Re: git: 83d0b8c089d8 - main - bsdinstall generate opt_osname.h in include

On Wed, Dec 6, 2023, 9:55 PM Simon J. Gerraty <sjg@juniper.net> wrote:

> Jessica Clarke <jrtc27@freebsd.org> wrote:
> > > Warner Losh <imp@bsdimp.com> wrote:
> > >> Silly question: why not just add it to CFLAGS with
> > >> -DOSNAME=\"${OSNAME}\" rather than generating this file?
> > >
> > > Actually it is an excellent question - I've no idea why opt_osname.h is
> > > needed.
> >
> > To quote the motivation from brd@’s original review:
> >
> > > The reason I did it using a file is so that make(1) would detect a
> > > change a rebuild if you change the value and do another build.
>
> A fair point.  Of course moot if using META_MODE.
> The other benefit of the header is only the files that include it will
> be rebuilt when the value changes whereas (with META_MODE) everything
> will be rebuilt if value is in CFLAGS.
>
> That can be mitigated by using per object CFLAGS, but all in all the
> header is a simpler solution.
>

This name never changes on practice.  We shouldn't optimize for a rare case
that causes build races. Who would ever change it in the same tree?

Warner

--sjg
>