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/arm/Makefile b/arch/arm/Makefile
index fa4ea9f..0b82865 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -14,9 +14,9 @@
CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
OBJCOPYFLAGS :=-O binary -R .note -R .comment -S
GZFLAGS :=-9
-#CFLAGS +=-pipe
+#KBUILD_CFLAGS +=-pipe
# Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:
-CFLAGS +=$(call cc-option,-marm,)
+KBUILD_CFLAGS +=$(call cc-option,-marm,)
# Do not use arch/arm/defconfig - it's always outdated.
# Select a platform tht is kept up-to-date
@@ -28,7 +28,7 @@
endif
ifeq ($(CONFIG_FRAME_POINTER),y)
-CFLAGS +=-fno-omit-frame-pointer -mapcs -mno-sched-prolog
+KBUILD_CFLAGS +=-fno-omit-frame-pointer -mapcs -mno-sched-prolog
endif
ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
@@ -85,7 +85,7 @@
endif
# Need -Uarm for gcc < 3.x
-CFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
+KBUILD_CFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
AFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float
CHECKFLAGS += -D__arm__