relocation_iterator RuntimeDyldMachO::processScatteredVANILLA(
unsigned SectionID, relocation_iterator RelI,
const ObjectFile &BaseObjT,
RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID) {
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 =
findOrEmitSection(Obj, TargetSection, IsCode, ObjSectionToID);
Addend -= SectionBaseAddr;
RelocationEntry R(SectionID, Offset, RelocType, Addend, IsPCRel, Size);
addRelocationForSection(R, TargetSectionID);
return ++RelI;
}
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();
}
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;
Symbol->getName(TargetName);
SymbolTableMap::const_iterator SI =
GlobalSymbolTable.find(TargetName.data());
if (SI != GlobalSymbolTable.end()) {
Value.SectionID = SI->second.first;
Value.Offset = SI->second.second + RE.Addend;
} else {
Value.SymbolName = TargetName.data();
Value.Offset = RE.Addend;
}
} else {
SectionRef Sec = Obj.getRelocationSection(RelInfo);
bool IsCode = Sec.isText();
Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
uint64_t Addr = Sec.getAddress();
Value.Offset = RE.Addend - Addr;
}
return Value;
}
void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
ObjectImage &ObjImg,
const relocation_iterator &RI,
unsigned OffsetToNextPC) {
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);
Value.Addend += RelocAddr + OffsetToNextPC;
}
}
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();
ErrorOr<StringRef> TargetNameOrErr = Symbol->getName();
if (std::error_code EC = TargetNameOrErr.getError())
report_fatal_error(EC.message());
StringRef TargetName = *TargetNameOrErr;
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();
Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
uint64_t Addr = Sec.getAddress();
Value.Offset = RE.Addend - Addr;
}
return Value;
}
relocation_iterator RuntimeDyldMachO::processRelocationRef(
unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
StubMap &Stubs) {
const ObjectFile *OF = Obj.getObjectFile();
const MachOObjectFile *MachO = static_cast<const MachOObjectFile *>(OF);
MachO::any_relocation_info RE =
MachO->getRelocation(RelI->getRawDataRefImpl());
uint32_t RelType = MachO->getAnyRelocationType(RE);
// FIXME: Properly handle scattered relocations.
// For now, optimistically skip these: they can often be ignored, as
// the static linker will already have applied the relocation, and it
// only needs to be reapplied if symbols move relative to one another.
// Note: This will fail horribly where the relocations *do* need to be
// applied, but that was already the case.
if (MachO->isRelocationScattered(RE))
return ++RelI;
RelocationValueRef Value;
SectionEntry &Section = Sections[SectionID];
bool isExtern = MachO->getPlainRelocationExternal(RE);
bool IsPCRel = MachO->getAnyRelocationPCRel(RE);
unsigned Size = MachO->getAnyRelocationLength(RE);
uint64_t Offset;
RelI->getOffset(Offset);
uint8_t *LocalAddress = Section.Address + Offset;
unsigned NumBytes = 1 << Size;
uint64_t Addend = 0;
memcpy(&Addend, LocalAddress, NumBytes);
if (isExtern) {
// Obtain the symbol name which is referenced in the relocation
symbol_iterator Symbol = RelI->getSymbol();
StringRef TargetName;
Symbol->getName(TargetName);
// First search for the symbol in the local symbol table
SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
if (lsi != Symbols.end()) {
Value.SectionID = lsi->second.first;
Value.Addend = lsi->second.second + Addend;
} else {
// Search for the symbol in the global symbol table
SymbolTableMap::const_iterator gsi =
GlobalSymbolTable.find(TargetName.data());
if (gsi != GlobalSymbolTable.end()) {
Value.SectionID = gsi->second.first;
Value.Addend = gsi->second.second + Addend;
} else {
Value.SymbolName = TargetName.data();
Value.Addend = Addend;
}
}
} else {
SectionRef Sec = MachO->getRelocationSection(RE);
bool IsCode = false;
Sec.isText(IsCode);
Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
uint64_t Addr;
Sec.getAddress(Addr);
Value.Addend = Addend - Addr;
if (IsPCRel)
Value.Addend += Offset + NumBytes;
}
if (Arch == Triple::x86_64 && (RelType == MachO::X86_64_RELOC_GOT ||
RelType == MachO::X86_64_RELOC_GOT_LOAD)) {
assert(IsPCRel);
assert(Size == 2);
StubMap::const_iterator i = Stubs.find(Value);
uint8_t *Addr;
if (i != Stubs.end()) {
Addr = Section.Address + i->second;
} else {
Stubs[Value] = Section.StubOffset;
uint8_t *GOTEntry = Section.Address + Section.StubOffset;
RelocationEntry RE(SectionID, Section.StubOffset,
MachO::X86_64_RELOC_UNSIGNED, 0, false, 3);
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);
else
addRelocationForSection(RE, Value.SectionID);
Section.StubOffset += 8;
Addr = GOTEntry;
}
resolveRelocation(Section, Offset, (uint64_t)Addr,
MachO::X86_64_RELOC_UNSIGNED, Value.Addend, true, 2);
} else if (Arch == Triple::arm && (RelType & 0xf) == MachO::ARM_RELOC_BR24) {
// This is an ARM branch relocation, need to use a stub function.
// Look up for existing stub.
StubMap::const_iterator i = Stubs.find(Value);
if (i != Stubs.end())
resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
RelType, 0, IsPCRel, Size);
else {
// Create a new stub function.
Stubs[Value] = Section.StubOffset;
uint8_t *StubTargetAddr =
createStubFunction(Section.Address + Section.StubOffset);
RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
MachO::GENERIC_RELOC_VANILLA, Value.Addend);
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);
else
addRelocationForSection(RE, Value.SectionID);
resolveRelocation(Section, Offset,
(uint64_t)Section.Address + Section.StubOffset, RelType,
0, IsPCRel, Size);
Section.StubOffset += getMaxStubSize();
}
} else {
RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, IsPCRel, Size);
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);
else
addRelocationForSection(RE, Value.SectionID);
}
return ++RelI;
}