Re: [Qemu-devel] [PATCH] replace O_SYNC with O_FSYNC

[Jamie Lokier <jamie@shareable.org>]

Filip Navara wrote:
> On Wed, Jun 24, 2009 at 8:54 PM, Andreas Färber<andreas.faerber@web.de> wrote:
> >
> > Am 24.06.2009 um 20:25 schrieb Jamie Lokier:
> >
> >> Andreas Färber wrote:
> >>>
> >>> Am 21.06.2009 um 01:25 schrieb Jamie Lokier:
> >>>
> >>>> François Revol wrote:
> >>>>>>
> >>>>>> On 06/20/2009 05:31 PM, Anthony Liguori wrote:
> >>>>>>>
> >>>>>>> Please [...] use C-style comments instead
> >>>>>>> of C++ style comments. [...]
> >>>>>>
> >>>>>> What do we have against C++ style comments?
> >>>>>
> >>>>> They are not valid in C code :P
> >>>>
> >>>> Wrong.
> >>>>
> >>>> Valid in GNU C for about 14 years, and ANSI/ISO C for about 10
> >>>> years...
> >>>>
> >>>> I'll be surprised if any C compiler used on any open source operating
> >>>> system, or any major commercial C compiler, doesn't accept them.
> >>>
> >>> Gladly even ten-year-old GCC 2.95.x supports 'em. But even a recent
> >>> GCC does not when compiled with -ansi, which is why system headers
> >>> still mustn't use them.
> >>
> >> This is wrong too.  They can be used in system headers.
> >
> > No, that is wrong. freetype2 definitely complained when Haiku had C99
> > comments in its POSIX system headers. ;)
> 
> #pragma GCC system_header

GCC has a notion of certain directories being system header
directories.

So you don't need #pragma for headers in those, and if freetype2 was
installed in them, that should have worked.

But if you install those headers in other places, then it doesn't
treat them as system headers and becomes more strict about the
language.

You can add more system header directories, but of course (nearly)
everyone uses -Idir to add directories as that's well known and portable.

-- Jamie