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//===- lib/ReaderWriter/MachO/MachONormalizedFileFromAtoms.cpp ------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file Converts from in-memory Atoms to in-memory normalized mach-o.
///
/// +------------+
/// | normalized |
/// +------------+
/// ^
/// |
/// |
/// +-------+
/// | Atoms |
/// +-------+
#include "MachONormalizedFile.h"
#include "ReferenceKinds.h"
#include "lld/Core/Error.h"
#include "lld/Core/LLVM.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MachO.h"
#include "llvm/Support/system_error.h"
#include <map>
using llvm::StringRef;
using llvm::dyn_cast;
using llvm::isa;
using namespace llvm::MachO;
using namespace lld::mach_o::normalized;
using namespace lld;
namespace {
struct AtomInfo {
const DefinedAtom *atom;
uint64_t offsetInSection;
};
struct SectionInfo {
SectionInfo(StringRef seg, StringRef sect, SectionType type, uint32_t attr=0);
StringRef segmentName;
StringRef sectionName;
SectionType type;
uint32_t attributes;
uint64_t address;
uint64_t size;
uint32_t alignment;
std::vector<AtomInfo> atomsAndOffsets;
uint32_t normalizedSectionIndex;
uint32_t finalSectionIndex;
};
SectionInfo::SectionInfo(StringRef sg, StringRef sct, SectionType t, uint32_t a)
: segmentName(sg), sectionName(sct), type(t), attributes(a),
address(0), size(0), alignment(0),
normalizedSectionIndex(0), finalSectionIndex(0) {
}
struct SegmentInfo {
SegmentInfo(StringRef name);
StringRef name;
uint64_t address;
uint64_t size;
uint32_t access;
std::vector<SectionInfo*> sections;
};
SegmentInfo::SegmentInfo(StringRef n)
: name(n), address(0), size(0), access(0) {
}
class Util {
public:
Util(const MachOLinkingContext &ctxt) : _context(ctxt), _entryAtom(nullptr) {}
void assignAtomsToSections(const lld::File &atomFile);
void organizeSections();
void assignAddressesToSections();
uint32_t fileFlags();
void copySegmentInfo(NormalizedFile &file);
void copySections(NormalizedFile &file);
void buildAtomToAddressMap();
void addSymbols(const lld::File &atomFile, NormalizedFile &file);
void addIndirectSymbols(const lld::File &atomFile, NormalizedFile &file);
void addRebaseAndBindingInfo(const lld::File &, NormalizedFile &file);
void addSectionRelocs(const lld::File &, NormalizedFile &file);
void addDependentDylibs(const lld::File &, NormalizedFile &file);
void copyEntryPointAddress(NormalizedFile &file);
private:
typedef std::map<DefinedAtom::ContentType, SectionInfo*> TypeToSection;
typedef llvm::DenseMap<const Atom*, uint64_t> AtomToAddress;
struct DylibInfo { int ordinal; bool hasWeak; bool hasNonWeak; };
typedef llvm::StringMap<DylibInfo> DylibPathToInfo;
SectionInfo *sectionForAtom(const DefinedAtom*);
SectionInfo *makeSection(DefinedAtom::ContentType);
void appendAtom(SectionInfo *sect, const DefinedAtom *atom);
SegmentInfo *segmentForName(StringRef segName);
void layoutSectionsInSegment(SegmentInfo *seg, uint64_t &addr);
void layoutSectionsInTextSegment(SegmentInfo *seg, uint64_t &addr);
void copySectionContent(SectionInfo *si, ContentBytes &content);
uint8_t scopeBits(const DefinedAtom* atom);
int dylibOrdinal(const SharedLibraryAtom *sa);
void segIndexForSection(const SectionInfo *sect,
uint8_t &segmentIndex, uint64_t &segmentStartAddr);
const Atom *targetOfLazyPointer(const DefinedAtom *lpAtom);
const Atom *targetOfStub(const DefinedAtom *stubAtom);
bool belongsInGlobalSymbolsSection(const DefinedAtom* atom);
void appendSection(SectionInfo *si, NormalizedFile &file);
void appendReloc(const DefinedAtom *atom, const Reference *ref,
Relocations &relocations);
static uint64_t alignTo(uint64_t value, uint8_t align2);
typedef llvm::DenseMap<const Atom*, uint32_t> AtomToIndex;
struct AtomAndIndex { const Atom *atom; uint32_t index; };
struct AtomSorter {
bool operator()(const AtomAndIndex &left, const AtomAndIndex &right);
};
struct SegmentSorter {
bool operator()(const SegmentInfo *left, const SegmentInfo *right);
static unsigned weight(const SegmentInfo *);
};
struct TextSectionSorter {
bool operator()(const SectionInfo *left, const SectionInfo *right);
static unsigned weight(const SectionInfo *);
};
const MachOLinkingContext &_context;
llvm::BumpPtrAllocator _allocator;
std::vector<SectionInfo*> _sectionInfos;
std::vector<SegmentInfo*> _segmentInfos;
TypeToSection _sectionMap;
AtomToAddress _atomToAddress;
DylibPathToInfo _dylibInfo;
const DefinedAtom *_entryAtom;
AtomToIndex _atomToSymbolIndex;
};
SectionInfo *Util::makeSection(DefinedAtom::ContentType type) {
switch ( type ) {
case DefinedAtom::typeCode:
return new (_allocator) SectionInfo("__TEXT", "__text",
S_REGULAR, S_ATTR_PURE_INSTRUCTIONS
| S_ATTR_SOME_INSTRUCTIONS);
case DefinedAtom::typeCString:
return new (_allocator) SectionInfo("__TEXT", "__cstring",
S_CSTRING_LITERALS);
case DefinedAtom::typeStub:
return new (_allocator) SectionInfo("__TEXT", "__stubs",
S_SYMBOL_STUBS, S_ATTR_PURE_INSTRUCTIONS);
case DefinedAtom::typeStubHelper:
return new (_allocator) SectionInfo("__TEXT", "__stub_helper",
S_REGULAR, S_ATTR_PURE_INSTRUCTIONS);
case DefinedAtom::typeLazyPointer:
return new (_allocator) SectionInfo("__DATA", "__la_symbol_ptr",
S_LAZY_SYMBOL_POINTERS);
case DefinedAtom::typeGOT:
return new (_allocator) SectionInfo("__DATA", "__got",
S_NON_LAZY_SYMBOL_POINTERS);
default:
llvm_unreachable("TO DO: add support for more sections");
break;
}
}
SectionInfo *Util::sectionForAtom(const DefinedAtom *atom) {
DefinedAtom::ContentType type = atom->contentType();
auto pos = _sectionMap.find(type);
if ( pos != _sectionMap.end() )
return pos->second;
SectionInfo *si = makeSection(type);
_sectionInfos.push_back(si);
_sectionMap[type] = si;
return si;
}
void Util::appendAtom(SectionInfo *sect, const DefinedAtom *atom) {
// Figure out offset for atom in this section given alignment constraints.
uint64_t offset = sect->size;
DefinedAtom::Alignment atomAlign = atom->alignment();
uint64_t align2 = 1 << atomAlign.powerOf2;
uint64_t requiredModulus = atomAlign.modulus;
uint64_t currentModulus = (offset % align2);
if ( currentModulus != requiredModulus ) {
if ( requiredModulus > currentModulus )
offset += requiredModulus-currentModulus;
else
offset += align2+requiredModulus-currentModulus;
}
// Record max alignment of any atom in this section.
if ( atomAlign.powerOf2 > sect->alignment )
sect->alignment = atomAlign.powerOf2;
// Assign atom to this section with this offset.
AtomInfo ai = {atom, offset};
sect->atomsAndOffsets.push_back(ai);
// Update section size to include this atom.
sect->size = offset + atom->size();
}
void Util::assignAtomsToSections(const lld::File &atomFile) {
for (const DefinedAtom *atom : atomFile.defined()) {
appendAtom(sectionForAtom(atom), atom);
}
}
SegmentInfo *Util::segmentForName(StringRef segName) {
for (SegmentInfo *si : _segmentInfos) {
if ( si->name.equals(segName) )
return si;
}
SegmentInfo *info = new (_allocator) SegmentInfo(segName);
if (segName.equals("__TEXT"))
info->access = VM_PROT_READ | VM_PROT_EXECUTE;
else if (segName.equals("__DATA"))
info->access = VM_PROT_READ | VM_PROT_WRITE;
else if (segName.equals("__PAGEZERO"))
info->access = 0;
_segmentInfos.push_back(info);
return info;
}
unsigned Util::SegmentSorter::weight(const SegmentInfo *seg) {
return llvm::StringSwitch<unsigned>(seg->name)
.Case("__PAGEZERO", 1)
.Case("__TEXT", 2)
.Case("__DATA", 3)
.Default(100);
}
bool Util::SegmentSorter::operator()(const SegmentInfo *left,
const SegmentInfo *right) {
return (weight(left) < weight(right));
}
unsigned Util::TextSectionSorter::weight(const SectionInfo *sect) {
return llvm::StringSwitch<unsigned>(sect->sectionName)
.Case("__text", 1)
.Case("__stubs", 2)
.Case("__stub_helper", 3)
.Case("__const", 4)
.Case("__cstring", 5)
.Case("__unwind_info", 98)
.Case("__eh_frame", 99)
.Default(10);
}
bool Util::TextSectionSorter::operator()(const SectionInfo *left,
const SectionInfo *right) {
return (weight(left) < weight(right));
}
void Util::organizeSections() {
if (_context.outputFileType() == llvm::MachO::MH_OBJECT) {
// Leave sections ordered as normalized file specified.
uint32_t sectionIndex = 1;
for (SectionInfo *si : _sectionInfos) {
si->finalSectionIndex = sectionIndex++;
}
} else {
// Main executables, need a zero-page segment
if (_context.outputFileType() == llvm::MachO::MH_EXECUTE)
segmentForName("__PAGEZERO");
// Group sections into segments.
for (SectionInfo *si : _sectionInfos) {
SegmentInfo *seg = segmentForName(si->segmentName);
seg->sections.push_back(si);
}
// Sort segments.
std::sort(_segmentInfos.begin(), _segmentInfos.end(), SegmentSorter());
// Sort sections within segments.
for (SegmentInfo *seg : _segmentInfos) {
if (seg->name.equals("__TEXT")) {
std::sort(seg->sections.begin(), seg->sections.end(),
TextSectionSorter());
}
}
// Record final section indexes.
uint32_t sectionIndex = 1;
for (SegmentInfo *seg : _segmentInfos) {
for (SectionInfo *sect : seg->sections) {
sect->finalSectionIndex = sectionIndex++;
}
}
}
}
uint64_t Util::alignTo(uint64_t value, uint8_t align2) {
return llvm::RoundUpToAlignment(value, 1 << align2);
}
void Util::layoutSectionsInSegment(SegmentInfo *seg, uint64_t &addr) {
seg->address = addr;
for (SectionInfo *sect : seg->sections) {
sect->address = alignTo(addr, sect->alignment);
addr += sect->size;
}
seg->size = llvm::RoundUpToAlignment(addr - seg->address,_context.pageSize());
}
// __TEXT segment lays out backwards so padding is at front after load commands.
void Util::layoutSectionsInTextSegment(SegmentInfo *seg, uint64_t &addr) {
seg->address = addr;
// Walks sections starting at end to calculate padding for start.
int64_t taddr = 0;
for (auto it = seg->sections.rbegin(); it != seg->sections.rend(); ++it) {
SectionInfo *sect = *it;
taddr -= sect->size;
taddr = taddr & (0 - (1 << sect->alignment));
}
int64_t padding = taddr;
while (padding < 0)
padding += _context.pageSize();
// Start assigning section address starting at padded offset.
addr += padding;
for (SectionInfo *sect : seg->sections) {
sect->address = alignTo(addr, sect->alignment);
addr = sect->address + sect->size;
}
seg->size = llvm::RoundUpToAlignment(addr - seg->address,_context.pageSize());
}
void Util::assignAddressesToSections() {
uint64_t address = 0; // FIXME
if (_context.outputFileType() != llvm::MachO::MH_OBJECT) {
for (SegmentInfo *seg : _segmentInfos) {
if (seg->name.equals("__PAGEZERO")) {
seg->size = _context.pageZeroSize();
address += seg->size;
}
else if (seg->name.equals("__TEXT"))
layoutSectionsInTextSegment(seg, address);
else
layoutSectionsInSegment(seg, address);
}
DEBUG_WITH_TYPE("WriterMachO-norm",
llvm::dbgs() << "assignAddressesToSections()\n";
for (SegmentInfo *sgi : _segmentInfos) {
llvm::dbgs() << " address=" << llvm::format("0x%08llX", sgi->address)
<< ", size=" << llvm::format("0x%08llX", sgi->size)
<< ", segment-name='" << sgi->name
<< "'\n";
for (SectionInfo *si : sgi->sections) {
llvm::dbgs()<< " addr=" << llvm::format("0x%08llX", si->address)
<< ", size=" << llvm::format("0x%08llX", si->size)
<< ", section-name='" << si->sectionName
<< "\n";
}
}
);
} else {
for (SectionInfo *sect : _sectionInfos) {
sect->address = alignTo(address, sect->alignment);
address = sect->address + sect->size;
}
DEBUG_WITH_TYPE("WriterMachO-norm",
llvm::dbgs() << "assignAddressesToSections()\n";
for (SectionInfo *si : _sectionInfos) {
llvm::dbgs() << " section=" << si->sectionName
<< " address= " << llvm::format("0x%08X", si->address)
<< " size= " << llvm::format("0x%08X", si->size)
<< "\n";
}
);
}
}
void Util::copySegmentInfo(NormalizedFile &file) {
for (SegmentInfo *sgi : _segmentInfos) {
Segment seg;
seg.name = sgi->name;
seg.address = sgi->address;
seg.size = sgi->size;
seg.access = sgi->access;
file.segments.push_back(seg);
}
}
void Util::appendSection(SectionInfo *si, NormalizedFile &file) {
// Add new empty section to end of file.sections.
Section temp;
file.sections.push_back(std::move(temp));
Section* normSect = &file.sections.back();
// Copy fields to normalized section.
normSect->segmentName = si->segmentName;
normSect->sectionName = si->sectionName;
normSect->type = si->type;
normSect->attributes = si->attributes;
normSect->address = si->address;
normSect->alignment = si->alignment;
// Record where normalized section is.
si->normalizedSectionIndex = file.sections.size()-1;
// Copy content from atoms to content buffer for section.
// FIXME: zerofill atoms/sections should not take up content space.
normSect->content.resize(si->size);
uint8_t *sectionContent = normSect->content.data();
for (AtomInfo &ai : si->atomsAndOffsets) {
// Copy raw bytes.
uint8_t *atomContent = reinterpret_cast<uint8_t*>
(&sectionContent[ai.offsetInSection]);
memcpy(atomContent, ai.atom->rawContent().data(), ai.atom->size());
// Apply fix-ups.
for (const Reference *ref : *ai.atom) {
uint32_t offset = ref->offsetInAtom();
uint64_t targetAddress = 0;
if ( ref->target() != nullptr )
targetAddress = _atomToAddress[ref->target()];
uint64_t fixupAddress = _atomToAddress[ai.atom] + offset;
_context.kindHandler().applyFixup(
ref->kindNamespace(), ref->kindArch(), ref->kindValue(),
ref->addend(), &atomContent[offset], fixupAddress, targetAddress);
}
}
}
void Util::copySections(NormalizedFile &file) {
file.sections.reserve(_sectionInfos.size());
// For final linked images, write sections grouped by segment.
if (_context.outputFileType() != llvm::MachO::MH_OBJECT) {
for (SegmentInfo *sgi : _segmentInfos) {
for (SectionInfo *si : sgi->sections) {
appendSection(si, file);
}
}
} else {
// Object files write sections in default order.
for (SectionInfo *si : _sectionInfos) {
appendSection(si, file);
}
}
}
void Util::copyEntryPointAddress(NormalizedFile &nFile) {
if (_context.outputTypeHasEntry()) {
nFile.entryAddress = _atomToAddress[_entryAtom];
}
}
void Util::buildAtomToAddressMap() {
DEBUG_WITH_TYPE("WriterMachO-address", llvm::dbgs()
<< "assign atom addresses:\n");
const bool lookForEntry = _context.outputTypeHasEntry();
for (SectionInfo *sect : _sectionInfos) {
for (const AtomInfo &info : sect->atomsAndOffsets) {
_atomToAddress[info.atom] = sect->address + info.offsetInSection;
if (lookForEntry && (info.atom->contentType() == DefinedAtom::typeCode) &&
(info.atom->size() != 0) &&
info.atom->name() == _context.entrySymbolName()) {
_entryAtom = info.atom;
}
DEBUG_WITH_TYPE("WriterMachO-address", llvm::dbgs()
<< " address="
<< llvm::format("0x%016X", _atomToAddress[info.atom])
<< " atom=" << info.atom
<< " name=" << info.atom->name() << "\n");
}
}
}
uint8_t Util::scopeBits(const DefinedAtom* atom) {
switch (atom->scope()) {
case Atom::scopeTranslationUnit:
return 0;
case Atom::scopeLinkageUnit:
return N_PEXT | N_EXT;
case Atom::scopeGlobal:
return N_EXT;
}
llvm_unreachable("Unknown scope");
}
bool Util::AtomSorter::operator()(const AtomAndIndex &left,
const AtomAndIndex &right) {
return (left.atom->name().compare(right.atom->name()) < 0);
}
bool Util::belongsInGlobalSymbolsSection(const DefinedAtom* atom) {
return (atom->scope() == Atom::scopeGlobal);
}
void Util::addSymbols(const lld::File &atomFile, NormalizedFile &file) {
// Mach-O symbol table has three regions: locals, globals, undefs.
// Add all local (non-global) symbols in address order
std::vector<AtomAndIndex> globals;
globals.reserve(512);
for (SectionInfo *sect : _sectionInfos) {
for (const AtomInfo &info : sect->atomsAndOffsets) {
const DefinedAtom *atom = info.atom;
if (!atom->name().empty()) {
if (belongsInGlobalSymbolsSection(atom)) {
AtomAndIndex ai = { atom, sect->finalSectionIndex };
globals.push_back(ai);
} else {
Symbol sym;
sym.name = atom->name();
sym.type = N_SECT;
sym.scope = scopeBits(atom);
sym.sect = sect->finalSectionIndex;
sym.desc = 0;
sym.value = _atomToAddress[atom];
file.localSymbols.push_back(sym);
}
}
}
}
// Sort global symbol alphabetically, then add to symbol table.
std::sort(globals.begin(), globals.end(), AtomSorter());
for (AtomAndIndex &ai : globals) {
Symbol sym;
sym.name = ai.atom->name();
sym.type = N_SECT;
sym.scope = scopeBits(static_cast<const DefinedAtom*>(ai.atom));
sym.sect = ai.index;
sym.desc = 0;
sym.value = _atomToAddress[ai.atom];
file.globalSymbols.push_back(sym);
}
// Sort undefined symbol alphabetically, then add to symbol table.
std::vector<AtomAndIndex> undefs;
undefs.reserve(128);
for (const UndefinedAtom *atom : atomFile.undefined()) {
AtomAndIndex ai = { atom, 0 };
undefs.push_back(ai);
}
for (const SharedLibraryAtom *atom : atomFile.sharedLibrary()) {
AtomAndIndex ai = { atom, 0 };
undefs.push_back(ai);
}
std::sort(undefs.begin(), undefs.end(), AtomSorter());
const uint32_t start = file.globalSymbols.size() + file.localSymbols.size();
for (AtomAndIndex &ai : undefs) {
Symbol sym;
sym.name = ai.atom->name();
sym.type = N_UNDF;
sym.scope = N_EXT;
sym.sect = 0;
sym.desc = 0;
sym.value = 0;
_atomToSymbolIndex[ai.atom] = file.undefinedSymbols.size() + start;
file.undefinedSymbols.push_back(sym);
}
}
const Atom *Util::targetOfLazyPointer(const DefinedAtom *lpAtom) {
for (const Reference *ref : *lpAtom) {
if (_context.kindHandler().isLazyTarget(*ref)) {
return ref->target();
}
}
return nullptr;
}
const Atom *Util::targetOfStub(const DefinedAtom *stubAtom) {
for (const Reference *ref : *stubAtom) {
if (const Atom *ta = ref->target()) {
if (const DefinedAtom *lpAtom = dyn_cast<DefinedAtom>(ta)) {
const Atom *target = targetOfLazyPointer(lpAtom);
if (target)
return target;
}
}
}
return nullptr;
}
void Util::addIndirectSymbols(const lld::File &atomFile, NormalizedFile &file) {
for (SectionInfo *si : _sectionInfos) {
Section &normSect = file.sections[si->normalizedSectionIndex];
switch (si->type) {
case llvm::MachO::S_NON_LAZY_SYMBOL_POINTERS:
for (const AtomInfo &info : si->atomsAndOffsets) {
bool foundTarget = false;
for (const Reference *ref : *info.atom) {
const Atom *target = ref->target();
if (target) {
if (isa<const SharedLibraryAtom>(target)) {
uint32_t index = _atomToSymbolIndex[target];
normSect.indirectSymbols.push_back(index);
foundTarget = true;
} else {
normSect.indirectSymbols.push_back(
llvm::MachO::INDIRECT_SYMBOL_LOCAL);
}
}
}
if (!foundTarget) {
normSect.indirectSymbols.push_back(
llvm::MachO::INDIRECT_SYMBOL_ABS);
}
}
break;
case llvm::MachO::S_LAZY_SYMBOL_POINTERS:
for (const AtomInfo &info : si->atomsAndOffsets) {
const Atom *target = targetOfLazyPointer(info.atom);
if (target) {
uint32_t index = _atomToSymbolIndex[target];
normSect.indirectSymbols.push_back(index);
}
}
break;
case llvm::MachO::S_SYMBOL_STUBS:
for (const AtomInfo &info : si->atomsAndOffsets) {
const Atom *target = targetOfStub(info.atom);
if (target) {
uint32_t index = _atomToSymbolIndex[target];
normSect.indirectSymbols.push_back(index);
}
}
break;
default:
break;
}
}
}
void Util::addDependentDylibs(const lld::File &atomFile,NormalizedFile &nFile) {
// Scan all imported symbols and build up list of dylibs they are from.
int ordinal = 1;
for (const SharedLibraryAtom *slAtom : atomFile.sharedLibrary()) {
StringRef loadPath = slAtom->loadName();
DylibPathToInfo::iterator pos = _dylibInfo.find(loadPath);
if (pos == _dylibInfo.end()) {
DylibInfo info;
info.ordinal = ordinal++;
info.hasWeak = slAtom->canBeNullAtRuntime();
info.hasNonWeak = !info.hasWeak;
_dylibInfo[loadPath] = info;
DependentDylib depInfo;
depInfo.path = loadPath;
depInfo.kind = llvm::MachO::LC_LOAD_DYLIB;
nFile.dependentDylibs.push_back(depInfo);
} else {
if ( slAtom->canBeNullAtRuntime() )
pos->second.hasWeak = true;
else
pos->second.hasNonWeak = true;
}
}
// Automatically weak link dylib in which all symbols are weak (canBeNull).
for (DependentDylib &dep : nFile.dependentDylibs) {
DylibInfo &info = _dylibInfo[dep.path];
if (info.hasWeak && !info.hasNonWeak)
dep.kind = llvm::MachO::LC_LOAD_WEAK_DYLIB;
}
}
int Util::dylibOrdinal(const SharedLibraryAtom *sa) {
return _dylibInfo[sa->loadName()].ordinal;
}
void Util::segIndexForSection(const SectionInfo *sect, uint8_t &segmentIndex,
uint64_t &segmentStartAddr) {
segmentIndex = 0;
for (const SegmentInfo *seg : _segmentInfos) {
if ((seg->address <= sect->address)
&& (seg->address+seg->size >= sect->address+sect->size)) {
segmentStartAddr = seg->address;
return;
}
++segmentIndex;
}
llvm_unreachable("section not in any segment");
}
void Util::appendReloc(const DefinedAtom *atom, const Reference *ref,
Relocations &relocations) {
// TODO: convert Reference to normalized relocation
}
void Util::addSectionRelocs(const lld::File &, NormalizedFile &file) {
if (_context.outputFileType() != llvm::MachO::MH_OBJECT)
return;
for (SectionInfo *si : _sectionInfos) {
Section &normSect = file.sections[si->normalizedSectionIndex];
for (const AtomInfo &info : si->atomsAndOffsets) {
const DefinedAtom *atom = info.atom;
for (const Reference *ref : *atom) {
appendReloc(atom, ref, normSect.relocations);
}
}
}
}
void Util::addRebaseAndBindingInfo(const lld::File &atomFile,
NormalizedFile &nFile) {
if (_context.outputFileType() == llvm::MachO::MH_OBJECT)
return;
uint8_t segmentIndex;
uint64_t segmentStartAddr;
for (SectionInfo *sect : _sectionInfos) {
segIndexForSection(sect, segmentIndex, segmentStartAddr);
for (const AtomInfo &info : sect->atomsAndOffsets) {
const DefinedAtom *atom = info.atom;
for (const Reference *ref : *atom) {
uint64_t segmentOffset = _atomToAddress[atom] + ref->offsetInAtom()
- segmentStartAddr;
const Atom* targ = ref->target();
if (_context.kindHandler().isPointer(*ref)) {
// A pointer to a DefinedAtom requires rebasing.
if (dyn_cast<DefinedAtom>(targ)) {
RebaseLocation rebase;
rebase.segIndex = segmentIndex;
rebase.segOffset = segmentOffset;
rebase.kind = llvm::MachO::REBASE_TYPE_POINTER;
nFile.rebasingInfo.push_back(rebase);
}
// A pointer to an SharedLibraryAtom requires binding.
if (const SharedLibraryAtom *sa = dyn_cast<SharedLibraryAtom>(targ)) {
BindLocation bind;
bind.segIndex = segmentIndex;
bind.segOffset = segmentOffset;
bind.kind = llvm::MachO::BIND_TYPE_POINTER;
bind.canBeNull = sa->canBeNullAtRuntime();
bind.ordinal = dylibOrdinal(sa);
bind.symbolName = targ->name();
bind.addend = ref->addend();
nFile.bindingInfo.push_back(bind);
}
}
if (_context.kindHandler().isLazyTarget(*ref)) {
BindLocation bind;
bind.segIndex = segmentIndex;
bind.segOffset = segmentOffset;
bind.kind = llvm::MachO::BIND_TYPE_POINTER;
bind.canBeNull = false; //sa->canBeNullAtRuntime();
bind.ordinal = 1;
bind.symbolName = targ->name();
bind.addend = ref->addend();
nFile.lazyBindingInfo.push_back(bind);
}
}
}
}
}
uint32_t Util::fileFlags() {
return 0; //FIX ME
}
} // end anonymous namespace
namespace lld {
namespace mach_o {
namespace normalized {
/// Convert a set of Atoms into a normalized mach-o file.
ErrorOr<std::unique_ptr<NormalizedFile>>
normalizedFromAtoms(const lld::File &atomFile,
const MachOLinkingContext &context) {
// The util object buffers info until the normalized file can be made.
Util util(context);
util.assignAtomsToSections(atomFile);
util.organizeSections();
util.assignAddressesToSections();
util.buildAtomToAddressMap();
std::unique_ptr<NormalizedFile> f(new NormalizedFile());
NormalizedFile &normFile = *f.get();
f->arch = context.arch();
f->fileType = context.outputFileType();
f->flags = util.fileFlags();
util.copySegmentInfo(normFile);
util.copySections(normFile);
util.addDependentDylibs(atomFile, normFile);
util.addSymbols(atomFile, normFile);
util.addIndirectSymbols(atomFile, normFile);
util.addRebaseAndBindingInfo(atomFile, normFile);
util.addSectionRelocs(atomFile, normFile);
util.copyEntryPointAddress(normFile);
return std::move(f);
}
} // namespace normalized
} // namespace mach_o
} // namespace lld
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