author | ksrini |
Sat, 27 Nov 2010 07:46:05 -0800 | |
changeset 7299 | 0b68a82ebb55 |
parent 5506 | 202f599c92aa |
child 7668 | d4a77089c587 |
child 7795 | 98021fc612af |
permissions | -rw-r--r-- |
2 | 1 |
/* |
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* Copyright (c) 2001, 2003, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package com.sun.java.util.jar.pack; |
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import com.sun.java.util.jar.pack.Package.Class; |
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import java.lang.reflect.Modifier; |
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7299
0b68a82ebb55
7002986: (pack200) intermittent failures compiling pack200
ksrini
parents:
5506
diff
changeset
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import java.util.Arrays; |
0b68a82ebb55
7002986: (pack200) intermittent failures compiling pack200
ksrini
parents:
5506
diff
changeset
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import java.util.Collection; |
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/** |
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* Represents a chunk of bytecodes. |
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* @author John Rose |
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*/ |
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class Code extends Attribute.Holder implements Constants { |
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Class.Method m; |
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||
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public Code(Class.Method m) { |
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this.m = m; |
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} |
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||
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public Class.Method getMethod() { |
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return m; |
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} |
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public Class thisClass() { |
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return m.thisClass(); |
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} |
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public Package getPackage() { |
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return m.thisClass().getPackage(); |
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} |
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public ConstantPool.Entry[] getCPMap() { |
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return m.getCPMap(); |
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} |
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static private final ConstantPool.Entry[] noRefs = ConstantPool.noRefs; |
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// The following fields are used directly by the ClassReader, etc. |
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int max_stack; |
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int max_locals; |
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ConstantPool.Entry handler_class[] = noRefs; |
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int handler_start[] = noInts; |
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int handler_end[] = noInts; |
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int handler_catch[] = noInts; |
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byte[] bytes; |
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Fixups fixups; // reference relocations, if any are required |
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Object insnMap; // array of instruction boundaries |
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int getLength() { return bytes.length; } |
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int getMaxStack() { |
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return max_stack; |
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} |
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void setMaxStack(int ms) { |
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max_stack = ms; |
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} |
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int getMaxNALocals() { |
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int argsize = m.getArgumentSize(); |
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return max_locals - argsize; |
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} |
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void setMaxNALocals(int ml) { |
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int argsize = m.getArgumentSize(); |
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max_locals = argsize + ml; |
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} |
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int getHandlerCount() { |
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assert(handler_class.length == handler_start.length); |
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assert(handler_class.length == handler_end.length); |
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assert(handler_class.length == handler_catch.length); |
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return handler_class.length; |
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} |
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void setHandlerCount(int h) { |
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if (h > 0) { |
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handler_class = new ConstantPool.Entry[h]; |
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handler_start = new int[h]; |
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handler_end = new int[h]; |
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handler_catch = new int[h]; |
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// caller must fill these in ASAP |
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} |
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} |
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void setBytes(byte[] bytes) { |
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this.bytes = bytes; |
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if (fixups != null) |
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fixups.setBytes(bytes); |
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} |
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void setInstructionMap(int[] insnMap, int mapLen) { |
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//int[] oldMap = null; |
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//assert((oldMap = getInstructionMap()) != null); |
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this.insnMap = allocateInstructionMap(insnMap, mapLen); |
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//assert(Arrays.equals(oldMap, getInstructionMap())); |
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} |
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void setInstructionMap(int[] insnMap) { |
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setInstructionMap(insnMap, insnMap.length); |
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} |
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int[] getInstructionMap() { |
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return expandInstructionMap(getInsnMap()); |
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} |
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void addFixups(Collection moreFixups) { |
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if (fixups == null) { |
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fixups = new Fixups(bytes); |
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} |
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assert(fixups.getBytes() == bytes); |
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fixups.addAll(moreFixups); |
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} |
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public void trimToSize() { |
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if (fixups != null) { |
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fixups.trimToSize(); |
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if (fixups.size() == 0) |
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fixups = null; |
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} |
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super.trimToSize(); |
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} |
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protected void visitRefs(int mode, Collection refs) { |
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int verbose = getPackage().verbose; |
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if (verbose > 2) |
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System.out.println("Reference scan "+this); |
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Class cls = thisClass(); |
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Package pkg = cls.getPackage(); |
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for (int i = 0; i < handler_class.length; i++) { |
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refs.add(handler_class[i]); |
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} |
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if (fixups != null) { |
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fixups.visitRefs(refs); |
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} else { |
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// References (to a local cpMap) are embedded in the bytes. |
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ConstantPool.Entry[] cpMap = getCPMap(); |
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for (Instruction i = instructionAt(0); i != null; i = i.next()) { |
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if (verbose > 4) |
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System.out.println(i); |
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int cpref = i.getCPIndex(); |
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if (cpref >= 0) { |
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refs.add(cpMap[cpref]); |
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} |
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} |
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} |
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// Handle attribute list: |
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super.visitRefs(mode, refs); |
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} |
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// Since bytecodes are the single largest contributor to |
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// package size, it's worth a little bit of trouble |
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// to reduce the per-bytecode memory footprint. |
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// In the current scheme, half of the bulk of these arrays |
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// due to bytes, and half to shorts. (Ints are insignificant.) |
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// Given an average of 1.8 bytes per instruction, this means |
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// instruction boundary arrays are about a 75% overhead--tolerable. |
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// (By using bytes, we get 33% savings over just shorts and ints. |
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// Using both bytes and shorts gives 66% savings over just ints.) |
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static final boolean shrinkMaps = true; |
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private Object allocateInstructionMap(int[] insnMap, int mapLen) { |
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int PClimit = getLength(); |
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if (shrinkMaps && PClimit <= Byte.MAX_VALUE - Byte.MIN_VALUE) { |
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byte[] map = new byte[mapLen+1]; |
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for (int i = 0; i < mapLen; i++) { |
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map[i] = (byte)(insnMap[i] + Byte.MIN_VALUE); |
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} |
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map[mapLen] = (byte)(PClimit + Byte.MIN_VALUE); |
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return map; |
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} else if (shrinkMaps && PClimit < Short.MAX_VALUE - Short.MIN_VALUE) { |
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short[] map = new short[mapLen+1]; |
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for (int i = 0; i < mapLen; i++) { |
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map[i] = (short)(insnMap[i] + Short.MIN_VALUE); |
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} |
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map[mapLen] = (short)(PClimit + Short.MIN_VALUE); |
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return map; |
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} else { |
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int[] map = new int[mapLen+1]; |
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for (int i = 0; i < mapLen; i++) { |
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map[i] = (int) insnMap[i]; |
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} |
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map[mapLen] = (int) PClimit; |
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return map; |
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} |
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} |
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private int[] expandInstructionMap(Object map0) { |
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int[] imap; |
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if (map0 instanceof byte[]) { |
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byte[] map = (byte[]) map0; |
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imap = new int[map.length-1]; |
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for (int i = 0; i < imap.length; i++) { |
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imap[i] = map[i] - Byte.MIN_VALUE; |
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} |
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} else if (map0 instanceof short[]) { |
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short[] map = (short[]) map0; |
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imap = new int[map.length-1]; |
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for (int i = 0; i < imap.length; i++) { |
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imap[i] = map[i] - Byte.MIN_VALUE; |
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} |
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} else { |
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int[] map = (int[]) map0; |
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imap = new int[map.length-1]; |
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for (int i = 0; i < imap.length; i++) { |
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imap[i] = map[i]; |
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} |
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} |
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return imap; |
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} |
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Object getInsnMap() { |
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// Build a map of instruction boundaries. |
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if (insnMap != null) { |
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return insnMap; |
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} |
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int[] map = new int[getLength()]; |
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int fillp = 0; |
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for (Instruction i = instructionAt(0); i != null; i = i.next()) { |
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map[fillp++] = i.getPC(); |
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} |
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// Make it byte[], short[], or int[] according to the max BCI. |
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insnMap = allocateInstructionMap(map, fillp); |
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//assert(assertBCICodingsOK()); |
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return insnMap; |
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} |
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/** Encode the given BCI as an instruction boundary number. |
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* For completeness, irregular (non-boundary) BCIs are |
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* encoded compactly immediately after the boundary numbers. |
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* This encoding is the identity mapping outside 0..length, |
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* and it is 1-1 everywhere. All by itself this technique |
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* improved zipped rt.jar compression by 2.6%. |
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*/ |
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public int encodeBCI(int bci) { |
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if (bci <= 0 || bci > getLength()) return bci; |
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Object map0 = getInsnMap(); |
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int i, len; |
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if (shrinkMaps && map0 instanceof byte[]) { |
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byte[] map = (byte[]) map0; |
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len = map.length; |
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i = Arrays.binarySearch(map, (byte)(bci + Byte.MIN_VALUE)); |
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} else if (shrinkMaps && map0 instanceof short[]) { |
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short[] map = (short[]) map0; |
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len = map.length; |
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i = Arrays.binarySearch(map, (short)(bci + Short.MIN_VALUE)); |
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} else { |
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int[] map = (int[]) map0; |
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len = map.length; |
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i = Arrays.binarySearch(map, (int)bci); |
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} |
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assert(i != -1); |
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assert(i != 0); |
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assert(i != len); |
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assert(i != -len-1); |
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return (i >= 0) ? i : len + bci - (-i-1); |
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} |
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public int decodeBCI(int bciCode) { |
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if (bciCode <= 0 || bciCode > getLength()) return bciCode; |
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Object map0 = getInsnMap(); |
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int i, len; |
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// len == map.length |
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// If bciCode < len, result is map[bciCode], the common and fast case. |
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// Otherwise, let map[i] be the smallest map[*] larger than bci. |
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// Then, required by the return statement of encodeBCI: |
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// bciCode == len + bci - i |
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// Thus: |
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// bci-i == bciCode-len |
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// map[i]-adj-i == bciCode-len ; adj in (0..map[i]-map[i-1]) |
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// We can solve this by searching for adjacent entries |
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// map[i-1], map[i] such that: |
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// map[i-1]-(i-1) <= bciCode-len < map[i]-i |
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// This can be approximated by searching map[i] for bciCode and then |
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// linear searching backward. Given the right i, we then have: |
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// bci == bciCode-len + i |
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// This linear search is at its worst case for indexes in the beginning |
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296 |
// of a large method, but it's not clear that this is a problem in |
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297 |
// practice, since BCIs are usually on instruction boundaries. |
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298 |
if (shrinkMaps && map0 instanceof byte[]) { |
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299 |
byte[] map = (byte[]) map0; |
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300 |
len = map.length; |
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301 |
if (bciCode < len) |
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302 |
return map[bciCode] - Byte.MIN_VALUE; |
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303 |
i = Arrays.binarySearch(map, (byte)(bciCode + Byte.MIN_VALUE)); |
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304 |
if (i < 0) i = -i-1; |
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305 |
int key = bciCode-len + Byte.MIN_VALUE; |
|
306 |
for (;; i--) { |
|
307 |
if (map[i-1]-(i-1) <= key) break; |
|
308 |
} |
|
309 |
} else if (shrinkMaps && map0 instanceof short[]) { |
|
310 |
short[] map = (short[]) map0; |
|
311 |
len = map.length; |
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312 |
if (bciCode < len) |
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313 |
return map[bciCode] - Short.MIN_VALUE; |
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314 |
i = Arrays.binarySearch(map, (short)(bciCode + Short.MIN_VALUE)); |
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315 |
if (i < 0) i = -i-1; |
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316 |
int key = bciCode-len + Short.MIN_VALUE; |
|
317 |
for (;; i--) { |
|
318 |
if (map[i-1]-(i-1) <= key) break; |
|
319 |
} |
|
320 |
} else { |
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321 |
int[] map = (int[]) map0; |
|
322 |
len = map.length; |
|
323 |
if (bciCode < len) |
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324 |
return map[bciCode]; |
|
325 |
i = Arrays.binarySearch(map, (int)bciCode); |
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326 |
if (i < 0) i = -i-1; |
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327 |
int key = bciCode-len; |
|
328 |
for (;; i--) { |
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329 |
if (map[i-1]-(i-1) <= key) break; |
|
330 |
} |
|
331 |
} |
|
332 |
return bciCode-len + i; |
|
333 |
} |
|
334 |
||
335 |
public void finishRefs(ConstantPool.Index ix) { |
|
336 |
if (fixups != null) { |
|
337 |
fixups.finishRefs(ix); |
|
338 |
fixups = null; |
|
339 |
} |
|
340 |
// Code attributes are finished in ClassWriter.writeAttributes. |
|
341 |
} |
|
342 |
||
343 |
Instruction instructionAt(int pc) { |
|
344 |
return Instruction.at(bytes, pc); |
|
345 |
} |
|
346 |
||
347 |
static boolean flagsRequireCode(int flags) { |
|
348 |
// A method's flags force it to have a Code attribute, |
|
349 |
// if the flags are neither native nor abstract. |
|
350 |
return (flags & (Modifier.NATIVE | Modifier.ABSTRACT)) == 0; |
|
351 |
} |
|
352 |
||
353 |
public String toString() { |
|
354 |
return m+".Code"; |
|
355 |
} |
|
356 |
||
357 |
/// Fetching values from my own array. |
|
358 |
public int getInt(int pc) { return Instruction.getInt(bytes, pc); } |
|
359 |
public int getShort(int pc) { return Instruction.getShort(bytes, pc); } |
|
360 |
public int getByte(int pc) { return Instruction.getByte(bytes, pc); } |
|
361 |
void setInt(int pc, int x) { Instruction.setInt(bytes, pc, x); } |
|
362 |
void setShort(int pc, int x) { Instruction.setShort(bytes, pc, x); } |
|
363 |
void setByte(int pc, int x) { Instruction.setByte(bytes, pc, x); } |
|
364 |
||
365 |
/* TEST CODE ONLY |
|
366 |
private boolean assertBCICodingsOK() { |
|
367 |
boolean ok = true; |
|
368 |
int len = java.lang.reflect.Array.getLength(insnMap); |
|
369 |
int base = 0; |
|
370 |
if (insnMap.getClass().getComponentType() == Byte.TYPE) |
|
371 |
base = Byte.MIN_VALUE; |
|
372 |
if (insnMap.getClass().getComponentType() == Short.TYPE) |
|
373 |
base = Short.MIN_VALUE; |
|
374 |
for (int i = -1, imax = getLength()+1; i <= imax; i++) { |
|
375 |
int bci = i; |
|
376 |
int enc = Math.min(-999, bci-1); |
|
377 |
int dec = enc; |
|
378 |
try { |
|
379 |
enc = encodeBCI(bci); |
|
380 |
dec = decodeBCI(enc); |
|
381 |
} catch (RuntimeException ee) { |
|
382 |
ee.printStackTrace(); |
|
383 |
} |
|
384 |
if (dec == bci) { |
|
385 |
//System.out.println("BCI="+bci+(enc<len?"":" ")+" enc="+enc); |
|
386 |
continue; |
|
387 |
} |
|
388 |
if (ok) { |
|
389 |
for (int q = 0; q <= 1; q++) { |
|
390 |
StringBuffer sb = new StringBuffer(); |
|
391 |
sb.append("bci "+(q==0?"map":"del")+"["+len+"] = {"); |
|
392 |
for (int j = 0; j < len; j++) { |
|
393 |
int mapi = ((Number)java.lang.reflect.Array.get(insnMap, j)).intValue() - base; |
|
394 |
mapi -= j*q; |
|
395 |
sb.append(" "+mapi); |
|
396 |
} |
|
397 |
sb.append(" }"); |
|
398 |
System.out.println("*** "+sb); |
|
399 |
} |
|
400 |
} |
|
401 |
System.out.println("*** BCI="+bci+" enc="+enc+" dec="+dec); |
|
402 |
ok = false; |
|
403 |
} |
|
404 |
return ok; |
|
405 |
} |
|
406 |
//*/ |
|
407 |
} |