[Macros] Use outermost source file for establishing (file)private access scope

Fixes rdar://114048069.

Author: DougGregor

lib/AST/Decl.cpp

@@ -4032,7 +4032,7 @@ getAccessScopeForFormalAccess(const ValueDecl *VD,
   case AccessLevel::Package: {
     auto pkg = resultDC->getPackageContext(/*lookupIfNotCurrent*/ true);
     if (!pkg) {
-      auto srcFile = resultDC->getParentSourceFile();
+      auto srcFile = resultDC->getOutermostParentSourceFile();
       // Check if the file containing package decls is an interface file; if an
       // interface file contains package decls, they must be usableFromInline or
       // inlinable and are accessed within the defining module, so package-name

lib/AST/DeclContext.cpp

@@ -407,7 +407,7 @@ DeclContext *DeclContext::getModuleScopeContext() const {
 
 void DeclContext::getSeparatelyImportedOverlays(
     ModuleDecl *declaring, SmallVectorImpl<ModuleDecl *> &overlays) const {
-  if (auto SF = getParentSourceFile())
+  if (auto SF = getOutermostParentSourceFile())
     SF->getSeparatelyImportedOverlays(declaring, overlays);
 }
 
@@ -1253,13 +1253,13 @@ getPrivateDeclContext(const DeclContext *DC, const SourceFile *useSF) {
 
   // use the type declaration as the private scope if it is in the same
   // file as useSF. This occurs for both extensions and declarations.
-  if (NTD->getParentSourceFile() == useSF)
+  if (NTD->getOutermostParentSourceFile() == useSF)
     return NTD;
 
   // Otherwise use the last extension declaration in the same file.
   const DeclContext *lastExtension = nullptr;
   for (ExtensionDecl *ED : NTD->getExtensions())
-    if (ED->getParentSourceFile() == useSF)
+    if (ED->getOutermostParentSourceFile() == useSF)
       lastExtension = ED;
 
   // If there's no last extension, return the supplied context.
@@ -1269,7 +1269,7 @@ getPrivateDeclContext(const DeclContext *DC, const SourceFile *useSF) {
 AccessScope::AccessScope(const DeclContext *DC, bool isPrivate)
     : Value(DC, isPrivate) {
   if (isPrivate) {
-    DC = getPrivateDeclContext(DC, DC->getParentSourceFile());
+    DC = getPrivateDeclContext(DC, DC->getOutermostParentSourceFile());
     Value.setPointer(DC);
   }
   if (!DC || isa<ModuleDecl>(DC) || isa<PackageUnit>(DC))
@@ -1319,8 +1319,8 @@ bool AccessScope::allowsPrivateAccess(const DeclContext *useDC, const DeclContex
     }
   }
   // Do not allow access if the sourceDC is in a different file
-  auto useSF = useDC->getParentSourceFile();
-  if (useSF != sourceDC->getParentSourceFile())
+  auto useSF = useDC->getOutermostParentSourceFile();
+  if (useSF != sourceDC->getOutermostParentSourceFile())
     return false;
 
   // Do not allow access if the sourceDC does not represent a type.

test/Macros/macro_expand_extensions.swift

@@ -3,6 +3,9 @@
 // RUN: %empty-directory(%t)
 // RUN: %host-build-swift -swift-version 5 -emit-library -o %t/%target-library-name(MacroDefinition) -module-name=MacroDefinition %S/Inputs/syntax_macro_definitions.swift -g -no-toolchain-stdlib-rpath
 
+// Check for errors first
+// RUN: %target-swift-frontend -enable-experimental-feature ExtensionMacros -swift-version 5 -typecheck -load-plugin-library %t/%target-library-name(MacroDefinition) %s -I %t -disable-availability-checking
+
 // RUN: %target-swift-frontend -enable-experimental-feature ExtensionMacros -swift-version 5 -typecheck -load-plugin-library %t/%target-library-name(MacroDefinition) %s -I %t -disable-availability-checking -dump-macro-expansions > %t/expansions-dump.txt 2>&1
 // RUN: %FileCheck -check-prefix=CHECK-DUMP %s < %t/expansions-dump.txt
 // RUN: %target-typecheck-verify-swift -enable-experimental-feature ExtensionMacros -swift-version 5 -load-plugin-library %t/%target-library-name(MacroDefinition) -module-name MacroUser -DTEST_DIAGNOSTICS -swift-version 5 -I %t
@@ -202,6 +205,12 @@ func testHasPropertyWrappers(hpw: HasPropertyWrappers) {
   requiresEquatable(hpw)
 }
 
+@Equatable
+struct HasPrivateMembers {
+  @NotEquatable
+  private var value: Int = 0
+}
+
 // Check that conformances implied by a macro-defined conformance are serialized
 // without issue.
 public protocol ImpliesHashable: Hashable { }