| Message ID | 1541386099-13118-1-git-send-email-yamada.masahiro@socionext.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: consolidate Clang compiler flags | expand |
On 05.11.2018 03:48, Masahiro Yamada wrote: > Add basic options for Clang such as --target, --prefix, --gcc-toolchain, > -no-integrated-as to a single variable CLANG_FLAGS. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > --- > > Makefile | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/Makefile b/Makefile > index 93315eb..58c838a 100644 > --- a/Makefile > +++ b/Makefile > @@ -487,18 +487,17 @@ endif > > ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) > ifneq ($(CROSS_COMPILE),) > -CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%)) > +CLANG_FLAGS = --target=$(notdir $(CROSS_COMPILE:%-=%)) > GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD))) > -CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR) > +CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR) So this will expand later now, is this ok? -- Stefan > GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) > endif > ifneq ($(GCC_TOOLCHAIN),) > -CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN) > +CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN) > endif > -KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > -KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > -KBUILD_CFLAGS += $(call cc-option, -no-integrated-as) > -KBUILD_AFLAGS += $(call cc-option, -no-integrated-as) > +CLANG_FLAGS += $(call cc-option, -no-integrated-as) > +KBUILD_CFLAGS += $(CLANG_FLAGS) > +KBUILD_AFLAGS += $(CLANG_FLAGS) > endif > > RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern > -mindirect-branch-register
On Mon, Nov 5, 2018 at 6:10 PM Stefan Agner <stefan@agner.ch> wrote: > > On 05.11.2018 03:48, Masahiro Yamada wrote: > > Add basic options for Clang such as --target, --prefix, --gcc-toolchain, > > -no-integrated-as to a single variable CLANG_FLAGS. > > > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > > --- > > > > Makefile | 13 ++++++------- > > 1 file changed, 6 insertions(+), 7 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index 93315eb..58c838a 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -487,18 +487,17 @@ endif > > > > ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) > > ifneq ($(CROSS_COMPILE),) > > -CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%)) > > +CLANG_FLAGS = --target=$(notdir $(CROSS_COMPILE:%-=%)) > > GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD))) > > -CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR) > > +CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR) > > So this will expand later now, is this ok? > > -- > Stefan > > > GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) > > endif > > ifneq ($(GCC_TOOLCHAIN),) > > -CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN) > > +CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN) > > endif > > -KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > > -KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > > -KBUILD_CFLAGS += $(call cc-option, -no-integrated-as) > > -KBUILD_AFLAGS += $(call cc-option, -no-integrated-as) > > +CLANG_FLAGS += $(call cc-option, -no-integrated-as) > > +KBUILD_CFLAGS += $(CLANG_FLAGS) > > +KBUILD_AFLAGS += $(CLANG_FLAGS) CLANG_FLAGS is expanded here because KBUILD_CFLAGS and KBUILD_AFLAGS are defined by using := So, it should be OK, but turning CLANG_FLAGS into a simple variable will be a little more efficient since $(call cc-option, -no-integrated-as) is evaluated just once. (Or, this cc-option may not be necessary any longer.) Will send v2. Thanks. > > endif > > > > RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern > > -mindirect-branch-register
On Mon, Nov 5, 2018 at 1:19 AM Masahiro Yamada <yamada.masahiro@socionext.com> wrote: > > On Mon, Nov 5, 2018 at 6:10 PM Stefan Agner <stefan@agner.ch> wrote: > > > > On 05.11.2018 03:48, Masahiro Yamada wrote: > > > Add basic options for Clang such as --target, --prefix, --gcc-toolchain, > > > -no-integrated-as to a single variable CLANG_FLAGS. > > > > > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> > > > --- > > > > > > Makefile | 13 ++++++------- > > > 1 file changed, 6 insertions(+), 7 deletions(-) > > > > > > diff --git a/Makefile b/Makefile > > > index 93315eb..58c838a 100644 > > > --- a/Makefile > > > +++ b/Makefile > > > @@ -487,18 +487,17 @@ endif > > > > > > ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) > > > ifneq ($(CROSS_COMPILE),) > > > -CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%)) > > > +CLANG_FLAGS = --target=$(notdir $(CROSS_COMPILE:%-=%)) > > > GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD))) > > > -CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR) > > > +CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR) > > > > So this will expand later now, is this ok? > > > > -- > > Stefan > > > > > GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) > > > endif > > > ifneq ($(GCC_TOOLCHAIN),) > > > -CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN) > > > +CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN) > > > endif > > > -KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > > > -KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > > > -KBUILD_CFLAGS += $(call cc-option, -no-integrated-as) > > > -KBUILD_AFLAGS += $(call cc-option, -no-integrated-as) > > > +CLANG_FLAGS += $(call cc-option, -no-integrated-as) > > > +KBUILD_CFLAGS += $(CLANG_FLAGS) > > > +KBUILD_AFLAGS += $(CLANG_FLAGS) > > > CLANG_FLAGS is expanded here because KBUILD_CFLAGS and KBUILD_AFLAGS > are defined by using := > > So, it should be OK, but turning CLANG_FLAGS into a simple variable > will be a little more efficient since $(call cc-option, -no-integrated-as) > is evaluated just once. > > (Or, this cc-option may not be necessary any longer.) > > Will send v2. If the ultimate goal is not evaluate cc-option more than once, removing cc-option from both KBUILD_CFLAGS and KBUILD_AFLAGS for clang is the better approach; we always want those for clang unconditionally. And if you by chance have an ancient version of clang that doesn't support those flags, you wont be able to compile a kernel anyways. Eventually we want to get Clang's integrated assembler in shape to be used to assemble the kernel, but I think we're a ways off there still.
diff --git a/Makefile b/Makefile index 93315eb..58c838a 100644 --- a/Makefile +++ b/Makefile @@ -487,18 +487,17 @@ endif ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) ifneq ($(CROSS_COMPILE),) -CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%)) +CLANG_FLAGS = --target=$(notdir $(CROSS_COMPILE:%-=%)) GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD))) -CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR) +CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR) GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) endif ifneq ($(GCC_TOOLCHAIN),) -CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN) +CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN) endif -KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) -KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) -KBUILD_CFLAGS += $(call cc-option, -no-integrated-as) -KBUILD_AFLAGS += $(call cc-option, -no-integrated-as) +CLANG_FLAGS += $(call cc-option, -no-integrated-as) +KBUILD_CFLAGS += $(CLANG_FLAGS) +KBUILD_AFLAGS += $(CLANG_FLAGS) endif RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
Add basic options for Clang such as --target, --prefix, --gcc-toolchain, -no-integrated-as to a single variable CLANG_FLAGS. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Makefile | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)