Re: gnulib largefile support

[Bruno Haible]

[CCing Ludovic. The thread starts at
<https://lists.gnu.org/archive/html/bug-gnulib/2011-11/msg00079.html>]

Nikos Mavrogiannopoulos wrote:
> Wouldn't it be better to add an option to enable
> it only in systems where it is desirable?

Like Eric said, large file support *is* desirable on all platforms.
The only reason that large file support is off by default is backward
compatibility.

> After adding few modules to gnulib the gnutls-guile library had few
> failures in testsuite in some arm and mips systems. After some
> investigation[0] it seems that the issue was that the new gnulib modules
> were depending on largefile module which defines a 64-bit off_t even on
> 32-bit systems.

You are confusing trigger and cause. While a gnulib update *triggered*
a malfunction [1], the *cause* was a guile bug [2], and it was fixed in
guile 2.0 already two years ago [3].

Ludo, I find that your fix in [4] is not optimal. While testing whether
guile was built to support large files or not (via GUILE_USE_64_CALLS)
certainly fixes the problem at hand, it does nothing about the real
problem. Namely, that guile will not work right with files > 2 GB.
The fix is to import the 'largefile' module from gnulib.

> Why adding getpass or fseek gnulib modules would enable
> largefile by default? 

Never use fseek(). Use fseeko() instead. This is documented in the gnulib
manual [5].

I'm not sure what 'fseek' and 'ftell' in guile/doc/sources/unix.texi
are referring to. Probably they should be replaced by 'fseeko' and 'ftello',
respectively.

Bruno

[1] http://lists.gnu.org/archive/html/gnutls-devel/2011-10/msg00084.html
[2] http://lists.gnu.org/archive/html/gnutls-devel/2011-11/msg00007.html
[3] http://lists.gnu.org/archive/html/gnutls-devel/2011-11/msg00014.html
[4] 
http://git.savannah.gnu.org/cgit/guile.git/commit/?id=f1ce9199335bebab1a62286ac965f33dc91ca97f
[5] https://www.gnu.org/software/gnulib/manual/html_node/fseek.html
-- 
In memoriam Hannah Szenes <http://en.wikipedia.org/wiki/Hannah_Szenes>