1 /* 2 * Copyright 2000-2001 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 package sun.jvm.hotspot.debugger; 26 27 /** Base class for all twos-complement machine descriptions, which 28 handles the cIntegerType{Min,Max}Value methods. */ 29 30 public abstract class MachineDescriptionTwosComplement { 31 32 /** Handles 1, 2, 4, and 8-byte signed integers */ 33 private static final long[] signedMinValues = { 34 Byte.MIN_VALUE, 35 Short.MIN_VALUE, 36 Integer.MIN_VALUE, 37 Long.MIN_VALUE 38 }; 39 40 /** Handles 1, 2, 4, and 8-byte signed integers */ 41 private static final long[] signedMaxValues = { 42 Byte.MAX_VALUE, 43 Short.MAX_VALUE, 44 Integer.MAX_VALUE, 45 Long.MAX_VALUE 46 }; 47 48 /** Handles 1, 2, and 4-byte unsigned integers properly, with a bug 49 in the 8-byte unsigned integer's constant */ 50 private static final long[] unsignedMaxValues = { 51 255L, 52 65535L, 53 4294967295L, 54 -1L 55 }; 56 57 public long cIntegerTypeMaxValue(long sizeInBytes, boolean isUnsigned) { 58 if (isUnsigned) { 59 // Would be nice to signal to the caller that 8-byte unsigned 60 // integers are not supported properly, but it looks like doing 61 // so at this level will cause problems above 62 63 return tableLookup(sizeInBytes, unsignedMaxValues); 64 } else { 65 return tableLookup(sizeInBytes, signedMaxValues); 66 } 67 }; 68 69 public long cIntegerTypeMinValue(long sizeInBytes, boolean isUnsigned) { 70 if (isUnsigned) { 71 return 0; 72 } 73 74 return tableLookup(sizeInBytes, signedMinValues); 75 } 76 77 // Nearly all of the supported machines are not LP64 */ 78 public boolean isLP64() { 79 return false; 80 } 81 82 private long tableLookup(long sizeInBytes, long[] table) { 83 switch ((int) sizeInBytes) { 84 case 1: 85 return table[0]; 86 case 2: 87 return table[1]; 88 case 4: 89 return table[2]; 90 case 8: 91 return table[3]; 92 default: 93 throw new IllegalArgumentException("C integer type of " + sizeInBytes + " not supported"); 94 } 95 } 96 }