OCaml 5.3 support (#2800)

.github/workflows/nix-build.yml

@@ -21,6 +21,7 @@ jobs:
           - 5_0
           - 5_1
           - 5_2
+          - 5_3
 
     runs-on: ubuntu-latest
     steps:
@@ -44,6 +45,7 @@ jobs:
           - {ocaml-version: '5_2', os: macos-13}
           - {ocaml-version: '4_14', os: macos-14}
           - {ocaml-version: '5_2', os: macos-14}
+          - {ocaml-version: '5_3', os: macos-14}
     runs-on: ${{ matrix.setup.os }}
     steps:
     - uses: actions/checkout@v4

.github/workflows/opam-ci.yml

@@ -21,10 +21,12 @@ jobs:
           - {ocaml-compiler: '4.10.x', os: ubuntu-latest}
           - {ocaml-compiler: '4.12.x', os: ubuntu-latest}
           - {ocaml-compiler: '4.14.x', os: ubuntu-latest}
+          - {ocaml-compiler: 'ocaml-base-compiler.5.3.0~alpha1', os: ubuntu-latest}
           - {ocaml-compiler: '4.06.x', os: macos-13}
           - {ocaml-compiler: '4.10.x', os: macos-13}
           - {ocaml-compiler: '4.12.x', os: macos-13}
           - {ocaml-compiler: '4.14.x', os: macos-13}
+          - {ocaml-compiler: 'ocaml-base-compiler.5.3.0~alpha1', os: macos-13}
             # looks like setup-ocaml@v3 can only run actions on windows for
             # OCaml >= 4.13
             # https://github.com/ocaml/setup-ocaml/issues/822#issuecomment-2215525942
@@ -58,6 +60,10 @@ jobs:
           path: _opam
           key: opam-${{ matrix.setup.os }}-${{ matrix.setup.ocaml-compiler }}-${{ hashFiles('**.opam') }}
 
+      - name: Pin utop for OCaml 5.3
+        if: ${{ matrix.setup.ocaml-compiler == 'ocaml-base-compiler.5.3.0~alpha1' }}
+        run: opam pin add utop --dev-repo
+
       - name: Install dependencies
         run: opam install . --deps-only
 

dune-project

@@ -34,14 +34,14 @@
   (ocaml
    (and
     (>= "4.06")
-    (< "5.3")))
+    (< "5.4")))
   (ocamlfind :build)
   (dune-build-info
    (>= 2.9.3))
   (menhir
    (>= "20180523"))
   (merlin-extend
-   (>= "0.6"))
+   (>= "0.6.2"))
   fix
   ppx_derivers
   cppo
@@ -57,7 +57,7 @@
   (ocaml
    (and
     (>= "4.06")
-    (< "5.3")))
+    (< "5.4")))
   (reason
    (= :version))
   (utop

flake.nix

@@ -12,7 +12,7 @@
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = nixpkgs.legacyPackages."${system}".extend (self: super: {
-          ocamlPackages = super.ocaml-ng.ocamlPackages_5_2;
+          ocamlPackages = super.ocaml-ng.ocamlPackages_5_3;
         });
         packages = pkgs.callPackage ./nix { nix-filter = nix-filter.lib; };
       in

nix/shell.nix

@@ -11,7 +11,12 @@
 
 mkShell {
   inputsFrom = [ reason ];
-  nativeBuildInputs = with ocamlPackages; [ utop merlin odoc ocamlformat ];
+  nativeBuildInputs = with ocamlPackages; [
+    utop
+    merlin
+    odoc
+    ocamlformat
+  ];
   buildInputs =
     with ocamlPackages; (if release-mode then [ cacert curl dune-release git ] else [ ]);
 }

reason.opam

@@ -16,11 +16,11 @@ homepage: "https://reasonml.github.io/"
 bug-reports: "https://github.com/reasonml/reason/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.06" & < "5.3"}
+  "ocaml" {>= "4.06" & < "5.4"}
   "ocamlfind" {build}
   "dune-build-info" {>= "2.9.3"}
   "menhir" {>= "20180523"}
-  "merlin-extend" {>= "0.6"}
+  "merlin-extend" {>= "0.6.2"}
   "fix"
   "ppx_derivers"
   "cppo"

rtop.opam

@@ -14,7 +14,7 @@ homepage: "https://reasonml.github.io/"
 bug-reports: "https://github.com/reasonml/reason/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.06" & < "5.3"}
+  "ocaml" {>= "4.06" & < "5.4"}
   "reason" {= version}
   "utop" {>= "2.0"}
   "cppo"

rtop/dune

@@ -17,6 +17,12 @@
  (action
   (run cppo -V OCAML:%{ocaml_version} %{deps} -o %{targets})))
 
+(rule
+ (targets reason_utop.ml)
+ (deps reason_utop.cppo.ml)
+ (action
+  (run cppo -V OCAML:%{ocaml_version} %{deps} -o %{targets})))
+
 (executable
  (name rtop)
  (public_name rtop)

rtop/reason_toploop.cppo.ml

@@ -31,6 +31,9 @@ let main () =
      List.exists ((=) "camlp4r") !Topfind.predicates then
     print_endline "Reason is incompatible with camlp4!"
   else begin
+#if OCAML_VERSION >= (5,3,0)
+    if not (Toploop.prepare Format.err_formatter ()) then raise (Compenv.Exit_with_status 2);
+#endif
     Toploop.parse_toplevel_phrase := (fun t ->
       if !Reason_utop.current_top = UTop then
         default_parse_toplevel_phrase t

rtop/reason_utop.ml → rtop/reason_utop.cppo.ml

@@ -64,19 +64,31 @@ let init_reason () =
 
     (* Printing in Reason syntax *)
     let open Reason_toolchain.From_current in
-    let wrap f g fmt x = g fmt (f x) in
+    let wrap f g fmt x =
+      g fmt (f x)
+    in
+#if OCAML_VERSION >= (5,3,0)
+    let wrap_doc f g fmt x =
+      let doc_f =
+        Format_doc.deprecated_printer (fun fmt -> Format.fprintf fmt "%a" g (f x))
+      in
+      doc_f fmt
+#else
+    let wrap_doc = wrap
+#endif
+    in
     Toploop.print_out_value := wrap copy_out_value Reason_oprint.print_out_value;
-    Toploop.print_out_type := wrap copy_out_type Reason_oprint.print_out_type;
+    Toploop.print_out_type := wrap_doc copy_out_type Reason_oprint.print_out_type;
     Toploop.print_out_class_type :=
-      wrap copy_out_class_type Reason_oprint.print_out_class_type;
+      wrap_doc copy_out_class_type Reason_oprint.print_out_class_type;
     Toploop.print_out_module_type :=
-      wrap copy_out_module_type Reason_oprint.print_out_module_type;
+      wrap_doc copy_out_module_type Reason_oprint.print_out_module_type;
     Toploop.print_out_type_extension :=
-      wrap copy_out_type_extension Reason_oprint.print_out_type_extension;
+      wrap_doc copy_out_type_extension Reason_oprint.print_out_type_extension;
     Toploop.print_out_sig_item :=
-      wrap copy_out_sig_item Reason_oprint.print_out_sig_item;
+      wrap_doc copy_out_sig_item Reason_oprint.print_out_sig_item;
     Toploop.print_out_signature :=
-      wrap (List.map copy_out_sig_item) Reason_oprint.print_out_signature;
+      wrap_doc (List.map copy_out_sig_item) Reason_oprint.print_out_signature;
     Toploop.print_out_phrase :=
       wrap copy_out_phrase Reason_oprint.print_out_phrase;
     let current_show_fn =
@@ -122,7 +134,7 @@ let init_ocaml () =
 let toggle_syntax () =
   match !current_top with RTop -> init_ocaml () | UTop -> init_reason ()
 
-let _ =
+let () =
   Hashtbl.add
     (Toploop.directive_table [@ocaml.warning "-3"])
     "toggle_syntax"

src/reason-parser/ocaml_util.cppo.ml

@@ -12,7 +12,17 @@ let print_loc ppf loc =
 
 
 let print_error loc f ppf x =
-#if OCAML_VERSION >= (4,8,0)
+#if OCAML_VERSION >= (5,3,0)
+  let error =
+    let f (fmt: Format_doc.formatter) err =
+      let doc_f =
+        Format_doc.deprecated_printer (fun fmt -> Format.fprintf fmt "%a" f err)
+      in
+      doc_f fmt
+    in
+    Location.error_of_printer ~loc f x in
+  Location.print_report ppf error
+#elif OCAML_VERSION >= (4,8,0)
   let error = Location.error_of_printer ~loc f x in
   Location.print_report ppf error
 #else