From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92DD4C433F5 for ; Mon, 3 Oct 2022 19:57:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229736AbiJCT5j (ORCPT ); Mon, 3 Oct 2022 15:57:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229605AbiJCT5g (ORCPT ); Mon, 3 Oct 2022 15:57:36 -0400 Received: from conssluserg-06.nifty.com (conssluserg-06.nifty.com [210.131.2.91]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E86F1491F3; Mon, 3 Oct 2022 12:57:34 -0700 (PDT) Received: from mail-oa1-f53.google.com (mail-oa1-f53.google.com [209.85.160.53]) (authenticated) by conssluserg-06.nifty.com with ESMTP id 293Jv77M013279; Tue, 4 Oct 2022 04:57:07 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-06.nifty.com 293Jv77M013279 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1664827028; bh=rfDWg500KpyWsspPqlZfTlWaAPRTsxHTFXFNMj2CpJs=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=SxqwIC2z48Hfs7jjHgSKtDD2E9KuMsY4u66pDaCd43Wb9ID1KaGo39AiIUq550dh4 zdErfOAGv/d8Qs7/YquNzzclgL0FhjA2qo5NPQyaD2smfPgWRR9Y4YqH5ixGAfrJZ8 unN1v2na+mtJKc7Ks0xKz4myVlTMo4KS80KVdZXIx7g8F3Y4QBAllNS37g1jF6ETkj OLczdSozNZrLamJpA+v9HrbiLrTUTvrXIWgVq07r0eCPkCbVpuPLPiKUOf8TI/J46f dXQMsXsJp0Uw5WSnREPWfhHxFLp0AViVQGMF0Q/OJZ2tIo6ktQtTRxOtRP9uCy3cb7 JgFAARXH6gEzw== X-Nifty-SrcIP: [209.85.160.53] Received: by mail-oa1-f53.google.com with SMTP id 586e51a60fabf-1321a1e94b3so8456422fac.1; Mon, 03 Oct 2022 12:57:07 -0700 (PDT) X-Gm-Message-State: ACrzQf0O4nIJoOeFGZNvjA+urX5vCX1wTU+SjKqjm7pfVP3iZ4nPCUT8 +A9isiXhT8LNpmihx7pwcpRJrJNHnR9yv4/nJbQ= X-Google-Smtp-Source: AMsMyM7lMzdXBL948OAVTq7cLkis+2F1ZkcYq4zedZ2wqpxW/zmbCJV27NfNVPuMoiFZl8/GpS05wG0i87u95KBzGHs= X-Received: by 2002:a05:6870:c58b:b0:10b:d21d:ad5e with SMTP id ba11-20020a056870c58b00b0010bd21dad5emr5970786oab.287.1664827026656; Mon, 03 Oct 2022 12:57:06 -0700 (PDT) MIME-Version: 1.0 References: <20221002181107.51286-1-masahiroy@kernel.org> <20221002181107.51286-2-masahiroy@kernel.org> In-Reply-To: From: Masahiro Yamada Date: Tue, 4 Oct 2022 04:56:28 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/3] Kconfig.debug: simplify the dependency of DEBUG_INFO_DWARF4/5 To: Nick Desaulniers Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, Nathan Chancellor Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 4, 2022 at 1:53 AM Nick Desaulniers wrote: > > On Sun, Oct 2, 2022 at 11:11 AM Masahiro Yamada wrote: > > > > Commit c0a5c81ca9be ("Kconfig.debug: drop GCC 5+ version check for > > DWARF5") could have cleaned up the code a bit deeper. > > > > "CC_IS_CLANG &&" is unneeded. No functional change is intended. > > This implies that there are only 2 compilers capable of building the > kernel; consider also removing > include/linux/compiler-intel.h > if ICC is no longer supported. Otherwise, what implications does this > patch have for ICC? I am just doing logical simplification in general. When A and B are bool, !A || (A && B) is always redundant. It can be simplified into !A || B So, this patch is irrelevant to the presence of the third compiler, ICC. Such an implication happened in commit c0a5c81ca9be. When you dropped GCC 5+ check, you converted "GCC_VERSION >= 50000" into "!CC_IS_CLANG" instead of "CC_IS_GCC". "CC_IS_GCC" and "!CC_IS_CLANG" are not equivalent, but a lot of code already expects that, and nobody asked "We have the third compiler, so do we need CC_IS_ICC?" I agree that we can drop ICC support, but I want to point out that ICC is DON'T_CARE to my patch. > > > > Signed-off-by: Masahiro Yamada > > --- > > > > lib/Kconfig.debug | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > > index d3e5f36bb01e..f4b2165f24db 100644 > > --- a/lib/Kconfig.debug > > +++ b/lib/Kconfig.debug > > @@ -264,7 +264,7 @@ config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT > > config DEBUG_INFO_DWARF4 > > bool "Generate DWARF Version 4 debuginfo" > > select DEBUG_INFO > > - depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) > > + depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502) > > help > > Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2 > > if using clang without clang's integrated assembler, and gdb 7.0+. > > @@ -276,7 +276,7 @@ config DEBUG_INFO_DWARF4 > > config DEBUG_INFO_DWARF5 > > bool "Generate DWARF Version 5 debuginfo" > > select DEBUG_INFO > > - depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) > > + depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502) > > help > > Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc > > 5.0+ accepts the -gdwarf-5 flag but only had partial support for some > > -- > > 2.34.1 > > > > > -- > Thanks, > ~Nick Desaulniers -- Best Regards Masahiro Yamada