From cff9e77783aceb52da705b7e2b2e45bfbc86c628 Mon Sep 17 00:00:00 2001 From: cor3ntin Date: Tue, 14 May 2024 06:15:01 +0200 Subject: [PATCH] [Clang][NFC] Mark P2552 as implemented. (#92007) 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. --- clang/test/SemaCXX/cxx2c-attributes.cpp | 20 ++++++++++++++++++++ clang/www/cxx_status.html | 2 +- 2 files changed, 21 insertions(+), 1 deletion(-) create mode 100644 clang/test/SemaCXX/cxx2c-attributes.cpp diff --git a/clang/test/SemaCXX/cxx2c-attributes.cpp b/clang/test/SemaCXX/cxx2c-attributes.cpp new file mode 100644 index 000000000000..c20a1b606a0f --- /dev/null +++ b/clang/test/SemaCXX/cxx2c-attributes.cpp @@ -0,0 +1,20 @@ +// RUN: %clang_cc1 %s -x c++ -std=c++11 -triple x86_64-pc-linux -fsyntax-only -verify -Wno-c++17-extensions +// RUN: %clang_cc1 %s -x c++ -std=c++11 -triple x86_64-windows-msvc -fsyntax-only -verify=msvc -Wno-c++17-extensions +// expected-no-diagnostics + +// Check we return non-zero values for supported attributes as per +// wg21.link/P2552 +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)); + +// We do not support [[no_unique_address]] in MSVC emulation mode +static_assert(__has_cpp_attribute(no_unique_address)); // msvc-error {{static assertion failed}} diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html index 1338f544ffcb..06777eaa6df6 100755 --- a/clang/www/cxx_status.html +++ b/clang/www/cxx_status.html @@ -130,7 +130,7 @@ C++23, informally referred to as C++26.

On the ignorability of standard attributes P2552R3 (DR) - No + Yes Static storage for braced initializers