[libc++] Header inclusion tests

[• Quuxplusone]

Summary

As mandated by the Standard's various synopses, e.g. [iterator.synopsis].
Searching the TeX source for '#include' is a good way to find all of these mandates.

The new tests are all autogenerated by utils/generate_header_inclusion_tests.py.
I was SHOCKED by how many mandates there are, and how many of them libc++ wasn't conforming with.

The <iterator> --> <concepts> edge is TODO'ed because that's D99041 / D99044.
All the other TODO'ed edges are because one or the other header doesn't exist in libc++ at all, yet (<ranges>, <coroutine>, <syncstream>).

[• Quuxplusone]

I had generated iterator.inclusions.pass.cpp before realizing it should have been TODO'ed. git rm the old version hanging around.

[cjdb]

Overall LGTM.

libcxx/include/chrono

16

Have we added <compare> support for <chrono> yet? If not, I'd prefer to keep it out of the synopsis. (If you're keeping it in, please add // C++20 or something.)

libcxx/test/libcxx/inclusions/algorithm.inclusions.pass.cpp

2

Can these please be placed under libcxx/test/std/.../${subclause}/${subclause}.syn/ instead? They're responsible for checking the synopsis, so I'd prefer they sit with the other tests of their category.

29

Missing new line.

[curdeius]

libcxx/utils/generate_header_inclusion_tests.py

21

A small comment on how to get/update this list would be nice (grepping draft's source TeX for #include and so on).

180

Nit: new line.

193

Depending on what we decide on .pass vs. .compile.pass, these tests are candidates for begin compile.pass tests (with a defensive return 1; in main).
And, as they're generated, there's less risk to make things incorrect (mind that I don't say "no risk" because someone might theoretically add runtime tests in this generator script).

[• Quuxplusone]

Add missing trailing newline.
Fix TEST_STD_VER == 11 -> TEST_STD_VER >= 11. (Anyone got a better "C++0x or later" check?)

[Mordante]

Nice to see this patch!

libcxx/utils/generate_header_inclusion_tests.py

171

Wouldn't it be nicer when the script produces properly formatted code?

[curdeius]

In D99309#2668368, @Quuxplusone wrote:

Add missing trailing newline.
Fix TEST_STD_VER == 11 -> TEST_STD_VER >= 11. (Anyone got a better "C++0x or later" check?)

Why not just TEST_STD_VER > 3? Cf. https://github.com/llvm/llvm-project/blob/main/libcxx/test/support/test_macros.h#L95.
This would remove special casing for v==11.

[• Quuxplusone]

libcxx/include/chrono

16

There's no particular "support" needed; I'm just making libc++ provide the header inclusion that is mandated by the Standard.

...On second glance, I guess you're objecting only to the comment on line 16, and not to the functional conformance improvement on line 830. Is that right? I have no strong objection to removing line 16 (and likewise throughout the comments), and am inclined to just do it. It'd shrink the diff, too!
Anyone else care to advocate for keeping these new synopsis comments?

libcxx/test/libcxx/inclusions/algorithm.inclusions.pass.cpp

2

Unfortunately there's no way to do that, without some human coming up with the ad-hoc list of subclauses and creating all those directories. And then we'd have the autogenerated tests scattered all over the codebase, which I foresee leading to problems as people add and remove autogenerated tests. So, no.

libcxx/utils/generate_header_inclusion_tests.py

171

Yes-ish, but my impression is we can't convince clang-format to accept this code.
Anyway, I just copy-pasted this line from the other two generator scripts.

[Mordante]

libcxx/utils/generate_header_inclusion_tests.py

171

Oke then let's keep it for now. Maybe once we tune clang-format further it will be possible to remove this line.

[• Quuxplusone]

Remove synopsis comments per cjdb's feedback.

Script improvements. Note that 03 is an octal constant; but I'm hoping nothing in our system complains about that. I didn't try very hard to find a way of printing it as an integer while still allowing us to use (and string-compare) strings like "2b" in the script.

[• Quuxplusone]

Rebase and update for D99041. <iterator> can now safely include <concepts>.
Also, poke buildbot, because it seems to be stuck.

[curdeius]

LGTM % nit and the pass/compile.pass naming decision.

libcxx/utils/generate_header_inclusion_tests.py

115–116

Nit: remove modern_.

[• Quuxplusone]

Any further comments from @cjdb? I plan to land this (with the modern_ removed) in a few hours.

[ldionne]

This LGTM with some comments. Huge thanks for writing this. You don't have to re-review if you apply my comments and other reviewer's outstanding comments:

• The section on Adding a new header TODO should be updated in Contributing.rst.
• Use .compile.pass.cpp BUT don't define main() - this way there's no possibility for confusion on whether the test should run or not.

libcxx/include/chrono

 // -*- C++ -*-
 //===---------------------------- chrono ----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_CHRONO
 #define _LIBCPP_CHRONO
 
 /*
     chrono synopsis
 
+#include <compare>
+
 namespace std
 {
 namespace chrono
 {
 
 template <class ToDuration, class Rep, class Period>
 constexpr
 ToDuration

 }  // chrono_literals
 }  // literals
 
 }  // std
 */
 
 #include <__config>
 #include <__availability>
+#include <compare>
 #include <ctime>
 #include <type_traits>
 #include <ratio>
 #include <limits>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/deque

 // -*- C++ -*-
 //===---------------------------- deque -----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_DEQUE
 #define _LIBCPP_DEQUE
 
 /*
     deque synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class T, class Allocator = allocator<T> >
 class deque
 {
 public:
     // types:
template <class T, class Allocator, class Predicate>
     erase_if(deque<T, Allocator>& c, Predicate pred);    // C++20
 
 }  // std
 
 */
 
 #include <__config>
 #include <__split_buffer>
+#include <compare>
 #include <type_traits>
 #include <initializer_list>
 #include <iterator>
 #include <algorithm>
 #include <stdexcept>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)

libcxx/include/filesystem

 // -*- C++ -*-
 //===--------------------------- filesystem -------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 #ifndef _LIBCPP_FILESYSTEM
 #define _LIBCPP_FILESYSTEM
 /*
     filesystem synopsis
 
+    #include <compare>
+
     namespace std { namespace filesystem {
 
     class path;
 
     void swap(path& lhs, path& rhs) noexcept;
     size_t hash_value(const path& p) noexcept;
 
     bool operator==(const path& lhs, const path& rhs) noexcept;

 
 */
 
 #include <__config>
 #include <__availability>
 #include <cstddef>
 #include <cstdlib>
 #include <chrono>
+#include <compare>
 #include <iterator>
 #include <iosfwd>
 #include <memory>
 #include <stack>
 #include <string>
 #include <system_error>
 #include <utility>
 #include <string_view>

libcxx/include/iterator

 // -*- C++ -*-
 //===-------------------------- iterator ----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_ITERATOR
 #define _LIBCPP_ITERATOR
 
 /*
     iterator synopsis
 
+#include <compare>
+
 namespace std
 {
 
 template<class Iterator>
 struct iterator_traits
 {
     typedef typename Iterator::difference_type difference_type;
     typedef typename Iterator::value_type value_type;

 }  // std
 
 */
 
 #include <__config>
 #include <iosfwd> // for forward declarations of vector and string.
 #include <__functional_base>
 #include <type_traits>
+#include <compare>
 #include <cstddef>
 #include <initializer_list>
 #include <__memory/base.h>
 #include <__memory/pointer_traits.h>
 #include <version>
 
 #include <__debug>
 

libcxx/include/map

 // -*- C++ -*-
 //===----------------------------- map ------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_MAP
 #define _LIBCPP_MAP
 
 /*
 
     map synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class Key, class T, class Compare = less<Key>,
           class Allocator = allocator<pair<const Key, T>>>
 class map
 {
 public:

 
 }  // std
 
 */
 
 #include <__config>
 #include <__tree>
 #include <__node_handle>
+#include <compare>
+#include <initializer_list>
 #include <iterator> // __libcpp_erase_if_container
 #include <memory>
 #include <utility>
 #include <functional>
 #include <initializer_list>
 #include <type_traits>
 #include <version>
 

libcxx/include/memory

 // -*- C++ -*-
 //===-------------------------- memory ------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_MEMORY
 #define _LIBCPP_MEMORY
 
 /*
     memory synopsis
 
+#include <compare>
+
 namespace std
 {
 
 struct allocator_arg_t { };
 inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
 
 template <class T, class Alloc> struct uses_allocator;
 

 }  // std
 
 */
 
 #include <__config>
 #include <__availability>
 #include <type_traits>
 #include <typeinfo>
+#include <compare>
 #include <cstddef>
 #include <cstdint>
 #include <new>
 #include <utility>
 #include <limits>
 #include <iterator>
 #include <__functional_base>
 #include <iosfwd>

libcxx/include/optional

 // -*- C++ -*-
 //===-------------------------- optional ----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_OPTIONAL
 #define _LIBCPP_OPTIONAL
 
 /*
     optional synopsis
 
-// C++1z
+#include <compare>
 
 namespace std {
   // 23.6.3, optional for object types
   template <class T> class optional;
 
   // 23.6.4, no-value state indicator
   struct nullopt_t{see below };
   inline constexpr nullopt_t nullopt(unspecified );

 } // namespace std
 
 */
 
 #include <__config>
 #include <__availability>
 #include <__debug>
 #include <__functional_base>
+#include <compare>
 #include <functional>
 #include <initializer_list>
 #include <new>
 #include <stdexcept>
 #include <type_traits>
 #include <utility>
 #include <version>
 

libcxx/include/queue

 // -*- C++ -*-
 //===--------------------------- queue ------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_QUEUE
 #define _LIBCPP_QUEUE
 
 /*
     queue synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class T, class Container = deque<T>>
 class queue
 {
 public:
     typedef Container                                container_type;
void swap(priority_queue<T, Container, Compare>& x,
             priority_queue<T, Container, Compare>& y)
             noexcept(noexcept(x.swap(y)));
 
 }  // std
 
 */
 
 #include <__config>
+#include <compare>
 #include <deque>
 #include <vector>
 #include <functional>
 #include <algorithm>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif

libcxx/include/regex

 // -*- C++ -*-
 //===--------------------------- regex ------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_REGEX
 #define _LIBCPP_REGEX
 
 /*
     regex synopsis
 
+#include <compare>
 #include <initializer_list>
 
 namespace std
 {
 
 namespace regex_constants
 {
 

 typedef regex_token_iterator<wstring::const_iterator> wsregex_token_iterator;
 
 } // std
 */
 
 #include <__config>
 #include <stdexcept>
 #include <__locale>
+#include <compare>
 #include <initializer_list>
 #include <utility>
 #include <iterator>
 #include <string>
 #include <memory>
 #include <vector>
 #include <deque>
 #include <version>

libcxx/include/set

 // -*- C++ -*-
 //===---------------------------- set -------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_SET
 #define _LIBCPP_SET
 
 /*
 
     set synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class Key, class Compare = less<Key>,
           class Allocator = allocator<Key>>
 class set
 {
 public:

 
 }  // std
 
 */
 
 #include <__config>
 #include <__tree>
 #include <__node_handle>
+#include <compare>
 #include <functional>
+#include <initializer_list>
 #include <iterator> // __libcpp_erase_if_container
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD

libcxx/include/stack

 // -*- C++ -*-
 //===---------------------------- stack -----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_STACK
 #define _LIBCPP_STACK
 
 /*
     stack synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class T, class Container = deque<T>>
 class stack
 {
 public:
     typedef Container                                container_type;

libcxx/include/streambuf

 // -*- C++ -*-
 //===------------------------- streambuf ----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP_STEAMBUF
-#define _LIBCPP_STEAMBUF
+#ifndef _LIBCPP_STREAMBUF
+#define _LIBCPP_STREAMBUF
 
 /*
     streambuf synopsis
 
 namespace std
 {
 
 template <class charT, class traits = char_traits<charT> >

 
 _LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ios<char>)
 _LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ios<wchar_t>)
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
-#endif  // _LIBCPP_STEAMBUF
+#endif  // _LIBCPP_STREAMBUF

libcxx/include/string

 // -*- C++ -*-
 //===--------------------------- string -----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_STRING
 #define _LIBCPP_STRING
 
 /*
     string synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class stateT>
 class fpos
 {
 private:
     stateT st;

 basic_string<char16_t> operator "" s( const char16_t *str, size_t len ); // C++14
 basic_string<char32_t> operator "" s( const char32_t *str, size_t len ); // C++14
 
 }  // std
 
 */
 
 #include <__config>
+#include <compare>
 #include <string_view>
 #include <iosfwd>
 #include <cstring>
 #include <cstdio>  // For EOF.
 #include <cwchar>
 #include <algorithm>
 #include <iterator>
 #include <utility>

libcxx/include/string_view

 // -*- C++ -*-
 //===------------------------ string_view ---------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_STRING_VIEW
 #define _LIBCPP_STRING_VIEW
 
 /*
 string_view synopsis
 
+#include <compare>
+
 namespace std {
 
     // 7.2, Class template basic_string_view
     template<class charT, class traits = char_traits<charT>>
         class basic_string_view;
 
     // 7.9, basic_string_view non-member comparison functions
     template<class charT, class traits>

 
 
 */
 
 #include <__config>
 #include <__string>
 #include <iosfwd>
 #include <algorithm>
+#include <compare>
 #include <iterator>
 #include <limits>
 #include <stdexcept>
 #include <version>
 #include <__debug>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/system_error

 // -*- C++ -*-
 //===---------------------------- system_error ----------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_SYSTEM_ERROR
 #define _LIBCPP_SYSTEM_ERROR
 
 /*
     system_error synopsis
 
+#include <compare>
+
 namespace std
 {
 
 class error_category
 {
 public:
     virtual ~error_category() noexcept;
 

 
 }  // std
 
 */
 
 #include <__config>
 #include <__errc>
 #include <__functional_base> // unary_function
+#include <compare>
 #include <stdexcept>
 #include <string>
 #include <type_traits>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 

libcxx/include/tuple

 // -*- C++ -*-
 //===--------------------------- tuple ------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_TUPLE
 #define _LIBCPP_TUPLE
 
 /*
     tuple synopsis
 
+#include <compare>
+
 namespace std
 {
 
 template <class... T>
 class tuple {
 public:
     explicit(see-below) constexpr tuple();
     explicit(see-below) tuple(const T&...);  // constexpr in C++14
template <class... Types>
   swap(tuple<Types...>& x, tuple<Types...>& y) noexcept(noexcept(x.swap(y)));
 
 }  // std
 
 */
 
 #include <__config>
 #include <__tuple>
+#include <compare>
 #include <cstddef>
 #include <type_traits>
 #include <__functional_base>
 #include <utility>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/typeindex

 // -*- C++ -*-
 //===-------------------------- typeindex ---------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_TYPEINDEX
 #define _LIBCPP_TYPEINDEX
 
 /*
 
     typeindex synopsis
 
+#include <compare>
+
 namespace std
 {
 
 class type_index
 {
 public:
     type_index(const type_info& rhs) noexcept;
 

 
 }  // std
 
 */
 
 #include <__config>
 #include <typeinfo>
 #include <__functional_base>
+#include <compare>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_TEMPLATE_VIS type_index

libcxx/include/unordered_map

 // -*- C++ -*-
 //===-------------------------- unordered_map -----------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_UNORDERED_MAP
 #define _LIBCPP_UNORDERED_MAP
 
 /*
 
     unordered_map synopsis
 
+#include <compare>
 #include <initializer_list>
 
 namespace std
 {
 
 template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
           class Alloc = allocator<pair<const Key, T>>>
 class unordered_map

 
 }  // std
 
 */
 
 #include <__config>
 #include <__hash_table>
 #include <__node_handle>
+#include <compare>
 #include <functional>
 #include <iterator> // __libcpp_erase_if_container
 #include <stdexcept>
 #include <tuple>
 #include <version>
 
 #include <__debug>
 

libcxx/include/unordered_set

 // -*- C++ -*-
 //===-------------------------- unordered_set -----------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_UNORDERED_SET
 #define _LIBCPP_UNORDERED_SET
 
 /*
 
     unordered_set synopsis
 
+#include <compare>
 #include <initializer_list>
 
 namespace std
 {
 
 template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
           class Alloc = allocator<Value>>
 class unordered_set
operator!=(const unordered_multiset<Value, Hash, Pred, Alloc>& x,
                const unordered_multiset<Value, Hash, Pred, Alloc>& y);
 }  // std
 
 */
 
 #include <__config>
 #include <__hash_table>
 #include <__node_handle>
+#include <compare>
 #include <functional>
 #include <iterator> // __libcpp_erase_if_container
 #include <version>
 
 #include <__debug>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/utility

 // -*- C++ -*-
 //===-------------------------- utility -----------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_UTILITY
 #define _LIBCPP_UTILITY
 
 /*
     utility synopsis
 
+#include <compare>
 #include <initializer_list>
 
 namespace std
 {
 
 template <class T>
     void
     swap(T& a, T& b);
template <class T>
     constexpr underlying_type_t<T> to_underlying( T value ) noexcept; // C++2b
 
 }  // std
 
 */
 
 #include <__config>
 #include <__tuple>
+#include <compare>
 #include <type_traits>
 #include <initializer_list>
 #include <cstddef>
 #include <cstring>
 #include <cstdint>
 #include <version>
 #include <__debug>
 

libcxx/include/variant

 // -*- C++ -*-
 //===------------------------------ variant -------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_VARIANT
 #define _LIBCPP_VARIANT
 
 /*
    variant synopsis
 
+#include <compare>
+
 namespace std {
 
   // 20.7.2, class template variant
   template <class... Types>
   class variant {
   public:
 
     // 20.7.2.1, constructors

 } // namespace std
 
 */
 
 #include <__config>
 #include <__availability>
 #include <__tuple>
 #include <array>
+#include <compare>
 #include <exception>
 #include <functional>
 #include <initializer_list>
 #include <new>
 #include <tuple>
 #include <type_traits>
 #include <utility>
 #include <limits>

libcxx/include/vector

 // -*- C++ -*-
 //===------------------------------ vector --------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_VECTOR
 #define _LIBCPP_VECTOR
 
 /*
     vector synopsis
 
+#include <compare>
+#include <initializer_list>
+
 namespace std
 {
 
 template <class T, class Allocator = allocator<T> >
 class vector
 {
 public:
     typedef T                                        value_type;

 
 */
 
 #include <__config>
 #include <iosfwd> // for forward declaration of vector
 #include <__bit_reference>
 #include <type_traits>
 #include <climits>
+#include <compare>
 #include <limits>
 #include <initializer_list>
 #include <memory>
 #include <stdexcept>
 #include <algorithm>
 #include <cstring>
 #include <version>
 #include <__split_buffer>

libcxx/test/libcxx/inclusions/algorithm.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <algorithm>
+
+// Test that <algorithm> includes all the other headers it's supposed to.
+
+#include <algorithm>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_ALGORITHM)
+ #   error "<algorithm> was expected to define _LIBCPP_ALGORITHM"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<algorithm> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/array.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <array>
+
+// Test that <array> includes all the other headers it's supposed to.
+
+#include <array>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_ARRAY)
+ #   error "<array> was expected to define _LIBCPP_ARRAY"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<array> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<array> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/bitset.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <bitset>
+
+// Test that <bitset> includes all the other headers it's supposed to.
+
+#include <bitset>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_BITSET)
+ #   error "<bitset> was expected to define _LIBCPP_BITSET"
+#endif
+#if !defined(_LIBCPP_IOSFWD)
+ #   error "<bitset> should include <iosfwd> in C++03 and later"
+#endif
+#if !defined(_LIBCPP_STRING)
+ #   error "<bitset> should include <string> in C++03 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/chrono.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03
+
+// <chrono>
+
+// Test that <chrono> includes all the other headers it's supposed to.
+
+#include <chrono>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_CHRONO)
+ #   error "<chrono> was expected to define _LIBCPP_CHRONO"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<chrono> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/cinttypes.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <cinttypes>
+
+// Test that <cinttypes> includes all the other headers it's supposed to.
+
+#include <cinttypes>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_CINTTYPES)
+ #   error "<cinttypes> was expected to define _LIBCPP_CINTTYPES"
+#endif
+#if !defined(_LIBCPP_CSTDINT)
+ #   error "<cinttypes> should include <cstdint> in C++03 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/complex.h.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <complex.h>
+
+// Test that <complex.h> includes all the other headers it's supposed to.
+
+#include <complex.h>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_COMPLEX_H)
+ #   error "<complex.h> was expected to define _LIBCPP_COMPLEX_H"
+#endif
+#if !defined(_LIBCPP_COMPLEX)
+ #   error "<complex.h> should include <complex> in C++03 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/deque.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <deque>
+
+// Test that <deque> includes all the other headers it's supposed to.
+
+#include <deque>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_DEQUE)
+ #   error "<deque> was expected to define _LIBCPP_DEQUE"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<deque> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<deque> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/filesystem.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03, c++11, c++14
+// UNSUPPORTED: libcpp-has-no-filesystem-library
+
+// <filesystem>
+
+// Test that <filesystem> includes all the other headers it's supposed to.
+
+#include <filesystem>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_FILESYSTEM)
+ #   error "<filesystem> was expected to define _LIBCPP_FILESYSTEM"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<filesystem> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/forward_list.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <forward_list>
+
+// Test that <forward_list> includes all the other headers it's supposed to.
+
+#include <forward_list>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_FORWARD_LIST)
+ #   error "<forward_list> was expected to define _LIBCPP_FORWARD_LIST"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<forward_list> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<forward_list> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/ios.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <ios>
+
+// Test that <ios> includes all the other headers it's supposed to.
+
+#include <ios>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_IOS)
+ #   error "<ios> was expected to define _LIBCPP_IOS"
+#endif
+#if !defined(_LIBCPP_IOSFWD)
+ #   error "<ios> should include <iosfwd> in C++03 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/iostream.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <iostream>
+
+// Test that <iostream> includes all the other headers it's supposed to.
+
+#include <iostream>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_IOSTREAM)
+ #   error "<iostream> was expected to define _LIBCPP_IOSTREAM"
+#endif
+#if !defined(_LIBCPP_IOS)
+ #   error "<iostream> should include <ios> in C++03 and later"
+#endif
+#if !defined(_LIBCPP_ISTREAM)
+ #   error "<iostream> should include <istream> in C++03 and later"
+#endif
+#if !defined(_LIBCPP_OSTREAM)
+ #   error "<iostream> should include <ostream> in C++03 and later"
+#endif
+#if !defined(_LIBCPP_STREAMBUF)
+ #   error "<iostream> should include <streambuf> in C++03 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/list.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <list>
+
+// Test that <list> includes all the other headers it's supposed to.
+
+#include <list>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_LIST)
+ #   error "<list> was expected to define _LIBCPP_LIST"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<list> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<list> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/map.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <map>
+
+// Test that <map> includes all the other headers it's supposed to.
+
+#include <map>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_MAP)
+ #   error "<map> was expected to define _LIBCPP_MAP"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<map> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<map> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/memory.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <memory>
+
+// Test that <memory> includes all the other headers it's supposed to.
+
+#include <memory>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_MEMORY)
+ #   error "<memory> was expected to define _LIBCPP_MEMORY"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<memory> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/optional.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <optional>
+
+// Test that <optional> includes all the other headers it's supposed to.
+
+#include <optional>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_OPTIONAL)
+ #   error "<optional> was expected to define _LIBCPP_OPTIONAL"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<optional> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/queue.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <queue>
+
+// Test that <queue> includes all the other headers it's supposed to.
+
+#include <queue>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_QUEUE)
+ #   error "<queue> was expected to define _LIBCPP_QUEUE"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<queue> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<queue> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/random.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <random>
+
+// Test that <random> includes all the other headers it's supposed to.
+
+#include <random>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_RANDOM)
+ #   error "<random> was expected to define _LIBCPP_RANDOM"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<random> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/regex.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: libcpp-has-no-localization
+
+// <regex>
+
+// Test that <regex> includes all the other headers it's supposed to.
+
+#include <regex>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_REGEX)
+ #   error "<regex> was expected to define _LIBCPP_REGEX"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<regex> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<regex> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/set.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <set>
+
+// Test that <set> includes all the other headers it's supposed to.
+
+#include <set>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_SET)
+ #   error "<set> was expected to define _LIBCPP_SET"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<set> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<set> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/stack.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <stack>
+
+// Test that <stack> includes all the other headers it's supposed to.
+
+#include <stack>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_STACK)
+ #   error "<stack> was expected to define _LIBCPP_STACK"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<stack> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<stack> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/string.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <string>
+
+// Test that <string> includes all the other headers it's supposed to.
+
+#include <string>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_STRING)
+ #   error "<string> was expected to define _LIBCPP_STRING"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<string> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<string> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/string_view.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <string_view>
+
+// Test that <string_view> includes all the other headers it's supposed to.
+
+#include <string_view>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_STRING_VIEW)
+ #   error "<string_view> was expected to define _LIBCPP_STRING_VIEW"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<string_view> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/system_error.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03
+
+// <system_error>
+
+// Test that <system_error> includes all the other headers it's supposed to.
+
+#include <system_error>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_SYSTEM_ERROR)
+ #   error "<system_error> was expected to define _LIBCPP_SYSTEM_ERROR"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<system_error> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/tgmath.h.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <tgmath.h>
+
+// Test that <tgmath.h> includes all the other headers it's supposed to.
+
+#include <tgmath.h>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_TGMATH_H)
+ #   error "<tgmath.h> was expected to define _LIBCPP_TGMATH_H"
+#endif
+#if !defined(_LIBCPP_CMATH)
+ #   error "<tgmath.h> should include <cmath> in C++03 and later"
+#endif
+#if !defined(_LIBCPP_COMPLEX)
+ #   error "<tgmath.h> should include <complex> in C++03 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/thread.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03
+// UNSUPPORTED: libcpp-has-no-threads
+
+// <thread>
+
+// Test that <thread> includes all the other headers it's supposed to.
+
+#include <thread>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_THREAD)
+ #   error "<thread> was expected to define _LIBCPP_THREAD"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<thread> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/tuple.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03
+
+// <tuple>
+
+// Test that <tuple> includes all the other headers it's supposed to.
+
+#include <tuple>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_TUPLE)
+ #   error "<tuple> was expected to define _LIBCPP_TUPLE"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<tuple> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/typeindex.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <typeindex>
+
+// Test that <typeindex> includes all the other headers it's supposed to.
+
+#include <typeindex>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_TYPEINDEX)
+ #   error "<typeindex> was expected to define _LIBCPP_TYPEINDEX"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<typeindex> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/unordered_map.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03
+
+// <unordered_map>
+
+// Test that <unordered_map> includes all the other headers it's supposed to.
+
+#include <unordered_map>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_UNORDERED_MAP)
+ #   error "<unordered_map> was expected to define _LIBCPP_UNORDERED_MAP"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<unordered_map> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<unordered_map> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/unordered_set.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03
+
+// <unordered_set>
+
+// Test that <unordered_set> includes all the other headers it's supposed to.
+
+#include <unordered_set>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_UNORDERED_SET)
+ #   error "<unordered_set> was expected to define _LIBCPP_UNORDERED_SET"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<unordered_set> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<unordered_set> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/utility.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <utility>
+
+// Test that <utility> includes all the other headers it's supposed to.
+
+#include <utility>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_UTILITY)
+ #   error "<utility> was expected to define _LIBCPP_UTILITY"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<utility> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<utility> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/valarray.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <valarray>
+
+// Test that <valarray> includes all the other headers it's supposed to.
+
+#include <valarray>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_VALARRAY)
+ #   error "<valarray> was expected to define _LIBCPP_VALARRAY"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<valarray> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/variant.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <variant>
+
+// Test that <variant> includes all the other headers it's supposed to.
+
+#include <variant>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_VARIANT)
+ #   error "<variant> was expected to define _LIBCPP_VARIANT"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<variant> should include <compare> in C++20 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/test/libcxx/inclusions/vector.inclusions.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by generate_header_inclusion_tests.py
+// and should not be edited manually.
+//
+// clang-format off
+
+// <vector>
+
+// Test that <vector> includes all the other headers it's supposed to.
+
+#include <vector>
+#include "test_macros.h"
+
+#if !defined(_LIBCPP_VECTOR)
+ #   error "<vector> was expected to define _LIBCPP_VECTOR"
+#endif
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_COMPARE)
+ #   error "<vector> should include <compare> in C++20 and later"
+#endif
+#if TEST_STD_VER >= 11 && !defined(_LIBCPP_INITIALIZER_LIST)
+ #   error "<vector> should include <initializer_list> in C++11 and later"
+#endif
+
+int main(int, char**) { return 0; }

libcxx/utils/generate_header_inclusion_tests.py

+#!/usr/bin/env python
+
+import os
+
+
+def get_libcxx_paths():
+    utils_path = os.path.dirname(os.path.abspath(__file__))
+    script_name = os.path.basename(__file__)
+    assert os.path.exists(utils_path)
+    src_root = os.path.dirname(utils_path)
+    test_path = os.path.join(src_root, 'test', 'libcxx', 'inclusions')
+    assert os.path.exists(test_path)
+    assert os.path.exists(os.path.join(test_path, 'algorithm.inclusions.pass.cpp'))
+    return script_name, src_root, test_path
+
+
+script_name, source_root, test_path = get_libcxx_paths()
+
+
+# This table was produced manually, by grepping the TeX source of the Standard's
+# library clauses for the string "#include". Each header's synopsis contains
+# explicit "#include" directives for its mandatory inclusions.
+# For example, [algorithm.syn] contains "#include <initializer_list>".
+#
+mandatory_inclusions = {
+    "algorithm": ["initializer_list"],
+    "array": ["compare", "initializer_list"],
+    "bitset": ["iosfwd", "string"],
+    "chrono": ["compare"],
+    "cinttypes": ["cstdint"],
+    "complex.h": ["complex"],
+    # TODO "coroutine": ["compare"],
+    "deque": ["compare", "initializer_list"],
+    "filesystem": ["compare"],
+    "forward_list": ["compare", "initializer_list"],
+    "ios": ["iosfwd"],
+    "iostream": ["ios", "istream", "ostream", "streambuf"],
+    # TODO "iterator": ["compare", "concepts"],
+    "list": ["compare", "initializer_list"],
+    "map": ["compare", "initializer_list"],
+    "memory": ["compare"],
+    "optional": ["compare"],
+    "queue": ["compare", "initializer_list"],
+    "random": ["initializer_list"],
+    # TODO "ranges": ["compare", "initializer_list", "iterator"],
+    "regex": ["compare", "initializer_list"],
+    "set": ["compare", "initializer_list"],
+    "stack": ["compare", "initializer_list"],
+    "string": ["compare", "initializer_list"],
+    "string_view": ["compare"],
+    # TODO "syncstream": ["ostream"],
+    "system_error": ["compare"],
+    "tgmath.h": ["cmath", "complex"],
+    "thread": ["compare"],
+    "tuple": ["compare"],
+    "typeindex": ["compare"],
+    "unordered_map": ["compare", "initializer_list"],
+    "unordered_set": ["compare", "initializer_list"],
+    "utility": ["compare", "initializer_list"],
+    "valarray": ["initializer_list"],
+    "variant": ["compare"],
+    "vector": ["compare", "initializer_list"],
+}
+
+new_in_version = {
+    "chrono": "11",
+    "compare": "20",
+    "concepts": "20",
+    "coroutine": "20",
+    "filesystem": "17",
+    "initializer_list": "11",
+    "optional": "17",
+    "system_error": "11",
+    "thread": "11",
+    "tuple": "11",
+    "unordered_map": "11",
+    "unordered_set": "11",
+    "string_view": "17",
+    "ranges": "20",
+    "syncstream": "20",
+    "variant": "17",
+}
+
+assert all(v == sorted(v) for k, v in mandatory_inclusions.items())
+
+# Map from each header to the Lit annotations that should be used for
+# tests that include that header.
+#
+# For example, when threads are not supported, any test
+# that includes <thread> should be marked as UNSUPPORTED, because including
+# <thread> is a hard error in that case.
+lit_markup = {
+  "atomic": ["UNSUPPORTED: libcpp-has-no-threads"],
+  "barrier": ["UNSUPPORTED: libcpp-has-no-threads"],
+  "filesystem": ["UNSUPPORTED: libcpp-has-no-filesystem-library"],
+  "iomanip": ["UNSUPPORTED: libcpp-has-no-localization"],
+  "istream": ["UNSUPPORTED: libcpp-has-no-localization"],
+  "latch": ["UNSUPPORTED: libcpp-has-no-threads"],
+  "locale": ["UNSUPPORTED: libcpp-has-no-localization"],
+  "ostream": ["UNSUPPORTED: libcpp-has-no-localization"],
+  "regex": ["UNSUPPORTED: libcpp-has-no-localization"],
+  "semaphore": ["UNSUPPORTED: libcpp-has-no-threads"],
+  "shared_mutex": ["UNSUPPORTED: libcpp-has-no-threads"],
+  "thread": ["UNSUPPORTED: libcpp-has-no-threads"],
+}
+
+
+def get_std_ver_test(includee):
+    v = new_in_version.get(includee, "03")
+    if v == "03":
+        return ''
+    if v == "11":
+        return 'TEST_STD_VER >= 11 && '
+    modern_versions = ["11", "14", "17", "20"]
+    return 'TEST_STD_VER > {} && '.format(max(i for i in modern_versions if i < v))
+
+
+def get_unsupported_line(includee):
+    v = new_in_version.get(includee, "03")
+    return {
+        "03": [],
+        "11": ['UNSUPPORTED: c++03'],
+        "14": ['UNSUPPORTED: c++03, c++11'],
+        "17": ['UNSUPPORTED: c++03, c++11, c++14'],
+        "20": ['UNSUPPORTED: c++03, c++11, c++14, c++17'],
+        "2b": ['UNSUPPORTED: c++03, c++11, c++14, c++17, c++20'],
+    }[v]
+
+
+def get_libcpp_header_symbol(header_name):
+    return '_LIBCPP_' + header_name.upper().replace('.', '_')
+
+
+def get_includer_symbol_test(includer):
+    symbol = get_libcpp_header_symbol(includer)
+    return """
+#if !defined({symbol})
+ #   error "{message}"
+#endif
+    """.strip().format(
+        symbol=symbol,
+        message="<{}> was expected to define {}".format(includer, symbol),
+    )
+
+def get_ifdef(includer, includee):
+    version = max(new_in_version.get(h, "03") for h in [includer, includee])
+    symbol = get_libcpp_header_symbol(includee)
+    return """
+#if {includee_test}!defined({symbol})
+ #   error "{message}"
+#endif
+    """.strip().format(
+        includee_test=get_std_ver_test(includee),
+        symbol=symbol,
+        message="<{}> should include <{}> in C++{} and later".format(includer, includee, version)
+    )
+
+
+test_body_template = """
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// WARNING: This test was generated by {script_name}
+// and should not be edited manually.
+//
+// clang-format off
+{markup}
+// <{header}>
+
+// Test that <{header}> includes all the other headers it's supposed to.
+
+#include <{header}>
+#include "test_macros.h"
+
+{test_includers_symbol}
+{test_per_includee}
+
+int main(int, char**) {{ return 0; }}
+""".strip()
+
+
+def produce_tests():
+    for includer, includees in mandatory_inclusions.items():
+        markup_tags = get_unsupported_line(includer) + lit_markup.get(includer, [])
+        test_body = test_body_template.format(
+            script_name=script_name,
+            header=includer,
+            markup=('\n' + '\n'.join('// ' + m for m in markup_tags) + '\n') if markup_tags else '',
+            test_includers_symbol=get_includer_symbol_test(includer),
+            test_per_includee='\n'.join(get_ifdef(includer, includee) for includee in includees),
+        )
+        test_name = "{header}.inclusions.pass.cpp".format(header=includer)
+        out_path = os.path.join(test_path, test_name)
+        with open(out_path, 'w', newline='\n') as f:
+            f.write(test_body + '\n')
+
+
+if __name__ == '__main__':
+    produce_tests()
+