[Bug c++/96876] New: missing check for destructibility of base classes in aggregate initialization

[Bug c++/96876] New: missing check for destructibility of base classes in aggregate initialization

[richard-gccbugzilla at metafoo dot co.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96876

            Bug ID: 96876
           Summary: missing check for destructibility of base classes in
                    aggregate initialization
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: richard-gccbugzilla at metafoo dot co.uk
  Target Milestone: ---

GCC accepts this invalid code (which is ill-formed because [dcl.init.aggr]/8
says it potentially-invokes the destructor for B, which [class.dtor]/15 says
requires the destructor to be accessible):

struct B {
protected:
    ~B() {}
};

struct C : B { int n; };

int f();

void g() {
    C c{{}, f()};
}

... and generates wrong code for this similar example:

#include <stdio.h>

struct B {
public:
    ~B() { puts("destroyed"); }
};

struct C : B { int n; };

int f() { throw "hello"; }

int main() {
    try {
    C c{{}, f()};
    } catch (const char*) {
    }
}

... which is required to print "destroyed" (when the B base class subobject is
destroyed during stack unwinding), but with GCC does not.

[Bug c++/96876] missing check for destructibility of base classes in aggregate initialization

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96876

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-08-31

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.  Doesn't seem to be a regression.

[Bug c++/96876] missing check for destructibility of base classes in aggregate initialization

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96876

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org
                 CC|                            |jason at gcc dot gnu.org

[Bug c++/96876] missing check for destructibility of base classes in aggregate initialization

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96876

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

https://gcc.gnu.org/g:53cac72cf0821217f99d0640ba72cc2999ec7dc0

commit r12-7117-g53cac72cf0821217f99d0640ba72cc2999ec7dc0
Author: Jason Merrill <jason@redhat.com>
Date:   Fri Feb 4 18:25:51 2022 -0500

    c++: cleanup constant-init'd members [PR96876]

    This is a case missed by my recent fixes to aggregate initialization and
    exception cleanup for PR94041 et al: we also need to clean up members with
    constant initialization if initialization of a later member throws.

    It also occurs to me that we needn't bother building the cleanups if
    -fno-exceptions; build_vec_init already doesn't.

            PR c++/96876

    gcc/cp/ChangeLog:

            * typeck2.cc (split_nonconstant_init_1): Push cleanups for
            preceding members with constant initialization.
            (maybe_push_temp_cleanup): Do nothing if -fno-exceptions.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp1z/aggr-base11.C: New test.
            * g++.dg/eh/aggregate2.C: New test.

[Bug c++/96876] missing check for destructibility of base classes in aggregate initialization

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96876

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for GCC 12.