From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 1A890385803B; Thu, 25 Mar 2021 18:58:38 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1A890385803B
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/99331] [8/9/10/11 Regression] -Wconversion false-positive
 in immediate context
Date: Thu, 25 Mar 2021 18:58:37 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: diagnostic
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: mpolacek at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 8.5
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-99331-4-ka4WCJF9a9@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-99331-4@http.gcc.gnu.org/bugzilla/>
References: <bug-99331-4@http.gcc.gnu.org/bugzilla/>
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 <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 25 Mar 2021 18:58:38 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99331

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:9efd72d28956eb79c7fca38e3c959733a3bb25bb

commit r11-7833-g9efd72d28956eb79c7fca38e3c959733a3bb25bb
Author: Marek Polacek <polacek@redhat.com>
Date:   Thu Mar 4 20:20:40 2021 -0500

    c++: -Wconversion vs value-dependent expressions [PR99331]

    This PR complains that we issue a -Wconversion warning in

      template <int N> struct X {};
      template <class T> X<sizeof(T)> foo();

    saying "conversion from 'long unsigned int' to 'int' may change value".
    While it's not technically wrong, I suspect -Wconversion warnings aren't
    all that useful for value-dependent expressions.  So this patch disables
    them.  This is a regression that started with r241425:

    @@ -7278,7 +7306,7 @@ convert_template_argument (tree parm,
              val =3D error_mark_node;
            }
        }
    -      else if (!dependent_template_arg_p (orig_arg)
    +      else if (!type_dependent_expression_p (orig_arg)
               && !uses_template_parms (t))
        /* We used to call digest_init here.  However, digest_init
           will report errors, which we don't want when complain

    Here orig_arg is SIZEOF_EXPR<T>; dependent_template_arg_p (orig_arg) was
    true, but type_dependent_expression_p (orig_arg) is false so we warn in
    convert_nontype_argument.

    gcc/cp/ChangeLog:

            PR c++/99331
            * call.c (build_converted_constant_expr_internal): Don't emit
            -Wconversion warnings.

    gcc/testsuite/ChangeLog:

            PR c++/99331
            * g++.dg/warn/Wconversion5.C: New test.=