From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6120 invoked by alias); 22 Dec 2001 07:36:03 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 6091 invoked by uid 71); 22 Dec 2001 07:36:02 -0000 Date: Fri, 21 Dec 2001 23:36:00 -0000 Message-ID: <20011222073602.6087.qmail@sources.redhat.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Zack Weinberg Subject: Re: bootstrap/5149: gcc-20011217 reads beyond EOF on cygwin Reply-To: Zack Weinberg X-SW-Source: 2001-12/txt/msg01061.txt.bz2 List-Id: The following reply was made to PR bootstrap/5149; it has been noted by GNATS. From: Zack Weinberg To: Neil Booth Cc: Werner Tuchan , neil@gcc.gnu.org, gcc-bugs@gcc.gnu.org, gcc-gnats@gcc.gnu.org Subject: Re: bootstrap/5149: gcc-20011217 reads beyond EOF on cygwin Date: Fri, 21 Dec 2001 23:27:58 -0800 On Thu, Dec 20, 2001 at 07:09:10PM +0000, Neil Booth wrote: > Zack Weinberg wrote:- > > > No. But the AC_FUNC_MMAP_FILE macro (gcc/aclocal.m4) already executes > > a test program to determine whether or not mmap works the way we want. > > It would be easy enough to add a check that byte (len+1) of its test > > file is a NUL. [And we'd better not be looking at byte len+2, or > > we'll segfault if the file length is one less than a multiple of > > PAGE_SIZE.] > > Looking at the dump Werner supplied, filled with 0xc0 and NULs, I fear > this could pass on cygwin by fluke. Better just to blacklist it IMO. > HAVE_BROKEN_MMAP or something. Agreed. Come to think of it, if we blacklist cygwin, I believe we can junk almost all of the mmap testing gook, both MMAP_FILE and MMAP_ANYWHERE. (Best check the mailing lists for the origins of those tests, first, though.) zw