Do not pass native include dirs when compiling bytecode

CHANGES.md

@@ -20,6 +20,9 @@ Unreleased
 - Add `ocaml` command subgroup for OCaml related commands such as `utop`, `top`,
   and `merlin` (#3936, @rgrinberg).
 
+- Do not pass include directories containing native objects when compiling
+  bytecode (#4200, @nojb)
+
 2.8.2 (21/01/2021)
 ------------------
 

bin/top.ml

@@ -47,7 +47,9 @@ let term =
       let requires =
         Dune_rules.Lib.closure ~linking:true libs |> Result.ok_exn
       in
-      let include_paths = Dune_rules.Lib.L.include_paths requires in
+      let include_paths =
+        Dune_rules.Lib.L.include_paths requires Dune_rules.Mode.Byte
+      in
       let files = link_deps requires in
       let* () =
         Memo.Build.run (do_build (List.map files ~f:(fun f -> Target.File f)))

src/dune_rules/compilation_context.ml

@@ -11,16 +11,18 @@ module Includes = struct
     | Error exn ->
       Cm_kind.Dict.make_all (Command.Args.Fail { fail = (fun () -> raise exn) })
     | Ok libs ->
-      let iflags = Lib.L.include_flags ~project libs in
+      let iflags mode = Lib.L.include_flags ~project libs mode in
       let cmi_includes =
         Command.Args.memo
           (Command.Args.S
-             [ iflags; Hidden_deps (Lib_file_deps.deps libs ~groups:[ Cmi ]) ])
+             [ iflags Byte
+             ; Hidden_deps (Lib_file_deps.deps libs ~groups:[ Cmi ])
+             ])
       in
       let cmx_includes =
         Command.Args.memo
           (Command.Args.S
-             [ iflags
+             [ iflags Native
              ; Hidden_deps
                  ( if opaque then
                    List.map libs ~f:(fun lib ->

src/dune_rules/lib.ml

@@ -486,7 +486,7 @@ module L = struct
             Command.Args.Path dir :: A "-I" :: acc)
       |> List.rev )
 
-  let include_paths ?project ts =
+  let include_paths ?project ts mode =
     let visible_cmi =
       match project with
       | None -> fun _ -> true
@@ -513,14 +513,18 @@ module L = struct
             else
               acc
           in
-          let native_dir = Obj_dir.native_dir obj_dir in
-          Path.Set.add acc native_dir)
+          match mode with
+          | Mode.Byte -> acc
+          | Native ->
+            let native_dir = Obj_dir.native_dir obj_dir in
+            Path.Set.add acc native_dir)
     in
     match ts with
     | [] -> dirs
     | x :: _ -> Path.Set.remove dirs x.lib_config.stdlib_dir
 
-  let include_flags ?project ts = to_iflags (include_paths ?project ts)
+  let include_flags ?project ts mode =
+    to_iflags (include_paths ?project ts mode)
 
   let c_include_paths ts =
     let dirs =
@@ -538,7 +542,9 @@ module L = struct
     let params = List.map link ~f:(fun t -> Link_params.get t mode) in
     let dirs =
       let dirs =
-        Path.Set.union (include_paths compile) (c_include_paths link)
+        Path.Set.union
+          (include_paths compile (Link_mode.mode mode))
+          (c_include_paths link)
       in
       List.fold_left params ~init:dirs ~f:(fun acc (p : Link_params.t) ->
           List.fold_left p.include_dirs ~init:acc ~f:Path.Set.add)

src/dune_rules/lib.mli

@@ -70,9 +70,9 @@ module L : sig
 
   val to_iflags : Path.Set.t -> _ Command.Args.t
 
-  val include_paths : ?project:Dune_project.t -> t -> Path.Set.t
+  val include_paths : ?project:Dune_project.t -> t -> Mode.t -> Path.Set.t
 
-  val include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t
+  val include_flags : ?project:Dune_project.t -> t -> Mode.t -> _ Command.Args.t
 
   val c_include_flags : t -> _ Command.Args.t
 

src/dune_rules/toplevel.ml

@@ -105,7 +105,9 @@ let setup_module_rules t =
   let main_ml =
     Action_builder.of_result_map requires_compile ~f:(fun libs ->
         Action_builder.return
-          (let include_dirs = Path.Set.to_list (Lib.L.include_paths libs) in
+          (let include_dirs =
+             Path.Set.to_list (Lib.L.include_paths libs Mode.Byte)
+           in
            let pp_ppx = pp_flags t in
            let pp_dirs = Source.pp_ml t.source ~include_dirs in
            let pp = Pp.seq pp_ppx pp_dirs in

test/blackbox-tests/test-cases/toplevel-integration.t/run.t

@@ -16,7 +16,6 @@ Test toplevel-init-file on a tiny project
 
   $ dune ocaml top
   #directory "$TESTCASE_ROOT/_build/default/.test.objs/byte";;
-  #directory "$TESTCASE_ROOT/_build/default/.test.objs/native";;
   #load "$TESTCASE_ROOT/_build/default/test.cma";;
 
   $ ocaml -stdin <<EOF