[{"id":3675432,"web_url":"http://patchwork.ozlabs.org/comment/3675432/","msgid":"","list_archive_url":null,"date":"2026-04-09T18:10:54","subject":"Re: [PATCH v2] c++/reflection: reject invalid template splice\n [PR123998]","submitter":{"id":4337,"url":"http://patchwork.ozlabs.org/api/people/4337/","name":"Jason Merrill","email":"jason@redhat.com"},"content":"On 4/8/26 3:35 PM, Marek Polacek wrote:\n> On Thu, Apr 02, 2026 at 05:41:38PM -0400, Jason Merrill wrote:\n>> Can we switch to using a different function name for testing for a\n>> reflection of a function template, even if it just returns\n>> really_overloaded_fn? This can be a later patch.\n> \n> Sure. For 16 or 17?\n\nFor 16, to avoid backporting hassle. Though I suppose that patch could \nbe backported first.\n\n>>> @@ -16810,13 +16810,18 @@ tsubst_splice_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)\n>>> \tSET_SPLICE_EXPR_MEMBER_ACCESS_P (op, true);\n>>> if (SPLICE_EXPR_ADDRESS_P (t))\n>>> \tSET_SPLICE_EXPR_ADDRESS_P (op, true);\n>>> + if (SPLICE_EXPR_TEMPLATE_P (t))\n>>> +\tSET_SPLICE_EXPR_TEMPLATE_P (op, true);\n>>> return op;\n>>> }\n>>> + const bool targs_p = (TREE_CODE (t) == TEMPLATE_ID_EXPR\n>>> +\t\t\t|| variable_template_p (op));\n>>\n>> Why || variable_template_p? Can't you have a variable template reflection\n>> without targs?\n> \n> I was trying to avoid adding SPLICE_EXPR_TARGS_P but it's probably not\n> going to work too well. And the == TEMPLATE_ID_EXPR check can never\n> be true.\n> \n> So this patch adds SPLICE_EXPR_TARGS_P so that we can check we're\n> coming from [:R:] in the SPLICE_EXPR. With that, I had to\n> add an error for DECL_TYPE_TEMPLATE_P in check_splice_expr to avoid\n> crashing in crash11.C.\n> \n> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?\n\nOK.\n\nJason","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=ORrTzgjR;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org;\n\tdkim=pass (1024-bit key,\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=ORrTzgjR","sourceware.org; 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