diff --git a/libcxx/include/__filesystem/u8path.h b/libcxx/include/__filesystem/u8path.h
--- a/libcxx/include/__filesystem/u8path.h
+++ b/libcxx/include/__filesystem/u8path.h
@@ -10,11 +10,19 @@
 #ifndef _LIBCPP___FILESYSTEM_U8PATH_H
 #define _LIBCPP___FILESYSTEM_U8PATH_H
 
+#include <__algorithm/unwrap_iter.h>
 #include <__availability>
 #include <__config>
 #include <__filesystem/path.h>
+#include <string>
 #include <type_traits>
 
+// Only required on Windows for __widen_from_utf8, and included conservatively
+// because it requires support for localization.
+#if defined(_LIBCPP_WIN32API)
+# include <locale>
+#endif
+
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
diff --git a/libcxx/include/barrier b/libcxx/include/barrier
--- a/libcxx/include/barrier
+++ b/libcxx/include/barrier
@@ -50,6 +50,7 @@
 #include <__config>
 #include <__thread/timed_backoff_policy.h>
 #include <atomic>
+#include <limits>
 #ifndef _LIBCPP_HAS_NO_TREE_BARRIER
 # include <memory>
 #endif
diff --git a/libcxx/include/latch b/libcxx/include/latch
--- a/libcxx/include/latch
+++ b/libcxx/include/latch
@@ -44,6 +44,7 @@
 #include <__availability>
 #include <__config>
 #include <atomic>
+#include <limits>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -3,7 +3,6 @@
 // include cycle.
 module std_config [system] [extern_c] {
   header "__config"
-  header "__config_site"
   export *
 }
 
@@ -370,7 +369,6 @@
     export *
   }
   module barrier {
-    requires cplusplus14
     header "barrier"
     export *
   }
@@ -698,7 +696,6 @@
     }
   }
   module latch {
-    requires cplusplus14
     header "latch"
     export *
   }
@@ -906,7 +903,6 @@
     export *
   }
   module semaphore {
-    requires cplusplus14
     header "semaphore"
     export *
   }
diff --git a/libcxx/include/semaphore b/libcxx/include/semaphore
--- a/libcxx/include/semaphore
+++ b/libcxx/include/semaphore
@@ -52,6 +52,7 @@
 #include <__thread/timed_backoff_policy.h>
 #include <__threading_support>
 #include <atomic>
+#include <limits>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
diff --git a/libcxx/include/span b/libcxx/include/span
--- a/libcxx/include/span
+++ b/libcxx/include/span
@@ -138,6 +138,7 @@
 #include <__ranges/enable_borrowed_range.h>
 #include <__ranges/enable_view.h>
 #include <__ranges/size.h>
+#include <__utility/forward.h>
 #include <array>        // for array
 #include <cstddef>      // for byte
 #include <iterator>     // for iterators
diff --git a/libcxx/test/libcxx/assertions/headers_declare_assertion_handler.sh.cpp b/libcxx/test/libcxx/assertions/headers_declare_assertion_handler.sh.cpp
--- a/libcxx/test/libcxx/assertions/headers_declare_assertion_handler.sh.cpp
+++ b/libcxx/test/libcxx/assertions/headers_declare_assertion_handler.sh.cpp
@@ -641,13 +641,13 @@
 #endif
 
 // RUN: %{build} -DTEST_119
-#if defined(TEST_119)
+#if defined(TEST_119) && __cplusplus >= 201103L
 #   include <experimental/algorithm>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
 
 // RUN: %{build} -DTEST_120
-#if defined(TEST_120) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if defined(TEST_120) && __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
@@ -665,13 +665,13 @@
 #endif
 
 // RUN: %{build} -DTEST_123
-#if defined(TEST_123)
+#if defined(TEST_123) && __cplusplus >= 201103L
 #   include <experimental/functional>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
 
 // RUN: %{build} -DTEST_124
-#if defined(TEST_124)
+#if defined(TEST_124) && __cplusplus >= 201103L
 #   include <experimental/iterator>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
@@ -695,7 +695,7 @@
 #endif
 
 // RUN: %{build} -DTEST_128
-#if defined(TEST_128)
+#if defined(TEST_128) && __cplusplus >= 201103L
 #   include <experimental/propagate_const>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
@@ -713,7 +713,7 @@
 #endif
 
 // RUN: %{build} -DTEST_131
-#if defined(TEST_131)
+#if defined(TEST_131) && __cplusplus >= 201103L
 #   include <experimental/simd>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
@@ -725,7 +725,7 @@
 #endif
 
 // RUN: %{build} -DTEST_133
-#if defined(TEST_133)
+#if defined(TEST_133) && __cplusplus >= 201103L
 #   include <experimental/type_traits>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
@@ -743,7 +743,7 @@
 #endif
 
 // RUN: %{build} -DTEST_136
-#if defined(TEST_136)
+#if defined(TEST_136) && __cplusplus >= 201103L
 #   include <experimental/utility>
     using HandlerType = decltype(std::__libcpp_assertion_handler);
 #endif
diff --git a/libcxx/test/libcxx/clang_tidy.sh.cpp b/libcxx/test/libcxx/clang_tidy.sh.cpp
--- a/libcxx/test/libcxx/clang_tidy.sh.cpp
+++ b/libcxx/test/libcxx/clang_tidy.sh.cpp
@@ -207,8 +207,10 @@
 #if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
 #   include <wctype.h>
 #endif
-#include <experimental/algorithm>
-#if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 201103L
+#   include <experimental/algorithm>
+#endif
+#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L
@@ -217,8 +219,12 @@
 #if __cplusplus >= 201103L
 #   include <experimental/forward_list>
 #endif
-#include <experimental/functional>
-#include <experimental/iterator>
+#if __cplusplus >= 201103L
+#   include <experimental/functional>
+#endif
+#if __cplusplus >= 201103L
+#   include <experimental/iterator>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/list>
 #endif
@@ -228,25 +234,33 @@
 #if __cplusplus >= 201103L
 #   include <experimental/memory_resource>
 #endif
-#include <experimental/propagate_const>
+#if __cplusplus >= 201103L
+#   include <experimental/propagate_const>
+#endif
 #if !defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L
 #   include <experimental/regex>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/set>
 #endif
-#include <experimental/simd>
+#if __cplusplus >= 201103L
+#   include <experimental/simd>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/string>
 #endif
-#include <experimental/type_traits>
+#if __cplusplus >= 201103L
+#   include <experimental/type_traits>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_map>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_set>
 #endif
-#include <experimental/utility>
+#if __cplusplus >= 201103L
+#   include <experimental/utility>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/vector>
 #endif
diff --git a/libcxx/test/libcxx/double_include.sh.cpp b/libcxx/test/libcxx/double_include.sh.cpp
--- a/libcxx/test/libcxx/double_include.sh.cpp
+++ b/libcxx/test/libcxx/double_include.sh.cpp
@@ -210,8 +210,10 @@
 #if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
 #   include <wctype.h>
 #endif
-#include <experimental/algorithm>
-#if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 201103L
+#   include <experimental/algorithm>
+#endif
+#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L
@@ -220,8 +222,12 @@
 #if __cplusplus >= 201103L
 #   include <experimental/forward_list>
 #endif
-#include <experimental/functional>
-#include <experimental/iterator>
+#if __cplusplus >= 201103L
+#   include <experimental/functional>
+#endif
+#if __cplusplus >= 201103L
+#   include <experimental/iterator>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/list>
 #endif
@@ -231,25 +237,33 @@
 #if __cplusplus >= 201103L
 #   include <experimental/memory_resource>
 #endif
-#include <experimental/propagate_const>
+#if __cplusplus >= 201103L
+#   include <experimental/propagate_const>
+#endif
 #if !defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L
 #   include <experimental/regex>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/set>
 #endif
-#include <experimental/simd>
+#if __cplusplus >= 201103L
+#   include <experimental/simd>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/string>
 #endif
-#include <experimental/type_traits>
+#if __cplusplus >= 201103L
+#   include <experimental/type_traits>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_map>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_set>
 #endif
-#include <experimental/utility>
+#if __cplusplus >= 201103L
+#   include <experimental/utility>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/vector>
 #endif
diff --git a/libcxx/test/libcxx/min_max_macros.compile.pass.cpp b/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
--- a/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
+++ b/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
@@ -329,9 +329,11 @@
 #   include <wctype.h>
 TEST_MACROS();
 #endif
-#include <experimental/algorithm>
+#if __cplusplus >= 201103L
+#   include <experimental/algorithm>
 TEST_MACROS();
-#if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#endif
+#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 TEST_MACROS();
 #endif
@@ -343,10 +345,14 @@
 #   include <experimental/forward_list>
 TEST_MACROS();
 #endif
-#include <experimental/functional>
+#if __cplusplus >= 201103L
+#   include <experimental/functional>
 TEST_MACROS();
-#include <experimental/iterator>
+#endif
+#if __cplusplus >= 201103L
+#   include <experimental/iterator>
 TEST_MACROS();
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/list>
 TEST_MACROS();
@@ -359,8 +365,10 @@
 #   include <experimental/memory_resource>
 TEST_MACROS();
 #endif
-#include <experimental/propagate_const>
+#if __cplusplus >= 201103L
+#   include <experimental/propagate_const>
 TEST_MACROS();
+#endif
 #if !defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L
 #   include <experimental/regex>
 TEST_MACROS();
@@ -369,14 +377,18 @@
 #   include <experimental/set>
 TEST_MACROS();
 #endif
-#include <experimental/simd>
+#if __cplusplus >= 201103L
+#   include <experimental/simd>
 TEST_MACROS();
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/string>
 TEST_MACROS();
 #endif
-#include <experimental/type_traits>
+#if __cplusplus >= 201103L
+#   include <experimental/type_traits>
 TEST_MACROS();
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_map>
 TEST_MACROS();
@@ -385,8 +397,10 @@
 #   include <experimental/unordered_set>
 TEST_MACROS();
 #endif
-#include <experimental/utility>
+#if __cplusplus >= 201103L
+#   include <experimental/utility>
 TEST_MACROS();
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/vector>
 TEST_MACROS();
diff --git a/libcxx/test/libcxx/modules_include.sh.cpp b/libcxx/test/libcxx/modules_include.sh.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/libcxx/modules_include.sh.cpp
@@ -0,0 +1,610 @@
+//===----------------------------------------------------------------------===//
+//
+// 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.
+
+// The system-provided <uchar.h> seems to be broken on AIX
+// XFAIL: LIBCXX-AIX-FIXME
+
+// GCC doesn't support -fcxx-modules
+// UNSUPPORTED: gcc
+
+// The Windows headers don't appear to be compatible with modules
+// UNSUPPORTED: windows
+
+// TODO: Some headers produce errors when we include them and the library has been
+//       configured without support for them, which breaks the modules build.
+// UNSUPPORTED: libcpp-has-no-localization, libcpp-has-no-filesystem-library, libcpp-has-no-threads, libcpp-has-no-wide-characters
+
+// Prevent <ext/hash_map> from generating deprecated warnings for this test.
+#if defined(__DEPRECATED)
+#    undef __DEPRECATED
+#endif
+
+#include <__config>
+
+/*
+BEGIN-SCRIPT
+
+for i, header in enumerate(public_headers):
+  print("// {}: %{{cxx}} %s %{{flags}} %{{compile_flags}} -fmodules -fcxx-modules -fsyntax-only -DTEST_{}".format('RUN', i))
+  if header in header_restrictions:
+    print("#if defined(TEST_{}) && {}".format(i, header_restrictions[header]))
+  else:
+    print("#if defined(TEST_{})".format(i))
+  print("#include <{}>".format(header))
+  print("#endif")
+
+END-SCRIPT
+*/
+
+// DO NOT MANUALLY EDIT ANYTHING BETWEEN THE MARKERS BELOW
+// GENERATED-MARKER
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_0
+#if defined(TEST_0)
+#include <algorithm>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_1
+#if defined(TEST_1)
+#include <any>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_2
+#if defined(TEST_2)
+#include <array>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_3
+#if defined(TEST_3)
+#include <atomic>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_4
+#if defined(TEST_4) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <barrier>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_5
+#if defined(TEST_5)
+#include <bit>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_6
+#if defined(TEST_6)
+#include <bitset>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_7
+#if defined(TEST_7)
+#include <cassert>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_8
+#if defined(TEST_8)
+#include <ccomplex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_9
+#if defined(TEST_9)
+#include <cctype>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_10
+#if defined(TEST_10)
+#include <cerrno>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_11
+#if defined(TEST_11)
+#include <cfenv>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_12
+#if defined(TEST_12)
+#include <cfloat>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_13
+#if defined(TEST_13)
+#include <charconv>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_14
+#if defined(TEST_14)
+#include <chrono>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_15
+#if defined(TEST_15)
+#include <cinttypes>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_16
+#if defined(TEST_16)
+#include <ciso646>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_17
+#if defined(TEST_17)
+#include <climits>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_18
+#if defined(TEST_18) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <clocale>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_19
+#if defined(TEST_19)
+#include <cmath>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_20
+#if defined(TEST_20) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <codecvt>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_21
+#if defined(TEST_21)
+#include <compare>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_22
+#if defined(TEST_22)
+#include <complex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_23
+#if defined(TEST_23)
+#include <complex.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_24
+#if defined(TEST_24)
+#include <concepts>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_25
+#if defined(TEST_25)
+#include <condition_variable>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_26
+#if defined(TEST_26)
+#include <coroutine>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_27
+#if defined(TEST_27)
+#include <csetjmp>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_28
+#if defined(TEST_28)
+#include <csignal>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_29
+#if defined(TEST_29)
+#include <cstdarg>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_30
+#if defined(TEST_30)
+#include <cstdbool>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_31
+#if defined(TEST_31)
+#include <cstddef>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_32
+#if defined(TEST_32)
+#include <cstdint>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_33
+#if defined(TEST_33)
+#include <cstdio>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_34
+#if defined(TEST_34)
+#include <cstdlib>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_35
+#if defined(TEST_35)
+#include <cstring>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_36
+#if defined(TEST_36)
+#include <ctgmath>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_37
+#if defined(TEST_37)
+#include <ctime>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_38
+#if defined(TEST_38)
+#include <ctype.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_39
+#if defined(TEST_39)
+#include <cuchar>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_40
+#if defined(TEST_40) && !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#include <cwchar>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_41
+#if defined(TEST_41) && !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#include <cwctype>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_42
+#if defined(TEST_42)
+#include <deque>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_43
+#if defined(TEST_43)
+#include <errno.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_44
+#if defined(TEST_44)
+#include <exception>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_45
+#if defined(TEST_45)
+#include <execution>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_46
+#if defined(TEST_46)
+#include <fenv.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_47
+#if defined(TEST_47) && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+#include <filesystem>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_48
+#if defined(TEST_48)
+#include <float.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_49
+#if defined(TEST_49)
+#include <format>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_50
+#if defined(TEST_50)
+#include <forward_list>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_51
+#if defined(TEST_51) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <fstream>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_52
+#if defined(TEST_52)
+#include <functional>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_53
+#if defined(TEST_53) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <future>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_54
+#if defined(TEST_54)
+#include <initializer_list>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_55
+#if defined(TEST_55)
+#include <inttypes.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_56
+#if defined(TEST_56) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <iomanip>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_57
+#if defined(TEST_57) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <ios>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_58
+#if defined(TEST_58)
+#include <iosfwd>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_59
+#if defined(TEST_59) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <iostream>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_60
+#if defined(TEST_60) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <istream>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_61
+#if defined(TEST_61)
+#include <iterator>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_62
+#if defined(TEST_62) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <latch>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_63
+#if defined(TEST_63)
+#include <limits>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_64
+#if defined(TEST_64)
+#include <limits.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_65
+#if defined(TEST_65)
+#include <list>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_66
+#if defined(TEST_66) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <locale>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_67
+#if defined(TEST_67) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <locale.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_68
+#if defined(TEST_68)
+#include <map>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_69
+#if defined(TEST_69)
+#include <math.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_70
+#if defined(TEST_70)
+#include <memory>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_71
+#if defined(TEST_71) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <mutex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_72
+#if defined(TEST_72)
+#include <new>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_73
+#if defined(TEST_73)
+#include <numbers>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_74
+#if defined(TEST_74)
+#include <numeric>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_75
+#if defined(TEST_75)
+#include <optional>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_76
+#if defined(TEST_76) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <ostream>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_77
+#if defined(TEST_77)
+#include <queue>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_78
+#if defined(TEST_78)
+#include <random>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_79
+#if defined(TEST_79)
+#include <ranges>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_80
+#if defined(TEST_80)
+#include <ratio>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_81
+#if defined(TEST_81) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <regex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_82
+#if defined(TEST_82)
+#include <scoped_allocator>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_83
+#if defined(TEST_83) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <semaphore>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_84
+#if defined(TEST_84)
+#include <set>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_85
+#if defined(TEST_85)
+#include <setjmp.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_86
+#if defined(TEST_86) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <shared_mutex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_87
+#if defined(TEST_87)
+#include <span>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_88
+#if defined(TEST_88) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <sstream>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_89
+#if defined(TEST_89)
+#include <stack>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_90
+#if defined(TEST_90) && __cplusplus > 202002L && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <stdatomic.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_91
+#if defined(TEST_91)
+#include <stdbool.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_92
+#if defined(TEST_92)
+#include <stddef.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_93
+#if defined(TEST_93)
+#include <stdexcept>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_94
+#if defined(TEST_94)
+#include <stdint.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_95
+#if defined(TEST_95)
+#include <stdio.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_96
+#if defined(TEST_96)
+#include <stdlib.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_97
+#if defined(TEST_97) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <streambuf>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_98
+#if defined(TEST_98)
+#include <string>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_99
+#if defined(TEST_99)
+#include <string.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_100
+#if defined(TEST_100)
+#include <string_view>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_101
+#if defined(TEST_101) && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+#include <strstream>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_102
+#if defined(TEST_102)
+#include <system_error>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_103
+#if defined(TEST_103)
+#include <tgmath.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_104
+#if defined(TEST_104) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <thread>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_105
+#if defined(TEST_105)
+#include <tuple>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_106
+#if defined(TEST_106)
+#include <type_traits>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_107
+#if defined(TEST_107)
+#include <typeindex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_108
+#if defined(TEST_108)
+#include <typeinfo>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_109
+#if defined(TEST_109)
+#include <uchar.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_110
+#if defined(TEST_110)
+#include <unordered_map>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_111
+#if defined(TEST_111)
+#include <unordered_set>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_112
+#if defined(TEST_112)
+#include <utility>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_113
+#if defined(TEST_113)
+#include <valarray>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_114
+#if defined(TEST_114)
+#include <variant>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_115
+#if defined(TEST_115)
+#include <vector>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_116
+#if defined(TEST_116)
+#include <version>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_117
+#if defined(TEST_117) && !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#include <wchar.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_118
+#if defined(TEST_118) && !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
+#include <wctype.h>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_119
+#if defined(TEST_119) && __cplusplus >= 201103L
+#include <experimental/algorithm>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_120
+#if defined(TEST_120) && __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#include <experimental/coroutine>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_121
+#if defined(TEST_121) && __cplusplus >= 201103L
+#include <experimental/deque>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_122
+#if defined(TEST_122) && __cplusplus >= 201103L
+#include <experimental/forward_list>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_123
+#if defined(TEST_123) && __cplusplus >= 201103L
+#include <experimental/functional>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_124
+#if defined(TEST_124) && __cplusplus >= 201103L
+#include <experimental/iterator>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_125
+#if defined(TEST_125) && __cplusplus >= 201103L
+#include <experimental/list>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_126
+#if defined(TEST_126) && __cplusplus >= 201103L
+#include <experimental/map>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_127
+#if defined(TEST_127) && __cplusplus >= 201103L
+#include <experimental/memory_resource>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_128
+#if defined(TEST_128) && __cplusplus >= 201103L
+#include <experimental/propagate_const>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_129
+#if defined(TEST_129) && !defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L
+#include <experimental/regex>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_130
+#if defined(TEST_130) && __cplusplus >= 201103L
+#include <experimental/set>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_131
+#if defined(TEST_131) && __cplusplus >= 201103L
+#include <experimental/simd>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_132
+#if defined(TEST_132) && __cplusplus >= 201103L
+#include <experimental/string>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_133
+#if defined(TEST_133) && __cplusplus >= 201103L
+#include <experimental/type_traits>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_134
+#if defined(TEST_134) && __cplusplus >= 201103L
+#include <experimental/unordered_map>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_135
+#if defined(TEST_135) && __cplusplus >= 201103L
+#include <experimental/unordered_set>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_136
+#if defined(TEST_136) && __cplusplus >= 201103L
+#include <experimental/utility>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_137
+#if defined(TEST_137) && __cplusplus >= 201103L
+#include <experimental/vector>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_138
+#if defined(TEST_138)
+#include <ext/hash_map>
+#endif
+// RUN: %{cxx} %s %{flags} %{compile_flags} -fmodules -fcxx-modules -fsyntax-only -DTEST_139
+#if defined(TEST_139)
+#include <ext/hash_set>
+#endif
+// GENERATED-MARKER
diff --git a/libcxx/test/libcxx/nasty_macros.compile.pass.cpp b/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
--- a/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
+++ b/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
@@ -324,8 +324,10 @@
 #if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
 #   include <wctype.h>
 #endif
-#include <experimental/algorithm>
-#if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 201103L
+#   include <experimental/algorithm>
+#endif
+#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L
@@ -334,8 +336,12 @@
 #if __cplusplus >= 201103L
 #   include <experimental/forward_list>
 #endif
-#include <experimental/functional>
-#include <experimental/iterator>
+#if __cplusplus >= 201103L
+#   include <experimental/functional>
+#endif
+#if __cplusplus >= 201103L
+#   include <experimental/iterator>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/list>
 #endif
@@ -345,25 +351,33 @@
 #if __cplusplus >= 201103L
 #   include <experimental/memory_resource>
 #endif
-#include <experimental/propagate_const>
+#if __cplusplus >= 201103L
+#   include <experimental/propagate_const>
+#endif
 #if !defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L
 #   include <experimental/regex>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/set>
 #endif
-#include <experimental/simd>
+#if __cplusplus >= 201103L
+#   include <experimental/simd>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/string>
 #endif
-#include <experimental/type_traits>
+#if __cplusplus >= 201103L
+#   include <experimental/type_traits>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_map>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_set>
 #endif
-#include <experimental/utility>
+#if __cplusplus >= 201103L
+#   include <experimental/utility>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/vector>
 #endif
diff --git a/libcxx/test/libcxx/no_assert_include.compile.pass.cpp b/libcxx/test/libcxx/no_assert_include.compile.pass.cpp
--- a/libcxx/test/libcxx/no_assert_include.compile.pass.cpp
+++ b/libcxx/test/libcxx/no_assert_include.compile.pass.cpp
@@ -207,8 +207,10 @@
 #if !defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
 #   include <wctype.h>
 #endif
-#include <experimental/algorithm>
-#if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
+#if __cplusplus >= 201103L
+#   include <experimental/algorithm>
+#endif
+#if __cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)
 #   include <experimental/coroutine>
 #endif
 #if __cplusplus >= 201103L
@@ -217,8 +219,12 @@
 #if __cplusplus >= 201103L
 #   include <experimental/forward_list>
 #endif
-#include <experimental/functional>
-#include <experimental/iterator>
+#if __cplusplus >= 201103L
+#   include <experimental/functional>
+#endif
+#if __cplusplus >= 201103L
+#   include <experimental/iterator>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/list>
 #endif
@@ -228,25 +234,33 @@
 #if __cplusplus >= 201103L
 #   include <experimental/memory_resource>
 #endif
-#include <experimental/propagate_const>
+#if __cplusplus >= 201103L
+#   include <experimental/propagate_const>
+#endif
 #if !defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L
 #   include <experimental/regex>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/set>
 #endif
-#include <experimental/simd>
+#if __cplusplus >= 201103L
+#   include <experimental/simd>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/string>
 #endif
-#include <experimental/type_traits>
+#if __cplusplus >= 201103L
+#   include <experimental/type_traits>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_map>
 #endif
 #if __cplusplus >= 201103L
 #   include <experimental/unordered_set>
 #endif
-#include <experimental/utility>
+#if __cplusplus >= 201103L
+#   include <experimental/utility>
+#endif
 #if __cplusplus >= 201103L
 #   include <experimental/vector>
 #endif
diff --git a/libcxx/utils/generate_header_tests.py b/libcxx/utils/generate_header_tests.py
--- a/libcxx/utils/generate_header_tests.py
+++ b/libcxx/utils/generate_header_tests.py
@@ -39,18 +39,25 @@
     "cwchar": "!defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)",
     "wchar.h": "!defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)",
 
-    "experimental/coroutine": "!defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)",
-
-    "experimental/regex": "!defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L",
+    "experimental/algorithm": "__cplusplus >= 201103L",
+    "experimental/coroutine": "__cplusplus >= 201103L && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES)",
     "experimental/deque": "__cplusplus >= 201103L",
-    "experimental/map": "__cplusplus >= 201103L",
-    "experimental/memory_resource": "__cplusplus >= 201103L",
     "experimental/forward_list": "__cplusplus >= 201103L",
+    "experimental/functional": "__cplusplus >= 201103L",
+    "experimental/iterator": "__cplusplus >= 201103L",
     "experimental/list": "__cplusplus >= 201103L",
+    "experimental/map": "__cplusplus >= 201103L",
+    "experimental/memory_resource": "__cplusplus >= 201103L",
+    "experimental/propagate_const": "__cplusplus >= 201103L",
+    "experimental/regex": "!defined(_LIBCPP_HAS_NO_LOCALIZATION) && __cplusplus >= 201103L",
     "experimental/set": "__cplusplus >= 201103L",
+    "experimental/simd": "__cplusplus >= 201103L",
+    "experimental/span": "__cplusplus >= 201103L",
     "experimental/string": "__cplusplus >= 201103L",
+    "experimental/type_traits": "__cplusplus >= 201103L",
     "experimental/unordered_map": "__cplusplus >= 201103L",
     "experimental/unordered_set": "__cplusplus >= 201103L",
+    "experimental/utility": "__cplusplus >= 201103L",
     "experimental/vector": "__cplusplus >= 201103L",
 }
 
@@ -133,6 +140,7 @@
     produce(test.joinpath('libcxx/clang_tidy.sh.cpp'), variables)
     produce(test.joinpath('libcxx/double_include.sh.cpp'), variables)
     produce(test.joinpath('libcxx/min_max_macros.compile.pass.cpp'), variables)
+    produce(test.joinpath('libcxx/modules_include.sh.cpp'), variables)
     produce(test.joinpath('libcxx/nasty_macros.compile.pass.cpp'), variables)
     produce(test.joinpath('libcxx/no_assert_include.compile.pass.cpp'), variables)
     produce(test.joinpath('libcxx/private_headers.verify.cpp'), variables)