Optimize parameters handling to do much less allocation

22 files changed, 114 insertions, 70 deletions

diff --git a/mcs/class/corlib/System.Diagnostics/StackTrace.cs b/mcs/class/corlib/System.Diagnostics/StackTrace.cs
index edd6a79d841..c9bb574a216 100644
--- a/mcs/class/corlib/System.Diagnostics/StackTrace.cs
+++ b/mcs/class/corlib/System.Diagnostics/StackTrace.cs
@@ -200,7 +200,7 @@ namespace System.Diagnostics {
 					sb.AppendFormat ("{0}.{1}", method.DeclaringType.FullName, method.Name);
 					/* Append parameter information */
 					sb.Append ("(");
-					ParameterInfo[] p = method.GetParameters ();
+					ParameterInfo[] p = method.GetParametersInternal ();
 					for (int j = 0; j < p.Length; ++j) {
 						if (j > 0)
 							sb.Append (", ");
diff --git a/mcs/class/corlib/System.Reflection.Emit/AssemblyBuilder.cs b/mcs/class/corlib/System.Reflection.Emit/AssemblyBuilder.cs
index c0586b55402..e53cdbb097e 100644
--- a/mcs/class/corlib/System.Reflection.Emit/AssemblyBuilder.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/AssemblyBuilder.cs
@@ -859,7 +859,7 @@ namespace System.Reflection.Emit
 			 */
 			if ((entry_point != null) && entry_point.DeclaringType.Module != mainModule) {
 				Type[] paramTypes;
-				if (entry_point.GetParameters ().Length == 1)
+				if (entry_point.GetParametersCount () == 1)
 					paramTypes = new Type [] { typeof (string) };
 				else
 					paramTypes = Type.EmptyTypes;
diff --git a/mcs/class/corlib/System.Reflection.Emit/ConstructorBuilder.cs b/mcs/class/corlib/System.Reflection.Emit/ConstructorBuilder.cs
index 2391dc8be2c..b0e6747bedf 100644
--- a/mcs/class/corlib/System.Reflection.Emit/ConstructorBuilder.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/ConstructorBuilder.cs
@@ -120,10 +120,10 @@ namespace System.Reflection.Emit {
 			return GetParametersInternal ();
 		}
 
-		internal ParameterInfo [] GetParametersInternal ()
+		internal override ParameterInfo [] GetParametersInternal ()
 		{
 			if (parameters == null)
-				return new ParameterInfo [0];
+				return EmptyArray<ParameterInfo>.Value;
 
 			ParameterInfo [] retval = new ParameterInfo [parameters.Length];
 			for (int i = 0; i < parameters.Length; i++)
@@ -133,7 +133,7 @@ namespace System.Reflection.Emit {
 			return retval;
 		}
 		
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
 			if (parameters == null)
 				return 0;
@@ -232,7 +232,7 @@ namespace System.Reflection.Emit {
 
 		public ParameterBuilder DefineParameter (int iSequence, ParameterAttributes attributes, string strParamName)
 		{
-			if (iSequence < 1 || iSequence > GetParameterCount ())
+			if (iSequence < 1 || iSequence > GetParametersCount ())
 				throw new ArgumentOutOfRangeException ("iSequence");
 			if (type.is_created)
 				throw not_after_created ();
diff --git a/mcs/class/corlib/System.Reflection.Emit/ConstructorOnTypeBuilderInst.cs b/mcs/class/corlib/System.Reflection.Emit/ConstructorOnTypeBuilderInst.cs
index ea3cee589d0..1f7b30dbce5 100644
--- a/mcs/class/corlib/System.Reflection.Emit/ConstructorOnTypeBuilderInst.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/ConstructorOnTypeBuilderInst.cs
@@ -104,6 +104,11 @@ namespace System.Reflection.Emit
 			if (!instantiation.IsCreated)
 				throw new NotSupportedException ();
 
+			return GetParametersInternal ();
+		}
+
+		internal override ParameterInfo[] GetParametersInternal ()
+		{
 			ParameterInfo [] res;
 			if (cb is ConstructorBuilder) {
 				ConstructorBuilder cbuilder = (ConstructorBuilder)cb;
@@ -129,9 +134,9 @@ namespace System.Reflection.Emit
 			}
 		}
 
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
-			return cb.GetParameterCount ();
+			return cb.GetParametersCount ();
 		}
 
 		public override Object Invoke (Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
diff --git a/mcs/class/corlib/System.Reflection.Emit/CustomAttributeBuilder.cs b/mcs/class/corlib/System.Reflection.Emit/CustomAttributeBuilder.cs
index 862420a6cc0..647736bf203 100644
--- a/mcs/class/corlib/System.Reflection.Emit/CustomAttributeBuilder.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/CustomAttributeBuilder.cs
@@ -148,7 +148,7 @@ namespace System.Reflection.Emit {
 				throw new ArgumentNullException ("namedFields");
 			if (fieldValues == null)
 				throw new ArgumentNullException ("fieldValues");
-			if (con.GetParameterCount () != constructorArgs.Length)
+			if (con.GetParametersCount () != constructorArgs.Length)
 				throw new ArgumentException ("Parameter count does not match " +
 						"passed in argument value count.");
 			if (namedProperties.Length != propertyValues.Length)
@@ -532,7 +532,8 @@ namespace System.Reflection.Emit {
 			ConstructorBuilder cb = ctor as ConstructorBuilder;
 			if (cb != null)
 				return cb.GetParametersInternal ();
-			return ctor.GetParameters ();
+				
+			return ctor.GetParametersInternal ();
 		}
 	}
 }
diff --git a/mcs/class/corlib/System.Reflection.Emit/DynamicMethod.cs b/mcs/class/corlib/System.Reflection.Emit/DynamicMethod.cs
index 931573d5449..0e87b8a340f 100644
--- a/mcs/class/corlib/System.Reflection.Emit/DynamicMethod.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/DynamicMethod.cs
@@ -245,9 +245,15 @@ namespace System.Reflection.Emit {
 			return MethodImplAttributes.IL | MethodImplAttributes.Managed;
 		}
 
-		public override ParameterInfo[] GetParameters () {
+		public override ParameterInfo[] GetParameters ()
+		{
+			return GetParametersInternal ();
+		}
+
+		internal override ParameterInfo[] GetParametersInternal ()
+		{
 			if (parameters == null)
-				return new ParameterInfo [0];
+				return EmptyArray<ParameterInfo>.Value;
 
 			ParameterInfo[] retval = new ParameterInfo [parameters.Length];
 			for (int i = 0; i < parameters.Length; i++) {
@@ -256,7 +262,7 @@ namespace System.Reflection.Emit {
 			return retval;
 		}
 		
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
 			return parameters == null ? 0 : parameters.Length;
 		}		
@@ -297,7 +303,7 @@ namespace System.Reflection.Emit {
 
 		public override string ToString () {
 			string parms = String.Empty;
-			ParameterInfo[] p = GetParameters ();
+			ParameterInfo[] p = GetParametersInternal ();
 			for (int i = 0; i < p.Length; ++i) {
 				if (i > 0)
 					parms = parms + ", ";
diff --git a/mcs/class/corlib/System.Reflection.Emit/ILGenerator.cs b/mcs/class/corlib/System.Reflection.Emit/ILGenerator.cs
index 2172b1e63f1..1c9c3f4c3d1 100644
--- a/mcs/class/corlib/System.Reflection.Emit/ILGenerator.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/ILGenerator.cs
@@ -525,7 +525,7 @@ namespace System.Reflection.Emit {
 			emit_int (token);
 			
 			if (opcode.StackBehaviourPop == StackBehaviour.Varpop)
-				cur_stack -= con.GetParameterCount ();
+				cur_stack -= con.GetParametersCount ();
 		}
 		
 		public virtual void Emit (OpCode opcode, double arg)
@@ -744,7 +744,7 @@ namespace System.Reflection.Emit {
 				cur_stack ++;
 
 			if (opcode.StackBehaviourPop == StackBehaviour.Varpop)
-				cur_stack -= meth.GetParameterCount ();
+				cur_stack -= meth.GetParametersCount ();
 		}
 
 		private void Emit (OpCode opcode, MethodInfo method, int token)
@@ -762,7 +762,7 @@ namespace System.Reflection.Emit {
 				cur_stack ++;
 
 			if (opcode.StackBehaviourPop == StackBehaviour.Varpop)
-				cur_stack -= method.GetParameterCount ();
+				cur_stack -= method.GetParametersCount ();
 		}
 
 		[CLSCompliant(false)]
diff --git a/mcs/class/corlib/System.Reflection.Emit/MethodBuilder.cs b/mcs/class/corlib/System.Reflection.Emit/MethodBuilder.cs
index 1beb945a8d2..f898bce399e 100644
--- a/mcs/class/corlib/System.Reflection.Emit/MethodBuilder.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/MethodBuilder.cs
@@ -219,6 +219,12 @@ namespace System.Reflection.Emit
 		{
 			if (!type.is_created)
 				throw NotSupported ();
+
+			return GetParametersInternal ();
+		}
+
+		internal override ParameterInfo[] GetParametersInternal ()
+		{
 			if (parameters == null)
 				return null;
 
@@ -229,7 +235,7 @@ namespace System.Reflection.Emit
 			return retval;
 		}
 		
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
 			if (parameters == null)
 				return 0;
diff --git a/mcs/class/corlib/System.Reflection.Emit/MethodOnTypeBuilderInst.cs b/mcs/class/corlib/System.Reflection.Emit/MethodOnTypeBuilderInst.cs
index aa19ecef3bf..1384f9971e4 100644
--- a/mcs/class/corlib/System.Reflection.Emit/MethodOnTypeBuilderInst.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/MethodOnTypeBuilderInst.cs
@@ -164,6 +164,11 @@ namespace System.Reflection.Emit
 
 		public override ParameterInfo [] GetParameters ()
 		{
+			return GetParametersInternal ();
+		}
+
+		internal override ParameterInfo [] GetParametersInternal ()
+		{
 			throw new NotSupportedException ();
 		}
 
@@ -173,9 +178,9 @@ namespace System.Reflection.Emit
 			}
 		}
 
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
-			return base_method.GetParameterCount ();
+			return base_method.GetParametersCount ();
 		}
 
 		public override Object Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
diff --git a/mcs/class/corlib/System.Reflection.Emit/MonoArrayMethod.cs b/mcs/class/corlib/System.Reflection.Emit/MonoArrayMethod.cs
index dc9ca4073ee..aa24bc34719 100644
--- a/mcs/class/corlib/System.Reflection.Emit/MonoArrayMethod.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/MonoArrayMethod.cs
@@ -79,12 +79,18 @@ namespace System.Reflection {
 		}
 
 		[MonoTODO("Not implemented.  Always returns an empty array")]
-		public override ParameterInfo[] GetParameters() {
-			return new ParameterInfo [0];
+		public override ParameterInfo[] GetParameters()
+		{
+			return GetParametersInternal ();			
 		}
+
+		internal override ParameterInfo[] GetParametersInternal ()
+		{
+			return EmptyArray<ParameterInfo>.Value;
+		}	
 		
 		[MonoTODO("Not implemented.  Always returns 0")]
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
 			return 0;
 		}		
diff --git a/mcs/class/corlib/System.Reflection.Emit/PropertyOnTypeBuilderInst.cs b/mcs/class/corlib/System.Reflection.Emit/PropertyOnTypeBuilderInst.cs
index 578cf06a5d1..1035f494c86 100644
--- a/mcs/class/corlib/System.Reflection.Emit/PropertyOnTypeBuilderInst.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/PropertyOnTypeBuilderInst.cs
@@ -115,7 +115,8 @@ namespace System.Reflection.Emit
 			MethodInfo method = GetGetMethod (true);
 			if (method != null)
 				return method.GetParameters ();
-			return new ParameterInfo [0];
+
+			return EmptyArray<ParameterInfo>.Value;
 		}
 
 		public override MethodInfo GetSetMethod (bool nonPublic)
diff --git a/mcs/class/corlib/System.Reflection.Emit/TypeBuilder.cs b/mcs/class/corlib/System.Reflection.Emit/TypeBuilder.cs
index 462717057cc..882d125442d 100644
--- a/mcs/class/corlib/System.Reflection.Emit/TypeBuilder.cs
+++ b/mcs/class/corlib/System.Reflection.Emit/TypeBuilder.cs
@@ -1459,7 +1459,7 @@ namespace System.Reflection.Emit
 					throw new Exception ("Error in customattr");
 				}
 				
-				var ctor_type = customBuilder.Ctor is ConstructorBuilder ? ((ConstructorBuilder)customBuilder.Ctor).parameters[0] : customBuilder.Ctor.GetParameters()[0].ParameterType;
+				var ctor_type = customBuilder.Ctor is ConstructorBuilder ? ((ConstructorBuilder)customBuilder.Ctor).parameters[0] : customBuilder.Ctor.GetParametersInternal()[0].ParameterType;
 				int pos = 6;
 				if (ctor_type.FullName == "System.Int16")
 					pos = 4;
diff --git a/mcs/class/corlib/System.Reflection/Binder.cs b/mcs/class/corlib/System.Reflection/Binder.cs
index 6d186c73edd..e6a1b202186 100644
--- a/mcs/class/corlib/System.Reflection/Binder.cs
+++ b/mcs/class/corlib/System.Reflection/Binder.cs
@@ -122,8 +122,8 @@ namespace System.Reflection
 				// If the argument types differ we
 				// have an ambigous match, as well
 				if (matchId >= 0) {
-					ParameterInfo[] p1 = m.GetParameters ();
-					ParameterInfo[] p2 = match [matchId].GetParameters ();
+					ParameterInfo[] p1 = m.GetParametersInternal ();
+					ParameterInfo[] p2 = match [matchId].GetParametersInternal ();
 					bool equal = true;
 
 					if (p1.Length != p2.Length)
@@ -181,7 +181,7 @@ namespace System.Reflection
 				MethodBase selected = null;
 				if (names != null) {
 					foreach (var m in match) {
-						var parameters = m.GetParameters ();
+						var parameters = m.GetParametersInternal ();
 						int i;
 
 						/*
@@ -234,7 +234,7 @@ namespace System.Reflection
 			// probably belongs in ReorderArgumentArray
 			static void AdjustArguments (MethodBase selected, ref object [] args)
 			{
-				var parameters = selected.GetParameters ();
+				var parameters = selected.GetParametersInternal ();
 				var parameters_length = parameters.Length;
 				if (parameters_length == 0)
 					return;
@@ -268,7 +268,7 @@ namespace System.Reflection
 			{
 				object [] newArgs = new object [args.Length];
 				Array.Copy (args, newArgs, args.Length);
-				ParameterInfo [] plist = selected.GetParameters ();
+				ParameterInfo [] plist = selected.GetParametersInternal ();
 				for (int n = 0; n < names.Length; n++)
 					for (int p = 0; p < plist.Length; p++) {
 						if (names [n] == plist [p].Name) {
@@ -480,9 +480,10 @@ namespace System.Reflection
 				MethodBase exact_match = null;
 				for (i = 0; i < match.Length; ++i) {
 					m = match [i];
-					ParameterInfo[] args = m.GetParameters ();
-					if (args.Length != types.Length)
+					if (m.GetParametersCount () != types.Length)
 						continue;
+
+					ParameterInfo[] args = m.GetParametersInternal ();
 					for (j = 0; j < types.Length; ++j) {
 						if (types [j] != args [j].ParameterType)
 							break;
@@ -504,10 +505,11 @@ namespace System.Reflection
 					for (i = 0; i < match.Length; ++i) {
 						m = match [i];
 
-						var pi = m.GetParameters ();
-						if (pi.Length == 0 || pi.Length > types.Length + 1)
+						var count = m.GetParametersCount ();
+						if (count == 0 || count > types.Length + 1)
 							continue;
 
+						var pi = m.GetParametersInternal ();
 						if (!Attribute.IsDefined (pi [pi.Length - 1], typeof (ParamArrayAttribute)))
 							continue;
 
@@ -531,7 +533,7 @@ namespace System.Reflection
 				MethodBase result = null;
 				for (i = 0; i < match.Length; ++i) {
 					m = match [i];
-					ParameterInfo[] args = m.GetParameters ();
+					ParameterInfo[] args = m.GetParametersInternal ();
 					if (args.Length != types.Length)
 						continue;
 					if (!check_arguments (types, args, allowByRefMatch))
@@ -550,7 +552,7 @@ namespace System.Reflection
 				// REVIEW: do we also need to implement best method match?
 				for (i = 0; i < match.Length; ++i) {
 					m = match [i];
-					ParameterInfo[] methodArgs = m.GetParameters ();
+					ParameterInfo[] methodArgs = m.GetParametersInternal ();
 					if (methodArgs.Length != types.Length)
 						continue;
 					for (j = 0; j < types.Length; ++j) {
@@ -578,8 +580,8 @@ namespace System.Reflection
 
 			MethodBase GetBetterMethod (MethodBase m1, MethodBase m2, Type [] types)
 			{
-				ParameterInfo [] pl1 = m1.GetParameters ();
-				ParameterInfo [] pl2 = m2.GetParameters ();
+				ParameterInfo [] pl1 = m1.GetParametersInternal ();
+				ParameterInfo [] pl2 = m2.GetParametersInternal ();
 				int prev = 0;
 				for (int i = 0; i < pl1.Length; i++) {
 					int cmp = CompareCloserType (pl1 [i].ParameterType, pl2 [i].ParameterType);
diff --git a/mcs/class/corlib/System.Reflection/EventInfo.cs b/mcs/class/corlib/System.Reflection/EventInfo.cs
index ec28771bc8f..f2f69b7707e 100644
--- a/mcs/class/corlib/System.Reflection/EventInfo.cs
+++ b/mcs/class/corlib/System.Reflection/EventInfo.cs
@@ -50,15 +50,16 @@ namespace System.Reflection {
 			get {
 				ParameterInfo[] p;
 				MethodInfo add = GetAddMethod (true);
-				p = add.GetParameters ();
+				p = add.GetParametersInternal ();
 				if (p.Length > 0) {
 					Type t = p [0].ParameterType;
 					/* is it alwasys the first arg?
 					if (!t.IsSubclassOf (typeof (System.Delegate)))
 						throw new Exception ("no delegate in event");*/
 					return t;
-				} else
-					return null;
+				}
+
+				return null;
 			}
 		}
 
@@ -245,11 +246,11 @@ namespace System.Reflection {
 			string frameName;
 
 			if (method.IsStatic) {
-				typeVector = new Type[] { method.GetParameters () [0].ParameterType };
+				typeVector = new Type[] { method.GetParametersInternal () [0].ParameterType };
 				addHandlerDelegateType = typeof (StaticAddEvent<>);
 				frameName = "StaticAddEventAdapterFrame";
 			} else {
-				typeVector = new Type[] { method.DeclaringType, method.GetParameters () [0].ParameterType };
+				typeVector = new Type[] { method.DeclaringType, method.GetParametersInternal () [0].ParameterType };
 				addHandlerDelegateType = typeof (AddEvent<,>);
 				frameName = "AddEventFrame";
 			}
diff --git a/mcs/class/corlib/System.Reflection/MethodBase.cs b/mcs/class/corlib/System.Reflection/MethodBase.cs
index 7e538f451e7..671f11d0057 100644
--- a/mcs/class/corlib/System.Reflection/MethodBase.cs
+++ b/mcs/class/corlib/System.Reflection/MethodBase.cs
@@ -88,10 +88,8 @@ namespace System.Reflection {
 		// This is a quick version for our own use. We should override
 		// it where possible so that it does not allocate an array.
 		//
-		internal virtual int GetParameterCount ()
-		{
-			throw new NotImplementedException ("must be implemented");
-		}
+		internal abstract ParameterInfo[] GetParametersInternal ();
+		internal abstract int GetParametersCount ();
 
 		internal virtual Type GetParameterType (int pos) {
 			throw new NotImplementedException ();
diff --git a/mcs/class/corlib/System.Reflection/MonoMethod.cs b/mcs/class/corlib/System.Reflection/MonoMethod.cs
index fe381b93a9d..8c07b1ec4ac 100644
--- a/mcs/class/corlib/System.Reflection/MonoMethod.cs
+++ b/mcs/class/corlib/System.Reflection/MonoMethod.cs
@@ -170,16 +170,24 @@ namespace System.Reflection {
 
 		public override ParameterInfo[] GetParameters ()
 		{
-			ParameterInfo[] src = MonoMethodInfo.GetParametersInfo (mhandle, this);
-			ParameterInfo[] res = new ParameterInfo [src.Length];
-			src.CopyTo (res, 0);
-			return res;
+			var src = MonoMethodInfo.GetParametersInfo (mhandle, this);
+			if (src.Length == 0)
+				return src;
+
+			// Have to clone because GetParametersInfo icall returns cached value
+			var dest = new ParameterInfo [src.Length];
+			Array.FastCopy (src, 0, dest, 0, src.Length);
+			return dest;
+		}
+
+		internal override ParameterInfo[] GetParametersInternal ()
+		{
+			return MonoMethodInfo.GetParametersInfo (mhandle, this);
 		}
 		
-		internal override int GetParameterCount ()
+		internal override int GetParametersCount ()
 		{
-			var pi = MonoMethodInfo.GetParametersInfo (mhandle, this);
-			return pi == null ? 0 : pi.Length;
+			return MonoMethodInfo.GetParametersInfo (mhandle, this).Length;
 		}
 
 		/*
@@ -197,7 +205,7 @@ namespace System.Reflection {
 				binder = Binder.DefaultBinder;
 
 			/*Avoid allocating an array every time*/
-			ParameterInfo[] pinfo = MonoMethodInfo.GetParametersInfo (mhandle, this);
+			ParameterInfo[] pinfo = GetParametersInternal ();
 			if (!binder.ConvertArgs (parameters, pinfo, culture, (invokeAttr & BindingFlags.ExactBinding) != 0))
 				throw new ArgumentException ("failed to convert parameters");
 
@@ -340,7 +348,7 @@ namespace System.Reflection {
 				sb.Append ("]");
 			}
 			sb.Append ("(");
-			ParameterInfo[] p = GetParameters ();
+			ParameterInfo[] p = GetParametersInternal ();
 			for (int i = 0; i < p.Length; ++i) {
 				if (i > 0)
 					sb.Append (", ");
@@ -476,7 +484,12 @@ namespace System.Reflection {
 			return MonoMethodInfo.GetParametersInfo (mhandle, this);
 		}
 
-		internal override int GetParameterCount ()
+		internal override ParameterInfo[] GetParametersInternal ()
+		{
+			return MonoMethodInfo.GetParametersInfo (mhandle, this);
+		}		
+
+		internal override int GetParametersCount ()
 		{
 			var pi = MonoMethodInfo.GetParametersInfo (mhandle, this);
 			return pi == null ? 0 : pi.Length;
diff --git a/mcs/class/corlib/System.Reflection/MonoProperty.cs b/mcs/class/corlib/System.Reflection/MonoProperty.cs
index f41512ca268..9760c197006 100644
--- a/mcs/class/corlib/System.Reflection/MonoProperty.cs
+++ b/mcs/class/corlib/System.Reflection/MonoProperty.cs
@@ -119,7 +119,7 @@ namespace System.Reflection {
 				if (info.get_method != null) {
 					return info.get_method.ReturnType;
 				} else {
-					ParameterInfo[] parameters = info.set_method.GetParameters ();
+					ParameterInfo[] parameters = info.set_method.GetParametersInternal ();
 					
 					return parameters [parameters.Length - 1].ParameterType;
 				}
@@ -184,11 +184,11 @@ namespace System.Reflection {
 			if (info.get_method != null) {
 				res = info.get_method.GetParameters ();
 			} else if (info.set_method != null) {
-				ParameterInfo[] src = info.set_method.GetParameters ();
+				ParameterInfo[] src = info.set_method.GetParametersInternal ();
 				res = new ParameterInfo [src.Length - 1];
 				Array.Copy (src, res, res.Length);
 			} else
-				return new ParameterInfo [0];
+				return EmptyArray<ParameterInfo>.Value;
 
 			for (int i = 0; i < res.Length; ++i) {
 				ParameterInfo pinfo = res [i];
diff --git a/mcs/class/corlib/System.Reflection/ParameterInfo.cs b/mcs/class/corlib/System.Reflection/ParameterInfo.cs
index eabb285ac3c..1a37b2635db 100644
--- a/mcs/class/corlib/System.Reflection/ParameterInfo.cs
+++ b/mcs/class/corlib/System.Reflection/ParameterInfo.cs
@@ -199,8 +199,8 @@ namespace System.Reflection
 					MethodInfo mi = prop.GetGetMethod (true);
 					if (mi == null)
 						mi = prop.GetSetMethod (true);
-					/*TODO expose and use a GetParametersNoCopy()*/
-					return mi.GetParameters () [PositionImpl].MetadataToken;
+
+					return mi.GetParametersInternal () [PositionImpl].MetadataToken;
 				} else if (MemberImpl is MethodBase) {
 					return GetMetadataToken ();
 				}
diff --git a/mcs/class/corlib/System/Attribute.cs b/mcs/class/corlib/System/Attribute.cs
index c82dd8406f4..48f5a0f5662 100644
--- a/mcs/class/corlib/System/Attribute.cs
+++ b/mcs/class/corlib/System/Attribute.cs
@@ -346,7 +346,7 @@ namespace System
 			var method = ((MethodInfo) member).GetBaseMethod ();
 
 			while (true) {
-				var param = method.GetParameters () [parameter.Position];
+				var param = method.GetParametersInternal () [parameter.Position];
 				if (param.IsDefined (attributeType, false))
 					return true;
 
@@ -377,7 +377,7 @@ namespace System
 			var custom_attributes = new List<Attribute> ();
 
 			while (true) {
-				var param = method.GetParameters () [parameter.Position];
+				var param = method.GetParametersInternal () [parameter.Position];
 				var param_attributes = (Attribute []) param.GetCustomAttributes (attributeType, false);
 				foreach (var param_attribute in param_attributes) {
 					var param_type = param_attribute.GetType ();
diff --git a/mcs/class/corlib/System/Delegate.cs b/mcs/class/corlib/System/Delegate.cs
index 4a936201b0b..7610e43dcba 100644
--- a/mcs/class/corlib/System/Delegate.cs
+++ b/mcs/class/corlib/System/Delegate.cs
@@ -191,8 +191,8 @@ namespace System
 				else
 					return null;
 
-			ParameterInfo[] delargs = invoke.GetParameters ();
-			ParameterInfo[] args = method.GetParameters ();
+			ParameterInfo[] delargs = invoke.GetParametersInternal ();
+			ParameterInfo[] args = method.GetParametersInternal ();
 
 			bool argLengthMatch;
 
@@ -311,7 +311,7 @@ namespace System
 				throw new ArgumentException ("type is not subclass of MulticastDelegate.");
 
 			MethodInfo invoke = type.GetMethod ("Invoke");
-			ParameterInfo [] delargs = invoke.GetParameters ();
+			ParameterInfo [] delargs = invoke.GetParametersInternal ();
 			Type[] delargtypes = new Type [delargs.Length];
 
 			for (int i=0; i<delargs.Length; i++)
@@ -408,7 +408,7 @@ namespace System
 				method_info = m_target.GetType ().GetMethod (data.method_name, mtypes);
 			}
 
-			if (Method.IsStatic && (args != null ? args.Length : 0) == Method.GetParameters ().Length - 1) {
+			if (Method.IsStatic && (args != null ? args.Length : 0) == Method.GetParametersCount () - 1) {
 				// The delegate is bound to m_target
 				if (args != null) {
 					object[] newArgs = new object [args.Length + 1];
diff --git a/mcs/class/corlib/System/Exception.cs b/mcs/class/corlib/System/Exception.cs
index 3fe55050099..0a9ef607c75 100644
--- a/mcs/class/corlib/System/Exception.cs
+++ b/mcs/class/corlib/System/Exception.cs
@@ -346,7 +346,7 @@ namespace System
 
 		internal void GetFullNameForStackTrace (StringBuilder sb, MethodBase mi)
 		{
-			ParameterInfo[] p = mi.GetParameters ();
+			ParameterInfo[] p = mi.GetParametersInternal ();
 			sb.Append (mi.DeclaringType.ToString ());
 			sb.Append (".");
 			sb.Append (mi.Name);
diff --git a/mcs/class/corlib/System/MonoType.cs b/mcs/class/corlib/System/MonoType.cs
index ab4829a3083..985fb497329 100644
--- a/mcs/class/corlib/System/MonoType.cs
+++ b/mcs/class/corlib/System/MonoType.cs
@@ -426,7 +426,7 @@ namespace System
 					else
 						throwMissingMethodDescription = "Cannot find method " + name + ".";
 				} else {
-					ParameterInfo[] parameters = m.GetParameters();
+					ParameterInfo[] parameters = m.GetParametersInternal();
 					for (int i = 0; i < parameters.Length; ++i) {
 						if (System.Reflection.Missing.Value == args [i] && (parameters [i].Attributes & ParameterAttributes.HasDefault) != ParameterAttributes.HasDefault)
 							throw new ArgumentException ("Used Missing.Value for argument without default value", "parameters");