From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id AA308158015 for ; Tue, 26 Dec 2023 14:02:29 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id C7E452BC017; Tue, 26 Dec 2023 14:02:28 +0000 (UTC) Received: from smtp.gentoo.org (mail.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id B14A92BC017 for ; Tue, 26 Dec 2023 14:02:28 +0000 (UTC) Received: from oystercatcher.gentoo.org (oystercatcher.gentoo.org [148.251.78.52]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp.gentoo.org (Postfix) with ESMTPS id CCB4D335DC3 for ; Tue, 26 Dec 2023 14:02:27 +0000 (UTC) Received: from localhost.localdomain (localhost [IPv6:::1]) by oystercatcher.gentoo.org (Postfix) with ESMTP id 3A3FE9C4 for ; Tue, 26 Dec 2023 14:02:26 +0000 (UTC) From: "Michał Górny" To: gentoo-commits@lists.gentoo.org Content-Transfer-Encoding: 8bit Content-type: text/plain; charset=UTF-8 Reply-To: gentoo-dev@lists.gentoo.org, "Michał Górny" Message-ID: <1703599329.2aea6c3ff2181ad96187e456a3307609fd288d4c.mgorny@gentoo> Subject: [gentoo-commits] repo/gentoo:master commit in: eclass/ X-VCS-Repository: repo/gentoo X-VCS-Files: eclass/toolchain-funcs.eclass X-VCS-Directories: eclass/ X-VCS-Committer: mgorny X-VCS-Committer-Name: Michał Górny X-VCS-Revision: 2aea6c3ff2181ad96187e456a3307609fd288d4c X-VCS-Branch: master Date: Tue, 26 Dec 2023 14:02:26 +0000 (UTC) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-commits@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply X-Archives-Salt: b75e9c52-ba49-4fd1-ac29-116c9da072fa X-Archives-Hash: c5ffdb2617de0a21d9c90864b05b55f7 commit: 2aea6c3ff2181ad96187e456a3307609fd288d4c Author: Michał Górny gentoo org> AuthorDate: Mon Dec 25 14:45:59 2023 +0000 Commit: Michał Górny gentoo org> CommitDate: Tue Dec 26 14:02:09 2023 +0000 URL: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=2aea6c3f toolchain-funcs.eclass: Add tc-is-lto function Add a function to check whether the C compiler is using LTO. To determine this, we compile a dummy source unit. In the GCC case, we check whether the resulting object file contains ".gnu.lto*" sections. In the clang case, we check whether a valid LLVM bytecode file was output rather than a regular object. The goal of this change is to reduce the amount of USE=lto abuse, and have a consistent cross-package way of enabling LTO via setting appropriate CFLAGS and CXXFLAGS. Closes: https://github.com/gentoo/gentoo/pull/34470 Signed-off-by: Michał Górny gentoo.org> eclass/toolchain-funcs.eclass | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/eclass/toolchain-funcs.eclass b/eclass/toolchain-funcs.eclass index 5da93063866b..cde84e6f34c8 100644 --- a/eclass/toolchain-funcs.eclass +++ b/eclass/toolchain-funcs.eclass @@ -1230,4 +1230,25 @@ tc-get-build-ptr-size() { die "Could not determine CBUILD pointer size" } +# @FUNCTION: tc-is-lto +# @RETURN: Shell true if we are using LTO, shell false otherwise +tc-is-lto() { + local f="${T}/test-lto.o" + + case $(tc-get-compiler-type) in + clang) + $(tc-getCC) ${CFLAGS} -c -o "${f}" -x c - <<<"" || die + # If LTO is used, clang will output bytecode and llvm-bcanalyzer + # will run successfully. Otherwise, it will output plain object + # file and llvm-bcanalyzer will exit with error. + llvm-bcanalyzer "${f}" &>/dev/null && return 0 + ;; + gcc) + $(tc-getCC) ${CFLAGS} -c -o "${f}" -x c - <<<"" || die + [[ $($(tc-getREADELF) -S "${f}") == *.gnu.lto* ]] && return 0 + ;; + esac + return 1 +} + fi