[Bug c++/53868] New: Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[Bug c++/53868] New: Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[hstong at ca dot ibm.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53868

             Bug #: 53868
           Summary: Temporary for indirect binding is not destroyed when
                    destructor from initializer temp throws
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hstong@ca.ibm.com
              Host: powerpc64-unknown-linux-gnu
            Target: powerpc64-unknown-linux-gnu


The temporary created for indirect binding should be completely constructed
(and from the output _it is_) before the destructors for temporaries in the
initializer are called.

In the following case, the destructor for a temporary in the initializer throws
an int. During stack unwinding, it seems the temporary bound to the reference
is missed.

### Self-contained source:> cat tempbindIndirect_inittempDtorThrows.cpp
extern "C" int printf(const char *, ...);
extern "C" void abort();

struct SubobjectInA {
   SubobjectInA();
   ~SubobjectInA();
};

struct A : SubobjectInA {
   A() = delete;
   A(const A &) = delete;
   A(A &&) { }
   A(int);
   ~A();
};

#define TRACE_FUNC( ... ) \
{   printf("%s\n", __PRETTY_FUNCTION__); __VA_ARGS__   }

struct Q {
   Q() : q(0)  TRACE_FUNC()
   ~Q();
   int q;
};

int main() {
   try { const A &a = Q().q; }
   catch (...) { return 0; }
   abort();
}

SubobjectInA::SubobjectInA()  TRACE_FUNC()
SubobjectInA::~SubobjectInA()  TRACE_FUNC()
A::A(int)  TRACE_FUNC()
A::~A()  TRACE_FUNC()
Q::~Q()  TRACE_FUNC( throw 0; )


### Compiler invocation:
g++-4.7.0 -std='c++11' tempbindIndirect_inittempDtorThrows.cpp -o test


### Compiler output:
(return code 0)


### Output from resulting executable:> ./test ; echo rc=$?
Q::Q()
SubobjectInA::SubobjectInA()
A::A(int)
Q::~Q()
rc=0


### Expected output:
Q::Q()
SubobjectInA::SubobjectInA()
A::A(int)
Q::~Q()
A::~A()
SubobjectInA::~SubobjectInA()
rc=0


### gcc -v output:> g++-4.7.0 -v
Using built-in specs.
COLLECT_GCC=g++-4.7.0
COLLECT_LTO_WRAPPER=/data/gcc/libexec/gcc/powerpc64-unknown-linux-gnu/4.7.0/lto-wrapper
Target: powerpc64-unknown-linux-gnu
Configured with: ../gcc-4.7.0/configure --prefix=/data/gcc
--program-suffix=-4.7.0 --disable-libssp --disable-libgcj
--enable-version-specific-runtime-libs --with-cpu=default32 --enable-secureplt
--with-long-double-128 --enable-shared --enable-__cxa_atexit
--enable-threads=posix --enable-languages=c,c++,fortran --with-mpfr=/usr/local/
--with-mpc=/usr/local/ --with-gmp=/usr/local/
Thread model: posix
gcc version 4.7.0 (GCC)

[Bug c++/53868] Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53868

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-07-06 08:17:16 UTC ---
(It doesn't matter for 4.7 but you need noexcept(false) on Q::~Q to use the
testcase on trunk)

[Bug c++/53868] Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53868

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|powerpc64-unknown-linux-gnu |
               Host|powerpc64-unknown-linux-gnu |
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=66139,
                   |                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=52320

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
clang and GCC both produce the same result while ICC produces the bug reporter
expected result.

This is also most likely related to PR 66139 and PR 52320.

[Bug c++/53868] Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53868

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2022-01-06
     Ever confirmed|0                           |1
                 CC|                            |jason at gcc dot gnu.org

[Bug c++/53868] Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53868

--- Comment #3 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:4c6afbbd48f0c40ddf949bc403d9bd5f5e14204f

commit r12-6332-g4c6afbbd48f0c40ddf949bc403d9bd5f5e14204f
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Jan 5 11:18:25 2022 -0500

    c++: clean up ref-extended temp on throwing dtor [PR53868]

    We have wrap_temporary_cleanups to handle the EH region nesting problems
    between cleanups for complete variables and cleanups for temporaries used
in
    their construction, but we weren't calling it for temporaries extended from
    binding to a reference.

    We still don't want this for array cleanups (since my PR94041 fix), so I
    move that exception from initialize_local_var to wrap_temporary_cleanups.

            PR c++/53868

    gcc/cp/ChangeLog:

            * decl.c (cp_finish_decl): Use wrap_temporary_cleanups for
            cleanups from set_up_extended_ref_temp.
            (wrap_temporary_cleanups): Ignore array cleanups.
            (initialize_local_var): Don't check for array here.
            * cp-tree.h (BIND_EXPR_VEC_DTOR): New.
            * init.c (build_vec_delete_1): Set it.

    gcc/testsuite/ChangeLog:

            * g++.dg/eh/ref-temp1.C: New test.
            * g++.dg/eh/ref-temp2.C: New test.

[Bug c++/53868] Temporary for indirect binding is not destroyed when destructor from initializer temp throws

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53868

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

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

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for GCC 12.