https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91434
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to Rajabharathi s from comment #3)
> (In reply to Jonathan Wakely from comment #2)
> > This code has undefined behaviour:
> >
> > int main()
> > {
> > FSPI pi;
> > FSPG* pg = new FSPG();
> > new (&pi.m_a) FSPGI(pg);
> > pi.m_a.~FSPGI();
> > return 0;
> > }
> >
> > pi.m_a is part of an object on the stack, so its destructor will run
> > automatically. If you invoke it explicitly as pi.m_a.~FSPGI() then you cause
> > the same object to be destroyed twice. This is undefined. You need to fix
> > your code.
>
>
> Thanks for your reply. I understand this.
> But since m_a is member variable of other object FSPI, this memory exists in
> stack until its destruction.
It violates C++ standard, where lifetime of an object is undefined after
destruction.
>
> m_g is set to NULL in destructor part when called for first time.
> So second time, this if condition should be false.
> If -fno-tree-dse option is used, then this if condition is false and works
> fine in 4.9.4.
Following should help in your case:
-flifetime-dse=0
>
> ~FSPGI()
> {cout << "FSPGI dtor\n";
>
> if(NULL != m_g)
> {
> cout << "m_g is not NULL\n";
> delete m_g;
> m_g = NULL;
> }
> }
>
> class FSPI
> {
>
> public:
> FSPI()
> {
> cout << "FSPI ctor\n";
> }
> ~FSPI()
> {
> cout << "FSPI dtor \n";
> }
> FSPGI m_a;
> };
