Compile and run Hello World!

pkg/compiler/lib/src/universe/codegen_world_builder.dart

 // Copyright (c) 2017, 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 world_builder;
 
 /// World builder specific to codegen.
 ///
 /// This adds additional access to liveness of selectors and elements.
 abstract class CodegenWorldBuilder implements WorldBuilder {
   /// Calls [f] with every instance field, together with its declarer, in an
   /// instance of [cls].
   void forEachInstanceField(
       ClassEntity cls, void f(ClassEntity declarer, FieldEntity field));
 
   /// Calls [f] for each parameter of [function] providing the type and name of
   /// the parameter and the [defaultValue] if the parameter is optional.
   void forEachParameter(FunctionEntity function,
       void f(DartType type, String name, ConstantValue defaultValue));
 
   void forEachInvokedName(
       f(String name, Map<Selector, SelectorConstraints> selectors));
 
   void forEachInvokedGetter(
       f(String name, Map<Selector, SelectorConstraints> selectors));
 
   void forEachInvokedSetter(
       f(String name, Map<Selector, SelectorConstraints> selectors));
 
-  /// Returns `true` if [field] constant or final with a constant initializer.
+  /// Returns `true` if [field] has a constant initializer.
   bool hasConstantFieldInitializer(FieldEntity field);
 
+  /// Returns the constant initializer for [field].
+  ConstantValue getConstantFieldInitializer(FieldEntity field);
+
   /// Returns `true` if [member] is invoked as a setter.
   bool hasInvokedSetter(MemberEntity member, ClosedWorld world);
 
   bool hasInvokedGetter(MemberEntity member, ClosedWorld world);
 
   Map<Selector, SelectorConstraints> invocationsByName(String name);
 
   Map<Selector, SelectorConstraints> getterInvocationsByName(String name);
 
   Map<Selector, SelectorConstraints> setterInvocationsByName(String name);
@@ skipping 511 matching lines @@
       ClosedWorld world,
       SelectorConstraintsStrategy selectorConstraintsStrategy)
       : super(elementEnvironment, nativeBasicData, world,
             selectorConstraintsStrategy);
 
   @override
   bool hasConstantFieldInitializer(FieldElement field) {
     return field.constant != null;
   }
 
+  @override
+  ConstantValue getConstantFieldInitializer(FieldElement field) {
+    assert(field.constant != null,
+        failedAt(field, "Field $field doesn't have a constant initial value."));
+    return _constants.getConstantValue(field.constant);
+  }
+
   /// Calls [f] with every instance field, together with its declarer, in an
   /// instance of [cls].
   void forEachInstanceField(
       ClassElement cls, void f(ClassEntity declarer, FieldEntity field)) {
     cls.implementation
         .forEachInstanceField(f, includeSuperAndInjectedMembers: true);
   }
 
   @override
   void forEachParameter(MethodElement function,
@@ skipping 52 matching lines @@
       SelectorConstraintsStrategy selectorConstraintsStrategy)
       : super(elementEnvironment, nativeBasicData, world,
             selectorConstraintsStrategy);
 
   @override
   bool hasConstantFieldInitializer(FieldEntity field) {
     return _elementMap.hasConstantFieldInitializer(field);
   }
 
   @override
+  ConstantValue getConstantFieldInitializer(FieldEntity field) {
+    return _elementMap.getConstantFieldInitializer(field);
+  }
+
+  @override
   void forEachParameter(FunctionEntity function,
       void f(DartType type, String name, ConstantValue defaultValue)) {
     _elementMap.forEachParameter(function, f);
   }
 
   @override
   void forEachInstanceField(
       ClassEntity cls, void f(ClassEntity declarer, FieldEntity field)) {
     _elementEnvironment.forEachClassMember(cls,
         (ClassEntity declarer, MemberEntity member) {
       if (member.isField && member.isInstanceMember) f(declarer, member);
     });
   }
 }