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, 4 insertions, 4 deletions

diff --git a/arch/v850/Makefile b/arch/v850/Makefile
index 8be9aacb20a7..8b629df0029a 100644
--- a/arch/v850/Makefile
+++ b/arch/v850/Makefile
@@ -16,11 +16,11 @@
 
 arch_dir = arch/v850
 
-CFLAGS += -mv850e
+KBUILD_CFLAGS += -mv850e
 # r16 is a fixed pointer to the current task
-CFLAGS += -ffixed-r16 -mno-prolog-function
-CFLAGS += -fno-builtin
-CFLAGS += -D__linux__ -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CFLAGS += -ffixed-r16 -mno-prolog-function
+KBUILD_CFLAGS += -fno-builtin
+KBUILD_CFLAGS += -D__linux__ -DUTS_SYSNAME=\"uClinux\"
 
 # By default, build a kernel that runs on the gdb v850 simulator.
 KBUILD_DEFCONFIG := sim_defconfig