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/i386/Makefile b/arch/i386/Makefile
index 5e50dbf..fc3c8e8 100644
--- a/arch/i386/Makefile
+++ b/arch/i386/Makefile
@@ -34,10 +34,10 @@
endif
CHECKFLAGS += -D__i386__
-CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return
+KBUILD_CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return
# prevent gcc from keeping the stack 16 byte aligned
-CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
+KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
# CPU-specific tuning. Anything which can be shared with UML should go here.
include $(srctree)/arch/i386/Makefile.cpu
@@ -51,7 +51,7 @@
# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
# a lot more stack due to the lack of sharing of stacklots:
-CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;)
+KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;)
# do binutils support CFI?
cflags-y += $(call as-instr,.cfi_startproc\n.cfi_rel_offset esp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
@@ -61,7 +61,7 @@
cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
-CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(cflags-y)
# Default subarch .c files
mcore-y := arch/x86/mach-default
@@ -116,7 +116,7 @@
drivers-$(CONFIG_PM) += arch/x86/power/
drivers-$(CONFIG_FB) += arch/x86/video/
-CFLAGS += $(mflags-y)
+KBUILD_CFLAGS += $(mflags-y)
AFLAGS += $(mflags-y)
boot := arch/x86/boot