From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ricardo Wurmus Subject: Re: =?utf-8?Q?=E2=80=98core-updates=E2=80=99?= is back! Date: Tue, 05 Sep 2017 15:21:46 +0200 Message-ID: <87h8whuvpx.fsf@elephly.net> References: <878ti3uzaz.fsf@gnu.org> <87val6zqg0.fsf@igalia.com> <87lgm14btg.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:48606) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpDoR-0006Uf-Vb for guix-devel@gnu.org; Tue, 05 Sep 2017 09:22:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dpDoN-0007oM-6D for guix-devel@gnu.org; Tue, 05 Sep 2017 09:22:43 -0400 In-reply-to: <87lgm14btg.fsf@gnu.org> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Ludovic =?utf-8?Q?Court=C3=A8s?= Cc: guix-devel Andy wrote: > It would be pretty cool if we could fix our O(n^2) problems in search > paths in this core-updates -- basically whenever you go to create an > environment, instead of making e.g. VAR=A:B:C:..., for all VARs > (LIBRARY_PATH, PKG_CONFIG_PATH, etc), instead we make a union directory > Z containing the union of A, B, C, etc and set VAR=Z. The goal would be > to fix quadratic run-time lookup costs by replacing it with a > compile-time computation. This applies to many lookups: PATH, -rpath, > etc. Ludo wrote: > A possible alternative solution for ld.so is at > . Do you know of any negative side effects this would have? For example, would it not become impossible to override libraries at runtime with LD_LIBRARY_PATH or LD_PRELOAD when “-lfoo” is replaced by the absolute file name of the “foo” library? -- Ricardo GPG: BCA6 89B6 3655 3801 C3C6 2150 197A 5888 235F ACAC https://elephly.net