[PATCH] kbuild: move .SECONDARY special target to Kbuild.include

[Masahiro Yamada]

In commit 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and
remove .PRECIOUS markers"), I missed one important feature of the
.SECONDARY target:

  .SECONDARY with no prerequisites causes all targets to be treated
   as secondary.

Kbuild's policy is, "Do not delete any intermediate files."
So, just move it to scripts/Kbuild.include, with no prerequisites.

Note:
If an intermediate file is generated by $(call if_changed,...), you
still need to add it to "targets" so its .*.cmd file is included.

The arm/arm64 crypto files are generated by $(call cmd,shipped),
so they do not need to be added to "targets", but need to be added
to "clean-files" so "make clean" can properly clean them away.

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

 arch/arm/crypto/Makefile   | 2 +-
 arch/arm64/crypto/Makefile | 2 +-
 scripts/Kbuild.include     | 3 +++
 scripts/Makefile.build     | 4 ----
 4 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile
index bd5bcee..89f88ab 100644
--- a/arch/arm/crypto/Makefile
+++ b/arch/arm/crypto/Makefile
@@ -65,4 +65,4 @@ $(src)/sha512-core.S_shipped: $(src)/sha512-armv4.pl
 	$(call cmd,perl)
 endif
 
-targets += sha256-core.S sha512-core.S
+clean-files += sha256-core.S sha512-core.S
diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
index f476fed..860d931 100644
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -75,4 +75,4 @@ $(src)/sha512-core.S_shipped: $(src)/sha512-armv8.pl
 	$(call cmd,perlasm)
 endif
 
-targets += sha256-core.S sha512-core.S
+clean-files += sha256-core.S sha512-core.S
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index bb01555..0454916 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -393,3 +393,6 @@ endef
 
 # delete partially updated (i.e. corrupted) files on error
 .DELETE_ON_ERROR:
+
+# do not delete intermediate files automatically
+.SECONDARY:
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a8e7ba9..604096a 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -546,8 +546,4 @@ $(shell mkdir -p $(obj-dirs))
 endif
 endif
 
-# Some files contained in $(targets) are intermediate artifacts.
-# We never want them to be removed automatically.
-.SECONDARY: $(targets)
-
 .PHONY: $(PHONY)
-- 
2.7.4