[libc++abi] Add a test to ensure the abi namespace alias is declared correctly

[philnik777]

No description provided.

[llvmbot]

@llvm/pr-subscribers-libcxxabi

Author: Nikolas Klauser (philnik777)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/167485.diff

1 Files Affected:

• (added) libcxxabi/test/namespace.compile.pass.cpp (+15)

diff --git a/libcxxabi/test/namespace.compile.pass.cpp b/libcxxabi/test/namespace.compile.pass.cpp
new file mode 100644
index 0000000000000..076c75c635718
--- /dev/null
+++ b/libcxxabi/test/namespace.compile.pass.cpp
@@ -0,0 +1,15 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include <cxxabi.h>
+
+// Make sure the `abi` namespace already exists
+namespace abi_should_exist = abi;
+
+// Make sure `abi` is an alias for `__cxxabiv1`
+namespace abi = __cxxabiv1;