private static bool MatchAttributeTarget(IAttributeTargetSymbol attributeTarget, AttributeLocation symbolPart, AttributeTargetSpecifierSyntax targetOpt, DiagnosticBag diagnostics)
{
IAttributeTargetSymbol attributesOwner = attributeTarget.AttributesOwner;
// Determine if the target symbol owns the attribute declaration.
// We need to report diagnostics only once, so do it when visiting attributes for the owner.
bool isOwner = symbolPart == AttributeLocation.None && ReferenceEquals(attributesOwner, attributeTarget);
if (targetOpt == null)
{
// only attributes with an explicit target match if the symbol doesn't own the attributes:
return isOwner;
}
AttributeLocation explicitTarget = targetOpt.GetAttributeLocation();
if (explicitTarget == AttributeLocation.None)
{
// error: unknown attribute location
if (isOwner)
{
//NOTE: ValueText so that we accept targets like "@return", to match dev10 (DevDiv #2591).
diagnostics.Add(ErrorCode.WRN_InvalidAttributeLocation,
targetOpt.Identifier.GetLocation(), targetOpt.Identifier.ValueText);
}
return false;
}
AttributeLocation allowedTargets = attributesOwner.AllowedAttributeLocations;
if ((explicitTarget & allowedTargets) == 0)
{
// error: invalid target for symbol
if (isOwner)
{
if (allowedTargets == AttributeLocation.None)
{
switch (attributeTarget.DefaultAttributeLocation)
{
case AttributeLocation.Assembly:
case AttributeLocation.Module:
// global attributes are disallowed in interactive code:
diagnostics.Add(ErrorCode.ERR_GlobalAttributesNotAllowed, targetOpt.Identifier.GetLocation());
break;
default:
// currently this can't happen
throw ExceptionUtilities.UnexpectedValue(attributeTarget.DefaultAttributeLocation);
}
}
else
{
diagnostics.Add(ErrorCode.WRN_AttributeLocationOnBadDeclaration,
targetOpt.Identifier.GetLocation(), targetOpt.Identifier.ToString(), allowedTargets.ToDisplayString());
}
}
return false;
}
if (symbolPart == AttributeLocation.None)
{
return explicitTarget == attributeTarget.DefaultAttributeLocation;
}
else
{
return explicitTarget == symbolPart;
}
}
