codegen+runtime: Add support for casting to enums with underlying types

This makes it possible to turn e.g. a u8 into an enum Foo: u8.
aatifs · Apr 30, 2023 · c682a12 · c682a12
1 parent 8f552fb
commit c682a12
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diff --git a/runtime/lib.h b/runtime/lib.h
@@ -230,6 +230,12 @@ ALWAYS_INLINE constexpr OutputType infallible_integer_cast(InputType input)
     }
 }
 
+template<typename OutputType, typename InputType>
+ALWAYS_INLINE constexpr OutputType infallible_enum_cast(InputType input)
+{
+    return static_cast<OutputType>(infallible_integer_cast<UnderlyingType<OutputType>>(input));
+}
+
 template<AK::Concepts::SpecializationOf<AK::NonnullRefPtr> T, AK::Concepts::SpecializationOf<AK::NonnullRefPtr> U>
 inline Optional<T> fallible_class_cast(U const& ptr)
 {
@@ -348,6 +354,7 @@ using JaktInternal::fallible_class_cast;
 using JaktInternal::fallible_integer_cast;
 using JaktInternal::infallible_class_cast;
 using JaktInternal::infallible_integer_cast;
+using JaktInternal::infallible_enum_cast;
 using JaktInternal::Range;
 using JaktInternal::unchecked_add;
 using JaktInternal::unchecked_div;

diff --git a/selfhost/codegen.jakt b/selfhost/codegen.jakt
@@ -2092,6 +2092,8 @@ struct CodeGenerator {
                                 cast_type = "infallible_class_cast"
                             } else if .program.is_integer(type_id) {
                                 cast_type = "infallible_integer_cast"
+                            } else if type is Enum(enum_id) and .program.is_integer(.program.get_enum(enum_id).underlying_type_id) {
+                                cast_type = "infallible_enum_cast"
                             }
                             yield cast_type
                         }