From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26020 invoked by alias); 23 Oct 2011 01:55:18 -0000 Received: (qmail 26010 invoked by uid 22791); 23 Oct 2011 01:55:18 -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, 23 Oct 2011 01:55:04 +0000 From: "redi at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/42356] improve list of candidates and error recovery for ambiguous call Date: Sun, 23 Oct 2011 01:55:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: enhancement X-Bugzilla-Who: redi at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned 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 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: 2011-10/txt/msg02340.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42356 --- Comment #17 from Jonathan Wakely 2011-10-23 01:54:17 UTC --- But for this testcase I don't want to be told overload resolution passed or failed, I want to be told it's ambiguous, because that's the error in the testcase that prevents it compiling, and the diagnostic should help fix that problem. You say clang's output is nicer, I think you should look again. Notice there are 6 overloads: freeListf(), freeListf(U), and freeListf(U,V), freeListf(), freeListf(U), and freeListf(U,V), Clang prints 4 errors (which appear to be duplicates, but actually refer to freeList and freeList but that's not shown). Why are the other two overloads not shown? Why doesn't it mention that the call is ambiguous? It fails to state the problem, and misleadingly implies overload resolution failed. G++ mentions all six and correctly says they're ambiguous. It would be better if it said why (name lookup found "newNode" in multiple base classes) as clang does for this code (which it gets right): template struct A { template void f(U); }; struct C : A, A { }; int main() { C c; c.f(); }