Testing file offset bits?

[Dirk Müller]

2013/2/16 Alexander Neundorf <neundorf at kde.org>:

> Dirk Mueller added it in 2008:
> http://websvn.kde.org/?view=revision&revision=829068
>
> If I remove every compiler flag where I'm not sure why it is needed, we'll be
> left with not much.

This flag is needed in order to be able to support files > 2GB even on
32bit platforms. The default is to use the non-64bit aware syscalls on
32bit platforms, which makes every application to SIGXFSZ (which is
equivalent to a crash) when they see or touch a file > 2GB.

This is an excellent default for upstream, but I decided back then
that KDE apps should be big-file aware right from the start. The
reason why this was implemented as a configure check rather than an
universation global setting is that back then there was btw software
that did not
compile properly on x86_64 when _FILE_OFFSET=64 was set (which was a
bug).

I still think the configure check is a better thing than
unconditionally adding it, but I don't care either way. the whole
thing can not be upstreamed though as this is a bold change of
defaults that we (KDE) can use, but not an upstream project like CMake
itself.