llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: cor3ntin (cor3ntin) <details> <summary>Changes</summary> wg21.link/P2552 suggest that __has_cpp_attribute should return a non-zero value for all attributes that the implementation does something interesting with. Clang does something meaninful with all attributes except for: - no_unique_address which we do not support for msvc target - carries_dependency which arguably does nothing interesting. P2552 shies away from specifying a behavior for that attribute (despite being the only one for which a recommandation would have been interesting, arguably) As such, we have nothing to change for this paper. This paper is a DR and clang always behaved reasonably. --- Full diff: https://github.com/llvm/llvm-project/pull/92007.diff 2 Files Affected: - (added) clang/test/SemaCXX/cxx2c-attributes.cpp (+23) - (modified) clang/www/cxx_status.html (+1-1) ``````````diff diff --git a/clang/test/SemaCXX/cxx2c-attributes.cpp b/clang/test/SemaCXX/cxx2c-attributes.cpp new file mode 100644 index 0000000000000..f9f76efd01be0 --- /dev/null +++ b/clang/test/SemaCXX/cxx2c-attributes.cpp @@ -0,0 +1,23 @@ +// RUN: %clang_cc1 -x c++ -std=c++11 -triple x86_64-pc-linux -fsyntax-only +// RUN: %clang_cc1 -x c++ -std=c++11 -triple x86_64-windows-msvc -fsyntax-only + +// Check we return non-zero values for supported attributes as per +// wg21.link/p2552r3.pdf +static_assert(__has_cpp_attribute(assume)); + +// The standard does not prescribe a behavior for [[carries_dependency]] + +static_assert(__has_cpp_attribute(deprecated)); +static_assert(__has_cpp_attribute(fallthrough)); +static_assert(__has_cpp_attribute(likely)); +static_assert(__has_cpp_attribute(unlikely)); +static_assert(__has_cpp_attribute(maybe_unused)); +static_assert(__has_cpp_attribute(nodiscard)); +static_assert(__has_cpp_attribute(noreturn)); + +#ifdef _MSC_VER +// We do not support [[no_unique_address]] in MSVC emulation mode +static_assert(__has_cpp_attribute(no_unique_address) == 0); +#else +static_assert(__has_cpp_attribute(no_unique_address)); +#endif diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html index 1338f544ffcb5..06777eaa6df69 100755 --- a/clang/www/cxx_status.html +++ b/clang/www/cxx_status.html @@ -130,7 +130,7 @@ <h2 id="cxx26">C++2c implementation status</h2> <tr> <td>On the ignorability of standard attributes</td> <td><a href="https://wg21.link/P2552R3";>P2552R3</a> (<a href="#dr">DR</a>)</td> - <td class="none" align="center">No</td> + <td class="full" align="center">Yes</td> </tr> <tr> <td>Static storage for braced initializers</td> `````````` </details> https://github.com/llvm/llvm-project/pull/92007 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
