diff --git a/tools/clang/include/clang/AST/ASTContext.h b/tools/clang/include/clang/AST/ASTContext.h
index 703f588c56..d7beffa25e 100644
--- a/tools/clang/include/clang/AST/ASTContext.h
+++ b/tools/clang/include/clang/AST/ASTContext.h
@@ -2072,6 +2072,10 @@ public:
void CollectInheritedProtocols(const Decl *CDecl,
llvm::SmallPtrSet<ObjCProtocolDecl*, 8> &Protocols);
+ /// \brief Return true if the specified type has unique object representations
+ /// according to (C++17 [meta.unary.prop]p9)
+ bool hasUniqueObjectRepresentations(QualType Ty) const;
+
//===--------------------------------------------------------------------===//
// Type Operators
//===--------------------------------------------------------------------===//
diff --git a/tools/clang/include/clang/Basic/TokenKinds.def b/tools/clang/include/clang/Basic/TokenKinds.def
index be67663a10..90ac33b9ea 100644
--- a/tools/clang/include/clang/Basic/TokenKinds.def
+++ b/tools/clang/include/clang/Basic/TokenKinds.def
@@ -448,6 +448,8 @@ TYPE_TRAIT_1(__is_pod, IsPOD, KEYCXX)
TYPE_TRAIT_1(__is_polymorphic, IsPolymorphic, KEYCXX)
TYPE_TRAIT_1(__is_trivial, IsTrivial, KEYCXX)
TYPE_TRAIT_1(__is_union, IsUnion, KEYCXX)
+TYPE_TRAIT_1(__has_unique_object_representations,
+ HasUniqueObjectRepresentations, KEYCXX)
// Clang-only C++ Type Traits
TYPE_TRAIT_N(__is_trivially_constructible, IsTriviallyConstructible, KEYCXX)
diff --git a/tools/clang/include/clang/Basic/TypeTraits.h b/tools/clang/include/clang/Basic/TypeTraits.h
index 6aadf795d8..8ecd63f9c3 100644
--- a/tools/clang/include/clang/Basic/TypeTraits.h
+++ b/tools/clang/include/clang/Basic/TypeTraits.h
@@ -70,7 +70,8 @@ namespace clang {
UTT_IsUnsigned,
UTT_IsVoid,
UTT_IsVolatile,
- UTT_Last = UTT_IsVolatile,
+ UTT_HasUniqueObjectRepresentations,
+ UTT_Last = UTT_HasUniqueObjectRepresentations,
BTT_IsBaseOf,
BTT_IsConvertible,
BTT_IsConvertibleTo,
diff --git a/tools/clang/lib/AST/ASTContext.cpp b/tools/clang/lib/AST/ASTContext.cpp
index c60373c5a9..1ce7d51857 100644
--- a/tools/clang/lib/AST/ASTContext.cpp
+++ b/tools/clang/lib/AST/ASTContext.cpp
@@ -1823,7 +1823,9 @@ TypeInfo ASTContext::getTypeInfoImpl(const Type *T) const {
}
case Type::MemberPointer: {
const MemberPointerType *MPT = cast<MemberPointerType>(T);
- std::tie(Width, Align) = ABI->getMemberPointerWidthAndAlign(MPT);
+ CXXABI::MemberPointerInfo MPI = ABI->getMemberPointerInfo(MPT);
+ Width = MPI.Width;
+ Align = MPI.Align;
break;
}
case Type::Complex: {
@@ -2107,6 +2109,171 @@ void ASTContext::CollectInheritedProtocols(const Decl *CDecl,
}
}
+static bool unionHasUniqueObjectRepresentations(const ASTContext &Context,
+ const RecordDecl *RD) {
+ assert(RD->isUnion() && "Must be union type");
+ CharUnits UnionSize = Context.getTypeSizeInChars(RD->getTypeForDecl());
+
+ for (const auto *Field : RD->fields()) {
+ if (!Context.hasUniqueObjectRepresentations(Field->getType()))
+ return false;
+ CharUnits FieldSize = Context.getTypeSizeInChars(Field->getType());
+ if (FieldSize != UnionSize)
+ return false;
+ }
+ return !RD->field_empty();
+}
+
+bool isStructEmpty(QualType Ty) {
+ const RecordDecl *RD = Ty->castAs<RecordType>()->getDecl();
+
+ if (!RD->field_empty())
+ return false;
+
+ if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RD))
+ return ClassDecl->isEmpty();
+
+ return true;
+}
+
+static llvm::Optional<int64_t>
+structHasUniqueObjectRepresentations(const ASTContext &Context,
+ const RecordDecl *RD) {
+ assert(!RD->isUnion() && "Must be struct/class type");
+ const auto &Layout = Context.getASTRecordLayout(RD);
+
+ int64_t CurOffsetInBits = 0;
+ if (const auto *ClassDecl = dyn_cast<CXXRecordDecl>(RD)) {
+ if (ClassDecl->isDynamicClass())
+ return llvm::None;
+
+ SmallVector<std::pair<QualType, int64_t>, 4> Bases;
+ for (const auto Base : ClassDecl->bases()) {
+ // Empty types can be inherited from, and non-empty types can potentially
+ // have tail padding, so just make sure there isn't an error.
+ if (!isStructEmpty(Base.getType())) {
+ llvm::Optional<int64_t> Size = structHasUniqueObjectRepresentations(
+ Context, Base.getType()->getAs<RecordType>()->getDecl());
+ if (!Size)
+ return llvm::None;
+ Bases.emplace_back(Base.getType(), Size.getValue());
+ }
+ }
+
+ std::sort(
+ Bases.begin(), Bases.end(), [&](const std::pair<QualType, int64_t> &L,
+ const std::pair<QualType, int64_t> &R) {
+ return Layout.getBaseClassOffset(L.first->getAsCXXRecordDecl()) <
+ Layout.getBaseClassOffset(R.first->getAsCXXRecordDecl());
+ });
+
+ for (const auto Base : Bases) {
+ int64_t BaseOffset = Context.toBits(
+ Layout.getBaseClassOffset(Base.first->getAsCXXRecordDecl()));
+ int64_t BaseSize = Base.second;
+ if (BaseOffset != CurOffsetInBits)
+ return llvm::None;
+ CurOffsetInBits = BaseOffset + BaseSize;
+ }
+ }
+
+ for (const auto *Field : RD->fields()) {
+ if (!Field->getType()->isReferenceType() &&
+ !Context.hasUniqueObjectRepresentations(Field->getType()))
+ return llvm::None;
+
+ int64_t FieldSizeInBits =
+ Context.toBits(Context.getTypeSizeInChars(Field->getType()));
+ if (Field->isBitField()) {
+ int64_t BitfieldSize = Field->getBitWidthValue(Context);
+
+ if (BitfieldSize > FieldSizeInBits)
+ return llvm::None;
+ FieldSizeInBits = BitfieldSize;
+ }
+
+ int64_t FieldOffsetInBits = Context.getFieldOffset(Field);
+
+ if (FieldOffsetInBits != CurOffsetInBits)
+ return llvm::None;
+
+ CurOffsetInBits = FieldSizeInBits + FieldOffsetInBits;
+ }
+
+ return CurOffsetInBits;
+}
+
+bool ASTContext::hasUniqueObjectRepresentations(QualType Ty) const {
+ // C++17 [meta.unary.prop]:
+ // The predicate condition for a template specialization
+ // has_unique_object_representations<T> shall be
+ // satisfied if and only if:
+ // (9.1) - T is trivially copyable, and
+ // (9.2) - any two objects of type T with the same value have the same
+ // object representation, where two objects
+ // of array or non-union class type are considered to have the same value
+ // if their respective sequences of
+ // direct subobjects have the same values, and two objects of union type
+ // are considered to have the same
+ // value if they have the same active member and the corresponding members
+ // have the same value.
+ // The set of scalar types for which this condition holds is
+ // implementation-defined. [ Note: If a type has padding
+ // bits, the condition does not hold; otherwise, the condition holds true
+ // for unsigned integral types. -- end note ]
+ assert(!Ty.isNull() && "Null QualType sent to unique object rep check");
+
+ // Arrays are unique only if their element type is unique.
+ if (Ty->isArrayType())
+ return hasUniqueObjectRepresentations(getBaseElementType(Ty));
+
+ // (9.1) - T is trivially copyable...
+ if (!Ty.isTriviallyCopyableType(*this))
+ return false;
+
+ // All integrals and enums are unique.
+ if (Ty->isIntegralOrEnumerationType())
+ return true;
+
+ // All other pointers are unique.
+ if (Ty->isPointerType())
+ return true;
+
+ if (Ty->isMemberPointerType()) {
+ const MemberPointerType *MPT = Ty->getAs<MemberPointerType>();
+ return !ABI->getMemberPointerInfo(MPT).HasPadding;
+ }
+
+ if (Ty->isRecordType()) {
+ const RecordDecl *Record = Ty->getAs<RecordType>()->getDecl();
+
+ if (Record->isInvalidDecl())
+ return false;
+
+ if (Record->isUnion())
+ return unionHasUniqueObjectRepresentations(*this, Record);
+
+ Optional<int64_t> StructSize =
+ structHasUniqueObjectRepresentations(*this, Record);
+
+ return StructSize &&
+ StructSize.getValue() == static_cast<int64_t>(getTypeSize(Ty));
+ }
+
+ // FIXME: More cases to handle here (list by rsmith):
+ // vectors (careful about, eg, vector of 3 foo)
+ // _Complex int and friends
+ // _Atomic T
+ // Obj-C block pointers
+ // Obj-C object pointers
+ // and perhaps OpenCL's various builtin types (pipe, sampler_t, event_t,
+ // clk_event_t, queue_t, reserve_id_t)
+ // There're also Obj-C class types and the Obj-C selector type, but I think it
+ // makes sense for those to return false here.
+
+ return false;
+}
+
unsigned ASTContext::CountNonClassIvars(const ObjCInterfaceDecl *OI) const {
unsigned count = 0;
// Count ivars declared in class extension.
diff --git a/tools/clang/lib/AST/CXXABI.h b/tools/clang/lib/AST/CXXABI.h
index 924ef00e81..06295b5817 100644
--- a/tools/clang/lib/AST/CXXABI.h
+++ b/tools/clang/lib/AST/CXXABI.h
@@ -31,9 +31,16 @@ class CXXABI {
public:
virtual ~CXXABI();
- /// Returns the width and alignment of a member pointer in bits.
- virtual std::pair<uint64_t, unsigned>
- getMemberPointerWidthAndAlign(const MemberPointerType *MPT) const = 0;
+ struct MemberPointerInfo {
+ uint64_t Width;
+ unsigned Align;
+ bool HasPadding;
+ };
+
+ /// Returns the width and alignment of a member pointer in bits, as well as
+ /// whether it has padding.
+ virtual MemberPointerInfo
+ getMemberPointerInfo(const MemberPointerType *MPT) const = 0;
/// Returns the default calling convention for C++ methods.
virtual CallingConv getDefaultMethodCallConv(bool isVariadic) const = 0;
diff --git a/tools/clang/lib/AST/ItaniumCXXABI.cpp b/tools/clang/lib/AST/ItaniumCXXABI.cpp
index 692a455eaf..d6bc16b635 100644
--- a/tools/clang/lib/AST/ItaniumCXXABI.cpp
+++ b/tools/clang/lib/AST/ItaniumCXXABI.cpp
@@ -101,15 +101,17 @@ protected:
public:
ItaniumCXXABI(ASTContext &Ctx) : Context(Ctx) { }
- std::pair<uint64_t, unsigned>
- getMemberPointerWidthAndAlign(const MemberPointerType *MPT) const override {
+ MemberPointerInfo
+ getMemberPointerInfo(const MemberPointerType *MPT) const override {
const TargetInfo &Target = Context.getTargetInfo();
TargetInfo::IntType PtrDiff = Target.getPtrDiffType(0);
- uint64_t Width = Target.getTypeWidth(PtrDiff);
- unsigned Align = Target.getTypeAlign(PtrDiff);
+ MemberPointerInfo MPI;
+ MPI.Width = Target.getTypeWidth(PtrDiff);
+ MPI.Align = Target.getTypeAlign(PtrDiff);
+ MPI.HasPadding = false;
if (MPT->isMemberFunctionPointer())
- Width = 2 * Width;
- return std::make_pair(Width, Align);
+ MPI.Width *= 2;
+ return MPI;
}
CallingConv getDefaultMethodCallConv(bool isVariadic) const override {
diff --git a/tools/clang/lib/AST/MicrosoftCXXABI.cpp b/tools/clang/lib/AST/MicrosoftCXXABI.cpp
index 73324e40f3..b19491f313 100644
--- a/tools/clang/lib/AST/MicrosoftCXXABI.cpp
+++ b/tools/clang/lib/AST/MicrosoftCXXABI.cpp
@@ -76,8 +76,8 @@ class MicrosoftCXXABI : public CXXABI {
public:
MicrosoftCXXABI(ASTContext &Ctx) : Context(Ctx) { }
- std::pair<uint64_t, unsigned>
- getMemberPointerWidthAndAlign(const MemberPointerType *MPT) const override;
+ MemberPointerInfo
+ getMemberPointerInfo(const MemberPointerType *MPT) const override;
CallingConv getDefaultMethodCallConv(bool isVariadic) const override {
if (!isVariadic &&
@@ -227,7 +227,7 @@ getMSMemberPointerSlots(const MemberPointerType *MPT) {
return std::make_pair(Ptrs, Ints);
}
-std::pair<uint64_t, unsigned> MicrosoftCXXABI::getMemberPointerWidthAndAlign(
+CXXABI::MemberPointerInfo MicrosoftCXXABI::getMemberPointerInfo(
const MemberPointerType *MPT) const {
// The nominal struct is laid out with pointers followed by ints and aligned
// to a pointer width if any are present and an int width otherwise.
@@ -237,22 +237,25 @@ std::pair<uint64_t, unsigned> MicrosoftCXXABI::getMemberPointerWidthAndAlign(
unsigned Ptrs, Ints;
std::tie(Ptrs, Ints) = getMSMemberPointerSlots(MPT);
- uint64_t Width = Ptrs * PtrSize + Ints * IntSize;
- unsigned Align;
+ MemberPointerInfo MPI;
+ MPI.HasPadding = false;
+ MPI.Width = Ptrs * PtrSize + Ints * IntSize;
// When MSVC does x86_32 record layout, it aligns aggregate member pointers to
// 8 bytes. However, __alignof usually returns 4 for data memptrs and 8 for
// function memptrs.
if (Ptrs + Ints > 1 && Target.getTriple().isArch32Bit())
- Align = 64;
+ MPI.Align = 64;
else if (Ptrs)
- Align = Target.getPointerAlign(0);
+ MPI.Align = Target.getPointerAlign(0);
else
- Align = Target.getIntAlign();
+ MPI.Align = Target.getIntAlign();
- if (Target.getTriple().isArch64Bit())
- Width = llvm::alignTo(Width, Align);
- return std::make_pair(Width, Align);
+ if (Target.getTriple().isArch64Bit()) {
+ MPI.Width = llvm::alignTo(MPI.Width, MPI.Align);
+ MPI.HasPadding = MPI.Width != (Ptrs * PtrSize + Ints * IntSize);
+ }
+ return MPI;
}
CXXABI *clang::CreateMicrosoftCXXABI(ASTContext &Ctx) {
diff --git a/tools/clang/lib/Parse/ParseExpr.cpp b/tools/clang/lib/Parse/ParseExpr.cpp
index 44b87af01a..73aac10c23 100644
--- a/tools/clang/lib/Parse/ParseExpr.cpp
+++ b/tools/clang/lib/Parse/ParseExpr.cpp
@@ -716,6 +716,7 @@ class CastExpressionIdValidator : public CorrectionCandidateCallback {
/// '__is_sealed' [MS]
/// '__is_trivial'
/// '__is_union'
+/// '__has_unique_object_representations'
///
/// [Clang] unary-type-trait:
/// '__is_aggregate'
diff --git a/tools/clang/lib/Sema/SemaExprCXX.cpp b/tools/clang/lib/Sema/SemaExprCXX.cpp
index a9cf3ec799..a7d75ad977 100644
--- a/tools/clang/lib/Sema/SemaExprCXX.cpp
+++ b/tools/clang/lib/Sema/SemaExprCXX.cpp
@@ -4141,6 +4141,7 @@ static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT,
case UTT_IsDestructible:
case UTT_IsNothrowDestructible:
case UTT_IsTriviallyDestructible:
+ case UTT_HasUniqueObjectRepresentations:
if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType())
return true;
@@ -4580,6 +4581,8 @@ static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
// Returns True if and only if T is a complete type at the point of the
// function call.
return !T->isIncompleteType();
+ case UTT_HasUniqueObjectRepresentations:
+ return C.hasUniqueObjectRepresentations(T);
}
}
diff --git a/tools/clang/test/SemaCXX/has_unique_object_reps_member_ptr.cpp b/tools/clang/test/SemaCXX/has_unique_object_reps_member_ptr.cpp
new file mode 100644
index 0000000000..b8e27f82ff
--- /dev/null
+++ b/tools/clang/test/SemaCXX/has_unique_object_reps_member_ptr.cpp
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -triple x86_64-linux-pc -DIS64 -fsyntax-only -verify -std=c++17 %s
+// RUN: %clang_cc1 -triple x86_64-windows-pc -DIS64 -fsyntax-only -verify -std=c++17 %s
+// RUN: %clang_cc1 -triple i386-linux-pc -fsyntax-only -verify -std=c++17 %s
+// RUN: %clang_cc1 -triple i386-windows-pc -DW32 -fsyntax-only -verify -std=c++17 %s
+// expected-no-diagnostics
+
+struct Base {};
+struct A : virtual Base {
+ virtual void n() {}
+};
+
+auto p = &A::n;
+static_assert(__has_unique_object_representations(decltype(p)));
+
+struct B {
+ decltype(p) x;
+ int b;
+#ifdef IS64
+ // required on 64 bit to fill out the tail padding.
+ int c;
+#endif
+};
+static_assert(__has_unique_object_representations(B));
+
+struct C { // has padding on Win32, but nothing else.
+ decltype(p) x;
+};
+#ifdef W32
+static_assert(!__has_unique_object_representations(C));
+#else
+static_assert(__has_unique_object_representations(C));
+#endif
diff --git a/tools/clang/test/SemaCXX/type-traits.cpp b/tools/clang/test/SemaCXX/type-traits.cpp
index 5879a77dd5..3c2f9c7f0f 100644
--- a/tools/clang/test/SemaCXX/type-traits.cpp
+++ b/tools/clang/test/SemaCXX/type-traits.cpp
@@ -2352,3 +2352,321 @@ void is_trivially_destructible_test() {
{ int arr[F(__is_trivially_destructible(void))]; }
{ int arr[F(__is_trivially_destructible(const volatile void))]; }
}
+
+// Instantiation of __has_unique_object_representations
+template <typename T>
+struct has_unique_object_representations {
+ static const bool value = __has_unique_object_representations(T);
+};
+
+static_assert(!has_unique_object_representations<void>::value, "void is never unique");
+static_assert(!has_unique_object_representations<const void>::value, "void is never unique");
+static_assert(!has_unique_object_representations<volatile void>::value, "void is never unique");
+static_assert(!has_unique_object_representations<const volatile void>::value, "void is never unique");
+
+static_assert(has_unique_object_representations<int>::value, "integrals are");
+static_assert(has_unique_object_representations<const int>::value, "integrals are");
+static_assert(has_unique_object_representations<volatile int>::value, "integrals are");
+static_assert(has_unique_object_representations<const volatile int>::value, "integrals are");
+
+static_assert(has_unique_object_representations<void *>::value, "as are pointers");
+static_assert(has_unique_object_representations<const void *>::value, "as are pointers");
+static_assert(has_unique_object_representations<volatile void *>::value, "are pointers");
+static_assert(has_unique_object_representations<const volatile void *>::value, "as are pointers");
+
+static_assert(has_unique_object_representations<int *>::value, "as are pointers");
+static_assert(has_unique_object_representations<const int *>::value, "as are pointers");
+static_assert(has_unique_object_representations<volatile int *>::value, "as are pointers");
+static_assert(has_unique_object_representations<const volatile int *>::value, "as are pointers");
+
+class C {};
+using FP = int (*)(int);
+using PMF = int (C::*)(int);
+using PMD = int C::*;
+
+static_assert(has_unique_object_representations<FP>::value, "even function pointers");
+static_assert(has_unique_object_representations<const FP>::value, "even function pointers");
+static_assert(has_unique_object_representations<volatile FP>::value, "even function pointers");
+static_assert(has_unique_object_representations<const volatile FP>::value, "even function pointers");
+
+static_assert(has_unique_object_representations<PMF>::value, "and pointer to members");
+static_assert(has_unique_object_representations<const PMF>::value, "and pointer to members");
+static_assert(has_unique_object_representations<volatile PMF>::value, "and pointer to members");
+static_assert(has_unique_object_representations<const volatile PMF>::value, "and pointer to members");
+
+static_assert(has_unique_object_representations<PMD>::value, "and pointer to members");
+static_assert(has_unique_object_representations<const PMD>::value, "and pointer to members");
+static_assert(has_unique_object_representations<volatile PMD>::value, "and pointer to members");
+static_assert(has_unique_object_representations<const volatile PMD>::value, "and pointer to members");
+
+static_assert(has_unique_object_representations<bool>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<char>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<signed char>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<unsigned char>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<short>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<unsigned short>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<int>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<unsigned int>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<long>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<unsigned long>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<long long>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<unsigned long long>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<wchar_t>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<char16_t>::value, "yes, all integral types");
+static_assert(has_unique_object_representations<char32_t>::value, "yes, all integral types");
+
+static_assert(!has_unique_object_representations<void>::value, "but not void!");
+static_assert(!has_unique_object_representations<decltype(nullptr)>::value, "or nullptr_t");
+static_assert(!has_unique_object_representations<float>::value, "definitely not Floating Point");
+static_assert(!has_unique_object_representations<double>::value, "definitely not Floating Point");
+static_assert(!has_unique_object_representations<long double>::value, "definitely not Floating Point");
+
+struct NoPadding {
+ int a;
+ int b;
+};
+
+static_assert(has_unique_object_representations<NoPadding>::value, "types without padding are");
+
+struct InheritsFromNoPadding : NoPadding {
+ int c;
+ int d;
+};
+
+static_assert(has_unique_object_representations<InheritsFromNoPadding>::value, "types without padding are");
+
+struct VirtuallyInheritsFromNoPadding : virtual NoPadding {
+ int c;
+ int d;
+};
+
+static_assert(!has_unique_object_representations<VirtuallyInheritsFromNoPadding>::value, "No virtual inheritence");
+
+struct Padding {
+ char a;
+ int b;
+};
+
+//static_assert(!has_unique_object_representations<Padding>::value, "but not with padding");
+
+struct InheritsFromPadding : Padding {
+ int c;
+ int d;
+};
+
+static_assert(!has_unique_object_representations<InheritsFromPadding>::value, "or its subclasses");
+
+struct TailPadding {
+ int a;
+ char b;
+};
+
+static_assert(!has_unique_object_representations<TailPadding>::value, "even at the end");
+
+struct TinyStruct {
+ char a;
+};
+
+static_assert(has_unique_object_representations<TinyStruct>::value, "Should be no padding");
+
+struct InheritsFromTinyStruct : TinyStruct {
+ int b;
+};
+
+static_assert(!has_unique_object_representations<InheritsFromTinyStruct>::value, "Inherit causes padding");
+
+union NoPaddingUnion {
+ int a;
+ unsigned int b;
+};
+
+static_assert(has_unique_object_representations<NoPaddingUnion>::value, "unions follow the same rules as structs");
+
+union PaddingUnion {
+ int a;
+ long long b;
+};
+
+static_assert(!has_unique_object_representations<PaddingUnion>::value, "unions follow the same rules as structs");
+
+struct NotTriviallyCopyable {
+ int x;
+ NotTriviallyCopyable(const NotTriviallyCopyable &) {}
+};
+
+static_assert(!has_unique_object_representations<NotTriviallyCopyable>::value, "must be trivially copyable");
+
+struct HasNonUniqueMember {
+ float x;
+};
+
+static_assert(!has_unique_object_representations<HasNonUniqueMember>::value, "all members must be unique");
+
+enum ExampleEnum { xExample,
+ yExample };
+enum LLEnum : long long { xLongExample,
+ yLongExample };
+
+static_assert(has_unique_object_representations<ExampleEnum>::value, "Enums are integrals, so unique!");
+static_assert(has_unique_object_representations<LLEnum>::value, "Enums are integrals, so unique!");
+
+enum class ExampleEnumClass { xExample,
+ yExample };
+enum class LLEnumClass : long long { xLongExample,
+ yLongExample };
+
+static_assert(has_unique_object_representations<ExampleEnumClass>::value, "Enums are integrals, so unique!");
+static_assert(has_unique_object_representations<LLEnumClass>::value, "Enums are integrals, so unique!");
+
+// because references aren't trivially copyable.
+static_assert(!has_unique_object_representations<int &>::value, "No references!");
+static_assert(!has_unique_object_representations<const int &>::value, "No references!");
+static_assert(!has_unique_object_representations<volatile int &>::value, "No references!");
+static_assert(!has_unique_object_representations<const volatile int &>::value, "No references!");
+static_assert(!has_unique_object_representations<Empty>::value, "No empty types!");
+static_assert(!has_unique_object_representations<EmptyUnion>::value, "No empty types!");
+
+class Compressed : Empty {
+ int x;
+};
+
+static_assert(has_unique_object_representations<Compressed>::value, "But inheriting from one is ok");
+
+class EmptyInheritor : Compressed {};
+
+static_assert(has_unique_object_representations<EmptyInheritor>::value, "As long as the base has items, empty is ok");
+
+class Dynamic {
+ virtual void A();
+ int i;
+};
+
+static_assert(!has_unique_object_representations<Dynamic>::value, "Dynamic types are not valid");
+
+class InheritsDynamic : Dynamic {
+ int j;
+};
+
+static_assert(!has_unique_object_representations<InheritsDynamic>::value, "Dynamic types are not valid");
+
+static_assert(has_unique_object_representations<int[42]>::value, "Arrays are fine, as long as their value type is");
+static_assert(has_unique_object_representations<int[]>::value, "Arrays are fine, as long as their value type is");
+static_assert(has_unique_object_representations<int[][42]>::value, "Arrays are fine, as long as their value type is");
+static_assert(!has_unique_object_representations<double[42]>::value, "So no array of doubles!");
+static_assert(!has_unique_object_representations<double[]>::value, "So no array of doubles!");
+static_assert(!has_unique_object_representations<double[][42]>::value, "So no array of doubles!");
+
+struct __attribute__((aligned(16))) WeirdAlignment {
+ int i;
+};
+union __attribute__((aligned(16))) WeirdAlignmentUnion {
+ int i;
+};
+static_assert(!has_unique_object_representations<WeirdAlignment>::value, "Alignment causes padding");
+static_assert(!has_unique_object_representations<WeirdAlignmentUnion>::value, "Alignment causes padding");
+static_assert(!has_unique_object_representations<WeirdAlignment[42]>::value, "Also no arrays that have padding");
+
+static_assert(!has_unique_object_representations<int(int)>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) const>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) volatile>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) const volatile>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) const &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) volatile &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) const volatile &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) &&>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) const &&>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) volatile &&>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int) const volatile &&>::value, "Functions are not unique");
+
+static_assert(!has_unique_object_representations<int(int, ...)>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) const>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) volatile>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) const volatile>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) const &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) volatile &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) const volatile &>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) &&>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) const &&>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) volatile &&>::value, "Functions are not unique");
+static_assert(!has_unique_object_representations<int(int, ...) const volatile &&>::value, "Functions are not unique");
+
+void foo(){
+ static auto lambda = []() {};
+ static_assert(!has_unique_object_representations<decltype(lambda)>::value, "Lambdas follow struct rules");
+ int i;
+ static auto lambda2 = [i]() {};
+ static_assert(has_unique_object_representations<decltype(lambda2)>::value, "Lambdas follow struct rules");
+}
+
+struct PaddedBitfield {
+ char c : 6;
+ char d : 1;
+};
+
+struct UnPaddedBitfield {
+ char c : 6;
+ char d : 2;
+};
+
+struct AlignedPaddedBitfield {
+ char c : 6;
+ __attribute__((aligned(1)))
+ char d : 2;
+};
+
+static_assert(!has_unique_object_representations<PaddedBitfield>::value, "Bitfield padding");
+static_assert(has_unique_object_representations<UnPaddedBitfield>::value, "Bitfield padding");
+static_assert(!has_unique_object_representations<AlignedPaddedBitfield>::value, "Bitfield padding");
+
+struct BoolBitfield {
+ bool b : 8;
+};
+
+static_assert(has_unique_object_representations<BoolBitfield>::value, "Bitfield bool");
+
+struct BoolBitfield2 {
+ bool b : 16;
+};
+
+static_assert(!has_unique_object_representations<BoolBitfield2>::value, "Bitfield bool");
+
+struct GreaterSizeBitfield {
+ //expected-warning@+1 {{width of bit-field 'n'}}
+ int n : 1024;
+};
+
+static_assert(sizeof(GreaterSizeBitfield) == 128, "Bitfield Size");
+static_assert(!has_unique_object_representations<GreaterSizeBitfield>::value, "Bitfield padding");
+
+struct StructWithRef {
+ int &I;
+};
+
+static_assert(has_unique_object_representations<StructWithRef>::value, "References are still unique");
+
+struct NotUniqueBecauseTailPadding {
+ int &r;
+ char a;
+};
+struct CanBeUniqueIfNoPadding : NotUniqueBecauseTailPadding {
+ char b[7];
+};
+
+static_assert(!has_unique_object_representations<NotUniqueBecauseTailPadding>::value,
+ "non trivial");
+// Can be unique on Itanium, since the is child class' data is 'folded' into the
+// parent's tail padding.
+static_assert(sizeof(CanBeUniqueIfNoPadding) != 16 ||
+ has_unique_object_representations<CanBeUniqueIfNoPadding>::value,
+ "inherit from std layout");
+
+namespace ErrorType {
+ struct S; //expected-note{{forward declaration of 'ErrorType::S'}}
+
+ struct T {
+ S t; //expected-error{{field has incomplete type 'ErrorType::S'}}
+ };
+ bool b = __has_unique_object_representations(T);
+};
--
2.14.1
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