[Buildroot] [autobuild.buildroot.net] Build results for 2017-02-20

[Thomas Petazzoni]

Hello,

On Wed, 22 Feb 2017 21:39:00 +0100, Peter Seiderer wrote:
> On Tue, 21 Feb 2017 08:29:02 +0100 (CET), Thomas Petazzoni <thomas.petazzoni at free-electrons.com> wrote:
> 
> >        sparc |                  libv4l-1.12.2 | NOK | http://autobuild.buildroot.net/results/3f13042565df20087e007949f653942c0462e334  
> 
> 
> From build-end.log:
> 
>   CXXLD    qv4l2
> 
> qv4l2-qv4l2.o: In function `QtPrivate::RefCount::deref()':
> qv4l2.cpp:(.text._ZN9QtPrivate8RefCount5derefEv[_ZN9QtPrivate8RefCount5derefEv]+0x24): undefined reference to `__sync_fetch_and_add_4'
> qv4l2-qv4l2.o: In function `QString::QString(QString const&)':
> qv4l2.cpp:(.text._ZN7QStringC2ERKS_[_ZN7QStringC5ERKS_]+0x54): undefined reference to `__sync_fetch_and_add_4'
> qv4l2-vbi-tab.o: In function `QtPrivate::RefCount::ref()':
> vbi-tab.cpp:(.text._ZN9QtPrivate8RefCount3refEv[_ZN9QtPrivate8RefCount3refEv]+0x24): undefined reference to `__sync_fetch_and_add_4'

This normally indicates that a dependency on BR2_TOOLCHAIN_HAS_SYNC_4
is missing.

> This can be fixed by adding the following two lines to package/libv4l/libv4l.mk:
> 
> LIBV4L_CONF_ENV += CXXFLAGS="$(TARGET_CXXFLAGS) -std=gnu++0x"
> LIBV4L_CONF_ENV += LDFLAGS="$(TARGET_LDFLAGS) -latomic"

Hum, so using gnu++0x forces to use __atomic built-ins instead of
__sync built-ins ?

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com