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
   |}]