/*
* Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
* 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.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.max.vm.stack;
import com.sun.max.annotate.*;
import com.sun.max.unsafe.*;
import com.sun.max.vm.jni.*;
/**
* Abstracts over one or more stack frames for non-Java code. The reason that a
* single object may represent multiple native frames is that it is impossible
* to know the stack layout employed by the compiler that generated the code.
* The only thing we can know for these frames is where the stack pointer and
* return instruction is Java code that transitioned the call stack from Java
* code into native code. This is known because all such transitions occur
* through a {@linkplain NativeStubGenerator native stub} which records the current
* {@link JavaFrameAnchor}.
*/
@HOSTED_ONLY
public final class NativeStackFrame extends StackFrame {
public NativeStackFrame(StackFrame callee, Pointer instructionPointer, Pointer framePointer, Pointer stackPointer) {
super(callee, instructionPointer, stackPointer, framePointer);
}
/**
* {@inheritDoc}
*
* Two native frames are the same iff their stack and frame pointers are identical.
*/
@Override
public boolean isSameFrame(StackFrame stackFrame) {
if (stackFrame instanceof NativeStackFrame) {
return stackFrame.sp.equals(sp) && stackFrame.fp.equals(fp);
}
return false;
}
@Override
public String toString() {
return "<native@" + ip.toHexString() + ">";
}
}