From patchwork Wed Feb 19 07:49:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 11390587 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 473CB924 for ; Wed, 19 Feb 2020 07:51:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2781D21D56 for ; Wed, 19 Feb 2020 07:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582098703; bh=AuiuY44Grg31bHYi1FEZ+W1LLV8zMJGA8HVNelAlbK4=; h=From:To:Cc:Subject:Date:List-ID:From; b=r5LhWBgw+lPvazuqzmz7epdjH8SzMIzhOGAy/8RAOmAe+l/MyCP3rmFrAtQMJkB3v Q0am5Hng0vRRpIuzs/Wr2iLeWAdelJymjBGP6jfS1CbJS3bLDsbMToBjgMXQ5egfgZ VvlVSUiUUbKRNPRzuDIuRCU44QfvQEnA4XkGO7WA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726766AbgBSHvm (ORCPT ); Wed, 19 Feb 2020 02:51:42 -0500 Received: from conuserg-09.nifty.com ([210.131.2.76]:34486 "EHLO conuserg-09.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726664AbgBSHvm (ORCPT ); Wed, 19 Feb 2020 02:51:42 -0500 Received: from localhost.localdomain (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-09.nifty.com with ESMTP id 01J7oBm0008413; Wed, 19 Feb 2020 16:50:12 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-09.nifty.com 01J7oBm0008413 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1582098613; bh=CmAkppl+SFFJV1RkBUsjbfUnoQtSHwVJbJtqBWpmqgs=; h=From:To:Cc:Subject:Date:From; b=s4e2LiFvAWd7foi/qebZk1ywEQ32xF0d+kOi1DjnzKKpbe5UQLKkqw8c8vcHIFVlp lN9rLpbyNAz2hdK5TVf4/kPse1mIRuW7/r0JjIi8EKBwdzwz2/Ne+VQHKcSyJcsz/A 17B8wd1IgKZvBL93419ZmZ1AjXGE0MY3haxcK0inoJAiAanJ0fGTzU34btlV+8lfyM YWjBxDtVvxQG79sgxvqeW/SggmrC5b5cvAb0Ky0qc/hQobueIL2XcHq6Q25Hkcr24l d11ENJQGH8SZaTFxsN61gaZotxPiAEueW+6KYAxDrh+MvlI8lAmaYIkqTyuflr7tFt 1zDTvo1+NMmDA== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Arnd Bergmann , Nicolas Pitre , Richard Cochran , Thomas Gleixner , John Stultz , Josh Triplett , Mark Brown , Ulf Magnusson , Geert Uytterhoeven , Masahiro Yamada , Jonathan Corbet , Michal Marek , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] kconfig: make 'imply' obey the direct dependency Date: Wed, 19 Feb 2020 16:49:50 +0900 Message-Id: <20200219074950.23344-1-masahiroy@kernel.org> 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 The 'imply' statement may create unmet direct dependency when the implied symbol depends on m. [Test Code] config FOO tristate "foo" imply BAZ config BAZ tristate "baz" depends on BAR config BAR def_tristate m config MODULES def_bool y option modules If you set FOO=y, BAZ is also promoted to y, which results in the following .config file: CONFIG_FOO=y CONFIG_BAZ=y CONFIG_BAR=m CONFIG_MODULES=y This ignores the dependency "BAZ depends on BAR". Unlike 'select', what is worse, Kconfig never shows the "WARNING: unmet direct dependencies detected for ..." for this case. Because 'imply' should be weaker than 'depends on', Kconfig should take the direct dependency into account. Describe this case in Documentation/kbuild/kconfig-language.rst for clarification. Commit 237e3ad0f195 ("Kconfig: Introduce the "imply" keyword") says that a symbol implied by y is restricted to y or n, excluding m. As for the combination of FOO=y and BAR=m, the case of BAZ=m is excluded by the 'imply', and BAZ=y is also excluded by 'depends on'. So, only the possible value is BAZ=n. Having said that, this case was probably "We don't care" at that time because Kconfig did not handle 'depends on m' correctly until commit f622f8279581 ("kconfig: warn unmet direct dependency of tristate symbols selected by y") fixed it. Backporting this to 4.19+ will probably be fine. If you care this problem on 4.14.x, you need to backport f622f8279581 as well. Signed-off-by: Masahiro Yamada Tested-by: Geert Uytterhoeven --- Documentation/kbuild/kconfig-language.rst | 7 +++++-- scripts/kconfig/symbol.c | 17 +++++++++++++---- 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst index d0111dd26410..9141f03ff744 100644 --- a/Documentation/kbuild/kconfig-language.rst +++ b/Documentation/kbuild/kconfig-language.rst @@ -159,11 +159,11 @@ applicable everywhere (see syntax). Given the following example:: config FOO - tristate + tristate "foo" imply BAZ config BAZ - tristate + tristate "baz" depends on BAR The following values are possible: @@ -174,6 +174,9 @@ applicable everywhere (see syntax). n y n N/m/y m y m M/y/n y y y Y/n + n m n N/m + m m m M/n + y m n N y n * N === === ============= ============== diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c index 8d38b700b314..6100e6ead8ad 100644 --- a/scripts/kconfig/symbol.c +++ b/scripts/kconfig/symbol.c @@ -221,7 +221,7 @@ static void sym_calc_visibility(struct symbol *sym) sym_set_changed(sym); } tri = no; - if (sym->implied.expr && sym->dir_dep.tri != no) + if (sym->implied.expr) tri = expr_calc_value(sym->implied.expr); if (tri == mod && sym_get_type(sym) == S_BOOLEAN) tri = yes; @@ -393,7 +393,17 @@ void sym_calc_value(struct symbol *sym) } if (sym->implied.tri != no) { sym->flags |= SYMBOL_WRITE; - newval.tri = EXPR_OR(newval.tri, sym->implied.tri); + newval.tri = EXPR_OR(newval.tri, + sym->implied.tri); + newval.tri = EXPR_AND(newval.tri, + sym->dir_dep.tri); + + if (newval.tri == mod && sym->implied.tri == yes) { + if (sym->dir_dep.tri == yes) + newval.tri = yes; + else + newval.tri = no; + } } } calc_newval: @@ -401,8 +411,7 @@ void sym_calc_value(struct symbol *sym) sym_warn_unmet_dep(sym); newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri); } - if (newval.tri == mod && - (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes)) + if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN) newval.tri = yes; break; case S_STRING: