[Buildroot] buildroot 2012.11 large file support

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Peter Korsgaard,

On Wed, 12 Dec 2012 21:15:44 +0100, Peter Korsgaard wrote:

>  Thomas> !largefile build is OK if we pass $(DISABLE_LARGEFILE) to
>  Thomas> gcc1 and gcc2 configure steps, so it solves the build
>  Thomas> problem. I haven't done more testing though (testing the
>  Thomas> generated code, building with largefile enabled, etc.).
> 
> Cool, great - I'll commit that then.
> 
>  Thomas> That said, doesn't --disable-largefile disables largefile
>  Thomas> support at the level of gcc itself, rather than taking into
>  Thomas> account the fact that largefile support is not available on
>  Thomas> the target? Of course, it has the consequence that
>  Thomas> _FILE_OFFSET_BITS is no longer defined to 64 in auto-conf.h,
>  Thomas> which works around the problem. But gcc (the host binary)
>  Thomas> should be capable of being built with largefile support on a
>  Thomas> 32 bits host, even if the 32 bits target has no largefile
>  Thomas> support.
> 
> So for the cross compiler to be able to access large files? Is that
> really important? I doubt people are using buildroot with 2G+
> source/object/library files?

It's not that we care too much about this (even though some crazy
library like Qt with debugging symbols reaches a very fat size, several
hundreds of MBs in size), but the fact that it is an ugly workaround to
use the side-effect of disabling largefile on gcc to make it play nice
with a target system that has largefile disabled.

Right now, when largefile is disabled for the target, it is disabled
for the cross gcc, when largefile is enabled for the target, it is
enabled for the cross gcc. Doesn't make much sense.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com