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* [PATCH] Add initial version of C++17 <memory_resource> header
@ 2018-07-24 21:12 Jonathan Wakely
  2018-07-25 11:01 ` Jonathan Wakely
  0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Wakely @ 2018-07-24 21:12 UTC (permalink / raw)
  To: libstdc++, gcc-patches

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This is missing the synchronized_pool_resource and
unsynchronized_pool_resource classes but is otherwise complete.

This is a new implementation, not based on the existing code in
<experimental/memory_resource>, but memory_resource and
polymorphic_allocator ended up looking almost the same anyway.

The constant_init kluge in src/c++17/memory_resource.cc is apparently
due to Richard Smith and ensures that the objects are constructed during
constant initialiation phase and not destroyed (because the
constant_init destructor doesn't destroy the union member and the
storage is not reused).

	* config/abi/pre/gnu.ver: Export new symbols.
	* configure: Regenerate.
	* include/Makefile.am: Add new <memory_resource> header.
	* include/Makefile.in: Regenerate.
	* include/precompiled/stdc++.h: Include <memory_resource> for C++17.
	* include/std/memory_resource: New header.
	(memory_resource, polymorphic_allocator, new_delete_resource)
	(null_memory_resource, set_default_resource, get_default_resource)
	(pool_options, monotonic_buffer_resource): Define.
	* src/Makefile.am: Add c++17 directory.
	* src/Makefile.in: Regenerate.
	* src/c++11/Makefile.am: Fix comment.
	* src/c++17/Makefile.am: Add makefile for new sub-directory.
	* src/c++17/Makefile.in: Generate.
	* src/c++17/memory_resource.cc: New.
	(newdel_res_t, null_res_t, constant_init, newdel_res, null_res)
	(default_res, new_delete_resource, null_memory_resource)
	(set_default_resource, get_default_resource): Define.
	* testsuite/20_util/memory_resource/1.cc: New test.
	* testsuite/20_util/memory_resource/2.cc: New test.
	* testsuite/20_util/monotonic_buffer_resource/1.cc: New test.
	* testsuite/20_util/monotonic_buffer_resource/allocate.cc: New test.
	* testsuite/20_util/monotonic_buffer_resource/deallocate.cc: New test.
	* testsuite/20_util/monotonic_buffer_resource/release.cc: New test.
	* testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc:
	New test.
	* testsuite/20_util/polymorphic_allocator/1.cc: New test.
	* testsuite/20_util/polymorphic_allocator/resource.cc: New test.
	* testsuite/20_util/polymorphic_allocator/select.cc: New test.
	* testsuite/util/testsuite_allocator.h (__gnu_test::memory_resource):
	Define concrete memory resource for testing.
	(__gnu_test::default_resource_mgr): Define RAII helper for changing
	default resource.

Tested powerpc64le-linux, committed to trunk.




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commit 05c7ae80dbd59fcef5d583eac15181afbc07a116
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Jul 24 14:19:19 2018 +0100

    Add initial version of C++17 <memory_resource> header
    
    This is missing the synchronized_pool_resource and
    unsynchronized_pool_resource classes but is otherwise complete.
    
    This is a new implementation, not based on the existing code in
    <experimental/memory_resource>, but memory_resource and
    polymorphic_allocator ended up looking almost the same anyway.
    
    The constant_init kluge in src/c++17/memory_resource.cc is apparently
    due to Richard Smith and ensures that the objects are constructed during
    constant initialiation phase and not destroyed (because the
    constant_init destructor doesn't destroy the union member and the
    storage is not reused).
    
            * config/abi/pre/gnu.ver: Export new symbols.
            * configure: Regenerate.
            * include/Makefile.am: Add new <memory_resource> header.
            * include/Makefile.in: Regenerate.
            * include/precompiled/stdc++.h: Include <memory_resource> for C++17.
            * include/std/memory_resource: New header.
            (memory_resource, polymorphic_allocator, new_delete_resource)
            (null_memory_resource, set_default_resource, get_default_resource)
            (pool_options, monotonic_buffer_resource): Define.
            * src/Makefile.am: Add c++17 directory.
            * src/Makefile.in: Regenerate.
            * src/c++11/Makefile.am: Fix comment.
            * src/c++17/Makefile.am: Add makefile for new sub-directory.
            * src/c++17/Makefile.in: Generate.
            * src/c++17/memory_resource.cc: New.
            (newdel_res_t, null_res_t, constant_init, newdel_res, null_res)
            (default_res, new_delete_resource, null_memory_resource)
            (set_default_resource, get_default_resource): Define.
            * testsuite/20_util/memory_resource/1.cc: New test.
            * testsuite/20_util/memory_resource/2.cc: New test.
            * testsuite/20_util/monotonic_buffer_resource/1.cc: New test.
            * testsuite/20_util/monotonic_buffer_resource/allocate.cc: New test.
            * testsuite/20_util/monotonic_buffer_resource/deallocate.cc: New test.
            * testsuite/20_util/monotonic_buffer_resource/release.cc: New test.
            * testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc:
            New test.
            * testsuite/20_util/polymorphic_allocator/1.cc: New test.
            * testsuite/20_util/polymorphic_allocator/resource.cc: New test.
            * testsuite/20_util/polymorphic_allocator/select.cc: New test.
            * testsuite/util/testsuite_allocator.h (__gnu_test::memory_resource):
            Define concrete memory resource for testing.
            (__gnu_test::default_resource_mgr): Define RAII helper for changing
            default resource.

diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index b09bdef6d09..36459e88b6a 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -2039,6 +2039,11 @@ GLIBCXX_3.4.26 {
     _ZNSt7__cxx1118basic_stringstreamI[cw]St11char_traitsI[cw]ESaI[cw]EEC[12]Ev;
     _ZNSt7__cxx1119basic_[io]stringstreamI[cw]St11char_traitsI[cw]ESaI[cw]EEC[12]Ev;
 
+    _ZNSt3pmr19new_delete_resourceEv;
+    _ZNSt3pmr20null_memory_resourceEv;
+    _ZNSt3pmr20get_default_resourceEv;
+    _ZNSt3pmr20set_default_resourceEPNS_15memory_resourceE;
+
 } GLIBCXX_3.4.25;
 
 # Symbols in the support library (libsupc++) have their own tag.
diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index d1453a5abce..9daa8856e70 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -54,6 +54,7 @@ std_headers = \
 	${std_srcdir}/locale \
 	${std_srcdir}/map \
 	${std_srcdir}/memory \
+	${std_srcdir}/memory_resource \
 	${std_srcdir}/mutex \
 	${std_srcdir}/numeric \
 	${std_srcdir}/optional \
diff --git a/libstdc++-v3/include/precompiled/stdc++.h b/libstdc++-v3/include/precompiled/stdc++.h
index 80769233eb3..1f537354052 100644
--- a/libstdc++-v3/include/precompiled/stdc++.h
+++ b/libstdc++-v3/include/precompiled/stdc++.h
@@ -128,7 +128,7 @@
 // #include <execution>
 #include <filesystem>
 #include <optional>
-// #include <memory_resource>
+#include <memory_resource>
 #include <string_view>
 #include <variant>
 #endif
diff --git a/libstdc++-v3/include/std/memory_resource b/libstdc++-v3/include/std/memory_resource
new file mode 100644
index 00000000000..b3f8f7d9477
--- /dev/null
+++ b/libstdc++-v3/include/std/memory_resource
@@ -0,0 +1,510 @@
+// <memory_resource> -*- C++ -*-
+
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file include/memory_resource
+ *  This is a Standard C++ Library header.
+ */
+
+#ifndef _GLIBCXX_MEMORY_RESOURCE
+#define _GLIBCXX_MEMORY_RESOURCE 1
+
+#pragma GCC system_header
+
+#if __cplusplus >= 201703L
+
+#include <bit>				// __ceil2, __log2p1
+#include <memory>			// align, allocator_arg_t, __uses_alloc
+#include <utility>			// pair, index_sequence
+#include <cstddef>			// size_t, max_align_t
+#include <debug/assertions.h>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+namespace pmr
+{
+// #define __cpp_lib_memory_resource 201603
+
+  class memory_resource;
+
+  template<typename _Tp>
+    class polymorphic_allocator;
+
+  // Global memory resources
+  memory_resource* new_delete_resource() noexcept;
+  memory_resource* null_memory_resource() noexcept;
+  memory_resource* set_default_resource(memory_resource* __r) noexcept;
+  memory_resource* get_default_resource() noexcept
+    __attribute__((__returns_nonnull__));
+
+  // Pool resource classes
+  struct pool_options;
+  class synchronized_pool_resource;
+  class unsynchronized_pool_resource;
+  class monotonic_buffer_resource;
+
+  /// Class memory_resource
+  class memory_resource
+  {
+    static constexpr size_t _S_max_align = alignof(max_align_t);
+
+  public:
+    memory_resource() = default;
+    memory_resource(const memory_resource&) = default;
+    virtual ~memory_resource() = default;
+
+    memory_resource& operator=(const memory_resource&) = default;
+
+    [[nodiscard]]
+    void*
+    allocate(size_t __bytes, size_t __alignment = _S_max_align)
+    __attribute__((__returns_nonnull__,__alloc_size__(2),__alloc_align__(3)))
+    { return do_allocate(__bytes, __alignment); }
+
+    void
+    deallocate(void* __p, size_t __bytes, size_t __alignment = _S_max_align)
+    __attribute__((__nonnull__))
+    { return do_deallocate(__p, __bytes, __alignment); }
+
+    bool
+    is_equal(const memory_resource& __other) const noexcept
+    { return do_is_equal(__other); }
+
+  private:
+    virtual void*
+    do_allocate(size_t __bytes, size_t __alignment) = 0;
+
+    virtual void
+    do_deallocate(void* __p, size_t __bytes, size_t __alignment) = 0;
+
+    virtual bool
+    do_is_equal(const memory_resource& __other) const noexcept = 0;
+  };
+
+  inline bool
+  operator==(const memory_resource& __a, const memory_resource& __b) noexcept
+  { return &__a == &__b || __a.is_equal(__b); }
+
+  inline bool
+  operator!=(const memory_resource& __a, const memory_resource& __b) noexcept
+  { return !(__a == __b); }
+
+
+  // C++17 23.12.3 Class template polymorphic_allocator
+  template<typename _Tp>
+    class polymorphic_allocator
+    {
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 2975. Missing case for pair construction in polymorphic allocators
+      template<typename _Up>
+	struct __not_pair { using type = void; };
+
+      template<typename _Up1, typename _Up2>
+	struct __not_pair<pair<_Up1, _Up2>> { };
+
+    public:
+      using value_type = _Tp;
+
+      polymorphic_allocator() noexcept
+      : _M_resource(get_default_resource())
+      { }
+
+      polymorphic_allocator(memory_resource* __r) noexcept
+      __attribute__((__nonnull__))
+      : _M_resource(__r)
+      { _GLIBCXX_DEBUG_ASSERT(__r); }
+
+      polymorphic_allocator(const polymorphic_allocator& __other) = default;
+
+      template<typename _Up>
+	polymorphic_allocator(const polymorphic_allocator<_Up>& __x) noexcept
+	: _M_resource(__x.resource())
+	{ }
+
+      polymorphic_allocator&
+      operator=(const polymorphic_allocator&) = delete;
+
+      [[nodiscard]]
+      _Tp*
+      allocate(size_t __n)
+      __attribute__((__returns_nonnull__))
+      {
+	if (__n > (numeric_limits<size_t>::max() / sizeof(_Tp)))
+	  std::__throw_bad_alloc();
+	return static_cast<_Tp*>(_M_resource->allocate(__n * sizeof(_Tp),
+						       alignof(_Tp)));
+      }
+
+      void
+      deallocate(_Tp* __p, size_t __n) noexcept
+      __attribute__((__nonnull__))
+      { _M_resource->deallocate(__p, __n * sizeof(_Tp), alignof(_Tp)); }
+
+      template<typename _Tp1, typename... _Args>
+	__attribute__((__nonnull__))
+	typename __not_pair<_Tp>::type
+	construct(_Tp1* __p, _Args&&... __args)
+	{
+	  // _GLIBCXX_RESOLVE_LIB_DEFECTS
+	  // 2969. polymorphic_allocator::construct() shouldn't pass resource()
+	  auto __use_tag
+	    = __use_alloc<_Tp1, polymorphic_allocator, _Args...>(*this);
+	  _S_construct(__use_tag, __p, std::forward<_Args>(__args)...);
+	}
+
+      template<typename _Tp1, typename _Tp2,
+	       typename... _Args1, typename... _Args2>
+	__attribute__((__nonnull__))
+	void
+	construct(pair<_Tp1, _Tp2>* __p, piecewise_construct_t,
+		  tuple<_Args1...> __x, tuple<_Args2...> __y)
+	{
+	  auto __x_tag =
+	    __use_alloc<_Tp1, polymorphic_allocator, _Args1...>(*this);
+	  auto __y_tag =
+	    __use_alloc<_Tp2, polymorphic_allocator, _Args2...>(*this);
+	  index_sequence_for<_Args1...> __x_i;
+	  index_sequence_for<_Args2...> __y_i;
+
+	  ::new(__p) pair<_Tp1, _Tp2>(piecewise_construct,
+				      _S_construct_p(__x_tag, __x, __x_i),
+				      _S_construct_p(__y_tag, __y, __y_i));
+	}
+
+      template<typename _Tp1, typename _Tp2>
+	__attribute__((__nonnull__))
+	void
+	construct(pair<_Tp1, _Tp2>* __p)
+	{ this->construct(__p, piecewise_construct, tuple<>(), tuple<>()); }
+
+      template<typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
+	__attribute__((__nonnull__))
+	void
+	construct(pair<_Tp1, _Tp2>* __p, _Up&& __x, _Vp&& __y)
+	{
+	  this->construct(__p, piecewise_construct,
+			  forward_as_tuple(std::forward<_Up>(__x)),
+			  forward_as_tuple(std::forward<_Vp>(__y)));
+	}
+
+      template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
+	__attribute__((__nonnull__))
+	void
+	construct(pair<_Tp1, _Tp2>* __p, const std::pair<_Up, _Vp>& __pr)
+	{
+	  this->construct(__p, piecewise_construct,
+			  forward_as_tuple(__pr.first),
+			  forward_as_tuple(__pr.second));
+	}
+
+      template<typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
+	__attribute__((__nonnull__))
+	void
+	construct(pair<_Tp1, _Tp2>* __p, pair<_Up, _Vp>&& __pr)
+	{
+	  this->construct(__p, piecewise_construct,
+			  forward_as_tuple(std::forward<_Up>(__pr.first)),
+			  forward_as_tuple(std::forward<_Vp>(__pr.second)));
+	}
+
+      template<typename _Up>
+	__attribute__((__nonnull__))
+	void
+	destroy(_Up* __p)
+	{ __p->~_Up(); }
+
+      polymorphic_allocator
+      select_on_container_copy_construction() const noexcept
+      { return polymorphic_allocator(); }
+
+      memory_resource*
+      resource() const noexcept
+      __attribute__((__returns_nonnull__))
+      { return _M_resource; }
+
+    private:
+      using __uses_alloc1_ = __uses_alloc1<polymorphic_allocator>;
+      using __uses_alloc2_ = __uses_alloc2<polymorphic_allocator>;
+
+      template<typename _Tp1, typename... _Args>
+	static void
+	_S_construct(__uses_alloc0, _Tp1* __p, _Args&&... __args)
+	{ ::new(__p) _Tp1(std::forward<_Args>(__args)...); }
+
+      template<typename _Tp1, typename... _Args>
+	static void
+	_S_construct(__uses_alloc1_ __ua, _Tp1* __p, _Args&&... __args)
+	{
+	  ::new(__p) _Tp1(allocator_arg, *__ua._M_a,
+			  std::forward<_Args>(__args)...);
+	}
+
+      template<typename _Tp1, typename... _Args>
+	static void
+	_S_construct(__uses_alloc2_ __ua, _Tp1* __p, _Args&&... __args)
+	{ ::new(__p) _Tp1(std::forward<_Args>(__args)..., *__ua._M_a); }
+
+      template<typename _Ind, typename... _Args>
+	static tuple<_Args&&...>
+	_S_construct_p(__uses_alloc0, _Ind, tuple<_Args...>& __t)
+	{ return std::move(__t); }
+
+      template<size_t... _Ind, typename... _Args>
+	static tuple<allocator_arg_t, polymorphic_allocator&, _Args&&...>
+	_S_construct_p(__uses_alloc1_ __ua, index_sequence<_Ind...>,
+		       tuple<_Args...>& __t)
+	{
+	  return {
+	      allocator_arg, *__ua._M_a, std::get<_Ind>(std::move(__t))...
+	  };
+	}
+
+      template<size_t... _Ind, typename... _Args>
+	static tuple<_Args&&..., polymorphic_allocator&>
+	_S_construct_p(__uses_alloc2_ __ua, index_sequence<_Ind...>,
+		       tuple<_Args...>& __t)
+	{ return { std::get<_Ind>(std::move(__t))..., *__ua._M_a }; }
+
+      memory_resource* _M_resource;
+    };
+
+  template<typename _Tp1, typename _Tp2>
+    inline bool
+    operator==(const polymorphic_allocator<_Tp1>& __a,
+	       const polymorphic_allocator<_Tp2>& __b) noexcept
+    { return *__a.resource() == *__b.resource(); }
+
+  template<typename _Tp1, typename _Tp2>
+    inline bool
+    operator!=(const polymorphic_allocator<_Tp1>& __a,
+	       const polymorphic_allocator<_Tp2>& __b) noexcept
+    { return !(__a == __b); }
+
+
+  struct pool_options
+  {
+    size_t max_blocks_per_chunk = 0;
+    size_t largest_required_pool_block = 0;
+  };
+
+  // TODO class synchronized_pool_resource;
+  // TODO class unsynchronized_pool_resource;
+
+  class monotonic_buffer_resource : public memory_resource
+  {
+  public:
+    explicit
+    monotonic_buffer_resource(memory_resource* __upstream) noexcept
+    __attribute__((__nonnull__))
+    : _M_upstream(__upstream)
+    { _GLIBCXX_DEBUG_ASSERT(__upstream != nullptr); }
+
+    monotonic_buffer_resource(size_t __initial_size,
+			      memory_resource* __upstream) noexcept
+    __attribute__((__nonnull__))
+    : _M_next_bufsiz(__initial_size),
+      _M_upstream(__upstream)
+    {
+      _GLIBCXX_DEBUG_ASSERT(__upstream != nullptr);
+      _GLIBCXX_DEBUG_ASSERT(__initial_size > 0);
+    }
+
+    monotonic_buffer_resource(void* __buffer, size_t __buffer_size,
+			      memory_resource* __upstream) noexcept
+    __attribute__((__nonnull__(4)))
+    : _M_current_buf(__buffer), _M_avail(__buffer_size),
+      _M_next_bufsiz(_S_next_bufsize(__buffer_size)),
+      _M_upstream(__upstream),
+      _M_orig_buf(__buffer), _M_orig_size(__buffer_size)
+    {
+      _GLIBCXX_DEBUG_ASSERT(__upstream != nullptr);
+      _GLIBCXX_DEBUG_ASSERT(__buffer != nullptr || __buffer_size == 0);
+    }
+
+    monotonic_buffer_resource() noexcept
+    : monotonic_buffer_resource(get_default_resource())
+    { }
+
+    explicit
+    monotonic_buffer_resource(size_t __initial_size) noexcept
+    : monotonic_buffer_resource(__initial_size, get_default_resource())
+    { }
+
+    monotonic_buffer_resource(void* __buffer, size_t __buffer_size) noexcept
+    : monotonic_buffer_resource(__buffer, __buffer_size, get_default_resource())
+    { }
+
+    monotonic_buffer_resource(const monotonic_buffer_resource&) = delete;
+
+    virtual ~monotonic_buffer_resource() { release(); }
+
+    monotonic_buffer_resource&
+    operator=(const monotonic_buffer_resource&) = delete;
+
+    void
+    release() noexcept
+    {
+      _Chunk::release(_M_head, _M_upstream);
+
+      // reset to initial state at contruction:
+      if ((_M_current_buf = _M_orig_buf))
+	{
+	  _M_avail = _M_orig_size;
+	  _M_next_bufsiz = _S_next_bufsize(_M_orig_size);
+	}
+      else
+	{
+	  _M_avail = 0;
+	  _M_next_bufsiz = _M_orig_size;
+	}
+    }
+
+    memory_resource*
+    upstream_resource() const noexcept
+    __attribute__((__returns_nonnull__))
+    { return _M_upstream; }
+
+  protected:
+    void*
+    do_allocate(size_t __bytes, size_t __alignment) override
+    {
+      if (__bytes == 0)
+	__bytes = 1; // Ensures we don't return the same pointer twice.
+
+      if (auto __p = std::align(__alignment, __bytes, _M_current_buf, _M_avail))
+	{
+	  _M_current_buf = (char*)_M_current_buf + __bytes;
+	  _M_avail -= __bytes;
+	  return __p;
+	}
+
+      const size_t __n = std::max(__bytes, _M_next_bufsiz);
+      const size_t __m = std::max(__alignment, alignof(std::max_align_t));
+      auto [__p, __size] = _Chunk::allocate(_M_upstream, __n, __m, _M_head);
+      _M_current_buf = (char*)__p + __bytes;
+      _M_avail = __size - __bytes;
+      _M_next_bufsiz *= _S_growth_factor;
+      return __p;
+    }
+
+    void
+    do_deallocate(void*, size_t, size_t) override
+    { }
+
+    bool
+    do_is_equal(const memory_resource& __other) const noexcept override
+    { return this == &__other; }
+
+  private:
+    static size_t
+    _S_next_bufsize(size_t __buffer_size) noexcept
+    {
+      if (__buffer_size == 0)
+	__buffer_size = 1;
+      return __buffer_size * _S_growth_factor;
+    }
+
+    static constexpr size_t _S_init_bufsize = 128 * sizeof(void*);
+    static constexpr float _S_growth_factor = 1.5;
+
+    void*	_M_current_buf = nullptr;
+    size_t	_M_avail = 0;
+    size_t	_M_next_bufsiz = _S_init_bufsize;
+
+    // Initial values set at construction and reused by release():
+    memory_resource* const	_M_upstream;
+    void* const			_M_orig_buf = nullptr;
+    size_t const		_M_orig_size = _M_next_bufsiz;
+
+    // Memory allocated by the upstream resource is managed in a linked list
+    // of _Chunk objects. A _Chunk object recording the size and alignment of
+    // the allocated block and a pointer to the previous chunk is placed
+    // at end of the block.
+    class _Chunk
+    {
+    public:
+      // Return the address and size of a block of memory allocated from __r,
+      // of at least __size bytes and aligned to __align.
+      // Add a new _Chunk to the front of the linked list at __head.
+      static pair<void*, size_t>
+      allocate(memory_resource* __r, size_t __size, size_t __align,
+	       _Chunk*& __head)
+      {
+	__size = std::__ceil2(__size + sizeof(_Chunk));
+	void* __p = __r->allocate(__size, __align);
+	// Add a chunk defined by (__p, __size, __align) to linked list __head.
+	void* const __back = (char*)__p + __size - sizeof(_Chunk);
+	__head = ::new(__back) _Chunk(__size, __align, __head);
+	return { __p, __size - sizeof(_Chunk) };
+      }
+
+      // Return every chunk in linked list __head to resource __r.
+      static void
+      release(_Chunk*& __head, memory_resource* __r) noexcept
+      {
+	_Chunk* __next = __head;
+	__head = nullptr;
+	while (__next)
+	  {
+	    _Chunk* __ch = __next;
+	    __builtin_memcpy(&__next, __ch->_M_next, sizeof(_Chunk*));
+
+	    __glibcxx_assert(__ch->_M_canary != 0);
+	    __glibcxx_assert(__ch->_M_canary == (__ch->_M_size|__ch->_M_align));
+
+	    if (__ch->_M_canary != (__ch->_M_size | __ch->_M_align))
+	      return; // buffer overflow detected!
+
+	    size_t __size = (1u << __ch->_M_size);
+	    size_t __align = (1u << __ch->_M_align);
+	    void* __start = (char*)(__ch + 1) - __size;
+	    __r->deallocate(__start, __size, __align);
+	  }
+      }
+
+    private:
+      _Chunk(size_t __size, size_t __align, _Chunk* __next) noexcept
+      : _M_size(std::__log2p1(__size) - 1),
+	_M_align(std::__log2p1(__align) - 1)
+      {
+	__builtin_memcpy(_M_next, &__next, sizeof(__next));
+	_M_canary = _M_size | _M_align;
+      }
+
+      unsigned char _M_canary;
+      unsigned char _M_size;
+      unsigned char _M_align;
+      unsigned char _M_next[sizeof(_Chunk*)];
+    };
+    static_assert(alignof(_Chunk) == 1);
+
+    _Chunk* _M_head = nullptr;
+  };
+
+} // namespace pmr
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std
+
+#endif // C++17
+#endif // _GLIBCXX_MEMORY_RESOURCE
diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index ba30dde8fec..09edcdbc471 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -28,7 +28,7 @@ else
 filesystem_dir =
 endif
 
-SUBDIRS = c++98 c++11 $(filesystem_dir)
+SUBDIRS = c++98 c++11 c++17 $(filesystem_dir)
 
 # Cross compiler support.
 if VTV_CYGMIN
@@ -58,6 +58,7 @@ endif
 
 vpath % $(top_srcdir)/src/c++98
 vpath % $(top_srcdir)/src/c++11
+vpath % $(top_srcdir)/src/c++17
 if ENABLE_FILESYSTEM_TS
 vpath % $(top_srcdir)/src/filesystem
 endif
@@ -92,13 +93,15 @@ libstdc___la_LIBADD = \
 	$(GLIBCXX_LIBS) \
 	$(top_builddir)/libsupc++/libsupc++convenience.la \
 	$(top_builddir)/src/c++98/libc++98convenience.la \
-	$(top_builddir)/src/c++11/libc++11convenience.la
+	$(top_builddir)/src/c++11/libc++11convenience.la \
+	$(top_builddir)/src/c++17/libc++17convenience.la
 
 libstdc___la_DEPENDENCIES = \
 	${version_dep} \
 	$(top_builddir)/libsupc++/libsupc++convenience.la \
 	$(top_builddir)/src/c++98/libc++98convenience.la \
-	$(top_builddir)/src/c++11/libc++11convenience.la
+	$(top_builddir)/src/c++11/libc++11convenience.la \
+	$(top_builddir)/src/c++17/libc++17convenience.la
 
 libstdc___la_LDFLAGS = \
 	-version-info $(libtool_VERSION) ${version_arg} -lm
@@ -148,8 +151,8 @@ compatibility-condvar.o: compatibility-condvar.cc
 # Thus, the shared libs have more compat symbols, which can be found
 # segregated in the sources with -D_GLIBCXX_SHARED.
 #
-# In the sub-directories of libsupc++, src/c++98, src/c++11, only
-# -prefer-pic objects are generated for the convenience libraries.
+# In the sub-directories of libsupc++, src/c++98, src/c++11, src/c++17,
+# only -prefer-pic objects are generated for the convenience libraries.
 #
 # In the main src directory, make shared and static objects just for
 # the compat libraries. Shared objects are compiled with -prefer-pic
diff --git a/libstdc++-v3/src/c++11/Makefile.am b/libstdc++-v3/src/c++11/Makefile.am
index 91bf6f8d642..a22258782cb 100644
--- a/libstdc++-v3/src/c++11/Makefile.am
+++ b/libstdc++-v3/src/c++11/Makefile.am
@@ -1,4 +1,4 @@
-## Makefile for the C++03 sources of the GNU C++ Standard library.
+## Makefile for the C++11 sources of the GNU C++ Standard library.
 ##
 ## Copyright (C) 1997-2018 Free Software Foundation, Inc.
 ##
diff --git a/libstdc++-v3/src/c++17/Makefile.am b/libstdc++-v3/src/c++17/Makefile.am
new file mode 100644
index 00000000000..21b64b52dc2
--- /dev/null
+++ b/libstdc++-v3/src/c++17/Makefile.am
@@ -0,0 +1,111 @@
+## Makefile for the C++17 sources of the GNU C++ Standard library.
+##
+## Copyright (C) 1997-2018 Free Software Foundation, Inc.
+##
+## This file is part of the libstdc++ version 3 distribution.
+## Process this file with automake to produce Makefile.in.
+
+## This file is part of the GNU ISO C++ Library.  This library is free
+## software; you can redistribute it and/or modify it under the
+## terms of the GNU General Public License as published by the
+## Free Software Foundation; either version 3, or (at your option)
+## any later version.
+
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+
+## You should have received a copy of the GNU General Public License along
+## with this library; see the file COPYING3.  If not see
+## <http://www.gnu.org/licenses/>.
+
+include $(top_srcdir)/fragment.am
+
+# Convenience library for C++17 runtime.
+noinst_LTLIBRARIES = libc++17convenience.la
+
+headers =
+
+sources = \
+	memory_resource.cc
+
+if ENABLE_DUAL_ABI
+extra_string_inst_sources =
+else
+extra_string_inst_sources =
+endif
+
+if ENABLE_EXTERN_TEMPLATE
+# XTEMPLATE_FLAGS = -fno-implicit-templates
+inst_sources = \
+	$(extra_string_inst_sources)
+else
+# XTEMPLATE_FLAGS =
+inst_sources =
+endif
+
+vpath % $(top_srcdir)/src/c++17
+
+libc__17convenience_la_SOURCES = $(sources)  $(inst_sources)
+
+# AM_CXXFLAGS needs to be in each subdirectory so that it can be
+# modified in a per-library or per-sub-library way.  Need to manually
+# set this option because CONFIG_CXXFLAGS has to be after
+# OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden
+# as the occasion calls for it.
+AM_CXXFLAGS = \
+	-std=gnu++17 \
+	$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+	$(XTEMPLATE_FLAGS) $(VTV_CXXFLAGS) \
+	$(WARN_CXXFLAGS) $(OPTIMIZE_CXXFLAGS) $(CONFIG_CXXFLAGS)
+
+AM_MAKEFLAGS = \
+	"gxx_include_dir=$(gxx_include_dir)"
+
+# Libtool notes
+
+# 1) In general, libtool expects an argument such as `--tag=CXX' when
+# using the C++ compiler, because that will enable the settings
+# detected when C++ support was being configured.  However, when no
+# such flag is given in the command line, libtool attempts to figure
+# it out by matching the compiler name in each configuration section
+# against a prefix of the command line.  The problem is that, if the
+# compiler name and its initial flags stored in the libtool
+# configuration file don't match those in the command line, libtool
+# can't decide which configuration to use, and it gives up.  The
+# correct solution is to add `--tag CXX' to LTCXXCOMPILE and maybe
+# CXXLINK, just after $(LIBTOOL), so that libtool doesn't have to
+# attempt to infer which configuration to use.
+#
+# The second tag argument, `--tag disable-shared` means that libtool
+# only compiles each source once, for static objects. In actuality,
+# glibcxx_lt_pic_flag and glibcxx_compiler_shared_flag are added to
+# the libtool command that is used create the object, which is
+# suitable for shared libraries.  The `--tag disable-shared` must be
+# placed after --tag CXX lest things CXX undo the affect of
+# disable-shared.
+
+# 2) Need to explicitly set LTCXXCOMPILE so that EXTRA_CXX_FLAGS is
+# last. (That way, things like -O2 passed down from the toplevel can
+# be overridden by --enable-debug.)
+LTCXXCOMPILE = \
+	$(LIBTOOL) --tag CXX --tag disable-shared \
+	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
+	--mode=compile $(CXX) $(TOPLEVEL_INCLUDES) \
+	$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS) $(EXTRA_CXX_FLAGS)
+
+LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS))
+
+# 3) We'd have a problem when building the shared libstdc++ object if
+# the rules automake generates would be used.  We cannot allow g++ to
+# be used since this would add -lstdc++ to the link line which of
+# course is problematic at this point.  So, we get the top-level
+# directory to configure libstdc++-v3 to use gcc as the C++
+# compilation driver.
+CXXLINK = \
+	$(LIBTOOL) --tag CXX --tag disable-shared \
+	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
+	--mode=link $(CXX) \
+	$(VTV_CXXLINKFLAGS) \
+	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
diff --git a/libstdc++-v3/src/c++17/Makefile.in b/libstdc++-v3/src/c++17/Makefile.in
new file mode 100644
index 00000000000..40b186e0a77
diff --git a/libstdc++-v3/src/c++17/memory_resource.cc b/libstdc++-v3/src/c++17/memory_resource.cc
new file mode 100644
index 00000000000..dd418c1b1aa
--- /dev/null
+++ b/libstdc++-v3/src/c++17/memory_resource.cc
@@ -0,0 +1,111 @@
+// <memory_resource> implementation -*- C++ -*-
+
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#include <memory_resource>
+#include <atomic>
+#include <new>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+namespace pmr
+{
+  namespace
+  {
+    class newdel_res_t final : public memory_resource
+    {
+      void*
+      do_allocate(size_t __bytes, size_t __alignment) override
+      { return ::operator new(__bytes, std::align_val_t(__alignment)); }
+
+      void
+      do_deallocate(void* __p, size_t __bytes, size_t __alignment) noexcept
+      override
+      { ::operator delete(__p, __bytes, std::align_val_t(__alignment)); }
+
+      bool
+      do_is_equal(const memory_resource& __other) const noexcept override
+      { return &__other == this; }
+    };
+
+    class null_res_t final : public memory_resource
+    {
+      void*
+      do_allocate(size_t, size_t) override
+      { std::__throw_bad_alloc(); }
+
+      void
+      do_deallocate(void*, size_t, size_t) noexcept override
+      { }
+
+      bool
+      do_is_equal(const memory_resource& __other) const noexcept override
+      { return &__other == this; }
+    };
+
+    template<typename T>
+      struct constant_init
+      {
+	union {
+	  unsigned char unused;
+	  T obj;
+	};
+	constexpr constant_init() : obj() { }
+
+	template<typename U>
+	  explicit constexpr constant_init(U arg) : obj(arg) { }
+
+	~constant_init() { /* do nothing, union member is not destroyed */ }
+      };
+
+    constant_init<newdel_res_t> newdel_res{};
+    constant_init<null_res_t> null_res{};
+    constant_init<atomic<memory_resource*>> default_res{&newdel_res.obj};
+  } // namespace
+
+  memory_resource*
+  new_delete_resource() noexcept
+  { return &newdel_res.obj; }
+
+  memory_resource*
+  null_memory_resource() noexcept
+  { return &null_res.obj; }
+
+  memory_resource*
+  set_default_resource(memory_resource* r) noexcept
+  {
+    if (r == nullptr)
+      r = new_delete_resource();
+    return default_res.obj.exchange(r);
+  }
+
+  memory_resource*
+  get_default_resource() noexcept
+  { return default_res.obj.load(); }
+
+} // namespace pmr
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std
+
+
diff --git a/libstdc++-v3/testsuite/20_util/memory_resource/1.cc b/libstdc++-v3/testsuite/20_util/memory_resource/1.cc
new file mode 100644
index 00000000000..d848374e71a
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/memory_resource/1.cc
@@ -0,0 +1,47 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <memory_resource>
+
+static_assert(std::is_abstract_v<std::pmr::memory_resource>);
+static_assert(std::is_polymorphic_v<std::pmr::memory_resource>);
+static_assert(!std::is_final_v<std::pmr::memory_resource>);
+
+struct R0 : std::pmr::memory_resource { };
+static_assert(std::is_abstract_v<R0>);
+
+struct R1 : R0 {
+  void* do_allocate(std::size_t, std::size_t) override;
+};
+static_assert(std::is_abstract_v<R1>);
+
+struct R2 : R1 {
+  void do_deallocate(void*, std::size_t, std::size_t) override;
+};
+static_assert(std::is_abstract_v<R2>);
+
+struct R3 : R2 {
+  bool do_is_equal(const std::pmr::memory_resource&) const noexcept override;
+};
+static_assert(!std::is_abstract_v<R3>);
+static_assert(std::is_default_constructible_v<R3>);
+static_assert(std::is_copy_constructible_v<R3>);
+static_assert(std::is_copy_assignable_v<R3>);
+static_assert(std::is_destructible_v<R3>);
diff --git a/libstdc++-v3/testsuite/20_util/memory_resource/2.cc b/libstdc++-v3/testsuite/20_util/memory_resource/2.cc
new file mode 100644
index 00000000000..b99aa49fce1
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/memory_resource/2.cc
@@ -0,0 +1,112 @@
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+// { dg-skip-if "" { *-*-* } { -fno-aligned-new } }
+
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+struct R : std::pmr::memory_resource {
+  void* do_allocate(std::size_t, std::size_t) override;
+  void do_deallocate(void*, std::size_t, std::size_t) override;
+  bool do_is_equal(const std::pmr::memory_resource&) const noexcept override;
+};
+
+bool called = false;
+
+void* R::do_allocate(std::size_t bytes, std::size_t a)
+{
+  called = true;
+  return ::operator new(bytes, std::align_val_t(a));
+}
+
+void R::do_deallocate(void* p, std::size_t bytes, std::size_t a)
+{
+  called = true;
+  ::operator delete(p, bytes, std::align_val_t(a));
+}
+
+bool R::do_is_equal(const std::pmr::memory_resource& r) const noexcept
+{
+  called = true;
+  return this == &r;
+}
+
+void
+test01()
+{
+  R res;
+  called = false;
+  auto p = res.allocate(1, 1);
+  VERIFY( called );
+  called = false;
+  res.deallocate(p, 1, 1);
+  VERIFY( called );
+  called = false;
+  VERIFY( res == res );
+  VERIFY( !called );
+  VERIFY( ! (res != res) );
+  VERIFY( !called );
+
+  struct X { int i = 0; };
+  struct MultipleInheritance : X, R { };
+  MultipleInheritance m;
+  VERIFY( m == m );
+  VERIFY( !called );
+  VERIFY( ! (m != m) );
+  VERIFY( !called );
+  VERIFY( m.is_equal(m) );
+  VERIFY( called );
+  called = false;
+  VERIFY( ! (m == res) );
+  VERIFY( called );
+  called = false;
+  VERIFY( m != res );
+  VERIFY( called );
+  called = false;
+  VERIFY( ! (res == m) );
+  VERIFY( called );
+  called = false;
+  VERIFY( res != m );
+  VERIFY( called );
+  called = false;
+}
+
+void
+test02()
+{
+  __gnu_test::memory_resource r1, r2;
+  VERIFY( r1 == r1 );
+  VERIFY( ! (r1 != r1) );
+  VERIFY( r1.is_equal(r1) );
+  VERIFY( r2 == r2 );
+  VERIFY( r2.is_equal(r2) );
+  VERIFY( ! (r1 == r2) );
+  VERIFY( r1 != r2 );
+  VERIFY( ! r1.is_equal(r2) );
+  VERIFY( ! (r2 == r1) );
+  VERIFY( r2 != r1 );
+  VERIFY( ! r2.is_equal(r1) );
+}
+
+int main()
+{
+  test01();
+  test02();
+}
diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/1.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/1.cc
new file mode 100644
index 00000000000..77fa38edbd8
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/1.cc
@@ -0,0 +1,53 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <memory_resource>
+
+using std::pmr::monotonic_buffer_resource;
+using std::pmr::memory_resource;
+using std::size_t;
+
+static_assert(std::is_base_of_v<memory_resource, monotonic_buffer_resource>);
+static_assert(!std::is_abstract_v<monotonic_buffer_resource>);
+
+static_assert(std::is_default_constructible_v<monotonic_buffer_resource>);
+static_assert(std::is_destructible_v<monotonic_buffer_resource>);
+static_assert(!std::is_copy_constructible_v<monotonic_buffer_resource>);
+static_assert(!std::is_copy_assignable_v<monotonic_buffer_resource>);
+static_assert(!std::is_move_constructible_v<monotonic_buffer_resource>);
+static_assert(!std::is_move_assignable_v<monotonic_buffer_resource>);
+
+static_assert(std::is_constructible_v<monotonic_buffer_resource,
+				      memory_resource*>);
+static_assert(std::is_constructible_v<monotonic_buffer_resource,
+				      size_t, memory_resource*>);
+static_assert(std::is_constructible_v<monotonic_buffer_resource,
+				      void*, size_t, memory_resource*>);
+
+static_assert(std::is_constructible_v<monotonic_buffer_resource,
+				      size_t>);
+static_assert(std::is_constructible_v<monotonic_buffer_resource,
+				      void*, size_t>);
+
+// Unary constructors are explicit.
+static_assert(!std::is_convertible_v<memory_resource*,
+				     monotonic_buffer_resource>);
+static_assert(!std::is_convertible_v<size_t,
+				     monotonic_buffer_resource>);
diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/allocate.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/allocate.cc
new file mode 100644
index 00000000000..d1c2715ef8d
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/allocate.cc
@@ -0,0 +1,221 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+void
+test01()
+{
+  __gnu_test::memory_resource r;
+
+  // test that it's possible to allocate after each of the constructors
+  {
+    std::pmr::monotonic_buffer_resource mr(&r);
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+  }
+  VERIFY( r.number_of_active_allocations() == 0 );
+  {
+    std::pmr::monotonic_buffer_resource mr(128, &r);
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+  }
+  VERIFY( r.number_of_active_allocations() == 0 );
+  {
+    unsigned char buf[64];
+    std::pmr::monotonic_buffer_resource mr((void*)buf, sizeof(buf), &r);
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+  }
+  VERIFY( r.number_of_active_allocations() == 0 );
+  {
+    std::pmr::monotonic_buffer_resource mr;
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+  }
+  {
+    std::pmr::monotonic_buffer_resource mr(64);
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+  }
+  {
+    unsigned char buf[64];
+    std::pmr::monotonic_buffer_resource mr((void*)buf, sizeof(buf));
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+  }
+}
+
+void
+test02()
+{
+  unsigned char buf[64];
+  std::pmr::monotonic_buffer_resource mr(buf, sizeof(buf));
+
+  auto p = mr.allocate(0);
+  VERIFY( p != nullptr );
+  auto q = mr.allocate(0);
+  VERIFY( q != nullptr );
+  VERIFY( p != q );
+
+  p = mr.allocate(0, 1);
+  VERIFY( p != nullptr );
+  q = mr.allocate(0, 1);
+  VERIFY( q != nullptr );
+  VERIFY( p != q );
+}
+
+void
+test03()
+{
+#if __cpp_exceptions
+  {
+    std::pmr::monotonic_buffer_resource mr(std::pmr::null_memory_resource());
+    bool caught = false;
+    try
+    {
+      (void) mr.allocate(1, 1);
+    }
+    catch (const std::bad_alloc&)
+    {
+      caught = true;
+    }
+    VERIFY( caught );
+  }
+  {
+    unsigned char buf[16];
+    std::pmr::monotonic_buffer_resource mr(buf, sizeof(buf),
+					   std::pmr::null_memory_resource());
+    (void) mr.allocate(16, 1);
+    bool caught = false;
+    try
+    {
+      (void) mr.allocate(1, 1);
+    }
+    catch (const std::bad_alloc&)
+    {
+      caught = true;
+    }
+    VERIFY( caught );
+  }
+#endif
+}
+
+void
+test04()
+{
+  auto buf = new unsigned char[512];
+  std::pmr::monotonic_buffer_resource mr(buf, 512,
+					 std::pmr::null_memory_resource());
+  std::size_t prev_size = 1;
+  void* prev_ptr = mr.allocate(prev_size, 1);
+  for (int i = 0; i < 9; ++i)
+  {
+    std::size_t size = 1 << i;
+    void* ptr = mr.allocate(size, 1);
+    VERIFY( ((char*)ptr - (char*)prev_ptr) == prev_size );
+    prev_ptr = ptr;
+    prev_size = size;
+  }
+}
+
+void
+test05()
+{
+  // test that returned pointer is correctly aligned
+  auto is_aligned = [](void* p, size_t alignment) -> bool {
+    return (reinterpret_cast<std::uintptr_t>(p) % alignment) == 0;
+  };
+
+  auto buf = new unsigned char[2048];
+  std::pmr::monotonic_buffer_resource mr(buf+1, 2047);
+  for (int i = 0; i < 9; ++i)
+  {
+    auto p = mr.allocate(1, 1 << i);
+    VERIFY( is_aligned(p, 1 << i) );
+    // Make next available byte misaligned:
+    (void) mr.allocate(1 << i, 1);
+  }
+}
+
+void
+test06()
+{
+  // check for geometric progression in buffer sizes from upstream
+
+  struct resource : __gnu_test::memory_resource
+  {
+    bool allocated = false;
+    std::size_t last_size = 0;
+
+    void*
+    do_allocate(size_t bytes, size_t align) override
+    {
+      allocated = true;
+      last_size = bytes;
+      return __gnu_test::memory_resource::do_allocate(bytes, align);
+    }
+  };
+
+  resource r;
+  std::pmr::monotonic_buffer_resource mr(32, &r);
+  std::size_t last_size = 0;
+
+  for (int i = 0; i < 100; ++i)
+  {
+    (void) mr.allocate(16);
+    if (r.allocated)
+    {
+      VERIFY(r.last_size >= last_size);
+      last_size = r.last_size;
+      r.allocated = false;
+    }
+  }
+}
+
+int
+main()
+{
+  test01();
+  test02();
+  test03();
+  test04();
+  test05();
+  test06();
+}
diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/deallocate.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/deallocate.cc
new file mode 100644
index 00000000000..427256d672a
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/deallocate.cc
@@ -0,0 +1,103 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+struct resource : __gnu_test::memory_resource
+{
+  int allocate_calls = 0;
+  int deallocate_calls = 0;
+
+  void*
+  do_allocate(std::size_t bytes, std::size_t align) override
+  {
+    ++allocate_calls;
+    return __gnu_test::memory_resource::do_allocate(bytes, align);
+  }
+
+  void
+  do_deallocate(void* p, std::size_t bytes, std::size_t align) override
+  {
+    ++deallocate_calls;
+    __gnu_test::memory_resource::do_deallocate(p, bytes, align);
+  }
+};
+
+void
+test01()
+{
+  resource r;
+
+  // test that it's possible to deallocate after each of the constructors
+  {
+    std::pmr::monotonic_buffer_resource mr(&r);
+    auto p = mr.allocate(1024);
+    VERIFY( p != nullptr );
+    const std::uintptr_t pi = reinterpret_cast<std::uintptr_t>(p);
+    mr.deallocate(p, 1024);
+    VERIFY( r.deallocate_calls == 0 );
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( pi != reinterpret_cast<std::uintptr_t>(q) );
+    mr.deallocate(q, 1024);
+    VERIFY( r.deallocate_calls == 0 );
+  }
+  VERIFY( r.deallocate_calls == r.allocate_calls );
+  VERIFY( r.number_of_active_allocations() == 0 );
+  {
+    r.deallocate_calls = r.allocate_calls = 0;
+    std::pmr::monotonic_buffer_resource mr(128, &r);
+    auto p = mr.allocate(64);
+    VERIFY( p != nullptr );
+    const std::uintptr_t pi = reinterpret_cast<std::uintptr_t>(p);
+    mr.deallocate(p, 64);
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+    VERIFY( pi != reinterpret_cast<std::uintptr_t>(q) );
+    mr.deallocate(q, 1024);
+    VERIFY( r.deallocate_calls == 0 );
+  }
+  VERIFY( r.number_of_active_allocations() == 0 );
+  {
+    r.deallocate_calls = r.allocate_calls = 0;
+    unsigned char buf[64];
+    std::pmr::monotonic_buffer_resource mr((void*)buf, sizeof(buf), &r);
+    auto p = mr.allocate(64);
+    VERIFY( p != nullptr );
+    const std::uintptr_t pi = reinterpret_cast<std::uintptr_t>(p);
+    mr.deallocate(p, 64);
+    auto q = mr.allocate(1024);
+    VERIFY( q != nullptr );
+    VERIFY( p != q );
+    VERIFY( pi != reinterpret_cast<std::uintptr_t>(q) );
+    mr.deallocate(q, 1024);
+    VERIFY( r.deallocate_calls == 0 );
+  }
+  VERIFY( r.deallocate_calls == r.allocate_calls );
+  VERIFY( r.number_of_active_allocations() == 0 );
+}
+
+int
+main()
+{
+  test01();
+}
diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
new file mode 100644
index 00000000000..0c7f31789e6
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
@@ -0,0 +1,172 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+struct resource : __gnu_test::memory_resource
+{
+  int allocate_calls = 0;
+  int deallocate_calls = 0;
+
+  void*
+  do_allocate(std::size_t bytes, std::size_t align) override
+  {
+    ++allocate_calls;
+    return __gnu_test::memory_resource::do_allocate(bytes, align);
+  }
+
+  void
+  do_deallocate(void* p, std::size_t bytes, std::size_t align) override
+  {
+    ++deallocate_calls;
+    __gnu_test::memory_resource::do_deallocate(p, bytes, align);
+  }
+};
+
+void
+test01()
+{
+  resource r;
+  std::pmr::monotonic_buffer_resource mbr(&r);
+  auto p = mbr.allocate(10, 16);
+  mbr.deallocate(p, 1, 2);
+  VERIFY( r.deallocate_calls == 0 );
+  p = mbr.allocate(10, 16);
+  p = mbr.allocate(10, 16);
+  p = mbr.allocate(10, 16);
+  p = mbr.allocate(1024, 64);
+  p = mbr.allocate(1024, 64);
+  p = mbr.allocate(128, 8);
+  p = mbr.allocate(128, 8);
+  p = mbr.allocate(128, 8);
+  p = mbr.allocate(128, 8);
+  p = mbr.allocate(128, 8);
+  p = mbr.allocate(128, 8);
+  p = mbr.allocate(128, 8);
+  mbr.deallocate(p, 1, 2);
+  p = mbr.allocate(1024, 16);
+  p = mbr.allocate(1024, 16);
+  mbr.deallocate(p, 1, 2);
+  VERIFY( r.deallocate_calls == 0 );
+  mbr.release();
+  VERIFY( r.deallocate_calls != 0 );
+  VERIFY( r.deallocate_calls == r.allocate_calls );
+  VERIFY( mbr.upstream_resource() == &r );
+  VERIFY( r.number_of_active_allocations() == 0 );
+}
+
+void
+test02()
+{
+  std::pmr::monotonic_buffer_resource mbr; // uses get_default_resource()
+  auto* const upstream = mbr.upstream_resource();
+  resource r;
+  __gnu_test::default_resource_mgr _(&r); // calls set_default_resource(&r)
+  mbr.release();
+  // release() doesn't change upstream resource:
+  VERIFY( mbr.upstream_resource() == upstream );
+}
+
+void
+test03()
+{
+  resource r;
+  __gnu_test::default_resource_mgr _(&r);
+  std::pmr::monotonic_buffer_resource mbr(16);
+  for (int i = 0; i < 100; ++i)
+    (void) mbr.allocate(4, 1);
+  const int allocations = r.allocate_calls;
+  VERIFY( allocations != 0 );
+  mbr.release();
+  VERIFY( r.allocate_calls == r.deallocate_calls );
+  VERIFY( r.number_of_active_allocations() == 0 );
+
+  // next_buffer_size should have been reset to the initial value,
+  // so the allocations from upstream should be the same as before.
+  r.allocate_calls = 0;
+  r.deallocate_calls = 0;
+  for (int i = 0; i < 100; ++i)
+    (void) mbr.allocate(4,1);
+  VERIFY( allocations == r.allocate_calls );
+}
+
+void
+test04()
+{
+  resource r;
+  unsigned char buffer[1024];
+  std::pmr::monotonic_buffer_resource mbr(buffer, sizeof(buffer), &r);
+  void* p = mbr.allocate(800, 16);
+  VERIFY( p == buffer );
+  VERIFY( r.allocate_calls == 0 );
+  p = mbr.allocate(300, 1);
+  VERIFY( p != buffer );
+  VERIFY( r.allocate_calls == 1 );
+  mbr.release();
+  VERIFY( r.deallocate_calls == 1 );
+  VERIFY( mbr.upstream_resource() == &r );
+  VERIFY( r.number_of_active_allocations() == 0 );
+  // initial buffer should be used again now:
+  p = mbr.allocate(1000);
+  VERIFY( p == buffer );
+  VERIFY( r.allocate_calls == 1 );
+}
+
+void
+test05() // LWG 3120
+{
+  char buffer[100];
+  {
+    std::pmr::monotonic_buffer_resource mr(buffer, sizeof(buffer),
+					    std::pmr::null_memory_resource());
+    mr.release();
+    (void) mr.allocate(60);
+  }
+
+  {
+    std::pmr::monotonic_buffer_resource mr(buffer, sizeof(buffer),
+					    std::pmr::null_memory_resource());
+    (void) mr.allocate(60);
+    mr.release();
+    (void) mr.allocate(60);
+  }
+
+  {
+    resource r;
+    std::pmr::monotonic_buffer_resource mr(&r);
+    for (int i = 0; i < 100; ++i)
+    {
+      (void) mr.allocate(1);
+      mr.release();
+    }
+    VERIFY( r.number_of_active_allocations() == 0 );
+  }
+}
+
+int
+main()
+{
+  test01();
+  test02();
+  test03();
+  test04();
+  test05();
+}
diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc
new file mode 100644
index 00000000000..c09294f4272
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc
@@ -0,0 +1,76 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+void
+test01()
+{
+  __gnu_test::memory_resource r;
+  const auto null = std::pmr::null_memory_resource();
+  const auto newdel = std::pmr::new_delete_resource();
+  std::pmr::set_default_resource(null);
+
+  {
+    std::pmr::monotonic_buffer_resource mr(&r);
+    VERIFY( mr.upstream_resource() == &r );
+    __gnu_test::default_resource_mgr _(newdel);
+    VERIFY( mr.upstream_resource() == &r );
+  }
+  {
+    std::pmr::monotonic_buffer_resource mr(128, &r);
+    VERIFY( mr.upstream_resource() == &r );
+    __gnu_test::default_resource_mgr _(newdel);
+    VERIFY( mr.upstream_resource() == &r );
+  }
+  {
+    unsigned char buf[64];
+    std::pmr::monotonic_buffer_resource mr((void*)buf, sizeof(buf), &r);
+    VERIFY( mr.upstream_resource() == &r );
+    __gnu_test::default_resource_mgr _(newdel);
+    VERIFY( mr.upstream_resource() == &r );
+  }
+  {
+    std::pmr::monotonic_buffer_resource mr;
+    VERIFY( mr.upstream_resource() == null );
+    __gnu_test::default_resource_mgr _(newdel);
+    VERIFY( mr.upstream_resource() == null );
+  }
+  {
+    std::pmr::monotonic_buffer_resource mr(64);
+    VERIFY( mr.upstream_resource() == null );
+    __gnu_test::default_resource_mgr _(newdel);
+    VERIFY( mr.upstream_resource() == null );
+  }
+  {
+    unsigned char buf[64];
+    std::pmr::monotonic_buffer_resource mr((void*)buf, sizeof(buf));
+    VERIFY( mr.upstream_resource() == null );
+    __gnu_test::default_resource_mgr _(newdel);
+    VERIFY( mr.upstream_resource() == null );
+  }
+}
+
+int
+main()
+{
+  test01();
+}
diff --git a/libstdc++-v3/testsuite/20_util/polymorphic_allocator/1.cc b/libstdc++-v3/testsuite/20_util/polymorphic_allocator/1.cc
new file mode 100644
index 00000000000..4bc7f79e2b6
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/polymorphic_allocator/1.cc
@@ -0,0 +1,36 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do compile { target c++17 } }
+
+#include <memory_resource>
+
+struct X { int i = 0; };
+
+using test_type = std::pmr::polymorphic_allocator<X>;
+
+static_assert(std::is_default_constructible_v<test_type>);
+static_assert(std::is_destructible_v<test_type>);
+static_assert(std::is_copy_constructible_v<test_type>);
+static_assert(!std::is_copy_assignable_v<test_type>);
+static_assert(std::is_constructible_v<test_type, std::pmr::memory_resource*>);
+
+static_assert(std::is_same_v<test_type::value_type, X>);
+
+static_assert(!std::is_polymorphic_v<test_type>);
+static_assert(!std::is_final_v<test_type>);
diff --git a/libstdc++-v3/testsuite/20_util/polymorphic_allocator/resource.cc b/libstdc++-v3/testsuite/20_util/polymorphic_allocator/resource.cc
new file mode 100644
index 00000000000..01f6ace2d80
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/polymorphic_allocator/resource.cc
@@ -0,0 +1,87 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+// { dg-skip-if "" { *-*-* } { -fno-aligned-new } }
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+struct X { int i = 0; };
+
+using test_type = std::pmr::polymorphic_allocator<X>;
+
+void
+test01()
+{
+  __gnu_test::memory_resource r;
+  test_type a(&r), b(&r);
+  VERIFY( a == a );
+  VERIFY( ! (a != a) );
+  VERIFY( a == b );
+  VERIFY( ! (a != b) );
+  VERIFY( a.resource() == &r );
+  VERIFY( a.resource() == b.resource() );
+
+  __gnu_test::memory_resource r2(r);
+  test_type c(&r2);
+  VERIFY( c.resource() == &r2 );
+  VERIFY( c.resource() != a.resource() );
+  VERIFY( c == a );
+}
+
+void
+test02()
+{
+  __gnu_test::memory_resource r1, r2;
+  test_type a(&r1), b(&r2);
+  VERIFY( a == a );
+  VERIFY( b == b );
+  VERIFY( ! (a == b) );
+  VERIFY( ! (b == a) );
+  VERIFY( a != b );
+  VERIFY( b != a );
+  VERIFY( a.resource() == &r1 );
+  VERIFY( a.resource() != b.resource() );
+
+  test_type c;
+  VERIFY( c == c );
+  VERIFY( ! (a == c) );
+  VERIFY( ! (c == a) );
+  VERIFY( ! (b == c) );
+  VERIFY( ! (c == b) );
+  VERIFY( a.resource() != c.resource() );
+  VERIFY( c.resource() == std::pmr::get_default_resource() );
+
+  std::pmr::set_default_resource(&r1);
+  VERIFY( c.resource() != &r1 );
+
+  test_type d;
+  VERIFY( d.resource() == &r1 );
+  VERIFY( d != c );
+  VERIFY( d == a );
+
+  std::pmr::set_default_resource(nullptr);
+}
+
+int
+main()
+{
+  test01();
+  test02();
+}
diff --git a/libstdc++-v3/testsuite/20_util/polymorphic_allocator/select.cc b/libstdc++-v3/testsuite/20_util/polymorphic_allocator/select.cc
new file mode 100644
index 00000000000..e5790c03223
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/polymorphic_allocator/select.cc
@@ -0,0 +1,58 @@
+// Copyright (C) 2018 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+// { dg-skip-if "" { *-*-* } { -fno-aligned-new } }
+
+#include <memory_resource>
+#include <testsuite_allocator.h>
+
+struct X { int i = 0; };
+
+using test_type = std::pmr::polymorphic_allocator<X>;
+
+void
+test01()
+{
+  test_type a, b;
+  VERIFY( a.select_on_container_copy_construction() == a );
+  VERIFY( a.select_on_container_copy_construction() == b );
+
+  __gnu_test::memory_resource r;
+  test_type c(&r);
+  VERIFY( c.select_on_container_copy_construction() != c );
+  VERIFY( c.select_on_container_copy_construction() == a );
+}
+
+void
+test02()
+{
+  __gnu_test::memory_resource r;
+  test_type a(&r);
+  VERIFY( a.select_on_container_copy_construction() != a );
+  std::pmr::set_default_resource(&r);
+  VERIFY( a.select_on_container_copy_construction() == a );
+  std::pmr::set_default_resource(nullptr);
+}
+
+int
+main()
+{
+  test01();
+  test02();
+}
diff --git a/libstdc++-v3/testsuite/util/testsuite_allocator.h b/libstdc++-v3/testsuite/util/testsuite_allocator.h
index 501a81f2276..03679aad8dc 100644
--- a/libstdc++-v3/testsuite/util/testsuite_allocator.h
+++ b/libstdc++-v3/testsuite/util/testsuite_allocator.h
@@ -31,6 +31,10 @@
 #include <ext/pointer.h>
 #include <ext/alloc_traits.h>
 #include <testsuite_hooks.h>
+#if __cplusplus >= 201703L
+# include <memory_resource>
+# include <new>
+#endif
 
 namespace __gnu_test
 {
@@ -691,7 +695,161 @@ namespace __gnu_test
       using PointerBase_void::PointerBase_void;
       typedef Derived pointer;
     };
-#endif
+#endif // C++11
+
+#if __cplusplus >= 201703L && __cpp_aligned_new
+    // A concrete memory_resource, with error checking.
+    class memory_resource : public std::pmr::memory_resource
+    {
+    public:
+      memory_resource()
+      : lists(new allocation_lists)
+      { }
+
+      memory_resource(const memory_resource& r) noexcept
+      : lists(r.lists)
+      { lists->refcount++; }
+
+      memory_resource& operator=(const memory_resource&) = delete;
+
+      ~memory_resource()
+      {
+	if (lists->refcount-- == 1)
+	  delete lists;  // last one out turns out the lights
+      }
+
+      struct bad_size { };
+      struct bad_alignment { };
+      struct bad_address { };
+
+      // Deallocate everything (moving the tracking info to the freed list)
+      void
+      deallocate_everything()
+      {
+	while (lists->active)
+	  {
+	    auto a = lists->active;
+	    // Intentionally virtual dispatch, to inform derived classes:
+	    this->do_deallocate(a->p, a->bytes, a->alignment);
+	  }
+      }
+
+      // Clear the freed list
+      void
+      forget_freed_allocations()
+      { lists->forget_allocations(lists->freed); }
+
+      // Count how many allocations have been done and not freed.
+      std::size_t
+      number_of_active_allocations() const noexcept
+      {
+	std::size_t n = 0;
+	for (auto a = lists->active; a != nullptr; a = a->next)
+	  ++n;
+	return n;
+      }
+
+    protected:
+      void*
+      do_allocate(std::size_t bytes, std::size_t alignment) override
+      {
+	// TODO perform a single allocation and put the allocation struct
+	// in the buffer using placement new? It means deallocation won't
+	// actually return memory to the OS, as it will stay in lists->freed.
+	//
+	// TODO adjust the returned pointer to be minimally aligned?
+	// e.g. if alignment==1 don't return something aligned to 2 bytes.
+	// Maybe not worth it, at least monotonic_buffer_resource will
+	// never ask upstream for anything with small alignment.
+	void* p = ::operator new(bytes, std::align_val_t(alignment));
+	lists->active = new allocation{p, bytes, alignment, lists->active};
+	return p;
+      }
+
+      void
+      do_deallocate(void* p, std::size_t bytes, std::size_t alignment) override
+      {
+	allocation** aptr = &lists->active;
+	while (*aptr)
+	  {
+	    allocation* a = *aptr;
+	    if (p == a->p)
+	      {
+		if (bytes != a->bytes)
+		  throw bad_size();
+		if (alignment != a->alignment)
+		  throw bad_alignment();
+		::operator delete(p, bytes, std::align_val_t(alignment));
+		*aptr = a->next;
+		a->next = lists->freed;
+		lists->freed = a;
+		return;
+	      }
+	    aptr = &a->next;
+	  }
+	throw bad_address();
+      }
+
+      bool
+      do_is_equal(const std::pmr::memory_resource& r) const noexcept override
+      {
+	// Equality is determined by sharing the same allocation_lists object.
+	if (auto p = dynamic_cast<const memory_resource*>(&r))
+	  return p->lists == lists;
+	return false;
+      }
+
+    private:
+      struct allocation
+      {
+	void* p;
+	std::size_t bytes;
+	std::size_t alignment;
+	allocation* next;
+      };
+
+      // Maintain list of allocated blocks and list of freed blocks.
+      // Copies of this memory_resource share the same ref-counted lists.
+      struct allocation_lists
+      {
+	unsigned refcount = 1;
+	allocation* active = nullptr;
+	allocation* freed = nullptr;
+
+	void forget_allocations(allocation*& list)
+	{
+	  while (list)
+	    {
+	      auto p = list;
+	      list = list->next;
+	      delete p;
+	    }
+	}
+
+	~allocation_lists()
+	{
+	  forget_allocations(active); // Anything in this list is a leak!
+	  forget_allocations(freed);
+	}
+      };
+
+      allocation_lists* lists;
+    };
+
+    // Set the default resource, and restore the previous one on destruction.
+    struct default_resource_mgr
+    {
+      explicit default_resource_mgr(std::pmr::memory_resource* r)
+      : prev(std::pmr::set_default_resource(r))
+      { }
+
+      ~default_resource_mgr()
+      { std::pmr::set_default_resource(prev); }
+
+      std::pmr::memory_resource* prev;
+    };
+
+#endif // C++17 && aligned-new
 
 } // namespace __gnu_test
 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Add initial version of C++17 <memory_resource> header
  2018-07-24 21:12 [PATCH] Add initial version of C++17 <memory_resource> header Jonathan Wakely
@ 2018-07-25 11:01 ` Jonathan Wakely
  2018-07-25 20:23   ` Jonathan Wakely
  0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Wakely @ 2018-07-25 11:01 UTC (permalink / raw)
  To: libstdc++, gcc-patches

[-- Attachment #1: Type: text/plain, Size: 2586 bytes --]

On 24/07/18 22:12 +0100, Jonathan Wakely wrote:
>This is missing the synchronized_pool_resource and
>unsynchronized_pool_resource classes but is otherwise complete.
>
>This is a new implementation, not based on the existing code in
><experimental/memory_resource>, but memory_resource and
>polymorphic_allocator ended up looking almost the same anyway.
>
>The constant_init kluge in src/c++17/memory_resource.cc is apparently
>due to Richard Smith and ensures that the objects are constructed during
>constant initialiation phase and not destroyed (because the
>constant_init destructor doesn't destroy the union member and the
>storage is not reused).
>
>	* config/abi/pre/gnu.ver: Export new symbols.
>	* configure: Regenerate.
>	* include/Makefile.am: Add new <memory_resource> header.
>	* include/Makefile.in: Regenerate.
>	* include/precompiled/stdc++.h: Include <memory_resource> for C++17.
>	* include/std/memory_resource: New header.
>	(memory_resource, polymorphic_allocator, new_delete_resource)
>	(null_memory_resource, set_default_resource, get_default_resource)
>	(pool_options, monotonic_buffer_resource): Define.
>	* src/Makefile.am: Add c++17 directory.
>	* src/Makefile.in: Regenerate.
>	* src/c++11/Makefile.am: Fix comment.
>	* src/c++17/Makefile.am: Add makefile for new sub-directory.
>	* src/c++17/Makefile.in: Generate.
>	* src/c++17/memory_resource.cc: New.
>	(newdel_res_t, null_res_t, constant_init, newdel_res, null_res)
>	(default_res, new_delete_resource, null_memory_resource)
>	(set_default_resource, get_default_resource): Define.
>	* testsuite/20_util/memory_resource/1.cc: New test.
>	* testsuite/20_util/memory_resource/2.cc: New test.
>	* testsuite/20_util/monotonic_buffer_resource/1.cc: New test.
>	* testsuite/20_util/monotonic_buffer_resource/allocate.cc: New test.
>	* testsuite/20_util/monotonic_buffer_resource/deallocate.cc: New test.
>	* testsuite/20_util/monotonic_buffer_resource/release.cc: New test.
>	* testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc:
>	New test.
>	* testsuite/20_util/polymorphic_allocator/1.cc: New test.
>	* testsuite/20_util/polymorphic_allocator/resource.cc: New test.
>	* testsuite/20_util/polymorphic_allocator/select.cc: New test.
>	* testsuite/util/testsuite_allocator.h (__gnu_test::memory_resource):
>	Define concrete memory resource for testing.
>	(__gnu_test::default_resource_mgr): Define RAII helper for changing
>	default resource.
>
>Tested powerpc64le-linux, committed to trunk.

I missed a change to acinclude.m4 that should have gone with this
patch. Now also committed to trunk.



[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 1477 bytes --]

commit cdaaa2b47d3fa093c741086e86d631d420a93663
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jul 25 11:52:19 2018 +0100

    Add new src/c++17 directory to list in acinclude.m4
    
            * acinclude.m4 (glibcxx_SUBDIRS): Add src/c++17.
            * src/Makefile.am: Add comment.
            * src/c++17/Makefile.in: Regenerate.

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index bbf3c8df3e1..6d68e907426 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -49,7 +49,7 @@ AC_DEFUN([GLIBCXX_CONFIGURE], [
   # Keep these sync'd with the list in Makefile.am.  The first provides an
   # expandable list at autoconf time; the second provides an expandable list
   # (i.e., shell variable) at configure time.
-  m4_define([glibcxx_SUBDIRS],[include libsupc++ src src/c++98 src/c++11 src/filesystem doc po testsuite python])
+  m4_define([glibcxx_SUBDIRS],[include libsupc++ src src/c++98 src/c++11 src/c++17 src/filesystem doc po testsuite python])
   SUBDIRS='glibcxx_SUBDIRS'
 
   # These need to be absolute paths, yet at the same time need to
diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index 09edcdbc471..9a2fe297ddb 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -28,6 +28,7 @@ else
 filesystem_dir =
 endif
 
+## Keep this list sync'd with acinclude.m4:GLIBCXX_CONFIGURE.
 SUBDIRS = c++98 c++11 c++17 $(filesystem_dir)
 
 # Cross compiler support.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Add initial version of C++17 <memory_resource> header
  2018-07-25 11:01 ` Jonathan Wakely
@ 2018-07-25 20:23   ` Jonathan Wakely
  2018-07-25 23:38     ` Jonathan Wakely
  0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Wakely @ 2018-07-25 20:23 UTC (permalink / raw)
  To: libstdc++, gcc-patches

[-- Attachment #1: Type: text/plain, Size: 2746 bytes --]

On 25/07/18 12:01 +0100, Jonathan Wakely wrote:
>On 24/07/18 22:12 +0100, Jonathan Wakely wrote:
>>This is missing the synchronized_pool_resource and
>>unsynchronized_pool_resource classes but is otherwise complete.
>>
>>This is a new implementation, not based on the existing code in
>><experimental/memory_resource>, but memory_resource and
>>polymorphic_allocator ended up looking almost the same anyway.
>>
>>The constant_init kluge in src/c++17/memory_resource.cc is apparently
>>due to Richard Smith and ensures that the objects are constructed during
>>constant initialiation phase and not destroyed (because the
>>constant_init destructor doesn't destroy the union member and the
>>storage is not reused).
>>
>>	* config/abi/pre/gnu.ver: Export new symbols.
>>	* configure: Regenerate.
>>	* include/Makefile.am: Add new <memory_resource> header.
>>	* include/Makefile.in: Regenerate.
>>	* include/precompiled/stdc++.h: Include <memory_resource> for C++17.
>>	* include/std/memory_resource: New header.
>>	(memory_resource, polymorphic_allocator, new_delete_resource)
>>	(null_memory_resource, set_default_resource, get_default_resource)
>>	(pool_options, monotonic_buffer_resource): Define.
>>	* src/Makefile.am: Add c++17 directory.
>>	* src/Makefile.in: Regenerate.
>>	* src/c++11/Makefile.am: Fix comment.
>>	* src/c++17/Makefile.am: Add makefile for new sub-directory.
>>	* src/c++17/Makefile.in: Generate.
>>	* src/c++17/memory_resource.cc: New.
>>	(newdel_res_t, null_res_t, constant_init, newdel_res, null_res)
>>	(default_res, new_delete_resource, null_memory_resource)
>>	(set_default_resource, get_default_resource): Define.
>>	* testsuite/20_util/memory_resource/1.cc: New test.
>>	* testsuite/20_util/memory_resource/2.cc: New test.
>>	* testsuite/20_util/monotonic_buffer_resource/1.cc: New test.
>>	* testsuite/20_util/monotonic_buffer_resource/allocate.cc: New test.
>>	* testsuite/20_util/monotonic_buffer_resource/deallocate.cc: New test.
>>	* testsuite/20_util/monotonic_buffer_resource/release.cc: New test.
>>	* testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc:
>>	New test.
>>	* testsuite/20_util/polymorphic_allocator/1.cc: New test.
>>	* testsuite/20_util/polymorphic_allocator/resource.cc: New test.
>>	* testsuite/20_util/polymorphic_allocator/select.cc: New test.
>>	* testsuite/util/testsuite_allocator.h (__gnu_test::memory_resource):
>>	Define concrete memory resource for testing.
>>	(__gnu_test::default_resource_mgr): Define RAII helper for changing
>>	default resource.
>>
>>Tested powerpc64le-linux, committed to trunk.
>
>I missed a change to acinclude.m4 that should have gone with this
>patch. Now also committed to trunk.

One of the tests also needs this fix.

Committed to trunk.



[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 1465 bytes --]

commit 4875590bba5e5b77878264870671071016ab7ca2
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jul 25 21:22:19 2018 +0100

    PR libstdc++/86676 Do not assume stack buffer is aligned
    
            PR libstdc++/86676
            * testsuite/20_util/monotonic_buffer_resource/release.cc: Allow for
            buffer being misaligned and so returned pointer not being at start.

diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
index 0c7f31789e6..ac70385961d 100644
--- a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
@@ -115,10 +115,12 @@ test04()
   unsigned char buffer[1024];
   std::pmr::monotonic_buffer_resource mbr(buffer, sizeof(buffer), &r);
   void* p = mbr.allocate(800, 16);
-  VERIFY( p == buffer );
+  VERIFY( p >= buffer && p < (buffer + 16) );
+  void* const p_in_buffer = p;
   VERIFY( r.allocate_calls == 0 );
   p = mbr.allocate(300, 1);
   VERIFY( p != buffer );
+  VERIFY( p != buffer );
   VERIFY( r.allocate_calls == 1 );
   mbr.release();
   VERIFY( r.deallocate_calls == 1 );
@@ -126,7 +128,7 @@ test04()
   VERIFY( r.number_of_active_allocations() == 0 );
   // initial buffer should be used again now:
   p = mbr.allocate(1000);
-  VERIFY( p == buffer );
+  VERIFY( p == p_in_buffer );
   VERIFY( r.allocate_calls == 1 );
 }
 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Add initial version of C++17 <memory_resource> header
  2018-07-25 20:23   ` Jonathan Wakely
@ 2018-07-25 23:38     ` Jonathan Wakely
  0 siblings, 0 replies; 4+ messages in thread
From: Jonathan Wakely @ 2018-07-25 23:38 UTC (permalink / raw)
  To: libstdc++, gcc-patches

[-- Attachment #1: Type: text/plain, Size: 2922 bytes --]

On 25/07/18 21:23 +0100, Jonathan Wakely wrote:
>On 25/07/18 12:01 +0100, Jonathan Wakely wrote:
>>On 24/07/18 22:12 +0100, Jonathan Wakely wrote:
>>>This is missing the synchronized_pool_resource and
>>>unsynchronized_pool_resource classes but is otherwise complete.
>>>
>>>This is a new implementation, not based on the existing code in
>>><experimental/memory_resource>, but memory_resource and
>>>polymorphic_allocator ended up looking almost the same anyway.
>>>
>>>The constant_init kluge in src/c++17/memory_resource.cc is apparently
>>>due to Richard Smith and ensures that the objects are constructed during
>>>constant initialiation phase and not destroyed (because the
>>>constant_init destructor doesn't destroy the union member and the
>>>storage is not reused).
>>>
>>>	* config/abi/pre/gnu.ver: Export new symbols.
>>>	* configure: Regenerate.
>>>	* include/Makefile.am: Add new <memory_resource> header.
>>>	* include/Makefile.in: Regenerate.
>>>	* include/precompiled/stdc++.h: Include <memory_resource> for C++17.
>>>	* include/std/memory_resource: New header.
>>>	(memory_resource, polymorphic_allocator, new_delete_resource)
>>>	(null_memory_resource, set_default_resource, get_default_resource)
>>>	(pool_options, monotonic_buffer_resource): Define.
>>>	* src/Makefile.am: Add c++17 directory.
>>>	* src/Makefile.in: Regenerate.
>>>	* src/c++11/Makefile.am: Fix comment.
>>>	* src/c++17/Makefile.am: Add makefile for new sub-directory.
>>>	* src/c++17/Makefile.in: Generate.
>>>	* src/c++17/memory_resource.cc: New.
>>>	(newdel_res_t, null_res_t, constant_init, newdel_res, null_res)
>>>	(default_res, new_delete_resource, null_memory_resource)
>>>	(set_default_resource, get_default_resource): Define.
>>>	* testsuite/20_util/memory_resource/1.cc: New test.
>>>	* testsuite/20_util/memory_resource/2.cc: New test.
>>>	* testsuite/20_util/monotonic_buffer_resource/1.cc: New test.
>>>	* testsuite/20_util/monotonic_buffer_resource/allocate.cc: New test.
>>>	* testsuite/20_util/monotonic_buffer_resource/deallocate.cc: New test.
>>>	* testsuite/20_util/monotonic_buffer_resource/release.cc: New test.
>>>	* testsuite/20_util/monotonic_buffer_resource/upstream_resource.cc:
>>>	New test.
>>>	* testsuite/20_util/polymorphic_allocator/1.cc: New test.
>>>	* testsuite/20_util/polymorphic_allocator/resource.cc: New test.
>>>	* testsuite/20_util/polymorphic_allocator/select.cc: New test.
>>>	* testsuite/util/testsuite_allocator.h (__gnu_test::memory_resource):
>>>	Define concrete memory resource for testing.
>>>	(__gnu_test::default_resource_mgr): Define RAII helper for changing
>>>	default resource.
>>>
>>>Tested powerpc64le-linux, committed to trunk.
>>
>>I missed a change to acinclude.m4 that should have gone with this
>>patch. Now also committed to trunk.
>
>One of the tests also needs this fix.

And another correction to the same test.

Tested powerpc-ibm-aix7.2.0.0, committed to trunk.



[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 995 bytes --]

commit 0dbdb55154fee2af4c02e45a373f5a2dc2985856
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Jul 26 00:35:57 2018 +0100

    PR libstdc++/86676 another alignment fix for test
    
            PR libstdc++/86676
            * testsuite/20_util/monotonic_buffer_resource/release.cc: Request
            same alignment for post-release allocation.

diff --git a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
index ac70385961d..8aab4692d52 100644
--- a/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
+++ b/libstdc++-v3/testsuite/20_util/monotonic_buffer_resource/release.cc
@@ -127,7 +127,7 @@ test04()
   VERIFY( mbr.upstream_resource() == &r );
   VERIFY( r.number_of_active_allocations() == 0 );
   // initial buffer should be used again now:
-  p = mbr.allocate(1000);
+  p = mbr.allocate(1000, 16);
   VERIFY( p == p_in_buffer );
   VERIFY( r.allocate_calls == 1 );
 }

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-07-25 23:38 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-24 21:12 [PATCH] Add initial version of C++17 <memory_resource> header Jonathan Wakely
2018-07-25 11:01 ` Jonathan Wakely
2018-07-25 20:23   ` Jonathan Wakely
2018-07-25 23:38     ` Jonathan Wakely

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