hphp/hack/src/hhbc/emit_function.ml

   1 (**
   2  * Copyright (c) 2017, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the BSD-style license found in the
   6  * LICENSE file in the "hack" directory of this source tree. An additional grant
   7  * of patent rights can be found in the PATENTS file in the same directory.
   8  *
   9 *)
  10
  11 open Instruction_sequence
  12 module A = Ast
  13 open Hh_core
  14
  15 let find_first_redeclaration pick_name_span l =
  16   let rec aux seen l =
  17     match l with
  18     | [] -> None
  19     | x :: xs ->
  20       match pick_name_span x with
  21       | Some (name, span) ->
  22         begin match SMap.get name seen with
  23         | None -> aux (SMap.add name span seen) xs
  24         | Some original -> Some (name, original, span)
  25         end
  26       | None -> aux seen xs in
  27   aux SMap.empty l
  28
  29 (* Given a function definition, emit code, and in the case of <<__Memoize>>,
  30  * a wrapper function
  31  *)
  32 let emit_function : A.fun_ * bool -> Hhas_function.t list =
  33   fun (ast_fun, is_top) ->
  34   let namespace = ast_fun.A.f_namespace in
  35   let original_id, _ =
  36     Hhbc_id.Function.elaborate_id namespace ast_fun.A.f_name in
  37   let function_is_async =
  38     ast_fun.Ast.f_fun_kind = Ast_defs.FAsync
  39     || ast_fun.Ast.f_fun_kind = Ast_defs.FAsyncGenerator in
  40   let function_attributes =
  41     Emit_attribute.from_asts namespace ast_fun.Ast.f_user_attributes in
  42   let is_memoize = Hhas_attribute.is_memoized function_attributes in
  43   let deprecation_info = Hhas_attribute.deprecation_info function_attributes in
  44   let inout_param_locations = List.filter_mapi ast_fun.Ast.f_params
  45       ~f:(fun i p -> if p.Ast.param_callconv <> Some Ast.Pinout
  46                      then None else Some (string_of_int i)) in
  47   let has_inout_args = List.length inout_param_locations <> 0 in
  48   let renamed_id =
  49     if is_memoize
  50     then Hhbc_id.Function.add_suffix
  51       original_id Emit_memoize_helpers.memoize_suffix
  52     else if has_inout_args
  53     then Hhbc_id.Function.add_suffix
  54       original_id (Emit_inout_helpers.inout_suffix inout_param_locations)
  55     else original_id in
  56   let scope = [Ast_scope.ScopeItem.Function ast_fun] in
  57   let function_body, function_is_generator, function_is_pair_generator =
  58     Emit_body.emit_body
  59       ~pos: ast_fun.A.f_span
  60       ~scope
  61       ~is_closure_body:false
  62       ~is_memoize
  63       ~is_async:function_is_async
  64       ~deprecation_info:(if is_memoize then None else deprecation_info)
  65       ~skipawaitable:(ast_fun.Ast.f_fun_kind = Ast_defs.FAsync)
  66       ~is_return_by_ref:ast_fun.Ast.f_ret_by_ref
  67       ~default_dropthrough:None
  68       ~return_value:instr_null
  69       ~namespace
  70       ~doc_comment:ast_fun.Ast.f_doc_comment
  71       ast_fun.Ast.f_params
  72       ast_fun.Ast.f_ret
  73       [Ast.Stmt (Ast.Block ast_fun.Ast.f_body)] in
  74   let normal_function =
  75     Hhas_function.make
  76       function_attributes
  77       renamed_id
  78       function_body
  79       (Hhas_pos.pos_to_span ast_fun.Ast.f_span)
  80       function_is_async
  81       function_is_generator
  82       function_is_pair_generator
  83       is_top
  84       false (*no_injection*)
  85       false (*inout_wrapper*)
  86   in
  87   if is_memoize
  88   then [normal_function;
  89     Emit_memoize_function.emit_wrapper_function
  90       ~original_id
  91       ~renamed_id
  92       ~is_method:false
  93       ~deprecation_info
  94       ast_fun]
  95   else if has_inout_args
  96   then [Emit_inout_function.emit_wrapper_function
  97           ~original_id
  98           ~renamed_id
  99           ~verify_ret:(ast_fun.Ast.f_ret <> None)
 100           ast_fun;
 101         normal_function]
 102   else [normal_function]
 103
 104 let emit_functions_from_program ast =
 105   List.concat_map (List.sort (fun (t1, _) (t2, _) -> compare t1 t2) ast)
 106   (fun (is_top, d) ->
 107     match d with Ast.Fun fd -> emit_function (fd, is_top) | _ -> [])