From patchwork Sun Dec 7 22:47:17 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Egas Ribeiro X-Patchwork-Id: 126097 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from vm01.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 056F74097731 for ; Sun, 7 Dec 2025 22:59:54 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 056F74097731 Authentication-Results: sourceware.org; dkim=pass (2048-bit key, secure) header.d=tecnico.ulisboa.pt header.i=@tecnico.ulisboa.pt header.a=rsa-sha256 header.s=mail2 header.b=EhAnJ1l6 X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from smtp1.tecnico.ulisboa.pt (smtp1.tecnico.ulisboa.pt [193.136.128.21]) by sourceware.org (Postfix) with ESMTPS id 3DEA74097731 for ; Sun, 7 Dec 2025 22:59:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 3DEA74097731 Authentication-Results: sourceware.org; dmarc=pass (p=quarantine dis=none) header.from=tecnico.ulisboa.pt Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tecnico.ulisboa.pt ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 3DEA74097731 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=193.136.128.21 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1765148349; cv=none; b=OmD0v+AZ8EfxjgJuLmEfEreuR2h9zooj0meAsp92vtI+aZVMmH16JfZ5w/zNh7Y4Hrizhbd4X2gRlHahRQltL/rXCKGOKd1hffjPh2buusF+o9XKRTWMPplB9Xf4i0VoU6nHUWx3uass8ORYElbXS6HUkjDa6kaiCgarMfbnpKc= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1765148349; c=relaxed/simple; bh=2nMnS8kojb1t1ieTryORdZa6EwdY7SqzYqQ/DRNzu9A=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=Em/9g19sKEvdsfZQGHttt4e8lTpPSiEFD+JMmiAj2+zdqgEL40tcKbXG42piCZC7trL1Inv4axbKbjJnDWcET+XH3VcYF5Un1kmddUWoCQpX8SOuraQPg28M/aXLgzcpr8F2G8Ff8Qo2f/xL278MHh6TDHwS3XzDC6+sCh1po2w= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3DEA74097731 Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp1.tecnico.ulisboa.pt (Postfix) with ESMTP id 47420600022C; Sun, 7 Dec 2025 22:59:07 +0000 (WET) X-Virus-Scanned: by amavis-2.13.0 (20230106) (Debian) at tecnico.ulisboa.pt Received: from smtp1.tecnico.ulisboa.pt ([127.0.0.1]) by localhost (smtp1.tecnico.ulisboa.pt [127.0.0.1]) (amavis, port 10025) with LMTP id gvLzxBYLOGxZ; Sun, 7 Dec 2025 22:59:05 +0000 (WET) Received: from mail1.tecnico.ulisboa.pt (mail1.ist.utl.pt [193.136.128.10]) by smtp1.tecnico.ulisboa.pt (Postfix) with ESMTPS id 9D342600086B; Sun, 7 Dec 2025 22:59:04 +0000 (WET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tecnico.ulisboa.pt; s=mail2; t=1765148344; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=2rIJhwbj26jmHolTaZX2M1Nn+NQEviqTaqfAwCGfM7k=; b=EhAnJ1l6Kiagv4MByyeis7lq/y/jaC0MaEOM6zaLpeejlIVr430ytHac/JfLRpeUaNgwbP nxlvsM+1BezOfMUovgNl5fQ9ebJ+AB7yHIlO4lLPgjWHTq6ublEzy4WlpWSdcY17NE+KU2 ub3djIOBBxnlf+zpgx7f5z3K1nVz3N05ZfG8W5QBprDlkfU5+9ob64QhdosjvRuN2LF6HW 9iloS9UuXAan1Fd9f9K8DoAgtWSEGaFQq1FkcEqGZ/Yj4hPdeKbN7P5A0rZciqitUFKb2r aDx0XugamOsXRA6SJgVVB2d6e9UlpzujgSB7kQ0dgJyUw31Z2QoA2IoBJgYlow== Received: from archlinux (bl23-255-114.dsl.telepac.pt [144.64.255.114]) (Authenticated sender: ist1110454) by mail1.tecnico.ulisboa.pt (Postfix) with ESMTPSA id 5F54C3600AF; Sun, 7 Dec 2025 22:59:04 +0000 (WET) From: Egas Ribeiro To: gcc-patches@gcc.gnu.org Cc: jason@redhat.com, ppalka@redhat.com, Egas Ribeiro Subject: [PATCH] c++: Fix ICE with type aliases in inherited CTAD [PR122070] Date: Sun, 7 Dec 2025 22:47:17 +0000 Message-ID: <20251207224715.1051833-3-egas.g.ribeiro@tecnico.ulisboa.pt> X-Mailer: git-send-email 2.52.0 MIME-Version: 1.0 X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, GIT_PATCH_0, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gcc-patches-bounces~patchwork=sourceware.org@gcc.gnu.org Regtested on x86_64-pc-linux-gnu, OK for trunk? -- >8 -- When processing inherited CTAD in C++23, type_targs_deducible_from can be called with a synthetic alias template whose TREE_VALUE is a type alias like std::string_view. Since type aliases don't have their own TEMPLATE_INFO, calling TI_TEMPLATE on a NULL TYPE_TEMPLATE_INFO_MAYBE_ALIAS result caused a segfault. This fix adds a NULL check and returns NULL_TREE when the type lacks template info, indicating it can't be deduced. PR c++/122070 gcc/cp/ChangeLog: * pt.cc (type_targs_deducible_from): Add NULL check for TYPE_TEMPLATE_INFO_MAYBE_ALIAS to prevent ICE with type aliases. gcc/testsuite/ChangeLog: * g++.dg/cpp23/class-deduction-inherited-ice.C: New test. Signed-off-by: Egas Ribeiro --- gcc/cp/pt.cc | 5 ++- .../cpp23/class-deduction-inherited-ice.C | 34 +++++++++++++++++++ 2 files changed, 38 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp23/class-deduction-inherited-ice.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 8498730b6e4..c99df255dd7 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -31630,7 +31630,10 @@ type_targs_deducible_from (tree tmpl, tree type) per alias_ctad_tweaks. */ tparms = INNERMOST_TEMPLATE_PARMS (TREE_PURPOSE (tmpl)); ttype = TREE_VALUE (tmpl); - tmpl = TI_TEMPLATE (TYPE_TEMPLATE_INFO_MAYBE_ALIAS (ttype)); + tree ti = TYPE_TEMPLATE_INFO_MAYBE_ALIAS (ttype); + if (!ti) + return NULL_TREE; + tmpl = TI_TEMPLATE (ti); } int len = TREE_VEC_LENGTH (tparms); diff --git a/gcc/testsuite/g++.dg/cpp23/class-deduction-inherited-ice.C b/gcc/testsuite/g++.dg/cpp23/class-deduction-inherited-ice.C new file mode 100644 index 00000000000..6724ce303d8 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/class-deduction-inherited-ice.C @@ -0,0 +1,34 @@ +// { dg-do compile { target c++23 } } +// PR c++/122070 + +namespace std { + template struct integral_constant { static constexpr T value = v; }; + using size_t = decltype(sizeof(0)); + + template + struct basic_string_view { + const CharT* ptr; + size_t len; + constexpr basic_string_view(const CharT* p) : ptr(p), len(0) { while (p && p[len]) ++len; } + }; + using string_view = basic_string_view; +} + +template +struct sized_string_view: std::string_view { + using std::string_view::string_view; +}; +template +sized_string_view(const char (&str)[N]) -> sized_string_view; + + +constexpr auto string_builder(auto first, auto second, auto... trailing) { + constexpr auto is_last = sizeof...(trailing) == 0; + auto buffer = 1; + if constexpr (is_last) { + return buffer; + } else + return string_builder(buffer, trailing...); +} + +constexpr auto copyright = string_builder(sized_string_view("a"), sized_string_view("b"), sized_string_view("c"));