From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 09B803858D3C; Tue, 17 May 2022 12:13:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 09B803858D3C From: "drepper.fsp+rhbz at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/105626] New: -Wformat should accept u8"" strings Date: Tue, 17 May 2022 12:13:41 +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: 12.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: drepper.fsp+rhbz at gmail dot com 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 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: Tue, 17 May 2022 12:13:42 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105626 Bug ID: 105626 Summary: -Wformat should accept u8"" strings Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: drepper.fsp+rhbz at gmail dot com Target Milestone: --- The discussion about this topic on gcc@ (https://gcc.gnu.org/pipermail/gcc/2022-May/238673.html) ended with the conclusion that gcc should not disregard the cast in code like this: #include int main() { printf((const char*) u8"test %d\n", 1); return 0; } With -Wformat this code produces with gcc 12: t.cc: In function =E2=80=98int main()=E2=80=99: t.cc:5:24: warning: format string is not an array of type =E2=80=98char=E2= =80=99 [-Wformat=3D] 5 | printf((const char*) u8"test %d\n", 1); | ^~~~~~~~~~~~~ Since a) there are no I/O functions for u8 strings in C++20 b) using u8 strings is necessary in reliable code c) it is safe to perform the analysis -Wformat does on u8 strings I suggest that u8 strings are allowed when testing for -Wformat.=