Support user generated custom native JS classes.

pkg/compiler/lib/src/js_emitter/native_emitter.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 dart2js.js_emitter;
 
 class NativeEmitter {
 
   // TODO(floitsch): the native-emitter should not know about ClassBuilders.
   final Map<Element, full_js_emitter.ClassBuilder> cachedBuilders;
@@ skipping 116 matching lines @@
         needed = true;
       } else if (interceptorClassesNeededByConstants.contains(classElement)) {
         needed = true;
       } else if (classesModifiedByEmitRTISupport.contains(classElement)) {
         // TODO(9556): Remove this test when [emitRuntimeTypeSupport] no longer
         // adds information to a class prototype or constructor.
         needed = true;
       } else if (extensionPoints.containsKey(cls)) {
         needed = true;
       }
-      if (cls.isNative &&
-          native.nativeTagsForcedNonLeaf(classElement)) {
+      if (classElement.isJsInterop) {
+        needed = true;  // TODO(jacobr): we don't need all interop classes.
+      } else if (cls.isNative && native.nativeTagsForcedNonLeaf(classElement)) {
         needed = true;
         nonLeafClasses.add(cls);
       }
 
       if (needed || neededClasses.contains(cls)) {
         neededClasses.add(cls);
         neededClasses.add(cls.superclass);
         nonLeafClasses.add(cls.superclass);
       }
     }
 
     // Collect all the tags that map to each native class.
 
     Map<Class, Set<String>> leafTags = new Map<Class, Set<String>>();
     Map<Class, Set<String>> nonleafTags = new Map<Class, Set<String>>();
 
     for (Class cls in classes) {
       if (!cls.isNative) continue;
+      if (cls.element.isJsInterop) continue;
       List<String> nativeTags = native.nativeTagsOfClass(cls.element);
 
       if (nonLeafClasses.contains(cls) ||
           extensionPoints.containsKey(cls)) {
         nonleafTags
             .putIfAbsent(cls, () => new Set<String>())
             .addAll(nativeTags);
       } else {
         Class sufficingInterceptor = cls;
         while (!neededClasses.contains(sufficingInterceptor)) {
@@ skipping 120 matching lines @@
   List<jsAst.Statement> generateParameterStubStatements(
       FunctionElement member,
       bool isInterceptedMethod,
       jsAst.Name invocationName,
       List<jsAst.Parameter> stubParameters,
       List<jsAst.Expression> argumentsBuffer,
       int indexOfLastOptionalArgumentInParameters) {
     // The target JS function may check arguments.length so we need to
     // make sure not to pass any unspecified optional arguments to it.
     // For example, for the following Dart method:
-    //   foo([x, y, z]);
+    //   foo({x, y, z});
     // The call:
     //   foo(y: 1)
     // must be turned into a JS call to:
     //   foo(null, y).
 
     List<jsAst.Statement> statements = <jsAst.Statement>[];
     potentiallyConvertDartClosuresToJs(statements, member, stubParameters);
 
     String target;
     jsAst.Expression receiver;
     List<jsAst.Expression> arguments;
 
     assert(invariant(member, nativeMethods.contains(member)));
     // When calling a JS method, we call it with the native name, and only the
     // arguments up until the last one provided.
     target = member.fixedBackendName;
 
     if (isInterceptedMethod) {
       receiver = argumentsBuffer[0];
       arguments = argumentsBuffer.sublist(1,
           indexOfLastOptionalArgumentInParameters + 1);
     } else {
       // Native methods that are not intercepted must be static.
       assert(invariant(member, member.isStatic));
-      receiver = js('this');
       arguments = argumentsBuffer.sublist(0,
           indexOfLastOptionalArgumentInParameters + 1);
+      if (member.isJsInterop) {
+        // fixedBackendPath is allowed to have the form foo.bar.baz for
+        // interop. This template is uncached to avoid possibly running out of
+        // memory when Dart2Js is run in server mode. In reality the risk of
+        // caching these templates causing an issue  is very low as each class
+        // and library that uses typed JavaScript interop will create only 1
+        // unique template.
+        receiver = js.uncachedExpressionTemplate(
+            backend.namer.fixedBackendPath(member)).instantiate([]);
+      } else {
+        receiver = js('this');
+      }
     }
     statements.add(
         js.statement('return #.#(#)', [receiver, target, arguments]));
 
     return statements;
   }
 
   bool isSupertypeOfNativeClass(ClassElement element) {
     if (backend.classesMixedIntoInterceptedClasses.contains(element)) {
       return true;
     }
 
     return subtypes[element] != null;
   }
 
   bool requiresNativeIsCheck(Element element) {
     // TODO(sra): Remove this function.  It determines if a native type may
     // satisfy a check against [element], in which case an interceptor must be
     // used.  We should also use an interceptor if the check can't be satisfied
     // by a native class in case we get a native instance that tries to spoof
     // the type info.  i.e the criteria for whether or not to use an interceptor
     // is whether the receiver can be native, not the type of the test.
     if (element == null || !element.isClass) return false;
     ClassElement cls = element;
     if (Elements.isNativeOrExtendsNative(cls)) return true;
     return isSupertypeOfNativeClass(element);
   }
 }