From owner-freebsd-hackers@freebsd.org Wed Sep 14 19:14:39 2016 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 410C3BD6C7C for ; Wed, 14 Sep 2016 19:14:39 +0000 (UTC) (envelope-from cedric.blancher@gmail.com) Received: from mail-pa0-x232.google.com (mail-pa0-x232.google.com [IPv6:2607:f8b0:400e:c03::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 13E2F13AD; Wed, 14 Sep 2016 19:14:39 +0000 (UTC) (envelope-from cedric.blancher@gmail.com) Received: by mail-pa0-x232.google.com with SMTP id cm16so8089880pac.0; Wed, 14 Sep 2016 12:14:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=jIj6XG1UgqebW9PxWEfkWO9+XGEa4AIujSaBT0tCbY8=; b=cq3JcV2IEF9bRNjlu6INcqVSODDdgxqC9ZwvWoChrezIEPixb2WBuYnguIYV2b+KzV xo9T8m0CIywfmmLTWj5jaZeV5eqQA3SC/i1wOEfiEk9sIrMd/Jwx5KjYNdxXstUiPeTS upB6+HPF6zfzBstHpL0x7O3s+V7T6DQoVpm//WTeWDFqiYz+5GM/V1Kv5br9NvULrBz9 KqyOp10HCEolFPPMB3oh1dijWXHHou5EKbxB8QPG92VibT7DjXQl2ALn0NMXCsAWhDpf 97lp6dL/c8lXOO9DGfXM5R5X6axCFblNwdwtuqoCMLCGRFlDKbk9cIaLOURpt2EY9pHS WVqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=jIj6XG1UgqebW9PxWEfkWO9+XGEa4AIujSaBT0tCbY8=; b=QhnGR8Cfk7wNSuGw+p7J9Zh4zqziBNNCZgbEIHRQJfWyK9cHTMG9Xyjcb7gFDLiBiX aD+iJcmhb+PoUadzTVF+bcN2Cs+Hv3pM7lsT80Lp1WrO3KF/zAmGfUUrxrjBs9JcJyol KftrlspYwb0nCeDIuf2OVdjQZrZgqPlrpBj3T4XSya6VfZJBzI/7FUfPAssNs0OeYSAt Vs+oD9FX+GmatilkFlTkbhP8SNpBhjj4+146QsRE+jl0NFWOfwi5fAgk5l+cKt8wyNga P3N5vSWG6oiglVk/rU6ex1lr8SHFyFaIC+JkFt8lWXi6HVf0wkAWQFbFuR/8HEm8Q3+Z urfQ== X-Gm-Message-State: AE9vXwOvONTs1zfmdk44VkF7/2yHCbA0v1ghjxLe8+QltYC6peu9x3LMMcJXjnid12QogoZyFQxF/g1X8naAtQ== X-Received: by 10.66.0.99 with SMTP id 3mr7365933pad.109.1473880478545; Wed, 14 Sep 2016 12:14:38 -0700 (PDT) MIME-Version: 1.0 Received: by 10.66.217.137 with HTTP; Wed, 14 Sep 2016 12:14:37 -0700 (PDT) In-Reply-To: <90f37d14-a187-06b2-6187-7a9c1890a73f@FreeBSD.org> References: <90f37d14-a187-06b2-6187-7a9c1890a73f@FreeBSD.org> From: Cedric Blancher Date: Wed, 14 Sep 2016 21:14:37 +0200 Message-ID: Subject: Re: Is replacing alloca(3) where possible a good thing to do? To: Pedro Giffuni Cc: FreeBSD Hackers Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Sep 2016 19:14:39 -0000 dtrace can do VLA Are there other arguments? Ced On 14 September 2016 at 21:11, Pedro Giffuni wrote: > > > On 14/09/2016 13:54, Cedric Blancher wrote: >> >> Who was the "principal Illumos developer"? I remember some heated >> discussions, mostly rooted in 'we stick with ANSI C' and because the >> CTF/dwarf tools in Illumos were unable to handle VLA and no one was >> interested in fixing the BUGS in their toolchain, so the cheapest >> solution was done: VLA was declared persona non grata. Saves company >> money. > > > Yes, the non-accessibility of VLAs for Dtrace was the main argument. This > was a private conversation with Garrett D'Amore who did some nice > enhancements to our printf(1). > >> Typical Sun policy which was one of the reasons which sealed the >> downfall of Sun Microsystems. >> >> But this is NO ARGUMENT for FreeBSD... > > > Our printf(1) implementation has all their enhancements but uses a VLA > instead of alloca. > > This said, whatever illumos wants to keep in their code is relevant as we > want to make it easy to merge ZFS and Dtrace changes back and forth. > > Pedro. -- Cedric Blancher [https://plus.google.com/u/0/+CedricBlancher/] Institute Pasteur