cvs commit: src/lib/msun/i387 fenv.c fenv.h

[Warner Losh]

From: Maxim Sobolev <sobomax at portaone.com>
Subject: Re: cvs commit: src/lib/msun/i387 fenv.c fenv.h
Date: Fri, 18 Mar 2005 09:44:25 +0200

> David Schultz wrote:
> > On Thu, Mar 17, 2005, Warner Losh wrote:
> > 
> >>>You had better bump the version number for libm before 6.0 rolls
> >>>around!!  I've just found a 3rd party binary-only package that
> >>>supports 'FreeBSD 5.x' but is linked against libm.so.2.  Ugh.  We
> >>>need to bury that mistake and NOT make it again.
> >>
> >>6.0 already has /lib/libm.so.3
> > 
> > 
> > So does 5.3.  I think Scott's point is that if we're going to bump
> > it for 6.X at all, we had better do it soon or risk running into
> > the same mess we had before.  I agree with that, although at
> > present I don't know of a compelling reason to do the bump the
> > libm version number at all.
> 
> Haven't several functions been removed from -CURRENT version of libm 
> recently? IMHO this provides sufficient reason for version bump. 
> Actually I think it makes sense to bump all libraries automatically when 
> -CURRENT goes one major number up. There is just no much sense in 
> preserving partial compatibility.

One of the problems with an overly agressive bumping is that if you
bump, you have to bump *EVERYTHING* that depends on the library to get
true compatbility, even the ports (and have different majors build
based on using libc.so.5 vs libc.so.6, a real pita).  When I looked
into the major abi issues we had a while ago, I came to this
conclusion.  I also came to the conclusion that we'd be better off
keeping compatibility and *NEVER* bumping a fundamental library's
major number to avoid these problems.  Alas, no one listens to me, and
they make incompatible changes (like removing functions), so we're
stuck in the false belief that major numbers are going to save us.[*]

Warner

[*] Please, let's not have the silly discussion we seem to have every
4 months about making libc.soemthing-other-than-major-here.  All the
times in the past, all the naive proposals were shown to have such bad
flaws as to be unworkable...