[m-rev.] diff: implement RTTI operations for C# foreign enumerations

[Julien Fischer]

Implement RTTI operations for C# foreign enumerations.

library/rtti_implementation.m
     Implement some missing RTTI operations for foreign enumerations in the C#
     grade.  (This would also handle the Java grade if that ever supports
     foreign enumerations.)

tests/hard_coded/foreign_enum_rtti.m:
      Use a C# foreign enumeration here.

Julien.

diff --git a/library/rtti_implementation.m b/library/rtti_implementation.m
index 645b6e6..c78eb71 100644
--- a/library/rtti_implementation.m
+++ b/library/rtti_implementation.m
@@ -876,14 +876,10 @@ type_info_num_functors(TypeInfo, NumFunctors) :-
          ; TypeCtorRep = tcr_reserved_addr_usereq
          ; TypeCtorRep = tcr_enum
          ; TypeCtorRep = tcr_enum_usereq
-        ),
-        NumFunctors = TypeCtorInfo ^ type_ctor_num_functors
-    ;
-        ( TypeCtorRep = tcr_foreign_enum
+        ; TypeCtorRep = tcr_foreign_enum
          ; TypeCtorRep = tcr_foreign_enum_usereq
          ),
-        % XXX todo
-        fail
+        NumFunctors = TypeCtorInfo ^ type_ctor_num_functors
      ;
          ( TypeCtorRep = tcr_dummy
          ; TypeCtorRep = tcr_notag
@@ -988,8 +984,8 @@ get_functor_impl(TypeInfo, FunctorNumber,
          ( TypeCtorRep = tcr_foreign_enum
          ; TypeCtorRep = tcr_foreign_enum_usereq
          ),
-        % XXX todo
-        fail
+        get_functor_foreign_enum(TypeCtorRep, TypeCtorInfo,
+            FunctorNumber, FunctorName, Arity, PseudoTypeInfoList, Names)
      ;
          ( TypeCtorRep = tcr_notag
          ; TypeCtorRep = tcr_notag_usereq
@@ -1103,6 +1099,21 @@ get_functor_enum(TypeCtorRep, TypeCtorInfo, FunctorNumber, FunctorName, Arity,
      PseudoTypeInfoList = [],
      Names = [].

+:- pred get_functor_foreign_enum(type_ctor_rep::in(foreign_enum),
+    type_ctor_info::in, int::in, string::out, int::out,
+    list(pseudo_type_info)::out, list(string)::out) is det.
+
+get_functor_foreign_enum(TypeCtorRep, TypeCtorInfo, FunctorNumber,
+        FunctorName, Arity, PseudoTypeInfoList, Names) :-
+    TypeFunctors = get_type_functors(TypeCtorInfo),
+    ForeignEnumFunctorDesc = get_foreign_enum_functor_desc(TypeCtorRep,
+        FunctorNumber, TypeFunctors),
+
+    FunctorName = ForeignEnumFunctorDesc ^ foreign_enum_functor_name,
+    Arity = 0,
+    PseudoTypeInfoList = [],
+    Names = [].
+
  :- pred get_functor_notag(type_ctor_rep::in(notag), type_ctor_info::in,
      int::in, string::out, int::out, list(pseudo_type_info)::out,
      list(string)::out) is det.
@@ -1228,8 +1239,10 @@ type_info_get_functor_ordinal(TypeInfo, FunctorNum, Ordinal) :-
          ( TypeCtorRep = tcr_foreign_enum
          ; TypeCtorRep = tcr_foreign_enum_usereq
          ),
-        % XXX todo
-        fail
+        TypeFunctors = get_type_functors(TypeCtorInfo),
+        ForeignEnumFunctorDesc = get_foreign_enum_functor_desc(TypeCtorRep,
+            FunctorNum, TypeFunctors),
+        Ordinal = foreign_enum_functor_ordinal(ForeignEnumFunctorDesc)
      ;
          ( TypeCtorRep = tcr_dummy
          ; TypeCtorRep = tcr_notag
@@ -1744,6 +1757,17 @@ is_exist_pseudo_type_info(_, _) :-

              case runtime.TypeCtorRep.MR_TYPECTOR_REP_FOREIGN_ENUM:
              case runtime.TypeCtorRep.MR_TYPECTOR_REP_FOREIGN_ENUM_USEREQ:
+                runtime.ForeignEnumFunctorDesc[] functors_foreign_enum =
+                    tc.type_functors.functors_foreign_enum();
+                if (
+                    FunctorNumber >= 0 &&
+                    FunctorNumber < functors_foreign_enum.Length
+                ) {
+                    new_data = ML_construct_static_member(tc,
+                        functors_foreign_enum[FunctorNumber].foreign_enum_functor_value);
+                }
+                break;
+
              case runtime.TypeCtorRep.MR_TYPECTOR_REP_NOTAG:
              case runtime.TypeCtorRep.MR_TYPECTOR_REP_NOTAG_USEREQ:
              case runtime.TypeCtorRep.MR_TYPECTOR_REP_NOTAG_GROUND:
@@ -5204,6 +5228,31 @@ enum_functor_ordinal(EnumFunctorDesc) = EnumFunctorDesc ^ unsafe_index(1).

  %---------------------------------------------------------------------------%

+:- func get_foreign_enum_functor_desc(type_ctor_rep, int, type_functors)
+    = foreign_enum_functor_desc.
+:- mode get_foreign_enum_functor_desc(in(foreign_enum), in, in) = out is det.
+
+get_foreign_enum_functor_desc(_, _, _) = _ :-
+    unexpected($module, $pred, "get_foreign_enum_functor_desc").
+
+:- pragma foreign_proc("C#",
+    get_foreign_enum_functor_desc(_TypeCtorRep::in(foreign_enum), X::in,
+        TypeFunctors::in) = (ForeignEnumFunctorDesc::out),
+    [will_not_call_mercury, promise_pure, thread_safe],
+"
+    ForeignEnumFunctorDesc = TypeFunctors.functors_foreign_enum()[X];
+").
+
+:- pragma foreign_proc("Java",
+    get_foreign_enum_functor_desc(_TypeCtorRep::in(foreign_enum), X::in,
+        TypeFunctors::in) = (ForeignEnumFunctorDesc::out),
+    [will_not_call_mercury, promise_pure, thread_safe],
+"
+    ForeignEnumFunctorDesc = TypeFunctors.functors_foreign_enum()[X];
+").
+
+%---------------------------------------------------------------------------%
+
  :- func foreign_enum_functor_desc(type_ctor_rep, int, type_functors)
      = foreign_enum_functor_desc.
  :- mode foreign_enum_functor_desc(in(foreign_enum), in, in) = out is det.
diff --git a/tests/hard_coded/foreign_enum_rtti.m b/tests/hard_coded/foreign_enum_rtti.m
index db05ca1..ce626cf 100644
--- a/tests/hard_coded/foreign_enum_rtti.m
+++ b/tests/hard_coded/foreign_enum_rtti.m
@@ -132,5 +132,12 @@ test_get_functor(TypeDesc, LexFunctorNum, !IO) :-
          baz - "CONSTANT3"
      ]).

+:- pragma foreign_enum("C#", foo/0,
+    [
+        foo - "2",
+        bar - "4",
+        baz - "6"
+    ]).
+
  %---------------------------------------------------------------------------%
  %---------------------------------------------------------------------------%