Merge pull request #61874 from slavapestov/mangle-opened-archetypes-workaround

IRGen: Workaround for mangling of opened archetypes

Author: slavapestov

lib/IRGen/GenHeap.cpp

@@ -1528,6 +1528,19 @@ class FixedBoxTypeInfoBase : public BoxTypeInfo {
       boxedInterfaceType = boxedType.mapTypeOutOfContext();
     }
 
+    {
+      // FIXME: This seems wrong. We used to just mangle opened archetypes as
+      // their interface type. Let's make that explicit now.
+      auto astType = boxedInterfaceType.getASTType();
+      astType = astType.transformRec([](Type t) -> Optional<Type> {
+        if (auto *openedExistential = t->getAs<OpenedArchetypeType>())
+          return openedExistential->getInterfaceType();
+        return None;
+      })->getCanonicalType();
+      boxedInterfaceType = SILType::getPrimitiveType(
+          astType, boxedInterfaceType.getCategory());
+    }
+
     auto boxDescriptor = IGF.IGM.getAddrOfBoxDescriptor(
         boxedInterfaceType,
         env ? env->getGenericSignature().getCanonicalSignature()

lib/IRGen/GenReflection.cpp

@@ -368,9 +368,6 @@ IRGenModule::getLoweredTypeRef(SILType loweredType,
   auto substTy =
     substOpaqueTypesWithUnderlyingTypes(loweredType, genericSig);
   auto type = substTy.getASTType();
-  if (substTy.hasArchetype())
-    type = type->mapTypeOutOfContext()->getCanonicalType();
-
   return getTypeRefImpl(*this, type, genericSig, role);
 }
 
@@ -1324,7 +1321,7 @@ class CaptureDescriptorBuilder : public ReflectionMetadataBuilder {
 
     // Now add typerefs of all of the captures.
     for (auto CaptureType : CaptureTypes) {
-      addLoweredTypeRef(CaptureType, sig);
+      addLoweredTypeRef(CaptureType.mapTypeOutOfContext(), sig);
     }
 
     // Add the pairs that make up the generic param -> metadata source map

test/Reflection/box_descriptor_with_opened_archetype.swift

@@ -0,0 +1,18 @@
+// RUN: %target-swift-frontend -emit-ir %s -disable-availability-checking
+
+public protocol P {}
+
+struct S<T>: P {
+  var x: Any
+  init() { fatalError() }
+}
+
+public func mangleArchetype(_ p: any P) -> any P {
+  p.open
+}
+
+extension P {
+  var open: some P {
+    S<Self>()
+  }
+}