From a4a6bf9dc8385c8a6b9e08440b9596d5db129c1c Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Tue, 11 Jun 2024 17:01:36 +0200
Subject: [PATCH 01/19] Add support for -H

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml | 43 +++++++++++++++--------
 src/dune_rules/lib.ml                 |  9 ++---
 src/dune_rules/lib.mli                |  2 ++
 src/dune_rules/lib_flags.ml           | 50 ++++++++++++++++++++-------
 src/dune_rules/lib_flags.mli          |  9 ++++-
 src/ocaml/version.ml                  |  1 +
 src/ocaml/version.mli                 |  3 ++
 7 files changed, 85 insertions(+), 32 deletions(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index 3fdfad25023..9e64b6e22e3 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -3,24 +3,26 @@ open Import
 module Includes = struct
   type t = Command.Args.without_targets Command.Args.t Lib_mode.Cm_kind.Map.t
 
-  let make ~project ~opaque ~requires : _ Lib_mode.Cm_kind.Map.t =
+  let make ~project ~opaque ~requires ~direct : _ Lib_mode.Cm_kind.Map.t =
     (* TODO : some of the requires can filtered out using [ocamldep] info *)
     let open Resolve.Memo.O in
-    let iflags libs mode = Lib_flags.L.include_flags ~project libs mode in
+    let iflags libs mode direct = Lib_flags.L.include_flags ~project libs mode ~direct in
     let make_includes_args ~mode groups =
       Command.Args.memo
         (Resolve.Memo.args
-           (let+ libs = requires in
+           (let+ libs = requires
+            and+ direct = direct in
             Command.Args.S
-              [ iflags libs mode; Hidden_deps (Lib_file_deps.deps libs ~groups) ]))
+              [ iflags libs mode direct; Hidden_deps (Lib_file_deps.deps libs ~groups) ]))
     in
     let cmi_includes = make_includes_args ~mode:(Ocaml Byte) [ Ocaml Cmi ] in
     let cmx_includes =
       Command.Args.memo
         (Resolve.Memo.args
-           (let+ libs = requires in
+           (let+ libs = requires
+            and+ direct = direct in
             Command.Args.S
-              [ iflags libs (Ocaml Native)
+              [ iflags libs (Ocaml Native) direct
               ; Hidden_deps
                   (if opaque
                    then
@@ -139,12 +141,24 @@ let create
   =
   let open Memo.O in
   let project = Scope.project scope in
-  let requires_compile =
+  let context = Super_context.context super_context in
+  let sandbox = Sandbox_config.no_special_requirements in
+  let* ocaml = Context.ocaml context in
+  let requires, direct =
     if Dune_project.implicit_transitive_deps project
-    then Memo.Lazy.force requires_link
-    else requires_compile
+    then Memo.Lazy.force requires_link, Resolve.Memo.return (fun _ -> true)
+    else if Version.supports_hidden_includes ocaml.version
+            && Dune_project.dune_version project >= (3, 17)
+    then (
+      let direct =
+        let open Resolve.Memo.O in
+        let+ requires = requires_compile in
+        let requires = Lib.Tbl.of_list_exn (List.map ~f:(fun lib -> lib, ()) requires) in
+        Lib.Tbl.mem requires
+      in
+      Memo.Lazy.force requires_link, direct)
+    else requires_compile, Resolve.Memo.return (fun _ -> true)
   in
-  let sandbox = Sandbox_config.no_special_requirements in
   let modes =
     let default =
       { Lib_mode.Map.ocaml = Mode.Dict.make_both (Some Mode_conf.Kind.Inherited)
@@ -153,8 +167,6 @@ let create
     in
     Option.value ~default modes |> Lib_mode.Map.map ~f:Option.is_some
   in
-  let context = Super_context.context super_context in
-  let* ocaml = Context.ocaml context in
   let opaque =
     let profile = Context.profile context in
     eval_opaque ocaml profile opaque
@@ -182,7 +194,7 @@ let create
   ; flags
   ; requires_compile
   ; requires_link
-  ; includes = Includes.make ~project ~opaque ~requires:requires_compile
+  ; includes = Includes.make ~project ~opaque ~requires ~direct
   ; preprocessing
   ; opaque
   ; stdlib
@@ -263,8 +275,11 @@ let for_module_generated_at_link_time cctx ~requires ~module_ =
        their implementation must also be compiled with -opaque *)
     Ocaml.Version.supports_opaque_for_mli cctx.ocaml.version
   in
+  let direct = Resolve.Memo.return (fun _ -> true) in
   let modules = singleton_modules module_ in
-  let includes = Includes.make ~project:(Scope.project cctx.scope) ~opaque ~requires in
+  let includes =
+    Includes.make ~project:(Scope.project cctx.scope) ~opaque ~requires ~direct
+  in
   { cctx with
     opaque
   ; flags = Ocaml_flags.empty
diff --git a/src/dune_rules/lib.ml b/src/dune_rules/lib.ml
index f129465994f..4df810e4745 100644
--- a/src/dune_rules/lib.ml
+++ b/src/dune_rules/lib.ml
@@ -350,6 +350,10 @@ module T = struct
     Dyn.record
       [ "name", Lib_name.to_dyn t.name; "loc", Loc.to_dyn_hum (Lib_info.loc t.info) ]
   ;;
+
+  (* We can't write a structural equality because of all the lazy fields *)
+  let equal : t -> t -> bool = phys_equal
+  let hash = Poly.hash
 end
 
 include T
@@ -469,11 +473,8 @@ let wrapped t =
      | Some (This x) -> Some x)
 ;;
 
-(* We can't write a structural equality because of all the lazy fields *)
-let equal : t -> t -> bool = phys_equal
-let hash = Poly.hash
-
 include Comparable.Make (T)
+module Tbl = Hashtbl.Make (T)
 
 module L = struct
   let top_closure l ~key ~deps =
diff --git a/src/dune_rules/lib.mli b/src/dune_rules/lib.mli
index 4952c57067e..9793f5654ec 100644
--- a/src/dune_rules/lib.mli
+++ b/src/dune_rules/lib.mli
@@ -235,3 +235,5 @@ module Local : sig
 
   include Comparable_intf.S with type key := t
 end
+
+module Tbl : Hashtbl.S with type key := t
diff --git a/src/dune_rules/lib_flags.ml b/src/dune_rules/lib_flags.ml
index 3eab4dd2fe8..af8d00fd22f 100644
--- a/src/dune_rules/lib_flags.ml
+++ b/src/dune_rules/lib_flags.ml
@@ -92,10 +92,17 @@ module L = struct
        |> List.rev)
   ;;
 
-  let remove_stdlib dirs libs =
+  let to_flags dirs =
+    Command.Args.S
+      (Path.Map.foldi dirs ~init:[] ~f:(fun dir direct acc ->
+         Command.Args.Path dir :: A (if direct then "-I" else "-H") :: acc)
+       |> List.rev)
+  ;;
+
+  let remove_stdlib dirs libs remove =
     match libs with
     | [] -> dirs
-    | lib :: _ -> Path.Set.remove dirs (Lib.lib_config lib).stdlib_dir
+    | lib :: _ -> remove dirs (Lib.lib_config lib).stdlib_dir
   ;;
 
   type mode =
@@ -103,8 +110,8 @@ module L = struct
     ; melange_emit : bool
     }
 
-  let include_paths =
-    let add_public_dir ~visible_cmi obj_dir acc mode =
+  let include_paths_gen ~init ~add ~remove =
+    let add_public_dir ~visible_cmi obj_dir acc mode add lib =
       match visible_cmi with
       | false -> acc
       | true ->
@@ -121,7 +128,7 @@ module L = struct
                   `import` information *)
                [ Obj_dir.melange_dir; Obj_dir.public_cmi_melange_dir ])
         in
-        List.fold_left public_cmi_dirs ~init:acc ~f:Path.Set.add
+        List.fold_left public_cmi_dirs ~init:acc ~f:(fun acc path -> add acc path lib)
     in
     fun ?project ts mode ->
       let visible_cmi =
@@ -139,24 +146,41 @@ module L = struct
              | _ -> true)
       in
       let dirs =
-        List.fold_left ts ~init:Path.Set.empty ~f:(fun acc t ->
+        List.fold_left ts ~init ~f:(fun acc t ->
           let obj_dir = Lib_info.obj_dir (Lib.info t) in
           let visible_cmi = visible_cmi t in
           match mode.lib_mode with
-          | Melange -> add_public_dir ~visible_cmi obj_dir acc mode
+          | Melange -> add_public_dir ~visible_cmi obj_dir acc mode add t
           | Ocaml ocaml_mode ->
-            let acc = add_public_dir ~visible_cmi obj_dir acc mode in
+            let acc = add_public_dir ~visible_cmi obj_dir acc mode add t in
             (match ocaml_mode with
              | Byte -> acc
              | Native ->
                let native_dir = Obj_dir.native_dir obj_dir in
-               Path.Set.add acc native_dir))
+               add acc native_dir t))
       in
-      remove_stdlib dirs ts
+      remove_stdlib dirs ts remove
   ;;
 
-  let include_flags ?project ts mode =
-    to_iflags (include_paths ?project ts { lib_mode = mode; melange_emit = false })
+  let include_flags ?project ?(direct = fun _ -> true) ts mode =
+    to_flags
+      (include_paths_gen
+         ?project
+         ts
+         { lib_mode = mode; melange_emit = false }
+         ~init:Path.Map.empty
+         ~add:(fun acc p l -> Path.Map.set acc p (direct l))
+         ~remove:Path.Map.remove)
+  ;;
+
+  let include_paths ?project ts mode =
+    include_paths_gen
+      ?project
+      ts
+      mode
+      ~init:Path.Set.empty
+      ~add:(fun acc p _ -> Path.Set.add acc p)
+      ~remove:Path.Set.remove
   ;;
 
   let melange_emission_include_flags ?project ts =
@@ -173,7 +197,7 @@ module L = struct
         let src_dir = Lib_info.src_dir (Lib.info t) in
         Path.Set.add acc src_dir)
     in
-    remove_stdlib dirs ts
+    remove_stdlib dirs ts Path.Set.remove
   ;;
 
   let c_include_flags ts sctx =
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index 1faa6dee7b7..d66c7deada5 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -24,7 +24,14 @@ module L : sig
 
   val to_iflags : Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
-  val include_flags : ?project:Dune_project.t -> t -> Lib_mode.t -> _ Command.Args.t
+
+  val include_flags
+    :  ?project:Dune_project.t
+    -> ?direct:(Lib.t -> bool)
+    -> t
+    -> Lib_mode.t
+    -> _ Command.Args.t
+
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t
   val c_include_flags : t -> Super_context.t -> _ Command.Args.t
   val toplevel_ld_paths : t -> Path.Set.t
diff --git a/src/ocaml/version.ml b/src/ocaml/version.ml
index fba7b9e1a25..3caf3c7c444 100644
--- a/src/ocaml/version.ml
+++ b/src/ocaml/version.ml
@@ -29,3 +29,4 @@ let supports_alerts version = version >= (4, 8, 0)
 let has_sandboxed_otherlibs version = version >= (5, 0, 0)
 let has_META_files version = version >= (5, 0, 0)
 let supports_bin_annot_occurrences version = version >= (5, 2, 0)
+let supports_hidden_includes version = version >= (5, 2, 0)
diff --git a/src/ocaml/version.mli b/src/ocaml/version.mli
index f7da69ad2b1..dc79429144e 100644
--- a/src/ocaml/version.mli
+++ b/src/ocaml/version.mli
@@ -76,3 +76,6 @@ val has_META_files : t -> bool
 
 (** Whether the compiler supports occurrences indexation *)
 val supports_bin_annot_occurrences : t -> bool
+
+(** Whether the compiler supports the -H flag *)
+val supports_hidden_includes : t -> bool

From 663ec11a39766d4968d3b7df353c935f920ed390 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Tue, 11 Jun 2024 17:04:46 +0200
Subject: [PATCH 02/19] Add tests

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 .../test-cases/hidden-deps.t/bar.ml           |  3 ++
 .../test-cases/hidden-deps.t/dune             | 18 ++++++++++
 .../test-cases/hidden-deps.t/foo.ml           |  3 ++
 .../test-cases/hidden-deps.t/run.ml           |  1 +
 .../test-cases/hidden-deps.t/run.t            | 36 +++++++++++++++++++
 .../test-cases/hidden-deps.t/runf.ml          |  1 +
 .../test-cases/hidden-deps.t/tyxml/dune       |  3 ++
 .../hidden-deps.t/tyxml/dune-project          |  2 ++
 .../test-cases/hidden-deps.t/tyxml/run.ml     |  2 ++
 .../test-cases/hidden-deps.t/tyxml/run.t      |  5 +++
 10 files changed, 74 insertions(+)
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/bar.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/dune
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/foo.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/run.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/run.t
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/runf.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune-project
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t

diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/bar.ml b/test/blackbox-tests/test-cases/hidden-deps.t/bar.ml
new file mode 100644
index 00000000000..e1ca0d9c772
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/bar.ml
@@ -0,0 +1,3 @@
+let x = 5
+
+let y = Foo.v
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/dune b/test/blackbox-tests/test-cases/hidden-deps.t/dune
new file mode 100644
index 00000000000..1807d44beba
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/dune
@@ -0,0 +1,18 @@
+(library
+ (name foo)
+ (modules foo))
+
+(library
+ (name bar)
+ (modules bar)
+ (libraries foo))
+
+(executable
+ (name run)
+ (modules run)
+ (libraries bar))
+
+ (executable
+ (name runf)
+ (modules runf)
+ (libraries bar))
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/foo.ml b/test/blackbox-tests/test-cases/hidden-deps.t/foo.ml
new file mode 100644
index 00000000000..233654b2d90
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/foo.ml
@@ -0,0 +1,3 @@
+let v = 9
+
+let w = 4
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/run.ml b/test/blackbox-tests/test-cases/hidden-deps.t/run.ml
new file mode 100644
index 00000000000..4be93f9760e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/run.ml
@@ -0,0 +1 @@
+let _ = Bar.y
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/run.t b/test/blackbox-tests/test-cases/hidden-deps.t/run.t
new file mode 100644
index 00000000000..f058673ff79
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/run.t
@@ -0,0 +1,36 @@
+Should include Foo with -H:
+
+  $ getincludes () {
+  > dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*" | sed s/\-$1//g | tr -d '[:space:]'
+  > }
+
+  $ supports_H=$(if ocamlc -H x --help >/dev/null 2>&1; then echo true; else echo false; fi)
+  $ fooincludes='.foo.objs/byte.foo.objs/byte.foo.objs/native'
+  $ cat >dune-project <<EOF
+  > (lang dune 3.17)
+  > (implicit_transitive_deps true)
+  > EOF
+
+  $ if $supports_H; then [ "$(getincludes I)" = $fooincludes ]; fi
+  $ if ! $supports_H; then [ "$(getincludes I)" = $fooincludes ]; fi
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.17)
+  > (implicit_transitive_deps false)
+  > EOF
+
+  $ if $supports_H; then [ "$(getincludes H)" = $fooincludes ]; fi
+  $ if ! $supports_H; then [ "$(getincludes I)" = '' ]; fi
+
+
+Test transitive deps can not be directly accessed, both for compiler versions supporting -H or not:
+  $ cat >dune-project <<EOF
+  > (lang dune 3.17)
+  > (implicit_transitive_deps false)
+  > EOF
+
+  $ dune build ./runf.exe 2>&1 | grep -v ocamlc
+  File "runf.ml", line 1, characters 16-21:
+  1 | let a = Bar.y + Foo.v
+                      ^^^^^
+  Error: Unbound module Foo
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/runf.ml b/test/blackbox-tests/test-cases/hidden-deps.t/runf.ml
new file mode 100644
index 00000000000..3e7e6b04ba1
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/runf.ml
@@ -0,0 +1 @@
+let a = Bar.y + Foo.v
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune
new file mode 100644
index 00000000000..fd768950796
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune
@@ -0,0 +1,3 @@
+(executable
+  (name run)
+  (libraries tyxml))
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune-project b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune-project
new file mode 100644
index 00000000000..fff9b78b842
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune-project
@@ -0,0 +1,2 @@
+(lang dune 3.17)
+(implicit_transitive_deps false)
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.ml b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.ml
new file mode 100644
index 00000000000..68818fbad58
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.ml
@@ -0,0 +1,2 @@
+open Tyxml.Html
+let _ = p [ a [ txt "a" ] ]
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t
new file mode 100644
index 00000000000..35c0613b159
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t
@@ -0,0 +1,5 @@
+Test if the issue #274 is solved: the tyxml.functor is included with -H flag in
+ITD = false case, and thus no type abstraction happens when it is used.
+
+  $ ocamlc -H x --help > /dev/null
+  $ if [ $? = 0 ]; then dune build fi

From 42f179869a88a9cb8a4fe65e17a588ec184e3939 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Fri, 14 Jun 2024 16:17:10 +0200
Subject: [PATCH 03/19] fix: requires_compile returns the correct deps

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index 9e64b6e22e3..bdd8f59f3fc 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -192,7 +192,7 @@ let create
   ; obj_dir
   ; modules = { modules; dep_graphs }
   ; flags
-  ; requires_compile
+  ; requires_compile = requires
   ; requires_link
   ; includes = Includes.make ~project ~opaque ~requires ~direct
   ; preprocessing

From 1bf8bf8d922e1a7df000680f69b074b41ab7ef8b Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Tue, 18 Jun 2024 15:06:37 +0200
Subject: [PATCH 04/19] add requires_hidden list + adpat lib_flags to use the
 new list

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml  | 75 +++++++++++++++++---------
 src/dune_rules/compilation_context.mli |  1 +
 src/dune_rules/lib_flags.ml            | 57 +++++++++-----------
 src/dune_rules/lib_flags.mli           |  9 +---
 4 files changed, 75 insertions(+), 67 deletions(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index bdd8f59f3fc..f65044cd025 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -3,38 +3,51 @@ open Import
 module Includes = struct
   type t = Command.Args.without_targets Command.Args.t Lib_mode.Cm_kind.Map.t
 
-  let make ~project ~opaque ~requires ~direct : _ Lib_mode.Cm_kind.Map.t =
+  let make
+    ~project
+    ~opaque
+    ~direct_requires
+    ~(hidden_requires : Lib_flags.L.t Resolve.Memo.t)
+    : _ Lib_mode.Cm_kind.Map.t
+    =
     (* TODO : some of the requires can filtered out using [ocamldep] info *)
     let open Resolve.Memo.O in
-    let iflags libs mode direct = Lib_flags.L.include_flags ~project libs mode ~direct in
+    let iflags direct_libs hidden_libs mode =
+      Lib_flags.L.include_flags ~project direct_libs hidden_libs mode
+    in
     let make_includes_args ~mode groups =
       Command.Args.memo
         (Resolve.Memo.args
-           (let+ libs = requires
-            and+ direct = direct in
+           (let+ direct_libs = direct_requires
+            and+ hidden_libs = hidden_requires in
             Command.Args.S
-              [ iflags libs mode direct; Hidden_deps (Lib_file_deps.deps libs ~groups) ]))
+              [ iflags direct_libs hidden_libs mode
+              ; Hidden_deps
+                  (Lib_file_deps.deps (List.concat [ direct_libs; hidden_libs ]) ~groups)
+              ]))
     in
     let cmi_includes = make_includes_args ~mode:(Ocaml Byte) [ Ocaml Cmi ] in
     let cmx_includes =
       Command.Args.memo
         (Resolve.Memo.args
-           (let+ libs = requires
-            and+ direct = direct in
+           (let+ direct_libs = direct_requires
+            and+ hidden_libs = hidden_requires in
             Command.Args.S
-              [ iflags libs (Ocaml Native) direct
+              [ iflags direct_libs hidden_libs (Ocaml Native)
               ; Hidden_deps
                   (if opaque
                    then
-                     List.map libs ~f:(fun lib ->
-                       ( lib
-                       , if Lib.is_local lib
-                         then [ Lib_file_deps.Group.Ocaml Cmi ]
-                         else [ Ocaml Cmi; Ocaml Cmx ] ))
+                     List.map
+                       (List.concat [ direct_libs; hidden_libs ])
+                       ~f:(fun lib ->
+                         ( lib
+                         , if Lib.is_local lib
+                           then [ Lib_file_deps.Group.Ocaml Cmi ]
+                           else [ Ocaml Cmi; Ocaml Cmx ] ))
                      |> Lib_file_deps.deps_with_exts
                    else
                      Lib_file_deps.deps
-                       libs
+                       (List.concat [ direct_libs; hidden_libs ])
                        ~groups:[ Lib_file_deps.Group.Ocaml Cmi; Ocaml Cmx ])
               ]))
     in
@@ -76,6 +89,7 @@ type t =
   ; modules : modules
   ; flags : Ocaml_flags.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
   ; includes : Includes.t
   ; preprocessing : Pp_spec.t
@@ -101,6 +115,7 @@ let obj_dir t = t.obj_dir
 let modules t = t.modules.modules
 let flags t = t.flags
 let requires_compile t = t.requires_compile
+let requires_hidden t = t.requires_hidden
 let requires_link t = Memo.Lazy.force t.requires_link
 let includes t = t.includes
 let preprocessing t = t.preprocessing
@@ -144,20 +159,22 @@ let create
   let context = Super_context.context super_context in
   let sandbox = Sandbox_config.no_special_requirements in
   let* ocaml = Context.ocaml context in
-  let requires, direct =
+  let direct_requires, hidden_requires =
     if Dune_project.implicit_transitive_deps project
-    then Memo.Lazy.force requires_link, Resolve.Memo.return (fun _ -> true)
+    then Memo.Lazy.force requires_link, Resolve.Memo.return []
     else if Version.supports_hidden_includes ocaml.version
             && Dune_project.dune_version project >= (3, 17)
     then (
-      let direct =
+      let requires_hidden =
         let open Resolve.Memo.O in
-        let+ requires = requires_compile in
-        let requires = Lib.Tbl.of_list_exn (List.map ~f:(fun lib -> lib, ()) requires) in
-        Lib.Tbl.mem requires
+        let+ requires = requires_compile
+        and+ requires_link = Memo.Lazy.force requires_link in
+        let requires_table = Table.create (module Lib) 500 in
+        let () = List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires in
+        List.filter requires_link ~f:(fun l -> not (Table.mem requires_table l))
       in
-      Memo.Lazy.force requires_link, direct)
-    else requires_compile, Resolve.Memo.return (fun _ -> true)
+      requires_compile, requires_hidden)
+    else requires_compile, Resolve.Memo.return []
   in
   let modes =
     let default =
@@ -192,9 +209,10 @@ let create
   ; obj_dir
   ; modules = { modules; dep_graphs }
   ; flags
-  ; requires_compile = requires
+  ; requires_compile = direct_requires
+  ; requires_hidden = hidden_requires
   ; requires_link
-  ; includes = Includes.make ~project ~opaque ~requires ~direct
+  ; includes = Includes.make ~project ~opaque ~direct_requires ~hidden_requires
   ; preprocessing
   ; opaque
   ; stdlib
@@ -275,10 +293,15 @@ let for_module_generated_at_link_time cctx ~requires ~module_ =
        their implementation must also be compiled with -opaque *)
     Ocaml.Version.supports_opaque_for_mli cctx.ocaml.version
   in
-  let direct = Resolve.Memo.return (fun _ -> true) in
+  let direct_requires = requires in
+  let hidden_requires = Resolve.Memo.return [] in
   let modules = singleton_modules module_ in
   let includes =
-    Includes.make ~project:(Scope.project cctx.scope) ~opaque ~requires ~direct
+    Includes.make
+      ~project:(Scope.project cctx.scope)
+      ~opaque
+      ~direct_requires
+      ~hidden_requires
   in
   { cctx with
     opaque
diff --git a/src/dune_rules/compilation_context.mli b/src/dune_rules/compilation_context.mli
index 643466e623a..9924ea719a6 100644
--- a/src/dune_rules/compilation_context.mli
+++ b/src/dune_rules/compilation_context.mli
@@ -55,6 +55,7 @@ val obj_dir : t -> Path.Build.t Obj_dir.t
 val modules : t -> Modules.With_vlib.t
 val flags : t -> Ocaml_flags.t
 val requires_link : t -> Lib.t list Resolve.Memo.t
+val requires_hidden : t -> Lib.t list Resolve.Memo.t
 val requires_compile : t -> Lib.t list Resolve.Memo.t
 val includes : t -> Command.Args.without_targets Command.Args.t Lib_mode.Cm_kind.Map.t
 val preprocessing : t -> Pp_spec.t
diff --git a/src/dune_rules/lib_flags.ml b/src/dune_rules/lib_flags.ml
index af8d00fd22f..496f1476ee7 100644
--- a/src/dune_rules/lib_flags.ml
+++ b/src/dune_rules/lib_flags.ml
@@ -92,17 +92,17 @@ module L = struct
        |> List.rev)
   ;;
 
-  let to_flags dirs =
+  let to_hflags dirs =
     Command.Args.S
-      (Path.Map.foldi dirs ~init:[] ~f:(fun dir direct acc ->
-         Command.Args.Path dir :: A (if direct then "-I" else "-H") :: acc)
+      (Path.Set.fold dirs ~init:[] ~f:(fun dir acc ->
+         Command.Args.Path dir :: A "-H" :: acc)
        |> List.rev)
   ;;
 
-  let remove_stdlib dirs libs remove =
+  let remove_stdlib dirs libs =
     match libs with
     | [] -> dirs
-    | lib :: _ -> remove dirs (Lib.lib_config lib).stdlib_dir
+    | lib :: _ -> Path.Set.remove dirs (Lib.lib_config lib).stdlib_dir
   ;;
 
   type mode =
@@ -110,8 +110,8 @@ module L = struct
     ; melange_emit : bool
     }
 
-  let include_paths_gen ~init ~add ~remove =
-    let add_public_dir ~visible_cmi obj_dir acc mode add lib =
+  let include_paths =
+    let add_public_dir ~visible_cmi obj_dir acc mode =
       match visible_cmi with
       | false -> acc
       | true ->
@@ -128,7 +128,7 @@ module L = struct
                   `import` information *)
                [ Obj_dir.melange_dir; Obj_dir.public_cmi_melange_dir ])
         in
-        List.fold_left public_cmi_dirs ~init:acc ~f:(fun acc path -> add acc path lib)
+        List.fold_left public_cmi_dirs ~init:acc ~f:Path.Set.add
     in
     fun ?project ts mode ->
       let visible_cmi =
@@ -146,41 +146,32 @@ module L = struct
              | _ -> true)
       in
       let dirs =
-        List.fold_left ts ~init ~f:(fun acc t ->
+        List.fold_left ts ~init:Path.Set.empty ~f:(fun acc t ->
           let obj_dir = Lib_info.obj_dir (Lib.info t) in
           let visible_cmi = visible_cmi t in
           match mode.lib_mode with
-          | Melange -> add_public_dir ~visible_cmi obj_dir acc mode add t
+          | Melange -> add_public_dir ~visible_cmi obj_dir acc mode
           | Ocaml ocaml_mode ->
-            let acc = add_public_dir ~visible_cmi obj_dir acc mode add t in
+            let acc = add_public_dir ~visible_cmi obj_dir acc mode in
             (match ocaml_mode with
              | Byte -> acc
              | Native ->
                let native_dir = Obj_dir.native_dir obj_dir in
-               add acc native_dir t))
+               Path.Set.add acc native_dir))
       in
-      remove_stdlib dirs ts remove
-  ;;
-
-  let include_flags ?project ?(direct = fun _ -> true) ts mode =
-    to_flags
-      (include_paths_gen
-         ?project
-         ts
-         { lib_mode = mode; melange_emit = false }
-         ~init:Path.Map.empty
-         ~add:(fun acc p l -> Path.Map.set acc p (direct l))
-         ~remove:Path.Map.remove)
+      remove_stdlib dirs ts
   ;;
 
-  let include_paths ?project ts mode =
-    include_paths_gen
-      ?project
-      ts
-      mode
-      ~init:Path.Set.empty
-      ~add:(fun acc p _ -> Path.Set.add acc p)
-      ~remove:Path.Set.remove
+  let include_flags ?project ts_direct ts_hidden mode =
+    let hidden_includes =
+      to_hflags
+        (include_paths ?project ts_hidden { lib_mode = mode; melange_emit = false })
+    in
+    let direct_includes =
+      to_iflags
+        (include_paths ?project ts_direct { lib_mode = mode; melange_emit = false })
+    in
+    Command.Args.S [ direct_includes; hidden_includes ]
   ;;
 
   let melange_emission_include_flags ?project ts =
@@ -197,7 +188,7 @@ module L = struct
         let src_dir = Lib_info.src_dir (Lib.info t) in
         Path.Set.add acc src_dir)
     in
-    remove_stdlib dirs ts Path.Set.remove
+    remove_stdlib dirs ts
   ;;
 
   let c_include_flags ts sctx =
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index d66c7deada5..5d8a3e3c4d3 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -24,14 +24,7 @@ module L : sig
 
   val to_iflags : Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
-
-  val include_flags
-    :  ?project:Dune_project.t
-    -> ?direct:(Lib.t -> bool)
-    -> t
-    -> Lib_mode.t
-    -> _ Command.Args.t
-
+  val include_flags : ?project:Dune_project.t -> t -> t -> Lib_mode.t -> _ Command.Args.t
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t
   val c_include_flags : t -> Super_context.t -> _ Command.Args.t
   val toplevel_ld_paths : t -> Path.Set.t

From 18935364a836b631039f3d55367f1d3b22aa6ac7 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Tue, 18 Jun 2024 15:12:28 +0200
Subject: [PATCH 05/19] removed Hashtbl from lib.ml + ocaml_index.ml adapted to
 requires_hidden (to be re-checked)

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/lib.ml                | 9 ++++-----
 src/dune_rules/lib.mli               | 2 --
 src/dune_rules/merlin/ocaml_index.ml | 6 ++----
 3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/src/dune_rules/lib.ml b/src/dune_rules/lib.ml
index 4df810e4745..f129465994f 100644
--- a/src/dune_rules/lib.ml
+++ b/src/dune_rules/lib.ml
@@ -350,10 +350,6 @@ module T = struct
     Dyn.record
       [ "name", Lib_name.to_dyn t.name; "loc", Loc.to_dyn_hum (Lib_info.loc t.info) ]
   ;;
-
-  (* We can't write a structural equality because of all the lazy fields *)
-  let equal : t -> t -> bool = phys_equal
-  let hash = Poly.hash
 end
 
 include T
@@ -473,8 +469,11 @@ let wrapped t =
      | Some (This x) -> Some x)
 ;;
 
+(* We can't write a structural equality because of all the lazy fields *)
+let equal : t -> t -> bool = phys_equal
+let hash = Poly.hash
+
 include Comparable.Make (T)
-module Tbl = Hashtbl.Make (T)
 
 module L = struct
   let top_closure l ~key ~deps =
diff --git a/src/dune_rules/lib.mli b/src/dune_rules/lib.mli
index 9793f5654ec..4952c57067e 100644
--- a/src/dune_rules/lib.mli
+++ b/src/dune_rules/lib.mli
@@ -235,5 +235,3 @@ module Local : sig
 
   include Comparable_intf.S with type key := t
 end
-
-module Tbl : Hashtbl.S with type key := t
diff --git a/src/dune_rules/merlin/ocaml_index.ml b/src/dune_rules/merlin/ocaml_index.ml
index 561f6a88099..70fde70d78a 100644
--- a/src/dune_rules/merlin/ocaml_index.ml
+++ b/src/dune_rules/merlin/ocaml_index.ml
@@ -32,11 +32,9 @@ let cctx_rules cctx =
 
            The implicit transitive libs correspond to the set:
            (requires_link \ req_compile) *)
-        let* req_link = Compilation_context.requires_link cctx in
-        let+ req_compile = Compilation_context.requires_compile cctx in
-        List.filter req_link ~f:(fun l -> not (List.exists req_compile ~f:(Lib.equal l)))
+        Compilation_context.requires_hidden cctx
       in
-      Lib_flags.L.include_flags non_compile_libs (Lib_mode.Ocaml Byte)
+      Lib_flags.L.include_flags [] non_compile_libs (Lib_mode.Ocaml Byte)
     in
     (* Indexing depends (recursively) on [required_compile] libs:
        - These libs's cmt files should be built before indexing starts

From 0c07a7702dcaf7c444078ff86283cabd34c65223 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Fri, 21 Jun 2024 11:53:11 +0200
Subject: [PATCH 06/19] some code cleaning

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml |  8 +-------
 src/dune_rules/lib_flags.ml           | 22 ++++++----------------
 src/dune_rules/lib_flags.mli          |  2 +-
 3 files changed, 8 insertions(+), 24 deletions(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index f65044cd025..9ac41c1fddb 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -3,13 +3,7 @@ open Import
 module Includes = struct
   type t = Command.Args.without_targets Command.Args.t Lib_mode.Cm_kind.Map.t
 
-  let make
-    ~project
-    ~opaque
-    ~direct_requires
-    ~(hidden_requires : Lib_flags.L.t Resolve.Memo.t)
-    : _ Lib_mode.Cm_kind.Map.t
-    =
+  let make ~project ~opaque ~direct_requires ~hidden_requires : _ Lib_mode.Cm_kind.Map.t =
     (* TODO : some of the requires can filtered out using [ocamldep] info *)
     let open Resolve.Memo.O in
     let iflags direct_libs hidden_libs mode =
diff --git a/src/dune_rules/lib_flags.ml b/src/dune_rules/lib_flags.ml
index 496f1476ee7..5472843ae4e 100644
--- a/src/dune_rules/lib_flags.ml
+++ b/src/dune_rules/lib_flags.ml
@@ -85,17 +85,10 @@ let link_deps sctx t mode =
 module L = struct
   type nonrec t = Lib.t list
 
-  let to_iflags dirs =
+  let to_iflags ?(flag = "-I") dirs =
     Command.Args.S
       (Path.Set.fold dirs ~init:[] ~f:(fun dir acc ->
-         Command.Args.Path dir :: A "-I" :: acc)
-       |> List.rev)
-  ;;
-
-  let to_hflags dirs =
-    Command.Args.S
-      (Path.Set.fold dirs ~init:[] ~f:(fun dir acc ->
-         Command.Args.Path dir :: A "-H" :: acc)
+         Command.Args.Path dir :: A flag :: acc)
        |> List.rev)
   ;;
 
@@ -163,14 +156,11 @@ module L = struct
   ;;
 
   let include_flags ?project ts_direct ts_hidden mode =
-    let hidden_includes =
-      to_hflags
-        (include_paths ?project ts_hidden { lib_mode = mode; melange_emit = false })
-    in
-    let direct_includes =
-      to_iflags
-        (include_paths ?project ts_direct { lib_mode = mode; melange_emit = false })
+    let include_paths ts =
+      include_paths ?project ts { lib_mode = mode; melange_emit = false }
     in
+    let hidden_includes = to_iflags (include_paths ts_hidden) ~flag:"-H" in
+    let direct_includes = to_iflags (include_paths ts_direct) in
     Command.Args.S [ direct_includes; hidden_includes ]
   ;;
 
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index 5d8a3e3c4d3..16a6bd0f223 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -22,7 +22,7 @@ end
 module L : sig
   type nonrec t = Lib.t list
 
-  val to_iflags : Path.Set.t -> _ Command.Args.t
+  val to_iflags : ?flag:string -> Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
   val include_flags : ?project:Dune_project.t -> t -> t -> Lib_mode.t -> _ Command.Args.t
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t

From 366ca5132eae63518054a7eacd43dbc81852d837 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Fri, 21 Jun 2024 16:46:16 +0200
Subject: [PATCH 07/19] add to_flags function

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/lib_flags.ml  | 7 +++++--
 src/dune_rules/lib_flags.mli | 3 ++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/dune_rules/lib_flags.ml b/src/dune_rules/lib_flags.ml
index 5472843ae4e..87c1569560b 100644
--- a/src/dune_rules/lib_flags.ml
+++ b/src/dune_rules/lib_flags.ml
@@ -85,13 +85,16 @@ let link_deps sctx t mode =
 module L = struct
   type nonrec t = Lib.t list
 
-  let to_iflags ?(flag = "-I") dirs =
+  let to_flags flag dirs =
     Command.Args.S
       (Path.Set.fold dirs ~init:[] ~f:(fun dir acc ->
          Command.Args.Path dir :: A flag :: acc)
        |> List.rev)
   ;;
 
+  let to_iflags dir = to_flags "-I" dir
+  let to_hflags dir = to_flags "-H" dir
+
   let remove_stdlib dirs libs =
     match libs with
     | [] -> dirs
@@ -159,7 +162,7 @@ module L = struct
     let include_paths ts =
       include_paths ?project ts { lib_mode = mode; melange_emit = false }
     in
-    let hidden_includes = to_iflags (include_paths ts_hidden) ~flag:"-H" in
+    let hidden_includes = to_hflags (include_paths ts_hidden) in
     let direct_includes = to_iflags (include_paths ts_direct) in
     Command.Args.S [ direct_includes; hidden_includes ]
   ;;
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index 16a6bd0f223..670a764584d 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -22,7 +22,8 @@ end
 module L : sig
   type nonrec t = Lib.t list
 
-  val to_iflags : ?flag:string -> Path.Set.t -> _ Command.Args.t
+  val to_iflags : Path.Set.t -> _ Command.Args.t
+  val to_hflags : Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
   val include_flags : ?project:Dune_project.t -> t -> t -> Lib_mode.t -> _ Command.Args.t
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t

From d9df9e4909c775d36972e90c1a2512ad4ac980e2 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Fri, 21 Jun 2024 16:46:44 +0200
Subject: [PATCH 08/19] add CHANGES file

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 doc/changes/10644.md | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 doc/changes/10644.md

diff --git a/doc/changes/10644.md b/doc/changes/10644.md
new file mode 100644
index 00000000000..1fd200e73e1
--- /dev/null
+++ b/doc/changes/10644.md
@@ -0,0 +1,6 @@
+- Add support for the -H flag (introduced in Ocaml compiler 5.2) in dune
+  (only supported for lang versions 3.17 and higher). This  adaptation gives
+  the correct semantics for `implicit_transitive_deps = false` mode, since then
+  transitive dependencies are included with -H flag and so are not directly accessible
+  but visible for the compiler. (#10644, fixes (#9333, #ocsigen/tyxml#274, #2733, #4963),
+  @MA0100)
\ No newline at end of file

From 3607a916cc1824090796ce776d09d6afabbfc91c Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Mon, 24 Jun 2024 17:25:05 +0200
Subject: [PATCH 09/19] Suggested edits

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 doc/changes/10644.md                  | 10 ++++------
 src/dune_rules/compilation_context.ml |  4 ++--
 src/dune_rules/lib_flags.mli          |  1 -
 3 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/doc/changes/10644.md b/doc/changes/10644.md
index 1fd200e73e1..893b0ce4969 100644
--- a/doc/changes/10644.md
+++ b/doc/changes/10644.md
@@ -1,6 +1,4 @@
-- Add support for the -H flag (introduced in Ocaml compiler 5.2) in dune
-  (only supported for lang versions 3.17 and higher). This  adaptation gives
-  the correct semantics for `implicit_transitive_deps = false` mode, since then
-  transitive dependencies are included with -H flag and so are not directly accessible
-  but visible for the compiler. (#10644, fixes (#9333, #ocsigen/tyxml#274, #2733, #4963),
-  @MA0100)
\ No newline at end of file
+- Add support for the -H flag (introduced in OCaml compiler 5.2) in dune
+  (only supported for lang versions 3.17 and higher). This adaptation gives
+  the correct semantics for `(implicit_transitive_deps false)`.
+  (#10644, fixes #9333, ocsigen/tyxml#274, #2733, #4963, @MA0100)
\ No newline at end of file
diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index 9ac41c1fddb..ff12da047f6 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -151,7 +151,6 @@ let create
   let open Memo.O in
   let project = Scope.project scope in
   let context = Super_context.context super_context in
-  let sandbox = Sandbox_config.no_special_requirements in
   let* ocaml = Context.ocaml context in
   let direct_requires, hidden_requires =
     if Dune_project.implicit_transitive_deps project
@@ -163,13 +162,14 @@ let create
         let open Resolve.Memo.O in
         let+ requires = requires_compile
         and+ requires_link = Memo.Lazy.force requires_link in
-        let requires_table = Table.create (module Lib) 500 in
+        let requires_table = Table.create (module Lib) 5 in
         let () = List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires in
         List.filter requires_link ~f:(fun l -> not (Table.mem requires_table l))
       in
       requires_compile, requires_hidden)
     else requires_compile, Resolve.Memo.return []
   in
+  let sandbox = Sandbox_config.no_special_requirements in
   let modes =
     let default =
       { Lib_mode.Map.ocaml = Mode.Dict.make_both (Some Mode_conf.Kind.Inherited)
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index 670a764584d..5d8a3e3c4d3 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -23,7 +23,6 @@ module L : sig
   type nonrec t = Lib.t list
 
   val to_iflags : Path.Set.t -> _ Command.Args.t
-  val to_hflags : Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
   val include_flags : ?project:Dune_project.t -> t -> t -> Lib_mode.t -> _ Command.Args.t
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t

From 923a0bcac40398ae36e10aa36eb5cf2f56306517 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Mon, 24 Jun 2024 17:26:16 +0200
Subject: [PATCH 10/19] corrected logic for computing additational_libs;
 ocaml_index.ml

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/merlin/ocaml_index.ml | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/dune_rules/merlin/ocaml_index.ml b/src/dune_rules/merlin/ocaml_index.ml
index 70fde70d78a..fd0227b77bd 100644
--- a/src/dune_rules/merlin/ocaml_index.ml
+++ b/src/dune_rules/merlin/ocaml_index.ml
@@ -24,17 +24,23 @@ let cctx_rules cctx =
     let obj_dir = Compilation_context.obj_dir cctx in
     let fn = index_path_in_obj_dir obj_dir in
     let additional_libs =
-      let open Resolve.Memo.O in
-      let+ non_compile_libs =
-        (* The indexer relies on the load_path of cmt files. When
-           [implicit_transitive_deps] is set to [false] some necessary paths will
-           be missing.These are passed to the indexer with the `-I` flag.
-
-           The implicit transitive libs correspond to the set:
-           (requires_link \ req_compile) *)
-        Compilation_context.requires_hidden cctx
-      in
-      Lib_flags.L.include_flags [] non_compile_libs (Lib_mode.Ocaml Byte)
+      let scope = Compilation_context.scope cctx in
+      let ocaml = Compilation_context.ocaml cctx in
+      if (not (Version.supports_hidden_includes ocaml.version))
+         || Dune_project.dune_version (Scope.project scope) < (3, 17)
+      then
+        let open Resolve.Memo.O in
+        let+ non_compile_libs =
+          (* This is only needed for the case where OCaml < 5.2 or the dune language version
+             < 3.17, since in the latter cases those additional libs will be already included in the compilation
+             with -H flag.*)
+          let* req_link = Compilation_context.requires_link cctx in
+          let+ req_compile = Compilation_context.requires_compile cctx in
+          List.filter req_link ~f:(fun l ->
+            not (List.exists req_compile ~f:(Lib.equal l)))
+        in
+        Lib_flags.L.include_flags non_compile_libs [] (Lib_mode.Ocaml Byte)
+      else Resolve.Memo.return Command.Args.empty
     in
     (* Indexing depends (recursively) on [required_compile] libs:
        - These libs's cmt files should be built before indexing starts

From 8e1757ffba6f5fff3584fbda94a3e4a7f478bf60 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Mon, 24 Jun 2024 17:28:52 +0200
Subject: [PATCH 11/19] ocaml_index: removed ocaml version check

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/merlin/ocaml_index.ml | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/dune_rules/merlin/ocaml_index.ml b/src/dune_rules/merlin/ocaml_index.ml
index fd0227b77bd..cfd52439211 100644
--- a/src/dune_rules/merlin/ocaml_index.ml
+++ b/src/dune_rules/merlin/ocaml_index.ml
@@ -25,9 +25,7 @@ let cctx_rules cctx =
     let fn = index_path_in_obj_dir obj_dir in
     let additional_libs =
       let scope = Compilation_context.scope cctx in
-      let ocaml = Compilation_context.ocaml cctx in
-      if (not (Version.supports_hidden_includes ocaml.version))
-         || Dune_project.dune_version (Scope.project scope) < (3, 17)
+      if Dune_project.dune_version (Scope.project scope) < (3, 17)
       then
         let open Resolve.Memo.O in
         let+ non_compile_libs =

From cdd08f7bd27502893180214ef2fc41ec17399244 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Thu, 27 Jun 2024 11:17:27 +0200
Subject: [PATCH 12/19] style modifications and small corrections

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 doc/changes/10644.md                  |  2 +-
 src/dune_rules/compilation_context.ml | 10 +++++-----
 src/dune_rules/lib_flags.ml           |  6 +++---
 src/dune_rules/lib_flags.mli          |  2 +-
 src/dune_rules/merlin/ocaml_index.ml  |  6 ++----
 5 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/doc/changes/10644.md b/doc/changes/10644.md
index 893b0ce4969..6b131abb95d 100644
--- a/doc/changes/10644.md
+++ b/doc/changes/10644.md
@@ -1,4 +1,4 @@
 - Add support for the -H flag (introduced in OCaml compiler 5.2) in dune
-  (only supported for lang versions 3.17 and higher). This adaptation gives
+  (requires lang versions 3.17). This adaptation gives
   the correct semantics for `(implicit_transitive_deps false)`.
   (#10644, fixes #9333, ocsigen/tyxml#274, #2733, #4963, @MA0100)
\ No newline at end of file
diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index ff12da047f6..93395a2da69 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -7,7 +7,7 @@ module Includes = struct
     (* TODO : some of the requires can filtered out using [ocamldep] info *)
     let open Resolve.Memo.O in
     let iflags direct_libs hidden_libs mode =
-      Lib_flags.L.include_flags ~project direct_libs hidden_libs mode
+      Lib_flags.L.include_flags ~project ~direct_libs ~hidden_libs mode
     in
     let make_includes_args ~mode groups =
       Command.Args.memo
@@ -17,7 +17,7 @@ module Includes = struct
             Command.Args.S
               [ iflags direct_libs hidden_libs mode
               ; Hidden_deps
-                  (Lib_file_deps.deps (List.concat [ direct_libs; hidden_libs ]) ~groups)
+                  (Lib_file_deps.deps (direct_libs @ hidden_libs) ~groups)
               ]))
     in
     let cmi_includes = make_includes_args ~mode:(Ocaml Byte) [ Ocaml Cmi ] in
@@ -32,7 +32,7 @@ module Includes = struct
                   (if opaque
                    then
                      List.map
-                       (List.concat [ direct_libs; hidden_libs ])
+                       (direct_libs @ hidden_libs)
                        ~f:(fun lib ->
                          ( lib
                          , if Lib.is_local lib
@@ -160,10 +160,10 @@ let create
     then (
       let requires_hidden =
         let open Resolve.Memo.O in
-        let+ requires = requires_compile
+        let+ requires_compile = requires_compile
         and+ requires_link = Memo.Lazy.force requires_link in
         let requires_table = Table.create (module Lib) 5 in
-        let () = List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires in
+        let () = List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires_compile in
         List.filter requires_link ~f:(fun l -> not (Table.mem requires_table l))
       in
       requires_compile, requires_hidden)
diff --git a/src/dune_rules/lib_flags.ml b/src/dune_rules/lib_flags.ml
index 87c1569560b..d8e7dabc509 100644
--- a/src/dune_rules/lib_flags.ml
+++ b/src/dune_rules/lib_flags.ml
@@ -158,12 +158,12 @@ module L = struct
       remove_stdlib dirs ts
   ;;
 
-  let include_flags ?project ts_direct ts_hidden mode =
+  let include_flags ?project ~direct_libs ~hidden_libs mode =
     let include_paths ts =
       include_paths ?project ts { lib_mode = mode; melange_emit = false }
     in
-    let hidden_includes = to_hflags (include_paths ts_hidden) in
-    let direct_includes = to_iflags (include_paths ts_direct) in
+    let hidden_includes = to_hflags (include_paths hidden_libs) in
+    let direct_includes = to_iflags (include_paths direct_libs) in
     Command.Args.S [ direct_includes; hidden_includes ]
   ;;
 
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index 5d8a3e3c4d3..5c9460d334b 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -24,7 +24,7 @@ module L : sig
 
   val to_iflags : Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
-  val include_flags : ?project:Dune_project.t -> t -> t -> Lib_mode.t -> _ Command.Args.t
+  val include_flags : ?project:Dune_project.t -> direct_libs:t -> hidden_libs:t -> Lib_mode.t -> _ Command.Args.t
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t
   val c_include_flags : t -> Super_context.t -> _ Command.Args.t
   val toplevel_ld_paths : t -> Path.Set.t
diff --git a/src/dune_rules/merlin/ocaml_index.ml b/src/dune_rules/merlin/ocaml_index.ml
index cfd52439211..873d41dc7a9 100644
--- a/src/dune_rules/merlin/ocaml_index.ml
+++ b/src/dune_rules/merlin/ocaml_index.ml
@@ -25,19 +25,17 @@ let cctx_rules cctx =
     let fn = index_path_in_obj_dir obj_dir in
     let additional_libs =
       let scope = Compilation_context.scope cctx in
+      (* Dune language >= 3.17 correctly passes the `-H` flag to the compiler. *)
       if Dune_project.dune_version (Scope.project scope) < (3, 17)
       then
         let open Resolve.Memo.O in
         let+ non_compile_libs =
-          (* This is only needed for the case where OCaml < 5.2 or the dune language version
-             < 3.17, since in the latter cases those additional libs will be already included in the compilation
-             with -H flag.*)
           let* req_link = Compilation_context.requires_link cctx in
           let+ req_compile = Compilation_context.requires_compile cctx in
           List.filter req_link ~f:(fun l ->
             not (List.exists req_compile ~f:(Lib.equal l)))
         in
-        Lib_flags.L.include_flags non_compile_libs [] (Lib_mode.Ocaml Byte)
+        Lib_flags.L.include_flags ~direct_libs:non_compile_libs ~hidden_libs:[] (Lib_mode.Ocaml Byte)
       else Resolve.Memo.return Command.Args.empty
     in
     (* Indexing depends (recursively) on [required_compile] libs:

From c8f4f7f4cd197ab718fddb2c1c2030d3e31c96f1 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Thu, 27 Jun 2024 11:22:12 +0200
Subject: [PATCH 13/19] separated tests and guarded them by ocaml version

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 test/blackbox-tests/test-cases/dune           | 10 ++++++++
 .../test-cases/hidden-deps-supported.t/bar.ml |  2 ++
 .../dune                                      |  0
 .../foo.ml                                    |  3 +--
 .../run.ml                                    |  0
 .../run.t                                     | 23 +++++++++++------
 .../hidden-deps-supported.t/runf.ml           |  1 +
 .../tyxml/dune                                |  0
 .../tyxml/dune-project                        |  0
 .../tyxml/run.ml                              |  0
 .../hidden-deps-unsupported.t/bar.ml          |  2 ++
 .../test-cases/hidden-deps-unsupported.t/dune | 13 ++++++++++
 .../hidden-deps-unsupported.t/foo.ml          |  2 ++
 .../hidden-deps-unsupported.t/run.ml          |  2 ++
 .../hidden-deps-unsupported.t/run.t           | 25 +++++++++++++++++++
 .../test-cases/hidden-deps.t/bar.ml           |  3 ---
 .../test-cases/hidden-deps.t/runf.ml          |  1 -
 .../test-cases/hidden-deps.t/tyxml/run.t      |  5 ----
 18 files changed, 74 insertions(+), 18 deletions(-)
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-supported.t/bar.ml
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/dune (100%)
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/foo.ml (50%)
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/run.ml (100%)
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/run.t (57%)
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-supported.t/runf.ml
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/tyxml/dune (100%)
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/tyxml/dune-project (100%)
 rename test/blackbox-tests/test-cases/{hidden-deps.t => hidden-deps-supported.t}/tyxml/run.ml (100%)
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-unsupported.t/bar.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-unsupported.t/foo.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.ml
 create mode 100644 test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
 delete mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/bar.ml
 delete mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/runf.ml
 delete mode 100644 test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t

diff --git a/test/blackbox-tests/test-cases/dune b/test/blackbox-tests/test-cases/dune
index 5eb82ae6938..0934807c370 100644
--- a/test/blackbox-tests/test-cases/dune
+++ b/test/blackbox-tests/test-cases/dune
@@ -164,3 +164,13 @@
 (cram
  (applies_to sandboxing-stale-directory-target)
  (deps %{bin:bash}))
+
+(cram
+ (applies_to hidden-deps-supported)
+ (enabled_if
+  (>= %{ocaml_version} 5.2.0)))
+
+(cram
+ (applies_to hidden-deps-unsupported)
+ (enabled_if
+  (< %{ocaml_version} 5.2.0)))
diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/bar.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/bar.ml
new file mode 100644
index 00000000000..98146d7098e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/bar.ml
@@ -0,0 +1,2 @@
+let x = 5
+let y = Foo.v
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/dune b/test/blackbox-tests/test-cases/hidden-deps-supported.t/dune
similarity index 100%
rename from test/blackbox-tests/test-cases/hidden-deps.t/dune
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/dune
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/foo.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/foo.ml
similarity index 50%
rename from test/blackbox-tests/test-cases/hidden-deps.t/foo.ml
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/foo.ml
index 233654b2d90..dfa3cba9d50 100644
--- a/test/blackbox-tests/test-cases/hidden-deps.t/foo.ml
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/foo.ml
@@ -1,3 +1,2 @@
 let v = 9
-
-let w = 4
\ No newline at end of file
+let w = 4
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/run.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml
similarity index 100%
rename from test/blackbox-tests/test-cases/hidden-deps.t/run.ml
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
similarity index 57%
rename from test/blackbox-tests/test-cases/hidden-deps.t/run.t
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
index f058673ff79..c4eae7ce6cb 100644
--- a/test/blackbox-tests/test-cases/hidden-deps.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
@@ -1,26 +1,26 @@
-Should include Foo with -H:
+This test is guarded by ocaml version >= 5.2, so it should include foo with -H when
+implicit_transitive_deps is set to false.
 
   $ getincludes () {
   > dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*" | sed s/\-$1//g | tr -d '[:space:]'
   > }
 
-  $ supports_H=$(if ocamlc -H x --help >/dev/null 2>&1; then echo true; else echo false; fi)
-  $ fooincludes='.foo.objs/byte.foo.objs/byte.foo.objs/native'
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps true)
   > EOF
+  $ echo "$(getincludes I)"
+  .foo.objs/byte.foo.objs/byte.foo.objs/native
 
-  $ if $supports_H; then [ "$(getincludes I)" = $fooincludes ]; fi
-  $ if ! $supports_H; then [ "$(getincludes I)" = $fooincludes ]; fi
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
   > EOF
 
-  $ if $supports_H; then [ "$(getincludes H)" = $fooincludes ]; fi
-  $ if ! $supports_H; then [ "$(getincludes I)" = '' ]; fi
+  $ echo "$(getincludes H)"
+  .foo.objs/byte.foo.objs/byte.foo.objs/native
+
 
 
 Test transitive deps can not be directly accessed, both for compiler versions supporting -H or not:
@@ -34,3 +34,12 @@ Test transitive deps can not be directly accessed, both for compiler versions su
   1 | let a = Bar.y + Foo.v
                       ^^^^^
   Error: Unbound module Foo
+
+Test if the issue #274 is solved: the tyxml.functor is included with -H flag in
+ITD = false case, and thus no type abstraction happens when it is used.
+
+  $ dune build --root=./tyxml
+  Entering directory 'tyxml'
+  Leaving directory 'tyxml'
+
+
diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/runf.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/runf.ml
new file mode 100644
index 00000000000..0d3f1db0e17
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/runf.ml
@@ -0,0 +1 @@
+let a = Bar.y + Foo.v
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune
similarity index 100%
rename from test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune-project b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune-project
similarity index 100%
rename from test/blackbox-tests/test-cases/hidden-deps.t/tyxml/dune-project
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune-project
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/run.ml
similarity index 100%
rename from test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.ml
rename to test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/run.ml
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/bar.ml b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/bar.ml
new file mode 100644
index 00000000000..98146d7098e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/bar.ml
@@ -0,0 +1,2 @@
+let x = 5
+let y = Foo.v
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune
new file mode 100644
index 00000000000..ddbc42cc062
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune
@@ -0,0 +1,13 @@
+(library
+ (name foo)
+ (modules foo))
+
+(library
+ (name bar)
+ (modules bar)
+ (libraries foo))
+
+(executable
+ (name run)
+ (modules run)
+ (libraries bar))
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/foo.ml b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/foo.ml
new file mode 100644
index 00000000000..dfa3cba9d50
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/foo.ml
@@ -0,0 +1,2 @@
+let v = 9
+let w = 4
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.ml b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.ml
new file mode 100644
index 00000000000..436b88a6649
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.ml
@@ -0,0 +1,2 @@
+let _ = Bar.y
+let _ = print_endline "yes"
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
new file mode 100644
index 00000000000..f3e5b97075e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
@@ -0,0 +1,25 @@
+This test is guarded by ocaml version <= 5.1, so it should not include foo
+when implicit_transitive_deps is set to false, i.e. testing backward compatibility of
+the new -H feature added.
+
+  $ getincludes () {
+  > dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*" | sed s/\-$1//g | tr -d '[:space:]'
+  > }
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.17)
+  > (implicit_transitive_deps true)
+  > EOF
+  $ echo "$(getincludes I)"
+  .foo.objs/byte.foo.objs/byte.foo.objs/native
+
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.17)
+  > (implicit_transitive_deps false)
+  > EOF
+
+  $ echo "$(getincludes I)"
+  
+
+
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/bar.ml b/test/blackbox-tests/test-cases/hidden-deps.t/bar.ml
deleted file mode 100644
index e1ca0d9c772..00000000000
--- a/test/blackbox-tests/test-cases/hidden-deps.t/bar.ml
+++ /dev/null
@@ -1,3 +0,0 @@
-let x = 5
-
-let y = Foo.v
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/runf.ml b/test/blackbox-tests/test-cases/hidden-deps.t/runf.ml
deleted file mode 100644
index 3e7e6b04ba1..00000000000
--- a/test/blackbox-tests/test-cases/hidden-deps.t/runf.ml
+++ /dev/null
@@ -1 +0,0 @@
-let a = Bar.y + Foo.v
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t b/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t
deleted file mode 100644
index 35c0613b159..00000000000
--- a/test/blackbox-tests/test-cases/hidden-deps.t/tyxml/run.t
+++ /dev/null
@@ -1,5 +0,0 @@
-Test if the issue #274 is solved: the tyxml.functor is included with -H flag in
-ITD = false case, and thus no type abstraction happens when it is used.
-
-  $ ocamlc -H x --help > /dev/null
-  $ if [ $? = 0 ]; then dune build fi

From 6ef7f54e311e3e1b59425cf9975840b990e816c2 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Thu, 27 Jun 2024 11:22:51 +0200
Subject: [PATCH 14/19] formatting

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml | 19 +++++++++----------
 src/dune_rules/lib_flags.mli          |  9 ++++++++-
 src/dune_rules/merlin/ocaml_index.ml  |  5 ++++-
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index 93395a2da69..49113f91c3f 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -16,8 +16,7 @@ module Includes = struct
             and+ hidden_libs = hidden_requires in
             Command.Args.S
               [ iflags direct_libs hidden_libs mode
-              ; Hidden_deps
-                  (Lib_file_deps.deps (direct_libs @ hidden_libs) ~groups)
+              ; Hidden_deps (Lib_file_deps.deps (direct_libs @ hidden_libs) ~groups)
               ]))
     in
     let cmi_includes = make_includes_args ~mode:(Ocaml Byte) [ Ocaml Cmi ] in
@@ -31,13 +30,11 @@ module Includes = struct
               ; Hidden_deps
                   (if opaque
                    then
-                     List.map
-                       (direct_libs @ hidden_libs)
-                       ~f:(fun lib ->
-                         ( lib
-                         , if Lib.is_local lib
-                           then [ Lib_file_deps.Group.Ocaml Cmi ]
-                           else [ Ocaml Cmi; Ocaml Cmx ] ))
+                     List.map (direct_libs @ hidden_libs) ~f:(fun lib ->
+                       ( lib
+                       , if Lib.is_local lib
+                         then [ Lib_file_deps.Group.Ocaml Cmi ]
+                         else [ Ocaml Cmi; Ocaml Cmx ] ))
                      |> Lib_file_deps.deps_with_exts
                    else
                      Lib_file_deps.deps
@@ -163,7 +160,9 @@ let create
         let+ requires_compile = requires_compile
         and+ requires_link = Memo.Lazy.force requires_link in
         let requires_table = Table.create (module Lib) 5 in
-        let () = List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires_compile in
+        let () =
+          List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires_compile
+        in
         List.filter requires_link ~f:(fun l -> not (Table.mem requires_table l))
       in
       requires_compile, requires_hidden)
diff --git a/src/dune_rules/lib_flags.mli b/src/dune_rules/lib_flags.mli
index 5c9460d334b..8a65f55a084 100644
--- a/src/dune_rules/lib_flags.mli
+++ b/src/dune_rules/lib_flags.mli
@@ -24,7 +24,14 @@ module L : sig
 
   val to_iflags : Path.Set.t -> _ Command.Args.t
   val include_paths : ?project:Dune_project.t -> t -> Lib_mode.t -> Path.Set.t
-  val include_flags : ?project:Dune_project.t -> direct_libs:t -> hidden_libs:t -> Lib_mode.t -> _ Command.Args.t
+
+  val include_flags
+    :  ?project:Dune_project.t
+    -> direct_libs:t
+    -> hidden_libs:t
+    -> Lib_mode.t
+    -> _ Command.Args.t
+
   val melange_emission_include_flags : ?project:Dune_project.t -> t -> _ Command.Args.t
   val c_include_flags : t -> Super_context.t -> _ Command.Args.t
   val toplevel_ld_paths : t -> Path.Set.t
diff --git a/src/dune_rules/merlin/ocaml_index.ml b/src/dune_rules/merlin/ocaml_index.ml
index 873d41dc7a9..7941191f70e 100644
--- a/src/dune_rules/merlin/ocaml_index.ml
+++ b/src/dune_rules/merlin/ocaml_index.ml
@@ -35,7 +35,10 @@ let cctx_rules cctx =
           List.filter req_link ~f:(fun l ->
             not (List.exists req_compile ~f:(Lib.equal l)))
         in
-        Lib_flags.L.include_flags ~direct_libs:non_compile_libs ~hidden_libs:[] (Lib_mode.Ocaml Byte)
+        Lib_flags.L.include_flags
+          ~direct_libs:non_compile_libs
+          ~hidden_libs:[]
+          (Lib_mode.Ocaml Byte)
       else Resolve.Memo.return Command.Args.empty
     in
     (* Indexing depends (recursively) on [required_compile] libs:

From 51d6e2fdf26d7bbcc441d95e65097b9c71377337 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Thu, 27 Jun 2024 15:06:24 +0200
Subject: [PATCH 15/19] cosmetic tweaks

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml                         | 4 +---
 test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml | 2 +-
 test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t  | 4 ----
 .../test-cases/hidden-deps-supported.t/tyxml/dune             | 3 ++-
 .../test-cases/hidden-deps-supported.t/tyxml/run.ml           | 2 +-
 test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune | 3 ++-
 .../blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t | 3 ---
 7 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index 49113f91c3f..ee4cb510600 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -160,9 +160,7 @@ let create
         let+ requires_compile = requires_compile
         and+ requires_link = Memo.Lazy.force requires_link in
         let requires_table = Table.create (module Lib) 5 in
-        let () =
-          List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires_compile
-        in
+        List.iter ~f:(fun lib -> Table.set requires_table lib ()) requires_compile;
         List.filter requires_link ~f:(fun l -> not (Table.mem requires_table l))
       in
       requires_compile, requires_hidden)
diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml
index 4be93f9760e..a956be2d6c3 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.ml
@@ -1 +1 @@
-let _ = Bar.y
\ No newline at end of file
+let _ = Bar.y
diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
index c4eae7ce6cb..3c6f0e6a5b0 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
@@ -12,7 +12,6 @@ implicit_transitive_deps is set to false.
   $ echo "$(getincludes I)"
   .foo.objs/byte.foo.objs/byte.foo.objs/native
 
-
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
@@ -22,7 +21,6 @@ implicit_transitive_deps is set to false.
   .foo.objs/byte.foo.objs/byte.foo.objs/native
 
 
-
 Test transitive deps can not be directly accessed, both for compiler versions supporting -H or not:
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
@@ -41,5 +39,3 @@ ITD = false case, and thus no type abstraction happens when it is used.
   $ dune build --root=./tyxml
   Entering directory 'tyxml'
   Leaving directory 'tyxml'
-
-
diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune
index fd768950796..14cd546b25b 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/dune
@@ -1,3 +1,4 @@
 (executable
   (name run)
-  (libraries tyxml))
\ No newline at end of file
+  (libraries tyxml))
+  
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/run.ml b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/run.ml
index 68818fbad58..66f0f01edf5 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/run.ml
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/tyxml/run.ml
@@ -1,2 +1,2 @@
 open Tyxml.Html
-let _ = p [ a [ txt "a" ] ]
\ No newline at end of file
+let _ = p [ a [ txt "a" ] ]
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune
index ddbc42cc062..c5481663927 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/dune
@@ -10,4 +10,5 @@
 (executable
  (name run)
  (modules run)
- (libraries bar))
\ No newline at end of file
+ (libraries bar))
+ 
\ No newline at end of file
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
index f3e5b97075e..958af1e7aaf 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
@@ -13,7 +13,6 @@ the new -H feature added.
   $ echo "$(getincludes I)"
   .foo.objs/byte.foo.objs/byte.foo.objs/native
 
-
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
@@ -21,5 +20,3 @@ the new -H feature added.
 
   $ echo "$(getincludes I)"
   
-
-

From 83bb651f7dab87fcf04103778edf092044955627 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=A1s=20Ojeda=20B=C3=A4r?= <n.oje.bar@gmail.com>
Date: Thu, 27 Jun 2024 15:03:04 +0200
Subject: [PATCH 16/19] Cleanup
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Nicolás Ojeda Bär <n.oje.bar@gmail.com>
---
 .../test-cases/hidden-deps-supported.t/run.t    | 17 +++++++++++------
 .../test-cases/hidden-deps-unsupported.t/run.t  | 13 ++++++++-----
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
index 3c6f0e6a5b0..fbcf2f5848d 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
@@ -2,26 +2,31 @@ This test is guarded by ocaml version >= 5.2, so it should include foo with -H w
 implicit_transitive_deps is set to false.
 
   $ getincludes () {
-  > dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*" | sed s/\-$1//g | tr -d '[:space:]'
+  >   dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*"
   > }
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps true)
   > EOF
-  $ echo "$(getincludes I)"
-  .foo.objs/byte.foo.objs/byte.foo.objs/native
+
+  $ getincludes I
+  -I .foo.objs/byte
+  -I .foo.objs/byte
+  -I .foo.objs/native
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
   > EOF
 
-  $ echo "$(getincludes H)"
-  .foo.objs/byte.foo.objs/byte.foo.objs/native
-
+  $ getincludes H
+  -H .foo.objs/byte
+  -H .foo.objs/byte
+  -H .foo.objs/native
 
 Test transitive deps can not be directly accessed, both for compiler versions supporting -H or not:
+
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
index 958af1e7aaf..d13228b4a3d 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
@@ -3,20 +3,23 @@ when implicit_transitive_deps is set to false, i.e. testing backward compatibili
 the new -H feature added.
 
   $ getincludes () {
-  > dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*" | sed s/\-$1//g | tr -d '[:space:]'
+  >   dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*"
   > }
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps true)
   > EOF
-  $ echo "$(getincludes I)"
-  .foo.objs/byte.foo.objs/byte.foo.objs/native
+
+  $ getincludes I
+  -I .foo.objs/byte
+  -I .foo.objs/byte
+  -I .foo.objs/native
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
   > EOF
 
-  $ echo "$(getincludes I)"
-  
+  $ getincludes I
+  [1]

From 2812ddb00c7e899aece29afbbd35f7fd8a2932a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=A1s=20Ojeda=20B=C3=A4r?= <n.oje.bar@gmail.com>
Date: Thu, 27 Jun 2024 15:20:33 +0200
Subject: [PATCH 17/19] Cleanup
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Nicolás Ojeda Bär <n.oje.bar@gmail.com>
---
 .../test-cases/hidden-deps-supported.t/run.t  | 21 ++++++++++++++-----
 .../hidden-deps-unsupported.t/run.t           | 19 +++++++++++++----
 2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
index fbcf2f5848d..37c46fa06c4 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-supported.t/run.t
@@ -2,7 +2,7 @@ This test is guarded by ocaml version >= 5.2, so it should include foo with -H w
 implicit_transitive_deps is set to false.
 
   $ getincludes () {
-  >   dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*"
+  >   dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -Eo '\-[IH] [a-z/.]+' | sort
   > }
 
   $ cat >dune-project <<EOF
@@ -10,20 +10,32 @@ implicit_transitive_deps is set to false.
   > (implicit_transitive_deps true)
   > EOF
 
-  $ getincludes I
+  $ getincludes
+  -I .bar.objs/byte
+  -I .bar.objs/byte
+  -I .bar.objs/native
   -I .foo.objs/byte
   -I .foo.objs/byte
   -I .foo.objs/native
+  -I .run.eobjs/byte
+  -I .run.eobjs/byte
+  -I .run.eobjs/native
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
   > EOF
 
-  $ getincludes H
+  $ getincludes
   -H .foo.objs/byte
   -H .foo.objs/byte
   -H .foo.objs/native
+  -I .bar.objs/byte
+  -I .bar.objs/byte
+  -I .bar.objs/native
+  -I .run.eobjs/byte
+  -I .run.eobjs/byte
+  -I .run.eobjs/native
 
 Test transitive deps can not be directly accessed, both for compiler versions supporting -H or not:
 
@@ -38,8 +50,7 @@ Test transitive deps can not be directly accessed, both for compiler versions su
                       ^^^^^
   Error: Unbound module Foo
 
-Test if the issue #274 is solved: the tyxml.functor is included with -H flag in
-ITD = false case, and thus no type abstraction happens when it is used.
+Test if #274 is fixed:
 
   $ dune build --root=./tyxml
   Entering directory 'tyxml'
diff --git a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
index d13228b4a3d..c51b4249eae 100644
--- a/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
+++ b/test/blackbox-tests/test-cases/hidden-deps-unsupported.t/run.t
@@ -3,7 +3,7 @@ when implicit_transitive_deps is set to false, i.e. testing backward compatibili
 the new -H feature added.
 
   $ getincludes () {
-  >   dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -E -o "\-$1\s(.foo)\S*"
+  >   dune build --verbose ./run.exe 2>&1 | grep run.ml | grep -Eo '\-[IH] [a-z/.]+' | sort
   > }
 
   $ cat >dune-project <<EOF
@@ -11,15 +11,26 @@ the new -H feature added.
   > (implicit_transitive_deps true)
   > EOF
 
-  $ getincludes I
+  $ getincludes
+  -I .bar.objs/byte
+  -I .bar.objs/byte
+  -I .bar.objs/native
   -I .foo.objs/byte
   -I .foo.objs/byte
   -I .foo.objs/native
+  -I .run.eobjs/byte
+  -I .run.eobjs/byte
+  -I .run.eobjs/native
 
   $ cat >dune-project <<EOF
   > (lang dune 3.17)
   > (implicit_transitive_deps false)
   > EOF
 
-  $ getincludes I
-  [1]
+  $ getincludes
+  -I .bar.objs/byte
+  -I .bar.objs/byte
+  -I .bar.objs/native
+  -I .run.eobjs/byte
+  -I .run.eobjs/byte
+  -I .run.eobjs/native

From c11722d0dc94d9b5eead0024a736de47436b6497 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Thu, 27 Jun 2024 15:49:56 +0200
Subject: [PATCH 18/19] tweaks

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index ee4cb510600..a4d69c0b654 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -38,7 +38,7 @@ module Includes = struct
                      |> Lib_file_deps.deps_with_exts
                    else
                      Lib_file_deps.deps
-                       (List.concat [ direct_libs; hidden_libs ])
+                     (direct_libs @ hidden_libs)
                        ~groups:[ Lib_file_deps.Group.Ocaml Cmi; Ocaml Cmx ])
               ]))
     in

From f1882cc5c4f3b5e09bb95673149a51ba7fea8b75 Mon Sep 17 00:00:00 2001
From: HasanA <mhmd_alameen1023@outlook.com>
Date: Thu, 27 Jun 2024 16:01:15 +0200
Subject: [PATCH 19/19] final formatting

Signed-off-by: HasanA <mhmd_alameen1023@outlook.com>
---
 src/dune_rules/compilation_context.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/dune_rules/compilation_context.ml b/src/dune_rules/compilation_context.ml
index a4d69c0b654..8bb1be96cd0 100644
--- a/src/dune_rules/compilation_context.ml
+++ b/src/dune_rules/compilation_context.ml
@@ -38,7 +38,7 @@ module Includes = struct
                      |> Lib_file_deps.deps_with_exts
                    else
                      Lib_file_deps.deps
-                     (direct_libs @ hidden_libs)
+                       (direct_libs @ hidden_libs)
                        ~groups:[ Lib_file_deps.Group.Ocaml Cmi; Ocaml Cmx ])
               ]))
     in