[libc++] Tolerate presence of __deallocate macro

[EricWF]

Summary

On Windows the identifier __deallocate is defined as a macro by one of the Windows system headers. Previously libc++ worked around this by #undef __deallocate and generating a warning. However this causes the WIN32 version of __threading_support to always generate a warning on Windows. This is not OK.

This patch renames all usages of __deallocate internally as to not conflict with the macro.

[smeenai]

I'm guessing always defining _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS on Windows isn't considered an acceptable workaround either?

[EricWF]

In D28426#638596, @smeenai wrote:

I'm guessing always defining _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS on Windows isn't considered an acceptable workaround either?

Not really, since that still breaks users of the __deallocate since we #undef it.

PS. I think Windows is the only platform where __deallocate is an issue, so defining _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS on Windows just makes the warnings dead code on all platforms.

[compnerd]

This is a really nice cleanup!

include/__hash_table

 #include <initializer_list>
 #include <memory>
 #include <iterator>
 #include <algorithm>
 #include <cmath>
 #include <utility>
 
 #include <__undef_min_max>
-#include <__undef___deallocate>
 
 #include <__debug>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
void __move_assign_alloc(__hash_table& __u, true_type)
         __bucket_list_.get_deleter().__alloc() =
                 _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
         __node_alloc() = _VSTD::move(__u.__node_alloc());
     }
     _LIBCPP_INLINE_VISIBILITY
         void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
 #endif // _LIBCPP_CXX03_LANG
 
-    void __deallocate(__next_pointer __np) _NOEXCEPT;
+    void __deallocate_node(__next_pointer __np) _NOEXCEPT;
     __next_pointer __detach() _NOEXCEPT;
 
     template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
     template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
 };
 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 inline

 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 __hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
 {
     static_assert((is_copy_constructible<key_equal>::value),
                  "Predicate must be copy-constructible.");
     static_assert((is_copy_constructible<hasher>::value),
                  "Hasher must be copy-constructible.");
-    __deallocate(__p1_.first().__next_);
+    __deallocate_node(__p1_.first().__next_);
 #if _LIBCPP_DEBUG_LEVEL >= 2
     __get_db()->__erase_c(this);
 #endif
 }
 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 void
 __hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
if (this != &__u)
         max_load_factor() = __u.max_load_factor();
         __assign_multi(__u.begin(), __u.end());
     }
     return *this;
 }
 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate(__next_pointer __np)
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np)
     _NOEXCEPT
 {
     __node_allocator& __na = __node_alloc();
     while (__np != nullptr)
     {
         __next_pointer __next = __np->__next_;
 #if _LIBCPP_DEBUG_LEVEL >= 2
         __c_node* __c = __get_db()->__find_c_and_lock(this);
#endif  // _LIBCPP_NO_EXCEPTIONS
                     __next_pointer __next = __cache->__next_;
                     __node_insert_multi(__cache->__upcast());
                     __cache = __next;
                 }
 #ifndef _LIBCPP_NO_EXCEPTIONS
             }
             catch (...)
             {
-                __deallocate(__cache);
+                __deallocate_node(__cache);
                 throw;
             }
 #endif  // _LIBCPP_NO_EXCEPTIONS
-            __deallocate(__cache);
+            __deallocate_node(__cache);
         }
         const_iterator __i = __u.begin();
         while (__u.size() != 0)
         {
             __node_holder __h = __construct_node(_NodeTypes::__move(__u.remove(__i++)->__value_));
             __node_insert_multi(__h.get());
             __h.release();
         }
#endif  // _LIBCPP_NO_EXCEPTIONS
                 __next_pointer __next = __cache->__next_;
                 __node_insert_unique(__cache->__upcast());
                 __cache = __next;
             }
 #ifndef _LIBCPP_NO_EXCEPTIONS
         }
         catch (...)
         {
-            __deallocate(__cache);
+            __deallocate_node(__cache);
             throw;
         }
 #endif  // _LIBCPP_NO_EXCEPTIONS
-        __deallocate(__cache);
+        __deallocate_node(__cache);
     }
     for (; __first != __last; ++__first)
         __insert_unique(*__first);
 }
 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 template <class _InputIterator>
 void
#endif  // _LIBCPP_NO_EXCEPTIONS
                 __next_pointer __next = __cache->__next_;
                 __node_insert_multi(__cache->__upcast());
                 __cache = __next;
             }
 #ifndef _LIBCPP_NO_EXCEPTIONS
         }
         catch (...)
         {
-            __deallocate(__cache);
+            __deallocate_node(__cache);
             throw;
         }
 #endif  // _LIBCPP_NO_EXCEPTIONS
-        __deallocate(__cache);
+        __deallocate_node(__cache);
     }
     for (; __first != __last; ++__first)
         __insert_multi(_NodeTypes::__get_value(*__first));
 }
 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 inline
 typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator

 }
 
 template <class _Tp, class _Hash, class _Equal, class _Alloc>
 void
 __hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
 {
     if (size() > 0)
     {
-        __deallocate(__p1_.first().__next_);
+        __deallocate_node(__p1_.first().__next_);
         __p1_.first().__next_ = nullptr;
         size_type __bc = bucket_count();
         for (size_type __i = 0; __i < __bc; ++__i)
             __bucket_list_[__i] = nullptr;
         size() = 0;
     }
 }
 

include/__sso_allocator

 
 #ifndef _LIBCPP___SSO_ALLOCATOR
 #define _LIBCPP___SSO_ALLOCATOR
 
 #include <__config>
 #include <type_traits>
 #include <new>
 
-#include <__undef___deallocate>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp, size_t _Np> class _LIBCPP_HIDDEN __sso_allocator;
 
_LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, typename __sso_allocator<void, _Np>::const_pointer = 0)
         }
         return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));
     }
     _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type)
     {
         if (__p == (pointer)&buf_)
             __allocated_ = false;
         else
-            _VSTD::__deallocate(__p);
+            _VSTD::__libcpp_deallocate(__p);
     }
     _LIBCPP_INLINE_VISIBILITY size_type max_size() const throw() {return size_type(~0) / sizeof(_Tp);}
 
     _LIBCPP_INLINE_VISIBILITY
     bool operator==(__sso_allocator& __a) const {return &buf_ == &__a.buf_;}
     _LIBCPP_INLINE_VISIBILITY
     bool operator!=(__sso_allocator& __a) const {return &buf_ != &__a.buf_;}
 };
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP___SSO_ALLOCATOR

include/__undef___deallocate

-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifdef __deallocate
-#if !defined(_LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS)
-#if defined(_MSC_VER) && !defined(__clang__)
-_LIBCPP_WARNING("macro __deallocate is incompatible with C++.  #undefining __deallocate")
-#else
-#warning: macro __deallocate is incompatible with C++.  #undefining __deallocate
-#endif
-#endif
-#undef __deallocate
-#endif

include/experimental/dynarray

 // -*- C++ -*-
 //===-------------------------- dynarray ----------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_DYNARRAY
 #define _LIBCPP_DYNARRAY
 
-#include <__config>
-#if _LIBCPP_STD_VER > 11
-
 /*
     dynarray synopsis
 
 namespace std { namespace experimental {
 
 template< typename T >
 class dynarray
 {
public:
 
     // mutating member functions:
     void fill(const T& v);
 };
 
 }}  // std::experimental
 
 */
+#include <__config>
+#if _LIBCPP_STD_VER > 11
 
 #include <__functional_base>
 #include <iterator>
 #include <stdexcept>
 #include <initializer_list>
 #include <new>
 #include <algorithm>
 
-#include <__undef___deallocate>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 namespace std { namespace experimental { inline namespace __array_extensions_v1 {
 
 template <class _Tp>
 struct _LIBCPP_TEMPLATE_VIS dynarray
private:
     static inline _LIBCPP_INLINE_VISIBILITY value_type* __allocate ( size_t count )
     {
         if ( numeric_limits<size_t>::max() / sizeof (value_type) <= count )
             __throw_bad_array_length();
 
         return static_cast<value_type *> (_VSTD::__allocate (sizeof(value_type) * count));
     }
 
-    static inline _LIBCPP_INLINE_VISIBILITY void __deallocate ( value_type* __ptr ) noexcept
+    static inline _LIBCPP_INLINE_VISIBILITY void __deallocate_value( value_type* __ptr ) noexcept
     {
-        _VSTD::__deallocate (static_cast<void *> (__ptr));
+        _VSTD::__libcpp_deallocate (static_cast<void *> (__ptr));
     }
 
 public:
 
     _LIBCPP_INLINE_VISIBILITY
     explicit dynarray(size_type __c);
     _LIBCPP_INLINE_VISIBILITY
     dynarray(size_type __c, const value_type& __v);

 
 template <class _Tp>
 inline
 dynarray<_Tp>::~dynarray()
 { 
     value_type *__data = data () + __size_;
     for ( size_t i = 0; i < __size_; ++i )
         (--__data)->value_type::~value_type();
-    __deallocate ( __base_ );
+    __deallocate_value( __base_ );
 }
 
 template <class _Tp>
 inline _LIBCPP_INLINE_VISIBILITY
 typename dynarray<_Tp>::reference
 dynarray<_Tp>::at(size_type __n)
 {
     if (__n >= __size_)

include/memory

 #include <stdexcept>
 #include <cstring>
 
 #if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
 #  include <atomic>
 #endif
 
 #include <__undef_min_max>
-#include <__undef___deallocate>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _ValueType>
public:
     _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
         {
         if (__n > max_size())
             __throw_length_error("allocator<T>::allocate(size_t n)"
                                  " 'n' exceeds maximum supported size");
         return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));
         }
     _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
-        {_VSTD::__deallocate((void*)__p);}
+        {_VSTD::__libcpp_deallocate((void*)__p);}
     _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
         {return size_type(~0) / sizeof(_Tp);}
 #if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
     template <class _Up, class... _Args>
         _LIBCPP_INLINE_VISIBILITY
         void
         construct(_Up* __p, _Args&&... __args)
         {
public:
     _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
     {
         if (__n > max_size())
             __throw_length_error("allocator<const T>::allocate(size_t n)"
                                  " 'n' exceeds maximum supported size");
         return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));
     }
     _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
-        {_VSTD::__deallocate((void*)__p);}
+        {_VSTD::__libcpp_deallocate((void*)__p);}
     _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
         {return size_type(~0) / sizeof(_Tp);}
 #if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
     template <class _Up, class... _Args>
         _LIBCPP_INLINE_VISIBILITY
         void
         construct(_Up* __p, _Args&&... __args)
         {

include/module.modulemap

module std [system] {
   module __mutex_base { header "__mutex_base" export * }
   module __split_buffer { header "__split_buffer" export * }
   module __sso_allocator { header "__sso_allocator" export * }
   module __std_stream { header "__std_stream" export * }
   module __string { header "__string" export * }
   module __tree { header "__tree" export * }
   module __tuple { header "__tuple" export * }
   module __undef_min_max { header "__undef_min_max" export * }
-  module __undef___deallocate { header "__undef___deallocate" export * }
 
   module experimental {
     requires cplusplus11
 
     module algorithm {
       header "experimental/algorithm"
       export *
     }

include/new

 
 #include <__config>
 #include <exception>
 #include <cstddef>
 #ifdef _LIBCPP_NO_EXCEPTIONS
 #include <cstdlib>
 #endif
 
-#include <__undef___deallocate>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 #if !(defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER >= 14 || \
     (defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309))
 # define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
 #endif

 inline _LIBCPP_INLINE_VISIBILITY void *__allocate(size_t __size) {
 #ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
   return ::operator new(__size);
 #else
   return __builtin_operator_new(__size);
 #endif
 }
 
-inline _LIBCPP_INLINE_VISIBILITY void __deallocate(void *__ptr) {
+inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate(void *__ptr) {
 #ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
   ::operator delete(__ptr);
 #else
   __builtin_operator_delete(__ptr);
 #endif
 }
 
 #ifdef _LIBCPP_BAD_ARRAY_LENGTH_DEFINED

include/valarray

 #include <cstddef>
 #include <cmath>
 #include <initializer_list>
 #include <algorithm>
 #include <functional>
 #include <new>
 
 #include <__undef_min_max>
-#include <__undef___deallocate>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template<class _Tp> class _LIBCPP_TEMPLATE_VIS valarray;

 template <class _Tp>
 void
 valarray<_Tp>::resize(size_t __n, value_type __x)
 {
     if (__begin_ != nullptr)
     {
         while (__end_ != __begin_)
             (--__end_)->~value_type();
-        _VSTD::__deallocate(__begin_);
+        _VSTD::__libcpp_deallocate(__begin_);
         __begin_ = __end_ = nullptr;
     }
     if (__n)
     {
         __begin_ = __end_ = static_cast<value_type*>(_VSTD::__allocate(__n * sizeof(value_type)));
 #ifndef _LIBCPP_NO_EXCEPTIONS
         try
         {

src/experimental/memory_resource.cpp

 public:
     ~__new_delete_memory_resource_imp() = default;
 
 protected:
     virtual void* do_allocate(size_t __size, size_t __align)
         { return __allocate(__size); }
 
     virtual void do_deallocate(void * __p, size_t, size_t)
-        { __deallocate(__p); }
+        { _VSTD::__libcpp_deallocate(__p); }
 
     virtual bool do_is_equal(memory_resource const & __other) const _NOEXCEPT
         { return &__other == this; }
 };
 
 // null_memory_resource()
 
 class _LIBCPP_TYPE_VIS __null_memory_resource_imp