Updated defines.h

Signed-off-by: Robear Selwans <robear.selwans@outlook.com>

defines.h

@@ -1,30 +1,81 @@
-#pragma once
+#ifndef EV_HEADERS_DEFINES_H
+#define EV_HEADERS_DEFINES_H
+
+#ifndef EV_OS_WINDOWS
+# define EV_OS_WINDOWS 0
+#endif
+#ifndef EV_OS_LINUX
+# define EV_OS_LINUX 0
+#endif
+#ifndef EV_OS_IOS
+# define EV_OS_IOS 0
+#endif
+#ifndef EV_OS_MACOS
+# define EV_OS_MACOS 0
+#endif
+#ifndef EV_OS_ANDROID
+# define EV_OS_ANDROID 0
+#endif
+#if (EV_OS_WINDOWS || EV_OS_LINUX || EV_OS_IOS || EV_OS_MACOS || EV_OS_ANDROID)
+# define EV_OS_DEFINED 1
+#else
+# define EV_OS_DEFINED 0
+#endif
+
+#ifndef EV_CC_MSVC
+# define EV_CC_MSVC 0
+#endif
+#ifndef EV_CC_GCC
+# define EV_CC_GCC 0
+#endif
+#ifndef EV_CC_CLANG
+# define EV_CC_CLANG 0
+#endif
+#if (EV_CC_MSVC || EV_CC_GCC || EV_CC_CLANG)
+# define EV_CC_DEFINED 1
+#else
+# define EV_CC_DEFINED 0
+#endif
 
 // Operating System Detection
+#if !EV_OS_DEFINED
 # if defined(_WIN32)
-# define EV_OS_WINDOWS
+#  undef EV_OS_WINDOWS
+#  define EV_OS_WINDOWS 1
 # elif defined(__linux__)
-# define EV_OS_LINUX
+#  undef EV_OS_LINUX
+#  define EV_OS_LINUX 1
 # elif defined(__APPLE__)
 #  include "TargetConditionals.h"
 #  if defined(TARGET_OS_IPHONE)
-#  define EV_OS_IOS
+#   undef EV_OS_IOS
+#   define EV_OS_IOS 1
 #  elif defined(TARGET_OS_MAC)
-#  define EV_OS_MACOS
+#   undef EV_OS_MACOS
+#   define EV_OS_MACOS 1
 #  elif defined(__ANDROID__)
-#  define EV_OS_ANDROID
+#   undef EV_OS_ANDROID
+#   define EV_OS_ANDROID 1
 #  endif
 # else
 #  error EV_OS_UNKNOWN
 # endif
+#endif
 
 // Compiler Detection
+#if !EV_CC_DEFINED
 # if defined(_MSC_VER)
-# define EV_CC_MSVC
+#  undef EV_CC_MSVC
+#  define EV_CC_MSVC 1
 # elif defined(__GNUC__)
-# define EV_CC_GCC
+#  undef EV_CC_GCC
+#  define EV_CC_GCC 1
 # elif defined(__clang)
-# define EV_CC_CLANG
+#  undef EV_CC_CLANG
+#  define EV_CC_CLANG 1
 # else
 #  error EV_CC_UNKNOWN
 # endif
+#endif
+
+#endif // EV_HEADERS_DEFINES_H