220 31240 article Path: news.gmane.org!.POSTED!not-for-mail From: Oliver Kowalke Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: P0534: call/cc, type safety and exceptions Date: Wed, 1 Mar 2017 12:30:32 +0100 Lines: 69 Approved: news@gmane.org Message-ID: References: <3a57e294-7254-4358-828d-c9f7757f5295@isocpp.org> <9deccbda-26ca-4ad8-a579-1feb674676a6@isocpp.org> <69ee11fb-5cd0-4e1e-8c61-2792fe062003@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=001a114c6fce2d20b30549a9a56f X-Trace: blaine.gmane.org 1488367864 20924 195.159.176.226 (1 Mar 2017 11:31:04 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 1 Mar 2017 11:31:04 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCLZHP5J7MHRB3PB3LCQKGQETDLFMPA@isocpp.org Wed Mar 01 12:30:55 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pf0-f200.google.com ([209.85.192.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cj2T2-0003mV-QF for gclcip-std-proposals@m.gmane.org; Wed, 01 Mar 2017 12:30:49 +0100 Original-Received: by mail-pf0-f200.google.com with SMTP id 6sf45772504pfd.6 for ; Wed, 01 Mar 2017 03:30:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:x-spam-checked-in-group:list-post :list-help:list-archive:list-subscribe:list-unsubscribe; bh=2dom29Elja+yghOWSLohjwlt8PvlSuzrbqcxLjHts1U=; b=jvWlPggixNAuKFJuL2pYJTrVEouvDXSgFTkbd2+dm3N2fl6jo2JFBLsf1k5Kthw5Ul mFTgJimbJF7Dd+tPcdvsrf7FQjnXfn+jVhxvuoe44VOTYaGGMlqtVjuziGUx06WGXsTg U3DrB/7V/cugo6XqrLYsqNEpzB7raGA29vYUgW+RGngaIIv8MlUOiLsO5044AI+bVsyG XFyEgZCemnCyuJ4pKaaN3yTL2wvD/8Em3LJp4kVSU130CoQfHziHA66A1mZ+G2GSKHdu c6o+SsPJAbYEIIXboaC5hqSh4I6whJM9VD1I7b6OxVhzwBXxOqgfbVYHRUCt/ibBpAmV z8vg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=2dom29Elja+yghOWSLohjwlt8PvlSuzrbqcxLjHts1U=; b=Ad0yghFt1Sy1gyZsTUnew0iklGmrjeyrfiZlfGmGHaM0SSAs79L1AMXK1wLshsAg8n QwG46el65Oa7AP85QvER47mBylUlBi5dhzcqzKMwHxxKIejXIOFe7VBI6NPLygOdYM1h UA6yUowj0LqxZfaOxary6b13wR1ROBa+YooHSxYEXDU0C1b1S1OkDbRl2cmniP2B1RwL ZvfKGc5io6GjAck0lCncBALlyHt76ALQHNF0JTtkECVt2bPnC2e2dQV3s8bPAMJVzpbr 9Mu22kZveodTN4ZBsKOYbxBWxL3SRkAQK+pIJRBYANDLxH7hDWQQsbHLacxX4mpoGZUC gEzw== X-Gm-Message-State: AMke39npG7Zo4fm/XLO5t40wGTgWZUilwy0skGcs33JnpW7manr53pia8CPA8u9sdE7ufg== X-Received: by 10.99.189.17 with SMTP id a17mr2631582pgf.53.1488367854407; Wed, 01 Mar 2017 03:30:54 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.68.202 with SMTP id p10ls440907otg.18.gmail; Wed, 01 Mar 2017 03:30:53 -0800 (PST) X-Received: by 10.129.137.7 with SMTP id z7mr367033ywf.122.1488367853640; Wed, 01 Mar 2017 03:30:53 -0800 (PST) Original-Received: from mail-yw0-x22a.google.com (mail-yw0-x22a.google.com. [2607:f8b0:4002:c05::22a]) by mx.google.com with ESMTPS id p65si519425ywb.29.2017.03.01.03.30.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Mar 2017 03:30:53 -0800 (PST) Received-SPF: pass (google.com: domain of oliver.kowalke@gmail.com designates 2607:f8b0:4002:c05::22a as permitted sender) client-ip=2607:f8b0:4002:c05::22a; Original-Received: by mail-yw0-x22a.google.com with SMTP id p77so28983554ywg.1 for ; Wed, 01 Mar 2017 03:30:53 -0800 (PST) X-Received: by 10.129.57.70 with SMTP id g67mr3036484ywa.119.1488367853049; Wed, 01 Mar 2017 03:30:53 -0800 (PST) Original-Received: by 10.129.173.21 with HTTP; Wed, 1 Mar 2017 03:30:32 -0800 (PST) In-Reply-To: <69ee11fb-5cd0-4e1e-8c61-2792fe062003@isocpp.org> X-Original-Sender: oliver.kowalke@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of oliver.kowalke@gmail.com designates 2607:f8b0:4002:c05::22a as permitted sender) smtp.mailfrom=oliver.kowalke@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:31240 Archived-At: --001a114c6fce2d20b30549a9a56f Content-Type: text/plain; charset=UTF-8 you can't use recovery after calling std::invloke() because during the execution of f the context associated with f.ctx/recovery might have been resumed (so recovery points somewhere in the stackframe) or the context was terminated before the exception is thrown out of f. suppose A calls callccc(f) -> that creates B : t.fctx/recovery points to the stack of A B resumes C (created somewhere/before A calls callcc() ...) C resumes A A terminates after A has terminated B is resumed (because A has specified B as the context that has to be resumed after A's termination) B resumes and throws an exception exception is catched in run() returning recovery ends up in UB because the stack space recovery points to is invalidated/deleted or was reused and overwritten .... -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CA%2Bwfc18uQYCsx7cRrg5VhkQYCU8RXFys3DV9j%3D7Xuww2nOtePA%40mail.gmail.com. --001a114c6fce2d20b30549a9a56f Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
you can't use = recovery after calling std::invloke() because during the execution of f the context a= ssociated with f.= ctx/recovery might have been resumed (so recovery points somewhere i= n the stackframe<= /span>) or the context was terminated before the exception is thrown out of= f.

suppose A calls callccc(f) -> that creates B : t.fctx/recovery points=C2= =A0 to the stack of A
B resumes C (created somewhere/before A call= s callcc()= ...)
C resumes A
A terminates
after A has termi= nated B is resumed (because A has specified B as the context that has to be= resumed after A's termination)
B resumes and throws an except= ion
exception is catched in run()
returning recovery ends up in UB because th= e stack space recovery points to is invalidated/deleted or was reused and o= verwritten ....

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To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CA%2Bwfc18uQY= Csx7cRrg5VhkQYCU8RXFys3DV9j%3D7Xuww2nOtePA%40mail.gmail.com.
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