From owner-freebsd-arm@FreeBSD.ORG Thu Aug 21 16:54:56 2014 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 78379778; Thu, 21 Aug 2014 16:54:56 +0000 (UTC) Received: from mail-lb0-x229.google.com (mail-lb0-x229.google.com [IPv6:2a00:1450:4010:c04::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C16DE3C5A; Thu, 21 Aug 2014 16:54:55 +0000 (UTC) Received: by mail-lb0-f169.google.com with SMTP id s7so8452084lbd.0 for ; Thu, 21 Aug 2014 09:54:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=aaiSe+1DBAXIMSvFC0rmkiS07nhUU7qJ5Mw+L7EhC0I=; b=zo+pKLxciQdPZzgOCpQR5Ayzc4+y6sl7O54RmFrqj0dyabxDm6+7LsGiHSlQsD2EJ+ uPFpo9Kk2wdLkuxobxq1efMbZKfuhMIj2iVyjl2yenGTm2SSpUw87NMUe4XPbK1IxUkP 4xoJgvd3ALQrFGmYZnb/0qt+PTpv3gZ+Wy0AJULb+X/zVtyEyY2d8wMz+tduK6aRkreX FQPBg/HdHZBOB9WsZLv6Umo2xFUjoHS00lFnpduxxWEQEhrz9WA+dOjiLzwDCzakFa9p HszBmjfx1/Fkt2+okBi3e4ClvDjJgJ/CyS5J3Fi4SCzzHtarFIH+LH55/HT30BCL42rn QeqQ== X-Received: by 10.112.50.230 with SMTP id f6mr47372905lbo.56.1408640093718; Thu, 21 Aug 2014 09:54:53 -0700 (PDT) Received: from [192.168.1.101] (c-d135e155.556-1-64736c11.cust.bredbandsbolaget.se. [85.225.53.209]) by mx.google.com with ESMTPSA id a12sm38785949lbq.0.2014.08.21.09.54.51 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 21 Aug 2014 09:54:52 -0700 (PDT) Content-Type: text/plain; charset=iso-8859-7 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: C++ exceptions in freebsd-arm doesn't seem to work From: Olavi Kumpulainen In-Reply-To: <1408562392.1150.4.camel@revolution.hippie.lan> Date: Thu, 21 Aug 2014 18:54:49 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <2C97B126-91FE-4E93-920F-6ED5045666A6@gmail.com> References: <1405809318.85788.35.camel@revolution.hippie.lan> <1406063473.71975.8.camel@revolution.hippie.lan> <53D2CFBE.3040207@fgznet.ch> <834BA562-84ED-425C-9D61-0A235A28A94A@gmail.com> <1408472517.56408.659.camel@revolution.hippie.lan> <1408562392.1150.4.camel@revolution.hippie.lan> To: Ian Lepore X-Mailer: Apple Mail (2.1878.6) Cc: freebsd-arm@freebsd.org X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Aug 2014 16:54:56 -0000 On 20 Aug 2014, at 21:19 , Ian Lepore wrote: > On Wed, 2014-08-20 at 19:19 +0200, Olavi Kumpulainen wrote: >> On 19 Aug 2014, at 20:21 , Ian Lepore wrote: >>=20 >>> On Tue, 2014-08-19 at 19:40 +0200, Olavi Kumpulainen wrote: >>>> On 25 Jul 2014, at 23:44 , Andreas Tobler = wrote: >>>>=20 >>>>> On 22.07.14 23:11, Ian Lepore wrote: >>>>>> On Sat, 2014-07-19 at 16:35 -0600, Ian Lepore wrote: >>>>>>> On Sat, 2014-06-07 at 14:12 +0200, Olavi Kumpulainen wrote: >>>>>>>> [c++ exceptions don't work and related discussion] >>>>>>>=20 >>>>>>> I checked in a partial fix for c++ exception handling in = r268893. It >>>>>>> fixes the specific problem you detailed above, which was = essentially >>>>>>> that the __gnu_Unwind_Find_exidx() function was not available in = any >>>>>>> shared library, making the unwinder fall back to using the = __exidx_start >>>>>>> and end symbols, which are only valid in a statically-linked = app. >>>>>>>=20 >>>>>>> With the new function in place, exceptions are closer to working = with >>>>>>> gcc 4.2.1, but still don't work with clang. With gcc, some = things work >>>>>>> and some things don't. For example if you throw an exception = and in the >>>>>>> same function have a catch with the right specific type it = segfaults, >>>>>>> but a catch(...) will catch it without problems. But you can = catch an >>>>>>> exception by type if the catch is in a function higher up the = call chain >>>>>>> from the place it was thrown. >>>>>>>=20 >>>>>>> We're continuing to debug this at $work, and welcome any input = if anyone >>>>>>> else makes progress with it. Right now we still don't know = whether the >>>>>>> segfaults are because of bad unwinder library code or bad unwind = data >>>>>>> emitted by gcc. (I sure hope it's the library, because that's = easier to >>>>>>> fix.) >>>>>>>=20 >>>>>>> On the clang front, it has been said that c++ exceptions work in = clang >>>>>>> 3.5, so we tried the clang-devel port, and it didn't just work. = But it >>>>>>> turns out that port hasn't been updated for quite a while, so we = may not >>>>>>> have tested the code that's supposed to work right. While = trying that I >>>>>>> discovered that clang 3.5 isn't scheduled for release for about = another >>>>>>> year, so that really isn't a viable solution for anyone with = near-term >>>>>>> needs, unless the required changes can be cherry-picked and = brought into >>>>>>> our version of 3.4. >>>>>>>=20 >>>>>>> -- Ian >>>>>>=20 >>>>>> Another update to this... today I committed r268993 and r268994, = and now >>>>>> I believe arm eabi c++ exceptions are fully working with gcc. I = haven't >>>>>> run an extensive test suite, but all the test cases we've been = using at >>>>>> $work to debug this now work correctly. >>>>>=20 >>>>> Thank you! Confirmed. My test cases which are working with = gcc-4.10 are now also working with the system gcc, 4.2.1. >>>>> I totally forgot about this change. I have it in my local gcc tree = since a while but I forgot about..... >>>>>=20 >>>>> Andreas >>>>>=20 >>>>>=20 >>>>=20 >>>> Please excuse my late reply. I=A2ve been away from keyboard for a = while. >>>>=20 >>>> I back-ported r268893, r268993 and r268994 to stable/10 for = beaglebone. C++ exceptions works for static builds, but not for binaries = linked to shared libs. >>>>=20 >>>> Since this seems to work ok in HEAD, I=A2m obviously missing = something. Do any of you guys have any ideas? >>>>=20 >>>> Cheers >>>>=20 >>>=20 >>> I'm not sure what you mean by "backported to stable/10", I merged = all >>> the necessary changes to stable-10 as r269792 on Aug 10. Are you >>> working with a checkout from earlier than that? If so, just = updating >>> should fix it for you. >>>=20 >>> -- Ian >>>=20 >>>=20 >>=20 >>=20 >> Updating to stable-10 as of today didn=A2t help. I=A2m running a = clean checkout except for a couple of drivers in the kernel. >> This makes me think I have a bad src.conf - How shall I configure the = build for this to work? >>=20 >> /Olavi >>=20 >>=20 >>=20 >>=20 >=20 > You need to use GCC, not clang, as the compiler. Exceptions are just > broken on clang 3.4, so we're waiting for 3.5 (should be released any > time now I think). >=20 > To compile with gcc, put this in your /etc/make.conf: >=20 > WITH_GCC=3Dyes > WITH_GNUCXX=3Dyes > WITH_GCC_BOOTSTRAP=3Dyes > WITHOUT_CLANG=3Dyes > WITHOUT_CLANG_IS_CC=3Dyes > WITHOUT_CLANG_BOOTSTRAP=3Dyes >=20 > -- Ian >=20 >=20 Thank you. It turned out that I already used these with the exception of = WITHOUT_CLANG_BOOTSTRAP. However, c++ exceptions in stable/10 is still defunct when I build it.=20= So instead I pulled master, built and installed that instead. And voila = - Exceptions do work!=20 Therefore it seems my build method, flags and environment is ok after = all. I glanced the commit logs in master but didn=A2t find anything = obvious, but still; something related seems missing in stable/10 if you = ask me. /Olavi