Assert that we don't mix K and J elements

pkg/compiler/lib/src/js_backend/backend.dart

Index: pkg/compiler/lib/src/js_backend/backend.dart
diff --git a/pkg/compiler/lib/src/js_backend/backend.dart b/pkg/compiler/lib/src/js_backend/backend.dart
index aa761c550cb717dcdfad4d91a41bbe27ae6728cf..f9bf86f03aa51f4ef37bb2ba9c1bee99e789a0f2 100644
--- a/pkg/compiler/lib/src/js_backend/backend.dart
+++ b/pkg/compiler/lib/src/js_backend/backend.dart
@@ -365,18 +365,13 @@ class JavaScriptBackend {
     return result;
   }
 
-  final RuntimeTypesNeedBuilder _rtiNeedBuilder;
-  RuntimeTypesNeed _rtiNeed;
-  final RuntimeTypesImpl _rti;
+  RuntimeTypesImpl _rti;
 
   RuntimeTypesEncoder _rtiEncoder;
 
   /// True if the html library has been loaded.
   bool htmlLibraryIsLoaded = false;
 
-  /// Resolution analysis for tracking reflective access to type variables.
-  TypeVariableResolutionAnalysis _typeVariableResolutionAnalysis;
-
   /// Codegen handler for reflective access to type variables.
   TypeVariableCodegenAnalysis _typeVariableCodegenAnalysis;
 
@@ -427,9 +422,6 @@ class JavaScriptBackend {
   JavaScriptBackendSerialization serialization;
 
   NativeDataBuilderImpl _nativeDataBuilder;
-  final NativeBasicDataBuilderImpl _nativeBasicDataBuilder =
-      new NativeBasicDataBuilderImpl();
-  NativeBasicDataImpl _nativeBasicData;
   NativeDataBuilder get nativeDataBuilder => _nativeDataBuilder;
   final NativeDataResolver _nativeDataResolver;
   OneShotInterceptorData _oneShotInterceptorData;
@@ -442,8 +434,6 @@ class JavaScriptBackend {
   native.NativeResolutionEnqueuer _nativeResolutionEnqueuer;
   native.NativeCodegenEnqueuer _nativeCodegenEnqueuer;
 
-  BackendImpacts impacts;
-
   Target _target;
 
   Tracer tracer;
@@ -454,31 +444,20 @@ class JavaScriptBackend {
       bool useMultiSourceInfo: false,
       bool useNewSourceInfo: false,
       bool useKernel: false})
-      : _rti = new RuntimeTypesImpl(
-            compiler.frontendStrategy.elementEnvironment,
-            compiler.frontendStrategy.dartTypes),
-        optimizerHints = new OptimizerHintsForTests(
+      : optimizerHints = new OptimizerHintsForTests(
             compiler.frontendStrategy.elementEnvironment,
             compiler.frontendStrategy.commonElements),
         this.sourceInformationStrategy =
             compiler.backendStrategy.sourceInformationStrategy,
         constantCompilerTask = new JavaScriptConstantTask(compiler),
-        _nativeDataResolver = new NativeDataResolverImpl(compiler),
-        _rtiNeedBuilder =
-            compiler.frontendStrategy.createRuntimeTypesNeedBuilder() {
+        _nativeDataResolver = new NativeDataResolverImpl(compiler) {
     CommonElements commonElements = compiler.frontendStrategy.commonElements;
     _target = new JavaScriptBackendTarget(this);
-    impacts = new BackendImpacts(compiler.options, commonElements);
     _mirrorsData = compiler.frontendStrategy.createMirrorsDataBuilder();
     _backendUsageBuilder = new BackendUsageBuilderImpl(commonElements);
     _checkedModeHelpers = new CheckedModeHelpers(commonElements);
     emitter =
         new CodeEmitterTask(compiler, generateSourceMap, useStartupEmitter);
-
-    _typeVariableResolutionAnalysis = new TypeVariableResolutionAnalysis(
-        compiler.frontendStrategy.elementEnvironment,
-        impacts,
-        _backendUsageBuilder);
     jsInteropAnalysis = new JsInteropAnalysis(this);
     _mirrorsResolutionAnalysis =
         compiler.frontendStrategy.createMirrorsResolutionAnalysis(this);
@@ -524,25 +503,6 @@ class JavaScriptBackend {
     return _customElementsCodegenAnalysis;
   }
 
-  NativeBasicData get nativeBasicData {
-    assert(
-        _nativeBasicData != null,
-        failedAt(NO_LOCATION_SPANNABLE,
-            "NativeBasicData has not been computed yet."));
-    return _nativeBasicData;
-  }
-
-  NativeBasicDataBuilder get nativeBasicDataBuilder => _nativeBasicDataBuilder;
-
-  /// Resolution analysis for tracking reflective access to type variables.
-  TypeVariableResolutionAnalysis get typeVariableResolutionAnalysis {
-    assert(
-        _typeVariableCodegenAnalysis == null,
-        failedAt(NO_LOCATION_SPANNABLE,
-            "TypeVariableHandler has already been created."));
-    return _typeVariableResolutionAnalysis;
-  }
-
   /// Codegen handler for reflective access to type variables.
   TypeVariableCodegenAnalysis get typeVariableCodegenAnalysis {
     assert(
@@ -586,32 +546,26 @@ class JavaScriptBackend {
     return _oneShotInterceptorData;
   }
 
-  RuntimeTypesNeed get rtiNeed {
+  RuntimeTypesChecksBuilder get rtiChecksBuilder {
     assert(
-        _rtiNeed != null,
+        _rti != null,
         failedAt(NO_LOCATION_SPANNABLE,
-            "RuntimeTypesNeed has not been computed yet."));
-    return _rtiNeed;
-  }
-
-  RuntimeTypesNeedBuilder get rtiNeedBuilder {
+            "RuntimeTypesChecksBuilder has not been created yet."));
     assert(
-        _rtiNeed == null,
+        !_rti.rtiChecksBuilderClosed,
         failedAt(NO_LOCATION_SPANNABLE,
-            "RuntimeTypesNeed has already been computed."));
-    return _rtiNeedBuilder;
+            "RuntimeTypesChecks has already been computed."));
+    return _rti;
   }
 
-  RuntimeTypesChecksBuilder get rtiChecksBuilder {
+  RuntimeTypesSubstitutions get rtiSubstitutions {
     assert(
-        !_rti.rtiChecksBuilderClosed,
+        _rti != null,
         failedAt(NO_LOCATION_SPANNABLE,
-            "RuntimeTypesChecks has already been computed."));
+            "RuntimeTypesSubstitutions has not been created yet."));
     return _rti;
   }
 
-  RuntimeTypesSubstitutions get rtiSubstitutions => _rti;
-
   RuntimeTypesEncoder get rtiEncoder {
     assert(
         _rtiEncoder != null,
@@ -726,8 +680,8 @@ class JavaScriptBackend {
 
   /// Called when the resolution queue has been closed.
   void onResolutionEnd() {
-    frontendStrategy.annotationProcesser
-        .processJsInteropAnnotations(nativeBasicData, nativeDataBuilder);
+    frontendStrategy.annotationProcesser.processJsInteropAnnotations(
+        frontendStrategy.nativeBasicData, nativeDataBuilder);
   }
 
   /// Called when the closed world from resolution has been computed.
@@ -740,11 +694,6 @@ class JavaScriptBackend {
     }
     mirrorsDataBuilder.computeMembersNeededForReflection(
         compiler.enqueuer.resolution.worldBuilder, closedWorld);
-    _rtiNeed = rtiNeedBuilder.computeRuntimeTypesNeed(
-        compiler.enqueuer.resolution.worldBuilder,
-        closedWorld,
-        compiler.frontendStrategy.dartTypes,
-        enableTypeAssertions: compiler.options.enableTypeAssertions);
     mirrorsResolutionAnalysis.onResolutionComplete();
   }
 
@@ -789,7 +738,16 @@ class JavaScriptBackend {
     ElementEnvironment elementEnvironment =
         compiler.frontendStrategy.elementEnvironment;
     CommonElements commonElements = compiler.frontendStrategy.commonElements;
-    _nativeBasicData = nativeBasicDataBuilder.close(elementEnvironment);
+    NativeBasicData nativeBasicData = compiler.frontendStrategy.nativeBasicData;
+    RuntimeTypesNeedBuilder rtiNeedBuilder =
+        compiler.frontendStrategy.createRuntimeTypesNeedBuilder();
+    BackendImpacts impacts =
+        new BackendImpacts(compiler.options, commonElements);
+    TypeVariableResolutionAnalysis typeVariableResolutionAnalysis =
+        new TypeVariableResolutionAnalysis(
+            compiler.frontendStrategy.elementEnvironment,
+            impacts,
+            _backendUsageBuilder);
     _nativeResolutionEnqueuer = new native.NativeResolutionEnqueuer(
         compiler.options,
         elementEnvironment,
@@ -848,6 +806,8 @@ class JavaScriptBackend {
             _nativeDataBuilder,
             interceptorDataBuilder,
             _backendUsageBuilder,
+            rtiNeedBuilder,
+            _nativeResolutionEnqueuer,
             const OpenWorldStrategy()),
         compiler.frontendStrategy.createResolutionWorkItemBuilder(
             nativeBasicData, _nativeDataBuilder, impactTransformer));
@@ -858,6 +818,8 @@ class JavaScriptBackend {
       CompilerTask task, Compiler compiler, ClosedWorld closedWorld) {
     ElementEnvironment elementEnvironment = closedWorld.elementEnvironment;
     CommonElements commonElements = closedWorld.commonElements;
+    BackendImpacts impacts =
+        new BackendImpacts(compiler.options, commonElements);
     _typeVariableCodegenAnalysis = new TypeVariableCodegenAnalysis(
         closedWorld.elementEnvironment, this, commonElements, mirrorsData);
     _lookupMapAnalysis = new LookupMapAnalysis(
@@ -869,28 +831,31 @@ class JavaScriptBackend {
         lookupMapResolutionAnalysis);
     _mirrorsCodegenAnalysis = mirrorsResolutionAnalysis.close();
     _customElementsCodegenAnalysis = new CustomElementsCodegenAnalysis(
-        constantSystem, commonElements, elementEnvironment, nativeBasicData);
+        constantSystem,
+        commonElements,
+        elementEnvironment,
+        closedWorld.nativeData);
     _nativeCodegenEnqueuer = new native.NativeCodegenEnqueuer(
         compiler.options,
         elementEnvironment,
         commonElements,
-        compiler.frontendStrategy.dartTypes,
+        closedWorld.dartTypes,
         emitter,
-        _nativeResolutionEnqueuer,
+        closedWorld.liveNativeClasses,
         closedWorld.nativeData);
     return new CodegenEnqueuer(
         task,
         compiler.options,
         const TreeShakingEnqueuerStrategy(),
         compiler.backendStrategy.createCodegenWorldBuilder(
-            nativeBasicData, closedWorld, const TypeMaskStrategy()),
+            closedWorld.nativeData, closedWorld, const TypeMaskStrategy()),
         compiler.backendStrategy.createCodegenWorkItemBuilder(closedWorld),
         new CodegenEnqueuerListener(
             elementEnvironment,
             commonElements,
             impacts,
             closedWorld.backendUsage,
-            rtiNeed,
+            closedWorld.rtiNeed,
             customElementsCodegenAnalysis,
             typeVariableCodegenAnalysis,
             lookupMapAnalysis,
@@ -938,8 +903,8 @@ class JavaScriptBackend {
 
   native.NativeEnqueuer get nativeCodegenEnqueuer => _nativeCodegenEnqueuer;
 
-  ClassElement defaultSuperclass(
-      CommonElements commonElements, ClassElement element) {
+  ClassElement defaultSuperclass(CommonElements commonElements,
+      NativeBasicData nativeBasicData, ClassElement element) {
     if (nativeBasicData.isJsInteropClass(element)) {
       return commonElements.jsJavaScriptObjectClass;
     }
@@ -1026,9 +991,9 @@ class JavaScriptBackend {
       AnnotationProcessor processor =
           compiler.frontendStrategy.annotationProcesser;
       if (canLibraryUseNative(library)) {
-        processor.extractNativeAnnotations(library, nativeBasicDataBuilder);
+        processor.extractNativeAnnotations(library);
       }
-      processor.extractJsInteropAnnotations(library, nativeBasicDataBuilder);
+      processor.extractJsInteropAnnotations(library);
     }
     Uri uri = library.canonicalUri;
     if (uri == Uris.dart_html) {
@@ -1066,6 +1031,12 @@ class JavaScriptBackend {
     _rtiEncoder = _namer.rtiEncoder = new RuntimeTypesEncoderImpl(
         namer, closedWorld.elementEnvironment, closedWorld.commonElements);
     emitter.createEmitter(namer, closedWorld, codegenWorldBuilder, sorter);
+    // TODO(johnniwinther): Share the impact object created in
+    // createCodegenEnqueuer.
+    BackendImpacts impacts =
+        new BackendImpacts(compiler.options, closedWorld.commonElements);
+    _rti = new RuntimeTypesImpl(
+        closedWorld.elementEnvironment, closedWorld.dartTypes);
     _codegenImpactTransformer = new CodegenImpactTransformer(
         compiler.options,
         closedWorld.elementEnvironment,
@@ -1074,7 +1045,7 @@ class JavaScriptBackend {
         checkedModeHelpers,
         closedWorld.nativeData,
         closedWorld.backendUsage,
-        rtiNeed,
+        closedWorld.rtiNeed,
         nativeCodegenEnqueuer,
         namer,
         oneShotInterceptorData,
@@ -1362,12 +1333,13 @@ class JavaScriptBackendTarget extends Target {
 
   @override
   ClassElement defaultSuperclass(ClassElement element) {
-    return _backend.defaultSuperclass(_commonElements, element);
+    return _backend.defaultSuperclass(
+        _commonElements, _backend.frontendStrategy.nativeBasicData, element);
   }
 
   @override
   bool isNativeClass(ClassEntity element) =>
-      _backend.nativeBasicData.isNativeClass(element);
+      _backend.compiler.frontendStrategy.nativeBasicData.isNativeClass(element);
 
   @override
   bool isForeign(Element element) =>