From patchwork Fri Sep 17 08:26:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Xinglu Chen X-Patchwork-Id: 33088 Return-Path: X-Original-To: patchwork@mira.cbaines.net Delivered-To: patchwork@mira.cbaines.net Received: by mira.cbaines.net (Postfix, from userid 113) id 3828C27BBE3; Fri, 17 Sep 2021 09:27:15 +0100 (BST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mira.cbaines.net X-Spam-Level: X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,T_DKIM_INVALID, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mira.cbaines.net (Postfix) with ESMTPS id CF98C27BBE1 for ; Fri, 17 Sep 2021 09:27:14 +0100 (BST) Received: from localhost ([::1]:41772 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mR9DF-0005Sn-Tk for patchwork@mira.cbaines.net; Fri, 17 Sep 2021 04:27:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44928) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mR9D4-0005Kr-5a for guix-patches@gnu.org; Fri, 17 Sep 2021 04:27:02 -0400 Received: from debbugs.gnu.org ([209.51.188.43]:46897) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mR9D3-00013w-TK for guix-patches@gnu.org; Fri, 17 Sep 2021 04:27:01 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1mR9D3-0001st-IN for guix-patches@gnu.org; Fri, 17 Sep 2021 04:27:01 -0400 X-Loop: help-debbugs@gnu.org Subject: [bug#50614] [PATCH] build: utils: Add =?utf-8?b?4oCYbGlzdC13aGVu?= =?utf-8?b?4oCZ?= macro. Resent-From: Xinglu Chen Original-Sender: "Debbugs-submit" Resent-CC: guix-patches@gnu.org Resent-Date: Fri, 17 Sep 2021 08:27:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 50614 X-GNU-PR-Package: guix-patches X-GNU-PR-Keywords: patch To: 50614@debbugs.gnu.org Cc: Sarah Morgensen , Liliana Marie Prikler Received: via spool by 50614-submit@debbugs.gnu.org id=B50614.16318672167232 (code B ref 50614); Fri, 17 Sep 2021 08:27:01 +0000 Received: (at 50614) by debbugs.gnu.org; 17 Sep 2021 08:26:56 +0000 Received: from localhost ([127.0.0.1]:58443 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mR9Cx-0001sZ-Pq for submit@debbugs.gnu.org; Fri, 17 Sep 2021 04:26:56 -0400 Received: from h87-96-130-155.cust.a3fiber.se ([87.96.130.155]:33300 helo=mail.yoctocell.xyz) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mR9Cw-0001sL-2L for 50614@debbugs.gnu.org; Fri, 17 Sep 2021 04:26:55 -0400 From: Xinglu Chen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yoctocell.xyz; s=mail; t=1631867204; bh=kf65h+k4wrgAm6eIOeqOs33UDqKrUmq0pRMkl2GKBzE=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=jDNQGHx/wuXtQ4GJZ7obXeGyxXRduj45cWzDbErysec+Qb8LQNf0qScGnT+dU8+AG biAjVTkAE6fxzOjZfY5uS9kFHbD35jSmBWuD+mGJtRmGetboq80JRIxYmhct55yscy ctg7ayXIK5T/NSCm6Ra6L95StjC2p1WULBsTS+kg= In-Reply-To: References: Message-Id: <08db559a4e24a409d332b3552d6a176de6353166.1631867018.git.public@yoctocell.xyz> Date: Fri, 17 Sep 2021 10:26:41 +0200 MIME-Version: 1.0 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: guix-patches@gnu.org List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-patches-bounces+patchwork=mira.cbaines.net@gnu.org Sender: "Guix-patches" X-getmail-retrieved-from-mailbox: Patches * guix/build/utils.scm (list-when): New syntax * tests/build-utils.scm ("list-when: expr1 is non-#f", list-when: expr1 is #f"): Test it. * guix.texi (Build Utilities): Document it. --- Changes since v1: * Rename ‘optional’ to ‘list-when’. * Make (list-when test consequent ...) equivalent to (if tests (list consequent ...) '()) doc/guix.texi | 35 +++++++++++++++++++++++++++++++++++ guix/build/utils.scm | 17 ++++++++++++++++- tests/build-utils.scm | 8 ++++++++ 3 files changed, 59 insertions(+), 1 deletion(-) base-commit: 22f7d4bce1e694b7ac38e62410d76a6d46d96c5d diff --git a/doc/guix.texi b/doc/guix.texi index 9a3e8ae12c..3b469c04c9 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -8801,6 +8801,41 @@ in a build phase of the @code{wireguard-tools} package: `("PATH" ":" prefix ,(list coreutils)))))) @end lisp +@subsection Miscellaneous + +@cindex miscellaneous build utilities +This section documents some miscellaneous utilities that are useful to +have. + +@deffn {Scheme Syntax} list-when @var{test} @var{consequent} @dots{} +Like @code{when} (@pxref{Conditionals,,, guile, GNU Guile Reference +Manual}), but if @var{test} evaluates to true, return @code{(list +@var{consequent} @dots{})}, and if @var{test} evaluates to false, return +the empty list. This is replaces the following idiom: +@end deffn + +@lisp +(if @var{test} + (list @var{consequent} @dots{}) + '()) +@end lisp + +with this: + +@lisp +(list-when @var{test} @var{consequent} @dots{}) +@end lisp + +It can be useful when certain targets require an additional configure +flags, e.g., + +@lisp +(arguments + `(#:configure-flags (list "--localstatedir=/var" + "--sysconfdir=/etc" + ,@@(list-when (hurd-target?) "--with-courage")))) +@end lisp + @subsection Build Phases @cindex build phases diff --git a/guix/build/utils.scm b/guix/build/utils.scm index 3beb7da67a..d3fb207ee5 100644 --- a/guix/build/utils.scm +++ b/guix/build/utils.scm @@ -8,6 +8,7 @@ ;;; Copyright © 2020 Efraim Flashner ;;; Copyright © 2020, 2021 Maxim Cournoyer ;;; Copyright © 2021 Maxime Devos +;;; Copyright © 2021 Xinglu Chen ;;; ;;; This file is part of GNU Guix. ;;; @@ -123,7 +124,9 @@ make-desktop-entry-file - locale-category->string)) + locale-category->string + + list-when)) ;;; @@ -1613,6 +1616,18 @@ returned." LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE LC_TIME))) + +;;; +;;; Misc. +;;; + +;; If EXPR1 evaluates to a non-#f value, return '(EXPR2 ...). Otherwise, +;; return an empty list. +(define-syntax list-when + (syntax-rules () + ((_ expr1 expr2 ...) + (if expr1 (list expr2 ...) '())))) + ;;; Local Variables: ;;; eval: (put 'call-with-output-file/atomic 'scheme-indent-function 1) ;;; eval: (put 'call-with-ascii-input-file 'scheme-indent-function 1) diff --git a/tests/build-utils.scm b/tests/build-utils.scm index 6b131c0af8..b558feb47d 100644 --- a/tests/build-utils.scm +++ b/tests/build-utils.scm @@ -3,6 +3,7 @@ ;;; Copyright © 2019 Ricardo Wurmus ;;; Copyright © 2021 Maxim Cournoyer ;;; Copyright © 2021 Maxime Devos +;;; Copyright © 2021 Xinglu Chen ;;; ;;; This file is part of GNU Guix. ;;; @@ -287,5 +288,12 @@ print('hello world')")) ("guile/bin" . ,(dirname (which "guile")))) "guile")))) +(test-equal "list-when: expr1 is non-#f" + (list 3 'bar) + (list-when 'foo (+ 1 2) 'bar)) + +(test-equal "list-when: expr1 is #f" + '() + (list-when #f (+ 2 3) 'bar)) (test-end)