/// <summary>
/// Converts access to a tuple instance into access into the underlying ValueTuple(s).
///
/// For instance, tuple.Item8
/// produces fieldAccess(field=Item1, receiver=fieldAccess(field=Rest, receiver=ValueTuple for tuple))
/// </summary>
private BoundExpression MakeTupleFieldAccess(
SyntaxNode syntax,
FieldSymbol tupleField,
BoundExpression rewrittenReceiver,
ConstantValue constantValueOpt,
LookupResultKind resultKind)
{
var tupleType = tupleField.ContainingType;
NamedTypeSymbol currentLinkType = tupleType.TupleUnderlyingType;
FieldSymbol underlyingField = tupleField.TupleUnderlyingField;
if ((object)underlyingField == null)
{
// Use-site error must have been reported elsewhere.
return(_factory.BadExpression(tupleField.Type.TypeSymbol));
}
if (rewrittenReceiver.Kind == BoundKind.DefaultExpression)
{
// Optimization: `default((int, string)).Item2` is simply `default(string)`
return(new BoundDefaultExpression(syntax, tupleField.Type.TypeSymbol));
}
if (!TypeSymbol.Equals(underlyingField.ContainingType, currentLinkType, TypeCompareKind.ConsiderEverything2))
{
WellKnownMember wellKnownTupleRest = TupleTypeSymbol.GetTupleTypeMember(TupleTypeSymbol.RestPosition, TupleTypeSymbol.RestPosition);
var tupleRestField = (FieldSymbol)TupleTypeSymbol.GetWellKnownMemberInType(currentLinkType.OriginalDefinition, wellKnownTupleRest, _diagnostics, syntax);
if ((object)tupleRestField == null)
{
// error tolerance for cases when Rest is missing
return(_factory.BadExpression(tupleField.Type.TypeSymbol));
}
// make nested field accesses to Rest
do
{
FieldSymbol nestedFieldSymbol = tupleRestField.AsMember(currentLinkType);
rewrittenReceiver = _factory.Field(rewrittenReceiver, nestedFieldSymbol);
currentLinkType = currentLinkType.TypeArgumentsNoUseSiteDiagnostics[TupleTypeSymbol.RestPosition - 1].TypeSymbol.TupleUnderlyingType;
}while (!TypeSymbol.Equals(underlyingField.ContainingType, currentLinkType, TypeCompareKind.ConsiderEverything2));
}
// make a field access for the most local access
return(_factory.Field(rewrittenReceiver, underlyingField));
}
/// <summary>
/// Converts access to a tuple instance into access into the underlying ValueTuple(s).
///
/// For instance, tuple.Item8
/// produces fieldAccess(field=Item1, receiver=fieldAccess(field=Rest, receiver=ValueTuple for tuple))
/// </summary>
private BoundExpression MakeTupleFieldAccess(
CSharpSyntaxNode syntax,
FieldSymbol tupleField,
BoundExpression rewrittenReceiver,
ConstantValue constantValueOpt,
LookupResultKind resultKind,
TypeSymbol type)
{
var tupleType = tupleField.ContainingType;
NamedTypeSymbol currentLinkType = tupleType.TupleUnderlyingType;
FieldSymbol underlyingField = tupleField.TupleUnderlyingField;
if ((object)underlyingField == null)
{
// Use-site error must have been reported elsewhere.
return(new BoundFieldAccess(syntax, rewrittenReceiver, tupleField, constantValueOpt, resultKind, type, hasErrors: true));
}
if (underlyingField.ContainingType != currentLinkType)
{
WellKnownMember wellKnownTupleRest = TupleTypeSymbol.GetTupleTypeMember(TupleTypeSymbol.RestPosition, TupleTypeSymbol.RestPosition);
var tupleRestField = (FieldSymbol)TupleTypeSymbol.GetWellKnownMemberInType(currentLinkType.OriginalDefinition, wellKnownTupleRest, _diagnostics, syntax);
if ((object)tupleRestField == null)
{
// error tolerance for cases when Rest is missing
return(new BoundFieldAccess(syntax, rewrittenReceiver, tupleField, constantValueOpt, resultKind, type, hasErrors: true));
}
// make nested field accesses to Rest
do
{
FieldSymbol nestedFieldSymbol = tupleRestField.AsMember(currentLinkType);
currentLinkType = currentLinkType.TypeArgumentsNoUseSiteDiagnostics[TupleTypeSymbol.RestPosition - 1].TupleUnderlyingType;
rewrittenReceiver = new BoundFieldAccess(syntax, rewrittenReceiver, nestedFieldSymbol, ConstantValue.NotAvailable, LookupResultKind.Viable, currentLinkType);
}while (underlyingField.ContainingType != currentLinkType);
}
// make a field access for the most local access
return(new BoundFieldAccess(syntax, rewrittenReceiver, underlyingField, constantValueOpt, resultKind, type));
}