[{"id":3681643,"web_url":"http://patchwork.ozlabs.org/comment/3681643/","msgid":"<61a930e0-e3eb-4fca-86af-75f268d15bf8@redhat.com>","list_archive_url":null,"date":"2026-04-23T19:16:31","subject":"Re: [PATCH v3] c++/reflection: ICE on member function template\n splicing [PR124794]","submitter":{"id":4337,"url":"http://patchwork.ozlabs.org/api/people/4337/","name":"Jason Merrill","email":"jason@redhat.com"},"content":"On 4/21/26 2:23 PM, feedable wrote:\n>>>>> gcc/testsuite/ChangeLog:\n>>>>>\n>>>>> * g++.dg/reflect/splice12.C: New test.\n>>>\n>>> Note that this test will have to be renamed to splice13.C.\n>>>\n> \n> Done\n> \n>>>>> + else if (BASELINK_P (expr))\n>>>>> + expr = build_baselink (access_path, BASELINK_BINFO (expr),\n>>>\n>>> Extra space before =. Also I guess BASELINK_ACCESS_BINFO instead of\n>>> BASELINK_BINFO?\n>>\n>> We want to use access_path (relative to the actual object_type) in place of\n>> BASELINK_ACCESS_BINFO, but indeed the access path should be the second\n>> argument rather than the first in both this call and the existing one.\n> \n> If I understand correctly, access_path is the endpoint of the search, so it\n> should go into BASELINK_BINFO, and it's the object type that should go\n> into BASELINK_ACCESS_BINFO (in both cases, actually), since it's the\n> place where we started the search.\n\nAh, true.\n\n>>>>> - member_access_p, template_p, targs_p,\n>>>>> + if (!check_splice_expr (loc, expr.get_start (), MAYBE_BASELINK_FUNCTIONS\n>>>>> (t),\n>>>>\n>>>> I think it's probably preferable for check_splice_expr to handle getting a\n>>>> BASELINK, since tsubst_splice_expr. Marek, thoughts?\n>>>\n>>> I think that's better. It looks like we'll need MAYBE_BASELINK_FUNCTIONS\n>>> before the gcc_checking_assert at the end of check_splice_expr for the\n>>> get_template_info check.\n\nI was thinking that we could just\n\nt = MAYBE_BASELINK_FUNCTIONS (t);\n\nat the top of check_splice_expr rather than change multiple places in \nthe function?\n\n> @@ -21455,6 +21455,24 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)\n> \telse\n> \t templ = tsubst_expr (templ, args, complain, in_decl);\n> \n> +\t/* ??? tsubst_splice_expr may throw us for a loop and return an\n> +\t address-of of the template decl instead of a plain template decl.\n> +\t Substitute the template-id first, and the address-of expr after\n> +\t that to get back on track.\n> +\t The proper solution here is to emit the OFFSET_REF during parsing,\n> +\t and get a clean template node from tsubst_splice_expr. However,\n> +\t OFFSET_REF expr requires a type to build, which we wouldn't know\n> +\t until the splice is performed. */\n\nWe can represent the address with ADDR_EXPR rather than OFFSET_REF; \nthat's already how we represent &C::f.\n\nIt might also make sense to move the template arguments inside the \nSPLICE_EXPR so that we have them available in tsubst_splice_expr. This \nseems reasonable since they are part of the splice*specifier.\n\nWhat do you think, Marek?\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=H0d1WfZ6;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=38.145.34.32; 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=H0d1WfZ6","sourceware.org; dmarc=pass (p=quarantine dis=none)\n header.from=redhat.com","sourceware.org; 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