RA22-015: Fix enum class subclasses scoping

contrib/lkt/language/parser.py

@@ -5,7 +5,8 @@ from langkit.dsl import (
     Struct, T, UserField, abstract, synthetic
 )
 from langkit.envs import (
-    EnvSpec, RefKind, add_env, add_to_env, add_to_env_kv, do, reference
+    EnvSpec, RefKind, add_env, add_to_env, add_to_env_kv, do, handle_children,
+    reference
 )
 from langkit.expressions import (
     AbstractKind, AbstractProperty, And, CharacterLiteral, Cond, EmptyEnv,
@@ -1319,9 +1320,9 @@ class EnumClassDecl(NamedTypeDecl):
 
     env_spec = EnvSpec(
         add_to_env_kv(Entity.name, Self),
-        add_env(),
+        handle_children(),
         add_to_env(Entity.alts.map(lambda alt: new_env_assoc(
-            key=alt.name, val=alt.node, dest_env=Self.children_env
+            key=alt.name, val=alt.node, dest_env=Self.decls.children_env
         )))
     )
 

testsuite/tests/contrib/lkt_semantic/test.lkt

@@ -101,3 +101,12 @@ val c : String = a (1)
 
 fun test_named_parameters(a: Int): Int = a
 val ss : Int = test_named_parameters(a=12)
+
+# Test resolution of enum class subclasses (should be accessible via dot
+# notation on the root enum class type).
+
+enum class EnClass (SubclassA, SubclassB, SubclassC) {}
+
+val en_class_inst : EnClass.SubclassB = EnClass.SubclassB()
+# Test that those classes don't leak
+val invalid_en_class : SubclassB = SubclassB()

testsuite/tests/contrib/lkt_semantic/test.out

@@ -652,3 +652,26 @@ Expr <NumLit test.lkt:103:40-103:42>
 Expr <CallExpr test.lkt:103:16-103:43>
      has type <StructDecl "Int" __prelude:1:10-1:23>
 
+Id   <RefId "EnClass" test.lkt:110:21-110:28>
+     references <EnumClassDecl "EnClass" test.lkt:108:1-108:56>
+
+Id   <RefId "SubclassB" test.lkt:110:29-110:38>
+     references <EnumClassAltDecl "SubclassB" test.lkt:108:32-108:41>
+
+Id   <RefId "EnClass" test.lkt:110:41-110:48>
+     references <EnumClassDecl "EnClass" test.lkt:108:1-108:56>
+
+Id   <RefId "SubclassB" test.lkt:110:49-110:58>
+     references <EnumClassAltDecl "SubclassB" test.lkt:108:32-108:41>
+
+Expr <CallExpr test.lkt:110:41-110:60>
+     has type <EnumClassAltDecl "SubclassB" test.lkt:108:32-108:41>
+
+test.lkt:112:24: error: Cannot find entity 'SubclassB' in this scope
+111 | val invalid_en_class : SubclassB = SubclassB()
+    |                        ^^^^^^^^^              
+
+test.lkt:112:36: error: Cannot find entity 'SubclassB' in this scope
+111 | val invalid_en_class : SubclassB = SubclassB()
+    |                                    ^^^^^^^^^  
+