Source maps: use ignoreList to hide runtime files

The generated code is also hidden by using a dummy file.

compiler/bin-js_of_ocaml/cmd_arg.ml

@@ -308,13 +308,10 @@ let options =
  in
  Some
  ( sm_output_file
- , { Source_map.Standard.version = 3
- ; file
+ , { Source_map.Standard.empty with
+   file
  ; sourceroot = sourcemap_root
- ; sources = []
  ; sources_content = (if sourcemap_don't_inline_content then None else Some [])
- ; names = []
- ; mappings = Source_map.Mappings.empty
  } )
  else None
  in
@@ -537,13 +534,10 @@ let options_runtime_only =
  in
  Some
  ( sm_output_file
- , { Source_map.Standard.version = 3
- ; file
+ , { Source_map.Standard.empty with
+   file
  ; sourceroot = sourcemap_root
- ; sources = []
  ; sources_content = (if sourcemap_don't_inline_content then None else Some [])
- ; names = []
- ; mappings = Source_map.Mappings.empty
  } )
  else None
  in

compiler/bin-js_of_ocaml/link.ml

@@ -102,13 +102,10 @@ let options =
  in
  Some
  ( sm_output_file
- , { Source_map.Standard.version = 3
- ; file
+ , { Source_map.Standard.empty with
+   file
  ; sourceroot = sourcemap_root
- ; sources = []
  ; sources_content = Some []
- ; names = []
- ; mappings = Source_map.Mappings.empty
  } )
  else None
  in

compiler/lib/js_output.ml

@@ -125,6 +125,8 @@ module Make (D : sig
 
  val get_name_index : string -> int
 
+ val hidden_location : Source_map.map
+
  val source_map_enabled : bool
 
  val accept_unnamed_var : bool
@@ -159,7 +161,7 @@ struct
  then
  match loc with
  | N | U | Pi { Parse_info.src = None | Some ""; _ } ->
- push_mapping (PP.pos f) (Source_map.Gen { gen_line = -1; gen_col = -1 })
+ push_mapping (PP.pos f) hidden_location
  | Pi { Parse_info.src = Some file; line; col; _ } ->
  push_mapping
  (PP.pos f)
@@ -201,10 +203,15 @@ struct
  (match loc with
  | None | Some { Parse_info.src = Some "" | None; _ } ->
  (* Use a dummy location. It is going to be ignored anyway *)
+ let ori_source =
+ match hidden_location with
+ | Source_map.Gen_Ori { ori_source; _ } -> ori_source
+ | _ -> 0
+ in
  Source_map.Gen_Ori_Name
  { gen_line = -1
  ; gen_col = -1
- ; ori_source = 0
+ ; ori_source
  ; ori_line = 1
  ; ori_col = 0
  ; ori_name = get_name_index nm
@@ -2040,6 +2047,7 @@ let program ?(accept_unnamed_var = false) f ?source_map p =
  | None | Some { Source_map.Standard.sources_content = None; _ } -> None
  | Some { Source_map.Standard.sources_content = Some _; _ } -> Some (ref [])
  in
+ let blackbox_file = "/builtin/blackbox.ml" in
  let push_mapping, get_file_index, get_name_index, source_map_enabled =
  let source_map_enabled =
  match source_map with
@@ -2066,7 +2074,9 @@ let program ?(accept_unnamed_var = false) f ?source_map p =
  match Builtins.find file with
  | Some f -> Some (Builtins.File.content f)
  | None ->
- if Sys.file_exists file && not (Sys.is_directory file)
+ if String.equal file blackbox_file
+ then Some "(* generated code *)"
+ else if Sys.file_exists file && not (Sys.is_directory file)
  then
  let content = Fs.read_file file in
  Some content
@@ -2094,13 +2104,24 @@ let program ?(accept_unnamed_var = false) f ?source_map p =
  pos)
  , source_map_enabled )
  in
+ let hidden_location =
+ Source_map.Gen_Ori
+ { gen_line = -1
+ ; gen_col = -1
+ ; ori_source = get_file_index blackbox_file
+ ; ori_line = 1
+ ; ori_col = 0
+ }
+ in
  let module O = Make (struct
  let push_mapping = push_mapping
 
  let get_name_index = get_name_index
 
  let get_file_index = get_file_index
 
+ let hidden_location = hidden_location
+
  let source_map_enabled = source_map_enabled
 
  let accept_unnamed_var = accept_unnamed_var
@@ -2128,6 +2149,10 @@ let program ?(accept_unnamed_var = false) f ?source_map p =
  | None -> filename
  | Some _ -> Filename.concat "/builtin" filename)
  in
+ let ignore_list =
+ List.filter sources ~f:(fun filename ->
+ String.length filename >= 9 && String.sub filename 0 9 = "/builtin/")
+ in
  let sm_mappings = Source_map.Mappings.decode sm.mappings in
  let mappings =
  List.rev_append_map !temp_mappings sm_mappings ~f:(fun (pos, m) ->
@@ -2146,7 +2171,14 @@ let program ?(accept_unnamed_var = false) f ?source_map p =
  { gen_line; gen_col; ori_source; ori_line; ori_col; ori_name })
  in
  let mappings = Source_map.Mappings.encode mappings in
- Some { sm with Source_map.Standard.sources; names; sources_content; mappings }
+ Some
+ { sm with
+ Source_map.Standard.sources
+ ; names
+ ; sources_content
+ ; mappings
+ ; ignore_list
+ }
  in
  PP.check f;
  (if stats ()

compiler/lib/source_map.ml

@@ -225,6 +225,11 @@ let string_of_stringlit (`Stringlit s) =
  | `String s -> s
  | _ -> invalid ()
 
+let int_of_intlit (`Intlit s) =
+ match Yojson.Safe.from_string s with
+ | `Int s -> s
+ | _ -> invalid ()
+
 let stringlit name rest : [ `Stringlit of string ] option =
  try
  match List.assoc name rest with
@@ -256,6 +261,17 @@ let list_stringlit_opt name rest =
  | _ -> invalid ()
  with Not_found -> None
 
+let list_intlit name rest =
+ try
+ match List.assoc name rest with
+ | `List l ->
+ Some
+ (List.map l ~f:(function
+ | `Intlit _ as s -> s
+ | _ -> invalid ()))
+ | _ -> invalid ()
+ with Not_found -> None
+
 module Standard = struct
  type t =
  { version : int
@@ -265,6 +281,7 @@ module Standard = struct
  ; sources_content : Source_content.t option list option
  ; names : string list
  ; mappings : Mappings.t
+ ; ignore_list : string list
  }
 
  let empty =
@@ -275,6 +292,7 @@ module Standard = struct
  ; sources_content = None
  ; names = []
  ; mappings = Mappings.empty
+ ; ignore_list = []
  }
 
  let maps ~sources_offset ~names_offset x =
@@ -400,6 +418,21 @@ module Standard = struct
  (List.map l ~f:(function
  | None -> `Null
  | Some x -> Source_content.to_json x))) )
+ ; ( "ignoreList"
+ , match t.ignore_list with
+ | [] -> None
+ | _ ->
+ Some
+ (`List
+ (let s = StringSet.of_list t.ignore_list in
+ List.filter_map
+ ~f:(fun x -> x)
+ (List.mapi
+ ~f:(fun i nm ->
+ if StringSet.mem nm s
+ then Some (`Intlit (string_of_int i))
+ else None)
+ t.sources))) )
  ])
 
  let of_json (json : Yojson.Raw.t) =
@@ -432,13 +465,25 @@ module Standard = struct
  | None -> Mappings.empty
  | Some s -> Mappings.of_string s
  in
+ let ignore_list =
+ let s =
+ IntSet.of_list
+ (List.map
+ ~f:int_of_intlit
+ (Option.value ~default:[] (list_intlit "ignoreList" rest)))
+ in
+ List.filter_map
+ ~f:(fun x -> x)
+ (List.mapi ~f:(fun i nm -> if IntSet.mem i s then Some nm else None) sources)
+ in
  { version = int_of_float (float_of_string version)
  ; file
  ; sourceroot
  ; names
  ; sources_content
  ; sources
  ; mappings
+ ; ignore_list
  }
  | _ -> invalid ()
 

compiler/lib/source_map.mli

@@ -79,6 +79,7 @@ module Standard : sig
  (** Left uninterpreted, since most useful operations can be performed efficiently
  directly on the encoded form, and a full decoding can be costly for big
  sourcemaps. *)
+ ; ignore_list : string list
  }
 
  val filter_map : t -> f:(int -> int option) -> t

compiler/tests-compiler/build_path_prefix_map.ml

@@ -44,5 +44,6 @@ let%expect_test _ =
  file: test.js
  sourceRoot: <none>
  sources:
+ - /builtin/blackbox.ml
  - /dune-root/test.ml
  |}]

compiler/tests-compiler/sourcemap.ml

@@ -82,14 +82,14 @@ let%expect_test _ =
  11: (globalThis));
  12:
  13: //# sourceMappingURL=test.map
- /dune-root/test.ml:1:0 -> 5:7
- null -> 5:17
+ /builtin/blackbox.ml:1:0 -> 5:7
+ /builtin/blackbox.ml:1:0 -> 5:17
  /dune-root/test.ml:1:4 -> 6:12
  /dune-root/test.ml:1:7 -> 6:15
  /dune-root/test.ml:1:11 -> 6:18
  /dune-root/test.ml:1:12 -> 6:28
  /dune-root/test.ml:1:12 -> 7:7
- null -> 7:14
+ /builtin/blackbox.ml:1:0 -> 7:14
  |}]
 
 let%expect_test _ =

compiler/tests-sourcemap/dump.reference

@@ -1,5 +1,4 @@
 sourcemap for test.bc.js
-/my/sourceRoot#d.ml:1:0 -> 7: var <>runtime = globalThis.jsoo_runtime;
 /my/sourceRoot#b.ml:1:4 -> 12: function <>f(x){return x - 1 | 0; }
 /my/sourceRoot#b.ml:1:6 -> 14: function f(<>x){return x - 1 | 0; }
 /my/sourceRoot#b.ml:1:10 -> 17: function f(x){<>return x - 1 | 0; }