From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 6AE073856089; Fri, 12 May 2023 14:09:47 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6AE073856089 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1683900587; bh=AUJxesEPJm4XOq+guOxhMYNgoEwSwdMMPZA7mKViit8=; h=From:To:Subject:Date:In-Reply-To:References:From; b=GmwNAG1IgmVIM2XaUZzsyoxcNs9a2C7/5rlAXNSP6GPSdxL9NeRQLouvnJXOGZ/3U QyPgA/i0PhNeaH2jlphMtaFuiUeygDMUfOvJSlftZxI3a3ggmjmvTZrBfRoI5wmj5W Ydt4eyjRWQDgvVAhNdPQexkwF09vuhwTrA25D3BU= From: "hubicka at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/106943] GCC building clang/llvm with LTO flags causes ICE in clang Date: Fri, 12 May 2023 14:09:46 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 12.2.0 X-Bugzilla-Keywords: needs-reduction, wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: hubicka at gcc dot gnu.org X-Bugzilla-Status: WAITING X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106943 Jan Hubicka changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |hubicka at gcc dot gnu.org --- Comment #13 from Jan Hubicka --- > What's the current best practice for LTO debugging? I don't imagine there= 's an > easy way to identify which of 2000 lto1 invocation crashes, or atta= ch gdb to it? Or at least generate a corefile What I do is to compile with --save-temps --verbose and then one can see wh= ich ltrans ICEd in error message from internal make. The dump also contains al= l of ltrans command lines (sometimes garbled by parallel output unoless you are willing to wait for -flto=3D1). Invoke the corresponding ltrnans command li= ne from gdb and wait for crash. Indeed it is quite long time problem with clang not building with lifetime = DSE and strict aliasing. I wonder why this is not fixed on clang side?=