Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/mscorlib/system/oleautbinder.cs

@@ -0,0 +1,172 @@
+// ==++==
+// 
+//   Copyright (c) Microsoft Corporation.  All rights reserved.
+// 
+// ==--==
+// This class represents the Ole Automation binder.
+
+// #define DISPLAY_DEBUG_INFO
+
+namespace System {
+
+    using System;
+    using System.Runtime.InteropServices;
+    using System.Reflection;
+    using Microsoft.Win32;
+    using CultureInfo = System.Globalization.CultureInfo;    
+
+    // Made serializable in anticipation of this class eventually having state.
+    [Serializable]
+    internal class OleAutBinder : DefaultBinder
+    {
+        // ChangeType
+        // This binder uses OLEAUT to change the type of the variant.
+        [System.Security.SecuritySafeCritical] // overrides transparent member
+        public override Object ChangeType(Object value, Type type, CultureInfo cultureInfo)
+        {
+            Variant myValue = new Variant(value);
+            if (cultureInfo == null)
+                cultureInfo = CultureInfo.CurrentCulture;
+                
+    #if DISPLAY_DEBUG_INFO      
+            Console.WriteLine("In OleAutBinder::ChangeType converting variant of type: {0} to type: {1}", myValue.VariantType, type.Name);
+    #endif
+
+            if (type.IsByRef)
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Stripping byref from the type to convert to.");
+    #endif      
+                type = type.GetElementType();
+            }
+
+            // If we are trying to convert from an object to another type then we don't
+            // need the OLEAUT change type, we can just use the normal COM+ mechanisms.
+            if (!type.IsPrimitive && type.IsInstanceOfType(value))
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Source variant can be assigned to destination type");
+    #endif      
+                return value;
+            }
+
+            Type srcType = value.GetType();
+
+            // Handle converting primitives to enums.
+            if (type.IsEnum && srcType.IsPrimitive)
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Converting primitive to enum");
+    #endif      
+                return Enum.Parse(type, value.ToString());
+            }
+
+#if !FEATURE_CORECLR
+            // Special case the convertion from DBNull.
+            if (srcType == typeof(DBNull))
+            {
+                // The requested type is a DBNull so no convertion is required.            
+                if (type == typeof(DBNull))
+                    return value;
+
+                // Visual J++ supported converting from DBNull to null so customers
+                // have requested (via a CDCR) that DBNull be convertible to null.
+                // We don't however allow this when converting to a value class, since null
+                // doesn't make sense for these, or to object since this would change existing
+                // semantics.               
+                if ((type.IsClass && type != typeof(Object)) || type.IsInterface)
+                    return null;
+            }
+#endif //!FEATURE_CORECLR
+
+#if FEATURE_COMINTEROP
+            // Use the OA variant lib to convert primitive types.
+            try
+            {
+#if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Using OAVariantLib.ChangeType() to do the conversion");
+#endif      
+                // Specify the LocalBool flag to have BOOL values converted to local language rather
+                // than 0 or -1.
+                Object RetObj = OAVariantLib.ChangeType(myValue, type, OAVariantLib.LocalBool, cultureInfo).ToObject();
+
+#if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Object returned from ChangeType is of type: " + RetObj.GetType().Name);
+#endif
+
+                return RetObj;
+            }
+#if DISPLAY_DEBUG_INFO      
+            catch(NotSupportedException e)
+#else
+            catch(NotSupportedException)
+#endif      
+            {
+#if DISPLAY_DEBUG_INFO      
+                Console.Write("Exception thrown: ");
+                Console.WriteLine(e);
+#endif      
+                throw new COMException(Environment.GetResourceString("Interop.COM_TypeMismatch"), unchecked((int)0x80020005));
+            }
+            
+#else // !FEATURE_COMINTEROP
+
+            return base.ChangeType(value, type, cultureInfo);
+
+#endif // !FEATURE_COMINTEROP
+        }
+        
+        
+#if !FEATURE_COMINTEROP         
+        // CanChangeType
+        public override bool CanChangeType(Object value, Type type, CultureInfo cultureInfo)
+        {
+            Variant myValue = new Variant(value);
+            if (cultureInfo == null)
+                cultureInfo = CultureInfo.CurrentCulture;
+                
+    #if DISPLAY_DEBUG_INFO      
+            Console.WriteLine("In OleAutBinder::CanChangeType converting variant of type: {0} to type: {1}", myValue.VariantType, type.Name);
+    #endif
+
+            // If we are trying to convert to variant then there is nothing to do.
+            if (type == typeof(Variant))
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Variant being changed to type variant is always legal");
+    #endif      
+                return true;
+            }
+    
+            if (type.IsByRef)
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Stripping byref from the type to convert to.");
+    #endif      
+                type = type.GetElementType();
+            }
+
+            // If we are trying to convert from an object to another type then we don't
+            // need the OLEAUT change type, we can just use the normal COM+ mechanisms.
+            if (!type.IsPrimitive && type.IsInstanceOfType(value))
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Source variant can be assigned to destination type");
+    #endif      
+                return true;
+            }
+
+            // Handle converting primitives to enums.
+            if (type.IsEnum && value.GetType().IsPrimitive)
+            {
+    #if DISPLAY_DEBUG_INFO      
+                Console.WriteLine("Converting primitive to enum");
+    #endif      
+                return true;
+            }
+
+            return base.CanChangeType(value, type, cultureInfo);
+        }
+#endif // FEATURE_COMINTEROP        
+    }
+}