From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4960 invoked by alias); 7 Aug 2011 21:21:13 -0000 Received: (qmail 4951 invoked by uid 22791); 7 Aug 2011 21:21:13 -0000 X-SWARE-Spam-Status: No, hits=-2.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 07 Aug 2011 21:20:59 +0000 From: "tkoenig at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/47659] -Wconversion[-extra] should emit warning for constant expressions X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: fortran X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: tkoenig at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P5 X-Bugzilla-Assigned-To: tkoenig at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Sun, 07 Aug 2011 21:21:00 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2011-08/txt/msg00804.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47659 --- Comment #3 from Thomas Koenig 2011-08-07 21:20:36 UTC --- Created attachment 24945 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24945 Proposed patch Here's a patch. For real a a = 2.3d0 it checks for truncation correctly and only warns if digits are lost. Unfortunately, for the case of double precision a a = 1.2 I don't see a good way of getting at the original string of numbers to see if the 1.2 would have been interpreted differently if it had been a double precision number. What should we do? Not warn for integers (like I did here) or warn unconditionally?