Port upstream's #12260 (ocaml-flambda#2067)

native_toplevel/opttoploop.ml

@@ -96,18 +96,17 @@ type directive_info = {
 
 let remembered = ref Ident.empty
 
-let rec remember phrase_name i = function
-  | [] -> ()
-  | Sig_module (_, _, { md_type = Mty_alias _; _ }, _, _)
-    :: rest ->
-      remember phrase_name i rest
-  | Sig_value  (id, _, _) :: rest
-  | Sig_module (id, _, _, _, _) :: rest
-  | Sig_typext (id, _, _, _) :: rest
-  | Sig_class  (id, _, _, _) :: rest ->
-      remembered := Ident.add id (phrase_name, i) !remembered;
-      remember phrase_name (succ i) rest
-  | _ :: rest -> remember phrase_name i rest
+let rec remember phrase_name signature =
+  let exported = List.filter Includemod.is_runtime_component signature in
+  List.iteri (fun i sg ->
+    match sg with
+    | Sig_value  (id, _, _)
+    | Sig_module (id, _, _, _, _)
+    | Sig_typext (id, _, _, _)
+    | Sig_class  (id, _, _, _) ->
+      remembered := Ident.add id (phrase_name, i) !remembered
+    | _ -> ())
+    exported
 
 let toplevel_value id =
   try Ident.find_same id !remembered
@@ -450,7 +449,7 @@ let execute_phrase print_outcome ppf phr =
             Translmod.transl_implementation compilation_unit (str, coercion)
               ~style:Plain_block
           in
-          remember compilation_unit 0 sg';
+          remember compilation_unit sg';
           compilation_unit, close_phrase res, required_globals, size
         else
           let size, res = Translmod.transl_store_phrases compilation_unit str in

ocaml/testsuite/tests/tool-toplevel/topeval.compilers.reference

@@ -7,4 +7,7 @@ val _bar : ('a, 'b) A.t -> 'a option = <fun>
 - : string = ""
 - : char = 'd'
 - : float = 42.
+external foo : int -> int -> int = "%addint"
+module S = String
+val x : int = 42
 

ocaml/testsuite/tests/tool-toplevel/topeval.ml

@@ -46,6 +46,13 @@ let List.(String.(_)) = 'd'
 let List.(_) : float = 42.0
 ;;
 
+(* issue #12257: external or module alias followed by regular value triggers
+   an exception in ocamlnat *)
+external foo : int -> int -> int = "%addint"
+module S = String
+let x = 42
+;;
+
 (* Check that frametables are correctly loaded by triggering GC *)
 let () =
   Gc.minor ();

ocaml/toplevel/native/topeval.ml

@@ -39,15 +39,17 @@ let global_symbol comp_unit =
 
 let remembered = ref Ident.empty
 
-let rec remember phrase_name i = function
-  | [] -> ()
-  | Sig_value  (id, _, _) :: rest
-  | Sig_module (id, _, _, _, _) :: rest
-  | Sig_typext (id, _, _, _) :: rest
-  | Sig_class  (id, _, _, _) :: rest ->
-      remembered := Ident.add id (phrase_name, i) !remembered;
-      remember phrase_name (succ i) rest
-  | _ :: rest -> remember phrase_name i rest
+let remember phrase_name signature =
+  let exported = List.filter Includemod.is_runtime_component signature in
+  List.iteri (fun i sg ->
+    match sg with
+    | Sig_value  (id, _, _)
+    | Sig_module (id, _, _, _, _)
+    | Sig_typext (id, _, _, _)
+    | Sig_class  (id, _, _, _) ->
+      remembered := Ident.add id (phrase_name, i) !remembered
+    | _ -> ())
+    exported
 
 let toplevel_value id =
   try Ident.find_same id !remembered
@@ -210,7 +212,7 @@ let execute_phrase print_outcome ppf phr =
             Translmod.transl_implementation phrase_comp_unit (str, Tcoerce_none)
               ~style:Plain_block
           in
-          remember compilation_unit 0 sg';
+          remember compilation_unit sg';
           compilation_unit, close_phrase res, required_globals, size
         else
           let size, res = Translmod.transl_store_phrases phrase_comp_unit str in