| /* |
| * reserved comment block |
| * DO NOT REMOVE OR ALTER! |
| */ |
| package com.sun.org.apache.bcel.internal.classfile; |
| |
| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Apache" and "Apache Software Foundation" and |
| * "Apache BCEL" must not be used to endorse or promote products |
| * derived from this software without prior written permission. For |
| * written permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * "Apache BCEL", nor may "Apache" appear in their name, without |
| * prior written permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| import com.sun.org.apache.bcel.internal.Constants; |
| import java.io.*; |
| |
| /** |
| * This class represents the constant pool, i.e., a table of constants, of |
| * a parsed classfile. It may contain null references, due to the JVM |
| * specification that skips an entry after an 8-byte constant (double, |
| * long) entry. Those interested in generating constant pools |
| * programatically should see <a href="../generic/ConstantPoolGen.html"> |
| * ConstantPoolGen</a>. |
| |
| * @see Constant |
| * @see com.sun.org.apache.bcel.internal.generic.ConstantPoolGen |
| * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> |
| */ |
| public class ConstantPool implements Cloneable, Node, Serializable { |
| private int constant_pool_count; |
| private Constant[] constant_pool; |
| |
| /** |
| * @param constant_pool Array of constants |
| */ |
| public ConstantPool(Constant[] constant_pool) |
| { |
| setConstantPool(constant_pool); |
| } |
| |
| /** |
| * Read constants from given file stream. |
| * |
| * @param file Input stream |
| * @throws IOException |
| * @throws ClassFormatException |
| */ |
| ConstantPool(DataInputStream file) throws IOException, ClassFormatException |
| { |
| byte tag; |
| |
| constant_pool_count = file.readUnsignedShort(); |
| constant_pool = new Constant[constant_pool_count]; |
| |
| /* constant_pool[0] is unused by the compiler and may be used freely |
| * by the implementation. |
| */ |
| for(int i=1; i < constant_pool_count; i++) { |
| constant_pool[i] = Constant.readConstant(file); |
| |
| /* Quote from the JVM specification: |
| * "All eight byte constants take up two spots in the constant pool. |
| * If this is the n'th byte in the constant pool, then the next item |
| * will be numbered n+2" |
| * |
| * Thus we have to increment the index counter. |
| */ |
| tag = constant_pool[i].getTag(); |
| if((tag == Constants.CONSTANT_Double) || (tag == Constants.CONSTANT_Long)) |
| i++; |
| } |
| } |
| |
| /** |
| * Called by objects that are traversing the nodes of the tree implicitely |
| * defined by the contents of a Java class. I.e., the hierarchy of methods, |
| * fields, attributes, etc. spawns a tree of objects. |
| * |
| * @param v Visitor object |
| */ |
| public void accept(Visitor v) { |
| v.visitConstantPool(this); |
| } |
| |
| /** |
| * Resolve constant to a string representation. |
| * |
| * @param constant Constant to be printed |
| * @return String representation |
| */ |
| public String constantToString(Constant c) |
| throws ClassFormatException |
| { |
| String str; |
| int i; |
| byte tag = c.getTag(); |
| |
| switch(tag) { |
| case Constants.CONSTANT_Class: |
| i = ((ConstantClass)c).getNameIndex(); |
| c = getConstant(i, Constants.CONSTANT_Utf8); |
| str = Utility.compactClassName(((ConstantUtf8)c).getBytes(), false); |
| break; |
| |
| case Constants.CONSTANT_String: |
| i = ((ConstantString)c).getStringIndex(); |
| c = getConstant(i, Constants.CONSTANT_Utf8); |
| str = "\"" + escape(((ConstantUtf8)c).getBytes()) + "\""; |
| break; |
| |
| case Constants.CONSTANT_Utf8: str = ((ConstantUtf8)c).getBytes(); break; |
| case Constants.CONSTANT_Double: str = "" + ((ConstantDouble)c).getBytes(); break; |
| case Constants.CONSTANT_Float: str = "" + ((ConstantFloat)c).getBytes(); break; |
| case Constants.CONSTANT_Long: str = "" + ((ConstantLong)c).getBytes(); break; |
| case Constants.CONSTANT_Integer: str = "" + ((ConstantInteger)c).getBytes(); break; |
| |
| case Constants.CONSTANT_NameAndType: |
| str = (constantToString(((ConstantNameAndType)c).getNameIndex(), |
| Constants.CONSTANT_Utf8) + " " + |
| constantToString(((ConstantNameAndType)c).getSignatureIndex(), |
| Constants.CONSTANT_Utf8)); |
| break; |
| |
| case Constants.CONSTANT_InterfaceMethodref: case Constants.CONSTANT_Methodref: |
| case Constants.CONSTANT_Fieldref: |
| str = (constantToString(((ConstantCP)c).getClassIndex(), |
| Constants.CONSTANT_Class) + "." + |
| constantToString(((ConstantCP)c).getNameAndTypeIndex(), |
| Constants.CONSTANT_NameAndType)); |
| break; |
| |
| default: // Never reached |
| throw new RuntimeException("Unknown constant type " + tag); |
| } |
| |
| return str; |
| } |
| |
| private static final String escape(String str) { |
| int len = str.length(); |
| StringBuffer buf = new StringBuffer(len + 5); |
| char[] ch = str.toCharArray(); |
| |
| for(int i=0; i < len; i++) { |
| switch(ch[i]) { |
| case '\n' : buf.append("\\n"); break; |
| case '\r' : buf.append("\\r"); break; |
| case '\t' : buf.append("\\t"); break; |
| case '\b' : buf.append("\\b"); break; |
| case '"' : buf.append("\\\""); break; |
| default: buf.append(ch[i]); |
| } |
| } |
| |
| return buf.toString(); |
| } |
| |
| |
| /** |
| * Retrieve constant at `index' from constant pool and resolve it to |
| * a string representation. |
| * |
| * @param index of constant in constant pool |
| * @param tag expected type |
| * @return String representation |
| */ |
| public String constantToString(int index, byte tag) |
| throws ClassFormatException |
| { |
| Constant c = getConstant(index, tag); |
| return constantToString(c); |
| } |
| |
| /** |
| * Dump constant pool to file stream in binary format. |
| * |
| * @param file Output file stream |
| * @throws IOException |
| */ |
| public void dump(DataOutputStream file) throws IOException |
| { |
| file.writeShort(constant_pool_count); |
| |
| for(int i=1; i < constant_pool_count; i++) |
| if(constant_pool[i] != null) |
| constant_pool[i].dump(file); |
| } |
| |
| /** |
| * Get constant from constant pool. |
| * |
| * @param index Index in constant pool |
| * @return Constant value |
| * @see Constant |
| */ |
| public Constant getConstant(int index) { |
| if (index >= constant_pool.length || index < 0) |
| throw new ClassFormatException("Invalid constant pool reference: " + |
| index + ". Constant pool size is: " + |
| constant_pool.length); |
| return constant_pool[index]; |
| } |
| |
| /** |
| * Get constant from constant pool and check whether it has the |
| * expected type. |
| * |
| * @param index Index in constant pool |
| * @param tag Tag of expected constant, i.e., its type |
| * @return Constant value |
| * @see Constant |
| * @throws ClassFormatException |
| */ |
| public Constant getConstant(int index, byte tag) |
| throws ClassFormatException |
| { |
| Constant c; |
| |
| c = getConstant(index); |
| |
| if(c == null) |
| throw new ClassFormatException("Constant pool at index " + index + " is null."); |
| |
| if(c.getTag() == tag) |
| return c; |
| else |
| throw new ClassFormatException("Expected class `" + Constants.CONSTANT_NAMES[tag] + |
| "' at index " + index + " and got " + c); |
| } |
| |
| /** |
| * @return Array of constants. |
| * @see Constant |
| */ |
| public Constant[] getConstantPool() { return constant_pool; } |
| /** |
| * Get string from constant pool and bypass the indirection of |
| * `ConstantClass' and `ConstantString' objects. I.e. these classes have |
| * an index field that points to another entry of the constant pool of |
| * type `ConstantUtf8' which contains the real data. |
| * |
| * @param index Index in constant pool |
| * @param tag Tag of expected constant, either ConstantClass or ConstantString |
| * @return Contents of string reference |
| * @see ConstantClass |
| * @see ConstantString |
| * @throws ClassFormatException |
| */ |
| public String getConstantString(int index, byte tag) |
| throws ClassFormatException |
| { |
| Constant c; |
| int i; |
| |
| c = getConstant(index, tag); |
| |
| /* This switch() is not that elegant, since the two classes have the |
| * same contents, they just differ in the name of the index |
| * field variable. |
| * But we want to stick to the JVM naming conventions closely though |
| * we could have solved these more elegantly by using the same |
| * variable name or by subclassing. |
| */ |
| switch(tag) { |
| case Constants.CONSTANT_Class: i = ((ConstantClass)c).getNameIndex(); break; |
| case Constants.CONSTANT_String: i = ((ConstantString)c).getStringIndex(); break; |
| default: |
| throw new RuntimeException("getConstantString called with illegal tag " + tag); |
| } |
| |
| // Finally get the string from the constant pool |
| c = getConstant(i, Constants.CONSTANT_Utf8); |
| return ((ConstantUtf8)c).getBytes(); |
| } |
| /** |
| * @return Length of constant pool. |
| */ |
| public int getLength() |
| { |
| return constant_pool_count; |
| } |
| |
| /** |
| * @param constant Constant to set |
| */ |
| public void setConstant(int index, Constant constant) { |
| constant_pool[index] = constant; |
| } |
| |
| /** |
| * @param constant_pool |
| */ |
| public void setConstantPool(Constant[] constant_pool) { |
| this.constant_pool = constant_pool; |
| constant_pool_count = (constant_pool == null)? 0 : constant_pool.length; |
| } |
| /** |
| * @return String representation. |
| */ |
| public String toString() { |
| StringBuffer buf = new StringBuffer(); |
| |
| for(int i=1; i < constant_pool_count; i++) |
| buf.append(i + ")" + constant_pool[i] + "\n"); |
| |
| return buf.toString(); |
| } |
| |
| /** |
| * @return deep copy of this constant pool |
| */ |
| public ConstantPool copy() { |
| ConstantPool c = null; |
| |
| try { |
| c = (ConstantPool)clone(); |
| } catch(CloneNotSupportedException e) {} |
| |
| c.constant_pool = new Constant[constant_pool_count]; |
| |
| for(int i=1; i < constant_pool_count; i++) { |
| if(constant_pool[i] != null) |
| c.constant_pool[i] = constant_pool[i].copy(); |
| } |
| |
| return c; |
| } |
| } |