Fix detection and display of explicitly implemented operators.

Author: siegfriedpammer

ICSharpCode.Decompiler.Tests/Output/CSharpAmbienceTests.cs

@@ -283,7 +283,17 @@ public void AutomaticProperty(ConversionFlags flags, string expectedOutput)
 		[TestCase(ILSpyMainTreeViewMemberFlags, "this[int] : int")]
 		public void Indexer(ConversionFlags flags, string expectedOutput)
 		{
-			var prop = compilation.FindType(typeof(CSharpAmbienceTests.Program)).GetProperties(p => p.IsIndexer).Single();
+			var prop = compilation.FindType(typeof(CSharpAmbienceTests.Program)).GetProperties(p => p.IsIndexer && !p.IsExplicitInterfaceImplementation).Single();
+			ambience.ConversionFlags = flags;
+
+			Assert.That(ambience.ConvertSymbol(prop), Is.EqualTo(expectedOutput));
+		}
+
+		[TestCase(StandardConversionFlags, "int Interface.this[int index] { get; }")]
+		[TestCase(ILSpyMainTreeViewMemberFlags, "Interface.this[int] : int")]
+		public void ExplicitIndexer(ConversionFlags flags, string expectedOutput)
+		{
+			var prop = compilation.FindType(typeof(CSharpAmbienceTests.Program)).GetProperties(p => p.IsIndexer && p.IsExplicitInterfaceImplementation).Single();
 			ambience.ConversionFlags = flags;
 
 			Assert.That(ambience.ConvertSymbol(prop), Is.EqualTo(expectedOutput));
@@ -323,7 +333,12 @@ ref struct RefStruct { }
 		readonly struct ReadonlyStruct { }
 		readonly ref struct ReadonlyRefStruct { }
 
-		class Program
+		interface Interface
+		{
+			int this[int x] { get; }
+		}
+
+		class Program : Interface
 		{
 			int test;
 			const int TEST2 = 2;
@@ -336,6 +351,12 @@ public int this[int index] {
 				}
 			}
 
+			int Interface.this[int index] {
+				get {
+					return index;
+				}
+			}
+
 			public event EventHandler ProgramChanged;
 
 			public event EventHandler SomeEvent {

ICSharpCode.Decompiler/CSharp/OutputVisitor/CSharpAmbience.cs

@@ -279,9 +279,20 @@ void WriteMemberDeclarationName(IMember member, TokenWriter writer, CSharpFormat
 				ConvertType(member.DeclaringType, writer, formattingPolicy);
 				writer.WriteToken(Roles.Dot, ".");
 			}
+			IType explicitInterfaceType = GetExplicitInterfaceType(member);
+			string name = member.Name;
+			if (explicitInterfaceType != null)
+			{
+				name = name.Substring(name.LastIndexOf('.') + 1);
+			}
 			switch (member.SymbolKind)
 			{
 				case SymbolKind.Indexer:
+					if (explicitInterfaceType != null)
+					{
+						ConvertType(explicitInterfaceType, writer, formattingPolicy);
+						writer.WriteToken(Roles.Dot, ".");
+					}
 					writer.WriteKeyword(Roles.Identifier, "this");
 					break;
 				case SymbolKind.Constructor:
@@ -292,11 +303,16 @@ void WriteMemberDeclarationName(IMember member, TokenWriter writer, CSharpFormat
 					WriteQualifiedName(member.DeclaringType.Name, writer, formattingPolicy);
 					break;
 				case SymbolKind.Operator:
-					switch (member.Name)
+					switch (name)
 					{
 						case "op_Implicit":
 							writer.WriteKeyword(OperatorDeclaration.ImplicitRole, "implicit");
 							writer.Space();
+							if (explicitInterfaceType != null)
+							{
+								ConvertType(explicitInterfaceType, writer, formattingPolicy);
+								writer.WriteToken(Roles.Dot, ".");
+							}
 							writer.WriteKeyword(OperatorDeclaration.OperatorKeywordRole, "operator");
 							writer.Space();
 							ConvertType(member.ReturnType, writer, formattingPolicy);
@@ -305,19 +321,29 @@ void WriteMemberDeclarationName(IMember member, TokenWriter writer, CSharpFormat
 						case "op_CheckedExplicit":
 							writer.WriteKeyword(OperatorDeclaration.ExplicitRole, "explicit");
 							writer.Space();
+							if (explicitInterfaceType != null)
+							{
+								ConvertType(explicitInterfaceType, writer, formattingPolicy);
+								writer.WriteToken(Roles.Dot, ".");
+							}
 							writer.WriteKeyword(OperatorDeclaration.OperatorKeywordRole, "operator");
 							writer.Space();
-							if (member.Name == "op_CheckedExplicit")
+							if (name == "op_CheckedExplicit")
 							{
 								writer.WriteToken(OperatorDeclaration.CheckedKeywordRole, "checked");
 								writer.Space();
 							}
 							ConvertType(member.ReturnType, writer, formattingPolicy);
 							break;
 						default:
+							if (explicitInterfaceType != null)
+							{
+								ConvertType(explicitInterfaceType, writer, formattingPolicy);
+								writer.WriteToken(Roles.Dot, ".");
+							}
 							writer.WriteKeyword(OperatorDeclaration.OperatorKeywordRole, "operator");
 							writer.Space();
-							var operatorType = OperatorDeclaration.GetOperatorType(member.Name);
+							var operatorType = OperatorDeclaration.GetOperatorType(name);
 							if (operatorType.HasValue && !((ConversionFlags & ConversionFlags.SupportOperatorChecked) == 0 && OperatorDeclaration.IsChecked(operatorType.Value)))
 							{
 								if (OperatorDeclaration.IsChecked(operatorType.Value))
@@ -335,7 +361,12 @@ void WriteMemberDeclarationName(IMember member, TokenWriter writer, CSharpFormat
 					}
 					break;
 				default:
-					writer.WriteIdentifier(Identifier.Create(member.Name));
+					if (explicitInterfaceType != null)
+					{
+						ConvertType(explicitInterfaceType, writer, formattingPolicy);
+						writer.WriteToken(Roles.Dot, ".");
+					}
+					writer.WriteIdentifier(Identifier.Create(name));
 					break;
 			}
 			WriteTypeParameters(node, writer, formattingPolicy);
@@ -407,6 +438,17 @@ public void ConvertType(IType type, TokenWriter writer, CSharpFormattingOptions
 			astType.AcceptVisitor(new CSharpOutputVisitor(writer, formattingPolicy));
 		}
 
+		IType GetExplicitInterfaceType(IMember member)
+		{
+			if (member.IsExplicitInterfaceImplementation)
+			{
+				var baseMember = member.ExplicitlyImplementedInterfaceMembers.FirstOrDefault();
+				if (baseMember != null)
+					return baseMember.DeclaringType;
+			}
+			return null;
+		}
+
 		public string ConvertConstantValue(object constantValue)
 		{
 			return TextWriterTokenWriter.PrintPrimitiveValue(constantValue);

ICSharpCode.Decompiler/CSharp/Syntax/TypeSystemAstBuilder.cs

@@ -1784,10 +1784,6 @@ public EntityDeclaration ConvertEntity(IEntity entity)
 				case SymbolKind.Event:
 					return ConvertEvent((IEvent)entity);
 				case SymbolKind.Method:
-					if (entity.Name.Contains(".op_"))
-					{
-						goto case SymbolKind.Operator;
-					}
 					return ConvertMethod((IMethod)entity);
 				case SymbolKind.Operator:
 					return ConvertOperator((IMethod)entity);

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataMethod.cs

@@ -96,6 +96,23 @@ internal MetadataMethod(MetadataModule module, MethodDefinitionHandle handle)
 					this.symbolKind = SymbolKind.Destructor;
 				}
 			}
+			else if ((attributes & MethodAttributes.Static) != 0 && typeParameters.Length == 0)
+			{
+				// Operators that are explicit interface implementations are not marked
+				// with MethodAttributes.SpecialName or MethodAttributes.RTSpecialName
+				string name = this.Name;
+				int index = name.LastIndexOf('.');
+				if (index > 0)
+				{
+					name = name.Substring(index + 1);
+
+					if (name.StartsWith("op_", StringComparison.Ordinal)
+						&& CSharp.Syntax.OperatorDeclaration.GetOperatorType(name) != null)
+					{
+						this.symbolKind = SymbolKind.Operator;
+					}
+				}
+			}
 			this.IsExtensionMethod = (attributes & MethodAttributes.Static) == MethodAttributes.Static
 				&& (module.TypeSystemOptions & TypeSystemOptions.ExtensionMethods) == TypeSystemOptions.ExtensionMethods
 				&& def.GetCustomAttributes().HasKnownAttribute(metadata, KnownAttribute.Extension);