From 54a702f70589926acf687f0cd5df24d07230c80e Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 23 Mar 2018 22:04:39 +0900 Subject: [PATCH] kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers GNU Make automatically deletes intermediate files that are updated in a chain of pattern rules. Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts Example 2) %.o <- %.c <- %.c_shipped A couple of makefiles mark such targets as .PRECIOUS to prevent Make from deleting them, but the correct way is to use .SECONDARY. .SECONDARY Prerequisites of this special target are treated as intermediate files but are never automatically deleted. .PRECIOUS When make is interrupted during execution, it may delete the target file it is updating if the file was modified since make started. If you mark the file as precious, make will never delete the file if interrupted. Both can avoid deletion of intermediate files, but the difference is the behavior when Make is interrupted; .SECONDARY deletes the target, but .PRECIOUS does not. The use of .PRECIOUS is relatively rare since we do not want to keep partially constructed (possibly corrupted) targets. Another difference is that .PRECIOUS works with pattern rules whereas .SECONDARY does not. .PRECIOUS: $(obj)/%.lex.c works, but .SECONDARY: $(obj)/%.lex.c has no effect. However, for the reason above, I do not want to use .PRECIOUS which could cause obscure build breakage. The targets specified as .SECONDARY must be explicit. $(targets) contains all targets that need to include .*.cmd files. So, the intermediates you want to keep are mostly in there. Therefore, mark $(targets) as .SECONDARY. It means primary targets are also marked as .SECONDARY, but I do not see any drawback for this. I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This will make Kbuild search for non-existing .*.cmd files, but this is not a noticeable performance issue. Signed-off-by: Masahiro Yamada Acked-by: Frank Rowand Acked-by: Ingo Molnar --- arch/arc/boot/dts/Makefile | 2 -- arch/arm/crypto/Makefile | 2 +- arch/arm64/crypto/Makefile | 2 +- arch/sparc/vdso/Makefile | 4 +--- arch/x86/entry/vdso/Makefile | 4 +--- drivers/of/unittest-data/Makefile | 4 ---- scripts/Makefile.build | 10 +++++++--- scripts/Makefile.lib | 3 --- 8 files changed, 11 insertions(+), 20 deletions(-) diff --git a/arch/arc/boot/dts/Makefile b/arch/arc/boot/dts/Makefile index 22a4c5d4702f..a83c4f5e928b 100644 --- a/arch/arc/boot/dts/Makefile +++ b/arch/arc/boot/dts/Makefile @@ -9,8 +9,6 @@ endif obj-y += $(builtindtb-y).dtb.o dtb-y := $(builtindtb-y).dtb -.SECONDARY: $(obj)/$(builtindtb-y).dtb.S - # for CONFIG_OF_ALL_DTBS test dtstree := $(srctree)/$(src) dtb- := $(patsubst $(dtstree)/%.dts,%.dtb, $(wildcard $(dtstree)/*.dts)) diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile index 3304e671918d..8de542c48ade 100644 --- a/arch/arm/crypto/Makefile +++ b/arch/arm/crypto/Makefile @@ -67,4 +67,4 @@ $(src)/sha512-core.S_shipped: $(src)/sha512-armv4.pl $(call cmd,perl) endif -.PRECIOUS: $(obj)/sha256-core.S $(obj)/sha512-core.S +targets += sha256-core.S sha512-core.S diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile index 8df9f326f449..f35ac684b1c0 100644 --- a/arch/arm64/crypto/Makefile +++ b/arch/arm64/crypto/Makefile @@ -78,4 +78,4 @@ $(src)/sha512-core.S_shipped: $(src)/sha512-armv8.pl $(call cmd,perlasm) endif -.PRECIOUS: $(obj)/sha256-core.S $(obj)/sha512-core.S +targets += sha256-core.S sha512-core.S diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile index a6615d8864f7..dd0b5a92ffd0 100644 --- a/arch/sparc/vdso/Makefile +++ b/arch/sparc/vdso/Makefile @@ -29,9 +29,7 @@ vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c) vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg) obj-y += $(vdso_img_objs) targets += $(vdso_img_cfiles) -targets += $(vdso_img_sodbg) -.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \ - $(vdso_img-y:%=$(obj)/vdso%.so) +targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so) export CPPFLAGS_vdso.lds += -P -C diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index 1943aebadede..d998a487c9b1 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -42,9 +42,7 @@ vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c) vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg) obj-y += $(vdso_img_objs) targets += $(vdso_img_cfiles) -targets += $(vdso_img_sodbg) -.SECONDARY: $(vdso_img-y:%=$(obj)/vdso-image-%.c) \ - $(vdso_img-y:%=$(obj)/vdso%.so) +targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so) export CPPFLAGS_vdso.lds += -P -C diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile index 87a65ca38583..013d85e694c6 100644 --- a/drivers/of/unittest-data/Makefile +++ b/drivers/of/unittest-data/Makefile @@ -30,7 +30,3 @@ DTC_FLAGS_testcases += -@ # suppress warnings about intentional errors DTC_FLAGS_testcases += -Wno-interrupts_property - -.PRECIOUS: \ - $(obj)/%.dtb.S \ - $(obj)/%.dtb diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 8c3ca611b978..8bdb1dc4072c 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -430,8 +430,6 @@ quiet_cmd_asn1_compiler = ASN.1 $@ cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ $(subst .h,.c,$@) $(subst .c,.h,$@) -.PRECIOUS: $(objtree)/$(obj)/%.asn1.c $(objtree)/$(obj)/%.asn1.h - $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler $(call cmd,asn1_compiler) @@ -544,10 +542,12 @@ targets := $(filter-out $(PHONY), $(targets)) intermediate_targets = $(foreach sfx, $(2), \ $(patsubst %$(strip $(1)),%$(sfx), \ $(filter %$(strip $(1)), $(targets)))) +# %.asn1.o <- %.asn1.[ch] <- %.asn1 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts # %.lex.o <- %.lex.c <- %.l # %.tab.o <- %.tab.[ch] <- %.y -targets += $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \ +targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \ + $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \ $(call intermediate_targets, .lex.o, .lex.c) \ $(call intermediate_targets, .tab.o, .tab.c .tab.h) @@ -587,6 +587,10 @@ $(shell mkdir -p $(obj-dirs)) endif endif +# Some files contained in $(targets) are intermediate artifacts. +# We never want them to be removed automatically. +.SECONDARY: $(targets) + # Declare the contents of the .PHONY variable as phony. We keep that # information in a variable se we can use it in if_changed and friends. diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 7f5bca0c3b7b..07d07409f16f 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -184,7 +184,6 @@ endef quiet_cmd_flex = LEX $@ cmd_flex = $(LEX) -o$@ -L $< -.PRECIOUS: $(obj)/%.lex.c $(obj)/%.lex.c: $(src)/%.l FORCE $(call if_changed,flex) @@ -193,14 +192,12 @@ $(obj)/%.lex.c: $(src)/%.l FORCE quiet_cmd_bison = YACC $@ cmd_bison = $(YACC) -o$@ -t -l $< -.PRECIOUS: $(obj)/%.tab.c $(obj)/%.tab.c: $(src)/%.y FORCE $(call if_changed,bison) quiet_cmd_bison_h = YACC $@ cmd_bison_h = bison -o/dev/null --defines=$@ -t -l $< -.PRECIOUS: $(obj)/%.tab.h $(obj)/%.tab.h: $(src)/%.y FORCE $(call if_changed,bison_h)