release/18.x: [libc++] Enable availability based on the compiler instead of __has_extension (#84065)

[llvmbot]

Backport 292a28d

Requested by: @ldionne

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: None (llvmbot)

Changes

Backport 292a28d

Requested by: @ldionne

---

Full diff: https://github.com/llvm/llvm-project/pull/84374.diff

2 Files Affected:

• (modified) libcxx/include/__availability (+3-4)
• (added) libcxx/test/libcxx/vendor/apple/availability-with-pedantic-errors.compile.pass.cpp (+22)

diff --git a/libcxx/include/__availability b/libcxx/include/__availability index c5069a027750ec..b8b2da9bb12265 100644 --- a/libcxx/include/__availability +++ b/libcxx/include/__availability @@ -72,11 +72,10 @@ # endif #endif -// Availability markup is disabled when building the library, or when the compiler +// Availability markup is disabled when building the library, or when a non-Clang +// compiler is used because only Clang supports the necessary attributes. // doesn't support the proper attributes. -#if defined(_LIBCPP_BUILDING_LIBRARY) || defined(_LIBCXXABI_BUILDING_LIBRARY) || \ - !__has_feature(attribute_availability_with_strict) || !__has_feature(attribute_availability_in_templates) || \ - !__has_extension(pragma_clang_attribute_external_declaration) +#if defined(_LIBCPP_BUILDING_LIBRARY) || defined(_LIBCXXABI_BUILDING_LIBRARY) || !defined(_LIBCPP_COMPILER_CLANG_BASED) # if !defined(_LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS) # define _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS # endif diff --git a/libcxx/test/libcxx/vendor/apple/availability-with-pedantic-errors.compile.pass.cpp b/libcxx/test/libcxx/vendor/apple/availability-with-pedantic-errors.compile.pass.cpp new file mode 100644 index 00000000000000..c55a0a4d6e5d1b --- /dev/null +++ b/libcxx/test/libcxx/vendor/apple/availability-with-pedantic-errors.compile.pass.cpp @@ -0,0 +1,22 @@ +//===----------------------------------------------------------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +// REQUIRES: stdlib=apple-libc++ + +// Test that using -pedantic-errors doesn't turn off availability annotations. +// This used to be the case because we used __has_extension(...) to enable the +// availability annotations, and -pedantic-errors changes the behavior of +// __has_extension(...) in an incompatible way. + +// ADDITIONAL_COMPILE_FLAGS: -pedantic-errors + +#include <__availability> + +#if defined(_LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS) +# error Availability annotations should be enabled on Apple platforms in the system configuration! +#endif 

[tstellar]

@ldionne Is the test failure legitimate?

[ldionne]

No, it's not legitimate. Our CI is rather unstable at the moment but this looks as good as it'll get.