Merge pull request #13288 from slavapestov/class-resilience-part-1

Class resilience part 1

Author: slavapestov

include/swift/Runtime/Metadata.h

@@ -1275,7 +1275,7 @@ struct TargetClassMetadata : public TargetHeapMetadata<Runtime> {
              ConstTargetMetadataPointer<Runtime, swift::TargetClassMetadata> superClass,
              StoredPointer data,
              ClassFlags flags,
-             ClassIVarDestroyer ivarDestroyer,
+             StoredPointer ivarDestroyer,
              StoredPointer size, StoredPointer addressPoint,
              StoredPointer alignMask,
              StoredPointer classSize, StoredPointer classAddressPoint)
@@ -1362,7 +1362,7 @@ struct TargetClassMetadata : public TargetHeapMetadata<Runtime> {
 
   /// A function for destroying instance variables, used to clean up
   /// after an early return from a constructor.
-  ClassIVarDestroyer IVarDestroyer; // TODO: Make target-agnostic size
+  StoredPointer IVarDestroyer;
 
   // After this come the class members, laid out as follows:
   //   - class members for the superclass (recursively)
@@ -1383,9 +1383,10 @@ struct TargetClassMetadata : public TargetHeapMetadata<Runtime> {
     Description = description;
   }
 
+  /// Only valid if the target is in-process.
   ClassIVarDestroyer getIVarDestroyer() const {
     assert(isTypeMetadata());
-    return IVarDestroyer;
+    return reinterpret_cast<ClassIVarDestroyer>(IVarDestroyer);
   }
 
   /// Is this class an artificial subclass, such as one dynamically

lib/IRGen/GenClass.cpp

@@ -258,6 +258,14 @@ namespace {
         auto superclass = superclassType.getClassOrBoundGenericClass();
         assert(superclass);
 
+        // If the superclass came from another module, we may have dropped
+        // stored properties due to the Swift language version availability of
+        // their types. In these cases we can't precisely lay out the ivars in
+        // the class object at compile time so we need to do runtime layout.
+        if (classHasIncompleteLayout(IGM, superclass)) {
+          ClassMetadataRequiresDynamicInitialization = true;
+        }
+
         if (superclass->hasClangNode()) {
           // If the superclass was imported from Objective-C, its size is
           // not known at compile time. However, since the field offset

lib/IRGen/GenKeyPath.cpp

@@ -908,10 +908,16 @@ IRGenModule::getAddrOfKeyPathPattern(KeyPathPattern *pattern,
             auto declaringClass =
               cast<ClassDecl>(overridden.getDecl()->getDeclContext());
             auto &metadataLayout = getMetadataLayout(declaringClass);
+            // FIXME: Resilience. We don't want vtable layout to be ABI, so this
+            // should be encoded as a reference to the method dispatch thunk
+            // instead.
             auto offset = metadataLayout.getStaticMethodOffset(overridden);
             idValue = llvm::ConstantInt::get(SizeTy, offset.getValue());
             idResolved = true;
           } else if (auto methodProto = dyn_cast<ProtocolDecl>(dc)) {
+            // FIXME: Resilience. We don't want witness table layout to be ABI,
+            // so this should be encoded as a reference to the method dispatch
+            // thunk instead.
             auto &protoInfo = getProtocolInfo(methodProto);
             auto index = protoInfo.getFunctionIndex(
                                  cast<AbstractFunctionDecl>(declRef.getDecl()));