1 /*
   2  * Copyright (c) 2009, 2015, 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 jdk.vm.ci.hotspot;
  24 
  25 import java.lang.invoke.*;
  26 import java.util.*;
  27 
  28 import jdk.vm.ci.meta.*;
  29 
  30 /**
  31  * Represents a constant non-{@code null} object reference, within the compiler and across the
  32  * compiler/runtime interface.
  33  */
  34 public interface HotSpotObjectConstant extends JavaConstant, HotSpotConstant, VMConstant {
  35 
  36     JavaConstant compress();
  37 
  38     JavaConstant uncompress();
  39 
  40     /**
  41      * Gets the resolved Java type of the object represented by this constant.
  42      */
  43     HotSpotResolvedObjectType getType();
  44 
  45     /**
  46      * Gets the result of {@link Class#getClassLoader()} for the {@link Class} object represented by
  47      * this constant.
  48      *
  49      * @return {@code null} if this constant does not represent a {@link Class} object
  50      */
  51     JavaConstant getClassLoader();
  52 
  53     /**
  54      * Gets the {@linkplain System#identityHashCode(Object) identity} has code for the object
  55      * represented by this constant.
  56      */
  57     int getIdentityHashCode();
  58 
  59     /**
  60      * Gets the result of {@link Class#getComponentType()} for the {@link Class} object represented
  61      * by this constant.
  62      *
  63      * @return {@code null} if this constant does not represent a {@link Class} object
  64      */
  65     JavaConstant getComponentType();
  66 
  67     /**
  68      * Gets the result of {@link Class#getSuperclass()} for the {@link Class} object represented by
  69      * this constant.
  70      *
  71      * @return {@code null} if this constant does not represent a {@link Class} object
  72      */
  73     JavaConstant getSuperclass();
  74 
  75     /**
  76      * Gets the result of {@link CallSite#getTarget()} for the {@link CallSite} object represented
  77      * by this constant.
  78      *
  79      * @param assumptions used to register an assumption that the {@link CallSite}'s target does not
  80      *            change
  81      * @return {@code null} if this constant does not represent a {@link CallSite} object
  82      */
  83     JavaConstant getCallSiteTarget(Assumptions assumptions);
  84 
  85     /**
  86      * Determines if this constant represents an {@linkplain String#intern() interned} string.
  87      */
  88     boolean isInternedString();
  89 
  90     /**
  91      * Gets the object represented by this constant represents if it is of a given type.
  92      *
  93      * @param type the expected type of the object represented by this constant. If the object is
  94      *            required to be of this type, then wrap the call to this method in
  95      *            {@link Objects#requireNonNull(Object)}.
  96      * @return the object value represented by this constant if it is an
  97      *         {@link ResolvedJavaType#isInstance(JavaConstant) instance of} {@code type} otherwise
  98      *         {@code null}
  99      */
 100     <T> T asObject(Class<T> type);
 101 
 102     /**
 103      * Gets the object represented by this constant represents if it is of a given type.
 104      *
 105      * @param type the expected type of the object represented by this constant. If the object is
 106      *            required to be of this type, then wrap the call to this method in
 107      *            {@link Objects#requireNonNull(Object)}.
 108      * @return the object value represented by this constant if it is an
 109      *         {@link ResolvedJavaType#isInstance(JavaConstant) instance of} {@code type} otherwise
 110      *         {@code null}
 111      */
 112     Object asObject(ResolvedJavaType type);
 113 }