Subject: Re: LGPL... variations on a theme
From: Bernard Lang <>
Date: Fri, 6 Jul 2001 12:54:15 +0200

On Fri, Jul 06, 2001 at 06:56:36PM +0900, Stephen J. Turnbull wrote:
> >>>>> "Bernard" == Bernard Lang <> writes:
>     Bernard> I do not understand ... it looks to me that a modified
>     Bernard> version of the library will inherit the libgcc exception,
>     Bernard> and be linkable as well.
> Any modification to libgcc reverts the license on libgcc to GPL.  This
> implies that if your version of GCC contains a modified libgcc, _all
> programs compiled with it in the normal way become subject to the
> GPL_.  This isn't what RMS had in mind (he wanted _running gcc_ to be
> free of licensing implications), so the exception is necessary.
> Similar exceptions are necessary for Bison.  The historical note on
> licensing ("Conditions" from the menu for "info Bison", short, but
> will help clarify I think) indicates that RMS was more reluctant in
> this case.  I'm not sure why, in principle it's the same I should
> think.  I suppose it has to do with the fact that the "helper
> functions" in libgcc are mostly completely obvious, while yyparse()
> from bison (which gets included in every program that uses a bison
> parser) is "real code".
>     >> Is it possible for them to release the library as a shared
>     >> library?  That would let them use the unmodified LGPL.
>     Bernard> apparently that is not easy
> Embedded systems come to mind.  If everything runs out of ROM, what
> does "dynamic linking" mean?  ;-)

Actually, their compiler is used also for embedded applications, with
severe constraints.

> Anyway, the library will be released as _source_; the modifications to
> turns something designed as a DLL into something statically linkable
> can't be tough.
>     Bernard> Is [the libgcc exception] much used ?
> Well, libgcc is referenced in the link command almost every time a
> non-GPL binary built with gcc is distributed.  I don't know how often
> those functions in libgcc are used, but surely neither do most of the
> non-GPL developers (including the *BSD people, whose software is all
> built with GCC!!)
> But that's exactly the saving that your clients are aiming at.

Not my clients :-)  ... but I will discuss this with them.

Actually I generally do all this for free.  I have a job that supports
me, and free software advocacy or consulting is my way of
contributing. (I know you did not mean "client" in a business sense)



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