When attempting to install the package x11-drivers/xf86-video-virtualbox, version 4.3.26, the build will fail.

Reproduction steps:

1. Start command for installing the x11-drivers/xf86-video-virtualbox package:

emerge xf86-video-virtualbox

Expected results:

1. Package was built and installed successfully.

Actual results:

1. The build fails with the following error (see build.log and emerge.info for full details):

---%---
In file included from /var/tmp/portage/x11-drivers/xf86-video-virtualbox-4.3.26/work/VirtualBox-4.3.26/include/iprt/types.h:116:0,
from /var/tmp/portage/x11-drivers/xf86-video-virtualbox-4.3.26/work/VirtualBox-4.3.26/include/iprt/heap.h:30,
from /var/tmp/portage/x11-drivers/xf86-video-virtualbox-4.3.26/work/VirtualBox-4.3.26/src/VBox/Runtime/common/alloc/heapsimple.cpp:32:
/lib/modules/3.19.3-1~exp1/build/include/linux/compiler.h:197:29: error: can’t set ‘no_instrument_function’ attribute after definition
static __always_inline void data_access_exceeds_word_size(void)
---%---

Additional notes:

The problem seems to be related to gcc version 4.8.4 (or, to be more precise, anything below version 4.9.0). A similar issue has been reported at:

• https://forums.gentoo.org/viewtopic-p-7721168.html?sid=1b6478ba2258f9cbe9c27f9ebf48941f

This further points to GCC bug:

• https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49718

I will attempt to unmask newer gcc for this purpose and see if the VirtualBox builds with that one (not sure how smart it is to mix gcc versions for different packages, hopefully it'll work for this one).