@@ -192,14 +192,6 @@ clean := -f $(srctree)/scripts/Makefile.clean obj
# $(Q)$(MAKE) $(hdr-inst)=dir
hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
-# Prefix -I with $(srctree) if it is not an absolute path.
-# skip if -I has no parameter
-addtree = $(if $(patsubst -I%,%,$(1)), \
-$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)),$(1))
-
-# Find all -I options and call addtree
-flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
-
# echo command.
# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
echo-cmd = $(if $($(quiet)cmd_$(1)),\
@@ -67,18 +67,16 @@ _hostc_flags = $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
_hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
$(HOSTCXXFLAGS_$(basetarget).o)
-__hostc_flags = $(_hostc_flags)
-__hostcxx_flags = $(_hostcxx_flags)
-
+# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
ifneq ($(srctree),.)
-__hostc_flags = -I$(obj) $(call flags,_hostc_flags)
-__hostcxx_flags = -I$(obj) $(call flags,_hostcxx_flags)
+_hostc_flags += -I $(objtree)/$(obj)
+_hostcxx_flags += -I $(objtree)/$(obj)
endif
endif
-hostc_flags = -Wp,-MD,$(depfile) $(__hostc_flags)
-hostcxx_flags = -Wp,-MD,$(depfile) $(__hostcxx_flags)
+hostc_flags = -Wp,-MD,$(depfile) $(_hostc_flags)
+hostcxx_flags = -Wp,-MD,$(depfile) $(_hostcxx_flags)
#####
# Compile programs on the host
@@ -137,36 +137,26 @@ _c_flags += $(if $(patsubst n%,, \
$(CFLAGS_KCOV))
endif
-__c_flags = $(_c_flags)
-__a_flags = $(_a_flags)
-__cpp_flags = $(_cpp_flags)
-
-# If building the kernel in a separate objtree expand all occurrences
-# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
+# $(srctree)/$(src) for including checkin headers from generated source files
+# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
ifneq ($(srctree),.)
-
-# -I$(obj) locates generated .h files
-# $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
-# and locates generated .h files
-# FIXME: Replace both with specific CFLAGS* statements in the makefiles
-__c_flags = $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \
- $(call flags,_c_flags)
-__a_flags = $(call flags,_a_flags)
-__cpp_flags = $(call flags,_cpp_flags)
+_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
+_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
+_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
endif
endif
c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
-include $(srctree)/include/linux/compiler_types.h \
- $(__c_flags) $(modkern_cflags) \
+ $(_c_flags) $(modkern_cflags) \
$(basename_flags) $(modname_flags)
a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
- $(__a_flags) $(modkern_aflags)
+ $(_a_flags) $(modkern_aflags)
cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
- $(__cpp_flags)
+ $(_cpp_flags)
ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
The 'addtree' and 'flags' in scripts/Kbuild.include are so compilecated and ugly. As I mentioned in [1], Kbuild should stop automatic prefixing of header search path options. Instead, in-kernel Makefiles should explicitly add $(srctree)/ to the search paths in the srctree. Kbuild still caters to add $(srctree)/$(src) and $(objtree)/$(obj) to the header search path for O= building, but never touches extra compiler options from ccflags-y etc. Going forward, in-kernel Makefiles should explicitly specify $(srctree)/ if extra search paths are needed. Example) ccflags-y += -I $(srctree)/foo/bar You do not have to change external module Makefiles because $(src) is already an absolute path for external modules. Example) ccflags-y += -I $(src)/foo/bar [1]: https://patchwork.kernel.org/patch/9632347/ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- scripts/Kbuild.include | 8 -------- scripts/Makefile.host | 12 +++++------- scripts/Makefile.lib | 26 ++++++++------------------ 3 files changed, 13 insertions(+), 33 deletions(-)