Tweaks from libstdc++-v3 reflection patch review.

2026-02-21 19:35:36 -05:00 · 2025-11-15 11:14:00 +01:00
parent b0cde4d637
commit 6ed71bbf5d
9 changed files with 79 additions and 175 deletions
--- a/libstdc++-v3/include/std/meta
+++ b/libstdc++-v3/include/std/meta
@@ -33,6 +33,11 @@
 #pragma GCC system_header
 #endif

+#define __glibcxx_want_reflection
+#include <bits/version.h>
+
+#if __glibcxx_reflection >= 202506L // C++ >= 26 && __cpp_impl_reflection
+
 #include <array>
 #include <initializer_list>
 #include <optional>
@@ -42,11 +47,6 @@
 #include <string_view>
 #include <vector>

-#define __glibcxx_want_reflection
-#include <bits/version.h>
-
-#if __glibcxx_reflection >= 202506L // C++ >= 26 && __cpp_impl_reflection
-
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -94,15 +94,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      source_location _M_where;

    public:
-      consteval exception(u8string_view __what, info __from,
-			  source_location __where
-			  = source_location::current()) noexcept
+      consteval
+      exception(u8string_view __what, info __from,
+		source_location __where = source_location::current()) noexcept
 	: _M_what{_S_exception_cvt_from_utf8(__what)}, _M_u8what{__what},
 	  _M_from{__from}, _M_where{__where} {}

-      consteval exception(string_view __what, info __from,
-			  source_location __where
-			  = source_location::current()) noexcept
+      consteval
+      exception(string_view __what, info __from,
+		source_location __where = source_location::current()) noexcept
 	: _M_what{__what}, _M_u8what{_S_exception_cvt_to_utf8(__what)},
 	  _M_from{__from}, _M_where{__where} {}

@@ -112,7 +112,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      exception& operator=(const exception&) = default;
      exception& operator=(exception&&) = default;

-      consteval const char *what() const noexcept override
+      consteval const char*
+      what() const noexcept override
      {
 	// If u8string is not empty and string is empty, conversion
 	// from UTF-8 to ordinary literal encoding failed.
@@ -128,10 +129,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      // Helper special template metafunctions to convert from UTF-8 to
      // ordinary literal encoding and vice versa.  On conversion failure
      // they just return an empty {,u8}string_view.
-      template<ranges::input_range _R>
-	static consteval u8string_view _S_exception_cvt_to_utf8(_R&&);
-      template<ranges::input_range _R>
-	static consteval string_view _S_exception_cvt_from_utf8(_R&&);
+      template<ranges::input_range _Rg>
+	static consteval u8string_view _S_exception_cvt_to_utf8(_Rg&&);
+      template<ranges::input_range _Rg>
+	static consteval string_view _S_exception_cvt_from_utf8(_Rg&&);
    };

    // [meta.reflection.operators], operator representations
@@ -363,15 +364,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      consteval _Tp extract(info);

    // [meta.reflection.substitute], reflection substitution
-    template<class _R>
-      concept reflection_range = ranges::input_range<_R>
-	&& same_as<ranges::range_value_t<_R>, info>
-	&& same_as<remove_cvref_t<ranges::range_reference_t<_R>>, info>;
+    template<class _Rg>
+      concept reflection_range = ranges::input_range<_Rg>
+	&& same_as<ranges::range_value_t<_Rg>, info>
+	&& same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>, info>;

-    template<reflection_range _R = initializer_list<info>>
-      consteval bool can_substitute(info, _R&&);
-    template<reflection_range _R = initializer_list<info>>
-      consteval info substitute(info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool can_substitute(info, _Rg&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval info substitute(info, _Rg&&);

    // [meta.reflection.result], expression result reflection
    template<typename _Tp>
@@ -385,11 +386,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      consteval info reflect_function(_Tp&);

    // [meta.reflection.array], promoting to static storage arrays
-    template<ranges::input_range _R>
-      consteval info reflect_constant_string(_R&&);
+    template<ranges::input_range _Rg>
+      consteval info reflect_constant_string(_Rg&&);

-    template<ranges::input_range _R>
-      consteval info reflect_constant_array(_R&&);
+    template<ranges::input_range _Rg>
+      consteval info reflect_constant_array(_Rg&&);

    // [meta.reflection.define.aggregate], class definition generation
    struct data_member_options {
@@ -416,8 +417,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    };
    consteval info data_member_spec(info, data_member_options);
    consteval bool is_data_member_spec(info);
-    template<reflection_range _R = initializer_list<info>>
-      consteval info define_aggregate(info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval info define_aggregate(info, _Rg&&);

    // associated with [meta.unary.cat], primary type categories
    consteval bool is_void_type(info);
@@ -462,8 +463,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    consteval bool is_unbounded_array_type(info);
    consteval bool is_scoped_enum_type(info);

-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_constructible_type(info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_constructible_type(info, _Rg&&);
    consteval bool is_default_constructible_type(info);
    consteval bool is_copy_constructible_type(info);
    consteval bool is_move_constructible_type(info);
@@ -477,8 +478,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION

    consteval bool is_destructible_type(info);

-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_trivially_constructible_type(info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_trivially_constructible_type(info, _Rg&&);
    consteval bool is_trivially_default_constructible_type(info);
    consteval bool is_trivially_copy_constructible_type(info);
    consteval bool is_trivially_move_constructible_type(info);
@@ -488,8 +489,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    consteval bool is_trivially_move_assignable_type(info);
    consteval bool is_trivially_destructible_type(info);

-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_nothrow_constructible_type(info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_nothrow_constructible_type(info, _Rg&&);
    consteval bool is_nothrow_default_constructible_type(info);
    consteval bool is_nothrow_copy_constructible_type(info);
    consteval bool is_nothrow_move_constructible_type(info);
@@ -525,15 +526,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    consteval bool is_layout_compatible_type(info, info);
    consteval bool is_pointer_interconvertible_base_of_type(info, info);

-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_invocable_type(info, _R&&);
-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_invocable_r_type(info, info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_invocable_type(info, _Rg&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_invocable_r_type(info, info, _Rg&&);

-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_nothrow_invocable_type(info, _R&&);
-    template<reflection_range _R = initializer_list<info>>
-      consteval bool is_nothrow_invocable_r_type(info, info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_nothrow_invocable_type(info, _Rg&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval bool is_nothrow_invocable_r_type(info, info, _Rg&&);

    // associated with [meta.trans.cv], const-volatile modifications
    consteval info remove_const(info);
@@ -563,13 +564,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    // associated with [meta.trans.other], other transformations
    consteval info remove_cvref(info);
    consteval info decay(info);
-    template<reflection_range _R = initializer_list<info>>
-      consteval info common_type(_R&&);
-    template<reflection_range _R = initializer_list<info>>
-      consteval info common_reference(_R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval info common_type(_Rg&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval info common_reference(_Rg&&);
    consteval info underlying_type(info);
-    template<reflection_range _R = initializer_list<info>>
-      consteval info invoke_result(info, _R&&);
+    template<reflection_range _Rg = initializer_list<info>>
+      consteval info invoke_result(info, _Rg&&);
    consteval info unwrap_reference(info);
    consteval info unwrap_ref_decay(info);

@@ -597,6 +598,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 				       "or complete class type reflection",
 				     ^^access_context::via);
 #else
+	  asm("");
 	  return *this;
 #endif
 	}
@@ -606,19 +608,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  } // namespace meta

  // [meta.define.static], promoting to static storage strings
-  template<ranges::input_range _R>
-    consteval const ranges::range_value_t<_R>*
-    define_static_string(_R&& __r)
+  template<ranges::input_range _Rg>
+    consteval const ranges::range_value_t<_Rg>*
+    define_static_string(_Rg&& __r)
    {
      auto __str = meta::reflect_constant_string(__r);
-      return meta::extract<const ranges::range_value_t<_R>*>(__str);
+      return meta::extract<const ranges::range_value_t<_Rg>*>(__str);
    }

-  template<ranges::input_range _R>
-    consteval span<const ranges::range_value_t<_R>>
-    define_static_array(_R&& __r)
+  template<ranges::input_range _Rg>
+    consteval span<const ranges::range_value_t<_Rg>>
+    define_static_array(_Rg&& __r)
    {
-      using _Tp = ranges::range_value_t<_R>;
+      using _Tp = ranges::range_value_t<_Rg>;
      auto __array = meta::reflect_constant_array(__r);
      auto __type = meta::type_of(__array);
      if (meta::is_array_type(__type))
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -834,19 +834,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    { };

  /// is_fundamental
+  template<typename _Tp>
+    struct is_fundamental
+    : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
+		   is_null_pointer<_Tp>
 #if __cpp_impl_reflection >= 202500L
-  template<typename _Tp>
-    struct is_fundamental
-    : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
-		   is_null_pointer<_Tp>, is_reflection<_Tp>>::type
-    { };
-#else
-  template<typename _Tp>
-    struct is_fundamental
-    : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
-		   is_null_pointer<_Tp>>::type
-    { };
+		   , is_reflection<_Tp>
 #endif
+		   >::type
+    { };

  /// is_object
 #if _GLIBCXX_USE_BUILTIN_TRAIT(__is_object)
@@ -3561,8 +3557,15 @@ template <typename _Tp>

 #if __cpp_impl_reflection >= 202500L // C++ >= 26
 template <typename _Tp>
-  inline constexpr bool is_reflection_v =
-    is_reflection<_Tp>::value;
+  inline constexpr bool is_reflection_v = false;
+template <>
+  inline constexpr bool is_reflection_v<decltype(^^int)> = true;
+template <>
+  inline constexpr bool is_reflection_v<const decltype(^^int)> = true;
+template <>
+  inline constexpr bool is_reflection_v<volatile decltype(^^int)> = true;
+template <>
+  inline constexpr bool is_reflection_v<const volatile decltype(^^int)> = true;
 #endif

 template <typename _Tp>
--- a/libstdc++-v3/testsuite/20_util/is_consteval_only/requirements/explicit_instantiation.cc
+++ b/libstdc++-v3/testsuite/20_util/is_consteval_only/requirements/explicit_instantiation.cc
@@ -1,23 +1,6 @@
 // { dg-do compile { target c++26 } }
 // { dg-additional-options "-freflection" }

-// Copyright (C) 2025 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
 // NB: This file is for testing type_traits with NO OTHER INCLUDES.

 #include <type_traits>
--- a/libstdc++-v3/testsuite/20_util/is_consteval_only/requirements/typedefs.cc
+++ b/libstdc++-v3/testsuite/20_util/is_consteval_only/requirements/typedefs.cc
@@ -1,24 +1,6 @@
 // { dg-do compile { target c++26 } }
 // { dg-additional-options "-freflection" }

-// Copyright (C) 2025 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-// 
 // NB: This file is for testing type_traits with NO OTHER INCLUDES.

 #include <type_traits>
--- a/libstdc++-v3/testsuite/20_util/is_consteval_only/value.cc
+++ b/libstdc++-v3/testsuite/20_util/is_consteval_only/value.cc
@@ -1,23 +1,6 @@
 // { dg-do compile { target c++26 } }
 // { dg-additional-options "-freflection" }

-// Copyright (C) 2025 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
 #include <type_traits>
 #include <testsuite_tr1.h>

--- a/libstdc++-v3/testsuite/20_util/is_reflection/requirements/explicit_instantiation.cc
+++ b/libstdc++-v3/testsuite/20_util/is_reflection/requirements/explicit_instantiation.cc
@@ -1,23 +1,6 @@
 // { dg-do compile { target c++26 } }
 // { dg-additional-options "-freflection" }

-// Copyright (C) 2025 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
 // NB: This file is for testing type_traits with NO OTHER INCLUDES.

 #include <type_traits>
--- a/libstdc++-v3/testsuite/20_util/is_reflection/requirements/typedefs.cc
+++ b/libstdc++-v3/testsuite/20_util/is_reflection/requirements/typedefs.cc
@@ -1,24 +1,6 @@
 // { dg-do compile { target c++26 } }
 // { dg-additional-options "-freflection" }

-// Copyright (C) 2025 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
-// 
 // NB: This file is for testing type_traits with NO OTHER INCLUDES.

 #include <type_traits>
--- a/libstdc++-v3/testsuite/20_util/is_reflection/value.cc
+++ b/libstdc++-v3/testsuite/20_util/is_reflection/value.cc
@@ -1,23 +1,6 @@
 // { dg-do compile { target c++26 } }
 // { dg-additional-options "-freflection" }

-// Copyright (C) 2025 Free Software Foundation, Inc.
-//
-// This file is part of the GNU ISO C++ Library.  This library is free
-// software; you can redistribute it and/or modify it under the
-// terms of the GNU General Public License as published by the
-// Free Software Foundation; either version 3, or (at your option)
-// any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License along
-// with this library; see the file COPYING3.  If not see
-// <http://www.gnu.org/licenses/>.
-
 #include <type_traits>
 #include <testsuite_tr1.h>

--- a/libstdc++-v3/testsuite/20_util/variable_templates_for_traits.cc
+++ b/libstdc++-v3/testsuite/20_util/variable_templates_for_traits.cc
@@ -335,6 +335,9 @@ static_assert(!is_convertible_v<const int&, int&>
 static_assert(is_reflection_v<decltype(^^int)>
 	      && is_reflection<decltype(^^int)>::value, "");
 static_assert(!is_reflection_v<int> && !is_reflection<int>::value, "");
+static_assert(is_consteval_only_v<decltype(^^int)>
+	      && is_consteval_only<decltype(^^int)>::value, "");
+static_assert(!is_consteval_only_v<int> && !is_consteval_only<int>::value, "");
 #endif

 static_assert(negation_v<false_type>, "");