Move some string methods in the interceptor, and support for optional parameters in intercepted met…

sdk/lib/_internal/compiler/implementation/js_backend/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 js_backend;
 
 /**
  * A function element that represents a closure call. The signature is copied
  * from the given element.
  */
@@ skipping 376 matching lines @@
     List<SourceString> names = selector.getOrderedNamedArguments();
 
     String invocationName =
         namer.instanceMethodInvocationName(member.getLibrary(), member.name,
                                            selector);
     if (alreadyGenerated.contains(invocationName)) return;
     alreadyGenerated.add(invocationName);
     CodeBuffer buffer = new CodeBuffer();
     buffer.add('function(');
 
+    JavaScriptBackend backend = compiler.backend;

[ahe, 2012/11/13 18:41:26]

Looks like this variable is only used once.

[ngeoffray, 2012/11/14 09:24:44]

Yes, but I need the 'cast' to JavaScriptBackend.

+    bool isInterceptorClass =
+        backend.isInterceptorClass(member.getEnclosingClass());
+
+    // If the method is in an interceptor class, we need to also pass
+    // the actual receiver.
+    int extraArgumentCount = isInterceptorClass ? 1 : 0;
+
     // The parameters that this stub takes.
-    List<String> parametersBuffer = new List<String>(selector.argumentCount);
+    List<String> parametersBuffer =
+        new List<String>(selector.argumentCount + extraArgumentCount);
     // The arguments that will be passed to the real method.
-    List<String> argumentsBuffer = new List<String>(parameters.parameterCount);
+    List<String> argumentsBuffer =
+        new List<String>(parameters.parameterCount + extraArgumentCount);
 
     int count = 0;
+    if (isInterceptorClass) {
+      count++;
+      // Use $ to avoid clashes with other parameter names.

[floitsch, 2012/11/13 18:20:01]

Too brittle. Discuss with Erik how this should be done.

[ngeoffray, 2012/11/14 09:18:43]

Note that this is not touched by the minifier. I could use Namer.isolateName
instead.

[floitsch, 2012/11/14 10:06:33]

1. It should go through the minifier (eventually).
2. If we change the isolate-name from "$" to something else you cannot be sure
anymore that the element-name will not clash with the isolate-name. Currently
"$" is always escaped by "getValid", but that's more of an accident.

[ngeoffray, 2012/11/14 10:10:58]

It doesn't have to be an accident, just an internal convention. If I'm not using
that convention, I think the only option is to go through the list of parameter
names, and make up one that isn't used (eg temp).

Note that I could also do the minifiying myself in this code (using a, b, c, d
as parameter names).

[floitsch, 2012/11/14 10:18:45]

Yes. there are several possibilities. That's why I propose to talk with Erik.

[floitsch, 2012/11/14 12:01:26]

As Erik suggests: this should work for now.
Please add a comment, that this works because "JsNames.getValid" below is
guaranteed never to return "$".
So this choice has nothing to do with the fact that the isolate is "$".

+      parametersBuffer[0] = r'$';
+      argumentsBuffer[0] = r'$';
+    }
+
     int indexOfLastOptionalArgumentInParameters = positionalArgumentCount - 1;
     TreeElements elements =
         compiler.enqueuer.resolution.getCachedElements(member);
 
     parameters.orderedForEachParameter((Element element) {
       String jsName = JsNames.getValid(element.name.slowToString());
-      if (count < positionalArgumentCount) {
+      if (count < positionalArgumentCount + extraArgumentCount) {
         parametersBuffer[count] = jsName;
         argumentsBuffer[count] = jsName;
       } else {
         int index = names.indexOf(element.name);
         if (index != -1) {
           indexOfLastOptionalArgumentInParameters = count;
           // The order of the named arguments is not the same as the
           // one in the real method (which is in Dart source order).
           argumentsBuffer[count] = jsName;
           parametersBuffer[selector.positionalArgumentCount + index] = jsName;
@@ skipping 1241 matching lines @@
 const String HOOKS_API_USAGE = """
 // Generated by dart2js, the Dart to JavaScript compiler.
 // The code supports the following hooks:
 // dartPrint(message)   - if this function is defined it is called
 //                        instead of the Dart [print] method.
 // dartMainRunner(main) - if this function is defined, the Dart [main]
 //                        method will not be invoked directly.
 //                        Instead, a closure that will invoke [main] is
 //                        passed to [dartMainRunner].
 """;