refactor(merlin): configure with source modules

We pass source modules (before preprocessing) when configuring merlin.

Signed-off-by: Andrey Popp <8mayday@gmail.com>

src/dune_rules/exe_rules.ml

@@ -117,15 +117,15 @@ let executables_rules
   =
   (* Use "eobjs" rather than "objs" to avoid a potential conflict with a library
      of the same name *)
-  let* modules, obj_dir =
+  let* source_modules, obj_dir =
     let first_exe = first_exe exes in
     Dir_contents.ocaml dir_contents
     >>| Ml_sources.modules_and_obj_dir ~for_:(Exe { first_exe })
   in
   let* () = Check_rules.add_obj_dir sctx ~obj_dir (Ocaml Byte) in
   let ctx = Super_context.context sctx in
   let project = Scope.project scope in
-  let programs = programs ~modules ~exes in
+  let programs = programs ~modules:source_modules ~exes in
   let explicit_js_mode = Dune_project.explicit_js_mode project in
   let linkages = linkages ctx ~exes ~explicit_js_mode in
   let* flags = Buildable_rules.ocaml_flags sctx ~dir exes.buildable.flags in
@@ -136,7 +136,7 @@ let executables_rules
       expander
       ~dir
       scope
-      modules
+      source_modules
   in
   let* cctx =
     let requires_compile = Lib.Compile.direct_requires compile_info in
@@ -249,7 +249,7 @@ let executables_rules
       ~requires:requires_compile
       ~stdlib_dir
       ~flags
-      ~modules
+      ~source_modules
       ~source_dirs:Path.Source.Set.empty
       ~libname:None
       ~obj_dir

src/dune_rules/lib_rules.ml

@@ -559,9 +559,6 @@ let library_rules
   ~dir_contents
   ~compile_info
   =
-  let source_modules =
-    Modules.fold_user_written source_modules ~init:[] ~f:(fun m acc -> m :: acc)
-  in
   let modules = Compilation_context.modules cctx in
   let obj_dir = Compilation_context.obj_dir cctx in
   let vimpl = Compilation_context.vimpl cctx in
@@ -611,14 +608,21 @@ let library_rules
   and+ () = Odoc.setup_library_odoc_rules cctx local_lib
   and+ () =
     Sub_system.gen_rules
-      { super_context = sctx; dir; stanza = lib; scope; source_modules; compile_info }
+      { super_context = sctx
+      ; dir
+      ; stanza = lib
+      ; scope
+      ; source_modules =
+          Modules.fold_user_written source_modules ~init:[] ~f:(fun m acc -> m :: acc)
+      ; compile_info
+      }
   in
   ( cctx
   , Merlin.make
       ~requires:requires_compile
       ~stdlib_dir
       ~flags
-      ~modules
+      ~source_modules
       ~source_dirs:Path.Source.Set.empty
       ~preprocess:(Preprocess.Per_module.without_instrumentation lib.buildable.preprocess)
       ~libname:(Some (snd lib.name))

src/dune_rules/melange/melange_rules.ml

@@ -211,7 +211,7 @@ let setup_emit_cmj_rules
   let f () =
     (* Use "mobjs" rather than "objs" to avoid a potential conflict with a library
        of the same name *)
-    let* modules, obj_dir =
+    let* source_modules, obj_dir =
       Dir_contents.ocaml dir_contents
       >>| Ml_sources.modules_and_obj_dir ~for_:(Melange { target = mel.target })
     in
@@ -230,7 +230,7 @@ let setup_emit_cmj_rules
         expander
         ~dir
         scope
-        modules
+        source_modules
     in
     let requires_link = Lib.Compile.requires_link compile_info in
     let* flags = ocaml_flags sctx ~dir mel.compile_flags in
@@ -287,7 +287,7 @@ let setup_emit_cmj_rules
         ~requires:requires_compile
         ~stdlib_dir
         ~flags
-        ~modules
+        ~source_modules
         ~source_dirs:Path.Source.Set.empty
         ~libname:None
         ~preprocess:(Preprocess.Per_module.without_instrumentation mel.preprocess)

src/dune_rules/merlin/merlin.ml

@@ -1,9 +1,13 @@
 open Import
 
-let remove_extension file =
+let strip_pp_extensions file =
   let dir = Path.Build.parent_exn file in
-  let basename, _ext = String.lsplit2_exn (Path.Build.basename file) ~on:'.' in
-  Path.Build.relative dir basename
+  let basename = Path.Build.basename file in
+  match String.split basename ~on:'.' with
+  | [] | [ _ ] | [ _; _ ] -> file
+  | name :: exts ->
+    let ext = Option.value_exn (List.last exts) in
+    Path.Build.relative dir (sprintf "%s.%s" name ext)
 ;;
 
 module Processed = struct
@@ -249,8 +253,9 @@ module Processed = struct
     let open Option.O in
     let+ { module_; opens } =
       let find file =
-        let file_without_ext = remove_extension file in
-        Path.Build.Map.find per_module_config file_without_ext
+        match Path.Build.Map.find per_module_config file with
+        | Some _ as s -> s
+        | None -> Path.Build.Map.find per_module_config (strip_pp_extensions file)
       in
       match find file with
       | Some _ as s -> s
@@ -372,7 +377,7 @@ module Unprocessed = struct
     ~preprocess
     ~libname
     ~source_dirs
-    ~modules
+    ~source_modules
     ~obj_dir
     ~dialects
     ~ident
@@ -407,7 +412,7 @@ module Unprocessed = struct
       ; extensions
       }
     in
-    { ident; config; modules }
+    { ident; config; modules = source_modules }
   ;;
 
   let encode_command =
@@ -600,8 +605,7 @@ module Unprocessed = struct
       (* And copy for each module the resulting pp flags *)
       Modules.fold_no_vlib modules ~init:[] ~f:(fun m init ->
         Module.sources m
-        |> Path.Build.Set.of_list_map ~f:(fun src ->
-          Path.as_in_build_dir_exn src |> remove_extension)
+        |> Path.Build.Set.of_list_map ~f:(fun src -> Path.as_in_build_dir_exn src)
         |> Path.Build.Set.fold ~init ~f:(fun src acc ->
           let config =
             { Processed.module_ = Module.set_pp m None

src/dune_rules/merlin/merlin.mli

@@ -47,7 +47,7 @@ val make
   -> preprocess:Preprocess.Without_instrumentation.t Preprocess.t Module_name.Per_item.t
   -> libname:Lib_name.Local.t option
   -> source_dirs:Path.Source.Set.t
-  -> modules:Modules.t
+  -> source_modules:Modules.t
   -> obj_dir:Path.Build.t Obj_dir.t
   -> dialects:Dialect.DB.t
   -> ident:Merlin_ident.t