[PATCH 1/5] kbuild: remove ifdef builtin-target / lib-target

[PATCH 1/5] kbuild: remove ifdef builtin-target / lib-target

[Masahiro Yamada]

I do not see a good reason to add ifdef here.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/Makefile.build | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 3665b1a0bc8e..9af88f4cacb8 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -384,16 +384,14 @@ $(obj)/%/built-in.a: $(obj)/% ;
 #
 # Rule to compile a set of .o files into one .a file (without symbol table)
 #
-ifdef builtin-target
 
 quiet_cmd_ar_builtin = AR      $@
       cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
 
-$(builtin-target): $(real-obj-y) FORCE
+$(obj)/built-in.a: $(real-obj-y) FORCE
 	$(call if_changed,ar_builtin)
 
 targets += $(builtin-target)
-endif # builtin-target
 
 #
 # Rule to create modules.order file
@@ -408,15 +406,11 @@ $(modorder-target): $(subdir-ym) FORCE
 #
 # Rule to compile a set of .o files into one .a file (with symbol table)
 #
-ifdef lib-target
-
-$(lib-target): $(lib-y) FORCE
+$(obj)/lib.a: $(lib-y) FORCE
 	$(call if_changed,ar)
 
 targets += $(lib-target)
 
-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
-- 
2.25.1

[PATCH 2/5] kbuild: clear KBUILD_MODULES in top Makefile if CONFIG_MODULES=n

[Masahiro Yamada]

Do not try to build any module-related artifacts when CONFIG_MODULES
is disabled.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 Makefile               | 4 ++++
 scripts/Makefile.build | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 1f5bbfb31103..72eb55a36545 100644
--- a/Makefile
+++ b/Makefile
@@ -1724,6 +1724,10 @@ build-dirs := $(foreach d, $(build-dirs), \
 
 endif
 
+ifndef CONFIG_MODULES
+KBUILD_MODULES :=
+endif
+
 # Handle descending into subdirectories listed in $(build-dirs)
 # Preset locale variables to speed up the build process. Limit locale
 # tweaks to this spot to avoid wrong language settings when running
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 9af88f4cacb8..f46d25441804 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -77,7 +77,7 @@ ifdef need-builtin
 builtin-target := $(obj)/built-in.a
 endif
 
-ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
+ifdef need-modorder
 modorder-target := $(obj)/modules.order
 endif
 
-- 
2.25.1

[PATCH 3/5] kbuild: move subdir-obj-y to scripts/Makefile.build

[Masahiro Yamada]

Save $(addprefix ...) for subdir-obj-y.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/Makefile.build | 2 ++
 scripts/Makefile.lib   | 5 -----
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index f46d25441804..ee283efc1b45 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -69,6 +69,8 @@ endif
 
 # ===========================================================================
 
+subdir-obj-y := $(filter %/built-in.a, $(real-obj-y))
+
 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
 lib-target := $(obj)/lib.a
 endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 52299d5dba28..a41a4bbd20e2 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -62,10 +62,6 @@ multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m
 multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))), $(m))))
 multi-used   := $(multi-used-y) $(multi-used-m)
 
-# $(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.a, $(obj-y))
-
 # Replace multi-part objects by their individual parts,
 # including built-in.a from subdirectories
 real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
@@ -91,7 +87,6 @@ targets		:= $(addprefix $(obj)/,$(targets))
 modorder	:= $(addprefix $(obj)/,$(modorder))
 obj-m		:= $(addprefix $(obj)/,$(obj-m))
 lib-y		:= $(addprefix $(obj)/,$(lib-y))
-subdir-obj-y	:= $(addprefix $(obj)/,$(subdir-obj-y))
 real-obj-y	:= $(addprefix $(obj)/,$(real-obj-y))
 real-obj-m	:= $(addprefix $(obj)/,$(real-obj-m))
 multi-used-m	:= $(addprefix $(obj)/,$(multi-used-m))
-- 
2.25.1

[PATCH 4/5] kbuild: rename subdir-obj-y to subdir-builtin

[Masahiro Yamada]

I think subdir-builtin is clearer.

While I was here, I made its build rule explicit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/Makefile.build | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index ee283efc1b45..323264607b9f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -69,7 +69,8 @@ endif
 
 # ===========================================================================
 
-subdir-obj-y := $(filter %/built-in.a, $(real-obj-y))
+# subdir-builtin may contain duplications. Use $(sort ...)
+subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
 
 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
 lib-target := $(obj)/lib.a
@@ -356,7 +357,7 @@ endif
 $(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
 	$(call if_changed_rule,as_o_S)
 
-targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
+targets += $(filter-out $(subdir-builtin), $(real-obj-y)) $(real-obj-m) $(lib-y)
 targets += $(extra-y) $(always-y) $(MAKECMDGOALS)
 
 # Linker scripts preprocessor (.lds.S -> .lds)
@@ -381,7 +382,7 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 # ---------------------------------------------------------------------------
 
 # To build objects in subdirs, we need to descend into the directories
-$(obj)/%/built-in.a: $(obj)/% ;
+$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
 
 #
 # Rule to compile a set of .o files into one .a file (without symbol table)
@@ -489,7 +490,7 @@ PHONY += $(subdir-ym)
 $(subdir-ym):
 	$(Q)$(MAKE) $(build)=$@ \
 	$(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
-	need-builtin=$(if $(filter $@/built-in.a, $(subdir-obj-y)),1) \
+	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
 	need-modorder=$(if $(need-modorder),$(if $(filter $@/modules.order, $(modorder)),1))
 
 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
-- 
2.25.1

[PATCH 5/5] kbuild: make modules.order rule consistent with built-in.a

[Masahiro Yamada]

built-in.a contains the built-in object paths from the current and sub
directories.

module.order collects the module paths from the current and sub
directories.

Make their build rules look more symmetrical.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/Makefile.build | 10 ++++++----
 scripts/Makefile.lib   |  2 ++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 323264607b9f..ee9a817e19a3 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -69,8 +69,9 @@ endif
 
 # ===========================================================================
 
-# subdir-builtin may contain duplications. Use $(sort ...)
+# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
+subdir-modorder := $(sort $(filter %/modules.order, $(modorder)))
 
 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
 lib-target := $(obj)/lib.a
@@ -383,6 +384,7 @@ $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
 
 # To build objects in subdirs, we need to descend into the directories
 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
+$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
 
 #
 # Rule to compile a set of .o files into one .a file (without symbol table)
@@ -401,9 +403,9 @@ targets += $(builtin-target)
 #
 # Create commands to either record .ko file or cat modules.order from
 # a subdirectory
-$(modorder-target): $(subdir-ym) FORCE
+$(obj)/modules.order: $(subdir-modorder) FORCE
 	$(Q){ $(foreach m, $(modorder), \
-	$(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
+	$(if $(filter $^, $m), cat $m, echo $m);) :; } \
 	| $(AWK) '!x[$$0]++' - > $@
 
 #
@@ -491,7 +493,7 @@ $(subdir-ym):
 	$(Q)$(MAKE) $(build)=$@ \
 	$(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
 	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
-	need-modorder=$(if $(need-modorder),$(if $(filter $@/modules.order, $(modorder)),1))
+	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
 
 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 # ---------------------------------------------------------------------------
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index a41a4bbd20e2..0d931cc0df94 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -35,7 +35,9 @@ lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
 # Determine modorder.
 # Unfortunately, we don't have information about ordering between -y
 # and -m subdirs.  Just put -y's first.
+ifdef need-modorder
 modorder	:= $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m:.o=.ko))
+endif
 
 # Handle objects in subdirs
 # ---------------------------------------------------------------------------
-- 
2.25.1

Re: [PATCH 1/5] kbuild: remove ifdef builtin-target / lib-target

[Masahiro Yamada]

On Fri, May 22, 2020 at 11:00 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> I do not see a good reason to add ifdef here.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---


Applied to linux-kbuild.



>  scripts/Makefile.build | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 3665b1a0bc8e..9af88f4cacb8 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -384,16 +384,14 @@ $(obj)/%/built-in.a: $(obj)/% ;
>  #
>  # Rule to compile a set of .o files into one .a file (without symbol table)
>  #
> -ifdef builtin-target
>
>  quiet_cmd_ar_builtin = AR      $@
>        cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
>
> -$(builtin-target): $(real-obj-y) FORCE
> +$(obj)/built-in.a: $(real-obj-y) FORCE
>         $(call if_changed,ar_builtin)
>
>  targets += $(builtin-target)
> -endif # builtin-target
>
>  #
>  # Rule to create modules.order file
> @@ -408,15 +406,11 @@ $(modorder-target): $(subdir-ym) FORCE
>  #
>  # Rule to compile a set of .o files into one .a file (with symbol table)
>  #
> -ifdef lib-target
> -
> -$(lib-target): $(lib-y) FORCE
> +$(obj)/lib.a: $(lib-y) FORCE
>         $(call if_changed,ar)
>
>  targets += $(lib-target)
>
> -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
> --
> 2.25.1
>


-- 
Best Regards
Masahiro Yamada