diff --git a/libcxx/docs/Contributing.rst b/libcxx/docs/Contributing.rst
--- a/libcxx/docs/Contributing.rst
+++ b/libcxx/docs/Contributing.rst
@@ -49,7 +49,7 @@
 
   - 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?
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -674,7 +674,6 @@
   __ranges/views.h
   __ranges/zip_view.h
   __split_buffer
-  __std_clang_module
   __std_mbstate_t.h
   __stop_token/atomic_unique_lock.h
   __stop_token/intrusive_list_view.h
@@ -1053,6 +1052,17 @@
   list(APPEND _all_includes "${dst}")
 endforeach()
 
+add_custom_command(
+  OUTPUT "${LIBCXX_GENERATED_INCLUDE_DIR}/__std_clang_module"
+         # Run this command on every build in case a public header was added or removed.
+         "${LIBCXX_GENERATED_INCLUDE_DIR}/__std_clang_module_run_every_build"
+  COMMAND "${Python3_EXECUTABLE}" "${CMAKE_CURRENT_SOURCE_DIR}/generate_std_clang_module_header.py"
+          --libcxx-python-module "${CMAKE_CURRENT_SOURCE_DIR}/../utils"
+          --libcxx-include-directory "${LIBCXX_GENERATED_INCLUDE_DIR}"
+  COMMENT "Generating CXX header __std_clang_module")
+list(APPEND _all_includes "${LIBCXX_GENERATED_INCLUDE_DIR}/__std_clang_module"
+                          "${LIBCXX_GENERATED_INCLUDE_DIR}/__std_clang_module_run_every_build")
+
 add_custom_target(generate-cxx-headers ALL DEPENDS ${_all_includes})
 
 add_library(cxx-headers INTERFACE)
diff --git a/libcxx/include/__std_clang_module b/libcxx/include/__std_clang_module
deleted file mode 100644
--- a/libcxx/include/__std_clang_module
+++ /dev/null
@@ -1,212 +0,0 @@
-// -*- 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
-//
-//===----------------------------------------------------------------------===//
-
-// 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>
-#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 <cinttypes>
-#include <ciso646>
-#include <climits>
-#include <cmath>
-#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 <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>
-#endif
-
-#if _LIBCPP_STD_VER >= 14
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <shared_mutex>
-#  endif
-#endif
-
-#if _LIBCPP_STD_VER >= 17
-#  ifndef _LIBCPP_HAS_NO_FILESYSTEM
-#    include <filesystem>
-#  endif
-#endif
-
-#if _LIBCPP_STD_VER >= 20
-#  include <coroutine>
-
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <barrier>
-#    include <latch>
-#    include <semaphore>
-#    include <stop_token>
-#  endif
-#endif
-
-#if _LIBCPP_STD_VER >= 23
-#  ifndef _LIBCPP_HAS_NO_THREADS
-#    include <stdatomic.h>
-#  endif
-#endif
diff --git a/libcxx/include/generate_std_clang_module_header.py b/libcxx/include/generate_std_clang_module_header.py
new file mode 100644
--- /dev/null
+++ b/libcxx/include/generate_std_clang_module_header.py
@@ -0,0 +1,72 @@
+import argparse
+import operator
+import os.path
+import sys
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--libcxx-python-module', required=True)
+parser.add_argument('--libcxx-include-directory', required=True)
+args = parser.parse_args()
+
+sys.path.append(args.libcxx_python_module)
+
+import libcxx.header_information
+
+public_headers = libcxx.header_information.public_headers
+header_include_requirements = libcxx.header_information.header_include_requirements
+always_available_headers = frozenset(public_headers).difference(*header_include_requirements.values())
+
+with open(os.path.join(args.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
+//
+//===----------------------------------------------------------------------===//
+
+// 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
+
+''')
+    for header in sorted(always_available_headers):
+        std_clang_module_header.write('#include <')
+        std_clang_module_header.write(header)
+        std_clang_module_header.write('>\n')
+    std_clang_module_header.write('\n')
+
+    for requirements, headers in sorted(header_include_requirements.items(), key=operator.itemgetter(0)):
+        if len(requirements) == 1:
+            std_clang_module_header.write('#ifndef ')
+            std_clang_module_header.write(requirements[0])
+        else:
+            std_clang_module_header.write('#if')
+            for index, requirement in enumerate(requirements):
+                if index > 0:
+                    std_clang_module_header.write(' &&')
+                std_clang_module_header.write(' !defined(')
+                std_clang_module_header.write(requirement)
+                std_clang_module_header.write(')')
+        std_clang_module_header.write('\n')
+
+        for header in sorted(headers):
+            std_clang_module_header.write('#  include <')
+            std_clang_module_header.write(header)
+            std_clang_module_header.write('>\n')
+        
+        std_clang_module_header.write('#endif\n\n')
diff --git a/libcxx/test/libcxx/assertions/headers_declare_verbose_abort.gen.py b/libcxx/test/libcxx/assertions/headers_declare_verbose_abort.gen.py
--- a/libcxx/test/libcxx/assertions/headers_declare_verbose_abort.gen.py
+++ b/libcxx/test/libcxx/assertions/headers_declare_verbose_abort.gen.py
@@ -14,7 +14,7 @@
 
 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.
diff --git a/libcxx/test/libcxx/clang_tidy.gen.py b/libcxx/test/libcxx/clang_tidy.gen.py
--- a/libcxx/test/libcxx/clang_tidy.gen.py
+++ b/libcxx/test/libcxx/clang_tidy.gen.py
@@ -12,7 +12,7 @@
 
 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
diff --git a/libcxx/test/libcxx/double_include.gen.py b/libcxx/test/libcxx/double_include.gen.py
--- a/libcxx/test/libcxx/double_include.gen.py
+++ b/libcxx/test/libcxx/double_include.gen.py
@@ -12,7 +12,7 @@
 
 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
diff --git a/libcxx/test/libcxx/header_inclusions.gen.py b/libcxx/test/libcxx/header_inclusions.gen.py
--- a/libcxx/test/libcxx/header_inclusions.gen.py
+++ b/libcxx/test/libcxx/header_inclusions.gen.py
@@ -13,7 +13,7 @@
 
 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('/', '_')}"
diff --git a/libcxx/test/libcxx/libcpp_version.gen.py b/libcxx/test/libcxx/libcpp_version.gen.py
--- a/libcxx/test/libcxx/libcpp_version.gen.py
+++ b/libcxx/test/libcxx/libcpp_version.gen.py
@@ -12,7 +12,7 @@
 
 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"""\
diff --git a/libcxx/test/libcxx/lint/lint_headers.sh.py b/libcxx/test/libcxx/lint/lint_headers.sh.py
--- a/libcxx/test/libcxx/lint/lint_headers.sh.py
+++ b/libcxx/test/libcxx/lint/lint_headers.sh.py
@@ -10,7 +10,8 @@
 
 def exclude_from_consideration(path):
     return (
-        path.endswith(".txt")
+        path.endswith(".py")
+        or path.endswith(".txt")
         or path.endswith(".modulemap.in")
         or os.path.basename(path) == "__config"
         or os.path.basename(path) == "__config_site.in"
diff --git a/libcxx/test/libcxx/module_std.gen.py b/libcxx/test/libcxx/module_std.gen.py
--- a/libcxx/test/libcxx/module_std.gen.py
+++ b/libcxx/test/libcxx/module_std.gen.py
@@ -21,7 +21,7 @@
 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
diff --git a/libcxx/test/libcxx/modules_include.gen.py b/libcxx/test/libcxx/modules_include.gen.py
--- a/libcxx/test/libcxx/modules_include.gen.py
+++ b/libcxx/test/libcxx/modules_include.gen.py
@@ -14,10 +14,11 @@
 
 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
+
+BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
 
 for header in public_headers:
-  BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
   print(f"""\
 //--- {header}.compile.pass.cpp
 // RUN{BLOCKLIT}: %{{cxx}} %s %{{flags}} %{{compile_flags}} -fmodules -fcxx-modules -fmodules-cache-path=%t -fsyntax-only
@@ -45,7 +46,7 @@
 #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
 
@@ -68,10 +69,6 @@
 // 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
 
 """)
diff --git a/libcxx/test/libcxx/no_assert_include.gen.py b/libcxx/test/libcxx/no_assert_include.gen.py
--- a/libcxx/test/libcxx/no_assert_include.gen.py
+++ b/libcxx/test/libcxx/no_assert_include.gen.py
@@ -13,7 +13,7 @@
 
 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':
diff --git a/libcxx/test/libcxx/system_reserved_names.gen.py b/libcxx/test/libcxx/system_reserved_names.gen.py
--- a/libcxx/test/libcxx/system_reserved_names.gen.py
+++ b/libcxx/test/libcxx/system_reserved_names.gen.py
@@ -13,7 +13,7 @@
 
 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"""\
diff --git a/libcxx/test/libcxx/transitive_includes.gen.py b/libcxx/test/libcxx/transitive_includes.gen.py
--- a/libcxx/test/libcxx/transitive_includes.gen.py
+++ b/libcxx/test/libcxx/transitive_includes.gen.py
@@ -20,7 +20,7 @@
 
 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
 
diff --git a/libcxx/utils/libcxx/test/header_information.py b/libcxx/utils/libcxx/header_information.py
rename from libcxx/utils/libcxx/test/header_information.py
rename to libcxx/utils/libcxx/header_information.py
--- a/libcxx/utils/libcxx/test/header_information.py
+++ b/libcxx/utils/libcxx/header_information.py
@@ -15,10 +15,8 @@
     "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",
     "experimental/deque": "// UNSUPPORTED: c++03",
     "experimental/forward_list": "// UNSUPPORTED: c++03",
-    "experimental/functional": "// UNSUPPORTED: c++03",
     "experimental/iterator": "// UNSUPPORTED: c++03",
     "experimental/list": "// UNSUPPORTED: c++03",
     "experimental/map": "// UNSUPPORTED: c++03",
@@ -59,16 +57,23 @@
     "wctype.h": "// UNSUPPORTED: no-wide-characters",
 }
 
-private_headers_still_public_in_modules = [
-    "__assert",
-    "__config",
-    "__config_site.in",
-    "__hash_table",
-    "__threading_support",
-    "__tree",
-    "__undef_macros",
-    "__verbose_abort",
-]
+header_include_requirements = {
+    # headers with #error directives
+    ("_LIBCPP_HAS_NO_ATOMIC_HEADER",): ("atomic",
+    # transitive includers of the above headers
+                                        "stdatomic.h"),
+    # headers with #error directives
+    ("_LIBCPP_HAS_NO_LOCALIZATION",): ("ios", "locale.h",
+    # transitive includers of the above headers
+                                       "clocale", "codecvt", "experimental/regex", "fstream", "iomanip", "iostream", "istream",
+                                       "locale", "ostream", "regex", "sstream", "streambuf", "strstream"),
+    # headers with #error directives
+    ("_LIBCPP_HAS_NO_THREADS",): ("barrier", "future", "latch", "semaphore", "shared_mutex", "stop_token", "thread"),
+    # headers with #error directives
+    ("_LIBCPP_HAS_NO_WIDE_CHARACTERS",): ("wchar.h", "wctype.h",
+    # transitive includers of the above headers
+                                          "cwchar", "cwctype")
+}
 
 # Headers that can't be included on their own. Most of these are conceptually
 # part of another header that were split out just for organization, but aren't
@@ -133,10 +138,11 @@
         not file.is_dir()
         and not file.name == "module.modulemap.in"
         and not file.name == "CMakeLists.txt"
+        and not file.name == "generate_std_clang_module_header.py"
         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()