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>
diff --git a/arch/blackfin/Makefile b/arch/blackfin/Makefile
index 2084166..52a6ac0 100644
--- a/arch/blackfin/Makefile
+++ b/arch/blackfin/Makefile
@@ -53,7 +53,7 @@
rev-$(CONFIG_BF_REV_NONE) := none
rev-$(CONFIG_BF_REV_ANY) := any
-CFLAGS += -mcpu=$(cpu-y)-$(rev-y)
+KBUILD_CFLAGS += -mcpu=$(cpu-y)-$(rev-y)
AFLAGS += -mcpu=$(cpu-y)-$(rev-y)
head-y := arch/$(ARCH)/mach-$(MACHINE)/head.o arch/$(ARCH)/kernel/init_task.o