Re: [PATCH 2/2] Enable 'make CONFIG_FOO=y oldconfig'

From: David Woodhouse
Date: Wed Aug 10 2011 - 19:17:35 EST

On Wed, 2011-08-10 at 18:33 -0400, Arnaud Lacombe wrote:
> > We're not enabling anything that we're later going to break. I can't see
> > many people *depending* on the fact that 'make CONFIG_SATA_MV=y
> > oldconfig' actually does *nothing* in some cases.
> >
> you are wrong, you ends up with half-baked compile-time dependency,
> which break the build:

s/*nothing*/nothing useful/, for crying out loud.

The point remains that we're not enabling anything which we're later
going to break. Nobody is going to come to *depend* on this behaviour.

And anyway, this behaviour exists even *before* my patches, as Michal
pointed out in a far more helpful and constructive fashion in
earlier today.

It's simple enough to fix, too:

diff --git a/Makefile b/Makefile
index 1fc5172..6cc7f7b 100644
--- a/Makefile
+++ b/Makefile
@@ -474,6 +474,9 @@ ifeq ($(KBUILD_EXTMOD),)

+# This could probably be simpler?
+CONFIG_OVERRIDES := $(patsubst line:%,%,$(filter line:%,$(foreach var, $(filter CONFIG_%,$(.VARIABLES)), $(origin $(var)):$(var))))
ifeq ($(mixed-targets),1)
# ===========================================================================
# We're called with mixed targets (*config and build targets).
@@ -507,6 +510,10 @@ else
# Build targets only - this includes vmlinux, arch specific targets, clean
# targets and others. In general all targets except *config targets.

+$(error Cannot perform build targets with CONFIG symbols overridden)
ifeq ($(KBUILD_EXTMOD),)
# Additional helpers built in scripts/
# Carefully list dependencies so we do not try to build scripts twice


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at