feat(oxcaml): support parameter implementation

doc/reference/dune/library.rst

@@ -210,6 +210,13 @@ order to declare a multi-directory library, you need to use the
    unless you use Dune to synthesize the ``depends`` and ``depopts`` sections
    of your opam file.
 
+.. describe:: (implements <name>)
+
+   ``name`` defines the name of the virtual library or the parameter library you
+   are implementing.
+
+   See :doc:`/virtual-libraries` or :doc:`/reference/dune/library_parameter`.
+
 .. describe:: (js_of_ocaml ...)
 
    Sets options for JavaScript compilation, see :ref:`jsoo-field`.

src/dune_rules/compilation_context.ml

@@ -87,14 +87,14 @@ type t =
   ; requires_compile : Lib.t list Resolve.Memo.t
   ; requires_hidden : Lib.t list Resolve.Memo.t
   ; requires_link : Lib.t list Resolve.t Memo.Lazy.t
+  ; implements : Virtual_rules.t
   ; includes : Includes.t
   ; preprocessing : Pp_spec.t
   ; opaque : bool
   ; stdlib : Ocaml_stdlib.t option
   ; js_of_ocaml : Js_of_ocaml.In_context.t option Js_of_ocaml.Mode.Pair.t
   ; sandbox : Sandbox_config.t
   ; package : Package.t option
-  ; vimpl : Vimpl.t option
   ; melange_package_name : Lib_name.t option
   ; modes : Lib_mode.Map.Set.t
   ; bin_annot : bool
@@ -121,7 +121,7 @@ let sandbox t = t.sandbox
 let set_sandbox t sandbox = { t with sandbox }
 let package t = t.package
 let melange_package_name t = t.melange_package_name
-let vimpl t = t.vimpl
+let implements t = t.implements
 let modes t = t.modes
 let bin_annot t = t.bin_annot
 let context t = Super_context.context t.super_context
@@ -142,7 +142,7 @@ let create
       ~js_of_ocaml
       ~package
       ~melange_package_name
-      ?vimpl
+      ?(implements = Virtual_rules.no_implements)
       ?modes
       ?bin_annot
       ?loc
@@ -185,7 +185,7 @@ let create
       ~sandbox
       ~obj_dir
       ~sctx:super_context
-      ~vimpl
+      ~impl:implements
       ~modules
   and+ bin_annot =
     match bin_annot with
@@ -200,6 +200,7 @@ let create
   ; requires_compile = direct_requires
   ; requires_hidden = hidden_requires
   ; requires_link
+  ; implements
   ; includes =
       Includes.make ~project ~opaque ~direct_requires ~hidden_requires ocaml.lib_config
   ; preprocessing
@@ -208,7 +209,6 @@ let create
   ; js_of_ocaml
   ; sandbox
   ; package
-  ; vimpl
   ; melange_package_name
   ; modes
   ; bin_annot

src/dune_rules/compilation_context.mli

@@ -33,7 +33,7 @@ val create
   -> js_of_ocaml:Js_of_ocaml.In_context.t option Js_of_ocaml.Mode.Pair.t
   -> package:Package.t option
   -> melange_package_name:Lib_name.t option
-  -> ?vimpl:Vimpl.t
+  -> ?implements:Virtual_rules.t
   -> ?modes:Mode_conf.Set.Details.t Lib_mode.Map.t
   -> ?bin_annot:bool
   -> ?loc:Loc.t
@@ -65,7 +65,7 @@ val js_of_ocaml : t -> Js_of_ocaml.In_context.t option Js_of_ocaml.Mode.Pair.t
 val sandbox : t -> Sandbox_config.t
 val set_sandbox : t -> Sandbox_config.t -> t
 val package : t -> Package.t option
-val vimpl : t -> Vimpl.t option
+val implements : t -> Virtual_rules.t
 val melange_package_name : t -> Lib_name.t option
 val modes : t -> Lib_mode.Map.Set.t
 val for_wrapped_compat : t -> t

src/dune_rules/dep_rules.ml

@@ -131,7 +131,7 @@ let rec deps_of
           ~obj_dir
           ~modules
           ~sandbox
-          ~vimpl
+          ~impl
           ~dir
           ~sctx
           ~ml_kind
@@ -156,14 +156,14 @@ let rec deps_of
     in
     match m with
     | Imported_from_vlib _ ->
-      let vimpl = Option.value_exn vimpl in
+      let vimpl = Virtual_rules.vimpl_exn impl in
       skip_if_source_absent (deps_of_vlib_module ~obj_dir ~vimpl ~dir ~sctx ~ml_kind) m
     | Normal m ->
       skip_if_source_absent
         (deps_of_module ~modules ~sandbox ~sctx ~dir ~obj_dir ~ml_kind)
         m
     | Impl_of_virtual_module impl_or_vlib ->
-      deps_of ~obj_dir ~modules ~sandbox ~vimpl ~dir ~sctx ~ml_kind
+      deps_of ~obj_dir ~modules ~sandbox ~impl ~dir ~sctx ~ml_kind
       @@
       let m = Ml_kind.Dict.get impl_or_vlib ml_kind in
       (match ml_kind with
@@ -198,20 +198,20 @@ let dict_of_func_concurrently f =
   Ml_kind.Dict.make ~impl ~intf
 ;;
 
-let for_module ~obj_dir ~modules ~sandbox ~vimpl ~dir ~sctx module_ =
+let for_module ~obj_dir ~modules ~sandbox ~impl ~dir ~sctx module_ =
   dict_of_func_concurrently
-    (deps_of ~obj_dir ~modules ~sandbox ~vimpl ~dir ~sctx (Normal module_))
+    (deps_of ~obj_dir ~modules ~sandbox ~impl ~dir ~sctx (Normal module_))
 ;;
 
-let rules ~obj_dir ~modules ~sandbox ~vimpl ~sctx ~dir =
+let rules ~obj_dir ~modules ~sandbox ~impl ~sctx ~dir =
   match Modules.With_vlib.as_singleton modules with
   | Some m -> Memo.return (Dep_graph.Ml_kind.dummy m)
   | None ->
     dict_of_func_concurrently (fun ~ml_kind ->
       let+ per_module =
         Modules.With_vlib.obj_map modules
         |> Parallel_map.parallel_map ~f:(fun _obj_name m ->
-          deps_of ~obj_dir ~modules ~sandbox ~vimpl ~sctx ~dir ~ml_kind m)
+          deps_of ~obj_dir ~modules ~sandbox ~impl ~sctx ~dir ~ml_kind m)
       in
       Dep_graph.make ~dir ~per_module)
 ;;

src/dune_rules/dep_rules.mli

@@ -6,7 +6,7 @@ val for_module
   :  obj_dir:Path.Build.t Obj_dir.t
   -> modules:Modules.With_vlib.t
   -> sandbox:Sandbox_config.t
-  -> vimpl:Vimpl.t option
+  -> impl:Virtual_rules.t
   -> dir:Path.Build.t
   -> sctx:Super_context.t
   -> Module.t
@@ -23,7 +23,7 @@ val rules
   :  obj_dir:Path.Build.t Obj_dir.t
   -> modules:Modules.With_vlib.t
   -> sandbox:Sandbox_config.t
-  -> vimpl:Vimpl.t option
+  -> impl:Virtual_rules.t
   -> sctx:Super_context.t
   -> dir:Path.Build.t
   -> Dep_graph.Ml_kind.t Memo.t

src/dune_rules/install_rules.ml

@@ -97,14 +97,16 @@ end = struct
       >>| Modules.With_vlib.modules
       >>| Option.some
     and+ foreign_archives =
-      match Lib_info.virtual_ lib with
-      | false -> Memo.return (Mode.Map.Multi.to_flat_list @@ Lib_info.foreign_archives lib)
-      | true ->
+      match Lib_info.kind lib with
+      | Dune_file _ ->
+        Memo.return (Mode.Map.Multi.to_flat_list @@ Lib_info.foreign_archives lib)
+      | Virtual ->
         let+ foreign_sources = Dir_contents.foreign_sources dir_contents in
         let name = Lib_info.name lib in
         let files = Foreign_sources.for_lib foreign_sources ~name in
         let { Lib_config.ext_obj; _ } = lib_config in
         Foreign.Sources.object_files files ~dir ~ext_obj
+      | Parameter -> Memo.return []
     in
     List.rev_append
       (List.rev_concat_map
@@ -209,7 +211,7 @@ end = struct
               ~libs:(Scope.libs scope)
               ~for_:(Library (Lib_info.lib_id info |> Lib_id.to_local_exn))
       and+ impl = Virtual_rules.impl sctx ~lib ~scope in
-      Vimpl.impl_modules impl modules |> Modules.With_vlib.split_by_lib
+      Virtual_rules.impl_modules impl modules |> Modules.With_vlib.split_by_lib
     in
     let lib_src_dir = Lib_info.src_dir info in
     let sources =
@@ -266,7 +268,6 @@ end = struct
     let { Lib_mode.Map.ocaml = { Mode.Dict.byte; native } as ocaml; melange } =
       Mode_conf.Lib.Set.eval lib.modes ~has_native
     in
-    let is_parameter = Library.is_parameter lib in
     let+ melange_runtime_entries = additional_deps lib.melange_runtime_deps
     and+ public_headers = additional_deps lib.public_headers
     and+ module_files =
@@ -293,26 +294,27 @@ end = struct
           | Some f -> [ cm_kind, f ])
         else []
       in
-      let common =
-        let virtual_library = Library.is_virtual lib in
-        fun m ->
-          let cm_file kind = Obj_dir.Module.cm_file obj_dir m ~kind in
-          let open Lib_mode.Cm_kind in
-          let cmi = if_ (native || byte) (Ocaml Cmi, cm_file (Ocaml Cmi)) in
-          let rest =
-            if is_parameter
-            then []
-            else
-              [ if_ native (Ocaml Cmx, cm_file (Ocaml Cmx))
-              ; if_ (byte && virtual_library) (Ocaml Cmo, cm_file (Ocaml Cmo))
-              ; if_
-                  (native && virtual_library)
-                  (Ocaml Cmx, Obj_dir.Module.o_file obj_dir m ~ext_obj)
-              ; if_ melange (Melange Cmi, cm_file (Melange Cmi))
-              ; if_ melange (Melange Cmj, cm_file (Melange Cmj))
+      let common m =
+        let cm_file kind = Obj_dir.Module.cm_file obj_dir m ~kind in
+        let open Lib_mode.Cm_kind in
+        let cmi = if_ (native || byte) (Ocaml Cmi, cm_file (Ocaml Cmi)) in
+        let common_module_impls virtual_only =
+          (if_ native (Ocaml Cmx, cm_file (Ocaml Cmx)) :: virtual_only)
+          @ [ if_ melange (Melange Cmi, cm_file (Melange Cmi))
+            ; if_ melange (Melange Cmj, cm_file (Melange Cmj))
+            ]
+        in
+        let rest =
+          match (lib.kind : Lib_kind.t) with
+          | Parameter -> []
+          | Virtual ->
+            common_module_impls
+              [ if_ byte (Ocaml Cmo, cm_file (Ocaml Cmo))
+              ; if_ native (Ocaml Cmx, Obj_dir.Module.o_file obj_dir m ~ext_obj)
               ]
-          in
-          cmi :: rest |> List.rev_concat
+          | _ -> common_module_impls []
+        in
+        cmi :: rest |> List.rev_concat
       in
       let set_dir m = List.rev_map ~f:(fun (cm_kind, p) -> cm_dir m cm_kind, p) in
       let+ modules_impl =
@@ -354,9 +356,9 @@ end = struct
       [ sources
       ; melange_runtime_entries
       ; List.rev_map module_files ~f:(fun (sub_dir, file) -> make_entry ?sub_dir Lib file)
-      ; (match is_parameter with
-         | true -> []
-         | false ->
+      ; (match lib.kind with
+         | Parameter -> []
+         | Virtual | Dune_file _ ->
            List.rev_concat
              [ List.rev_map lib_files ~f:(fun (section, file) -> make_entry section file)
              ; List.rev_map execs ~f:(make_entry Libexec)
@@ -837,8 +839,9 @@ end = struct
           let* { Scope.DB.Lib_entry.Set.libraries; _ } = Action_builder.of_memo entries in
           match
             List.find_map libraries ~f:(fun lib ->
-              let info = Lib.Local.info lib in
-              Option.some_if (Lib_info.virtual_ info) lib)
+              match Lib_info.kind (Lib.Local.info lib) with
+              | Parameter | Virtual -> Some lib
+              | Dune_file _ -> None)
           with
           | None -> Action_builder.lines_of meta_template
           | Some vlib ->

src/dune_rules/lib.ml

@@ -235,15 +235,16 @@ module Error = struct
       ]
   ;;
 
-  let not_virtual_lib ~loc ~impl ~not_vlib =
-    let impl = Lib_info.name impl in
-    let not_vlib = Lib_info.name not_vlib in
+  let not_implementable ~loc ~lib ~not_impl =
+    let lib = Lib_info.name lib in
+    let not_impl = Lib_info.name not_impl in
     make
       ~loc
       [ Pp.textf
-          "Library %S is not virtual. It cannot be implemented by %S."
-          (Lib_name.to_string not_vlib)
-          (Lib_name.to_string impl)
+          "Library %S is neither a virtual library nor a library parameter. It cannot be \
+           implemented by %S."
+          (Lib_name.to_string not_impl)
+          (Lib_name.to_string lib)
       ]
   ;;
 end
@@ -724,12 +725,12 @@ end = struct
         let rec loop acc = function
           | [] -> Resolve.Memo.return acc
           | (lib, stack) :: libs ->
-            let virtual_ = Lib_info.virtual_ lib.info in
-            (match lib.implements, virtual_ with
-             | None, false -> loop acc libs
-             | Some _, true -> assert false (* can't be virtual and implement *)
-             | None, true -> loop (Map.set acc lib (No_impl stack)) libs
-             | Some vlib, false ->
+            (match lib.implements, Lib_info.kind lib.info with
+             | None, Dune_file _ -> loop acc libs
+             | None, (Parameter | Virtual) -> loop (Map.set acc lib (No_impl stack)) libs
+             | Some _, (Parameter | Virtual) ->
+               assert false (* can't be virtual and implement *)
+             | Some vlib, Dune_file _ ->
                let* vlib = Memo.return vlib in
                (match Map.find acc vlib with
                 | None ->
@@ -945,11 +946,11 @@ end = struct
       | Some ((loc, _) as name) ->
         let res =
           let open Resolve.Memo.O in
-          let* vlib = resolve_forbid_ignore name in
-          let virtual_ = Lib_info.virtual_ vlib.info in
-          match virtual_ with
-          | false -> Error.not_virtual_lib ~loc ~impl:info ~not_vlib:vlib.info
-          | true -> Resolve.Memo.return vlib
+          let* implements = resolve_forbid_ignore name in
+          match Lib_info.kind implements.info with
+          | Dune_file _ ->
+            Error.not_implementable ~loc ~lib:info ~not_impl:implements.info
+          | Parameter | Virtual -> Resolve.Memo.return implements
         in
         Memo.map res ~f:Option.some
     in