Merge libc++, libc++abi and libunwind version 8.0.0.

Ports build by naddy@
Tested by visa on octeon
Tested by kettenis on macppc and sparc64

3 files changed, 183 insertions, 421 deletions

diff --git a/lib/libcxx/include/__config b/lib/libcxx/include/__config
index d6942af125d..5295b77d4cf 100644
--- a/lib/libcxx/include/__config
+++ b/lib/libcxx/include/__config
@@ -33,14 +33,10 @@
 #  define _GNUC_VER_NEW 0
 #endif
 
-#define _LIBCPP_VERSION 7000
+#define _LIBCPP_VERSION 8000
 
 #ifndef _LIBCPP_ABI_VERSION
-#  ifdef __Fuchsia__
-#    define _LIBCPP_ABI_VERSION 2
-#  else
-#    define _LIBCPP_ABI_VERSION 1
-#  endif
+#  define _LIBCPP_ABI_VERSION 1
 #endif
 
 #ifndef _LIBCPP_STD_VER
@@ -99,6 +95,8 @@
 // Use the smallest possible integer type to represent the index of the variant.
 // Previously libc++ used "unsigned int" exclusivly.
 #  define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION
+// Unstable attempt to provide a more optimized std::function
+#  define _LIBCPP_ABI_OPTIMIZED_FUNCTION
 #elif _LIBCPP_ABI_VERSION == 1
 #  if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
 // Enable compiling copies of now inline methods into the dylib to support
@@ -123,7 +121,9 @@
 #define _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_X##_LIBCPP_Y
 #define _LIBCPP_CONCAT(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y)
 
-#define _LIBCPP_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION)
+#ifndef _LIBCPP_ABI_NAMESPACE
+# define _LIBCPP_ABI_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION)
+#endif
 
 #if __cplusplus < 201103L
 #define _LIBCPP_CXX03_LANG
@@ -362,6 +362,18 @@
 #  endif // __linux__
 #endif
 
+#ifndef _LIBCPP_CXX03_LANG
+# define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp)
+#elif defined(_LIBCPP_COMPILER_CLANG)
+# define _LIBCPP_ALIGNOF(_Tp) _Alignof(_Tp)
+#else
+// This definition is potentially buggy, but it's only taken with GCC in C++03,
+// which we barely support anyway. See llvm.org/PR39713
+# define _LIBCPP_ALIGNOF(_Tp) __alignof(_Tp)
+#endif
+
+#define _LIBCPP_PREFERRED_ALIGNOF(_Tp) __alignof(_Tp)
+
 #if defined(_LIBCPP_COMPILER_CLANG)
 
 // _LIBCPP_ALTERNATE_STRING_LAYOUT is an old name for
@@ -376,7 +388,7 @@
 #  define _ALIGNAS_TYPE(x) alignas(x)
 #  define _ALIGNAS(x) alignas(x)
 #else
-#  define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))))
+#  define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
 #  define _ALIGNAS(x) __attribute__((__aligned__(x)))
 #endif
 
@@ -476,16 +488,6 @@ typedef __char32_t char32_t;
 #define _LIBCPP_IS_LITERAL(T) __is_literal(T)
 #endif
 
-// Inline namespaces are available in Clang regardless of C++ dialect.
-#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {inline namespace _LIBCPP_NAMESPACE {
-#define _LIBCPP_END_NAMESPACE_STD  } }
-#define _VSTD std::_LIBCPP_NAMESPACE
-
-namespace std {
-  inline namespace _LIBCPP_NAMESPACE {
-  }
-}
-
 #if !defined(_LIBCPP_HAS_NO_ASAN) && !__has_feature(address_sanitizer)
 #define _LIBCPP_HAS_NO_ASAN
 #endif
@@ -505,10 +507,15 @@ namespace std {
 
 #define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))
 
+// No apple compilers support ""d and ""y at this time.
+#if _LIBCPP_CLANG_VER < 800 || defined(__apple_build_version__)
+#define	_LIBCPP_HAS_NO_CXX20_CHRONO_LITERALS
+#endif
+
 #elif defined(_LIBCPP_COMPILER_GCC)
 
 #define _ALIGNAS(x) __attribute__((__aligned__(x)))
-#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))))
+#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
 
 #define _LIBCPP_NORETURN __attribute__((noreturn))
 
@@ -575,15 +582,6 @@ namespace std {
 
 #endif  // __GXX_EXPERIMENTAL_CXX0X__
 
-#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std { inline namespace _LIBCPP_NAMESPACE {
-#define _LIBCPP_END_NAMESPACE_STD  } }
-#define _VSTD std::_LIBCPP_NAMESPACE
-
-namespace std {
-  inline namespace _LIBCPP_NAMESPACE {
-  }
-}
-
 #if !defined(_LIBCPP_HAS_NO_ASAN) && !defined(__SANITIZE_ADDRESS__)
 #define _LIBCPP_HAS_NO_ASAN
 #endif
@@ -619,13 +617,6 @@ namespace std {
 #define _ALIGNAS_TYPE(x) alignas(x)
 #define _LIBCPP_HAS_NO_VARIADICS
 
-#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {
-#define _LIBCPP_END_NAMESPACE_STD  }
-#define _VSTD std
-
-namespace std {
-}
-
 #define _LIBCPP_WEAK
 
 #define _LIBCPP_HAS_NO_ASAN
@@ -637,7 +628,7 @@ namespace std {
 #elif defined(_LIBCPP_COMPILER_IBM)
 
 #define _ALIGNAS(x) __attribute__((__aligned__(x)))
-#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))))
+#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
 #define _ATTRIBUTE(x) __attribute__((x))
 #define _LIBCPP_NORETURN __attribute__((noreturn))
 
@@ -653,15 +644,6 @@ namespace std {
 #define __MULTILOCALE_API
 #endif
 
-#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {inline namespace _LIBCPP_NAMESPACE {
-#define _LIBCPP_END_NAMESPACE_STD  } }
-#define _VSTD std::_LIBCPP_NAMESPACE
-
-namespace std {
-  inline namespace _LIBCPP_NAMESPACE {
-  }
-}
-
 #define _LIBCPP_HAS_NO_ASAN
 
 #define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))
@@ -670,20 +652,6 @@ namespace std {
 
 #endif // _LIBCPP_COMPILER_[CLANG|GCC|MSVC|IBM]
 
-#if _LIBCPP_STD_VER >= 17
-#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
-  _LIBCPP_BEGIN_NAMESPACE_STD inline namespace __fs { namespace filesystem {
-#else
-#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
-  _LIBCPP_BEGIN_NAMESPACE_STD namespace __fs { namespace filesystem {
-#endif
-
-#define _LIBCPP_END_NAMESPACE_FILESYSTEM \
-  _LIBCPP_END_NAMESPACE_STD } }
-
-#define _VSTD_FS _VSTD::__fs::filesystem
-
-
 #if defined(_LIBCPP_OBJECT_FORMAT_COFF)
 
 #ifdef _DLL
@@ -697,33 +665,29 @@ namespace std {
 #  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
 #  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
 #  define _LIBCPP_OVERRIDABLE_FUNC_VIS
+#  define _LIBCPP_EXPORTED_FROM_ABI
 #elif defined(_LIBCPP_BUILDING_LIBRARY)
 #  define _LIBCPP_DLL_VIS __declspec(dllexport)
 #  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
 #  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
 #  define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
+#  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
 #else
 #  define _LIBCPP_DLL_VIS __declspec(dllimport)
 #  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
 #  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
 #  define _LIBCPP_OVERRIDABLE_FUNC_VIS
+#  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllimport)
 #endif
 
 #define _LIBCPP_TYPE_VIS            _LIBCPP_DLL_VIS
 #define _LIBCPP_FUNC_VIS            _LIBCPP_DLL_VIS
-#define _LIBCPP_EXTERN_VIS          _LIBCPP_DLL_VIS
 #define _LIBCPP_EXCEPTION_ABI       _LIBCPP_DLL_VIS
 #define _LIBCPP_HIDDEN
 #define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
 #define _LIBCPP_TEMPLATE_VIS
 #define _LIBCPP_ENUM_VIS
 
-#if defined(_LIBCPP_COMPILER_MSVC)
-#  define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __forceinline
-#else
-#  define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __attribute__ ((__always_inline__))
-#endif
-
 #endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)
 
 #ifndef _LIBCPP_HIDDEN
@@ -771,8 +735,12 @@ namespace std {
 #  endif
 #endif
 
-#ifndef _LIBCPP_EXTERN_VIS
-#define _LIBCPP_EXTERN_VIS
+#ifndef _LIBCPP_EXPORTED_FROM_ABI
+#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
+#    define _LIBCPP_EXPORTED_FROM_ABI __attribute__((__visibility__("default")))
+#  else
+#    define _LIBCPP_EXPORTED_FROM_ABI
+#  endif
 #endif
 
 #ifndef _LIBCPP_OVERRIDABLE_FUNC_VIS
@@ -813,6 +781,15 @@ namespace std {
 #  define _LIBCPP_INTERNAL_LINKAGE _LIBCPP_ALWAYS_INLINE
 #endif
 
+#if __has_attribute(exclude_from_explicit_instantiation)
+#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__ ((__exclude_from_explicit_instantiation__))
+#else
+   // Try to approximate the effect of exclude_from_explicit_instantiation
+   // (which is that entities are not assumed to be provided by explicit
+   // template instantitations in the dylib) by always inlining those entities.
+#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
+#endif
+
 #ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU
 #  ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT
 #    define _LIBCPP_HIDE_FROM_ABI_PER_TU 0
@@ -825,21 +802,42 @@ namespace std {
 #  if _LIBCPP_HIDE_FROM_ABI_PER_TU
 #    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE
 #  else
-#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_ALWAYS_INLINE
+#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
 #  endif
 #endif
 
-// Just so we can migrate to _LIBCPP_HIDE_FROM_ABI gradually.
-#define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI
-
-#ifndef _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __attribute__((__visibility__("default"), __always_inline__))
+#ifdef _LIBCPP_BUILDING_LIBRARY
+#  if _LIBCPP_ABI_VERSION > 1
+#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
 #  else
-#    define _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY __attribute__((__always_inline__))
+#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1
 #  endif
+#else
+#  define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
+#endif
+
+// Just so we can migrate to the new macros gradually.
+#define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI
+
+// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
+#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std { inline namespace _LIBCPP_ABI_NAMESPACE {
+#define _LIBCPP_END_NAMESPACE_STD  } }
+#define _VSTD std::_LIBCPP_ABI_NAMESPACE
+_LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER >= 17
+#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
+  _LIBCPP_BEGIN_NAMESPACE_STD inline namespace __fs { namespace filesystem {
+#else
+#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
+  _LIBCPP_BEGIN_NAMESPACE_STD namespace __fs { namespace filesystem {
 #endif
 
+#define _LIBCPP_END_NAMESPACE_FILESYSTEM \
+  _LIBCPP_END_NAMESPACE_STD } }
+
+#define _VSTD_FS _VSTD::__fs::filesystem
+
 #ifndef _LIBCPP_PREFERRED_OVERLOAD
 #  if __has_attribute(__enable_if__)
 #    define _LIBCPP_PREFERRED_OVERLOAD __attribute__ ((__enable_if__(true, "")))
@@ -1000,7 +998,14 @@ template <unsigned> struct __static_assert_check {};
 // If we are getting operator new from the MSVC CRT, then allocation overloads
 // for align_val_t were added in 19.12, aka VS 2017 version 15.3.
 #if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
-#define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
+#  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
+#elif defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#  define _LIBCPP_DEFER_NEW_TO_VCRUNTIME
+#  if !defined(__cpp_aligned_new)
+     // We're defering to Microsoft's STL to provide aligned new et al. We don't
+     // have it unless the language feature test macro is defined.
+#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
+#  endif
 #endif
 
 #if defined(__APPLE__)
@@ -1008,16 +1013,11 @@ template <unsigned> struct __static_assert_check {};
       defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
 #    define __MAC_OS_X_VERSION_MIN_REQUIRED __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__
 #  endif
-#  if defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
-#    if __MAC_OS_X_VERSION_MIN_REQUIRED < 1060
-#      define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
-#    endif
-#  endif
 #endif // defined(__APPLE__)
 
 #if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) && \
-    !defined(_LIBCPP_BUILDING_LIBRARY) && \
-    (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606)
+    (defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) || \
+    (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606))
 #  define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
 #endif
 
@@ -1029,18 +1029,46 @@ template <unsigned> struct __static_assert_check {};
 #define _LIBCPP_WCTYPE_IS_MASK
 #endif
 
-#if _LIBCPP_STD_VER > 11
-#  define _LIBCPP_DEPRECATED [[deprecated]]
+#if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
+#define _LIBCPP_NO_HAS_CHAR8_T
+#endif
+
+// Deprecation macros.
+// Deprecations warnings are only enabled when _LIBCPP_ENABLE_DEPRECATION_WARNINGS is defined.
+#if defined(_LIBCPP_ENABLE_DEPRECATION_WARNINGS)
+#  if __has_attribute(deprecated)
+#    define _LIBCPP_DEPRECATED __attribute__ ((deprecated))
+#  elif _LIBCPP_STD_VER > 11
+#    define _LIBCPP_DEPRECATED [[deprecated]]
+#  else
+#    define _LIBCPP_DEPRECATED
+#  endif
 #else
 #  define _LIBCPP_DEPRECATED
 #endif
 
+#if !defined(_LIBCPP_CXX03_LANG)
+#  define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
+#else
+#  define _LIBCPP_DEPRECATED_IN_CXX11
+#endif
+
+#if _LIBCPP_STD_VER >= 14
+#  define _LIBCPP_DEPRECATED_IN_CXX14 _LIBCPP_DEPRECATED
+#else
+#  define _LIBCPP_DEPRECATED_IN_CXX14
+#endif
+
+#if _LIBCPP_STD_VER >= 17
+#  define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
+#else
+#  define _LIBCPP_DEPRECATED_IN_CXX17
+#endif
+
 #if _LIBCPP_STD_VER <= 11
 #  define _LIBCPP_EXPLICIT_AFTER_CXX11
-#  define _LIBCPP_DEPRECATED_AFTER_CXX11
 #else
 #  define _LIBCPP_EXPLICIT_AFTER_CXX11 explicit
-#  define _LIBCPP_DEPRECATED_AFTER_CXX11 [[deprecated]]
 #endif
 
 #if _LIBCPP_STD_VER > 11 && !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
@@ -1061,8 +1089,30 @@ template <unsigned> struct __static_assert_check {};
 #  define _LIBCPP_CONSTEXPR_AFTER_CXX17
 #endif
 
-#if __has_cpp_attribute(nodiscard) && _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17)
-#  define _LIBCPP_NODISCARD_AFTER_CXX17 [[nodiscard]]
+// The _LIBCPP_NODISCARD_ATTRIBUTE should only be used to define other
+// NODISCARD macros to the correct attribute.
+#if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
+#  define _LIBCPP_NODISCARD_ATTRIBUTE [[nodiscard]]
+#elif defined(_LIBCPP_COMPILER_CLANG) && !defined(_LIBCPP_CXX03_LANG)
+#  define _LIBCPP_NODISCARD_ATTRIBUTE [[clang::warn_unused_result]]
+#else
+// We can't use GCC's [[gnu::warn_unused_result]] and
+// __attribute__((warn_unused_result)), because GCC does not silence them via
+// (void) cast.
+#  define _LIBCPP_NODISCARD_ATTRIBUTE
+#endif
+
+// _LIBCPP_NODISCARD_EXT may be used to apply [[nodiscard]] to entities not
+// specified as such as an extension.
+#if defined(_LIBCPP_ENABLE_NODISCARD) && !defined(_LIBCPP_DISABLE_NODISCARD_EXT)
+#  define _LIBCPP_NODISCARD_EXT _LIBCPP_NODISCARD_ATTRIBUTE
+#else
+#  define _LIBCPP_NODISCARD_EXT
+#endif
+
+#if !defined(_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17) && \
+    (_LIBCPP_STD_VER > 17 || defined(_LIBCPP_ENABLE_NODISCARD))
+#  define _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_NODISCARD_ATTRIBUTE
 #else
 #  define _LIBCPP_NODISCARD_AFTER_CXX17
 #endif
@@ -1119,6 +1169,7 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
       defined(__Fuchsia__) || \
       defined(__NetBSD__) || \
       defined(__linux__) || \
+      defined(__GNU__) || \
       defined(__APPLE__) || \
       defined(__CloudABI__) || \
       defined(__sun__) || \
@@ -1226,8 +1277,12 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  define _LIBCPP_DIAGNOSE_ERROR(...)
 #endif
 
-#if __has_attribute(fallthough) || _GNUC_VER >= 700
 // Use a function like macro to imply that it must be followed by a semicolon
+#if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
+#  define _LIBCPP_FALLTHROUGH() [[fallthrough]]
+#elif __has_cpp_attribute(clang::fallthrough)
+#  define _LIBCPP_FALLTHROUGH() [[clang::fallthrough]]
+#elif __has_attribute(fallthough) || _GNUC_VER >= 700
 #  define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
 #else
 #  define _LIBCPP_FALLTHROUGH() ((void)0)
@@ -1281,9 +1336,15 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
      __attribute__((availability(ios,strict,introduced=10.0)))                 \
      __attribute__((availability(tvos,strict,introduced=10.0)))                \
      __attribute__((availability(watchos,strict,introduced=3.0)))
-#  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS __attribute__((unavailable))
-#  define _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH __attribute__((unavailable))
-#  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST __attribute__((unavailable))
+#  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS                             \
+     __attribute__((availability(macosx,strict,introduced=10.14)))             \
+     __attribute__((availability(ios,strict,introduced=12.0)))                 \
+     __attribute__((availability(tvos,strict,introduced=12.0)))                \
+     __attribute__((availability(watchos,strict,introduced=5.0)))
+#  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS                              \
+     _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
+#  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST                                    \
+     _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
 #  define _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS                             \
      __attribute__((availability(macosx,strict,introduced=10.12)))             \
      __attribute__((availability(ios,strict,introduced=10.0)))                 \
@@ -1307,8 +1368,8 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
      __attribute__((availability(ios,strict,introduced=7.0)))
 #else
 #  define _LIBCPP_AVAILABILITY_SHARED_MUTEX
+#  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
 #  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
 #  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST
 #  define _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS
 #  define _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE
@@ -1320,26 +1381,30 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 
 // Define availability that depends on _LIBCPP_NO_EXCEPTIONS.
 #ifdef _LIBCPP_NO_EXCEPTIONS
-#  define _LIBCPP_AVAILABILITY_DYNARRAY
 #  define _LIBCPP_AVAILABILITY_FUTURE
 #  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
+#  define _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
+#  define _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
 #else
-#  define _LIBCPP_AVAILABILITY_DYNARRAY _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
-#  define _LIBCPP_AVAILABILITY_FUTURE _LIBCPP_AVAILABILITY_FUTURE_ERROR
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST                              \
-     _LIBCPP_AVAILABILITY_BAD_ANY_CAST
-#endif
-
-// Availability of stream API in the dylib got dropped and re-added.  The
-// extern template should effectively be available at:
-//    availability(macosx,introduced=10.9)
-//    availability(ios,introduced=7.0)
-#if defined(_LIBCPP_USE_AVAILABILITY_APPLE) &&                                 \
+#  define _LIBCPP_AVAILABILITY_FUTURE                    _LIBCPP_AVAILABILITY_FUTURE_ERROR
+#  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST        _LIBCPP_AVAILABILITY_BAD_ANY_CAST
+#  define _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
+#  define _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS  _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
+#endif
+
+// The stream API was dropped and re-added in the dylib shipped on macOS
+// and iOS. We can only assume the dylib to provide these definitions for
+// macosx >= 10.9 and ios >= 7.0. Otherwise, the definitions are available
+// from the headers, but not from the dylib. Explicit instantiation
+// declarations for streams exist conditionally to this; if we provide
+// an explicit instantiation declaration and we try to deploy to a dylib
+// that does not provide those symbols, we'll get a load-time error.
+#if !defined(_LIBCPP_BUILDING_LIBRARY) &&                                      \
     ((defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) &&                \
       __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1090) ||                 \
      (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) &&               \
       __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 70000))
-#define _LIBCPP_AVAILABILITY_NO_STREAMS_EXTERN_TEMPLATE
+#  define _LIBCPP_DO_NOT_ASSUME_STREAMS_EXPLICIT_INSTANTIATION_IN_DYLIB
 #endif
 
 #if defined(_LIBCPP_COMPILER_IBM)
@@ -1382,6 +1447,8 @@ _LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
 #  endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
 #endif // _LIBCPP_NO_AUTO_LINK
 
+#define _LIBCPP_UNUSED_VAR(x) ((void)(x))
+
 #endif // __cplusplus
 
 #endif // _LIBCPP_CONFIG
diff --git a/lib/libcxx/include/__locale b/lib/libcxx/include/__locale
index 79063e08c85..af5e5d02e83 100644
--- a/lib/libcxx/include/__locale
+++ b/lib/libcxx/include/__locale
@@ -1255,13 +1255,13 @@ struct __narrow_to_utf8<8>
 };
 
 template <>
-struct __narrow_to_utf8<16>
+struct _LIBCPP_TEMPLATE_VIS __narrow_to_utf8<16>
     : public codecvt<char16_t, char, mbstate_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     __narrow_to_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
 
-    ~__narrow_to_utf8();
+    _LIBCPP_EXPORTED_FROM_ABI ~__narrow_to_utf8();
 
     template <class _OutputIterator, class _CharT>
     _LIBCPP_INLINE_VISIBILITY
@@ -1289,13 +1289,13 @@ struct __narrow_to_utf8<16>
 };
 
 template <>
-struct __narrow_to_utf8<32>
+struct _LIBCPP_TEMPLATE_VIS __narrow_to_utf8<32>
     : public codecvt<char32_t, char, mbstate_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     __narrow_to_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
 
-    ~__narrow_to_utf8();
+    _LIBCPP_EXPORTED_FROM_ABI ~__narrow_to_utf8();
 
     template <class _OutputIterator, class _CharT>
     _LIBCPP_INLINE_VISIBILITY
@@ -1345,13 +1345,13 @@ struct __widen_from_utf8<8>
 };
 
 template <>
-struct __widen_from_utf8<16>
+struct _LIBCPP_TEMPLATE_VIS __widen_from_utf8<16>
     : public codecvt<char16_t, char, mbstate_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     __widen_from_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
 
-    ~__widen_from_utf8();
+    _LIBCPP_EXPORTED_FROM_ABI ~__widen_from_utf8();
 
     template <class _OutputIterator>
     _LIBCPP_INLINE_VISIBILITY
@@ -1379,13 +1379,13 @@ struct __widen_from_utf8<16>
 };
 
 template <>
-struct __widen_from_utf8<32>
+struct _LIBCPP_TEMPLATE_VIS __widen_from_utf8<32>
     : public codecvt<char32_t, char, mbstate_t>
 {
     _LIBCPP_INLINE_VISIBILITY
     __widen_from_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
 
-    ~__widen_from_utf8();
+    _LIBCPP_EXPORTED_FROM_ABI ~__widen_from_utf8();
 
     template <class _OutputIterator>
     _LIBCPP_INLINE_VISIBILITY
diff --git a/lib/libcxx/include/experimental/dynarray b/lib/libcxx/include/experimental/dynarray
deleted file mode 100644
index a60c87c3f97..00000000000
--- a/lib/libcxx/include/experimental/dynarray
+++ /dev/null
@@ -1,305 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- dynarray ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_DYNARRAY
-#define _LIBCPP_DYNARRAY
-
-/*
-    dynarray synopsis
-
-namespace std { namespace experimental {
-
-template< typename T >
-class dynarray
-{
-    // types:
-    typedef       T                               value_type;
-    typedef       T&                              reference;
-    typedef const T&                              const_reference;
-    typedef       T*                              pointer;
-    typedef const T*                              const_pointer;
-    typedef       implementation-defined          iterator;
-    typedef       implementation-defined          const_iterator;
-    typedef reverse_iterator<iterator>            reverse_iterator;
-    typedef reverse_iterator<const_iterator>      const_reverse_iterator;
-    typedef size_t                                size_type;
-    typedef ptrdiff_t                             difference_type;
-
-public:
-    // construct/copy/destroy:
-    explicit dynarray(size_type c);
-    dynarray(size_type c, const T& v);
-    dynarray(const dynarray& d);
-    dynarray(initializer_list<T>);
-
-    template <class Alloc>
-      dynarray(allocator_arg_t, const Alloc& a, size_type c, const Alloc& alloc);
-    template <class Alloc>
-      dynarray(allocator_arg_t, const Alloc& a, size_type c, const T& v, const Alloc& alloc);
-    template <class Alloc>
-      dynarray(allocator_arg_t, const Alloc& a, const dynarray& d, const Alloc& alloc);
-    template <class Alloc>
-      dynarray(allocator_arg_t, const Alloc& a, initializer_list<T>, const Alloc& alloc);
-    dynarray& operator=(const dynarray&) = delete;
-    ~dynarray();
-
-    // iterators:
-    iterator       begin()        noexcept;
-    const_iterator begin()  const noexcept;
-    const_iterator cbegin() const noexcept;
-    iterator       end()          noexcept;
-    const_iterator end()    const noexcept;
-    const_iterator cend()   const noexcept;
-
-    reverse_iterator       rbegin()        noexcept;
-    const_reverse_iterator rbegin()  const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    reverse_iterator       rend()          noexcept;
-    const_reverse_iterator rend()    const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    // capacity:
-    size_type size()     const noexcept;
-    size_type max_size() const noexcept;
-    bool      empty()    const noexcept;
-
-    // element access:
-    reference       operator[](size_type n);
-    const_reference operator[](size_type n) const;
-
-    reference       front();
-    const_reference front() const;
-    reference       back();
-    const_reference back()  const;
-
-    const_reference at(size_type n) const;
-    reference       at(size_type n);
-
-    // data access:
-    T*       data()       noexcept;
-    const T* data() const noexcept;
-
-    // mutating member functions:
-    void fill(const T& v);
-};
-
-}}  // std::experimental
-
-*/
-#include <__config>
-#if _LIBCPP_STD_VER > 11
-
-#include <__functional_base>
-#include <iterator>
-#include <stdexcept>
-#include <initializer_list>
-#include <new>
-#include <algorithm>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-namespace std { namespace experimental { inline namespace __array_extensions_v1 {
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_DYNARRAY dynarray
-{
-public:
-    // types:
-    typedef dynarray __self;
-    typedef _Tp                                   value_type;
-    typedef value_type&                           reference;
-    typedef const value_type&                     const_reference;
-    typedef value_type*                           iterator;
-    typedef const value_type*                     const_iterator;
-    typedef value_type*                           pointer;
-    typedef const value_type*                     const_pointer;
-    typedef size_t                                size_type;
-    typedef ptrdiff_t                             difference_type;
-    typedef std::reverse_iterator<iterator>       reverse_iterator;
-    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
-
-private:
-    size_t                  __size_;
-    value_type *            __base_;
-    _LIBCPP_INLINE_VISIBILITY dynarray () noexcept :  __size_(0), __base_(nullptr) {}
-    
-    static inline _LIBCPP_INLINE_VISIBILITY
-    value_type* __allocate(size_t __count) {
-        if (numeric_limits<size_t>::max() / sizeof (value_type) <= __count)
-            __throw_bad_array_length();
-
-        return static_cast<value_type *>(
-            _VSTD::__libcpp_allocate(sizeof(value_type) * __count, __alignof(value_type)));
-    }
-
-    static inline _LIBCPP_INLINE_VISIBILITY
-    void __deallocate_value(value_type* __ptr ) noexcept {
-        _VSTD::__libcpp_deallocate(static_cast<void *>(__ptr), __alignof(value_type));
-    }
-
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit dynarray(size_type __c);
-    _LIBCPP_INLINE_VISIBILITY
-    dynarray(size_type __c, const value_type& __v);
-    _LIBCPP_INLINE_VISIBILITY
-    dynarray(const dynarray& __d);
-    _LIBCPP_INLINE_VISIBILITY
-    dynarray(initializer_list<value_type>);
-
-//  We're not implementing these right now.
-//  Updated with the resolution of LWG issue #2255
-//     template <typename _Alloc>
-//       dynarray(allocator_arg_t, const _Alloc& __alloc, size_type __c);
-//     template <typename _Alloc>
-//       dynarray(allocator_arg_t, const _Alloc& __alloc, size_type __c, const value_type& __v);
-//     template <typename _Alloc>
-//       dynarray(allocator_arg_t, const _Alloc& __alloc, const dynarray& __d);
-//     template <typename _Alloc>
-//       dynarray(allocator_arg_t, const _Alloc& __alloc, initializer_list<value_type>);
-
-    dynarray& operator=(const dynarray&) = delete;
-    _LIBCPP_INLINE_VISIBILITY
-    ~dynarray();
-
-    // iterators:
-    inline _LIBCPP_INLINE_VISIBILITY iterator       begin()        noexcept { return iterator(data()); }
-    inline _LIBCPP_INLINE_VISIBILITY const_iterator begin()  const noexcept { return const_iterator(data()); }
-    inline _LIBCPP_INLINE_VISIBILITY const_iterator cbegin() const noexcept { return const_iterator(data()); }
-    inline _LIBCPP_INLINE_VISIBILITY iterator       end()          noexcept { return iterator(data() + __size_); }
-    inline _LIBCPP_INLINE_VISIBILITY const_iterator end()    const noexcept { return const_iterator(data() + __size_); }
-    inline _LIBCPP_INLINE_VISIBILITY const_iterator cend()   const noexcept { return const_iterator(data() + __size_); }
-
-    inline _LIBCPP_INLINE_VISIBILITY reverse_iterator       rbegin()        noexcept { return reverse_iterator(end()); }
-    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator rbegin()  const noexcept { return const_reverse_iterator(end()); }
-    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
-    inline _LIBCPP_INLINE_VISIBILITY reverse_iterator       rend()          noexcept { return reverse_iterator(begin()); }
-    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator rend()    const noexcept { return const_reverse_iterator(begin()); }
-    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator crend()   const noexcept { return const_reverse_iterator(begin()); }
-
-    // capacity:
-    inline _LIBCPP_INLINE_VISIBILITY size_type size()     const noexcept { return __size_; }
-    inline _LIBCPP_INLINE_VISIBILITY size_type max_size() const noexcept { return __size_; }
-    inline _LIBCPP_INLINE_VISIBILITY bool      empty()    const noexcept { return __size_ == 0; }
-
-    // element access:
-    inline _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __n)       { return data()[__n]; }
-    inline _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __n) const { return data()[__n]; }
-
-    inline _LIBCPP_INLINE_VISIBILITY reference       front()       { return data()[0]; }
-    inline _LIBCPP_INLINE_VISIBILITY const_reference front() const { return data()[0]; }
-    inline _LIBCPP_INLINE_VISIBILITY reference       back()        { return data()[__size_-1]; }
-    inline _LIBCPP_INLINE_VISIBILITY const_reference back()  const { return data()[__size_-1]; }
-
-    inline _LIBCPP_INLINE_VISIBILITY const_reference at(size_type __n) const;
-    inline _LIBCPP_INLINE_VISIBILITY reference       at(size_type __n);
-
-    // data access:
-    inline _LIBCPP_INLINE_VISIBILITY _Tp*       data()       noexcept { return __base_; }
-    inline _LIBCPP_INLINE_VISIBILITY const _Tp* data() const noexcept { return __base_; }
-
-    // mutating member functions:
-    inline _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __v) { fill_n(begin(), __size_, __v); }
-};
-
-template <class _Tp>
-inline
-dynarray<_Tp>::dynarray(size_type __c) : dynarray ()
-{
-    __base_ = __allocate (__c);
-    value_type *__data = data ();
-    for ( __size_ = 0; __size_ < __c; ++__size_, ++__data )
-        ::new (__data) value_type;
-}
-
-template <class _Tp>
-inline
-dynarray<_Tp>::dynarray(size_type __c, const value_type& __v) : dynarray ()
-{
-    __base_ = __allocate (__c);
-    value_type *__data = data ();
-    for ( __size_ = 0; __size_ < __c; ++__size_, ++__data )
-        ::new (__data) value_type (__v);
-}
-
-template <class _Tp>
-inline
-dynarray<_Tp>::dynarray(initializer_list<value_type> __il) : dynarray ()
-{
-    size_t sz = __il.size();
-    __base_ = __allocate (sz);
-    value_type *__data = data ();
-    auto src = __il.begin();
-    for ( __size_ = 0; __size_ < sz; ++__size_, ++__data, ++src )
-        ::new (__data) value_type (*src);
-}
-
-template <class _Tp>
-inline
-dynarray<_Tp>::dynarray(const dynarray& __d) : dynarray ()
-{
-    size_t sz = __d.size();
-    __base_ = __allocate (sz);
-    value_type *__data = data ();
-    auto src = __d.begin();
-    for ( __size_ = 0; __size_ < sz; ++__size_, ++__data, ++src )
-        ::new (__data) value_type (*src);
-}
-
-template <class _Tp>
-inline
-dynarray<_Tp>::~dynarray()
-{ 
-    value_type *__data = data () + __size_;
-    for ( size_t i = 0; i < __size_; ++i )
-        (--__data)->value_type::~value_type();
-    __deallocate_value( __base_ );
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename dynarray<_Tp>::reference
-dynarray<_Tp>::at(size_type __n)
-{
-    if (__n >= __size_)
-        __throw_out_of_range("dynarray::at");
-
-    return data()[__n];
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename dynarray<_Tp>::const_reference
-dynarray<_Tp>::at(size_type __n) const
-{
-    if (__n >= __size_)
-        __throw_out_of_range("dynarray::at");
-
-    return data()[__n];
-}
-
-}}}
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-template <class _Tp, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<std::experimental::dynarray<_Tp>, _Alloc> : true_type {};
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // if _LIBCPP_STD_VER > 11 
-#endif  // _LIBCPP_DYNARRAY