Generate dune file version correctly

Signed-off-by: Rudi Grinberg <rudi.grinberg@gmail.com>

src/install_rules.ml

@@ -39,8 +39,9 @@ module Gen(P : Install_params) = struct
   let gen_lib_dune_file lib =
     SC.add_rule sctx
       (Build.arr (fun () ->
+         let lang = Option.value_exn (Lib.defined_using_lang lib) in
          Format.asprintf "%a@." (Sexp.pp Dune)
-           (Lib.Sub_system.dump_config lib |> Installed_dune_file.gen))
+           (Lib.Sub_system.dump_config lib |> Installed_dune_file.gen ~lang))
        >>> Build.write_file_dyn
              (lib_dune_file ~dir:(Lib.src_dir lib) ~name:(Lib.name lib)))
 

src/installed_dune_file.ml

@@ -27,10 +27,10 @@ let of_sexp =
   let open Sexp.Of_sexp in
   let version =
     plain_string (fun ~loc -> function
-      | "1" -> ()
-      | _ ->
+      | "1" | "2" -> ()
+      | v ->
         of_sexp_errorf loc
-          "Unsupported version, only version 1 is supported")
+          "Unsupported version %S, only version 1 is supported" v)
   in
   sum
     [ "dune",
@@ -68,7 +68,7 @@ let load fname =
       (Univ_map.singleton (Syntax.key Stanza.syntax) syntax)
       (Io.Sexp.load ~lexer ~mode:Single fname))
 
-let gen confs =
+let gen ~(lang : File_tree.Dune_file.Kind.t) confs =
   let sexps =
     Sub_system_name.Map.to_list confs
     |> List.map ~f:(fun (name, (ver, conf)) ->
@@ -80,6 +80,9 @@ let gen confs =
   in
   Sexp.List
     [ Sexp.unsafe_atom_of_string "dune"
-    ; Sexp.unsafe_atom_of_string "1"
+    ; Sexp.unsafe_atom_of_string
+        (match lang with
+         | Jbuild -> "1"
+         | Dune -> "2")
     ; List sexps
     ]

src/installed_dune_file.mli

@@ -3,4 +3,7 @@
 open Stdune
 
 val load : Path.t -> Jbuild.Sub_system_info.t Sub_system_name.Map.t
-val gen : (Syntax.Version.t * Sexp.t) Sub_system_name.Map.t -> Sexp.t
+val gen
+  : lang:File_tree.Dune_file.Kind.t
+  -> (Syntax.Version.t * Sexp.t) Sub_system_name.Map.t
+  -> Sexp.t

src/lib.ml

@@ -63,6 +63,7 @@ module Info = struct
     ; pps              : (Loc.t * Jbuild.Pp.t) list
     ; optional         : bool
     ; virtual_deps     : (Loc.t * string) list
+    ; defined_using_lang : File_tree.Dune_file.Kind.t option
     ; sub_systems      : Jbuild.Sub_system_info.t Sub_system_name.Map.t
     }
 
@@ -114,6 +115,11 @@ module Info = struct
     ; ppx_runtime_deps = conf.ppx_runtime_libraries
     ; pps = Jbuild.Preprocess_map.pps conf.buildable.preprocess
     ; sub_systems = conf.sub_systems
+    ; defined_using_lang =
+        Some
+          (match conf.project.kind with
+           | Dune -> Dune
+           | Jbuilder -> Jbuild)
     }
 
   let of_findlib_package pkg =
@@ -143,6 +149,7 @@ module Info = struct
     ; (* We don't know how these are named for external libraries *)
       foreign_archives = Mode.Dict.make_both []
     ; sub_systems      = sub_systems
+    ; defined_using_lang = None
     }
 end
 
@@ -237,6 +244,7 @@ type t =
   ; resolved_selects  : Resolved_select.t list
   ; optional          : bool
   ; user_written_deps : Jbuild.Lib_deps.t
+  ; defined_using_lang : File_tree.Dune_file.Kind.t option
   ; (* This is mutable to avoid this error:
 
        {[
@@ -343,6 +351,8 @@ let plugins      t = t.plugins
 let jsoo_runtime t = t.jsoo_runtime
 let unique_id    t = t.unique_id
 
+let defined_using_lang t = t.defined_using_lang
+
 let src_dir t = t.src_dir
 let obj_dir t = t.obj_dir
 
@@ -662,6 +672,7 @@ let rec instantiate db name (info : Info.t) ~stack ~hidden =
     ; optional          = info.optional
     ; user_written_deps = Info.user_written_deps info
     ; sub_systems       = Sub_system_name.Map.empty
+    ; defined_using_lang = info.defined_using_lang
     }
   in
   t.sub_systems <-

src/lib.mli

@@ -26,6 +26,8 @@ val archives     : t -> Path.t list Mode.Dict.t
 val plugins      : t -> Path.t list Mode.Dict.t
 val jsoo_runtime : t -> Path.t list
 
+val defined_using_lang : t -> File_tree.Dune_file.Kind.t option
+
 (** A unique integer identifier. It is only unique for the duration of
     the process *)
 val unique_id : t -> int
@@ -103,6 +105,7 @@ module Info : sig
     ; pps              : (Loc.t * Jbuild.Pp.t) list
     ; optional         : bool
     ; virtual_deps     : (Loc.t * string) list
+    ; defined_using_lang : File_tree.Dune_file.Kind.t option
     ; sub_systems      : Jbuild.Sub_system_info.t Sub_system_name.Map.t
     }
 

test/blackbox-tests/test-cases/inline_tests/run.t

@@ -22,7 +22,7 @@
 
   $ dune runtest dune-file
   (dune
-   1
+   2
    ((inline_tests.backend
      1.0
      ((runner_libraries (str))