Author: cor3ntin Date: 2025-05-02T19:36:53+02:00 New Revision: e59ed0fb0f3324ae3fce4080e15472a316713dfd
URL: https://github.com/llvm/llvm-project/commit/e59ed0fb0f3324ae3fce4080e15472a316713dfd DIFF: https://github.com/llvm/llvm-project/commit/e59ed0fb0f3324ae3fce4080e15472a316713dfd.diff LOG: [Clang] __has_unique_object_representations should not accept Incomplete[] (#138291) This implements [LWG4113](https://cplusplus.github.io/LWG/issue411) This is technically a breaking change, but it's a fix, and I think anyone who relies on this today is in a world of hurt. Fixes #118350 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaExprCXX.cpp clang/test/SemaCXX/type-traits.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 7f58aea5f83ad..792ef88b5c87d 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -559,6 +559,9 @@ Bug Fixes to Compiler Builtins ``void(char *, char *)`` to ``void(void *, void *)`` to match GCC's signature for the same builtin. (#GH47833) +- ``__has_unique_object_representations(Incomplete[])`` is no longer accepted, per + `LWG4113 <https://cplusplus.github.io/LWG/issue4113>`_. + Bug Fixes to Attribute Support ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - Fixed crash when a parameter to the ``clang::annotate`` attribute evaluates to ``void``. See #GH119125 diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp index 9ff4bc6c7e38f..235ea1529b0b8 100644 --- a/clang/lib/Sema/SemaExprCXX.cpp +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -5418,6 +5418,15 @@ static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, return !S.RequireCompleteType( Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); + // has_unique_object_representations<T> + // remove_all_extents_t<T> shall be a complete type or cv void (LWG4113). + case UTT_HasUniqueObjectRepresentations: + ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0); + if (ArgTy->isVoidType()) + return true; + return !S.RequireCompleteType( + Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); + // C++1z [meta.unary.prop]: // remove_all_extents_t<T> shall be a complete type or cv void. case UTT_IsTrivial: @@ -5445,13 +5454,8 @@ static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, case UTT_HasTrivialCopy: case UTT_HasTrivialDestructor: case UTT_HasVirtualDestructor: - // has_unique_object_representations<T> when T is an array is defined in terms - // of has_unique_object_representations<remove_all_extents_t<T>>, so the base - // type needs to be complete even if the type is an incomplete array type. - case UTT_HasUniqueObjectRepresentations: ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0); [[fallthrough]]; - // C++1z [meta.unary.prop]: // T shall be a complete type, cv void, or an array of unknown bound. case UTT_IsDestructible: diff --git a/clang/test/SemaCXX/type-traits.cpp b/clang/test/SemaCXX/type-traits.cpp index b130024503101..7768f61ac2d00 100644 --- a/clang/test/SemaCXX/type-traits.cpp +++ b/clang/test/SemaCXX/type-traits.cpp @@ -3383,6 +3383,16 @@ static_assert(!__has_unique_object_representations(float), "definitely not Float static_assert(!__has_unique_object_representations(double), "definitely not Floating Point"); static_assert(!__has_unique_object_representations(long double), "definitely not Floating Point"); + +static_assert(!__has_unique_object_representations(AnIncompleteType[])); +//expected-error@-1 {{incomplete type 'AnIncompleteType' used in type trait expression}} +static_assert(!__has_unique_object_representations(AnIncompleteType[][1])); +//expected-error@-1 {{incomplete type 'AnIncompleteType' used in type trait expression}} +static_assert(!__has_unique_object_representations(AnIncompleteType[1])); +//expected-error@-1 {{incomplete type 'AnIncompleteType' used in type trait expression}} +static_assert(!__has_unique_object_representations(AnIncompleteType)); +//expected-error@-1 {{incomplete type 'AnIncompleteType' used in type trait expression}} + struct NoPadding { int a; int b; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
