Re: kbuild variable $(src) broken in 2.6.23-rc3?

[Sam Ravnborg <sam@ravnborg.org>]

On Wed, May 28, 2008 at 10:18:03PM +0200, Andrea Arcangeli wrote:
> On Wed, May 28, 2008 at 09:13:15PM +0200, Sam Ravnborg wrote:
> > Inspect the gcc commandlien to see if the last -I
> > contains the expected value (which is `pwd`)
> 
> I can reproduce a failure, not sure if it's the same one but it ends
> up with -I. Actually on the good build it seems the -I wasn't there at
> all.

I tracked it down now (a simple bisect would have doen the trick too).
It was the introduction of KBUILD_EXTRA_SYMBOLS that caused
us troubles because we started to include the Makefile
in Makefile.modpost and thus ccflags-y (EXTRA_CFLAGS) were
assigned the value "-I$(src)" but $(src) was not defined so
we ended up with an empty -I which then picked up the following
parameter on the command line.

I cooked up the following fix:

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index a098a04..28ef233 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -37,6 +37,10 @@
 # symbols in the final module linking stage
 # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
 # This is solely usefull to speed up test compiles
+
+# Assign src as it may be used in ccflags-y
+src = .
+
 PHONY := _modpost
 _modpost: __modpost
 

Please let me know if this solves your problem or more issues reamin.

	Sam