From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11973 invoked by alias); 4 May 2003 20:56:01 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 11949 invoked by uid 71); 4 May 2003 20:56:00 -0000 Date: Sun, 04 May 2003 20:56:00 -0000 Message-ID: <20030504205600.11948.qmail@sources.redhat.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Zack Weinberg Subject: Re: preprocessor/10613: Please make -Wtrigraphs the default Reply-To: Zack Weinberg X-SW-Source: 2003-05/txt/msg00252.txt.bz2 List-Id: The following reply was made to PR preprocessor/10613; it has been noted by GNATS. From: Zack Weinberg To: Neil Booth Cc: Hallvard B Furuseth , gcc-gnats@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: Re: preprocessor/10613: Please make -Wtrigraphs the default Date: Sun, 04 May 2003 13:55:35 -0700 Neil Booth writes: > This is a patch for preprocessor/10613 and preprocessor/10614. We warn > about trigraphs, unless an explicit -trigraphs (or -std implying > -trigraphs) is given. -Wall still implies -Wtrigraphs. Looks good. The only thing I have to say is that this bit of documentation > This option is in effect unless trigraphs are turned on, and is > implied by @option{-Wall}. With the exception of a trigraph that > would form an escaped newline, warnings are not given for trigraphs > within comments as they do not affect the meaning of the program. is confusing. I would say instead Most trigraphs in comments cannot affect the meaning of the program. However, a trigraph that would form an escaped newline (@samp{??/} at the end of a line) can, by changing where the comment begins or ends. Therefore, only trigraphs that would form escaped newlines produce warnings inside a comment. This option is implied by @option{-Wall}. If @option{-Wall} is not given, this option is still enabled unless trigraphs are enabled. To get trigraph conversion without warnings, but get the other @option{-Wall} warnings, use @samp{-trigraphs -Wall -Wno-trigraphs}. zw