From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 6ACB53894C00; Thu, 22 Apr 2021 13:12:43 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6ACB53894C00 From: "georg.schwab at emocean dot io" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/100210] New: [[nodiscard]] constructor causes warning on arm-linux-gnueabihf Date: Thu, 22 Apr 2021 13:12:43 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 10.2.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: georg.schwab at emocean dot io X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone cf_gcctarget attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Apr 2021 13:12:43 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100210 Bug ID: 100210 Summary: [[nodiscard]] constructor causes warning on arm-linux-gnueabihf Product: gcc Version: 10.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: georg.schwab at emocean dot io Target Milestone: --- Target: arm-linux-gnueabihf Created attachment 50655 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D50655&action=3Dedit offending code The code below causes a warning under arm-linux-gnueabihf when using -Wunused-result. Under x86_64-linux-gnu and aarch64-linux-gnu, the code compiles without warnings. (Tested on Ubuntu 20.04.1 LTS for x86_64) Offending Code: =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D struct X { [[nodiscard]] X(int); }; void t() { X x(0); } Command Line and Output: =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D $ arm-linux-gnueabihf-g++-10 -c -Wunused-result nodiscard-constructor.cpp nodiscard-constructor.cpp: In function =E2=80=98void t()=E2=80=99: nodiscard-constructor.cpp:8:7: warning: ignoring return value of =E2=80=98X= ::X(int)=E2=80=99, declared with attribute =E2=80=98nodiscard=E2=80=99 [-Wunused-result] 8 | X x(0); | ^ nodiscard-constructor.cpp:3:16: note: declared here 3 | [[nodiscard]] X(int); | ^ nodiscard-constructor.cpp:8:7: warning: ignoring return value of =E2=80=98X= ::X(int)=E2=80=99, declared with attribute =E2=80=98nodiscard=E2=80=99 [-Wunused-result] 8 | X x(0); | ^ nodiscard-constructor.cpp:3:16: note: declared here 3 | [[nodiscard]] X(int); |=