/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.debug.core.model;
import org.eclipse.debug.core.DebugException;
/**
* A stack frame represents an execution context in a suspended thread.
* A stack frame contains variables representing visible locals and arguments at
* the current execution location. Minimally, a stack frame supports
* the following:
* <ul>
* <li>suspend/resume (convenience to resume this stack frame's thread)
* <li>stepping
* <li>termination (convenience to terminate this stack frame's thread or debug target)
* </ul>
* <p>
* A debug model implementation may choose to re-use or discard
* stack frames on iterative thread suspensions. Clients
* cannot assume that stack frames are identical or equal across
* iterative thread suspensions and must check for equality on iterative
* suspensions if they wish to re-use the objects.
* </p>
* <p>
* A debug model implementation that preserves equality
* across iterative suspensions may display more desirable behavior in
* some clients. For example, if stack frames are preserved
* while stepping, a UI client would be able to update the UI incrementally,
* rather than collapse and redraw the entire list.
* </p>
* <p>
* Clients may implement this interface.
* </p>
* @see IStep
* @see ISuspendResume
* @see ITerminate
*/
public interface IStackFrame extends IDebugElement, IStep, ISuspendResume, ITerminate {
/**
* Returns the thread this stack frame is contained in.
*
* @return thread
* @since 2.0
*/
public IThread getThread();
/**
* Returns the visible variables in this stack frame. An empty
* collection is returned if there are no visible variables.
*
* @return collection of visible variables
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
* @since 2.0
*/
public IVariable[] getVariables() throws DebugException;
/**
* Returns whether this stack frame currently contains any visible variables.
*
* @return whether this stack frame currently contains any visible variables
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
* @since 2.0
*/
public boolean hasVariables() throws DebugException;
/**
* Returns the line number of the instruction pointer in
* this stack frame that corresponds to a line in an associated source
* element, or <code>-1</code> if line number information
* is unavailable.
*
* @return line number of instruction pointer in this stack frame, or
* <code>-1</code> if line number information is unavailable
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
*/
public int getLineNumber() throws DebugException;
/**
* Returns the index of the first character in the associated source
* element that corresponds to the current location of the instruction pointer
* in this stack frame, or <code>-1</code> if the information is unavailable.
* <p>
* If a debug model supports expression level stepping, the start/end
* character ranges are used to highlight the expression within a line
* that is being executed.
* </p>
* @return index of the first character in the associated source
* element that corresponds to the current location of the instruction pointer
* in this stack frame, or <code>-1</code> if the information is unavailable
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
* @since 2.0
*/
public int getCharStart() throws DebugException;
/**
* Returns the index of the last character in the associated source
* element that corresponds to the current location of the instruction pointer
* in this stack frame, or <code>-1</code> if the information is unavailable.
* <p>
* If a debug model supports expression level stepping, the start/end
* character ranges are used to highlight the expression within a line
* that is being executed.
* </p>
* @return index of the last character in the associated source
* element that corresponds to the current location of the instruction pointer
* in this stack frame, or <code>-1</code> if the information is unavailable
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
* @since 2.0
*/
public int getCharEnd() throws DebugException;
/**
* Returns the name of this stack frame. Name format is debug model
* specific, and should be specified by a debug model.
*
* @return this frame's name
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
*/
public String getName() throws DebugException;
/**
* Returns the register groups assigned to this stack frame,
* or an empty collection if no register groups are assigned
* to this stack frame.
*
* @return the register groups assigned to this stack frame
* or an empty collection if no register groups are assigned
* to this stack frame
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
* @since 2.0
*/
public IRegisterGroup[] getRegisterGroups() throws DebugException;
/**
* Returns whether this stack frame contains any register groups.
*
* @return whether this stack frame contains any visible register groups
* @exception DebugException if this method fails. Reasons include:
* <ul><li>Failure communicating with the debug target. The DebugException's
* status code contains the underlying exception responsible for
* the failure.</li>
* </ul>
* @since 2.0
*/
public boolean hasRegisterGroups() throws DebugException;
}