/// <summary>
/// Look up and cross-link all field types etc.
/// </summary>
internal void CrossLink()
{
if (Proto.HasExtendee)
{
IDescriptor extendee = File.DescriptorPool.LookupSymbol(Proto.Extendee, this);
if (!(extendee is MessageDescriptor))
{
throw new DescriptorValidationException(this, "\"" + Proto.Extendee + "\" is not a message type.");
}
containingType = (MessageDescriptor)extendee;
if (!containingType.IsExtensionNumber(FieldNumber))
{
throw new DescriptorValidationException(this,
"\"" + containingType.FullName + "\" does not declare " +
FieldNumber + " as an extension number.");
}
}
if (Proto.HasTypeName)
{
IDescriptor typeDescriptor =
File.DescriptorPool.LookupSymbol(Proto.TypeName, this);
if (!Proto.HasType)
{
// Choose field type based on symbol.
if (typeDescriptor is MessageDescriptor)
{
fieldType = FieldType.Message;
mappedType = MappedType.Message;
}
else if (typeDescriptor is EnumDescriptor)
{
fieldType = FieldType.Enum;
mappedType = MappedType.Enum;
}
else
{
throw new DescriptorValidationException(this, "\"" + Proto.TypeName + "\" is not a type.");
}
}
if (MappedType == MappedType.Message)
{
if (!(typeDescriptor is MessageDescriptor))
{
throw new DescriptorValidationException(this,
"\"" + Proto.TypeName + "\" is not a message type.");
}
messageType = (MessageDescriptor)typeDescriptor;
if (Proto.HasDefaultValue)
{
throw new DescriptorValidationException(this, "Messages can't have default values.");
}
}
else if (MappedType == Descriptors.MappedType.Enum)
{
if (!(typeDescriptor is EnumDescriptor))
{
throw new DescriptorValidationException(this, "\"" + Proto.TypeName + "\" is not an enum type.");
}
enumType = (EnumDescriptor)typeDescriptor;
}
else
{
throw new DescriptorValidationException(this, "Field with primitive type has type_name.");
}
}
else
{
if (MappedType == MappedType.Message || MappedType == MappedType.Enum)
{
throw new DescriptorValidationException(this, "Field with message or enum type missing type_name.");
}
}
// We don't attempt to parse the default value until here because for
// enums we need the enum type's descriptor.
if (Proto.HasDefaultValue)
{
if (IsRepeated)
{
throw new DescriptorValidationException(this, "Repeated fields cannot have default values.");
}
try
{
switch (FieldType)
{
case FieldType.Int32:
case FieldType.SInt32:
case FieldType.SFixed32:
defaultValue = TextFormat.ParseInt32(Proto.DefaultValue);
break;
case FieldType.UInt32:
case FieldType.Fixed32:
defaultValue = TextFormat.ParseUInt32(Proto.DefaultValue);
break;
case FieldType.Int64:
case FieldType.SInt64:
case FieldType.SFixed64:
defaultValue = TextFormat.ParseInt64(Proto.DefaultValue);
break;
case FieldType.UInt64:
case FieldType.Fixed64:
defaultValue = TextFormat.ParseUInt64(Proto.DefaultValue);
break;
case FieldType.Float:
defaultValue = TextFormat.ParseFloat(Proto.DefaultValue);
break;
case FieldType.Double:
defaultValue = TextFormat.ParseDouble(Proto.DefaultValue);
break;
case FieldType.Bool:
if (Proto.DefaultValue == "true")
{
defaultValue = true;
}
else if (Proto.DefaultValue == "false")
{
defaultValue = false;
}
else
{
throw new FormatException("Boolean values must be \"true\" or \"false\"");
}
break;
case FieldType.String:
defaultValue = Proto.DefaultValue;
break;
case FieldType.Bytes:
try
{
defaultValue = TextFormat.UnescapeBytes(Proto.DefaultValue);
}
catch (FormatException e)
{
throw new DescriptorValidationException(this,
"Couldn't parse default value: " + e.Message);
}
break;
case FieldType.Enum:
defaultValue = enumType.FindValueByName(Proto.DefaultValue);
if (defaultValue == null)
{
throw new DescriptorValidationException(this,
"Unknown enum default value: \"" +
Proto.DefaultValue + "\"");
}
break;
case FieldType.Message:
case FieldType.Group:
throw new DescriptorValidationException(this, "Message type had default value.");
}
}
catch (FormatException e)
{
DescriptorValidationException validationException =
new DescriptorValidationException(this,
"Could not parse default value: \"" + Proto.DefaultValue +
"\"", e);
throw validationException;
}
}
else
{
// Determine the default default for this field.
if (IsRepeated)
{
defaultValue = Lists <object> .Empty;
}
else
{
switch (MappedType)
{
case MappedType.Enum:
// We guarantee elsewhere that an enum type always has at least
// one possible value.
defaultValue = enumType.Values[0];
break;
case MappedType.Message:
defaultValue = null;
break;
default:
defaultValue = GetDefaultValueForMappedType(MappedType);
break;
}
}
}
if (!IsExtension)
{
File.DescriptorPool.AddFieldByNumber(this);
}
if (containingType != null && containingType.Options.MessageSetWireFormat)
{
if (IsExtension)
{
if (!IsOptional || FieldType != FieldType.Message)
{
throw new DescriptorValidationException(this,
"Extensions of MessageSets must be optional messages.");
}
}
else
{
throw new DescriptorValidationException(this, "MessageSets cannot have fields, only extensions.");
}
}
}