Compare the package names of the accessing module and the decl's defining module.

Update tests.

include/swift/AST/Module.h

@@ -480,8 +480,8 @@ public:
     return Identifier();
   }
 
-  bool inPackage(std::string packageName) {
-    return !getPackageName().empty() && getPackageName().str() == packageName;
+  bool inSamePackage(ModuleDecl *other) {
+    return !getPackageName().empty() && getPackageName() == other->getPackageName();
   }
 
   /// Get the package associated with this module

lib/AST/Decl.cpp

@@ -2957,14 +2957,16 @@ bool AbstractStorageDecl::isResilient() const {
   if (getAttrs().hasAttribute<FixedLayoutAttr>())
     return false;
 
+  // If we're an instance property of a nominal type, query the type.
   if (!isStatic())
     if (auto *nominalDecl = getDeclContext()->getSelfNominalTypeDecl())
       return nominalDecl->isResilient();
 
   // Non-public global and static variables always have a
   // fixed layout.
-  if (!getFormalAccessScope(/*useDC=*/nullptr,
-                            /*treatUsableFromInlineAsPublic=*/true).isPublicOrPackage())
+  auto accessScope = getFormalAccessScope(/*useDC=*/nullptr,
+                                          /*treatUsableFromInlineAsPublic=*/true);
+  if (!accessScope.isPublicOrPackage())
     return false;
 
   if (!getModuleContext()->isResilient())
@@ -2973,8 +2975,7 @@ bool AbstractStorageDecl::isResilient() const {
   // Allows bypassing resilience checks for package decls
   // at use site within a package if opted in, whether the
   // loaded module was built resiliently or not.
-  return !getDeclContext()->bypassResilienceInPackage(getFormalAccessScope(/*useDC=*/nullptr,
-                                                                           /*treatUsableFromInlineAsPublic=*/true).isPackage());
+  return !getDeclContext()->bypassResilienceInPackage(accessScope.isPackage());
 }
 
 bool AbstractStorageDecl::isResilient(ModuleDecl *M,
@@ -5050,8 +5051,9 @@ bool NominalTypeDecl::isResilient() const {
   // Allows bypassing resilience checks for package decls
   // at use site within a package if opted in, whether the
   // loaded module was built resiliently or not.
-  return !getDeclContext()->bypassResilienceInPackage(getFormalAccessScope(/*useDC=*/nullptr,
-                                                                           /*treatUsableFromInlineAsPublic=*/true).isPackage());
+  auto accessScope = getFormalAccessScope(/*useDC=*/nullptr,
+                                          /*treatUsableFromInlineAsPublic=*/true);
+  return !getDeclContext()->bypassResilienceInPackage(accessScope.isPackage());
 }
 
 DestructorDecl *NominalTypeDecl::getValueTypeDestructor() {

lib/AST/DeclContext.cpp

@@ -302,12 +302,12 @@ PackageUnit *DeclContext::getPackageContext(bool lookupIfNotCurrent) const {
 
 bool DeclContext::bypassResilienceInPackage(bool isForPackageDecl) const {
   // Bypassing resilience checks only applies to package types (and possibly
-  // public types in a package in the future). Allowed only if opted-in for
-  // bypassing checks, client and defining module are in the same package,
-  // and defining module is a binary module.
+  // public types in the same package in the future). Allowed only if opted-in
+  // for bypassing optimization, client and defining module are in the same
+  // package, and defining module is a binary module.
   return isForPackageDecl &&
          getASTContext().LangOpts.EnableBypassResilienceInPackage &&
-         getParentModule()->inPackage(getASTContext().LangOpts.PackageName) &&
+         getParentModule()->inSamePackage(getASTContext().MainModule) &&
          !getParentModule()->isBuiltFromInterface();
 }
 

lib/AST/ProtocolConformance.cpp

@@ -349,6 +349,7 @@ bool NormalProtocolConformance::isResilient() const {
   // individual witnesses.
   if (!getDeclContext()->getSelfNominalTypeDecl()->isResilient())
     return false;
+
   return getDeclContext()->getParentModule()->isResilient();
 }
 

lib/Sema/ImportResolution.cpp

@@ -762,7 +762,7 @@ void UnboundImport::validateInterfaceWithPackageName(ModuleDecl *topLevelModule,
 
   // If source file is .swift or non-interface, show diags when importing an interface file
   ASTContext &ctx = topLevelModule->getASTContext();
-  if (topLevelModule->inPackage(ctx.LangOpts.PackageName) &&
+  if (topLevelModule->inSamePackage(ctx.MainModule) &&
       topLevelModule->isBuiltFromInterface() &&
       !topLevelModule->getModuleSourceFilename().endswith(".package.swiftinterface")) {
       ctx.Diags.diagnose(import.module.getModulePath().front().Loc,

test/IRGen/package_resilience.swift

@@ -221,7 +221,7 @@ public func memoryLayoutDotSizeWithResilientStruct() -> Int {
 // CHECK-LABEL: define{{.*}} swiftcc {{i32|i64}} @"$s18package_resilience40memoryLayoutDotStrideWithResilientStructSiyF"()
 public func memoryLayoutDotStrideWithResilientStruct() -> Int {
   // CHECK: ret [[INT]] [[#WORDSIZE + WORDSIZE]]
-  return MemoryLayout<Size>.size
+  return MemoryLayout<Size>.stride
 }
 
 // CHECK-LABEL: define{{.*}} swiftcc {{i32|i64}} @"$s18package_resilience43memoryLayoutDotAlignmentWithResilientStructSiyF"()

test/Sema/package_resilience_bypass_exhaustive_switch.swift

@@ -13,6 +13,17 @@
 
 //--- Utils.swift
 
+package enum PkgEnum {
+  case one
+  case two(Int)
+}
+
+@usableFromInline
+package enum UfiPkgEnum {
+  case one
+  case two(Int)
+}
+
 public enum PublicEnum {
   case one
   case two(Int)
@@ -24,31 +35,6 @@ public enum FrozenPublicEnum {
   case two(Int)
 }
 
-package enum PkgEnum {
-  case one
-  case two(Int)
-}
-
-public struct PublicStruct {
-  public var publicVar: Int
-}
-
-package enum PkgEnumWithPublicCase {
-  case one
-  case two(PublicStruct)
-}
-
-package enum PkgEnumWithExistentialCase {
-  case one
-  case two(any StringProtocol)
-}
-
-@usableFromInline
-package enum UfiPkgEnum {
-  case one
-  case two(Int)
-}
-
 //--- ClientDefault.swift
 import Utils
 
@@ -61,7 +47,16 @@ func f(_ arg: PkgEnum) -> Int {
   }
 }
 
-public func g(_ arg: PublicEnum) -> Int {
+func g(_ arg: UfiPkgEnum) -> Int {
+  switch arg { // expected-warning {{switch covers known cases, but 'UfiPkgEnum' may have additional unknown values}} {{none}} expected-note {{handle unknown values using "@unknown default"}}
+  case .one:
+    return 1
+  case .two(let val):
+    return 2 + val
+  }
+}
+
+public func h(_ arg: PublicEnum) -> Int {
   switch arg { // expected-warning {{switch covers known cases, but 'PublicEnum' may have additional unknown values}} {{none}} expected-note {{handle unknown values using "@unknown default"}}
   case .one:
     return 1
@@ -70,7 +65,7 @@ public func g(_ arg: PublicEnum) -> Int {
   }
 }
 
-public func h(_ arg: FrozenPublicEnum) -> Int {
+public func k(_ arg: FrozenPublicEnum) -> Int {
   switch arg { // no-warning
   case .one:
     return 1
@@ -92,8 +87,19 @@ func f(_ arg: PkgEnum) -> Int {
   }
 }
 
+// Warning still shows up for usableFromInline package enum as the optimization is targeted for
+// decls with package access, not the elevated public access. This might be allowed later.
+func g(_ arg: UfiPkgEnum) -> Int {
+  switch arg { // expected-warning {{switch covers known cases, but 'UfiPkgEnum' may have additional unknown values}} {{none}} expected-note {{handle unknown values using "@unknown default"}}
+  case .one:
+    return 1
+  case .two(let val):
+    return 2 + val
+  }
+}
+
 // Warning still shows up for public enum as the optimization is targeted for package types.
-public func g(_ arg: PublicEnum) -> Int {
+public func h(_ arg: PublicEnum) -> Int {
   switch arg { // expected-warning {{switch covers known cases, but 'PublicEnum' may have additional unknown values}} {{none}} expected-note {{handle unknown values using "@unknown default"}}
   case .one:
     return 1
@@ -102,7 +108,7 @@ public func g(_ arg: PublicEnum) -> Int {
   }
 }
 
-public func h(_ arg: FrozenPublicEnum) -> Int {
+public func k(_ arg: FrozenPublicEnum) -> Int {
   switch arg { // no-warning
   case .one:
     return 1