Sema: Warn on all non-resilient uses of @_implementationOnly, even for clang targets

The warnings about `using '@_implementationOnly' without enabling library evolution for 'client'
may lead to instability during execution` and `@_implementationOnly' is deprecated, use
'internal import' instead` were wrongly restricted to only Swift import targets.
Make sure they are raised for clang module targets as well.

rdar://135233043

Author: xymus

lib/Sema/ImportResolution.cpp

@@ -792,18 +792,15 @@ void UnboundImport::validateInterfaceWithPackageName(ModuleDecl *topLevelModule,
 
 void UnboundImport::validateResilience(NullablePtr<ModuleDecl> topLevelModule,
                                        SourceFile &SF) {
-  ASTContext &ctx = SF.getASTContext();
-
-  // Per getTopLevelModule(), we'll only get nullptr here for non-Swift modules,
-  // so these two really mean the same thing.
-  if (!topLevelModule || topLevelModule.get()->isNonSwiftModule())
+  if (!topLevelModule)
     return;
 
   // If the module we're validating is the builtin one, then just return because
   // this module is essentially a header only import and does not concern
   // itself with resiliency. This can occur when one has passed
   // '-enable-builtin-module' and is explicitly importing the Builtin module in
   // their sources.
+  ASTContext &ctx = SF.getASTContext();
   if (topLevelModule.get() == ctx.TheBuiltinModule)
     return;
 
@@ -841,7 +838,8 @@ void UnboundImport::validateResilience(NullablePtr<ModuleDecl> topLevelModule,
   }
 
   // Report public imports of non-resilient modules from a resilient module.
-  if (import.options.contains(ImportFlags::ImplementationOnly) ||
+  if (topLevelModule.get()->isNonSwiftModule() ||
+      import.options.contains(ImportFlags::ImplementationOnly) ||
       import.accessLevel < AccessLevel::Public)
     return;
 

test/Sema/implementation-only-import-from-non-resilient.swift

@@ -1,10 +1,10 @@
 // RUN: %empty-directory(%t)
-// RUN: split-file %s %t
+// RUN: split-file %s %t --leading-lines
 
 /// Build 2 libs.
-// RUN: %target-swift-frontend -emit-module %t/empty.swift -o %t/A.swiftmodule \
+// RUN: %target-swift-frontend -emit-module %t/empty.swift -o %t/SwiftModuleA.swiftmodule \
 // RUN:   -enable-library-evolution -swift-version 5
-// RUN: %target-swift-frontend -emit-module %t/empty.swift -o %t/B.swiftmodule \
+// RUN: %target-swift-frontend -emit-module %t/empty.swift -o %t/SwiftModuleB.swiftmodule \
 // RUN:   -enable-library-evolution -swift-version 5
 
 /// Build a client with and without library-evolution.
@@ -19,18 +19,47 @@
 // RUN: %target-swift-frontend -typecheck %t/Crypto.swift -I %t -verify \
 // RUN:   -module-name Crypto
 
+//--- module.modulemap
+module ClangModuleA {
+    header "ClangModuleA.h"
+
+    module Submodule {
+        header "ClangSubmodule.h"
+    }
+}
+
+module ClangModuleB {
+    header "ClangModuleB.h"
+}
+
+//--- ClangModuleA.h
+//--- ClangSubmodule.h
+//--- ClangModuleB.h
+
 //--- empty.swift
 
 //--- client-non-resilient.swift
-@_implementationOnly import A // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'main' may lead to instability during execution}}
-import B
+@_implementationOnly import SwiftModuleA // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'main' may lead to instability during execution}}
+@_implementationOnly import SwiftModuleA // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'main' may lead to instability during execution}}
+import SwiftModuleB
+
+@_implementationOnly import ClangModuleA // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'main' may lead to instability during execution}}
+@_implementationOnly import ClangModuleA.Submodule // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'main' may lead to instability during execution}}
+import ClangModuleB
 
 //--- client-resilient.swift
-@_implementationOnly import A
+@_implementationOnly import SwiftModuleA
+// expected-warning @-1 {{'@_implementationOnly' is deprecated, use 'internal import' instead}}
+import SwiftModuleB
+
+@_implementationOnly import ClangModuleA
+// expected-warning @-1 {{'@_implementationOnly' is deprecated, use 'internal import' instead}}
+@_implementationOnly import ClangModuleA.Submodule
 // expected-warning @-1 {{'@_implementationOnly' is deprecated, use 'internal import' instead}}
-import B
+import ClangModuleB
 
 //--- Crypto.swift
-@_implementationOnly import A // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'Crypto' may lead to instability during execution}}
-import B
+@_implementationOnly import SwiftModuleA // expected-warning {{using '@_implementationOnly' without enabling library evolution for 'Crypto' may lead to instability during execution}}
+import SwiftModuleB
 @_implementationOnly import CCryptoBoringSSL
+import ClangModuleB