bootstrap/5149: gcc-20011217 reads beyond EOF on cygwin

[Neil Booth]

The following reply was made to PR bootstrap/5149; it has been noted by GNATS.

From: Neil Booth <neil@daikokuya.demon.co.uk>
To: Werner Tuchan <tuwn@gmx.net>, neil@gcc.gnu.org, gcc-bugs@gcc.gnu.org,
	gcc-gnats@gcc.gnu.org, cygwin@cygwin.com
Cc:  
Subject: Re: bootstrap/5149: gcc-20011217 reads beyond EOF on cygwin
Date: Fri, 21 Dec 2001 18:48:12 +0000

 Christopher Faylor wrote:-
 
 > Can I ask why we'd be reading beyond EOF?  Is it guaranteed that bytes beyond
 > EOF will be zero on UNIX?
 
 This was discussed in September (see thread in gcc@ entitled "Bumming
 cycles out of parse_identifier").  It was decided that all known
 current Unix implementations have zeros until the next page boundary.
 Assuming EOF is indicated by a NUL is used as a lexer optimization.
 
 Neil.