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/xtensa/Makefile b/arch/xtensa/Makefile
index acf05be..56685a8 100644
--- a/arch/xtensa/Makefile
+++ b/arch/xtensa/Makefile
@@ -28,11 +28,9 @@
export PLATFORM
# temporarily until string.h is fixed
-cflags-y += -ffreestanding
+KBUILD_CFLAGS += -ffreestanding
-cflags-y += -pipe -mlongcalls
-
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -pipe -mlongcalls
KBUILD_DEFCONFIG := iss_defconfig
@@ -56,7 +54,7 @@
#
-LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
head-y := arch/xtensa/kernel/head.o
core-y += arch/xtensa/kernel/ arch/xtensa/mm/