[libc++] Remove the need for _LIBCPP_TEMPLATE_VIS

libcxx/.clang-format

@@ -45,7 +45,6 @@ AttributeMacros: [
                   '_LIBCPP_OVERRIDABLE_FUNC_VIS',
                   '_LIBCPP_STANDALONE_DEBUG',
                   '_LIBCPP_TEMPLATE_DATA_VIS',
-                  '_LIBCPP_TEMPLATE_VIS',
                   '_LIBCPP_THREAD_SAFETY_ANNOTATION',
                   '_LIBCPP_USING_IF_EXISTS',
                   '_LIBCPP_WEAK',

libcxx/docs/DesignDocs/VisibilityMacros.rst

@@ -64,25 +64,13 @@ Visibility Macros
   ABI, we should create a new _LIBCPP_HIDE_FROM_ABI_AFTER_XXX macro, and we can
   use it to start removing symbols from the ABI after that stable version.
 
-**_LIBCPP_TEMPLATE_VIS**
-  Mark a type's typeinfo and vtable as having default visibility.
-  This macro has no effect on the visibility of the type's member functions.
-
-  **GCC Behavior**: GCC does not support Clang's `type_visibility(...)`
-  attribute. With GCC the `visibility(...)` attribute is used and member
-  functions are affected.
-
-  **Windows Behavior**: DLLs do not support dllimport/export on class templates.
-  The macro has an empty definition on this platform.
-
 **_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS**
   Mark the member functions, typeinfo, and vtable of the type named in
   an extern template declaration as being exported by the libc++ library.
   This attribute must be specified on all extern class template declarations.
 
-  This macro is used to override the `_LIBCPP_TEMPLATE_VIS` attribute
-  specified on the primary template and to export the member functions produced
-  by the explicit instantiation in the dylib.
+  This macro is used to export the member functions produced by the explicit
+  instantiation in the dylib.
 
   **Windows Behavior**: `extern template` and `dllexport` are fundamentally
   incompatible *on a class template* on Windows; the former suppresses

libcxx/include/__chrono/duration.h

@@ -32,7 +32,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace chrono {
 
 template <class _Rep, class _Period = ratio<1> >
-class _LIBCPP_TEMPLATE_VIS duration;
+class duration;
 
 template <class _Tp>
 inline const bool __is_duration_v = false;
@@ -52,7 +52,7 @@ inline const bool __is_duration_v<const volatile duration<_Rep, _Period> > = tru
 } // namespace chrono
 
 template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-struct _LIBCPP_TEMPLATE_VIS common_type<chrono::duration<_Rep1, _Period1>, chrono::duration<_Rep2, _Period2> > {
+struct common_type<chrono::duration<_Rep1, _Period1>, chrono::duration<_Rep2, _Period2> > {
   typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type, __ratio_gcd<_Period1, _Period2> > type;
 };
 
@@ -107,15 +107,15 @@ inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _ToDuration duration_cast(const d
 }
 
 template <class _Rep>
-struct _LIBCPP_TEMPLATE_VIS treat_as_floating_point : is_floating_point<_Rep> {};
+struct treat_as_floating_point : is_floating_point<_Rep> {};
 
 #if _LIBCPP_STD_VER >= 17
 template <class _Rep>
 inline constexpr bool treat_as_floating_point_v = treat_as_floating_point<_Rep>::value;
 #endif
 
 template <class _Rep>
-struct _LIBCPP_TEMPLATE_VIS duration_values {
+struct duration_values {
 public:
   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR _Rep zero() _NOEXCEPT { return _Rep(0); }
   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR _Rep max() _NOEXCEPT { return numeric_limits<_Rep>::max(); }
@@ -156,7 +156,7 @@ inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _ToDuration round(const duration<
 // duration
 
 template <class _Rep, class _Period>
-class _LIBCPP_TEMPLATE_VIS duration {
+class duration {
   static_assert(!__is_duration_v<_Rep>, "A duration representation can not be a duration");
   static_assert(__is_ratio_v<_Period>, "Second template parameter of duration must be a std::ratio");
   static_assert(_Period::num > 0, "duration period must be positive");

libcxx/include/__chrono/formatter.h

@@ -698,7 +698,7 @@ __format_chrono(const _Tp& __value,
 } // namespace __formatter
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS __formatter_chrono {
+struct __formatter_chrono {
 public:
   template <class _ParseContext>
   _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator
@@ -716,7 +716,7 @@ struct _LIBCPP_TEMPLATE_VIS __formatter_chrono {
 };
 
 template <class _Duration, __fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::sys_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::sys_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -730,7 +730,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::sys_time<_Duration>, _CharT> : pub
 #      if _LIBCPP_HAS_EXPERIMENTAL_TZDB
 
 template <class _Duration, __fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::utc_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::utc_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -741,7 +741,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::utc_time<_Duration>, _CharT> : pub
 };
 
 template <class _Duration, __fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::tai_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::tai_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -752,7 +752,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::tai_time<_Duration>, _CharT> : pub
 };
 
 template <class _Duration, __fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::gps_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::gps_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -766,7 +766,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::gps_time<_Duration>, _CharT> : pub
 #    endif   // _LIBCPP_HAS_TIME_ZONE_DATABASE && _LIBCPP_HAS_FILESYSTEM
 
 template <class _Duration, __fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::file_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::file_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -777,7 +777,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::file_time<_Duration>, _CharT> : pu
 };
 
 template <class _Duration, __fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::local_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::local_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -811,7 +811,7 @@ struct formatter<chrono::duration<_Rep, _Period>, _CharT> : public __formatter_c
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::day, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::day, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -822,7 +822,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::day, _CharT> : public __formatter_
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::month, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -833,7 +833,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month, _CharT> : public __formatte
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::year, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -844,7 +844,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year, _CharT> : public __formatter
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::weekday, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -855,7 +855,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday, _CharT> : public __format
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday_indexed, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::weekday_indexed, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -866,7 +866,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday_indexed, _CharT> : public
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday_last, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::weekday_last, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -877,7 +877,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday_last, _CharT> : public __f
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_day, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::month_day, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -888,7 +888,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_day, _CharT> : public __form
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_day_last, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::month_day_last, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -899,7 +899,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_day_last, _CharT> : public _
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_weekday, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::month_weekday, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -910,7 +910,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_weekday, _CharT> : public __
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_weekday_last, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::month_weekday_last, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -921,7 +921,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_weekday_last, _CharT> : publ
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::year_month, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -932,7 +932,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month, _CharT> : public __for
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_day, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::year_month_day, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -943,7 +943,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_day, _CharT> : public _
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_day_last, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::year_month_day_last, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -954,7 +954,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_day_last, _CharT> : pub
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_weekday, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::year_month_weekday, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 
@@ -965,7 +965,7 @@ struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_weekday, _CharT> : publ
 };
 
 template <__fmt_char_type _CharT>
-struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_weekday_last, _CharT> : public __formatter_chrono<_CharT> {
+struct formatter<chrono::year_month_weekday_last, _CharT> : public __formatter_chrono<_CharT> {
 public:
   using _Base _LIBCPP_NODEBUG = __formatter_chrono<_CharT>;
 

libcxx/include/__chrono/parser_std_format_spec.h

@@ -139,7 +139,7 @@ _LIBCPP_HIDE_FROM_ABI constexpr void __validate_time_zone(__flags __flags) {
 }
 
 template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS __parser_chrono {
+class __parser_chrono {
   using _ConstIterator _LIBCPP_NODEBUG = typename basic_format_parse_context<_CharT>::const_iterator;
 
 public:

libcxx/include/__chrono/time_point.h

@@ -31,7 +31,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace chrono {
 
 template <class _Clock, class _Duration = typename _Clock::duration>
-class _LIBCPP_TEMPLATE_VIS time_point {
+class time_point {
   static_assert(__is_duration_v<_Duration>, "Second template parameter of time_point must be a std::chrono::duration");
 
 public:
@@ -76,8 +76,7 @@ class _LIBCPP_TEMPLATE_VIS time_point {
 } // namespace chrono
 
 template <class _Clock, class _Duration1, class _Duration2>
-struct _LIBCPP_TEMPLATE_VIS
-common_type<chrono::time_point<_Clock, _Duration1>, chrono::time_point<_Clock, _Duration2> > {
+struct common_type<chrono::time_point<_Clock, _Duration1>, chrono::time_point<_Clock, _Duration2> > {
   typedef chrono::time_point<_Clock, typename common_type<_Duration1, _Duration2>::type> type;
 };
 

libcxx/include/__compare/common_comparison_category.h

@@ -72,7 +72,7 @@ _LIBCPP_HIDE_FROM_ABI constexpr auto __get_comp_type() {
 
 // [cmp.common], common comparison category type
 template <class... _Ts>
-struct _LIBCPP_TEMPLATE_VIS common_comparison_category {
+struct common_comparison_category {
   using type _LIBCPP_NODEBUG = decltype(__comp_detail::__get_comp_type<_Ts...>());
 };
 

libcxx/include/__compare/compare_three_way.h

@@ -22,7 +22,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if _LIBCPP_STD_VER >= 20
 
-struct _LIBCPP_TEMPLATE_VIS compare_three_way {
+struct compare_three_way {
   template <class _T1, class _T2>
     requires three_way_comparable_with<_T1, _T2>
   constexpr _LIBCPP_HIDE_FROM_ABI auto operator()(_T1&& __t, _T2&& __u) const

libcxx/include/__compare/compare_three_way_result.h

@@ -34,8 +34,7 @@ struct _LIBCPP_HIDE_FROM_ABI __compare_three_way_result<
 };
 
 template <class _Tp, class _Up = _Tp>
-struct _LIBCPP_TEMPLATE_VIS _LIBCPP_NO_SPECIALIZATIONS compare_three_way_result
-    : __compare_three_way_result<_Tp, _Up, void> {};
+struct _LIBCPP_NO_SPECIALIZATIONS compare_three_way_result : __compare_three_way_result<_Tp, _Up, void> {};
 
 template <class _Tp, class _Up = _Tp>
 using compare_three_way_result_t = typename compare_three_way_result<_Tp, _Up>::type;

libcxx/include/__config

@@ -389,9 +389,8 @@ typedef __char32_t char32_t;
 
 #    define _LIBCPP_HIDDEN
 #    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-#    define _LIBCPP_TEMPLATE_VIS
 #    define _LIBCPP_TEMPLATE_DATA_VIS
-#    define _LIBCPP_TYPE_VISIBILITY_DEFAULT
+#    define _LIBCPP_NAMESPACE_VISIBILITY
 
 #  else
 
@@ -419,17 +418,12 @@ typedef __char32_t char32_t;
 #      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
 #    endif
 
-// GCC doesn't support the type_visibility attribute, so we have to keep the visibility attribute on templates
-#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && !__has_attribute(__type_visibility__)
-#      define _LIBCPP_TEMPLATE_VIS __attribute__((__visibility__("default")))
-#    else
-#      define _LIBCPP_TEMPLATE_VIS
-#    endif
-
 #    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__)
-#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT __attribute__((__type_visibility__("default")))
+#      define _LIBCPP_NAMESPACE_VISIBILITY __attribute__((__type_visibility__("default")))
+#    elif !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
+#      define _LIBCPP_NAMESPACE_VISIBILITY __attribute__((__visibility__("default")))
 #    else
-#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT
+#      define _LIBCPP_NAMESPACE_VISIBILITY
 #    endif
 
 #  endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)
@@ -577,15 +571,17 @@ typedef __char32_t char32_t;
 #    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS
 #  endif
 
-// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
 // clang-format off
-#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                               \
-                                      namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std {                                  \
-                               inline namespace _LIBCPP_ABI_NAMESPACE {
-#  define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_POP_EXTENSION_DIAGNOSTICS
+#  define _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD                                                                      \
+    _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS namespace _LIBCPP_NAMESPACE_VISIBILITY std {
+
+#  define _LIBCPP_END_UNVERSIONED_NAMESPACE_STD } _LIBCPP_POP_EXTENSION_DIAGNOSTICS
+
+#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD inline namespace _LIBCPP_ABI_NAMESPACE {
+#  define _LIBCPP_END_NAMESPACE_STD } _LIBCPP_END_UNVERSIONED_NAMESPACE_STD
 
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace std { namespace experimental {
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL }}
+#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL _LIBCPP_BEGIN_UNVERSIONED_NAMESPACE_STD namespace experimental {
+#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL } _LIBCPP_END_UNVERSIONED_NAMESPACE_STD
 
 #define _LIBCPP_BEGIN_NAMESPACE_LFTS _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v1 {
 #define _LIBCPP_END_NAMESPACE_LFTS } _LIBCPP_END_NAMESPACE_EXPERIMENTAL