| Message ID | 1488174052-2530-1-git-send-email-yamada.masahiro@socionext.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 2017-02-27 at 14:40 +0900, Masahiro Yamada wrote: > Since commit 6b22b3d1614a ("kbuild: Allow using host dtc instead of > kernel's copy"), it is possible to use an external dtc. In this > case, we do not know which options are supported on it. > > Commit bc553986a2f7 ("dtc: turn off dtc unit address warnings by > default") gives -Wno-unit_address_vs_reg, but this options is only > recognized by v1.4.2 or later. > > If an older version is specified, the build fails: But the option to use an external dtc was intended to allow testing of newer versions. If there's no reason to use this option to run an older version, why bother trying to support that? [...] > --- a/scripts/Kbuild.include > +++ b/scripts/Kbuild.include > @@ -171,6 +171,20 @@ ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) > # Usage: $(call ld-ifversion, -ge, 22252, y) > ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4)) > > +# dtc-option > +# Usage: DTC_FLAGS += $(call dtc-option,-Wno-unit_address_vs_reg) > +# > +# When we use the external dtc, check if the desired options are supported. > +# When we use the kernel's copy (scripts/dtc/dtc), just use the fixed option. > +# Until Kbuild descends into the scripts/dtc/ directory, scripts/dtc/dtc may > +# not exist, i.e. $(call try-run,...) may not work. > +ifeq ("$(origin DTC)", "command line") [...] It could also be specified as an environment variable (assignment with "?=" doesn't override them, but "=" does). Ben.
Ben Hutchings <ben@decadent.org.uk> writes: > [ Unknown signature status ] > On Mon, 2017-02-27 at 14:40 +0900, Masahiro Yamada wrote: >> Since commit 6b22b3d1614a ("kbuild: Allow using host dtc instead of >> kernel's copy"), it is possible to use an external dtc. In this >> case, we do not know which options are supported on it. >> >> Commit bc553986a2f7 ("dtc: turn off dtc unit address warnings by >> default") gives -Wno-unit_address_vs_reg, but this options is only >> recognized by v1.4.2 or later. >> >> If an older version is specified, the build fails: > > But the option to use an external dtc was intended to allow testing of > newer versions. If there's no reason to use this option to run an > older version, why bother trying to support that? +1 That's a lot of added complexity, when the answer could just be "use the kernel dtc". cheers -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Makefile b/Makefile index b83109b..4c4647a 100644 --- a/Makefile +++ b/Makefile @@ -356,6 +356,7 @@ STRIP = $(CROSS_COMPILE)strip OBJCOPY = $(CROSS_COMPILE)objcopy OBJDUMP = $(CROSS_COMPILE)objdump AWK = awk +DTC = scripts/dtc/dtc GENKSYMS = scripts/genksyms/genksyms INSTALLKERNEL := installkernel DEPMOD = /sbin/depmod @@ -365,6 +366,7 @@ CHECK = sparse CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ -Wbitwise -Wno-return-void $(CF) +DTC_FLAGS := NOSTDINC_FLAGS = CFLAGS_MODULE = AFLAGS_MODULE = @@ -419,7 +421,7 @@ export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE -export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS +export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS DTC DTC_FLAGS export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV CFLAGS_KCOV CFLAGS_KASAN CFLAGS_UBSAN diff --git a/arch/c6x/boot/dts/Makefile b/arch/c6x/boot/dts/Makefile index c7528b0..459955b 100644 --- a/arch/c6x/boot/dts/Makefile +++ b/arch/c6x/boot/dts/Makefile @@ -2,7 +2,7 @@ # Makefile for device trees # -DTC_FLAGS ?= -p 1024 +DTC_FLAGS += -p 1024 ifneq ($(DTB),) obj-y += linked_dtb.o diff --git a/arch/microblaze/boot/dts/Makefile b/arch/microblaze/boot/dts/Makefile index a3d2e42..5addb5b 100644 --- a/arch/microblaze/boot/dts/Makefile +++ b/arch/microblaze/boot/dts/Makefile @@ -15,4 +15,4 @@ quiet_cmd_cp = CP $< $@$2 cmd_cp = cat $< >$@$2 || (rm -f $@ && echo false) # Rule to build device tree blobs -DTC_FLAGS := -p 1024 +DTC_FLAGS += -p 1024 diff --git a/arch/openrisc/boot/dts/Makefile b/arch/openrisc/boot/dts/Makefile index b092d30..f4048d1 100644 --- a/arch/openrisc/boot/dts/Makefile +++ b/arch/openrisc/boot/dts/Makefile @@ -7,4 +7,4 @@ obj-y += $(BUILTIN_DTB) clean-files := *.dtb.S -#DTC_FLAGS ?= -p 1024 +#DTC_FLAGS += -p 1024 diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile index e82f333..5350b67 100644 --- a/arch/powerpc/boot/Makefile +++ b/arch/powerpc/boot/Makefile @@ -50,7 +50,7 @@ endif BOOTCFLAGS += -I$(objtree)/$(obj) -I$(srctree)/$(obj) -DTC_FLAGS ?= -p 1024 +DTC_FLAGS += -p 1024 $(obj)/4xx.o: BOOTCFLAGS += -mcpu=405 $(obj)/ebony.o: BOOTCFLAGS += -mcpu=405 diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index d6ca649..adabbb5 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -171,6 +171,20 @@ ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh) # Usage: $(call ld-ifversion, -ge, 22252, y) ld-ifversion = $(shell [ $(ld-version) $(1) $(2) ] && echo $(3) || echo $(4)) +# dtc-option +# Usage: DTC_FLAGS += $(call dtc-option,-Wno-unit_address_vs_reg) +# +# When we use the external dtc, check if the desired options are supported. +# When we use the kernel's copy (scripts/dtc/dtc), just use the fixed option. +# Until Kbuild descends into the scripts/dtc/ directory, scripts/dtc/dtc may +# not exist, i.e. $(call try-run,...) may not work. +ifeq ("$(origin DTC)", "command line") +dtc-option = $(call try-run,\ + echo '/dts-v1/; / {};' | $(DTC) $(1),$(1),$(2)) +else +dtc-option = $(1) +endif + ###### ### diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 7c321a6..17d4030 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -69,4 +69,8 @@ KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare) KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length) KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized) endif + +# Disable noisy checks by default +DTC_FLAGS += $(call dtc-option,-Wno-unit_address_vs_reg) + endif diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 0a07f90..6228c9b 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -276,12 +276,6 @@ cmd_gzip = (cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@) || \ # DTC # --------------------------------------------------------------------------- -DTC ?= $(objtree)/scripts/dtc/dtc - -# Disable noisy checks by default -ifeq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),) -DTC_FLAGS += -Wno-unit_address_vs_reg -endif # Generate an assembly file to wrap the output of the device tree compiler quiet_cmd_dt_S_dtb= DTB $@
Since commit 6b22b3d1614a ("kbuild: Allow using host dtc instead of kernel's copy"), it is possible to use an external dtc. In this case, we do not know which options are supported on it. Commit bc553986a2f7 ("dtc: turn off dtc unit address warnings by default") gives -Wno-unit_address_vs_reg, but this options is only recognized by v1.4.2 or later. If an older version is specified, the build fails: $ dtc --version Version: DTC 1.4.0 $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- DTC=dtc dtbs [ snip ] DTC arch/arm64/boot/dts/al/alpine-v2-evp.dtb FATAL ERROR: Unrecognized check name "unit_address_vs_reg" make[2]: *** [arch/arm64/boot/dts/al/alpine-v2-evp.dtb] Error 1 make[1]: *** [arch/arm64/boot/dts/al] Error 2 make: *** [dtbs] Error 2 This commit adds a new helper dtc-option to check if the given option is supported, like cc-option, ld-option, etc. The check for the -Wno-unit_address_vs_reg has been moved from Makefile.lib to Makefile.extrawarn. Since Makefile.lib is included recursively, it is not efficient to evaluate the $(call dtc-option) at every descend. On the other hand, Makefile.extrawarn is included just once from the top Makefile. Besides, it seems more suitable to collect extra warning things into the Makefile.extrawarn. The variable, DTC, has also been moved to the top Makefile so that the Makefile.extrawarn can reference it. Here is one problem for the dtc-option helper; the kernel's copy (scripts/dtc/dtc) is not compiled until Kbuild descends into the scripts/dtc/ directory. This happens later after Makefile.extrawarn is evaluated. So, dtc-options should its job only when DTC is overridden from the command line (i.e. pre-built dtc is used). If the kernel's copy is used, dtc-option falls back to a fixed option because we know which options are supported on the internal one. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- Makefile | 4 +++- arch/c6x/boot/dts/Makefile | 2 +- arch/microblaze/boot/dts/Makefile | 2 +- arch/openrisc/boot/dts/Makefile | 2 +- arch/powerpc/boot/Makefile | 2 +- scripts/Kbuild.include | 14 ++++++++++++++ scripts/Makefile.extrawarn | 4 ++++ scripts/Makefile.lib | 6 ------ 8 files changed, 25 insertions(+), 11 deletions(-)