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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Baptiste Daroussin <bapt@freebsd.org>
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Date: Wed, 02 May 2012 18:13:45 +0200
In-Reply-To: <20120502145045.GP31034@azathoth.lan> (Baptiste Daroussin's
	message of "Wed, 2 May 2012 16:50:46 +0200")
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Cc: Konstantin Belousov <kostikbel@gmail.com>, freebsd-arch@freebsd.org
Subject: Re: Switching /etc/*.db from bdb to tinycdb
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Baptiste Daroussin <bapt@freebsd.org> writes:
> Konstantin Belousov <kostikbel@gmail.com> writes:
> > The reasoning is that we do not want our libc unneccessary interpose
> > symbols from third-party libs, and do not want to make a surprise for
> > somebody who wants to use the never version of the same library, or use
> > a symbol not documented in SUSv4 etc while linking to libc/libpthread
> > only.
> I do understand that, I know need to learn how we can do that cleaning

If we go that route, I would suggest having the complete library as
libcdb, and a copy of the read part hidden inside libc for getpw*() etc.

To hide the cdb code inside libc, you need to add

#define cdb_foo _cdb_foo

to src/lib/libc/include/namespace.h and

#undef cdb_foo

to src/lib/libc/include/un-namespace.h, for appropriate values of "foo"
("init", "find" etc.), then wrap the #include directives in the cdb
source with #include <namespace.h> /* ... */ #include <un-namespace.h>.
Within libc, you must call _cdb_foo() instead of cdb_foo(); outside of
libc, you call cdb_foo() as usual, and link with -lcdb.

To avoid duplicating the cdb source code, you will need to create
src/lib/libcdb/{un-,}namespace.h as empty files and add -I${SRCDIR} to
CFLAGS in src/lib/libcdb/Makefile.

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no