Gate coroutines behind directory

Summary:
We want to gate coroutines behind a specific directory in `www` when we ship to `www`. I have chosen to gate it behind `flib/core/hack/lib/experimental` for the time being.

Added this as a `tast_check`, which involved added `at_method_` to the visitor.

Differential Revision: D8555694

fbshipit-source-id: 1016e792d07cd4ba15b14367e699a5cf0f1e6603

hphp/hack/src/annotated_ast/aast.ml

@@ -360,8 +360,10 @@ and gconst = {
  cst_is_define: bool;
}

and fun_def = fun_

and def =
  | Fun of fun_
  | Fun of fun_def
  | Class of class_
  | Typedef of typedef
  | Constant of gconst

hphp/hack/src/errors/error_codes.ml

@@ -492,6 +492,7 @@ module Typing                               = struct
  | ReassignMutableThis
  | MutableExpressionAsMultipleMutableArguments
  | InvalidUnsetTargetInRx
  | CoroutineOutsideExperimental
  (* EXTEND HERE WITH NEW VALUES IF NEEDED *)
  [@@ deriving enum, show { with_path = false } ]
  let err_code = to_enum

hphp/hack/src/errors/errors.ml

@@ -2719,6 +2719,10 @@ let invalid_ppl_static_call pos reason =
  let error_msg = "Cannot call a static method on a <<__PPL>> class "^reason in
  add (Typing.err_code Typing.InvalidPPLStaticCall) pos error_msg

let coroutine_outside_experimental pos =
  add (Typing.err_code Typing.CoroutineOutsideExperimental) pos
    Coroutine_errors.error_message

let return_disposable_mismatch pos1_return_disposable pos1 pos2 =
  let m1 = "This is marked <<__ReturnDisposable>>." in
  let m2 = "This is not marked <<__ReturnDisposable>>." in

hphp/hack/src/errors/errors_sig.ml

@@ -472,6 +472,7 @@ module type S = sig
  val coroutinness_mismatch : bool -> Pos.t -> Pos.t -> unit
  val invalid_ppl_call : Pos.t -> string -> unit
  val invalid_ppl_static_call : Pos.t -> string -> unit
  val coroutine_outside_experimental : Pos.t -> unit
  val return_disposable_mismatch : bool -> Pos.t -> Pos.t -> unit
  val fun_reactivity_mismatch : Pos.t -> string -> Pos.t -> string -> unit
  val frozen_in_incorrect_scope : Pos.t -> unit

hphp/hack/src/stubs/coroutine_check.ml

@@ -0,0 +1,12 @@
(**
 * Copyright (c) 2018, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the "hack" directory of this source tree.
 *
 *)

let handler = object
  inherit Tast_visitor.handler_base
end

hphp/hack/src/stubs/coroutine_errors.ml

@@ -0,0 +1,10 @@
(**
 * Copyright (c) 2018, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the "hack" directory of this source tree.
 *
 *)

let error_message = ""

hphp/hack/src/typing/tast_check/tast_check.ml

@@ -13,6 +13,7 @@ let visitor = Tast_visitor.iter_with [
  Tautology_check.handler;
  Type_test_hint_check.handler;
  Ppl_check.handler;
  Coroutine_check.handler;
]

let program = visitor#go

hphp/hack/src/typing/tast_env.ml

@@ -63,6 +63,8 @@ let save = Typing_env.save SMap.empty
let forward_compat_ge = Typing_env.forward_compat_ge
let error_if_forward_compat_ge = Typing_env.error_if_forward_compat_ge

let get_file = Typing_env.get_file

let fully_expand = Typing_expand.fully_expand

let get_class_ids = Typing_utils.get_class_ids

hphp/hack/src/typing/tast_env.mli

@@ -64,6 +64,9 @@ val forward_compat_ge : env -> int -> bool
val error_if_forward_compat_ge : env -> int -> (unit -> unit) -> unit
(** Call the func if the forward compatibility level is new enough *)

val get_file : env -> Relative_path.t
(* Return the {!Relative_path.t} of the file the env is from *)

val expand_type : env -> Tast.ty -> env * Tast.ty
(** Expand a type variable ({!Typing_defs.Tvar}) to the type it refers to. *)

hphp/hack/src/typing/tast_visitor.ml

@@ -104,10 +104,11 @@ end
class type handler = object
  method minimum_forward_compat_level : int

  method at_fun_ : Env.t -> Tast.fun_ -> unit
  method at_class_ : Env.t -> Tast.class_ -> unit
  method at_typedef : Env.t -> Tast.typedef -> unit
  method at_gconst : Env.t -> Tast.gconst -> unit
  method at_fun_def : Env.t -> Tast.fun_def -> unit
  method at_method_ : Env.t -> Tast.method_ -> unit

  method at_expr : Env.t -> Tast.expr -> unit
  method at_stmt : Env.t -> Tast.stmt -> unit
@@ -126,10 +127,11 @@ end
class virtual handler_base : handler = object
  method minimum_forward_compat_level = 0

  method at_fun_ _ _ = ()
  method at_class_ _ _ = ()
  method at_typedef _ _ = ()
  method at_gconst _ _ = ()
  method at_fun_def _ _ = ()
  method at_method_ _ _ = ()

  method at_expr _ _ = ()
  method at_stmt _ _ = ()
@@ -147,10 +149,6 @@ let iter_with (handlers : handler list) : iter = object

  inherit iter as super

  method! on_fun_ env x =
    List.iter handlers (if_enabled env (fun v -> v#at_fun_ env x));
    super#on_fun_ env x;

  method! on_class_ env x =
    List.iter handlers (if_enabled env (fun v -> v#at_class_ env x));
    super#on_class_ env x;
@@ -163,6 +161,14 @@ let iter_with (handlers : handler list) : iter = object
    List.iter handlers (if_enabled env (fun v -> v#at_gconst env x));
    super#on_gconst env x;

  method! on_fun_def env x =
    List.iter handlers (if_enabled env (fun v -> v#at_fun_def env x));
    super#on_fun_def env x;

  method! on_method_ env x =
    List.iter handlers (if_enabled env (fun v -> v#at_method_ env x));
    super#on_method_ env x;

  method! on_expr env x =
    List.iter handlers (if_enabled env (fun v -> v#at_expr env x));
    super#on_expr env x;

hphp/hack/test/errors/error_map.ml

@@ -486,4 +486,5 @@ InvalidTraversableInRx = 4267
ReassignMutableThis = 4268
MutableExpressionAsMultipleMutableArguments = 4269
InvalidUnsetTargetInRx = 4270
CoroutineOutsideExperimental = 4271
  |}]