Re: Allow (O=...) from file

[Sam Ravnborg <sam@ravnborg.org>]

On Tue, Dec 04, 2007 at 09:04:33PM -0600, Jay Cliburn wrote:
> Sam,
> 
> This piece of the top-level Makefile in current git causes an
> out-of-tree driver Makefile to fail.
> 
> 101 ifdef O
> 102   ifeq ("$(origin O)", "command line")
> 103     KBUILD_OUTPUT := $(O)
> 104   endif
> 105 endif
> 
> The out-of-tree driver Makefile contains an O=... directive that
> (correctly) does _not_ specify the kernel source dir, and apparently
> isn't overridden by the command line either. If in the above Makefile
> snippet I change "command line" to "file", my out-of-tree make
> succeeds. What do you think about allowing O= to come from a file in
> addition to the command line?

When you change "command line" to "file" you actually makes kbuild
ignore the O=... value which is why it succeeds.
The problem we solve with the error below is that in some case
the Makefile for the kernel were overwritten.
And I do not really understand why this does not happen in yours
and Erik's case.

Anyway - the right fix seems to detect that the two directories
are equal and then just ignore the O=... setting.
But I am lacking time atm to fix it - only sparsely working on
Linux the next few weeks.

	Sam