Re: kbuild: Implicit dependence on the C compiler

[Matt Mackall <mpm@selenic.com>]

On Tue, Jan 18, 2005 at 07:35:43PM +0000, H. Peter Anvin wrote:
> Followup to:  <20050118190513.GA16120@mars.ravnborg.org>
> By author:    Sam Ravnborg <sam@ravnborg.org>
> In newsgroup: linux.dev.kernel
> > 
> > To give some background info about why kbuild does what it does.
> > A kernel being compiled partly with and partly without say -regparm=3
> > will result in a non-workable kernel.
> > 
> > The same goes for a kernel that is partly built using gcc 2.96, partly
> > using 3.3.4 for example.
> > 
> > So kbuild pr. default will force a recompile for any .o file where
> > opions to gcc differ, or name of gcc has changed. Today no check has
> > been implemented to check the actual gcc executable timestamp - and
> > neither is this planned.
> > 
> 
> I would argue that "name of gcc has changed" is possibly a condition
> that does more harm than good.  It is just as frequently used to have
> wrappers, like distcc, as it is to have different versions.

Disagree. I switch compilers all the time and kbuild does the right
thing for me.

I do occassionally feel your 'make install' pain and some sort of
'make __install' might be called for.

-- 
Mathematics is the supreme nostalgia of our time.