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::isCompatibleFormat(const ObjectBuffer *InputBuffer) const {
113 if (InputBuffer->getBufferSize() < 4)
115 StringRef Magic(InputBuffer->getBufferStart(), 4);
116 if (Magic == "\xFE\xED\xFA\xCE")
118 if (Magic == "\xCE\xFA\xED\xFE")
120 if (Magic == "\xFE\xED\xFA\xCF")
122 if (Magic == "\xCF\xFA\xED\xFE")
127 bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile *Obj) const {
128 return Obj->isMachO();
131 template <typename Impl>
132 void RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(ObjectImage &ObjImg,
133 ObjSectionToIDMap &SectionMap) {
134 unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;
135 unsigned TextSID = RTDYLD_INVALID_SECTION_ID;
136 unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;
137 ObjSectionToIDMap::iterator i, e;
139 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
140 const SectionRef &Section = i->first;
142 Section.getName(Name);
143 if (Name == "__eh_frame")
144 EHFrameSID = i->second;
145 else if (Name == "__text")
147 else if (Name == "__gcc_except_tab")
148 ExceptTabSID = i->second;
150 impl().finalizeSection(ObjImg, i->second, Section);
152 UnregisteredEHFrameSections.push_back(
153 EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));
156 template <typename Impl>
157 unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(unsigned char *P,
158 int64_t DeltaForText,
159 int64_t DeltaForEH) {
160 typedef typename Impl::TargetPtrT TargetPtrT;
162 DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
163 << ", Delta for EH: " << DeltaForEH << "\n");
164 uint32_t Length = *((uint32_t *)P);
166 unsigned char *Ret = P + Length;
167 uint32_t Offset = *((uint32_t *)P);
168 if (Offset == 0) // is a CIE
172 TargetPtrT FDELocation = *((TargetPtrT*)P);
173 TargetPtrT NewLocation = FDELocation - DeltaForText;
174 *((TargetPtrT*)P) = NewLocation;
175 P += sizeof(TargetPtrT);
177 // Skip the FDE address range
178 P += sizeof(TargetPtrT);
180 uint8_t Augmentationsize = *P;
182 if (Augmentationsize != 0) {
183 TargetPtrT LSDA = *((TargetPtrT *)P);
184 TargetPtrT NewLSDA = LSDA - DeltaForEH;
185 *((TargetPtrT *)P) = NewLSDA;
191 static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {
192 int64_t ObjDistance = A->ObjAddress - B->ObjAddress;
193 int64_t MemDistance = A->LoadAddress - B->LoadAddress;
194 return ObjDistance - MemDistance;
197 template <typename Impl>
198 void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {
202 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
203 EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
204 if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
205 SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)
207 SectionEntry *Text = &Sections[SectionInfo.TextSID];
208 SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];
209 SectionEntry *ExceptTab = nullptr;
210 if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
211 ExceptTab = &Sections[SectionInfo.ExceptTabSID];
213 int64_t DeltaForText = computeDelta(Text, EHFrame);
214 int64_t DeltaForEH = 0;
216 DeltaForEH = computeDelta(ExceptTab, EHFrame);
218 unsigned char *P = EHFrame->Address;
219 unsigned char *End = P + EHFrame->Size;
221 P = processFDE(P, DeltaForText, DeltaForEH);
224 MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
227 UnregisteredEHFrameSections.clear();
230 std::unique_ptr<RuntimeDyldMachO>
231 llvm::RuntimeDyldMachO::create(Triple::ArchType Arch, RTDyldMemoryManager *MM) {
234 llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
236 case Triple::arm: return make_unique<RuntimeDyldMachOARM>(MM);
237 case Triple::aarch64: return make_unique<RuntimeDyldMachOAArch64>(MM);
238 case Triple::x86: return make_unique<RuntimeDyldMachOI386>(MM);
239 case Triple::x86_64: return make_unique<RuntimeDyldMachOX86_64>(MM);
243 } // end namespace llvm