[libc++] Switch to the new testing configurations by default

[ldionne]

Summary

We've been meaning to remove support for the legacy testing configuration
for a long time. This patch switches the default from the legacy config
to the appropriate new-style configuration based on a few hints.

We've been running with the new-style configuration for more than a year
in our CI, however it's possible that this will uncover issues with some
users that run the tests on platforms that we don't support yet with the
new-style configs. Unfortunately, there is no way to know about it other
than to land this patch and see whether anything breaks.

[mstorsjo]

libcxx/CMakeLists.txt

143

This is all a matter of taste, but I'd find elseif(MINGW) elseif(WIN32) #clang-cl elseif(... more straightforward, instead of the WIN32 AND NOT MINGW followed by the complement of the negation.

Alternatively, depending on which one to single out, one could also use elseif (MSVC) # clang-cl elseif (MINGW), as MSVC is defined in clang-cl configurations.

[ldionne]

libcxx/CMakeLists.txt

143

You're right, I'll improve this in the next rev.

[ldionne]

Address comments and add message to show which config we're using

[ldionne]

Rebase onto main -- that should fix the bootstrapping build.

[ldionne]

I will land this tomorrow morning and watch out for any fallout this might have. I hope it won't but it might break some builders that use configurations we don't test in CI right now.

libcxx/CMakeLists.txt

option(LIBCXX_ENABLE_VENDOR_AVAILABILITY_ANNOTATIONS
    to provide compile-time errors when using features unavailable on some version of
    the shared library they shipped should turn this on and see `include/__availability`
    for more details." OFF)
 option(LIBCXX_ENABLE_INCOMPLETE_FEATURES
     "Whether to enable support for incomplete library features. Incomplete features
     are new library features under development. These features don't guarantee
     ABI stability nor the quality of completed library features. Vendors
     shipping the library may want to disable this option." ON)
-set(LIBCXX_TEST_CONFIG "legacy.cfg.in" CACHE STRING
+
+if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-shared-gcc.cfg.in")
+elseif(MINGW)
+  set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-mingw.cfg.in")
+elseif(WIN32) # clang-cl
+  if (LIBCXX_ENABLE_SHARED)
+    set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-shared-clangcl.cfg.in")
+  else()
+    set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-static-clangcl.cfg.in")
+  endif()
+else()
+  if (LIBCXX_ENABLE_SHARED)
+    set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-shared.cfg.in")
+  else()
+    set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-static.cfg.in")
+  endif()
+endif()
+set(LIBCXX_TEST_CONFIG "${LIBCXX_DEFAULT_TEST_CONFIG}" CACHE STRING
     "The path to the Lit testing configuration to use when running the tests.
      If a relative path is provided, it is assumed to be relative to '<monorepo>/libcxx/test/configs'.")
 if (NOT IS_ABSOLUTE "${LIBCXX_TEST_CONFIG}")
   set(LIBCXX_TEST_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/test/configs/${LIBCXX_TEST_CONFIG}")
 endif()
+message(STATUS "Using libc++ testing configuration: ${LIBCXX_TEST_CONFIG}")
 set(LIBCXX_TEST_PARAMS "" CACHE STRING
     "A list of parameters to run the Lit test suite with.")
 
 # Benchmark options -----------------------------------------------------------
 option(LIBCXX_INCLUDE_BENCHMARKS "Build the libc++ benchmarks and their dependencies" ON)
 
 set(LIBCXX_BENCHMARK_TEST_ARGS_DEFAULT --benchmark_min_time=0.01)
 set(LIBCXX_BENCHMARK_TEST_ARGS "${LIBCXX_BENCHMARK_TEST_ARGS_DEFAULT}" CACHE STRING

libcxx/docs/ReleaseNotes.rst

 
 - Previously, the C++ ABI library headers would be installed inside ``<prefix>/include/c++/v1``
   alongside the libc++ headers as part of building libc++. This is not the case anymore -- the
   ABI library is expected to install its headers where it wants them as part of its own build.
   Note that no action is required for most users, who build libc++ against libc++abi, since
   libc++abi already installs its headers in the right location. However, vendors building
   libc++ against alternate ABI libraries should make sure that their ABI library installs
   its own headers.
+
+- The legacy testing configuration is now deprecated and will be removed in the next release. For
+  most users, this should not have any impact. However, if you are testing libc++ in a configuration
+  or on a platform that used to be supported by the legacy testing configuration and isn't supported
+  by one of the configurations in ``libcxx/test/configs``, please reach out to the libc++ developers
+  to get your configuration supported officially.

libcxx/utils/ci/run-buildbot

check-generated-output)
     ! grep -rn '[^ -~]' libcxx/include/ || false
 
     # Reject patches that introduce dependency cycles in the headers.
     python3 libcxx/utils/graph_header_deps.py >/dev/null
 ;;
 generic-cxx03)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx03.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-cxx11)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx11.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-cxx14)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx14.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-cxx17)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx17.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-cxx20)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx20.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-cxx2b)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx2b.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-assertions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-assertions.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-debug-iterators)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-debug-iterators.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-noexceptions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-noexceptions.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-modules)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-modules.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-static)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-static.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-static.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-static.cfg.in"
     check-runtimes
 ;;
 generic-clang-13)
     export CC=clang-13
     export CXX=clang++-13
     clean
-    generate-cmake -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
-                   -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
+    generate-cmake -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-clang-14)
     export CC=clang-14
     export CXX=clang++-14
     clean
-    generate-cmake -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
-                   -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
+    generate-cmake -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-gcc)
     export CC=gcc-11
     export CXX=g++-11
     clean
-    generate-cmake -DLIBCXX_TEST_CONFIG="llvm-libc++-shared-gcc.cfg.in" \
-                   -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in" \
+    generate-cmake -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in" \
                    -DLIBCXX_ENABLE_WERROR=NO
     check-runtimes
 ;;
 generic-gcc-cxx11)
     export CC=gcc-11
     export CXX=g++-11
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-cxx11.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared-gcc.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in" \
                    -DLIBCXX_ENABLE_WERROR=NO
     check-runtimes
 ;;
 generic-asan)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-asan.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-msan)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-msan.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-tsan)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-tsan.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-ubsan)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-ubsan.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-with_llvm_unwinder)
     clean
     generate-cmake -DLIBCXXABI_USE_LLVM_UNWINDER=ON \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-singlethreaded)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-singlethreaded.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-no-debug)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-debug.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-no-filesystem)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-filesystem.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-no-random_device)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-random_device.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-no-localization)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-localization.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-no-unicode)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-unicode.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-no-wide-characters)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-wide-characters.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 generic-no-experimental)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-no-experimental.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
     check-abi-list
 ;;
 generic-abi-unstable)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-abi-unstable.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 apple-system)
     clean
 
     arch="$(uname -m)"
     xcrun --sdk macosx                                              \
generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Apple.cmake" \
                    -DLIBCXXABI_TEST_CONFIG="apple-libc++abi-backdeployment.cfg.in" \
                    -DLIBCXX_TEST_PARAMS="${PARAMS}" \
                    -DLIBCXXABI_TEST_PARAMS="${PARAMS}"
 
     check-runtimes
 ;;
 benchmarks)
     clean
-    generate-cmake -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
-                   -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
+    generate-cmake -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-cxx-benchmarks
 ;;
 documentation)
     clean
     generate-cmake -DLLVM_ENABLE_SPHINX=ON
 
     echo "+++ Generating documentation"
     ${NINJA} -vC "${BUILD_DIR}" docs-libcxx-html
${CMAKE} \
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
           -DLLVM_ENABLE_PROJECTS="clang" \
           -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
           -DLLVM_RUNTIME_TARGETS="$(c++ --print-target-triple)" \
           -DLLVM_TARGETS_TO_BUILD="host" \
           -DRUNTIMES_BUILD_ALLOW_DARWIN=ON \
           -DLLVM_ENABLE_ASSERTIONS=ON \
           -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Generic-modules.cmake" \
-          -DRUNTIMES_LIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
           -DRUNTIMES_LIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
 
     echo "+++ Running the libc++ and libc++abi tests"
     ${NINJA} -C "${BUILD_DIR}" check-runtimes
 
     echo "--- Installing libc++ and libc++abi to a fake location"
     ${NINJA} -C "${BUILD_DIR}" install-runtimes
 ;;
${CMAKE} \
           -DCMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
           -DLLVM_LIT_ARGS="-sv --show-unsupported --xunit-xml-output test-results.xml" \
           -DLIBCXX_CXX_ABI=libcxxabi
     check-runtimes
 ;;
 aarch64)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/AArch64.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 aarch64-noexceptions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/AArch64.cmake" \
                    -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
                    -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 # Aka Armv8 32 bit
 armv8)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Arm.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 armv8-noexceptions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv8Thumb-noexceptions.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 # Armv7 32 bit. One building Arm only one Thumb only code.
 armv7)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Arm.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 armv7-noexceptions)
     clean
     generate-cmake -C "${MONOREPO_ROOT}/libcxx/cmake/caches/Armv7Thumb-noexceptions.cmake" \
-                   -DLIBCXX_TEST_CONFIG="llvm-libc++-shared.cfg.in" \
                    -DLIBUNWIND_TEST_CONFIG="llvm-libunwind-shared.cfg.in"
     check-runtimes
 ;;
 clang-cl-dll)
     clean
     # TODO: Currently, building with the experimental library breaks running
     # tests (the test linking look for the c++experimental library with the
     # wrong name, and the statically linked c++experimental can't be linked
     # correctly when libc++ visibility attributes indicate dllimport linkage
     # anyway), thus just disable the experimental library. Remove this
     # setting when cmake and the test driver does the right thing automatically.
-    generate-cmake-libcxx-win -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF \
-                              -DLIBCXX_TEST_CONFIG="llvm-libc++-shared-clangcl.cfg.in"
+    generate-cmake-libcxx-win -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF
     echo "+++ Running the libc++ tests"
     ${NINJA} -vC "${BUILD_DIR}" check-cxx
 ;;
 clang-cl-static)
     clean
-    generate-cmake-libcxx-win -DLIBCXX_ENABLE_SHARED=OFF \
-                              -DLIBCXX_TEST_CONFIG="llvm-libc++-static-clangcl.cfg.in"
+    generate-cmake-libcxx-win -DLIBCXX_ENABLE_SHARED=OFF
     echo "+++ Running the libc++ tests"
     ${NINJA} -vC "${BUILD_DIR}" check-cxx
 ;;
 mingw-dll)
     clean
     # Explicitly specify the compiler with a triple prefix. The CI
     # environment has got two installations of Clang; the default one
     # defaults to MSVC mode, while there's an installation of llvm-mingw
     # further back in PATH. By calling the compiler with an explicit
     # triple prefix, we use the one that is bundled with a mingw sysroot.
     generate-cmake \
           -DCMAKE_C_COMPILER=x86_64-w64-mingw32-clang \
           -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-clang++ \
-          -DLIBCXX_TEST_CONFIG="llvm-libc++-mingw.cfg.in" \
           -C "${MONOREPO_ROOT}/libcxx/cmake/caches/MinGW.cmake"
     echo "+++ Running the libc++ tests"
     ${NINJA} -vC "${BUILD_DIR}" check-cxx
 ;;
 mingw-static)
     clean
     generate-cmake \
           -DCMAKE_C_COMPILER=x86_64-w64-mingw32-clang \
           -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-clang++ \
-          -DLIBCXX_TEST_CONFIG="llvm-libc++-mingw.cfg.in" \
           -C "${MONOREPO_ROOT}/libcxx/cmake/caches/MinGW.cmake" \
           -DLIBCXX_ENABLE_SHARED=OFF \
           -DLIBUNWIND_ENABLE_SHARED=OFF
     echo "+++ Running the libc++ tests"
     ${NINJA} -vC "${BUILD_DIR}" check-cxx
 ;;
 aix)
     export CC=ibm-clang