Mono.CSharp.InterfaceMemberBase.CheckOverrideAgainstBase C# (CSharp) Method

		protected virtual bool CheckOverrideAgainstBase (MemberSpec base_member)
		{
			bool ok = true;

			if ((base_member.Modifiers & (Modifiers.ABSTRACT | Modifiers.VIRTUAL | Modifiers.OVERRIDE)) == 0) {
				Report.SymbolRelatedToPreviousError (base_member);
				Report.Error (506, Location,
					"`{0}': cannot override inherited member `{1}' because it is not marked virtual, abstract or override",
					 GetSignatureForError (), TypeManager.CSharpSignature (base_member));
				ok = false;
			}

			// Now we check that the overriden method is not final	
			if ((base_member.Modifiers & Modifiers.SEALED) != 0) {
				Report.SymbolRelatedToPreviousError (base_member);
				Report.Error (239, Location, "`{0}': cannot override inherited member `{1}' because it is sealed",
							  GetSignatureForError (), TypeManager.CSharpSignature (base_member));
				ok = false;
			}

			var base_member_type = ((IInterfaceMemberSpec) base_member).MemberType;
			if (!TypeSpecComparer.Override.IsEqual (MemberType, base_member_type)) {
				Report.SymbolRelatedToPreviousError (base_member);
				if (this is PropertyBasedMember) {
					Report.Error (1715, Location, "`{0}': type must be `{1}' to match overridden member `{2}'",
						GetSignatureForError (), TypeManager.CSharpName (base_member_type), TypeManager.CSharpSignature (base_member));
				} else {
					Report.Error (508, Location, "`{0}': return type must be `{1}' to match overridden member `{2}'",
						GetSignatureForError (), TypeManager.CSharpName (base_member_type), TypeManager.CSharpSignature (base_member));
				}
				ok = false;
			}

			return ok;
		}