1 /*
   2  * Copyright (c) 2015, 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.core.common.type;
  24 
  25 import org.graalvm.compiler.core.common.LIRKind;
  26 import org.graalvm.compiler.core.common.spi.LIRKindTool;
  27 import org.graalvm.compiler.debug.GraalError;
  28 
  29 import jdk.vm.ci.meta.Constant;
  30 import jdk.vm.ci.meta.MemoryAccessProvider;
  31 import jdk.vm.ci.meta.MetaAccessProvider;
  32 import jdk.vm.ci.meta.PrimitiveConstant;
  33 import jdk.vm.ci.meta.ResolvedJavaType;
  34 
  35 /**
  36  * Type describing pointers to raw memory. This stamp is used for example for direct pointers to
  37  * fields or array elements.
  38  */
  39 public class RawPointerStamp extends AbstractPointerStamp {
  40 
  41     protected RawPointerStamp() {
  42         super(false, false);
  43     }
  44 
  45     @Override
  46     public LIRKind getLIRKind(LIRKindTool tool) {
  47         return tool.getWordKind();
  48     }
  49 
  50     @Override
  51     protected AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull) {
  52         // RawPointerStamp is a singleton
  53         assert newNonNull == nonNull() && newAlwaysNull == alwaysNull();
  54         return this;
  55     }
  56 
  57     @Override
  58     public Stamp meet(Stamp other) {
  59         assert isCompatible(other);
  60         return this;
  61     }
  62 
  63     @Override
  64     public Stamp improveWith(Stamp other) {
  65         return this;
  66     }
  67 
  68     @Override
  69     public Stamp join(Stamp other) {
  70         assert isCompatible(other);
  71         return this;
  72     }
  73 
  74     @Override
  75     public Stamp unrestricted() {
  76         return this;
  77     }
  78 
  79     @Override
  80     public Stamp empty() {
  81         // there is no empty pointer stamp
  82         return this;
  83     }
  84 
  85     @Override
  86     public boolean hasValues() {
  87         return true;
  88     }
  89 
  90     @Override
  91     public ResolvedJavaType javaType(MetaAccessProvider metaAccess) {
  92         throw GraalError.shouldNotReachHere("pointer has no Java type");
  93     }
  94 
  95     @Override
  96     public Stamp constant(Constant c, MetaAccessProvider meta) {
  97         return this;
  98     }
  99 
 100     @Override
 101     public boolean isCompatible(Stamp other) {
 102         return other instanceof RawPointerStamp;
 103     }
 104 
 105     @Override
 106     public boolean isCompatible(Constant constant) {
 107         if (constant instanceof PrimitiveConstant) {
 108             return ((PrimitiveConstant) constant).getJavaKind().isNumericInteger();
 109         } else {
 110             return constant instanceof DataPointerConstant;
 111         }
 112     }
 113 
 114     @Override
 115     public Constant readConstant(MemoryAccessProvider provider, Constant base, long displacement) {
 116         throw GraalError.shouldNotReachHere("can't read raw pointer");
 117     }
 118 
 119     @Override
 120     public String toString() {
 121         return "void*";
 122     }
 123 }