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/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index f4779cd..08fbe6c 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -1099,7 +1099,7 @@
specified options when building the target vmlinux.lds.
When building the *.lds target, kbuild uses the variables:
- CPPFLAGS : Set in top-level Makefile
+ KBUILD_CPPFLAGS : Set in top-level Makefile
EXTRA_CPPFLAGS : May be set in the kbuild makefile
CPPFLAGS_$(@F) : Target specific flags.
Note that the full filename is used in this
diff --git a/Makefile b/Makefile
index ad0add0..ed65de7 100644
--- a/Makefile
+++ b/Makefile
@@ -318,7 +318,7 @@
$(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include) \
-include include/linux/autoconf.h
-CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
+KBUILD_CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common \
@@ -334,7 +334,7 @@
export CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE
export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
-export CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
+export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
@@ -523,9 +523,10 @@
# disable pointer signed / unsigned warnings in gcc 4.0
KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
-# Add user supplied AFLAGS and CFLAGS as the last assignments
-KBUILD_AFLAGS += $(AFLAGS)
-KBUILD_CFLAGS += $(CFLAGS)
+# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
+KBUILD_CPPFLAGS += $(CPPFLAGS)
+KBUILD_AFLAGS += $(AFLAGS)
+KBUILD_CFLAGS += $(CFLAGS)
# Use --build-id when available.
LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
@@ -1507,7 +1508,7 @@
a_flags = -Wp,-MD,$(depfile) $(KBUILD_AFLAGS) $(AFLAGS_KERNEL) \
- $(NOSTDINC_FLAGS) $(CPPFLAGS) \
+ $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) \
$(modkern_aflags) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)
quiet_cmd_as_o_S = AS $@
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index b762d23..0d450e7 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -32,11 +32,11 @@
endif
ifeq ($(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 9708a29..34951aa 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -29,7 +29,7 @@
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)
$(error Sorry, you need a newer version of the assember, one that is built from \
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 462bb89..4e16534 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -75,7 +75,7 @@
AFLAGS-$(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)
diff --git a/arch/ppc/Makefile b/arch/ppc/Makefile
index dd63ccb..95894ef 100644
--- a/arch/ppc/Makefile
+++ b/arch/ppc/Makefile
@@ -22,7 +22,7 @@
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 8836f0d..bcfd6ea 100644
--- a/arch/um/Makefile-x86_64
+++ b/arch/um/Makefile-x86_64
@@ -14,7 +14,7 @@
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
diff --git a/drivers/atm/Makefile b/drivers/atm/Makefile
index 1b16f81..e4fa996 100644
--- a/drivers/atm/Makefile
+++ b/drivers/atm/Makefile
@@ -41,7 +41,7 @@
# guess the target endianess to choose the right PCA-200E firmware image
ifeq ($(CONFIG_ATM_FORE200E_PCA_DEFAULT_FW),y)
byteorder.h := include$(if $(patsubst $(srctree),,$(objtree)),2)/asm/byteorder.h
- CONFIG_ATM_FORE200E_PCA_FW := $(obj)/pca200e$(if $(shell $(CC) $(CPPFLAGS) -E -dM $(byteorder.h) | grep ' __LITTLE_ENDIAN '),.bin,_ecd.bin2)
+ CONFIG_ATM_FORE200E_PCA_FW := $(obj)/pca200e$(if $(shell $(CC) $(KBUILD_CPPFLAGS) -E -dM $(byteorder.h) | grep ' __LITTLE_ENDIAN '),.bin,_ecd.bin2)
endif
endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 2837ada..95e6e0f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -86,7 +86,7 @@
_c_flags = $(KBUILD_CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$(basetarget).o)
_a_flags = $(KBUILD_AFLAGS) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)
-_cpp_flags = $(CPPFLAGS) $(EXTRA_CPPFLAGS) $(CPPFLAGS_$(@F))
+_cpp_flags = $(KBUILD_CPPFLAGS) $(EXTRA_CPPFLAGS) $(CPPFLAGS_$(@F))
# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
@@ -106,11 +106,11 @@
__cpp_flags = $(call flags,_cpp_flags)
endif
-c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(CPPFLAGS) \
+c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) \
$(__c_flags) $(modkern_cflags) \
-D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags)
-a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(CPPFLAGS) \
+a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) \
$(__a_flags) $(modkern_aflags)
cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(__cpp_flags)