[libc-commits] [libc] [libc] remove #include <fcntl.h> and add proxy or type (PR #113836)

[via libc-commits]

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@@ -0,0 +1,39 @@
+//===-- Including fcntl.h in overlay mode ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_HDR_FCNTL_OVERLAY_H
+#define LLVM_LIBC_HDR_FCNTL_OVERLAY_H
+
+#ifdef LIBC_FULL_BUILD
+#error "This header should only be included in overlay mode"
+#endif
+
+// Overlay mode
+
+// glibc <stdio.h> header might provide extern inline definitions for few
+// functions, causing external alias errors.  They are guarded by
+// `__USE_EXTERN_INLINES` macro.  We temporarily disable `__USE_EXTERN_INLINES`
+// macro by defining `__NO_INLINE__` before including <stdio.h>.
+// And the same with `__USE_FORTIFY_LEVEL`, which will be temporarily disabled
+// with `_FORTIFY_SOURCE`.
+
+#ifdef __USE_FORTIFY_LEVEL
+#define LIBC_OLD_USE_FORTIFY_LEVEL __USE_FORTIFY_LEVEL
+#undef __USE_FORTIFY_LEVEL
+#define __USE_FORTIFY_LEVEL 0
+#endif
+
+#include <fcntl.h>
+
+#ifdef LIBC_OLD_USE_FORTIFY_LEVEL
+#undef __USE_FORTIFY_LEVEL
+#define __USE_FORTIFY_LEVEL LIBC_OLD_USE_FORTIFY_LEVEL
+#undef LIBC_OLD_USE_FORTIFY_LEVEL
+#endif
+
+#endif // LLVM_LIBC_HDR_STDIO_OVERLAY_H
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lntue wrote:

nit: `FCNTL_OVERLAY`

https://github.com/llvm/llvm-project/pull/113836