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fuchsia / third_party / swift / 10f8a9466bee1c9f66eb3c2038cc82f802b763f8 / . / include / swift / Reflection / ReflectionContext.h
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//===--- ReflectionContext.h - Swift Type Reflection Context ----*- 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
//
//===----------------------------------------------------------------------===//
//
// Implements the context for reflection of values in the address space of a
// remote process.
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_REFLECTION_REFLECTIONCONTEXT_H
#define SWIFT_REFLECTION_REFLECTIONCONTEXT_H
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/Object/COFF.h"
#include "llvm/Support/Memory.h"
#include "swift/ABI/Enum.h"
#include "swift/ABI/ObjectFile.h"
#include "swift/Remote/MemoryReader.h"
#include "swift/Remote/MetadataReader.h"
#include "swift/Reflection/Records.h"
#include "swift/Reflection/RuntimeInternals.h"
#include "swift/Reflection/TypeLowering.h"
#include "swift/Reflection/TypeRef.h"
#include "swift/Reflection/TypeRefBuilder.h"
#include "swift/Basic/Unreachable.h"
#include <set>
#include <unordered_map>
#include <utility>
#include <vector>
#include <inttypes.h>
namespace {
template <unsigned PointerSize> struct MachOTraits;
template <> struct MachOTraits<4> {
using Header = const struct llvm::MachO::mach_header;
using SegmentCmd = const struct llvm::MachO::segment_command;
using Section = const struct llvm::MachO::section;
static constexpr size_t MagicNumber = llvm::MachO::MH_MAGIC;
};
template <> struct MachOTraits<8> {
using Header = const struct llvm::MachO::mach_header_64;
using SegmentCmd = const struct llvm::MachO::segment_command_64;
using Section = const struct llvm::MachO::section_64;
static constexpr size_t MagicNumber = llvm::MachO::MH_MAGIC_64;
};
template <unsigned char ELFClass> struct ELFTraits;
template <> struct ELFTraits<llvm::ELF::ELFCLASS32> {
using Header = const struct llvm::ELF::Elf32_Ehdr;
using Section = const struct llvm::ELF::Elf32_Shdr;
using Offset = llvm::ELF::Elf32_Off;
using Size = llvm::ELF::Elf32_Word;
static constexpr unsigned char ELFClass = llvm::ELF::ELFCLASS32;
};
template <> struct ELFTraits<llvm::ELF::ELFCLASS64> {
using Header = const struct llvm::ELF::Elf64_Ehdr;
using Section = const struct llvm::ELF::Elf64_Shdr;
using Offset = llvm::ELF::Elf64_Off;
using Size = llvm::ELF::Elf64_Xword;
static constexpr unsigned char ELFClass = llvm::ELF::ELFCLASS64;
};
} // namespace
namespace swift {
namespace reflection {
using swift::remote::MemoryReader;
using swift::remote::RemoteAddress;
template <typename Runtime>
class ReflectionContext
: public remote::MetadataReader<Runtime, TypeRefBuilder> {
using super = remote::MetadataReader<Runtime, TypeRefBuilder>;
using super::readMetadata;
using super::readObjCClassName;
std::unordered_map<typename super::StoredPointer, const TypeInfo *> Cache;
/// All buffers we need to keep around long term. This will automatically free them
/// when this object is destroyed.
std::vector<MemoryReader::ReadBytesResult> savedBuffers;
std::vector<std::tuple<RemoteAddress, RemoteAddress>> imageRanges;
public:
using super::getBuilder;
using super::readDemanglingForContextDescriptor;
using super::readGenericArgFromMetadata;
using super::readIsaMask;
using super::readMetadataAndValueErrorExistential;
using super::readMetadataAndValueOpaqueExistential;
using super::readMetadataFromInstance;
using super::readTypeFromMetadata;
using super::stripSignedPointer;
using typename super::StoredPointer;
using typename super::StoredSignedPointer;
using typename super::StoredSize;
explicit ReflectionContext(std::shared_ptr<MemoryReader> reader)
: super(std::move(reader), *this)
{}
ReflectionContext(const ReflectionContext &other) = delete;
ReflectionContext &operator=(const ReflectionContext &other) = delete;
MemoryReader &getReader() {
return *this->Reader;
}
unsigned getSizeOfHeapObject() {
// This must match sizeof(HeapObject) for the target.
return sizeof(StoredPointer) * 2;
}
template <typename T> bool readMachOSections(RemoteAddress ImageStart) {
auto Buf =
this->getReader().readBytes(ImageStart, sizeof(typename T::Header));
if (!Buf)
return false;
auto Header = reinterpret_cast<typename T::Header *>(Buf.get());
assert(Header->magic == T::MagicNumber && "invalid MachO file");
auto NumCommands = Header->sizeofcmds;
// The layout of the executable is such that the commands immediately follow
// the header.
auto CmdStartAddress =
RemoteAddress(ImageStart.getAddressData() + sizeof(typename T::Header));
uint32_t SegmentCmdHdrSize = sizeof(typename T::SegmentCmd);
uint64_t Offset = 0;
// Find the __TEXT segment.
typename T::SegmentCmd *Command = nullptr;
for (unsigned I = 0; I < NumCommands; ++I) {
auto CmdBuf = this->getReader().readBytes(
RemoteAddress(CmdStartAddress.getAddressData() + Offset),
SegmentCmdHdrSize);
auto CmdHdr = reinterpret_cast<typename T::SegmentCmd *>(CmdBuf.get());
if (strncmp(CmdHdr->segname, "__TEXT", sizeof(CmdHdr->segname)) == 0) {
Command = CmdHdr;
savedBuffers.push_back(std::move(CmdBuf));
break;
}
Offset += CmdHdr->cmdsize;
}
// No __TEXT segment, bail out.
if (!Command)
return false;
// Find the load command offset.
auto loadCmdOffset = ImageStart.getAddressData() + Offset + sizeof(typename T::Header);
// Read the load command.
auto LoadCmdAddress = reinterpret_cast<const char *>(loadCmdOffset);
auto LoadCmdBuf = this->getReader().readBytes(
RemoteAddress(LoadCmdAddress), sizeof(typename T::SegmentCmd));
auto LoadCmd = reinterpret_cast<typename T::SegmentCmd *>(LoadCmdBuf.get());
// The sections start immediately after the load command.
unsigned NumSect = LoadCmd->nsects;
auto SectAddress = reinterpret_cast<const char *>(loadCmdOffset) +
sizeof(typename T::SegmentCmd);
auto Sections = this->getReader().readBytes(
RemoteAddress(SectAddress), NumSect * sizeof(typename T::Section));
auto Slide = ImageStart.getAddressData() - Command->vmaddr;
std::string Prefix = "__swift5";
uint64_t RangeStart = UINT64_MAX;
uint64_t RangeEnd = UINT64_MAX;
auto SectionsBuf = reinterpret_cast<const char *>(Sections.get());
for (unsigned I = 0; I < NumSect; ++I) {
auto S = reinterpret_cast<typename T::Section *>(
SectionsBuf + (I * sizeof(typename T::Section)));
if (strncmp(S->sectname, Prefix.c_str(), strlen(Prefix.c_str())) != 0)
continue;
if (RangeStart == UINT64_MAX && RangeEnd == UINT64_MAX) {
RangeStart = S->addr + Slide;
RangeEnd = S->addr + S->size + Slide;
continue;
}
RangeStart = std::min(RangeStart, (uint64_t)S->addr + Slide);
RangeEnd = std::max(RangeEnd, (uint64_t)(S->addr + S->size + Slide));
// Keep the range rounded to 8 byte alignment on both ends so we don't
// introduce misaligned pointers mapping between local and remote
// address space.
RangeStart = RangeStart & ~7;
RangeEnd = RangeEnd + 7 & ~7;
}
if (RangeStart == UINT64_MAX && RangeEnd == UINT64_MAX)
return false;
auto SectBuf = this->getReader().readBytes(RemoteAddress(RangeStart),
RangeEnd - RangeStart);
auto findMachOSectionByName = [&](llvm::StringRef Name)
-> std::pair<RemoteRef<void>, uint64_t> {
for (unsigned I = 0; I < NumSect; ++I) {
auto S = reinterpret_cast<typename T::Section *>(
SectionsBuf + (I * sizeof(typename T::Section)));
if (strncmp(S->sectname, Name.data(), strlen(Name.data())) != 0)
continue;
auto RemoteSecStart = S->addr + Slide;
auto SectBufData = reinterpret_cast<const char *>(SectBuf.get());
auto LocalSectStart =
reinterpret_cast<const char *>(SectBufData + RemoteSecStart - RangeStart);
auto StartRef = RemoteRef<void>(RemoteSecStart, LocalSectStart);
return {StartRef, S->size};
}
return {nullptr, 0};
};
SwiftObjectFileFormatMachO ObjectFileFormat;
auto FieldMdSec = findMachOSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::fieldmd));
auto AssocTySec = findMachOSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::assocty));
auto BuiltinTySec = findMachOSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::builtin));
auto CaptureSec = findMachOSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::capture));
auto TypeRefMdSec = findMachOSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::typeref));
auto ReflStrMdSec = findMachOSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::reflstr));
if (FieldMdSec.first == nullptr &&
AssocTySec.first == nullptr &&
BuiltinTySec.first == nullptr &&
CaptureSec.first == nullptr &&
TypeRefMdSec.first == nullptr &&
ReflStrMdSec.first == nullptr)
return false;
ReflectionInfo info = {
{FieldMdSec.first, FieldMdSec.second},
{AssocTySec.first, AssocTySec.second},
{BuiltinTySec.first, BuiltinTySec.second},
{CaptureSec.first, CaptureSec.second},
{TypeRefMdSec.first, TypeRefMdSec.second},
{ReflStrMdSec.first, ReflStrMdSec.second}};
this->addReflectionInfo(info);
// Find the __DATA segment.
for (unsigned I = 0; I < NumCommands; ++I) {
auto CmdBuf = this->getReader().readBytes(
RemoteAddress(CmdStartAddress.getAddressData() + Offset),
SegmentCmdHdrSize);
auto CmdHdr = reinterpret_cast<typename T::SegmentCmd *>(CmdBuf.get());
if (strncmp(CmdHdr->segname, "__DATA", sizeof(CmdHdr->segname)) == 0) {
auto DataSegmentEnd =
ImageStart.getAddressData() + CmdHdr->vmaddr + CmdHdr->vmsize;
assert(DataSegmentEnd > ImageStart.getAddressData() &&
"invalid range for __DATA");
imageRanges.push_back(
std::make_tuple(ImageStart, RemoteAddress(DataSegmentEnd)));
break;
}
Offset += CmdHdr->cmdsize;
}
savedBuffers.push_back(std::move(Buf));
savedBuffers.push_back(std::move(SectBuf));
savedBuffers.push_back(std::move(Sections));
return true;
}
bool readPECOFFSections(RemoteAddress ImageStart) {
auto DOSHdrBuf = this->getReader().readBytes(
ImageStart, sizeof(llvm::object::dos_header));
auto DOSHdr =
reinterpret_cast<const llvm::object::dos_header *>(DOSHdrBuf.get());
auto COFFFileHdrAddr = ImageStart.getAddressData() +
DOSHdr->AddressOfNewExeHeader +
sizeof(llvm::COFF::PEMagic);
auto COFFFileHdrBuf = this->getReader().readBytes(
RemoteAddress(COFFFileHdrAddr), sizeof(llvm::object::coff_file_header));
auto COFFFileHdr = reinterpret_cast<const llvm::object::coff_file_header *>(
COFFFileHdrBuf.get());
auto SectionTableAddr = COFFFileHdrAddr +
sizeof(llvm::object::coff_file_header) +
COFFFileHdr->SizeOfOptionalHeader;
auto SectionTableBuf = this->getReader().readBytes(
RemoteAddress(SectionTableAddr),
sizeof(llvm::object::coff_section) * COFFFileHdr->NumberOfSections);
auto findCOFFSectionByName = [&](llvm::StringRef Name)
-> std::pair<RemoteRef<void>, uint64_t> {
for (size_t i = 0; i < COFFFileHdr->NumberOfSections; ++i) {
const llvm::object::coff_section *COFFSec =
reinterpret_cast<const llvm::object::coff_section *>(
SectionTableBuf.get()) +
i;
llvm::StringRef SectionName =
(COFFSec->Name[llvm::COFF::NameSize - 1] == 0)
? COFFSec->Name
: llvm::StringRef(COFFSec->Name, llvm::COFF::NameSize);
if (SectionName != Name)
continue;
auto Addr = ImageStart.getAddressData() + COFFSec->VirtualAddress;
auto Buf = this->getReader().readBytes(RemoteAddress(Addr),
COFFSec->VirtualSize);
auto BufStart = Buf.get();
savedBuffers.push_back(std::move(Buf));
auto Begin = RemoteRef<void>(Addr, BufStart);
auto Size = COFFSec->VirtualSize;
// FIXME: This code needs to be cleaned up and updated
// to make it work for 32 bit platforms.
Begin = Begin.atByteOffset(8);
Size -= 16;
return {Begin, Size};
}
return {nullptr, 0};
};
SwiftObjectFileFormatCOFF ObjectFileFormat;
auto FieldMdSec = findCOFFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::fieldmd));
auto AssocTySec = findCOFFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::assocty));
auto BuiltinTySec = findCOFFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::builtin));
auto CaptureSec = findCOFFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::capture));
auto TypeRefMdSec = findCOFFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::typeref));
auto ReflStrMdSec = findCOFFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::reflstr));
if (FieldMdSec.first == nullptr &&
AssocTySec.first == nullptr &&
BuiltinTySec.first == nullptr &&
CaptureSec.first == nullptr &&
TypeRefMdSec.first == nullptr &&
ReflStrMdSec.first == nullptr)
return false;
ReflectionInfo Info = {
{FieldMdSec.first, FieldMdSec.second},
{AssocTySec.first, AssocTySec.second},
{BuiltinTySec.first, BuiltinTySec.second},
{CaptureSec.first, CaptureSec.second},
{TypeRefMdSec.first, TypeRefMdSec.second},
{ReflStrMdSec.first, ReflStrMdSec.second}};
this->addReflectionInfo(Info);
return true;
}
bool readPECOFF(RemoteAddress ImageStart) {
auto Buf = this->getReader().readBytes(ImageStart,
sizeof(llvm::object::dos_header));
if (!Buf)
return false;
auto DOSHdr = reinterpret_cast<const llvm::object::dos_header *>(Buf.get());
auto PEHeaderAddress =
ImageStart.getAddressData() + DOSHdr->AddressOfNewExeHeader;
Buf = this->getReader().readBytes(RemoteAddress(PEHeaderAddress),
sizeof(llvm::COFF::PEMagic));
if (!Buf)
return false;
if (memcmp(Buf.get(), llvm::COFF::PEMagic, sizeof(llvm::COFF::PEMagic)))
return false;
return readPECOFFSections(ImageStart);
}
template <typename T>
bool readELFSections(RemoteAddress ImageStart,
llvm::Optional<llvm::sys::MemoryBlock> FileBuffer) {
// When reading from the FileBuffer we can simply return a pointer to
// the underlying data.
// When reading from the process, we need to keep the memory around
// until the end of the function, so we store it inside ReadDataBuffer.
// We do this so in both cases we can return a simple pointer.
std::vector<MemoryReader::ReadBytesResult> ReadDataBuffer;
auto readData = [&](uint64_t Offset, uint64_t Size) -> const void * {
if (FileBuffer.hasValue()) {
auto Buffer = FileBuffer.getValue();
if (Offset + Size > Buffer.allocatedSize())
return nullptr;
return (const void *)((uint64_t)Buffer.base() + Offset);
} else {
MemoryReader::ReadBytesResult Buf =
this->getReader().readBytes(ImageStart + Offset, Size);
if (!Buf)
return nullptr;
ReadDataBuffer.push_back(std::move(Buf));
return ReadDataBuffer.back().get();
}
};
const void *Buf = readData(0, sizeof(typename T::Header));
if (!Buf)
return false;
auto Hdr = reinterpret_cast<const typename T::Header *>(Buf);
assert(Hdr->getFileClass() == T::ELFClass && "invalid ELF file class");
// From the header, grab information about the section header table.
uint64_t SectionHdrAddress = Hdr->e_shoff;
uint16_t SectionHdrNumEntries = Hdr->e_shnum;
uint16_t SectionEntrySize = Hdr->e_shentsize;
if (sizeof(typename T::Section) > SectionEntrySize)
return false;
if (SectionHdrNumEntries == 0)
return false;
// Collect all the section headers, we need them to look up the
// reflection sections (by name) and the string table.
// We read the section headers from the FileBuffer, since they are
// not mapped in the child process.
std::vector<const typename T::Section *> SecHdrVec;
for (unsigned I = 0; I < SectionHdrNumEntries; ++I) {
uint64_t Offset = SectionHdrAddress + (I * SectionEntrySize);
auto SecBuf = readData(Offset, sizeof(typename T::Section));
if (!SecBuf)
return false;
const typename T::Section *SecHdr =
reinterpret_cast<const typename T::Section *>(SecBuf);
SecHdrVec.push_back(SecHdr);
}
// This provides quick access to the section header string table index.
// We also here handle the unlikely even where the section index overflows
// and it's just a pointer to secondary storage (SHN_XINDEX).
uint32_t SecIdx = Hdr->e_shstrndx;
if (SecIdx == llvm::ELF::SHN_XINDEX) {
assert(!SecHdrVec.empty() && "malformed ELF object");
SecIdx = SecHdrVec[0]->sh_link;
}
assert(SecIdx < SecHdrVec.size() && "malformed ELF object");
const typename T::Section *SecHdrStrTab = SecHdrVec[SecIdx];
typename T::Offset StrTabOffset = SecHdrStrTab->sh_offset;
typename T::Size StrTabSize = SecHdrStrTab->sh_size;
auto StrTabBuf = readData(StrTabOffset, StrTabSize);
if (!StrTabBuf)
return false;
auto StrTab = reinterpret_cast<const char *>(StrTabBuf);
bool Error = false;
auto findELFSectionByName =
[&](llvm::StringRef Name) -> std::pair<RemoteRef<void>, uint64_t> {
if (Error)
return {nullptr, 0};
// Now for all the sections, find their name.
for (const typename T::Section *Hdr : SecHdrVec) {
uint32_t Offset = Hdr->sh_name;
const char *Start = (const char *)StrTab + Offset;
uint64_t StringSize = strnlen(Start, StrTabSize - Offset);
if (StringSize > StrTabSize - Offset) {
Error = true;
break;
}
std::string SecName(Start, StringSize);
if (SecName != Name)
continue;
RemoteAddress SecStart =
RemoteAddress(ImageStart.getAddressData() + Hdr->sh_addr);
auto SecSize = Hdr->sh_size;
MemoryReader::ReadBytesResult SecBuf;
if (FileBuffer.hasValue()) {
// sh_offset gives us the offset to the section in the file,
// while sh_addr gives us the offset in the process.
auto Offset = Hdr->sh_offset;
if (FileBuffer->allocatedSize() < Offset + SecSize) {
Error = true;
break;
}
auto *Buf = malloc(SecSize);
SecBuf = MemoryReader::ReadBytesResult(
Buf, [](const void *ptr) { free(const_cast<void *>(ptr)); });
memcpy((void *)Buf,
(const void *)((uint64_t)FileBuffer->base() + Offset),
SecSize);
} else {
SecBuf = this->getReader().readBytes(SecStart, SecSize);
}
auto SecContents =
RemoteRef<void>(SecStart.getAddressData(), SecBuf.get());
savedBuffers.push_back(std::move(SecBuf));
return {SecContents, SecSize};
}
return {nullptr, 0};
};
SwiftObjectFileFormatELF ObjectFileFormat;
auto FieldMdSec = findELFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::fieldmd));
auto AssocTySec = findELFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::assocty));
auto BuiltinTySec = findELFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::builtin));
auto CaptureSec = findELFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::capture));
auto TypeRefMdSec = findELFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::typeref));
auto ReflStrMdSec = findELFSectionByName(
ObjectFileFormat.getSectionName(ReflectionSectionKind::reflstr));
if (Error)
return false;
// We succeed if at least one of the sections is present in the
// ELF executable.
if (FieldMdSec.first == nullptr &&
AssocTySec.first == nullptr &&
BuiltinTySec.first == nullptr &&
CaptureSec.first == nullptr &&
TypeRefMdSec.first == nullptr &&
ReflStrMdSec.first == nullptr)
return false;
ReflectionInfo info = {
{FieldMdSec.first, FieldMdSec.second},
{AssocTySec.first, AssocTySec.second},
{BuiltinTySec.first, BuiltinTySec.second},
{CaptureSec.first, CaptureSec.second},
{TypeRefMdSec.first, TypeRefMdSec.second},
{ReflStrMdSec.first, ReflStrMdSec.second}};
this->addReflectionInfo(info);
return true;
}
/// Parses metadata information from an ELF image. Because the Section
/// Header Table maybe be missing (for example, when reading from a
/// process) this method optionally receives a buffer with the contents
/// of the image's file, from where it will the necessary information.
///
///
/// \param[in] ImageStart
/// A remote address pointing to the start of the image in the running
/// process.
///
/// \param[in] FileBuffer
/// A buffer which contains the contents of the image's file
/// in disk. If missing, all the information will be read using the
/// instance's memory reader.
///
/// \return
/// /b True if the metadata information was parsed successfully,
/// /b false otherwise.
bool readELF(RemoteAddress ImageStart, llvm::Optional<llvm::sys::MemoryBlock> FileBuffer) {
auto Buf =
this->getReader().readBytes(ImageStart, sizeof(llvm::ELF::Elf64_Ehdr));
// Read the header.
auto Hdr = reinterpret_cast<const llvm::ELF::Elf64_Ehdr *>(Buf.get());
if (!Hdr->checkMagic())
return false;
// Check if we have a ELFCLASS32 or ELFCLASS64
unsigned char FileClass = Hdr->getFileClass();
if (FileClass == llvm::ELF::ELFCLASS64) {
return readELFSections<ELFTraits<llvm::ELF::ELFCLASS64>>(
ImageStart, FileBuffer);
} else if (FileClass == llvm::ELF::ELFCLASS32) {
return readELFSections<ELFTraits<llvm::ELF::ELFCLASS32>>(
ImageStart, FileBuffer);
} else {
return false;
}
}
bool addImage(RemoteAddress ImageStart) {
// Read the first few bytes to look for a magic header.
auto Magic = this->getReader().readBytes(ImageStart, sizeof(uint32_t));
if (!Magic)
return false;
uint32_t MagicWord;
memcpy(&MagicWord, Magic.get(), sizeof(MagicWord));
// 32- and 64-bit Mach-O.
if (MagicWord == llvm::MachO::MH_MAGIC) {
return readMachOSections<MachOTraits<4>>(ImageStart);
}
if (MagicWord == llvm::MachO::MH_MAGIC_64) {
return readMachOSections<MachOTraits<8>>(ImageStart);
}
// PE. (This just checks for the DOS header; `readPECOFF` will further
// validate the existence of the PE header.)
auto MagicBytes = (const char*)Magic.get();
if (MagicBytes[0] == 'M' && MagicBytes[1] == 'Z') {
return readPECOFF(ImageStart);
}
// ELF.
if (MagicBytes[0] == llvm::ELF::ElfMagic[0]
&& MagicBytes[1] == llvm::ELF::ElfMagic[1]
&& MagicBytes[2] == llvm::ELF::ElfMagic[2]
&& MagicBytes[3] == llvm::ELF::ElfMagic[3]) {
return readELF(ImageStart, llvm::Optional<llvm::sys::MemoryBlock>());
}
// We don't recognize the format.
return false;
}
void addReflectionInfo(ReflectionInfo I) {
getBuilder().addReflectionInfo(I);
}
bool ownsObject(RemoteAddress ObjectAddress) {
auto MetadataAddress = readMetadataFromInstance(ObjectAddress.getAddressData());
if (!MetadataAddress)
return true;
return ownsAddress(RemoteAddress(*MetadataAddress));
}
/// Returns true if the address falls within a registered image.
bool ownsAddressRaw(RemoteAddress Address) {
for (auto Range : imageRanges) {
auto Start = std::get<0>(Range);
auto End = std::get<1>(Range);
if (Start.getAddressData() <= Address.getAddressData()
&& Address.getAddressData() < End.getAddressData())
return true;
}
return false;
}
/// Returns true if the address is known to the reflection context.
/// Currently, that means that either the address falls within a registered
/// image, or the address points to a Metadata whose type context descriptor
/// is within a registered image.
bool ownsAddress(RemoteAddress Address) {
if (ownsAddressRaw(Address))
return true;
// This is usually called on a Metadata address which might have been
// on the heap. Try reading it and looking up its type context descriptor
// instead.
if (auto Metadata = readMetadata(Address.getAddressData()))
if (auto DescriptorAddress =
super::readAddressOfNominalTypeDescriptor(Metadata, true))
if (ownsAddressRaw(RemoteAddress(DescriptorAddress)))
return true;
return false;
}
/// Return a description of the layout of a class instance with the given
/// metadata as its isa pointer.
const TypeInfo *
getMetadataTypeInfo(StoredPointer MetadataAddress,
remote::TypeInfoProvider *ExternalTypeInfo) {
// See if we cached the layout already
auto found = Cache.find(MetadataAddress);
if (found != Cache.end())
return found->second;
auto &TC = getBuilder().getTypeConverter();
const TypeInfo *TI = nullptr;
auto TR = readTypeFromMetadata(MetadataAddress);
auto kind = this->readKindFromMetadata(MetadataAddress);
if (TR != nullptr && kind) {
switch (*kind) {
case MetadataKind::Class: {
// Figure out where the stored properties of this class begin
// by looking at the size of the superclass
auto start =
this->readInstanceStartAndAlignmentFromClassMetadata(MetadataAddress);
// Perform layout
if (start)
TI = TC.getClassInstanceTypeInfo(TR, *start, ExternalTypeInfo);
break;
}
default:
break;
}
}
// Cache the result for future lookups
Cache[MetadataAddress] = TI;
return TI;
}
/// Return a description of the layout of a class instance with the given
/// metadata as its isa pointer.
const TypeInfo *
getInstanceTypeInfo(StoredPointer ObjectAddress,
remote::TypeInfoProvider *ExternalTypeInfo) {
auto MetadataAddress = readMetadataFromInstance(ObjectAddress);
if (!MetadataAddress)
return nullptr;
auto kind = this->readKindFromMetadata(*MetadataAddress);
if (!kind)
return nullptr;
switch (*kind) {
case MetadataKind::Class:
return getMetadataTypeInfo(*MetadataAddress, ExternalTypeInfo);
case MetadataKind::HeapLocalVariable: {
auto CDAddr = this->readCaptureDescriptorFromMetadata(*MetadataAddress);
if (!CDAddr)
return nullptr;
if (!CDAddr->isResolved())
return nullptr;
// FIXME: Non-generic SIL boxes also use the HeapLocalVariable metadata
// kind, but with a null capture descriptor right now (see
// FixedBoxTypeInfoBase::allocate).
//
// Non-generic SIL boxes share metadata among types with compatible
// layout, but we need some way to get an outgoing pointer map for them.
auto CD = getBuilder().getCaptureDescriptor(
CDAddr->getResolvedAddress().getAddressData());
if (CD == nullptr)
return nullptr;
auto Info = getBuilder().getClosureContextInfo(CD);
return getClosureContextInfo(ObjectAddress, Info, ExternalTypeInfo);
}
case MetadataKind::HeapGenericLocalVariable: {
// Generic SIL @box type - there is always an instantiated metadata
// pointer for the boxed type.
if (auto Meta = readMetadata(*MetadataAddress)) {
auto GenericHeapMeta =
cast<TargetGenericBoxHeapMetadata<Runtime>>(Meta.getLocalBuffer());
return getMetadataTypeInfo(GenericHeapMeta->BoxedType,
ExternalTypeInfo);
}
return nullptr;
}
case MetadataKind::ErrorObject:
// Error boxed existential on non-Objective-C runtime target
return nullptr;
default:
return nullptr;
}
}
bool projectExistential(RemoteAddress ExistentialAddress,
const TypeRef *ExistentialTR,
const TypeRef **OutInstanceTR,
RemoteAddress *OutInstanceAddress,
remote::TypeInfoProvider *ExternalTypeInfo) {
if (ExistentialTR == nullptr)
return false;
auto ExistentialTI = getTypeInfo(ExistentialTR, ExternalTypeInfo);
if (ExistentialTI == nullptr)
return false;
auto ExistentialRecordTI = dyn_cast<const RecordTypeInfo>(ExistentialTI);
if (ExistentialRecordTI == nullptr)
return false;
switch (ExistentialRecordTI->getRecordKind()) {
// Class existentials have trivial layout.
// It is itself the pointer to the instance followed by the witness tables.
case RecordKind::ClassExistential:
// This is just AnyObject.
*OutInstanceTR = ExistentialRecordTI->getFields()[0].TR;
*OutInstanceAddress = ExistentialAddress;
return true;
case RecordKind::OpaqueExistential: {
auto OptMetaAndValue =
readMetadataAndValueOpaqueExistential(ExistentialAddress);
if (!OptMetaAndValue)
return false;
auto InstanceTR = readTypeFromMetadata(
OptMetaAndValue->MetadataAddress.getAddressData());
if (!InstanceTR)
return false;
*OutInstanceTR = InstanceTR;
*OutInstanceAddress = OptMetaAndValue->PayloadAddress;
return true;
}
case RecordKind::ErrorExistential: {
auto OptMetaAndValue =
readMetadataAndValueErrorExistential(ExistentialAddress);
if (!OptMetaAndValue)
return false;
// FIXME: Check third value, 'IsBridgedError'
auto InstanceTR = readTypeFromMetadata(
OptMetaAndValue->MetadataAddress.getAddressData());
if (!InstanceTR)
return false;
*OutInstanceTR = InstanceTR;
*OutInstanceAddress = OptMetaAndValue->PayloadAddress;
return true;
}
default:
return false;
}
}
/// Projects the value of an enum.
///
/// Takes the address and typeref for an enum and determines the
/// index of the currently-selected case within the enum.
/// You can use this index with `swift_reflection_childOfTypeRef`
/// to get detailed information about the specific case.
///
/// Returns true if the enum case could be successfully determined. In
/// particular, note that this code may return false for valid in-memory data
/// if the compiler used a strategy we do not yet understand.
bool projectEnumValue(RemoteAddress EnumAddress, const TypeRef *EnumTR,
int *CaseIndex,
remote::TypeInfoProvider *ExternalTypeInfo) {
// Get the TypeInfo and sanity-check it
if (EnumTR == nullptr) {
return false;
}
auto TI = getTypeInfo(EnumTR, ExternalTypeInfo);
if (TI == nullptr) {
return false;
}
auto EnumTI = dyn_cast<const EnumTypeInfo>(TI);
if (EnumTI == nullptr){
return false;
}
return EnumTI->projectEnumValue(getReader(), EnumAddress, CaseIndex);
}
/// Return a description of the layout of a value with the given type.
const TypeInfo *getTypeInfo(const TypeRef *TR,
remote::TypeInfoProvider *ExternalTypeInfo) {
if (TR == nullptr) {
return nullptr;
} else {
return getBuilder().getTypeConverter().getTypeInfo(TR, ExternalTypeInfo);
}
}
/// Iterate the protocol conformance cache tree rooted at NodePtr, calling
/// Call with the type and protocol in each node.
void iterateConformanceTree(StoredPointer NodePtr,
std::function<void(StoredPointer Type, StoredPointer Proto)> Call) {
if (!NodePtr)
return;
auto NodeBytes = getReader().readBytes(RemoteAddress(NodePtr),
sizeof(ConformanceNode<Runtime>));
auto NodeData =
reinterpret_cast<const ConformanceNode<Runtime> *>(NodeBytes.get());
if (!NodeData)
return;
Call(NodeData->Type, NodeData->Proto);
iterateConformanceTree(NodeData->Left, Call);
iterateConformanceTree(NodeData->Right, Call);
}
void IterateConformanceTable(
RemoteAddress ConformancesPtr,
std::function<void(StoredPointer Type, StoredPointer Proto)> Call) {
auto MapBytes = getReader().readBytes(RemoteAddress(ConformancesPtr),
sizeof(ConcurrentHashMap<Runtime>));
auto MapData =
reinterpret_cast<const ConcurrentHashMap<Runtime> *>(MapBytes.get());
if (!MapData)
return;
auto Count = MapData->ElementCount;
auto Size = Count * sizeof(ConformanceCacheEntry<Runtime>);
auto ElementsBytes =
getReader().readBytes(RemoteAddress(MapData->Elements), Size);
auto ElementsData =
reinterpret_cast<const ConformanceCacheEntry<Runtime> *>(
ElementsBytes.get());
if (!ElementsData)
return;
for (StoredSize i = 0; i < Count; i++) {
auto &Element = ElementsData[i];
Call(Element.Type, Element.Proto);
}
}
/// Iterate the protocol conformance cache in the target process, calling Call
/// with the type and protocol of each conformance. Returns None on success,
/// and a string describing the error on failure.
llvm::Optional<std::string> iterateConformances(
std::function<void(StoredPointer Type, StoredPointer Proto)> Call) {
std::string ConformancesPointerName =
"_swift_debug_protocolConformanceStatePointer";
auto ConformancesAddrAddr =
getReader().getSymbolAddress(ConformancesPointerName);
if (!ConformancesAddrAddr)
return "unable to look up debug variable " + ConformancesPointerName;
auto ConformancesAddr =
getReader().readPointer(ConformancesAddrAddr, sizeof(StoredPointer));
if (!ConformancesAddr)
return "unable to read value of " + ConformancesPointerName;
auto Root = getReader().readPointer(ConformancesAddr->getResolvedAddress(),
sizeof(StoredPointer));
auto ReaderCount = Root->getResolvedAddress().getAddressData();
// ReaderCount will be the root pointer if the conformance cache is a
// ConcurrentMap. It's very unlikely that there would ever be more readers
// than the least valid pointer value, so compare with that to distinguish.
// TODO: once the old conformance cache is gone for good, remove that code.
uint64_t LeastValidPointerValue;
if (!getReader().queryDataLayout(
DataLayoutQueryType::DLQ_GetLeastValidPointerValue, nullptr,
&LeastValidPointerValue)) {
return std::string("unable to query least valid pointer value");
}
if (ReaderCount < LeastValidPointerValue)
IterateConformanceTable(ConformancesAddr->getResolvedAddress(), Call);
else {
// The old code has the root address at this location.
auto RootAddr = ReaderCount;
iterateConformanceTree(RootAddr, Call);
}
return llvm::None;
}
/// Fetch the metadata pointer from a metadata allocation, or 0 if this
/// allocation's tag is not handled or an error occurred.
StoredPointer allocationMetadataPointer(
MetadataAllocation<Runtime> Allocation) {
if (Allocation.Tag == GenericMetadataCacheTag) {
struct GenericMetadataCacheEntry {
StoredPointer Left, Right;
StoredPointer LockedStorage;
uint8_t LockedStorageKind;
uint8_t TrackingInfo;
uint16_t NumKeyParameters;
uint16_t NumWitnessTables;
uint32_t Hash;
StoredPointer Value;
};
auto AllocationBytes =
getReader().readBytes(RemoteAddress(Allocation.Ptr),
Allocation.Size);
auto Entry = reinterpret_cast<const GenericMetadataCacheEntry *>(
AllocationBytes.get());
if (!Entry)
return 0;
return Entry->Value;
}
return 0;
}
/// Get the name of a metadata tag, if known.
llvm::Optional<std::string> metadataAllocationTagName(int Tag) {
switch (Tag) {
#define TAG(name, value) \
case value: \
return std::string(#name);
#include "../../../stdlib/public/runtime/MetadataAllocatorTags.def"
default:
return llvm::None;
}
}
llvm::Optional<MetadataCacheNode<Runtime>>
metadataAllocationCacheNode(MetadataAllocation<Runtime> Allocation) {
switch (Allocation.Tag) {
case BoxesTag:
case ObjCClassWrappersTag:
case FunctionTypesTag:
case MetatypeTypesTag:
case ExistentialMetatypeValueWitnessTablesTag:
case ExistentialMetatypesTag:
case ExistentialTypesTag:
case OpaqueExistentialValueWitnessTablesTag:
case ClassExistentialValueWitnessTablesTag:
case ForeignWitnessTablesTag:
case TupleCacheTag:
case GenericMetadataCacheTag:
case ForeignMetadataCacheTag:
case GenericWitnessTableCacheTag: {
auto NodeBytes = getReader().readBytes(
RemoteAddress(Allocation.Ptr), sizeof(MetadataCacheNode<Runtime>));
auto Node =
reinterpret_cast<const MetadataCacheNode<Runtime> *>(NodeBytes.get());
if (!Node)
return llvm::None;
return *Node;
}
default:
return llvm::None;
}
}
/// Iterate the metadata allocations in the target process, calling Call with
/// each allocation found. Returns None on success, and a string describing
/// the error on failure.
llvm::Optional<std::string> iterateMetadataAllocations(
std::function<void (MetadataAllocation<Runtime>)> Call) {
std::string IterationEnabledName =
"_swift_debug_metadataAllocationIterationEnabled";
std::string AllocationPoolPointerName =
"_swift_debug_allocationPoolPointer";
auto IterationEnabledAddr =
getReader().getSymbolAddress(IterationEnabledName);
if (!IterationEnabledAddr)
return "unable to look up debug variable " + IterationEnabledName;
char IterationEnabled;
if (!getReader().readInteger(IterationEnabledAddr, &IterationEnabled))
return "failed to read value of " + IterationEnabledName;
if (!IterationEnabled)
return std::string("remote process does not have metadata allocation "
"iteration enabled");
auto AllocationPoolAddrAddr =
getReader().getSymbolAddress(AllocationPoolPointerName);
if (!AllocationPoolAddrAddr)
return "unable to look up debug variable " + AllocationPoolPointerName;
auto AllocationPoolAddr =
getReader().readPointer(AllocationPoolAddrAddr, sizeof(StoredPointer));
if (!AllocationPoolAddr)
return "failed to read value of " + AllocationPoolPointerName;
struct PoolRange {
StoredPointer Begin;
StoredSize Remaining;
};
struct PoolTrailer {
StoredPointer PrevTrailer;
StoredSize PoolSize;
};
struct alignas(StoredPointer) AllocationHeader {
uint16_t Size;
uint16_t Tag;
};
auto PoolBytes = getReader()
.readBytes(AllocationPoolAddr->getResolvedAddress(), sizeof(PoolRange));
auto Pool = reinterpret_cast<const PoolRange *>(PoolBytes.get());
if (!Pool)
return std::string("failure reading allocation pool contents");
auto TrailerPtr = Pool->Begin + Pool->Remaining;
while (TrailerPtr) {
auto TrailerBytes = getReader()
.readBytes(RemoteAddress(TrailerPtr), sizeof(PoolTrailer));
auto Trailer = reinterpret_cast<const PoolTrailer *>(TrailerBytes.get());
if (!Trailer)
break;
auto PoolStart = TrailerPtr - Trailer->PoolSize;
auto PoolBytes = getReader()
.readBytes(RemoteAddress(PoolStart), Trailer->PoolSize);
auto PoolPtr = (const char *)PoolBytes.get();
if (!PoolPtr)
break;
uintptr_t Offset = 0;
while (Offset < Trailer->PoolSize) {
auto AllocationPtr = PoolPtr + Offset;
auto Header = (const AllocationHeader *)AllocationPtr;
if (Header->Size == 0)
break;
auto RemoteAddr = PoolStart + Offset + sizeof(AllocationHeader);
MetadataAllocation<Runtime> Allocation;
Allocation.Tag = Header->Tag;
Allocation.Ptr = RemoteAddr;
Allocation.Size = Header->Size;
Call(Allocation);
Offset += sizeof(AllocationHeader) + Header->Size;
}
TrailerPtr = Trailer->PrevTrailer;
}
return llvm::None;
}
llvm::Optional<std::string> iterateMetadataAllocationBacktraces(
std::function<void(StoredPointer, uint32_t, const StoredPointer *)>
Call) {
std::string BacktraceListName =
"_swift_debug_metadataAllocationBacktraceList";
auto BacktraceListAddr = getReader().getSymbolAddress(BacktraceListName);
if (!BacktraceListAddr)
return "unable to look up debug variable " + BacktraceListName;
auto BacktraceListNextPtr =
getReader().readPointer(BacktraceListAddr, sizeof(StoredPointer));
if (!BacktraceListNextPtr)
return llvm::None;
auto BacktraceListNext = BacktraceListNextPtr->getResolvedAddress();
while (BacktraceListNext) {
auto HeaderBytes = getReader().readBytes(
RemoteAddress(BacktraceListNext),
sizeof(MetadataAllocationBacktraceHeader<Runtime>));
auto HeaderPtr =
reinterpret_cast<const MetadataAllocationBacktraceHeader<Runtime> *>(
HeaderBytes.get());
if (HeaderPtr == nullptr) {
// FIXME: std::stringstream would be better, but LLVM's standard library
// introduces a vtable and we don't want that.
char result[128];
std::snprintf(result, sizeof(result),
"unable to read Next pointer %#" PRIx64,
BacktraceListNext.getAddressData());
return std::string(result);
}
auto BacktraceAddrPtr =
BacktraceListNext +
sizeof(MetadataAllocationBacktraceHeader<Runtime>);
auto BacktraceBytes =
getReader().readBytes(RemoteAddress(BacktraceAddrPtr),
HeaderPtr->Count * sizeof(StoredPointer));
auto BacktracePtr =
reinterpret_cast<const StoredPointer *>(BacktraceBytes.get());
Call(HeaderPtr->Allocation, HeaderPtr->Count, BacktracePtr);
BacktraceListNext = RemoteAddress(HeaderPtr->Next);
}
return llvm::None;
}
private:
const TypeInfo *
getClosureContextInfo(StoredPointer Context, const ClosureContextInfo &Info,
remote::TypeInfoProvider *ExternalTypeInfo) {
RecordTypeInfoBuilder Builder(getBuilder().getTypeConverter(),
RecordKind::ClosureContext);
auto Metadata = readMetadataFromInstance(Context);
if (!Metadata)
return nullptr;
// Calculate the offset of the first capture.
// See GenHeap.cpp, buildPrivateMetadata().
auto OffsetToFirstCapture =
this->readOffsetToFirstCaptureFromMetadata(*Metadata);
if (!OffsetToFirstCapture)
return nullptr;
// Initialize the builder.
Builder.addField(*OffsetToFirstCapture,
/*alignment=*/sizeof(StoredPointer),
/*numExtraInhabitants=*/0,
/*bitwiseTakable=*/true);
// Skip the closure's necessary bindings struct, if it's present.
auto SizeOfNecessaryBindings = Info.NumBindings * sizeof(StoredPointer);
Builder.addField(/*size=*/SizeOfNecessaryBindings,
/*alignment=*/sizeof(StoredPointer),
/*numExtraInhabitants=*/0,
/*bitwiseTakable=*/true);
// FIXME: should be unordered_set but I'm too lazy to write a hash
// functor
std::set<std::pair<const TypeRef *, const MetadataSource *>> Done;
GenericArgumentMap Subs;
ArrayRef<const TypeRef *> CaptureTypes = Info.CaptureTypes;
// Closure context element layout depends on the layout of the
// captured types, but captured types might depend on element
// layout (of previous elements). Use an iterative approach to
// solve the problem.
while (!CaptureTypes.empty()) {
const TypeRef *OrigCaptureTR = CaptureTypes[0];
// If we failed to demangle the capture type, we cannot proceed.
if (OrigCaptureTR == nullptr)
return nullptr;
const TypeRef *SubstCaptureTR = nullptr;
// If we have enough substitutions to make this captured value's
// type concrete, or we know it's size anyway (because it is a
// class reference or metatype, for example), go ahead and add
// it to the layout.
if (OrigCaptureTR->isConcreteAfterSubstitutions(Subs))
SubstCaptureTR = OrigCaptureTR->subst(getBuilder(), Subs);
else if (getBuilder().getTypeConverter().hasFixedSize(OrigCaptureTR))
SubstCaptureTR = OrigCaptureTR;
if (SubstCaptureTR != nullptr) {
Builder.addField("", SubstCaptureTR, ExternalTypeInfo);
if (Builder.isInvalid())
return nullptr;
// Try the next capture type.
CaptureTypes = CaptureTypes.slice(1);
continue;
}
// Ok, we do not have enough substitutions yet. Perhaps we have
// enough elements figured out that we can pick off some
// metadata sources though, and use those to derive some new
// substitutions.
bool Progress = false;
for (auto Source : Info.MetadataSources) {
// Don't read a source more than once.
if (Done.count(Source))
continue;
// If we don't have enough information to read this source
// (because it is fulfilled by metadata from a capture at
// at unknown offset), keep going.
if (!isMetadataSourceReady(Source.second, Builder))
continue;
auto Metadata = readMetadataSource(Context, Source.second, Builder);
if (!Metadata)
return nullptr;
auto *SubstTR = readTypeFromMetadata(*Metadata);
if (SubstTR == nullptr)
return nullptr;
if (!TypeRef::deriveSubstitutions(Subs, Source.first, SubstTR))
return nullptr;
Done.insert(Source);
Progress = true;
}
// If we failed to make any forward progress above, we're stuck
// and cannot close out this layout.
if (!Progress)
return nullptr;
}
// Ok, we have a complete picture now.
return Builder.build();
}
/// Checks if we have enough information to read the given metadata
/// source.
///
/// \param Builder Used to obtain offsets of elements known so far.
bool isMetadataSourceReady(const MetadataSource *MS,
const RecordTypeInfoBuilder &Builder) {
switch (MS->getKind()) {
case MetadataSourceKind::ClosureBinding:
return true;
case MetadataSourceKind::ReferenceCapture: {
unsigned Index = cast<ReferenceCaptureMetadataSource>(MS)->getIndex();
return Index < Builder.getNumFields();
}
case MetadataSourceKind::MetadataCapture: {
unsigned Index = cast<MetadataCaptureMetadataSource>(MS)->getIndex();
return Index < Builder.getNumFields();
}
case MetadataSourceKind::GenericArgument: {
auto Base = cast<GenericArgumentMetadataSource>(MS)->getSource();
return isMetadataSourceReady(Base, Builder);
}
case MetadataSourceKind::Self:
case MetadataSourceKind::SelfWitnessTable:
return true;
}
swift_unreachable("Unhandled MetadataSourceKind in switch.");
}
/// Read metadata for a captured generic type from a closure context.
///
/// \param Context The closure context in the remote process.
///
/// \param MS The metadata source, which must be "ready" as per the
/// above.
///
/// \param Builder Used to obtain offsets of elements known so far.
llvm::Optional<StoredPointer>
readMetadataSource(StoredPointer Context,
const MetadataSource *MS,
const RecordTypeInfoBuilder &Builder) {
switch (MS->getKind()) {
case MetadataSourceKind::ClosureBinding: {
unsigned Index = cast<ClosureBindingMetadataSource>(MS)->getIndex();
// Skip the context's HeapObject header
// (one word each for isa pointer and reference counts).
//
// Metadata and conformance tables are stored consecutively after
// the heap object header, in the 'necessary bindings' area.
//
// We should only have the index of a type metadata record here.
unsigned Offset = getSizeOfHeapObject() +
sizeof(StoredPointer) * Index;
StoredPointer MetadataAddress;
if (!getReader().readInteger(RemoteAddress(Context + Offset),
&MetadataAddress))
break;
return MetadataAddress;
}
case MetadataSourceKind::ReferenceCapture: {
unsigned Index = cast<ReferenceCaptureMetadataSource>(MS)->getIndex();
// We should already have enough type information to know the offset
// of this capture in the context.
unsigned CaptureOffset = Builder.getFieldOffset(Index);
StoredPointer CaptureAddress;
if (!getReader().readInteger(RemoteAddress(Context + CaptureOffset),
&CaptureAddress))
break;
// Read the requested capture's isa pointer.
return readMetadataFromInstance(CaptureAddress);
}
case MetadataSourceKind::MetadataCapture: {
unsigned Index = cast<MetadataCaptureMetadataSource>(MS)->getIndex();
// We should already have enough type information to know the offset
// of this capture in the context.
unsigned CaptureOffset = Builder.getFieldOffset(Index);
StoredPointer CaptureAddress;
if (!getReader().readInteger(RemoteAddress(Context + CaptureOffset),
&CaptureAddress))
break;
return CaptureAddress;
}
case MetadataSourceKind::GenericArgument: {
auto *GAMS = cast<GenericArgumentMetadataSource>(MS);
auto Base = readMetadataSource(Context, GAMS->getSource(), Builder);
if (!Base)
break;
unsigned Index = GAMS->getIndex();
auto Arg = readGenericArgFromMetadata(*Base, Index);
if (!Arg)
break;
return *Arg;
}
case MetadataSourceKind::Self:
case MetadataSourceKind::SelfWitnessTable:
break;
}
return llvm::None;
}
};
} // end namespace reflection
} // end namespace swift
#endif // SWIFT_REFLECTION_REFLECTIONCONTEXT_H