/// <summary>
/// Return the extension method in reduced form if the extension method
/// is applicable, and satisfies type parameter constraints, based on the
/// "this" argument type. Otherwise, returns null.
/// </summary>
public static MethodSymbol Create(MethodSymbol method, TypeSymbol receiverType, Compilation compilation)
{
Debug.Assert(method.IsExtensionMethod && method.MethodKind != MethodKind.ReducedExtension);
Debug.Assert(method.ParameterCount > 0);
Debug.Assert((object)receiverType != null);
HashSet <DiagnosticInfo> useSiteDiagnostics = null;
method = method.InferExtensionMethodTypeArguments(receiverType, compilation, ref useSiteDiagnostics);
if ((object)method == null)
{
return(null);
}
var conversions = new TypeConversions(method.ContainingAssembly.CorLibrary);
var conversion = conversions.ConvertExtensionMethodThisArg(method.Parameters[0].Type, receiverType, ref useSiteDiagnostics);
if (!conversion.Exists)
{
return(null);
}
if (useSiteDiagnostics != null)
{
foreach (var diag in useSiteDiagnostics)
{
if (diag.Severity == DiagnosticSeverity.Error)
{
return(null);
}
}
}
return(Create(method));
}
/// <summary>
/// Return the extension method in reduced form if the extension method
/// is applicable, and satisfies type parameter constraints, based on the
/// "this" argument type. Otherwise, returns null.
/// </summary>
public static MethodSymbol Create(MethodSymbol method, TypeSymbol receiverType, Compilation compilation)
{
Debug.Assert(method.IsExtensionMethod && method.MethodKind != MethodKind.ReducedExtension);
Debug.Assert(method.ParameterCount > 0);
Debug.Assert((object)receiverType != null);
HashSet<DiagnosticInfo> useSiteDiagnostics = null;
method = method.InferExtensionMethodTypeArguments(receiverType, compilation, ref useSiteDiagnostics);
if ((object)method == null)
{
return null;
}
var conversions = new TypeConversions(method.ContainingAssembly.CorLibrary);
var conversion = conversions.ConvertExtensionMethodThisArg(method.Parameters[0].Type, receiverType, ref useSiteDiagnostics);
if (!conversion.Exists)
{
return null;
}
if (useSiteDiagnostics != null)
{
foreach (var diag in useSiteDiagnostics)
{
if (diag.Severity == DiagnosticSeverity.Error)
{
return null;
}
}
}
return Create(method);
}