| /* |
| * 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 BytecodeLookupswitch extends Bytecode { |
| BytecodeLookupswitch(Method method, int bci) { |
| super(method, bci); |
| } |
| |
| // Attributes |
| public int defaultOffset() { return javaSignedWordAt(alignedOffset(1 + 0*jintSize)); } |
| public int numberOfPairs() { return javaSignedWordAt(alignedOffset(1 + 1*jintSize)); } |
| public LookupswitchPair pairAt(int i) { |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(0 <= i && i < numberOfPairs(), "pair index out of bounds"); |
| } |
| return new LookupswitchPair(method, bci + alignedOffset(1 + (1 + i)*2*jintSize)); |
| } |
| |
| public void verify() { |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(isValid(), "check lookupswitch"); |
| } |
| } |
| |
| public boolean isValid() { |
| boolean result = javaCode() == Bytecodes._lookupswitch; |
| if (result == false) return false; |
| int i = numberOfPairs() - 1; |
| while (i-- > 0) { |
| if(pairAt(i).match() > pairAt(i+1).match()) |
| return false; // unsorted lookup table |
| } |
| return true; |
| } |
| |
| public static BytecodeLookupswitch at(Method method, int bci) { |
| BytecodeLookupswitch b = new BytecodeLookupswitch(method, bci); |
| if (Assert.ASSERTS_ENABLED) { |
| b.verify(); |
| } |
| return b; |
| } |
| |
| /** Like at, but returns null if the BCI is not at lookupswitch */ |
| public static BytecodeLookupswitch atCheck(Method method, int bci) { |
| BytecodeLookupswitch b = new BytecodeLookupswitch(method, bci); |
| return (b.isValid() ? b : null); |
| } |
| |
| public static BytecodeLookupswitch at(BytecodeStream bcs) { |
| return new BytecodeLookupswitch(bcs.method(), bcs.bci()); |
| } |
| |
| public String toString() { |
| StringBuffer buf = new StringBuffer(); |
| buf.append("lookupswitch"); |
| buf.append(spaces); |
| buf.append("default: "); |
| buf.append(Integer.toString(bci() + defaultOffset())); |
| buf.append(comma); |
| int i = numberOfPairs() - 1; |
| while (i-- > 0) { |
| LookupswitchPair pair = pairAt(i); |
| buf.append("case "); |
| buf.append(Integer.toString(pair.match())); |
| buf.append(':'); |
| buf.append(Integer.toString(bci() + pair.offset())); |
| buf.append(comma); |
| } |
| |
| return buf.toString(); |
| } |
| } |