Re: [gentoo-dev] CFLAGS moved to ebuilds.

[John Nilsson]

On 12/09/03 03:25:38, Marius Mauch wrote:
> On 12/09/03  John Nilsson wrote:
>
> > It was suggested in a discussion (bug[35184]) that this was files
> as
> a
> >
> > GLEP. This is just a quick dirty draft. Any comments would be
> > apreciated.
>
> While it might be a good idea on the first view it has a number of
> problems:
>
> - the effect of -f and -O flags can be dependent on the hardware, e.
> g.
> -O3 creates bigger binaries that are faster than -O2 on a Xeon, but
> slower on a Duron or Celeron (due to different cache sizes). I'm sure
> this also applies to other flags. Further -O3 toggles different -f
> flags
> on different architectures (-fomit-frame-pointer on some non-x86
> archs).

How is this related to this scheme? Also bugs in gcc should be fixed in  
gcc.

> - developer time: it would need an extreme amount of developer time
> to
> test all possible combinations for all C/C++ based packages, even if
> it's only done for new ebuilds.

They wouldn't. Most packages would use a standard set of cflags and  
with time user tests and patches would move these towards the optimal.

> - user confusion: users will be very confused about this change when
> they CFLAGS don't work anymore (and allowing them to override them
> will
> negate most of the benefits of this proposal)

Those people who don't use default flags would probably find per  
package optimization a nice feature.

> - compatibility: each new gcc version has some new flags, so all
> these
> per-package flags would ahve to be revised as soon as there is a new
> gcc
> version out (with new version I mean the x or y in x.y.z).


probably and hopefully ;)

One might have a compiler theme file with cascading (as in css) 
settings.

/John