[oe] [meta-oe][PATCH] meson: export native env only for native build

[Alexander Kanavin]

On 11/13/2017 09:27 PM, Martin Kelly wrote:
> Although the meson crossfile should take care of setting the right cross
> environment for a target build, meson slurps any set CFLAGS, CXXFLAGS,
> LDFLAGS, and CPPFLAGS from the environment and injects them into the
> build (see mesonbuild/environment.py:get_args_from_envvars for details).
> 
> This means that we are seeing native CFLAGS, CXXFLAGS, LDFLAGS, and
> CPPFLAGS in the target build, which is wrong and causes build failures
> when target and native have libraries in common (the linker gets
> confused and bails).
> 
> That said, we *do* need to set certain vars for all builds so that meson
> can find the right build tools. Without this, meson will fail during its
> sanity checking step because it will determine the build tools to be
> unrunnable since they output target instead of native artifacts.
> 
> The solution to all of this is to set CC, CXX, LD, and AR globally to
> the native tools while setting the other native vars *only* for the
> native build. For target builds, these vars will get overridden by the
> cross file as we expect.

Hello Martin,

meson support will land in oe-core shortly (and will be removed from 
meta-oe), so can you please check if my patchset is doing the right thing?
http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/log/?h=akanavin/meson

Alex