[libc++] Add the version header to all headers.

Some headers which require the version header depend on other headers to
provide it. Include the version header in all top-level headers to make
sure a header cleanup can't remove the version header.

Note this doesn't add the version header to the c headers.

Reviewed By: #libc, Quuxplusone, ldionne

Differential Revision: https://reviews.llvm.org/D116172

libcxx/include/bitset

@@ -120,6 +120,7 @@ template <size_t N> struct hash<std::bitset<N>>;
 #include <iosfwd>
 #include <stdexcept>
 #include <string>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/codecvt

@@ -56,6 +56,7 @@ class codecvt_utf8_utf16
 
 #include <__config>
 #include <__locale>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/compare

@@ -145,6 +145,7 @@ namespace std {
 #include <__compare/three_way_comparable.h>
 #include <__compare/weak_order.h>
 #include <__config>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/condition_variable

@@ -109,6 +109,7 @@ public:
 #include <__config>
 #include <__mutex_base>
 #include <memory>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/execution

@@ -11,6 +11,7 @@
 #define _LIBCPP_EXECUTION
 
 #include <__config>
+#include <version>
 
 #if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
 #   include <__pstl_execution>

libcxx/include/fstream

@@ -187,6 +187,7 @@ typedef basic_fstream<wchar_t> wfstream;
 #include <cstdlib>
 #include <istream>
 #include <ostream>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
 #   include <filesystem>

libcxx/include/future

@@ -374,6 +374,7 @@ template <class R, class Alloc> struct uses_allocator<packaged_task<R>, Alloc>;
 #include <mutex>
 #include <system_error>
 #include <thread>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/ios

@@ -214,6 +214,7 @@ storage-class-specifier const error_category& iostream_category() noexcept;
 #include <__locale>
 #include <iosfwd>
 #include <system_error>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
 #include <atomic>     // for __xindex_

libcxx/include/iosfwd

@@ -96,6 +96,7 @@ using u32streampos = fpos<char_traits<char32_t>::state_type>;
 
 #include <__config>
 #include <__mbstate_t.h>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/iostream

@@ -38,6 +38,7 @@ extern wostream wclog;
 #include <istream>
 #include <ostream>
 #include <streambuf>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/latch

@@ -43,6 +43,7 @@ namespace std
 #include <__availability>
 #include <__config>
 #include <atomic>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/queue

@@ -213,6 +213,7 @@ template <class T, class Container, class Compare>
 #include <deque>
 #include <functional>
 #include <vector>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/random

@@ -1715,6 +1715,7 @@ class piecewise_linear_distribution
 #include <__random/uniform_real_distribution.h>
 #include <__random/weibull_distribution.h>
 #include <initializer_list>
+#include <version>
 
 #include <algorithm>   // for backward compatibility; TODO remove it
 #include <cmath>       // for backward compatibility; TODO remove it

libcxx/include/ratio

@@ -81,6 +81,7 @@ typedef ratio<1000000000000000000000000, 1> yotta;  // not supported
 #include <climits>
 #include <cstdint>
 #include <type_traits>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/semaphore

@@ -49,6 +49,7 @@ using binary_semaphore = counting_semaphore<1>;
 #include <__config>
 #include <__threading_support>
 #include <atomic>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/sstream

@@ -184,6 +184,7 @@ typedef basic_stringstream<wchar_t> wstringstream;
 #include <istream>
 #include <ostream>
 #include <string>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/stack

@@ -91,6 +91,7 @@ template <class T, class Container>
 #include <__memory/uses_allocator.h>
 #include <__utility/forward.h>
 #include <deque>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/streambuf

@@ -110,6 +110,7 @@ protected:
 #include <__config>
 #include <ios>
 #include <iosfwd>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/strstream

@@ -132,6 +132,7 @@ private:
 #include <__config>
 #include <istream>
 #include <ostream>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/system_error

@@ -150,6 +150,7 @@ template <> struct hash<std::error_condition>;
 #include <stdexcept>
 #include <string>
 #include <type_traits>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/thread

@@ -97,6 +97,7 @@ void sleep_for(const chrono::duration<Rep, Period>& rel_time);
 #include <system_error>
 #include <tuple>
 #include <type_traits>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/typeindex

@@ -49,6 +49,7 @@ struct hash<type_index>
 #include <__functional_base>
 #include <compare>
 #include <typeinfo>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/valarray

@@ -348,6 +348,7 @@ template <class T> unspecified2 end(const valarray<T>& v);
 #include <functional>
 #include <initializer_list>
 #include <new>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/utils/graph_header_deps.py

@@ -14,7 +14,7 @@ import sys
 
 
 def is_config_header(h):
-    return os.path.basename(h) in ['__config', '__libcpp_version', '__undef_macros']
+    return os.path.basename(h) in ['__config', '__libcpp_version', '__undef_macros', 'version']
 
 
 def is_experimental_header(h):