Date: Mon, 29 Jul 1996 16:57:21 +0400 (MSD)
From: "Alexander V. Lukyanov" <lav AT video DOT yars DOT free DOT net>
Message-Id: <199607291257.QAA26578@video.yars.free.net>
To: dj AT delorie DOT com
Cc: djgpp-workers AT delorie DOT com, eliz AT is DOT elta DOT co DOT il
Subject: Re: Long double support

> > The old routine will be linked anyway, since the new one will be only
> > called for '%Le' (probably it could be modified to support other
> > formats, but it is for long doubles only).
> 
> How will the linker know if you use %Le in a printf format?

Of course it won't! But it does not need to. Libc will contain, say,
an empty long double->string converting function, returning ERR, and
libm will contain full-functional such a function. Then, doprnt will
call the function for '%Le' and if it returns ERR, doprnt will fall-back
to old converting routine, which is always linked in for other formats.