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 SymbolTableMap::const_iterator SI =
68 GlobalSymbolTable.find(TargetName.data());
69 if (SI != GlobalSymbolTable.end()) {
70 Value.SectionID = SI->second.first;
71 Value.Offset = SI->second.second + RE.Addend;
73 Value.SymbolName = TargetName.data();
74 Value.Offset = RE.Addend;
77 SectionRef Sec = Obj.getRelocationSection(RelInfo);
78 bool IsCode = Sec.isText();
79 Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
80 uint64_t Addr = Sec.getAddress();
81 Value.Offset = RE.Addend - Addr;
87 void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
88 const ObjectFile &BaseTObj,
89 const relocation_iterator &RI,
90 unsigned OffsetToNextPC) {
91 const MachOObjectFile &Obj =
92 static_cast<const MachOObjectFile &>(BaseTObj);
93 MachO::any_relocation_info RelInfo =
94 Obj.getRelocation(RI->getRawDataRefImpl());
96 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
98 uint64_t RelocAddr = 0;
99 RI->getAddress(RelocAddr);
100 Value.Offset += RelocAddr + OffsetToNextPC;
104 void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
105 uint64_t Value) const {
106 const SectionEntry &Section = Sections[RE.SectionID];
107 uint8_t *LocalAddress = Section.Address + RE.Offset;
108 uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
110 dbgs() << "resolveRelocation Section: " << RE.SectionID
111 << " LocalAddress: " << format("%p", LocalAddress)
112 << " FinalAddress: " << format("0x%016" PRIx64, FinalAddress)
113 << " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend
114 << " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType
115 << " Size: " << (1 << RE.Size) << "\n";
119 RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,
121 section_iterator SI = Obj.section_begin();
122 section_iterator SE = Obj.section_end();
124 for (; SI != SE; ++SI) {
125 uint64_t SAddr = SI->getAddress();
126 uint64_t SSize = SI->getSize();
127 if ((Addr >= SAddr) && (Addr < SAddr + SSize))
135 // Populate __pointers section.
136 void RuntimeDyldMachO::populateIndirectSymbolPointersSection(
137 const MachOObjectFile &Obj,
138 const SectionRef &PTSection,
139 unsigned PTSectionID) {
140 assert(!Obj.is64Bit() &&
141 "Pointer table section not supported in 64-bit MachO.");
143 MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
144 MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
145 uint32_t PTSectionSize = Sec32.size;
146 unsigned FirstIndirectSymbol = Sec32.reserved1;
147 const unsigned PTEntrySize = 4;
148 unsigned NumPTEntries = PTSectionSize / PTEntrySize;
149 unsigned PTEntryOffset = 0;
151 assert((PTSectionSize % PTEntrySize) == 0 &&
152 "Pointers section does not contain a whole number of stubs?");
154 DEBUG(dbgs() << "Populating pointer table section "
155 << Sections[PTSectionID].Name
156 << ", Section ID " << PTSectionID << ", "
157 << NumPTEntries << " entries, " << PTEntrySize
158 << " bytes each:\n");
160 for (unsigned i = 0; i < NumPTEntries; ++i) {
161 unsigned SymbolIndex =
162 Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
163 symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
164 StringRef IndirectSymbolName;
165 SI->getName(IndirectSymbolName);
166 DEBUG(dbgs() << " " << IndirectSymbolName << ": index " << SymbolIndex
167 << ", PT offset: " << PTEntryOffset << "\n");
168 RelocationEntry RE(PTSectionID, PTEntryOffset,
169 MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
170 addRelocationForSymbol(RE, IndirectSymbolName);
171 PTEntryOffset += PTEntrySize;
175 bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile &Obj) const {
176 return Obj.isMachO();
179 template <typename Impl>
180 void RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &Obj,
181 ObjSectionToIDMap &SectionMap) {
182 unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
183 unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
184 unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
186 for (const auto &Section : Obj.sections()) {
188 Section.getName(Name);
190 // Force emission of the __text, __eh_frame, and __gcc_except_tab sections
191 // if they're present. Otherwise call down to the impl to handle other
192 // sections that have already been emitted.
193 if (Name == "__text")
194 TextSID = findOrEmitSection(Obj, Section, true, SectionMap);
195 else if (Name == "__eh_frame")
196 EHFrameSID = findOrEmitSection(Obj, Section, false, SectionMap);
197 else if (Name == "__gcc_except_tab")
198 ExceptTabSID = findOrEmitSection(Obj, Section, true, SectionMap);
200 auto I = SectionMap.find(Section);
201 if (I != SectionMap.end())
202 impl().finalizeSection(Obj, I->second, Section);
205 UnregisteredEHFrameSections.push_back(
206 EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
209 template <typename Impl>
210 unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(unsigned char *P,
211 int64_t DeltaForText,
212 int64_t DeltaForEH) {
213 typedef typename Impl::TargetPtrT TargetPtrT;
215 DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
216 << ", Delta for EH: " << DeltaForEH << "\n");
217 uint32_t Length = readBytesUnaligned(P, 4);
219 unsigned char *Ret = P + Length;
220 uint32_t Offset = readBytesUnaligned(P, 4);
221 if (Offset == 0) // is a CIE
225 TargetPtrT FDELocation = readBytesUnaligned(P, sizeof(TargetPtrT));
226 TargetPtrT NewLocation = FDELocation - DeltaForText;
227 writeBytesUnaligned(NewLocation, P, sizeof(TargetPtrT));
229 P += sizeof(TargetPtrT);
231 // Skip the FDE address range
232 P += sizeof(TargetPtrT);
234 uint8_t Augmentationsize = *P;
236 if (Augmentationsize != 0) {
237 TargetPtrT LSDA = readBytesUnaligned(P, sizeof(TargetPtrT));
238 TargetPtrT NewLSDA = LSDA - DeltaForEH;
239 writeBytesUnaligned(NewLSDA, P, sizeof(TargetPtrT));
245 static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {
246 int64_t ObjDistance =
247 static_cast<int64_t>(A->ObjAddress) - static_cast<int64_t>(B->ObjAddress);
248 int64_t MemDistance = A->LoadAddress - B->LoadAddress;
249 return ObjDistance - MemDistance;
252 template <typename Impl>
253 void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
257 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
258 EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
259 if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
260 SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)
262 SectionEntry *Text = &Sections[SectionInfo.TextSID];
263 SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];
264 SectionEntry *ExceptTab = nullptr;
265 if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
266 ExceptTab = &Sections[SectionInfo.ExceptTabSID];
268 int64_t DeltaForText = computeDelta(Text, EHFrame);
269 int64_t DeltaForEH = 0;
271 DeltaForEH = computeDelta(ExceptTab, EHFrame);
273 unsigned char *P = EHFrame->Address;
274 unsigned char *End = P + EHFrame->Size;
276 P = processFDE(P, DeltaForText, DeltaForEH);
279 MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
282 UnregisteredEHFrameSections.clear();
285 std::unique_ptr<RuntimeDyldMachO>
286 RuntimeDyldMachO::create(Triple::ArchType Arch, RTDyldMemoryManager *MM) {
289 llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
291 case Triple::arm: return make_unique<RuntimeDyldMachOARM>(MM);
292 case Triple::aarch64: return make_unique<RuntimeDyldMachOAArch64>(MM);
293 case Triple::x86: return make_unique<RuntimeDyldMachOI386>(MM);
294 case Triple::x86_64: return make_unique<RuntimeDyldMachOX86_64>(MM);
298 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
299 RuntimeDyldMachO::loadObject(const object::ObjectFile &O) {
300 unsigned SectionStartIdx, SectionEndIdx;
301 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
302 return llvm::make_unique<LoadedMachOObjectInfo>(*this, SectionStartIdx,
306 } // end namespace llvm