Re: response file support in GCC

[Ralf Wildenhues]

Hi Gary,

* Gary V. Vaughan wrote on Thu, Nov 24, 2005 at 01:57:00PM CET:
> Ralf Wildenhues wrote:
> >With response file support in GCC [1] we need to adjust Libtool
> >accordingly.  Minimally to let the option through as below, but
> >ideally we should probably parse its contents.
> 
> The spec says that the file must contain whitespace separated arguments,
> so parsing should be a cinch.

Yes, but I believe the "recursinve include" semantics are not trivial;
but I don't remember the whole discussion and its resolution, I read
most of it at the time it was first discussed and have not reread it.

> Is the patch necessary?

Yes.  Or a similar one, FWIW.

> Won't @foo be treated as a file name and passed
> through to the compiler driver by libtool anyway?

No.  You could `-Wc,@foo' of course, but..

> Or do you need to preserve relative argument order here?

 ..this would still be an issue.  This is of course not handled by my
simplistic patch.

> >Any volunteers?  Comments?
> 
> After parsing we might want to change the arguments parsed from the file,
> and presumably the file is used because the arguments are too long to pass
> on the command line.  In that case, I suppose we might be able to cope
> by using partial linking.

Or piecewise archiving, sure, *we* have all that machinery in place.

> Since this is a gccism, and we'd like for libtool to present a portable
> interface, I think that proper support for response files should be for
> libtool to parse and interpret them, and rely on partial linking to help
> us keep inside the command line length limits.

Erm.  We have -objectlist.  I have yet to see a different need for
response file semantics in libtool.

> That way libtool users
> get to use response files regardless of the underlying compiler.  In the
> fullness of time, we might test for compiler response file support, and
> have libtool write long command lines into its own response file instead
> of using partial linking where possible.

This is what I was thinking of, too.  :)
Not that we're likely to need it much with linker scripts, though.

> Regardless, this all sounds like post-2.0 to me...

Sure.  I just wanted to notify so we are aware.

> can you add a TODO item please?

Oh, my previous mail was intended to be the TODO item, on your TODO
page, along with its URL when in the archive -- done now.  :)

Cheers,
Ralf