hidden_path: use distinct source and build paths

src/dot-merlin/dot_merlin_reader.ml

@@ -326,7 +326,7 @@ let empty_config = {
 let prepend_config ~cwd ~cfg =
   List.fold_left ~init:cfg ~f:(fun cfg (d : Merlin_dot_protocol.Directive.Raw.t) ->
     match d with
-    | `B _ | `H _ | `S _ | `CMI _ | `CMT _  as directive ->
+    | `B _ | `S _ | `BH _ | `SH _ | `CMI _ | `CMT _  as directive ->
       { cfg with to_canonicalize = (cwd, directive) :: cfg.to_canonicalize }
     | `EXT _ | `SUFFIX _ | `FLG _ | `READER _
     | (`EXCLUDE_QUERY_DIR | `USE_PPX_CACHE | `UNKNOWN_TAG _) as directive ->
@@ -454,8 +454,9 @@ let postprocess cfg =
         let dirs =
           match directive with
           | `B path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `B p)
-          | `H path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `H p)
           | `S path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `S p)
+          | `BH path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `BH p)
+          | `SH path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `SH p)
           | `CMI path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `CMI p)
           | `CMT path -> List.map (expand ~stdlib dir path) ~f:(fun p -> `CMT p)
         in

src/dot-protocol/merlin_dot_protocol.ml

@@ -31,7 +31,12 @@ open Merlin_utils.Std.Result
 
 module Directive = struct
   type include_path =
-    [ `B of string | `H of string | `S of string | `CMI of string | `CMT of string ]
+    [ `B of string
+    | `S of string
+    | `BH of string
+    | `SH of string
+    | `CMI of string
+    | `CMT of string ]
 
   type no_processing_required =
     [ `EXT of string list
@@ -82,7 +87,8 @@ module Sexp = struct
       begin match tag with
         | "S" -> `S value
         | "B" -> `B value
-        | "H" -> `H value
+        | "SH" -> `SH value
+        | "BH" -> `BH value
         | "CMI" -> `CMI value
         | "CMT" -> `CMT value
         | "STDLIB" -> `STDLIB value
@@ -112,8 +118,9 @@ module Sexp = struct
         let single s = [ Atom s ] in
         match t with
         | `B s -> ("B", single s)
-        | `H s -> ("H", single s)
         | `S s -> ("S", single s)
+        | `BH s -> ("BH", single s)
+        | `SH s -> ("SH", single s)
         | `CMI s -> ("CMI", single s)
         | `CMT s -> ("CMT", single s)
         | `EXT ss -> ("EXT", [ List (atoms_of_strings ss) ])

src/dot-protocol/merlin_dot_protocol.mli

@@ -43,7 +43,12 @@ really do not want to load them. *)
 
 module Directive : sig
   type include_path =
-    [ `B of string | `H of string| `S of string | `CMI of string | `CMT of string ]
+    [ `B of string
+    | `S of string
+    | `BH of string
+    | `SH of string
+    | `CMI of string
+    | `CMT of string ]
 
   type no_processing_required =
     [ `EXT of string list

src/kernel/mconfig.ml

@@ -71,8 +71,9 @@ let marg_commandline f =
 
 type merlin = {
   build_path  : string list;
-  hidden_path : string list;
   source_path : string list;
+  hidden_build_path  : string list;
+  hidden_source_path : string list;
   cmi_path    : string list;
   cmt_path    : string list;
   extensions  : string list;
@@ -105,6 +106,8 @@ let dump_merlin x =
   `Assoc [
     "build_path"   , `List (List.map ~f:Json.string x.build_path);
     "source_path"  , `List (List.map ~f:Json.string x.source_path);
+    "hidden_build_path" , `List (List.map ~f:Json.string x.hidden_build_path);
+    "hidden_source_path", `List (List.map ~f:Json.string x.hidden_source_path);
     "cmi_path"     , `List (List.map ~f:Json.string x.cmi_path);
     "cmt_path"     , `List (List.map ~f:Json.string x.cmt_path);
     "flags_applied", `List (List.map ~f:dump_flag_list x.flags_applied);
@@ -245,6 +248,8 @@ let get_external_config path t =
       merlin with
       build_path = dot.build_path @ merlin.build_path;
       source_path = dot.source_path @ merlin.source_path;
+      hidden_build_path = dot.hidden_build_path @ merlin.hidden_build_path;
+      hidden_source_path = dot.hidden_source_path @ merlin.hidden_source_path;
       cmi_path = dot.cmi_path @ merlin.cmi_path;
       cmt_path = dot.cmt_path @ merlin.cmt_path;
       exclude_query_dir = dot.exclude_query_dir || merlin.exclude_query_dir;
@@ -275,6 +280,18 @@ let merlin_flags = [
         {merlin with source_path = dir :: merlin.source_path}),
     "<dir> Add <dir> to merlin source path"
   );
+  (
+    "-hidden-build-path",
+    marg_path (fun dir merlin ->
+        {merlin with hidden_build_path = dir :: merlin.hidden_build_path}),
+    "<dir> Add <dir> to merlin hidden build path"
+  );
+  (
+    "-hidden-source-path",
+    marg_path (fun dir merlin ->
+        {merlin with hidden_source_path = dir :: merlin.hidden_source_path}),
+    "<dir> Add <dir> to merlin hidden source path"
+  );
   (
     "-cmi-path",
     marg_path (fun dir merlin ->
@@ -616,8 +633,9 @@ let initial = {
   };
   merlin = {
     build_path  = [];
-    hidden_path = [];
     source_path = [];
+    hidden_build_path  = [];
+    hidden_source_path = [];
     cmi_path    = [];
     cmt_path    = [];
     extensions  = [];
@@ -763,8 +781,8 @@ let build_path config = (
   result'
 )
 
-let hidden_path config =
-  config.merlin.hidden_path @ config.ocaml.hidden_dirs
+let hidden_build_path config =
+  config.merlin.hidden_build_path @ config.ocaml.hidden_dirs
 
 let cmt_path config = (
   let dirs =

src/kernel/mconfig.mli

@@ -29,8 +29,9 @@ val dump_ocaml : ocaml -> json
 
 type merlin = {
   build_path  : string list;
-  hidden_path : string list;
   source_path : string list;
+  hidden_build_path  : string list;
+  hidden_source_path : string list;
   cmi_path    : string list;
   cmt_path    : string list;
   extensions  : string list;
@@ -111,7 +112,7 @@ val source_path : t -> string list
 
 val build_path : t -> string list
 
-val hidden_path : t -> string list
+val hidden_build_path : t -> string list
 
 val cmt_path : t -> string list
 

src/kernel/mconfig_dot.ml

@@ -34,8 +34,9 @@ type directive = Merlin_dot_protocol.directive
 
 type config = {
   build_path   : string list;
-  hidden_path  : string list;
   source_path  : string list;
+  hidden_build_path  : string list;
+  hidden_source_path : string list;
   cmi_path     : string list;
   cmt_path     : string list;
   flags        : string list with_workdir list;
@@ -49,7 +50,8 @@ type config = {
 
 let empty_config = {
   build_path   = [];
-  hidden_path  = [];
+  hidden_build_path =[];
+  hidden_source_path = [];
   source_path  = [];
   cmi_path     = [];
   cmt_path     = [];
@@ -236,8 +238,9 @@ let prepend_config ~dir:cwd configurator (directives : directive list) config =
   List.fold_left ~init:(config, []) ~f:(fun (config, errors) ->
     function
     | `B path -> {config with build_path = path :: config.build_path}, errors
-    | `H path -> {config with hidden_path = path :: config.hidden_path}, errors
     | `S path -> {config with source_path = path :: config.source_path}, errors
+    | `BH path -> {config with hidden_build_path = path :: config.hidden_build_path}, errors
+    | `SH path -> {config with hidden_source_path = path :: config.hidden_source_path}, errors
     | `CMI path -> {config with cmi_path = path :: config.cmi_path}, errors
     | `CMT path -> {config with cmt_path = path :: config.cmt_path}, errors
     | `EXT exts ->
@@ -270,8 +273,9 @@ let postprocess_config config =
   let clean list = List.rev (List.filter_dup list) in
   {
     build_path   = clean config.build_path;
-    hidden_path  = clean config.hidden_path;
     source_path  = clean config.source_path;
+    hidden_build_path  = clean config.hidden_build_path;
+    hidden_source_path = clean config.hidden_source_path;
     cmi_path     = clean config.cmi_path;
     cmt_path     = clean config.cmt_path;
     extensions   = clean config.extensions;

src/kernel/mconfig_dot.mli

@@ -30,8 +30,9 @@ open Std
 
 type config = {
   build_path   : string list;
-  hidden_path  : string list;
   source_path  : string list;
+  hidden_build_path  : string list;
+  hidden_source_path : string list;
   cmi_path     : string list;
   cmt_path     : string list;
   flags        : string list with_workdir list;

src/kernel/mocaml.ml

@@ -47,7 +47,7 @@ let setup_reader_config config = (
 let setup_typer_config config = (
   setup_reader_config config;
   let visible = Mconfig.build_path config in
-  let hidden = Mconfig.hidden_path config in
+  let hidden = Mconfig.hidden_build_path config in
   Load_path.(init ~auto_include:no_auto_include ~visible ~hidden);
 )
 

tests/test-dirs/config/dot-merlin-reader/quoting.t

@@ -14,6 +14,8 @@
   {
     "build_path": [],
     "source_path": [],
+    "hidden_build_path": [],
+    "hidden_source_path": [],
     "cmi_path": [],
     "cmt_path": [],
     "flags_applied": [