1 /*
   2  * Copyright 2000-2009 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.code;
  26 
  27 import java.io.*;
  28 import java.util.*;
  29 import sun.jvm.hotspot.debugger.*;
  30 import sun.jvm.hotspot.runtime.*;
  31 import sun.jvm.hotspot.types.*;
  32 
  33 /** PcDescs map a physical PC (given as offset from start of nmethod)
  34     to the corresponding source scope and byte code index. */
  35 
  36 public class PCDesc extends VMObject {
  37   private static CIntegerField pcOffsetField;
  38   private static CIntegerField scopeDecodeOffsetField;
  39   private static CIntegerField pcFlagsField;
  40 
  41   static {
  42     VM.registerVMInitializedObserver(new Observer() {
  43         public void update(Observable o, Object data) {
  44           initialize(VM.getVM().getTypeDataBase());
  45         }
  46       });
  47   }
  48 
  49   private static void initialize(TypeDataBase db) {
  50     Type type = db.lookupType("PcDesc");
  51 
  52     pcOffsetField          = type.getCIntegerField("_pc_offset");
  53     scopeDecodeOffsetField = type.getCIntegerField("_scope_decode_offset");
  54     pcFlagsField           = type.getCIntegerField("_flags");
  55   }
  56 
  57   public PCDesc(Address addr) {
  58     super(addr);
  59   }
  60 
  61   // FIXME: add additional constructor probably needed for ScopeDesc::sender()
  62 
  63   public int getPCOffset() {
  64     return (int) pcOffsetField.getValue(addr);
  65   }
  66 
  67   public int getScopeDecodeOffset() {
  68     return ((int) scopeDecodeOffsetField.getValue(addr));
  69   }
  70 
  71   public Address getRealPC(NMethod code) {
  72     return code.instructionsBegin().addOffsetTo(getPCOffset());
  73   }
  74 
  75 
  76   public boolean getReexecute() {
  77     int flags = (int)pcFlagsField.getValue(addr);
  78     return ((flags & 0x1)== 1); //first is the reexecute bit
  79   }
  80 
  81   public void print(NMethod code) {
  82     printOn(System.out, code);
  83   }
  84 
  85   public void printOn(PrintStream tty, NMethod code) {
  86     tty.println("PCDesc(" + getRealPC(code) + "):");
  87     for (ScopeDesc sd = code.getScopeDescAt(getRealPC(code));
  88          sd != null;
  89          sd = sd.sender()) {
  90       tty.print(" ");
  91       sd.getMethod().printValueOn(tty);
  92       tty.print("  @" + sd.getBCI());
  93       tty.print("  reexecute=" + sd.getReexecute());
  94       tty.println();
  95     }
  96   }
  97 }