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, 6 insertions, 6 deletions

diff --git a/arch/h8300/Makefile b/arch/h8300/Makefile
index 53b5c1edf596..330e05f28f90 100644
--- a/arch/h8300/Makefile
+++ b/arch/h8300/Makefile
@@ -30,16 +30,16 @@ ldflags-$(CONFIG_CPU_H8300H)	:= -mh8300helf
 cflags-$(CONFIG_CPU_H8S)        := -ms
 ldflags-$(CONFIG_CPU_H8S)       := -mh8300self
 
-CFLAGS += $(cflags-y)
-CFLAGS += -mint32 -fno-builtin
-CFLAGS += -g
-CFLAGS += -D__linux__
-CFLAGS += -DUTS_SYSNAME=\"uClinux\"
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += -mint32 -fno-builtin
+KBUILD_CFLAGS += -g
+KBUILD_CFLAGS += -D__linux__
+KBUILD_CFLAGS += -DUTS_SYSNAME=\"uClinux\"
 AFLAGS += -DPLATFORM=$(PLATFORM) -DMODEL=$(MODEL) $(cflags-y)
 LDFLAGS += $(ldflags-y)
 
 CROSS_COMPILE = h8300-elf-
-LIBGCC := $(shell $(CROSS-COMPILE)$(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CROSS-COMPILE)$(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 
 head-y := arch/$(ARCH)/platform/$(PLATFORM)/$(BOARD)/crt0_$(MODEL).o