From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 59A1F3858D20; Wed, 15 Nov 2023 17:03:30 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 59A1F3858D20 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1700067810; bh=4QS3P6JrY2zsIhIM3/xlsMpMPuig8JAEf0abv1f9ZVU=; h=From:To:Subject:Date:In-Reply-To:References:From; b=jJxm9pb/E0f0/uO+vuRF+wS4ZOgFmJ8s+Xqe0ELctOhjy9q2wyaigeMZLb9HkA7+3 L0qFhz+AmCyu8BCxdOzPM7cjUk3nXMIg7bcB5Z46j7Ke7M/qoEVYbizkp/5Xzx8Mg9 TTnBQAvGcunZPr7fMnIv9F65ePRRu7L1gPOui6mc= From: "cvs-commit at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/112269] [14 Regression] x86_64 GNU/Linux '-m32' multilib 'libstdc++-v3/include/complex:1493: internal compiler error: in tsubst_expr, at cp/pt.cc:21534' since r14-4796-g3e3d73ed5e85e7 Date: Wed, 15 Nov 2023 17:03:28 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 14.0 X-Bugzilla-Keywords: ice-checking, ice-on-valid-code, testsuite-fail X-Bugzilla-Severity: normal X-Bugzilla-Who: cvs-commit at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: ppalka at gcc dot gnu.org X-Bugzilla-Target-Milestone: 14.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112269 --- Comment #12 from CVS Commits --- The master branch has been updated by Patrick Palka : https://gcc.gnu.org/g:6665a8572c8f24bd55c6081c91f461442c94dcfb commit r14-5502-g6665a8572c8f24bd55c6081c91f461442c94dcfb Author: Patrick Palka Date: Wed Nov 15 12:03:16 2023 -0500 c++: constantness of local var in constexpr fn [PR111703, PR112269] potential_constant_expression was incorrectly treating most local variables from a constexpr function as constant because it wasn't considering the 'now' parameter. This patch fixes this by relaxing its var_in_maybe_constexpr_fn checks accordingly, which turns out to partially fix two recently reported regressions: PR111703 is a regression caused by r11-550-gf65a3299a521a4 for restrict= ing constexpr evaluation during warning-dependent folding. The mechanism is intended to restrict only constant evaluation of the instantiated non-dependent expression, but it also ends up restricting constant evaluation occurring during instantiation of the expression, in particu= lar when instantiating the converted argument 'x' (a VIEW_CONVERT_EXPR) into a copy constructor call. This seems like a flaw in the mechanism, thou= gh I don't know if we want to fix the mechanism or get rid of it completely since the original testcases which motivated the mechanism are fixed mo= re simply by r13-1225-gb00b95198e6720. In any case, this patch partially fixes this by making us correctly treat 'x' as non-constant which preve= nts the problematic warning-dependent folding from occurring at all. PR112269 is caused by r14-4796-g3e3d73ed5e85e7 for merging tsubst_copy into tsubst_copy_and_build. tsubst_copy used to exit early when 'args' was empty, behavior which that commit deliberately didn't preserve. This early exit masked the fact that COMPLEX_EXPR wasn't handled by tsubst at all, and is a tree code that apparently we could see during warning-dependent folding on some targets. A complete fix is to add handling for this tree code in tsubst_expr, but this patch should fix the reported testsuite failures since the COMPLEX_EXPRs that crop up in are considered non-constant expressions after this patch. PR c++/111703 PR c++/112269 gcc/cp/ChangeLog: * constexpr.cc (potential_constant_expression_1) : Only consider var_in_maybe_constexpr_fn if 'now' is false. : Likewise. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-fn8.C: New test.=