46 #ifndef LLVM_SUPPORT_TRAILINGOBJECTS_H
47 #define LLVM_SUPPORT_TRAILINGOBJECTS_H
55 #include <type_traits>
59 namespace trailing_objects_internal {
65 FirstAlignment =
alignof(
First),
71 Alignment = FirstAlignment > RestAlignment ? FirstAlignment : RestAlignment
77 enum { Alignment =
alignof(
First) };
106 template <
int Align,
typename BaseTy,
typename TopTrailingObj,
typename PrevTy,
113 template <
int Align,
typename BaseTy,
typename TopTrailingObj,
typename PrevTy,
114 typename NextTy,
typename... MoreTys>
123 struct RequiresRealignment {
124 static const bool value =
alignof(PrevTy) <
alignof(NextTy);
127 static constexpr
bool requiresRealignment() {
128 return RequiresRealignment::value;
133 using ParentType::getTrailingObjectsImpl;
144 static const NextTy *
147 auto *
Ptr = TopTrailingObj::getTrailingObjectsImpl(
149 TopTrailingObj::callNumTrailingObjects(
152 if (requiresRealignment())
153 return reinterpret_cast<const NextTy *
>(
156 return reinterpret_cast<const NextTy *
>(
Ptr);
162 auto *
Ptr = TopTrailingObj::getTrailingObjectsImpl(
164 TopTrailingObj::callNumTrailingObjects(
167 if (requiresRealignment())
168 return reinterpret_cast<NextTy *
>(
alignAddr(
Ptr, Align::Of<NextTy>()));
170 return reinterpret_cast<NextTy *
>(
Ptr);
177 size_t SizeSoFar,
size_t Count1,
179 return ParentType::additionalSizeToAllocImpl(
180 (requiresRealignment() ?
llvm::alignTo<
alignof(NextTy)>(SizeSoFar)
182 sizeof(NextTy) * Count1,
189 template <
int Align,
typename BaseTy,
typename TopTrailingObj,
typename PrevTy>
196 static void getTrailingObjectsImpl();
211 template <
typename BaseTy,
typename... TrailingTys>
213 trailing_objects_internal::AlignmentCalcHelper<
214 TrailingTys...>::Alignment,
215 BaseTy, TrailingObjects<BaseTy, TrailingTys...>,
216 BaseTy, TrailingTys...> {
218 template <
int A,
typename B,
typename T,
typename P,
typename...
M>
221 template <
typename... Tys>
class Foo {};
225 BaseTy,
TrailingObjects<BaseTy, TrailingTys...>, BaseTy, TrailingTys...>
229 using ParentType::getTrailingObjectsImpl;
235 static void verifyTrailingObjectsAssertions() {
236 static_assert(std::is_final<BaseTy>(),
"BaseTy must be final.");
240 static const BaseTy *
241 getTrailingObjectsImpl(
const BaseTy *Obj,
242 TrailingObjectsBase::OverloadToken<BaseTy>) {
247 getTrailingObjectsImpl(BaseTy *Obj,
248 TrailingObjectsBase::OverloadToken<BaseTy>) {
260 callNumTrailingObjects(
const BaseTy *Obj,
261 TrailingObjectsBase::OverloadToken<BaseTy>) {
265 template <
typename T>
266 static size_t callNumTrailingObjects(
const BaseTy *Obj,
267 TrailingObjectsBase::OverloadToken<T>) {
268 return Obj->numTrailingObjects(TrailingObjectsBase::OverloadToken<T>());
274 using ParentType::OverloadToken;
278 template <
typename T>
279 using OverloadToken =
typename ParentType::template OverloadToken<T>;
286 verifyTrailingObjectsAssertions();
289 return this->getTrailingObjectsImpl(
290 static_cast<const BaseTy *
>(
this),
298 verifyTrailingObjectsAssertions();
301 return this->getTrailingObjectsImpl(
311 template <
typename... Tys>
312 static constexpr std::enable_if_t<
313 std::is_same<Foo<TrailingTys...>, Foo<Tys...>>::value,
size_t>
315 TrailingTys,
size_t>::
type... Counts) {
316 return ParentType::additionalSizeToAllocImpl(0, Counts...);
323 template <
typename... Tys>
324 static constexpr std::enable_if_t<
325 std::is_same<Foo<TrailingTys...>, Foo<Tys...>>::value,
size_t>
327 TrailingTys,
size_t>::
type... Counts) {
328 return sizeof(BaseTy) + ParentType::additionalSizeToAllocImpl(0, Counts...);
354 enum { Size = totalSizeToAlloc<Tys...>(Counts...) };
356 alignas(BaseTy)
char buffer[Size];
366 assert(
p &&
"FixedSizeStorageOwner owns null?");
371 const BaseTy *
get()
const {
return p; }