Emit constants using ASTs

sdk/lib/_internal/compiler/implementation/js_backend/namer.dart

 // Copyright (c) 2011, 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;
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer {
@@ skipping 390 matching lines @@
 
   String getLazyInitializerName(Element element) {
     assert(Elements.isStaticOrTopLevelField(element));
     return getMappedGlobalName("get\$${getName(element)}");
   }
 
   String isolatePropertiesAccess(Element element) {
     return "$ISOLATE.$ISOLATE_PROPERTIES.${getName(element)}";
   }
 
-  String isolatePropertiesAccessForConstant(String constantName) {
-    return "$ISOLATE.$ISOLATE_PROPERTIES.$constantName";
+  js.Expression isolatePropertiesAccessForConstant(String constantName) {

[ngeoffray, 2012/11/27 09:26:28]

I'd prefer not having this method here. The namer is pretty consistent in
returning strings.

[sra1, 2012/11/28 03:59:44]

I might agree, but that leaves the question of where to put this method?
In this case I will fold it into ConstantReferenceEmitter.

isolateAccess will need to be converted to return an expression too, but it is
called from 25 places in 6 files.  Better to have one place that knows how to
'index' the current isolate than 25.  Consider what happens if we wrap the code
in a function - 25 places to update expression from an access path to a simple
local variable.

[ngeoffray, 2012/11/28 09:25:21]

So maybe the isolateAccess, isolateBailoutAccess... methods that do property
access on the isolate should really not be in the namer. We should get a js.Ast
builder class that helps for doing these operations.

[floitsch, 2012/11/28 10:04:32]

I agree. And it should probably be the emitter anyways that should give that
information.

+    //  $ISOLATE.$ISOLATE_PROPERTIES.$constantName
+    return new js.PropertyAccess.field(
+        new js.PropertyAccess.field(
+            new js.VariableUse(ISOLATE), ISOLATE_PROPERTIES),
+        constantName);
   }
 
   String isolateAccess(Element element) {
     return "$CURRENT_ISOLATE.${getName(element)}";
   }
 
   String isolateBailoutAccess(Element element) {
     String newName = getMappedGlobalName('${getName(element)}\$bailout');
     return '$CURRENT_ISOLATE.$newName';
   }
 
   String isolateLazyInitializerAccess(Element element) {
     return "$CURRENT_ISOLATE.${getLazyInitializerName(element)}";
   }
 
   String operatorIs(Element element) {
     // TODO(erikcorry): Reduce from is$x to ix when we are minifying.
     return 'is\$${getName(element)}';
   }
 
   String safeName(String name) {
     if (jsReserved.contains(name) || name.startsWith('\$')) {
       name = "\$$name";
       assert(!jsReserved.contains(name));
     }
     return name;
   }
 }