Re: Fix hashtable node deallocation

[François Dumont <frs dot dumont at gmail dot com>]

Still waiting for this (I hope) last fix before gcc 9 release...

We could perhaps make:
      _Pointer_adapter(element_type* __arg = 0)

explicit to find out if there are other places where we miss to properly 
call pointer_traits<>::pointer_to. But I aren't sure we can do it in 
this extension and I haven't tried yet.

François

On 12/16/18 2:16 PM, François Dumont wrote:
> Gentle reminder, we still have this issue pending.
>
>     * include/bits/hashtable_policy.h
> (_Hashtable_alloc<>::_M_deallocate_node_ptr(__node_type*)): New.
>     (_Hashtable_alloc<>::_M_deallocate_node(__node_type*)): Use latter.
> (_ReuseOrAllocNode<>::operator<_Arg>()(_Arg&&)): Likewise.
>     * libstdc++-v3/testsuite/util/testsuite_allocator.h
>     (CustomPointerAlloc<>::allocate(size_t, pointer)): Replace by...
>     (CustomPointerAlloc<>::allocate(size_t, const_void_pointer)): 
> ...this.
>
> François
>
> On 11/29/18 7:08 AM, François Dumont wrote:
> > I am unclear about this patch, is it accepted ?
> >
> >
> > On 11/19/18 10:19 PM, François Dumont wrote:
> > > On 11/19/18 1:34 PM, Jonathan Wakely wrote:
> > > > On 10/11/18 22:40 +0100, François Dumont wrote:
> > > > > While working on a hashtable enhancement I noticed that we are not 
> > > > > using the correct method to deallocate node if the constructor 
> > > > > throws in _ReuseOrAllocNode operator(). I had to introduce a new 
> > > > > _M_deallocate_node_ptr for that as node value shall not be destroy 
> > > > > again.
> > > > >
> > > > > I also check other places and noticed that a __node_type 
> > > > > destructor call was missing.
> > > >
> > > > That's intentional. The type has a trivial destructor, so its storage
> > > > can just be reused, we don't need to destroy it.
> > > Ok, do you want to also remove the other call to ~__node_type() then ?
> > >
> > > Here is the updated patch and the right ChangeLog entry:
> > >
> > >     * include/bits/hashtable_policy.h
> > > (_Hashtable_alloc<>::_M_deallocate_node_ptr(__node_type*)): New.
> > > (_Hashtable_alloc<>::_M_deallocate_node(__node_type*)): Use latter.
> > > (_ReuseOrAllocNode<>::operator<_Arg>()(_Arg&&)): Likewise.
> > >     (_Hashtable_alloc<>::_M_allocate_node): Add ~__node_type call.
> > >     * libstdc++-v3/testsuite/util/testsuite_allocator.h
> > >     (CustomPointerAlloc<>::allocate(size_t, pointer)): Replace by...
> > >     (CustomPointerAlloc<>::allocate(size_t, const_void_pointer)): 
> > > ...this.
> > >     * testsuite/23_containers/unordered_set/allocator/ext_ptr.cc: Add
> > >     check.
> > >
> > > Ok to commit ?
> > >
> > > François