src/jas/ClassEnv.java

package jas;

import java.io.*;
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Vector;


/**
 * This is the place where all information about the class to
 * be created resides.
 *
 * @author $Author: jonmeyerny $
 * @version $Revision: 1.1 $
 */

public class ClassEnv implements RuntimeConstants
{
  int magic;
  short version_lo, version_hi;
  CP this_class, super_class;
  short class_access;
  Hashtable cpe, cpe_index;
  Vector interfaces;
  Vector vars;
  Vector methods;
  SourceAttr source;
  SignatureAttr signature;
  SourceDebugExtensionAttr debug;
  EnclosingMethodAttr enclosing;
  DeprecatedAttr depr;
  InnerClassesAttr innerclasses;
  AnnotationAttr annVis, annInvis;
  Vector generic;

  public ClassEnv()
  {
                                // Fill in reasonable defaults
    magic = JAVA_MAGIC;
    version_lo = (short) JAVA_MINOR_VERSION;
    version_hi = (short) JAVA_VERSION;
                                // Initialize bags
    cpe = new Hashtable();
    cpe_index = null;
    interfaces = new Vector();
    vars = new Vector();
    methods = new Vector();
    annVis = annInvis = null;
    generic = new Vector();
  }

  /**
   * Define this class to have this name.
   * @param name CPE representing name for class. (This is usually
   * a ClassCP)
   */
  public void setClass(CP name)
  {  this_class = name; addCPItem(name); }
  /**
   * Define this class to have this superclass
   * @param name CPE representing name for class. (This is usually
   * a ClassCP)
   */
  public void setSuperClass(CP name)
  {  super_class = name; addCPItem(name); }

  /**
   * Set the class access for this class. Constants understood
   * by this are present along with the java Beta distribution.
   * @param access number representing access permissions for
   *        the entire class.
   * @see RuntimeConstants
   */
  public void setClassAccess(short access)
  { class_access  = access; }

  /**
   * Add this CP to the list of interfaces supposedly implemented by
   * this class. Note that the CP ought to be a ClassCP to make
   * sense to the VM.
   */

  public void addInterface(CP ifc)
  {
    addCPItem(ifc);
    interfaces.addElement(ifc);
  }

  /**
   * Add this to the list of interfaces supposedly implemented
   * by this class. Note that each CP is usually a ClassCP.
   * @param ilist An array of CP items representing the
   *          interfaces implemented by this class.
   */
  public void addInterface(CP ilist[])
  {
    for (int i=0; i<ilist.length; i++)
      {
        interfaces.addElement(ilist[i]);
        addCPItem(ilist[i]);
      }
  }

  public void addField(Var v)
  {
    vars.addElement(v);
    v.resolve(this);
  }
  /**
   * Write the contents of the class.
   *
   * @param out DataOutputStream on which the contents are written.
   */
  public void write(DataOutputStream out)
    throws IOException, jasError
  {
				// Headers
    out.writeInt(magic);
    out.writeShort(version_lo);
    out.writeShort(version_hi);

				// cpe items
    int curidx = 1;
				// make up indices for entries
    cpe_index = new Hashtable();
    for (Enumeration e = cpe.elements(); e.hasMoreElements();)
      {
        CP tmp = (CP)(e.nextElement());
        cpe_index.put(tmp.getUniq(), new Integer(curidx));
        curidx++;
        if ((tmp instanceof LongCP) ||
            (tmp instanceof DoubleCP))
          curidx++;
      }
    out.writeShort((short)curidx);

				// Now write out all the entries
    for (Enumeration e = cpe.elements(); e.hasMoreElements();)
      {
        CP now = (CP) (e.nextElement());
        now.write(this, out);
      }

				// Class hierarchy/access
    out.writeShort(class_access);
    out.writeShort(getCPIndex(this_class));
    out.writeShort(getCPIndex(super_class));
                                // interfaces
    out.writeShort(interfaces.size());
    for (Enumeration e = interfaces.elements(); e.hasMoreElements();)
      {
        CP c = (CP)(e.nextElement());
        out.writeShort(getCPIndex(c));
      }
                                // variables
    out.writeShort(vars.size());
    for (Enumeration e = vars.elements(); e.hasMoreElements();)
      {
        Var v = (Var)(e.nextElement());
        v.write(this, out);
      }

                                // methods
    out.writeShort(methods.size());
    for (Enumeration e = methods.elements(); e.hasMoreElements();)
      {
        Method m = (Method)(e.nextElement());
        m.write(this, out);
      }
                                // additional attributes
    short numExtra = 0;
    if (source != null)
      { numExtra++; }
    if (debug != null)
      { numExtra++; }
    if (enclosing != null)
      { numExtra++; }
    if (signature != null)
      { numExtra++; }
    if (innerclasses != null)
      { numExtra++; }
    if (depr != null)
      { numExtra++; }
    if (annVis != null)
      { numExtra++; }
    if (annInvis != null)
      { numExtra++; }
    numExtra += generic.size();

    out.writeShort(numExtra);
    if (source != null)
      { source.write(this, out); }
    if (debug != null)
      { debug.write(this, out); }
    if (enclosing != null)
      { enclosing.write(this, out); }
    if (signature != null)
      { signature.write(this, out); }
    if (innerclasses != null)
      { innerclasses.write(this, out); }
    if (depr != null)
      { depr.write(this, out); }
    if (annVis != null)
      { annVis.write(this, out); }
    if (annInvis != null)
      { annInvis.write(this, out); }
    for (Enumeration gen=generic.elements(); gen.hasMoreElements(); )
      {
        GenericAttr gattr = (GenericAttr)gen.nextElement();
        gattr.write(this, out);
      }
    out.flush();
  }

  /**
   * This is the method to add CPE items to a class. CPE items for
   * a class are "uniquefied". Ie, if you add a CPE items whose
   * contents already exist in the class, only one entry is finally
   * written out when the class is written.
   *
   * @param cp Item to be added to the class
   */

  public void addCPItem(CP cp)
  {
    String uniq = cp.getUniq();
    CP intern;

    if ((intern = (CP)(cpe.get(uniq))) == null)
      {
				// add it
        cpe.put(uniq, cp);
				// resolve it so it adds anything
				// which it depends on
        cp.resolve(this);
      }
  }

  /**
   * Add an attribute specifying the name of the source file
   * for the class
   * @param source SourceAttribute specifying the source for the file
   */

  public void setSource(SourceAttr source)
  { this.source = source; source.resolve(this); }

  /**
   * Add an attribute specifying the name of the source file
   * for the clas.
   * @param source String with the name of the class
   */
  public void setSource(String source)
  { this.source = new SourceAttr(source); this.source.resolve(this); }

  /**
   * Add an attribute specifying extended debug information
   * @param debug String the extended debug information
   */
  public void setSourceDebugExtension(String debug)
  {
    if ( this.debug != null )
        this.debug.append(debug);
    else {
        this.debug = new SourceDebugExtensionAttr(debug);
        this.debug.resolve(this);
    }
  }


  /**
   * Add an attribute specifying the enclosing method of this class
   * @param cls String the enclosing class
   * @param mtd String the enclosing method
   * @param dsc String the enclosing method descriptor
   */
  public void setEnclosingMethod(String cls, String mtd, String dsc)
  { this.enclosing = new EnclosingMethodAttr(cls, mtd, dsc);
    this.enclosing.resolve(this); }


  /**
   * Add an attribute specifying the signature of this class
   * @param sig String the signature
   */
  public void setSignature(String sig)
  { this.signature = new SignatureAttr(sig);
    this.signature.resolve(this); }


  public void setDeprecated(DeprecatedAttr depr)
  { this.depr = depr; depr.resolve(this); }

  /**
   * Add a generic attribute to the class file. A generic attribute
   * contains a stream of uninterpreted bytes which is ignored by
   * the VM (as long as its name doesn't conflict with other names
   * for attributes that are understood by the VM)
   */
  public void addGenericAttr(GenericAttr g)
  { generic.addElement(g); g.resolve(this); }

  public void addInnerClass(short iacc, String name, String inner, String outer)
  {
    if(innerclasses == null) {
      innerclasses = new InnerClassesAttr();
      innerclasses.resolve(this);
    }
    InnerClass ic = new InnerClass(iacc, name, inner, outer);
    ic.resolve(this);
    innerclasses.addInnerClass(ic);
  }

  /*
   * procedure group for annotation description
  */
  public Annotation addAnnotation(boolean visible, String clsname)
  {
    Annotation ann = new Annotation(clsname);
    AnnotationAttr aa = visible ? annVis : annInvis;
    if(aa == null) {
      aa = new AnnotationAttr(visible);
      if(visible) annVis = aa;
      else annInvis = aa;
    }
    aa.add(ann);
    return(ann);
  }

  public void endHeader()
  {
    if(annVis != null) annVis.resolve(this);
    if(annInvis != null) annInvis.resolve(this);
  }

  /**
   * This allows more control over generating CP's for methods
   * if you feel so inclined.
   */
  public void addMethod(Method m)
  {
    m.resolve(this);
    methods.addElement(m);
  }

  short getCPIndex(CP cp)
    throws jasError
  {
    if (cpe_index == null)
      throw new jasError("Internal error: CPE index has not been generated");

    Integer idx = (Integer)(cpe_index.get(cp.getUniq()));
    if (idx == null)
      throw new jasError("Item " + cp + " not in the class");
    return ((short)(idx.intValue()));
  }

  /**
   * Change the bytecode version of this class
   * The version will be version_high.version_low
   * @param version_high short
   * @param version_low short
   */
  public void setVersion(short version_high, short version_low)
  {
    version_hi = version_high;
    version_lo = version_low;
  }
}