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Date: Tue, 6 May 2003 22:27:56 +0400
From: "Andrey A. Chernov" <ache@nagual.pp.ru>
To: Dag-Erling Smorgrav <des@ofug.org>
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cc: freebsd-arch@freebsd.org
Subject: Re: `Hiding' libc symbols
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On Tue, May 06, 2003 at 19:56:27 +0200, Dag-Erling Smorgrav wrote:
>  - If you stayed awake through the previous paragraph you should by
>    now have concluded that it simply is not possible for the linker to
>    enforce namespaces like Andrey wants it to, because a) the linker
>    can't know what headers were included; b) the exact set of reserved
>    names can vary from compilation unit to compilation unit within the
>    same application and c) namespace issues affect portions of the
>    code which are outside the linker's purview (such as the names of
>    function arguments and static or automatic variables).  Namespaces
>    are a source code issue and cannot be handled anywhere but at the
>    source code level.

There is no problem. Each *.h function prototype can be accompanied with
some assembler instruction making it strong reference. The same thing can
be conditionalized at the header level using _POSIX_SOURCE or other
defines. So, linker will know, what headers are included.