[oe] [meta-oe][PATCH] tbb: check the version of the cross gcc instead of host gcc

[Diego Rondini]

Hi all,

I'm hitting an OpenCV crash that is caused by libtbb.
The problem is described here:
https://software.intel.com/en-us/forums/intel-threading-building-blocks/topic/636519
https://software.intel.com/en-us/forums/intel-threading-building-blocks/topic/641654

GCC versions >= 6.x default optimizations are too aggressive for TBB.
TBB disabled those optimizations in release 2017.0:
https://github.com/01org/tbb/blob/615bb971db8784ab6c005a856e8ed3e8cea61d9b/CHANGES#L377
but if the host gcc version is detected, instead of the cross gcc, the
optimization is not disabled, thus uncovering the crash.

My suggestion is to backport this commit:
http://cgit.openembedded.org/meta-openembedded/log/meta-oe/recipes-support/tbb?h=master
in pyro, rocko and sumo.
The commit will allow to properly detect cross gcc version (which is
>= 6.x in all the above releases), and thus deactivate the compiler
optimization causing the crash.

I've tested on rocko, and the backported patch fixes the crash I'm experiencing.

Best regards,
Diego Rondini
Sr. Embedded Engineer

Kynetics
www.kynetics.com