Re: Warning starting Emacs (Cygwin)

[Eli Zaretskii <eliz@gnu.org>]

> From: Dan Nicolaescu <dann@ics.uci.edu>
> Date: Sat, 02 Aug 2008 12:30:29 -0700
> Cc: emacs-devel@gnu.org, Angelo Graziosi <angelo.graziosi@alice.it>
> 
> Chong Yidong <cyd@stupidchicken.com> writes:
> 
>   > Dan Nicolaescu <dann@ics.uci.edu> writes:
>   > 
>   > > Unfortunately none of these ring a bell to me.  Yidong I assume this
>   > > code is the reason you added the HAVE_GETRLIMIT autoconf check, can you
>   > > guess what can be wrong here?
>   > 
>   > The reason I added the getrlimit check was because of the bug reported
>   > here (bug#86):
> 
> The check is very likely fine, I was hoping you understand the code the
> macro guards...  Please see Angelo's messages, he gives a lot of details
> that might ring a bell.

It's quite clear from what Angelo wrote that Cygwin's getrlimit is not
a fully functional emulation.  Just to be sure, I looked into the
Cygwin sources and found this gem:

    extern "C" int
    getrlimit (int resource, struct rlimit *rlp)
    {

      [...]

      switch (resource)
	{
	[...]
	case RLIMIT_AS:
	  rlp->rlim_cur = 0x80000000UL;
	  rlp->rlim_max = 0x80000000UL;
	  break;

This obviously cannot work with vm-limit.c.

I think the test in configure should compare rlim_cur with rlim_max,
and if they are identical, deduce that getrlimit is non-functional and
not set HAVE_GETRLIMIT.