Calling Extensions and Extension Functions

To load an extension library (or to obtain a handle for an already loaded extension library), use AddExtension. An extension library can be unloaded with RemoveExtension.

Extension commands can be called using CallExtension.

Extension Functions

Extension functions are functions that are exported by extension libraries. They can use any function prototype and are called directly using C function pointers.

They are not extension commands and are not available via debugger commands. Extension functions cannot be called remotely; they must be called directly. Hence they cannot be used from debugging clients. They can only be called when the client object is inside the host engine - when not remotely debugging or when using a smart client.

Extension functions are identified within extension libraries by the "_EFN_" prepended to their names.

To obtain a pointer to an extension function, use GetExtensionFunction. The type of this function pointer should match the prototype of the extension function. The extension function can now be called just like any other function pointer in C.

Example

If the following extension function was included in an extension library and loaded into the debugger engine:


HRESULT CALLBACK
_EFN_GetObject(IDebugClient * client, SomeObject * obj);

It could be called using:


typedef ULONG (CALLBACK * GET_OBJECT)(IDebugClient * client, SomeObject * obj);



HRESULT status = S_OK;
GET_OBJECT extFn = NULL;
SomeObject myObj;

if (g_DebugControl->
        GetExtensionFunction(0,
                             "GetObject",
                             (FARPROC *) &extFn ) == S_OK &&
    extFn)
{
    status = (*extFn)(client, &myObj);
}

 

 

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