hphp/hack/src/typing/typing_env_from_def.ml

   1 (*
   2  * Copyright (c) 2018, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the MIT license found in the
   6  * LICENSE file in the "hack" directory of this source tree.
   7  *
   8  *)
   9
  10 open Hh_prelude
  11 open Typing_defs
  12 module Env = Typing_env
  13 module MakeType = Typing_make_type
  14
  15 (*****************************************************************************)
  16 (* Construct a Typing_env from an AAST toplevel definition.
  17  *)
  18 (*****************************************************************************)
  19
  20 open Aast
  21
  22 let fun_env ?origin ctx fd =
  23   let f = fd.fd_fun in
  24   let file = Pos.filename (fst f.f_name) in
  25   let droot = Some (Typing_deps.Dep.Fun (snd f.f_name)) in
  26   let env = Typing_env_types.empty ?origin ctx file ~mode:fd.fd_mode ~droot in
  27   Typing_inference_env.Identifier_provider.reinitialize ();
  28   env
  29
  30 (* Given a class definition construct a type consisting of the
  31  * class instantiated at its generic parameters. *)
  32 let get_self_from_c c =
  33   let tparams =
  34     List.map c.c_tparams ~f:(fun { tp_name = (p, s); _ } ->
  35         mk
  36           ( Reason.Rwitness_from_decl (Pos_or_decl.of_raw_pos p),
  37             Tgeneric (s, []) ))
  38   in
  39   let (name_pos, name) = c.c_name in
  40   let name_pos = Pos_or_decl.of_raw_pos name_pos in
  41   mk (Reason.Rwitness_from_decl name_pos, Tapply ((name_pos, name), tparams))
  42
  43 (** Set 'self' identifier and type in environment. *)
  44 let set_self env c =
  45   let self_id = snd c.c_name in
  46   let self = get_self_from_c c in
  47   (* For enums, localize makes self:: into an abstract type, which we don't
  48    * want *)
  49   let (env, self_ty) =
  50     match c.c_kind with
  51     | Ast_defs.Cenum_class _
  52     | Ast_defs.Cenum ->
  53       ( env,
  54         MakeType.class_type (Reason.Rwitness (fst c.c_name)) (snd c.c_name) []
  55       )
  56     | Ast_defs.Cinterface
  57     | Ast_defs.Cclass _
  58     | Ast_defs.Ctrait ->
  59       let ((env, ty_err_opt), res) =
  60         Typing_phase.localize_no_subst env ~ignore_errors:true self
  61       in
  62       Option.iter ty_err_opt ~f:Errors.add_typing_error;
  63       (env, res)
  64   in
  65   let env = Env.set_self env self_id self_ty in
  66   let env =
  67     Env.add_upper_bound env Naming_special_names.Typehints.this self_ty
  68   in
  69   let env =
  70     if c.c_final then
  71       Env.add_lower_bound env Naming_special_names.Typehints.this self_ty
  72     else
  73       env
  74   in
  75   env
  76
  77 let set_parent env c =
  78   (* In order to type-check a class, we need to know what "parent"
  79    * refers to. Sometimes people write "parent::", when that happens,
  80    * we need to know the type of parent.
  81    *)
  82   match c.c_extends with
  83   | ((_, Happly ((_, parent_id), _)) as parent_ty) :: _ ->
  84     let parent_ty = Decl_hint.hint env.Typing_env_types.decl_env parent_ty in
  85     Env.set_parent env parent_id parent_ty
  86   (* The only case where we have more than one parent class is when
  87    * dealing with interfaces and interfaces cannot use parent.
  88    *)
  89   | _ :: _
  90   | _ ->
  91     env
  92
  93 let class_env ?origin ctx c =
  94   let file = Pos.filename (fst c.c_name) in
  95   let droot = Some (Typing_deps.Dep.Type (snd c.c_name)) in
  96   let env = Typing_env_types.empty ?origin ctx file ~mode:c.c_mode ~droot in
  97   Typing_inference_env.Identifier_provider.reinitialize ();
  98   let env = set_self env c in
  99   let env = set_parent env c in
 100   env
 101
 102 let typedef_env ?origin ctx t =
 103   let file = Pos.filename (fst t.t_kind) in
 104   let droot = Some (Typing_deps.Dep.Type (snd t.t_name)) in
 105   let env = Typing_env_types.empty ?origin ctx file ~mode:t.t_mode ~droot in
 106   Typing_inference_env.Identifier_provider.reinitialize ();
 107   env
 108
 109 let gconst_env ?origin ctx cst =
 110   let file = Pos.filename (fst cst.cst_name) in
 111   let droot = Some (Typing_deps.Dep.GConst (snd cst.cst_name)) in
 112   let env = Typing_env_types.empty ?origin ctx file ~mode:cst.cst_mode ~droot in
 113   Typing_inference_env.Identifier_provider.reinitialize ();
 114   env