[OE-core] [PATCH 1/4] base.bbclass: Remove invalid ccache related code

[richard.purdie at linuxfoundation.org]

On Tue, 2018-12-11 at 17:24 +0800, Robert Yang wrote:
> 
> On 12/10/18 6:29 PM, Richard Purdie wrote:
> > On Sun, 2018-12-09 at 18:24 -0800, Robert Yang wrote:
> > > The code is in setup_hosttools_dir(), it searches ccache in PATH
> > > in
> > > reverse order, I can't figure out what it is used for, maybe it
> > > is
> > > aimed to use host's ccache rather than recipe-sysroot-
> > > native/usr/bin/ccache, but the later one isn't in original PATH,
> > > so
> > > remove the code.
> > > 
> > > Signed-off-by: Robert Yang <liezhi.yang at windriver.com>
> > > ---
> > >   meta/classes/base.bbclass | 2 --
> > >   1 file changed, 2 deletions(-)
> > 
> > We should document it and I think its still needed.
> > 
> > Some distros have a "gcc" which automatically wraps ccache behind
> > the
> > scenes. This code lets us find the real gcc and bypass ccache.
> 
> Ah, thanks for the explanations, I got it now. I think that we don't
> need the
> code any more since we don't use host's ccache, and I have removed
> ccache from
> HOSTTOOLS.
> 
> I will update commit message and send a V2.

No, that isn't correct :(

The problem is that "gcc" can be linked directly to ccache by the host
distro. This means you end up using the host ccache just by calling
"gcc". This code is still needed if we want to control ccache and be
able to disable it and use ccache-native for determinism.

Cheers,

Richard