[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #14 from Jonathan Wakely  ---
P.S. if that failure only appeared recently it would be more useful to mail the
libstdc++ list than to add a comment to an old bug that hasn't been touched in
years.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #13 from Jonathan Wakely  ---
Should be fixed at g:01079b6a9236bd467b445fafaff2659840789a85

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[rimvydas.jas at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #12 from Rimvydas (RJ)  ---
Missing #include  in testsuite gives

/z/gg/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc:
In function 'bool aligned(void*)':
/z/gg/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc:62:
error: 'uintptr_t' in namespace 'std' does not name a type
compiler exited with status 1
FAIL: experimental/memory_resource/new_delete_resource.cc (test for excess
errors)
Excess errors:
/z/gg/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc:62:
error: 'uintptr_t' in namespace 'std' does not name a type

UNRESOLVED: experimental/memory_resource/new_delete_resource.cc compilation
failed to produce executable

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #11 from Jonathan Wakely  ---
Author: redi
Date: Mon Jul 23 19:40:28 2018
New Revision: 262935

URL: https://gcc.gnu.org/viewcvs?rev=262935=gcc=rev
Log:
PR libstdc++/70940 optimize pmr::resource_adaptor for allocators using malloc

pmr::resource_adaptor can avoid allocating an oversized buffer and doing
manual alignment within that buffer when the wrapped allocator is known
to always meet the requested alignment. Specifically, if the allocator
is known to use malloc or new directly, then we can call the allocator
directly for any fundamental alignment.

PR libstdc++/70940
* include/experimental/memory_resource
(__resource_adaptor_common::_AlignMgr::_M_unadjust): Add assertion.
(__resource_adaptor_common::__guaranteed_alignment): New helper to
give maximum alignment an allocator guarantees. Specialize for known
allocators using new and malloc.
(__resource_adaptor_imp::do_allocate): Use __guaranteed_alignment.
(__resource_adaptor_imp::do_deallocate): Likewise.
* testsuite/experimental/memory_resource/new_delete_resource.cc:
Check that new and delete are called with expected sizes.

Modified:
trunk/libstdc++-v3/ChangeLog
trunk/libstdc++-v3/include/experimental/memory_resource
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #10 from Jonathan Wakely  ---
Author: redi
Date: Thu Jun 21 16:24:00 2018
New Revision: 261851

URL: https://gcc.gnu.org/viewcvs?rev=261851=gcc=rev
Log:
PR libstdc++/70940 make pmr::resource_adaptor return aligned memory

PR libstdc++/70940
* include/experimental/memory_resource
(__resource_adaptor_imp::do_deallocate): Add missing return.
* testsuite/experimental/memory_resource/new_delete_resource.cc: New.
* testsuite/experimental/memory_resource/resource_adaptor.cc: Test
resource_adaptor with std::allocator, __gnu_cxx::new_allocator and
__gnu_cxx::malloc_allocator.

Added:
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/new_delete_resource.cc
Modified:
trunk/libstdc++-v3/ChangeLog
trunk/libstdc++-v3/include/experimental/memory_resource
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/resource_adaptor.cc

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Jonathan Wakely  changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution|--- |FIXED
   Target Milestone|--- |9.0

--- Comment #9 from Jonathan Wakely  ---
(In reply to Eric Fiselier from comment #0)
> Furthermore it seems that do_allocate returns ill-aligned pointers. It seems
> that do_allocate(s, a) returns the pointers from
> 'Allocator.allocate(...)' directly even though they have no alignment
> guarantees.

Fixed by allocating a buffer with additional space. The returned pointer is
adjusted to the next alignment boundary, and a token is stored at the end of
the allocated buffer to allow removing the adjustment to retrieve the original
pointer for deallocation.

(In reply to Jonathan Wakely from comment #1)
> __null_memory_resource doesn't need to be a class template.

Fixed by using a local class.

> new_delete_resource() returns something that:
> - doesn't have the required is_equal() behaviour.
> - only uses new/delete if std::allocator uses __gnu_cxx::new_allocator.

Fixed by using new_allocator directly.

> And another one from Eric:
> Your new_delete_resource() also unnecessarily pads the allocation size
> before invoking ::operator new, but that isn't a real bug.

I'm not going to fix that for the TS. Without C++17's aligned new we can't rely
on calling new/delete directly (at least not for extended alignments). Going
via resource_adaptor<__gnu_cxx::new_allocator> gives us the alignment
guarantees, at the expense of some extra padding. I considered adding
specialization to resource_adaptor so that when using new_allocator (or
std::allocator when that uses new_allocator) it would avoid doing the padding
for fundamental alignments. Maybe at a later date.

For C++17's std::pmr::new_delete_resource() we can just use aligned new
directly  and don't need to wrap new_allocator and over-allocate (and if
the user uses -fno-aligned-new they don't get a new_delete_resource).

Closing as fixed on trunk.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #8 from Jonathan Wakely  ---
Author: redi
Date: Thu Jun 21 14:01:11 2018
New Revision: 261849

URL: https://gcc.gnu.org/viewcvs?rev=261849=gcc=rev
Log:
PR libstdc++/70940 make pmr::resource_adaptor return aligned memory

PR libstdc++/70940
* include/experimental/memory_resource (__resource_adaptor_common):
New base class.
(__resource_adaptor_common::_AlignMgr): Helper for obtaining aligned
pointer from unaligned, and vice versa.
(__resource_adaptor_imp::do_allocate): Use _AlignMgr to adjust
allocated pointer to meet alignment request.
(__resource_adaptor_imp::do_deallocate): Use _AlignMgr to retrieve
original pointer for deallocation.
(__resource_adaptor_imp::do_is_equal): Reformat.
(__resource_adaptor_imp::_S_aligned_size): Remove.
(__resource_adaptor_imp::_S_supported): Remove.
(new_delete_resource): Use __gnu_cxx::new_allocator.
* testsuite/experimental/memory_resource/resource_adaptor.cc: Test
extended alignments and use debug_allocator to check for matching
allocate/deallocate pairs.

Modified:
trunk/libstdc++-v3/ChangeLog
trunk/libstdc++-v3/include/experimental/memory_resource
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/resource_adaptor.cc

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Jonathan Wakely  changed:

   What|Removed |Added

   Target Milestone|7.4 |---

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Richard Biener  changed:

   What|Removed |Added

   Target Milestone|7.3 |7.4

--- Comment #7 from Richard Biener  ---
GCC 7.3 is being released, adjusting target milestone.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Richard Biener  changed:

   What|Removed |Added

   Target Milestone|7.2 |7.3

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Richard Biener  changed:

   What|Removed |Added

   Target Milestone|7.2 7.2 |7.3 7.3

--- Comment #7 from Richard Biener  ---
GCC 7.2 is being released, adjusting target milestone.

--- Comment #8 from Richard Biener  ---
GCC 7.2 is being released, adjusting target milestone.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Richard Biener  changed:

   What|Removed |Added

   Target Milestone|7.2 7.2 |7.3 7.3

--- Comment #7 from Richard Biener  ---
GCC 7.2 is being released, adjusting target milestone.

--- Comment #8 from Richard Biener  ---
GCC 7.2 is being released, adjusting target milestone.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Jakub Jelinek  changed:

   What|Removed |Added

   Target Milestone|7.0 |7.2

--- Comment #6 from Jakub Jelinek  ---
GCC 7.1 has been released.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Jonathan Wakely  changed:

   What|Removed |Added

   Target Milestone|6.2 |7.0

--- Comment #5 from Jonathan Wakely  ---
The worst problems are fixed on the gcc-6-branch for 6.2

I'll keep this open for the other issues but only plan to fix them on trunk.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #4 from Jonathan Wakely  ---
Author: redi
Date: Sat Aug  6 12:20:31 2016
New Revision: 239199

URL: https://gcc.gnu.org/viewcvs?rev=239199=gcc=rev
Log:
libstdc++/70940 Start fixing polymorphic memory resources

Backport from mainline
2016-05-04  Jonathan Wakely  

PR libstdc++/70940
* include/experimental/memory_resource
(__resource_adaptor_imp::do_allocate): Do not default-construct
rebound allocator.
(__resource_adaptor_imp::do_deallocate): Likewise. Use
allocator_traits to get pointer type.
(__null_memory_resource::do_allocate): Remove unused parameters.
(__null_memory_resource::do_deallocate): Likewise.
(__null_memory_resource::do_is_equal): Likewise. Add return statement.
* testsuite/experimental/type_erased_allocator/1.cc: Combine with ...
* testsuite/experimental/type_erased_allocator/1_neg.cc: This, and
move to ...
* testsuite/experimental/memory_resource/1.cc: Here.
* testsuite/experimental/memory_resource/null_memory_resource.cc: New.
* testsuite/experimental/memory_resource/resource_adaptor.cc: New.

Added:
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/memory_resource/
   
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/memory_resource/1.cc
  - copied, changed from r239198,
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/type_erased_allocator/1.cc
   
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/memory_resource/null_memory_resource.cc
  - copied, changed from r239198,
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/type_erased_allocator/1_neg.cc
   
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/memory_resource/resource_adaptor.cc
Removed:
   
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/type_erased_allocator/1.cc
   
branches/gcc-6-branch/libstdc++-v3/testsuite/experimental/type_erased_allocator/1_neg.cc
Modified:
branches/gcc-6-branch/libstdc++-v3/ChangeLog
branches/gcc-6-branch/libstdc++-v3/include/experimental/memory_resource

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Jonathan Wakely  changed:

   What|Removed |Added

 Status|NEW |ASSIGNED
   Assignee|unassigned at gcc dot gnu.org  |redi at gcc dot gnu.org
   Target Milestone|--- |6.2

--- Comment #3 from Jonathan Wakely  ---
(In reply to Eric Fiselier from comment #0)
> resource_adapter incorrectly requires that the Allocator provide:
>   * A pointer typedef.
>   * A default constructor.

Those errors are fixed on trunk now.

(In reply to Jonathan Wakely from comment #1)
> Also:
> 
> __null_memory_resource::do_is_equal() is missing a return statement, so
> returns garbage off the stack.

So is this.

The rest isn't yet.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #2 from Jonathan Wakely  ---
Author: redi
Date: Wed May  4 12:08:45 2016
New Revision: 235868

URL: https://gcc.gnu.org/viewcvs?rev=235868=gcc=rev
Log:
libstdc++/70940 Start fixing polymorphic memory resources

PR libstdc++/70940
* include/experimental/memory_resource
(__resource_adaptor_imp::do_allocate): Do not default-construct
rebound allocator.
(__resource_adaptor_imp::do_deallocate): Likewise. Use
allocator_traits to get pointer type.
(__null_memory_resource::do_allocate): Remove unused parameters.
(__null_memory_resource::do_deallocate): Likewise.
(__null_memory_resource::do_is_equal): Likewise. Add return statement.
* testsuite/experimental/type_erased_allocator/1.cc: Combine with ...
* testsuite/experimental/type_erased_allocator/1_neg.cc: This, and
move to ...
* testsuite/experimental/memory_resource/1.cc: Here.
* testsuite/experimental/memory_resource/null_memory_resource.cc: New.
* testsuite/experimental/memory_resource/resource_adaptor.cc: New.

Added:
trunk/libstdc++-v3/testsuite/experimental/memory_resource/
trunk/libstdc++-v3/testsuite/experimental/memory_resource/1.cc
  - copied, changed from r235859,
trunk/libstdc++-v3/testsuite/experimental/type_erased_allocator/1.cc
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/null_memory_resource.cc
  - copied, changed from r235859,
trunk/libstdc++-v3/testsuite/experimental/type_erased_allocator/1_neg.cc
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/resource_adaptor.cc
Removed:
trunk/libstdc++-v3/testsuite/experimental/type_erased_allocator/1.cc
trunk/libstdc++-v3/testsuite/experimental/type_erased_allocator/1_neg.cc
Modified:
trunk/libstdc++-v3/ChangeLog
trunk/libstdc++-v3/include/experimental/memory_resource

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #1 from Jonathan Wakely  ---
Also:

__null_memory_resource::do_is_equal() is missing a return statement, so returns
garbage off the stack.

__null_memory_resource doesn't need to be a class template.

new_delete_resource() returns something that:
- doesn't have the required is_equal() behaviour.
- only uses new/delete if std::allocator uses __gnu_cxx::new_allocator.

And another one from Eric:
Your new_delete_resource() also unnecessarily pads the allocation size before
invoking ::operator new, but that isn't a real bug.

[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

Jonathan Wakely  changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
   Last reconfirmed||2016-05-04
 Ever confirmed|0   |1