kbuild: enable 'make CFLAGS=...' to add additional options to CC

The variable CFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of CFLAGS with KBUILD_CFLAGS all over the
tree and enabling one to use:
make CFLAGS=...
to specify additional gcc commandline options.

One usecase is when trying to find gcc bugs but other
use cases has been requested too.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k

Test was simple to do a defconfig build, apply the patch and check
that nothing got rebuild.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/m68knommu/Makefile b/arch/m68knommu/Makefile
index 1305cc980023..1c1fbb69ff26 100644
--- a/arch/m68knommu/Makefile
+++ b/arch/m68knommu/Makefile
@@ -104,9 +104,9 @@ cflags-$(CONFIG_M68360)		:= -m68332
 
 AFLAGS += $(cflags-y)
 
-CFLAGS += $(cflags-y)
-CFLAGS += -D__linux__
-CFLAGS += -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -D__linux__
+KBUILD_CFLAGS += -DUTS_SYSNAME=\"uClinux\"
 
 head-y := arch/m68knommu/platform/$(cpuclass-y)/head.o