static library, with MinGW/Clang on Windows.
 
 lit_config.load_config(config, '@CMAKE_CURRENT_BINARY_DIR@/cmake-bridge.cfg')
 
 config.substitutions.append(('%{flags}', ''))
 config.substitutions.append(('%{compile_flags}',
     '-nostdinc++ -I %{include} -I %{cxx-include} -I %{cxx-target-include} %{maybe-include-libunwind} -I %{libcxx}/test/support -I %{libcxx}/src -D_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS'
 ))
 config.substitutions.append(('%{link_flags}',
-    '-nostdlib++ -L %{lib} -lc++ -lc++abi'
+    '-nostdlib++ -L %{lib} -lc++'
 ))
 config.substitutions.append(('%{exec}',
     '%{executor} --execdir %T --env PATH=%{lib} -- '
 ))
 
 import os, site
 site.addsitedir(os.path.join('@LIBCXXABI_LIBCXX_PATH@', 'utils'))
 import libcxx.test.params, libcxx.test.config
 libcxx.test.config.configure(
     libcxx.test.params.DEFAULT_PARAMETERS,
     libcxx.test.features.DEFAULT_FEATURES,
     config,
     lit_config
 )