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Attaching to the Program

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Note

This article applies to Visual Studio 2015. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

After you have registered your programs with the appropriate port, you must attach the debugger to the program you want to debug.

Choosing How to Attach

There are three ways in which the session debug manager (SDM) attempts to attach to the program being debugged.

  1. For programs that are launched by the debug engine through the LaunchSuspended method (typical of interpreted languages, for example), the SDM obtains the IDebugProgramNodeAttach2 interface from the IDebugProgramNode2 object associated with the program being attached to. If the SDM can obtain the IDebugProgramNodeAttach2 interface, the SDM then calls the OnAttach method. The IDebugProgramNodeAttach2::OnAttach method returns S_OK to indicate that it did not attach to the program and that other attempts can be made to attach to the program.

  2. If the SDM can obtain the IDebugProgramEx2 interface from the program being attached to, the SDM calls the Attach method. This approach is typical for programs that were launched remotely by the port supplier.

  3. If the program cannot be attached through the IDebugProgramNodeAttach2::OnAttach or IDebugProgramEx2::Attach methods, the SDM loads the debug engine (if not already loaded) by calling the CoCreateInstance function and then calls the Attach method. This approach is typical for programs launched locally by a port supplier.

    It is also possible for a custom port supplier to call the IDebugEngine2::Attach method in the custom port supplier's implementation of the IDebugProgramEx2::Attach method. Typically in this case, the custom port supplier launches the debug engine on the remote machine.

    Attachment is achieved when the session debug manager (SDM) calls the Attach method.

    If you run your DE in the same process as the application to be debugged, then you must implement the following methods of IDebugProgramNode2:

  1. Send an IDebugEngineCreateEvent2 event object to the SDM. For more information, see Sending Events.

  2. Call the GetProgramId method on the IDebugProgram2 object that was passed to the IDebugEngine2::Attach method.

    This returns a GUID that is used to identify the program. The GUID must be stored in the object that represents the local program to the DE, and it must be returned when the IDebugProgram2::GetProgramId method is called on the IDebugProgram2 interface.

    Note

    If you implement the IDebugProgramNodeAttach2 interface, the program's GUID is passed to the IDebugProgramNodeAttach2::OnAttach method. This GUID is used for the program's GUID returned by the IDebugProgram2::GetProgramId method.

  3. Send an IDebugProgramCreateEvent2 event object to notify the SDM that the local IDebugProgram2 object was created to represent the program to the DE. For details, see Sending Events.

    Note

    This is not the same IDebugProgram2 object that was passed into the IDebugEngine2::Attach method. The previously passed IDebugProgram2 object is recognized by the port only and is a separate object.

See Also

Launch-based Attachment
Sending Events
LaunchSuspended
IDebugProgram2
IDebugProgramCreateEvent2
IDebugProgramNodeAttach2
OnAttach
IDebugProgramNode2
GetProgramId
IDebugProgramEx2
Attach
Attach