[OE-core] [PATCH] kernel.bbclass: Allow ${S} to be overridden

[Patrick Ohly]

On Fri, 2016-11-11 at 19:39 +0000, Paul Barker wrote:
> On Wed, 9 Nov 2016 15:42:29 -0800
> Andre McCurdy <armccurdy at gmail.com> wrote:
> 
> > The solution I use (learned the hard way) is to ensure that "S = ..."
> > comes after "inherit kernel" in the kernel recipe.
> > 
> 
> Ok, yea, this works for me.
> 
> Is this expected? S is set to ${STAGING_KERNEL_DIR} at the start of
> kernel.bbclass. The base_do_unpack_append() function is defined later
> in kernel.bbclass. If S is set to ${WORKDIR}/${BP} only after
> kernel.bbclass is inherited, then that's after base_do_unpack_append()
> has been parsed.

Parsing itself does not expand variable references (*), so it is
possible to use a variable that gets changed later on and use the value
that the variable eventually ends up having.

(*) There's one exception - the := assignment expands based on the
currently defined variables at the time of parsing the assignment.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.