Don't constant fold metatypes that indirectly contain resilient types

Author: kubamracek

SwiftCompilerSources/Sources/Optimizer/Utilities/OptUtils.swift

@@ -506,12 +506,15 @@ extension Instruction {
 
     // Metatypes (and upcasts of them to existentials) can be used as static initializers for SE-0492, as long as they
     // do not require an accessor to reference the metadata (i.e. are not generic, not resilient and not a class).
+    // See also irgen::isCanonicalCompleteTypeMetadataStaticallyAddressable.
     case let mti as MetatypeInst:
+      let silType = mti.type.loweredInstanceTypeOfMetatype(in: parentFunction)
+      let instanceType = mti.type.canonicalType.instanceTypeOfMetatype
       if !mti.type.isGenericAtAnyLevel,
-        !mti.type.canonicalType.instanceTypeOfMetatype.isClass,
-        let nominal = mti.type.canonicalType.instanceTypeOfMetatype.nominal,
+        !instanceType.isClass,
+        let nominal = instanceType.nominal,
         !nominal.isGenericAtAnyLevel,
-        !nominal.isResilient(in: mti.parentFunction) {
+        silType.isFixedABI(in: mti.parentFunction) {
         return true
       }
       return false

SwiftCompilerSources/Sources/SIL/Type.swift

@@ -103,6 +103,10 @@ public struct Type : TypeProperties, CustomStringConvertible, NoReflectionChildr
     bridged.isAddressableForDeps(function.bridged)
   }
 
+  public func isFixedABI(in function: Function) -> Bool {
+    bridged.isFixedABI(function.bridged)
+  }
+
   /// If this is a raw layout type, returns the substituted like-type.
   public var rawLayoutSubstitutedLikeType: AST.`Type`? {
     .init(bridgedOrNil: bridged.getRawLayoutSubstitutedLikeType())

include/swift/SIL/SILBridging.h

@@ -291,6 +291,7 @@ struct BridgedType {
   BRIDGED_INLINE bool isExactSuperclassOf(BridgedType t) const;
   BRIDGED_INLINE bool isMarkedAsImmortal() const;
   BRIDGED_INLINE bool isAddressableForDeps(BridgedFunction f) const;
+  BRIDGED_INLINE bool isFixedABI(BridgedFunction f) const;
   BRIDGED_INLINE SWIFT_IMPORT_UNSAFE BridgedASTType getRawLayoutSubstitutedLikeType() const;
   BRIDGED_INLINE SWIFT_IMPORT_UNSAFE BridgedASTType getRawLayoutSubstitutedCountType() const;
   BRIDGED_INLINE bool mayHaveCustomDeinit(BridgedFunction f) const;

include/swift/SIL/SILBridgingImpl.h

@@ -402,6 +402,10 @@ bool BridgedType::isAddressableForDeps(BridgedFunction f) const {
   return unbridged().isAddressableForDeps(*f.getFunction());
 }
 
+bool BridgedType::isFixedABI(BridgedFunction f) const {
+  return unbridged().isFixedABI(*f.getFunction());
+}
+
 BridgedASTType BridgedType::getRawLayoutSubstitutedLikeType() const {
   return {unbridged().getRawLayoutSubstitutedLikeType().getPointer()};
 }

test/SILOptimizer/static_init_metatypes3.swift

@@ -0,0 +1,25 @@
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+// RUN: %target-swift-frontend -parse-as-library -emit-module -o %t/MyModule.swiftmodule %t/MyModule.swift -O
+// RUN: %target-swift-frontend -parse-as-library -I %t %t/Main.swift -O -emit-ir | %FileCheck %s
+
+// BEGIN MyModule.swift
+
+public struct NonResilientTypeContainingAResilientType {
+    var m: Mirror? = nil
+}
+
+// BEGIN Main.swift
+
+import MyModule
+
+public protocol MyProtocol {}
+
+public struct MyStruct: MyProtocol {
+    public var x: NonResilientTypeContainingAResilientType? = nil
+}
+
+public let glob: [any MyProtocol.Type] = [MyStruct.self]
+
+// CHECK: @"$s4Main4globSayAA10MyProtocol_pXpGvp" = {{.*}}global %TSa zeroinitializer