Implement the infrastructure for feature-test macros. Very few actual feature test macros, though. Reviewed as: https://reviews.llvm.org/D51955

llvm-svn: 342073

Author: mclow

libcxx/include/algorithm

@@ -646,6 +646,7 @@ template <class BidirectionalIterator, class Compare>
 #include <iterator>
 #include <cstddef>
 #include <bit>
+#include <version>
 
 #include <__debug>
 

libcxx/include/any

@@ -87,6 +87,7 @@ namespace std {
 #include <typeinfo>
 #include <type_traits>
 #include <cstdlib>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/array

@@ -112,6 +112,7 @@ template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexce
 #include <algorithm>
 #include <stdexcept>
 #include <cstdlib> // for _LIBCPP_UNREACHABLE
+#include <version>
 #include <__debug>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)

libcxx/include/atomic

@@ -544,6 +544,7 @@ void atomic_signal_fence(memory_order m) noexcept;
 #include <cstddef>
 #include <cstdint>
 #include <type_traits>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
@@ -559,10 +560,6 @@ void atomic_signal_fence(memory_order m) noexcept;
 #error C++ standard library is incompatible with <stdatomic.h>
 #endif
 
-#if _LIBCPP_STD_VER > 14
-# define __cpp_lib_atomic_is_always_lock_free 201603L
-#endif
-
 #define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \
   _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \
                            __m == memory_order_acquire || \

libcxx/include/bit

@@ -21,6 +21,7 @@ namespace std {
 */
 
 #include <__config>
+#include <version>
 
 #if defined(__IBMCPP__)
 #include "support/ibm/support.h"

libcxx/include/chrono

@@ -798,6 +798,7 @@ constexpr chrono::year                                  operator ""y(unsigned lo
 #include <type_traits>
 #include <ratio>
 #include <limits>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/cmath

@@ -303,6 +303,7 @@ long double    truncl(long double x);
 
 #include <__config>
 #include <math.h>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/complex

@@ -245,6 +245,7 @@ template<class T, class charT, class traits>
 #include <stdexcept>
 #include <cmath>
 #include <sstream>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/cstddef

@@ -35,6 +35,7 @@ Types:
 */
 
 #include <__config>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/deque

@@ -161,6 +161,7 @@ template <class T, class Allocator>
 #include <iterator>
 #include <algorithm>
 #include <stdexcept>
+#include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header