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>

5 files changed, 6 insertions, 6 deletions

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index b762d235b81a..0d450e757e0e 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -32,11 +32,11 @@ KBUILD_CFLAGS	+=-fno-omit-frame-pointer -mapcs -mno-sched-prolog
 endif
 
 ifeq ($(CONFIG_CPU_BIG_ENDIAN),y)
-CPPFLAGS        += -mbig-endian
+KBUILD_CPPFLAGS += -mbig-endian
 AS              += -EB
 LD              += -EB
 else
-CPPFLAGS        += -mlittle-endian
+KBUILD_CPPFLAGS += -mlittle-endian
 AS              += -EL
 LD              += -EL
 endif
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index 9708a29c70b5..34951aa2370b 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -29,7 +29,7 @@ cflags-y	:= -pipe $(EXTRA) -ffixed-r13 -mfixed-range=f12-f15,f32-f127 \
 CFLAGS_KERNEL   := -mconstant-gp
 
 GAS_STATUS      = $(shell $(srctree)/arch/ia64/scripts/check-gas "$(CC)" "$(OBJDUMP)")
-CPPFLAGS += $(shell $(srctree)/arch/ia64/scripts/toolchain-flags "$(CC)" "$(OBJDUMP)" "$(READELF)")
+KBUILD_CPPFLAGS += $(shell $(srctree)/arch/ia64/scripts/toolchain-flags "$(CC)" "$(OBJDUMP)" "$(READELF)")
 
 ifeq ($(GAS_STATUS),buggy)
 $(error Sorry, you need a newer version of the assember, one that is built from \
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 462bb89b67e8..4e165342210a 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -75,7 +75,7 @@ CPPFLAGS-$(CONFIG_PPC32) := -Iarch/$(ARCH)
 AFLAGS-$(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)
diff --git a/arch/ppc/Makefile b/arch/ppc/Makefile
index dd63ccb66732..95894ef7beaa 100644
--- a/arch/ppc/Makefile
+++ b/arch/ppc/Makefile
@@ -22,7 +22,7 @@ endif
 
 LDFLAGS_vmlinux := -Ttext $(KERNELLOAD) -Bstatic
 # The -Iarch/$(ARCH)/include is temporary while we are merging
-CPPFLAGS        += -Iarch/$(ARCH) -Iarch/$(ARCH)/include
+KBUILD_CPPFLAGS += -Iarch/$(ARCH) -Iarch/$(ARCH)/include
 KBUILD_AFLAGS   += -Iarch/$(ARCH)
 KBUILD_CFLAGS   += -Iarch/$(ARCH) -msoft-float -pipe \
                 -ffixed-r2 -mmultiple
diff --git a/arch/um/Makefile-x86_64 b/arch/um/Makefile-x86_64
index 8836f0df36aa..bcfd6ea30030 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -14,7 +14,7 @@ KBUILD_CFLAGS += $(_extra_flags_)
 CHECKFLAGS  += -m64
 KBUILD_AFLAGS += -m64
 LDFLAGS += -m elf_x86_64
-CPPFLAGS += -m64
+KBUILD_CPPFLAGS += -m64
 
 ELF_ARCH := i386:x86-64
 ELF_FORMAT := elf64-x86-64