[libc++] Refactor the configuration macros to being always defined (#112094)

This is a follow-up to #89178. This updates the `<__config_site>`
macros.

[libc++][test] Make the feature-test macro tests more portable (#74185)

Found while running libc++'s test suite with MSVC's STL.

This is a followup to @philnik777's recent #71002 (thank you!) whi

[libc++][test] Make the feature-test macro tests more portable (#74185)

Found while running libc++'s test suite with MSVC's STL.

This is a followup to @philnik777's recent #71002 (thank you!) which
provided the existing examples of `__cpp_lib_barrier` and
`__cpp_lib_polymorphic_allocator`:

https://github.com/llvm/llvm-project/blob/66a3e4fafb6eae19764f8a192ca3a116c0554211/libcxx/utils/generate_feature_test_macro_components.py#L199-L203

https://github.com/llvm/llvm-project/blob/66a3e4fafb6eae19764f8a192ca3a116c0554211/libcxx/utils/generate_feature_test_macro_components.py#L866-L870

Applying that new pattern to the feature-test macros here gets their
corresponding tests passing for us.

:robot: Only `generate_feature_test_macro_components.py` was manually
updated; the other files were regenerated.

show more ...

[libc++][NFC] Refactor _LIBCPP_AVAILABILITY_HAS_* macros to always be defined (#71002)

This makes the conditionals quite a bit simpler to understand, since it
avoids double negatives and makes sure

[libc++][NFC] Refactor _LIBCPP_AVAILABILITY_HAS_* macros to always be defined (#71002)

This makes the conditionals quite a bit simpler to understand, since it
avoids double negatives and makes sure we have <__availability>
included. For vendors which use availability macros, it also enforces
that they check when specific features are introduced and define the
macro for their platform appropriately.

show more ...

[libc++] Adds C++26 support.

Clang has been updated to support C++26, this adds the same support for
libc++. At the moment C++23 and C++26 are identical. During the next
plenary in June the first C+

[libc++] Adds C++26 support.

Clang has been updated to support C++26, this adds the same support for
libc++. At the moment C++23 and C++26 are identical. During the next
plenary in June the first C++26 papers will be voted on.

Note like Clang this patch uses C++26 is the internal part and C++2c in
the user visible part.

Depends on D150795

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D151026

show more ...

[libc++] Updates C++2b to C++23.

During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.

This updates the reference to c++2b to c++23 and updat

[libc++] Updates C++2b to C++23.

During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.

This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.

Note since we use clang-tidy 16 a small work-around is needed. Clang
knows -std=c++23 but clang-tidy not so for now force the lit compiler
flag to use -std=c++2b instead of -std=c++23.

Reviewed By: #libc, philnik, jloser, ldionne

Differential Revision: https://reviews.llvm.org/D150795

show more ...

[libc++] Systematically define a macro to check whether a feature is unavailable

Previously, we inconsistently defined whether a feature was unavailable
on a given deployment target. We would have a

[libc++] Systematically define a macro to check whether a feature is unavailable

Previously, we inconsistently defined whether a feature was unavailable
on a given deployment target. We would have availability attributes for
all features, but only some features had the equivalent of a _HAS_NO_FOO
macro in the form of the DISABLE_FTM___foo macros. Instead, systematically
define a _HAS_NO_FOO macro, which makes it easier to understand how to
add availability markup for a new platform.

Differential Revision: https://reviews.llvm.org/D147226

show more ...

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

This was mentioned in review D131326.

Reviewed By: var-const, #libc, philnik

Differential Revision: https://reviews.llvm.org/D132293

[runtimes] Rename various libcpp-has-no-XYZ Lit features to just no-XYZ

Since those features are general properties of the environment, it makes
sense to use them from libc++abi too, and so the name

[runtimes] Rename various libcpp-has-no-XYZ Lit features to just no-XYZ

Since those features are general properties of the environment, it makes
sense to use them from libc++abi too, and so the name libcpp-has-no-xxx
doesn't make sense.

Differential Revision: https://reviews.llvm.org/D126482

show more ...

[libc++] Make .version.pass.cpp tests be compile-only tests

We don't really need to run them.