Sema: Support newer import restrictions with cross-import overlays

Add support for access-level on imports and `@_spiOnly imports` to cross
import overlays. The overlay inherits the most restrictive import
access-level of the declaring module and the bystander module.

rdar://129606112

lib/Sema/ImportResolution.cpp

@@ -1354,6 +1354,13 @@ UnboundImport::UnboundImport(
   if (declaringOptions.contains(ImportFlags::ImplementationOnly) ||
       bystandingOptions.contains(ImportFlags::ImplementationOnly))
     import.options |= ImportFlags::ImplementationOnly;
+  if (declaringOptions.contains(ImportFlags::SPIOnly) ||
+      bystandingOptions.contains(ImportFlags::SPIOnly))
+    import.options |= ImportFlags::SPIOnly;
+
+  // Pick the most restrictive access level.
+  import.accessLevel = std::min(declaringImport.accessLevel,
+                                bystandingImport.accessLevel);
 
   // If either have a `@_documentation(visibility: <access>)` attribute, the
   // cross-import has the more restrictive of the two.

lib/Sema/TypeCheckAccess.cpp

@@ -404,12 +404,13 @@ static void noteLimitingImport(const Decl *userDecl,
                      limitImport->accessLevel,
                      limitImport->module.importedModule);
 
-    ctx.Diags.diagnose(limitImport->importLoc,
-                       diag::decl_import_via_here,
-                       VD,
-                       limitImport->accessLevel,
-                       limitImport->module.importedModule);
-  } else {
+    if (limitImport->importLoc.isValid())
+      ctx.Diags.diagnose(limitImport->importLoc,
+                         diag::decl_import_via_here,
+                         VD,
+                         limitImport->accessLevel,
+                         limitImport->module.importedModule);
+  } else if (limitImport->importLoc.isValid()) {
     ctx.Diags.diagnose(limitImport->importLoc, diag::module_imported_here,
                        limitImport->module.importedModule,
                        limitImport->accessLevel);

test/CrossImport/access-level-imports-errors.swift

@@ -0,0 +1,68 @@
+/// Check semantic verification cross-import overlays with non-public imports.
+
+// RUN: %empty-directory(%t)
+// RUN: cp -r %S/Inputs/lib-templates/* %t/
+// RUN: split-file --leading-lines %s %t
+
+//--- BothPublic.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/BothPublic.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+
+public import DeclaringLibrary
+public import BystandingLibrary
+
+public func fn(_: OverlayLibraryTy) {}
+
+
+//--- BothHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/BothHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -verify
+
+internal import DeclaringLibrary
+internal import BystandingLibrary
+
+public func fn(_: OverlayLibraryTy) {}
+// expected-error @-1 {{function cannot be declared public because its parameter uses an internal type}}
+// expected-note @-2 {{struct 'OverlayLibraryTy' is imported by this file as 'internal' from '_OverlayLibrary'}}
+
+
+//--- FirstHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/FirstHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -verify
+
+internal import DeclaringLibrary
+public import BystandingLibrary // expected-warning {{public import of 'BystandingLibrary' was not used in public declarations or inlinable code}}
+
+public func fn(_: OverlayLibraryTy) {}
+// expected-error @-1 {{function cannot be declared public because its parameter uses an internal type}}
+// expected-note @-2 {{struct 'OverlayLibraryTy' is imported by this file as 'internal' from '_OverlayLibrary'}}
+
+
+//--- SecondHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/SecondHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -verify
+
+public import DeclaringLibrary // expected-warning {{public import of 'DeclaringLibrary' was not used in public declarations or inlinable code}}
+internal import BystandingLibrary
+
+public func fn(_: OverlayLibraryTy) {}
+// expected-error @-1 {{function cannot be declared public because its parameter uses an internal type}}
+// expected-note @-2 {{struct 'OverlayLibraryTy' is imported by this file as 'internal' from '_OverlayLibrary'}}
+
+
+//--- PrivateVsInternal.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/PrivateVsInternal.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -verify
+
+private import DeclaringLibrary
+internal import BystandingLibrary
+
+internal func fn(_: OverlayLibraryTy) {}
+// expected-error @-1 {{function cannot be declared internal because its parameter uses a private type}}
+// expected-note @-2 {{struct 'OverlayLibraryTy' is imported by this file as 'private' from '_OverlayLibrary'}}
+
+
+//--- InternalVsPrivate.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/InternalVsPrivate.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -verify
+
+internal import DeclaringLibrary
+private import BystandingLibrary
+
+internal func fn(_: OverlayLibraryTy) {}
+// expected-error @-1 {{function cannot be declared internal because its parameter uses a private type}}
+// expected-note @-2 {{struct 'OverlayLibraryTy' is imported by this file as 'private' from '_OverlayLibrary'}}

test/CrossImport/with-access-level-import.swift

@@ -0,0 +1,71 @@
+/// Check cross-import overlays with non-public imports.
+
+// RUN: %empty-directory(%t)
+// RUN: cp -r %S/Inputs/lib-templates/* %t/
+// RUN: split-file --leading-lines %s %t
+
+//--- BothPublic.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/BothPublic.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/BothPublic.swift < %t.swiftinterface
+
+public import DeclaringLibrary
+public import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// CHECK-DAG: import DeclaringLibrary
+// CHECK-DAG: import BystandingLibrary
+// CHECK-DAG: import _OverlayLibrary
+
+
+//--- BothHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/BothHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/BothHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefix NEGATIVE %t/BothHidden.swift < %t.swiftinterface
+
+internal import DeclaringLibrary
+internal import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// NEGATIVE-NOT: import DeclaringLibrary
+// NEGATIVE-NOT: import BystandingLibrary
+// NEGATIVE-NOT: import _OverlayLibrary
+
+
+//--- FirstHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/FirstHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/FirstHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefix NEGATIVE %t/FirstHidden.swift < %t.swiftinterface
+
+internal import DeclaringLibrary
+public import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// CHECK-DAG: import BystandingLibrary
+// NEGATIVE-NOT: import DeclaringLibrary
+// NEGATIVE-NOT: import _OverlayLibrary
+
+
+//--- SecondHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/SecondHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/SecondHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefix NEGATIVE %t/SecondHidden.swift < %t.swiftinterface
+
+public import DeclaringLibrary
+internal import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// CHECK-DAG: import DeclaringLibrary
+// NEGATIVE-NOT: import BystandingLibrary
+// NEGATIVE-NOT: import _OverlayLibrary

test/CrossImport/with-spi-only-import.swift

@@ -0,0 +1,86 @@
+/// Check cross-import overlays with @_spiOnly imports.
+
+// RUN: %empty-directory(%t)
+// RUN: cp -r %S/Inputs/lib-templates/* %t/
+// RUN: split-file --leading-lines %s %t
+
+//--- BothPublic.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/BothPublic.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -emit-private-module-interface-path %t.private.swiftinterface -swift-version 6
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.private.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/BothPublic.swift < %t.swiftinterface
+// RUN: %FileCheck %t/BothPublic.swift < %t.private.swiftinterface
+
+import DeclaringLibrary
+import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// CHECK-DAG: import DeclaringLibrary
+// CHECK-DAG: import BystandingLibrary
+// CHECK-DAG: import _OverlayLibrary
+
+
+//--- BothHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/BothHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -emit-private-module-interface-path %t.private.swiftinterface -swift-version 6
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.private.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/BothHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefix NEGATIVE %t/BothHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefixes CHECK,PRIVATE %t/BothHidden.swift < %t.private.swiftinterface
+
+@_spiOnly import DeclaringLibrary
+@_spiOnly import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// NEGATIVE-NOT: import DeclaringLibrary
+// NEGATIVE-NOT: import BystandingLibrary
+// NEGATIVE-NOT: import _OverlayLibrary
+// PRIVATE-DAG: import DeclaringLibrary
+// PRIVATE-DAG: import BystandingLibrary
+// PRIVATE-DAG: import _OverlayLibrary
+
+
+//--- FirstHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/FirstHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -emit-private-module-interface-path %t.private.swiftinterface -swift-version 6
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.private.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/FirstHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefix NEGATIVE %t/FirstHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefixes CHECK,PRIVATE %t/FirstHidden.swift < %t.private.swiftinterface
+
+@_spiOnly import DeclaringLibrary
+import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// CHECK-DAG: import BystandingLibrary
+// NEGATIVE-NOT: import DeclaringLibrary
+// NEGATIVE-NOT: import _OverlayLibrary
+// PRIVATE-DAG: import DeclaringLibrary
+// PRIVATE-DAG: import _OverlayLibrary
+
+
+//--- SecondHidden.swift
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %t/SecondHidden.swift -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary -emit-private-module-interface-path %t.private.swiftinterface -swift-version 6
+// RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %target-swift-typecheck-module-from-interface(%t.private.swiftinterface) -enable-cross-import-overlays -I %t/lib/swift -module-name ClientLibrary
+// RUN: %FileCheck %t/SecondHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefix NEGATIVE %t/SecondHidden.swift < %t.swiftinterface
+// RUN: %FileCheck -check-prefixes CHECK,PRIVATE %t/SecondHidden.swift < %t.private.swiftinterface
+
+import DeclaringLibrary
+@_spiOnly import BystandingLibrary
+
+// CHECK: // swift-interface-format-version
+// CHECK: // swift-module-flags: {{.*}} -module-name ClientLibrary
+// CHECK-DAG: import Swift
+// CHECK-DAG: import DeclaringLibrary
+// NEGATIVE-NOT: import BystandingLibrary
+// NEGATIVE-NOT: import _OverlayLibrary
+// PRIVATE-DAG: import BystandingLibrary
+// PRIVATE-DAG: import _OverlayLibrary