1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.nodes.util;
  24 
  25 import org.graalvm.compiler.core.common.spi.ConstantFieldProvider;
  26 import org.graalvm.compiler.core.common.spi.ConstantFieldProvider.ConstantFieldTool;
  27 import org.graalvm.compiler.nodes.ConstantNode;
  28 
  29 import jdk.vm.ci.meta.ConstantReflectionProvider;
  30 import jdk.vm.ci.meta.JavaConstant;
  31 import jdk.vm.ci.meta.MetaAccessProvider;
  32 import jdk.vm.ci.meta.ResolvedJavaField;
  33 
  34 public class ConstantFoldUtil {
  35 
  36     public static ConstantNode tryConstantFold(ConstantFieldProvider fieldProvider, ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, ResolvedJavaField field,
  37                     JavaConstant receiver) {
  38         if (!field.isStatic()) {
  39             if (receiver == null || receiver.isNull()) {
  40                 return null;
  41             }
  42         }
  43 
  44         return fieldProvider.readConstantField(field, new ConstantFieldTool<ConstantNode>() {
  45 
  46             @Override
  47             public JavaConstant readValue() {
  48                 return constantReflection.readFieldValue(field, receiver);
  49             }
  50 
  51             @Override
  52             public JavaConstant getReceiver() {
  53                 return receiver;
  54             }
  55 
  56             @Override
  57             public ConstantNode foldConstant(JavaConstant ret) {
  58                 if (ret != null) {
  59                     return ConstantNode.forConstant(ret, metaAccess);
  60                 } else {
  61                     return null;
  62                 }
  63             }
  64 
  65             @Override
  66             public ConstantNode foldStableArray(JavaConstant ret, int stableDimensions, boolean isDefaultStable) {
  67                 if (ret != null) {
  68                     return ConstantNode.forConstant(ret, stableDimensions, isDefaultStable, metaAccess);
  69                 } else {
  70                     return null;
  71                 }
  72             }
  73         });
  74     }
  75 }