Based on the following Linux commits:
- 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers")
- 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include")
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.
.SECONDARY with no prerequisites causes all targets to be treated as secondary. This agrees the policy of Kbuild.
scripts/Kbuild.include seems a suitable place to add it because it is included from almost all sub-makes.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
dts/Makefile | 3 --- examples/standalone/Makefile | 1 - post/lib_powerpc/fpu/Makefile | 3 --- scripts/Kbuild.include | 3 +++ scripts/Makefile.build | 2 -- scripts/Makefile.lib | 3 --- 6 files changed, 3 insertions(+), 12 deletions(-)
diff --git a/dts/Makefile b/dts/Makefile index cd6e9a9..a7a6043 100644 --- a/dts/Makefile +++ b/dts/Makefile @@ -43,9 +43,6 @@ endif arch-dtbs: $(Q)$(MAKE) $(build)=$(ARCH_PATH) dtbs
-.SECONDARY: $(obj)/dt.dtb.S $(obj)/dt-spl.dtb.S - - ifeq ($(CONFIG_SPL_BUILD),y) obj-$(CONFIG_OF_EMBED) := dt-spl.dtb.o # support "out-of-tree" build for dtb-spl diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile index f01816f..0b17a91 100644 --- a/examples/standalone/Makefile +++ b/examples/standalone/Makefile @@ -26,7 +26,6 @@ LIB = $(obj)/libstubs.o LIBOBJS-$(CONFIG_PPC) += ppc_longjmp.o ppc_setjmp.o LIBOBJS-y += stubs.o
-.SECONDARY: $(call objectify,$(COBJS)) targets += $(patsubst $(obj)/%,%,$(LIB)) $(COBJS) $(LIBOBJS-y)
LIBOBJS := $(addprefix $(obj)/,$(LIBOBJS-y)) diff --git a/post/lib_powerpc/fpu/Makefile b/post/lib_powerpc/fpu/Makefile index 404eefc..9b2c1fa 100644 --- a/post/lib_powerpc/fpu/Makefile +++ b/post/lib_powerpc/fpu/Makefile @@ -11,9 +11,6 @@ targets += $(objs-before-objcopy) $(foreach m, $(objs-before-objcopy), $(eval CFLAGS_REMOVE_$m := -msoft-float)) ccflags-y := -mhard-float -fkeep-inline-functions
-# Do not delete intermidiate files (*.o) -.SECONDARY: $(call objectify, $(objs-before-objcopy)) - obj-y := $(objs-before-objcopy:.o=_.o)
OBJCOPYFLAGS := -R .gnu.attributes diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 460acd6..b8969e2 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -318,6 +318,9 @@ endif # delete partially updated (i.e. corrupted) files on error .DELETE_ON_ERROR:
+# do not delete intermediate files automatically +.SECONDARY: + ifdef CONFIG_SPL_BUILD SPL_ := SPL_ ifeq ($(CONFIG_TPL_BUILD),y) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 482ed0c..f7a0412 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -331,8 +331,6 @@ 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)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index a4f16bb..a5b57fc 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -214,7 +214,6 @@ endef quiet_cmd_flex = LEX $@ cmd_flex = $(LEX) -o$@ -L $<
-.PRECIOUS: $(obj)/%.lex.c $(obj)/%.lex.c: $(src)/%.l FORCE $(call if_changed,flex)
@@ -223,14 +222,12 @@ $(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 = $(YACC) -o/dev/null --defines=$@ -t -l $<
-.PRECIOUS: $(obj)/%.tab.h $(obj)/%.tab.h: $(src)/%.y FORCE $(call if_changed,bison_h)