1 files changed, 58 insertions, 0 deletions
diff --git a/mfbt/tests/TestWinArchDefs.cpp b/mfbt/tests/TestWinArchDefs.cpp
new file mode 100644
index 0000000000..d8965d3d7c
--- /dev/null
+++ b/mfbt/tests/TestWinArchDefs.cpp
@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This code tests the consistency of architecture-specific predefined macros
+// inherited from MSVC, before and after windows.h inclusion. See
+// https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros for a
+// list of such macros.
+
+// If this test compiles, it is successful. See bug 1866562 for an example
+// where mingwclang builds were failing to compile this code.
+
+#if defined(_M_IX86)
+constexpr auto kIX86 = _M_IX86;
+#endif
+
+#if defined(_M_X64)
+constexpr auto kX64 = _M_X64;
+#endif
+
+#if defined(_M_AMD64)
+constexpr auto kAMD64 = _M_AMD64;
+#endif
+
+#if defined(_M_ARM)
+constexpr auto kARM = _M_ARM;
+#endif
+
+#if defined(_M_ARM64)
+constexpr auto kARM64 = _M_ARM64;
+#endif
+
+#include <windows.h>
+
+#if defined(_M_IX86)
+static_assert(kIX86 == _M_IX86);
+#endif
+
+#if defined(_M_X64)
+static_assert(kX64 == _M_X64);
+#endif
+
+#if defined(_M_AMD64)
+static_assert(kAMD64 == _M_AMD64);
+#endif
+
+#if defined(_M_ARM)
+static_assert(kARM == _M_ARM);
+#endif
+
+#if defined(_M_ARM64)
+static_assert(kARM64 == _M_ARM64);
+#endif
+
+// If this test compiles, it is successful.
+int main() { return 0; }