[vm] Allow vm tests to import private platform libraries for testing purposes

Issue #36097

Change-Id: I1acec0b7c683ffa363e9b6f7056e76ea2f61d27d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/114843
Reviewed-by: Johnni Winther <[email protected]>
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Martin Kustermann <[email protected]>

Author: mkustermann

pkg/vm/lib/target/vm.dart

@@ -349,6 +349,13 @@ class VmTarget extends Target {
         ]));
   }
 
+  // In addition to the default implementation, we allow VM tests to import
+  // private platform libraries - such as `dart:_internal` - for testing
+  // purposes.
+  bool allowPlatformPrivateLibraryAccess(Uri importer, Uri imported) =>
+      super.allowPlatformPrivateLibraryAccess(importer, imported) ||
+      importer.path.contains('runtime/tests/vm/dart');
+
   // TODO(sigmund,ahe): limit this to `dart-ext` libraries only (see
   // https://github.com/dart-lang/sdk/issues/29763).
   @override

runtime/tests/vm/dart/internal_platform_library_import_test.dart

@@ -0,0 +1,10 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:_internal';
+
+void main(List<String> args) {
+  // Ensure we can import and use members of `dart:_internal`.
+  print(unsafeCast);
+}