Re: Additional link flags for HP aCC and SGI CC

[Bob Friesenhahn]

On Tue, 24 Aug 2004, Gary V. Vaughan wrote:
> > Libtool does not really work without autoconf.  If you choose to use an
> > installed libtool script and use a compiler, or compiler options which
> > vary from those used when libtool was configured, then incorrect
> > operation may result.  It is best to use libtool in conjunction with
> > autoconf and do most of the special configuration work in autoconf.
>
> I would say that is working around an implementation fault in libtool
> then! :-(

It is more of a design limitation than a fault.  Libtool caches 
knowledge of tool operation based on the options which were provided. 
If the compiler changes, or a user-provided option changes how a tool 
works, then the cached configuration information is not valid, and 
wrong results may be produced.

> Although I haven't tried it, I would hope that the installed libtool is
> still broadly useful where the user targets the same compiler that libtool
> was built for... if not, we shouldn't be installing it!  I know that there
> are some compiler options that effectively run a different backend, and
> I think that it is understandable that libtool fails in those cases, but
> the rest of the time libtool was designed to be useful from a vanilla
> Makefile with no automake or autoconf pretense.

Right.  But if libtool is built using default options and then a 
libtool user later specifies 'CFLAGS=Wc,-pthread -m64' 
'LDFLAGS=Wl,-pthread', what happens?  A completely different set of 
libraries/tools may be used!  This is just one example of how an 
installed libtool may be used incorrectly.

Bob
======================================
Bob Friesenhahn
address@hidden
http://www.simplesystems.org/users/bfriesen