/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
package sun.jvm.hotspot.runtime;
import java.util.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.types.*;
/** <P> A JavaCallWrapper is constructed before each JavaCall and
destroyed after the call. Its purpose is to allocate/deallocate a
new handle block and to save/restore the last Java fp/sp. A
pointer to the JavaCallWrapper is stored on the stack. </P>
<P> NOTE: this port is very minimal and is only designed to get
frame traversal working. FIXME: we will have to add platform-
specific stuff later and therefore a factory for these
objects. </P> */
public class JavaCallWrapper extends VMObject {
protected static AddressField anchorField;
private static AddressField lastJavaSPField;
private static AddressField lastJavaPCField;
static {
VM.registerVMInitializedObserver(new Observer() {
public void update(Observable o, Object data) {
initialize(VM.getVM().getTypeDataBase());
}
});
}
private static synchronized void initialize(TypeDataBase db) {
Type type = db.lookupType("JavaCallWrapper");
Type anchorType = db.lookupType("JavaFrameAnchor");
anchorField = type.getAddressField("_anchor");
lastJavaSPField = anchorType.getAddressField("_last_Java_sp");
lastJavaPCField = anchorType.getAddressField("_last_Java_pc");
}
public JavaCallWrapper(Address addr) {
super(addr);
}
public Address getLastJavaSP() {
return lastJavaSPField.getValue(addr.addOffsetTo(anchorField.getOffset()));
}
public Address getLastJavaPC() {
return lastJavaPCField.getValue(addr.addOffsetTo(anchorField.getOffset()));
}
}