[{"id":3675463,"web_url":"http://patchwork.ozlabs.org/comment/3675463/","msgid":"<0630c64f-0b0b-436d-8589-d26685fa0294@redhat.com>","list_archive_url":null,"date":"2026-04-09T18:51:59","subject":"Re: [PATCH] c++, contracts: Account for lambda captures in pre/post\n [PR124648].","submitter":{"id":4337,"url":"http://patchwork.ozlabs.org/api/people/4337/","name":"Jason Merrill","email":"jason@redhat.com"},"content":"On 4/8/26 5:53 AM, Iain Sandoe wrote:\n> This is a second issue that appears once the exclusion of implicit\n> lambda captures is fixed. Tested on x86_64-darwin, powerpc64le-linux\n> OK for trunk/when?\n> thanks\n> Iain\n> \n> --- 8< ---\n> \n> When we have lambda captures, they appear in the vars slot of a bind\n> expression at the outer operator() body.\n> \n> We need these to be visible for any pre or post conditions that might\n> use them, therefore (when a lambda has captures) nest the application\n> of contract pre and post conditions within the lambda outer bind\n> expression.\n> \n> \tPR c++/124648\n> \n> gcc/cp/ChangeLog:\n> \n> \t* contracts.cc (maybe_apply_function_contracts): Nest pre and\n> \tpost conditions inside the outer bind expression of a lambda\n> \twith captures.\n> \n> Signed-off-by: Iain Sandoe \n> ---\n> gcc/cp/contracts.cc | 12 ++++++++++++\n> 1 file changed, 12 insertions(+)\n> \n> diff --git a/gcc/cp/contracts.cc b/gcc/cp/contracts.cc\n> index d2dba3c62e6..760327d2020 100644\n> --- a/gcc/cp/contracts.cc\n> +++ b/gcc/cp/contracts.cc\n> @@ -1352,6 +1352,18 @@ maybe_apply_function_contracts (tree fndecl)\n> DECL_SAVED_TREE (fndecl) = push_stmt_list ();\n> }\n> \n> + /* If we have a lambda with captures, ensure that those captures are in-\n> + scope for pre and post conditions. */\n> + if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fndecl))\n\nThis could be LAMBDA_FUNCTION_P. OK with that change.\n\n> + && TREE_CODE (fnbody) == BIND_EXPR)\n> + {\n> + tree extract = BIND_EXPR_BODY (fnbody);\n> + BIND_EXPR_BODY (fnbody) = NULL_TREE;\n> + add_stmt (fnbody);\n> + BIND_EXPR_BODY (fnbody) = push_stmt_list ();\n> + fnbody = extract;\n> + }\n> +\n> /* Now add the pre and post conditions to the existing function body.\n> This copies the approach used for function try blocks. */\n> tree compound_stmt = begin_compound_stmt (0);","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=fPgYCVdG;\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=fPgYCVdG","sourceware.org; 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