--- mstools/h/errno.h	2018/08/09 18:20:29	1.1.1.2
+++ mstools/h/errno.h	2018/08/09 18:21:07	1.1.1.3
@@ -1,7 +1,7 @@
 /***
 *errno.h - system wide error numbers (set by system calls)
 *
-*	Copyright (c) 1985-1990, Microsoft Corporation. All rights reserved.
+*	Copyright (c) 1985-1992, Microsoft Corporation. All rights reserved.
 *
 *Purpose:
 *	This file defines the system-wide error numbers (set by
@@ -18,16 +18,42 @@ extern "C" {
 #endif
 
 
-#ifndef MIPS
-#if (_MSC_VER <= 600)
-#define __cdecl _cdecl
-#endif
+/*
+ * Conditional macro definition for function calling type and variable type
+ * qualifiers.
+ */
+#if   ( (_MSC_VER >= 800) && (_M_IX86 >= 300) )
+
+/*
+ * Definitions for MS C8-32 (386/486) compiler
+ */
+#define _CRTAPI1 __cdecl
+#define _CRTAPI2 __cdecl
+
+#elif ( _MSC_VER == 600 )
+
+/*
+ * Definitions for old MS C6-386 compiler
+ */
+#define _CRTAPI1 _cdecl
+#define _CRTAPI2 _cdecl
+#define _M_IX86  300
+
+#else
+
+/*
+ * Other compilers (e.g., MIPS)
+ */
+#define _CRTAPI1
+#define _CRTAPI2
+
 #endif
 
+
 /* declare reference to errno */
 
 #ifdef	_MT
-extern int * _errno(void);
+extern int * _CRTAPI1 _errno(void);
 #define errno	(*_errno())
 #else
 extern int errno;