GCC for Mac OS X (fwd)

[Theodore C. Belding]

---------- Forwarded message ----------
Date: Fri, 11 Feb 2000 15:34:31 -0800
From: Stan Shebs <address@hidden>
To: address@hidden
Subject: GCC for Mac OS X

Hi all, some of you may know me from GDB, and a few with long memories
may remember that I did a couple Mac ports of GNU a while back (those
silly mpw-* files scattered everywhere are my fault).

I've just started working for Apple's Mac OS X tools team.  This may come
as a surprise, but Mac OS X is basically FreeBSD 3.2 with a GUI.  Not only
that, but in a few months it will be shipping on every new Mac - so yes
indeed, your grandmother will be running Unix!

Anyway, my tasks here are twofold: 1) to reduce the divergence between
Apple's GCC and FSF GCC, and 2) to help improve the compiler in various
ways.  Apple has a half-dozen engineers working on GCC that have been
quietly following along with the development trunk, but the set of
patches is still pretty large.  I'll be looking at the local patches,
and sending in those that seem worthwhile for the mainstream.  (Apple
has a blanket assignment for GDB already, but I think we still need to
do one for GCC.)

At the same time, now that GCC is being used heavily by Apple's OS
developers, as well as by 3rd parties busily porting to Mac OS X,
a number of issues have cropped up.  While the team here is obligated
to resolve them one way or another, ideally we'd like to do things in
a way that will be of interest to the whole GCC community, and so I
plan to be sending a lot of mail to this list (get your killfiles set
up now :-) ), asking for ideas and suggestions.

So far I'm aware of about four major areas that need attention:

1. C++ support.  Apparently there have been a number of reports of
C++ constructs allowed by other Mac compilers, but that fail with GCC.
Some cases are just user error, others are compiler limitations.
I'll report on these as specific cases come up.

2. Objective C.  ObjC has not seen a lot of evolution lately, but
it's still in use.

3. PowerPC code quality.  Apple has more than a few bit-twiddling
graphics engineers who pore over inner loops and such.  They need
the compiler to generate faster code.  Exception handling and
AltiVec support are two specific areas; for instance, Apple is
using a big hairy patch from Motorola for AltiVec code gen, but
from what I've seen of the patch so far, it seems problematic
for mainstream GCC.

4. Compiler turnaround.  Mac developers are used to the fast
compile times offered by Metrowerks, and are dismayed by GCC's
slowness.  Do we need precompiled headers?  Should file system
probes be cached?  There are a lot of theories going around, but
facts are in short supply.  But however it's accomplished, the
compiler needs to go faster.

I'm sure more issues will arise in the future, but these are
the current biggies for which I'll be asking for guidance.
Thanks for your attention, and looking forward to working with
everybody on improving GCC!

Stan Shebs
address@hidden


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