bug#15094: Fix for posix_memalign on Cygwin

[Ken Brown]

On 8/15/2013 9:00 AM, Ken Brown wrote:
> On 8/15/2013 7:51 AM, Ken Brown wrote:
> > On 8/14/2013 10:46 PM, Eli Zaretskii wrote:
> > > > Date: Wed, 14 Aug 2013 15:52:53 -0400
> > > > From: Ken Brown <kbrown@cornell.edu>
> > > > CC: 15094@debbugs.gnu.org
> > > >
> > > > /* Cygwin allows applications to provide their own malloc.  As of
> > > > cygwin-1.7.24, applications that provide their own malloc are also
> > > > allowed to provide their own posix_memalign (but not memalign).  Calls
> > > > to memalign are handled by Cygwin's memalign, which always returns
> > > > ENOSYS if the application has defined its own malloc.  So we have to
> > > > rename memalign in order to make sure that posix_memalign calls
> > > > Emacs's memalign rather than Cygwin's.  */
> > >
> > > How does Cygwin memalign come into play, when Emacs provides its own?
> >
> > As I said in the comment, Cygwin does not let applications define their
> > own memalign.  During linking, calls to memalign become calls to
> > Cygwin's memalign.
>
> Hold on...I think I'm missing something obvious.  I have to recheck this.

Thanks for pressing me on this, Eli.  I did of course miss the obvious 
fact that posix_memalign in gmalloc.c will use memalign as defined in 
the same file.  I'll revert the change.  I'll also use the opportunity 
to update some comments elsewhere in the code.

Sorry for the noise.

Ken