code: /**
   * Copyright (c) 2004-2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * 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.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package avrora.monitors;
  
  import avrora.arch.AbstractInstr;
  import avrora.arch.legacy.*;
  import avrora.core.Program;
  import avrora.core.SourceMapping;
  import avrora.sim.Simulator;
  import avrora.sim.State;
  import avrora.sim.output.SimPrinter;
  import cck.text.StringUtil;
  import cck.text.Terminal;
  
  /**
   * The <code>Break</code> monitor prints a stack trace when the
   * program being simulated executes a break instruction.  Breaks are
   * are good implementation for assertion failures and similar.
   *
   * @author Reet D. Dhakal
   * @author John Regehr
   * @author Ben L. Titzer
   */
  public class BreakMonitor extends MonitorFactory {
  
      public class Mon implements Monitor {
          public final Simulator simulator;
          public final SimPrinter printer;
          public final CallTrace trace;
          public final CallStack stack;
          private final SourceMapping sourceMap;
  
          Mon(Simulator s) {
              simulator = s;
              printer = s.getPrinter();
              trace = new CallTrace(s);
              stack = new CallStack();
              trace.attachMonitor(stack);
  
              Program p = s.getProgram();
              sourceMap = p.getSourceMapping();
              for (int pc = 0; pc < p.program_end; pc = p.getNextPC(pc)) {
                  AbstractInstr i = p.readInstr(pc);
                  if (i != null && i instanceof LegacyInstr.BREAK)
                      s.insertProbe(new BreakProbe(), pc);
              }
          }
  
          public class BreakProbe extends Simulator.Probe.Empty {
  
              public void fireBefore(State state, int pc) {
                  LegacyState s = (LegacyState) simulator.getState();
  
                  StringBuffer buf = printer.getBuffer();
                  buf.append("break instruction @ ");
                  Terminal.append(Terminal.COLOR_CYAN, buf, StringUtil.addrToString(pc));
                  buf.append(", r30:r31 = ");
                  int v = s.getRegisterWord(LegacyRegister.getRegisterByNumber(30));
                  Terminal.append(Terminal.COLOR_GREEN, buf, StringUtil.to0xHex(v, 4));
                  printer.printBuffer(buf);
  
                  stack.printStack(printer, sourceMap);
              }
          }
  
          public void report() {
              // do nothing
          }
      }
  
      public BreakMonitor() {
          super("The \"break\" monitor watches for execution of an AVR break " +
                  "instruction, which can be used to implement things like assertion " +
                  "failures.  When a break is executed the simulator prints a stack " +
                  "trace.");
      }
  
      public Monitor newMonitor(Simulator s) {
          return new Mon(s);
      }
  }
  