[Bug c++/104225] New: accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[Bug c++/104225] New: accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

            Bug ID: 104225
           Summary: accepts-invalid new expression that uses deleted
                    implicit default constructor of class specialization
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ppalka at gcc dot gnu.org
  Target Milestone: ---

The following testcase compiles without error, but should be rejected because
it uses B's deleted default constructor:

class A { ~A(); };
template <class> class B { A f = 1; };
int main() {
  new B<int>;
}

[Bug c++/104225] [9/10/11/12 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-01-25
     Ever confirmed|0                           |1
                 CC|                            |jason at gcc dot gnu.org
      Known to work|                            |8.5.0
            Summary|accepts-invalid new         |[9/10/11/12 Regression]
                   |expression that uses        |accepts-invalid new
                   |deleted implicit default    |expression that uses
                   |constructor of class        |deleted implicit default
                   |specialization              |constructor of class
                   |                            |specialization
             Status|UNCONFIRMED                 |NEW
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=101532
   Target Milestone|---                         |9.5
           Keywords|                            |accepts-invalid
      Known to fail|                            |10.3.0, 11.2.0, 12.0, 9.4.0

--- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Started with r9-6097.

[Bug c++/104225] [9/10/11/12 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:bc90dd0ecf02e11d47d1af7f627e2e2acaa40106

commit r12-6863-gbc90dd0ecf02e11d47d1af7f627e2e2acaa40106
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Jan 25 15:04:49 2022 -0500

    c++: deleted fn and noexcept inst [PR101532, PR104225]

    Here when attempting to use B's implicitly deleted default constructor,
    mark_used rightfully returns false, but for the wrong reason: it
    tries to instantiate the synthesized noexcept specifier which then only
    silently fails because get_defaulted_eh_spec suppresses diagnostics
    for deleted functions.  This lack of diagnostics causes us to crash on
    the first testcase below (thanks to the assert in finish_expr_stmt), and
    silently accept the second testcase.

    To fix this, this patch makes mark_used avoid attempting to instantiate
    the noexcept specifier of a deleted function, so that we'll instead
    directly reject (and diagnose) the function due to its deletedness.

            PR c++/101532
            PR c++/104225

    gcc/cp/ChangeLog:

            * decl2.cc (mark_used): Don't consider maybe_instantiate_noexcept
            on a deleted function.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/nsdmi-template21.C: New test.
            * g++.dg/cpp0x/nsdmi-template21a.C: New test.

[Bug c++/104225] [9/10/11/12 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org
         Resolution|---                         |FIXED

--- Comment #3 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed.

[Bug c++/104225] [9/10/11 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |NEW
            Summary|[9/10/11/12 Regression]     |[9/10/11 Regression]
                   |accepts-invalid new         |accepts-invalid new
                   |expression that uses        |expression that uses
                   |deleted implicit default    |deleted implicit default
                   |constructor of class        |constructor of class
                   |specialization              |specialization
         Resolution|FIXED                       |---

--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> ---
(In reply to Patrick Palka from comment #3)
> Fixed.

... for GCC 12 so far.

[Bug c++/104225] [9/10/11 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |12.0
      Known to fail|12.0                        |
           Priority|P3                          |P2

[Bug c++/104225] [9/10/11 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:1429db66619d2b801ac0b586b5eed74ab54a35b0

commit r11-9840-g1429db66619d2b801ac0b586b5eed74ab54a35b0
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Jan 25 15:04:49 2022 -0500

    c++: deleted fn and noexcept inst [PR101532, PR104225]

    Here when attempting to use B's implicitly deleted default constructor,
    mark_used rightfully returns false, but for the wrong reason: it
    tries to instantiate the synthesized noexcept specifier which then only
    silently fails because get_defaulted_eh_spec suppresses diagnostics
    for deleted functions.  This lack of diagnostics causes us to crash on
    the first testcase below (thanks to the assert in finish_expr_stmt), and
    silently accept the second testcase.

    To fix this, this patch makes mark_used avoid attempting to instantiate
    the noexcept specifier of a deleted function, so that we'll instead
    directly reject (and diagnose) the function due to its deletedness.

            PR c++/101532
            PR c++/104225

    gcc/cp/ChangeLog:

            * decl2.c (mark_used): Don't consider maybe_instantiate_noexcept
            on a deleted function.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/nsdmi-template21.C: New test.
            * g++.dg/cpp0x/nsdmi-template21a.C: New test.

    (cherry picked from commit bc90dd0ecf02e11d47d1af7f627e2e2acaa40106)

[Bug c++/104225] [9/10 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:ad0398474aff6bb7726e9117711b0a111a4b69e7

commit r10-10602-gad0398474aff6bb7726e9117711b0a111a4b69e7
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Jan 25 15:04:49 2022 -0500

    c++: deleted fn and noexcept inst [PR101532, PR104225]

    Here when attempting to use B's implicitly deleted default constructor,
    mark_used rightfully returns false, but for the wrong reason: it
    tries to instantiate the synthesized noexcept specifier which then only
    silently fails because get_defaulted_eh_spec suppresses diagnostics
    for deleted functions.  This lack of diagnostics causes us to crash on
    the first testcase below (thanks to the assert in finish_expr_stmt), and
    silently accept the second testcase.

    To fix this, this patch makes mark_used avoid attempting to instantiate
    the noexcept specifier of a deleted function, so that we'll instead
    directly reject (and diagnose) the function due to its deletedness.

            PR c++/101532
            PR c++/104225

    gcc/cp/ChangeLog:

            * decl2.c (mark_used): Don't consider maybe_instantiate_noexcept
            on a deleted function.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/nsdmi-template21.C: New test.
            * g++.dg/cpp0x/nsdmi-template21a.C: New test.

    (cherry picked from commit bc90dd0ecf02e11d47d1af7f627e2e2acaa40106)

[Bug c++/104225] [9 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:4df77364f7fd9ce88c012843fff124346e4d3c06

commit r9-10155-g4df77364f7fd9ce88c012843fff124346e4d3c06
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Jan 25 15:04:49 2022 -0500

    c++: deleted fn and noexcept inst [PR101532, PR104225]

    Here when attempting to use B's implicitly deleted default constructor,
    mark_used rightfully returns false, but for the wrong reason: it
    tries to instantiate the synthesized noexcept specifier which then only
    silently fails because get_defaulted_eh_spec suppresses diagnostics
    for deleted functions.  This lack of diagnostics causes us to crash on
    the first testcase below (thanks to the assert in finish_expr_stmt), and
    silently accept the second testcase.

    To fix this, this patch makes mark_used avoid attempting to instantiate
    the noexcept specifier of a deleted function, so that we'll instead
    directly reject (and diagnose) the function due to its deletedness.

            PR c++/101532
            PR c++/104225

    gcc/cp/ChangeLog:

            * decl2.c (mark_used): Don't consider maybe_instantiate_noexcept
            on a deleted function.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/nsdmi-template21.C: New test.
            * g++.dg/cpp0x/nsdmi-template21a.C: New test.

    (cherry picked from commit bc90dd0ecf02e11d47d1af7f627e2e2acaa40106)

[Bug c++/104225] [9 Regression] accepts-invalid new expression that uses deleted implicit default constructor of class specialization

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104225

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #8 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for 9.5/10.4/11.3/12.