dart2js: Emit constants in new emitter.

sdk/lib/_internal/compiler/implementation/js_emitter/program_builder.dart

 // Copyright (c) 2014, 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 dart2js.js_emitter.program_builder;
 
 import 'model.dart';
 import '../common.dart';
 import '../js/js.dart' as js;
 
@@ skipping 24 matching lines @@
   Universe get universe => _compiler.codegenWorld;
 
   /// Mapping from [ClassElement] to constructed [Class]. We need this to
   /// update the superclass in the [Class].
   final Map<ClassElement, Class> _classes = <ClassElement, Class>{};
 
   /// Mapping from [OutputUnit] to constructed [Output]. We need this to
   /// generate the deferredLoadingMap (to know which hunks to load).
   final Map<OutputUnit, Output> _outputs = <OutputUnit, Output>{};
 
+  /// Mapping from [ConstantValue] to constructed [Constant]. We need this to
+  /// update field-initializers to point to the ConstantModel.
+  final Map<ConstantValue, Constant> _constants = <ConstantValue, Constant>{};
+
   Program buildProgram() {
-    Set<ClassElement> neededClasses = _task.neededClasses;
-    Iterable<Element> neededStatics = backend.generatedCode.keys
-        .where((Element e) => !e.isInstanceMember && !e.isField);
-
     _task.outputClassLists.forEach(_registry.registerElements);
     _task.outputStaticLists.forEach(_registry.registerElements);
 
     // TODO(kasperl): There's code that implicitly needs access to the special
     // $ holder so we have to register that. Can we track if we have to?
     _registry.registerHolder(r'$');
 
     MainOutput mainOutput = _buildMainOutput(_registry.mainFragment);
     Iterable<Output> deferredOutputs = _registry.deferredFragments
         .map((fragment) => _buildDeferredOutput(mainOutput, fragment));
@@ skipping 29 matching lines @@
     });
     return loadMap;
   }
 
   MainOutput _buildMainOutput(Fragment fragment) {
     // Construct the main output from the libraries and the registered holders.
     MainOutput result = new MainOutput(
         "",  // The empty string is the name for the main output file.
         namer.elementAccess(_compiler.mainFunction),
         _buildLibraries(fragment),
+        _buildConstants(_task.outputConstantLists[fragment.outputUnit]),
         _registry.holders.toList(growable: false));
     _outputs[fragment.outputUnit] = result;
     return result;
   }
 
   /// Returns a name composed of the main output file name and [name].
   String _outputFileName(String name) {
     assert(name != "");
     String outPath = _compiler.outputUri != null
         ? _compiler.outputUri.path
         : "out";
     String outName = outPath.substring(outPath.lastIndexOf('/') + 1);
     return "${outName}_$name";
   }
 
   DeferredOutput _buildDeferredOutput(MainOutput mainOutput,
                                       Fragment fragment) {
     DeferredOutput result = new DeferredOutput(
         _outputFileName(fragment.name), fragment.name,
-        mainOutput, _buildLibraries(fragment));
+        mainOutput, _buildLibraries(fragment),
+        _buildConstants(_task.outputConstantLists[fragment.outputUnit]));
     _outputs[fragment.outputUnit] = result;
     return result;
   }
 
+  List<Constant> _buildConstants(List<ConstantValue> constantValues) {

[kasperl, 2014/10/16 07:01:57]

Should this be _buildConstantsForFragment to avoid repeating the
_task.outputConstantLists[fragment.outputUnit]) code?

[floitsch, 2014/10/16 12:59:54]

Done.

+    if (constantValues == null) return const <Constant>[];
+    return constantValues.map((ConstantValue constantValue) {
+      assert(!_constants.containsKey(constantValue));
+      String name = namer.constantName(constantValue);
+      String constantObject = namer.globalObjectForConstant(constantValue);
+      Holder holder = _registry.registerHolder(constantObject);
+      Constant constant = new Constant(name, holder, constantValue);
+      _constants[constantValue] = constant;
+      return constant;
+    }).toList();
+  }
+
   List<Library> _buildLibraries(Fragment fragment) {
     List<Library> libraries = new List<Library>(fragment.length);
     int count = 0;
     fragment.forEach((LibraryElement library, List<Element> elements) {
       libraries[count++] = _buildLibrary(library, elements);
     });
     return libraries;
   }
 
   // Note that a library-element may have multiple [Library]s, if it is split
@@ skipping 49 matching lines @@
   }
 
   StaticMethod _buildStaticMethodTearOff(FunctionElement element) {
     String name = namer.getStaticClosureName(element);
     String holder = namer.globalObjectFor(element);
     // TODO(kasperl): This clearly doesn't work yet.
     js.Expression code = js.string("<<unimplemented>>");
     return new StaticMethod(name, _registry.registerHolder(holder), code);
   }
 }