From patchwork Sat Jul 6 16:25:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 11033949 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A4E86138D for ; Sat, 6 Jul 2019 16:26:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8FD3B284B9 for ; Sat, 6 Jul 2019 16:26:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 82931284C0; Sat, 6 Jul 2019 16:26:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CEEBA284B9 for ; Sat, 6 Jul 2019 16:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726698AbfGFQ0P (ORCPT ); Sat, 6 Jul 2019 12:26:15 -0400 Received: from conuserg-12.nifty.com ([210.131.2.79]:38596 "EHLO conuserg-12.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726522AbfGFQ0P (ORCPT ); Sat, 6 Jul 2019 12:26:15 -0400 Received: from grover.flets-west.jp (softbank126026094249.bbtec.net [126.26.94.249]) (authenticated) by conuserg-12.nifty.com with ESMTP id x66GPBsN009054; Sun, 7 Jul 2019 01:25:12 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-12.nifty.com x66GPBsN009054 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1562430312; bh=X6cih5B3K2ei50R7X1Bl4X3Q5BgxxbeaDmtWdcAgytM=; h=From:To:Cc:Subject:Date:From; b=GB2BXtfeXIx3aQHmtoCkIutsS3zwmBEq76NmgPcHEhZBjOWNsBx2L+MziWBruk7NH 12ywrIxdo1fWios7cK8sjwd0UcIavrJqfw1HRhuPnGtGL0Dk3Xc+Fwq88Nw20C4AJM T3yK6L3q45/MHsST+jLPn92s+jTCCyJQxU1XpzrFDoLZa811vkAnYnWzKqAKTnOnfG /VRtJUTpCa3x1YjZkjS9nAwXs8gc46wXmCoeN+0fi9AlIn76WhUv1LKddhuZnq0HDE RZ4Jm9tyYElZ4EbvVaz/x7dcXHWVe8EFyLzM22SKj4ty55VOIsRLAX6e6IbG591SEs zqqouvEgQRy/w== X-Nifty-SrcIP: [126.26.94.249] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Sam Ravnborg , Masahiro Yamada , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Jonathan Corbet , Michal Marek Subject: [PATCH v2] kbuild: get rid of misleading $(AS) from documents Date: Sun, 7 Jul 2019 01:25:08 +0900 Message-Id: <20190706162508.8529-1-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The assembler files in the kernel are *.S instead of *.s, so they must be preprocessed. Since 'as' of GNU binutils is not able to preprocess, we always use $(CC) as an assembler driver. $(AS) is almost unused in Kbuild. As of writing, there is just one place that directly invokes $(AS). $ git grep -e '$(AS)' -e '${AS}' -e '$AS' -e '$(AS:' -e '${AS:' -- :^Documentation drivers/net/wan/Makefile: AS68K = $(AS) The documentation about *_AFLAGS* sounds like the flags were passed to $(AS). This is somewhat misleading. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor --- Changes in v2: - Rephrase without using "assembling" Documentation/kbuild/kbuild.txt | 5 ++--- Documentation/kbuild/makefiles.txt | 12 ++++++------ 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt index 9c230ea71963..2c6188abb213 100644 --- a/Documentation/kbuild/kbuild.txt +++ b/Documentation/kbuild/kbuild.txt @@ -31,12 +31,11 @@ Additional options to the assembler (for built-in and modules). AFLAGS_MODULE -------------------------------------------------- -Additional module specific options to use for $(AS). +Additional assembler options for modules. AFLAGS_KERNEL -------------------------------------------------- -Additional options for $(AS) when used for assembler -code for code that is compiled as built-in. +Additional assembler options for built-in. KCFLAGS -------------------------------------------------- diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index d65ad5746f94..895bbbf38a0c 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -306,7 +306,7 @@ more details, with real examples. variable $(KBUILD_CFLAGS) and uses it for compilation flags for the entire tree. - asflags-y specifies options for assembling with $(AS). + asflags-y specifies assembler options. Example: #arch/sparc/kernel/Makefile @@ -441,7 +441,7 @@ more details, with real examples. as-instr checks if the assembler reports a specific instruction and then outputs either option1 or option2 C escapes are supported in the test instruction - Note: as-instr-option uses KBUILD_AFLAGS for $(AS) options + Note: as-instr-option uses KBUILD_AFLAGS for assembler options cc-option cc-option is used to check if $(CC) supports a given option, and if @@ -814,7 +814,7 @@ When kbuild executes, the following steps are followed (roughly): In this example, the binary $(obj)/image is a binary version of vmlinux. The usage of $(call if_changed,xxx) will be described later. - KBUILD_AFLAGS $(AS) assembler flags + KBUILD_AFLAGS assembler flags Default value - see top level Makefile Append or modify as required per architecture. @@ -853,15 +853,15 @@ When kbuild executes, the following steps are followed (roughly): The first example utilises the trick that a config option expands to 'y' when selected. - KBUILD_AFLAGS_KERNEL $(AS) options specific for built-in + KBUILD_AFLAGS_KERNEL Assembler options specific for built-in $(KBUILD_AFLAGS_KERNEL) contains extra C compiler flags used to compile resident kernel code. - KBUILD_AFLAGS_MODULE Options for $(AS) when building modules + KBUILD_AFLAGS_MODULE Assembler options specific for modules $(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that - are used for $(AS). + are used for assembler. From commandline AFLAGS_MODULE shall be used (see kbuild.txt). KBUILD_CFLAGS_KERNEL $(CC) options specific for built-in