Backport fixes for libc++ std module generation

[iana]

Summary

The backport had a few simple merge conflicts, creating a PR to run it through CI.

[iana]

Update nasty_macros.gen.py's path to header_information

libcxx/docs/Contributing.rst

 - Did you update the synopsis of the relevant headers?
 - Did you update the relevant files to track implementation status (in ``docs/Status/``)?
 - Did you mark all functions and type declarations with the :ref:`proper visibility macro <visibility-macros>`?
 - Did you add all new named declarations to the ``std`` module?
 - If you added a header:
 
   - Did you add it to ``include/module.modulemap.in``?
   - Did you add it to ``include/CMakeLists.txt``?
-  - If it's a public header, did you update ``utils/libcxx/test/header_information.py``?
+  - If it's a public header, did you update ``utils/libcxx/header_information.py``?
 
 - Did you add the relevant feature test macro(s) for your feature? Did you update the ``generate_feature_test_macro_components.py`` script with it?
 - Did you run the ``libcxx-generate-files`` target and verify its output?
 
 The review process
 ==================
 
 After uploading your patch, you should see that the "libc++" review group is automatically

libcxx/include/__std_clang_module

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // 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 entire header is generated by
+// utils/generate_std_clang_module_header.py
+// DO NOT MODIFY!
+
 // This header should not be directly included, it's exclusively to import all
 // of the libc++ public clang modules for the `std` clang module to export. In
 // other words, it's to facilitate `@import std;` in Objective-C++ and `import std`
 // in Swift to expose all of the libc++ interfaces. This is generally not
 // recommended, however there are some clients that need to import all of libc++
 // without knowing what "all" is.
 #if !__building_module(std)
 #  error "Do not include this header directly, include individual headers instead"
 #endif
 
-#include <__availability>
 #include <__config>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 #include <algorithm>
 #include <any>
 #include <array>
-#include <atomic>
+#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
+#  include <atomic>
+#endif
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <barrier>
+#endif
 #include <bit>
 #include <bitset>
-#include <charconv>
-#include <chrono>
-#include <compare>
-#include <complex>
-#include <concepts>
-#include <condition_variable>
-#include <deque>
-#include <exception>
-#include <execution>
-#include <expected>
-#include <format>
-#include <forward_list>
-#include <functional>
-#include <initializer_list>
-#include <iosfwd>
-#include <iterator>
-#include <limits>
-#include <list>
-#include <map>
-#include <mdspan>
-#include <memory>
-#include <memory_resource>
-#include <new>
-#include <numbers>
-#include <numeric>
-#include <optional>
-#include <queue>
-#include <random>
-#include <ranges>
-#include <ratio>
-#include <scoped_allocator>
-#include <set>
-#include <source_location>
-#include <span>
-#include <stack>
-#include <stdexcept>
-#include <string>
-#include <string_view>
-#include <system_error>
-#include <tuple>
-#include <type_traits>
-#include <typeindex>
-#include <typeinfo>
-#include <unordered_map>
-#include <unordered_set>
-#include <utility>
-#include <valarray>
-#include <variant>
-#include <vector>
-#include <version>
-
 #include <cassert>
 #include <ccomplex>
 #include <cctype>
 #include <cerrno>
 #include <cfenv>
 #include <cfloat>
+#include <charconv>
+#include <chrono>
 #include <cinttypes>
 #include <ciso646>
 #include <climits>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <clocale>
+#endif
 #include <cmath>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <codecvt>
+#endif
+#include <compare>
+#include <complex.h>
+#include <complex>
+#include <concepts>
+#include <condition_variable>
+#include <coroutine>
 #include <csetjmp>
 #include <csignal>
 #include <cstdarg>
 #include <cstdbool>
 #include <cstddef>
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <ctgmath>
 #include <ctime>
-#include <cuchar>
-
-#include <complex.h>
 #include <ctype.h>
-#include <errno.h>
-#include <fenv.h>
-#include <float.h>
-#include <inttypes.h>
-#include <limits.h>
-#include <math.h>
-#include <setjmp.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <tgmath.h>
-#include <uchar.h>
-
-#ifndef _LIBCPP_HAS_NO_LOCALIZATION
-#  include <codecvt>
-#  ifndef _LIBCPP_HAS_NO_FILESYSTEM
-#    include <fstream>
-#  endif
-#  include <iomanip>
-#  include <ios>
-#  include <iostream>
-#  include <istream>
-#  include <locale>
-#  include <ostream>
-#  include <regex>
-#  include <sstream>
-#  include <streambuf>
-#  include <strstream>
-
-#  include <clocale>
-
-#  include <locale.h>
-#endif
-
-#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+#include <cuchar>
+#if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
 #  include <cwchar>
-#  include <cwctype>
-
-#  include <wchar.h>
-#  include <wctype.h>
 #endif
-
-#ifdef _LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT
-#  include <print>
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <future>
-#    include <mutex>
-#    include <thread>
-#  endif
-
-#  include <experimental/deque>
-#  include <experimental/forward_list>
-#  include <experimental/iterator>
-#  include <experimental/list>
-#  include <experimental/map>
-#  include <experimental/memory_resource>
-#  include <experimental/propagate_const>
-#  ifndef _LIBCPP_HAS_NO_LOCALIZATION
-#    include <experimental/regex>
-#  endif
-#  include <experimental/set>
-#  include <experimental/simd>
-#  include <experimental/string>
-#  include <experimental/type_traits>
-#  include <experimental/unordered_map>
-#  include <experimental/unordered_set>
-#  include <experimental/utility>
-#  include <experimental/vector>
+#if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#  include <cwctype>
+#endif
+#include <deque>
+#include <errno.h>
+#include <exception>
+#include <execution>
+#include <expected>
+#include <experimental/deque>
+#include <experimental/forward_list>
+#include <experimental/iterator>
+#include <experimental/list>
+#include <experimental/map>
+#include <experimental/memory_resource>
+#include <experimental/propagate_const>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <experimental/regex>
+#endif
+#include <experimental/set>
+#include <experimental/simd>
+#include <experimental/string>
+#include <experimental/type_traits>
+#include <experimental/unordered_map>
+#include <experimental/unordered_set>
+#include <experimental/utility>
+#include <experimental/vector>
+#include <fenv.h>
+#include <filesystem>
+#include <float.h>
+#include <format>
+#include <forward_list>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <fstream>
 #endif
-
-#if _LIBCPP_STD_VER >= 14
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <shared_mutex>
-#  endif
+#include <functional>
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <future>
+#endif
+#include <initializer_list>
+#include <inttypes.h>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <iomanip>
 #endif
-
-#if _LIBCPP_STD_VER >= 17
-#  ifndef _LIBCPP_HAS_NO_FILESYSTEM
-#    include <filesystem>
-#  endif
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <ios>
+#endif
+#include <iosfwd>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <iostream>
 #endif
-
-#if _LIBCPP_STD_VER >= 20
-#  include <coroutine>
-
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <barrier>
-#    include <latch>
-#    include <semaphore>
-#    include <stop_token>
-#  endif
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <istream>
+#endif
+#include <iterator>
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <latch>
+#endif
+#include <limits.h>
+#include <limits>
+#include <list>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <locale.h>
+#endif
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <locale>
+#endif
+#include <map>
+#include <math.h>
+#include <mdspan>
+#include <memory>
+#include <memory_resource>
+#include <mutex>
+#include <new>
+#include <numbers>
+#include <numeric>
+#include <optional>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <ostream>
+#endif
+#include <print>
+#include <queue>
+#include <random>
+#include <ranges>
+#include <ratio>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <regex>
+#endif
+#include <scoped_allocator>
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <semaphore>
+#endif
+#include <set>
+#include <setjmp.h>
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <shared_mutex>
+#endif
+#include <source_location>
+#include <span>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <sstream>
 #endif
-
-#if _LIBCPP_STD_VER >= 23
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <stdatomic.h>
-#  endif
+#include <stack>
+#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
+#  include <stdatomic.h>
+#endif
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdexcept>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <stop_token>
+#endif
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <streambuf>
+#endif
+#include <string.h>
+#include <string>
+#include <string_view>
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#  include <strstream>
+#endif
+#include <system_error>
+#include <tgmath.h>
+#if !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <thread>
+#endif
+#include <tuple>
+#include <type_traits>
+#include <typeindex>
+#include <typeinfo>
+#include <uchar.h>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <valarray>
+#include <variant>
+#include <vector>
+#include <version>
+#if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#  include <wchar.h>
+#endif
+#if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#  include <wctype.h>
 #endif

libcxx/include/module.modulemap.in

module std_array [system] {
   header "array"
   export *
 }
 module std_atomic [system] {
   header "atomic"
   export *
 }
 module std_barrier [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "barrier"
   export *
 }
 module std_bit [system] {
   header "bit"
   export *
 }
 module std_bitset [system] {
   header "bitset"
   export *
 }
 module std_charconv [system] {
   header "charconv"
   export *
 }
 module std_chrono [system] {
   header "chrono"
   export *
 }
 module std_codecvt [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "codecvt"
   export *
 }
 module std_compare [system] {
   header "compare"
   export *
 }
 module std_complex [system] {
module std_execution [system] {
   header "execution"
   export *
 }
 module std_expected [system] {
   header "expected"
   export *
 }
 module std_filesystem [system] {
-  @requires_LIBCXX_ENABLE_FILESYSTEM@
   header "filesystem"
   export *
 }
 module std_format [system] {
   header "format"
   export *
 }
 module std_forward_list [system] {
   header "forward_list"
   export *
 }
 module std_fstream [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
-  @requires_LIBCXX_ENABLE_FILESYSTEM@
   header "fstream"
   export *
 }
 module std_functional [system] {
   header "functional"
   export *
 }
 module std_future [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "future"
   export *
 }
 module std_initializer_list [system] {
   header "initializer_list"
   export *
 }
 module std_iomanip [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "iomanip"
   export *
 }
 module std_ios [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "ios"
   export *
 }
 module std_iosfwd [system] {
   header "iosfwd"
   export *
 }
 module std_iostream [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "iostream"
   export *
 }
 module std_istream [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "istream"
   export *
 }
 module std_iterator [system] {
   header "iterator"
   export *
 }
 module std_latch [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "latch"
   export *
 }
 module std_limits [system] {
   header "limits"
   export *
 }
 module std_list [system] {
   header "list"
   export *
 }
 module std_locale [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "locale"
   export *
 }
 module std_map [system] {
   header "map"
   export *
 }
 module std_mdspan [system] {
module std_numeric [system] {
   header "numeric"
   export *
 }
 module std_optional [system] {
   header "optional"
   export *
 }
 module std_ostream [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "ostream"
   export *
 }
 module std_print [system] {
   header "print"
   export *
 }
 module std_queue [system] {
   header "queue"
   export *
 }
 module std_random [system] {
   header "random"
   export *
 }
 module std_ranges [system] {
   header "ranges"
   export *
 }
 module std_ratio [system] {
   header "ratio"
   export *
 }
 module std_regex [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "regex"
   export *
 }
 module std_scoped_allocator [system] {
   header "scoped_allocator"
   export *
 }
 module std_semaphore [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "semaphore"
   export *
 }
 module std_set [system] {
   header "set"
   export *
 }
 module std_shared_mutex [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "shared_mutex"
   export std_version
 }
 module std_source_location [system] {
   header "source_location"
   export *
 }
 module std_span [system] {
   header "span"
   export std_private_ranges_enable_borrowed_range
   export std_version
   export std_private_span_span_fwd
 }
 module std_sstream [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "sstream"
   export *
 }
 module std_stack [system] {
   header "stack"
   export *
 }
 module std_stdexcept [system] {
   header "stdexcept"
   export *
 }
 module std_stop_token {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "stop_token"
   export *
 }
 module std_streambuf [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "streambuf"
   export *
 }
 module std_string [system] {
   header "string"
   export *
 }
 module std_string_view [system] {
   header "string_view"
   export *
 }
 module std_strstream [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "strstream"
   export *
 }
 module std_system_error [system] {
   header "system_error"
   export *
 }
 module std_thread [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
   header "thread"
   export *
 }
 module std_tuple [system] {
   header "tuple"
   export *
 }
 module std_type_traits [system] {
module std_ciso646 [system] {
   header "ciso646"
   export *
 }
 module std_climits [system] {
   header "climits"
   export *
 }
 module std_clocale [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "clocale"
   export *
 }
 module std_cmath [system] {
   header "cmath"
   export *
 }
 module std_csetjmp [system] {
module std_ctime [system] {
   header "ctime"
   export *
 }
 module std_cuchar [system] {
   header "cuchar"
   export *
 }
 module std_cwchar [system] {
-  @requires_LIBCXX_ENABLE_WIDE_CHARACTERS@
   header "cwchar"
   export *
 }
 module std_cwctype [system] {
-  @requires_LIBCXX_ENABLE_WIDE_CHARACTERS@
   header "cwctype"
   export *
 }
 
 // C standard library interfaces augmented/replaced in C++
 // <assert.h> provided by C library.
 module std_complex_h [system] {
   header "complex.h"
module std_inttypes_h [system] {
   export *
 }
 // <iso646.h> provided by compiler.
 module std_limits_h [system] {
   header "limits.h"
   export *
 }
 module std_locale_h [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "locale.h"
   export *
 }
 module std_math_h [system] {
   header "math.h"
   export *
 }
 module std_setjmp_h [system] {
   header "setjmp.h"
   export *
 }
 // <signal.h> provided by C library.
 // FIXME: <stdalign.h> is missing.
 // <stdarg.h> provided by compiler.
 module std_stdatomic_h [system] {
-  @requires_LIBCXX_ENABLE_THREADS@
-  requires cplusplus23
   header "stdatomic.h"
   export *
 }
 module std_stdbool_h [system] {
   // <stdbool.h>'s __bool_true_false_are_defined macro requires textual inclusion.
   textual header "stdbool.h"
   export *
 }
module std_tgmath_h [system] {
   export *
 }
 module std_uchar_h [system] {
   header "uchar.h"
   export *
 }
 // <time.h> provided by C library.
 module std_wchar_h [system] {
-  @requires_LIBCXX_ENABLE_WIDE_CHARACTERS@
   // <wchar.h>'s __need_* macros require textual inclusion.
   textual header "wchar.h"
   export *
 }
 module std_wctype_h [system] {
-  @requires_LIBCXX_ENABLE_WIDE_CHARACTERS@
   header "wctype.h"
   export *
 }
 
 // Experimental C++ standard library interfaces
 module std_experimental [system] {
-  requires cplusplus11
-
   module deque {
     header "experimental/deque"
     export *
   }
   module forward_list {
     header "experimental/forward_list"
     export *
   }
module std_private_config            [system] {
   textual header "__config"
   export *
 }
 module std_private_hash_table        [system] {
   header "__hash_table"
   export *
 }
 module std_private_locale            [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "__locale"
   export *
 }
 module std_private_mbstate_t         [system] {
   header "__mbstate_t.h"
   export *
 }
 module std_private_node_handle       [system] {

 module std_private_chrono_convert_to_tm          [system] { header "__chrono/convert_to_tm.h" }
 module std_private_chrono_day                    [system] { header "__chrono/day.h" }
 module std_private_chrono_duration               [system] {
   header "__chrono/duration.h"
   export std_private_type_traits_is_convertible
 }
 module std_private_chrono_file_clock             [system] { header "__chrono/file_clock.h" }
 module std_private_chrono_formatter              [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "__chrono/formatter.h"
 }
 module std_private_chrono_hh_mm_ss               [system] { header "__chrono/hh_mm_ss.h" }
 module std_private_chrono_high_resolution_clock  [system] {
   header "__chrono/high_resolution_clock.h"
   export std_private_chrono_steady_clock
   export std_private_chrono_system_clock
 }
 module std_private_chrono_literals               [system] { header "__chrono/literals.h" }
 module std_private_chrono_month                  [system] { header "__chrono/month.h" }
 module std_private_chrono_month_weekday          [system] { header "__chrono/month_weekday.h" }
 module std_private_chrono_monthday               [system] { header "__chrono/monthday.h" }
 module std_private_chrono_ostream                [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "__chrono/ostream.h"
 }
 module std_private_chrono_parser_std_format_spec [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "__chrono/parser_std_format_spec.h"
 }
 module std_private_chrono_statically_widen       [system] { header "__chrono/statically_widen.h" }
 module std_private_chrono_steady_clock           [system] {
   header "__chrono/steady_clock.h"
   export std_private_chrono_time_point
 }
 module std_private_chrono_system_clock           [system] {

 module std_private_ranges_enable_view                [system] { header "__ranges/enable_view.h" }
 module std_private_ranges_filter_view                [system] {
   header "__ranges/filter_view.h"
   export std_private_ranges_range_adaptor
 }
 module std_private_ranges_from_range                 [system] { header "__ranges/from_range.h" }
 module std_private_ranges_iota_view                  [system] { header "__ranges/iota_view.h" }
 module std_private_ranges_istream_view               [system] {
-  @requires_LIBCXX_ENABLE_LOCALIZATION@
   header "__ranges/istream_view.h"
 }
 module std_private_ranges_join_view                  [system] {
   header "__ranges/join_view.h"
   export std_private_iterator_iterator_with_data
   export std_private_iterator_segmented_iterator
 }
 module std_private_ranges_lazy_split_view            [system] {

libcxx/test/libcxx/assertions/headers_declare_verbose_abort.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Test that all public C++ headers define the verbose termination function, which
 # is required for users to be able to include any public header and then override
 # the function using a strong definition.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 for header in public_headers:
     # Skip C compatibility headers.
     if header.endswith('.h'):
         continue
 
     BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
     print(f"""\
 //--- {header}.compile.pass.cpp
 {lit_header_restrictions.get(header, '')}
 
 // XFAIL{BLOCKLIT}: availability-verbose_abort-missing
 
 #include <{header}>
 using HandlerType = decltype(std::__libcpp_verbose_abort);
 """)

libcxx/test/libcxx/clang_tidy.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Run our custom libc++ clang-tidy checks on all public headers.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 for header in public_headers:
   BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
   print(f"""\
 //--- {header}.sh.cpp
 
 // REQUIRES{BLOCKLIT}: has-clang-tidy
 

libcxx/test/libcxx/double_include.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Test that we can include each header in two TU's and link them together.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 for header in public_headers:
   BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
   print(f"""\
 //--- {header}.sh.cpp
 {lit_header_restrictions.get(header, '')}
 
 // RUN{BLOCKLIT}: %{{cxx}} -c %s -o %t.first.o %{{flags}} %{{compile_flags}}

libcxx/test/libcxx/header_inclusions.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Test that all headers include all the other headers they're supposed to, as
 # prescribed by the Standard.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers, mandatory_inclusions
+from libcxx.header_information import lit_header_restrictions, public_headers, mandatory_inclusions
 
 for header in public_headers:
   header_guard = lambda h: f"_LIBCPP_{h.upper().replace('.', '_').replace('/', '_')}"
 
   # <cassert> has no header guards
   if header == 'cassert':
     checks = ''
   else:

libcxx/test/libcxx/libcpp_version.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Test that all headers define the _LIBCPP_VERSION macro.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 for header in public_headers:
   print(f"""\
 //--- {header}.compile.pass.cpp
 {lit_header_restrictions.get(header, '')}
 
 #include <{header}>
 
 #ifndef _LIBCPP_VERSION
 # error <{header}> does not seem to define _LIBCPP_VERSION
 #endif
 """)

libcxx/test/libcxx/module_std.gen.py

 # to be one monolitic test. Since the test doesn't take very long it's
 # not a huge issue.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import toplevel_headers
+from libcxx.header_information import toplevel_headers
 
 BLOCKLIT = (
     ""  # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
 )
 
 ### Remove the headers that have no module associated with them
 
 # Note all C-headers using .h are filtered in the loop.

libcxx/test/libcxx/modules_include.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Test that we can include each header in a TU while using modules.
 # This is important notably because the LLDB data formatters use
 # libc++ headers with modules enabled.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
-for header in public_headers:
-  BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
+
+for header in public_headers:
   print(f"""\
 //--- {header}.compile.pass.cpp
 // RUN{BLOCKLIT}: %{{cxx}} %s %{{flags}} %{{compile_flags}} -fmodules -fcxx-modules -fmodules-cache-path=%t -fsyntax-only
 
 // UNSUPPORTED{BLOCKLIT}: use_module_std
 
 // GCC doesn't support -fcxx-modules
 // UNSUPPORTED{BLOCKLIT}: gcc

 // TODO: Investigate this failure
 // UNSUPPORTED{BLOCKLIT}: LIBCXX-FREEBSD-FIXME
 
 {lit_header_restrictions.get(header, '')}
 
 #include <{header}>
 """)
 
-print(f"""
+print(f"""\
 //--- __std_clang_module.compile.pass.mm
 // RUN{BLOCKLIT}: %{{cxx}} %s %{{flags}} %{{compile_flags}} -fmodules -fcxx-modules -fmodules-cache-path=%t -fsyntax-only
 
 // REQUIRES{BLOCKLIT}: modules-build
 // UNSUPPORTED{BLOCKLIT}: use_module_std
 
 // GCC doesn't support -fcxx-modules
 // UNSUPPORTED{BLOCKLIT}: gcc
 
 // The Windows headers don't appear to be compatible with modules
 // UNSUPPORTED{BLOCKLIT}: windows
 // UNSUPPORTED{BLOCKLIT}: buildhost=windows
 
 // The AIX headers don't appear to be compatible with modules
 // UNSUPPORTED{BLOCKLIT}: LIBCXX-AIX-FIXME
 
 // The Android headers don't appear to be compatible with modules yet
 // XFAIL{BLOCKLIT}: LIBCXX-ANDROID-FIXME
 
 // TODO: Investigate this failure
 // UNSUPPORTED{BLOCKLIT}: LIBCXX-FREEBSD-FIXME
 
-// Lit seems to compile this twice: once with the default flags and once with with
-// the flags specified in the RUN directive. Guard the first compile from failing.
-#if __has_feature(modules)
 @import std;
-#endif
 
 """)

libcxx/test/libcxx/nasty_macros.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Test that headers are not tripped up by the surrounding code defining various
 # alphabetic macros.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 for header in public_headers:
   print(f"""\
 //--- {header}.compile.pass.cpp
 {lit_header_restrictions.get(header, '')}
 
 #define NASTY_MACRO This should not be expanded!!!
 

libcxx/test/libcxx/no_assert_include.gen.py

 #===----------------------------------------------------------------------===##
 #
 # 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
 #
 #===----------------------------------------------------------------------===##
 
 # Ensure that none of the standard C++ headers implicitly include cassert or
 # assert.h (because assert() is implemented as a macro).
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 for header in public_headers:
   if header == 'cassert':
     continue
 
   print(f"""\
 //--- {header}.compile.pass.cpp
 {lit_header_restrictions.get(header, '')}
 
 #include <{header}>
 
 #ifdef assert
 # error "Do not include cassert or assert.h in standard header files"
 #endif
 """)

libcxx/test/libcxx/transitive_includes.gen.py

 # This is not meant to block libc++ from removing unused transitive includes
 # forever, however we do try to group removals for a couple of releases
 # to avoid breaking users at every release.
 
 # RUN: %{python} %s %{libcxx}/utils
 
 import sys
 sys.path.append(sys.argv[1])
-from libcxx.test.header_information import lit_header_restrictions, public_headers
+from libcxx.header_information import lit_header_restrictions, public_headers
 
 import re
 
 # To re-generate the list of expected headers, temporarily set this to True, and run this test.
 # Note that this needs to be done for all supported language versions of libc++:
 # for std in c++03 c++11 c++14 c++17 c++20 c++23 c++26; do <build>/bin/llvm-lit --param std=$std ${path_to_this_file}; done
 regenerate_expected_results = False
 

libcxx/utils/CMakeLists.txt

 add_custom_target(libcxx-generate-feature-test-macros
     COMMAND "${Python3_EXECUTABLE}" "${LIBCXX_SOURCE_DIR}/utils/generate_feature_test_macro_components.py"
     COMMENT "Generate the <version> header and tests for feature test macros.")
 
+add_custom_target(libcxx-generate-std-clang-module-header
+  COMMAND "${Python3_EXECUTABLE}" "${CMAKE_CURRENT_SOURCE_DIR}/generate_std_clang_module_header.py"
+  COMMENT "Generate the <__std_clang_module> header")
+
 add_custom_target(libcxx-generate-extended-grapheme-cluster-tables
     COMMAND
         "${Python3_EXECUTABLE}"
         "${LIBCXX_SOURCE_DIR}/utils/generate_extended_grapheme_cluster_table.py"
         "${LIBCXX_SOURCE_DIR}/include/__format/extended_grapheme_cluster_table.h"
     COMMENT "Generate the extended grapheme cluster header.")
 
 add_custom_target(libcxx-generate-extended-grapheme-cluster-tests

 add_custom_target(libcxx-generate-iwyu-mapping
     COMMAND
         "${Python3_EXECUTABLE}"
         "${LIBCXX_SOURCE_DIR}/utils/generate_iwyu_mapping.py"
     COMMENT "Generate the mapping file for include-what-you-use")
 
 add_custom_target(libcxx-generate-files
     DEPENDS libcxx-generate-feature-test-macros
+            libcxx-generate-std-clang-module-header
             libcxx-generate-extended-grapheme-cluster-tables
             libcxx-generate-extended-grapheme-cluster-tests
             libcxx-generate-escaped-output-table
             libcxx-generate-width-estimation-table
             libcxx-generate-iwyu-mapping
     COMMENT "Create all the auto-generated files in libc++ and its tests.")

libcxx/utils/generate_std_clang_module_header.py

+# ===----------------------------------------------------------------------===##
+#
+# 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
+#
+# ===----------------------------------------------------------------------===##
+
+import operator
+import os.path
+
+import libcxx.header_information
+
+header_restrictions = libcxx.header_information.header_restrictions
+
+libcxx_include_directory = os.path.join(
+    os.path.dirname(os.path.dirname(os.path.realpath(__file__))), "include"
+)
+with open(
+    os.path.join(libcxx_include_directory, "__std_clang_module"), "w"
+) as std_clang_module_header:
+    std_clang_module_header.write(
+        """\
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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 entire header is generated by
+// utils/generate_std_clang_module_header.py
+// DO NOT MODIFY!
+
+// This header should not be directly included, it's exclusively to import all
+// of the libc++ public clang modules for the `std` clang module to export. In
+// other words, it's to facilitate `@import std;` in Objective-C++ and `import std`
+// in Swift to expose all of the libc++ interfaces. This is generally not
+// recommended, however there are some clients that need to import all of libc++
+// without knowing what "all" is.
+#if !__building_module(std)
+#  error "Do not include this header directly, include individual headers instead"
+#endif
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+"""
+    )
+    # Include the angle brackets in sorting so that <a.h> sorts before <a>
+    # like check-format wants.
+    for include, header in sorted([(f"<{header}>", header) for header in libcxx.header_information.public_headers]):
+        header_restriction = header_restrictions.get(header)
+        if header_restriction:
+            std_clang_module_header.write(f"#if {header_restriction}\n")
+            std_clang_module_header.write(f"#  include {include}\n")
+            std_clang_module_header.write(f"#endif\n")
+        else:
+            std_clang_module_header.write(f"#include {include}\n")

libcxx/utils/libcxx/header_information.py

 # ===----------------------------------------------------------------------===##
 #
 # 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
 #
 # ===----------------------------------------------------------------------===##
 
 import os, pathlib
 
+header_restrictions = {
+    # headers with #error directives
+    "atomic": "!defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)",
+    "stdatomic.h": "!defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)",
+
+    # headers with #error directives
+    "ios": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "locale.h": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    # transitive includers of the above headers
+    "clocale": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "codecvt": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "experimental/regex": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "fstream": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "iomanip": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "iostream": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "istream": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "locale": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "ostream": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "regex": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "sstream": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "streambuf": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+    "strstream": "!defined(_LIBCPP_HAS_NO_LOCALIZATION)",
+
+    # headers with #error directives
+    "barrier": "!defined(_LIBCPP_HAS_NO_THREADS)",
+    "future": "!defined(_LIBCPP_HAS_NO_THREADS)",
+    "latch": "!defined(_LIBCPP_HAS_NO_THREADS)",
+    "semaphore": "!defined(_LIBCPP_HAS_NO_THREADS)",
+    "shared_mutex": "!defined(_LIBCPP_HAS_NO_THREADS)",
+    "stop_token": "!defined(_LIBCPP_HAS_NO_THREADS)",
+    "thread": "!defined(_LIBCPP_HAS_NO_THREADS)",
+
+    # headers with #error directives
+    "wchar.h": "!defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)",
+    "wctype.h": "!defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)",
+    # transitive includers of the above headers
+    "cwchar": "!defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)",
+    "cwctype": "!defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)",
+}
+
 lit_header_restrictions = {
     "barrier": "// UNSUPPORTED: no-threads, c++03, c++11, c++14, c++17",
     "clocale": "// UNSUPPORTED: no-localization",
     "codecvt": "// UNSUPPORTED: no-localization",
     "coroutine": "// UNSUPPORTED: c++03, c++11, c++14, c++17",
     "cwchar": "// UNSUPPORTED: no-wide-characters",
     "cwctype": "// UNSUPPORTED: no-wide-characters",
     "experimental/algorithm": "// UNSUPPORTED: c++03",
def is_header(file):
     """Returns whether the given file is a header (i.e. not a directory or the modulemap file)."""
     return (
         not file.is_dir()
         and not file.name == "module.modulemap.in"
         and not file.name == "CMakeLists.txt"
         and file.name != "libcxx.imp"
     )
 
-libcxx_root = pathlib.Path(os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))))
+libcxx_root = pathlib.Path(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
 include = pathlib.Path(os.path.join(libcxx_root, "include"))
 test = pathlib.Path(os.path.join(libcxx_root, "test"))
 assert libcxx_root.exists()
 
 toplevel_headers = sorted(
     p.relative_to(include).as_posix() for p in include.glob("[a-z]*") if is_header(p)
 )
 experimental_headers = sorted(