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//===-- RuntimeDyldMachO.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implementation of the MC-JIT runtime dynamic linker.
//
//===----------------------------------------------------------------------===//
#include "RuntimeDyldMachO.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "Targets/RuntimeDyldMachOARM.h"
#include "Targets/RuntimeDyldMachOAArch64.h"
#include "Targets/RuntimeDyldMachOI386.h"
#include "Targets/RuntimeDyldMachOX86_64.h"
using namespace llvm;
using namespace llvm::object;
#define DEBUG_TYPE "dyld"
namespace llvm {
uint64_t RuntimeDyldMachO::decodeAddend(uint8_t *LocalAddress, unsigned NumBytes,
uint32_t RelType) const {
uint64_t Addend = 0;
memcpy(&Addend, LocalAddress, NumBytes);
return Addend;
}
RelocationValueRef RuntimeDyldMachO::getRelocationValueRef(
ObjectImage &ObjImg, const relocation_iterator &RI,
const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID,
const SymbolTableMap &Symbols) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
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;
Symbol->getName(TargetName);
SymbolTableMap::const_iterator SI = Symbols.find(TargetName.data());
if (SI != Symbols.end()) {
Value.SectionID = SI->second.first;
Value.Addend = SI->second.second + RE.Addend;
} else {
SI = GlobalSymbolTable.find(TargetName.data());
if (SI != GlobalSymbolTable.end()) {
Value.SectionID = SI->second.first;
Value.Addend = SI->second.second + RE.Addend;
} else {
Value.SymbolName = TargetName.data();
Value.Addend = RE.Addend;
}
}
} else {
SectionRef Sec = Obj.getRelocationSection(RelInfo);
bool IsCode = false;
Sec.isText(IsCode);
Value.SectionID = findOrEmitSection(ObjImg, Sec, IsCode, ObjSectionToID);
uint64_t Addr;
Sec.getAddress(Addr);
Value.Addend = RE.Addend - Addr;
}
return Value;
}
void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
ObjectImage &ObjImg,
const relocation_iterator &RI) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RI->getRawDataRefImpl());
bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
if (IsPCRel) {
uint64_t RelocAddr = 0;
RI->getAddress(RelocAddr);
unsigned RelocSize = Obj.getAnyRelocationLength(RelInfo);
Value.Addend += RelocAddr + (1ULL << RelocSize);
}
}
void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
uint64_t Value) const {
const SectionEntry &Section = Sections[RE.SectionID];
uint8_t *LocalAddress = Section.Address + RE.Offset;
uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
dbgs() << "resolveRelocation Section: " << RE.SectionID
<< " LocalAddress: " << format("%p", LocalAddress)
<< " FinalAddress: " << format("%p", FinalAddress)
<< " Value: " << format("%p", Value) << " Addend: " << RE.Addend
<< " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType
<< " Size: " << (1 << RE.Size) << "\n";
}
bool RuntimeDyldMachO::writeBytesUnaligned(uint8_t *Addr, uint64_t Value,
unsigned Size) {
for (unsigned i = 0; i < Size; ++i) {
*Addr++ = (uint8_t)Value;
Value >>= 8;
}
return false;
}
bool
RuntimeDyldMachO::isCompatibleFormat(const ObjectBuffer *InputBuffer) const {
if (InputBuffer->getBufferSize() < 4)
return false;
StringRef Magic(InputBuffer->getBufferStart(), 4);
if (Magic == "\xFE\xED\xFA\xCE")
return true;
if (Magic == "\xCE\xFA\xED\xFE")
return true;
if (Magic == "\xFE\xED\xFA\xCF")
return true;
if (Magic == "\xCF\xFA\xED\xFE")
return true;
return false;
}
bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile *Obj) const {
return Obj->isMachO();
}
static unsigned char *processFDE(unsigned char *P, intptr_t DeltaForText,
intptr_t DeltaForEH) {
DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
<< ", Delta for EH: " << DeltaForEH << "\n");
uint32_t Length = *((uint32_t *)P);
P += 4;
unsigned char *Ret = P + Length;
uint32_t Offset = *((uint32_t *)P);
if (Offset == 0) // is a CIE
return Ret;
P += 4;
intptr_t FDELocation = *((intptr_t *)P);
intptr_t NewLocation = FDELocation - DeltaForText;
*((intptr_t *)P) = NewLocation;
P += sizeof(intptr_t);
// Skip the FDE address range
P += sizeof(intptr_t);
uint8_t Augmentationsize = *P;
P += 1;
if (Augmentationsize != 0) {
intptr_t LSDA = *((intptr_t *)P);
intptr_t NewLSDA = LSDA - DeltaForEH;
*((intptr_t *)P) = NewLSDA;
}
return Ret;
}
static intptr_t computeDelta(SectionEntry *A, SectionEntry *B) {
intptr_t ObjDistance = A->ObjAddress - B->ObjAddress;
intptr_t MemDistance = A->LoadAddress - B->LoadAddress;
return ObjDistance - MemDistance;
}
void RuntimeDyldMachO::registerEHFrames() {
if (!MemMgr)
return;
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];
intptr_t DeltaForText = computeDelta(Text, EHFrame);
intptr_t DeltaForEH = 0;
if (ExceptTab)
DeltaForEH = computeDelta(ExceptTab, EHFrame);
unsigned char *P = EHFrame->Address;
unsigned char *End = P + EHFrame->Size;
do {
P = processFDE(P, DeltaForText, DeltaForEH);
} while (P != End);
MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
EHFrame->Size);
}
UnregisteredEHFrameSections.clear();
}
std::unique_ptr<RuntimeDyldMachO>
llvm::RuntimeDyldMachO::create(Triple::ArchType Arch, RTDyldMemoryManager *MM) {
switch (Arch) {
default:
llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
break;
case Triple::arm: return make_unique<RuntimeDyldMachOARM>(MM);
case Triple::arm64: return make_unique<RuntimeDyldMachOAArch64>(MM);
case Triple::x86: return make_unique<RuntimeDyldMachOI386>(MM);
case Triple::x86_64: return make_unique<RuntimeDyldMachOX86_64>(MM);
}
}
} // end namespace llvm
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