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1//===-- RuntimeDyldMachOX86_64.h ---- MachO/X86_64 specific code. -*- C++ -*-=//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOX86_64_H10#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOX86_64_H11 12#include "../RuntimeDyldMachO.h"13 14#define DEBUG_TYPE "dyld"15 16namespace llvm {17 18class RuntimeDyldMachOX86_6419 : public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOX86_64> {20public:21 22 typedef uint64_t TargetPtrT;23 24 RuntimeDyldMachOX86_64(RuntimeDyld::MemoryManager &MM,25 JITSymbolResolver &Resolver)26 : RuntimeDyldMachOCRTPBase(MM, Resolver) {}27 28 unsigned getMaxStubSize() const override { return 8; }29 30 Align getStubAlignment() override { return Align(8); }31 32 Expected<relocation_iterator>33 processRelocationRef(unsigned SectionID, relocation_iterator RelI,34 const ObjectFile &BaseObjT,35 ObjSectionToIDMap &ObjSectionToID,36 StubMap &Stubs) override {37 const MachOObjectFile &Obj =38 static_cast<const MachOObjectFile &>(BaseObjT);39 MachO::any_relocation_info RelInfo =40 Obj.getRelocation(RelI->getRawDataRefImpl());41 uint32_t RelType = Obj.getAnyRelocationType(RelInfo);42 43 if (RelType == MachO::X86_64_RELOC_SUBTRACTOR)44 return processSubtractRelocation(SectionID, RelI, Obj, ObjSectionToID);45 46 assert(!Obj.isRelocationScattered(RelInfo) &&47 "Scattered relocations not supported on X86_64");48 49 RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));50 RE.Addend = memcpyAddend(RE);51 RelocationValueRef Value;52 if (auto ValueOrErr = getRelocationValueRef(Obj, RelI, RE, ObjSectionToID))53 Value = *ValueOrErr;54 else55 return ValueOrErr.takeError();56 57 bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);58 if (!IsExtern && RE.IsPCRel)59 makeValueAddendPCRel(Value, RelI, 1 << RE.Size);60 61 switch (RelType) {62 UNIMPLEMENTED_RELOC(MachO::X86_64_RELOC_TLV);63 default:64 if (RelType > MachO::X86_64_RELOC_TLV)65 return make_error<RuntimeDyldError>(("MachO X86_64 relocation type " +66 Twine(RelType) +67 " is out of range").str());68 break;69 }70 71 if (RE.RelType == MachO::X86_64_RELOC_GOT ||72 RE.RelType == MachO::X86_64_RELOC_GOT_LOAD)73 processGOTRelocation(RE, Value, Stubs);74 else {75 RE.Addend = Value.Offset;76 if (Value.SymbolName)77 addRelocationForSymbol(RE, Value.SymbolName);78 else79 addRelocationForSection(RE, Value.SectionID);80 }81 82 return ++RelI;83 }84 85 void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {86 LLVM_DEBUG(dumpRelocationToResolve(RE, Value));87 const SectionEntry &Section = Sections[RE.SectionID];88 uint8_t *LocalAddress = Section.getAddressWithOffset(RE.Offset);89 90 // If the relocation is PC-relative, the value to be encoded is the91 // pointer difference.92 if (RE.IsPCRel) {93 // FIXME: It seems this value needs to be adjusted by 4 for an effective94 // PC address. Is that expected? Only for branches, perhaps?95 uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset);96 Value -= FinalAddress + 4;97 }98 99 switch (RE.RelType) {100 default:101 llvm_unreachable("Invalid relocation type!");102 case MachO::X86_64_RELOC_SIGNED_1:103 case MachO::X86_64_RELOC_SIGNED_2:104 case MachO::X86_64_RELOC_SIGNED_4:105 case MachO::X86_64_RELOC_SIGNED:106 case MachO::X86_64_RELOC_UNSIGNED:107 case MachO::X86_64_RELOC_BRANCH:108 writeBytesUnaligned(Value + RE.Addend, LocalAddress, 1 << RE.Size);109 break;110 case MachO::X86_64_RELOC_SUBTRACTOR: {111 uint64_t SectionABase = Sections[RE.Sections.SectionA].getLoadAddress();112 uint64_t SectionBBase = Sections[RE.Sections.SectionB].getLoadAddress();113 assert((Value == SectionABase || Value == SectionBBase) &&114 "Unexpected SUBTRACTOR relocation value.");115 Value = SectionABase - SectionBBase + RE.Addend;116 writeBytesUnaligned(Value, LocalAddress, 1 << RE.Size);117 break;118 }119 }120 }121 122 Error finalizeSection(const ObjectFile &Obj, unsigned SectionID,123 const SectionRef &Section) {124 return Error::success();125 }126 127private:128 void processGOTRelocation(const RelocationEntry &RE,129 RelocationValueRef &Value, StubMap &Stubs) {130 SectionEntry &Section = Sections[RE.SectionID];131 assert(RE.IsPCRel);132 assert(RE.Size == 2);133 Value.Offset -= RE.Addend;134 RuntimeDyldMachO::StubMap::const_iterator i = Stubs.find(Value);135 uint8_t *Addr;136 if (i != Stubs.end()) {137 Addr = Section.getAddressWithOffset(i->second);138 } else {139 Stubs[Value] = Section.getStubOffset();140 uint8_t *GOTEntry = Section.getAddressWithOffset(Section.getStubOffset());141 RelocationEntry GOTRE(RE.SectionID, Section.getStubOffset(),142 MachO::X86_64_RELOC_UNSIGNED, Value.Offset, false,143 3);144 if (Value.SymbolName)145 addRelocationForSymbol(GOTRE, Value.SymbolName);146 else147 addRelocationForSection(GOTRE, Value.SectionID);148 Section.advanceStubOffset(8);149 Addr = GOTEntry;150 }151 RelocationEntry TargetRE(RE.SectionID, RE.Offset,152 MachO::X86_64_RELOC_UNSIGNED, RE.Addend, true, 2);153 resolveRelocation(TargetRE, (uint64_t)Addr);154 }155 156 Expected<relocation_iterator>157 processSubtractRelocation(unsigned SectionID, relocation_iterator RelI,158 const MachOObjectFile &BaseObj,159 ObjSectionToIDMap &ObjSectionToID) {160 const MachOObjectFile &Obj = BaseObj;161 MachO::any_relocation_info RE =162 Obj.getRelocation(RelI->getRawDataRefImpl());163 164 unsigned Size = Obj.getAnyRelocationLength(RE);165 uint64_t Offset = RelI->getOffset();166 uint8_t *LocalAddress = Sections[SectionID].getAddressWithOffset(Offset);167 unsigned NumBytes = 1 << Size;168 int64_t Addend =169 SignExtend64(readBytesUnaligned(LocalAddress, NumBytes), NumBytes * 8);170 171 unsigned SectionBID = ~0U;172 uint64_t SectionBOffset = 0;173 174 MachO::any_relocation_info RelInfo =175 Obj.getRelocation(RelI->getRawDataRefImpl());176 177 bool AIsExternal = BaseObj.getPlainRelocationExternal(RelInfo);178 179 if (AIsExternal) {180 Expected<StringRef> SubtrahendNameOrErr = RelI->getSymbol()->getName();181 if (!SubtrahendNameOrErr)182 return SubtrahendNameOrErr.takeError();183 auto SubtrahendI = GlobalSymbolTable.find(*SubtrahendNameOrErr);184 SectionBID = SubtrahendI->second.getSectionID();185 SectionBOffset = SubtrahendI->second.getOffset();186 } else {187 SectionRef SecB = Obj.getAnyRelocationSection(RelInfo);188 bool IsCode = SecB.isText();189 Expected<unsigned> SectionBIDOrErr =190 findOrEmitSection(Obj, SecB, IsCode, ObjSectionToID);191 if (!SectionBIDOrErr)192 return SectionBIDOrErr.takeError();193 SectionBID = *SectionBIDOrErr;194 Addend += SecB.getAddress();195 }196 197 ++RelI;198 199 unsigned SectionAID = ~0U;200 uint64_t SectionAOffset = 0;201 202 RelInfo = Obj.getRelocation(RelI->getRawDataRefImpl());203 204 bool BIsExternal = BaseObj.getPlainRelocationExternal(RelInfo);205 if (BIsExternal) {206 Expected<StringRef> MinuendNameOrErr = RelI->getSymbol()->getName();207 if (!MinuendNameOrErr)208 return MinuendNameOrErr.takeError();209 auto MinuendI = GlobalSymbolTable.find(*MinuendNameOrErr);210 SectionAID = MinuendI->second.getSectionID();211 SectionAOffset = MinuendI->second.getOffset();212 } else {213 SectionRef SecA = Obj.getAnyRelocationSection(RelInfo);214 bool IsCode = SecA.isText();215 Expected<unsigned> SectionAIDOrErr =216 findOrEmitSection(Obj, SecA, IsCode, ObjSectionToID);217 if (!SectionAIDOrErr)218 return SectionAIDOrErr.takeError();219 SectionAID = *SectionAIDOrErr;220 Addend -= SecA.getAddress();221 }222 223 RelocationEntry R(SectionID, Offset, MachO::X86_64_RELOC_SUBTRACTOR, (uint64_t)Addend,224 SectionAID, SectionAOffset, SectionBID, SectionBOffset,225 false, Size);226 227 addRelocationForSection(R, SectionAID);228 229 return ++RelI;230 }231 232};233}234 235#undef DEBUG_TYPE236 237#endif238