From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: linux-kbuild@vger.kernel.org
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] kbuild: do not create built-in.a that is never linked to vmlinux
Date: Thu, 12 Sep 2019 16:33:33 +0900 [thread overview]
Message-ID: <20190912073336.7036-1-yamada.masahiro@socionext.com> (raw)
Both 'obj-y += foo/' and 'obj-m += foo/' requrest Kbuild to visit the
sub-directory foo/, but the difference is that only the former combines
foo/built-in.a into the built-in.a of the current directory because
everything in sub-directories visited by obj-m is supposed to be modular.
So, it makes sense to create built-in.a only if that sub-directory is
reachable by the chain of obj-y. Otherwise, built-in.a will not be
linked into vmlinux anyway. If an orphan built-in.a is created, it is
very likely a Makefile bug.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
scripts/Makefile.build | 2 +-
scripts/Makefile.lib | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 9fa09361aa5d..54fc68168686 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -66,7 +66,7 @@ lib-target := $(obj)/lib.a
real-obj-y += $(obj)/lib-ksyms.o
endif
-ifneq ($(strip $(real-obj-y) $(need-builtin)),)
+ifdef need-builtin
builtin-target := $(obj)/built-in.a
endif
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 264611972c4a..07095d3789a1 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -35,7 +35,11 @@ __subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
subdir-y += $(__subdir-y)
__subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m)))
subdir-m += $(__subdir-m)
+ifdef need-builtin
obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
+else
+obj-y := $(filter-out %/, $(obj-y))
+endif
obj-m := $(filter-out %/, $(obj-m))
# Subdirectories we need to descend into
--
2.17.1
next reply other threads:[~2019-09-12 7:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-12 7:33 Masahiro Yamada [this message]
2019-09-12 7:33 ` [PATCH 2/3] kbuild: warn orphan obj-y objects Masahiro Yamada
2019-09-12 7:33 ` [PATCH 3/3] kbuild: change need-modorder implementation slightly Masahiro Yamada
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190912073336.7036-1-yamada.masahiro@socionext.com \
--to=yamada.masahiro@socionext.com \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=michal.lkml@markovi.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.