From patchwork Thu Nov 21 19:41:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Harald van Dijk X-Patchwork-Id: 1199118 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=gcc-patches-return-514352-incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=gigawatt.nl Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b="pvPCePv2"; dkim=pass (1024-bit key; secure) header.d=gigawatt.nl header.i=@gigawatt.nl header.b="JteDHk4P"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47Jqgc3vygz9sPV for ; Fri, 22 Nov 2019 06:41:30 +1100 (AEDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:to :from:subject:message-id:date:mime-version:content-type; q=dns; s=default; b=p4rGIxCq8IIYPvoYlwrdLmlHUTpfC/BVS82G1iiBL2ECk8Qjjr y/9qhKFi8rXmgg91P02CsSIOSHYv/IL4KwWpOo8nEUrd9p3ozsEpoZIVedG/3Gsz gH2FHvNZ8lkgMZFN5V0EHCzyj7bnVSYoKmyzkEZow4fbax6+eowSyRy+0= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:to :from:subject:message-id:date:mime-version:content-type; s= default; bh=OzzgFg+pgGZwiueKHpWdInim0nE=; b=pvPCePv2YW3kZ7ZLrGXp gN/ytsmcAUc7fTfOk1mFpCUtU76i4/7gtXGKek2kvBiBRcOmWw0ydDNTmFPoK9C5 uMb/YQ77WdPXItJD2U9inHt7nkofePrGwG2KeLbjEcwotCUKQFrMzT9EPT50U3D9 lMCioxOHE/ofJTFkvw8ieCs= Received: (qmail 118099 invoked by alias); 21 Nov 2019 19:41:23 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 118091 invoked by uid 89); 21 Nov 2019 19:41:23 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-8.4 required=5.0 tests=AWL, BAYES_00, CLAIM_SUBJECT, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_PASS autolearn=ham version=3.3.1 spammy=conform, H*F:D*nl, HX-Spam-Relays-External:sk:mail.gi, H*RU:sk:mail.gi X-HELO: mail.gigawatt.nl Received: from mail.gigawatt.nl (HELO mail.gigawatt.nl) (51.68.198.76) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 21 Nov 2019 19:41:21 +0000 Received: from [192.168.1.2] (hvdijk.plus.com [81.174.157.28]) by mail.gigawatt.nl (Postfix) with ESMTPSA id 47FFF753 for ; Thu, 21 Nov 2019 20:41:18 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.gigawatt.nl 47FFF753 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gigawatt.nl; s=default; t=1574365278; bh=ZU7VuqvkSJeQkXXjAiQhn2+SoWUGUq25N3UMKVVY6hs=; h=To:From:Subject:Date:From; b=JteDHk4PLFRR/dS1AZ4qN+KruEQMslyUrlhLm/nQoYcT2jPGQRgeF+3uoYV7/1vIg o/Oyn/ly5b5QHlekSTpRETnMNngy7xDq/Akb+WUejM8TaUG2oII26jkyC5e8EHKcyA u99GftS8Vm74yQQUbJsPWojWi7pwA7YRmaH2qehc= To: GCC Patches From: Harald van Dijk Subject: [PATCH] doc: Remove claim about ISO C Message-ID: <7f9cd171-05ac-be8f-a6ca-2c007d4b2acb@gigawatt.nl> Date: Thu, 21 Nov 2019 19:41:32 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:71.0) Gecko/20100101 Thunderbird/71.0 MIME-Version: 1.0 Hi, The patch to make -fcommon the default introduces a bogus claim into the GCC documentation. I already raised this issue on the patch itself, where it was unfortunately ignored. Please find attached a followup patch to remove this bogus claim. -fcommon was claimed to be incompatible with ISO C for preventing duplicate definitions from being diagnosed. It does, but as that elicits undefined behaviour (the requirement that there shall be no more than one external definition is not a constraint), ISO C does not require any diagnostic for it. In the absence of any other rule this would violate, both -fcommon and -fno-common are fully compatible with all versions of ISO C. Cheers, Harald van Dijk * doc/invoke.texi (-fcommon): Remove claim about ISO C. --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -14141,9 +14141,9 @@ than one compilation unit. The @option{-fcommon} places uninitialized global variables in a common block. This allows the linker to resolve all tentative definitions of the same variable in different compilation units to the same object, or to a non-tentative -definition. This behavior does not conform to ISO C, is inconsistent with C++, -and on many targets implies a speed and code size penalty on global variable -references. It is mainly useful to enable legacy code to link without errors. +definition. This behavior is inconsistent with C++, and on many targets implies +a speed and code size penalty on global variable references. It is mainly +useful to enable legacy code to link without errors. @item -fno-ident @opindex fno-ident