Replace __attribute__ keywords with a macro to improve compiler compatibility.

src/compatibility.h

@@ -0,0 +1,58 @@
+/*
+	Copyright 2014 Michele "King_DuckZ" Santullo
+
+	This file is part of CloonelJump.
+
+	CloonelJump is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	CloonelJump is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with CloonelJump.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#ifndef id45CDD1DAEF4F42968E3C89F68FDDA9BC
+#define id45CDD1DAEF4F42968E3C89F68FDDA9BC
+
+#if defined(__GNUC__)
+#	if defined(__clang__)
+#		if !defined(__has_attribute)
+			//Fall back to version number comparing
+#		else
+#			if __has_attribute(flatten)
+#				define a_flatten __attribute__((flatten))
+#			else
+#				define a_flatten
+#			endif
+#			if __has_attribute(always_inline)
+#				define a_always_inline __attribute__((always_inline))
+#			else
+#				define a_always_inline
+#			endif
+#			if __has_attribute(pure)
+#				define a_pure __attribute__((pure))
+#			else
+#				define a_pure
+#			endif
+#		endif
+#	else
+		//Fix here if you get warnings about unsupported attributes on your compiler
+#		define a_flatten __attribute__((flatten))
+#		define a_always_inline __attribute__((always_inline))
+#		define a_pure __attribute__((pure))
+#	endif
+#else
+#	warning "Unsupported compiler, please fill this section or file a bug"
+#	define a_flatten
+#	define a_always_inline
+#	define a_pure
+#endif
+
+#endif