From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jeffrey Walton Newsgroups: gmane.emacs.devel Subject: warning: unsequenced modification and access to 'sa_avail' Date: Sat, 27 Mar 2021 12:05:00 -0400 Message-ID: Reply-To: noloader@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4576"; mail-complaints-to="usenet@ciao.gmane.io" To: Emacs developers Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Mar 27 17:07:37 2021 Return-path: Envelope-to: ged-emacs-devel@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 1lQBTM-00010r-BS for ged-emacs-devel@m.gmane-mx.org; Sat, 27 Mar 2021 17:07:36 +0100 Original-Received: from localhost ([::1]:42672 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lQBTL-0000GY-Dp for ged-emacs-devel@m.gmane-mx.org; Sat, 27 Mar 2021 12:07:35 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:48866) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lQBRE-0007O9-Ho for emacs-devel@gnu.org; Sat, 27 Mar 2021 12:05:24 -0400 Original-Received: from mail-io1-xd35.google.com ([2607:f8b0:4864:20::d35]:35837) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lQBRC-0008ON-QH for emacs-devel@gnu.org; Sat, 27 Mar 2021 12:05:24 -0400 Original-Received: by mail-io1-xd35.google.com with SMTP id x17so8522586iog.2 for ; Sat, 27 Mar 2021 09:05:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:reply-to:from:date:message-id:subject:to; bh=E4NrSirdkhS7w5vAlsHaUYDVZFmWK6KBAliqvSOf4F4=; b=f8a5JzBRYv9KVvFtkigYrLRjpNjPMUjo6IwaSo/TonJ+wYkMqRDe7Mgk4FU5lHVHSR ksjOQz+BRG1O07+IMz5kkEPxmfKDJl+0v0QCOIHqfU8kRlEYNcPwhN1D8g6EktFB4NB5 tjH2RfmDwEFN0UHdrKOWlZLUkodrAZbBROTegS63JoZb6bJtcxKVNp2LpAdFQwYDxu3h evcTk8/hRH10fKmEHKmwpuUCybszl6rJw+NDIlOm9HmhR+fAyz5VDvMlfrZIr7aTxgiQ 9WRgb6Ct0f/suKH6xDKfkUu5OKAb0KIGloN+UF/2V1cCZhXoxYVgwISn+9MtZ3Q87WuM S+Cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:reply-to:from:date:message-id :subject:to; bh=E4NrSirdkhS7w5vAlsHaUYDVZFmWK6KBAliqvSOf4F4=; b=ir7cbqtPVdaQY9Z+tLp/YTzH6Pc77Tmp296FdTH+GsZAjhOnfCnhaV0jIxfPuDG6yp CbVSM8Uai9sFG9CyXeNNW6rg5sa0jGdja4iqDBS7hR8uehKQAyBVBVVbXp82QIfKX6KJ 82pZNzhUv4wKCwcpwhh6g2w0a3RYx25RLZSh//XTuPJG8uTUlRgh+2h9PnV2MzPiGCvI yGp9MbkyNqwl/hz3mevNqPj9IxAQ1x2Xn3LtKNi+4+iOGpFqt+WKHi9zUBiyNkJtvMlQ 0oVKP5eZdXuJBCDN2W4wstqLfUVKRXe2IQ1KZt34AJbVhHMMN/wKkvOcpRJJqNPV+Da6 FWDw== X-Gm-Message-State: AOAM533hTpVDbKUrwpz4HjJ75UA1idDkRN3Tar+H19J/6G5zPPkuol7y 5gz7vykwWXgP1WQbF7Ci9YC1dqVJrv2Fahu6MJn9+4f8Olbsmg== X-Google-Smtp-Source: ABdhPJzpJ6IrQ3cQNIcB84x0ywT0xw7bFS6gqNVizUX6KxDBHk7ph8+1ysejCdzYpQX1mlsAWBu4BtqYoVcdCT5e5qc= X-Received: by 2002:a02:6a5a:: with SMTP id m26mr16738291jaf.17.1616861121444; Sat, 27 Mar 2021 09:05:21 -0700 (PDT) Received-SPF: pass client-ip=2607:f8b0:4864:20::d35; envelope-from=noloader@gmail.com; helo=mail-io1-xd35.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:267103 Archived-At: Hi Everyone, I'm building Emacs 27.2 on the Apple M1 machine. I think the compiler is complaining about undefined behavior: sa_avail -= (size), alloca (size) I think it is equivalent to something like this: data[i] = data[i++]; /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I. -I../lib -I../lib -I/usr/local/include/libxml2 -I/usr/local/include -MMD -MF deps/doc.d -MP -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes -Wno-initializer-overrides -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common -arch arm64 -fPIC -pthread doc.c /usr/bin/clang -c -I/usr/local/include -DNDEBUG -Demacs -I. -I. -I../lib -I../lib -I/usr/local/include/libxml2 -I/usr/local/include -MMD -MF deps/editfns.d -MP -I/usr/local/include -I/usr/local/include/p11-kit-1 -Wno-switch -Wno-pointer-sign -Wno-string-plus-int -Wno-unknown-attributes -Wno-initializer-overrides -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -g2 -O2 -fno-common -arch arm64 -fPIC -pthread editfns.c editfns.c:2063:18: warning: unsequenced modification and access to 'sa_avail' [-Wunsequenced] .deletions = SAFE_ALLOCA (del_bytes), ^ ./lisp.h:4817:9: note: expanded from macro 'SAFE_ALLOCA' ? AVAIL_ALLOCA (size) \ ^ ./lisp.h:4812:38: note: expanded from macro 'AVAIL_ALLOCA' #define AVAIL_ALLOCA(size) (sa_avail -= (size), alloca (size)) ^ Jeff