Revert "Remove Registry from registerMetadataConstant" and "Serialize metadata"

pkg/compiler/lib/src/compile_time_constants.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 dart2js.compile_time_constant_evaluator;
 
 import 'common.dart';
 import 'common/resolution.dart' show Resolution;
 import 'common/tasks.dart' show CompilerTask, Measurer;
 import 'compiler.dart' show Compiler;
@@ skipping 147 matching lines @@
 
   ConstantCompilerBase(this.compiler, this.constantSystem);
 
   DiagnosticReporter get reporter => compiler.reporter;
 
   CoreTypes get coreTypes => compiler.coreTypes;
 
   @override
   @deprecated
   ConstantValue getConstantValueForVariable(VariableElement element) {
-    ConstantExpression constant = initialVariableValues[element.declaration];
-    // TODO(johnniwinther): Support eager evaluation of the constant.
-    return constant != null ? getConstantValue(constant) : null;
+    return getConstantValue(initialVariableValues[element.declaration]);
   }
 
   ConstantExpression compileConstant(VariableElement element) {
     return internalCompileVariable(element, true, true);
   }
 
   @override
   void evaluate(ConstantExpression constant) {
     constantValueMap.putIfAbsent(constant, () {
       return constant.evaluate(
@@ skipping 134 matching lines @@
       cacheConstantValue(constant.expression, constant.value);
       return constant.expression;
     }
     return null;
   }
 
   bool hasConstantValue(ConstantExpression expression) {
     return constantValueMap.containsKey(expression);
   }
 
-  @override
   ConstantValue getConstantValue(ConstantExpression expression) {
-    assert(invariant(CURRENT_ELEMENT_SPANNABLE, expression != null,
-        message: "ConstantExpression is null in getConstantValue."));
-    // TODO(johnniwinther): ensure expressions have been evaluated at this
-    // point. This can't be enabled today due to dartbug.com/26406.
-    if (compiler.serialization.supportsDeserialization) {
-      evaluate(expression);
-    }
-    ConstantValue value = constantValueMap[expression];
-    if (value == null &&
-        expression != null &&
-        expression.kind == ConstantExpressionKind.ERRONEOUS) {
-      // TODO(johnniwinther): When the Dart constant system sees a constant
-      // expression as erroneous but the JavaScript constant system finds it ok
-      // we have store a constant value for the erroneous constant expression.
-      // Ensure the computed constant expressions are always the same; that only
-      // the constant values may be different.
-      value = new NullConstantValue();
-    }
-    return value;
+    return constantValueMap[expression];
   }
 
   ConstantExpression compileNode(Node node, TreeElements elements,
       {bool enforceConst: true}) {
     return compileNodeWithDefinitions(node, elements, isConst: enforceConst);
   }
 
   ConstantExpression compileMetadata(
       MetadataAnnotation metadata, Node node, TreeElements elements) {
     return compileNodeWithDefinitions(node, elements);
@@ skipping 17 matching lines @@
       : super(compiler, const DartConstantSystem());
 
   ConstantExpression getConstantForNode(Node node, TreeElements definitions) {
     return definitions.getConstant(node);
   }
 
   ConstantExpression compileNodeWithDefinitions(
       Node node, TreeElements definitions,
       {bool isConst: true}) {
     ConstantExpression constant = definitions.getConstant(node);
-    if (constant != null && hasConstantValue(constant)) {
+    if (constant != null && getConstantValue(constant) != null) {
       return constant;
     }
     constant =
         super.compileNodeWithDefinitions(node, definitions, isConst: isConst);
     if (constant != null) {
       definitions.setConstant(node, constant);
     }
     return constant;
   }
 }
@@ skipping 995 matching lines @@
 class _CompilerEnvironment implements Environment {
   final Compiler compiler;
 
   _CompilerEnvironment(this.compiler);
 
   @override
   String readFromEnvironment(String name) {
     return compiler.fromEnvironment(name);
   }
 }