Check for compile-time constants in DartCompiler

compiler/java/com/google/dart/compiler/resolver/MemberBuilder.java

 // 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.
 
 package com.google.dart.compiler.resolver;
 
 import com.google.dart.compiler.DartCompilerContext;
 import com.google.dart.compiler.DartCompilerErrorCode;
 import com.google.dart.compiler.ErrorCode;
 import com.google.dart.compiler.ast.DartClass;
@@ skipping 205 matching lines @@
           return (ConstructorElement) e;
       }
       // If the constructor name resolves to a class or there was an error,
       // create the unnamed constructor.
       return Elements.constructorFromMethodNode(method, "", (ClassElement) currentHolder,
                                                 (ClassElement) e);
     }
 
     private FieldElement buildField(DartField fieldNode, Type type) {
       assert !fieldNode.getModifiers().isAbstractField();
+      Modifiers modifiers = fieldNode.getModifiers();
+      if (modifiers.isFinal() && (modifiers.isStatic() || context == topLevelContext)) {
+        // final toplevel fields are implicitly compile-time constants.
+        modifiers = modifiers.makeStatic();
+        // Set the "const" modifier so that it is easy to compare a constant field to other
+        // types of constant expressions.
+        modifiers = modifiers.makeConstant();
+      }

[ngeoffray, 2011/10/17 10:59:38]

Since all initializations must be constant, do you still need to make these
changes on the modifiers?

[zundel, 2011/10/17 14:14:26]

This is just for help in evaluating whether an expression is constant.  If the
expression is a const contructor, it will be set to isConstant().  If it is a
field or a variable, it will be set to isFinal().  It just makes it easier to
check isConstant() on the element in CompileTimeConstant Visitor without picking
out what kind of element it is.

       FieldElement fieldElement = fieldNode.getSymbol();
       if (fieldElement == null) {
-        fieldElement = Elements.fieldFromNode(fieldNode, currentHolder, fieldNode.getModifiers());
+        fieldElement = Elements.fieldFromNode(fieldNode, currentHolder, modifiers);
         addField(currentHolder, fieldElement);
       } else {
         // This is a top-level element, and an element was already created in
         // TopLevelElementBuilder.
         Elements.addField(currentHolder, fieldElement);
         assertTopLevel(fieldNode);
       }
       fieldElement.setType(type);
       return recordElement(fieldNode, fieldElement);
     }
@@ skipping 245 matching lines @@
         }
       }
       return element;
     }
 
     void resolutionError(DartNode node, ErrorCode errorCode, Object... arguments) {
       topLevelContext.resolutionError(node, errorCode, arguments);
     }
   }
 }