From owner-freebsd-hackers@freebsd.org Thu Mar 28 14:45:25 2019 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 25E32155F905 for ; Thu, 28 Mar 2019 14:45:25 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-lj1-f180.google.com (mail-lj1-f180.google.com [209.85.208.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4AC0274E1B for ; Thu, 28 Mar 2019 14:45:24 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-lj1-f180.google.com with SMTP id k23so8565508lji.13 for ; Thu, 28 Mar 2019 07:45:24 -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=HCunTQuX4bSMUWTsL34qDoJS201TtLVEQ+yjnCQ/ju4=; b=iVlVYmQ9sHTOVPc/NR4NiLlglkozrQVrvuHyeD2l9nNAgJj0gizcDmy+oIIMwbKnme T7oBEbLnK0nk16792niWdwJxOCTA07B67jR8DZOtrc3sCw7qQu80TwMdMNvxr7P2CsOR 6YqVNlwGE+LPzu7dn6HXlTnxJfqM0d0QXU4QBC1Fq7sZk2yDZ7QPYtEAsdwOhwRRkSyw J2IDcZ8YI3Sd0UdxvdLZ+oZyy9vrWeyXfX/mazKTD4wbw+4uTMRFAE/BiRi+DXUTbwMa EhRViQIxwCeCTXaYJj5GS55lv9BmubrJVtsumIFlYX6shq6HjTQgEDmYblwjf7W8/HmS vE3Q== X-Gm-Message-State: APjAAAVgrrs6eatVKrTXItF28CuWknyTuLFwnGY1/d4pzC2kObJx6iNb bZWcWa0ywiZhea9dXvkgmYWZL8nZ46I+yF7PR/o= X-Google-Smtp-Source: APXvYqw+IQ5+lNDLWaqWg4nu5vBMX0ixZgQ1xO/Ca+abvjyYwxhvIgLGI8ymlIfhk8PFOyPmZL5bV2xqSZt08UyFPoA= X-Received: by 2002:a2e:8582:: with SMTP id b2mr8877664lji.24.1553783843912; Thu, 28 Mar 2019 07:37:23 -0700 (PDT) MIME-Version: 1.0 References: <1fd4571d-0da1-e325-b6a1-a3cc12f2f05d@embedded-brains.de> In-Reply-To: <1fd4571d-0da1-e325-b6a1-a3cc12f2f05d@embedded-brains.de> From: Alan Somers Date: Thu, 28 Mar 2019 08:37:12 -0600 Message-ID: Subject: Re: What is the purpose of BURN_BRIDGES? To: Sebastian Huber Cc: FreeBSD Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 4AC0274E1B X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of asomers@gmail.com designates 209.85.208.180 as permitted sender) smtp.mailfrom=asomers@gmail.com X-Spamd-Result: default: False [-3.06 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.998,0]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; IP_SCORE(-1.30)[ip: (-0.40), ipnet: 209.85.128.0/17(-3.87), asn: 15169(-2.15), country: US(-0.07)]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; DMARC_NA(0.00)[freebsd.org]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_TRACE(0.00)[0:+]; TO_DN_ALL(0.00)[]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[180.208.85.209.list.dnswl.org : 127.0.5.0]; NEURAL_HAM_SHORT(-0.75)[-0.751,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_TLS_LAST(0.00)[]; FORGED_SENDER(0.30)[asomers@freebsd.org,asomers@gmail.com]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[asomers@freebsd.org,asomers@gmail.com]; SUBJECT_ENDS_QUESTION(1.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Mar 2019 14:45:25 -0000 On Thu, Mar 28, 2019 at 6:46 AM Sebastian Huber wrote: > > Hello, > > I turned on BURN_BRIDGES in my global kernel configuration and now I get > undefined references, e.g. > > > No BURN_BRIDGES conditional compilation. Is this option supposed to > work? What is its purpose? I enabled it to get rid of some legacy stuff > in bpf.c. > > -- > Sebastian Huber, embedded brains GmbH I've often wondered that myself. "svn blame" turns up the following. Evidentially the code didn't disappear in 6.0 after all. ------------------------------------------------------------------------ r116236 | imp | 2003-06-11 22:39:32 -0600 (Wed, 11 Jun 2003) | 5 lines New global option: BURN_BRIDGES Compile out code that will disappear in 6.0, per Peter Wemm's bridge burning proposal.