llvm-6502/lib/Object/MachOObjectFile.cpp
Rafael Espindola 8bf80061ba Fix MachO's getRelocationAdditionalInfo.
It was returning the loaded address of the section containing the relocation,
which really doesn't seem to be the intent of this function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179255 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-11 02:21:31 +00:00

578 lines
18 KiB
C++

//===- MachOObjectFile.cpp - Mach-O object file binding ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the MachOObjectFile class, which binds the MachOObject
// class to the generic ObjectFile wrapper.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/MachO.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Object/MachOFormat.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MemoryBuffer.h"
#include <cctype>
#include <cstring>
#include <limits>
using namespace llvm;
using namespace object;
namespace llvm {
namespace object {
MachOObjectFileBase::MachOObjectFileBase(MemoryBuffer *Object, bool Is64bits,
error_code &ec)
: ObjectFile(getMachOType(true, Is64bits), Object) {
}
bool MachOObjectFileBase::is64Bit() const {
return isa<MachOObjectFile64Le>(this);
}
const MachOObjectFileBase::LoadCommand *
MachOObjectFileBase::getLoadCommandInfo(unsigned Index) const {
uint64_t Offset;
uint64_t NewOffset = getHeaderSize();
const LoadCommand *Load;
unsigned I = 0;
do {
Offset = NewOffset;
StringRef Data = getData(Offset, sizeof(LoadCommand));
Load = reinterpret_cast<const LoadCommand*>(Data.data());
NewOffset = Offset + Load->Size;
++I;
} while (I != Index + 1);
return Load;
}
void MachOObjectFileBase::ReadULEB128s(uint64_t Index,
SmallVectorImpl<uint64_t> &Out) const {
DataExtractor extractor(ObjectFile::getData(), true, 0);
uint32_t offset = Index;
uint64_t data = 0;
while (uint64_t delta = extractor.getULEB128(&offset)) {
data += delta;
Out.push_back(data);
}
}
const MachOObjectFileBase::Header *MachOObjectFileBase::getHeader() const {
StringRef Data = getData(0, sizeof(Header));
return reinterpret_cast<const Header*>(Data.data());
}
unsigned MachOObjectFileBase::getHeaderSize() const {
return is64Bit() ? macho::Header64Size : macho::Header32Size;
}
StringRef MachOObjectFileBase::getData(size_t Offset, size_t Size) const {
return ObjectFile::getData().substr(Offset, Size);
}
ObjectFile *ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
StringRef Magic = Buffer->getBuffer().slice(0, 4);
error_code ec;
bool Is64Bits = Magic == "\xFE\xED\xFA\xCF" || Magic == "\xCF\xFA\xED\xFE";
ObjectFile *Ret;
if (Is64Bits)
Ret = new MachOObjectFile64Le(Buffer, ec);
else
Ret = new MachOObjectFile32Le(Buffer, ec);
if (ec)
return NULL;
return Ret;
}
/*===-- Symbols -----------------------------------------------------------===*/
void MachOObjectFileBase::moveToNextSymbol(DataRefImpl &DRI) const {
uint32_t LoadCommandCount = getHeader()->NumLoadCommands;
while (DRI.d.a < LoadCommandCount) {
const LoadCommand *Command = getLoadCommandInfo(DRI.d.a);
if (Command->Type == macho::LCT_Symtab) {
const SymtabLoadCommand *SymtabLoadCmd =
reinterpret_cast<const SymtabLoadCommand*>(Command);
if (DRI.d.b < SymtabLoadCmd->NumSymbolTableEntries)
return;
}
DRI.d.a++;
DRI.d.b = 0;
}
}
const MachOObjectFileBase::SymbolTableEntryBase *
MachOObjectFileBase::getSymbolTableEntryBase(DataRefImpl DRI) const {
const LoadCommand *Command = getLoadCommandInfo(DRI.d.a);
const SymtabLoadCommand *SymtabLoadCmd =
reinterpret_cast<const SymtabLoadCommand*>(Command);
return getSymbolTableEntryBase(DRI, SymtabLoadCmd);
}
const MachOObjectFileBase::SymbolTableEntryBase *
MachOObjectFileBase::getSymbolTableEntryBase(DataRefImpl DRI,
const SymtabLoadCommand *SymtabLoadCmd) const {
uint64_t SymbolTableOffset = SymtabLoadCmd->SymbolTableOffset;
unsigned Index = DRI.d.b;
unsigned SymbolTableEntrySize = is64Bit() ?
sizeof(MachOObjectFile64Le::SymbolTableEntry) :
sizeof(MachOObjectFile32Le::SymbolTableEntry);
uint64_t Offset = SymbolTableOffset + Index * SymbolTableEntrySize;
StringRef Data = getData(Offset, SymbolTableEntrySize);
return reinterpret_cast<const SymbolTableEntryBase*>(Data.data());
}
error_code MachOObjectFileBase::getSymbolNext(DataRefImpl DRI,
SymbolRef &Result) const {
DRI.d.b++;
moveToNextSymbol(DRI);
Result = SymbolRef(DRI, this);
return object_error::success;
}
error_code MachOObjectFileBase::getSymbolName(DataRefImpl DRI,
StringRef &Result) const {
const LoadCommand *Command = getLoadCommandInfo(DRI.d.a);
const SymtabLoadCommand *SymtabLoadCmd =
reinterpret_cast<const SymtabLoadCommand*>(Command);
StringRef StringTable = getData(SymtabLoadCmd->StringTableOffset,
SymtabLoadCmd->StringTableSize);
const SymbolTableEntryBase *Entry =
getSymbolTableEntryBase(DRI, SymtabLoadCmd);
uint32_t StringIndex = Entry->StringIndex;
const char *Start = &StringTable.data()[StringIndex];
Result = StringRef(Start);
return object_error::success;
}
error_code MachOObjectFileBase::getSymbolNMTypeChar(DataRefImpl DRI,
char &Result) const {
const SymbolTableEntryBase *Entry = getSymbolTableEntryBase(DRI);
uint8_t Type = Entry->Type;
uint16_t Flags = Entry->Flags;
char Char;
switch (Type & macho::STF_TypeMask) {
case macho::STT_Undefined:
Char = 'u';
break;
case macho::STT_Absolute:
case macho::STT_Section:
Char = 's';
break;
default:
Char = '?';
break;
}
if (Flags & (macho::STF_External | macho::STF_PrivateExtern))
Char = toupper(static_cast<unsigned char>(Char));
Result = Char;
return object_error::success;
}
error_code MachOObjectFileBase::getSymbolFlags(DataRefImpl DRI,
uint32_t &Result) const {
const SymbolTableEntryBase *Entry = getSymbolTableEntryBase(DRI);
uint8_t MachOType = Entry->Type;
uint16_t MachOFlags = Entry->Flags;
// TODO: Correctly set SF_ThreadLocal
Result = SymbolRef::SF_None;
if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeUndefined)
Result |= SymbolRef::SF_Undefined;
if (MachOFlags & macho::STF_StabsEntryMask)
Result |= SymbolRef::SF_FormatSpecific;
if (MachOType & MachO::NlistMaskExternal) {
Result |= SymbolRef::SF_Global;
if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeUndefined)
Result |= SymbolRef::SF_Common;
}
if (MachOFlags & (MachO::NListDescWeakRef | MachO::NListDescWeakDef))
Result |= SymbolRef::SF_Weak;
if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeAbsolute)
Result |= SymbolRef::SF_Absolute;
return object_error::success;
}
error_code MachOObjectFileBase::getSymbolSection(DataRefImpl Symb,
section_iterator &Res) const {
const SymbolTableEntryBase *Entry = getSymbolTableEntryBase(Symb);
uint8_t index = Entry->SectionIndex;
if (index == 0)
Res = end_sections();
else
Res = section_iterator(SectionRef(Sections[index-1], this));
return object_error::success;
}
error_code MachOObjectFileBase::getSymbolType(DataRefImpl Symb,
SymbolRef::Type &Res) const {
const SymbolTableEntryBase *Entry = getSymbolTableEntryBase(Symb);
uint8_t n_type = Entry->Type;
Res = SymbolRef::ST_Other;
// If this is a STAB debugging symbol, we can do nothing more.
if (n_type & MachO::NlistMaskStab) {
Res = SymbolRef::ST_Debug;
return object_error::success;
}
switch (n_type & MachO::NlistMaskType) {
case MachO::NListTypeUndefined :
Res = SymbolRef::ST_Unknown;
break;
case MachO::NListTypeSection :
Res = SymbolRef::ST_Function;
break;
}
return object_error::success;
}
error_code MachOObjectFileBase::getSymbolValue(DataRefImpl Symb,
uint64_t &Val) const {
report_fatal_error("getSymbolValue unimplemented in MachOObjectFileBase");
}
symbol_iterator MachOObjectFileBase::begin_symbols() const {
// DRI.d.a = segment number; DRI.d.b = symbol index.
DataRefImpl DRI;
moveToNextSymbol(DRI);
return symbol_iterator(SymbolRef(DRI, this));
}
symbol_iterator MachOObjectFileBase::end_symbols() const {
DataRefImpl DRI;
DRI.d.a = getHeader()->NumLoadCommands;
return symbol_iterator(SymbolRef(DRI, this));
}
symbol_iterator MachOObjectFileBase::begin_dynamic_symbols() const {
// TODO: implement
report_fatal_error("Dynamic symbols unimplemented in MachOObjectFileBase");
}
symbol_iterator MachOObjectFileBase::end_dynamic_symbols() const {
// TODO: implement
report_fatal_error("Dynamic symbols unimplemented in MachOObjectFileBase");
}
library_iterator MachOObjectFileBase::begin_libraries_needed() const {
// TODO: implement
report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
}
library_iterator MachOObjectFileBase::end_libraries_needed() const {
// TODO: implement
report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
}
StringRef MachOObjectFileBase::getLoadName() const {
// TODO: Implement
report_fatal_error("get_load_name() unimplemented in MachOObjectFileBase");
}
/*===-- Sections ----------------------------------------------------------===*/
std::size_t MachOObjectFileBase::getSectionIndex(DataRefImpl Sec) const {
SectionList::const_iterator loc =
std::find(Sections.begin(), Sections.end(), Sec);
assert(loc != Sections.end() && "Sec is not a valid section!");
return std::distance(Sections.begin(), loc);
}
const MachOObjectFileBase::SectionBase*
MachOObjectFileBase::getSectionBase(DataRefImpl DRI) const {
const LoadCommand *Command = getLoadCommandInfo(DRI.d.a);
uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(Command);
bool Is64 = is64Bit();
unsigned SegmentLoadSize =
Is64 ? sizeof(MachOObjectFile64Le::SegmentLoadCommand) :
sizeof(MachOObjectFile32Le::SegmentLoadCommand);
unsigned SectionSize = Is64 ? sizeof(MachOObjectFile64Le::Section) :
sizeof(MachOObjectFile32Le::Section);
uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + DRI.d.b * SectionSize;
return reinterpret_cast<const SectionBase*>(SectionAddr);
}
static StringRef parseSegmentOrSectionName(const char *P) {
if (P[15] == 0)
// Null terminated.
return P;
// Not null terminated, so this is a 16 char string.
return StringRef(P, 16);
}
ArrayRef<char> MachOObjectFileBase::getSectionRawName(DataRefImpl DRI) const {
const SectionBase *Base = getSectionBase(DRI);
return ArrayRef<char>(Base->Name);
}
error_code MachOObjectFileBase::getSectionName(DataRefImpl DRI,
StringRef &Result) const {
ArrayRef<char> Raw = getSectionRawName(DRI);
Result = parseSegmentOrSectionName(Raw.data());
return object_error::success;
}
ArrayRef<char>
MachOObjectFileBase::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
const SectionBase *Base = getSectionBase(Sec);
return ArrayRef<char>(Base->SegmentName);
}
StringRef
MachOObjectFileBase::getSectionFinalSegmentName(DataRefImpl DRI) const {
ArrayRef<char> Raw = getSectionRawFinalSegmentName(DRI);
return parseSegmentOrSectionName(Raw.data());
}
error_code MachOObjectFileBase::isSectionData(DataRefImpl DRI,
bool &Result) const {
// FIXME: Unimplemented.
Result = false;
return object_error::success;
}
error_code MachOObjectFileBase::isSectionBSS(DataRefImpl DRI,
bool &Result) const {
// FIXME: Unimplemented.
Result = false;
return object_error::success;
}
error_code
MachOObjectFileBase::isSectionRequiredForExecution(DataRefImpl Sec,
bool &Result) const {
// FIXME: Unimplemented.
Result = true;
return object_error::success;
}
error_code MachOObjectFileBase::isSectionVirtual(DataRefImpl Sec,
bool &Result) const {
// FIXME: Unimplemented.
Result = false;
return object_error::success;
}
error_code MachOObjectFileBase::isSectionReadOnlyData(DataRefImpl Sec,
bool &Result) const {
// Consider using the code from isSectionText to look for __const sections.
// Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
// to use section attributes to distinguish code from data.
// FIXME: Unimplemented.
Result = false;
return object_error::success;
}
relocation_iterator MachOObjectFileBase::getSectionRelBegin(DataRefImpl Sec) const {
DataRefImpl ret;
ret.d.b = getSectionIndex(Sec);
return relocation_iterator(RelocationRef(ret, this));
}
section_iterator MachOObjectFileBase::end_sections() const {
DataRefImpl DRI;
DRI.d.a = getHeader()->NumLoadCommands;
return section_iterator(SectionRef(DRI, this));
}
/*===-- Relocations -------------------------------------------------------===*/
error_code MachOObjectFileBase::getRelocationNext(DataRefImpl Rel,
RelocationRef &Res) const {
++Rel.d.a;
Res = RelocationRef(Rel, this);
return object_error::success;
}
// Helper to advance a section or symbol iterator multiple increments at a time.
template<class T>
error_code advance(T &it, size_t Val) {
error_code ec;
while (Val--) {
it.increment(ec);
}
return ec;
}
template<class T>
void advanceTo(T &it, size_t Val) {
if (error_code ec = advance(it, Val))
report_fatal_error(ec.message());
}
void
MachOObjectFileBase::printRelocationTargetName(const RelocationEntry *RE,
raw_string_ostream &fmt) const {
unsigned Arch = getArch();
bool isScattered = (Arch != Triple::x86_64) &&
(RE->Word0 & macho::RF_Scattered);
// Target of a scattered relocation is an address. In the interest of
// generating pretty output, scan through the symbol table looking for a
// symbol that aligns with that address. If we find one, print it.
// Otherwise, we just print the hex address of the target.
if (isScattered) {
uint32_t Val = RE->Word1;
error_code ec;
for (symbol_iterator SI = begin_symbols(), SE = end_symbols(); SI != SE;
SI.increment(ec)) {
if (ec) report_fatal_error(ec.message());
uint64_t Addr;
StringRef Name;
if ((ec = SI->getAddress(Addr)))
report_fatal_error(ec.message());
if (Addr != Val) continue;
if ((ec = SI->getName(Name)))
report_fatal_error(ec.message());
fmt << Name;
return;
}
// If we couldn't find a symbol that this relocation refers to, try
// to find a section beginning instead.
for (section_iterator SI = begin_sections(), SE = end_sections(); SI != SE;
SI.increment(ec)) {
if (ec) report_fatal_error(ec.message());
uint64_t Addr;
StringRef Name;
if ((ec = SI->getAddress(Addr)))
report_fatal_error(ec.message());
if (Addr != Val) continue;
if ((ec = SI->getName(Name)))
report_fatal_error(ec.message());
fmt << Name;
return;
}
fmt << format("0x%x", Val);
return;
}
StringRef S;
bool isExtern = (RE->Word1 >> 27) & 1;
uint32_t Val = RE->Word1 & 0xFFFFFF;
if (isExtern) {
symbol_iterator SI = begin_symbols();
advanceTo(SI, Val);
SI->getName(S);
} else {
section_iterator SI = begin_sections();
advanceTo(SI, Val);
SI->getName(S);
}
fmt << S;
}
error_code MachOObjectFileBase::getLibraryNext(DataRefImpl LibData,
LibraryRef &Res) const {
report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
}
error_code MachOObjectFileBase::getLibraryPath(DataRefImpl LibData,
StringRef &Res) const {
report_fatal_error("Needed libraries unimplemented in MachOObjectFileBase");
}
error_code MachOObjectFileBase::getRelocationAdditionalInfo(DataRefImpl Rel,
int64_t &Res) const {
Res = 0;
return object_error::success;
}
/*===-- Miscellaneous -----------------------------------------------------===*/
uint8_t MachOObjectFileBase::getBytesInAddress() const {
return is64Bit() ? 8 : 4;
}
StringRef MachOObjectFileBase::getFileFormatName() const {
if (!is64Bit()) {
switch (getHeader()->CPUType) {
case llvm::MachO::CPUTypeI386:
return "Mach-O 32-bit i386";
case llvm::MachO::CPUTypeARM:
return "Mach-O arm";
case llvm::MachO::CPUTypePowerPC:
return "Mach-O 32-bit ppc";
default:
assert((getHeader()->CPUType & llvm::MachO::CPUArchABI64) == 0 &&
"64-bit object file when we're not 64-bit?");
return "Mach-O 32-bit unknown";
}
}
// Make sure the cpu type has the correct mask.
assert((getHeader()->CPUType & llvm::MachO::CPUArchABI64)
== llvm::MachO::CPUArchABI64 &&
"32-bit object file when we're 64-bit?");
switch (getHeader()->CPUType) {
case llvm::MachO::CPUTypeX86_64:
return "Mach-O 64-bit x86-64";
case llvm::MachO::CPUTypePowerPC64:
return "Mach-O 64-bit ppc64";
default:
return "Mach-O 64-bit unknown";
}
}
unsigned MachOObjectFileBase::getArch() const {
switch (getHeader()->CPUType) {
case llvm::MachO::CPUTypeI386:
return Triple::x86;
case llvm::MachO::CPUTypeX86_64:
return Triple::x86_64;
case llvm::MachO::CPUTypeARM:
return Triple::arm;
case llvm::MachO::CPUTypePowerPC:
return Triple::ppc;
case llvm::MachO::CPUTypePowerPC64:
return Triple::ppc64;
default:
return Triple::UnknownArch;
}
}
} // end namespace object
} // end namespace llvm