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/s390/Makefile b/arch/s390/Makefile
index 143ed8e..62a0da4 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -15,7 +15,7 @@
ifndef CONFIG_64BIT
LDFLAGS := -m elf_s390
-CFLAGS += -m31
+KBUILD_CFLAGS += -m31
AFLAGS += -m31
UTS_MACHINE := s390
STACK_SIZE := 8192
@@ -23,7 +23,7 @@
else
LDFLAGS := -m elf64_s390
MODFLAGS += -fpic -D__PIC__
-CFLAGS += -m64
+KBUILD_CFLAGS += -m64
AFLAGS += -m64
UTS_MACHINE := s390x
STACK_SIZE := 16384
@@ -77,8 +77,8 @@
cflags-$(CONFIG_WARN_STACK) += -mwarn-framesize=$(CONFIG_WARN_STACK_SIZE)
endif
-CFLAGS += -mbackchain -msoft-float $(cflags-y)
-CFLAGS += -pipe -fno-strength-reduce -Wno-sign-compare
+KBUILD_CFLAGS += -mbackchain -msoft-float $(cflags-y)
+KBUILD_CFLAGS += -pipe -fno-strength-reduce -Wno-sign-compare
AFLAGS += $(aflags-y)
OBJCOPYFLAGS := -O binary