From patchwork Sat Mar 5 03:19:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artemiy Volkov X-Patchwork-Id: 11212 Received: (qmail 106503 invoked by alias); 5 Mar 2016 03:20:52 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 105961 invoked by uid 89); 5 Mar 2016 03:20:34 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=BAYES_00, FREEMAIL_FROM, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 spammy=586, 588, 2, 0, ranking X-HELO: mail-lb0-f195.google.com Received: from mail-lb0-f195.google.com (HELO mail-lb0-f195.google.com) (209.85.217.195) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Sat, 05 Mar 2016 03:20:33 +0000 Received: by mail-lb0-f195.google.com with SMTP id vk4so6499721lbb.1 for ; Fri, 04 Mar 2016 19:20:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=PcMAX92qr69V4/KpuEvDQhsGUYExbRRL3wkYy2gJ2t0=; b=in5CNdL/8uWaOW7nij2OlF9KYBXCyLatXrlEgmDuWJ0qNhyqQwfCaplqJZHgLf1+bA 5712K6TW4/mWDczXfJznK/iPkF0zEZiWf+ZrhiSgi9CJKXaiBVz+wD1uGdB4jW414usv iH2QjjD0ekw35MRPLcdKwdMs216wCb++N1B0SNaTs4IhaV2WqSJGbWIPfD1pwtRpM752 UKSz9b3t8tDvM3yggZrXBi0V+t4fbyWE2ozG1NiB0Iy/OtuMtCznJjfjE9dQwUsQILtT kEmDuJ3t78oj6VuzLj+uRe+f4YvVJrjNGSrReS0snPN675OO20wJrVXG2arZoeTsMIAR CGAQ== X-Gm-Message-State: AD7BkJIz0TvWUOVomP9/1bONbJ2av1Ubi+6P++ML96WsR9QJXyDugJYzGq6Poth2tdDT5w== X-Received: by 10.112.67.1 with SMTP id j1mr3322309lbt.103.1457148030193; Fri, 04 Mar 2016 19:20:30 -0800 (PST) Received: from arch.smware.local (108-60-110-19.static.wiline.com. [108.60.110.19]) by smtp.gmail.com with ESMTPSA id jr10sm1020677lbc.42.2016.03.04.19.20.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 04 Mar 2016 19:20:29 -0800 (PST) From: Artemiy Volkov To: gdb-patches@sourceware.org Cc: keiths@redhat.com, palves@redhat.com, Artemiy Volkov Subject: [PATCH v3 10/11] [PR gdb/14441] gdb: gdbtypes: add rvalue references to overloading resolution Date: Fri, 4 Mar 2016 19:19:14 -0800 Message-Id: <1457147955-21871-11-git-send-email-artemiyv@acm.org> In-Reply-To: <1457147955-21871-1-git-send-email-artemiyv@acm.org> References: <1453229609-20159-1-git-send-email-artemiyv@acm.org> <1457147955-21871-1-git-send-email-artemiyv@acm.org> X-IsSubscribed: yes This patch introduces changes to rank_one_type() dealing with ranking an rvalue reference type when selecting a best viable function from a set of candidate functions. The 4 new added rules for rvalue references are: 1) An rvalue argument cannot be bound to a non-const lvalue reference parameter and an lvalue argument cannot be bound to an rvalue reference parameter. [C++11 13.3.3.1.4p3] 2) If a conversion to one type of reference is an identity conversion, and a conversion to the second type of reference is a non-identity conversion, choose the first type. [C++11 13.3.3.2p3] 3) An rvalue should be first tried to bind to an rvalue reference, and then to an lvalue reference. [C++11 13.3.3.2p3] 4) An lvalue reference to a function gets higher priority than an rvalue reference to a function. [C++11 13.3.3.2p3] gdb/ChangeLog: 2016-03-04 Artemiy Volkov * gdbtypes.c (rank_one_type): Implement overloading resolution rules regarding rvalue references. --- gdb/gdbtypes.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 3 deletions(-) diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c index ce4b9be..c5b8ab5 100644 --- a/gdb/gdbtypes.c +++ b/gdb/gdbtypes.c @@ -58,6 +58,8 @@ const struct rank VOID_PTR_CONVERSION_BADNESS = {2,0}; const struct rank BOOL_CONVERSION_BADNESS = {3,0}; const struct rank BASE_CONVERSION_BADNESS = {2,0}; const struct rank REFERENCE_CONVERSION_BADNESS = {2,0}; +const struct rank LVALUE_REFERENCE_TO_RVALUE_BINDING_BADNESS = {5,0}; +const struct rank DIFFERENT_REFERENCE_TYPE_BADNESS = {6,0}; const struct rank NULL_POINTER_CONVERSION_BADNESS = {2,0}; const struct rank NS_POINTER_CONVERSION_BADNESS = {10,0}; const struct rank NS_INTEGER_POINTER_CONVERSION_BADNESS = {3,0}; @@ -3466,15 +3468,65 @@ rank_one_type (struct type *parm, struct type *arg, struct value *value) { struct rank rank = {0,0}; - if (types_equal (parm, arg)) - return EXACT_MATCH_BADNESS; - /* Resolve typedefs */ if (TYPE_CODE (parm) == TYPE_CODE_TYPEDEF) parm = check_typedef (parm); if (TYPE_CODE (arg) == TYPE_CODE_TYPEDEF) arg = check_typedef (arg); + if (value != NULL) + { + /* An rvalue argument cannot be bound to a non-const lvalue + reference parameter... */ + if (VALUE_LVAL (value) == not_lval + && TYPE_CODE (parm) == TYPE_CODE_REF + && !TYPE_CONST (parm->main_type->target_type)) + return INCOMPATIBLE_TYPE_BADNESS; + + /* ... and an lvalue argument cannot be bound to an rvalue + reference parameter. [C++ 13.3.3.1.4p3] */ + if (VALUE_LVAL (value) != not_lval + && TYPE_CODE (parm) == TYPE_CODE_RVALUE_REF) + return INCOMPATIBLE_TYPE_BADNESS; + } + + if (types_equal (parm, arg)) + return EXACT_MATCH_BADNESS; + + /* An lvalue reference to a function should get higher priority than an + rvalue reference to a function. */ + + if (value != NULL && TYPE_CODE (arg) == TYPE_CODE_RVALUE_REF + && TYPE_CODE (TYPE_TARGET_TYPE (arg)) == TYPE_CODE_FUNC) + { + return (sum_ranks (rank_one_type (parm, + lookup_pointer_type (TYPE_TARGET_TYPE (arg)), NULL), + DIFFERENT_REFERENCE_TYPE_BADNESS)); + } + + /* If a conversion to one type of reference is an identity conversion, and a + conversion to the second type of reference is a non-identity conversion, + choose the first type. */ + + if (value != NULL && TYPE_IS_REFERENCE (parm) && TYPE_IS_REFERENCE (arg) + && TYPE_CODE (parm) != TYPE_CODE (arg)) + { + return (sum_ranks (rank_one_type (TYPE_TARGET_TYPE (parm), + TYPE_TARGET_TYPE (arg), NULL), DIFFERENT_REFERENCE_TYPE_BADNESS)); + } + + /* An rvalue should be first tried to bind to an rvalue reference, and then to + an lvalue reference. */ + + if (value != NULL && TYPE_CODE (parm) == TYPE_CODE_REF + && VALUE_LVAL (value) == not_lval) + { + if (TYPE_IS_REFERENCE (arg)) + arg = TYPE_TARGET_TYPE (arg); + return (sum_ranks (rank_one_type (TYPE_TARGET_TYPE (parm), arg, NULL), + LVALUE_REFERENCE_TO_RVALUE_BINDING_BADNESS)); + } + /* See through references, since we can almost make non-references references. */