Fix PR#7182: external in recursive module

Changes

@@ -468,6 +468,8 @@ Bug fixes:
   (Jacques Garrigue, report by Jeremy Yallop)
 - PR#7160: Type synonym definitions can weaken gadt constructor types
   (Jacques Garrigue, report by Mikhail Mandrykin)
+- PR#7182: Assertion failure with recursive modules and externals
+  (Jacques Garrigue, report by Jeremy Yallop)
 - GPR#205: Clear caml_backtrace_last_exn before registering as root
   (report and fix by Frederic Bour)
 - GPR#220: minor -dsource error on recursive modules

bytecomp/translmod.ml

@@ -215,15 +215,19 @@ let init_shape modl =
   and init_shape_struct env sg =
     match sg with
       [] -> []
-    | Sig_value(id, vdesc) :: rem ->
+    | Sig_value(_id, {val_kind=Val_reg; val_type=ty}) :: rem ->
         let init_v =
-          match Ctype.expand_head env vdesc.val_type with
+          match Ctype.expand_head env ty with
             {desc = Tarrow(_,_,_,_)} ->
               Const_pointer 0 (* camlinternalMod.Function *)
           | {desc = Tconstr(p, _, _)} when Path.same p Predef.path_lazy_t ->
               Const_pointer 1 (* camlinternalMod.Lazy *)
           | _ -> raise Not_found in
         init_v :: init_shape_struct env rem
+    | Sig_value(_, {val_kind=Val_prim _}) :: rem ->
+        init_shape_struct env rem
+    | Sig_value _ :: _rem ->
+        assert false
     | Sig_type(id, tdecl, _) :: rem ->
         init_shape_struct (Env.add_type ~check:false id tdecl env) rem
     | Sig_typext(id, ext, _) :: rem ->

testsuite/tests/typing-modules-bugs/pr7182_ok.ml

@@ -0,0 +1,3 @@
+module rec M
+    : sig external f : int -> int = "%identity" end
+    = struct external f : int -> int = "%identity" end