fix functors

Author: tsnobip

compiler/syntax/src/jsx_common.ml

@@ -13,6 +13,9 @@ type jsx_config = {
      [module_expr]), which would otherwise see [nested_modules = []] and wipe
      hoisted bindings added for earlier structure items. *)
   mutable structure_depth: int;
+  (* Inside [Pmod_functor] bodies, hoisting [File$M = M.make] at the file top
+     would reference [M] as a functor (illegal). Skip hoists when > 0. *)
+  mutable functor_depth: int;
 }
 
 (* Helper method to look up the [@react.component] attribute *)

compiler/syntax/src/jsx_ppx.ml

@@ -85,6 +85,19 @@ let get_mapper ~config =
     | 4 -> module_binding4 mapper mb
     | _ -> default_mapper.module_binding mapper mb
   in
+  let module_expr mapper me =
+    match (config.version, me.pmod_desc) with
+    | 4, Pmod_functor _ -> (
+      config.functor_depth <- config.functor_depth + 1;
+      try
+        let m = default_mapper.module_expr mapper me in
+        config.functor_depth <- config.functor_depth - 1;
+        m
+      with e ->
+        config.functor_depth <- config.functor_depth - 1;
+        raise e)
+    | _ -> default_mapper.module_expr mapper me
+  in
   let save_config () =
     {
       config with
@@ -142,7 +155,7 @@ let get_mapper ~config =
     result
   in
 
-  {default_mapper with expr; module_binding; signature; structure}
+  {default_mapper with expr; module_binding; module_expr; signature; structure}
 
 let rewrite_implementation ~jsx_version ~jsx_module (code : Parsetree.structure)
     : Parsetree.structure =
@@ -154,6 +167,7 @@ let rewrite_implementation ~jsx_version ~jsx_module (code : Parsetree.structure)
       has_component = false;
       hoisted_structure_items = [];
       structure_depth = 0;
+      functor_depth = 0;
     }
   in
   let mapper = get_mapper ~config in
@@ -169,6 +183,7 @@ let rewrite_signature ~jsx_version ~jsx_module (code : Parsetree.signature) :
       has_component = false;
       hoisted_structure_items = [];
       structure_depth = 0;
+      functor_depth = 0;
     }
   in
   let mapper = get_mapper ~config in

compiler/syntax/src/jsx_v4.ml

@@ -132,8 +132,8 @@ let unnamespace_module_name file_name =
 
 let maybe_hoist_nested_make_component ~(config : Jsx_common.jsx_config)
     ~empty_loc ~full_module_name fn_name =
-  match (fn_name, config.nested_modules) with
-  | "make", _ :: _ ->
+  match (fn_name, config.nested_modules, config.functor_depth) with
+  | "make", _ :: _, 0 ->
     config.hoisted_structure_items <-
       make_hoisted_component_binding ~empty_loc ~full_module_name
         config.nested_modules