Files
swift-mirror/stdlib/public/runtime/BytecodeLayouts.cpp
Dario Rexin fd4ef74266 Merge pull request #67067 from drexin/wip-refactor-simple-enum-tag
[Runtime] Abstract handling of simple single payload enum handling
2023-06-30 17:03:02 -07:00

1064 lines
40 KiB
C++

//===--- RuntimeValueWitness.cpp - Value Witness Runtime Implementation---===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Implementations of runtime determined value witness functions
// This file is intended to be statically linked into executables until it is
// fully added to the runtime.
//
//===----------------------------------------------------------------------===//
#include "BytecodeLayouts.h"
#include "../SwiftShims/swift/shims/HeapObject.h"
#include "EnumImpl.h"
#include "WeakReference.h"
#include "swift/ABI/MetadataValues.h"
#include "swift/ABI/System.h"
#include "swift/Runtime/Error.h"
#include "swift/Runtime/HeapObject.h"
#include "llvm/Support/SwapByteOrder.h"
#include <cstdint>
#include <functional>
#include <limits>
#include <optional>
#include <type_traits>
#if SWIFT_OBJC_INTEROP
#include "swift/Runtime/ObjCBridge.h"
#include <Block.h>
#endif
#if SWIFT_PTRAUTH
#include <ptrauth.h>
#endif
using namespace swift;
static Metadata *getExistentialTypeMetadata(OpaqueValue *object) {
return reinterpret_cast<Metadata**>(object)[NumWords_ValueBuffer];
}
template <typename FnTy>
static const FnTy readRelativeFunctionPointer(LayoutStringReader &reader) {
static_assert(std::is_pointer<FnTy>::value);
auto absolute = reader.layoutStr + reader.offset;
auto relativeOffset =
(uintptr_t)(intptr_t)(int32_t)reader.readBytes<intptr_t>();
FnTy fn;
#if SWIFT_PTRAUTH
fn = (FnTy)ptrauth_sign_unauthenticated(
(void *)((uintptr_t)absolute + relativeOffset),
ptrauth_key_function_pointer, 0);
#else
fn = (FnTy)((uintptr_t)absolute + relativeOffset);
#endif
return fn;
}
typedef Metadata *(*MetadataAccessor)(const Metadata *const *);
static const Metadata *getResilientTypeMetadata(const Metadata *metadata,
LayoutStringReader &reader) {
auto fn = readRelativeFunctionPointer<MetadataAccessor>(reader);
return fn(metadata->getGenericArgs());
}
typedef void (*DestrFn)(void*);
struct DestroyFuncAndMask {
DestrFn fn;
bool isIndirect;
};
static void skipDestroy(void* ignore) { }
static void existential_destroy(OpaqueValue* object) {
auto* metadata = getExistentialTypeMetadata(object);
if (metadata->getValueWitnesses()->isValueInline()) {
metadata->vw_destroy(object);
} else {
swift_release(*(HeapObject**)object);
}
}
template <typename Handler, typename... Params>
inline static bool handleNextRefCount(const Metadata *metadata,
LayoutStringReader &reader,
uintptr_t &addrOffset, Params... params) {
uint64_t skip = reader.readBytes<uint64_t>();
auto tag = static_cast<RefCountingKind>(skip >> 56);
skip &= ~(0xffULL << 56);
addrOffset += skip;
if (SWIFT_UNLIKELY(tag == RefCountingKind::End)) {
return false;
} else if (SWIFT_UNLIKELY(tag == RefCountingKind::Metatype)) {
auto *type = reader.readBytes<const Metadata *>();
Handler::handleMetatype(type, addrOffset, std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag == RefCountingKind::Resilient)) {
auto *type = getResilientTypeMetadata(metadata, reader);
Handler::handleMetatype(type, addrOffset, std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag ==
RefCountingKind::SinglePayloadEnumSimple)) {
Handler::handleSinglePayloadEnumSimple(reader, addrOffset,
std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag == RefCountingKind::SinglePayloadEnumFN)) {
Handler::handleSinglePayloadEnumFN(reader, false, addrOffset,
std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag ==
RefCountingKind::SinglePayloadEnumFNResolved)) {
Handler::handleSinglePayloadEnumFN(reader, true, addrOffset,
std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag == RefCountingKind::SinglePayloadEnumGeneric)) {
Handler::handleSinglePayloadEnumGeneric(reader, addrOffset,
std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag == RefCountingKind::MultiPayloadEnumFN)) {
Handler::handleMultiPayloadEnumFN(metadata, reader, false, addrOffset,
std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag ==
RefCountingKind::MultiPayloadEnumFNResolved)) {
Handler::handleMultiPayloadEnumFN(metadata, reader, true, addrOffset,
std::forward<Params>(params)...);
} else if (SWIFT_UNLIKELY(tag == RefCountingKind::MultiPayloadEnumGeneric)) {
Handler::handleMultiPayloadEnumGeneric(metadata, reader, addrOffset,
std::forward<Params>(params)...);
} else {
Handler::handleReference(tag, addrOffset, std::forward<Params>(params)...);
}
return true;
}
template <unsigned N, typename Handler, typename... Params>
inline static void handleRefCounts(const Metadata *metadata,
LayoutStringReader &reader,
uintptr_t &addrOffset, Params... params) {
if (N == 0) {
while (handleNextRefCount<Handler>(metadata, reader, addrOffset,
std::forward<Params>(params)...)) {
}
} else {
for (unsigned i = 0; i < N; i++) {
handleNextRefCount<Handler>(metadata, reader, addrOffset,
std::forward<Params>(params)...);
}
}
}
template <unsigned N, typename Handler, typename... Params>
inline static void handleRefCounts(const Metadata *metadata, Params... params) {
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize};
uintptr_t addrOffset = 0;
handleRefCounts<N, Handler>(metadata, reader, addrOffset,
std::forward<Params>(params)...);
}
static uint64_t readTagBytes(const uint8_t *addr, uint8_t byteCount) {
switch (byteCount) {
case 1:
return addr[0];
case 2: {
uint16_t res = 0;
memcpy(&res, addr, sizeof(uint16_t));
return res;
}
case 4: {
uint32_t res = 0;
memcpy(&res, addr, sizeof(uint32_t));
return res;
}
case 8: {
uint64_t res = 0;
memcpy(&res, addr, sizeof(uint64_t));
return res;
}
default:
swift_unreachable("Unsupported tag byte length.");
}
}
static void handleSinglePayloadEnumSimple(LayoutStringReader &reader,
uint8_t *addr,
uintptr_t &addrOffset) {
auto byteCountsAndOffset = reader.readBytes<uint64_t>();
auto extraTagBytesPattern = (uint8_t)(byteCountsAndOffset >> 62);
auto xiTagBytesPattern = ((uint8_t)(byteCountsAndOffset >> 59)) & 0x7;
auto xiTagBytesOffset =
byteCountsAndOffset & std::numeric_limits<uint32_t>::max();
if (extraTagBytesPattern) {
auto extraTagBytes = 1 << (extraTagBytesPattern - 1);
auto payloadSize = reader.readBytes<size_t>();
auto tagBytes =
readTagBytes(addr + addrOffset + payloadSize, extraTagBytes);
if (tagBytes) {
reader.skip(sizeof(uint64_t) + sizeof(size_t));
goto noPayload;
}
} else {
reader.skip(sizeof(size_t));
}
if (xiTagBytesPattern) {
auto zeroTagValue = reader.readBytes<uint64_t>();
auto xiTagValues = reader.readBytes<size_t>();
auto xiTagBytes = 1 << (xiTagBytesPattern - 1);
uint64_t tagBytes =
readTagBytes(addr + addrOffset + xiTagBytesOffset, xiTagBytes) -
zeroTagValue;
if (tagBytes >= xiTagValues) {
reader.skip(sizeof(size_t) * 2);
return;
}
} else {
reader.skip(sizeof(uint64_t) + sizeof(size_t));
}
noPayload:
auto refCountBytes = reader.readBytes<size_t>();
auto skip = reader.readBytes<size_t>();
reader.skip(refCountBytes);
addrOffset += skip;
}
typedef unsigned (*GetEnumTagFn)(const uint8_t *);
static void handleSinglePayloadEnumFN(LayoutStringReader &reader, bool resolved,
uint8_t *addr, uintptr_t &addrOffset) {
GetEnumTagFn getEnumTag;
if (resolved) {
getEnumTag = reader.readBytes<GetEnumTagFn>();
} else {
getEnumTag = readRelativeFunctionPointer<GetEnumTagFn>(reader);
}
unsigned enumTag = getEnumTag(addr + addrOffset);
if (enumTag == 0) {
reader.skip(sizeof(size_t) * 2);
} else {
auto refCountBytes = reader.readBytes<size_t>();
auto skip = reader.readBytes<size_t>();
reader.skip(refCountBytes);
addrOffset += skip;
}
}
static void handleSinglePayloadEnumGeneric(LayoutStringReader &reader,
uint8_t *addr,
uintptr_t &addrOffset) {
auto tagBytesAndOffset = reader.readBytes<uint64_t>();
auto extraTagBytesPattern = (uint8_t)(tagBytesAndOffset >> 62);
auto xiTagBytesOffset =
tagBytesAndOffset & std::numeric_limits<uint32_t>::max();
const Metadata *xiType = nullptr;
if (extraTagBytesPattern) {
auto extraTagBytes = 1 << (extraTagBytesPattern - 1);
auto payloadSize = reader.readBytes<size_t>();
auto tagBytes =
readTagBytes(addr + addrOffset + payloadSize, extraTagBytes);
if (tagBytes) {
reader.skip(sizeof(uint64_t) + sizeof(size_t));
goto noPayload;
}
} else {
reader.skip(sizeof(size_t));
}
xiType = reader.readBytes<const Metadata *>();
if (xiType) {
auto numEmptyCases = reader.readBytes<unsigned>();
auto tag = xiType->vw_getEnumTagSinglePayload(
(const OpaqueValue *)(addr + addrOffset + xiTagBytesOffset),
numEmptyCases);
if (tag == 0) {
reader.skip(sizeof(size_t) * 2);
return;
}
} else {
reader.skip(sizeof(uint64_t) + sizeof(size_t));
}
noPayload:
auto refCountBytes = reader.readBytes<size_t>();
auto skip = reader.readBytes<size_t>();
reader.skip(refCountBytes);
addrOffset += skip;
}
template <typename Handler, typename... Params>
static void handleMultiPayloadEnumFN(const Metadata *metadata,
LayoutStringReader &reader, bool resolved,
uintptr_t &addrOffset, uint8_t *addr,
Params... params) {
GetEnumTagFn getEnumTag;
if (resolved) {
getEnumTag = reader.readBytes<GetEnumTagFn>();
} else {
getEnumTag = readRelativeFunctionPointer<GetEnumTagFn>(reader);
}
size_t numPayloads = reader.readBytes<size_t>();
size_t refCountBytes = reader.readBytes<size_t>();
size_t enumSize = reader.readBytes<size_t>();
unsigned enumTag = getEnumTag(addr + addrOffset);
if (enumTag < numPayloads) {
size_t refCountOffset = reader.peekBytes<size_t>(enumTag * sizeof(size_t));
LayoutStringReader nestedReader = reader;
nestedReader.skip((numPayloads * sizeof(size_t)) + refCountOffset);
uintptr_t nestedAddrOffset = addrOffset;
handleRefCounts<0, Handler>(metadata, nestedReader, nestedAddrOffset, addr,
std::forward<Params>(params)...);
}
reader.skip(refCountBytes + (numPayloads * sizeof(size_t)));
addrOffset += enumSize;
}
template <typename Handler, typename... Params>
static void handleMultiPayloadEnumGeneric(const Metadata *metadata,
LayoutStringReader &reader,
uintptr_t &addrOffset, uint8_t *addr,
Params... params) {
auto tagBytes = reader.readBytes<size_t>();
auto numPayloads = reader.readBytes<size_t>();
auto refCountBytes = reader.readBytes<size_t>();
auto enumSize = reader.readBytes<size_t>();
auto tagBytesOffset = enumSize - tagBytes;
auto enumTag = readTagBytes(addr + addrOffset + tagBytesOffset, tagBytes);
if (enumTag < numPayloads) {
size_t refCountOffset = reader.peekBytes<size_t>(enumTag * sizeof(size_t));
LayoutStringReader nestedReader = reader;
nestedReader.skip((numPayloads * sizeof(size_t)) + refCountOffset);
uintptr_t nestedAddrOffset = addrOffset;
handleRefCounts<0, Handler>(metadata, nestedReader, nestedAddrOffset, addr,
std::forward<Params>(params)...);
}
reader.skip(refCountBytes + (numPayloads * sizeof(size_t)));
addrOffset += enumSize;
}
const DestroyFuncAndMask destroyTable[] = {
{(DestrFn)&skipDestroy, false},
{(DestrFn)&swift_errorRelease, true},
{(DestrFn)&swift_release, true},
{(DestrFn)&swift_unownedRelease, true},
{(DestrFn)&swift_weakDestroy, false},
{(DestrFn)&swift_unknownObjectRelease, true},
{(DestrFn)&swift_unknownObjectUnownedDestroy, false},
{(DestrFn)&swift_unknownObjectWeakDestroy, false},
{(DestrFn)&swift_bridgeObjectRelease, true},
#if SWIFT_OBJC_INTEROP
{(DestrFn)&_Block_release, true},
{(DestrFn)&swift_unknownObjectRelease, true},
#else
{nullptr, true},
{nullptr, true},
#endif
// TODO: how to handle Custom?
{nullptr, true},
{nullptr, true},
{nullptr, true},
{(DestrFn)&existential_destroy, false},
};
struct DestroyHandler {
static inline void handleMetatype(const Metadata *type, uintptr_t addrOffset,
uint8_t *addr) {
type->vw_destroy((OpaqueValue *)(addr + addrOffset));
}
static inline void handleSinglePayloadEnumSimple(LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *addr) {
::handleSinglePayloadEnumSimple(reader, addr, addrOffset);
}
static inline void handleSinglePayloadEnumFN(LayoutStringReader &reader,
bool resolved,
uintptr_t &addrOffset,
uint8_t *addr) {
::handleSinglePayloadEnumFN(reader, resolved, addr, addrOffset);
}
static inline void handleSinglePayloadEnumGeneric(LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *addr) {
::handleSinglePayloadEnumGeneric(reader, addr, addrOffset);
}
static inline void handleMultiPayloadEnumFN(const Metadata *metadata,
LayoutStringReader &reader,
bool resolved,
uintptr_t &addrOffset,
uint8_t *addr) {
::handleMultiPayloadEnumFN<DestroyHandler>(metadata, reader, resolved,
addrOffset, addr);
}
static inline void handleMultiPayloadEnumGeneric(const Metadata *metadata,
LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *addr) {
::handleMultiPayloadEnumGeneric<DestroyHandler>(metadata, reader,
addrOffset, addr);
}
static inline void handleReference(RefCountingKind tag, uintptr_t addrOffset,
uint8_t *addr) {
const auto &destroyFunc = destroyTable[static_cast<uint8_t>(tag)];
if (SWIFT_LIKELY(destroyFunc.isIndirect)) {
destroyFunc.fn(
(void *)((*(uintptr_t *)(addr + addrOffset))));
} else {
destroyFunc.fn(((void *)(addr + addrOffset)));
}
}
};
extern "C" void
swift_generic_destroy(swift::OpaqueValue *address, const Metadata *metadata) {
handleRefCounts<0, DestroyHandler>(metadata, (uint8_t *)address);
}
struct RetainFuncAndMask {
void* fn;
bool isSingle;
};
#if SWIFT_OBJC_INTEROP
void* Block_copyForwarder(void** dest, const void** src) {
*dest = _Block_copy(*src);
return *dest;
}
#endif
typedef void* (*RetainFn)(void*);
typedef void* (*CopyInitFn)(void*, void*);
void* skipRetain(void* ignore) { return nullptr; }
void* existential_initializeWithCopy(OpaqueValue* dest, OpaqueValue* src) {
auto* metadata = getExistentialTypeMetadata(src);
return metadata->vw_initializeBufferWithCopyOfBuffer((ValueBuffer*)dest,
(ValueBuffer*)src);
}
const RetainFuncAndMask retainTable[] = {
{(void*)&skipRetain, true},
{(void*)&swift_errorRetain, true},
{(void*)&swift_retain, true},
{(void*)&swift_unownedRetain, true},
{(void*)&swift_weakCopyInit, false},
{(void*)&swift_unknownObjectRetain, true},
{(void*)&swift_unknownObjectUnownedCopyInit, false},
{(void*)&swift_unknownObjectWeakCopyInit, false},
{(void*)&swift_bridgeObjectRetain, true},
#if SWIFT_OBJC_INTEROP
{(void*)&Block_copyForwarder, false},
{(void*)&objc_retain, true},
#else
{nullptr, true},
{nullptr, true},
#endif
// TODO: how to handle Custom?
{nullptr, true},
{nullptr, true},
{nullptr, true},
{(void*)&existential_initializeWithCopy, false},
};
struct CopyHandler {
static inline void handleMetatype(const Metadata *type, uintptr_t addrOffset,
uint8_t *dest, uint8_t *src) {
type->vw_initializeWithCopy((OpaqueValue*)((uintptr_t)dest + addrOffset),
(OpaqueValue*)((uintptr_t)src + addrOffset));
}
static inline void handleSinglePayloadEnumSimple(LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *dest,
uint8_t *src) {
::handleSinglePayloadEnumSimple(reader, src, addrOffset);
}
static inline void handleSinglePayloadEnumFN(LayoutStringReader &reader,
bool resolved,
uintptr_t &addrOffset,
uint8_t *dest, uint8_t *src) {
::handleSinglePayloadEnumFN(reader, resolved, src, addrOffset);
}
static inline void handleSinglePayloadEnumGeneric(LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *dest,
uint8_t *src) {
::handleSinglePayloadEnumGeneric(reader, src, addrOffset);
}
static inline void handleMultiPayloadEnumFN(const Metadata *metadata,
LayoutStringReader &reader,
bool resolved,
uintptr_t &addrOffset,
uint8_t *dest, uint8_t *src) {
::handleMultiPayloadEnumFN<CopyHandler>(metadata, reader, resolved,
addrOffset, dest, src);
}
static inline void handleMultiPayloadEnumGeneric(const Metadata *metadata,
LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *dest,
uint8_t *src) {
::handleMultiPayloadEnumGeneric<CopyHandler>(metadata, reader, addrOffset,
dest, src);
}
static inline void handleReference(RefCountingKind tag, uintptr_t addrOffset,
uint8_t *dest, uint8_t *src) {
const auto &retainFunc = retainTable[static_cast<uint8_t>(tag)];
if (SWIFT_LIKELY(retainFunc.isSingle)) {
((RetainFn)retainFunc.fn)(*(void**)(((uintptr_t)dest + addrOffset)));
} else {
((CopyInitFn)retainFunc.fn)((void*)((uintptr_t)dest + addrOffset),
(void*)((uintptr_t)src + addrOffset));
}
}
};
extern "C" swift::OpaqueValue *
swift_generic_initWithCopy(swift::OpaqueValue *dest, swift::OpaqueValue *src,
const Metadata *metadata) {
size_t size = metadata->vw_size();
memcpy(dest, src, size);
handleRefCounts<0, CopyHandler>(metadata, (uint8_t *)dest, (uint8_t *)src);
return dest;
}
struct TakeHandler {
static inline void handleMetatype(const Metadata *type, uintptr_t addrOffset,
uint8_t *dest, uint8_t *src) {
if (SWIFT_UNLIKELY(!type->getValueWitnesses()->isBitwiseTakable())) {
type->vw_initializeWithTake(
(OpaqueValue*)((uintptr_t)dest + addrOffset),
(OpaqueValue*)((uintptr_t)src + addrOffset));
}
}
static inline void handleSinglePayloadEnumSimple(LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *dest,
uint8_t *src) {
::handleSinglePayloadEnumSimple(reader, src, addrOffset);
}
static inline void handleSinglePayloadEnumFN(LayoutStringReader &reader,
bool resolved,
uintptr_t &addrOffset,
uint8_t *dest, uint8_t *src) {
::handleSinglePayloadEnumFN(reader, resolved, src, addrOffset);
}
static inline void handleSinglePayloadEnumGeneric(LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *dest,
uint8_t *src) {
::handleSinglePayloadEnumGeneric(reader, src, addrOffset);
}
static inline void handleMultiPayloadEnumFN(const Metadata *metadata,
LayoutStringReader &reader,
bool resolved,
uintptr_t &addrOffset,
uint8_t *dest, uint8_t *src) {
::handleMultiPayloadEnumFN<TakeHandler>(metadata, reader, resolved,
addrOffset, dest, src);
}
static inline void handleMultiPayloadEnumGeneric(const Metadata *metadata,
LayoutStringReader &reader,
uintptr_t &addrOffset,
uint8_t *dest,
uint8_t *src) {
::handleMultiPayloadEnumGeneric<TakeHandler>(metadata, reader, addrOffset,
dest, src);
}
static inline void handleReference(RefCountingKind tag, uintptr_t addrOffset,
uint8_t *dest, uint8_t *src) {
if (tag == RefCountingKind::UnknownWeak) {
swift_unknownObjectWeakTakeInit(
(WeakReference*)((uintptr_t)dest + addrOffset),
(WeakReference*)((uintptr_t)src + addrOffset));
} else if (tag == RefCountingKind::Existential) {
auto *type = getExistentialTypeMetadata(
(OpaqueValue*)((uintptr_t)src + addrOffset));
if (SWIFT_UNLIKELY(!type->getValueWitnesses()->isBitwiseTakable())) {
type->vw_initializeWithTake(
(OpaqueValue *)((uintptr_t)dest + addrOffset),
(OpaqueValue *)((uintptr_t)src + addrOffset));
}
}
}
};
extern "C" swift::OpaqueValue *
swift_generic_initWithTake(swift::OpaqueValue *dest, swift::OpaqueValue *src,
const Metadata *metadata) {
size_t size = metadata->vw_size();
memcpy(dest, src, size);
if (SWIFT_LIKELY(metadata->getValueWitnesses()->isBitwiseTakable())) {
return dest;
}
handleRefCounts<0, TakeHandler>(metadata, (uint8_t *)dest, (uint8_t *)src);
return dest;
}
extern "C" swift::OpaqueValue *
swift_generic_assignWithCopy(swift::OpaqueValue *dest, swift::OpaqueValue *src,
const Metadata *metadata) {
swift_generic_destroy(dest, metadata);
return swift_generic_initWithCopy(dest, src, metadata);
}
extern "C" swift::OpaqueValue *
swift_generic_assignWithTake(swift::OpaqueValue *dest, swift::OpaqueValue *src,
const Metadata *metadata) {
swift_generic_destroy(dest, metadata);
return swift_generic_initWithTake(dest, src, metadata);
}
extern "C" unsigned swift_singletonEnum_getEnumTag(swift::OpaqueValue *address,
const Metadata *metadata) {
return 0;
}
template <typename T>
static inline T handleSinglePayloadEnumSimpleTag(
LayoutStringReader &reader, uint8_t *addr,
std::function<std::optional<T>(size_t, size_t, uint8_t)>
extraTagBytesHandler,
std::function<T(size_t, uint64_t, uint8_t, unsigned, size_t, uint8_t)>
xiHandler) {
auto byteCountsAndOffset = reader.readBytes<uint64_t>();
auto extraTagBytesPattern = (uint8_t)(byteCountsAndOffset >> 62);
auto xiTagBytesPattern = ((uint8_t)(byteCountsAndOffset >> 59)) & 0x7;
auto xiTagBytesOffset =
byteCountsAndOffset & std::numeric_limits<uint32_t>::max();
auto numExtraTagBytes = 1 << (extraTagBytesPattern - 1);
auto payloadSize = reader.readBytes<size_t>();
auto zeroTagValue = reader.readBytes<uint64_t>();
auto payloadNumExtraInhabitants = reader.readBytes<size_t>();
if (extraTagBytesPattern) {
if (auto result = extraTagBytesHandler(payloadNumExtraInhabitants,
payloadSize, numExtraTagBytes)) {
return *result;
}
}
return xiHandler(payloadNumExtraInhabitants, zeroTagValue, xiTagBytesPattern,
xiTagBytesOffset, payloadSize, numExtraTagBytes);
}
extern "C" unsigned swift_enumSimple_getEnumTag(swift::OpaqueValue *address,
const Metadata *metadata) {
auto addr = reinterpret_cast<uint8_t *>(address);
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize + sizeof(uint64_t)};
auto extraTagBytesHandler =
[addr](size_t payloadNumExtraInhabitants, size_t payloadSize,
uint8_t numExtraTagBytes) -> std::optional<unsigned> {
auto tagBytes = readTagBytes(addr + payloadSize, numExtraTagBytes);
if (tagBytes) {
unsigned caseIndexFromExtraTagBits =
payloadSize >= 4 ? 0 : (tagBytes - 1U) << (payloadSize * 8U);
unsigned caseIndexFromValue = loadEnumElement(addr, payloadSize);
unsigned noPayloadIndex =
(caseIndexFromExtraTagBits | caseIndexFromValue) +
payloadNumExtraInhabitants;
return noPayloadIndex + 1;
}
return std::nullopt;
};
auto xihandler = [addr](size_t payloadNumExtraInhabitants,
uint64_t zeroTagValue, uint8_t xiTagBytesPattern,
unsigned xiTagBytesOffset, size_t payloadSize,
uint8_t numExtraTagBytes) -> unsigned {
auto xiTagBytes = 1 << (xiTagBytesPattern - 1);
uint64_t tagBytes =
readTagBytes(addr + xiTagBytesOffset, xiTagBytes) -
zeroTagValue;
if (tagBytes < payloadNumExtraInhabitants) {
return tagBytes + 1;
}
return 0;
};
return handleSinglePayloadEnumSimpleTag<unsigned>(
reader, addr, extraTagBytesHandler, xihandler);
}
extern "C"
unsigned swift_enumFn_getEnumTag(swift::OpaqueValue *address,
const Metadata *metadata) {
auto addr = reinterpret_cast<const uint8_t *>(address);
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize + sizeof(uint64_t)};
auto getEnumTag = readRelativeFunctionPointer<GetEnumTagFn>(reader);
return getEnumTag(addr);
}
extern "C" unsigned
swift_multiPayloadEnumGeneric_getEnumTag(swift::OpaqueValue *address,
const Metadata *metadata) {
auto addr = reinterpret_cast<const uint8_t *>(address);
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize + sizeof(uint64_t)};
auto tagBytes = reader.readBytes<size_t>();
auto numPayloads = reader.readBytes<size_t>();
reader.skip(sizeof(size_t));
auto enumSize = reader.readBytes<size_t>();
auto payloadSize = enumSize - tagBytes;
auto enumTag = (unsigned)readTagBytes(addr + payloadSize, tagBytes);
if (enumTag < numPayloads) {
return enumTag;
}
auto payloadValue = loadEnumElement(addr, payloadSize);
if (payloadSize >= 4) {
return numPayloads + payloadValue;
} else {
unsigned numPayloadBits = payloadSize * CHAR_BIT;
return (payloadValue | (enumTag - numPayloads) << numPayloadBits) +
numPayloads;
}
}
extern "C" void swift_multiPayloadEnumGeneric_destructiveInjectEnumTag(
swift::OpaqueValue *address, unsigned tag, const Metadata *metadata) {
auto addr = reinterpret_cast<uint8_t *>(address);
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize + sizeof(uint64_t)};
auto numTagBytes = reader.readBytes<size_t>();
auto numPayloads = reader.readBytes<size_t>();
reader.skip(sizeof(size_t));
auto enumSize = reader.readBytes<size_t>();
auto payloadSize = enumSize - numTagBytes;
if (tag < numPayloads) {
// For a payload case, store the tag after the payload area.
auto tagBytes = addr + payloadSize;
storeEnumElement(tagBytes, tag, numTagBytes);
} else {
// For an empty case, factor out the parts that go in the payload and
// tag areas.
unsigned whichEmptyCase = tag - numPayloads;
unsigned whichTag, whichPayloadValue;
if (payloadSize >= 4) {
whichTag = numPayloads;
whichPayloadValue = whichEmptyCase;
} else {
unsigned numPayloadBits = payloadSize * CHAR_BIT;
whichTag = numPayloads + (whichEmptyCase >> numPayloadBits);
whichPayloadValue = whichEmptyCase & ((1U << numPayloadBits) - 1U);
}
auto tagBytes = addr + payloadSize;
storeEnumElement(tagBytes, whichTag, numTagBytes);
storeEnumElement(addr, whichPayloadValue, payloadSize);
}
}
template <typename T>
static inline T handleSinglePayloadEnumGenericTag(
LayoutStringReader &reader, uint8_t *addr,
std::function<std::optional<T>(const Metadata *, size_t, uint8_t)>
extraTagBytesHandler,
std::function<T(const Metadata *, unsigned, unsigned, size_t, uint8_t)>
xiHandler) {
auto tagBytesAndOffset = reader.readBytes<uint64_t>();
auto extraTagBytesPattern = (uint8_t)(tagBytesAndOffset >> 62);
auto xiTagBytesOffset =
tagBytesAndOffset & std::numeric_limits<uint32_t>::max();
auto numExtraTagBytes = 1 << (extraTagBytesPattern - 1);
auto payloadSize = reader.readBytes<size_t>();
auto xiType = reader.readBytes<const Metadata *>();
if (extraTagBytesPattern) {
if (auto result =
extraTagBytesHandler(xiType, payloadSize, numExtraTagBytes)) {
return *result;
}
}
auto numEmptyCases = reader.readBytes<unsigned>();
return xiHandler(xiType, xiTagBytesOffset, numEmptyCases, payloadSize,
numExtraTagBytes);
}
extern "C" unsigned
swift_singlePayloadEnumGeneric_getEnumTag(swift::OpaqueValue *address,
const Metadata *metadata) {
auto addr = reinterpret_cast<uint8_t *>(address);
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize + sizeof(uint64_t)};
auto extraTagBytesHandler =
[addr](const Metadata *xiType, size_t payloadSize,
uint8_t numExtraTagBytes) -> std::optional<unsigned> {
auto tagBytes = readTagBytes(addr + payloadSize, numExtraTagBytes);
if (tagBytes) {
unsigned payloadNumExtraInhabitants =
xiType ? xiType->vw_getNumExtraInhabitants() : 0;
unsigned caseIndexFromExtraTagBits =
payloadSize >= 4 ? 0 : (tagBytes - 1U) << (payloadSize * 8U);
unsigned caseIndexFromValue = loadEnumElement(addr, payloadSize);
unsigned noPayloadIndex =
(caseIndexFromExtraTagBits | caseIndexFromValue) +
payloadNumExtraInhabitants;
return noPayloadIndex + 1;
}
return std::nullopt;
};
auto xihandler = [addr](const Metadata *xiType, unsigned xiTagBytesOffset,
unsigned numEmptyCases, size_t payloadSize,
uint8_t numExtraTagBytes) -> unsigned {
if (xiType) {
return xiType->vw_getEnumTagSinglePayload(
(const OpaqueValue *)(addr + xiTagBytesOffset), numEmptyCases);
}
return 0;
};
return handleSinglePayloadEnumGenericTag<unsigned>(
reader, addr, extraTagBytesHandler, xihandler);
}
extern "C" void swift_singlePayloadEnumGeneric_destructiveInjectEnumTag(
swift::OpaqueValue *address, unsigned tag, const Metadata *metadata) {
auto addr = reinterpret_cast<uint8_t *>(address);
LayoutStringReader reader{metadata->getLayoutString(),
layoutStringHeaderSize + sizeof(uint64_t)};
auto extraTagBytesHandler =
[=](const Metadata *xiType, size_t payloadSize,
uint8_t numExtraTagBytes) -> std::optional<bool> {
unsigned payloadNumExtraInhabitants =
xiType ? xiType->vw_getNumExtraInhabitants() : 0;
if (tag <= payloadNumExtraInhabitants) {
return std::nullopt;
}
unsigned noPayloadIndex = tag - 1;
unsigned caseIndex = noPayloadIndex - payloadNumExtraInhabitants;
unsigned payloadIndex, extraTagIndex;
if (payloadSize >= 4) {
extraTagIndex = 1;
payloadIndex = caseIndex;
} else {
unsigned payloadBits = payloadSize * 8U;
extraTagIndex = 1U + (caseIndex >> payloadBits);
payloadIndex = caseIndex & ((1U << payloadBits) - 1U);
}
// Store into the value.
if (payloadSize)
storeEnumElement(addr, payloadIndex, payloadSize);
if (numExtraTagBytes)
storeEnumElement(addr + payloadSize, extraTagIndex, numExtraTagBytes);
return true;
};
auto xihandler = [=](const Metadata *xiType, unsigned xiTagBytesOffset,
unsigned numEmptyCases, size_t payloadSize,
uint8_t numExtraTagBytes) -> bool {
unsigned payloadNumExtraInhabitants =
xiType ? xiType->vw_getNumExtraInhabitants() : 0;
if (tag <= payloadNumExtraInhabitants) {
if (numExtraTagBytes != 0)
storeEnumElement(addr + payloadSize, 0, numExtraTagBytes);
if (tag == 0)
return true;
xiType->vw_storeEnumTagSinglePayload(
(swift::OpaqueValue *)(addr + xiTagBytesOffset), tag, numEmptyCases);
}
return true;
};
handleSinglePayloadEnumGenericTag<bool>(reader, addr, extraTagBytesHandler,
xihandler);
}
extern "C" swift::OpaqueValue *
swift_generic_initializeBufferWithCopyOfBuffer(swift::ValueBuffer *dest,
swift::ValueBuffer *src,
const Metadata *metadata) {
if (metadata->getValueWitnesses()->isValueInline()) {
return swift_generic_initWithCopy((swift::OpaqueValue *)dest,
(swift::OpaqueValue *)src, metadata);
} else {
memcpy(dest, src, sizeof(swift::HeapObject *));
swift_retain(*(swift::HeapObject **)src);
return (swift::OpaqueValue *)&(*(swift::HeapObject **)dest)[1];
}
}
void swift::swift_resolve_resilientAccessors(uint8_t *layoutStr,
size_t layoutStrOffset,
const uint8_t *fieldLayoutStr,
const Metadata *fieldType) {
LayoutStringWriter writer{layoutStr, layoutStrOffset};
LayoutStringReader reader{fieldLayoutStr, layoutStringHeaderSize};
while (true) {
size_t currentOffset = reader.offset;
uint64_t size = reader.readBytes<uint64_t>();
RefCountingKind tag = (RefCountingKind)(size >> 56);
size &= ~(0xffULL << 56);
switch (tag) {
case RefCountingKind::End:
return;
case RefCountingKind::Resilient: {
auto *type = getResilientTypeMetadata(fieldType, reader);
writer.offset = layoutStrOffset + currentOffset - layoutStringHeaderSize;
uint64_t tagAndOffset =
(((uint64_t)RefCountingKind::Metatype) << 56) | size;
writer.writeBytes(tagAndOffset);
writer.writeBytes(type);
break;
}
case RefCountingKind::Metatype:
reader.skip(sizeof(uintptr_t));
break;
case RefCountingKind::SinglePayloadEnumSimple:
reader.skip((3 * sizeof(uint64_t)) + (4 * sizeof(size_t)));
break;
case RefCountingKind::SinglePayloadEnumFN: {
auto getEnumTag = readRelativeFunctionPointer<GetEnumTagFn>(reader);
writer.offset = layoutStrOffset + currentOffset - layoutStringHeaderSize;
uint64_t tagAndOffset =
(((uint64_t)RefCountingKind::SinglePayloadEnumFNResolved) << 56) |
size;
writer.writeBytes(tagAndOffset);
writer.writeBytes(getEnumTag);
reader.skip(2 * sizeof(size_t));
break;
}
case RefCountingKind::SinglePayloadEnumFNResolved:
reader.skip(3 * sizeof(size_t));
break;
case RefCountingKind::SinglePayloadEnumGeneric: {
reader.skip(sizeof(uint64_t) + // tag + offset
sizeof(uint64_t) + // extra tag bytes + XI offset
sizeof(size_t) + // payload size
sizeof(uintptr_t) + // XI metadata
sizeof(unsigned)); // num empty cases
auto refCountBytes = reader.readBytes<size_t>();
reader.skip(sizeof(size_t) + // bytes to skip if no payload case
refCountBytes);
break;
}
case RefCountingKind::MultiPayloadEnumFN: {
auto getEnumTag = readRelativeFunctionPointer<GetEnumTagFn>(reader);
writer.offset = layoutStrOffset + currentOffset - layoutStringHeaderSize;
uint64_t tagAndOffset =
(((uint64_t)RefCountingKind::MultiPayloadEnumFNResolved) << 56) |
size;
writer.writeBytes(tagAndOffset);
writer.writeBytes(getEnumTag);
size_t numCases = reader.readBytes<size_t>();
// skip ref count bytes
reader.skip(sizeof(size_t));
size_t casesBeginOffset =
layoutStrOffset + reader.offset + (numCases * sizeof(size_t));
for (size_t j = 0; j < numCases; j++) {
size_t caseOffset = reader.readBytes<size_t>();
const uint8_t *caseLayoutString = fieldLayoutStr + reader.offset +
(numCases * sizeof(size_t)) +
caseOffset;
swift_resolve_resilientAccessors(layoutStr,
casesBeginOffset + caseOffset,
caseLayoutString, fieldType);
}
break;
}
case RefCountingKind::MultiPayloadEnumFNResolved: {
// skip function pointer
reader.skip(sizeof(uintptr_t));
size_t numCases = reader.readBytes<size_t>();
size_t refCountBytes = reader.readBytes<size_t>();
// skip enum size, offsets and ref counts
reader.skip(sizeof(size_t) + (numCases * sizeof(size_t)) + refCountBytes);
break;
}
case RefCountingKind::MultiPayloadEnumGeneric: {
reader.skip(sizeof(size_t));
auto numPayloads = reader.readBytes<size_t>();
auto refCountBytes = reader.readBytes<size_t>();
reader.skip(sizeof(size_t) * (numPayloads + 1) + refCountBytes);
break;
}
default:
break;
}
}
}
extern "C"
void swift_generic_instantiateLayoutString(const uint8_t* layoutStr,
Metadata* type) {
type->setLayoutString(layoutStr);
}