Do not allow native syntax on all libraries.

dart/frog/leg/native_handler.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.
 
 #library('native');
 #import('../../lib/uri/uri.dart');
 #import('leg.dart');
 #import('elements/elements.dart');
 #import('scanner/scannerlib.dart');
 #import('ssa/ssa.dart');
 #import('tree/tree.dart');
 #import('util/util.dart');
 
-void processNativeClasses(Compiler compiler,
-                          CompilationUnitElement compilationUnit) {
-  for (Link<Element> link = compilationUnit.topLevelElements;
-       !link.isEmpty(); link = link.tail) {
-    Element element = link.head;
-    if (element.kind == ElementKind.CLASS) {
-      ClassElement classElement = element;
-      if (classElement.isNative()) {
-        compiler.registerInstantiatedClass(classElement);
-        // Also parse the node to know all its methods because
-        // otherwise it will only be parsed if there is a call to
-        // one of its constructor.
-        element.parseNode(compiler);
-        // Resolve to setup the inheritance.
-        element.resolve(compiler);
+class NativeHandler extends CompilerTask {
+  NativeHandler(Compiler compiler)
+    : allowedLibraries = new Set<LibraryElement>(),
+      super(compiler);
+
+  Set<LibraryElement> allowedLibraries;
+
+  void processNativeClasses(CompilationUnitElement compilationUnit) {
+    return measure(() {
+      for (Link<Element> link = compilationUnit.topLevelElements;
+           !link.isEmpty(); link = link.tail) {
+        Element element = link.head;
+        if (element.kind == ElementKind.CLASS) {
+          ClassElement classElement = element;
+          if (classElement.isNative()) {
+            compiler.registerInstantiatedClass(classElement);
+            // Also parse the node to know all its methods because
+            // otherwise it will only be parsed if there is a call to
+            // one of its constructor.
+            element.parseNode(compiler);
+            // Resolve to setup the inheritance.
+            element.resolve(compiler);
+          }
+        }
       }
+    });
+  }
+
+  void checkNativeSupport(LibraryElement library, Uri uri) {
+    String libraryName = uri.toString();
+    if (library.script.name.contains('dart/frog/tests/native/src')
+        || libraryName == 'dart:dom'
+        || libraryName == 'dart:html') {
+      allowedLibraries.add(library);
+      library.define(new ForeignElement(
+          const SourceString('native'), library), compiler);
     }
   }
 }
 
-void checkNativeSupport(Compiler compiler,
-                        LibraryElement library,
-                        Uri uri) {
-  String libraryName = uri.toString();
-  if (library.script.name.contains('dart/frog/tests/native/src')
-      || libraryName == 'dart:dom'
-      || libraryName == 'dart:html') {
-    library.define(new ForeignElement(
-        const SourceString('native'), library), compiler);
+
+void checkAllowedLibrary(ElementListener listener, Token token) {

[ahe, 2012/03/06 08:12:44]

Extracting the compiler from the ElementListener is problematic. I think this
will break mini_parser.

How about passing in a native handler to the ElementListener created in
dart/frog/leg/scanner/scanner_task.dart (assuming that all the following methods
are instance methods on the native handler).

[ngeoffray, 2012/03/06 12:48:49]

Unfortunately, this does not work that well. See listener.dart line 1456. The
compiler is not available.

At this point, I'd rather do a "if (listener.listener is Compiler)".

[ahe, 2012/03/06 13:08:30]

It will work fine. We can do a VC and I can explain what I mean.

+  Compiler compiler = listener.listener;
+  LibraryElement currentLibrary = listener.compilationUnitElement.getLibrary();
+  if (!compiler.nativeHandler.allowedLibraries.contains(currentLibrary)) {
+    listener.unexpected(token);
   }
 }
 
-Token handleNativeBlockToSkip(Listener listener, Token token) {
- token = token.next;
+Token handleNativeBlockToSkip(ElementListener listener, Token token) {
+  checkAllowedLibrary(listener, token);
+  token = token.next;
   if (token.kind === STRING_TOKEN) {
     token = token.next;
   }
   if (token.stringValue === '{') {
     BeginGroupToken beginGroupToken = token;
     token = beginGroupToken.endGroup;
   }
   return token;
 }
 
 Token handleNativeClassBodyToSkip(Listener listener, Token token) {
+  checkAllowedLibrary(listener, token);
   listener.handleIdentifier(token);
   token = token.next;
   if (token.kind !== STRING_TOKEN) {
     return listener.unexpected(token);
   }
   token = token.next;
   if (token.stringValue !== '{') {
     return listener.unexpected(token);
   }
   BeginGroupToken beginGroupToken = token;
   token = beginGroupToken.endGroup;
   return token;
 }
 
 Token handleNativeClassBody(Listener listener, Token token) {
+  checkAllowedLibrary(listener, token);
   token = token.next;
   if (token.kind !== STRING_TOKEN) {
     listener.unexpected(token);
   } else {
     token = token.next;
   }
   return token;
 }
 
 Token handleNativeFunctionBody(ElementListener listener, Token token) {
+  checkAllowedLibrary(listener, token);
   Token begin = token;
   listener.beginExpressionStatement(token);
   listener.handleIdentifier(token);
   token = token.next;
   if (token.kind === STRING_TOKEN) {
     listener.beginLiteralString(token);
     listener.endLiteralString(0);
     listener.pushNode(new NodeList.singleton(listener.popNode()));
     listener.endSend(token);
     token = token.next;
@@ skipping 121 matching lines @@
   } else if (!node.arguments.tail.isEmpty()) {
     builder.compiler.cancel('More than one argument to native');
   } else {
     LiteralString jsCode = node.arguments.head;
     int start = jsCode.value.slowToString()[0] === '@' ? 1 : 0;
     builder.push(new HForeign(builder.unquote(jsCode, start),
                               const SourceString('Object'),
                               <HInstruction>[]));
   }
 }