error instead of raise

Author: riaqn

ocaml/testsuite/tests/typing-modes/modes.ml

@@ -291,16 +291,18 @@ Error: Optional parameters cannot be polymorphic
    another PR. Here, we test that they at least parse. *)
 let foo ((x @ unique once), (y@local unique)) = x + y
 [%%expect{|
->> Fatal error: Mode expressions on patterns are not supported yet
-Uncaught exception: Misc.Fatal_error
-
+Line 1, characters 14-25:
+1 | let foo ((x @ unique once), (y@local unique)) = x + y
+                  ^^^^^^^^^^^
+Error: Mode annotations on patterns are not supported yet.
 |}]
 
 let foo ((x : _ @@ unique once), (y : _ @@ local unique)) = x + y
 [%%expect{|
->> Fatal error: Mode expressions on patterns are not supported yet
-Uncaught exception: Misc.Fatal_error
-
+Line 1, characters 19-30:
+1 | let foo ((x : _ @@ unique once), (y : _ @@ local unique)) = x + y
+                       ^^^^^^^^^^^
+Error: Mode annotations on patterns are not supported yet.
 |}]
 
 (* let-bound function *)
@@ -335,7 +337,8 @@ module type S = sig
   val x : string -> string @ local @@ foo bar
 end
 [%%expect{|
->> Fatal error: Modalities not supported in value declarations
-Uncaught exception: Misc.Fatal_error
-
+Line 337, characters 38-45:
+337 |   val x : string -> string @ local @@ foo bar
+                                            ^^^^^^^
+Error: Modalities on value descriptions are not supported yet.
 |}]

ocaml/typing/typecore.ml

@@ -228,6 +228,7 @@ type error =
   | Exclave_returns_not_local
   | Unboxed_int_literals_not_supported
   | Function_type_not_rep of type_expr * Jkind.Violation.t
+  | Modes_on_pattern
 
 exception Error of Location.t * Env.t * error
 exception Error_forward of Location.error
@@ -2463,7 +2464,7 @@ and type_pat_aux
       pat_env = !env }
   in
   match Jane_syntax.Mode_expr.maybe_of_attrs sp.ppat_attributes with
-  | Some _, _ -> Misc.fatal_error "Mode expressions on patterns are not supported yet"
+  | Some modes, _ -> raise (Error (modes.loc, !env, Modes_on_pattern))
   | None, _ ->
   match Jane_syntax.Pattern.of_ast sp with
   | Some (jpat, attrs) -> begin
@@ -4962,7 +4963,7 @@ let may_lower_contravariant_then_generalize env exp =
 
 (* This added mode attribute is read and removed by
     [alloc_mode_from_pexp_constraint_typ_attrs] or
-    [alloc_mode_from_pexp_constraint_typ_attrs]. *)
+    [alloc_mode_from_ppat_constraint_typ_attrs]. *)
 let add_mode_annot_attrs mode_annot_attr typ =
   match mode_annot_attr with
   | None -> typ
@@ -10121,6 +10122,9 @@ let report_error ~loc env = function
         "@[Function arguments and returns must be representable.@]@ %a"
         (Jkind.Violation.report_with_offender
            ~offender:(fun ppf -> Printtyp.type_expr ppf ty)) violation
+  | Modes_on_pattern ->
+      Location.errorf ~loc
+        "@[Mode annotations on patterns are not supported yet.@]"
 
 let report_error ~loc env err =
   Printtyp.wrap_printing_env ~error:true env

ocaml/typing/typecore.mli

@@ -293,6 +293,7 @@ type error =
   | Exclave_returns_not_local
   | Unboxed_int_literals_not_supported
   | Function_type_not_rep of type_expr * Jkind.Violation.t
+  | Modes_on_pattern
 
 exception Error of Location.t * Env.t * error
 exception Error_forward of Location.error

ocaml/typing/typedecl.ml

@@ -101,6 +101,7 @@ type error =
   | Local_not_enabled
   | Unexpected_jkind_any_in_primitive of string
   | Useless_layout_poly
+  | Modalities_on_value_description
 
 open Typedtree
 
@@ -2388,7 +2389,7 @@ let error_if_containing_unexpected_jkind prim env cty ty =
 (* Translate a value declaration *)
 let transl_value_decl env loc valdecl =
   match Jane_syntax.Mode_expr.maybe_of_attrs valdecl.pval_type.ptyp_attributes with
-  | Some _, _ -> Misc.fatal_error "Modalities not supported in value declarations"
+  | Some modes, _ -> raise (Error(modes.loc, Modalities_on_value_description))
   | None, _ ->
   let cty = Typetexp.transl_type_scheme env valdecl.pval_type in
   (* CR layouts v5: relax this to check for representability. *)
@@ -3146,6 +3147,9 @@ let report_error ppf = function
         "@[[@@layout_poly] on this external declaration has no@ \
            effect. Consider removing it or adding a type@ \
            variable for it to operate on.@]"
+  | Modalities_on_value_description ->
+      fprintf ppf
+        "@[Modalities on value descriptions are not supported yet.@]"
 
 let () =
   Location.register_error_of_exn

ocaml/typing/typedecl.mli

@@ -145,6 +145,7 @@ type error =
   | Local_not_enabled
   | Unexpected_jkind_any_in_primitive of string
   | Useless_layout_poly
+  | Modalities_on_value_description
 
 exception Error of Location.t * error