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/sparc64/Makefile b/arch/sparc64/Makefile
index cad10c5..b083dc4 100644
--- a/arch/sparc64/Makefile
+++ b/arch/sparc64/Makefile
@@ -39,17 +39,17 @@
endif
ifneq ($(NEW_GCC),y)
- CFLAGS := $(CFLAGS) -pipe -mno-fpu -mtune=ultrasparc -mmedlow \
+ KBUILD_CFLAGS += -pipe -mno-fpu -mtune=ultrasparc -mmedlow \
-ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare
else
- CFLAGS := $(CFLAGS) -m64 -pipe -mno-fpu -mcpu=ultrasparc -mcmodel=medlow \
+ KBUILD_CFLAGS += -m64 -pipe -mno-fpu -mcpu=ultrasparc -mcmodel=medlow \
-ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wno-sign-compare \
$(CC_UNDECL)
AFLAGS += -m64 -mcpu=ultrasparc $(CC_UNDECL)
endif
ifeq ($(CONFIG_MCOUNT),y)
- CFLAGS := $(CFLAGS) -pg
+ KBUILD_CFLAGS += -pg
endif
head-y := arch/sparc64/kernel/head.o arch/sparc64/kernel/init_task.o