[PATCH v2 01/11] kbuild: do not create empty modules.order in the prepare stage

From: Masahiro Yamada
Date: Tue Jul 09 2019 - 03:15:10 EST


Currently, $(objtree)/modules.order is touched in two places.

In the 'prepare0' rule, scripts/Makefile.build creates an empty
modules.order while processing 'obj=.'

In the 'modules' rule, the top-level Makefile overwrites it with
the correct list of modules.

While this might be a good side-effect that modules.order is made
empty every time (probably this is not intended functionality),
I personally do not like this behavior.

Create modules.order only when it is sensible to do so.

Going forward, $(objtree)/modules.order lists the modules that
was built in the last successful build.

This also avoids creating pointless files:

scripts/basic/modules.order
scripts/dtc/modules.order
scripts/gcc-plugins/modules.order
scripts/genksyms/modules.order
scripts/mod/modules.order
scripts/modules.order
scripts/selinux/genheaders/modules.order
scripts/selinux/mdp/modules.order
scripts/selinux/modules.order

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2:
- inverted the logic "preparing" -> need-modorder


Makefile | 4 ++--
scripts/Makefile.build | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 5c75ea7177f6..d8421d245f75 100644
--- a/Makefile
+++ b/Makefile
@@ -1076,7 +1076,7 @@ $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;

PHONY += $(vmlinux-dirs)
$(vmlinux-dirs): prepare
- $(Q)$(MAKE) $(build)=$@ need-builtin=1
+ $(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1

filechk_kernel.release = \
echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
@@ -1611,7 +1611,7 @@ $(objtree)/Module.symvers:
module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
PHONY += $(module-dirs) modules
$(module-dirs): prepare $(objtree)/Module.symvers
- $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
+ $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@) need-modorder=1

modules: $(module-dirs)
@$(kecho) ' Building modules, stage 2.';
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 776842b7e6a3..e9b3d88257dd 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -63,7 +63,7 @@ ifneq ($(strip $(real-obj-y) $(need-builtin)),)
builtin-target := $(obj)/built-in.a
endif

-ifdef CONFIG_MODULES
+ifeq ($(CONFIG_MODULES)$(need-modorder),y1)
modorder-target := $(obj)/modules.order
endif

--
2.17.1