kbuild: rename built-in.o to built-in.a

Incremental linking is gone, so rename built-in.o to built-in.a, which
is the usual extension for archive files.

This patch does two things, first is a simple search/replace:

git grep -l 'built-in\.o' | xargs sed -i 's/built-in\.o/built-in\.a/g'

The second is to invert nesting of nested text manipulations to avoid
filtering built-in.a out from libs-y2:

-libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.a, $(libs-y)))
+libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/Makefile.build

@@ -77,7 +77,7 @@ obj-y += $(obj)/lib-ksyms.o
 endif
 
 ifneq ($(strip $(obj-y) $(need-builtin)),)
-builtin-target := $(obj)/built-in.o
+builtin-target := $(obj)/built-in.a
 endif
 
 modorder-target := $(obj)/modules.order
@@ -104,7 +104,7 @@ ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
   cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
 endif
 
-# Do section mismatch analysis for each module/built-in.o
+# Do section mismatch analysis for each module/built-in.a
 ifdef CONFIG_DEBUG_SECTION_MISMATCH
   cmd_secanalysis = ; scripts/mod/modpost $@
 endif
@@ -458,15 +458,15 @@ $(sort $(subdir-obj-y)): $(subdir-ym) ;
 #
 ifdef builtin-target
 
-# built-in.o archives are made with no symbol table or index which
+# built-in.a archives are made with no symbol table or index which
 # makes them small and fast, but unable to be used by the linker.
-# scripts/link-vmlinux.sh builds an aggregate built-in.o with a symbol
+# scripts/link-vmlinux.sh builds an aggregate built-in.a with a symbol
 # table and index.
 cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
 cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS)
 quiet_cmd_link_o_target = AR      $@
 
-# If the list of objects to link is empty, just create an empty built-in.o
+# If the list of objects to link is empty, just create an empty built-in.a
 cmd_link_o_target = $(if $(strip $(obj-y)),\
 		      $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
 		      $(cmd_secanalysis),\

scripts/Makefile.lib

@@ -27,7 +27,7 @@ modorder	:= $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko
 
 # Handle objects in subdirs
 # ---------------------------------------------------------------------------
-# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o
+# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.a
 #   and add the directory to the list of dirs to descend into: $(subdir-y)
 # o if we encounter foo/ in $(obj-m), remove it from $(obj-m)
 #   and add the directory to the list of dirs to descend into: $(subdir-m)
@@ -35,7 +35,7 @@ __subdir-y	:= $(patsubst %/,%,$(filter %/, $(obj-y)))
 subdir-y	+= $(__subdir-y)
 __subdir-m	:= $(patsubst %/,%,$(filter %/, $(obj-m)))
 subdir-m	+= $(__subdir-m)
-obj-y		:= $(patsubst %/, %/built-in.o, $(obj-y))
+obj-y		:= $(patsubst %/, %/built-in.a, $(obj-y))
 obj-m		:= $(filter-out %/, $(obj-m))
 
 # Subdirectories we need to descend into
@@ -54,7 +54,7 @@ multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y)))
 
 # $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to
 # tell kbuild to descend
-subdir-obj-y := $(filter %/built-in.o, $(obj-y))
+subdir-obj-y := $(filter %/built-in.a, $(obj-y))
 
 # Replace multi-part objects by their individual parts, look at local dir only
 real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))

scripts/link-vmlinux.sh

@@ -4,7 +4,7 @@
 # link vmlinux
 #
 # vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
-# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.o files
+# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.a files
 # from top-level directories in the kernel tree, others are specified in
 # arch/$(ARCH)/Makefile. Ordering when linking is important, and
 # $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives
@@ -18,7 +18,7 @@
 #   |   +--< init/version.o + more
 #   |
 #   +--< $(KBUILD_VMLINUX_MAIN)
-#   |    +--< drivers/built-in.o mm/built-in.o + more
+#   |    +--< drivers/built-in.a mm/built-in.a + more
 #   |
 #   +--< $(KBUILD_VMLINUX_LIBS)
 #   |    +--< lib/lib.a + more
@@ -51,13 +51,13 @@ info()
 #
 # Traditional incremental style of link does not require this step
 #
-# built-in.o output file
+# built-in.a output file
 #
 archive_builtin()
 {
-	info AR built-in.o
-	rm -f built-in.o;
-	${AR} rcsTP${KBUILD_ARFLAGS} built-in.o			\
+	info AR built-in.a
+	rm -f built-in.a;
+	${AR} rcsTP${KBUILD_ARFLAGS} built-in.a			\
 				${KBUILD_VMLINUX_INIT}		\
 				${KBUILD_VMLINUX_MAIN}
 }
@@ -69,7 +69,7 @@ modpost_link()
 	local objects
 
 	objects="--whole-archive				\
-		built-in.o					\
+		built-in.a					\
 		--no-whole-archive				\
 		--start-group					\
 		${KBUILD_VMLINUX_LIBS}				\
@@ -88,7 +88,7 @@ vmlinux_link()
 
 	if [ "${SRCARCH}" != "um" ]; then
 		objects="--whole-archive			\
-			built-in.o				\
+			built-in.a				\
 			--no-whole-archive			\
 			--start-group				\
 			${KBUILD_VMLINUX_LIBS}			\
@@ -99,7 +99,7 @@ vmlinux_link()
 			-T ${lds} ${objects}
 	else
 		objects="-Wl,--whole-archive			\
-			built-in.o				\
+			built-in.a				\
 			-Wl,--no-whole-archive			\
 			-Wl,--start-group			\
 			${KBUILD_VMLINUX_LIBS}			\
@@ -164,7 +164,7 @@ cleanup()
 	rm -f .tmp_System.map
 	rm -f .tmp_kallsyms*
 	rm -f .tmp_vmlinux*
-	rm -f built-in.o
+	rm -f built-in.a
 	rm -f System.map
 	rm -f vmlinux
 	rm -f vmlinux.o

scripts/namespace.pl

@@ -164,7 +164,7 @@ sub linux_objects
 	s:^\./::;
 	if (/.*\.o$/ &&
 		! (
-		m:/built-in.o$:
+		m:/built-in.a$:
 		|| m:arch/x86/vdso/:
 		|| m:arch/x86/boot/:
 		|| m:arch/ia64/ia32/ia32.o$: