[PATCH v2 3/4] kbuild: add real-prereqs shorthand for $(filter-out FORCE,$^)

Masahiro Yamada
2019-01-17T10:02:43Z

In Kbuild, if_changed and friends must have FORCE as a prerequisite.

Hence, $(filter-out FORCE,$^) or $(filter-out $(PHONY),$^) is a common
pattern to get the names of all the prerequisites except phony targets.

Add real-prereqs as a shorthand.

Note:
We cannot replace $(filter %.o,$^) in cmd_link_multi-m because $^ may
include auto-generated dependencies from the .*.cmd file when a single
object module is changed into a multi object module. Refer to commit
69ea912fda74 ("kbuild: remove unneeded link_multi_deps"). I added some
comment to avoid accidental breakage.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

The patch context depends on some other ones.
Please use 'git am -C1' if you want to test this
on Linus' tree.

Changes in v2:
- clean up arch/s390/boot/Makefile as well

Documentation/devicetree/bindings/Makefile | 2 +-
arch/mips/boot/Makefile | 2 +-
arch/powerpc/boot/Makefile | 2 +-
arch/s390/boot/Makefile | 2 +-
arch/x86/realmode/rm/Makefile | 3 +--
scripts/Kbuild.include | 4 ++++
scripts/Makefile.build | 9 ++++++---
scripts/Makefile.lib | 18 +++++++++---------
scripts/Makefile.modpost | 2 +-
9 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
index 6e5cef0..e4eb5d1 100644
--- a/Documentation/devicetree/bindings/Makefile
+++ b/Documentation/devicetree/bindings/Makefile
@@ -15,7 +15,7 @@ DT_TMP_SCHEMA := processed-schema.yaml
extra-y += $(DT_TMP_SCHEMA)

quiet_cmd_mk_schema = SCHEMA $@
- cmd_mk_schema = $(DT_MK_SCHEMA) $(DT_MK_SCHEMA_FLAGS) -o $@ $(filter-out FORCE, $^)
+ cmd_mk_schema = $(DT_MK_SCHEMA) $(DT_MK_SCHEMA_FLAGS) -o $@ $(real-prereqs)

DT_DOCS = $(shell cd $(srctree)/$(src) && find * -name '*.yaml')
DT_SCHEMA_FILES ?= $(addprefix $(src)/,$(DT_DOCS))
diff --git a/arch/mips/boot/Makefile b/arch/mips/boot/Makefile
index 35704c2..3ce4dd5 100644
--- a/arch/mips/boot/Makefile
+++ b/arch/mips/boot/Makefile
@@ -115,7 +115,7 @@ endif
targets += vmlinux.its.S

quiet_cmd_its_cat = CAT $@
- cmd_its_cat = cat $(filter-out $(PHONY), $^) >$@
+ cmd_its_cat = cat $(real-prereqs) >$@

$(obj)/vmlinux.its.S: $(addprefix $(srctree)/arch/mips/$(PLATFORM)/,$(ITS_INPUTS)) FORCE
$(call if_changed,its_cat)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 0e8dadd..73d1f35 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -218,7 +218,7 @@ quiet_cmd_bootas = BOOTAS $@
cmd_bootas = $(BOOTCC) -Wp,-MD,$(depfile) $(BOOTAFLAGS) -c -o $@ $<

quiet_cmd_bootar = BOOTAR $@
- cmd_bootar = $(BOOTAR) $(BOOTARFLAGS) $@.$$$$ $(filter-out FORCE,$^); mv $@.$$$$ $@
+ cmd_bootar = $(BOOTAR) $(BOOTARFLAGS) $@.$$$$ $(real-prereqs); mv $@.$$$$ $@

$(obj-libfdt): $(obj)/%.o: $(srctree)/scripts/dtc/libfdt/%.c FORCE
$(call if_changed_dep,bootcc)
diff --git a/arch/s390/boot/Makefile b/arch/s390/boot/Makefile
index b4d8a42..11ca879 100644
--- a/arch/s390/boot/Makefile
+++ b/arch/s390/boot/Makefile
@@ -58,7 +58,7 @@ $(obj)/compressed/vmlinux: $(obj)/startup.a FORCE
$(Q)$(MAKE) $(build)=$(obj)/compressed $@

quiet_cmd_ar = AR $@
- cmd_ar = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(filter $(OBJECTS), $^)
+ cmd_ar = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)

$(obj)/startup.a: $(OBJECTS) FORCE
$(call if_changed,ar)
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index 4463fa7..394377c 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -37,8 +37,7 @@ REALMODE_OBJS = $(addprefix $(obj)/,$(realmode-y))
sed-pasyms := -n -r -e 's/^([0-9a-fA-F]+) [ABCDGRSTVW] (.+)$$/pa_\2 = \2;/p'

quiet_cmd_pasyms = PASYMS $@
- cmd_pasyms = $(NM) $(filter-out FORCE,$^) | \
- sed $(sed-pasyms) | sort | uniq > $@
+ cmd_pasyms = $(NM) $(real-prereqs) | sed $(sed-pasyms) | sort | uniq > $@

targets += pasyms.h
$(obj)/pasyms.h: $(REALMODE_OBJS) FORCE
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 3081603..d93250b 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -24,6 +24,10 @@ depfile = $(subst $(comma),_,$(dot-target).d)
basetarget = $(basename $(notdir $@))

###
+# real prerequisites without phony targets
+real-prereqs = $(filter-out $(PHONY), $^)
+
+###
# Escape single quote for use in echo statements
escsq = $(subst $(squote),'\$(squote)',$1)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 681ab58..9800178 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -399,8 +399,7 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
ifdef builtin-target

quiet_cmd_ar_builtin = AR $@
- cmd_ar_builtin = rm -f $@; \
- $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(filter $(real-obj-y), $^)
+ cmd_ar_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)

$(builtin-target): $(real-obj-y) FORCE
$(call if_changed,ar_builtin)
@@ -428,7 +427,7 @@ ifdef lib-target
quiet_cmd_link_l_target = AR $@

# lib target archives do get a symbol table and index
-cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
+cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(real-prereqs)

$(lib-target): $(lib-y) FORCE
$(call if_changed,link_l_target)
@@ -453,6 +452,10 @@ targets += $(obj)/lib-ksyms.o

endif

+# NOTE:
+# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
+# module is turned into a multi object module, $^ will contain header file
+# dependencies recorded in the .*.cmd file.
quiet_cmd_link_multi-m = LD [M] $@
cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) $(cmd_secanalysis)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index ebaa348..c6fc295 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -231,7 +231,7 @@ $(obj)/%: $(src)/%_shipped
# ---------------------------------------------------------------------------

quiet_cmd_ld = LD $@
-cmd_ld = $(LD) $(ld_flags) $(filter-out FORCE,$^) -o $@
+ cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@

# Objcopy
# ---------------------------------------------------------------------------
@@ -243,7 +243,7 @@ cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
# ---------------------------------------------------------------------------

quiet_cmd_gzip = GZIP $@
- cmd_gzip = cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@
+ cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@

# DTC
# ---------------------------------------------------------------------------
@@ -321,7 +321,7 @@ dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
# append the size as a 32-bit littleendian number as gzip does.
size_append = printf $(shell \
dec_size=0; \
-for F in $(filter-out FORCE,$^); do \
+for F in $(real-prereqs); do \
fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
dec_size=$$(expr $$dec_size + $$fsize); \
done; \
@@ -335,19 +335,19 @@ printf "%08x\n" $$dec_size | \
)

quiet_cmd_bzip2 = BZIP2 $@
- cmd_bzip2 = (cat $(filter-out FORCE,$^) | bzip2 -9 && $(size_append)) > $@
+ cmd_bzip2 = (cat $(real-prereqs) | bzip2 -9 && $(size_append)) > $@

# Lzma
# ---------------------------------------------------------------------------

quiet_cmd_lzma = LZMA $@
- cmd_lzma = (cat $(filter-out FORCE,$^) | lzma -9 && $(size_append)) > $@
+ cmd_lzma = (cat $(real-prereqs) | lzma -9 && $(size_append)) > $@

quiet_cmd_lzo = LZO $@
- cmd_lzo = (cat $(filter-out FORCE,$^) | lzop -9 && $(size_append)) > $@
+ cmd_lzo = (cat $(real-prereqs) | lzop -9 && $(size_append)) > $@

quiet_cmd_lz4 = LZ4 $@
- cmd_lz4 = (cat $(filter-out FORCE,$^) | lz4c -l -c1 stdin stdout && \
+ cmd_lz4 = (cat $(real-prereqs) | lz4c -l -c1 stdin stdout && \
$(size_append)) > $@

# U-Boot mkimage
@@ -390,11 +390,11 @@ quiet_cmd_uimage = UIMAGE $@
# big dictionary would increase the memory usage too much in the multi-call
# decompression mode. A BCJ filter isn't used either.
quiet_cmd_xzkern = XZKERN $@
-cmd_xzkern = (cat $(filter-out FORCE,$^) | \
+ cmd_xzkern = (cat $(real-prereqs) | \
sh $(srctree)/scripts/xz_wrap.sh && $(size_append)) > $@

quiet_cmd_xzmisc = XZMISC $@
-cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
+ cmd_xzmisc = (cat $(real-prereqs) | \
xz --check=crc32 --lzma2=dict=1MiB) > $@

# ASM offsets
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 7d4af0d0..c0b7f52 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -122,7 +122,7 @@ quiet_cmd_ld_ko_o = LD [M] $@
cmd_ld_ko_o = \
$(LD) -r $(KBUILD_LDFLAGS) \
$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
- -o $@ $(filter-out FORCE,$^) ; \
+ -o $@ $(real-prereqs) ; \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)

$(modules): %.ko :%.o %.mod.o FORCE
--
2.7.4