From ba5c77b4d9ccfbe014bf529708929b6b6d5e15cb Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Mon, 29 Apr 2024 13:04:54 -0400
Subject: [PATCH 01/11] Revert "First stab at minimal `-H` support.  Untested."

This reverts commit a2fd8acdf62fdbd31a66bdb816c0fe98d889fce2.
---
 src/analysis/locate.ml                        |  8 +-
 src/frontend/ocamlmerlin/old/old_command.ml   |  4 +-
 src/frontend/query_commands.ml                |  8 +-
 src/kernel/mconfig.ml                         | 79 +++++--------------
 src/kernel/mconfig.mli                        |  9 +--
 src/kernel/mconfig_dot.ml                     | 19 +----
 src/kernel/mconfig_dot.mli                    |  6 +-
 src/kernel/mocaml.ml                          |  4 +-
 src/kernel/mppx.ml                            |  4 +-
 .../config/dot-merlin-reader/quoting.t        |  5 +-
 10 files changed, 37 insertions(+), 109 deletions(-)

diff --git a/src/analysis/locate.ml b/src/analysis/locate.ml
index 45e7d05f0..3f2e83ae1 100644
--- a/src/analysis/locate.ml
+++ b/src/analysis/locate.ml
@@ -423,12 +423,8 @@ module Utils = struct
     find_file_with_path ~config ?with_fallback file @@
         match file with
         | ML  _ | MLI _  | MLL _ -> Mconfig.source_path config
-        | CMT _ | CMTI _         ->
-          let Mconfig.{ visible; hidden } = Mconfig.build_path config in
-          visible @ hidden
-        | CMS _ | CMSI _         ->
-          let Mconfig.{ visible; hidden } = Mconfig.build_path config in
-          visible @ hidden
+        | CMT _ | CMTI _         -> Mconfig.build_path config
+        | CMS _ | CMSI _         -> Mconfig.build_path config
 end
 
 let move_to filename artifact =
diff --git a/src/frontend/ocamlmerlin/old/old_command.ml b/src/frontend/ocamlmerlin/old/old_command.ml
index e8f40423f..ca0751687 100644
--- a/src/frontend/ocamlmerlin/old/old_command.ml
+++ b/src/frontend/ocamlmerlin/old/old_command.ml
@@ -59,9 +59,7 @@ let customize config =
     let merlin = config.merlin in
     let merlin =
       match var with
-      | `Build -> {merlin with build_path =
-                                 { visible = f merlin.build_path.visible;
-                                   hidden = f merlin.build_path.hidden }}
+      | `Build -> {merlin with build_path = f merlin.build_path}
       | `Source -> {merlin with source_path = f merlin.source_path}
     in
     {config with merlin}
diff --git a/src/frontend/query_commands.ml b/src/frontend/query_commands.ml
index 70b500b58..b7c73f5e3 100644
--- a/src/frontend/query_commands.ml
+++ b/src/frontend/query_commands.ml
@@ -181,8 +181,7 @@ let dump pipeline = function
 
   | [`String "paths"] ->
     let paths = Mconfig.build_path (Mpipeline.final_config pipeline) in
-    `Assoc [ "visible", `List (List.map paths.visible ~f:(fun s -> `String s));
-             "hidden", `List (List.map paths.hidden ~f:(fun s -> `String s)) ]
+    `List (List.map paths ~f:(fun s -> `String s))
 
   | [`String "typedtree"] ->
     let tree =
@@ -798,8 +797,7 @@ let dispatch pipeline (type a) : a Query_protocol.t -> a =
         try
           find_in_path_uncap (Mconfig.source_path config) x
         with Not_found -> try
-            let Mconfig.{visible; hidden} = Mconfig.build_path config in
-            find_in_path_uncap (visible @ hidden) x
+            find_in_path_uncap (Mconfig.build_path config) x
           with Not_found ->
             aux xs
     in
@@ -827,7 +825,7 @@ let dispatch pipeline (type a) : a Query_protocol.t -> a =
 
   | Path_list `Build ->
     let config = Mpipeline.final_config pipeline in
-    Mconfig.(config.merlin.build_path.visible @ config.merlin.build_path.hidden)
+    Mconfig.(config.merlin.build_path)
 
   | Path_list `Source ->
     let config = Mpipeline.final_config pipeline in
diff --git a/src/kernel/mconfig.ml b/src/kernel/mconfig.ml
index 1df121db1..64f8a9972 100644
--- a/src/kernel/mconfig.ml
+++ b/src/kernel/mconfig.ml
@@ -6,7 +6,6 @@ let {Logger. log} = Logger.for_section "Mconfig"
 
 type ocaml = {
   include_dirs         : string list;
-  hidden_include_dirs  : string list;
   no_std_include       : bool;
   unsafe               : bool;
   classic              : bool;
@@ -34,7 +33,6 @@ let dump_warnings st =
 
 let dump_ocaml x = `Assoc [
     "include_dirs"         , `List (List.map ~f:Json.string x.include_dirs);
-    "hidden_include_dirs"  , `List (List.map ~f:Json.string x.hidden_include_dirs);
     "no_std_include"       , `Bool x.no_std_include;
     "unsafe"               , `Bool x.unsafe;
     "classic"              , `Bool x.classic;
@@ -73,12 +71,8 @@ let marg_commandline f =
 
 (** {1 Merlin high-level settings} *)
 
-type include_paths =
-  { visible : string list;
-    hidden : string list }
-
 type merlin = {
-  build_path  : include_paths;
+  build_path  : string list;
   source_path : string list;
   cmi_path    : string list;
   cmt_path    : string list;
@@ -109,11 +103,7 @@ let dump_merlin x =
     dump_with_workdir (Json.list Json.string) flags
   in
   `Assoc [
-    "build_path"   ,
-      `Assoc [
-        "visible", `List (List.map ~f:Json.string x.build_path.visible);
-        "hidden", `List (List.map ~f:Json.string x.build_path.hidden)
-      ];
+    "build_path"   , `List (List.map ~f:Json.string x.build_path);
     "source_path"  , `List (List.map ~f:Json.string x.source_path);
     "cmi_path"     , `List (List.map ~f:Json.string x.cmi_path);
     "cmt_path"     , `List (List.map ~f:Json.string x.cmt_path);
@@ -242,11 +232,6 @@ let rec normalize t =
   ) else
     normalize (normalize_step t)
 
-let merge_build_paths
-      (dot_bp : Mconfig_dot.include_paths) (merlin_bp : include_paths) =
-  { visible = dot_bp.visible @ merlin_bp.visible;
-    hidden = dot_bp.hidden @ merlin_bp.hidden }
-
 let get_external_config path t =
   let path = Misc.canonicalize_filename path in
   let directory = Filename.dirname path in
@@ -257,7 +242,7 @@ let get_external_config path t =
     let merlin = t.merlin in
     let merlin = {
       merlin with
-      build_path = merge_build_paths dot.build_path merlin.build_path;
+      build_path = dot.build_path @ merlin.build_path;
       source_path = dot.source_path @ merlin.source_path;
       cmi_path = dot.cmi_path @ merlin.cmi_path;
       cmt_path = dot.cmt_path @ merlin.cmt_path;
@@ -280,13 +265,9 @@ let merlin_flags = [
   (
     "-build-path",
     marg_path (fun dir merlin ->
-      let build_path =
-        { merlin.build_path with visible = dir :: merlin.build_path.visible }
-      in
-        {merlin with build_path = build_path}),
+        {merlin with build_path = dir :: merlin.build_path}),
     "<dir> Add <dir> to merlin build path"
   );
-  (* CR ccasinghino: Do we want a similar flag for hidden includes? *)
   (
     "-source-path",
     marg_path (fun dir merlin ->
@@ -590,12 +571,6 @@ let ocaml_flags = [
         {ocaml with include_dirs = dir :: ocaml.include_dirs}),
     "<dir> Add <dir> to the list of include directories"
   );
-  (
-    "-H",
-    marg_path (fun dir ocaml ->
-        {ocaml with hidden_include_dirs = dir :: ocaml.hidden_include_dirs}),
-    "<dir> Add <dir> to the list of hidden include directories"
-  );
   (
     "-nostdlib",
     Marg.unit (fun ocaml -> {ocaml with no_std_include = true}),
@@ -737,7 +712,6 @@ let ocaml_flags = [
 let initial = {
   ocaml = {
     include_dirs         = [];
-    hidden_include_dirs  = [];
     no_std_include       = false;
     unsafe               = false;
     classic              = false;
@@ -757,7 +731,7 @@ let initial = {
     as_parameter         = false;
   };
   merlin = {
-    build_path  = {visible = []; hidden = []};
+    build_path  = [];
     source_path = [];
     cmi_path    = [];
     cmt_path    = [];
@@ -875,45 +849,34 @@ let source_path config =
   |> List.filter_dup
 
 let build_path config = (
-  let visible =
+  let dirs =
     match config.ocaml.threads with
     | `None -> config.ocaml.include_dirs
     | `Threads -> "+threads" :: config.ocaml.include_dirs
     | `Vmthreads -> "+vmthreads" :: config.ocaml.include_dirs
   in
-  let visible =
+  let dirs =
     config.merlin.cmi_path @
-    config.merlin.build_path.visible @
-    visible
-  in
-  let hidden =
-    config.merlin.build_path.hidden @
-    config.ocaml.hidden_include_dirs
+    config.merlin.build_path @
+    dirs
   in
   let stdlib = stdlib config in
-  let visible =
-    List.map ~f:(Misc.expand_directory stdlib) visible
-  in
-  let hidden =
-    List.rev_map ~f:(Misc.expand_directory stdlib) hidden
+  let exp_dirs =
+    List.map ~f:(Misc.expand_directory stdlib) dirs
   in
   let stdlib = if config.ocaml.no_std_include then [] else [stdlib] in
-  let visible = List.rev_append visible stdlib in
-  let visible =
+  let dirs = List.rev_append exp_dirs stdlib in
+  let result =
     if config.merlin.exclude_query_dir
-    then visible
-    else config.query.directory :: visible
+    then dirs
+    else config.query.directory :: dirs
   in
-  let visible' = List.filter_dup visible in
-  let hidden' = List.filter_dup hidden in
+  let result' = List.filter_dup result in
   log ~title:"build_path" "%d items in path, %d after deduplication"
-    (List.length visible) (List.length visible');
-  log ~title:"hidden_build_path" "%d items in path, %d after deduplication"
-    (List.length hidden) (List.length hidden');
-  { visible = visible'; hidden = hidden' }
+    (List.length result) (List.length result');
+  result'
 )
 
-(* CR -H: What is `cmt_path` and does it need to consider hidden_includes?  *)
 let cmt_path config = (
   let dirs =
     match config.ocaml.threads with
@@ -923,7 +886,7 @@ let cmt_path config = (
   in
   let dirs =
     config.merlin.cmt_path @
-    config.merlin.build_path.visible @
+    config.merlin.build_path @
     dirs
   in
   let stdlib = stdlib config in
@@ -935,9 +898,7 @@ let cmt_path config = (
 )
 
 let global_modules ?(include_current=false) config = (
-  (* CR -H: I took a look at a couple uses of `global_modules` and the `.visible` below
-     seems fine, but I'm not confident *)
-  let modules = Misc.modules_in_path ~ext:".cmi" (build_path config).visible in
+  let modules = Misc.modules_in_path ~ext:".cmi" (build_path config) in
   if include_current then modules
   else match config.query.filename with
     | "" -> modules
diff --git a/src/kernel/mconfig.mli b/src/kernel/mconfig.mli
index 37276b631..3e6fa15ab 100644
--- a/src/kernel/mconfig.mli
+++ b/src/kernel/mconfig.mli
@@ -4,7 +4,6 @@ open Std
 
 type ocaml = {
   include_dirs         : string list;
-  hidden_include_dirs  : string list;
   no_std_include       : bool;
   unsafe               : bool;
   classic              : bool;
@@ -29,12 +28,8 @@ val dump_ocaml : ocaml -> json
 
 (** {1 Merlin high-level settings} *)
 
-type include_paths =
-  { visible : string list;
-    hidden : string list }
-
 type merlin = {
-  build_path  : include_paths;
+  build_path  : string list;
   source_path : string list;
   cmi_path    : string list;
   cmt_path    : string list;
@@ -113,7 +108,7 @@ val document_arguments : out_channel -> unit
 
 val source_path : t -> string list
 
-val build_path : t -> include_paths
+val build_path : t -> string list
 
 val cmt_path : t -> string list
 
diff --git a/src/kernel/mconfig_dot.ml b/src/kernel/mconfig_dot.ml
index 4fcec16ce..13ad8eba9 100644
--- a/src/kernel/mconfig_dot.ml
+++ b/src/kernel/mconfig_dot.ml
@@ -32,12 +32,8 @@ let {Logger. log} = Logger.for_section "Mconfig_dot"
 
 type directive = Merlin_dot_protocol.directive
 
-type include_paths =
-  { visible : string list;
-    hidden : string list }
-
 type config = {
-  build_path   : include_paths;
+  build_path   : string list;
   source_path  : string list;
   cmi_path     : string list;
   cmt_path     : string list;
@@ -51,7 +47,7 @@ type config = {
 }
 
 let empty_config = {
-  build_path   = {visible = []; hidden = []};
+  build_path   = [];
   source_path  = [];
   cmi_path     = [];
   cmt_path     = [];
@@ -237,13 +233,7 @@ end
 let prepend_config ~dir:cwd configurator (directives : directive list) config =
   List.fold_left ~init:(config, []) ~f:(fun (config, errors) ->
     function
-    | `B path ->
-      (* CR -H: Probably some way to put hidden includes in merlin files is needed
-         eventually. *)
-      let build_path = { config.build_path with
-                         visible = path :: config.build_path.visible }
-      in
-      {config with build_path = build_path}, errors
+    | `B path -> {config with build_path = path :: config.build_path}, errors
     | `S path -> {config with source_path = path :: config.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
@@ -276,8 +266,7 @@ let prepend_config ~dir:cwd configurator (directives : directive list) config =
 let postprocess_config config =
   let clean list = List.rev (List.filter_dup list) in
   {
-    build_path   = { visible = clean config.build_path.visible;
-                     hidden = clean config.build_path.hidden };
+    build_path   = clean config.build_path;
     source_path  = clean config.source_path;
     cmi_path     = clean config.cmi_path;
     cmt_path     = clean config.cmt_path;
diff --git a/src/kernel/mconfig_dot.mli b/src/kernel/mconfig_dot.mli
index 3b6c3dcdc..7e1ad9a1e 100644
--- a/src/kernel/mconfig_dot.mli
+++ b/src/kernel/mconfig_dot.mli
@@ -28,12 +28,8 @@
 
 open Std
 
-type include_paths =
-  { visible : string list;
-    hidden : string list }
-
 type config = {
-  build_path   : include_paths;
+  build_path   : string list;
   source_path  : string list;
   cmi_path     : string list;
   cmt_path     : string list;
diff --git a/src/kernel/mocaml.ml b/src/kernel/mocaml.ml
index a0019349f..971c951db 100644
--- a/src/kernel/mocaml.ml
+++ b/src/kernel/mocaml.ml
@@ -49,8 +49,8 @@ let setup_reader_config config = (
 
 let setup_typer_config config = (
   setup_reader_config config;
-  let Mconfig.{ visible; hidden } = Mconfig.build_path config in
-  Load_path.(init ~auto_include:no_auto_include ~visible ~hidden);
+  (* CR 5.1.1minus-4: is this right? *)
+  Load_path.(init ~auto_include:no_auto_include ~visible:(Mconfig.build_path config) ~hidden:[]);
 )
 
 (** Switchable implementation of Oprint *)
diff --git a/src/kernel/mppx.ml b/src/kernel/mppx.ml
index 78a09737c..4e1fea600 100644
--- a/src/kernel/mppx.ml
+++ b/src/kernel/mppx.ml
@@ -2,7 +2,6 @@ open Mconfig
 
 let {Logger. log} = Logger.for_section "Mppx"
 
-(* CR -H: do we need to do something for hidden includes here? *)
 let with_include_dir path f =
   let saved = !Clflags.include_dirs in
   let restore () = Clflags.include_dirs := saved in
@@ -20,11 +19,10 @@ let with_include_dir path f =
   restore ();
   result
 
-(* CR -H: do we need to do something for hidden includes here? *)
 let rewrite parsetree cfg =
   let ppx = cfg.ocaml.ppx in
   (* add include path attribute to the parsetree *)
-  with_include_dir (Mconfig.build_path cfg).visible @@ fun () ->
+  with_include_dir (Mconfig.build_path cfg) @@ fun () ->
   match
     Pparse.apply_rewriters ~restore:false ~ppx ~tool_name:"merlin" parsetree
   with
diff --git a/tests/test-dirs/config/dot-merlin-reader/quoting.t b/tests/test-dirs/config/dot-merlin-reader/quoting.t
index d9bf8896c..e99dfaeb7 100644
--- a/tests/test-dirs/config/dot-merlin-reader/quoting.t
+++ b/tests/test-dirs/config/dot-merlin-reader/quoting.t
@@ -12,10 +12,7 @@
 
   $ echo | $MERLIN single dump-configuration -filename test.ml 2> /dev/null | jq '.value.merlin'
   {
-    "build_path": {
-      "visible": [],
-      "hidden": []
-    },
+    "build_path": [],
     "source_path": [],
     "cmi_path": [],
     "cmt_path": [],

From f78fdfad7c7dc46c9056cc0f3be9d7cda3a31aa2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulysse=20G=C3=A9rard?= <thevoodoos@gmail.com>
Date: Mon, 5 Feb 2024 18:51:54 +0100
Subject: [PATCH 02/11] upgrade: support for hidden dependencies

---
 src/dot-merlin/dot_merlin_reader.ml      |  5 ++++-
 src/dot-protocol/merlin_dot_protocol.ml  |  4 +++-
 src/dot-protocol/merlin_dot_protocol.mli |  2 +-
 src/kernel/mconfig.ml                    | 15 +++++++++++++++
 src/kernel/mconfig.mli                   |  4 ++++
 src/kernel/mconfig_dot.ml                |  4 ++++
 src/kernel/mconfig_dot.mli               |  1 +
 src/kernel/mocaml.ml                     |  5 +++--
 src/kernel/mtyper.ml                     |  2 +-
 9 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/src/dot-merlin/dot_merlin_reader.ml b/src/dot-merlin/dot_merlin_reader.ml
index e3a1aaba0..e768d6cac 100644
--- a/src/dot-merlin/dot_merlin_reader.ml
+++ b/src/dot-merlin/dot_merlin_reader.ml
@@ -72,6 +72,8 @@ module Cache = File_cache.Make (struct
 
           else if String.is_prefixed ~by:"B " line then
             tell (`B (String.drop 2 line))
+          else if String.is_prefixed ~by:"H " line then
+            tell (`S (String.drop 2 line))
           else if String.is_prefixed ~by:"S " line then
             tell (`S (String.drop 2 line))
           else if String.is_prefixed ~by:"SRC " line then
@@ -324,7 +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 _ | `S _ | `CMI _ | `CMT _  as directive ->
+    | `B _ | `H _ | `S _ | `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 ->
@@ -452,6 +454,7 @@ 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)
           | `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)
diff --git a/src/dot-protocol/merlin_dot_protocol.ml b/src/dot-protocol/merlin_dot_protocol.ml
index 97648d931..ba7ea25d0 100644
--- a/src/dot-protocol/merlin_dot_protocol.ml
+++ b/src/dot-protocol/merlin_dot_protocol.ml
@@ -31,7 +31,7 @@ open Merlin_utils.Std.Result
 
 module Directive = struct
   type include_path =
-    [ `B of string | `S of string | `CMI of string | `CMT of string ]
+    [ `B of string | `H of string | `S of string | `CMI of string | `CMT of string ]
 
   type no_processing_required =
     [ `EXT of string list
@@ -82,6 +82,7 @@ module Sexp = struct
       begin match tag with
         | "S" -> `S value
         | "B" -> `B value
+        | "H" -> `H value
         | "CMI" -> `CMI value
         | "CMT" -> `CMT value
         | "STDLIB" -> `STDLIB value
@@ -111,6 +112,7 @@ 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)
         | `CMI s -> ("CMI", single s)
         | `CMT s -> ("CMT", single s)
diff --git a/src/dot-protocol/merlin_dot_protocol.mli b/src/dot-protocol/merlin_dot_protocol.mli
index c238b813a..2acff7bbf 100644
--- a/src/dot-protocol/merlin_dot_protocol.mli
+++ b/src/dot-protocol/merlin_dot_protocol.mli
@@ -43,7 +43,7 @@ really do not want to load them. *)
 
 module Directive : sig
   type include_path =
-    [ `B of string | `S of string | `CMI of string | `CMT of string ]
+    [ `B of string | `H of string| `S of string | `CMI of string | `CMT of string ]
 
   type no_processing_required =
     [ `EXT of string list
diff --git a/src/kernel/mconfig.ml b/src/kernel/mconfig.ml
index 64f8a9972..e78f99825 100644
--- a/src/kernel/mconfig.ml
+++ b/src/kernel/mconfig.ml
@@ -6,6 +6,7 @@ let {Logger. log} = Logger.for_section "Mconfig"
 
 type ocaml = {
   include_dirs         : string list;
+  hidden_dirs          : string list;
   no_std_include       : bool;
   unsafe               : bool;
   classic              : bool;
@@ -33,6 +34,7 @@ let dump_warnings st =
 
 let dump_ocaml x = `Assoc [
     "include_dirs"         , `List (List.map ~f:Json.string x.include_dirs);
+    "hidden_dirs"          , `List (List.map ~f:Json.string x.hidden_dirs);
     "no_std_include"       , `Bool x.no_std_include;
     "unsafe"               , `Bool x.unsafe;
     "classic"              , `Bool x.classic;
@@ -73,6 +75,7 @@ let marg_commandline f =
 
 type merlin = {
   build_path  : string list;
+  hidden_path : string list;
   source_path : string list;
   cmi_path    : string list;
   cmt_path    : string list;
@@ -571,6 +574,13 @@ let ocaml_flags = [
         {ocaml with include_dirs = dir :: ocaml.include_dirs}),
     "<dir> Add <dir> to the list of include directories"
   );
+  (
+    "-H",
+    marg_path (fun dir ocaml ->
+        {ocaml with hidden_dirs = dir :: ocaml.hidden_dirs}),
+    "<dir>  Add <dir> to the list of \"hidden\" include directories\n\
+    \ (Like -I, but the program can not directly reference these dependencies)"
+  );
   (
     "-nostdlib",
     Marg.unit (fun ocaml -> {ocaml with no_std_include = true}),
@@ -712,6 +722,7 @@ let ocaml_flags = [
 let initial = {
   ocaml = {
     include_dirs         = [];
+    hidden_dirs          = [];
     no_std_include       = false;
     unsafe               = false;
     classic              = false;
@@ -732,6 +743,7 @@ let initial = {
   };
   merlin = {
     build_path  = [];
+    hidden_path = [];
     source_path = [];
     cmi_path    = [];
     cmt_path    = [];
@@ -877,6 +889,9 @@ let build_path config = (
   result'
 )
 
+let hidden_path config =
+  config.merlin.hidden_path @ config.ocaml.hidden_dirs
+
 let cmt_path config = (
   let dirs =
     match config.ocaml.threads with
diff --git a/src/kernel/mconfig.mli b/src/kernel/mconfig.mli
index 3e6fa15ab..c529f5e48 100644
--- a/src/kernel/mconfig.mli
+++ b/src/kernel/mconfig.mli
@@ -4,6 +4,7 @@ open Std
 
 type ocaml = {
   include_dirs         : string list;
+  hidden_dirs          : string list;
   no_std_include       : bool;
   unsafe               : bool;
   classic              : bool;
@@ -30,6 +31,7 @@ val dump_ocaml : ocaml -> json
 
 type merlin = {
   build_path  : string list;
+  hidden_path : string list;
   source_path : string list;
   cmi_path    : string list;
   cmt_path    : string list;
@@ -110,6 +112,8 @@ val source_path : t -> string list
 
 val build_path : t -> string list
 
+val hidden_path : t -> string list
+
 val cmt_path : t -> string list
 
 val global_modules : ?include_current:bool -> t -> string list
diff --git a/src/kernel/mconfig_dot.ml b/src/kernel/mconfig_dot.ml
index 13ad8eba9..a4d7ff1a9 100644
--- a/src/kernel/mconfig_dot.ml
+++ b/src/kernel/mconfig_dot.ml
@@ -34,6 +34,7 @@ type directive = Merlin_dot_protocol.directive
 
 type config = {
   build_path   : string list;
+  hidden_path  : string list;
   source_path  : string list;
   cmi_path     : string list;
   cmt_path     : string list;
@@ -48,6 +49,7 @@ type config = {
 
 let empty_config = {
   build_path   = [];
+  hidden_path  = [];
   source_path  = [];
   cmi_path     = [];
   cmt_path     = [];
@@ -234,6 +236,7 @@ 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
     | `CMI path -> {config with cmi_path = path :: config.cmi_path}, errors
     | `CMT path -> {config with cmt_path = path :: config.cmt_path}, errors
@@ -267,6 +270,7 @@ 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;
     cmi_path     = clean config.cmi_path;
     cmt_path     = clean config.cmt_path;
diff --git a/src/kernel/mconfig_dot.mli b/src/kernel/mconfig_dot.mli
index 7e1ad9a1e..60636e37e 100644
--- a/src/kernel/mconfig_dot.mli
+++ b/src/kernel/mconfig_dot.mli
@@ -30,6 +30,7 @@ open Std
 
 type config = {
   build_path   : string list;
+  hidden_path  : string list;
   source_path  : string list;
   cmi_path     : string list;
   cmt_path     : string list;
diff --git a/src/kernel/mocaml.ml b/src/kernel/mocaml.ml
index 971c951db..a843757df 100644
--- a/src/kernel/mocaml.ml
+++ b/src/kernel/mocaml.ml
@@ -49,8 +49,9 @@ let setup_reader_config config = (
 
 let setup_typer_config config = (
   setup_reader_config config;
-  (* CR 5.1.1minus-4: is this right? *)
-  Load_path.(init ~auto_include:no_auto_include ~visible:(Mconfig.build_path config) ~hidden:[]);
+  let visible = Mconfig.build_path config in
+  let hidden = Mconfig.hidden_path config in
+  Load_path.(init ~auto_include:no_auto_include ~visible ~hidden);
 )
 
 (** Switchable implementation of Oprint *)
diff --git a/src/kernel/mtyper.ml b/src/kernel/mtyper.ml
index 14e48e4fe..ab8623858 100644
--- a/src/kernel/mtyper.ml
+++ b/src/kernel/mtyper.ml
@@ -150,7 +150,7 @@ let run config parsetree =
   if not (Env.check_state_consistency ()) then (
     (* Resetting the local store will clear the load_path cache.
        Save it now, reset the store and then restore the path. *)
-    let { visible; hidden } : Load_path.paths = Load_path.get_paths () in
+    let { Load_path.visible; hidden } = Load_path.get_paths () in
     Mocaml.flush_caches ();
     Local_store.reset ();
     Load_path.reset ();

From bba99fe30a315b2e4200f6f8c133e45c8b5eb096 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulysse=20G=C3=A9rard?= <thevoodoos@gmail.com>
Date: Fri, 26 Apr 2024 16:39:24 +0200
Subject: [PATCH 03/11] hidden_path: use distinct source and build paths

---
 src/dot-merlin/dot_merlin_reader.ml           |  5 ++--
 src/dot-protocol/merlin_dot_protocol.ml       | 13 +++++++---
 src/dot-protocol/merlin_dot_protocol.mli      |  7 ++++-
 src/kernel/mconfig.ml                         | 26 ++++++++++++++++---
 src/kernel/mconfig.mli                        |  5 ++--
 src/kernel/mconfig_dot.ml                     | 12 ++++++---
 src/kernel/mconfig_dot.mli                    |  3 ++-
 src/kernel/mocaml.ml                          |  2 +-
 .../config/dot-merlin-reader/quoting.t        |  2 ++
 9 files changed, 57 insertions(+), 18 deletions(-)

diff --git a/src/dot-merlin/dot_merlin_reader.ml b/src/dot-merlin/dot_merlin_reader.ml
index e768d6cac..fa8401dd3 100644
--- a/src/dot-merlin/dot_merlin_reader.ml
+++ b/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
diff --git a/src/dot-protocol/merlin_dot_protocol.ml b/src/dot-protocol/merlin_dot_protocol.ml
index ba7ea25d0..6798632b6 100644
--- a/src/dot-protocol/merlin_dot_protocol.ml
+++ b/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) ])
diff --git a/src/dot-protocol/merlin_dot_protocol.mli b/src/dot-protocol/merlin_dot_protocol.mli
index 2acff7bbf..96e34972d 100644
--- a/src/dot-protocol/merlin_dot_protocol.mli
+++ b/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
diff --git a/src/kernel/mconfig.ml b/src/kernel/mconfig.ml
index e78f99825..846f122ad 100644
--- a/src/kernel/mconfig.ml
+++ b/src/kernel/mconfig.ml
@@ -75,8 +75,9 @@ 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;
@@ -108,6 +109,8 @@ 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);
@@ -247,6 +250,8 @@ 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;
@@ -277,6 +282,18 @@ 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 ->
@@ -743,8 +760,9 @@ let initial = {
   };
   merlin = {
     build_path  = [];
-    hidden_path = [];
     source_path = [];
+    hidden_build_path  = [];
+    hidden_source_path = [];
     cmi_path    = [];
     cmt_path    = [];
     extensions  = [];
@@ -889,8 +907,8 @@ 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 =
diff --git a/src/kernel/mconfig.mli b/src/kernel/mconfig.mli
index c529f5e48..e903cc6a8 100644
--- a/src/kernel/mconfig.mli
+++ b/src/kernel/mconfig.mli
@@ -31,8 +31,9 @@ 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;
@@ -112,7 +113,7 @@ 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
 
diff --git a/src/kernel/mconfig_dot.ml b/src/kernel/mconfig_dot.ml
index a4d7ff1a9..a5303f7a5 100644
--- a/src/kernel/mconfig_dot.ml
+++ b/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;
diff --git a/src/kernel/mconfig_dot.mli b/src/kernel/mconfig_dot.mli
index 60636e37e..548b907e9 100644
--- a/src/kernel/mconfig_dot.mli
+++ b/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;
diff --git a/src/kernel/mocaml.ml b/src/kernel/mocaml.ml
index a843757df..fec1d67ef 100644
--- a/src/kernel/mocaml.ml
+++ b/src/kernel/mocaml.ml
@@ -50,7 +50,7 @@ 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);
 )
 
diff --git a/tests/test-dirs/config/dot-merlin-reader/quoting.t b/tests/test-dirs/config/dot-merlin-reader/quoting.t
index e99dfaeb7..59ce479a5 100644
--- a/tests/test-dirs/config/dot-merlin-reader/quoting.t
+++ b/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": [

From 3bc2c996dd1365bb42633dcc053da3571173c7c9 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Mon, 29 Apr 2024 15:35:15 -0400
Subject: [PATCH 04/11] Add test and fix bug

---
 src/dot-merlin/dot_merlin_reader.ml           |  6 +-
 .../config/dot-merlin-reader/load-config.t    | 60 +++++++++++++++++++
 2 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 tests/test-dirs/config/dot-merlin-reader/load-config.t

diff --git a/src/dot-merlin/dot_merlin_reader.ml b/src/dot-merlin/dot_merlin_reader.ml
index fa8401dd3..44fca4c5d 100644
--- a/src/dot-merlin/dot_merlin_reader.ml
+++ b/src/dot-merlin/dot_merlin_reader.ml
@@ -72,10 +72,12 @@ module Cache = File_cache.Make (struct
 
           else if String.is_prefixed ~by:"B " line then
             tell (`B (String.drop 2 line))
-          else if String.is_prefixed ~by:"H " line then
-            tell (`S (String.drop 2 line))
           else if String.is_prefixed ~by:"S " line then
             tell (`S (String.drop 2 line))
+          else if String.is_prefixed ~by:"BH " line then
+            tell (`BH (String.drop 3 line))
+          else if String.is_prefixed ~by:"SH " line then
+            tell (`SH (String.drop 3 line))
           else if String.is_prefixed ~by:"SRC " line then
             tell (`S (String.drop 4 line))
           else if String.is_prefixed ~by:"CMI " line then
diff --git a/tests/test-dirs/config/dot-merlin-reader/load-config.t b/tests/test-dirs/config/dot-merlin-reader/load-config.t
new file mode 100644
index 000000000..7bb9b7671
--- /dev/null
+++ b/tests/test-dirs/config/dot-merlin-reader/load-config.t
@@ -0,0 +1,60 @@
+  $ cat > .merlin <<EOF
+  > B build/dir
+  > S source/dir
+  > BH build-hidden/dir
+  > SH source-hidden/dir
+  > EOF
+
+  $ FILE=$(pwd)/test.ml; dot-merlin-reader <<EOF | sed 's#[0-9]*:#?:#g'
+  > (4:File${#FILE}:$FILE)
+  > EOF
+  ((?:B?:$TESTCASE_ROOT/build/dir)(?:S?:$TESTCASE_ROOT/source/dir)(?:BH?:$TESTCASE_ROOT/build-hidden/dir)(?:SH?:$TESTCASE_ROOT/source-hidden/dir))
+
+  $ echo | $MERLIN single dump-configuration -filename test.ml 2> /dev/null | jq '.value.merlin'
+  {
+    "build_path": [
+      "$TESTCASE_ROOT/build/dir"
+    ],
+    "source_path": [
+      "$TESTCASE_ROOT/source/dir"
+    ],
+    "hidden_build_path": [
+      "$TESTCASE_ROOT/build-hidden/dir"
+    ],
+    "hidden_source_path": [
+      "$TESTCASE_ROOT/source-hidden/dir"
+    ],
+    "cmi_path": [],
+    "cmt_path": [],
+    "flags_applied": [],
+    "extensions": [],
+    "suffixes": [
+      {
+        "impl": ".ml",
+        "intf": ".mli"
+      },
+      {
+        "impl": ".re",
+        "intf": ".rei"
+      }
+    ],
+    "stdlib": "lib/ocaml",
+    "reader": [],
+    "protocol": "json",
+    "log_file": null,
+    "log_sections": [],
+    "flags_to_apply": [],
+    "failures": [],
+    "assoc_suffixes": [
+      {
+        "extension": ".re",
+        "reader": "reason"
+      },
+      {
+        "extension": ".rei",
+        "reader": "reason"
+      }
+    ]
+  }
+
+  $ rm .merlin

From 3b908bc33340d9033fce97b6994df05ee0115a59 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Tue, 30 Apr 2024 18:30:09 -0400
Subject: [PATCH 05/11] Create test for BH and SH

---
 tests/test-dirs/hidden-deps.t/a/a.ml       |   1 +
 tests/test-dirs/hidden-deps.t/a/a.mli      |   1 +
 tests/test-dirs/hidden-deps.t/b/b.ml       |   2 +
 tests/test-dirs/hidden-deps.t/b/b.mli      |   2 +
 tests/test-dirs/hidden-deps.t/build.sh     |  43 ++++++++
 tests/test-dirs/hidden-deps.t/c/correct.ml |   3 +
 tests/test-dirs/hidden-deps.t/c/error.ml   |   3 +
 tests/test-dirs/hidden-deps.t/run.t        | 118 +++++++++++++++++++++
 8 files changed, 173 insertions(+)
 create mode 100644 tests/test-dirs/hidden-deps.t/a/a.ml
 create mode 100644 tests/test-dirs/hidden-deps.t/a/a.mli
 create mode 100644 tests/test-dirs/hidden-deps.t/b/b.ml
 create mode 100644 tests/test-dirs/hidden-deps.t/b/b.mli
 create mode 100755 tests/test-dirs/hidden-deps.t/build.sh
 create mode 100644 tests/test-dirs/hidden-deps.t/c/correct.ml
 create mode 100644 tests/test-dirs/hidden-deps.t/c/error.ml
 create mode 100644 tests/test-dirs/hidden-deps.t/run.t

diff --git a/tests/test-dirs/hidden-deps.t/a/a.ml b/tests/test-dirs/hidden-deps.t/a/a.ml
new file mode 100644
index 000000000..e46c633fc
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/a/a.ml
@@ -0,0 +1 @@
+let a = 10
diff --git a/tests/test-dirs/hidden-deps.t/a/a.mli b/tests/test-dirs/hidden-deps.t/a/a.mli
new file mode 100644
index 000000000..3f79c8149
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/a/a.mli
@@ -0,0 +1 @@
+val a : int
diff --git a/tests/test-dirs/hidden-deps.t/b/b.ml b/tests/test-dirs/hidden-deps.t/b/b.ml
new file mode 100644
index 000000000..7a9a2287f
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/b/b.ml
@@ -0,0 +1,2 @@
+include A
+let b = 20
diff --git a/tests/test-dirs/hidden-deps.t/b/b.mli b/tests/test-dirs/hidden-deps.t/b/b.mli
new file mode 100644
index 000000000..63567b698
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/b/b.mli
@@ -0,0 +1,2 @@
+val a : int
+val b : int
diff --git a/tests/test-dirs/hidden-deps.t/build.sh b/tests/test-dirs/hidden-deps.t/build.sh
new file mode 100755
index 000000000..64a32dd01
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/build.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+set -e
+cd "$(dirname "$0")"
+
+OCAMLC=/j/office/app/ocaml/prod/5.1.1minus/5.1.1minus-13-d49e4649/el8+fl2/bin/ocamlc
+BUILD="$(realpath ./_build)"
+
+rm -rf $BUILD
+mkdir -p $BUILD/a
+mkdir -p $BUILD/b
+mkdir -p $BUILD/c
+
+# cd a
+# $OCAMLC -c a.mli -o $BUILD/a/a.cmi
+# $OCAMLC -c -I $BUILD/a a.ml -o $BUILD/a/a.cmo
+# $OCAMLC -a $BUILD/a/a.cmo -o $BUILD/a/a.cma
+
+# cd ../b
+# $OCAMLC -c b.mli -o $BUILD/b/b.cmi
+# $OCAMLC -c -I $BUILD/a -I $BUILD/b b.ml -o $BUILD/b/b.cmo
+# $OCAMLC -a -I $BUILD/a $BUILD/b/b.cmo -o $BUILD/b/b.cma
+
+# cd ../c
+# $OCAMLC -I $BUILD/a -H $BUILD/b $BUILD/a/a.cma $BUILD/b/b.cma c.ml -o $BUILD/c/c
+
+
+
+cp a/*.ml a/*.mli $BUILD/a
+cd $BUILD/a
+$OCAMLC -c -bin-annot a.mli -o a.cmi
+$OCAMLC -c -bin-annot a.ml -o a.cmo
+$OCAMLC -a -bin-annot a.cmo -o a.cma
+cd ../..
+
+cp b/*.ml b/*.mli $BUILD/b
+cd $BUILD/b
+$OCAMLC -c -bin-annot b.mli -o b.cmi
+$OCAMLC -c -bin-annot -I $BUILD/a b.ml -o b.cmo
+$OCAMLC -a -bin-annot -I $BUILD/a b.cmo -o b.cma
+cd ../..
+
+# cd ../c
+# $OCAMLC -I $BUILD/a -H $BUILD/b $BUILD/a/a.cma $BUILD/b/b.cma c.ml -o $BUILD/c/c
diff --git a/tests/test-dirs/hidden-deps.t/c/correct.ml b/tests/test-dirs/hidden-deps.t/c/correct.ml
new file mode 100644
index 000000000..00eec83ea
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/c/correct.ml
@@ -0,0 +1,3 @@
+let c = B.a + B.b
+
+let () = print_endline (Int.to_string c)
diff --git a/tests/test-dirs/hidden-deps.t/c/error.ml b/tests/test-dirs/hidden-deps.t/c/error.ml
new file mode 100644
index 000000000..1c2f4da76
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/c/error.ml
@@ -0,0 +1,3 @@
+let c = A.a + B.b
+
+let () = print_endline (Int.to_string c)
diff --git a/tests/test-dirs/hidden-deps.t/run.t b/tests/test-dirs/hidden-deps.t/run.t
new file mode 100644
index 000000000..d16ab98f2
--- /dev/null
+++ b/tests/test-dirs/hidden-deps.t/run.t
@@ -0,0 +1,118 @@
+Test that Merlin correctly handles BH and SH directives.
+These are for hidden dependencies and correspond to the
+-H compiler flag.
+
+Start by building some dependencies. C depends on B
+which depends on A. A will be a hidden dependency of C,
+while B will be direct.
+
+B exposes a variable from A, allowing C to directly use
+it via B.
+
+  $ mkdir -p _build/a
+  $ cp a/*.ml* _build/a
+  $ pushd _build/a > /dev/null
+  $ $OCAMLC -c -bin-annot a.mli -o a.cmi
+  $ $OCAMLC -c -bin-annot a.ml -o a.cmo
+  $ popd > /dev/null
+
+  $ mkdir -p _build/b
+  $ cp b/*.ml* _build/b
+  $ pushd _build/b > /dev/null
+  $ $OCAMLC -c -bin-annot b.mli -o b.cmi
+  $ $OCAMLC -c -bin-annot -I ../a b.ml -o b.cmo
+  $ popd > /dev/null
+
+Merlin does not report errors when there are none
+
+  $ $MERLIN single errors -filename c/correct.ml < c/correct.ml | jq ".value"
+  []
+
+Merlin can locate a value in an interface from a direct dependency
+
+  $ $MERLIN single locate -position 1:17 -look-for interface -filename c/correct.ml < c/correct.ml | jq ".value"
+  {
+    "file": "$TESTCASE_ROOT/b/b.mli",
+    "pos": {
+      "line": 2,
+      "col": 0
+    }
+  }
+
+Merlin can locate a value in an interface from a hidden dependency
+
+  $ $MERLIN single locate -position 1:11 -look-for interface -filename c/correct.ml < c/correct.ml | jq ".value"
+  {
+    "file": "$TESTCASE_ROOT/b/b.mli",
+    "pos": {
+      "line": 1,
+      "col": 0
+    }
+  }
+
+Merlin can locate a value in an implementation from a direct dependency
+
+  $ $MERLIN single locate -position 1:17 -look-for implementation -filename c/correct.ml < c/correct.ml | jq ".value"
+  {
+    "file": "$TESTCASE_ROOT/b/b.ml",
+    "pos": {
+      "line": 2,
+      "col": 4
+    }
+  }
+
+Merlin can locate a value in an implementation from a hidden dependency
+
+  $ $MERLIN single locate -position 1:11 -look-for implementation -filename c/correct.ml < c/correct.ml | jq ".value"
+
+Merlin reports an error when a hidden dependency is directly used
+
+  $ $MERLIN single errors -filename c/error.ml < c/error.ml | jq ".value"
+  [
+    {
+      "start": {
+        "line": 1,
+        "col": 8
+      },
+      "end": {
+        "line": 1,
+        "col": 11
+      },
+      "type": "typer",
+      "sub": [],
+      "valid": true,
+      "message": "Unbound module A"
+    }
+  ]
+
+Merlin can locate a value in an interface from a direct dependency when there is an error
+
+  $ $MERLIN single locate -position 1:17 -look-for interface -filename c/error.ml < c/error.ml | jq ".value"
+  {
+    "file": "$TESTCASE_ROOT/b/b.mli",
+    "pos": {
+      "line": 2,
+      "col": 0
+    }
+  }
+
+Merlin fails locate a value in an interface from a hidden dependency that is illegally used
+
+  $ $MERLIN single locate -position 1:11 -look-for interface -filename c/error.ml < c/error.ml | jq ".value"
+  "Not in environment 'A.a'"
+
+Merlin can locate a value in an implementation from a direct dependency when there is an error
+
+  $ $MERLIN single locate -position 1:17 -look-for implementation -filename c/error.ml < c/error.ml | jq ".value"
+  {
+    "file": "$TESTCASE_ROOT/b/b.ml",
+    "pos": {
+      "line": 2,
+      "col": 4
+    }
+  }
+
+Merlin fails locate a value in an implementation from a hidden dependency that is illegally used
+
+  $ $MERLIN single locate -position 1:11 -look-for implementation -filename c/error.ml < c/error.ml | jq ".value"
+  "Not in environment 'A.a'"

From 39d854c11da6eb79292f7c1b0605fb0acba878c3 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Wed, 1 May 2024 11:51:14 -0400
Subject: [PATCH 06/11] Fix failing tests

---
 src/analysis/locate.ml              |  8 ++++----
 src/frontend/query_commands.ml      |  8 ++++++--
 src/kernel/mconfig.ml               |  3 +++
 src/kernel/mconfig.mli              |  2 ++
 src/kernel/mppx.ml                  | 18 +++++++++++++-----
 tests/test-dirs/hidden-deps.t/run.t |  7 +++++++
 6 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/src/analysis/locate.ml b/src/analysis/locate.ml
index 3f2e83ae1..a36026698 100644
--- a/src/analysis/locate.ml
+++ b/src/analysis/locate.ml
@@ -389,7 +389,7 @@ module Utils = struct
     let files =
       List.concat_map ~f:(fun synonym_pair ->
         find_all_in_path_uncap ~src_suffix_pair:synonym_pair ~with_fallback
-          (Mconfig.source_path config) file
+          (Mconfig.source_path config @ Mconfig.hidden_source_path config) file
       ) Mconfig.(config.merlin.suffixes)
     in
     List.dedup_adjacent files ~cmp:String.compare
@@ -422,9 +422,9 @@ module Utils = struct
   let find_file ~config ?with_fallback (file : File.t) =
     find_file_with_path ~config ?with_fallback file @@
         match file with
-        | ML  _ | MLI _  | MLL _ -> Mconfig.source_path config
-        | CMT _ | CMTI _         -> Mconfig.build_path config
-        | CMS _ | CMSI _         -> Mconfig.build_path config
+        | ML  _ | MLI _  | MLL _ -> Mconfig.source_path config @ Mconfig.hidden_source_path config
+        | CMT _ | CMTI _         -> Mconfig.build_path config @ Mconfig.hidden_build_path config
+        | CMS _ | CMSI _         -> Mconfig.build_path config @ Mconfig.hidden_build_path config
 end
 
 let move_to filename artifact =
diff --git a/src/frontend/query_commands.ml b/src/frontend/query_commands.ml
index b7c73f5e3..a221883c2 100644
--- a/src/frontend/query_commands.ml
+++ b/src/frontend/query_commands.ml
@@ -183,6 +183,10 @@ let dump pipeline = function
     let paths = Mconfig.build_path (Mpipeline.final_config pipeline) in
     `List (List.map paths ~f:(fun s -> `String s))
 
+  | [`String "hidden-paths"] ->
+    let paths = Mconfig.hidden_build_path (Mpipeline.final_config pipeline) in
+    `List (List.map paths ~f:(fun s -> `String s))
+
   | [`String "typedtree"] ->
     let tree =
       Mpipeline.typer_result pipeline
@@ -795,9 +799,9 @@ let dispatch pipeline (type a) : a Query_protocol.t -> a =
       | [] -> raise Not_found
       | x :: xs ->
         try
-          find_in_path_uncap (Mconfig.source_path config) x
+          find_in_path_uncap (Mconfig.source_path config @ Mconfig.hidden_source_path config) x
         with Not_found -> try
-            find_in_path_uncap (Mconfig.build_path config) x
+            find_in_path_uncap (Mconfig.build_path config @ Mconfig.hidden_build_path config) x
           with Not_found ->
             aux xs
     in
diff --git a/src/kernel/mconfig.ml b/src/kernel/mconfig.ml
index 846f122ad..f8b4e6fd4 100644
--- a/src/kernel/mconfig.ml
+++ b/src/kernel/mconfig.ml
@@ -878,6 +878,9 @@ let source_path config =
      config.merlin.source_path]
   |> List.filter_dup
 
+let hidden_source_path config =
+  config.merlin.hidden_source_path @ config.ocaml.hidden_dirs
+
 let build_path config = (
   let dirs =
     match config.ocaml.threads with
diff --git a/src/kernel/mconfig.mli b/src/kernel/mconfig.mli
index e903cc6a8..609e9edc5 100644
--- a/src/kernel/mconfig.mli
+++ b/src/kernel/mconfig.mli
@@ -111,6 +111,8 @@ val document_arguments : out_channel -> unit
 
 val source_path : t -> string list
 
+val hidden_source_path : t -> string list
+
 val build_path : t -> string list
 
 val hidden_build_path : t -> string list
diff --git a/src/kernel/mppx.ml b/src/kernel/mppx.ml
index 4e1fea600..43bb0f0d1 100644
--- a/src/kernel/mppx.ml
+++ b/src/kernel/mppx.ml
@@ -2,10 +2,15 @@ open Mconfig
 
 let {Logger. log} = Logger.for_section "Mppx"
 
-let with_include_dir path f =
-  let saved = !Clflags.include_dirs in
-  let restore () = Clflags.include_dirs := saved in
-  Clflags.include_dirs := path;
+let with_include_dir ~visible_path ~hidden_path f =
+  let saved_visible = !Clflags.include_dirs in
+  let saved_hidden = !Clflags.hidden_include_dirs in
+  let restore () =
+    Clflags.include_dirs := saved_visible;
+    Clflags.hidden_include_dirs := saved_hidden
+  in
+  Clflags.include_dirs := visible_path;
+  Clflags.hidden_include_dirs := hidden_path;
   let result =
     begin
       try
@@ -22,7 +27,10 @@ let with_include_dir path f =
 let rewrite parsetree cfg =
   let ppx = cfg.ocaml.ppx in
   (* add include path attribute to the parsetree *)
-  with_include_dir (Mconfig.build_path cfg) @@ fun () ->
+  with_include_dir
+    ~visible_path:(Mconfig.build_path cfg)
+    ~hidden_path:(Mconfig.hidden_build_path cfg)
+  @@ fun () ->
   match
     Pparse.apply_rewriters ~restore:false ~ppx ~tool_name:"merlin" parsetree
   with
diff --git a/tests/test-dirs/hidden-deps.t/run.t b/tests/test-dirs/hidden-deps.t/run.t
index d16ab98f2..ea09aea36 100644
--- a/tests/test-dirs/hidden-deps.t/run.t
+++ b/tests/test-dirs/hidden-deps.t/run.t
@@ -64,6 +64,13 @@ Merlin can locate a value in an implementation from a direct dependency
 Merlin can locate a value in an implementation from a hidden dependency
 
   $ $MERLIN single locate -position 1:11 -look-for implementation -filename c/correct.ml < c/correct.ml | jq ".value"
+  {
+    "file": "$TESTCASE_ROOT/a/a.ml",
+    "pos": {
+      "line": 1,
+      "col": 4
+    }
+  }
 
 Merlin reports an error when a hidden dependency is directly used
 

From 7a7015254796788cc2d30e0e34eeef80537553a7 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Wed, 1 May 2024 13:35:23 -0400
Subject: [PATCH 07/11] Fix tests that fail to run on CI

---
 tests/test-dirs/hidden-deps.t/build.sh | 43 --------------------------
 tests/test-dirs/hidden-deps.t/run.t    |  8 ++---
 2 files changed, 4 insertions(+), 47 deletions(-)
 delete mode 100755 tests/test-dirs/hidden-deps.t/build.sh

diff --git a/tests/test-dirs/hidden-deps.t/build.sh b/tests/test-dirs/hidden-deps.t/build.sh
deleted file mode 100755
index 64a32dd01..000000000
--- a/tests/test-dirs/hidden-deps.t/build.sh
+++ /dev/null
@@ -1,43 +0,0 @@
-#!/bin/bash
-set -e
-cd "$(dirname "$0")"
-
-OCAMLC=/j/office/app/ocaml/prod/5.1.1minus/5.1.1minus-13-d49e4649/el8+fl2/bin/ocamlc
-BUILD="$(realpath ./_build)"
-
-rm -rf $BUILD
-mkdir -p $BUILD/a
-mkdir -p $BUILD/b
-mkdir -p $BUILD/c
-
-# cd a
-# $OCAMLC -c a.mli -o $BUILD/a/a.cmi
-# $OCAMLC -c -I $BUILD/a a.ml -o $BUILD/a/a.cmo
-# $OCAMLC -a $BUILD/a/a.cmo -o $BUILD/a/a.cma
-
-# cd ../b
-# $OCAMLC -c b.mli -o $BUILD/b/b.cmi
-# $OCAMLC -c -I $BUILD/a -I $BUILD/b b.ml -o $BUILD/b/b.cmo
-# $OCAMLC -a -I $BUILD/a $BUILD/b/b.cmo -o $BUILD/b/b.cma
-
-# cd ../c
-# $OCAMLC -I $BUILD/a -H $BUILD/b $BUILD/a/a.cma $BUILD/b/b.cma c.ml -o $BUILD/c/c
-
-
-
-cp a/*.ml a/*.mli $BUILD/a
-cd $BUILD/a
-$OCAMLC -c -bin-annot a.mli -o a.cmi
-$OCAMLC -c -bin-annot a.ml -o a.cmo
-$OCAMLC -a -bin-annot a.cmo -o a.cma
-cd ../..
-
-cp b/*.ml b/*.mli $BUILD/b
-cd $BUILD/b
-$OCAMLC -c -bin-annot b.mli -o b.cmi
-$OCAMLC -c -bin-annot -I $BUILD/a b.ml -o b.cmo
-$OCAMLC -a -bin-annot -I $BUILD/a b.cmo -o b.cma
-cd ../..
-
-# cd ../c
-# $OCAMLC -I $BUILD/a -H $BUILD/b $BUILD/a/a.cma $BUILD/b/b.cma c.ml -o $BUILD/c/c
diff --git a/tests/test-dirs/hidden-deps.t/run.t b/tests/test-dirs/hidden-deps.t/run.t
index ea09aea36..e596538c5 100644
--- a/tests/test-dirs/hidden-deps.t/run.t
+++ b/tests/test-dirs/hidden-deps.t/run.t
@@ -11,17 +11,17 @@ it via B.
 
   $ mkdir -p _build/a
   $ cp a/*.ml* _build/a
-  $ pushd _build/a > /dev/null
+  $ cd _build/a
   $ $OCAMLC -c -bin-annot a.mli -o a.cmi
   $ $OCAMLC -c -bin-annot a.ml -o a.cmo
-  $ popd > /dev/null
+  $ cd ../..
 
   $ mkdir -p _build/b
   $ cp b/*.ml* _build/b
-  $ pushd _build/b > /dev/null
+  $ cd _build/b
   $ $OCAMLC -c -bin-annot b.mli -o b.cmi
   $ $OCAMLC -c -bin-annot -I ../a b.ml -o b.cmo
-  $ popd > /dev/null
+  $ cd ../..
 
 Merlin does not report errors when there are none
 

From 62395d752dee58369213e5902971e81d07b1cdae Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Wed, 1 May 2024 13:56:05 -0400
Subject: [PATCH 08/11] Add .merlin file to tests

---
 tests/test-dirs/hidden-deps.t/run.t | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/test-dirs/hidden-deps.t/run.t b/tests/test-dirs/hidden-deps.t/run.t
index e596538c5..82bfddb00 100644
--- a/tests/test-dirs/hidden-deps.t/run.t
+++ b/tests/test-dirs/hidden-deps.t/run.t
@@ -23,6 +23,15 @@ it via B.
   $ $OCAMLC -c -bin-annot -I ../a b.ml -o b.cmo
   $ cd ../..
 
+Create a .merlin file
+
+  $ cat >c/.merlin <<EOF
+  > BH ../_build/a
+  > SH ../a
+  > B ../_build/b
+  > S ../b
+  > EOF
+
 Merlin does not report errors when there are none
 
   $ $MERLIN single errors -filename c/correct.ml < c/correct.ml | jq ".value"

From ac10df3c7c0e1173f42afe76dc28924ccb7f56a1 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Fri, 3 May 2024 11:45:07 -0400
Subject: [PATCH 09/11] Refactor tests

---
 tests/test-dirs/{dash-h.t/run.t => hidden-deps/dash-h.t}          | 0
 .../test-dirs/{hidden-deps.t => hidden-deps/directives.t}/a/a.ml  | 0
 .../test-dirs/{hidden-deps.t => hidden-deps/directives.t}/a/a.mli | 0
 .../test-dirs/{hidden-deps.t => hidden-deps/directives.t}/b/b.ml  | 0
 .../test-dirs/{hidden-deps.t => hidden-deps/directives.t}/b/b.mli | 0
 .../{hidden-deps.t => hidden-deps/directives.t}/c/correct.ml      | 0
 .../{hidden-deps.t => hidden-deps/directives.t}/c/error.ml        | 0
 tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/run.t | 0
 8 files changed, 0 insertions(+), 0 deletions(-)
 rename tests/test-dirs/{dash-h.t/run.t => hidden-deps/dash-h.t} (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/a/a.ml (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/a/a.mli (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/b/b.ml (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/b/b.mli (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/c/correct.ml (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/c/error.ml (100%)
 rename tests/test-dirs/{hidden-deps.t => hidden-deps/directives.t}/run.t (100%)

diff --git a/tests/test-dirs/dash-h.t/run.t b/tests/test-dirs/hidden-deps/dash-h.t
similarity index 100%
rename from tests/test-dirs/dash-h.t/run.t
rename to tests/test-dirs/hidden-deps/dash-h.t
diff --git a/tests/test-dirs/hidden-deps.t/a/a.ml b/tests/test-dirs/hidden-deps/directives.t/a/a.ml
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/a/a.ml
rename to tests/test-dirs/hidden-deps/directives.t/a/a.ml
diff --git a/tests/test-dirs/hidden-deps.t/a/a.mli b/tests/test-dirs/hidden-deps/directives.t/a/a.mli
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/a/a.mli
rename to tests/test-dirs/hidden-deps/directives.t/a/a.mli
diff --git a/tests/test-dirs/hidden-deps.t/b/b.ml b/tests/test-dirs/hidden-deps/directives.t/b/b.ml
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/b/b.ml
rename to tests/test-dirs/hidden-deps/directives.t/b/b.ml
diff --git a/tests/test-dirs/hidden-deps.t/b/b.mli b/tests/test-dirs/hidden-deps/directives.t/b/b.mli
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/b/b.mli
rename to tests/test-dirs/hidden-deps/directives.t/b/b.mli
diff --git a/tests/test-dirs/hidden-deps.t/c/correct.ml b/tests/test-dirs/hidden-deps/directives.t/c/correct.ml
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/c/correct.ml
rename to tests/test-dirs/hidden-deps/directives.t/c/correct.ml
diff --git a/tests/test-dirs/hidden-deps.t/c/error.ml b/tests/test-dirs/hidden-deps/directives.t/c/error.ml
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/c/error.ml
rename to tests/test-dirs/hidden-deps/directives.t/c/error.ml
diff --git a/tests/test-dirs/hidden-deps.t/run.t b/tests/test-dirs/hidden-deps/directives.t/run.t
similarity index 100%
rename from tests/test-dirs/hidden-deps.t/run.t
rename to tests/test-dirs/hidden-deps/directives.t/run.t

From 90c05225ab493437cc549d01ac097a2558ebb317 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Fri, 3 May 2024 11:54:42 -0400
Subject: [PATCH 10/11] Update docs for dump

---
 src/frontend/ocamlmerlin/new/new_commands.ml | 2 +-
 src/frontend/query_commands.ml               | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/frontend/ocamlmerlin/new/new_commands.ml b/src/frontend/ocamlmerlin/new/new_commands.ml
index 645d5f37c..cb4f44dbb 100644
--- a/src/frontend/ocamlmerlin/new/new_commands.ml
+++ b/src/frontend/ocamlmerlin/new/new_commands.ml
@@ -701,7 +701,7 @@ The return value has the shape:
   command "dump"
     ~spec:[
       arg "-what" "<source|parsetree|ppxed-source|ppxed-parsetree|typedtree\
-                   |env|fullenv|browse|tokens|flags|warnings|exn|paths> \
+                   |env|fullenv|browse|tokens|flags|warnings|exn|paths|hidden-paths> \
                    Information to dump ()"
         (Marg.param "string" (fun what _ -> what));
     ]
diff --git a/src/frontend/query_commands.ml b/src/frontend/query_commands.ml
index a221883c2..2409c75f9 100644
--- a/src/frontend/query_commands.ml
+++ b/src/frontend/query_commands.ml
@@ -202,8 +202,8 @@ let dump pipeline = function
     `String (to_string ())
 
   | _ -> failwith "known dump commands: \
-                   paths, exn, warnings, flags, tokens, browse, source, \
-                   parsetree, ppxed-source, ppxed-parsetree, typedtree, \
+                   paths, hidden-paths, exn, warnings, flags, tokens, browse, \
+                   source, parsetree, ppxed-source, ppxed-parsetree, typedtree, \
                    env/fullenv (at {col:, line:})"
 
 let reconstruct_identifier pipeline pos = function

From d2b8b00c757936d58993577033eed139a2af2525 Mon Sep 17 00:00:00 2001
From: Liam Stevenson <lstevenson@janestreet.com>
Date: Fri, 3 May 2024 11:59:14 -0400
Subject: [PATCH 11/11] Add -H deps to Path_list

---
 src/frontend/query_commands.ml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/frontend/query_commands.ml b/src/frontend/query_commands.ml
index 2409c75f9..7ac8087c4 100644
--- a/src/frontend/query_commands.ml
+++ b/src/frontend/query_commands.ml
@@ -829,11 +829,11 @@ let dispatch pipeline (type a) : a Query_protocol.t -> a =
 
   | Path_list `Build ->
     let config = Mpipeline.final_config pipeline in
-    Mconfig.(config.merlin.build_path)
+    Mconfig.(config.merlin.build_path @ config.merlin.hidden_build_path)
 
   | Path_list `Source ->
     let config = Mpipeline.final_config pipeline in
-    Mconfig.(config.merlin.source_path)
+    Mconfig.(config.merlin.source_path @ config.merlin.hidden_source_path)
 
   | Occurrences (`Ident_at pos, _scope) ->
     let typer = Mpipeline.typer_result pipeline in