lib: establish Zircon libc++ and KTL foundation

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/ktl/include/__configuration/platform.h b/lib/ktl/include/__configuration/platform.h
new file mode 100644
index 0000000..b15e1e0
--- /dev/null
+++ b/lib/ktl/include/__configuration/platform.h
@@ -0,0 +1,23 @@
+// Copyright 2025 The Fuchsia Authors
+//
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT
+
+#ifndef ZIRCON_KERNEL_LIB_KTL_INCLUDE___CONFIGURATION_PLATFORM_H_
+#define ZIRCON_KERNEL_LIB_KTL_INCLUDE___CONFIGURATION_PLATFORM_H_
+
+// Other libc++ headers use <__configuration/platform.h> but libc++'s
+// <__configuration/platform.h> does not yet recognize the `__PE_COFF__`
+// predefine. Until we support this new predefine upstream,
+// we must define _LIBCPP_OBJECT_FORMAT_COFF for UEFI targets here.
+// TODO(https://fxbug.dev/435771251) -- Support `__PE_COFF__` predefine
+// upstream.
+
+#if defined(__PE_COFF__)
+#define _LIBCPP_OBJECT_FORMAT_COFF 2  // Tell libc++ this is PE-COFF.
+#endif // __PE_COFF__
+
+#include_next <__configuration/platform.h>
+
+#endif  // ZIRCON_KERNEL_LIB_KTL_INCLUDE___CONFIGURATION_PLATFORM_H_