From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by sourceware.org (Postfix) with ESMTPS id 9D522385E009 for ; Thu, 26 Mar 2020 02:47:32 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 9D522385E009 Received: by mail-wr1-x441.google.com with SMTP id 65so6035294wrl.1 for ; Wed, 25 Mar 2020 19:47:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=dWywMHFqrpKHbedZO1AJPG8z+7ITSx4VDxo2r6SOYpU=; b=EFuH8B1zPeVpBj9wtCOkZaf/LZczbcMDsFfdnS9gTAFDY6eIW14REPZG3NPm/D4RQe RyuGTaFwp4RUrM/SJc5VUo/I00KyBHmTHrapJEiAeCsHG2lG/vS4/IrlTRMmkPweL/C7 ZKhiYKPXrzC4CnAybDm7Tg7CT+BERc5+57z41yevu3Hku5APHcaqb70cuDczmgZ2RDPS ef7SmlfW6oZLtlLvdyssAHQeJz13fCqMcC5p/pvB0Lj/HDsKTa1MITpH0vyxXFbV59ZD sqtOBBndSb+fy/fRAFKB3+K6JJEjwdi7JRiNwdE8w7XC+T7vHT7y7H1eGYSOpv62w0zb AJbg== X-Gm-Message-State: ANhLgQ1pnLDipcB5K0NVQpOYuAyd3tlOnFPw0mokOReJHMSEUviUfHg4 Ei/blyNKEbzHpEpah7zH27f2PqEjjLlSsE0Y5hdNFrhS X-Google-Smtp-Source: ADFU+vuwlMmC9k2erP0kUrPgzUuRqq8+9rGNtC97066WxVXZXjPnyQfUEXi5ADvK5JZYdrclVYQk04zrp1dCKvGAAR0= X-Received: by 2002:a5d:5106:: with SMTP id s6mr6605169wrt.24.1585190851600; Wed, 25 Mar 2020 19:47:31 -0700 (PDT) MIME-Version: 1.0 References: <20200220155820.22809-1-tromey@adacore.com> <87sgip6rk9.fsf@tromey.com> <665eda59-ae52-42f4-b3b2-e3a070036ca8@linaro.org> <8736adi7f5.fsf@tromey.com> <9b864a68-3c28-9c25-6e3d-252777143e52@linaro.org> <87blojdgfc.fsf@tromey.com> In-Reply-To: <87blojdgfc.fsf@tromey.com> From: Luis Machado Date: Wed, 25 Mar 2020 23:47:20 -0300 Message-ID: Subject: Re: [PATCH] Find tailcall frames before inline frames To: Tom Tromey Cc: Tom Tromey , "gdb-patches\\@sourceware.org" X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, HTML_MESSAGE, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Mar 2020 02:47:34 -0000 On Wed, Mar 25, 2020, 22:59 Tom Tromey wrote: > >>>>> "Luis" == Luis Machado writes: > > Luis> Having spent a few days trying to understand this problem, it seems > Luis> all of these fi->level assertions (including > Luis> https://sourceware.org/bugzilla/show_bug.cgi?id=22748) are related > to > Luis> attempting to unwind from places not safe to do so. That is, we're > Luis> trying to unwind some content (registers for example) before a given > Luis> frame is assigned a frame id. > > Yes, I agree. > > Luis> I think dwarf2_tailcall_sniffer_first would have to be called from > Luis> somewhere else, or conditions put in place. But I'm afraid adding > more > Luis> conditions would complicate things further. And this code is already > Luis> reasonably complicated. > > Luis> Since this is causing a number of inlining test failures for aarch64 > Luis> and, from what i saw, some other architectures like s390, should we > Luis> consider reverting this while we discuss/review a reworked version of > Luis> the patch? > > I think that would be fine. I haven't found the time to really dig into > it. > > I suspect that maybe the architectures doing this aren't playing by the > rules. > Even so, though, it doesn't change that this used to work and now doesn't. > It could be. I noticed aarch64 doesn't implement gdbarch_unwind_pc. But s390 does. It is hard to tell what is wrong given different unwinding implementations may give correct results, even with wrong assumptions. > Tom >