| /* |
| * Copyright (c) 2001, 2003, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| package sun.jvm.hotspot.interpreter; |
| |
| import sun.jvm.hotspot.oops.*; |
| import sun.jvm.hotspot.utilities.*; |
| |
| public class BytecodeTableswitch extends Bytecode { |
| BytecodeTableswitch(Method method, int bci) { |
| super(method, bci); |
| } |
| |
| |
| // Attributes |
| public int defaultOffset() { return javaSignedWordAt(alignedOffset(1 + 0*jintSize)); } |
| public int lowKey() { return javaSignedWordAt(alignedOffset(1 + 1*jintSize)); } |
| public int highKey() { return javaSignedWordAt(alignedOffset(1 + 2*jintSize)); } |
| public int length() { return highKey()-lowKey()+1; } |
| public int destOffsetAt(int i) { |
| int x2 = alignedOffset(1 + (3 + i)*jintSize); |
| int val = javaSignedWordAt(x2); |
| return javaSignedWordAt(alignedOffset(1 + (3 + i)*jintSize)); |
| } |
| |
| public void verify() { |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(isValid(), "check tableswitch"); |
| } |
| } |
| |
| public boolean isValid() { |
| boolean result = javaCode() == Bytecodes._tableswitch; |
| if (result == false) return false; |
| int lo = lowKey(); |
| int hi = highKey(); |
| if (hi < lo) // incorrect hi/lo values in tableswitch |
| return false; |
| |
| int i = hi - lo - 1 ; |
| while (i-- > 0) { |
| // no special check needed |
| } |
| return true; |
| } |
| |
| public static BytecodeTableswitch at(Method method, int bci) { |
| BytecodeTableswitch b = new BytecodeTableswitch(method, bci); |
| if (Assert.ASSERTS_ENABLED) { |
| b.verify(); |
| } |
| return b; |
| } |
| |
| /** Like at, but returns null if the BCI is not at tableswitch */ |
| public static BytecodeTableswitch atCheck(Method method, int bci) { |
| BytecodeTableswitch b = new BytecodeTableswitch(method, bci); |
| return (b.isValid() ? b : null); |
| } |
| |
| public static BytecodeTableswitch at(BytecodeStream bcs) { |
| return new BytecodeTableswitch(bcs.method(), bcs.bci()); |
| } |
| |
| public String toString() { |
| StringBuffer buf = new StringBuffer(); |
| buf.append("tableswitch"); |
| buf.append(spaces); |
| buf.append("default: "); |
| buf.append(Integer.toString(bci() + defaultOffset())); |
| buf.append(comma); |
| int lo = lowKey(); |
| int hi = highKey(); |
| int i = hi - lo - 1 ; |
| while (i-- > 0) { |
| buf.append("case "); |
| buf.append(Integer.toString(lo + i)); |
| buf.append(':'); |
| buf.append(Integer.toString(bci() + destOffsetAt(i))); |
| buf.append(comma); |
| } |
| return buf.toString(); |
| } |
| } |