From 37b2a751b9401e1b831aa89b940836d0f829bb94 Mon Sep 17 00:00:00 2001
From: hendricks266 <hendricks266@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Mon, 10 Jul 2017 13:44:04 +0000
Subject: [PATCH] compat.h: Add preliminary FALLTHROUGH macro to support

git-svn-id: https://svn.eduke32.com/eduke32@6353 1a8010ca-5511-0410-912e-c29ae57300e0
---
 source/build/include/compat.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/source/build/include/compat.h b/source/build/include/compat.h
index ff7869466..01e2876c6 100644
--- a/source/build/include/compat.h
+++ b/source/build/include/compat.h
@@ -30,6 +30,9 @@
 #ifndef __has_extension
 # define __has_extension __has_feature // Compatibility with pre-3.0 compilers.
 #endif
+#ifndef __has_cpp_attribute
+# define __has_cpp_attribute(x) 0
+#endif
 
 #ifdef _MSC_VER
 # define EDUKE32_MSVC_PREREQ(major) ((major) <= (_MSC_VER))
@@ -223,6 +226,17 @@
 # define CONSTEXPR_CXX14
 #endif
 
+#if __has_cpp_attribute(fallthrough)
+# define FALLTHROUGH [[fallthrough]]
+#elif __has_cpp_attribute(clang::fallthrough)
+# define FALLTHROUGH [[clang::fallthrough]]
+#elif __has_cpp_attribute(gnu::fallthrough)
+# define FALLTHROUGH [[gnu::fallthrough]]
+#else
+# define FALLTHROUGH
+#endif
+
+
 ////////// Platform detection //////////
 
 #if defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ || defined __bsdi__ || defined __DragonFly__