private static ShouldSerialize?GetShouldSerialize( Compilation compilation, AttributedMembers attrMembers, SerializerTypes types, INamedTypeSymbol rowType, Location?location, ImmutableArray <AttributeSyntax> attrs, ref ImmutableArray <Diagnostic> diags ) { var shouldSerialize = Utils.GetMethodFromAttribute( attrMembers, "ShouldSerializeType", Diagnostics.ShouldSerializeTypeSpecifiedMultipleTimes, "ShouldSerializeMethodName", Diagnostics.ShouldSerializeMethodNameSpecifiedMultipleTimes, Diagnostics.ShouldSerializeBothMustBeSet, location, attrs, ref diags ); if (shouldSerialize == null) { return(null); } var(type, mtd) = shouldSerialize.Value; var shouldSerializeMtd = Utils.GetMethod(type, mtd, location, ref diags); if (shouldSerializeMtd == null) { return(null); } if (shouldSerializeMtd.IsGenericMethod) { var diag = Diagnostics.MethodCannotBeGeneric(location, shouldSerializeMtd); diags = diags.Add(diag); return(null); } var accessible = shouldSerializeMtd.IsAccessible(attrMembers); if (!accessible) { var diag = Diagnostics.MethodNotPublicOrInternal(location, shouldSerializeMtd); diags = diags.Add(diag); return(null); } if (!shouldSerializeMtd.ReturnType.Equals(types.BuiltIn.Bool, SymbolEqualityComparer.Default)) { var diag = Diagnostics.MethodMustReturnBool(location, shouldSerializeMtd); diags = diags.Add(diag); return(null); } var shouldSerializeParams = shouldSerializeMtd.Parameters; var isStatic = shouldSerializeMtd.IsStatic; bool takesContext; bool takesRow; if (isStatic) { // can legally take // 1. no parameters // 2. one parameter, a type which declares the annotated member // 3. one parameter, in WriteContext // 4. two parameters // 1. the type which declares the annotated member, or one which can be assigned to it, and // 2. in WriteContext if (shouldSerializeParams.Length == 0) { // fine! takesContext = false; takesRow = false; } else if (shouldSerializeParams.Length == 1) { var p0 = shouldSerializeParams[0]; if (p0.IsInWriteContext(types.OurTypes)) { takesRow = false; takesContext = true; } else { if (!p0.IsNormalParameterOfType(compilation, rowType)) { var diag = Diagnostics.BadShouldSerializeParameters_StaticOne(location, shouldSerializeMtd, rowType); diags = diags.Add(diag); return(null); } takesRow = true; takesContext = false; } } else if (shouldSerializeParams.Length == 2) { var p0 = shouldSerializeParams[0]; if (!p0.IsNormalParameterOfType(compilation, rowType)) { var diag = Diagnostics.BadShouldSerializeParameters_StaticTwo(location, shouldSerializeMtd, rowType); diags = diags.Add(diag); return(null); } var p1 = shouldSerializeParams[1]; if (!p1.IsInWriteContext(types.OurTypes)) { var diag = Diagnostics.BadShouldSerializeParameters_StaticTwo(location, shouldSerializeMtd, rowType); diags = diags.Add(diag); return(null); } takesRow = true; takesContext = true; } else { var diag = Diagnostics.BadShouldSerializeParameters_TooMany(location, shouldSerializeMtd); diags = diags.Add(diag); return(null); } } else { // can legally take // 1. no parameters // 2. one in WriteContext parameter var onType = shouldSerializeMtd.ContainingType; if (!onType.Equals(rowType, SymbolEqualityComparer.Default)) { var diag = Diagnostics.ShouldSerializeInstanceOnWrongType(location, shouldSerializeMtd, rowType); diags = diags.Add(diag); return(null); } takesRow = true; if (shouldSerializeParams.Length == 0) { takesContext = false; } else if (shouldSerializeParams.Length == 1) { var p0 = shouldSerializeParams[0]; if (!p0.IsInWriteContext(types.OurTypes)) { var diag = Diagnostics.BadShouldSerializeParameters_InstanceOne(location, shouldSerializeMtd); diags = diags.Add(diag); return(null); } takesContext = true; } else { var diag = Diagnostics.BadShouldSerializeParameters_TooMany(location, shouldSerializeMtd); diags = diags.Add(diag); return(null); } } return(new ShouldSerialize(shouldSerializeMtd, isStatic, takesRow, takesContext)); }