diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -202,6 +202,9 @@ - Fix crash when evaluating consteval constructor of derived class whose base has more than one field. (`#60166 `_) +- Fix bug in the computation of the ``__has_unique_object_representations`` + builtin for types with unnamed bitfields. + (`#61336 `_) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp --- a/clang/lib/AST/ASTContext.cpp +++ b/clang/lib/AST/ASTContext.cpp @@ -2831,13 +2831,17 @@ return structHasUniqueObjectRepresentations(Context, RD); } -template +template static std::optional structSubobjectsHaveUniqueObjectRepresentations( const RangeT &Subobjects, int64_t CurOffsetInBits, const ASTContext &Context, const clang::ASTRecordLayout &Layout) { for (const auto *Subobject : Subobjects) { std::optional SizeInBits = getSubobjectSizeInBits(Subobject, Context); + if constexpr (CheckUnnamedBitFields) { + if (Subobject->isUnnamedBitfield()) + return std::nullopt; + } if (!SizeInBits) return std::nullopt; if (*SizeInBits != 0) { @@ -2873,15 +2877,15 @@ }); std::optional OffsetAfterBases = - structSubobjectsHaveUniqueObjectRepresentations(Bases, CurOffsetInBits, - Context, Layout); + structSubobjectsHaveUniqueObjectRepresentations( + Bases, CurOffsetInBits, Context, Layout); if (!OffsetAfterBases) return std::nullopt; CurOffsetInBits = *OffsetAfterBases; } std::optional OffsetAfterFields = - structSubobjectsHaveUniqueObjectRepresentations( + structSubobjectsHaveUniqueObjectRepresentations( RD->fields(), CurOffsetInBits, Context, Layout); if (!OffsetAfterFields) return std::nullopt; diff --git a/clang/test/SemaCXX/type-traits.cpp b/clang/test/SemaCXX/type-traits.cpp --- a/clang/test/SemaCXX/type-traits.cpp +++ b/clang/test/SemaCXX/type-traits.cpp @@ -2878,9 +2878,15 @@ char d : 2; }; +struct UnnamedBitfield { + int named : 8; + int : 24; +}; + static_assert(!has_unique_object_representations::value, "Bitfield padding"); static_assert(has_unique_object_representations::value, "Bitfield padding"); static_assert(!has_unique_object_representations::value, "Bitfield padding"); +static_assert(!has_unique_object_representations::value, "Bitfield padding"); struct BoolBitfield { bool b : 8;