From b2a09344350508f6431b19733dfe4b8cc4feeea5 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 30 Dec 2018 22:59:20 +0900 Subject: kbuild: add .SECONDARY special target 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") This consolidates those two commits and adjusts commit log for barebox. 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 arch/arm/crypto/Makefile marks 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. I deleted 'SECONDARY' (no dot) from images/Makefile, which I guess a typo. Signed-off-by: Masahiro Yamada Signed-off-by: Sascha Hauer --- arch/arm/crypto/Makefile | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/arm/crypto') diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile index 372bf8d699..fda4eeafec 100644 --- a/arch/arm/crypto/Makefile +++ b/arch/arm/crypto/Makefile @@ -13,5 +13,3 @@ quiet_cmd_perl = PERL $@ $(src)/sha256-core.S_shipped: $(src)/sha256-armv4.pl $(call cmd,perl) - -.PRECIOUS: $(obj)/sha256-core.S -- cgit v1.2.3