/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.vm;
import org.jnode.annotation.MagicPermission;
import org.jnode.vm.classmgr.VmCompiledCode;
import org.jnode.vm.classmgr.VmMethod;
import org.vmmagic.unboxed.Address;
@MagicPermission
final class VmStackFrameEnumerator {
/**
* Stack frame reader
*/
private final VmStackReader reader;
/**
* Address of current stack frame
*/
private Address framePtr;
/**
* Index in address map of current stack frame method (deals with inlined methods)
*/
private int codeIndex;
/**
* Compiled code for the current frame
*/
private VmCompiledCode cc;
/**
* Initialize this instance.
*
* @param reader
* @param framePtr
* @param instrPtr
*/
public VmStackFrameEnumerator(VmStackReader reader, Address framePtr, Address instrPtr) {
this.reader = reader;
reset(framePtr, instrPtr);
}
/**
* Initialize this instance.
* Set the enumerator to enumerate the stack of the current thread.
*
* @param reader
*/
public VmStackFrameEnumerator(VmStackReader reader) {
this.reader = reader;
final Address curFrame = VmMagic.getCurrentFrame();
reset(reader.getPrevious(curFrame), reader.getReturnAddress(curFrame));
}
/**
* Reset the enumerator to the given pointers.
*
* @param framePtr
* @param instrPtr
*/
public final void reset(Address framePtr, Address instrPtr) {
this.framePtr = framePtr;
initializeCodeIndex(instrPtr);
}
/**
* Is the current frameptr valid.
*
* @return
*/
public final boolean isValid() {
return reader.isValid(framePtr);
}
/**
* Move to the next stack position.
*/
public final void next() {
if (reader.isValid(framePtr)) {
if (cc != null) {
final int newIndex = cc.getAddressMap().getCallSiteIndex(codeIndex);
if (newIndex >= 0) {
codeIndex = newIndex;
return;
}
}
final Address nextIP = reader.getReturnAddress(framePtr).add(-1);
this.framePtr = reader.getPrevious(framePtr);
initializeCodeIndex(nextIP);
}
}
/**
* Gets the method at the current stack position.
*
* @return
*/
public final VmMethod getMethod() {
VmMethod m = null;
if (cc != null) {
m = cc.getAddressMap().getMethodAtIndex(codeIndex);
}
if (m == null) {
m = cc.getMethod();
}
if (m == null) {
m = reader.getMethod(framePtr);
}
return m;
}
/**
* Gets the method at the current stack position.
*
* @return
*/
public final int getProgramCounter() {
if (cc != null) {
return cc.getAddressMap().getProgramCounterAtIndex(codeIndex);
} else {
return -1;
}
}
/**
* Gets the line number at the current stack position.
*
* @return
*/
public final int getLineNumber() {
return getMethod().getBytecode().getLineNr(getProgramCounter());
}
private void initializeCodeIndex(Address instrPtr) {
cc = reader.getCompiledCode(framePtr);
if (cc != null) {
codeIndex = cc.getAddressMapIndex(instrPtr);
} else {
codeIndex = -1;
}
}
}