From 22f26f21774f838e97921952d8c5c4aab3da2ea4 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 7 Apr 2022 00:30:21 +0900 Subject: [PATCH] kbuild: get rid of duplication in *.mod files It is allowed to add the same objects multiple times to obj-y / obj-m: obj-y += foo.o foo.o foo.o obj-m += bar.o bar.o bar.o It is also allowed to add the same objects multiple times to a composite module: obj-m += foo.o foo-y := foo1.o foo2.o foo2.o foo1.o This flexibility is useful because the same object might be selected by different CONFIG options, like this: obj-m += foo.o foo-y := foo1.o foo-$(CONFIG_FOO_X) += foo2.o foo-$(CONFIG_FOO_Y) += foo2.o The duplicated objects are omitted at link time. It works naturally in Makefiles because GNU Make removes duplication in $^ without changing the order. It is working well, almost... A small flaw I notice is, *.mod contains duplication in such a case. This is probably not a big deal. As far as I know, the only small problem is scripts/mod/sumversion.c parses the same file multiple times. I am fixing this because I plan to reuse *.mod for other purposes, where the duplication can be problematic. The code change is quite simple. We already use awk to drop duplicated lines in modules.order (see cmd_modules_order in the same file). I copied the code, but changed RS to use spaces as record separators. I also changed the file format to list one object per line. Signed-off-by: Masahiro Yamada --- scripts/Makefile.build | 3 ++- scripts/mod/sumversion.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 6ae92d1..f7a30f3 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -303,7 +303,8 @@ $(obj)/%.prelink.o: $(obj)/%.o FORCE $(call if_changed,cc_prelink_modules) endif -cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) > $@ +cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \ + $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@ $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE $(call if_changed,mod) diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c index 0125698..79bb9ea 100644 --- a/scripts/mod/sumversion.c +++ b/scripts/mod/sumversion.c @@ -398,7 +398,7 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen) buf = read_text_file(filelist); md4_init(&md); - while ((fname = strsep(&buf, " \n"))) { + while ((fname = strsep(&buf, "\n"))) { if (!*fname) continue; if (!(is_static_library(fname)) && -- 2.7.4