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 
  24 
  25 package org.graalvm.compiler.core.common.type;
  26 
  27 import org.graalvm.compiler.core.common.LIRKind;
  28 import org.graalvm.compiler.core.common.spi.LIRKindTool;
  29 import org.graalvm.compiler.debug.GraalError;
  30 
  31 import jdk.vm.ci.meta.Constant;
  32 import jdk.vm.ci.meta.MemoryAccessProvider;
  33 import jdk.vm.ci.meta.MetaAccessProvider;
  34 import jdk.vm.ci.meta.PrimitiveConstant;
  35 import jdk.vm.ci.meta.ResolvedJavaType;
  36 
  37 /**
  38  * Type describing pointers to raw memory. This stamp is used for example for direct pointers to
  39  * fields or array elements.
  40  */
  41 public class RawPointerStamp extends AbstractPointerStamp {
  42 
  43     protected RawPointerStamp() {
  44         super(false, false);
  45     }
  46 
  47     @Override
  48     public LIRKind getLIRKind(LIRKindTool tool) {
  49         return tool.getWordKind();
  50     }
  51 
  52     @Override
  53     protected AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull) {
  54         // RawPointerStamp is a singleton
  55         assert newNonNull == nonNull() && newAlwaysNull == alwaysNull();
  56         return this;
  57     }
  58 
  59     @Override
  60     public Stamp meet(Stamp other) {
  61         assert isCompatible(other);
  62         return this;
  63     }
  64 
  65     @Override
  66     public Stamp improveWith(Stamp other) {
  67         return this;
  68     }
  69 
  70     @Override
  71     public Stamp join(Stamp other) {
  72         assert isCompatible(other);
  73         return this;
  74     }
  75 
  76     @Override
  77     public Stamp unrestricted() {
  78         return this;
  79     }
  80 
  81     @Override
  82     public Stamp empty() {
  83         // there is no empty pointer stamp
  84         return this;
  85     }
  86 
  87     @Override
  88     public boolean hasValues() {
  89         return true;
  90     }
  91 
  92     @Override
  93     public ResolvedJavaType javaType(MetaAccessProvider metaAccess) {
  94         throw GraalError.shouldNotReachHere("pointer has no Java type");
  95     }
  96 
  97     @Override
  98     public Stamp constant(Constant c, MetaAccessProvider meta) {
  99         return this;
 100     }
 101 
 102     @Override
 103     public boolean isCompatible(Stamp other) {
 104         return other instanceof RawPointerStamp;
 105     }
 106 
 107     @Override
 108     public boolean isCompatible(Constant constant) {
 109         if (constant instanceof PrimitiveConstant) {
 110             return ((PrimitiveConstant) constant).getJavaKind().isNumericInteger();
 111         } else {
 112             return constant instanceof DataPointerConstant;
 113         }
 114     }
 115 
 116     @Override
 117     public Constant readConstant(MemoryAccessProvider provider, Constant base, long displacement) {
 118         throw GraalError.shouldNotReachHere("can't read raw pointer");
 119     }
 120 
 121     @Override
 122     public String toString() {
 123         return "void*";
 124     }
 125 }