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- /*
- * Javassist, a Java-bytecode translator toolkit.
- * Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. Alternatively, the contents of this file may be used under
- * the terms of the GNU Lesser General Public License Version 2.1 or later,
- * or the Apache License Version 2.0.
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- */
-
- package javassist.bytecode;
-
- import java.io.ByteArrayOutputStream;
- import java.io.DataInputStream;
- import java.io.IOException;
- import java.util.Map;
-
- import javassist.CannotCompileException;
- import javassist.bytecode.StackMapTable.InsertLocal;
- import javassist.bytecode.StackMapTable.NewRemover;
- import javassist.bytecode.StackMapTable.Shifter;
-
- /**
- * Another <code>stack_map</code> attribute defined in CLDC 1.1 for J2ME.
- *
- * <p>This is an entry in the attributes table of a Code attribute.
- * It was introduced by J2ME CLDC 1.1 (JSR 139) for pre-verification.
- *
- * <p>According to the CLDC specification, the sizes of some fields are not 16bit
- * but 32bit if the code size is more than 64K or the number of the local variables
- * is more than 64K. However, for the J2ME CLDC technology, they are always 16bit.
- * The implementation of the StackMap class assumes they are 16bit.
- *
- * @see MethodInfo#doPreverify
- * @see StackMapTable
- * @since 3.12
- */
- public class StackMap extends AttributeInfo {
- /**
- * The name of this attribute <code>"StackMap"</code>.
- */
- public static final String tag = "StackMap";
-
-
- /**
- * Constructs a <code>stack_map</code> attribute.
- */
- StackMap(ConstPool cp, byte[] newInfo) {
- super(cp, tag, newInfo);
- }
-
- StackMap(ConstPool cp, int name_id, DataInputStream in)
- throws IOException
- {
- super(cp, name_id, in);
- }
-
- /**
- * Returns <code>number_of_entries</code>.
- */
- public int numOfEntries() {
- return ByteArray.readU16bit(info, 0);
- }
-
- /**
- * <code>Top_variable_info.tag</code>.
- */
- public static final int TOP = 0;
-
- /**
- * <code>Integer_variable_info.tag</code>.
- */
- public static final int INTEGER = 1;
-
- /**
- * <code>Float_variable_info.tag</code>.
- */
- public static final int FLOAT = 2;
-
- /**
- * <code>Double_variable_info.tag</code>.
- */
- public static final int DOUBLE = 3;
-
- /**
- * <code>Long_variable_info.tag</code>.
- */
- public static final int LONG = 4;
-
- /**
- * <code>Null_variable_info.tag</code>.
- */
- public static final int NULL = 5;
-
- /**
- * <code>UninitializedThis_variable_info.tag</code>.
- */
- public static final int THIS = 6;
-
- /**
- * <code>Object_variable_info.tag</code>.
- */
- public static final int OBJECT = 7;
-
- /**
- * <code>Uninitialized_variable_info.tag</code>.
- */
- public static final int UNINIT = 8;
-
- /**
- * Makes a copy.
- */
- public AttributeInfo copy(ConstPool newCp, Map classnames) {
- Copier copier = new Copier(this, newCp, classnames);
- copier.visit();
- return copier.getStackMap();
- }
-
- /**
- * A code walker for a StackMap attribute.
- */
- public static class Walker {
- byte[] info;
-
- /**
- * Constructs a walker.
- */
- public Walker(StackMap sm) {
- info = sm.get();
- }
-
- /**
- * Visits each entry of the stack map frames.
- */
- public void visit() {
- int num = ByteArray.readU16bit(info, 0);
- int pos = 2;
- for (int i = 0; i < num; i++) {
- int offset = ByteArray.readU16bit(info, pos);
- int numLoc = ByteArray.readU16bit(info, pos + 2);
- pos = locals(pos + 4, offset, numLoc);
- int numStack = ByteArray.readU16bit(info, pos);
- pos = stack(pos + 2, offset, numStack);
- }
- }
-
- /**
- * Invoked when <code>locals</code> of <code>stack_map_frame</code>
- * is visited.
- */
- public int locals(int pos, int offset, int num) {
- return typeInfoArray(pos, offset, num, true);
- }
-
- /**
- * Invoked when <code>stack</code> of <code>stack_map_frame</code>
- * is visited.
- */
- public int stack(int pos, int offset, int num) {
- return typeInfoArray(pos, offset, num, false);
- }
-
- /**
- * Invoked when an array of <code>verification_type_info</code> is
- * visited.
- *
- * @param num the number of elements.
- * @param isLocals true if this array is for <code>locals</code>.
- * false if it is for <code>stack</code>.
- */
- public int typeInfoArray(int pos, int offset, int num, boolean isLocals) {
- for (int k = 0; k < num; k++)
- pos = typeInfoArray2(k, pos);
-
- return pos;
- }
-
- int typeInfoArray2(int k, int pos) {
- byte tag = info[pos];
- if (tag == OBJECT) {
- int clazz = ByteArray.readU16bit(info, pos + 1);
- objectVariable(pos, clazz);
- pos += 3;
- }
- else if (tag == UNINIT) {
- int offsetOfNew = ByteArray.readU16bit(info, pos + 1);
- uninitialized(pos, offsetOfNew);
- pos += 3;
- }
- else {
- typeInfo(pos, tag);
- pos++;
- }
-
- return pos;
- }
-
- /**
- * Invoked when an element of <code>verification_type_info</code>
- * (except <code>Object_variable_info</code> and
- * <code>Uninitialized_variable_info</code>) is visited.
- */
- public void typeInfo(int pos, byte tag) {}
-
- /**
- * Invoked when an element of type <code>Object_variable_info</code>
- * is visited.
- */
- public void objectVariable(int pos, int clazz) {}
-
- /**
- * Invoked when an element of type <code>Uninitialized_variable_info</code>
- * is visited.
- */
- public void uninitialized(int pos, int offset) {}
- }
-
- static class Copier extends Walker {
- byte[] dest;
- ConstPool srcCp, destCp;
- Map classnames;
-
- Copier(StackMap map, ConstPool newCp, Map classnames) {
- super(map);
- srcCp = map.getConstPool();
- dest = new byte[info.length];
- destCp = newCp;
- this.classnames = classnames;
- }
-
- public void visit() {
- int num = ByteArray.readU16bit(info, 0);
- ByteArray.write16bit(num, dest, 0);
- super.visit();
- }
-
- public int locals(int pos, int offset, int num) {
- ByteArray.write16bit(offset, dest, pos - 4);
- return super.locals(pos, offset, num);
- }
-
- public int typeInfoArray(int pos, int offset, int num, boolean isLocals) {
- ByteArray.write16bit(num, dest, pos - 2);
- return super.typeInfoArray(pos, offset, num, isLocals);
- }
-
- public void typeInfo(int pos, byte tag) {
- dest[pos] = tag;
- }
-
- public void objectVariable(int pos, int clazz) {
- dest[pos] = OBJECT;
- int newClazz = srcCp.copy(clazz, destCp, classnames);
- ByteArray.write16bit(newClazz, dest, pos + 1);
- }
-
- public void uninitialized(int pos, int offset) {
- dest[pos] = UNINIT;
- ByteArray.write16bit(offset, dest, pos + 1);
- }
-
- public StackMap getStackMap() {
- return new StackMap(destCp, dest);
- }
- }
-
- /**
- * Updates this stack map table when a new local variable is inserted
- * for a new parameter.
- *
- * @param index the index of the added local variable.
- * @param tag the type tag of that local variable.
- * It is available by <code>StackMapTable.typeTagOf(char)</code>.
- * @param classInfo the index of the <code>CONSTANT_Class_info</code> structure
- * in a constant pool table. This should be zero unless the tag
- * is <code>ITEM_Object</code>.
- *
- * @see javassist.CtBehavior#addParameter(javassist.CtClass)
- * @see StackMapTable#typeTagOf(char)
- * @see ConstPool
- */
- public void insertLocal(int index, int tag, int classInfo)
- throws BadBytecode
- {
- byte[] data = new InsertLocal(this, index, tag, classInfo).doit();
- this.set(data);
- }
-
- static class SimpleCopy extends Walker {
- Writer writer;
-
- SimpleCopy(StackMap map) {
- super(map);
- writer = new Writer();
- }
-
- byte[] doit() {
- visit();
- return writer.toByteArray();
- }
-
- public void visit() {
- int num = ByteArray.readU16bit(info, 0);
- writer.write16bit(num);
- super.visit();
- }
-
- public int locals(int pos, int offset, int num) {
- writer.write16bit(offset);
- return super.locals(pos, offset, num);
- }
-
- public int typeInfoArray(int pos, int offset, int num, boolean isLocals) {
- writer.write16bit(num);
- return super.typeInfoArray(pos, offset, num, isLocals);
- }
-
- public void typeInfo(int pos, byte tag) {
- writer.writeVerifyTypeInfo(tag, 0);
- }
-
- public void objectVariable(int pos, int clazz) {
- writer.writeVerifyTypeInfo(OBJECT, clazz);
- }
-
- public void uninitialized(int pos, int offset) {
- writer.writeVerifyTypeInfo(UNINIT, offset);
- }
- }
-
- static class InsertLocal extends SimpleCopy {
- private int varIndex;
- private int varTag, varData;
-
- InsertLocal(StackMap map, int varIndex, int varTag, int varData) {
- super(map);
- this.varIndex = varIndex;
- this.varTag = varTag;
- this.varData = varData;
- }
-
- public int typeInfoArray(int pos, int offset, int num, boolean isLocals) {
- if (!isLocals || num < varIndex)
- return super.typeInfoArray(pos, offset, num, isLocals);
-
- writer.write16bit(num + 1);
- for (int k = 0; k < num; k++) {
- if (k == varIndex)
- writeVarTypeInfo();
-
- pos = typeInfoArray2(k, pos);
- }
-
- if (num == varIndex)
- writeVarTypeInfo();
-
- return pos;
- }
-
- private void writeVarTypeInfo() {
- if (varTag == OBJECT)
- writer.writeVerifyTypeInfo(OBJECT, varData);
- else if (varTag == UNINIT)
- writer.writeVerifyTypeInfo(UNINIT, varData);
- else
- writer.writeVerifyTypeInfo(varTag, 0);
- }
- }
-
- void shiftPc(int where, int gapSize, boolean exclusive)
- throws BadBytecode
- {
- new Shifter(this, where, gapSize, exclusive).visit();
- }
-
- static class Shifter extends Walker {
- private int where, gap;
- private boolean exclusive;
-
- public Shifter(StackMap smt, int where, int gap, boolean exclusive) {
- super(smt);
- this.where = where;
- this.gap = gap;
- this.exclusive = exclusive;
- }
-
- public int locals(int pos, int offset, int num) {
- if (exclusive ? where <= offset : where < offset)
- ByteArray.write16bit(offset + gap, info, pos - 4);
-
- return super.locals(pos, offset, num);
- }
-
- public void uninitialized(int pos, int offset) {
- if (where <= offset)
- ByteArray.write16bit(offset + gap, info, pos + 1);
- }
- }
-
- /**
- * @see CodeIterator.Switcher#adjustOffsets(int, int)
- */
- void shiftForSwitch(int where, int gapSize) throws BadBytecode {
- new SwitchShifter(this, where, gapSize).visit();
- }
-
- static class SwitchShifter extends Walker {
- private int where, gap;
-
- public SwitchShifter(StackMap smt, int where, int gap) {
- super(smt);
- this.where = where;
- this.gap = gap;
- }
-
- public int locals(int pos, int offset, int num) {
- if (where == pos + offset)
- ByteArray.write16bit(offset - gap, info, pos - 4);
- else if (where == pos)
- ByteArray.write16bit(offset + gap, info, pos - 4);
-
- return super.locals(pos, offset, num);
- }
- }
-
- /**
- * Undocumented method. Do not use; internal-use only.
- *
- * <p>This method is for javassist.convert.TransformNew.
- * It is called to update the stack map when
- * the NEW opcode (and the following DUP) is removed.
- *
- * @param where the position of the removed NEW opcode.
- */
- public void removeNew(int where) throws CannotCompileException {
- byte[] data = new NewRemover(this, where).doit();
- this.set(data);
- }
-
- static class NewRemover extends SimpleCopy {
- int posOfNew;
-
- NewRemover(StackMap map, int where) {
- super(map);
- posOfNew = where;
- }
-
- public int stack(int pos, int offset, int num) {
- return stackTypeInfoArray(pos, offset, num);
- }
-
- private int stackTypeInfoArray(int pos, int offset, int num) {
- int p = pos;
- int count = 0;
- for (int k = 0; k < num; k++) {
- byte tag = info[p];
- if (tag == OBJECT)
- p += 3;
- else if (tag == UNINIT) {
- int offsetOfNew = ByteArray.readU16bit(info, p + 1);
- if (offsetOfNew == posOfNew)
- count++;
-
- p += 3;
- }
- else
- p++;
- }
-
- writer.write16bit(num - count);
- for (int k = 0; k < num; k++) {
- byte tag = info[pos];
- if (tag == OBJECT) {
- int clazz = ByteArray.readU16bit(info, pos + 1);
- objectVariable(pos, clazz);
- pos += 3;
- }
- else if (tag == UNINIT) {
- int offsetOfNew = ByteArray.readU16bit(info, pos + 1);
- if (offsetOfNew != posOfNew)
- uninitialized(pos, offsetOfNew);
-
- pos += 3;
- }
- else {
- typeInfo(pos, tag);
- pos++;
- }
- }
-
- return pos;
- }
- }
-
- /**
- * Prints this stack map.
- */
- public void print(java.io.PrintWriter out) {
- new Printer(this, out).print();
- }
-
- static class Printer extends Walker {
- private java.io.PrintWriter writer;
-
- public Printer(StackMap map, java.io.PrintWriter out) {
- super(map);
- writer = out;
- }
-
- public void print() {
- int num = ByteArray.readU16bit(info, 0);
- writer.println(num + " entries");
- visit();
- }
-
- public int locals(int pos, int offset, int num) {
- writer.println(" * offset " + offset);
- return super.locals(pos, offset, num);
- }
- }
-
- /**
- * Internal use only.
- */
- public static class Writer {
- // see javassist.bytecode.stackmap.MapMaker
-
- private ByteArrayOutputStream output;
-
- /**
- * Constructs a writer.
- */
- public Writer() {
- output = new ByteArrayOutputStream();
- }
-
- /**
- * Converts the written data into a byte array.
- */
- public byte[] toByteArray() {
- return output.toByteArray();
- }
-
- /**
- * Converts to a <code>StackMap</code> attribute.
- */
- public StackMap toStackMap(ConstPool cp) {
- return new StackMap(cp, output.toByteArray());
- }
-
- /**
- * Writes a <code>union verification_type_info</code> value.
- *
- * @param data <code>cpool_index</code> or <code>offset</code>.
- */
- public void writeVerifyTypeInfo(int tag, int data) {
- output.write(tag);
- if (tag == StackMap.OBJECT || tag == StackMap.UNINIT)
- write16bit(data);
- }
-
- /**
- * Writes a 16bit value.
- */
- public void write16bit(int value) {
- output.write((value >>> 8) & 0xff);
- output.write(value & 0xff);
- }
- }
- }
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