Debug.java

package org.nanovm.converter;

//
//  NanoVMTool, Converter and Upload Tool for the NanoVM
//  Copyright (C) 2005 by Till Harbaum <Till@Harbaum.org>
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
//  Parts of this tool are based on public domain code written by Kimberley
//  Burchett: http://www.kimbly.com/code/classfile/
//

import java.io.PrintStream;

/**
* All classfile debugging information gets piped through this class.  
* You can turn off categories of debug information by setting the 
* appropriate String to null.
*/
public class Debug {
  public static String strClass = "class: ";
  public static String strConstPool = "CP: ";
  public static String strField = "field: ";
  public static String strMethod = "method: ";
  public static String strCode = "code: ";
  public static String strInterface = "interface: ";
  public static String strLineNumbers = "line numbers: ";
  public static String strLocalVariables = "local variables: ";
  public static String strInnerClasses = "inner classes: ";
  public static String strUnknownAttribute = "unknown attribute: ";
  public static String strBadData = "bad data: ";
  
  /**
   * Indent subsequent messages.  Subsequent messages will be indented by 
   * two spaces until outdent() is called.  All calls to indent() should eventually
   * be followed by a call to outdent().
   */
  public static void indent() {
    indentLevel++;
  }
  /**
   * Outdent subsequent messages.  This should only be called after a previous
   * call to indent().
   */
  public static void outdent() {
    indentLevel--;
  }
  
  /**
   * Enable or disable printing of any debug message.
   */
  public static void setEnabled(boolean e) {
    enabled = e;
  }
  /**
   * Get whether printing of debug messages is enabled.
   */
  public static boolean isEnabled() {
    return enabled;
  }
  
  /**
   * Redirect where debug messages are sent.
   */
  public static void setOutput(PrintStream out) {
    msgs = out;
  }
  /**
   * Get the destination of debug messages.
   */
  public static PrintStream getOutput() {
    return msgs;
  }
  
  /**
   * Print a debug message.  If the prefix is null, the message is not printed.
   * The message will be prefixed by blank space, the length of which is
   * determined by the current level of indentation.
   */
  public static void println(String prefix, String msg) {
    if (enabled && prefix != null) {
      for (int i = 0; i < indentLevel; i++)
	msgs.print("  ");
      msgs.println(prefix + msg);
    }
  }
  
  private static PrintStream msgs = System.out;
  private static boolean enabled = true;
  private static int indentLevel = 0;
}