private static Func <LightLambda, Delegate> MakeRunDelegateCtor(Type delegateType)
{
var method = delegateType.GetMethod("Invoke");
var paramInfos = method.GetParameters();
Type[] paramTypes;
string name = "Run";
if (paramInfos.Length >= MaxParameters)
{
return(null);
}
if (method.ReturnType == typeof(void))
{
name += "Void";
paramTypes = new Type[paramInfos.Length];
}
else
{
paramTypes = new Type[paramInfos.Length + 1];
paramTypes[paramTypes.Length - 1] = method.ReturnType;
}
MethodInfo runMethod;
if (method.ReturnType == typeof(void) && paramTypes.Length == 2 &&
paramInfos[0].ParameterType.IsByRef && paramInfos[1].ParameterType.IsByRef)
{
runMethod = typeof(LightLambda).GetMethod("RunVoidRef2", BindingFlags.NonPublic | BindingFlags.Instance);
paramTypes[0] = paramInfos[0].ParameterType.GetElementType();
paramTypes[1] = paramInfos[1].ParameterType.GetElementType();
}
else if (method.ReturnType == typeof(void) && paramTypes.Length == 0)
{
runMethod = typeof(LightLambda).GetMethod("RunVoid0", BindingFlags.NonPublic | BindingFlags.Instance);
}
else
{
for (int i = 0; i < paramInfos.Length; i++)
{
paramTypes[i] = paramInfos[i].ParameterType;
if (paramTypes[i].IsByRef)
{
return(null);
}
}
if (DelegateHelpers.MakeDelegate(paramTypes) == delegateType)
{
name = "Make" + name + paramInfos.Length;
MethodInfo ctorMethod = typeof(LightLambda).GetMethod(name, BindingFlags.NonPublic | BindingFlags.Static).MakeGenericMethod(paramTypes);
return(_runCache[delegateType] = (Func <LightLambda, Delegate>)ctorMethod.CreateDelegate(typeof(Func <LightLambda, Delegate>)));
}
runMethod = typeof(LightLambda).GetMethod(name + paramInfos.Length, BindingFlags.NonPublic | BindingFlags.Instance);
}
#if FEATURE_LCG
try {
DynamicMethod dm = new DynamicMethod("FastCtor", typeof(Delegate), new[] { typeof(LightLambda) }, typeof(LightLambda), true);
var ilgen = dm.GetILGenerator();
ilgen.Emit(OpCodes.Ldarg_0);
ilgen.Emit(OpCodes.Ldftn, runMethod.IsGenericMethodDefinition ? runMethod.MakeGenericMethod(paramTypes) : runMethod);
ilgen.Emit(OpCodes.Newobj, delegateType.GetConstructor(new[] { typeof(object), typeof(IntPtr) }));
ilgen.Emit(OpCodes.Ret);
return(_runCache[delegateType] = (Func <LightLambda, Delegate>)dm.CreateDelegate(typeof(Func <LightLambda, Delegate>)));
} catch (SecurityException) {
}
#endif
// we don't have permission for restricted skip visibility dynamic methods, use the slower Delegate.CreateDelegate.
var targetMethod = runMethod.IsGenericMethodDefinition ? runMethod.MakeGenericMethod(paramTypes) : runMethod;
return(_runCache[delegateType] = lambda => targetMethod.CreateDelegate(delegateType, lambda));
}