https://github.com/Endilll created https://github.com/llvm/llvm-project/pull/189307
This PR adds a test for [CWG3088](https://cplusplus.github.io/CWG/issues/3088.html) "Clarify macro treatment of identifiers with special meaning". [[cpp.replace.general] paragraph 9](https://eel.is/c++draft/cpp.replace.general#9) reads as follows: > A translation unit shall not `#define` or `#undef` macro names lexically > identical to keywords, to the identifiers listed in Table > [4](https://eel.is/c++draft/lex.name#tab:lex.name.special), or to the > [_attribute-token_](https://eel.is/c++draft/dcl.attr.grammar#nt:attribute-token)s > described in [[dcl.attr]](https://eel.is/c++draft/dcl.attr), except that the > macro names `likely` and `unlikely` may be defined as function-like macros > and may be > undefined[.](https://eel.is/c++draft/cpp.replace.general#9.sentence-1) > > [Note [1](https://eel.is/c++draft/cpp.replace.general#note-1): An alternative > token ([[lex.digraph]](https://eel.is/c++draft/lex.digraph)) is not an > identifier, even when its spelling consists entirely of letters and > underscores[.](https://eel.is/c++draft/cpp.replace.general#9.sentence-2) > Therefore it is not possible to define a macro whose name is the same as that > of an alternative > token[.](https://eel.is/c++draft/cpp.replace.general#9.sentence-3) — end note] Since C++98 and up until [P2843R3](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p2843r3.pdf) "Preprocessing is never undefined", which was voted into C++26 **not** as a DR, this rule has been living as [macro.names]/2 in library introduction, but that paper made it a part of the core language. I believe that formally: - we should not diagnose anything before C++26 if the standard library is not used, and - we should diagnose everything in C++26 and newer modes. But in practice we've been diagnosing everything except for attributes in all language modes with some exceptions that are likely bugs. >From 4c00efdc8dd7511c18adf97d3613aade48a1e3ce Mon Sep 17 00:00:00 2001 From: Vlad Serebrennikov <[email protected]> Date: Mon, 30 Mar 2026 06:35:40 +0300 Subject: [PATCH] [clang] Add test for CWG3088 about macros that define special identifiers --- clang/test/CXX/drs/cwg3088.cpp | 270 +++++++++++++++++++++++++++++++++ clang/test/CXX/drs/cwg30xx.cpp | 2 + 2 files changed, 272 insertions(+) create mode 100644 clang/test/CXX/drs/cwg3088.cpp diff --git a/clang/test/CXX/drs/cwg3088.cpp b/clang/test/CXX/drs/cwg3088.cpp new file mode 100644 index 0000000000000..f152a5388211f --- /dev/null +++ b/clang/test/CXX/drs/cwg3088.cpp @@ -0,0 +1,270 @@ +// RUN: %clang_cc1 -std=c++98 -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected +// RUN: %clang_cc1 -std=c++11 -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected,since-cxx11 +// RUN: %clang_cc1 -std=c++14 -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected,since-cxx11 +// RUN: %clang_cc1 -std=c++17 -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected,since-cxx11 +// RUN: %clang_cc1 -std=c++20 -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected,since-cxx11,since-cxx20 +// RUN: %clang_cc1 -std=c++23 -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected,since-cxx11,since-cxx20 +// RUN: %clang_cc1 -std=c++2c -fexceptions -fcxx-exceptions -pedantic-errors %s -verify-directives -verify=expected,since-cxx11,since-cxx20 + +namespace cwg3088 { // cwg3088: partial +#define asm +// expected-error@-1 {{keyword is hidden by macro definition}} +#define auto +// expected-error@-1 {{keyword is hidden by macro definition}} +#define bool +// expected-error@-1 {{keyword is hidden by macro definition}} +#define break +// expected-error@-1 {{keyword is hidden by macro definition}} +#define case +// expected-error@-1 {{keyword is hidden by macro definition}} +#define catch +// expected-error@-1 {{keyword is hidden by macro definition}} +#define char +// expected-error@-1 {{keyword is hidden by macro definition}} +#define class +// expected-error@-1 {{keyword is hidden by macro definition}} +#define const +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define const_cast +// expected-error@-1 {{keyword is hidden by macro definition}} +#define continue +// expected-error@-1 {{keyword is hidden by macro definition}} +#define default +// expected-error@-1 {{keyword is hidden by macro definition}} +#define delete +// expected-error@-1 {{keyword is hidden by macro definition}} +#define do +// expected-error@-1 {{keyword is hidden by macro definition}} +#define double +// expected-error@-1 {{keyword is hidden by macro definition}} +#define dynamic_cast +// expected-error@-1 {{keyword is hidden by macro definition}} +#define else +// expected-error@-1 {{keyword is hidden by macro definition}} +#define enum +// expected-error@-1 {{keyword is hidden by macro definition}} +#define explicit +// expected-error@-1 {{keyword is hidden by macro definition}} +#define export +// expected-error@-1 {{keyword is hidden by macro definition}} +#define extern +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define false +// expected-error@-1 {{keyword is hidden by macro definition}} +#define float +// expected-error@-1 {{keyword is hidden by macro definition}} +#define for +// expected-error@-1 {{keyword is hidden by macro definition}} +#define friend +// expected-error@-1 {{keyword is hidden by macro definition}} +#define goto +// expected-error@-1 {{keyword is hidden by macro definition}} +#define if +// expected-error@-1 {{keyword is hidden by macro definition}} +#define inline +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define int +// expected-error@-1 {{keyword is hidden by macro definition}} +#define long +// expected-error@-1 {{keyword is hidden by macro definition}} +#define mutable +// expected-error@-1 {{keyword is hidden by macro definition}} +#define namespace +// expected-error@-1 {{keyword is hidden by macro definition}} +#define new +// expected-error@-1 {{keyword is hidden by macro definition}} +#define operator +// expected-error@-1 {{keyword is hidden by macro definition}} +#define private +// expected-error@-1 {{keyword is hidden by macro definition}} +#define protected +// expected-error@-1 {{keyword is hidden by macro definition}} +#define public +// expected-error@-1 {{keyword is hidden by macro definition}} +#define register +// expected-error@-1 {{keyword is hidden by macro definition}} +#define reinterpret_cast +// expected-error@-1 {{keyword is hidden by macro definition}} +#define return +// expected-error@-1 {{keyword is hidden by macro definition}} +#define short +// expected-error@-1 {{keyword is hidden by macro definition}} +#define signed +// expected-error@-1 {{keyword is hidden by macro definition}} +#define sizeof +// expected-error@-1 {{keyword is hidden by macro definition}} +#define static +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define static_cast +// expected-error@-1 {{keyword is hidden by macro definition}} +#define struct +// expected-error@-1 {{keyword is hidden by macro definition}} +#define switch +// expected-error@-1 {{keyword is hidden by macro definition}} +#define template +// expected-error@-1 {{keyword is hidden by macro definition}} +#define this +// expected-error@-1 {{keyword is hidden by macro definition}} +#define throw +// expected-error@-1 {{keyword is hidden by macro definition}} +#define true +// expected-error@-1 {{keyword is hidden by macro definition}} +#define try +// expected-error@-1 {{keyword is hidden by macro definition}} +#define typedef +// expected-error@-1 {{keyword is hidden by macro definition}} +#define typeid +// expected-error@-1 {{keyword is hidden by macro definition}} +#define typename +// expected-error@-1 {{keyword is hidden by macro definition}} +#define union +// expected-error@-1 {{keyword is hidden by macro definition}} +#define unsigned +// expected-error@-1 {{keyword is hidden by macro definition}} +#define using +// expected-error@-1 {{keyword is hidden by macro definition}} +#define virtual +// expected-error@-1 {{keyword is hidden by macro definition}} +#define void +// expected-error@-1 {{keyword is hidden by macro definition}} +#define volatile +// expected-error@-1 {{keyword is hidden by macro definition}} +#define wchar_t +// expected-error@-1 {{keyword is hidden by macro definition}} +#define while +// expected-error@-1 {{keyword is hidden by macro definition}} +#define and +// expected-error@-1 {{C++ operator 'and' (aka '&&') used as a macro name}} +#define and_eq +// expected-error@-1 {{C++ operator 'and_eq' (aka '&=') used as a macro name}} +#define bitand +// expected-error@-1 {{C++ operator 'bitand' (aka '&') used as a macro name}} +#define bitor +// expected-error@-1 {{C++ operator 'bitor' (aka '|') used as a macro name}} +#define compl +// expected-error@-1 {{C++ operator 'compl' (aka '~') used as a macro name}} +#define not +// expected-error@-1 {{C++ operator 'not' (aka '!') used as a macro name}} +#define not_eq +// expected-error@-1 {{C++ operator 'not_eq' (aka '!=') used as a macro name}} +#define or +// expected-error@-1 {{C++ operator 'or' (aka '||') used as a macro name}} +#define or_eq +// expected-error@-1 {{C++ operator 'or_eq' (aka '|=') used as a macro name}} +#define xor +// expected-error@-1 {{C++ operator 'xor' (aka '^') used as a macro name}} +#define xor_eq +// expected-error@-1 {{C++ operator 'xor_eq' (aka '^=') used as a macro name}} + +#if __cplusplus >= 201103L +#define alignas +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define alignof +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define chat16_t +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define char32_t +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define constexpr +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define decltype +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define noexcept +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define nullptr +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define static_assert +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define thread_local +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} + +// Identifiers with special meaning introduced in C++11 + +#define final +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} +#define override +// since-cxx11-error@-1 {{keyword is hidden by macro definition}} + +// Attributes introduced in C++11 + +// carries_dependency was retroactively removed by P3475R2 +#define noreturn +// FIXME-since-cxx11-error@-1 {{}} +#endif + +#if __cplusplus >= 201402L +// Attributes introduced in C++14 + +#define deprecated +#endif + +#if __cplusplus >= 201703L +// Attributes introduced in C++17 + +#define fallthrough +// FIXME-since-cxx17-error@-1 {{attribute is hidden by macro definition}} +#define maybe_unused +// FIXME-since-cxx17-error@-1 {{attribute is hidden by macro definition}} +#define nodiscard +// FIXME-since-cxx17-error@-1 {{attribute is hidden by macro definition}} +#endif + +#if __cplusplus >= 202002L +#define char8_t +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define concept +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define consteval +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define constinit +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define co_await +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define co_return +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define co_yield +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} +#define requires +// since-cxx20-error@-1 {{keyword is hidden by macro definition}} + +// Identifiers with special meaning introduced in C++20 + +#define import +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define module +// FIXME-error@-1 {{keyword is hidden by macro definition}} + +// Attributes introduced in C++20 + +#define likely +// FIXME-since-cxx20-error@-1 {{attribute is hidden by macro definition}} +#define no_unique_address +// FIXME-since-cxx20-error@-1 {{attribute is hidden by macro definition}} +#define unlikely +// FIXME-since-cxx20-error@-1 {{attribute is hidden by macro definition}} +#endif + +#if __cplusplus >= 202302L +// Attributes introduced in C++23 + +#define assume +// FIXME-since-cxx23-error@-1 {{attribute is hidden by macro definition}} +#endif + +#if __cplusplus >= 202600L +#define contract_assert +// FIXME-error@-1 {{keyword is hidden by macro definition}} + +// Identifiers with special meaning introduced in C++26 + +#define post +// FIXME-error@-1 {{keyword is hidden by macro definition}} +#define pre +// FIXME-error@-1 {{keyword is hidden by macro definition}} + +// Attributes introduced in C++26 + +#define indeterminate +// FIXME-since-cxx26-error@-1 {{attribute is hidden by macro definition}} +#endif +} // namespace cwg3088 diff --git a/clang/test/CXX/drs/cwg30xx.cpp b/clang/test/CXX/drs/cwg30xx.cpp index 356c2cd68b4b7..84b0da6a1662a 100644 --- a/clang/test/CXX/drs/cwg30xx.cpp +++ b/clang/test/CXX/drs/cwg30xx.cpp @@ -21,3 +21,5 @@ void f( } } // namespace cwg3005 + +// cwg3088 is in cwg3088.cpp _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
