5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Masahiro Yamada masahiroy@kernel.org
[ Upstream commit 30a7729771731971839cc969d2a321e6ea7a144b ]
This omits system headers from the generated header dependency.
System headers are not updated unless you upgrade the compiler. Nor do they contain CONFIG options, so fixdep does not need to parse them.
Having said that, the effect of this optimization will be quite small because the kernel code generally does not include system headers except <stdarg.h>. Host programs include a lot of system headers, but there are not so many in the kernel tree.
At first, keeping system headers in .*.cmd files might be useful to detect the compiler update, but there is no guarantee that <stdarg.h> is included from every file. So, I implemented a more reliable way in the previous commit.
Signed-off-by: Masahiro Yamada masahiroy@kernel.org Stable-dep-of: 02e9a22ceef0 ("kbuild: hdrcheck: fix cross build with clang") Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/Kbuild.include | 2 +- scripts/Makefile.host | 4 ++-- scripts/Makefile.lib | 8 ++++---- usr/include/Makefile | 2 +- 4 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 5d247d8f1e044..82eb69f07b356 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -16,7 +16,7 @@ pound := # dot-target = $(dir $@).$(notdir $@)
### -# The temporary file to save gcc -MD generated dependencies must not +# The temporary file to save gcc -MMD generated dependencies must not # contain a comma depfile = $(subst $(comma),_,$(dot-target).d)
diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 4c51c95d40f47..a0a4af508f155 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -92,8 +92,8 @@ _hostcxx_flags += -I $(objtree)/$(obj) endif endif
-hostc_flags = -Wp,-MD,$(depfile) $(_hostc_flags) -hostcxx_flags = -Wp,-MD,$(depfile) $(_hostcxx_flags) +hostc_flags = -Wp,-MMD,$(depfile) $(_hostc_flags) +hostcxx_flags = -Wp,-MMD,$(depfile) $(_hostcxx_flags)
##### # Compile programs on the host diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index a6d0044328b1f..9339fadb6a169 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -160,22 +160,22 @@ modkern_aflags = $(if $(part-of-module), \ $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \ $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
-c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ +c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ -include $(srctree)/include/linux/compiler_types.h \ $(_c_flags) $(modkern_cflags) \ $(basename_flags) $(modname_flags)
-a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ +a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(_a_flags) $(modkern_aflags)
-cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ +cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(_cpp_flags)
ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
-dtc_cpp_flags = -Wp,-MD,$(depfile).pre.tmp -nostdinc \ +dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \ $(addprefix -I,$(DTC_INCLUDE)) \ -undef -D__DTS__
diff --git a/usr/include/Makefile b/usr/include/Makefile index e2840579156a9..6c4b79d4558d6 100644 --- a/usr/include/Makefile +++ b/usr/include/Makefile @@ -8,7 +8,7 @@ # We cannot go as far as adding -Wpedantic since it emits too many warnings. UAPI_CFLAGS := -std=c90 -Wall -Werror=implicit-function-declaration
-override c_flags = $(UAPI_CFLAGS) -Wp,-MD,$(depfile) -I$(objtree)/usr/include +override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
# The following are excluded for now because they fail to build. #