Re: [Sbcl-help] Re: Problems with large files on sbcl/linux-x86

[Andreas F. <as...@bo...>]

Today, Juho Snellman <js...@ik...> wrote:
> <as...@bo...> wrote:
>> A "file not found" error sounds like a bug, though. I'll look into
>> it.
>
> If you don't use the magic defines that were mentioned upthread to
> get stat64(), stat() will fail with ENOENT on files larger than 2GB.

Oh, ok (:

Anyway, I tried to get largefile support on x86/linux to work today
and it looks like a no-go:

LARGEFILE support comes in 2 flavours: you get a 64 bit off_t and
either use stat64 (and lseek64 etc.) or you get the C preprocessor to
re-write all occurrences of stat to stat64.

Rewriting the functions works for the runtime. It doesn't work on the
lisp side, though; sb-alien doesn't use the preprocessor at all: when
it uses stat, it uses the 32-bit version. So we would either have to
conditionalize on 32bit off_t and linux everywhere and use the *64
functions, or we have to write wrappers in c land and use those. But
that's not enough: AFAICT from reading
http://ac-archive.sourceforge.net/largefile/, we will have to do that
not just in sb-unix, but in every other library (think cffi-posix) as
well. This is just a bit too much of a nightmare to attempt.

So, if you want to open large (>2GB) files with sbcl on x86, you will
have to use an os with non-broken file offsets; as stated upthread,
FreeBSD is sane in this regard.

Cheers,
-- 
Andreas Fuchs, (http://|im:asf@|mailto:asf@)boinkor.net, antifuchs