[libc++] ADL-proof <vector> by adding _VSTD:: qualification on calls.

(1) Add _VSTD:: qualification to __swap_allocator.

(2) Add _VSTD:: qualification consistently to __to_address.

(3) Add some more missing _VSTD:: to <vector>, with a regression test.
This part is cleanup after d9a4f936d05.

Note that a vector whose allocator actually runs afoul of any of these ADL calls will
likely also run afoul of simple things like `v1 == v2` (which is also an ADL call).
But, still, libc++ should be consistent in qualifying function calls wherever possible.

Relevant blog post: https://quuxplusone.github.io/blog/2019/09/26/uglification-doesnt-stop-adl/

Differential Revision: https://reviews.llvm.org/D91708

10 files changed, 59 insertions, 22 deletions

diff --git a/libcxx/include/__hash_table b/libcxx/include/__hash_table
index 4e615d4fac01..a004d59a4a08 100644
--- a/libcxx/include/__hash_table
+++ b/libcxx/include/__hash_table
@@ -2728,9 +2728,9 @@ __hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
     __u.__bucket_list_.reset(__npp);
     }
     _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
-    __swap_allocator(__bucket_list_.get_deleter().__alloc(),
+    _VSTD::__swap_allocator(__bucket_list_.get_deleter().__alloc(),
              __u.__bucket_list_.get_deleter().__alloc());
-    __swap_allocator(__node_alloc(), __u.__node_alloc());
+    _VSTD::__swap_allocator(__node_alloc(), __u.__node_alloc());
     _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
     __p2_.swap(__u.__p2_);
     __p3_.swap(__u.__p3_);
diff --git a/libcxx/include/__split_buffer b/libcxx/include/__split_buffer
index d2128049efa0..b1fbddcc6093 100644
--- a/libcxx/include/__split_buffer
+++ b/libcxx/include/__split_buffer
@@ -279,7 +279,7 @@ void
 __split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type)
 {
     while (__begin_ != __new_begin)
-        __alloc_traits::destroy(__alloc(), __to_address(__begin_++));
+        __alloc_traits::destroy(__alloc(), _VSTD::__to_address(__begin_++));
 }
 
 template <class _Tp, class _Allocator>
@@ -296,7 +296,7 @@ void
 __split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT
 {
     while (__new_last != __end_)
-        __alloc_traits::destroy(__alloc(), __to_address(--__end_));
+        __alloc_traits::destroy(__alloc(), _VSTD::__to_address(--__end_));
 }
 
 template <class _Tp, class _Allocator>
@@ -416,7 +416,7 @@ __split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
     _VSTD::swap(__begin_, __x.__begin_);
     _VSTD::swap(__end_, __x.__end_);
     _VSTD::swap(__end_cap(), __x.__end_cap());
-    __swap_allocator(__alloc(), __x.__alloc());
+    _VSTD::__swap_allocator(__alloc(), __x.__alloc());
 }
 
 template <class _Tp, class _Allocator>
diff --git a/libcxx/include/__tree b/libcxx/include/__tree
index 4e131a165f7e..404351b4bd88 100644
--- a/libcxx/include/__tree
+++ b/libcxx/include/__tree
@@ -1819,7 +1819,7 @@ __tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
     using _VSTD::swap;
     swap(__begin_node_, __t.__begin_node_);
     swap(__pair1_.first(), __t.__pair1_.first());
-    __swap_allocator(__node_alloc(), __t.__node_alloc());
+    _VSTD::__swap_allocator(__node_alloc(), __t.__node_alloc());
     __pair3_.swap(__t.__pair3_);
     if (size() == 0)
         __begin_node() = __end_node();
diff --git a/libcxx/include/deque b/libcxx/include/deque
index c2ea5f2dbe6d..c66b10225bc0 100644
--- a/libcxx/include/deque
+++ b/libcxx/include/deque
@@ -1237,7 +1237,7 @@ __deque_base<_Tp, _Allocator>::swap(__deque_base& __c)
     __map_.swap(__c.__map_);
     _VSTD::swap(__start_, __c.__start_);
     _VSTD::swap(size(), __c.size());
-    __swap_allocator(__alloc(), __c.__alloc());
+    _VSTD::__swap_allocator(__alloc(), __c.__alloc());
 }
 
 template <class _Tp, class _Allocator>
@@ -2376,7 +2376,7 @@ deque<_Tp, _Allocator>::__append(_ForIter __f, _ForIter __l,
     for (__deque_block_range __br : __deque_range(__base::end(), __base::end() + __n)) {
       _ConstructTransaction __tx(this, __br);
       for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void)++__f) {
-        __alloc_traits::construct(__a, std::__to_address(__tx.__pos_), *__f);
+        __alloc_traits::construct(__a, _VSTD::__to_address(__tx.__pos_), *__f);
       }
     }
 }
@@ -2393,7 +2393,7 @@ deque<_Tp, _Allocator>::__append(size_type __n)
     for (__deque_block_range __br : __deque_range(__base::end(), __base::end() + __n)) {
       _ConstructTransaction __tx(this, __br);
       for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
-        __alloc_traits::construct(__a, std::__to_address(__tx.__pos_));
+        __alloc_traits::construct(__a, _VSTD::__to_address(__tx.__pos_));
       }
     }
 }
@@ -2410,7 +2410,7 @@ deque<_Tp, _Allocator>::__append(size_type __n, const value_type& __v)
     for (__deque_block_range __br : __deque_range(__base::end(), __base::end() + __n)) {
       _ConstructTransaction __tx(this, __br);
       for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
-        __alloc_traits::construct(__a, std::__to_address(__tx.__pos_), __v);
+        __alloc_traits::construct(__a, _VSTD::__to_address(__tx.__pos_), __v);
       }
     }
 
@@ -2708,7 +2708,7 @@ void
 deque<_Tp, _Allocator>::pop_front()
 {
     allocator_type& __a = __base::__alloc();
-    __alloc_traits::destroy(__a, __to_address(*(__base::__map_.begin() +
+    __alloc_traits::destroy(__a, _VSTD::__to_address(*(__base::__map_.begin() +
                                                     __base::__start_ / __base::__block_size) +
                                                     __base::__start_ % __base::__block_size));
     --__base::size();
@@ -2723,7 +2723,7 @@ deque<_Tp, _Allocator>::pop_back()
     _LIBCPP_ASSERT(!empty(), "deque::pop_back called for empty deque");
     allocator_type& __a = __base::__alloc();
     size_type __p = __base::size() + __base::__start_ - 1;
-    __alloc_traits::destroy(__a, __to_address(*(__base::__map_.begin() +
+    __alloc_traits::destroy(__a, _VSTD::__to_address(*(__base::__map_.begin() +
                                                     __p / __base::__block_size) +
                                                     __p % __base::__block_size));
     --__base::size();
diff --git a/libcxx/include/forward_list b/libcxx/include/forward_list
index 3bd8db8b7d4d..96b537c751b1 100644
--- a/libcxx/include/forward_list
+++ b/libcxx/include/forward_list
@@ -603,7 +603,7 @@ __forward_list_base<_Tp, _Alloc>::swap(__forward_list_base& __x)
                     __is_nothrow_swappable<__node_allocator>::value)
 #endif
 {
-    __swap_allocator(__alloc(), __x.__alloc(),
+    _VSTD::__swap_allocator(__alloc(), __x.__alloc(),
             integral_constant<bool, __node_traits::propagate_on_container_swap::value>());
     using _VSTD::swap;
     swap(__before_begin()->__next_, __x.__before_begin()->__next_);
diff --git a/libcxx/include/list b/libcxx/include/list
index 1c085b4e6dfa..7e4c76ddb8d3 100644
--- a/libcxx/include/list
+++ b/libcxx/include/list
@@ -783,7 +783,7 @@ __list_imp<_Tp, _Alloc>::swap(__list_imp& __c)
                    "list::swap: Either propagate_on_container_swap must be true"
                    " or the allocators must compare equal");
     using _VSTD::swap;
-    __swap_allocator(__node_alloc(), __c.__node_alloc());
+    _VSTD::__swap_allocator(__node_alloc(), __c.__node_alloc());
     swap(__sz(), __c.__sz());
     swap(__end_, __c.__end_);
     if (__sz() == 0)
diff --git a/libcxx/include/memory b/libcxx/include/memory
index eee0bdf8f975..6781e4acef4e 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -4898,7 +4898,7 @@ void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
     _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
 #endif
 {
-    __swap_allocator(__a1, __a2,
+    _VSTD::__swap_allocator(__a1, __a2,
       integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
 }
 
diff --git a/libcxx/include/string b/libcxx/include/string
index c900d9609ed4..9f7a2a9e5cb0 100644
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -3438,7 +3438,7 @@ basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
         __alloc_traits::is_always_equal::value ||
         __alloc() == __str.__alloc(), "swapping non-equal allocators");
     _VSTD::swap(__r_.first(), __str.__r_.first());
-    __swap_allocator(__alloc(), __str.__alloc());
+    _VSTD::__swap_allocator(__alloc(), __str.__alloc());
 }
 
 // find
diff --git a/libcxx/include/vector b/libcxx/include/vector
index f425774413c7..bc83656db12a 100644
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -951,7 +951,7 @@ vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, a
 {
 
     __annotate_delete();
-    __construct_backward_with_exception_guarantees(this->__alloc(), this->__begin_, this->__end_, __v.__begin_);
+    _VSTD::__construct_backward_with_exception_guarantees(this->__alloc(), this->__begin_, this->__end_, __v.__begin_);
     _VSTD::swap(this->__begin_, __v.__begin_);
     _VSTD::swap(this->__end_, __v.__end_);
     _VSTD::swap(this->__end_cap(), __v.__end_cap());
@@ -966,8 +966,8 @@ vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, a
 {
     __annotate_delete();
     pointer __r = __v.__begin_;
-    __construct_backward_with_exception_guarantees(this->__alloc(), this->__begin_, __p, __v.__begin_);
-    __construct_forward_with_exception_guarantees(this->__alloc(), __p, this->__end_, __v.__end_);
+    _VSTD::__construct_backward_with_exception_guarantees(this->__alloc(), this->__begin_, __p, __v.__begin_);
+    _VSTD::__construct_forward_with_exception_guarantees(this->__alloc(), __p, this->__end_, __v.__end_);
     _VSTD::swap(this->__begin_, __v.__begin_);
     _VSTD::swap(this->__end_, __v.__end_);
     _VSTD::swap(this->__end_cap(), __v.__end_cap());
@@ -1074,7 +1074,7 @@ typename enable_if
 vector<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last, size_type __n)
 {
     _ConstructTransaction __tx(*this, __n);
-    __construct_range_forward(this->__alloc(), __first, __last, __tx.__pos_);
+    _VSTD::__construct_range_forward(this->__alloc(), __first, __last, __tx.__pos_);
 }
 
 //  Default constructs __n objects starting at __end_
@@ -2054,7 +2054,7 @@ vector<_Tp, _Allocator>::swap(vector& __x)
     _VSTD::swap(this->__begin_, __x.__begin_);
     _VSTD::swap(this->__end_, __x.__end_);
     _VSTD::swap(this->__end_cap(), __x.__end_cap());
-    __swap_allocator(this->__alloc(), __x.__alloc(),
+    _VSTD::__swap_allocator(this->__alloc(), __x.__alloc(),
         integral_constant<bool,__alloc_traits::propagate_on_container_swap::value>());
 #if _LIBCPP_DEBUG_LEVEL == 2
     __get_db()->swap(this, &__x);
@@ -3232,7 +3232,7 @@ vector<bool, _Allocator>::swap(vector& __x)
     _VSTD::swap(this->__begin_, __x.__begin_);
     _VSTD::swap(this->__size_, __x.__size_);
     _VSTD::swap(this->__cap(), __x.__cap());
-    __swap_allocator(this->__alloc(), __x.__alloc(),
+    _VSTD::__swap_allocator(this->__alloc(), __x.__alloc(),
         integral_constant<bool, __alloc_traits::propagate_on_container_swap::value>());
 }
 
diff --git a/libcxx/test/libcxx/containers/sequences/vector/robust_against_adl.pass.cpp b/libcxx/test/libcxx/containers/sequences/vector/robust_against_adl.pass.cpp
new file mode 100644
index 000000000000..26a8ac430141
--- /dev/null
+++ b/libcxx/test/libcxx/containers/sequences/vector/robust_against_adl.pass.cpp
@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <vector>
+
+#include <vector>
+
+#include "test_macros.h"
+
+struct Incomplete;
+template<class T> struct Holder { T t; };
+
+template<class T, class AdlTrap = Holder<Incomplete>>
+struct MyAlloc {
+    using value_type = T;
+    T *allocate(int n) { return std::allocator<T>().allocate(n); }
+    void deallocate(T *p, int n) { return std::allocator<T>().deallocate(p, n); }
+};
+
+int main(int, char**)
+{
+    std::vector<int, MyAlloc<int>> v;
+    std::vector<int, MyAlloc<int>> w;
+    v.push_back(1);
+    v.insert(v.end(), 2);
+    v.insert(v.end(), w.begin(), w.end());
+    v.pop_back();
+    v.erase(v.begin());
+    v.erase(v.begin(), v.end());
+    v.swap(w);
+    return 0;
+}