From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#63556: 29.0.90; Use of _Generic breaks Emacs build on GCC <4.9 Date: Thu, 18 May 2023 17:12:27 +0300 Message-ID: <83r0rdvid0.fsf@gnu.org> References: <4b378d55-ef65-7a0f-b03d-e304785cf60d@cs.ucla.edu> <87v8gp51ys.fsf@yahoo.com> <83wn15vpb0.fsf@gnu.org> <87r0rd4vww.fsf@yahoo.com> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39138"; mail-complaints-to="usenet@ciao.gmane.io" Cc: sbaugh@janestreet.com, eggert@cs.ucla.edu, 63556@debbugs.gnu.org To: Po Lu Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Thu May 18 16:13:15 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pzeNV-0009uX-36 for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 18 May 2023 16:13:13 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pzeNM-00005X-Jw; Thu, 18 May 2023 10:13:04 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzeNL-00005O-8d for bug-gnu-emacs@gnu.org; Thu, 18 May 2023 10:13:03 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pzeNL-0005X0-0S for bug-gnu-emacs@gnu.org; Thu, 18 May 2023 10:13:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pzeNK-0003Lh-Bz for bug-gnu-emacs@gnu.org; Thu, 18 May 2023 10:13:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 18 May 2023 14:13:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 63556 X-GNU-PR-Package: emacs Original-Received: via spool by 63556-submit@debbugs.gnu.org id=B63556.168441914712821 (code B ref 63556); Thu, 18 May 2023 14:13:02 +0000 Original-Received: (at 63556) by debbugs.gnu.org; 18 May 2023 14:12:27 +0000 Original-Received: from localhost ([127.0.0.1]:53975 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pzeMl-0003Kj-Gd for submit@debbugs.gnu.org; Thu, 18 May 2023 10:12:27 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:55502) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pzeMh-0003KQ-LT for 63556@debbugs.gnu.org; Thu, 18 May 2023 10:12:26 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzeMb-0005ME-9u; Thu, 18 May 2023 10:12:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=JmpM75UGetfpiSeE0J+g8bKBoIUDGS/3Ny50BEqVLN4=; b=erDVFn93dwxx eY56eSLwpUDLFGQiVIEmkJRQmhKtCzh7Aa6JaubEZY+hBOJAi5wzm7gEZhtXNIS2BmshcuTARfd22 /WOlKGK5YslReaLzbndt2La4I/CNUQXzRDWYh1B89X1ik35l2qToG+ciOomNaxohhhsqlvjxHWuwH b8YEILgBV5HQ1hAPeyqEU5HbIQmC0Scq6JzOTixQZGjh5LpMhOqy9Lp95aKXWpBmLNH7pegVSTKSm eJSEUUHatlOzWWdSXxISc3jdpmxWiVn9jfGNzj+5ldZ1w9tu1dTIhnwDLx+ZXQVSZiLLcjw3pvd6A dO1l08TkWH5I/gQ2q3dUsA==; Original-Received: from [87.69.77.57] (helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzeMa-0001sW-Pw; Thu, 18 May 2023 10:12:17 -0400 In-Reply-To: <87r0rd4vww.fsf@yahoo.com> (message from Po Lu on Thu, 18 May 2023 21:21:51 +0800) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:261932 Archived-At: > From: Po Lu > Cc: eggert@cs.ucla.edu, sbaugh@janestreet.com, 63556@debbugs.gnu.org > Date: Thu, 18 May 2023 21:21:51 +0800 > > Eli Zaretskii writes: > > > Depends on how complex is that, and what problem does it solve. > > The problem of using `long long' on systems with less than 64 > significant bits in their words. I don't think that's a particularly > good idea -- once such uses pile up, Emacs will gradually become slower > and slower on such systems. What does this have to do with _Generic? > >> #define foo(expression) \ > >> (sizeof (expression) == sizeof (signed char) \ > >> ? code_for_signed_char \ > >> : (sizeof (expression) == sizeof (short int) \ > >> ? code_for_short_int \ > >> : (sizeof (expression) == sizeof (int) \ > >> ? code_for_int \ > >> ... and so on > > > > AFAIR, sizeof is a compile-time expression, the preprocessor cannot > > evaluate it. > > It doesn't have to be evaluated by the preprocessor (and nor is > _Generic.) It just needs to expand to an expression that does the right > thing. And what is "the right thing" in this case? I guess I don't understand what this has to do with _Generic.