Re: GDB plugin proposal

[Fernando Nasser <fnasser at redhat dot com>]

Scott Moser wrote:
> 
>    - From what I understand (not a lawyer), modules would be required to
>      be GPLed for a few reasons:
>       1. to call 'add_cmd' you need to include gdbcmd.h , which is GPLed

Leave the call to add_cmd() inside gdb, in the code that loads a
plug-in.
So, your plug-in code just provides a description in a standard format
and does not have to include the GPL'ed header file.

Besides, we may change add_cmd() and plug-ins would stop working, so it
is
better to define and interface at a higher level of abstraction anyway.


>       4. the README from gdb/gdbtk/library/plugins/HOW-TO mentions "As the
>       plug-ins will be loaded into Insight/GDB for execution, the terms of
>       the GPL also apply to the plug-in code."  I believe the same would
>       apply for plugins of this nature.

I wrote that based on list discussions (among Engineers, mind you -- not 
lawyers).  It is based on the assumption that only general purpose
libraries
that are part of the standard OS distribution (or a major component) can
be binary only. But that is the conservative approach.


>    - if 'plugin unload' proves difficult (at first glance, it seems maybe), it
>      could possibly be left out, as loading and unloading doesn't provide much
>      foreseeable benefit

Someone can have created user defined commands, added commands to
breakpoints
etc.  It can be done but will require a major rewrite of CLI code.  I
also
believe it does not add much and doesn't worth the effort.


>    - Its possible that GDB would eventually want to allow an LGPL like
>      interface for plugins so that binary only plugins could be created.
> 

We are trying to create a libgdb which would be used to create the 
interactive debugger as well as be incorporated into other tools.
Once this is achieved, the possibility of making the libgdb a LGPL'ed
library will have to be discussed.





-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9