Stub implementation of patch invariants for the patch refactoring.

lib/compiler/implementation/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.
 
 /**
  * The [ConstantHandler] keeps track of compile-time constants,
  * initializations of global and static fields, and default values of
  * optional parameters.
  */
 class ConstantHandler extends CompilerTask {
@@ skipping 517 matching lines @@
       if (folded === null) return signalNotCompileTimeConstant(send);
       return folded;
     }
     return signalNotCompileTimeConstant(send);
   }
 
   Constant visitSendSet(SendSet node) {
     return signalNotCompileTimeConstant(node);
   }
 
-  /** Returns the list of constants that are passed to the static function. */
+  /**
+   * Returns the list of constants that are passed to the static function.
+   *
+   * Invariant: [target] must be an implementation element.
+   */
   List<Constant> evaluateArgumentsToConstructor(Node node,
                                                 Selector selector,
                                                 Link<Node> arguments,
                                                 FunctionElement target) {
+    assert(invariant(node, target.isImplementation));
     List<Constant> compiledArguments = <Constant>[];
 
     Function compileArgument = evaluateConstant;
     Function compileConstant = compiler.compileConstant;
     bool succeeded = selector.addArgumentsToList(arguments,
                                                  compiledArguments,
                                                  target,
                                                  compileArgument,
                                                  compileConstant,
                                                  compiler);
@@ skipping 11 matching lines @@
     }
 
     Send send = node.send;
     FunctionElement constructor = elements[send];
     ClassElement classElement = constructor.getEnclosingClass();
     if (classElement.isInterface()) {
       compiler.resolver.resolveMethodElement(constructor);
       constructor = constructor.defaultImplementation;
       classElement = constructor.getEnclosingClass();
     }
+    // The constructor must be an implementation to ensure that field
+    // initializers are handled correctly.
+    constructor = constructor.implementation;
+    assert(invariant(node, constructor.isImplementation));
 
     Selector selector = elements.getSelector(send);
     List<Constant> arguments = evaluateArgumentsToConstructor(
         node, selector, send.arguments, constructor);
     ConstructorEvaluator evaluator =
-        new ConstructorEvaluator(constructor, constantSystem, compiler);
+        new ConstructorEvaluator(node, constructor, constantSystem, compiler);
     evaluator.evaluateConstructorFieldValues(arguments);
     List<Constant> jsNewArguments = evaluator.buildJsNewArguments(classElement);
 
     compiler.enqueuer.codegen.registerInstantiatedClass(classElement);
     // TODO(floitsch): take generic types into account.
     DartType type = classElement.computeType(compiler);
     Constant constant = new ConstructedConstant(type, jsNewArguments);
     compiler.constantHandler.registerCompileTimeConstant(constant);
     return constant;
   }
@@ skipping 29 matching lines @@
       : super(constantSystem, elements, compiler, isConst: true);
 
   error(Node node) {
     // Just fail without reporting it anywhere.
     throw new CompileTimeConstantError(
         MessageKind.NOT_A_COMPILE_TIME_CONSTANT, const []);
   }
 }
 
 class ConstructorEvaluator extends CompileTimeConstantEvaluator {
-  FunctionElement constructor;
+  final FunctionElement constructor;
   final Map<Element, Constant> definitions;
   final Map<Element, Constant> fieldValues;
 
-  ConstructorEvaluator(FunctionElement constructor,
+  /**
+   * Documentation wanted -- johnniwinther
+   *
+   * Invariant: [constructor] must be an implementation element.
+   */
+  ConstructorEvaluator(Node node,
+                       FunctionElement constructor,
                        ConstantSystem constantSystem,
                        Compiler compiler)
       : this.constructor = constructor,
         this.definitions = new Map<Element, Constant>(),
         this.fieldValues = new Map<Element, Constant>(),
         super(constantSystem,
-              compiler.resolver.resolveMethodElement(constructor),
+              compiler.resolver.resolveMethodElement(constructor.declaration),
               compiler,
-              isConst: true);
+              isConst: true) {
+    assert(invariant(node, constructor.isImplementation));
+  }
 
   Constant visitSend(Send send) {
     Element element = elements[send];
     if (Elements.isLocal(element)) {
       Constant constant = definitions[element];
       if (constant === null) {
         compiler.internalError("Local variable without value", node: send);
       }
       return constant;
     }
@@ skipping 41 matching lines @@
   }
 
   void evaluateSuperOrRedirectSend(Node currentNode,
                                    Selector selector,
                                    Link<Node> arguments,
                                    FunctionElement targetConstructor) {
     List<Constant> compiledArguments = evaluateArgumentsToConstructor(
         currentNode, selector, arguments, targetConstructor);
 
     ConstructorEvaluator evaluator = new ConstructorEvaluator(
-        targetConstructor, constantSystem, compiler);
+        currentNode, targetConstructor, constantSystem, compiler);
     evaluator.evaluateConstructorFieldValues(compiledArguments);
     // Copy over the fieldValues from the super/redirect-constructor.
     // No need to go through [updateFieldValue] because the
     // assignments have already been checked in checked mode.
     evaluator.fieldValues.forEach((key, value) => fieldValues[key] = value);
   }
 
   /**
    * Runs through the initializers of the given [constructor] and updates
    * the [fieldValues] map.
@@ skipping 76 matching lines @@
       Constant fieldValue = fieldValues[field];
       if (fieldValue === null) {
         // Use the default value.
         fieldValue = compiler.compileConstant(field);
       }
       jsNewArguments.add(fieldValue);
     });
     return jsNewArguments;
   }
 }