llvm/lib/ExecutionEngine/JITLink/MachO_x86_64.cpp

   1 //===---- MachO_x86_64.cpp -JIT linker implementation for MachO/x86-64 ----===//
   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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // MachO/x86-64 jit-link implementation.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h"
  14 #include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
  15 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
  16
  17 #include "DefineExternalSectionStartAndEndSymbols.h"
  18 #include "MachOLinkGraphBuilder.h"
  19
  20 #define DEBUG_TYPE "jitlink"
  21
  22 using namespace llvm;
  23 using namespace llvm::jitlink;
  24
  25 namespace {
  26
  27 class MachOLinkGraphBuilder_x86_64 : public MachOLinkGraphBuilder {
  28 public:
  29   MachOLinkGraphBuilder_x86_64(const object::MachOObjectFile &Obj,
  30                                SubtargetFeatures Features)
  31       : MachOLinkGraphBuilder(Obj, Triple("x86_64-apple-darwin"),
  32                               std::move(Features), x86_64::getEdgeKindName) {}
  33
  34 private:
  35   enum MachONormalizedRelocationType : unsigned {
  36     MachOBranch32,
  37     MachOPointer32,
  38     MachOPointer64,
  39     MachOPointer64Anon,
  40     MachOPCRel32,
  41     MachOPCRel32Minus1,
  42     MachOPCRel32Minus2,
  43     MachOPCRel32Minus4,
  44     MachOPCRel32Anon,
  45     MachOPCRel32Minus1Anon,
  46     MachOPCRel32Minus2Anon,
  47     MachOPCRel32Minus4Anon,
  48     MachOPCRel32GOTLoad,
  49     MachOPCRel32GOT,
  50     MachOPCRel32TLV,
  51     MachOSubtractor32,
  52     MachOSubtractor64,
  53   };
  54
  55   static Expected<MachONormalizedRelocationType>
  56   getRelocKind(const MachO::relocation_info &RI) {
  57     switch (RI.r_type) {
  58     case MachO::X86_64_RELOC_UNSIGNED:
  59       if (!RI.r_pcrel) {
  60         if (RI.r_length == 3)
  61           return RI.r_extern ? MachOPointer64 : MachOPointer64Anon;
  62         else if (RI.r_extern && RI.r_length == 2)
  63           return MachOPointer32;
  64       }
  65       break;
  66     case MachO::X86_64_RELOC_SIGNED:
  67       if (RI.r_pcrel && RI.r_length == 2)
  68         return RI.r_extern ? MachOPCRel32 : MachOPCRel32Anon;
  69       break;
  70     case MachO::X86_64_RELOC_BRANCH:
  71       if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
  72         return MachOBranch32;
  73       break;
  74     case MachO::X86_64_RELOC_GOT_LOAD:
  75       if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
  76         return MachOPCRel32GOTLoad;
  77       break;
  78     case MachO::X86_64_RELOC_GOT:
  79       if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
  80         return MachOPCRel32GOT;
  81       break;
  82     case MachO::X86_64_RELOC_SUBTRACTOR:
  83       if (!RI.r_pcrel && RI.r_extern) {
  84         if (RI.r_length == 2)
  85           return MachOSubtractor32;
  86         else if (RI.r_length == 3)
  87           return MachOSubtractor64;
  88       }
  89       break;
  90     case MachO::X86_64_RELOC_SIGNED_1:
  91       if (RI.r_pcrel && RI.r_length == 2)
  92         return RI.r_extern ? MachOPCRel32Minus1 : MachOPCRel32Minus1Anon;
  93       break;
  94     case MachO::X86_64_RELOC_SIGNED_2:
  95       if (RI.r_pcrel && RI.r_length == 2)
  96         return RI.r_extern ? MachOPCRel32Minus2 : MachOPCRel32Minus2Anon;
  97       break;
  98     case MachO::X86_64_RELOC_SIGNED_4:
  99       if (RI.r_pcrel && RI.r_length == 2)
 100         return RI.r_extern ? MachOPCRel32Minus4 : MachOPCRel32Minus4Anon;
 101       break;
 102     case MachO::X86_64_RELOC_TLV:
 103       if (RI.r_pcrel && RI.r_extern && RI.r_length == 2)
 104         return MachOPCRel32TLV;
 105       break;
 106     }
 107
 108     return make_error<JITLinkError>(
 109         "Unsupported x86-64 relocation: address=" +
 110         formatv("{0:x8}", RI.r_address) +
 111         ", symbolnum=" + formatv("{0:x6}", RI.r_symbolnum) +
 112         ", kind=" + formatv("{0:x1}", RI.r_type) +
 113         ", pc_rel=" + (RI.r_pcrel ? "true" : "false") +
 114         ", extern=" + (RI.r_extern ? "true" : "false") +
 115         ", length=" + formatv("{0:d}", RI.r_length));
 116   }
 117
 118   using PairRelocInfo = std::tuple<Edge::Kind, Symbol *, uint64_t>;
 119
 120   // Parses paired SUBTRACTOR/UNSIGNED relocations and, on success,
 121   // returns the edge kind and addend to be used.
 122   Expected<PairRelocInfo> parsePairRelocation(
 123       Block &BlockToFix, MachONormalizedRelocationType SubtractorKind,
 124       const MachO::relocation_info &SubRI, orc::ExecutorAddr FixupAddress,
 125       const char *FixupContent, object::relocation_iterator &UnsignedRelItr,
 126       object::relocation_iterator &RelEnd) {
 127     using namespace support;
 128
 129     assert(((SubtractorKind == MachOSubtractor32 && SubRI.r_length == 2) ||
 130             (SubtractorKind == MachOSubtractor64 && SubRI.r_length == 3)) &&
 131            "Subtractor kind should match length");
 132     assert(SubRI.r_extern && "SUBTRACTOR reloc symbol should be extern");
 133     assert(!SubRI.r_pcrel && "SUBTRACTOR reloc should not be PCRel");
 134
 135     if (UnsignedRelItr == RelEnd)
 136       return make_error<JITLinkError>("x86_64 SUBTRACTOR without paired "
 137                                       "UNSIGNED relocation");
 138
 139     auto UnsignedRI = getRelocationInfo(UnsignedRelItr);
 140
 141     if (SubRI.r_address != UnsignedRI.r_address)
 142       return make_error<JITLinkError>("x86_64 SUBTRACTOR and paired UNSIGNED "
 143                                       "point to different addresses");
 144
 145     if (SubRI.r_length != UnsignedRI.r_length)
 146       return make_error<JITLinkError>("length of x86_64 SUBTRACTOR and paired "
 147                                       "UNSIGNED reloc must match");
 148
 149     Symbol *FromSymbol;
 150     if (auto FromSymbolOrErr = findSymbolByIndex(SubRI.r_symbolnum))
 151       FromSymbol = FromSymbolOrErr->GraphSymbol;
 152     else
 153       return FromSymbolOrErr.takeError();
 154
 155     // Read the current fixup value.
 156     uint64_t FixupValue = 0;
 157     if (SubRI.r_length == 3)
 158       FixupValue = *(const little64_t *)FixupContent;
 159     else
 160       FixupValue = *(const little32_t *)FixupContent;
 161
 162     // Find 'ToSymbol' using symbol number or address, depending on whether the
 163     // paired UNSIGNED relocation is extern.
 164     Symbol *ToSymbol = nullptr;
 165     if (UnsignedRI.r_extern) {
 166       // Find target symbol by symbol index.
 167       if (auto ToSymbolOrErr = findSymbolByIndex(UnsignedRI.r_symbolnum))
 168         ToSymbol = ToSymbolOrErr->GraphSymbol;
 169       else
 170         return ToSymbolOrErr.takeError();
 171     } else {
 172       auto ToSymbolSec = findSectionByIndex(UnsignedRI.r_symbolnum - 1);
 173       if (!ToSymbolSec)
 174         return ToSymbolSec.takeError();
 175       ToSymbol = getSymbolByAddress(*ToSymbolSec, ToSymbolSec->Address);
 176       assert(ToSymbol && "No symbol for section");
 177       FixupValue -= ToSymbol->getAddress().getValue();
 178     }
 179
 180     Edge::Kind DeltaKind;
 181     Symbol *TargetSymbol;
 182     uint64_t Addend;
 183
 184     bool FixingFromSymbol = true;
 185     if (&BlockToFix == &FromSymbol->getAddressable()) {
 186       if (LLVM_UNLIKELY(&BlockToFix == &ToSymbol->getAddressable())) {
 187         // From and To are symbols in the same block. Decide direction by offset
 188         // instead.
 189         if (ToSymbol->getAddress() > FixupAddress)
 190           FixingFromSymbol = true;
 191         else if (FromSymbol->getAddress() > FixupAddress)
 192           FixingFromSymbol = false;
 193         else
 194           FixingFromSymbol = FromSymbol->getAddress() >= ToSymbol->getAddress();
 195       } else
 196         FixingFromSymbol = true;
 197     } else {
 198       if (&BlockToFix == &ToSymbol->getAddressable())
 199         FixingFromSymbol = false;
 200       else {
 201         // BlockToFix was neither FromSymbol nor ToSymbol.
 202         return make_error<JITLinkError>("SUBTRACTOR relocation must fix up "
 203                                         "either 'A' or 'B' (or a symbol in one "
 204                                         "of their alt-entry groups)");
 205       }
 206     }
 207
 208     if (FixingFromSymbol) {
 209       TargetSymbol = ToSymbol;
 210       DeltaKind = (SubRI.r_length == 3) ? x86_64::Delta64 : x86_64::Delta32;
 211       Addend = FixupValue + (FixupAddress - FromSymbol->getAddress());
 212       // FIXME: handle extern 'from'.
 213     } else {
 214       TargetSymbol = FromSymbol;
 215       DeltaKind =
 216           (SubRI.r_length == 3) ? x86_64::NegDelta64 : x86_64::NegDelta32;
 217       Addend = FixupValue - (FixupAddress - ToSymbol->getAddress());
 218     }
 219
 220     return PairRelocInfo(DeltaKind, TargetSymbol, Addend);
 221   }
 222
 223   Error addRelocations() override {
 224     using namespace support;
 225     auto &Obj = getObject();
 226
 227     LLVM_DEBUG(dbgs() << "Processing relocations:\n");
 228
 229     for (const auto &S : Obj.sections()) {
 230
 231       orc::ExecutorAddr SectionAddress(S.getAddress());
 232
 233       // Skip relocations virtual sections.
 234       if (S.isVirtual()) {
 235         if (S.relocation_begin() != S.relocation_end())
 236           return make_error<JITLinkError>("Virtual section contains "
 237                                           "relocations");
 238         continue;
 239       }
 240
 241       auto NSec =
 242           findSectionByIndex(Obj.getSectionIndex(S.getRawDataRefImpl()));
 243       if (!NSec)
 244         return NSec.takeError();
 245
 246       // Skip relocations for MachO sections without corresponding graph
 247       // sections.
 248       {
 249         if (!NSec->GraphSection) {
 250           LLVM_DEBUG({
 251             dbgs() << "  Skipping relocations for MachO section "
 252                    << NSec->SegName << "/" << NSec->SectName
 253                    << " which has no associated graph section\n";
 254           });
 255           continue;
 256         }
 257       }
 258
 259       // Add relocations for section.
 260       for (auto RelItr = S.relocation_begin(), RelEnd = S.relocation_end();
 261            RelItr != RelEnd; ++RelItr) {
 262
 263         MachO::relocation_info RI = getRelocationInfo(RelItr);
 264
 265         // Find the address of the value to fix up.
 266         auto FixupAddress = SectionAddress + (uint32_t)RI.r_address;
 267
 268         LLVM_DEBUG({
 269           dbgs() << "  " << NSec->SectName << " + "
 270                  << formatv("{0:x8}", RI.r_address) << ":\n";
 271         });
 272
 273         // Find the block that the fixup points to.
 274         Block *BlockToFix = nullptr;
 275         {
 276           auto SymbolToFixOrErr = findSymbolByAddress(*NSec, FixupAddress);
 277           if (!SymbolToFixOrErr)
 278             return SymbolToFixOrErr.takeError();
 279           BlockToFix = &SymbolToFixOrErr->getBlock();
 280         }
 281
 282         if (FixupAddress + orc::ExecutorAddrDiff(1ULL << RI.r_length) >
 283             BlockToFix->getAddress() + BlockToFix->getContent().size())
 284           return make_error<JITLinkError>(
 285               "Relocation extends past end of fixup block");
 286
 287         // Get a pointer to the fixup content.
 288         const char *FixupContent = BlockToFix->getContent().data() +
 289                                    (FixupAddress - BlockToFix->getAddress());
 290
 291         size_t FixupOffset = FixupAddress - BlockToFix->getAddress();
 292
 293         // The target symbol and addend will be populated by the switch below.
 294         Symbol *TargetSymbol = nullptr;
 295         uint64_t Addend = 0;
 296
 297         // Validate the relocation kind.
 298         auto MachORelocKind = getRelocKind(RI);
 299         if (!MachORelocKind)
 300           return MachORelocKind.takeError();
 301
 302         Edge::Kind Kind = Edge::Invalid;
 303
 304         switch (*MachORelocKind) {
 305         case MachOBranch32:
 306           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 307             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 308           else
 309             return TargetSymbolOrErr.takeError();
 310           Addend = *(const little32_t *)FixupContent;
 311           Kind = x86_64::BranchPCRel32;
 312           break;
 313         case MachOPCRel32:
 314           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 315             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 316           else
 317             return TargetSymbolOrErr.takeError();
 318           Addend = *(const little32_t *)FixupContent - 4;
 319           Kind = x86_64::Delta32;
 320           break;
 321         case MachOPCRel32GOTLoad:
 322           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 323             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 324           else
 325             return TargetSymbolOrErr.takeError();
 326           Addend = *(const little32_t *)FixupContent;
 327           Kind = x86_64::RequestGOTAndTransformToPCRel32GOTLoadREXRelaxable;
 328           if (FixupOffset < 3)
 329             return make_error<JITLinkError>("GOTLD at invalid offset " +
 330                                             formatv("{0}", FixupOffset));
 331           break;
 332         case MachOPCRel32GOT:
 333           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 334             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 335           else
 336             return TargetSymbolOrErr.takeError();
 337           Addend = *(const little32_t *)FixupContent - 4;
 338           Kind = x86_64::RequestGOTAndTransformToDelta32;
 339           break;
 340         case MachOPCRel32TLV:
 341           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 342             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 343           else
 344             return TargetSymbolOrErr.takeError();
 345           Addend = *(const little32_t *)FixupContent;
 346           Kind = x86_64::RequestTLVPAndTransformToPCRel32TLVPLoadREXRelaxable;
 347           if (FixupOffset < 3)
 348             return make_error<JITLinkError>("TLV at invalid offset " +
 349                                             formatv("{0}", FixupOffset));
 350           break;
 351         case MachOPointer32:
 352           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 353             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 354           else
 355             return TargetSymbolOrErr.takeError();
 356           Addend = *(const ulittle32_t *)FixupContent;
 357           Kind = x86_64::Pointer32;
 358           break;
 359         case MachOPointer64:
 360           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 361             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 362           else
 363             return TargetSymbolOrErr.takeError();
 364           Addend = *(const ulittle64_t *)FixupContent;
 365           Kind = x86_64::Pointer64;
 366           break;
 367         case MachOPointer64Anon: {
 368           orc::ExecutorAddr TargetAddress(*(const ulittle64_t *)FixupContent);
 369           auto TargetNSec = findSectionByIndex(RI.r_symbolnum - 1);
 370           if (!TargetNSec)
 371             return TargetNSec.takeError();
 372           if (auto TargetSymbolOrErr =
 373                   findSymbolByAddress(*TargetNSec, TargetAddress))
 374             TargetSymbol = &*TargetSymbolOrErr;
 375           else
 376             return TargetSymbolOrErr.takeError();
 377           Addend = TargetAddress - TargetSymbol->getAddress();
 378           Kind = x86_64::Pointer64;
 379           break;
 380         }
 381         case MachOPCRel32Minus1:
 382         case MachOPCRel32Minus2:
 383         case MachOPCRel32Minus4:
 384           if (auto TargetSymbolOrErr = findSymbolByIndex(RI.r_symbolnum))
 385             TargetSymbol = TargetSymbolOrErr->GraphSymbol;
 386           else
 387             return TargetSymbolOrErr.takeError();
 388           Addend = *(const little32_t *)FixupContent - 4;
 389           Kind = x86_64::Delta32;
 390           break;
 391         case MachOPCRel32Anon: {
 392           orc::ExecutorAddr TargetAddress(FixupAddress + 4 +
 393                                           *(const little32_t *)FixupContent);
 394           auto TargetNSec = findSectionByIndex(RI.r_symbolnum - 1);
 395           if (!TargetNSec)
 396             return TargetNSec.takeError();
 397           if (auto TargetSymbolOrErr =
 398                   findSymbolByAddress(*TargetNSec, TargetAddress))
 399             TargetSymbol = &*TargetSymbolOrErr;
 400           else
 401             return TargetSymbolOrErr.takeError();
 402           Addend = TargetAddress - TargetSymbol->getAddress() - 4;
 403           Kind = x86_64::Delta32;
 404           break;
 405         }
 406         case MachOPCRel32Minus1Anon:
 407         case MachOPCRel32Minus2Anon:
 408         case MachOPCRel32Minus4Anon: {
 409           orc::ExecutorAddrDiff Delta =
 410               4 + orc::ExecutorAddrDiff(
 411                       1ULL << (*MachORelocKind - MachOPCRel32Minus1Anon));
 412           orc::ExecutorAddr TargetAddress =
 413               FixupAddress + Delta + *(const little32_t *)FixupContent;
 414           auto TargetNSec = findSectionByIndex(RI.r_symbolnum - 1);
 415           if (!TargetNSec)
 416             return TargetNSec.takeError();
 417           if (auto TargetSymbolOrErr =
 418                   findSymbolByAddress(*TargetNSec, TargetAddress))
 419             TargetSymbol = &*TargetSymbolOrErr;
 420           else
 421             return TargetSymbolOrErr.takeError();
 422           Addend = TargetAddress - TargetSymbol->getAddress() - Delta;
 423           Kind = x86_64::Delta32;
 424           break;
 425         }
 426         case MachOSubtractor32:
 427         case MachOSubtractor64: {
 428           // We use Delta32/Delta64 to represent SUBTRACTOR relocations.
 429           // parsePairRelocation handles the paired reloc, and returns the
 430           // edge kind to be used (either Delta32/Delta64, or
 431           // NegDelta32/NegDelta64, depending on the direction of the
 432           // subtraction) along with the addend.
 433           auto PairInfo =
 434               parsePairRelocation(*BlockToFix, *MachORelocKind, RI,
 435                                   FixupAddress, FixupContent, ++RelItr, RelEnd);
 436           if (!PairInfo)
 437             return PairInfo.takeError();
 438           std::tie(Kind, TargetSymbol, Addend) = *PairInfo;
 439           assert(TargetSymbol && "No target symbol from parsePairRelocation?");
 440           break;
 441         }
 442         }
 443
 444         LLVM_DEBUG({
 445           dbgs() << "    ";
 446           Edge GE(Kind, FixupAddress - BlockToFix->getAddress(), *TargetSymbol,
 447                   Addend);
 448           printEdge(dbgs(), *BlockToFix, GE, x86_64::getEdgeKindName(Kind));
 449           dbgs() << "\n";
 450         });
 451         BlockToFix->addEdge(Kind, FixupAddress - BlockToFix->getAddress(),
 452                             *TargetSymbol, Addend);
 453       }
 454     }
 455     return Error::success();
 456   }
 457 };
 458
 459 Error buildGOTAndStubs_MachO_x86_64(LinkGraph &G) {
 460   x86_64::GOTTableManager GOT;
 461   x86_64::PLTTableManager PLT(GOT);
 462   visitExistingEdges(G, GOT, PLT);
 463   return Error::success();
 464 }
 465
 466 } // namespace
 467
 468 namespace llvm {
 469 namespace jitlink {
 470
 471 class MachOJITLinker_x86_64 : public JITLinker<MachOJITLinker_x86_64> {
 472   friend class JITLinker<MachOJITLinker_x86_64>;
 473
 474 public:
 475   MachOJITLinker_x86_64(std::unique_ptr<JITLinkContext> Ctx,
 476                         std::unique_ptr<LinkGraph> G,
 477                         PassConfiguration PassConfig)
 478       : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {}
 479
 480 private:
 481   Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const {
 482     return x86_64::applyFixup(G, B, E, nullptr);
 483   }
 484 };
 485
 486 Expected<std::unique_ptr<LinkGraph>>
 487 createLinkGraphFromMachOObject_x86_64(MemoryBufferRef ObjectBuffer) {
 488   auto MachOObj = object::ObjectFile::createMachOObjectFile(ObjectBuffer);
 489   if (!MachOObj)
 490     return MachOObj.takeError();
 491
 492   auto Features = (*MachOObj)->getFeatures();
 493   if (!Features)
 494     return Features.takeError();
 495
 496   return MachOLinkGraphBuilder_x86_64(**MachOObj, std::move(*Features))
 497       .buildGraph();
 498 }
 499
 500 void link_MachO_x86_64(std::unique_ptr<LinkGraph> G,
 501                        std::unique_ptr<JITLinkContext> Ctx) {
 502
 503   PassConfiguration Config;
 504
 505   if (Ctx->shouldAddDefaultTargetPasses(G->getTargetTriple())) {
 506     // Add eh-frame passes.
 507     Config.PrePrunePasses.push_back(createEHFrameSplitterPass_MachO_x86_64());
 508     Config.PrePrunePasses.push_back(createEHFrameEdgeFixerPass_MachO_x86_64());
 509
 510     // Add compact unwind splitter pass.
 511     Config.PrePrunePasses.push_back(
 512         CompactUnwindSplitter("__LD,__compact_unwind"));
 513
 514     // Add a mark-live pass.
 515     if (auto MarkLive = Ctx->getMarkLivePass(G->getTargetTriple()))
 516       Config.PrePrunePasses.push_back(std::move(MarkLive));
 517     else
 518       Config.PrePrunePasses.push_back(markAllSymbolsLive);
 519
 520     // Resolve any external section start / end symbols.
 521     Config.PostAllocationPasses.push_back(
 522         createDefineExternalSectionStartAndEndSymbolsPass(
 523             identifyMachOSectionStartAndEndSymbols));
 524
 525     // Add an in-place GOT/Stubs pass.
 526     Config.PostPrunePasses.push_back(buildGOTAndStubs_MachO_x86_64);
 527
 528     // Add GOT/Stubs optimizer pass.
 529     Config.PreFixupPasses.push_back(x86_64::optimizeGOTAndStubAccesses);
 530   }
 531
 532   if (auto Err = Ctx->modifyPassConfig(*G, Config))
 533     return Ctx->notifyFailed(std::move(Err));
 534
 535   // Construct a JITLinker and run the link function.
 536   MachOJITLinker_x86_64::link(std::move(Ctx), std::move(G), std::move(Config));
 537 }
 538
 539 LinkGraphPassFunction createEHFrameSplitterPass_MachO_x86_64() {
 540   return DWARFRecordSectionSplitter("__TEXT,__eh_frame");
 541 }
 542
 543 LinkGraphPassFunction createEHFrameEdgeFixerPass_MachO_x86_64() {
 544   return EHFrameEdgeFixer("__TEXT,__eh_frame", x86_64::PointerSize,
 545                           x86_64::Pointer32, x86_64::Pointer64, x86_64::Delta32,
 546                           x86_64::Delta64, x86_64::NegDelta32);
 547 }
 548
 549 } // end namespace jitlink
 550 } // end namespace llvm