| Message ID | 1521810279-6282-10-git-send-email-yamada.masahiro@socionext.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/23/18 06:04, Masahiro Yamada wrote: > GNU Make automatically deletes intermediate files that are updated > in a chain of pattern rules. > > Example 1) %.dtb.o <- %.dtb.S <- %.dtb.S <- %.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 to avoid 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 likely to be contained in > $(targets). So, mark it as .SECONDARY. The exception is when they > are created by $(call cmd,...) instead of $(call if_changed,...) > since the former does not need to include .*.cmd file. In this > case, makefiles need to mark them .SECONDARY by themselves, like > arch/arm(64)/crypto/Makefile. > > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Frank Rowand <frowand.list@gmail.com> -Frank > --- > > arch/arc/boot/dts/Makefile | 2 -- > arch/arm/crypto/Makefile | 2 +- > arch/arm64/crypto/Makefile | 2 +- > arch/metag/boot/dts/Makefile | 2 -- > drivers/of/unittest-data/Makefile | 4 ---- > scripts/Makefile.build | 6 ++++-- > scripts/Makefile.lib | 3 --- > 7 files changed, 6 insertions(+), 15 deletions(-) > > diff --git a/arch/arc/boot/dts/Makefile b/arch/arc/boot/dts/Makefile > index 22a4c5d..a83c4f5 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 30ef8e2..3d59567 100644 > --- a/arch/arm/crypto/Makefile > +++ b/arch/arm/crypto/Makefile > @@ -63,4 +63,4 @@ $(src)/sha256-core.S_shipped: $(src)/sha256-armv4.pl > $(src)/sha512-core.S_shipped: $(src)/sha512-armv4.pl > $(call cmd,perl) > > -.PRECIOUS: $(obj)/sha256-core.S $(obj)/sha512-core.S > +.SECONDARY: $(obj)/sha256-core.S $(obj)/sha512-core.S > diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile > index cee9b8d9..fceb638 100644 > --- a/arch/arm64/crypto/Makefile > +++ b/arch/arm64/crypto/Makefile > @@ -76,4 +76,4 @@ $(src)/sha256-core.S_shipped: $(src)/sha512-armv8.pl > $(src)/sha512-core.S_shipped: $(src)/sha512-armv8.pl > $(call cmd,perlasm) > > -.PRECIOUS: $(obj)/sha256-core.S $(obj)/sha512-core.S > +.SECONDARY: $(obj)/sha256-core.S $(obj)/sha512-core.S > diff --git a/arch/metag/boot/dts/Makefile b/arch/metag/boot/dts/Makefile > index f0a180f..16505aa 100644 > --- a/arch/metag/boot/dts/Makefile > +++ b/arch/metag/boot/dts/Makefile > @@ -12,5 +12,3 @@ endif > > dtb-$(CONFIG_METAG_BUILTIN_DTB) += $(builtindtb-y).dtb > obj-$(CONFIG_METAG_BUILTIN_DTB) += $(builtindtb-y).dtb.o > - > -.SECONDARY: $(obj)/$(builtindtb-y).dtb.S > diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile > index 333bc4c..0fb87cb 100644 > --- a/drivers/of/unittest-data/Makefile > +++ b/drivers/of/unittest-data/Makefile > @@ -12,7 +12,3 @@ DTC_FLAGS_overlay := -@ > DTC_FLAGS_overlay_bad_phandle := -@ > DTC_FLAGS_overlay_bad_symbol := -@ > DTC_FLAGS_overlay_base := -@ > - > -.PRECIOUS: \ > - $(obj)/%.dtb.S \ > - $(obj)/%.dtb > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > index cc081af..4397adb 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 FORCE > $(call if_changed,asn1_compiler) > @@ -590,6 +588,10 @@ $(shell mkdir -p $(obj-dirs)) > endif > endif > > +# Some 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 7a1fa92..c114ce5 100644 > --- a/scripts/Makefile.lib > +++ b/scripts/Makefile.lib > @@ -183,7 +183,6 @@ endef > quiet_cmd_flex = LEX $@ > cmd_flex = $(LEX) -o$@ -L $< > > -.PRECIOUS: $(obj)/%.lex.c > $(obj)/%.lex.c: $(src)/%.l FORCE > $(call if_changed,flex) > > @@ -192,14 +191,12 @@ $(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) > > -- 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/arch/arc/boot/dts/Makefile b/arch/arc/boot/dts/Makefile index 22a4c5d..a83c4f5 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 30ef8e2..3d59567 100644 --- a/arch/arm/crypto/Makefile +++ b/arch/arm/crypto/Makefile @@ -63,4 +63,4 @@ $(src)/sha256-core.S_shipped: $(src)/sha256-armv4.pl $(src)/sha512-core.S_shipped: $(src)/sha512-armv4.pl $(call cmd,perl) -.PRECIOUS: $(obj)/sha256-core.S $(obj)/sha512-core.S +.SECONDARY: $(obj)/sha256-core.S $(obj)/sha512-core.S diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile index cee9b8d9..fceb638 100644 --- a/arch/arm64/crypto/Makefile +++ b/arch/arm64/crypto/Makefile @@ -76,4 +76,4 @@ $(src)/sha256-core.S_shipped: $(src)/sha512-armv8.pl $(src)/sha512-core.S_shipped: $(src)/sha512-armv8.pl $(call cmd,perlasm) -.PRECIOUS: $(obj)/sha256-core.S $(obj)/sha512-core.S +.SECONDARY: $(obj)/sha256-core.S $(obj)/sha512-core.S diff --git a/arch/metag/boot/dts/Makefile b/arch/metag/boot/dts/Makefile index f0a180f..16505aa 100644 --- a/arch/metag/boot/dts/Makefile +++ b/arch/metag/boot/dts/Makefile @@ -12,5 +12,3 @@ endif dtb-$(CONFIG_METAG_BUILTIN_DTB) += $(builtindtb-y).dtb obj-$(CONFIG_METAG_BUILTIN_DTB) += $(builtindtb-y).dtb.o - -.SECONDARY: $(obj)/$(builtindtb-y).dtb.S diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile index 333bc4c..0fb87cb 100644 --- a/drivers/of/unittest-data/Makefile +++ b/drivers/of/unittest-data/Makefile @@ -12,7 +12,3 @@ DTC_FLAGS_overlay := -@ DTC_FLAGS_overlay_bad_phandle := -@ DTC_FLAGS_overlay_bad_symbol := -@ DTC_FLAGS_overlay_base := -@ - -.PRECIOUS: \ - $(obj)/%.dtb.S \ - $(obj)/%.dtb diff --git a/scripts/Makefile.build b/scripts/Makefile.build index cc081af..4397adb 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 FORCE $(call if_changed,asn1_compiler) @@ -590,6 +588,10 @@ $(shell mkdir -p $(obj-dirs)) endif endif +# Some 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 7a1fa92..c114ce5 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -183,7 +183,6 @@ endef quiet_cmd_flex = LEX $@ cmd_flex = $(LEX) -o$@ -L $< -.PRECIOUS: $(obj)/%.lex.c $(obj)/%.lex.c: $(src)/%.l FORCE $(call if_changed,flex) @@ -192,14 +191,12 @@ $(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)
GNU Make automatically deletes intermediate files that are updated in a chain of pattern rules. Example 1) %.dtb.o <- %.dtb.S <- %.dtb.S <- %.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 to avoid 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 likely to be contained in $(targets). So, mark it as .SECONDARY. The exception is when they are created by $(call cmd,...) instead of $(call if_changed,...) since the former does not need to include .*.cmd file. In this case, makefiles need to mark them .SECONDARY by themselves, like arch/arm(64)/crypto/Makefile. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> --- arch/arc/boot/dts/Makefile | 2 -- arch/arm/crypto/Makefile | 2 +- arch/arm64/crypto/Makefile | 2 +- arch/metag/boot/dts/Makefile | 2 -- drivers/of/unittest-data/Makefile | 4 ---- scripts/Makefile.build | 6 ++++-- scripts/Makefile.lib | 3 --- 7 files changed, 6 insertions(+), 15 deletions(-)