Transform RequiresLocationAttribute to 'ref readonly' on function pointers.

ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj

@@ -153,7 +153,7 @@
     <None Include="TestCases\Pretty\Records.cs" />
     <Compile Include="TestCases\VBPretty\Issue2192.cs" />
     <Compile Include="Util\FileUtilityTests.cs" />
-    <None Include="TestCases\Pretty\FunctionPointers.cs" />
+    <Compile Include="TestCases\Pretty\FunctionPointers.cs" />
     <None Include="TestCases\Pretty\CS9_ExtensionGetEnumerator.cs" />
     <None Include="TestCases\Pretty\UsingVariables.cs" />
     <None Include="TestCases\Pretty\AsyncForeach.cs" />

ICSharpCode.Decompiler.Tests/TestCases/Pretty/DynamicTests.cs

@@ -1,4 +1,7 @@
 using System;
+#if CS120
+using System.Collections.Generic;
+#endif
 
 namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 {
@@ -74,6 +77,12 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 		}
 #endif
 
+#if CS120
+		private static void CallWithRefReadonly(ref readonly Dictionary<object, dynamic> d)
+		{
+		}
+#endif
+
 		private static void CallWithRef(ref dynamic d)
 		{
 		}

ICSharpCode.Decompiler.Tests/TestCases/Pretty/FunctionPointers.cs

@@ -95,8 +95,11 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 		public unsafe delegate*<object, ref readonly dynamic> F12;
 		public unsafe delegate*<in dynamic, object> F13;
 		public unsafe delegate*<out dynamic, object> F14;
-		public unsafe D<delegate*<dynamic>[], dynamic> F15;
-		public unsafe delegate*<A<object>.B<dynamic>> F16;
+#if CS120
+		public unsafe delegate*<ref readonly dynamic, object> F15;
+#endif
+		public unsafe D<delegate*<dynamic>[], dynamic> F16;
+		public unsafe delegate*<A<object>.B<dynamic>> F17;
 	}
 
 	internal class FunctionPointersWithNativeIntegerTypes

ICSharpCode.Decompiler.Tests/TestCases/Pretty/RefLocalsAndReturns.cs

@@ -326,6 +326,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
 		{
 			return ref x;
 		}
+
 		public ref readonly int M2(ref readonly int x)
 		{
 			return ref x;

ICSharpCode.Decompiler/TypeSystem/FunctionPointerType.cs

@@ -58,17 +58,22 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			{
 				IType paramType = p;
 				ReferenceKind kind = ReferenceKind.None;
-				if (p is ModifiedType modreq)
+				if (p is ModifiedType mod)
 				{
-					if (modreq.Modifier.IsKnownType(KnownAttribute.In))
+					if (mod.Modifier.IsKnownType(KnownAttribute.In))
 					{
 						kind = ReferenceKind.In;
-						paramType = modreq.ElementType;
+						paramType = mod.ElementType;
 					}
-					else if (modreq.Modifier.IsKnownType(KnownAttribute.Out))
+					else if (mod.Modifier.IsKnownType(KnownAttribute.Out))
 					{
 						kind = ReferenceKind.Out;
-						paramType = modreq.ElementType;
+						paramType = mod.ElementType;
+					}
+					else if (mod.Modifier.IsKnownType(KnownAttribute.RequiresLocation))
+					{
+						kind = ReferenceKind.RefReadOnly;
+						paramType = mod.ElementType;
 					}
 				}
 				if (paramType.Kind == TypeKind.ByReference)