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, 2 insertions, 2 deletions

diff --git a/arch/sh64/Makefile b/arch/sh64/Makefile
index ebf20043991c..9e874de0a096 100644
--- a/arch/sh64/Makefile
+++ b/arch/sh64/Makefile
@@ -26,7 +26,7 @@ LDFLAGS			+= -EB  -mshelf32_linux
 endif
 
 # No requirements for endianess support from AFLAGS, 'as' always run through gcc
-CFLAGS          += $(cpu-y)
+KBUILD_CFLAGS           += $(cpu-y)
 
 LDFLAGS_vmlinux += --defsym phys_stext=_stext-$(CONFIG_CACHED_MEMORY_OFFSET) \
                   --defsym phys_stext_shmedia=phys_stext+1 \
@@ -57,7 +57,7 @@ ifneq ($(machine-y),)
 core-y  += arch/sh64/mach-$(machine-y)/
 endif
 
-LIBGCC := $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 libs-y  += arch/$(ARCH)/lib/ $(LIBGCC)
 
 drivers-$(CONFIG_OPROFILE)      += arch/sh64/oprofile/