1 //===-- RuntimeDyldMachO.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #include "RuntimeDyldMachO.h"
15 #include "Targets/RuntimeDyldMachOAArch64.h"
16 #include "Targets/RuntimeDyldMachOARM.h"
17 #include "Targets/RuntimeDyldMachOI386.h"
18 #include "Targets/RuntimeDyldMachOX86_64.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/StringRef.h"
23 using namespace llvm::object;
25 #define DEBUG_TYPE "dyld"
29 class LoadedMachOObjectInfo : public RuntimeDyld::LoadedObjectInfo {
31 LoadedMachOObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
33 : RuntimeDyld::LoadedObjectInfo(RTDyld, BeginIdx, EndIdx) {}
35 OwningBinary<ObjectFile>
36 getObjectForDebug(const ObjectFile &Obj) const override {
37 return OwningBinary<ObjectFile>();
45 int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const {
46 unsigned NumBytes = 1 << RE.Size;
47 uint8_t *Src = Sections[RE.SectionID].Address + RE.Offset;
49 return static_cast<int64_t>(readBytesUnaligned(Src, NumBytes));
52 RelocationValueRef RuntimeDyldMachO::getRelocationValueRef(
53 const ObjectFile &BaseTObj, const relocation_iterator &RI,
54 const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) {
56 const MachOObjectFile &Obj =
57 static_cast<const MachOObjectFile &>(BaseTObj);
58 MachO::any_relocation_info RelInfo =
59 Obj.getRelocation(RI->getRawDataRefImpl());
60 RelocationValueRef Value;
62 bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);
64 symbol_iterator Symbol = RI->getSymbol();
66 Symbol->getName(TargetName);
67 RTDyldSymbolTable::const_iterator SI =
68 GlobalSymbolTable.find(TargetName.data());
69 if (SI != GlobalSymbolTable.end()) {
70 const auto &SymInfo = SI->second;
71 Value.SectionID = SymInfo.getSectionID();
72 Value.Offset = SymInfo.getOffset() + RE.Addend;
74 Value.SymbolName = TargetName.data();
75 Value.Offset = RE.Addend;
78 SectionRef Sec = Obj.getRelocationSection(RelInfo);
79 bool IsCode = Sec.isText();
80 Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
81 uint64_t Addr = Sec.getAddress();
82 Value.Offset = RE.Addend - Addr;
88 void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
89 const ObjectFile &BaseTObj,
90 const relocation_iterator &RI,
91 unsigned OffsetToNextPC) {
92 const MachOObjectFile &Obj =
93 static_cast<const MachOObjectFile &>(BaseTObj);
94 MachO::any_relocation_info RelInfo =
95 Obj.getRelocation(RI->getRawDataRefImpl());
97 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
99 uint64_t RelocAddr = 0;
100 RI->getAddress(RelocAddr);
101 Value.Offset += RelocAddr + OffsetToNextPC;
105 void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
106 uint64_t Value) const {
107 const SectionEntry &Section = Sections[RE.SectionID];
108 uint8_t *LocalAddress = Section.Address + RE.Offset;
109 uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
111 dbgs() << "resolveRelocation Section: " << RE.SectionID
112 << " LocalAddress: " << format("%p", LocalAddress)
113 << " FinalAddress: " << format("0x%016" PRIx64, FinalAddress)
114 << " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend
115 << " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType
116 << " Size: " << (1 << RE.Size) << "\n";
120 RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,
122 section_iterator SI = Obj.section_begin();
123 section_iterator SE = Obj.section_end();
125 for (; SI != SE; ++SI) {
126 uint64_t SAddr = SI->getAddress();
127 uint64_t SSize = SI->getSize();
128 if ((Addr >= SAddr) && (Addr < SAddr + SSize))
136 // Populate __pointers section.
137 void RuntimeDyldMachO::populateIndirectSymbolPointersSection(
138 const MachOObjectFile &Obj,
139 const SectionRef &PTSection,
140 unsigned PTSectionID) {
141 assert(!Obj.is64Bit() &&
142 "Pointer table section not supported in 64-bit MachO.");
144 MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
145 MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
146 uint32_t PTSectionSize = Sec32.size;
147 unsigned FirstIndirectSymbol = Sec32.reserved1;
148 const unsigned PTEntrySize = 4;
149 unsigned NumPTEntries = PTSectionSize / PTEntrySize;
150 unsigned PTEntryOffset = 0;
152 assert((PTSectionSize % PTEntrySize) == 0 &&
153 "Pointers section does not contain a whole number of stubs?");
155 DEBUG(dbgs() << "Populating pointer table section "
156 << Sections[PTSectionID].Name
157 << ", Section ID " << PTSectionID << ", "
158 << NumPTEntries << " entries, " << PTEntrySize
159 << " bytes each:\n");
161 for (unsigned i = 0; i < NumPTEntries; ++i) {
162 unsigned SymbolIndex =
163 Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
164 symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
165 StringRef IndirectSymbolName;
166 SI->getName(IndirectSymbolName);
167 DEBUG(dbgs() << " " << IndirectSymbolName << ": index " << SymbolIndex
168 << ", PT offset: " << PTEntryOffset << "\n");
169 RelocationEntry RE(PTSectionID, PTEntryOffset,
170 MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
171 addRelocationForSymbol(RE, IndirectSymbolName);
172 PTEntryOffset += PTEntrySize;
176 bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile &Obj) const {
177 return Obj.isMachO();
180 template <typename Impl>
181 void RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &ObjImg,
182 ObjSectionToIDMap &SectionMap) {
183 unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
184 unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
185 unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
186 ObjSectionToIDMap::iterator i, e;
188 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
189 const SectionRef &Section = i->first;
191 Section.getName(Name);
192 if (Name == "__eh_frame")
193 EHFrameSID = i->second;
194 else if (Name == "__text")
196 else if (Name == "__gcc_except_tab")
197 ExceptTabSID = i->second;
199 impl().finalizeSection(ObjImg, i->second, Section);
201 UnregisteredEHFrameSections.push_back(
202 EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
205 template <typename Impl>
206 unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(unsigned char *P,
207 int64_t DeltaForText,
208 int64_t DeltaForEH) {
209 typedef typename Impl::TargetPtrT TargetPtrT;
211 DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
212 << ", Delta for EH: " << DeltaForEH << "\n");
213 uint32_t Length = readBytesUnaligned(P, 4);
215 unsigned char *Ret = P + Length;
216 uint32_t Offset = readBytesUnaligned(P, 4);
217 if (Offset == 0) // is a CIE
221 TargetPtrT FDELocation = readBytesUnaligned(P, sizeof(TargetPtrT));
222 TargetPtrT NewLocation = FDELocation - DeltaForText;
223 writeBytesUnaligned(NewLocation, P, sizeof(TargetPtrT));
225 P += sizeof(TargetPtrT);
227 // Skip the FDE address range
228 P += sizeof(TargetPtrT);
230 uint8_t Augmentationsize = *P;
232 if (Augmentationsize != 0) {
233 TargetPtrT LSDA = readBytesUnaligned(P, sizeof(TargetPtrT));
234 TargetPtrT NewLSDA = LSDA - DeltaForEH;
235 writeBytesUnaligned(NewLSDA, P, sizeof(TargetPtrT));
241 static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {
242 int64_t ObjDistance = A->ObjAddress - B->ObjAddress;
243 int64_t MemDistance = A->LoadAddress - B->LoadAddress;
244 return ObjDistance - MemDistance;
247 template <typename Impl>
248 void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
252 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
253 EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
254 if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
255 SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)
257 SectionEntry *Text = &Sections[SectionInfo.TextSID];
258 SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];
259 SectionEntry *ExceptTab = nullptr;
260 if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
261 ExceptTab = &Sections[SectionInfo.ExceptTabSID];
263 int64_t DeltaForText = computeDelta(Text, EHFrame);
264 int64_t DeltaForEH = 0;
266 DeltaForEH = computeDelta(ExceptTab, EHFrame);
268 unsigned char *P = EHFrame->Address;
269 unsigned char *End = P + EHFrame->Size;
271 P = processFDE(P, DeltaForText, DeltaForEH);
274 MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
277 UnregisteredEHFrameSections.clear();
280 std::unique_ptr<RuntimeDyldMachO>
281 RuntimeDyldMachO::create(Triple::ArchType Arch, RTDyldMemoryManager *MM) {
284 llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
286 case Triple::arm: return make_unique<RuntimeDyldMachOARM>(MM);
287 case Triple::aarch64: return make_unique<RuntimeDyldMachOAArch64>(MM);
288 case Triple::x86: return make_unique<RuntimeDyldMachOI386>(MM);
289 case Triple::x86_64: return make_unique<RuntimeDyldMachOX86_64>(MM);
293 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
294 RuntimeDyldMachO::loadObject(const object::ObjectFile &O) {
295 unsigned SectionStartIdx, SectionEndIdx;
296 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
297 return llvm::make_unique<LoadedMachOObjectInfo>(*this, SectionStartIdx,
301 } // end namespace llvm