Files
swift-mirror/stdlib/runtime/KnownMetadata.cpp
2014-04-22 22:24:57 +00:00

224 lines
8.2 KiB
C++

//===--- KnownMetadata.cpp - Swift Language ABI Known Metadata Objects ----===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// Definitions of some builtin metadata objects.
//
//===----------------------------------------------------------------------===//
#include "swift/Runtime/Metadata.h"
#include "swift/Runtime/HeapObject.h"
#include "MetadataImpl.h"
#include <cstring>
#include <climits>
using namespace swift;
using namespace metadataimpl;
/// Copy a value from one object to another based on the size in the
/// given type metadata.
OpaqueValue *swift::swift_copyPOD(OpaqueValue *dest, OpaqueValue *src,
const Metadata *type) {
return (OpaqueValue*) memcpy(dest, src, type->getValueWitnesses()->size);
}
/// A function which does a naive copy.
template <class T> static T *copy(T *dest, T *src, const Metadata *self) {
*dest = *src;
return dest;
}
/// A function which returns back a static metatype.
const Metadata *swift::swift_staticTypeof(OpaqueValue *src,
const Metadata *self) {
return self;
}
// Work around a Xcode 4.5 bug (rdar://12288058) by explicitly
// instantiating this function template at the types we'll need.
#define INSTANTIATE(TYPE) \
template TYPE *copy<TYPE>(TYPE*, TYPE*, const Metadata*);
INSTANTIATE(bool);
INSTANTIATE(uint8_t);
INSTANTIATE(uint16_t);
INSTANTIATE(uint32_t);
INSTANTIATE(uint64_t);
INSTANTIATE(uintptr_t);
#undef INSTANTIATE
#define POD_VALUE_WITNESS_TABLE(TYPE, SIZE) { \
(value_witness_types::destroyBuffer*) &doNothing, \
(value_witness_types::initializeBufferWithCopyOfBuffer*) &copy<TYPE>, \
(value_witness_types::projectBuffer*) &projectBuffer, \
(value_witness_types::deallocateBuffer*) &doNothing, \
(value_witness_types::destroy*) &doNothing, \
(value_witness_types::initializeBufferWithCopy*) &copy<TYPE>, \
(value_witness_types::initializeWithCopy*) &copy<TYPE>, \
(value_witness_types::assignWithCopy*) &copy<TYPE>, \
(value_witness_types::initializeBufferWithTake*) &copy<TYPE>, \
(value_witness_types::initializeWithTake*) &copy<TYPE>, \
(value_witness_types::assignWithTake*) &copy<TYPE>, \
(value_witness_types::allocateBuffer*) &projectBuffer, \
(value_witness_types::typeOf*) &swift_staticTypeof, \
(value_witness_types::size) (SIZE), \
ValueWitnessFlags().withAlignment(SIZE).withPOD(true) \
.withInlineStorage(true), \
(value_witness_types::stride) (SIZE) \
}
namespace {
// A type sized and aligned the way Swift wants Int128 (and Float80/Float128)
// to be sized and aligned.
struct alignas(16) int128_like {
char data[16];
};
}
// We use explicit sizes and alignments here just in case the C ABI
// under-aligns any or all of them.
const ValueWitnessTable swift::_TWVBi8_ =
ValueWitnessTableForBox<NativeBox<uint8_t, 1>>::table;
const ValueWitnessTable swift::_TWVBi16_ =
ValueWitnessTableForBox<NativeBox<uint16_t, 2>>::table;
const ValueWitnessTable swift::_TWVBi32_ =
ValueWitnessTableForBox<NativeBox<uint32_t, 4>>::table;
const ValueWitnessTable swift::_TWVBi64_ =
ValueWitnessTableForBox<NativeBox<uint64_t, 8>>::table;
const ValueWitnessTable swift::_TWVBi128_ =
ValueWitnessTableForBox<NativeBox<int128_like, 16>>::table;
/// A function to get the dynamic class type of a Swift heap object.
const Metadata *swift::swift_objectTypeof(OpaqueValue *obj,
const Metadata *self) {
auto *heapRef = *reinterpret_cast<HeapObject**>(obj);
auto *classMetadata = static_cast<const ClassMetadata*>(heapRef->metadata);
// If the heap metadata for the object is not a type, give up and return the
// static type.
if (!classMetadata->isTypeMetadata())
return self;
return classMetadata;
}
/// Store an invalid pointer value as an extra inhabitant of a heap object.
void swift::swift_storeHeapObjectExtraInhabitant(HeapObject **dest,
int index) {
using namespace heap_object_abi;
// This must be consistent with the storeHeapObjectExtraInhabitant
// implementation in IRGen's GenType.cpp.
// FIXME: We could use high spare bits to produce extra inhabitants, but we
// probably won't need to.
*dest = (HeapObject*)((uintptr_t)index << ObjCReservedLowBits);
}
/// Return the extra inhabitant index for an invalid pointer value, or -1 if
/// the pointer is valid.
int swift::swift_getHeapObjectExtraInhabitantIndex(HeapObject * const* src) {
using namespace heap_object_abi;
// This must be consistent with the getHeapObjectExtraInhabitant
// implementation in IRGen's GenType.cpp.
uintptr_t val = (uintptr_t)*src;
// Return -1 for valid pointers.
// FIXME: We could use high spare bits to produce extra inhabitants, but we
// probably won't need to.
if (val >= LeastValidPointerValue)
return -1;
// Return -1 for ObjC tagged pointers.
// FIXME: This check is unnecessary for known-Swift types.
if (val & ObjCReservedBitsMask)
return -1;
return (int)(val >> ObjCReservedLowBits);
}
/// The basic value-witness table for Swift object pointers.
const ExtraInhabitantsValueWitnessTable swift::_TWVBo =
ValueWitnessTableForBox<SwiftRetainableBox>::table;
/// The value-witness table for pointer-aligned unmanaged pointer types.
const ExtraInhabitantsValueWitnessTable swift::_TWVMBo =
ValueWitnessTableForBox<PointerPointerBox>::table;
/*** Objective-C pointers ****************************************************/
// This section can reasonably be suppressed in builds that don't
// need to support Objective-C.
// ObjC runtime entrypoints.
extern "C" const void *object_getClass(void *);
/// A function to get the Swift type metadata wrapper for an ObjC object's
/// dynamic type.
const Metadata *swift::swift_objcTypeof(OpaqueValue *src, const Metadata *self)
{
auto object = *reinterpret_cast<HeapObject**>(src);
return swift_unknownTypeOf(object);
}
const Metadata *swift::swift_unknownTypeOf(HeapObject *object)
{
auto theClass = object_getClass(object);
auto classAsMetadata = reinterpret_cast<const ClassMetadata*>(theClass);
if (classAsMetadata->isTypeMetadata()) return classAsMetadata;
return swift_getObjCClassMetadata(classAsMetadata);
}
/// The basic value-witness table for ObjC object pointers.
const ExtraInhabitantsValueWitnessTable swift::_TWVBO =
ValueWitnessTableForBox<ObjCRetainableBox>::table;
/*** Functions ***************************************************************/
/// The basic value-witness table for function types.
const ValueWitnessTable swift::_TWVFT_T_ =
ValueWitnessTableForBox<AggregateBox<NativeBox<void*>,
SwiftRetainableBox>>::table;
/*** Empty tuples ************************************************************/
/// The basic value-witness table for empty types.
const ValueWitnessTable swift::_TWVT_ =
ValueWitnessTableForBox<AggregateBox<>>::table;
/*** Known metadata **********************************************************/
// Define some builtin opaque metadata.
#define OPAQUE_METADATA(TYPE) \
const FullOpaqueMetadata swift::_TMd##TYPE = { \
{ &_TWV##TYPE }, \
{ { MetadataKind::Opaque } } \
};
OPAQUE_METADATA(Bi8_)
OPAQUE_METADATA(Bi16_)
OPAQUE_METADATA(Bi32_)
OPAQUE_METADATA(Bi64_)
OPAQUE_METADATA(Bi128_)
OPAQUE_METADATA(Bo)
OPAQUE_METADATA(BO)
/// The standard metadata for the empty tuple.
const FullMetadata<TupleTypeMetadata> swift::_TMdT_ = {
{ &_TWVT_ }, // ValueWitnesses
{
{ MetadataKind::Tuple }, // Kind
0, // NumElements
nullptr // Labels
}
};