From owner-freebsd-bugs@freebsd.org Sun Sep 24 17:19:59 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D98F8E2BCB6 for ; Sun, 24 Sep 2017 17:19:59 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C7D557F49D for ; Sun, 24 Sep 2017 17:19:59 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v8OHJxfA046277 for ; Sun, 24 Sep 2017 17:19:59 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 222563] libcxxrt abi::__cxa_demangle() does not successfully demangle names Date: Sun, 24 Sep 2017 17:19:59 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: ian@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 24 Sep 2017 17:20:00 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D222563 Bug ID: 222563 Summary: libcxxrt abi::__cxa_demangle() does not successfully demangle names Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: ian@FreeBSD.org Created attachment 186671 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D186671&action= =3Dedit Small c++ program to demonstrate the problem The attached small c++ program should print the demangled names of a couple symbols when it runs, but it does not: # make tester && ./tester c++ -O -pipe tester.cc -o tester name '3Foo' =3D '3Foo' status=3D-2 name 'Z4mainE3Bar' =3D '(null)' status=3D-2 The current demangling code in libcxxrt is a snapshot of the libelftc deman= gler from 10-ish years ago. If you replace it with the current libelftc demangl= ing code and make some other small changes you can get abi::__cxa_demangle() to= the point where it returns the same slightly-less-wrong results as c++filt (see= PR 222562). Part of the problem with abi::__cxa_demangle() is that it is not correctly glued to the libelftc demangling code. The demangler wants to see a prefix= on the symbol name, like what you see in nm(1) output. That is, typeid(bar).name() returns "Z4mainE3Bar" and the demangle code expects "_ZTSZ4mainE3Bar". (This is the small change I referred to above.) One potential fix for this would be to examine llvm's libcxxabi and possibly import its demangler (or maybe the entire library). I gather this libcxxabi didn't exist when we created/imported libcxxrt. --=20 You are receiving this mail because: You are the assignee for the bug.=