[libcxx] Use custom allocator's `construct` in C++03 when available.

Makes libc++ behavior consistent between C++03 and C++11.

Can use `decltype` in C++03 because `include/__config` defines a macro when
`decltype` is not available.

Reviewers: mclow.lists, EricWF, erik.pilkington, ldionne

Reviewed By: ldionne

Subscribers: dexonsmith, cfe-commits, howard.hinnant, ldionne, christof, jkorous, Quuxplusone

Differential Revision: https://reviews.llvm.org/D48753

4 files changed, 166 insertions, 1 deletions

diff --git a/libcxx/test/libcxx/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp b/libcxx/test/libcxx/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp
new file mode 100644
index 00000000000..998d0b74edd
--- /dev/null
+++ b/libcxx/test/libcxx/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp
@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <vector>
+
+// template <class InputIter> vector(InputIter first, InputIter last);
+
+#include <vector>
+#include <cassert>
+
+#include "min_allocator.h"
+
+void test_ctor_under_alloc() {
+  int arr1[] = {42};
+  int arr2[] = {1, 101, 42};
+  {
+    typedef std::vector<int, cpp03_allocator<int> > C;
+    typedef C::allocator_type Alloc;
+    {
+      Alloc::construct_called = false;
+      C v(arr1, arr1 + 1);
+      assert(Alloc::construct_called);
+    }
+    {
+      Alloc::construct_called = false;
+      C v(arr2, arr2 + 3);
+      assert(Alloc::construct_called);
+    }
+  }
+  {
+    typedef std::vector<int, cpp03_overload_allocator<int> > C;
+    typedef C::allocator_type Alloc;
+    {
+      Alloc::construct_called = false;
+      C v(arr1, arr1 + 1);
+      assert(Alloc::construct_called);
+    }
+    {
+      Alloc::construct_called = false;
+      C v(arr2, arr2 + 3);
+      assert(Alloc::construct_called);
+    }
+  }
+}
+
+int main() {
+  test_ctor_under_alloc();
+}
diff --git a/libcxx/test/libcxx/containers/sequences/vector/vector.cons/construct_iter_iter_alloc.pass.cpp b/libcxx/test/libcxx/containers/sequences/vector/vector.cons/construct_iter_iter_alloc.pass.cpp
new file mode 100644
index 00000000000..c4950fbe637
--- /dev/null
+++ b/libcxx/test/libcxx/containers/sequences/vector/vector.cons/construct_iter_iter_alloc.pass.cpp
@@ -0,0 +1,57 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <vector>
+
+// template <class InputIter> vector(InputIter first, InputIter last,
+//                                   const allocator_type& a);
+
+#include <vector>
+#include <cassert>
+
+#include "min_allocator.h"
+
+void test_ctor_under_alloc() {
+  int arr1[] = {42};
+  int arr2[] = {1, 101, 42};
+  {
+    typedef std::vector<int, cpp03_allocator<int> > C;
+    typedef C::allocator_type Alloc;
+    Alloc a;
+    {
+      Alloc::construct_called = false;
+      C v(arr1, arr1 + 1, a);
+      assert(Alloc::construct_called);
+    }
+    {
+      Alloc::construct_called = false;
+      C v(arr2, arr2 + 3, a);
+      assert(Alloc::construct_called);
+    }
+  }
+  {
+    typedef std::vector<int, cpp03_overload_allocator<int> > C;
+    typedef C::allocator_type Alloc;
+    Alloc a;
+    {
+      Alloc::construct_called = false;
+      C v(arr1, arr1 + 1, a);
+      assert(Alloc::construct_called);
+    }
+    {
+      Alloc::construct_called = false;
+      C v(arr2, arr2 + 3, a);
+      assert(Alloc::construct_called);
+    }
+  }
+}
+
+int main() {
+  test_ctor_under_alloc();
+}
diff --git a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp
index 1a812876bf0..1060b73434d 100644
--- a/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp
+++ b/libcxx/test/std/utilities/memory/allocator.traits/allocator.traits.members/destroy.pass.cpp
@@ -73,7 +73,7 @@ int main()
       std::aligned_storage<sizeof(VT)>::type store;
       std::allocator_traits<Alloc>::destroy(a, (VT*)&store);
     }
-#if TEST_STD_VER >= 11
+#if defined(_LIBCPP_VERSION) || TEST_STD_VER >= 11
     {
         A0::count = 0;
         b_destroy = 0;
diff --git a/libcxx/test/support/min_allocator.h b/libcxx/test/support/min_allocator.h
index a3af9e1db66..45474939744 100644
--- a/libcxx/test/support/min_allocator.h
+++ b/libcxx/test/support/min_allocator.h
@@ -14,6 +14,7 @@
 #include <cstdlib>
 #include <cstddef>
 #include <cassert>
+#include <climits>
 
 #include "test_macros.h"
 
@@ -131,6 +132,59 @@ public:
     friend bool operator!=(malloc_allocator x, malloc_allocator y) {return !(x == y);}
 };
 
+template <class T>
+struct cpp03_allocator : bare_allocator<T>
+{
+    typedef T value_type;
+    typedef value_type* pointer;
+
+    static bool construct_called;
+
+    // Returned value is not used but it's not prohibited.
+    pointer construct(pointer p, const value_type& val)
+    {
+        ::new(p) value_type(val);
+        construct_called = true;
+        return p;
+    }
+
+    std::size_t max_size() const
+    {
+        return UINT_MAX / sizeof(T);
+    }
+};
+template <class T> bool cpp03_allocator<T>::construct_called = false;
+
+template <class T>
+struct cpp03_overload_allocator : bare_allocator<T>
+{
+    typedef T value_type;
+    typedef value_type* pointer;
+
+    static bool construct_called;
+
+    void construct(pointer p, const value_type& val)
+    {
+        construct(p, val, std::is_class<T>());
+    }
+    void construct(pointer p, const value_type& val, std::true_type)
+    {
+        ::new(p) value_type(val);
+        construct_called = true;
+    }
+    void construct(pointer p, const value_type& val, std::false_type)
+    {
+        ::new(p) value_type(val);
+        construct_called = true;
+    }
+
+    std::size_t max_size() const
+    {
+        return UINT_MAX / sizeof(T);
+    }
+};
+template <class T> bool cpp03_overload_allocator<T>::construct_called = false;
+
 
 #if TEST_STD_VER >= 11