[libc++] Improves feature-test macro diagnostics.

[Mordante]

Summary

This was mentioned in review D131326.

[var-const]

Thanks for addressing this! I think this reads a lot better than the previous version. The double negation is still there, but it looks like it would require disproportional effort to get rid of that, and this looks like a very nice improvement.

libcxx/utils/generate_feature_test_macro_components.py

985

Optional: do you think surrounding the expanded text with some symbol (e.g. quotes or backticks) will make the resulting string easier to read? E.g. (note the quotes):

__cpp_lib_shared_mutex should not be defined when the requirement "!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)" is not met!

[Mordante]

Thanks for the reviews!

libcxx/utils/generate_feature_test_macro_components.py

985

Good suggestion: I will use the single quote to avoid escapes in the generated message.

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

 #   ifndef __cpp_lib_atomic_wait
 #     error "__cpp_lib_atomic_wait should be defined in c++20"
 #   endif
 #   if __cpp_lib_atomic_wait != 201907L
 #     error "__cpp_lib_atomic_wait should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_atomic_wait
-#     error "__cpp_lib_atomic_wait should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait) is not defined!"
+#     error "__cpp_lib_atomic_wait should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait)' is not met!"
 #   endif
 # endif
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # ifndef __cpp_lib_atomic_flag_test
 #   error "__cpp_lib_atomic_flag_test should be defined in c++2b"
 # endif

 #   ifndef __cpp_lib_atomic_wait
 #     error "__cpp_lib_atomic_wait should be defined in c++2b"
 #   endif
 #   if __cpp_lib_atomic_wait != 201907L
 #     error "__cpp_lib_atomic_wait should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_atomic_wait
-#     error "__cpp_lib_atomic_wait should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait) is not defined!"
+#     error "__cpp_lib_atomic_wait should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait)' is not met!"
 #   endif
 # endif
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_barrier
 #     error "__cpp_lib_barrier should be defined in c++20"
 #   endif
 #   if __cpp_lib_barrier != 201907L
 #     error "__cpp_lib_barrier should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_barrier
-#     error "__cpp_lib_barrier should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier) is not defined!"
+#     error "__cpp_lib_barrier should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)
 #   ifndef __cpp_lib_barrier
 #     error "__cpp_lib_barrier should be defined in c++2b"
 #   endif
 #   if __cpp_lib_barrier != 201907L
 #     error "__cpp_lib_barrier should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_barrier
-#     error "__cpp_lib_barrier should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier) is not defined!"
+#     error "__cpp_lib_barrier should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_filesystem
 #     error "__cpp_lib_filesystem should be defined in c++17"
 #   endif
 #   if __cpp_lib_filesystem != 201703L
 #     error "__cpp_lib_filesystem should have the value 201703L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_filesystem
-#     error "__cpp_lib_filesystem should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem) is not defined!"
+#     error "__cpp_lib_filesystem should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER == 20
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)
 #   ifndef __cpp_lib_filesystem
 #     error "__cpp_lib_filesystem should be defined in c++20"
 #   endif
 #   if __cpp_lib_filesystem != 201703L
 #     error "__cpp_lib_filesystem should have the value 201703L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_filesystem
-#     error "__cpp_lib_filesystem should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem) is not defined!"
+#     error "__cpp_lib_filesystem should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)
 #   ifndef __cpp_lib_filesystem
 #     error "__cpp_lib_filesystem should be defined in c++2b"
 #   endif
 #   if __cpp_lib_filesystem != 201703L
 #     error "__cpp_lib_filesystem should have the value 201703L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_filesystem
-#     error "__cpp_lib_filesystem should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem) is not defined!"
+#     error "__cpp_lib_filesystem should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_format
 #     error "__cpp_lib_format should be defined in c++20"
 #   endif
 #   if __cpp_lib_format != 202106L
 #     error "__cpp_lib_format should have the value 202106L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_format
-#     error "__cpp_lib_format should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT) is not defined!"
+#     error "__cpp_lib_format should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)
 #   ifndef __cpp_lib_format
 #     error "__cpp_lib_format should be defined in c++2b"
 #   endif
 #   if __cpp_lib_format != 202106L
 #     error "__cpp_lib_format should have the value 202106L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_format
-#     error "__cpp_lib_format should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT) is not defined!"
+#     error "__cpp_lib_format should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_latch
 #     error "__cpp_lib_latch should be defined in c++20"
 #   endif
 #   if __cpp_lib_latch != 201907L
 #     error "__cpp_lib_latch should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_latch
-#     error "__cpp_lib_latch should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch) is not defined!"
+#     error "__cpp_lib_latch should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch)
 #   ifndef __cpp_lib_latch
 #     error "__cpp_lib_latch should be defined in c++2b"
 #   endif
 #   if __cpp_lib_latch != 201907L
 #     error "__cpp_lib_latch should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_latch
-#     error "__cpp_lib_latch should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch) is not defined!"
+#     error "__cpp_lib_latch should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_hardware_interference_size
 #     error "__cpp_lib_hardware_interference_size should be defined in c++17"
 #   endif
 #   if __cpp_lib_hardware_interference_size != 201703L
 #     error "__cpp_lib_hardware_interference_size should have the value 201703L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_hardware_interference_size
-#     error "__cpp_lib_hardware_interference_size should not be defined when defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE) is not defined!"
+#     error "__cpp_lib_hardware_interference_size should not be defined when the requirement 'defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_launder
 #   error "__cpp_lib_launder should be defined in c++17"
 # endif
 # if __cpp_lib_launder != 201606L
 #   error "__cpp_lib_launder should have the value 201606L in c++17"
 # endif
 
 #elif TEST_STD_VER == 20
 
 # if TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L
 #   ifndef __cpp_lib_destroying_delete
 #     error "__cpp_lib_destroying_delete should be defined in c++20"
 #   endif
 #   if __cpp_lib_destroying_delete != 201806L
 #     error "__cpp_lib_destroying_delete should have the value 201806L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_destroying_delete
-#     error "__cpp_lib_destroying_delete should not be defined when TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L is not defined!"
+#     error "__cpp_lib_destroying_delete should not be defined when the requirement 'TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L' is not met!"
 #   endif
 # endif
 
 # if defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)
 #   ifndef __cpp_lib_hardware_interference_size
 #     error "__cpp_lib_hardware_interference_size should be defined in c++20"
 #   endif
 #   if __cpp_lib_hardware_interference_size != 201703L
 #     error "__cpp_lib_hardware_interference_size should have the value 201703L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_hardware_interference_size
-#     error "__cpp_lib_hardware_interference_size should not be defined when defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE) is not defined!"
+#     error "__cpp_lib_hardware_interference_size should not be defined when the requirement 'defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_launder
 #   error "__cpp_lib_launder should be defined in c++20"
 # endif
 # if __cpp_lib_launder != 201606L
 #   error "__cpp_lib_launder should have the value 201606L in c++20"
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L
 #   ifndef __cpp_lib_destroying_delete
 #     error "__cpp_lib_destroying_delete should be defined in c++2b"
 #   endif
 #   if __cpp_lib_destroying_delete != 201806L
 #     error "__cpp_lib_destroying_delete should have the value 201806L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_destroying_delete
-#     error "__cpp_lib_destroying_delete should not be defined when TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L is not defined!"
+#     error "__cpp_lib_destroying_delete should not be defined when the requirement 'TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L' is not met!"
 #   endif
 # endif
 
 # if defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)
 #   ifndef __cpp_lib_hardware_interference_size
 #     error "__cpp_lib_hardware_interference_size should be defined in c++2b"
 #   endif
 #   if __cpp_lib_hardware_interference_size != 201703L
 #     error "__cpp_lib_hardware_interference_size should have the value 201703L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_hardware_interference_size
-#     error "__cpp_lib_hardware_interference_size should not be defined when defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE) is not defined!"
+#     error "__cpp_lib_hardware_interference_size should not be defined when the requirement 'defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_launder
 #   error "__cpp_lib_launder should be defined in c++2b"
 # endif
 # if __cpp_lib_launder != 201606L
 #   error "__cpp_lib_launder should have the value 201606L in c++2b"
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if defined(__cpp_char8_t)
 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_semaphore
 #     error "__cpp_lib_semaphore should be defined in c++20"
 #   endif
 #   if __cpp_lib_semaphore != 201907L
 #     error "__cpp_lib_semaphore should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_semaphore
-#     error "__cpp_lib_semaphore should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore) is not defined!"
+#     error "__cpp_lib_semaphore should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore)
 #   ifndef __cpp_lib_semaphore
 #     error "__cpp_lib_semaphore should be defined in c++2b"
 #   endif
 #   if __cpp_lib_semaphore != 201907L
 #     error "__cpp_lib_semaphore should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_semaphore
-#     error "__cpp_lib_semaphore should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore) is not defined!"
+#     error "__cpp_lib_semaphore should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++14"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++14"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER == 17
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)
 #   ifndef __cpp_lib_shared_mutex
 #     error "__cpp_lib_shared_mutex should be defined in c++17"
 #   endif
 #   if __cpp_lib_shared_mutex != 201505L
 #     error "__cpp_lib_shared_mutex should have the value 201505L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_mutex
-#     error "__cpp_lib_shared_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex) is not defined!"
+#     error "__cpp_lib_shared_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)
 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++17"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER == 20
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)
 #   ifndef __cpp_lib_shared_mutex
 #     error "__cpp_lib_shared_mutex should be defined in c++20"
 #   endif
 #   if __cpp_lib_shared_mutex != 201505L
 #     error "__cpp_lib_shared_mutex should have the value 201505L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_mutex
-#     error "__cpp_lib_shared_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex) is not defined!"
+#     error "__cpp_lib_shared_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)
 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++20"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 20
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)
 #   ifndef __cpp_lib_shared_mutex
 #     error "__cpp_lib_shared_mutex should be defined in c++2b"
 #   endif
 #   if __cpp_lib_shared_mutex != 201505L
 #     error "__cpp_lib_shared_mutex should have the value 201505L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_mutex
-#     error "__cpp_lib_shared_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex) is not defined!"
+#     error "__cpp_lib_shared_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)
 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++2b"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 #endif // TEST_STD_VER > 20
 

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

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_constexpr_string
 #   error "__cpp_lib_constexpr_string should be defined in c++20"
 # endif
 # if __cpp_lib_constexpr_string != 201907L
 #   error "__cpp_lib_constexpr_string should have the value 201907L in c++20"

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_constexpr_string
 #   error "__cpp_lib_constexpr_string should be defined in c++2b"
 # endif
 # if __cpp_lib_constexpr_string != 201907L
 #   error "__cpp_lib_constexpr_string should have the value 201907L in c++2b"

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

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_constexpr_string_view
 #   error "__cpp_lib_constexpr_string_view should be defined in c++20"
 # endif
 # if __cpp_lib_constexpr_string_view != 201811L
 #   error "__cpp_lib_constexpr_string_view should have the value 201811L in c++20"

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_constexpr_string_view
 #   error "__cpp_lib_constexpr_string_view should be defined in c++2b"
 # endif
 # if __cpp_lib_constexpr_string_view != 201811L
 #   error "__cpp_lib_constexpr_string_view should have the value 201811L in c++2b"

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

 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++14"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++14"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 # ifdef __cpp_lib_shift
 #   error "__cpp_lib_shift should not be defined before c++20"
 # endif
 
 # ifdef __cpp_lib_smart_ptr_for_overwrite

 #   ifndef __cpp_lib_filesystem
 #     error "__cpp_lib_filesystem should be defined in c++17"
 #   endif
 #   if __cpp_lib_filesystem != 201703L
 #     error "__cpp_lib_filesystem should have the value 201703L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_filesystem
-#     error "__cpp_lib_filesystem should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem) is not defined!"
+#     error "__cpp_lib_filesystem should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)' is not met!"
 #   endif
 # endif
 
 # ifdef __cpp_lib_format
 #   error "__cpp_lib_format should not be defined before c++20"
 # endif
 
 # ifndef __cpp_lib_gcd_lcm

 #   ifndef __cpp_lib_hardware_interference_size
 #     error "__cpp_lib_hardware_interference_size should be defined in c++17"
 #   endif
 #   if __cpp_lib_hardware_interference_size != 201703L
 #     error "__cpp_lib_hardware_interference_size should have the value 201703L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_hardware_interference_size
-#     error "__cpp_lib_hardware_interference_size should not be defined when defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE) is not defined!"
+#     error "__cpp_lib_hardware_interference_size should not be defined when the requirement 'defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_has_unique_object_representations
 #   error "__cpp_lib_has_unique_object_representations should be defined in c++17"
 # endif
 # if __cpp_lib_has_unique_object_representations != 201606L
 #   error "__cpp_lib_has_unique_object_representations should have the value 201606L in c++17"

 #   ifndef __cpp_lib_shared_mutex
 #     error "__cpp_lib_shared_mutex should be defined in c++17"
 #   endif
 #   if __cpp_lib_shared_mutex != 201505L
 #     error "__cpp_lib_shared_mutex should have the value 201505L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_mutex
-#     error "__cpp_lib_shared_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex) is not defined!"
+#     error "__cpp_lib_shared_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_shared_ptr_arrays
 #   error "__cpp_lib_shared_ptr_arrays should be defined in c++17"
 # endif
 # if __cpp_lib_shared_ptr_arrays != 201611L
 #   error "__cpp_lib_shared_ptr_arrays should have the value 201611L in c++17"

 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++17"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++17"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 # ifdef __cpp_lib_shift
 #   error "__cpp_lib_shift should not be defined before c++20"
 # endif
 
 # ifdef __cpp_lib_smart_ptr_for_overwrite

 #   ifndef __cpp_lib_atomic_wait
 #     error "__cpp_lib_atomic_wait should be defined in c++20"
 #   endif
 #   if __cpp_lib_atomic_wait != 201907L
 #     error "__cpp_lib_atomic_wait should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_atomic_wait
-#     error "__cpp_lib_atomic_wait should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait) is not defined!"
+#     error "__cpp_lib_atomic_wait should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)
 #   ifndef __cpp_lib_barrier
 #     error "__cpp_lib_barrier should be defined in c++20"
 #   endif
 #   if __cpp_lib_barrier != 201907L
 #     error "__cpp_lib_barrier should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_barrier
-#     error "__cpp_lib_barrier should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier) is not defined!"
+#     error "__cpp_lib_barrier should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)' is not met!"
 #   endif
 # endif
 
 # ifdef __cpp_lib_bind_back
 #   error "__cpp_lib_bind_back should not be defined before c++2b"
 # endif
 
 # ifndef __cpp_lib_bind_front

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++20"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_chrono
 #   error "__cpp_lib_chrono should be defined in c++20"
 # endif
 # if __cpp_lib_chrono != 201611L
 #   error "__cpp_lib_chrono should have the value 201611L in c++20"

 #   ifndef __cpp_lib_destroying_delete
 #     error "__cpp_lib_destroying_delete should be defined in c++20"
 #   endif
 #   if __cpp_lib_destroying_delete != 201806L
 #     error "__cpp_lib_destroying_delete should have the value 201806L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_destroying_delete
-#     error "__cpp_lib_destroying_delete should not be defined when TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L is not defined!"
+#     error "__cpp_lib_destroying_delete should not be defined when the requirement 'TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_enable_shared_from_this
 #   error "__cpp_lib_enable_shared_from_this should be defined in c++20"
 # endif
 # if __cpp_lib_enable_shared_from_this != 201603L
 #   error "__cpp_lib_enable_shared_from_this should have the value 201603L in c++20"

 #   ifndef __cpp_lib_filesystem
 #     error "__cpp_lib_filesystem should be defined in c++20"
 #   endif
 #   if __cpp_lib_filesystem != 201703L
 #     error "__cpp_lib_filesystem should have the value 201703L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_filesystem
-#     error "__cpp_lib_filesystem should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem) is not defined!"
+#     error "__cpp_lib_filesystem should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)
 #   ifndef __cpp_lib_format
 #     error "__cpp_lib_format should be defined in c++20"
 #   endif
 #   if __cpp_lib_format != 202106L
 #     error "__cpp_lib_format should have the value 202106L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_format
-#     error "__cpp_lib_format should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT) is not defined!"
+#     error "__cpp_lib_format should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_gcd_lcm
 #   error "__cpp_lib_gcd_lcm should be defined in c++20"
 # endif
 # if __cpp_lib_gcd_lcm != 201606L
 #   error "__cpp_lib_gcd_lcm should have the value 201606L in c++20"

 #   ifndef __cpp_lib_hardware_interference_size
 #     error "__cpp_lib_hardware_interference_size should be defined in c++20"
 #   endif
 #   if __cpp_lib_hardware_interference_size != 201703L
 #     error "__cpp_lib_hardware_interference_size should have the value 201703L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_hardware_interference_size
-#     error "__cpp_lib_hardware_interference_size should not be defined when defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE) is not defined!"
+#     error "__cpp_lib_hardware_interference_size should not be defined when the requirement 'defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_has_unique_object_representations
 #   error "__cpp_lib_has_unique_object_representations should be defined in c++20"
 # endif
 # if __cpp_lib_has_unique_object_representations != 201606L
 #   error "__cpp_lib_has_unique_object_representations should have the value 201606L in c++20"

 #   ifndef __cpp_lib_latch
 #     error "__cpp_lib_latch should be defined in c++20"
 #   endif
 #   if __cpp_lib_latch != 201907L
 #     error "__cpp_lib_latch should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_latch
-#     error "__cpp_lib_latch should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch) is not defined!"
+#     error "__cpp_lib_latch should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_launder
 #   error "__cpp_lib_launder should be defined in c++20"
 # endif
 # if __cpp_lib_launder != 201606L
 #   error "__cpp_lib_launder should have the value 201606L in c++20"

 #   ifndef __cpp_lib_semaphore
 #     error "__cpp_lib_semaphore should be defined in c++20"
 #   endif
 #   if __cpp_lib_semaphore != 201907L
 #     error "__cpp_lib_semaphore should have the value 201907L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_semaphore
-#     error "__cpp_lib_semaphore should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore) is not defined!"
+#     error "__cpp_lib_semaphore should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)
 #   ifndef __cpp_lib_shared_mutex
 #     error "__cpp_lib_shared_mutex should be defined in c++20"
 #   endif
 #   if __cpp_lib_shared_mutex != 201505L
 #     error "__cpp_lib_shared_mutex should have the value 201505L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_mutex
-#     error "__cpp_lib_shared_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex) is not defined!"
+#     error "__cpp_lib_shared_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_shared_ptr_arrays
 #   error "__cpp_lib_shared_ptr_arrays should be defined in c++20"
 # endif
 # if __cpp_lib_shared_ptr_arrays != 201707L
 #   error "__cpp_lib_shared_ptr_arrays should have the value 201707L in c++20"

 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++20"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++20"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_shift
 #   error "__cpp_lib_shift should be defined in c++20"
 # endif
 # if __cpp_lib_shift != 201806L
 #   error "__cpp_lib_shift should have the value 201806L in c++20"

 #   ifndef __cpp_lib_atomic_wait
 #     error "__cpp_lib_atomic_wait should be defined in c++2b"
 #   endif
 #   if __cpp_lib_atomic_wait != 201907L
 #     error "__cpp_lib_atomic_wait should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_atomic_wait
-#     error "__cpp_lib_atomic_wait should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait) is not defined!"
+#     error "__cpp_lib_atomic_wait should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_atomic_wait)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)
 #   ifndef __cpp_lib_barrier
 #     error "__cpp_lib_barrier should be defined in c++2b"
 #   endif
 #   if __cpp_lib_barrier != 201907L
 #     error "__cpp_lib_barrier should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_barrier
-#     error "__cpp_lib_barrier should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier) is not defined!"
+#     error "__cpp_lib_barrier should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_barrier)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_VERSION)
 #   ifndef __cpp_lib_bind_back
 #     error "__cpp_lib_bind_back should be defined in c++2b"
 #   endif
 #   if __cpp_lib_bind_back != 202202L

 #   ifndef __cpp_lib_char8_t
 #     error "__cpp_lib_char8_t should be defined in c++2b"
 #   endif
 #   if __cpp_lib_char8_t != 201907L
 #     error "__cpp_lib_char8_t should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_char8_t
-#     error "__cpp_lib_char8_t should not be defined when defined(__cpp_char8_t) is not defined!"
+#     error "__cpp_lib_char8_t should not be defined when the requirement 'defined(__cpp_char8_t)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_chrono
 #   error "__cpp_lib_chrono should be defined in c++2b"
 # endif
 # if __cpp_lib_chrono != 201611L
 #   error "__cpp_lib_chrono should have the value 201611L in c++2b"

 #   ifndef __cpp_lib_destroying_delete
 #     error "__cpp_lib_destroying_delete should be defined in c++2b"
 #   endif
 #   if __cpp_lib_destroying_delete != 201806L
 #     error "__cpp_lib_destroying_delete should have the value 201806L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_destroying_delete
-#     error "__cpp_lib_destroying_delete should not be defined when TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L is not defined!"
+#     error "__cpp_lib_destroying_delete should not be defined when the requirement 'TEST_STD_VER > 17 && defined(__cpp_impl_destroying_delete) && __cpp_impl_destroying_delete >= 201806L' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_enable_shared_from_this
 #   error "__cpp_lib_enable_shared_from_this should be defined in c++2b"
 # endif
 # if __cpp_lib_enable_shared_from_this != 201603L
 #   error "__cpp_lib_enable_shared_from_this should have the value 201603L in c++2b"

 #   ifndef __cpp_lib_filesystem
 #     error "__cpp_lib_filesystem should be defined in c++2b"
 #   endif
 #   if __cpp_lib_filesystem != 201703L
 #     error "__cpp_lib_filesystem should have the value 201703L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_filesystem
-#     error "__cpp_lib_filesystem should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem) is not defined!"
+#     error "__cpp_lib_filesystem should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_filesystem)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)
 #   ifndef __cpp_lib_format
 #     error "__cpp_lib_format should be defined in c++2b"
 #   endif
 #   if __cpp_lib_format != 202106L
 #     error "__cpp_lib_format should have the value 202106L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_format
-#     error "__cpp_lib_format should not be defined when !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT) is not defined!"
+#     error "__cpp_lib_format should not be defined when the requirement '!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_gcd_lcm
 #   error "__cpp_lib_gcd_lcm should be defined in c++2b"
 # endif
 # if __cpp_lib_gcd_lcm != 201606L
 #   error "__cpp_lib_gcd_lcm should have the value 201606L in c++2b"

 #   ifndef __cpp_lib_hardware_interference_size
 #     error "__cpp_lib_hardware_interference_size should be defined in c++2b"
 #   endif
 #   if __cpp_lib_hardware_interference_size != 201703L
 #     error "__cpp_lib_hardware_interference_size should have the value 201703L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_hardware_interference_size
-#     error "__cpp_lib_hardware_interference_size should not be defined when defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE) is not defined!"
+#     error "__cpp_lib_hardware_interference_size should not be defined when the requirement 'defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_has_unique_object_representations
 #   error "__cpp_lib_has_unique_object_representations should be defined in c++2b"
 # endif
 # if __cpp_lib_has_unique_object_representations != 201606L
 #   error "__cpp_lib_has_unique_object_representations should have the value 201606L in c++2b"

 #   ifndef __cpp_lib_latch
 #     error "__cpp_lib_latch should be defined in c++2b"
 #   endif
 #   if __cpp_lib_latch != 201907L
 #     error "__cpp_lib_latch should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_latch
-#     error "__cpp_lib_latch should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch) is not defined!"
+#     error "__cpp_lib_latch should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_launder
 #   error "__cpp_lib_launder should be defined in c++2b"
 # endif
 # if __cpp_lib_launder != 201606L
 #   error "__cpp_lib_launder should have the value 201606L in c++2b"

 #   ifndef __cpp_lib_semaphore
 #     error "__cpp_lib_semaphore should be defined in c++2b"
 #   endif
 #   if __cpp_lib_semaphore != 201907L
 #     error "__cpp_lib_semaphore should have the value 201907L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_semaphore
-#     error "__cpp_lib_semaphore should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore) is not defined!"
+#     error "__cpp_lib_semaphore should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore)' is not met!"
 #   endif
 # endif
 
 # if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)
 #   ifndef __cpp_lib_shared_mutex
 #     error "__cpp_lib_shared_mutex should be defined in c++2b"
 #   endif
 #   if __cpp_lib_shared_mutex != 201505L
 #     error "__cpp_lib_shared_mutex should have the value 201505L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_mutex
-#     error "__cpp_lib_shared_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex) is not defined!"
+#     error "__cpp_lib_shared_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_mutex)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_shared_ptr_arrays
 #   error "__cpp_lib_shared_ptr_arrays should be defined in c++2b"
 # endif
 # if __cpp_lib_shared_ptr_arrays != 201707L
 #   error "__cpp_lib_shared_ptr_arrays should have the value 201707L in c++2b"

 #   ifndef __cpp_lib_shared_timed_mutex
 #     error "__cpp_lib_shared_timed_mutex should be defined in c++2b"
 #   endif
 #   if __cpp_lib_shared_timed_mutex != 201402L
 #     error "__cpp_lib_shared_timed_mutex should have the value 201402L in c++2b"
 #   endif
 # else
 #   ifdef __cpp_lib_shared_timed_mutex
-#     error "__cpp_lib_shared_timed_mutex should not be defined when !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex) is not defined!"
+#     error "__cpp_lib_shared_timed_mutex should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_shared_timed_mutex)' is not met!"
 #   endif
 # endif
 
 # ifndef __cpp_lib_shift
 #   error "__cpp_lib_shift should be defined in c++2b"
 # endif
 # if __cpp_lib_shift != 201806L
 #   error "__cpp_lib_shift should have the value 201806L in c++2b"

libcxx/utils/generate_feature_test_macro_components.py

 #   ifndef {name}
 #     error "{name} should be defined in {std}"
 #   endif
 #   if {name} != {value}
 #     error "{name} should have the value {value} in {std}"
 #   endif
 # else
 #   ifdef {name}
-#     error "{name} should not be defined when {test_suite_guard} is not defined!"
+#     error "{name} should not be defined when the requirement '{test_suite_guard}' is not met!"
 #   endif
 # endif
 """,
 
   "unimplemented": """
 # if !defined(_LIBCPP_VERSION)
 #   ifndef {name}
 #     error "{name} should be defined in {std}"