Upgrade vendored Flow parser to 0.320.0

CHANGELOG.md

@@ -57,6 +57,7 @@
 
 #### :house: Internal
 
+- Upgrade the vendored Flow parser from 0.267.0 to 0.320.0, the final release of the OCaml implementation. https://github.com/rescript-lang/rescript/pull/8588
 - Vendor the Flow parser 0.267.0 sources used by the compiler, removing the external `flow_parser` dependency and establishing a maintained baseline for future OCaml upgrades. https://github.com/rescript-lang/rescript/pull/8587
 - Store processed external declarations as structured data instead of serialized values in `pval_prim`, and lower external calls during Lambda translation. This removes `Pccall`, `external_spec`, and the unsupported `%absfloat` primitive. The AST, CMI, and CMT magic numbers are bumped (`ResImpl01301`/`ResIntf01301`, `Caml1999I025`, `Caml1999T026`). https://github.com/rescript-lang/rescript/pull/8581
 - Resolve dynamic-import targets during Lambda translation and store the module and export path directly in `Pimport`. This removes the `dynamic_import` flags from `Pjs_call` and `Lglobal_module`, along with backend expression-shape detection. https://github.com/rescript-lang/rescript/pull/8582

compiler/flow_parser/README.md

@@ -2,20 +2,31 @@
 
 This directory contains the OCaml Flow parser used by the ReScript compiler.
 
-- Upstream fork: https://github.com/rescript-lang/flow
-- Flow parser version: `0.267.0`
-- Source commit: `9ea4062c0b7e037415c4413a7634c459ebd5c31b`
+- Upstream repository: https://github.com/facebook/flow
+- Flow parser version: `0.320.0`
+- Parser and Sedlex source commit: `7c64d4b077bc6fc45c12cee3cfa7368fdb2186ce`
+- Collection source commit: `9ea4062c0b7e037415c4413a7634c459ebd5c31b`
+  from Flow parser 0.267.0
 - Original source directories: `src/parser`, `src/third-party/sedlex`,
   `src/third-party/sedlex-ppx`, and `src/hack_forked/utils/collections`
 
+The collection helpers retain the MIT-licensed 0.267.0 sources. Their code is
+identical in Flow 0.320.0, but that release replaces their MIT notices with
+"Confidential and proprietary" notices that do not grant redistribution
+rights.
+
 The Dune files were adapted to build these sources as private libraries inside
 the ReScript repository. Sources used only by the upstream JavaScript and C API
 targets are not included. One ambiguous Sedlex documentation comment was
-converted to a regular comment so the vendored sources build with ReScript's
-warning settings.
+converted to a regular comment and one unused loop index was renamed so the
+vendored sources build with ReScript's warning settings. One `List.is_empty`
+call uses an empty-list comparison to retain OCaml 5.0 compatibility. The
+Sedlex PPX uses `Ast_helper.Exp.fun_` to generate single-argument functions
+with newer ppxlib versions.
 
 Vendored sources are excluded from the repository-wide OCamlformat check so
 that they remain comparable with their upstream versions.
 
-The Flow sources are licensed under the MIT licence in `LICENSE`. Vendored
-Sedlex and collections sources retain their own licence files.
+The Flow parser and retained collection sources are licensed under the MIT
+licence in `LICENSE` and their source headers. Vendored Sedlex and collection
+third-party sources retain the licence files in their respective directories.

compiler/flow_parser/flow_sedlexing/flow_sedlexing.ml

@@ -285,3 +285,12 @@ let string_of_utf8 (lexbuf : int array) : string =
 
 let backoff lexbuf npos =
   lexbuf.pos <- lexbuf.pos - npos
+
+let peek lexbuf n =
+  let i = lexbuf.pos + n in
+  if i >= lexbuf.len then
+    -1
+  else
+    lexbuf.buf.!(i)
+
+let bump lexbuf n = lexbuf.pos <- lexbuf.pos + n

compiler/flow_parser/flow_sedlexing/flow_sedlexing.mli

@@ -32,7 +32,7 @@ module Utf8 : sig
   val from_string : string -> lexbuf
   val sub_lexeme : lexbuf -> int -> int -> string
   val lexeme : lexbuf -> string
-  (* This API avoids another allocation. *)
+  (* This API avoids another allocation *)
   val lexeme_to_buffer : lexbuf -> Buffer.t -> unit
   val lexeme_to_buffer2 : lexbuf -> Buffer.t -> Buffer.t -> unit
 end
@@ -45,3 +45,5 @@ val string_of_utf8 : int array -> string
 val current_code_point : lexbuf -> int
 val backoff : lexbuf -> int -> unit
 val set_lexeme_start : lexbuf -> int -> unit
+val peek : lexbuf -> int -> int
+val bump : lexbuf -> int -> unit

compiler/flow_parser/flow_sedlexing_ppx/ppx_sedlex.ml

@@ -4,7 +4,6 @@
 
 open Ppxlib
 open Ast_builder.Default
-open Ast_helper
 
 (* let ocaml_version = Versions.ocaml_408 *)
 
@@ -360,14 +359,7 @@ let gen_state lexbuf auto i (trans, final) =
       (appfun (partition_name partition) [[%expr Sedlexing.__private__next_int [%e evar ~loc lexbuf]]])
       (cases @ [case ~lhs:[%pat? _] ~guard:None ~rhs:[%expr Sedlexing.backtrack [%e evar ~loc lexbuf]]])
   in
-  let ret body =
-    let lhs = pvar ~loc lexbuf in
-    [
-      value_binding ~loc
-        ~pat:(pvar ~loc (state_fun i))
-        ~expr:(Exp.fun_ ~loc Nolabel None lhs body);
-    ]
-  in
+  let ret body = [ value_binding ~loc ~pat:(pvar ~loc (state_fun i)) ~expr:(Ast_helper.Exp.fun_ ~loc Nolabel None (pvar ~loc lexbuf) body) ] in
   match best_final final with
     | None -> ret (body ())
     | Some _ when Array.length trans = 0 -> []

compiler/flow_parser/parser/comment_attachment.ml

@@ -134,7 +134,7 @@ class ['loc] trailing_comments_remover ~after_pos =
       let open Ast.Class.Implements.Interface in
       let (loc, { id = id_; targs }) = interface in
       if targs = None then
-        id this#identifier id_ interface (fun id' -> (loc, { id = id'; targs }))
+        id this#generic_identifier_type id_ interface (fun id' -> (loc, { id = id'; targs }))
       else
         id (map_opt this#type_args) targs interface (fun targs' ->
             (loc, { id = id_; targs = targs' })
@@ -143,7 +143,7 @@ class ['loc] trailing_comments_remover ~after_pos =
     method! component_declaration _loc component =
       let open Ast.Statement.ComponentDeclaration in
       let { body; comments; _ } = component in
-      let body' = this#component_body body in
+      let body' = map_opt this#component_body body in
       let comments' = this#syntax_opt comments in
       if body == body' && comments == comments' then
         component
@@ -189,7 +189,7 @@ class ['loc] trailing_comments_remover ~after_pos =
           (loc, { params with comments = comments' })
       )
 
-    method! function_type _loc func =
+    method! function_type func =
       let open Ast.Type.Function in
       let { return; comments; _ } = func in
       let return' = this#function_type_return_annotation return in
@@ -209,16 +209,20 @@ class ['loc] trailing_comments_remover ~after_pos =
           git
         else
           Qualified (loc, { qualified with id = id' })
+      | ImportTypeAnnot _ -> git
 
-    method! import _loc expr =
+    method! import expr =
       let open Ast.Expression.Import in
       let { comments; _ } = expr in
       id this#syntax_opt comments expr (fun comments' -> { expr with comments = comments' })
 
     method! interface_type _loc t =
       let open Ast.Type.Interface in
       let { body; comments; _ } = t in
-      let body' = map_loc this#object_type body in
+      let body' =
+        let (bloc, b) = body in
+        id this#object_type b body (fun b' -> (bloc, b'))
+      in
       let comments' = this#syntax_opt comments in
       if body == body' && comments == comments' then
         t
@@ -300,7 +304,7 @@ class ['loc] trailing_comments_remover ~after_pos =
       let { comments; _ } = expr in
       id this#syntax_opt comments expr (fun comments' -> { expr with comments = comments' })
 
-    method! object_type _loc obj =
+    method! object_type obj =
       let open Ast.Type.Object in
       let { comments; _ } = obj in
       id this#syntax_opt comments obj (fun comments' -> { obj with comments = comments' })
@@ -485,12 +489,19 @@ let object_key_remove_trailing env key =
 
 let generic_type_remove_trailing env ty =
   let { remove_trailing; _ } = trailing_and_remover env in
-  remove_trailing ty (fun remover ty -> map_loc remover#generic_type ty)
+  remove_trailing ty (fun remover ty ->
+      let (tyloc, t) = ty in
+      id remover#generic_type t ty (fun t' -> (tyloc, t'))
+  )
 
 let generic_type_list_remove_trailing env extends =
   let { remove_trailing; _ } = trailing_and_remover env in
   remove_trailing extends (fun remover extends ->
-      id_list_last (map_loc remover#generic_type) extends
+      id_list_last
+        (fun ty ->
+          let (tyloc, t) = ty in
+          id remover#generic_type t ty (fun t' -> (tyloc, t')))
+        extends
   )
 
 let class_implements_remove_trailing env implements =
@@ -499,7 +510,7 @@ let class_implements_remove_trailing env implements =
 
 let string_literal_remove_trailing env str =
   let { remove_trailing; _ } = trailing_and_remover env in
-  remove_trailing str (fun remover (loc, str) -> (loc, remover#string_literal loc str))
+  remove_trailing str (fun remover (loc, str) -> (loc, remover#string_literal str))
 
 let statement_add_comments
     ((loc, stmt) : (Loc.t, Loc.t) Statement.t) (comments : (Loc.t, unit) Syntax.t option) :
@@ -557,6 +568,11 @@ let statement_add_comments
         { s with ExportDefaultDeclaration.comments = merge_comments comments }
     | ExportNamedDeclaration ({ ExportNamedDeclaration.comments; _ } as s) ->
       ExportNamedDeclaration { s with ExportNamedDeclaration.comments = merge_comments comments }
+    | ExportAssignment ({ ExportAssignment.comments; _ } as s) ->
+      ExportAssignment { s with ExportAssignment.comments = merge_comments comments }
+    | NamespaceExportDeclaration ({ NamespaceExportDeclaration.comments; _ } as s) ->
+      NamespaceExportDeclaration
+        { s with NamespaceExportDeclaration.comments = merge_comments comments }
     | Expression ({ Expression.comments; _ } as s) ->
       Expression { s with Expression.comments = merge_comments comments }
     | For ({ For.comments; _ } as s) -> For { s with For.comments = merge_comments comments }
@@ -569,12 +585,16 @@ let statement_add_comments
     | If ({ If.comments; _ } as s) -> If { s with If.comments = merge_comments comments }
     | ImportDeclaration ({ ImportDeclaration.comments; _ } as s) ->
       ImportDeclaration { s with ImportDeclaration.comments = merge_comments comments }
+    | ImportEqualsDeclaration ({ ImportEqualsDeclaration.comments; _ } as s) ->
+      ImportEqualsDeclaration { s with ImportEqualsDeclaration.comments = merge_comments comments }
     | InterfaceDeclaration ({ Interface.comments; _ } as s) ->
       InterfaceDeclaration { s with Interface.comments = merge_comments comments }
     | Labeled ({ Labeled.comments; _ } as s) ->
       Labeled { s with Labeled.comments = merge_comments comments }
     | Match ({ Match.comments; _ } as s) ->
       Match { s with Match.comments = merge_comments comments }
+    | RecordDeclaration ({ RecordDeclaration.comments; _ } as s) ->
+      RecordDeclaration { s with RecordDeclaration.comments = merge_comments comments }
     | Return ({ Return.comments; _ } as s) ->
       Return { s with Return.comments = merge_comments comments }
     | Switch ({ Switch.comments; _ } as s) ->
@@ -737,6 +757,10 @@ let object_type_property_comment_bounds property =
       let collector = new comment_bounds_collector ~loc in
       ignore (collector#object_mapped_type_property p);
       collector
+    | PrivateField ((loc, _) as p) ->
+      let collector = new comment_bounds_collector ~loc in
+      ignore (collector#object_private_field_type p);
+      collector
   in
   collect_without_trailing_line_comment collector