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 
  24 
  25 package org.graalvm.compiler.core.common.spi;
  26 
  27 import org.graalvm.compiler.options.OptionValues;
  28 
  29 import jdk.vm.ci.meta.JavaConstant;
  30 import jdk.vm.ci.meta.ResolvedJavaField;
  31 
  32 /**
  33  * Implements the logic that decides whether a field read should be constant folded.
  34  */
  35 public interface ConstantFieldProvider {
  36 
  37     public interface ConstantFieldTool<T> {
  38 
  39         OptionValues getOptions();
  40 
  41         JavaConstant readValue();
  42 
  43         JavaConstant getReceiver();
  44 
  45         T foldConstant(JavaConstant ret);
  46 
  47         T foldStableArray(JavaConstant ret, int stableDimensions, boolean isDefaultStable);
  48     }
  49 
  50     /**
  51      * Decide whether a read from the {@code field} should be constant folded. This should return
  52      * {@link ConstantFieldTool#foldConstant} or {@link ConstantFieldTool#foldStableArray} if the
  53      * read should be constant folded, or {@code null} otherwise.
  54      */
  55     <T> T readConstantField(ResolvedJavaField field, ConstantFieldTool<T> tool);
  56 }