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