From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2122) id EC7143850426; Tue, 8 Dec 2020 20:13:08 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org EC7143850426 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jason Merrill To: gcc-cvs@gcc.gnu.org Subject: [gcc r11-5865] c++: Distinguish ambiguity from no valid candidate X-Act-Checkin: gcc X-Git-Author: Jason Merrill X-Git-Refname: refs/heads/master X-Git-Oldrev: 447f99b3b8baabbfb33b29123113637e54c5e652 X-Git-Newrev: a988a398d6daef3072cd2d07a21980911d8f93fc Message-Id: <20201208201308.EC7143850426@sourceware.org> Date: Tue, 8 Dec 2020 20:13:08 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Dec 2020 20:13:09 -0000 https://gcc.gnu.org/g:a988a398d6daef3072cd2d07a21980911d8f93fc commit r11-5865-ga988a398d6daef3072cd2d07a21980911d8f93fc Author: Jason Merrill Date: Mon Dec 7 17:21:47 2020 -0500 c++: Distinguish ambiguity from no valid candidate Several recent C++ features are specified to try overload resolution, and if no viable candidate is found, do something else. But our error return doesn't distinguish between that situation and finding multiple viable candidates that end up being ambiguous. We're already trying to separately return the single function we found even if it ends up being ill-formed for some reason; for ambiguity let's pass back error_mark_node, to be distinguished from NULL_TREE meaning no viable candidate. gcc/cp/ChangeLog: * call.c (build_new_op_1): Set *overload for ambiguity. (build_new_method_call_1): Likewise. Diff: --- gcc/cp/call.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/gcc/cp/call.c b/gcc/cp/call.c index f1e0bcb796b..221e3de0c70 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -6357,6 +6357,8 @@ build_new_op_1 (const op_location_t &loc, enum tree_code code, int flags, print_z_candidates (loc, candidates); } result = error_mark_node; + if (overload) + *overload = error_mark_node; } else if (TREE_CODE (cand->fn) == FUNCTION_DECL) { @@ -10438,6 +10440,8 @@ build_new_method_call_1 (tree instance, tree fns, vec **args, free (pretty_name); } call = error_mark_node; + if (fn_p) + *fn_p = error_mark_node; } else {