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llvm-project/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo 
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

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//===-- RuntimeDyldMachO.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Implementation of the MC-JIT runtime dynamic linker.
//
//===----------------------------------------------------------------------===//
#include "RuntimeDyldMachO.h"
#include "Targets/RuntimeDyldMachOAArch64.h"
#include "Targets/RuntimeDyldMachOARM.h"
#include "Targets/RuntimeDyldMachOI386.h"
#include "Targets/RuntimeDyldMachOX86_64.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
using namespace llvm;
using namespace llvm::object;
#define DEBUG_TYPE "dyld"
namespace {
class LoadedMachOObjectInfo final
: public LoadedObjectInfoHelper<LoadedMachOObjectInfo,
RuntimeDyld::LoadedObjectInfo> {
public:
LoadedMachOObjectInfo(RuntimeDyldImpl &RTDyld,
ObjSectionToIDMap ObjSecToIDMap)
: LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
OwningBinary<ObjectFile>
getObjectForDebug(const ObjectFile &Obj) const override {
return OwningBinary<ObjectFile>();
}
};
}
namespace llvm {
int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const {
unsigned NumBytes = 1 << RE.Size;
uint8_t *Src = Sections[RE.SectionID].getAddress() + RE.Offset;
return static_cast<int64_t>(readBytesUnaligned(Src, NumBytes));
}
Expected<relocation_iterator>
RuntimeDyldMachO::processScatteredVANILLA(
unsigned SectionID, relocation_iterator RelI,
const ObjectFile &BaseObjT,
RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID,
bool TargetIsLocalThumbFunc) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile&>(BaseObjT);
MachO::any_relocation_info RE =
Obj.getRelocation(RelI->getRawDataRefImpl());
SectionEntry &Section = Sections[SectionID];
uint32_t RelocType = Obj.getAnyRelocationType(RE);
bool IsPCRel = Obj.getAnyRelocationPCRel(RE);
unsigned Size = Obj.getAnyRelocationLength(RE);
uint64_t Offset = RelI->getOffset();
uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
unsigned NumBytes = 1 << Size;
int64_t Addend = readBytesUnaligned(LocalAddress, NumBytes);
unsigned SymbolBaseAddr = Obj.getScatteredRelocationValue(RE);
section_iterator TargetSI = getSectionByAddress(Obj, SymbolBaseAddr);
assert(TargetSI != Obj.section_end() && "Can't find section for symbol");
uint64_t SectionBaseAddr = TargetSI->getAddress();
SectionRef TargetSection = *TargetSI;
bool IsCode = TargetSection.isText();
uint32_t TargetSectionID = ~0U;
if (auto TargetSectionIDOrErr =
findOrEmitSection(Obj, TargetSection, IsCode, ObjSectionToID))
TargetSectionID = *TargetSectionIDOrErr;
else
return TargetSectionIDOrErr.takeError();
Addend -= SectionBaseAddr;
RelocationEntry R(SectionID, Offset, RelocType, Addend, IsPCRel, Size);
R.IsTargetThumbFunc = TargetIsLocalThumbFunc;
addRelocationForSection(R, TargetSectionID);
return ++RelI;
}
Expected<RelocationValueRef>
RuntimeDyldMachO::getRelocationValueRef(
const ObjectFile &BaseTObj, const relocation_iterator &RI,
const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile &>(BaseTObj);
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RI->getRawDataRefImpl());
RelocationValueRef Value;
bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);
if (IsExternal) {
symbol_iterator Symbol = RI->getSymbol();
StringRef TargetName;
if (auto TargetNameOrErr = Symbol->getName())
TargetName = *TargetNameOrErr;
else
return TargetNameOrErr.takeError();
RTDyldSymbolTable::const_iterator SI =
GlobalSymbolTable.find(TargetName.data());
if (SI != GlobalSymbolTable.end()) {
const auto &SymInfo = SI->second;
Value.SectionID = SymInfo.getSectionID();
Value.Offset = SymInfo.getOffset() + RE.Addend;
} else {
Value.SymbolName = TargetName.data();
Value.Offset = RE.Addend;
}
} else {
SectionRef Sec = Obj.getAnyRelocationSection(RelInfo);
bool IsCode = Sec.isText();
if (auto SectionIDOrErr = findOrEmitSection(Obj, Sec, IsCode,
ObjSectionToID))
Value.SectionID = *SectionIDOrErr;
else
return SectionIDOrErr.takeError();
uint64_t Addr = Sec.getAddress();
Value.Offset = RE.Addend - Addr;
}
return Value;
}
void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
const relocation_iterator &RI,
unsigned OffsetToNextPC) {
auto &O = *cast<MachOObjectFile>(RI->getObject());
section_iterator SecI = O.getRelocationRelocatedSection(RI);
Value.Offset += RI->getOffset() + OffsetToNextPC + SecI->getAddress();
}
void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
uint64_t Value) const {
const SectionEntry &Section = Sections[RE.SectionID];
uint8_t *LocalAddress = Section.getAddress() + RE.Offset;
uint64_t FinalAddress = Section.getLoadAddress() + RE.Offset;
dbgs() << "resolveRelocation Section: " << RE.SectionID
<< " LocalAddress: " << format("%p", LocalAddress)
<< " FinalAddress: " << format("0x%016" PRIx64, FinalAddress)
<< " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend
<< " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType
<< " Size: " << (1 << RE.Size) << "\n";
}
section_iterator
RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,
uint64_t Addr) {
section_iterator SI = Obj.section_begin();
section_iterator SE = Obj.section_end();
for (; SI != SE; ++SI) {
uint64_t SAddr = SI->getAddress();
uint64_t SSize = SI->getSize();
if ((Addr >= SAddr) && (Addr < SAddr + SSize))
return SI;
}
return SE;
}
// Populate __pointers section.
Error RuntimeDyldMachO::populateIndirectSymbolPointersSection(
const MachOObjectFile &Obj,
const SectionRef &PTSection,
unsigned PTSectionID) {
assert(!Obj.is64Bit() &&
"Pointer table section not supported in 64-bit MachO.");
MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
uint32_t PTSectionSize = Sec32.size;
unsigned FirstIndirectSymbol = Sec32.reserved1;
const unsigned PTEntrySize = 4;
unsigned NumPTEntries = PTSectionSize / PTEntrySize;
unsigned PTEntryOffset = 0;
assert((PTSectionSize % PTEntrySize) == 0 &&
"Pointers section does not contain a whole number of stubs?");
LLVM_DEBUG(dbgs() << "Populating pointer table section "
<< Sections[PTSectionID].getName() << ", Section ID "
<< PTSectionID << ", " << NumPTEntries << " entries, "
<< PTEntrySize << " bytes each:\n");
for (unsigned i = 0; i < NumPTEntries; ++i) {
unsigned SymbolIndex =
Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
StringRef IndirectSymbolName;
if (auto IndirectSymbolNameOrErr = SI->getName())
IndirectSymbolName = *IndirectSymbolNameOrErr;
else
return IndirectSymbolNameOrErr.takeError();
LLVM_DEBUG(dbgs() << " " << IndirectSymbolName << ": index " << SymbolIndex
<< ", PT offset: " << PTEntryOffset << "\n");
RelocationEntry RE(PTSectionID, PTEntryOffset,
MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
addRelocationForSymbol(RE, IndirectSymbolName);
PTEntryOffset += PTEntrySize;
}
return Error::success();
}
bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile &Obj) const {
return Obj.isMachO();
}
template <typename Impl>
Error
RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &Obj,
ObjSectionToIDMap &SectionMap) {
unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
for (const auto &Section : Obj.sections()) {
StringRef Name;
Section.getName(Name);
// Force emission of the __text, __eh_frame, and __gcc_except_tab sections
// if they're present. Otherwise call down to the impl to handle other
// sections that have already been emitted.
if (Name == "__text") {
if (auto TextSIDOrErr = findOrEmitSection(Obj, Section, true, SectionMap))
TextSID = *TextSIDOrErr;
else
return TextSIDOrErr.takeError();
} else if (Name == "__eh_frame") {
if (auto EHFrameSIDOrErr = findOrEmitSection(Obj, Section, false,
SectionMap))
EHFrameSID = *EHFrameSIDOrErr;
else
return EHFrameSIDOrErr.takeError();
} else if (Name == "__gcc_except_tab") {
if (auto ExceptTabSIDOrErr = findOrEmitSection(Obj, Section, true,
SectionMap))
ExceptTabSID = *ExceptTabSIDOrErr;
else
return ExceptTabSIDOrErr.takeError();
} else {
auto I = SectionMap.find(Section);
if (I != SectionMap.end())
if (auto Err = impl().finalizeSection(Obj, I->second, Section))
return Err;
}
}
UnregisteredEHFrameSections.push_back(
EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
return Error::success();
}
template <typename Impl>
unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(uint8_t *P,
int64_t DeltaForText,
int64_t DeltaForEH) {
typedef typename Impl::TargetPtrT TargetPtrT;
LLVM_DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
<< ", Delta for EH: " << DeltaForEH << "\n");
uint32_t Length = readBytesUnaligned(P, 4);
P += 4;
uint8_t *Ret = P + Length;
uint32_t Offset = readBytesUnaligned(P, 4);
if (Offset == 0) // is a CIE
return Ret;
P += 4;
TargetPtrT FDELocation = readBytesUnaligned(P, sizeof(TargetPtrT));
TargetPtrT NewLocation = FDELocation - DeltaForText;
writeBytesUnaligned(NewLocation, P, sizeof(TargetPtrT));
P += sizeof(TargetPtrT);
// Skip the FDE address range
P += sizeof(TargetPtrT);
uint8_t Augmentationsize = *P;
P += 1;
if (Augmentationsize != 0) {
TargetPtrT LSDA = readBytesUnaligned(P, sizeof(TargetPtrT));
TargetPtrT NewLSDA = LSDA - DeltaForEH;
writeBytesUnaligned(NewLSDA, P, sizeof(TargetPtrT));
}
return Ret;
}
static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {
int64_t ObjDistance = static_cast<int64_t>(A->getObjAddress()) -
static_cast<int64_t>(B->getObjAddress());
int64_t MemDistance = A->getLoadAddress() - B->getLoadAddress();
return ObjDistance - MemDistance;
}
template <typename Impl>
void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)
continue;
SectionEntry *Text = &Sections[SectionInfo.TextSID];
SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];
SectionEntry *ExceptTab = nullptr;
if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
ExceptTab = &Sections[SectionInfo.ExceptTabSID];
int64_t DeltaForText = computeDelta(Text, EHFrame);
int64_t DeltaForEH = 0;
if (ExceptTab)
DeltaForEH = computeDelta(ExceptTab, EHFrame);
uint8_t *P = EHFrame->getAddress();
uint8_t *End = P + EHFrame->getSize();
while (P != End) {
P = processFDE(P, DeltaForText, DeltaForEH);
}
MemMgr.registerEHFrames(EHFrame->getAddress(), EHFrame->getLoadAddress(),
EHFrame->getSize());
}
UnregisteredEHFrameSections.clear();
}
std::unique_ptr<RuntimeDyldMachO>
RuntimeDyldMachO::create(Triple::ArchType Arch,
RuntimeDyld::MemoryManager &MemMgr,
JITSymbolResolver &Resolver) {
switch (Arch) {
default:
llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
break;
case Triple::arm:
return make_unique<RuntimeDyldMachOARM>(MemMgr, Resolver);
case Triple::aarch64:
return make_unique<RuntimeDyldMachOAArch64>(MemMgr, Resolver);
case Triple::x86:
return make_unique<RuntimeDyldMachOI386>(MemMgr, Resolver);
case Triple::x86_64:
return make_unique<RuntimeDyldMachOX86_64>(MemMgr, Resolver);
}
}
std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
RuntimeDyldMachO::loadObject(const object::ObjectFile &O) {
if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
return llvm::make_unique<LoadedMachOObjectInfo>(*this,
*ObjSectionToIDOrErr);
else {
HasError = true;
raw_string_ostream ErrStream(ErrorStr);
logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream);
return nullptr;
}
}
} // end namespace llvm
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