Re: [Bug pch/14400] Cannot compile qt-x11-free-3.3.0

[Ian Lance Taylor <ian@wasabisystems.com>]

"geoffk at apple dot com" <gcc-bugzilla@gcc.gnu.org> writes:

> On Mar 29, 2004, at 11:06 PM, Ian Lance Taylor wrote:

> > PR 14206 is fixed on mainline by RTH's patch.  For 3.4 I put in a doc
> > fix.

> I've now caught up enough that I read RTH's patch (I've been on 
> vacation).  Yes, that patch should fix this problem too.  I'd suggest 
> backporting it to 3.4.

We can do that.  However, I am still troubled by the fact that the
default fallback for gt_pch_get_address/gt_pch_use_address is
unreliable.  RTH's patch may well fix the problem on GNU/Linux for all
but strange cases.  But it seems to me that with that patch PCH will
work reasonably on GNU/Linux and on Darwin, but will not work reliably
on any other system.

That is, I don't think that any system can reliably use
mmap_gt_pch_get_address/mmap_gt_pch_use_address, although they are the
default functions on a system which supports mmap.

Is it better to have PCH which unpredictably fails or PCH which
reliably fails?  Right now, in mainline, I think we have the former,
except on GNU/Linux and Darwin.

Ian