Re: Soname for 32bit/64bit Linux

[Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>]

> There is nothing really preventing us from putting a library, libfoo,
> with different ABIs in a directory, say /usr/lib. The only problem
> is the linker will search for libfoo.so and libfoo.a when -lfoo is
> passed. It may not find the right one.
> 
> To resolve it, we require
> 
> 1. soname of a shared object for libfoo, should not be libfoo.so. The
> real filename of a shared object for libfoo, should not be libfoo.so
> either.

Why is this needed? At least 32 and 64bit ABI are easily detectable by both
linker and run-time linker and ldconfig, so I wonder why should we bloat
our executables (because it will appear in their DT_NEEDEDs) and libraries.
The only exception I see here is the soname of the dynamic linker itself, as
it is the kernel who looks that up and it does not go through any search
paths, so dynamic linker's soname has to be different, that's all IMHO.

> 
> 2. soname of a shared object for libfoo should encode ABI, which
> is calling convention plus the data structure for libfoo and
> data structure for libc used to compile libfoo. We can use
> 
> libfoo-${libc_version}-${ABI}.so.${libfoo_version}

This one is really needed if you want to keep libraries of different ABIs in
one directory. The question is whether you want that...

Cheers,
    Jakub
___________________________________________________________________
Jakub Jelinek | jj@sunsite.mff.cuni.cz | http://sunsite.mff.cuni.cz
Administrator of SunSITE Czech Republic, MFF, Charles University
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UltraLinux  |  http://ultra.linux.cz/  |  http://ultra.penguin.cz/
Linux version 2.2.5 on a sparc64 machine (3958.37 BogoMips)
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