[MethodImplAttribute(MethodImplOptions.NoInlining)] // Methods containing StackCrawlMark local var has to be marked non-inlineable
static public T CreateInstance <T>()
{
RuntimeType rt = typeof(T) as RuntimeType;
#if !FEATURE_CORECLR
if (FrameworkEventSource.IsInitialized && FrameworkEventSource.Log.IsEnabled(EventLevel.Informational, FrameworkEventSource.Keywords.DynamicTypeUsage) && rt != null)
{
FrameworkEventSource.Log.ActivatorCreateInstanceT(rt.GetFullNameForEtw());
}
#endif
// This is a hack to maintain compatibility with V2. Without this we would throw a NotSupportedException for void[].
// Array, Ref, and Pointer types don't have default constructors.
if (rt.HasElementType)
{
throw new MissingMethodException(Environment.GetResourceString("Arg_NoDefCTor"));
}
StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller;
// Skip the CreateInstanceCheckThis call to avoid perf cost and to maintain compatibility with V2 (throwing the same exceptions).
#if FEATURE_CORECLR
// In SL2/3 CreateInstance<T> doesn't do any security checks. This would mean that Assembly B can create instances of an internal
// type in Assembly A upon A's request:
// TypeInAssemblyA.DoWork() { AssemblyB.Create<InternalTypeInAssemblyA>();}
// TypeInAssemblyB.Create<T>() {return new T();}
// This violates type safety but we saw multiple user apps that have put a dependency on it. So for compatability we allow this if
// the SL app was built against SL2/3.
// Note that in SL2/3 it is possible for app code to instantiate public transparent types with public critical default constructors.
// Fortunately we don't have such types in out platform assemblies.
if (CompatibilitySwitches.IsAppEarlierThanSilverlight4 ||
CompatibilitySwitches.IsAppEarlierThanWindowsPhone8)
{
return((T)rt.CreateInstanceSlow(true /*publicOnly*/, true /*skipCheckThis*/, false /*fillCache*/, ref stackMark));
}
else
#endif // FEATURE_CORECLR
return((T)rt.CreateInstanceDefaultCtor(true /*publicOnly*/, true /*skipCheckThis*/, true /*fillCache*/, ref stackMark));
}