| //===--- HeapObject.h -------------------------------------------*- C++ -*-===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| #ifndef SWIFT_STDLIB_SHIMS_HEAPOBJECT_H |
| #define SWIFT_STDLIB_SHIMS_HEAPOBJECT_H |
| |
| #include "RefCount.h" |
| |
| #ifdef __cplusplus |
| #include <type_traits> |
| #include "swift/Basic/type_traits.h" |
| |
| namespace swift { |
| |
| struct InProcess; |
| |
| template <typename Target> struct TargetHeapMetadata; |
| using HeapMetadata = TargetHeapMetadata<InProcess>; |
| #else |
| typedef struct HeapMetadata HeapMetadata; |
| #endif |
| |
| // The members of the HeapObject header that are not shared by a |
| // standard Objective-C instance |
| #define SWIFT_HEAPOBJECT_NON_OBJC_MEMBERS \ |
| InlineRefCounts refCounts |
| |
| /// The Swift heap-object header. |
| struct HeapObject { |
| /// This is always a valid pointer to a metadata object. |
| HeapMetadata const *metadata; |
| |
| SWIFT_HEAPOBJECT_NON_OBJC_MEMBERS; |
| // FIXME: allocate two words of metadata on 32-bit platforms |
| |
| #ifdef __cplusplus |
| HeapObject() = default; |
| |
| // Initialize a HeapObject header as appropriate for a newly-allocated object. |
| constexpr HeapObject(HeapMetadata const *newMetadata) |
| : metadata(newMetadata) |
| , refCounts(InlineRefCounts::Initialized) |
| { } |
| #endif |
| }; |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| SWIFT_RUNTIME_STDLIB_INTERFACE |
| void _swift_instantiateInertHeapObject(void *address, |
| const HeapMetadata *metadata); |
| |
| #ifdef __cplusplus |
| } // extern "C" |
| #endif |
| |
| #ifdef __cplusplus |
| static_assert(swift::IsTriviallyConstructible<HeapObject>::value, |
| "HeapObject must be trivially initializable"); |
| static_assert(std::is_trivially_destructible<HeapObject>::value, |
| "HeapObject must be trivially destructible"); |
| // FIXME: small header for 32-bit |
| //static_assert(sizeof(HeapObject) == 2*sizeof(void*), |
| // "HeapObject must be two pointers long"); |
| static_assert(alignof(HeapObject) == alignof(void*), |
| "HeapObject must be pointer-aligned"); |
| |
| } // end namespace swift |
| #endif |
| |
| #endif |