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-i386 b/arch/um/Makefile-i386
index c9f1c5b..26bc786 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -15,7 +15,7 @@
ifeq ("$(origin SUBARCH)", "command line")
ifneq ("$(shell uname -m | sed -e s/i.86/i386/)", "$(SUBARCH)")
-CFLAGS += $(call cc-option,-m32)
+KBUILD_CFLAGS += $(call cc-option,-m32)
AFLAGS += $(call cc-option,-m32)
LINK-y += $(call cc-option,-m32)
UML_OBJCOPYFLAGS += -F $(ELF_FORMAT)
@@ -36,4 +36,4 @@
# an unresolved reference.
cflags-y += -ffreestanding
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)