refactor: move toplevel stanza to own module (ocaml#9483)

Signed-off-by: Rudi Grinberg <[email protected]>

src/dune_rules/dune_file.ml

@@ -1723,44 +1723,6 @@ module Tests = struct
   let single = gen_parse (field "name" (located string) >>| List.singleton)
 end
 
-module Toplevel = struct
-  type t =
-    { name : string
-    ; libraries : (Loc.t * Lib_name.t) list
-    ; loc : Loc.t
-    ; pps : Preprocess.Without_instrumentation.t Preprocess.t
-    }
-
-  include Stanza.Make (struct
-      type nonrec t = t
-
-      include Poly
-    end)
-
-  let decode =
-    let open Dune_lang.Decoder in
-    fields
-      (let+ loc = loc
-       and+ name = field "name" string
-       and+ libraries = field "libraries" (repeat (located Lib_name.decode)) ~default:[]
-       and+ pps =
-         field
-           "preprocess"
-           (Dune_lang.Syntax.since Stanza.syntax (2, 5) >>> Preprocess.decode)
-           ~default:Preprocess.No_preprocessing
-       in
-       match pps with
-       | Preprocess.Pps _ | No_preprocessing -> { name; libraries; loc; pps }
-       | Action (loc, _) | Future_syntax loc ->
-         User_error.raise
-           ~loc
-           [ Pp.text
-               "Toplevel does not currently support action or future_syntax \
-                preprocessing."
-           ])
-  ;;
-end
-
 module Documentation = struct
   type t =
     { loc : Loc.t
@@ -2004,8 +1966,8 @@ module Stanzas = struct
             [ Include_subdirs.make_stanza (loc, t) ] )
         ; ( "toplevel"
           , let+ () = Dune_lang.Syntax.since Stanza.syntax (1, 7)
-            and+ t = Toplevel.decode in
-            [ Toplevel.make_stanza t ] )
+            and+ t = Toplevel_stanza.decode in
+            [ Toplevel_stanza.make_stanza t ] )
         ; ( "deprecated_library_name"
           , let+ () = Dune_lang.Syntax.since Stanza.syntax (2, 0)
             and+ t = Deprecated_library_name.decode in

src/dune_rules/dune_file.mli

@@ -297,17 +297,6 @@ module Tests : sig
   include Stanza.S with type t := t
 end
 
-module Toplevel : sig
-  type t =
-    { name : string
-    ; libraries : (Loc.t * Lib_name.t) list
-    ; loc : Loc.t
-    ; pps : Preprocess.Without_instrumentation.t Preprocess.t
-    }
-
-  include Stanza.S with type t := t
-end
-
 module Include_subdirs : sig
   type qualification =
     | Unqualified

src/dune_rules/gen_rules.ml

@@ -109,7 +109,7 @@ end = struct
     let toplevel_setup = Toplevel.Stanza.setup in
     let open Dune_file in
     match Stanza.repr stanza with
-    | Toplevel.T toplevel ->
+    | Toplevel_stanza.T toplevel ->
       let+ () = toplevel_setup ~sctx ~dir ~toplevel in
       empty_none
     | Library.T lib ->

src/dune_rules/stanzas/toplevel_stanza.ml

@@ -0,0 +1,36 @@
+open Import
+
+type t =
+  { name : string
+  ; libraries : (Loc.t * Lib_name.t) list
+  ; loc : Loc.t
+  ; pps : Preprocess.Without_instrumentation.t Preprocess.t
+  }
+
+include Stanza.Make (struct
+    type nonrec t = t
+
+    include Poly
+  end)
+
+let decode =
+  let open Dune_lang.Decoder in
+  fields
+    (let+ loc = loc
+     and+ name = field "name" string
+     and+ libraries = field "libraries" (repeat (located Lib_name.decode)) ~default:[]
+     and+ pps =
+       field
+         "preprocess"
+         (Dune_lang.Syntax.since Stanza.syntax (2, 5) >>> Preprocess.decode)
+         ~default:Preprocess.No_preprocessing
+     in
+     match pps with
+     | Preprocess.Pps _ | No_preprocessing -> { name; libraries; loc; pps }
+     | Action (loc, _) | Future_syntax loc ->
+       User_error.raise
+         ~loc
+         [ Pp.text
+             "Toplevel does not currently support action or future_syntax preprocessing."
+         ])
+;;

src/dune_rules/stanzas/toplevel_stanza.mli

@@ -0,0 +1,12 @@
+open Import
+
+type t =
+  { name : string
+  ; libraries : (Loc.t * Lib_name.t) list
+  ; loc : Loc.t
+  ; pps : Preprocess.Without_instrumentation.t Preprocess.t
+  }
+
+include Stanza.S with type t := t
+
+val decode : t Dune_sexp.Decoder.t

src/dune_rules/toplevel.ml

@@ -30,7 +30,7 @@ module Source = struct
 
   let make ~dir ~loc ~main ~name = { dir; main; name; loc }
 
-  let of_stanza ~dir ~(toplevel : Dune_file.Toplevel.t) =
+  let of_stanza ~dir ~(toplevel : Toplevel_stanza.t) =
     { dir = Path.Build.relative dir (toplevel_dir_prefix ^ toplevel.name)
     ; name = toplevel.name
     ; loc = toplevel.loc
@@ -174,7 +174,7 @@ let print_toplevel_init_file { include_paths; files_to_load; uses; pp; ppx; code
 ;;
 
 module Stanza = struct
-  let setup ~sctx ~dir ~(toplevel : Dune_file.Toplevel.t) =
+  let setup ~sctx ~dir ~(toplevel : Toplevel_stanza.t) =
     let open Memo.O in
     let source = Source.of_stanza ~dir ~toplevel in
     let* expander = Super_context.expander sctx ~dir in

src/dune_rules/toplevel.mli

@@ -35,6 +35,6 @@ module Stanza : sig
   val setup
     :  sctx:Super_context.t
     -> dir:Path.Build.t
-    -> toplevel:Dune_file.Toplevel.t
+    -> toplevel:Toplevel_stanza.t
     -> unit Memo.t
 end