Re: [XEN PATCH v5 07/16] xen/build: Start using if_changed

[Julien Grall <julien@xxxxxxx>]

Hi,

On 21/04/2020 17:11, Anthony PERARD wrote:
> This patch start to use if_changed introduced in a previous commit.
>
> Whenever if_changed is called, the target must have FORCE as
> dependency so that if_changed can check if the command line to be
> run has changed, so the macro $(real-prereqs) must be used to
> discover the dependencies without "FORCE".
>
> Whenever a target isn't in obj-y, it should be added to extra-y so the
> .*.cmd dependency file associated with the target can be loaded. This
> is done for xsm/flask/ and both common/lib{elf,fdt}/ and
> arch/x86/Makefile.
>
> For the targets that generate .*.d dependency files, there's going to
> be two dependency files (.*.d and .*.cmd) until we can merge them
> together in a later patch via fixdep from Linux.
>
> One cleanup, libelf-relocate.o doesn't exist anymore.
>
> We import cmd_ld and cmd_objcopy from Linux v5.4.
>
> Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
For the Arm bits:

Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

> ---
>
> Notes:
>      v4:
>      - typos
>      - fix missing FORCE in libfdt/Makefile
>      - typo flask vs flash in xsm
>      - in xsm, use *_H_DEPEND in command lines of mkaccess and mkflask
>        instead of $(real-prereq) to avoid including the script as argument of
>        itself.
>
>   xen/Rules.mk               | 68 +++++++++++++++++++++++++++-----------
>   xen/arch/arm/Makefile      |  4 +--
>   xen/arch/x86/Makefile      |  1 +
>   xen/arch/x86/efi/Makefile  |  7 ++--
>   xen/common/libelf/Makefile | 12 ++++---
>   xen/common/libfdt/Makefile | 11 +++---
>   xen/xsm/flask/Makefile     | 17 +++++++---
>   7 files changed, 85 insertions(+), 35 deletions(-)
>
> diff --git a/xen/Rules.mk b/xen/Rules.mk
> index 21cac7f5f51a..2e28c572305a 100644
> --- a/xen/Rules.mk
> +++ b/xen/Rules.mk
> @@ -56,6 +56,18 @@ SPECIAL_DATA_SECTIONS := rodata $(foreach a,1 2 4 8 16, \
>   
>   include Makefile
>   
> +# Linking
> +# ---------------------------------------------------------------------------
> +
> +quiet_cmd_ld = LD      $@
> +cmd_ld = $(LD) $(XEN_LDFLAGS) -r -o $@ $(real-prereqs)
> +
> +# Objcopy
> +# ---------------------------------------------------------------------------
> +
> +quiet_cmd_objcopy = OBJCOPY $@
> +cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $< $@
> +
>   define gendep
>       ifneq ($(1),$(subst /,:,$(1)))
>           DEPS += $(dir $(1)).$(notdir $(1)).d
> @@ -164,29 +176,47 @@ else
>         $(CC) $(c_flags) -c $< -o $@
>   endif
>   
> -%.o: %.S Makefile
> -       $(CC) $(a_flags) -c $< -o $@
> +quiet_cmd_cc_o_S = CC      $@
> +cmd_cc_o_S = $(CC) $(a_flags) -c $< -o $@
> +
> +%.o: %.S FORCE
> +       $(call if_changed,cc_o_S)
> +
> +
> +quiet_cmd_obj_init_o = INIT_O  $@
> +define cmd_obj_init_o
> +    $(OBJDUMP) -h $< | sed -n '/[0-9]/{s,00*,0,g;p;}' | while read idx name sz 
> rest; do \
> +        case "$$name" in \
> +        .*.local) ;; \
> +        .text|.text.*|.data|.data.*|.bss) \
> +            test $$sz != 0 || continue; \
> +            echo "Error: size of $<:$$name is 0x$$sz" >&2; \
> +            exit $$(expr $$idx + 1);; \
> +        esac; \
> +    done; \
> +    $(OBJCOPY) $(foreach s,$(SPECIAL_DATA_SECTIONS),--rename-section 
> .$(s)=.init.$(s)) $< $@
> +endef
> +
> +$(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): %.init.o: %.o FORCE
> +       $(call if_changed,obj_init_o)
> +
> +quiet_cmd_cpp_i_c = CPP     $@
> +cmd_cpp_i_c = $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) $< -o $@
> +
> +quiet_cmd_cc_s_c = CC      $@
> +cmd_cc_s_c = $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -S $< -o $@
>   
> -$(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): %.init.o: %.o Makefile
> -       $(OBJDUMP) -h $< | sed -n '/[0-9]/{s,00*,0,g;p;}' | while read idx name 
> sz rest; do \
> -               case "$$name" in \
> -               .*.local) ;; \
> -               .text|.text.*|.data|.data.*|.bss) \
> -                       test $$sz != 0 || continue; \
> -                       echo "Error: size of $<:$$name is 0x$$sz" >&2; \
> -                       exit $$(expr $$idx + 1);; \
> -               esac; \
> -       done
> -       $(OBJCOPY) $(foreach s,$(SPECIAL_DATA_SECTIONS),--rename-section 
> .$(s)=.init.$(s)) $< $@
> +quiet_cmd_s_S = CPP     $@
> +cmd_s_S = $(CPP) $(filter-out -Wa$(comma)%,$(a_flags)) $< -o $@
>   
> -%.i: %.c Makefile
> -       $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) $< -o $@
> +%.i: %.c FORCE
> +       $(call if_changed,cpp_i_c)
>   
> -%.s: %.c Makefile
> -       $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -S $< -o $@
> +%.s: %.c FORCE
> +       $(call if_changed,cc_s_c)
>   
> -%.s: %.S Makefile
> -       $(CPP) $(filter-out -Wa$(comma)%,$(a_flags)) $< -o $@
> +%.s: %.S FORCE
> +       $(call if_changed,cpp_s_S)
>   
>   # Add intermediate targets:
>   # When building objects with specific suffix patterns, add intermediate
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 9f1ab2335756..b79ad55646bd 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -97,8 +97,8 @@ prelink_lto.o: $(ALL_OBJS)
>   prelink.o: $(patsubst %/built_in.o,%/built_in_bin.o,$(ALL_OBJS)) prelink_lto.o
>         $(LD) $(XEN_LDFLAGS) -r -o $@ $^
>   else
> -prelink.o: $(ALL_OBJS)
> -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> +prelink.o: $(ALL_OBJS) FORCE
> +       $(call if_changed,ld)
>   endif
>   
>   $(TARGET)-syms: prelink.o xen.lds
> diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
> index a805e9982e85..44137d919b66 100644
> --- a/xen/arch/x86/Makefile
> +++ b/xen/arch/x86/Makefile
> @@ -71,6 +71,7 @@ obj-$(CONFIG_TBOOT) += tboot.o
>   obj-y += hpet.o
>   obj-y += vm_event.o
>   obj-y += xstate.o
> +extra-y += asm-macros.i
>   
>   x86_emulate.o: x86_emulate/x86_emulate.c x86_emulate/x86_emulate.h
>   
> diff --git a/xen/arch/x86/efi/Makefile b/xen/arch/x86/efi/Makefile
> index 490d791aae2d..3e4c395b7535 100644
> --- a/xen/arch/x86/efi/Makefile
> +++ b/xen/arch/x86/efi/Makefile
> @@ -1,7 +1,10 @@
>   CFLAGS-y += -fshort-wchar
>   
> -%.o: %.ihex
> -       $(OBJCOPY) -I ihex -O binary $< $@
> +quiet_cmd_objcopy_o_ihex = OBJCOPY $@
> +cmd_objcopy_o_ihex = $(OBJCOPY) -I ihex -O binary $< $@
> +
> +%.o: %.ihex FORCE
> +       $(call if_changed,objcopy_o_ihex)
>   
>   boot.init.o: buildid.o
>   
> diff --git a/xen/common/libelf/Makefile b/xen/common/libelf/Makefile
> index 464c448d9d37..a92326c982e9 100644
> --- a/xen/common/libelf/Makefile
> +++ b/xen/common/libelf/Makefile
> @@ -1,12 +1,16 @@
>   obj-bin-y := libelf.o
>   nocov-y += libelf.o
> +libelf-objs := libelf-tools.o libelf-loader.o libelf-dominfo.o
>   
>   SECTIONS := text data $(SPECIAL_DATA_SECTIONS)
> +OBJCOPYFLAGS := $(foreach s,$(SECTIONS),--rename-section .$(s)=.init.$(s))
>   
>   CFLAGS-y += -Wno-pointer-sign
>   
> -libelf.o: libelf-temp.o Makefile
> -       $(OBJCOPY) $(foreach s,$(SECTIONS),--rename-section .$(s)=.init.$(s)) 
> $< $@
> +libelf.o: libelf-temp.o FORCE
> +       $(call if_changed,objcopy)
>   
> -libelf-temp.o: libelf-tools.o libelf-loader.o libelf-dominfo.o #libelf-relocate.o
> -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> +libelf-temp.o: $(libelf-objs) FORCE
> +       $(call if_changed,ld)
> +
> +extra-y += libelf-temp.o $(libelf-objs)
> diff --git a/xen/common/libfdt/Makefile b/xen/common/libfdt/Makefile
> index e2a5e59380a0..6bd207cf8ffa 100644
> --- a/xen/common/libfdt/Makefile
> +++ b/xen/common/libfdt/Makefile
> @@ -1,14 +1,17 @@
>   include Makefile.libfdt
>   
>   SECTIONS := text data $(SPECIAL_DATA_SECTIONS)
> +OBJCOPYFLAGS := $(foreach s,$(SECTIONS),--rename-section .$(s)=.init.$(s))
>   
>   obj-y += libfdt.o
>   nocov-y += libfdt.o
>   
>   CFLAGS-y += -I$(BASEDIR)/include/xen/libfdt/
>   
> -libfdt.o: libfdt-temp.o Makefile
> -       $(OBJCOPY) $(foreach s,$(SECTIONS),--rename-section .$(s)=.init.$(s)) 
> $< $@
> +libfdt.o: libfdt-temp.o FORCE
> +       $(call if_changed,objcopy)
>   
> -libfdt-temp.o: $(LIBFDT_OBJS)
> -       $(LD) $(XEN_LDFLAGS) -r -o $@ $^
> +libfdt-temp.o: $(LIBFDT_OBJS) FORCE
> +       $(call if_changed,ld)
> +
> +extra-y += libfdt-temp.o $(LIBFDT_OBJS)
> diff --git a/xen/xsm/flask/Makefile b/xen/xsm/flask/Makefile
> index 6db396347b1f..eebfceecc5fb 100644
> --- a/xen/xsm/flask/Makefile
> +++ b/xen/xsm/flask/Makefile
> @@ -20,12 +20,21 @@ AV_H_FILES = include/av_perm_to_string.h 
> include/av_permissions.h
>   ALL_H_FILES = $(FLASK_H_FILES) $(AV_H_FILES)
>   
>   $(obj-y) ss/built_in.o: $(ALL_H_FILES)
> +extra-y += $(ALL_H_FILES)
>   
> -$(subst include/,%/,$(FLASK_H_FILES)): $(FLASK_H_DEPEND)
> -       $(CONFIG_SHELL) policy/mkflask.sh $(AWK) include $(FLASK_H_DEPEND)
> +mkflask := policy/mkflask.sh
> +quiet_cmd_mkflask = MKFLASK $@
> +cmd_mkflask = $(CONFIG_SHELL) $(mkflask) $(AWK) include $(FLASK_H_DEPEND)
>   
> -$(subst include/,%/,$(AV_H_FILES)): $(AV_H_DEPEND)
> -       $(CONFIG_SHELL) policy/mkaccess_vector.sh $(AWK) $(AV_H_DEPEND)
> +$(subst include/,%/,$(FLASK_H_FILES)): $(FLASK_H_DEPEND) $(mkflask) FORCE
> +       $(call if_changed,mkflask)
> +
> +mkaccess := policy/mkaccess_vector.sh
> +quiet_cmd_mkaccess = MKACCESS VECTOR $@
> +cmd_mkaccess = $(CONFIG_SHELL) $(mkaccess) $(AWK) $(AV_H_DEPEND)
> +
> +$(subst include/,%/,$(AV_H_FILES)): $(AV_H_DEPEND) $(mkaccess) FORCE
> +       $(call if_changed,mkaccess)
>   
>   obj-bin-$(CONFIG_XSM_FLASK_POLICY) += flask-policy.o
>   flask-policy.o: policy.bin
--
Julien Grall