org.aspectj/bcel-builder/src/org/aspectj/apache/bcel/classfile/Signature.java

package org.aspectj.apache.bcel.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/>.
 * 
 * Extended by Adrian Colyer, June 2005 to support unpacking of Signature
 * attribute
 */


import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import org.aspectj.apache.bcel.Constants;

/**
 * This class is derived from <em>Attribute</em> and represents a reference
 * to a <href="http://wwwipd.ira.uka.de/~pizza/gj/">GJ</a> attribute.
 *
 * @version $Id: Signature.java,v 1.6.6.1 2007/02/09 10:45:09 aclement Exp $
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @see     Attribute
 */
public final class Signature extends Attribute {
  private int signature_index;
  
  /**
   * Initialize from another object. Note that both objects use the same
   * references (shallow copy). Use clone() for a physical copy.
   */
  public Signature(Signature c) {
    this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());
  }

  /**
   * Construct object from file stream.
   * @param name_index Index in constant pool to CONSTANT_Utf8
   * @param length Content length in bytes
   * @param file Input stream
   * @param constant_pool Array of constants
   * @throws IOException
   */
  Signature(int name_index, int length, DataInputStream file,
	   ConstantPool constant_pool) throws IOException
  {
    this(name_index, length, file.readUnsignedShort(), constant_pool);
  }

  /**
   * @param name_index Index in constant pool to CONSTANT_Utf8
   * @param length Content length in bytes
   * @param constant_pool Array of constants
   * @param Signature_index Index in constant pool to CONSTANT_Utf8
   */
  public Signature(int name_index, int length, int signature_index,
		  ConstantPool constant_pool)
  {
    super(Constants.ATTR_SIGNATURE, name_index, length, constant_pool);
    this.signature_index = signature_index;
  }

  /**
   * 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.visitSignature(this);
   }
   
  /**
   * Dump source file attribute to file stream in binary format.
   *
   * @param file Output file stream
   * @throws IOException
   */ 
  public final void dump(DataOutputStream file) throws IOException
  {
    super.dump(file);
    file.writeShort(signature_index);
  }    

  /**
   * @return Index in constant pool of source file name.
   */  
  public final int getSignatureIndex() { return signature_index; }    

  /**
   * @param Signature_index.
   */
  public final void setSignatureIndex(int signature_index) {
    this.signature_index = signature_index;
  }    

  /**
   * @return GJ signature.
   */ 
  public final String getSignature() {
    ConstantUtf8 c = (ConstantUtf8)constant_pool.getConstant(signature_index, 
							     Constants.CONSTANT_Utf8);
    return c.getBytes();
  }

  /**
   * Extends ByteArrayInputStream to make 'unreading' chars possible.
   */
  private static final class MyByteArrayInputStream extends ByteArrayInputStream {
    MyByteArrayInputStream(String data) { super(data.getBytes()); }
    final int  mark()                   { return pos; }
    final String getData()              { return new String(buf); }
    final void reset(int p)             { pos = p; }
    final void unread()                 { if(pos > 0) pos--; }
  }

  private static boolean identStart(int ch) {
    return ch == 'T' || ch == 'L';
  }

  private static boolean identPart(int ch) {
    return ch == '/' || ch == ';';
  }

  private static final void matchIdent(MyByteArrayInputStream in, StringBuffer buf) {
    int ch;

    if((ch = in.read()) == -1)
      throw new RuntimeException("Illegal signature: " + in.getData() +
				 " no ident, reaching EOF");

    //System.out.println("return from ident:" + (char)ch);

    if(!identStart(ch)) {
      StringBuffer buf2 = new StringBuffer();

      int count = 1;
      while(Character.isJavaIdentifierPart((char)ch)) {
	buf2.append((char)ch);
	count++;
	ch = in.read();
      }
      
      if(ch == ':') { // Ok, formal parameter
	in.skip("Ljava/lang/Object".length());
	buf.append(buf2);

        ch = in.read();
	in.unread();
	//System.out.println("so far:" + buf2 + ":next:" +(char)ch);
      } else {
	for(int i=0; i < count; i++)
	  in.unread();
      }

      return;
    }

    StringBuffer buf2 = new StringBuffer();
    ch = in.read();

    do {
      buf2.append((char)ch);
      ch = in.read();
      //System.out.println("within ident:"+ (char)ch);

    } while((ch != -1) && (Character.isJavaIdentifierPart((char)ch) || (ch == '/')));

    buf.append(buf2.toString().replace('/', '.'));

    //System.out.println("regular return ident:"+ (char)ch + ":" + buf2);

    if(ch != -1)
      in.unread();
  }

  private static final void matchGJIdent(MyByteArrayInputStream in,
					 StringBuffer buf)
  {
    int ch;

    matchIdent(in, buf);

    ch = in.read();
    if((ch == '<') || ch == '(') { // Parameterized or method
      //System.out.println("Enter <");
      buf.append((char)ch);
      matchGJIdent(in, buf);
      
      while(((ch = in.read()) != '>') && (ch != ')')) { // List of parameters
	if(ch == -1)
	  throw new RuntimeException("Illegal signature: " + in.getData() +
				     " reaching EOF");

	//System.out.println("Still no >");
	buf.append(", ");
	in.unread();
	matchGJIdent(in, buf); // Recursive call
      }

      //System.out.println("Exit >");

      buf.append((char)ch);
    } else
      in.unread();

    ch = in.read();
    if(identStart(ch)) {
      in.unread();
      matchGJIdent(in, buf);
    } else if(ch == ')') {
      in.unread();
      return;
    } else if(ch != ';')
      throw new RuntimeException("Illegal signature: " + in.getData() + " read " +
				 (char)ch);
  }

  public static String translate(String s) {
    //System.out.println("Sig:" + s);
    StringBuffer buf = new StringBuffer();

    matchGJIdent(new MyByteArrayInputStream(s), buf);

    return buf.toString();
  }

  public static final boolean isFormalParameterList(String s) {
    return s.startsWith("<") && (s.indexOf(':') > 0);
  }

  public static final boolean isActualParameterList(String s) {
    return s.startsWith("L") && s.endsWith(">;");
  }    

  /**
   * @return String representation
   */ 
  public final String toString() {
    String s = getSignature();

    return "Signature(" + s + ")";
  }    

  /**
   * @return deep copy of this attribute
   */
  public Attribute copy(ConstantPool constant_pool) {
    return (Signature)clone();
  }

  // =============================================
  // AMC extensions
  
  private ClassSignature classSig;
  private MethodTypeSignature methodSig;
  private FieldTypeSignature fieldSig;
  
  public ClassSignature asClassSignature() {
	  if (classSig == null) {
		  GenericSignatureParser parser = new GenericSignatureParser();
		  classSig = parser.parseAsClassSignature(getSignature());
	  }
	  return classSig;
  }
  
  public MethodTypeSignature asMethodTypeSignature() {
	  if (methodSig == null) {
		  GenericSignatureParser parser = new GenericSignatureParser();
		  methodSig = parser.parseAsMethodSignature(getSignature());
	  }
	  return methodSig;	  
  }
  
  public FieldTypeSignature asFieldTypeSignature() {
	  if (fieldSig == null) {
		  GenericSignatureParser parser = new GenericSignatureParser();
		  fieldSig = parser.parseAsFieldSignature(getSignature());		  
	  }
	  return fieldSig;
  }
  
  /**
   * structure holding a parsed class signature
   */
  public static class ClassSignature {
	  public FormalTypeParameter[] formalTypeParameters = new FormalTypeParameter[0];
	  public ClassTypeSignature superclassSignature;
	  public ClassTypeSignature[] superInterfaceSignatures = new ClassTypeSignature[0];
	  public String toString() {
		  StringBuffer ret = new StringBuffer();
		  ret.append(formalTypeParameters.toString());
		  ret.append(superclassSignature.toString());
		  for (int i = 0; i < superInterfaceSignatures.length; i++) {
			ret.append(superInterfaceSignatures[i].toString());
		  }
		  return ret.toString();
	  }
  }
  
  public static class MethodTypeSignature { 
	  public FormalTypeParameter[] formalTypeParameters = new FormalTypeParameter[0];
	  public TypeSignature[] parameters = new TypeSignature[0];
	  public TypeSignature returnType;
	  public FieldTypeSignature[] throwsSignatures = new FieldTypeSignature[0];
	  
	  public MethodTypeSignature(
			  FormalTypeParameter[] aFormalParameterList,
			  TypeSignature[] aParameterList,
			  TypeSignature aReturnType,
			  FieldTypeSignature[] aThrowsSignatureList
	  		) {
		  this.formalTypeParameters = aFormalParameterList;
		  this.parameters = aParameterList;
		  this.returnType = aReturnType;
		  this.throwsSignatures = aThrowsSignatureList;
	  }
	  
	  public String toString() {
		  StringBuffer sb = new StringBuffer();
		  if (formalTypeParameters.length > 0) {
			  sb.append("<");
			  for (int i = 0; i < formalTypeParameters.length; i++) {
				  sb.append(formalTypeParameters[i].toString());
			  }
			  sb.append(">");
		  }
		  sb.append("(");
		  for (int i = 0; i < parameters.length; i++) {
			  sb.append(parameters[i].toString());
		  }
		  sb.append(")");
		  sb.append(returnType.toString());
		  for (int i = 0; i < throwsSignatures.length; i++) {
			  sb.append("^");
			  sb.append(throwsSignatures[i].toString());
		  }
		  return sb.toString();
	  }
  }
  
  /**
   * structure capturing a FormalTypeParameter from the Signature grammar
   */
  public static class FormalTypeParameter {
	  public String identifier;
	  public FieldTypeSignature classBound;
	  public FieldTypeSignature[] interfaceBounds;
	  public String toString() {
		  StringBuffer ret =  new StringBuffer();
		  ret.append("T");
		  ret.append(identifier);
		  ret.append(":");
		  ret.append(classBound.toString());
		  for (int i = 0; i < interfaceBounds.length; i++) {
			ret.append(":");
			ret.append(interfaceBounds[i].toString());
		  }
		  return ret.toString();
	  }
  }
  
  public static abstract class TypeSignature {
	  public boolean isBaseType() { return false; }
  }
  
  public static class BaseTypeSignature extends TypeSignature {
	  private String sig;
	  public BaseTypeSignature(String aPrimitiveType) {
		  sig = aPrimitiveType;
	  }
	  public boolean isBaseType() { return true; }
	  public String toString() {
		  return sig;
	  }
  }
  
  public static abstract class FieldTypeSignature extends TypeSignature {
	  public boolean isClassTypeSignature() { return false; }
	  public boolean isTypeVariableSignature() { return false; }
	  public boolean isArrayTypeSignature() { return false; }
  }
  
  public static class ClassTypeSignature extends FieldTypeSignature {
	  public String classSignature;
	  public SimpleClassTypeSignature outerType;
	  public SimpleClassTypeSignature[] nestedTypes; 
	  public ClassTypeSignature(String sig,String identifier) { 
		  this.classSignature = sig;
		  this.outerType = new SimpleClassTypeSignature(identifier);
		  this.nestedTypes = new SimpleClassTypeSignature[0];
	  }
	  public ClassTypeSignature(String sig, SimpleClassTypeSignature outer, SimpleClassTypeSignature[] inners) {
		  this.classSignature = sig;
		  this.outerType = outer;
		  this.nestedTypes = inners;
	  }
	  public boolean isClassTypeSignature() { return true; }
	  
	  public String toString() {
		  return classSignature;
	  }
  }

  public static class TypeVariableSignature extends FieldTypeSignature {
	  public String typeVariableName;
	  public TypeVariableSignature(String typeVarToken) {
		  this.typeVariableName = typeVarToken.substring(1);
	  }
	  public boolean isTypeVariableSignature() { return true; }
	  public String toString() {
		  return "T" + typeVariableName + ";";
	  }
  }

  public static class ArrayTypeSignature extends FieldTypeSignature {
	  public TypeSignature typeSig;
	  public ArrayTypeSignature(TypeSignature aTypeSig) {
		  this.typeSig = aTypeSig;
	  }
	  public boolean isArrayTypeSignature() { return true; }
	  public String toString() {
		  return "[" + typeSig.toString();
	  }
  }

  public static class SimpleClassTypeSignature {
	  public String identifier;
	  public TypeArgument[] typeArguments;
	  
	  public SimpleClassTypeSignature(String identifier) {
		  this.identifier = identifier;
		  this.typeArguments = new TypeArgument[0];
	  }
	  
	  public SimpleClassTypeSignature(String identifier, TypeArgument[] args) {
		  this.identifier = identifier;
		  this.typeArguments = args;
	  }
	  
	  public String toString() {
		  StringBuffer sb = new StringBuffer();
		  sb.append(identifier);
		  if (typeArguments.length > 0) {
			  sb.append("<");
			  for (int i = 0; i < typeArguments.length; i++) {
				  sb.append(typeArguments[i].toString());
			  }
			  sb.append(">");
		  }
		  return sb.toString();
	  }
  }
  
  public static class TypeArgument {
	  public boolean isWildcard = false;
	  public boolean isPlus = false; 
	  public boolean isMinus = false;
	  public FieldTypeSignature signature;  // null if isWildcard
	  
	  public TypeArgument() {
		  isWildcard = true;
	  }
	  
	  public TypeArgument(boolean plus, boolean minus, FieldTypeSignature aSig) {
		  this.isPlus = plus;
		  this.isMinus = minus;
		  this.signature = aSig;
	  }
	  
	  public String toString() {
		  if (isWildcard) return "*";
		  StringBuffer sb = new StringBuffer();
		  if (isPlus) sb.append("+");
		  if (isMinus) sb.append("-");
		  sb.append(signature.toString());
		  return sb.toString();
	  }
  }
  
}