[libc++] Require concepts support for <numbers>

[ldionne]

Summary

Similar to <concepts> we need to protect the header and test against inclusion and being run if concepts aren't supported by the compiler.

[tambre]

D77505 broke a bunch of bots. This fixes the regression.

I lack commit privileges. Please land as "Raul Tambre <[e-mail]>"

[kamleshbhalui]

In D82171#2103042, @tambre wrote:

D77505 broke a bunch of bots. This fixes the regression.

I lack commit privileges. Please land as "Raul Tambre <[e-mail]>"

you need to fix this test file too libcxx/test/std/language.support/support.limits/support.limits.general/numbers.version.pass.cpp.

[ldionne]

Fix feature-test macro generation

[ldionne]

Thanks @tambre , going to commit this now.

libcxx/utils/generate_feature_test_macro_components.py

607

@tambre This is the part that was missing. I added that and re-generated the files.

libcxx/include/numbers

namespace std::numbers {
   inline constexpr double inv_sqrt3  = inv_sqrt3_v<double>;
   inline constexpr double egamma     = egamma_v<double>;
   inline constexpr double phi        = phi_v<double>;
 }
 */
 
 #include <__config>
 
-#if _LIBCPP_STD_VER > 17
+#if _LIBCPP_STD_VER > 17 && defined(__cpp_concepts) && __cpp_concepts >= 201811L
 
 #include <type_traits>
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 

 inline constexpr double phi        = phi_v<double>;
 
 } // namespace numbers
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
-#endif //_LIBCPP_STD_VER > 17
+#endif //_LIBCPP_STD_VER > 17 && defined(__cpp_concepts) && __cpp_concepts >= 201811L
 
 #endif // _LIBCPP_NUMBERS

libcxx/include/version

 # define __cpp_lib_endian                               201907L
 # define __cpp_lib_erase_if                             202002L
 // # define __cpp_lib_generic_unordered_lookup             201811L
 # define __cpp_lib_interpolate                          201902L
 # if !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
 #   define __cpp_lib_is_constant_evaluated              201811L
 # endif
 # define __cpp_lib_list_remove_return_type              201806L
-# define __cpp_lib_math_constants                       201907L
+# if defined(__cpp_concepts) && __cpp_concepts >= 201811L
+#   define __cpp_lib_math_constants                     201907L
+# endif
 // # define __cpp_lib_ranges                               201811L
 # define __cpp_lib_span                                 202002L
 // # define __cpp_lib_three_way_comparison                 201711L
 # define __cpp_lib_to_array                             201907L
 #endif
 
 #endif // _LIBCPP_VERSIONH

libcxx/test/std/language.support/support.limits/support.limits.general/numbers.version.pass.cpp

 #elif TEST_STD_VER == 17
 
 # ifdef __cpp_lib_math_constants
 #   error "__cpp_lib_math_constants should not be defined before c++2a"
 # endif
 
 #elif TEST_STD_VER > 17
 
-# ifndef __cpp_lib_math_constants
-#   error "__cpp_lib_math_constants should be defined in c++2a"
-# endif
-# if __cpp_lib_math_constants != 201907L
-#   error "__cpp_lib_math_constants should have the value 201907L in c++2a"
-# endif
+# if defined(__cpp_concepts) && __cpp_concepts >= 201811L
+#   ifndef __cpp_lib_math_constants
+#     error "__cpp_lib_math_constants should be defined in c++2a"
+#   endif
+#   if __cpp_lib_math_constants != 201907L
+#     error "__cpp_lib_math_constants should have the value 201907L in c++2a"
+#   endif
+# else
+#   ifdef __cpp_lib_math_constants
+#     error "__cpp_lib_math_constants should not be defined when defined(__cpp_concepts) && __cpp_concepts >= 201811L is not defined!"
+#   endif
+# endif
 
 #endif // TEST_STD_VER > 17
 
 int main(int, char**) { return 0; }

libcxx/test/std/language.support/support.limits/support.limits.general/version.version.pass.cpp

 
 # ifndef __cpp_lib_map_try_emplace
 #   error "__cpp_lib_map_try_emplace should be defined in c++2a"
 # endif
 # if __cpp_lib_map_try_emplace != 201411L
 #   error "__cpp_lib_map_try_emplace should have the value 201411L in c++2a"
 # endif
 
-# ifndef __cpp_lib_math_constants
-#   error "__cpp_lib_math_constants should be defined in c++2a"
-# endif
-# if __cpp_lib_math_constants != 201907L
-#   error "__cpp_lib_math_constants should have the value 201907L in c++2a"
-# endif
+# if defined(__cpp_concepts) && __cpp_concepts >= 201811L
+#   ifndef __cpp_lib_math_constants
+#     error "__cpp_lib_math_constants should be defined in c++2a"
+#   endif
+#   if __cpp_lib_math_constants != 201907L
+#     error "__cpp_lib_math_constants should have the value 201907L in c++2a"
+#   endif
+# else
+#   ifdef __cpp_lib_math_constants
+#     error "__cpp_lib_math_constants should not be defined when defined(__cpp_concepts) && __cpp_concepts >= 201811L is not defined!"
+#   endif
+# endif
 
 # if !defined(_LIBCPP_VERSION)
 #   ifndef __cpp_lib_math_special_functions
 #     error "__cpp_lib_math_special_functions should be defined in c++2a"
 #   endif
 #   if __cpp_lib_math_special_functions != 201603L
 #     error "__cpp_lib_math_special_functions should have the value 201603L in c++2a"
 #   endif

libcxx/test/std/numerics/numbers/defined.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
 
 #include <numbers>
 
 // We are testing if these are defined by taking an address. Don't care if the result is unused.
 #if defined(__clang__)
 #   pragma clang diagnostic ignored "-Wunused-variable"
 #endif
 

libcxx/test/std/numerics/numbers/illformed.verify.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
 
 #include <numbers>
 
 // Initializing the primary template is ill-formed.
 int log2e{std::numbers::log2e_v<
     int>}; // expected-error-re@numbers:* {{static_assert failed {{.*}} "A program that instantiates a primary template of a mathematical constant variable template is ill-formed."}}
 int log10e{std::numbers::log10e_v<int>};
 int pi{std::numbers::pi_v<int>};

libcxx/test/std/numerics/numbers/specialize.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
 
 #include <cassert>
 #include <numbers>
 
 // We are testing if template instantiation works. Don't care if the result is unused.
 #if defined(__clang__)
 #   pragma clang diagnostic ignored "-Wunused-variable"
 #endif

libcxx/test/std/numerics/numbers/user_type.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
 
 #include <numbers>
 
 struct user {
   int value;
 };
 
 template <>

libcxx/test/std/numerics/numbers/value.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
 
 #include <cassert>
 #include <numbers>
 
 constexpr bool tests() {
   assert(std::numbers::e == 0x1.5bf0a8b145769p+1);
   assert(std::numbers::e_v<double> == 0x1.5bf0a8b145769p+1);
   assert(std::numbers::e_v<long double> == 0x1.5bf0a8b145769p+1l);

libcxx/utils/generate_feature_test_macro_components.py

feature_test_macros = sorted([ add_version_header(x) for x in [
    },
    "headers": ["span"],
    },
   {"name": "__cpp_lib_math_constants",
    "values": {
      "c++2a": int(201907),
    },
    "headers": ["numbers"],
+   "depends": "defined(__cpp_concepts) && __cpp_concepts >= 201811L",
+   "internal_depends": "defined(__cpp_concepts) && __cpp_concepts >= 201811L",
    },
 ]], key=lambda tc: tc["name"])
 
 def get_std_dialects():
   std_dialects = ['c++14', 'c++17', 'c++2a']
   return list(std_dialects)
 
 def get_first_std(d):