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.Addend = SI->second.second + RE.Addend;
58 SI = GlobalSymbolTable.find(TargetName.data());
59 if (SI != GlobalSymbolTable.end()) {
60 Value.SectionID = SI->second.first;
61 Value.Addend = SI->second.second + RE.Addend;
63 Value.SymbolName = TargetName.data();
64 Value.Addend = RE.Addend;
68 SectionRef Sec = Obj.getRelocationSection(RelInfo);
71 Value.SectionID = findOrEmitSection(ObjImg, Sec, IsCode, ObjSectionToID);
74 Value.Addend = 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.Addend += 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 static unsigned char *processFDE(unsigned char *P, intptr_t DeltaForText,
132 intptr_t DeltaForEH) {
133 DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText
134 << ", Delta for EH: " << DeltaForEH << "\n");
135 uint32_t Length = *((uint32_t *)P);
137 unsigned char *Ret = P + Length;
138 uint32_t Offset = *((uint32_t *)P);
139 if (Offset == 0) // is a CIE
143 intptr_t FDELocation = *((intptr_t *)P);
144 intptr_t NewLocation = FDELocation - DeltaForText;
145 *((intptr_t *)P) = NewLocation;
146 P += sizeof(intptr_t);
148 // Skip the FDE address range
149 P += sizeof(intptr_t);
151 uint8_t Augmentationsize = *P;
153 if (Augmentationsize != 0) {
154 intptr_t LSDA = *((intptr_t *)P);
155 intptr_t NewLSDA = LSDA - DeltaForEH;
156 *((intptr_t *)P) = NewLSDA;
162 static intptr_t computeDelta(SectionEntry *A, SectionEntry *B) {
163 intptr_t ObjDistance = A->ObjAddress - B->ObjAddress;
164 intptr_t MemDistance = A->LoadAddress - B->LoadAddress;
165 return ObjDistance - MemDistance;
168 void RuntimeDyldMachO::registerEHFrames() {
172 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
173 EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];
174 if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||
175 SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)
177 SectionEntry *Text = &Sections[SectionInfo.TextSID];
178 SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];
179 SectionEntry *ExceptTab = nullptr;
180 if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)
181 ExceptTab = &Sections[SectionInfo.ExceptTabSID];
183 intptr_t DeltaForText = computeDelta(Text, EHFrame);
184 intptr_t DeltaForEH = 0;
186 DeltaForEH = computeDelta(ExceptTab, EHFrame);
188 unsigned char *P = EHFrame->Address;
189 unsigned char *End = P + EHFrame->Size;
191 P = processFDE(P, DeltaForText, DeltaForEH);
194 MemMgr->registerEHFrames(EHFrame->Address, EHFrame->LoadAddress,
197 UnregisteredEHFrameSections.clear();
200 std::unique_ptr<RuntimeDyldMachO>
201 llvm::RuntimeDyldMachO::create(Triple::ArchType Arch, RTDyldMemoryManager *MM) {
204 llvm_unreachable("Unsupported target for RuntimeDyldMachO.");
206 case Triple::arm: return make_unique<RuntimeDyldMachOARM>(MM);
207 case Triple::aarch64: return make_unique<RuntimeDyldMachOAArch64>(MM);
208 case Triple::x86: return make_unique<RuntimeDyldMachOI386>(MM);
209 case Triple::x86_64: return make_unique<RuntimeDyldMachOX86_64>(MM);
213 } // end namespace llvm