conditionalize the changes in ocaml/ocaml#13193

jscomp/stdlib/camlinternalMod.cppo.ml

@@ -71,9 +71,17 @@ let rec update_mod_field modu i shape n =
   | Value _ ->
      () (* the value is already there *)
   | Class ->
+#if OCAML_VERSION >= (5, 3, 0)
      assert (Obj.tag n = 0 && Obj.size n = 3);
+#else
+     assert (Obj.tag n = 0 && Obj.size n = 4);
+#endif
      let cl = Obj.field modu i in
+#if OCAML_VERSION >= (5, 3, 0)
      for j = 0 to 2 do
+#else
+     for j = 0 to 3 do
+#endif
        Obj.set_field cl j (Obj.field n j)
      done
   | Module comps ->

jscomp/stdlib/camlinternalOO.cppo.ml

@@ -329,7 +329,12 @@ let init_class table =
   table.initializers <- List.rev table.initializers;
   resize table (3 + Obj.magic table.methods.(1) * 16 / Sys.word_size)
 
+
+#if OCAML_VERSION >= (5, 3, 0)
 let inherits cla vals virt_meths concr_meths (_, super, env) top =
+#else
+let inherits cla vals virt_meths concr_meths (_, super, _, env) top =
+#endif
   narrow cla vals virt_meths concr_meths;
   let init =
     if top then super cla env else Obj.repr (super cla) in
@@ -345,7 +350,11 @@ let make_class pub_meths class_init =
   let table = create_table pub_meths in
   let env_init = class_init table in
   init_class table;
+#if OCAML_VERSION >= (5, 3, 0)
   (env_init (Obj.repr 0), class_init, Obj.repr 0)
+#else
+  (env_init (Obj.repr 0), class_init, env_init, Obj.repr 0)
+#endif
 
 type init_table = { mutable env_init: t; mutable class_init: table -> t }
 [@@warning "-unused-field"]

jscomp/stdlib/camlinternalOO.cppo.mli

@@ -46,10 +46,18 @@ val create_table : string array -> table
 val init_class : table -> unit
 val inherits :
     table -> string array -> string array -> string array ->
+#if OCAML_VERSION >= (5, 3, 0)
     (t * (table -> obj -> Obj.t) * obj) -> bool -> Obj.t array
+#else
+    (t * (table -> obj -> Obj.t) * t * obj) -> bool -> Obj.t array
+#endif
 val make_class :
     string array -> (table -> Obj.t -> t) ->
+#if OCAML_VERSION >= (5, 3, 0)
     (t * (table -> Obj.t -> t) * Obj.t)
+#else
+    (t * (table -> Obj.t -> t) * (Obj.t -> t) * Obj.t)
+#endif
 type init_table
 val make_class_store :
     string array -> (table -> t) -> init_table -> unit

jscomp/stdlib/dune

@@ -71,7 +71,15 @@
  (deps camlinternalMod.cppo.ml)
  (target camlinternalMod.ml)
  (action
-  (run cppo -D=BS %{env:CPPO_FLAGS=} %{deps} -o %{target})))
+  (run
+   cppo
+   -D=BS
+   -V
+   OCAML:%{ocaml_version}
+   %{env:CPPO_FLAGS=}
+   %{deps}
+   -o
+   %{target})))
 
 (rule
  (deps camlinternalMod.cppo.mli)
@@ -83,13 +91,29 @@
  (deps camlinternalOO.cppo.ml)
  (target camlinternalOO.ml)
  (action
-  (run cppo -D=BS %{env:CPPO_FLAGS=} %{deps} -o %{target})))
+  (run
+   cppo
+   -D=BS
+   -V
+   OCAML:%{ocaml_version}
+   %{env:CPPO_FLAGS=}
+   %{deps}
+   -o
+   %{target})))
 
 (rule
  (deps camlinternalOO.cppo.mli)
  (target camlinternalOO.mli)
  (action
-  (run cppo -D=BS %{env:CPPO_FLAGS=} %{deps} -o %{target})))
+  (run
+   cppo
+   -D=BS
+   -V
+   OCAML:%{ocaml_version}
+   %{env:CPPO_FLAGS=}
+   %{deps}
+   -o
+   %{target})))
 
 (rule
  (deps float.cppo.ml)

test/blackbox-tests/mel-as-variants-lists.t

@@ -16,7 +16,7 @@
   > type (_, _) x =
   >   | [] : ('a, 'a) x
   >   | ( :: ) : 'a * ('ty, 'v) x -> ('a -> 'ty, 'v) x
-  > let rec f : type a b. (a, string ref) x -> string =
+  > let rec f : type a. (a, string ref) x -> string =
   >  fun x -> match x with [] -> "empty" | _ :: xs -> f xs
   > EOF
 
@@ -47,7 +47,7 @@
   > 
   > let x : _ x = []
   > 
-  > let rec f : type a b. (a, string ref) x -> string =
+  > let rec f : type a. (a, string ref) x -> string =
   >  fun x -> match x with [] -> "empty" | _ :: xs -> f xs
   > EOF
 
@@ -82,7 +82,7 @@
   > let x : _ x = []
   > let y : _ x = [ 2 ]
   > 
-  > let rec f : type a b. (a, string ref) x -> string =
+  > let rec f : type a. (a, string ref) x -> string =
   >  fun x -> match x with [] -> "empty" | _ :: xs -> f xs
   > EOF