Split the filesystem conditionals into a separate header to share wit…

…h detection.

src/common/filesystem_utils.cpp

@@ -20,40 +20,7 @@
 #define USE_FINAL_FS 0
 
 #else
-// If the C++ macro is set to the version containing C++17, it must support
-// the final C++17 package
-#if __cplusplus >= 201703L
-#define USE_EXPERIMENTAL_FS 0
-#define USE_FINAL_FS 1
-
-#elif defined(_MSC_VER) && _MSC_VER >= 1900
-
-#if defined(_HAS_CXX17) && _HAS_CXX17
-// When MSC supports c++17 use <filesystem> package.
-#define USE_EXPERIMENTAL_FS 0
-#define USE_FINAL_FS 1
-#endif  // !_HAS_CXX17
-
-// Right now, GCC still only supports the experimental filesystem items starting in GCC 6
-#elif (__GNUC__ >= 6)
-#define USE_EXPERIMENTAL_FS 1
-#define USE_FINAL_FS 0
-
-// If Clang, check for feature support
-#elif defined(__clang__) && (__cpp_lib_filesystem || __cpp_lib_experimental_filesystem)
-#if __cpp_lib_filesystem
-#define USE_EXPERIMENTAL_FS 0
-#define USE_FINAL_FS 1
-#else
-#define USE_EXPERIMENTAL_FS 1
-#define USE_FINAL_FS 0
-#endif
-
-// If all above fails, fall back to standard C++ and OS-specific items
-#else
-#define USE_EXPERIMENTAL_FS 0
-#define USE_FINAL_FS 0
-#endif
+#include "stdfs_conditions.h"
 #endif
 
 #if USE_FINAL_FS == 1

src/common/stdfs_conditions.h

@@ -0,0 +1,45 @@
+// Copyright (c) 2017-2021 The Khronos Group Inc.
+// Copyright (c) 2017 Valve Corporation
+// Copyright (c) 2017 LunarG, Inc.
+//
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+#ifndef _STDFS_CONDITIONS_H
+#define _STDFS_CONDITIONS_H
+
+// If the C++ macro is set to the version containing C++17, it must support
+// the final C++17 package
+#if __cplusplus >= 201703L
+#define USE_EXPERIMENTAL_FS 0
+#define USE_FINAL_FS 1
+
+#elif defined(_MSC_VER) && _MSC_VER >= 1900
+
+#if defined(_HAS_CXX17) && _HAS_CXX17
+// When MSC supports c++17 use <filesystem> package.
+#define USE_EXPERIMENTAL_FS 0
+#define USE_FINAL_FS 1
+#endif  // !_HAS_CXX17
+
+// GCC supports the experimental filesystem items starting in GCC 6
+#elif (__GNUC__ >= 6)
+#define USE_EXPERIMENTAL_FS 1
+#define USE_FINAL_FS 0
+
+// If Clang, check for feature support
+#elif defined(__clang__) && (__cpp_lib_filesystem || __cpp_lib_experimental_filesystem)
+#if __cpp_lib_filesystem
+#define USE_EXPERIMENTAL_FS 0
+#define USE_FINAL_FS 1
+#else
+#define USE_EXPERIMENTAL_FS 1
+#define USE_FINAL_FS 0
+#endif
+
+// If all above fails, fall back to standard C++ and OS-specific items
+#else
+#define USE_EXPERIMENTAL_FS 0
+#define USE_FINAL_FS 0
+#endif
+
+#endif  // !_STDFS_CONDITIONS_H