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 "llvm/ADT/STLExtras.h"
16 #include "llvm/ADT/StringRef.h"
18 #include "Targets/RuntimeDyldMachOARM.h"
19 #include "Targets/RuntimeDyldMachOAArch64.h"
20 #include "Targets/RuntimeDyldMachOI386.h"
21 #include "Targets/RuntimeDyldMachOX86_64.h"
24 using namespace llvm::object;
26 #define DEBUG_TYPE "dyld"
30 int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const {
31 unsigned NumBytes = 1 << RE.Size;
32 uint8_t *Src = Sections[RE.SectionID].Address + RE.Offset;
34 return static_cast<int64_t>(readBytesUnaligned(Src, NumBytes));
37 RelocationValueRef RuntimeDyldMachO::getRelocationValueRef(
38 ObjectImage &ObjImg, const relocation_iterator &RI,
39 const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID,
40 const SymbolTableMap &Symbols) {
42 const MachOObjectFile &Obj =
43 static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
44 MachO::any_relocation_info RelInfo =
45 Obj.getRelocation(RI->getRawDataRefImpl());
46 RelocationValueRef Value;
48 bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);
50 symbol_iterator Symbol = RI->getSymbol();
52 Symbol->getName(TargetName);
53 SymbolTableMap::const_iterator SI = Symbols.find(TargetName.data());
54 if (SI != Symbols.end()) {
55 Value.SectionID = SI->second.first;
56 Value.Offset = SI->second.second + RE.Addend;
58 SI = GlobalSymbolTable.find(TargetName.data());
59 if (SI != GlobalSymbolTable.end()) {
60 Value.SectionID = SI->second.first;
61 Value.Offset = SI->second.second + RE.Addend;
63 Value.SymbolName = TargetName.data();
64 Value.Offset = RE.Addend;
68 SectionRef Sec = Obj.getRelocationSection(RelInfo);
71 Value.SectionID = findOrEmitSection(ObjImg, Sec, IsCode, ObjSectionToID);
74 Value.Offset = RE.Addend - Addr;
80 void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,
82 const relocation_iterator &RI,
83 unsigned OffsetToNextPC) {
84 const MachOObjectFile &Obj =
85 static_cast<const MachOObjectFile &>(*ObjImg.getObjectFile());
86 MachO::any_relocation_info RelInfo =
87 Obj.getRelocation(RI->getRawDataRefImpl());
89 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
91 uint64_t RelocAddr = 0;
92 RI->getAddress(RelocAddr);
93 Value.Offset += RelocAddr + OffsetToNextPC;
97 void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,
98 uint64_t Value) const {
99 const SectionEntry &Section = Sections[RE.SectionID];
100 uint8_t *LocalAddress = Section.Address + RE.Offset;
101 uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
103 dbgs() << "resolveRelocation Section: " << RE.SectionID
104 << " LocalAddress: " << format("%p", LocalAddress)
105 << " FinalAddress: " << format("0x%016" PRIx64, FinalAddress)
106 << " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend
107 << " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType
108 << " Size: " << (1 << RE.Size) << "\n";
112 RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,
114 section_iterator SI = Obj.section_begin();
115 section_iterator SE = Obj.section_end();
117 for (; SI != SE; ++SI) {
118 uint64_t SAddr, SSize;
119 SI->getAddress(SAddr);
121 if ((Addr >= SAddr) && (Addr < SAddr + SSize))
129 // Populate __pointers section.
130 void RuntimeDyldMachO::populateIndirectSymbolPointersSection(
131 MachOObjectFile &Obj,
132 const SectionRef &PTSection,
133 unsigned PTSectionID) {
134 assert(!Obj.is64Bit() &&
135 "Pointer table section not supported in 64-bit MachO.");
137 MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();
138 MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());
139 uint32_t PTSectionSize = Sec32.size;
140 unsigned FirstIndirectSymbol = Sec32.reserved1;
141 const unsigned PTEntrySize = 4;
142 unsigned NumPTEntries = PTSectionSize / PTEntrySize;
143 unsigned PTEntryOffset = 0;
145 assert((PTSectionSize % PTEntrySize) == 0 &&
146 "Pointers section does not contain a whole number of stubs?");
148 DEBUG(dbgs() << "Populating pointer table section "
149 << Sections[PTSectionID].Name
150 << ", Section ID " << PTSectionID << ", "
151 << NumPTEntries << " entries, " << PTEntrySize
152 << " bytes each:\n");
154 for (unsigned i = 0; i < NumPTEntries; ++i) {
155 unsigned SymbolIndex =
156 Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);
157 symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);
158 StringRef IndirectSymbolName;
159 SI->getName(IndirectSymbolName);
160 DEBUG(dbgs() << " " << IndirectSymbolName << ": index " << SymbolIndex
161 << ", PT offset: " << PTEntryOffset << "\n");
162 RelocationEntry RE(PTSectionID, PTEntryOffset,
163 MachO::GENERIC_RELOC_VANILLA, 0, false, 2);
164 addRelocationForSymbol(RE, IndirectSymbolName);
165 PTEntryOffset += PTEntrySize;
170 RuntimeDyldMachO::isCompatibleFormat(const ObjectBuffer *InputBuffer) const {
171 if (InputBuffer->getBufferSize() < 4)
173 StringRef Magic(InputBuffer->getBufferStart(), 4);
174 if (Magic == "\xFE\xED\xFA\xCE")
176 if (Magic == "\xCE\xFA\xED\xFE")
178 if (Magic == "\xFE\xED\xFA\xCF")
180 if (Magic == "\xCF\xFA\xED\xFE")
185 bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile *Obj) const {
186 return Obj->isMachO();
189 template <typename Impl>
190 void RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(ObjectImage &ObjImg,
191 ObjSectionToIDMap &SectionMap) {
192 unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
193 unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
194 unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
195 ObjSectionToIDMap::iterator i, e;
197 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
198 const SectionRef &Section = i->first;
200 Section.getName(Name);
201 if (Name == "__eh_frame")
202 EHFrameSID = i->second;
203 else if (Name == "__text")
205 else if (Name == "__gcc_except_tab")
206 ExceptTabSID = i->second;
208 impl().finalizeSection(ObjImg, i->second, Section);
210 UnregisteredEHFrameSections.push_back(
211 EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
214 template <typename Impl>
215 unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(unsigned char *P,
216 int64_t DeltaForText,
217 int64_t DeltaForEH) {
218 typedef typename Impl::TargetPtrT TargetPtrT;
220 DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
221 << ", Delta for EH: " << DeltaForEH << "\n");
222 uint32_t Length = *((uint32_t *)P);
224 unsigned char *Ret = P + Length;
225 uint32_t Offset = *((uint32_t *)P);
226 if (Offset == 0) // is a CIE
230 TargetPtrT FDELocation = *((TargetPtrT*)P);
231 TargetPtrT NewLocation = FDELocation - DeltaForText;
232 *((TargetPtrT*)P) = NewLocation;
233 P += sizeof(TargetPtrT);
235 // Skip the FDE address range
236 P += sizeof(TargetPtrT);
238 uint8_t Augmentationsize = *P;
240 if (Augmentationsize != 0) {
241 TargetPtrT LSDA = *((TargetPtrT *)P);
242 TargetPtrT NewLSDA = LSDA - DeltaForEH;
243 *((TargetPtrT *)P) = NewLSDA;
249 static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {
250 int64_t ObjDistance = A->ObjAddress - B->ObjAddress;
251 int64_t MemDistance = A->LoadAddress - B->LoadAddress;
252 return ObjDistance - MemDistance;
255 template <typename Impl>
256 void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
260 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
261 EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
262 if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
263 SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)
265 SectionEntry *Text = &Sections[SectionInfo.TextSID];
266 SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];
267 SectionEntry *ExceptTab = nullptr;
268 if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
269 ExceptTab = &Sections[SectionInfo.ExceptTabSID];
271 int64_t DeltaForText = computeDelta(Text, EHFrame);
272 int64_t DeltaForEH = 0;
274 DeltaForEH = computeDelta(ExceptTab, EHFrame);
276 unsigned char *P = EHFrame->Address;
277 unsigned char *End = P + EHFrame->Size;
279 P = processFDE(P, DeltaForText, DeltaForEH);
282 MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
285 UnregisteredEHFrameSections.clear();
288 std::unique_ptr<RuntimeDyldMachO>
289 llvm::RuntimeDyldMachO::create(Triple::ArchType Arch, RTDyldMemoryManager *MM) {
292 llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
294 case Triple::arm: return make_unique<RuntimeDyldMachOARM>(MM);
295 case Triple::aarch64: return make_unique<RuntimeDyldMachOAArch64>(MM);
296 case Triple::x86: return make_unique<RuntimeDyldMachOI386>(MM);
297 case Triple::x86_64: return make_unique<RuntimeDyldMachOX86_64>(MM);
301 } // end namespace llvm