[libcxx-commits] [libcxx] [libc++] Add tests for the ABI break introduced by switching to _LIBCPP_COMPRESSED_PAIR (PR #154559)

[Louis Dionne via libcxx-commits]

================
@@ -0,0 +1,161 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: libcpp-has-abi-fix-unordered-container-size-type, libcpp-abi-no-compressed-pair-padding
+
+// XFAIL: FROZEN-CXX03-HEADERS-FIXME
+
+#include <cstdint>
+#include <map>
+
+#include "min_allocator.h"
+#include "test_allocator.h"
+#include "test_macros.h"
+
+template <class T>
+class small_pointer {
+  std::uint16_t offset;
+};
+
+template <class T>
+class small_iter_allocator {
+public:
+  using value_type      = T;
+  using pointer         = small_pointer<T>;
+  using size_type       = std::uint16_t;
+  using difference_type = std::int16_t;
+
+  small_iter_allocator() TEST_NOEXCEPT {}
+
+  template <class U>
+  small_iter_allocator(small_iter_allocator<U>) TEST_NOEXCEPT {}
+
+  T* allocate(std::size_t n);
+  void deallocate(T* p, std::size_t);
+
+  friend bool operator==(small_iter_allocator, small_iter_allocator) { return true; }
+  friend bool operator!=(small_iter_allocator, small_iter_allocator) { return false; }
+};
+
+template <class T>
+class final_small_iter_allocator final {
+public:
+  using value_type      = T;
+  using pointer         = small_pointer<T>;
+  using size_type       = std::uint16_t;
+  using difference_type = std::int16_t;
+
+  final_small_iter_allocator() TEST_NOEXCEPT {}
+
+  template <class U>
+  final_small_iter_allocator(final_small_iter_allocator<U>) TEST_NOEXCEPT {}
+
+  T* allocate(std::size_t n);
+  void deallocate(T* p, std::size_t);
+
+  friend bool operator==(final_small_iter_allocator, final_small_iter_allocator) { return true; }
+  friend bool operator!=(final_small_iter_allocator, final_small_iter_allocator) { return false; }
+};
+
+struct allocator_base {};
+
+template <class T>
+struct common_base_allocator : allocator_base {
+  using value_type = T;
+
+  common_base_allocator() TEST_NOEXCEPT {}
+
+  template <class U>
+  common_base_allocator(common_base_allocator<U>) TEST_NOEXCEPT {}
+
+  T* allocate(std::size_t n);
+  void deallocate(T* p, std::size_t);
+
+  friend bool operator==(common_base_allocator, common_base_allocator);
----------------
ldionne wrote:

```
vector/abi.compile.pass.cpp:63:70: error: friend declaration ‘bool operator==(common_base_allocator<T>, common_base_allocator<T>)’ declares a non-template function [-Werror=non-template-friend]
```


https://github.com/llvm/llvm-project/pull/154559