await AST node for expressions (#7368)

* wip: await AST

* Restore ast ppx test.

* cleanup

* Clean up `cli.bsc.js` invocation and mentions.

* final cleanup

Author: cristianoc

CHANGELOG.md

@@ -25,6 +25,7 @@
 - Remove `Stdlib_Char` module for now. https://github.com/rescript-lang/rescript/pull/7367
 - Convert internal JavaScript codebase into ESM, ReScript package itself is now ESM (`"type": "module"`). https://github.com/rescript-lang/rescript/pull/6899
 - Add built-in support for the JavaScript `in` operator. https://github.com/rescript-lang/rescript/pull/7342
+- AST cleanup: add `Pexp_await` ast node instead of `res.await` attribute. (The attribute is still used for await on modules currently). https://github.com/rescript-lang/rescript/pull/7368
 
 #### :nail_care: Polish
 

CONTRIBUTING.md

@@ -123,19 +123,19 @@ After adding a new file to the repository that should go into the npm package -
 
 ```sh
 make lib # Build compiler and standard library
-./cli/bsc myTestFile.res
+./cli/bsc.js myTestFile.res
 ```
 
 To view the untyped tree of the file run:
 
 ```sh
-./cli/bsc -dparsetree myTestFile.res
+./cli/bsc.js -dparsetree myTestFile.res
 ```
 
 To view the typed tree of the file run:
 
 ```sh
-./cli/bsc -dtypedtree myTestFile.res
+./cli/bsc.js -dtypedtree myTestFile.res
 ```
 
 ### Project

analysis/src/CompletionFrontEnd.ml

@@ -312,11 +312,12 @@ let rec exprToContextPathInner ~(inJsxContext : bool) (e : Parsetree.expression)
     if List.length exprs = List.length exprsAsContextPaths then
       Some (CTuple exprsAsContextPaths)
     else None
+  | Pexp_await e -> exprToContextPathInner ~inJsxContext e
   | _ -> None
 
 and exprToContextPath ~(inJsxContext : bool) (e : Parsetree.expression) =
   match
-    ( Res_parsetree_viewer.has_await_attribute e.pexp_attributes,
+    ( Res_parsetree_viewer.expr_is_await e,
       exprToContextPathInner ~inJsxContext e )
   with
   | true, Some ctxPath -> Some (CPAwait ctxPath)

analysis/src/Utils.ml

@@ -111,6 +111,7 @@ let identifyPexp pexp =
   | Pexp_pack _ -> "Pexp_pack"
   | Pexp_extension _ -> "Pexp_extension"
   | Pexp_open _ -> "Pexp_open"
+  | Pexp_await _ -> "Pexp_await"
 
 let identifyPpat pat =
   match pat with

compiler/frontend/bs_ast_mapper.ml

@@ -366,6 +366,7 @@ module E = struct
     | Pexp_open (ovf, lid, e) ->
       open_ ~loc ~attrs ovf (map_loc sub lid) (sub.expr sub e)
     | Pexp_extension x -> extension ~loc ~attrs (sub.extension sub x)
+    | Pexp_await e -> await ~loc ~attrs (sub.expr sub e)
 end
 
 module P = struct

compiler/frontend/bs_builtin_ppx.ml

@@ -242,10 +242,12 @@ let expr_mapper ~async_context ~in_function_def (self : mapper)
          || Ast_attributes.has_await_payload attrs2 ->
     check_await ();
     result
-  | _ when Ast_attributes.has_await_payload e.pexp_attributes ->
-    check_await ();
-    Ast_await.create_await_expression result
-  | _ -> result
+  | _ -> (
+    match result.pexp_desc with
+    | Pexp_await e ->
+      check_await ();
+      Ast_await.create_await_expression e
+    | _ -> result)
 
 let typ_mapper (self : mapper) (typ : Parsetree.core_type) =
   Ast_core_type_class_type.typ_mapper self typ

compiler/ml/ast_helper.ml

@@ -180,7 +180,7 @@ module Exp = struct
   let pack ?loc ?attrs a = mk ?loc ?attrs (Pexp_pack a)
   let open_ ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_open (a, b, c))
   let extension ?loc ?attrs a = mk ?loc ?attrs (Pexp_extension a)
-
+  let await ?loc ?attrs a = mk ?loc ?attrs (Pexp_await a)
   let case lhs ?guard rhs = {pc_lhs = lhs; pc_guard = guard; pc_rhs = rhs}
 end
 

compiler/ml/ast_helper.mli

@@ -210,6 +210,7 @@ module Exp : sig
   val extension : ?loc:loc -> ?attrs:attrs -> extension -> expression
 
   val case : pattern -> ?guard:expression -> expression -> case
+  val await : ?loc:loc -> ?attrs:attrs -> expression -> expression
 end
 
 (** Value declarations *)

compiler/ml/ast_iterator.ml

@@ -344,6 +344,7 @@ module E = struct
       iter_loc sub lid;
       sub.expr sub e
     | Pexp_extension x -> sub.extension sub x
+    | Pexp_await e -> sub.expr sub e
 end
 
 module P = struct

compiler/ml/ast_mapper.ml

@@ -329,6 +329,7 @@ module E = struct
     | Pexp_open (ovf, lid, e) ->
       open_ ~loc ~attrs ovf (map_loc sub lid) (sub.expr sub e)
     | Pexp_extension x -> extension ~loc ~attrs (sub.extension sub x)
+    | Pexp_await e -> await ~loc ~attrs (sub.expr sub e)
 end
 
 module P = struct