Introduce nint/nuint types and their conversions in the type system

ICSharpCode.Decompiler.Tests/Semantics/ConversionTests.cs

@@ -32,6 +32,8 @@ namespace ICSharpCode.Decompiler.Tests.Semantics
 	// assign short names to the fake reflection types
 	using Null = ICSharpCode.Decompiler.TypeSystem.ReflectionHelper.Null;
 	using dynamic = ICSharpCode.Decompiler.TypeSystem.ReflectionHelper.Dynamic;
+	using nuint = ICSharpCode.Decompiler.TypeSystem.ReflectionHelper.NUInt;
+	using nint = ICSharpCode.Decompiler.TypeSystem.ReflectionHelper.NInt;
 	using C = Conversion;
 
 	[TestFixture, Parallelizable(ParallelScope.All)]
@@ -56,6 +58,13 @@ namespace ICSharpCode.Decompiler.Tests.Semantics
 			return conversions.ImplicitConversion(from2, to2);
 		}
 
+		Conversion ExplicitConversion(Type from, Type to)
+		{
+			IType from2 = compilation.FindType(from);
+			IType to2 = compilation.FindType(to);
+			return conversions.ExplicitConversion(from2, to2);
+		}
+
 		[Test]
 		public void IdentityConversions()
 		{
@@ -285,6 +294,126 @@ namespace ICSharpCode.Decompiler.Tests.Semantics
 			Assert.AreEqual(C.None, ImplicitConversion(typeof(int*), typeof(dynamic)));
 		}
 
+		[Test]
+		public void ConversionToNInt()
+		{
+			// Test based on the table in https://github.com/dotnet/csharplang/blob/master/proposals/native-integers.md
+			Assert.AreEqual(C.UnboxingConversion, ExplicitConversion(typeof(object), typeof(nint)));
+			Assert.AreEqual(C.ExplicitPointerConversion, ExplicitConversion(typeof(void*), typeof(nint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(sbyte), typeof(nint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(byte), typeof(nint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(short), typeof(nint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(ushort), typeof(nint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(int), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(uint), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(long), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(ulong), typeof(nint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(char), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(float), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(double), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(decimal), typeof(nint)));
+			Assert.AreEqual(C.IdentityConversion, ExplicitConversion(typeof(IntPtr), typeof(nint)));
+			Assert.AreEqual(C.None, ExplicitConversion(typeof(UIntPtr), typeof(nint)));
+		}
+
+		[Test]
+		public void ConversionToNUInt()
+		{
+			// Test based on the table in https://github.com/dotnet/csharplang/blob/master/proposals/native-integers.md
+			Assert.AreEqual(C.UnboxingConversion, ExplicitConversion(typeof(object), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitPointerConversion, ExplicitConversion(typeof(void*), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(sbyte), typeof(nuint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(byte), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(short), typeof(nuint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(ushort), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(int), typeof(nuint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(uint), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(long), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(ulong), typeof(nuint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(char), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(float), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(double), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(decimal), typeof(nuint)));
+			Assert.AreEqual(C.None, ExplicitConversion(typeof(IntPtr), typeof(nuint)));
+			Assert.AreEqual(C.IdentityConversion, ExplicitConversion(typeof(UIntPtr), typeof(nuint)));
+		}
+
+		[Test]
+		public void ConversionFromNInt()
+		{
+			// Test based on the table in https://github.com/dotnet/csharplang/blob/master/proposals/native-integers.md
+			Assert.AreEqual(C.BoxingConversion, ExplicitConversion(typeof(nint), typeof(object)));
+			Assert.AreEqual(C.ExplicitPointerConversion, ExplicitConversion(typeof(nint), typeof(void*)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(nuint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(sbyte)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(byte)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(short)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(ushort)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(int)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(uint)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(long)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(ulong)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(char)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(float)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(double)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nint), typeof(decimal)));
+			Assert.AreEqual(C.IdentityConversion, ExplicitConversion(typeof(nint), typeof(IntPtr)));
+			Assert.AreEqual(C.None, ExplicitConversion(typeof(nint), typeof(UIntPtr)));
+		}
+
+		[Test]
+		public void ConversionFromNUInt()
+		{
+			// Test based on the table in https://github.com/dotnet/csharplang/blob/master/proposals/native-integers.md
+			Assert.AreEqual(C.BoxingConversion, ExplicitConversion(typeof(nuint), typeof(object)));
+			Assert.AreEqual(C.ExplicitPointerConversion, ExplicitConversion(typeof(nuint), typeof(void*)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(nint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(sbyte)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(byte)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(short)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(ushort)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(int)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(uint)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(long)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(ulong)));
+			Assert.AreEqual(C.ExplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(char)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(float)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(double)));
+			Assert.AreEqual(C.ImplicitNumericConversion, ExplicitConversion(typeof(nuint), typeof(decimal)));
+			Assert.AreEqual(C.None, ExplicitConversion(typeof(nuint), typeof(IntPtr)));
+			Assert.AreEqual(C.IdentityConversion, ExplicitConversion(typeof(nuint), typeof(UIntPtr)));
+		}
+
+
+		[Test]
+		public void NIntEnumConversion()
+		{
+			var explicitEnumConversion = C.EnumerationConversion(isImplicit: false, isLifted: false);
+			Assert.AreEqual(explicitEnumConversion, ExplicitConversion(typeof(nint), typeof(StringComparison)));
+			Assert.AreEqual(explicitEnumConversion, ExplicitConversion(typeof(nuint), typeof(StringComparison)));
+			Assert.AreEqual(explicitEnumConversion, ExplicitConversion(typeof(StringComparison), typeof(nint)));
+			Assert.AreEqual(explicitEnumConversion, ExplicitConversion(typeof(StringComparison), typeof(nuint)));
+		}
+
+		[Test]
+		public void IntegerLiteralToNIntConversions()
+		{
+			Assert.IsTrue(IntegerLiteralConversion(0, typeof(nint)));
+			Assert.IsTrue(IntegerLiteralConversion(-1, typeof(nint)));
+			Assert.IsFalse(IntegerLiteralConversion(uint.MaxValue, typeof(nint)));
+			Assert.IsFalse(IntegerLiteralConversion(long.MaxValue, typeof(nint)));
+		}
+
+
+		[Test]
+		public void IntegerLiteralToNUIntConversions()
+		{
+			Assert.IsTrue(IntegerLiteralConversion(0, typeof(nuint)));
+			Assert.IsFalse(IntegerLiteralConversion(-1, typeof(nuint)));
+			Assert.IsTrue(IntegerLiteralConversion(uint.MaxValue, typeof(nuint)));
+			Assert.IsFalse(IntegerLiteralConversion(long.MaxValue, typeof(nuint)));
+		}
+
 		[Test]
 		public void UnconstrainedTypeParameter()
 		{

ICSharpCode.Decompiler/CSharp/Resolver/CSharpConversions.cs

@@ -326,10 +326,12 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 			/* char   */ { false, true , true , true , true , true  },
 			/* sbyte  */ { true , false, true , false, true , false },
 			/* byte   */ { true , true , true , true , true , true  },
-			/* short  */ { false, false, true , false, true , false },
-			/* ushort */ { false, false, true , true , true , true  },
-			/* int    */ { false, false, false, false, true , false },
-			/* uint   */ { false, false, false, false, true , true  },
+			/* short  */ { true , false, true , false, true , false },
+			/* ushort */ { false, true , true , true , true , true  },
+			/* int    */ { false, false, true , false, true , false },
+			/* uint   */ { false, false, false, true , true , true  },
+			/* long   */ { false, false, false, false, true , false },
+			/* ulong  */ { false, false, false, false, false, true  },
 		};
 
 		bool ImplicitNumericConversion(IType fromType, IType toType)
@@ -337,7 +339,29 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 			// C# 4.0 spec: §6.1.2
 
 			TypeCode from = ReflectionHelper.GetTypeCode(fromType);
+			if (from == TypeCode.Empty) {
+				// When converting from a native-sized integer, treat it as 64-bits
+				switch (fromType.Kind) {
+					case TypeKind.NInt:
+						from = TypeCode.Int64;
+						break;
+					case TypeKind.NUInt:
+						from = TypeCode.UInt64;
+						break;
+				}
+			}
 			TypeCode to = ReflectionHelper.GetTypeCode(toType);
+			if (to == TypeCode.Empty) {
+				// When converting to a native-sized integer, only 32-bits can be stored safely
+				switch (toType.Kind) {
+					case TypeKind.NInt:
+						to = TypeCode.Int32;
+						break;
+					case TypeKind.NUInt:
+						to = TypeCode.UInt32;
+						break;
+				}
+			}
 			if (to >= TypeCode.Single && to <= TypeCode.Decimal) {
 				// Conversions to float/double/decimal exist from all integral types,
 				// and there's a conversion from float to double.
@@ -345,7 +369,7 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 					|| from == TypeCode.Single && to == TypeCode.Double;
 			} else {
 				// Conversions to integral types: look at the table
-				return from >= TypeCode.Char && from <= TypeCode.UInt32
+				return from >= TypeCode.Char && from <= TypeCode.UInt64
 					&& to >= TypeCode.Int16 && to <= TypeCode.UInt64
 					&& implicitNumericConversionLookup[from - TypeCode.Char, to - TypeCode.Int16];
 			}
@@ -353,6 +377,11 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 
 		bool IsNumericType(IType type)
 		{
+			switch (type.Kind) {
+				case TypeKind.NInt:
+				case TypeKind.NUInt:
+					return true;
+			}
 			TypeCode c = ReflectionHelper.GetTypeCode(type);
 			return c >= TypeCode.Char && c <= TypeCode.Decimal;
 		}
@@ -693,7 +722,11 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 				return false;
 			// C# 4.0 spec: §6.1.9
 			TypeCode fromTypeCode = ReflectionHelper.GetTypeCode(rr.Type);
-			TypeCode toTypeCode = ReflectionHelper.GetTypeCode(NullableType.GetUnderlyingType(toType));
+			toType = NullableType.GetUnderlyingType(toType);
+			TypeCode toTypeCode = ReflectionHelper.GetTypeCode(toType);
+			if (toType.Kind == TypeKind.NUInt) {
+				toTypeCode = TypeCode.UInt32;
+			}
 			if (fromTypeCode == TypeCode.Int64) {
 				long val = (long)rr.ConstantValue;
 				return val >= 0 && toTypeCode == TypeCode.UInt64;
@@ -772,6 +805,11 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 
 		bool IsIntegerType(IType type)
 		{
+			switch (type.Kind) {
+				case TypeKind.NInt:
+				case TypeKind.NUInt:
+					return true;
+			}
 			TypeCode c = ReflectionHelper.GetTypeCode(type);
 			return c >= TypeCode.SByte && c <= TypeCode.UInt64;
 		}

ICSharpCode.Decompiler/TypeSystem/NormalizeTypeVisitor.cs

@@ -15,6 +15,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			ReplaceClassTypeParametersWithDummy = false,
 			ReplaceMethodTypeParametersWithDummy = false,
 			DynamicAndObject = true,
+			IntPtrToNInt = true,
 			TupleToUnderlyingType = true,
 			RemoveModOpt = true,
 			RemoveModReq = true,
@@ -33,6 +34,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		public bool ReplaceClassTypeParametersWithDummy = true;
 		public bool ReplaceMethodTypeParametersWithDummy = true;
 		public bool DynamicAndObject = true;
+		public bool IntPtrToNInt = true;
 		public bool TupleToUnderlyingType = true;
 		public bool RemoveNullability = true;
 
@@ -51,13 +53,18 @@ namespace ICSharpCode.Decompiler.TypeSystem
 
 		public override IType VisitTypeDefinition(ITypeDefinition type)
 		{
-			if (DynamicAndObject && type.KnownTypeCode == KnownTypeCode.Object) {
-				// Instead of normalizing dynamic->object,
-				// we do this the opposite direction, so that we don't need a compilation to find the object type.
-				if (RemoveNullability)
-					return SpecialType.Dynamic;
-				else
-					return SpecialType.Dynamic.ChangeNullability(type.Nullability);
+			switch (type.KnownTypeCode) {
+				case KnownTypeCode.Object when DynamicAndObject:
+					// Instead of normalizing dynamic->object,
+					// we do this the opposite direction, so that we don't need a compilation to find the object type.
+					if (RemoveNullability)
+						return SpecialType.Dynamic;
+					else
+						return SpecialType.Dynamic.ChangeNullability(type.Nullability);
+				case KnownTypeCode.IntPtr when IntPtrToNInt:
+					return SpecialType.NInt;
+				case KnownTypeCode.UIntPtr when IntPtrToNInt:
+					return SpecialType.NUInt;
 			}
 			return base.VisitTypeDefinition(type);
 		}

ICSharpCode.Decompiler/TypeSystem/ReflectionHelper.cs

@@ -36,7 +36,17 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		/// A reflection class used to represent <c>dynamic</c>.
 		/// </summary>
 		public sealed class Dynamic {}
-		
+
+		/// <summary>
+		/// A reflection class used to represent <c>nint</c>.
+		/// </summary>
+		public sealed class NInt { }
+
+		/// <summary>
+		/// A reflection class used to represent <c>nuint</c>.
+		/// </summary>
+		public sealed class NUInt { }
+
 		/// <summary>
 		/// A reflection class used to represent an unbound type argument.
 		/// </summary>
@@ -101,6 +111,10 @@ namespace ICSharpCode.Decompiler.TypeSystem
 			} else if (type.DeclaringType != null) {
 				if (type == typeof(Dynamic))
 					return SpecialType.Dynamic;
+				else if (type == typeof(NInt))
+					return SpecialType.NInt;
+				else if (type == typeof(NUInt))
+					return SpecialType.NUInt;
 				else if (type == typeof(Null))
 					return SpecialType.NullType;
 				else if (type == typeof(UnboundTypeArgument))

ICSharpCode.Decompiler/TypeSystem/SpecialType.cs

@@ -46,7 +46,17 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		/// Type representing the C# 'dynamic' type.
 		/// </summary>
 		public readonly static SpecialType Dynamic = new SpecialType(TypeKind.Dynamic, "dynamic", isReferenceType: true);
-		
+
+		/// <summary>
+		/// Type representing the C# 9 'nint' type.
+		/// </summary>
+		public readonly static SpecialType NInt = new SpecialType(TypeKind.NInt, "nint", isReferenceType: false);
+
+		/// <summary>
+		/// Type representing the C# 9 'nuint' type.
+		/// </summary>
+		public readonly static SpecialType NUInt = new SpecialType(TypeKind.NUInt, "nuint", isReferenceType: false);
+
 		/// <summary>
 		/// Type representing the result of the C# '__arglist()' expression.
 		/// </summary>

ICSharpCode.Decompiler/TypeSystem/TypeKind.cs

@@ -94,5 +94,14 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		/// Modified type, with required modifier.
 		/// </summary>
 		ModReq,
+
+		/// <summary>
+		/// C# 9 <c>nint</c>
+		/// </summary>
+		NInt,
+		/// <summary>
+		/// C# 9 <c>nuint</c>
+		/// </summary>
+		NUInt,
 	}
 }