Re: A plea for dynamically loadable extension modules

[David Hansen]

On Sun, 19 Aug 2007 08:52:29 +0530 dhruva wrote:

> On 8/19/07, Leo <address@hidden> wrote:
>> But is it OK to include this patch¹ in Emacs? It allows C DEFUN
>> functions to be placed in external libraries and dynamically loaded when
>> they were needed.
>
> I personally feel it would be an extremely nice feature to have the
> above functionality in Emacs. If the concern is to make sure such
> libraries are released under GPL, I propose the following method:
>
> 1. All dynamic libraries loaded dynamically (through explicit call to
> LoadLibrary/dlopen) must expose a function 'IsGPLed'
> 2. In main Emacs, we load it and look for that function
> (GetProcAdderess/dlsym) and execute if found. It could return a
> 'bool'.
> 3. The absence of the function or a false return can prevent loading
> that extension library
> 4. We could cover the meaning and legal bindings of having 'IsGPLed'
> somewhere in the license and it is the responsibility of the
> library/owner to make sure it is completely covered under GPL if the
> function is implemented to return 'true' and Emacs does not take any
> responsibility beyond checking for the function and it's return value
> and no more.
>
> Would this be a feasible approach?

Isn't that similar to what Linux does with kernel modules?  I think what
the FSF wants to avoid is exactly the current situation with Linux and
some non free kernel modules.

David