- 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.
- * It may contain null references, due to the JVM specification that skips
- * an entry after an 8-byte constant (double, long) entry.
- *
- * @version $Id: ConstantPool.java,v 1.1.1.1 2001/10/29 19:59:59 jvanzyl Exp $
- * @see Constant
- * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
- */
- public class ConstantPool implements Cloneable, Node {
- 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
- * @throw IOException
- * @throw ClassFormatError
- */
- ConstantPool(DataInputStream file) throws IOException, ClassFormatError
- {
- 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 ClassFormatError
- {
- 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 ClassFormatError
- {
- Constant c = getConstant(index, tag);
- return constantToString(c);
- }
-
- /**
- * Dump constant pool to file stream in binary format.
- *
- * @param file Output file stream
- * @throw 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 ClassFormatError("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
- * @throw ClassFormatError
- */
- public Constant getConstant(int index, byte tag)
- throws ClassFormatError
- {
- Constant c;
-
- c = getConstant(index);
-
- if(c == null)
- throw new ClassFormatError("Constant pool at index " + index + " is null.");
-
- if(c.getTag() == tag)
- return c;
- else
- throw new ClassFormatError("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
- * @throw ClassFormatError
- */
- public String getConstantString(int index, byte tag)
- throws ClassFormatError
- {
- Constant c;
- int i;
- String s;
-
- 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;
- }
- }