Re: [EXTERNAL] Re: Q: library dependencies

Hi Bob,



On Fri, Sep 25, 2020 at 10:45 AM Bob Friesenhahn <
[email protected]> wrote:

> On Fri, 25 Sep 2020, Oleg Smolsky wrote:
>
> > Well, AFAIK any well-formed .a file (an archive) is a static lib. And
> these
> > can be passed to the linker. Are you saying that libtool extracts the
> > individual .o files instead passing -lfoo (for libfoo.a)?
>
> Exactly!  It might as well be a tar file except that the 'ar' archiver
> knows how to add/update/remove files from it and that is not possible
> with a tar file.  The ability to do incremental updates of the archive
> file is important as objects are built/rebuilt.  The 'make' program
> itself already understands archive files.
>

I did not know this about libtool and convenience libraries. Do you have
any historical notion of why this was done? I ask because this sort of
behaviour total defeats the linker's ability to discard unused objects,
does it not?

Thanks,
John