1 /*

     2  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 package sun.jvm.hotspot.debugger.cdbg.basic.x86;

    26 

    27 import sun.jvm.hotspot.debugger.*;

    28 import sun.jvm.hotspot.debugger.x86.*;

    29 import sun.jvm.hotspot.debugger.cdbg.*;

    30 import sun.jvm.hotspot.debugger.cdbg.basic.*;

    31 

    32 /** Basic X86 frame functionality providing sender() functionality. */

    33 

    34 public class X86CFrame extends BasicCFrame {

    35   private Address ebp;

    36   private Address pc;

    37 

    38   private static final int ADDRESS_SIZE = 4;

    39 

    40   /** Constructor for topmost frame */

    41   public X86CFrame(CDebugger dbg, Address ebp, Address pc) {

    42     super(dbg);

    43     this.ebp = ebp;

    44     this.pc  = pc;

    45   }

    46 

    47   public CFrame sender(ThreadProxy thread) {

    48     X86ThreadContext context = (X86ThreadContext) thread.getContext();

    49     Address esp = context.getRegisterAsAddress(X86ThreadContext.ESP);

    50 

    51     if ( (ebp == null) || ebp.lessThan(esp) ) {

    52       return null;

    53     }

    54 

    55     Address nextEBP = ebp.getAddressAt( 0 * ADDRESS_SIZE);

    56     if (nextEBP == null) {

    57       return null;

    58     }

    59     Address nextPC  = ebp.getAddressAt( 1 * ADDRESS_SIZE);

    60     if (nextPC == null) {

    61       return null;

    62     }

    63     return new X86CFrame(dbg(), nextEBP, nextPC);

    64   }

    65 

    66   public Address pc() {

    67     return pc;

    68   }

    69 

    70   public Address localVariableBase() {

    71     return ebp;

    72   }

    73 }