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From:   Masahiro Yamada <masahiroy@kernel.org>
To:     linux-kbuild@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH 7/7] kbuild: read *.mod to get objects passed to $(LD) or $(AR)
Date:   Thu,  7 Apr 2022 00:30:23 +0900
Message-Id: <20220406153023.500847-8-masahiroy@kernel.org>
In-Reply-To: <20220406153023.500847-1-masahiroy@kernel.org>
References: <20220406153023.500847-1-masahiroy@kernel.org>
MIME-Version: 1.0
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ld and ar support @file, which command-line options are read from.

Now that *.mod lists the member objects in the correct order, without
duplication, it is ready to be passed to ld and ar.

By using the @file syntax, people will not be worried about the pitfall
described in the NOTE.

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

 scripts/Makefile.build | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 3da731cf6978..f6a506318795 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -450,22 +450,18 @@ quiet_cmd_ar_lib = AR      $@
 $(obj)/lib.a: $(lib-y) FORCE
 	$(call if_changed,ar_lib)
 
-# NOTE:
-# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
-# module is turned into a multi object module, $^ will contain header file
-# dependencies recorded in the .*.cmd file.
 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
 quiet_cmd_link_multi-m = AR [M]  $@
 cmd_link_multi-m =						\
 	$(cmd_update_lto_symversions);				\
 	rm -f $@; 						\
-	$(AR) cDPrsT $@ $(filter %.o,$^)
+	$(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@)
 else
 quiet_cmd_link_multi-m = LD [M]  $@
-      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
+      cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@)
 endif
 
-$(multi-obj-m): FORCE
+$(multi-obj-m): %.o: %.mod FORCE
 	$(call if_changed,link_multi-m)
 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
 
-- 
2.32.0