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