From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: "Daniel Colascione" Newsgroups: gmane.emacs.devel Subject: Re: Help please! To track down GC trying to free an already freed object. Date: Tue, 2 Apr 2019 13:33:02 -0700 Message-ID: <4a2df4442b4acf2eb2dabd3c2c4227c5.squirrel@dancol.org> References: <20190402112537.GA6212@ACM> <20190402202412.GA25792@ACM> Mime-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="210319"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: SquirrelMail/1.4.23 [SVN] Cc: Daniel Colascione , emacs-devel@gnu.org To: "Alan Mackenzie" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Apr 02 22:33:19 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hBQ5p-000sRe-T4 for ged-emacs-devel@m.gmane.org; Tue, 02 Apr 2019 22:33:14 +0200 Original-Received: from localhost ([127.0.0.1]:37276 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBQ5o-0004xz-Sc for ged-emacs-devel@m.gmane.org; Tue, 02 Apr 2019 16:33:12 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:35676) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBQ5i-0004xs-Hr for emacs-devel@gnu.org; Tue, 02 Apr 2019 16:33:07 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hBQ5h-0006nd-KY for emacs-devel@gnu.org; Tue, 02 Apr 2019 16:33:06 -0400 Original-Received: from dancol.org ([2600:3c01::f03c:91ff:fedf:adf3]:46350) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hBQ5g-0006n5-QD for emacs-devel@gnu.org; Tue, 02 Apr 2019 16:33:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=dancol.org; s=x; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:To:From:Subject:Date:References:In-Reply-To:Message-ID; bh=aC1974uX1rQ/GbruWUn/iGDpfPukIX19kA3B5ul+4kk=; b=rX5jdufKn0eCNeBO36rY2ad5tm7RzMYqUpVHkl8vdYRZrTqGTlIOJGjudpNl0iiCaZGJY0Fa7pLnH2xbRLscQkVzXzLvs3RPqbWmGLe8cK1dpIu3Bf+KhOHLlNjB0o427NeGqVHqnhM2BSfzetzUYDmvmWTBVtlmCGwt2pS4X1l7VFHnUTb2lOk8inraryCpf9wGujGky5RD/uPS6Uj0cr1SEYSz67qUAF0OFymXRxmN07FP/VFri9OGMrxSZ1A1zZcqc2wcbfwk0aoP+7bUW/PixY/75go1hhAG6wiBS+Ut0c+Kxj2wgTBUiipmbjgX88wUE5/97RQvYcV7pT4z9A==; Original-Received: from localhost ([127.0.0.1] helo=dancol.org) by dancol.org with esmtp (Exim 4.84_2) (envelope-from ) id 1hBQ5e-0006Wp-74; Tue, 02 Apr 2019 13:33:02 -0700 Original-Received: from 127.0.0.1 (SquirrelMail authenticated user dancol) by dancol.org with HTTP; Tue, 2 Apr 2019 13:33:02 -0700 In-Reply-To: <20190402202412.GA25792@ACM> X-Priority: 3 (Normal) Importance: Normal X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2600:3c01::f03c:91ff:fedf:adf3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:234899 Archived-At: > Hello, Daniel. > > On Tue, Apr 02, 2019 at 12:09:59 -0700, Daniel Colascione wrote: >> > Hello, Emacs. > >> > I get this problem after a recent merge of master into >> > /scratch/accurate-warning-pos (my branch where I'm trying to implement >> > correct source positions in the byte compiler's warning messages). >> This >> > was a large merge, including bringing in the portable dumper. > >> > Emacs aborts at mark_object L+179 (in alloc.c), because a pseudovector >> > being freed already has type PVEC_FREE, i.e. has been freed already. >> > This object is a "symbol with position", a type of pseudovector which >> > doesn't yet exist outside of this scratch branch. > >> Out of curiosity, why do we need a new C-level type here? > > It's to help solve a bug in the byte compiler, which up until recently > was intractable. The byte compiler frequently (?usually) reports > incorrect line/column numbers in its warning messages. This is due to > the kludge it uses to keep track of them. > > The only current candidate for a fix is for the reader, on a flag being > bound to non-nil, to return "symbols with position" rather than standard > symbols. The "position" associated with the symbol is it's textual > offset from the beginning of the construct in the source file being read. So if I read symbol foo from file1.el and symbol foo from file2.el, I get two different symbol-with-location instances, each tagged with a different source location? Do these symbol objects compare eq to each other?