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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE4D8C433E6 for ; Wed, 13 Jan 2021 17:52:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9758B21534 for ; Wed, 13 Jan 2021 17:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727930AbhAMRwI (ORCPT ); Wed, 13 Jan 2021 12:52:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725843AbhAMRwH (ORCPT ); Wed, 13 Jan 2021 12:52:07 -0500 Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48491C061575; Wed, 13 Jan 2021 09:51:27 -0800 (PST) Received: by mail-qk1-x730.google.com with SMTP id w79so2959562qkb.5; Wed, 13 Jan 2021 09:51:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=phNMVGOT8C1SF9CCO/PujkTaq0U+NXoha8y1/r4kCQY=; b=kT4D5XuLD2lvcKR+ovpDo4Eh/HtUuSJFKh0+5hJbBIgDVlSsh8/yMC2KAUTSNcsR6Q 6Tqbi0+2IOrctM/0PBwx452S4rw9x9xtWxNNCP7MAv3gmv9yUWGyAchKgll6r39N6xaB JqXNbOOD8YgqId8PzKj0Ssfgto75YwbWZrAj4MaJ8WBpNe+ZTgu5s0cRMN0AfJ1Q3IZd NR+tPpRB/9qZy6iDrJyhoZv+qk6QNZT5+qeKaWEgySJbBRqICAs3TFAD08TrZ3VjW7pF p4xZnYJd3SWwwnv7o+ZaJVcBTvY3+SRCl0A2FLmysteyL1KiOyE/cPtJNJeFhcqA2uKD WLyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=phNMVGOT8C1SF9CCO/PujkTaq0U+NXoha8y1/r4kCQY=; b=GlDFo0eD4+wI2btRmCzolsNk55EasZOucb+F8xAq1Houg/BbopzsZ2rA2zPgdMlWfR cZd/6i6NtQE68fMMZwcR9HHXg6KRJKinIGun+8+aKWpcwZaUQCTSOsxjt5x3EjT/0Whm HuCxHUlT/rycI1iX0SoWcx/mp4feMgOLL0uuZP4rkJ6ihVDAXcjCQtEZPfJBOq2GVspr iIzzwI5B0qH6IclSgZfCRrIUl80TkdZUbbdOEXnDOKsKH4JH7Y69ADtkqGvjEXBaiN+o y/GALryXbkxFDo4N1yst9e5A7bU13ZlQ9lupMqph47BV7YZGj8E0bBP6jRcb+lejKJDX YOXQ== X-Gm-Message-State: AOAM533i00SYmkuI3ZkuVsCA6TJJwLQHSSIrGsm+EvAM1DgBkzhnCkkh nf9uoMWhLBAl+0D6n790/cM= X-Google-Smtp-Source: ABdhPJxs33thgKGgieEbI1p2yYVwC5v03/TUhLo1O0DVEAGaAnGckUHh8P1SNcdLqKgSEvAqdPXsJw== X-Received: by 2002:ae9:ef12:: with SMTP id d18mr3347716qkg.473.1610560286030; Wed, 13 Jan 2021 09:51:26 -0800 (PST) Received: from ubuntu-m3-large-x86 ([2604:1380:45f1:1d00::1]) by smtp.gmail.com with ESMTPSA id k7sm1340519qtg.65.2021.01.13.09.51.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Jan 2021 09:51:25 -0800 (PST) Date: Wed, 13 Jan 2021 10:51:23 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Masahiro Yamada , Andrew Morton , Sedat Dilek , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, Jakub Jelinek , Fangrui Song , Caroline Tice , Nick Clifton Subject: Re: [PATCH v4 2/3] Kbuild: make DWARF version a choice Message-ID: <20210113175123.GB4158893@ubuntu-m3-large-x86> References: <20210113003235.716547-1-ndesaulniers@google.com> <20210113003235.716547-3-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210113003235.716547-3-ndesaulniers@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 12, 2021 at 04:32:34PM -0800, Nick Desaulniers wrote: > Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice. Adds an > explicit CONFIG_DEBUG_INFO_DWARF2, which is the default. Does so in a > way that's forward compatible with existing configs, and makes adding > future versions more straightforward. > > Suggested-by: Fangrui Song > Suggested-by: Masahiro Yamada > Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor > --- > Makefile | 14 +++++++++----- > lib/Kconfig.debug | 21 ++++++++++++++++----- > 2 files changed, 25 insertions(+), 10 deletions(-) > > diff --git a/Makefile b/Makefile > index d49c3f39ceb4..656fff17b331 100644 > --- a/Makefile > +++ b/Makefile > @@ -826,12 +826,16 @@ else > DEBUG_CFLAGS += -g > endif > > -ifneq ($(LLVM_IAS),1) > -KBUILD_AFLAGS += -Wa,-gdwarf-2 > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF2) := 2 > +dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 > +DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) > +ifneq ($(dwarf-version-y)$(LLVM_IAS),21) > +# Binutils 2.35+ required for -gdwarf-4+ support. > +dwarf-aflag := $(call as-option,-Wa$(comma)-gdwarf-$(dwarf-version-y)) > +ifdef CONFIG_CC_IS_CLANG > +DEBUG_CFLAGS += $(dwarf-aflag) > endif > - > -ifdef CONFIG_DEBUG_INFO_DWARF4 > -DEBUG_CFLAGS += -gdwarf-4 > +KBUILD_AFLAGS += $(dwarf-aflag) > endif > > ifdef CONFIG_DEBUG_INFO_REDUCED > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index dd7d8d35b2a5..e80770fac4f0 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -256,13 +256,24 @@ config DEBUG_INFO_SPLIT > to know about the .dwo files and include them. > Incompatible with older versions of ccache. > > +choice > + prompt "DWARF version" > + help > + Which version of DWARF debug info to emit. > + > +config DEBUG_INFO_DWARF2 > + bool "Generate DWARF Version 2 debuginfo" > + help > + Generate DWARF v2 debug info. > + > config DEBUG_INFO_DWARF4 > - bool "Generate dwarf4 debuginfo" > + bool "Generate DWARF Version 4 debuginfo" > help > - Generate dwarf4 debug info. This requires recent versions > - of gcc and gdb. It makes the debug information larger. > - But it significantly improves the success of resolving > - variables in gdb on optimized code. > + Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. > + It makes the debug information larger, but it significantly > + improves the success of resolving variables in gdb on optimized code. > + > +endchoice # "DWARF version" > > config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > -- > 2.30.0.284.gd98b1dd5eaa7-goog >