kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP
The variable CPPFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
This patch replace use of CPPFLAGS with KBUILD_CPPFLAGS all over the
tree and enabling one to use:
make CPPFLAGS=...
to specify additional CPP commandline options.
Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k, s390
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 462bb89..4e16534 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -75,7 +75,7 @@
AFLAGS-$(CONFIG_PPC32) := -Iarch/$(ARCH)
CFLAGS-$(CONFIG_PPC64) := -mminimal-toc -mtraceback=none -mcall-aixdesc
CFLAGS-$(CONFIG_PPC32) := -Iarch/$(ARCH) -ffixed-r2 -mmultiple
-CPPFLAGS += $(CPPFLAGS-y)
+KBUILD_CPPFLAGS += $(CPPFLAGS-y)
KBUILD_AFLAGS += $(AFLAGS-y)
KBUILD_CFLAGS += -msoft-float -pipe $(CFLAGS-y)
CPP = $(CC) -E $(KBUILD_CFLAGS)