From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 43546 invoked by alias); 7 Jun 2017 19:23:16 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 43502 invoked by uid 89); 7 Jun 2017 19:23:15 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.3 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,FROM_LOCAL_NOVOWEL,HK_RANDOM_ENVFROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=no version=3.3.2 spammy=Hx-languages-length:1463 X-Spam-User: qpsmtpd, 2 recipients X-HELO: mail-yb0-f178.google.com Received: from mail-yb0-f178.google.com (HELO mail-yb0-f178.google.com) (209.85.213.178) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 07 Jun 2017 19:23:14 +0000 Received: by mail-yb0-f178.google.com with SMTP id f192so5048230yba.2; Wed, 07 Jun 2017 12:23:18 -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:in-reply-to:references:from:date :message-id:subject:to:cc; bh=m4tq/ts1wmXi7tAC6qP99MqtDtV19qlHPNhp0hRT5dM=; b=FmUbPq5LxoZ795yFeBOhAvgQAzyGLhLhzA6eHqmV2EGXIAQIjsmUOUy4RF5C3dKRfo GLH7AsKEf8c3K1yjvENnXpAP5kRjSFLMt6HkrFR4kuWnA4MrDgQ9g2dWu8zJIBeTEULf fa23wpfZEYnblnfxpygug+CDQy6e/E0d/sslRqHFjFwcr7emLjTPBgTVv7kGgUG40D6y ZQ4rtYqfqGz4myz3fVROGFWWOgnexLQqkgrq9hueK5U2yLjqp7Y+j6/PWWroHlnLLpox oFujbEZp/gF+3e1Ku3ntw2+CguT0phnQWvkU0gLymzhIGUcc9TieuoK7wpSThN7m81hu u/ww== X-Gm-Message-State: AODbwcC4nxsLq0FK70p+Lw7udkpzmQO5F6T2O6/XRxp9NuCAuKppPt4z 43E8sNujVE7QyZiEX4DwXJLsLQ8s2g== X-Received: by 10.37.64.21 with SMTP id n21mr8332908yba.205.1496863397240; Wed, 07 Jun 2017 12:23:17 -0700 (PDT) MIME-Version: 1.0 Received: by 10.37.207.14 with HTTP; Wed, 7 Jun 2017 12:23:16 -0700 (PDT) In-Reply-To: <35e4d259-0fcd-520a-51c3-ee7496c303e6@redhat.com> References: <1495487553-19078-1-git-send-email-jcmvbkbc@gmail.com> <35e4d259-0fcd-520a-51c3-ee7496c303e6@redhat.com> From: Max Filippov Date: Wed, 07 Jun 2017 19:23:00 -0000 Message-ID: Subject: Re: [RFC 0/5] xtensa: support dynamic configuration To: Nick Clifton Cc: binutils@sourceware.org, gdb-patches@sourceware.org, Sterling Augustine , David Weatherford , Maxim Grigoriev , Woody LaRue Content-Type: text/plain; charset="UTF-8" X-SW-Source: 2017-06/txt/msg00176.txt.bz2 Hi Nick, On Tue, Jun 6, 2017 at 5:41 AM, Nick Clifton wrote: >> Built toolchain takes configuration >> parameters from the shared object specified in the environment variable. > > Using environment variables to pass configuration information is a bad idea. > > The problem is that it can be very hard to debug problems when environment > variables are involved. Often they are not included in bug reports, which > makes reproducing the problem tricky. > > At the very least you should also provide a command line option which > specifies the path to a file containing the configuration information. If > specified this option should override the environment variable. Ok, let me look at it. > There is also the issue of versioning to consider. Does the configuration > information contain a version number ? What happens if the configuration > information is out of date with respect to the compiler/linker or if the > tools are older than the configuration information ? My intention was to keep versioning of each entity contained in the plugin private to that entity users, because some users may already have some versioning scheme. Regarding the configuration information: its structure size is used as its version, and the structure may only be extended at its end. Newer tools will reject using older configuration, older tools will accept newer configuration. -- Thanks. -- Max