protected override void OnGenerate(ILGenerator il)
{
if (!_enumerable.Type.TryGetInterface(typeof(IEnumerable <>), out var enumerableType))
{
throw new InvalidOperationException("Could not enumerate the type " + _enumerable.Type.FullName);
}
var getEnumerator = ILSnippet.Call(_enumerable, enumerableType.GetRuntimeMethod("GetEnumerator", Type.EmptyTypes));
var elementType = enumerableType.GetTypeInfo().GetGenericArguments()[0];
var itLocal = il.NewLocal(getEnumerator.ReturnType);
il.Set(itLocal, getEnumerator);
il.Try(() => {
var itHeadLabel = il.NewLabel();
var itBodyLabel = il.NewLabel();
itHeadLabel.TransferLong();
var itVarLocal = il.NewLocal(elementType);
itBodyLabel.Mark();
il.Set(itVarLocal, ILPointer.Property(itLocal, "Current"));
_iterateBody.Invoke(il, itVarLocal);
itHeadLabel.Mark();
il.InvokeMethod(itLocal, EnumeratorMoveNext);
itBodyLabel.TransferLongIfTrue();
})
.Finally(() => {
var endLabel = il.NewLabel();
endLabel.TransferIfNull(itLocal);
il.InvokeMethod(itLocal, DisposableDispose);
endLabel.Mark();
})
.End();
}
public static void Set(this ILGenerator il, ILPointer instance, PropertyInfo property, ILPointer value)
{
var p = ILPointer.Property(instance, property);
il.Set(p, value);
}
