private static async Task <Document> UseBitShiftOperatorAsync(
Document document,
EnumDeclarationSyntax enumDeclaration,
CancellationToken cancellationToken)
{
SemanticModel semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
EnumDeclarationSyntax newEnumDeclaration = enumDeclaration.ReplaceNodes(
GetExpressionsToRewrite(),
(expression, _) =>
{
Optional <object> constantValue = semanticModel.GetConstantValue(expression, cancellationToken);
var power = (int)Math.Log(Convert.ToDouble(constantValue.Value), 2);
BinaryExpressionSyntax leftShift = LeftShiftExpression(NumericLiteralExpression(1), NumericLiteralExpression(power));
return(leftShift.WithTriviaFrom(expression));
});
return(await document.ReplaceNodeAsync(enumDeclaration, newEnumDeclaration, cancellationToken).ConfigureAwait(false));
IEnumerable <ExpressionSyntax> GetExpressionsToRewrite()
{
foreach (EnumMemberDeclarationSyntax member in enumDeclaration.Members)
{
ExpressionSyntax expression = member.EqualsValue?.Value.WalkDownParentheses();
if (expression != null &&
semanticModel.GetDeclaredSymbol(member, cancellationToken) is IFieldSymbol fieldSymbol &&
fieldSymbol.HasConstantValue)
{
EnumFieldSymbolInfo fieldInfo = EnumFieldSymbolInfo.Create(fieldSymbol);
if (fieldInfo.Value > 1 &&
!fieldInfo.HasCompositeValue())
{
yield return(expression);
}
}
}
}
}
private static Task <Document> RefactorAsync(
Document document,
EnumDeclarationSyntax enumDeclaration,
INamedTypeSymbol enumSymbol,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
ulong value = 0;
SpecialType numericType = enumSymbol.EnumUnderlyingType.SpecialType;
IEnumerable <EnumMemberDeclarationSyntax> newMembers = (enumSymbol.HasAttribute(MetadataNames.System_FlagsAttribute))
? enumDeclaration.Members.Select(f => CreateNewFlagsMember(f))
: enumDeclaration.Members.Select(f => CreateNewMember(f));
EnumDeclarationSyntax newEnumDeclaration = enumDeclaration.ReplaceNodes(
enumDeclaration.Members,
(f, _) =>
{
return((enumSymbol.HasAttribute(MetadataNames.System_FlagsAttribute))
? CreateNewFlagsMember(f)
: CreateNewMember(f));
});
return(document.ReplaceNodeAsync(enumDeclaration, newEnumDeclaration, cancellationToken));
EnumMemberDeclarationSyntax CreateNewFlagsMember(EnumMemberDeclarationSyntax enumMember)
{
if (!ConvertHelpers.CanConvertFromUInt64(value, numericType))
{
return(enumMember);
}
IFieldSymbol fieldSymbol = semanticModel.GetDeclaredSymbol(enumMember, cancellationToken);
if (fieldSymbol.HasConstantValue &&
FlagsUtility <ulong> .Instance.IsComposite(SymbolUtility.GetEnumValueAsUInt64(fieldSymbol.ConstantValue, enumSymbol)))
{
return(enumMember);
}
EnumMemberDeclarationSyntax newEnumMember = CreateNewEnumMember(enumMember, value, numericType);
value = (value == 0) ? 1 : value * 2;
return(newEnumMember);
}
EnumMemberDeclarationSyntax CreateNewMember(EnumMemberDeclarationSyntax enumMember)
{
if (!ConvertHelpers.CanConvertFromUInt64(value, numericType))
{
return(enumMember);
}
EnumMemberDeclarationSyntax newEnumMember = CreateNewEnumMember(enumMember, value, numericType);
value++;
return(newEnumMember);
}
}