Support serialization of WorldImpact

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

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 486 matching lines @@
   JavaScriptConstantTask constantCompilerTask;
 
   JavaScriptImpactTransformer impactTransformer;
 
   PatchResolverTask patchResolverTask;
 
   bool enabledNoSuchMethod = false;
 
   SourceInformationStrategy sourceInformationStrategy;
 
+  JavaScriptBackendSerialization serialization;
+
+  final NativeData nativeData = new NativeData();
+
   final BackendHelpers helpers;
   final BackendImpacts impacts;
 
   JavaScriptBackend(Compiler compiler,
                     {bool generateSourceMap: true,
                      bool useStartupEmitter: false,
                      bool useNewSourceInfo: false})
       : namer = determineNamer(compiler),
         oneShotInterceptors = new Map<jsAst.Name, Selector>(),
         interceptedElements = new Map<String, Set<Element>>(),
@@ skipping 18 matching lines @@
     jsInteropAnalysis = new JsInteropAnalysis(this);
 
     noSuchMethodRegistry = new NoSuchMethodRegistry(this);
     constantCompilerTask = new JavaScriptConstantTask(compiler);
     impactTransformer = new JavaScriptImpactTransformer(this);
     patchResolverTask = new PatchResolverTask(compiler);
     functionCompiler = compiler.useCpsIr
          ? new CpsFunctionCompiler(
              compiler, this, sourceInformationStrategy)
          : new SsaFunctionCompiler(this, sourceInformationStrategy);
+    serialization = new JavaScriptBackendSerialization(this);
   }
 
   ConstantSystem get constantSystem => constants.constantSystem;
 
   DiagnosticReporter get reporter => compiler.reporter;
 
   CoreClasses get coreClasses => compiler.coreClasses;
 
   CoreTypes get coreTypes => compiler.coreTypes;
 
@@ skipping 38 matching lines @@
   }
 
   /// The backend must *always* call this method when enqueuing an
   /// element. Calls done by the backend are not seen by global
   /// optimizations, so they would make these optimizations unsound.
   /// Therefore we need to collect the list of helpers the backend may
   /// use.
   // TODO(johnniwinther): Replace this with a more precise modelling; type
   // inference of these elements is disabled.
   Element registerBackendUse(Element element) {
-    if (element != null) {
-      bool registerUse = false;
-      if (element == helpers.streamIteratorConstructor ||
-          element == helpers.compiler.symbolConstructor ||
-          element == helpers.compiler.symbolValidatedConstructor ||
-          element == helpers.syncCompleterConstructor ||
-          element == coreClasses.symbolClass ||
-          element == helpers.objectNoSuchMethod) {
-        // TODO(johnniwinther): These are valid but we could be more precise.
-        registerUse = true;
-      } else if (element.implementationLibrary.isPatch ||
-                 element.library == helpers.jsHelperLibrary ||
-                 element.library == helpers.interceptorsLibrary ||
-                 element.library == helpers.isolateHelperLibrary) {
-        // TODO(johnniwinther): We should be more precise about these.
-        registerUse = true;
-      } else if (element == coreClasses.listClass ||
-                 element == helpers.mapLiteralClass ||
-                 element == coreClasses.functionClass ||
-                 element == coreClasses.stringClass) {
-        // TODO(johnniwinther): Avoid these.
-        registerUse = true;
-      }
-      if (!registerUse) {
-        assert(invariant(element, false,
-            message: "Backend use of $element is not allowed."));
-        return element;
-      }
-      helpersUsed.add(element.declaration);
-      if (element.isClass && element.isPatched) {
-        // Both declaration and implementation may declare fields, so we
-        // add both to the list of helpers.
-        helpersUsed.add(element.implementation);
-      }
+    if (element == null) return null;
+    assert(invariant(element, _isValidBackendUse(element),
+        message: "Backend use of $element is not allowed."));
+    helpersUsed.add(element.declaration);
+    if (element.isClass && element.isPatched) {
+      // Both declaration and implementation may declare fields, so we
+      // add both to the list of helpers.
+      helpersUsed.add(element.implementation);
     }
     return element;
   }
 
+  bool _isValidBackendUse(Element element) {
+    assert(invariant(element, element.isDeclaration,
+        message: ""));
+    if (element == helpers.streamIteratorConstructor ||
+        element == helpers.compiler.symbolConstructor ||
+        element == helpers.compiler.symbolValidatedConstructor ||
+        element == helpers.syncCompleterConstructor ||
+        element == coreClasses.symbolClass ||
+        element == helpers.objectNoSuchMethod) {
+      // TODO(johnniwinther): These are valid but we could be more precise.
+      return true;
+    } else if (element.implementationLibrary.isPatch ||

[Siggi Cherem (dart-lang), 2016/03/17 15:33:45]

nit, can be done later: any reason why not merge all the conditions as a single
expression ||? The current structure of if-else makes it seem like there is more
to it than just a list of possible cases.

[Johnni Winther, 2016/03/18 08:11:32]

They are grouped by the TODOs (the reasons for allowing their backend use).

+               // Needed to detect deserialized injected elements, that is
+               // element declared in patch files.
+               (element.library.isPlatformLibrary &&
+                element.sourcePosition.uri.path.contains(
+                    '_internal/js_runtime/lib/')) ||
+               element.library == helpers.jsHelperLibrary ||
+               element.library == helpers.interceptorsLibrary ||
+               element.library == helpers.isolateHelperLibrary) {
+      // TODO(johnniwinther): We should be more precise about these.
+      return true;
+    } else if (element == coreClasses.listClass ||
+               element == helpers.mapLiteralClass ||
+               element == coreClasses.functionClass ||
+               element == coreClasses.stringClass) {
+      // TODO(johnniwinther): Avoid these.
+      return true;
+    }
+    return false;
+  }
+
   bool usedByBackend(Element element) {
     if (element.isParameter
         || element.isInitializingFormal
         || element.isField) {
       if (usedByBackend(element.enclosingElement)) return true;
     }
     return helpersUsed.contains(element.declaration);
   }
 
   bool invokedReflectively(Element element) {
@@ skipping 54 matching lines @@
     return !selector.isGetter && !compiler.hasIncrementalSupport;
   }
 
   /**
    * Returns `true` if [member] is called from a subclass via `super`.
    */
   bool isAliasedSuperMember(FunctionElement member) {
     return aliasedSuperMembers.contains(member);
   }
 
-  /// The JavaScript names for elements implemented via typed JavaScript
-  /// interop.
-  Map<Element, String> jsInteropNames = <Element, String>{};
-
-  /// The JavaScript names for native JavaScript elements implemented.
-  Map<Element, String> nativeMemberName = <Element, String>{};
-
-  /// Tag info for native JavaScript classes names. See
-  /// [setNativeClassTagInfo].
-  Map<ClassElement, String> nativeClassTagInfo = <ClassElement, String>{};
-
-  /// Returns `true` if [element] is explicitly marked as part of JsInterop.
-  bool _isJsInterop(Element element) {
-    return jsInteropNames.containsKey(element.declaration);
-  }
-
-  /// Returns [element] as an explicit part of JsInterop. The js interop name is
-  /// expected to be computed later.
-  void markAsJsInterop(Element element) {
-    jsInteropNames[element.declaration] = null;
-  }
-
-  /// Sets the explicit js interop [name] for [element].
-  void setJsInteropName(Element element, String name) {
-    assert(invariant(element,
-        isJsInterop(element),
-        message:
-          'Element $element is not js interop but given a js interop name.'));
-    jsInteropNames[element.declaration] = name;
-  }
-
-  /// Returns the explicit js interop name for [element].
-  String getJsInteropName(Element element) {
-    return jsInteropNames[element.declaration];
-  }
-
   /// Returns `true` if [element] is part of JsInterop.
   @override
-  bool isJsInterop(Element element) {
-    // An function is part of JsInterop in the following cases:
-    // * It has a jsInteropName annotation
-    // * It is external member of a class or library tagged as JsInterop.
-    if (element.isFunction || element.isConstructor || element.isAccessor) {
-      FunctionElement function = element;
-      if (!function.isExternal) return false;
-
-      if (_isJsInterop(function)) return true;
-      if (function.isClassMember) return isJsInterop(function.contextClass);
-      if (function.isTopLevel) return isJsInterop(function.library);
-      return false;
-    } else {
-      return _isJsInterop(element);
-    }
-  }
-
-  /// Returns `true` if the name of [element] is fixed for the generated
-  /// JavaScript.
-  bool hasFixedBackendName(Element element) {
-    return isJsInterop(element) ||
-        nativeMemberName.containsKey(element.declaration);
-  }
-
-  String _jsNameHelper(Element element) {
-    String jsInteropName = jsInteropNames[element.declaration];
-    assert(invariant(element,
-        !(_isJsInterop(element) && jsInteropName == null),
-        message:
-            'Element $element is js interop but js interop name has not yet '
-            'been computed.'));
-    if (jsInteropName != null && jsInteropName.isNotEmpty) {
-      return jsInteropName;
-    }
-    return element.isLibrary ? 'self' : element.name;
-  }
-
-  /// Computes the name for [element] to use in the generated JavaScript. This
-  /// is either given through a native annotation or a js interop annotation.
-  String getFixedBackendName(Element element) {
-    String name = nativeMemberName[element.declaration];
-    if (name == null && isJsInterop(element)) {
-      // If an element isJsInterop but _isJsInterop is false that means it is
-      // considered interop as the parent class is interop.
-      name = _jsNameHelper(
-          element.isConstructor ? element.enclosingClass : element);
-      nativeMemberName[element.declaration] = name;
-    }
-    return name;
-  }
+  bool isJsInterop(Element element) => nativeData.isJsInterop(element);
 
   /// Whether [element] corresponds to a native JavaScript construct either
   /// through the native mechanism (`@Native(...)` or the `native` pseudo
   /// keyword) which is only allowed for internal libraries or via the typed
   /// JavaScriptInterop mechanism which is allowed for user libraries.
   @override
-  bool isNative(Element element) {
-    if (isJsInterop(element)) return true;
-    if (element.isClass) {
-      return nativeClassTagInfo.containsKey(element.declaration);
-    } else {
-      return nativeMemberName.containsKey(element.declaration);
-    }
-  }
-
-  /// Sets the native [name] for the member [element]. This name is used for
-  /// [element] in the generated JavaScript.
-  void setNativeMemberName(MemberElement element, String name) {
-    // TODO(johnniwinther): Avoid setting this more than once. The enqueuer
-    // might enqueue [element] several times (before processing it) and computes
-    // name on each call to `internalAddToWorkList`.
-    assert(invariant(element,
-        nativeMemberName[element.declaration] == null ||
-        nativeMemberName[element.declaration] == name,
-        message:
-          "Native member name set inconsistently on $element: "
-          "Existing name '${nativeMemberName[element.declaration]}', "
-          "new name '$name'."));
-    nativeMemberName[element.declaration] = name;
-  }
-
-  /// Sets the native tag info for [cls].
-  ///
-  /// The tag info string contains comma-separated 'words' which are either
-  /// dispatch tags (having JavaScript identifier syntax) and directives that
-  /// begin with `!`.
-  void setNativeClassTagInfo(ClassElement cls, String tagInfo) {
-    // TODO(johnniwinther): Assert that this is only called once. The memory
-    // compiler copies pre-processed elements into a new compiler through
-    // [Compiler.onLibraryScanned] and thereby causes multiple calls to this
-    // method.
-    assert(invariant(cls,
-        nativeClassTagInfo[cls.declaration] == null ||
-        nativeClassTagInfo[cls.declaration] == tagInfo,
-        message:
-          "Native tag info set inconsistently on $cls: "
-          "Existing tag info '${nativeClassTagInfo[cls.declaration]}', "
-          "new tag info '$tagInfo'."));
-    nativeClassTagInfo[cls.declaration] = tagInfo;
-  }
-
-  /// Returns the list of native tag words for [cls].
-  List<String> getNativeTagsOfClassRaw(ClassElement cls) {
-    String quotedName = nativeClassTagInfo[cls.declaration];
-    return quotedName.substring(1, quotedName.length - 1).split(',');
-  }
-
-  /// Returns the list of non-directive native tag words for [cls].
-  List<String> getNativeTagsOfClass(ClassElement cls) {
-    return getNativeTagsOfClassRaw(cls).where(
-        (s) => !s.startsWith('!')).toList();
-  }
-
-  /// Returns `true` if [cls] has a `!nonleaf` tag word.
-  bool hasNativeTagsForcedNonLeaf(ClassElement cls) {
-    return getNativeTagsOfClassRaw(cls).contains('!nonleaf');
-  }
+  bool isNative(Element element) => nativeData.isNative(element);
 
   bool isNativeOrExtendsNative(ClassElement element) {
     if (element == null) return false;
     if (isNative(element) || isJsInterop(element)) {
       return true;
     }
     assert(element.isResolved);
     return isNativeOrExtendsNative(element.superclass);
   }
 
@@ skipping 122 matching lines @@
 
   void validateInterceptorImplementsAllObjectMethods(
       ClassElement interceptorClass) {
     if (interceptorClass == null) return;
     interceptorClass.ensureResolved(resolution);
     coreClasses.objectClass.forEachMember((_, Element member) {
       if (member.isGenerativeConstructor) return;
       Element interceptorMember = interceptorClass.lookupMember(member.name);
       // Interceptors must override all Object methods due to calling convention
       // differences.
-      assert(interceptorMember.enclosingClass == interceptorClass);
+      assert(invariant(
+          interceptorMember,
+          interceptorMember.enclosingClass == interceptorClass,
+          message:
+            "Member ${member.name} not overridden in ${interceptorClass}. "
+            "Found $interceptorMember from "
+            "${interceptorMember.enclosingClass}."));
     });
   }
 
   void addInterceptorsForNativeClassMembers(
       ClassElement cls, Enqueuer enqueuer) {
     if (enqueuer.isResolutionQueue) {
       cls.ensureResolved(resolution);
       cls.forEachMember((ClassElement classElement, Element member) {
         if (member.name == Identifiers.call) {
           reporter.reportErrorMessage(
@@ skipping 179 matching lines @@
             compiler.globalDependencies);
         enqueueClass(enqueuer, helpers.jsJavaScriptObjectClass, registry);
         enqueueClass(enqueuer, helpers.jsPlainJavaScriptObjectClass, registry);
         enqueueClass(enqueuer, helpers.jsJavaScriptFunctionClass, registry);
       } else if (cls == helpers.mapLiteralClass) {
         // For map literals, the dependency between the implementation class
         // and [Map] is not visible, so we have to add it manually.
         Element getFactory(String name, int arity) {
           // The constructor is on the patch class, but dart2js unit tests don't
           // have a patch class.
-          ClassElement implementation = cls.patch != null ? cls.patch : cls;
+          ClassElement implementation = cls.implementation;
           ConstructorElement ctor = implementation.lookupConstructor(name);
           if (ctor == null ||
               (Name.isPrivateName(name) &&
                ctor.library != helpers.mapLiteralClass.library)) {
             reporter.internalError(
                 helpers.mapLiteralClass,
                 "Map literal class ${helpers.mapLiteralClass} missing "
                 "'$name' constructor"
                 "  ${helpers.mapLiteralClass.constructors}");
           }
           return ctor;
         }
         Element getMember(String name) {
           // The constructor is on the patch class, but dart2js unit tests don't
           // have a patch class.
-          ClassElement implementation = cls.patch != null ? cls.patch : cls;
+          ClassElement implementation = cls.implementation;
           Element element = implementation.lookupLocalMember(name);
           if (element == null || !element.isFunction || !element.isStatic) {
             reporter.internalError(helpers.mapLiteralClass,
                 "Map literal class ${helpers.mapLiteralClass} missing "
                 "'$name' static member function");
           }
           return element;
         }
         helpers.mapLiteralConstructor = getFactory('_literal', 1);
         helpers.mapLiteralConstructorEmpty = getFactory('_empty', 0);
@@ skipping 1427 matching lines @@
   @override
   Uri resolvePatchUri(String libraryName, Uri platformConfigUri) {
     String patchLocation = _patchLocations[libraryName];
     if (patchLocation == null) return null;
     return platformConfigUri.resolve(patchLocation);
   }
 
   @override
   ImpactStrategy createImpactStrategy(
       {bool supportDeferredLoad: true,
-       bool supportDumpInfo: true}) {
+       bool supportDumpInfo: true,
+       bool supportSerialization: true}) {
     return new JavaScriptImpactStrategy(
         resolution,
         compiler.dumpInfoTask,
         supportDeferredLoad: supportDeferredLoad,
-        supportDumpInfo: supportDumpInfo);
+        supportDumpInfo: supportDumpInfo,
+        supportSerialization: supportSerialization);
   }
 }
 
 /// Handling of special annotations for tests.
 class Annotations {
   static final Uri PACKAGE_EXPECT =
       new Uri(scheme: 'package', path: 'expect/expect.dart');
 
   final Compiler compiler;
 
@@ skipping 455 matching lines @@
   final Element annotatedElement;
 
   const Dependency(this.constant, this.annotatedElement);
 }
 
 class JavaScriptImpactStrategy extends ImpactStrategy {
   final Resolution resolution;
   final DumpInfoTask dumpInfoTask;
   final bool supportDeferredLoad;
   final bool supportDumpInfo;
+  final bool supportSerialization;
 
   JavaScriptImpactStrategy(this.resolution,
                            this.dumpInfoTask,
                            {this.supportDeferredLoad,
-                            this.supportDumpInfo});
+                            this.supportDumpInfo,
+                            this.supportSerialization});
 
   @override
   void visitImpact(Element element,
                    WorldImpact impact,
                    WorldImpactVisitor visitor,
                    ImpactUseCase impactUse) {
     // TODO(johnniwinther): Compute the application strategy once for each use.
     if (impactUse == ResolutionEnqueuer.IMPACT_USE) {
-      if (supportDeferredLoad) {
+      if (supportDeferredLoad || supportSerialization) {
         impact.apply(visitor);
       } else {
         impact.apply(visitor);
         resolution.uncacheWorldImpact(element);
       }
     } else if (impactUse == DeferredLoadTask.IMPACT_USE) {
       impact.apply(visitor);
       // Impacts are uncached globally in [onImpactUsed].
     } else if (impactUse == DumpInfoTask.IMPACT_USE) {
       impact.apply(visitor);
       dumpInfoTask.unregisterImpact(element);
     } else {
       impact.apply(visitor);
     }
   }
 
   @override
   void onImpactUsed(ImpactUseCase impactUse) {
-    if (impactUse == DeferredLoadTask.IMPACT_USE) {
+    if (impactUse == DeferredLoadTask.IMPACT_USE &&
+        !supportSerialization) {
+      // TODO(johnniwinther): Allow emptying when serialization has been
+      // performed.
       resolution.emptyCache();
     }
   }
 }