[libcxx] [test] Fix the new_faligned_allocation.pass.cpp test for MSVC

[mstorsjo]

Summary

Such environments do have aligned allocation functions these days, but
the RTTI type name test needs to be adjusted for the MSVC C++ ABI.

[• Quuxplusone]

libcxx/test/libcxx/language.support/support.dynamic/new_faligned_allocation.pass.cpp

80

Shouldn't this use TEST_COMPILER_C1XX? Tests generally don't mess with implementation macros like _MSC_VER directly, but only through the test_macros.h helpers.

[mstorsjo]

libcxx/test/libcxx/language.support/support.dynamic/new_faligned_allocation.pass.cpp

80

This isn’t so much about the compiler itself, but the platform ABI. With clang-cl, you don’t get that macro defined, but only TEST_COMPILER_CLANG, while it obeys the Microsoft C++ ABI. I don’t see any existing defines there for that aspect.

[• Quuxplusone]

libcxx/test/libcxx/language.support/support.dynamic/new_faligned_allocation.pass.cpp

80

Well, I'm not interested in blocking this over that, so ship it, I guess. :)

libcxx/test/libcxx/language.support/support.dynamic/new_faligned_allocation.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // test libc++'s implementation of align_val_t, and the relevant new/delete
 // overloads in all dialects when -faligned-allocation is present.
 
-// Libc++ defers to the underlying MSVC library to provide the new/delete
-// definitions, which does not yet provide aligned allocation
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // The dylibs shipped before macosx10.13 do not contain the aligned allocation
 // functions, so trying to force using those with -faligned-allocation results
 // in a link error.
 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11|12}}
 
 // Libcxx when built for z/OS doesn't contain the aligned allocation functions,
 // nor does the dynamic library shipped with z/OS.
 // UNSUPPORTED: target={{.+}}-zos{{.*}}
#endif
     assert(ptr);
     assert(reinterpret_cast<std::uintptr_t>(ptr) % 128 == 0);
     ::operator delete[](ptr, std::align_val_t(128), std::nothrow);
   }
 #ifndef TEST_HAS_NO_RTTI
   {
     // Check that libc++ doesn't define align_val_t in a versioning namespace.
     // And that it mangles the same in C++03 through C++17
+#ifdef _MSC_VER
+    // MSVC uses a different C++ ABI with a different name mangling scheme.
+    // The type id name doesn't seem to contain the mangled form at all.
+    assert(typeid(std::align_val_t).name() == std::string("enum std::align_val_t"));
+#else
     assert(typeid(std::align_val_t).name() == std::string("St11align_val_t"));
+#endif
   }
 #endif
 
   return 0;
 }