/// <summary>
/// Given a symbol, finds the symbol that actually defines the name that we're using.
/// </summary>
public static async Task <ISymbol> FindDefinitionSymbolAsync(
ISymbol symbol, Solution solution, CancellationToken cancellationToken)
{
Contract.ThrowIfNull(symbol);
Contract.ThrowIfNull(solution);
// Make sure we're on the original source definition if we can be
var foundSymbol = await SymbolFinder.FindSourceDefinitionAsync(
symbol, solution, cancellationToken).ConfigureAwait(false);
var bestSymbol = foundSymbol ?? symbol;
symbol = bestSymbol;
// If we're renaming a property, it might be a synthesized property for a method
// backing field.
if (symbol.Kind == SymbolKind.Parameter)
{
if (symbol.ContainingSymbol.Kind == SymbolKind.Method)
{
var containingMethod = (IMethodSymbol)symbol.ContainingSymbol;
if (containingMethod.AssociatedSymbol is IPropertySymbol)
{
var associatedPropertyOrEvent = (IPropertySymbol)containingMethod.AssociatedSymbol;
var ordinal = containingMethod.Parameters.IndexOf((IParameterSymbol)symbol);
if (ordinal < associatedPropertyOrEvent.Parameters.Length)
{
return(associatedPropertyOrEvent.Parameters[ordinal]);
}
}
}
}
// if we are renaming a compiler generated delegate for an event, cascade to the event
if (symbol.Kind == SymbolKind.NamedType)
{
var typeSymbol = (INamedTypeSymbol)symbol;
if (typeSymbol.IsImplicitlyDeclared && typeSymbol.IsDelegateType() && typeSymbol.AssociatedSymbol != null)
{
return(typeSymbol.AssociatedSymbol);
}
}
// If we are renaming a constructor or destructor, we wish to rename the whole type
if (symbol.Kind == SymbolKind.Method)
{
var methodSymbol = (IMethodSymbol)symbol;
if (methodSymbol.MethodKind is MethodKind.Constructor or
MethodKind.StaticConstructor or
MethodKind.Destructor)
{
return(methodSymbol.ContainingType);
}
}
// If we are renaming a backing field for a property, cascade to the property
if (symbol.Kind == SymbolKind.Field)
{
var fieldSymbol = (IFieldSymbol)symbol;
if (fieldSymbol.IsImplicitlyDeclared &&
fieldSymbol.AssociatedSymbol.IsKind(SymbolKind.Property))
{
return(fieldSymbol.AssociatedSymbol);
}
}
// in case this is e.g. an overridden property accessor, we'll treat the property itself as the definition symbol
var property = await RenameUtilities.TryGetPropertyFromAccessorOrAnOverrideAsync(bestSymbol, solution, cancellationToken).ConfigureAwait(false);
return(property ?? bestSymbol);
}
