/// <summary>
/// Creates a new <see cref="CodeTypeDeclaration"/> that is the generated form of
/// the given <paramref name="enumType"/>.
/// </summary>
/// <param name="enumType">The enum type to generate.</param>
/// <param name="codeGenerator">The current proxy generator context.</param>
/// <returns>The newly generated enum type declaration.</returns>
internal static CodeTypeDeclaration CreateEnumTypeDeclaration(Type enumType, CodeDomClientCodeGenerator codeGenerator)
{
System.Diagnostics.Debug.Assert(enumType.IsEnum, "Type must be an enum type");
CodeTypeDeclaration typeDecl = CodeGenUtilities.CreateTypeDeclaration(enumType);
typeDecl.IsEnum = true;
// Always force generated enums to be public
typeDecl.TypeAttributes |= TypeAttributes.Public;
// Enums deriving from anything but int get an explicit base type
Type underlyingType = enumType.GetEnumUnderlyingType();
if (underlyingType != typeof(int))
{
typeDecl.BaseTypes.Add(new CodeTypeReference(underlyingType));
}
typeDecl.Comments.AddRange(CodeGenUtilities.GenerateSummaryCodeComment($"Enum {enumType.Name}", codeGenerator.IsCSharp));
// Generate [DataContract] if it appears in the original only. Use Reflection only because that matches
// what WCF will do.
DataContractAttribute dataContractAttr = (DataContractAttribute)Attribute.GetCustomAttribute(enumType, typeof(DataContractAttribute));
if (dataContractAttr != null)
{
CodeAttributeDeclaration attrDecl = CodeGenUtilities.CreateDataContractAttributeDeclaration(enumType, codeGenerator, typeDecl);
typeDecl.CustomAttributes.Add(attrDecl);
}
string[] memberNames = Enum.GetNames(enumType);
Type enumValueType = Enum.GetUnderlyingType(enumType);
for (int i = 0; i < memberNames.Length; ++i)
{
string memberName = memberNames[i];
CodeTypeReference enumTypeRef = CodeGenUtilities.GetTypeReference(enumValueType, codeGenerator, typeDecl);
CodeMemberField enumMember = new CodeMemberField(enumTypeRef, memberName);
enumMember.Comments.AddRange(CodeGenUtilities.GenerateSummaryCodeComment(memberName, codeGenerator.IsCSharp));
// Generate an initializer for the enum member.
// GetRawConstantValue is the safest way to get the raw value of the enum field
// and works for both Reflection and ReflectionOnly loaded assemblies.
FieldInfo fieldInfo = enumType.GetField(memberName);
if (fieldInfo != null)
{
object memberValue = fieldInfo.GetRawConstantValue();
Debug.Assert(memberValue != null, "Enum type's GetRawConstantValue should never return null");
// We special-case MinValue and MaxValue for the integral types
// because VisualBasic will generate overflow compiler error for
// Int64.MinValue. If we detect a known MinValue or MaxValue for
// this integral type, we generate that reference, otherwise we
// just generate a constant integral value of the enum's type
object[] minMaxValues = null;
CodeGenUtilities.integralMinMaxValues.TryGetValue(underlyingType, out minMaxValues);
Debug.Assert(minMaxValues == null || minMaxValues.Length == 3, "integralMinMaxValues elements must always contain 3 values");
// Gen xxx.MinValue if it matches, but give precedence to matching a true zero,
// which is the min value for the unsigned integral types
// minMaxValues[0]: the MinValue for this type
// minMaxValues[1]: the MaxValue for this type
// minMaxValues[2]: the zero for this type (memberValue is not boxed and cannot be cast)
if (minMaxValues != null && !memberValue.Equals(minMaxValues[2]) && memberValue.Equals(minMaxValues[0]))
{
enumMember.InitExpression = new CodeFieldReferenceExpression(new CodeTypeReferenceExpression(underlyingType), "MinValue");
}
// Gen xxx.MaxValue if it matches
else if (minMaxValues != null && memberValue.Equals(minMaxValues[1]))
{
enumMember.InitExpression = new CodeFieldReferenceExpression(new CodeTypeReferenceExpression(underlyingType), "MaxValue");
}
// All other cases generate an integral constant.
// CodeDom knows how to generate the right integral constant based on memberValue's type.
else
{
enumMember.InitExpression = new CodePrimitiveExpression(memberValue);
}
}
typeDecl.Members.Add(enumMember);
// Generate an [EnumMember] if appropriate
EnumMemberAttribute enumMemberAttr = (EnumMemberAttribute)Attribute.GetCustomAttribute(fieldInfo, typeof(EnumMemberAttribute));
if (enumMemberAttr != null)
{
CodeAttributeDeclaration enumAttrDecl = CodeGenUtilities.CreateEnumMemberAttributeDeclaration(fieldInfo, codeGenerator, typeDecl);
enumMember.CustomAttributes.Add(enumAttrDecl);
}
// Propagate any other attributes that can be seen by the client
CustomAttributeGenerator.GenerateCustomAttributes(
codeGenerator,
typeDecl,
ex => string.Format(CultureInfo.CurrentCulture, Resource.ClientCodeGen_Attribute_ThrewException_CodeTypeMember, ex.Message, fieldInfo.Name, typeDecl.Name, ex.InnerException.Message),
fieldInfo.GetCustomAttributes(false).Cast <Attribute>().Where(a => a.GetType() != typeof(EnumMemberAttribute)),
enumMember.CustomAttributes,
enumMember.Comments);
}
// Attributes marked with [Flag] propagate it
if (enumType.GetCustomAttributes(typeof(FlagsAttribute), false).Length > 0)
{
CodeAttributeDeclaration attrDecl = CodeGenUtilities.CreateAttributeDeclaration(typeof(FlagsAttribute), codeGenerator, typeDecl);
typeDecl.CustomAttributes.Add(attrDecl);
}
return(typeDecl);
}
