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/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 69ecea6..36d2bb5 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -9,7 +9,7 @@
#We #undef __x86_64__ for kernelspace, not for userspace where
#it's needed for headers to work!
ARCH_KERNEL_DEFINES = -U__$(SUBARCH)__
-CFLAGS += $(_extra_flags_)
+KBUILD_CFLAGS += $(_extra_flags_)
CHECKFLAGS += -m64
AFLAGS += -m64