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d42f2049f7
For key paths without generic or subscript parameterization, we can turn the compiler-generated key path pattern into a global object in-place.
82 lines
2.3 KiB
C++
82 lines
2.3 KiB
C++
//===--- HeapObject.h -------------------------------------------*- C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_STDLIB_SHIMS_HEAPOBJECT_H
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#define SWIFT_STDLIB_SHIMS_HEAPOBJECT_H
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#include "RefCount.h"
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#ifdef __cplusplus
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#include <type_traits>
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#include "swift/Basic/type_traits.h"
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namespace swift {
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struct InProcess;
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template <typename Target> struct TargetHeapMetadata;
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using HeapMetadata = TargetHeapMetadata<InProcess>;
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#else
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typedef struct HeapMetadata HeapMetadata;
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#endif
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// The members of the HeapObject header that are not shared by a
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// standard Objective-C instance
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#define SWIFT_HEAPOBJECT_NON_OBJC_MEMBERS \
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InlineRefCounts refCounts
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/// The Swift heap-object header.
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struct HeapObject {
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/// This is always a valid pointer to a metadata object.
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HeapMetadata const *metadata;
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SWIFT_HEAPOBJECT_NON_OBJC_MEMBERS;
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// FIXME: allocate two words of metadata on 32-bit platforms
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#ifdef __cplusplus
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HeapObject() = default;
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// Initialize a HeapObject header as appropriate for a newly-allocated object.
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constexpr HeapObject(HeapMetadata const *newMetadata)
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: metadata(newMetadata)
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, refCounts(InlineRefCounts::Initialized)
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{ }
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#endif
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};
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#ifdef __cplusplus
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extern "C" {
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#endif
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SWIFT_RUNTIME_STDLIB_INTERFACE
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void _swift_instantiateInertHeapObject(void *address,
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const HeapMetadata *metadata);
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#ifdef __cplusplus
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} // extern "C"
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#endif
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#ifdef __cplusplus
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static_assert(swift::IsTriviallyConstructible<HeapObject>::value,
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"HeapObject must be trivially initializable");
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static_assert(std::is_trivially_destructible<HeapObject>::value,
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"HeapObject must be trivially destructible");
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// FIXME: small header for 32-bit
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//static_assert(sizeof(HeapObject) == 2*sizeof(void*),
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// "HeapObject must be two pointers long");
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static_assert(alignof(HeapObject) == alignof(void*),
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"HeapObject must be pointer-aligned");
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} // end namespace swift
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#endif
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#endif
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