lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp

   1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #define DEBUG_TYPE "dyld"
  15 #include "RuntimeDyldELF.h"
  16 #include "JITRegistrar.h"
  17 #include "ObjectImageCommon.h"
  18 #include "llvm/ADT/IntervalMap.h"
  19 #include "llvm/ADT/OwningPtr.h"
  20 #include "llvm/ADT/STLExtras.h"
  21 #include "llvm/ADT/StringRef.h"
  22 #include "llvm/ADT/Triple.h"
  23 #include "llvm/ExecutionEngine/ObjectBuffer.h"
  24 #include "llvm/ExecutionEngine/ObjectImage.h"
  25 #include "llvm/Object/ELF.h"
  26 #include "llvm/Object/ObjectFile.h"
  27 #include "llvm/Support/ELF.h"
  28 using namespace llvm;
  29 using namespace llvm::object;
  30
  31 namespace {
  32
  33 static inline
  34 error_code check(error_code Err) {
  35   if (Err) {
  36     report_fatal_error(Err.message());
  37   }
  38   return Err;
  39 }
  40
  41 template<class ELFT>
  42 class DyldELFObject
  43   : public ELFObjectFile<ELFT> {
  44   LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
  45
  46   typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
  47   typedef Elf_Sym_Impl<ELFT> Elf_Sym;
  48   typedef
  49     Elf_Rel_Impl<ELFT, false> Elf_Rel;
  50   typedef
  51     Elf_Rel_Impl<ELFT, true> Elf_Rela;
  52
  53   typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
  54
  55   typedef typename ELFDataTypeTypedefHelper<
  56           ELFT>::value_type addr_type;
  57
  58 public:
  59   DyldELFObject(MemoryBuffer *Wrapper, error_code &ec);
  60
  61   void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
  62   void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
  63
  64   // Methods for type inquiry through isa, cast and dyn_cast
  65   static inline bool classof(const Binary *v) {
  66     return (isa<ELFObjectFile<ELFT> >(v)
  67             && classof(cast<ELFObjectFile
  68                 <ELFT> >(v)));
  69   }
  70   static inline bool classof(
  71       const ELFObjectFile<ELFT> *v) {
  72     return v->isDyldType();
  73   }
  74 };
  75
  76 template<class ELFT>
  77 class ELFObjectImage : public ObjectImageCommon {
  78   protected:
  79     DyldELFObject<ELFT> *DyldObj;
  80     bool Registered;
  81
  82   public:
  83     ELFObjectImage(ObjectBuffer *Input,
  84                  DyldELFObject<ELFT> *Obj)
  85     : ObjectImageCommon(Input, Obj),
  86       DyldObj(Obj),
  87       Registered(false) {}
  88
  89     virtual ~ELFObjectImage() {
  90       if (Registered)
  91         deregisterWithDebugger();
  92     }
  93
  94     // Subclasses can override these methods to update the image with loaded
  95     // addresses for sections and common symbols
  96     virtual void updateSectionAddress(const SectionRef &Sec, uint64_t Addr)
  97     {
  98       DyldObj->updateSectionAddress(Sec, Addr);
  99     }
 100
 101     virtual void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr)
 102     {
 103       DyldObj->updateSymbolAddress(Sym, Addr);
 104     }
 105
 106     virtual void registerWithDebugger()
 107     {
 108       JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
 109       Registered = true;
 110     }
 111     virtual void deregisterWithDebugger()
 112     {
 113       JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
 114     }
 115 };
 116
 117 // The MemoryBuffer passed into this constructor is just a wrapper around the
 118 // actual memory.  Ultimately, the Binary parent class will take ownership of
 119 // this MemoryBuffer object but not the underlying memory.
 120 template<class ELFT>
 121 DyldELFObject<ELFT>::DyldELFObject(MemoryBuffer *Wrapper, error_code &ec)
 122   : ELFObjectFile<ELFT>(Wrapper, ec) {
 123   this->isDyldELFObject = true;
 124 }
 125
 126 template<class ELFT>
 127 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
 128                                                uint64_t Addr) {
 129   DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
 130   Elf_Shdr *shdr = const_cast<Elf_Shdr*>(
 131                           reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
 132
 133   // This assumes the address passed in matches the target address bitness
 134   // The template-based type cast handles everything else.
 135   shdr->sh_addr = static_cast<addr_type>(Addr);
 136 }
 137
 138 template<class ELFT>
 139 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
 140                                               uint64_t Addr) {
 141
 142   Elf_Sym *sym = const_cast<Elf_Sym*>(
 143     ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
 144
 145   // This assumes the address passed in matches the target address bitness
 146   // The template-based type cast handles everything else.
 147   sym->st_value = static_cast<addr_type>(Addr);
 148 }
 149
 150 } // namespace
 151
 152 namespace llvm {
 153
 154 StringRef RuntimeDyldELF::getEHFrameSection() {
 155   for (int i = 0, e = Sections.size(); i != e; ++i) {
 156     if (Sections[i].Name == ".eh_frame")
 157       return StringRef((const char*)Sections[i].Address, Sections[i].Size);
 158   }
 159   return StringRef();
 160 }
 161
 162 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
 163   if (Buffer->getBufferSize() < ELF::EI_NIDENT)
 164     llvm_unreachable("Unexpected ELF object size");
 165   std::pair<unsigned char, unsigned char> Ident = std::make_pair(
 166                          (uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
 167                          (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
 168   error_code ec;
 169
 170   if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
 171     DyldELFObject<ELFType<support::little, 4, false> > *Obj =
 172       new DyldELFObject<ELFType<support::little, 4, false> >(
 173         Buffer->getMemBuffer(), ec);
 174     return new ELFObjectImage<ELFType<support::little, 4, false> >(Buffer, Obj);
 175   }
 176   else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) {
 177     DyldELFObject<ELFType<support::big, 4, false> > *Obj =
 178       new DyldELFObject<ELFType<support::big, 4, false> >(
 179         Buffer->getMemBuffer(), ec);
 180     return new ELFObjectImage<ELFType<support::big, 4, false> >(Buffer, Obj);
 181   }
 182   else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) {
 183     DyldELFObject<ELFType<support::big, 8, true> > *Obj =
 184       new DyldELFObject<ELFType<support::big, 8, true> >(
 185         Buffer->getMemBuffer(), ec);
 186     return new ELFObjectImage<ELFType<support::big, 8, true> >(Buffer, Obj);
 187   }
 188   else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
 189     DyldELFObject<ELFType<support::little, 8, true> > *Obj =
 190       new DyldELFObject<ELFType<support::little, 8, true> >(
 191         Buffer->getMemBuffer(), ec);
 192     return new ELFObjectImage<ELFType<support::little, 8, true> >(Buffer, Obj);
 193   }
 194   else
 195     llvm_unreachable("Unexpected ELF format");
 196 }
 197
 198 RuntimeDyldELF::~RuntimeDyldELF() {
 199 }
 200
 201 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
 202                                              uint64_t Offset,
 203                                              uint64_t Value,
 204                                              uint32_t Type,
 205                                              int64_t Addend) {
 206   switch (Type) {
 207   default:
 208     llvm_unreachable("Relocation type not implemented yet!");
 209   break;
 210   case ELF::R_X86_64_64: {
 211     uint64_t *Target = reinterpret_cast<uint64_t*>(Section.Address + Offset);
 212     *Target = Value + Addend;
 213     DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend))
 214                  << " at " << format("%p\n",Target));
 215     break;
 216   }
 217   case ELF::R_X86_64_32:
 218   case ELF::R_X86_64_32S: {
 219     Value += Addend;
 220     assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
 221            (Type == ELF::R_X86_64_32S &&
 222              ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
 223     uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
 224     uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
 225     *Target = TruncatedAddr;
 226     DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr)
 227                  << " at " << format("%p\n",Target));
 228     break;
 229   }
 230   case ELF::R_X86_64_PC32: {
 231     // Get the placeholder value from the generated object since
 232     // a previous relocation attempt may have overwritten the loaded version
 233     uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
 234                                                                    + Offset);
 235     uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
 236     uint64_t  FinalAddress = Section.LoadAddress + Offset;
 237     int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
 238     assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
 239     int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
 240     *Target = TruncOffset;
 241     break;
 242   }
 243   }
 244 }
 245
 246 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
 247                                           uint64_t Offset,
 248                                           uint32_t Value,
 249                                           uint32_t Type,
 250                                           int32_t Addend) {
 251   switch (Type) {
 252   case ELF::R_386_32: {
 253     // Get the placeholder value from the generated object since
 254     // a previous relocation attempt may have overwritten the loaded version
 255     uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
 256                                                                    + Offset);
 257     uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
 258     *Target = *Placeholder + Value + Addend;
 259     break;
 260   }
 261   case ELF::R_386_PC32: {
 262     // Get the placeholder value from the generated object since
 263     // a previous relocation attempt may have overwritten the loaded version
 264     uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress
 265                                                                    + Offset);
 266     uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset);
 267     uint32_t  FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
 268     uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
 269     *Target = RealOffset;
 270     break;
 271     }
 272     default:
 273       // There are other relocation types, but it appears these are the
 274       // only ones currently used by the LLVM ELF object writer
 275       llvm_unreachable("Relocation type not implemented yet!");
 276       break;
 277   }
 278 }
 279
 280 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
 281                                               uint64_t Offset,
 282                                               uint64_t Value,
 283                                               uint32_t Type,
 284                                               int64_t Addend) {
 285   uint32_t *TargetPtr = reinterpret_cast<uint32_t*>(Section.Address + Offset);
 286   uint64_t FinalAddress = Section.LoadAddress + Offset;
 287
 288   DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
 289                << format("%llx", Section.Address + Offset)
 290                << " FinalAddress: 0x" << format("%llx",FinalAddress)
 291                << " Value: 0x" << format("%llx",Value)
 292                << " Type: 0x" << format("%x",Type)
 293                << " Addend: 0x" << format("%llx",Addend)
 294                << "\n");
 295
 296   switch (Type) {
 297   default:
 298     llvm_unreachable("Relocation type not implemented yet!");
 299     break;
 300   case ELF::R_AARCH64_ABS64: {
 301     uint64_t *TargetPtr = reinterpret_cast<uint64_t*>(Section.Address + Offset);
 302     *TargetPtr = Value + Addend;
 303     break;
 304   }
 305   case ELF::R_AARCH64_PREL32: { // test-shift.ll (.eh_frame)
 306     uint64_t Result = Value + Addend - FinalAddress;
 307     assert(static_cast<int64_t>(Result) >= INT32_MIN &&
 308            static_cast<int64_t>(Result) <= UINT32_MAX);
 309     *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
 310     break;
 311   }
 312   case ELF::R_AARCH64_CALL26: // fallthrough
 313   case ELF::R_AARCH64_JUMP26: {
 314     // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
 315     // calculation.
 316     uint64_t BranchImm = Value + Addend - FinalAddress;
 317
 318     // "Check that -2^27 <= result < 2^27".
 319     assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
 320            static_cast<int64_t>(BranchImm) < (1LL << 27));
 321     // Immediate goes in bits 25:0 of B and BL.
 322     *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
 323     break;
 324   }
 325   case ELF::R_AARCH64_MOVW_UABS_G3: {
 326     uint64_t Result = Value + Addend;
 327     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
 328     *TargetPtr |= Result >> (48 - 5);
 329     // Shift is "lsl #48", in bits 22:21
 330     *TargetPtr |= 3 << 21;
 331     break;
 332   }
 333   case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
 334     uint64_t Result = Value + Addend;
 335     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
 336     *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
 337     // Shift is "lsl #32", in bits 22:21
 338     *TargetPtr |= 2 << 21;
 339     break;
 340   }
 341   case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
 342     uint64_t Result = Value + Addend;
 343     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
 344     *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
 345     // Shift is "lsl #16", in bits 22:21
 346     *TargetPtr |= 1 << 21;
 347     break;
 348   }
 349   case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
 350     uint64_t Result = Value + Addend;
 351     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
 352     *TargetPtr |= ((Result & 0xffffU) << 5);
 353     // Shift is "lsl #0", in bits 22:21. No action needed.
 354     break;
 355   }
 356   }
 357 }
 358
 359 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
 360                                           uint64_t Offset,
 361                                           uint32_t Value,
 362                                           uint32_t Type,
 363                                           int32_t Addend) {
 364   // TODO: Add Thumb relocations.
 365   uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
 366   uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
 367   Value += Addend;
 368
 369   DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
 370                << Section.Address + Offset
 371                << " FinalAddress: " << format("%p",FinalAddress)
 372                << " Value: " << format("%x",Value)
 373                << " Type: " << format("%x",Type)
 374                << " Addend: " << format("%x",Addend)
 375                << "\n");
 376
 377   switch(Type) {
 378   default:
 379     llvm_unreachable("Not implemented relocation type!");
 380
 381   // Write a 32bit value to relocation address, taking into account the
 382   // implicit addend encoded in the target.
 383   case ELF::R_ARM_TARGET1 :
 384   case ELF::R_ARM_ABS32 :
 385     *TargetPtr += Value;
 386     break;
 387
 388   // Write first 16 bit of 32 bit value to the mov instruction.
 389   // Last 4 bit should be shifted.
 390   case ELF::R_ARM_MOVW_ABS_NC :
 391     // We are not expecting any other addend in the relocation address.
 392     // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
 393     // non-contiguous fields.
 394     assert((*TargetPtr & 0x000F0FFF) == 0);
 395     Value = Value & 0xFFFF;
 396     *TargetPtr |= Value & 0xFFF;
 397     *TargetPtr |= ((Value >> 12) & 0xF) << 16;
 398     break;
 399
 400   // Write last 16 bit of 32 bit value to the mov instruction.
 401   // Last 4 bit should be shifted.
 402   case ELF::R_ARM_MOVT_ABS :
 403     // We are not expecting any other addend in the relocation address.
 404     // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
 405     assert((*TargetPtr & 0x000F0FFF) == 0);
 406     Value = (Value >> 16) & 0xFFFF;
 407     *TargetPtr |= Value & 0xFFF;
 408     *TargetPtr |= ((Value >> 12) & 0xF) << 16;
 409     break;
 410
 411   // Write 24 bit relative value to the branch instruction.
 412   case ELF::R_ARM_PC24 :    // Fall through.
 413   case ELF::R_ARM_CALL :    // Fall through.
 414   case ELF::R_ARM_JUMP24 :
 415     int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
 416     RelValue = (RelValue & 0x03FFFFFC) >> 2;
 417     *TargetPtr &= 0xFF000000;
 418     *TargetPtr |= RelValue;
 419     break;
 420   }
 421 }
 422
 423 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
 424                                            uint64_t Offset,
 425                                            uint32_t Value,
 426                                            uint32_t Type,
 427                                            int32_t Addend) {
 428   uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset);
 429   Value += Addend;
 430
 431   DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
 432                << Section.Address + Offset
 433                << " FinalAddress: "
 434                << format("%p",Section.LoadAddress + Offset)
 435                << " Value: " << format("%x",Value)
 436                << " Type: " << format("%x",Type)
 437                << " Addend: " << format("%x",Addend)
 438                << "\n");
 439
 440   switch(Type) {
 441   default:
 442     llvm_unreachable("Not implemented relocation type!");
 443     break;
 444   case ELF::R_MIPS_32:
 445     *TargetPtr = Value + (*TargetPtr);
 446     break;
 447   case ELF::R_MIPS_26:
 448     *TargetPtr = ((*TargetPtr) & 0xfc000000) | (( Value & 0x0fffffff) >> 2);
 449     break;
 450   case ELF::R_MIPS_HI16:
 451     // Get the higher 16-bits. Also add 1 if bit 15 is 1.
 452     Value += ((*TargetPtr) & 0x0000ffff) << 16;
 453     *TargetPtr = ((*TargetPtr) & 0xffff0000) |
 454                  (((Value + 0x8000) >> 16) & 0xffff);
 455     break;
 456    case ELF::R_MIPS_LO16:
 457     Value += ((*TargetPtr) & 0x0000ffff);
 458     *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
 459     break;
 460    }
 461 }
 462
 463 // Return the .TOC. section address to R_PPC64_TOC relocations.
 464 uint64_t RuntimeDyldELF::findPPC64TOC() const {
 465   // The TOC consists of sections .got, .toc, .tocbss, .plt in that
 466   // order. The TOC starts where the first of these sections starts.
 467   SectionList::const_iterator it = Sections.begin();
 468   SectionList::const_iterator ite = Sections.end();
 469   for (; it != ite; ++it) {
 470     if (it->Name == ".got" ||
 471         it->Name == ".toc" ||
 472         it->Name == ".tocbss" ||
 473         it->Name == ".plt")
 474       break;
 475   }
 476   if (it == ite) {
 477     // This may happen for
 478     // * references to TOC base base (sym@toc, .odp relocation) without
 479     // a .toc directive.
 480     // In this case just use the first section (which is usually
 481     // the .odp) since the code won't reference the .toc base
 482     // directly.
 483     it = Sections.begin();
 484   }
 485   assert (it != ite);
 486   // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
 487   // thus permitting a full 64 Kbytes segment.
 488   return it->LoadAddress + 0x8000;
 489 }
 490
 491 // Returns the sections and offset associated with the ODP entry referenced
 492 // by Symbol.
 493 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
 494                                          ObjSectionToIDMap &LocalSections,
 495                                          RelocationValueRef &Rel) {
 496   // Get the ELF symbol value (st_value) to compare with Relocation offset in
 497   // .opd entries
 498
 499   error_code err;
 500   for (section_iterator si = Obj.begin_sections(),
 501      se = Obj.end_sections(); si != se; si.increment(err)) {
 502     StringRef SectionName;
 503     check(si->getName(SectionName));
 504     if (SectionName != ".opd")
 505       continue;
 506
 507     for (relocation_iterator i = si->begin_relocations(),
 508          e = si->end_relocations(); i != e;) {
 509       check(err);
 510
 511       // The R_PPC64_ADDR64 relocation indicates the first field
 512       // of a .opd entry
 513       uint64_t TypeFunc;
 514       check(i->getType(TypeFunc));
 515       if (TypeFunc != ELF::R_PPC64_ADDR64) {
 516         i.increment(err);
 517         continue;
 518       }
 519
 520       SymbolRef TargetSymbol;
 521       uint64_t TargetSymbolOffset;
 522       int64_t TargetAdditionalInfo;
 523       check(i->getSymbol(TargetSymbol));
 524       check(i->getOffset(TargetSymbolOffset));
 525       check(i->getAdditionalInfo(TargetAdditionalInfo));
 526
 527       i = i.increment(err);
 528       if (i == e)
 529         break;
 530       check(err);
 531
 532       // Just check if following relocation is a R_PPC64_TOC
 533       uint64_t TypeTOC;
 534       check(i->getType(TypeTOC));
 535       if (TypeTOC != ELF::R_PPC64_TOC)
 536         continue;
 537
 538       // Finally compares the Symbol value and the target symbol offset
 539       // to check if this .opd entry refers to the symbol the relocation
 540       // points to.
 541       if (Rel.Addend != (intptr_t)TargetSymbolOffset)
 542         continue;
 543
 544       section_iterator tsi(Obj.end_sections());
 545       check(TargetSymbol.getSection(tsi));
 546       Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections);
 547       Rel.Addend = (intptr_t)TargetAdditionalInfo;
 548       return;
 549     }
 550   }
 551   llvm_unreachable("Attempting to get address of ODP entry!");
 552 }
 553
 554 // Relocation masks following the #lo(value), #hi(value), #higher(value),
 555 // and #highest(value) macros defined in section 4.5.1. Relocation Types
 556 // in PPC-elf64abi document.
 557 //
 558 static inline
 559 uint16_t applyPPClo (uint64_t value)
 560 {
 561   return value & 0xffff;
 562 }
 563
 564 static inline
 565 uint16_t applyPPChi (uint64_t value)
 566 {
 567   return (value >> 16) & 0xffff;
 568 }
 569
 570 static inline
 571 uint16_t applyPPChigher (uint64_t value)
 572 {
 573   return (value >> 32) & 0xffff;
 574 }
 575
 576 static inline
 577 uint16_t applyPPChighest (uint64_t value)
 578 {
 579   return (value >> 48) & 0xffff;
 580 }
 581
 582 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
 583                                             uint64_t Offset,
 584                                             uint64_t Value,
 585                                             uint32_t Type,
 586                                             int64_t Addend) {
 587   uint8_t* LocalAddress = Section.Address + Offset;
 588   switch (Type) {
 589   default:
 590     llvm_unreachable("Relocation type not implemented yet!");
 591   break;
 592   case ELF::R_PPC64_ADDR16_LO :
 593     writeInt16BE(LocalAddress, applyPPClo (Value + Addend));
 594     break;
 595   case ELF::R_PPC64_ADDR16_HI :
 596     writeInt16BE(LocalAddress, applyPPChi (Value + Addend));
 597     break;
 598   case ELF::R_PPC64_ADDR16_HIGHER :
 599     writeInt16BE(LocalAddress, applyPPChigher (Value + Addend));
 600     break;
 601   case ELF::R_PPC64_ADDR16_HIGHEST :
 602     writeInt16BE(LocalAddress, applyPPChighest (Value + Addend));
 603     break;
 604   case ELF::R_PPC64_ADDR14 : {
 605     assert(((Value + Addend) & 3) == 0);
 606     // Preserve the AA/LK bits in the branch instruction
 607     uint8_t aalk = *(LocalAddress+3);
 608     writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
 609   } break;
 610   case ELF::R_PPC64_ADDR32 : {
 611     int32_t Result = static_cast<int32_t>(Value + Addend);
 612     if (SignExtend32<32>(Result) != Result)
 613       llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
 614     writeInt32BE(LocalAddress, Result);
 615   } break;
 616   case ELF::R_PPC64_REL24 : {
 617     uint64_t FinalAddress = (Section.LoadAddress + Offset);
 618     int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
 619     if (SignExtend32<24>(delta) != delta)
 620       llvm_unreachable("Relocation R_PPC64_REL24 overflow");
 621     // Generates a 'bl <address>' instruction
 622     writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
 623   } break;
 624   case ELF::R_PPC64_REL32 : {
 625     uint64_t FinalAddress = (Section.LoadAddress + Offset);
 626     int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
 627     if (SignExtend32<32>(delta) != delta)
 628       llvm_unreachable("Relocation R_PPC64_REL32 overflow");
 629     writeInt32BE(LocalAddress, delta);
 630   } break;
 631   case ELF::R_PPC64_ADDR64 :
 632     writeInt64BE(LocalAddress, Value + Addend);
 633     break;
 634   case ELF::R_PPC64_TOC :
 635     writeInt64BE(LocalAddress, findPPC64TOC());
 636     break;
 637   case ELF::R_PPC64_TOC16 : {
 638     uint64_t TOCStart = findPPC64TOC();
 639     Value = applyPPClo((Value + Addend) - TOCStart);
 640     writeInt16BE(LocalAddress, applyPPClo(Value));
 641   } break;
 642   case ELF::R_PPC64_TOC16_DS : {
 643     uint64_t TOCStart = findPPC64TOC();
 644     Value = ((Value + Addend) - TOCStart);
 645     writeInt16BE(LocalAddress, applyPPClo(Value));
 646   } break;
 647   }
 648 }
 649
 650 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
 651                                               uint64_t Offset,
 652                                               uint64_t Value,
 653                                               uint32_t Type,
 654                                               int64_t Addend) {
 655   uint8_t *LocalAddress = Section.Address + Offset;
 656   switch (Type) {
 657   default:
 658     llvm_unreachable("Relocation type not implemented yet!");
 659     break;
 660   case ELF::R_390_PC16DBL:
 661   case ELF::R_390_PLT16DBL: {
 662     int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
 663     assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
 664     writeInt16BE(LocalAddress, Delta / 2);
 665     break;
 666   }
 667   case ELF::R_390_PC32DBL:
 668   case ELF::R_390_PLT32DBL: {
 669     int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
 670     assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
 671     writeInt32BE(LocalAddress, Delta / 2);
 672     break;
 673   }
 674   case ELF::R_390_PC32: {
 675     int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
 676     assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
 677     writeInt32BE(LocalAddress, Delta);
 678     break;
 679   }
 680   case ELF::R_390_64:
 681     writeInt64BE(LocalAddress, Value + Addend);
 682     break;
 683   }
 684 }
 685
 686 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
 687                                        uint64_t Value) {
 688   const SectionEntry &Section = Sections[RE.SectionID];
 689   return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend);
 690 }
 691
 692 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
 693                                        uint64_t Offset,
 694                                        uint64_t Value,
 695                                        uint32_t Type,
 696                                        int64_t Addend) {
 697   switch (Arch) {
 698   case Triple::x86_64:
 699     resolveX86_64Relocation(Section, Offset, Value, Type, Addend);
 700     break;
 701   case Triple::x86:
 702     resolveX86Relocation(Section, Offset,
 703                          (uint32_t)(Value & 0xffffffffL), Type,
 704                          (uint32_t)(Addend & 0xffffffffL));
 705     break;
 706   case Triple::aarch64:
 707     resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
 708     break;
 709   case Triple::arm:    // Fall through.
 710   case Triple::thumb:
 711     resolveARMRelocation(Section, Offset,
 712                          (uint32_t)(Value & 0xffffffffL), Type,
 713                          (uint32_t)(Addend & 0xffffffffL));
 714     break;
 715   case Triple::mips:    // Fall through.
 716   case Triple::mipsel:
 717     resolveMIPSRelocation(Section, Offset,
 718                           (uint32_t)(Value & 0xffffffffL), Type,
 719                           (uint32_t)(Addend & 0xffffffffL));
 720     break;
 721   case Triple::ppc64:
 722     resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
 723     break;
 724   case Triple::systemz:
 725     resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
 726     break;
 727   default: llvm_unreachable("Unsupported CPU type!");
 728   }
 729 }
 730
 731 void RuntimeDyldELF::processRelocationRef(unsigned SectionID,
 732                                           RelocationRef RelI,
 733                                           ObjectImage &Obj,
 734                                           ObjSectionToIDMap &ObjSectionToID,
 735                                           const SymbolTableMap &Symbols,
 736                                           StubMap &Stubs) {
 737   uint64_t RelType;
 738   Check(RelI.getType(RelType));
 739   int64_t Addend;
 740   Check(RelI.getAdditionalInfo(Addend));
 741   SymbolRef Symbol;
 742   Check(RelI.getSymbol(Symbol));
 743
 744   // Obtain the symbol name which is referenced in the relocation
 745   StringRef TargetName;
 746   Symbol.getName(TargetName);
 747   DEBUG(dbgs() << "\t\tRelType: " << RelType
 748                << " Addend: " << Addend
 749                << " TargetName: " << TargetName
 750                << "\n");
 751   RelocationValueRef Value;
 752   // First search for the symbol in the local symbol table
 753   SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
 754   SymbolRef::Type SymType;
 755   Symbol.getType(SymType);
 756   if (lsi != Symbols.end()) {
 757     Value.SectionID = lsi->second.first;
 758     Value.Addend = lsi->second.second + Addend;
 759   } else {
 760     // Search for the symbol in the global symbol table
 761     SymbolTableMap::const_iterator gsi =
 762         GlobalSymbolTable.find(TargetName.data());
 763     if (gsi != GlobalSymbolTable.end()) {
 764       Value.SectionID = gsi->second.first;
 765       Value.Addend = gsi->second.second + Addend;
 766     } else {
 767       switch (SymType) {
 768         case SymbolRef::ST_Debug: {
 769           // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
 770           // and can be changed by another developers. Maybe best way is add
 771           // a new symbol type ST_Section to SymbolRef and use it.
 772           section_iterator si(Obj.end_sections());
 773           Symbol.getSection(si);
 774           if (si == Obj.end_sections())
 775             llvm_unreachable("Symbol section not found, bad object file format!");
 776           DEBUG(dbgs() << "\t\tThis is section symbol\n");
 777           // Default to 'true' in case isText fails (though it never does).
 778           bool isCode = true;
 779           si->isText(isCode);
 780           Value.SectionID = findOrEmitSection(Obj,
 781                                               (*si),
 782                                               isCode,
 783                                               ObjSectionToID);
 784           Value.Addend = Addend;
 785           break;
 786         }
 787         case SymbolRef::ST_Unknown: {
 788           Value.SymbolName = TargetName.data();
 789           Value.Addend = Addend;
 790           break;
 791         }
 792         default:
 793           llvm_unreachable("Unresolved symbol type!");
 794           break;
 795       }
 796     }
 797   }
 798   uint64_t Offset;
 799   Check(RelI.getOffset(Offset));
 800
 801   DEBUG(dbgs() << "\t\tSectionID: " << SectionID
 802                << " Offset: " << Offset
 803                << "\n");
 804   if (Arch == Triple::aarch64 &&
 805       (RelType == ELF::R_AARCH64_CALL26 ||
 806        RelType == ELF::R_AARCH64_JUMP26)) {
 807     // This is an AArch64 branch relocation, need to use a stub function.
 808     DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
 809     SectionEntry &Section = Sections[SectionID];
 810
 811     // Look for an existing stub.
 812     StubMap::const_iterator i = Stubs.find(Value);
 813     if (i != Stubs.end()) {
 814         resolveRelocation(Section, Offset,
 815                           (uint64_t)Section.Address + i->second, RelType, 0);
 816       DEBUG(dbgs() << " Stub function found\n");
 817     } else {
 818       // Create a new stub function.
 819       DEBUG(dbgs() << " Create a new stub function\n");
 820       Stubs[Value] = Section.StubOffset;
 821       uint8_t *StubTargetAddr = createStubFunction(Section.Address +
 822                                                    Section.StubOffset);
 823
 824       RelocationEntry REmovz_g3(SectionID,
 825                                 StubTargetAddr - Section.Address,
 826                                 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
 827       RelocationEntry REmovk_g2(SectionID,
 828                                 StubTargetAddr - Section.Address + 4,
 829                                 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
 830       RelocationEntry REmovk_g1(SectionID,
 831                                 StubTargetAddr - Section.Address + 8,
 832                                 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
 833       RelocationEntry REmovk_g0(SectionID,
 834                                 StubTargetAddr - Section.Address + 12,
 835                                 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
 836
 837       if (Value.SymbolName) {
 838         addRelocationForSymbol(REmovz_g3, Value.SymbolName);
 839         addRelocationForSymbol(REmovk_g2, Value.SymbolName);
 840         addRelocationForSymbol(REmovk_g1, Value.SymbolName);
 841         addRelocationForSymbol(REmovk_g0, Value.SymbolName);
 842       } else {
 843         addRelocationForSection(REmovz_g3, Value.SectionID);
 844         addRelocationForSection(REmovk_g2, Value.SectionID);
 845         addRelocationForSection(REmovk_g1, Value.SectionID);
 846         addRelocationForSection(REmovk_g0, Value.SectionID);
 847       }
 848       resolveRelocation(Section, Offset,
 849                         (uint64_t)Section.Address + Section.StubOffset,
 850                         RelType, 0);
 851       Section.StubOffset += getMaxStubSize();
 852     }
 853   } else if (Arch == Triple::arm &&
 854       (RelType == ELF::R_ARM_PC24 ||
 855        RelType == ELF::R_ARM_CALL ||
 856        RelType == ELF::R_ARM_JUMP24)) {
 857     // This is an ARM branch relocation, need to use a stub function.
 858     DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
 859     SectionEntry &Section = Sections[SectionID];
 860
 861     // Look for an existing stub.
 862     StubMap::const_iterator i = Stubs.find(Value);
 863     if (i != Stubs.end()) {
 864         resolveRelocation(Section, Offset,
 865                           (uint64_t)Section.Address + i->second, RelType, 0);
 866       DEBUG(dbgs() << " Stub function found\n");
 867     } else {
 868       // Create a new stub function.
 869       DEBUG(dbgs() << " Create a new stub function\n");
 870       Stubs[Value] = Section.StubOffset;
 871       uint8_t *StubTargetAddr = createStubFunction(Section.Address +
 872                                                    Section.StubOffset);
 873       RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
 874                          ELF::R_ARM_ABS32, Value.Addend);
 875       if (Value.SymbolName)
 876         addRelocationForSymbol(RE, Value.SymbolName);
 877       else
 878         addRelocationForSection(RE, Value.SectionID);
 879
 880       resolveRelocation(Section, Offset,
 881                         (uint64_t)Section.Address + Section.StubOffset,
 882                         RelType, 0);
 883       Section.StubOffset += getMaxStubSize();
 884     }
 885   } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
 886              RelType == ELF::R_MIPS_26) {
 887     // This is an Mips branch relocation, need to use a stub function.
 888     DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
 889     SectionEntry &Section = Sections[SectionID];
 890     uint8_t *Target = Section.Address + Offset;
 891     uint32_t *TargetAddress = (uint32_t *)Target;
 892
 893     // Extract the addend from the instruction.
 894     uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
 895
 896     Value.Addend += Addend;
 897
 898     //  Look up for existing stub.
 899     StubMap::const_iterator i = Stubs.find(Value);
 900     if (i != Stubs.end()) {
 901       resolveRelocation(Section, Offset,
 902                         (uint64_t)Section.Address + i->second, RelType, 0);
 903       DEBUG(dbgs() << " Stub function found\n");
 904     } else {
 905       // Create a new stub function.
 906       DEBUG(dbgs() << " Create a new stub function\n");
 907       Stubs[Value] = Section.StubOffset;
 908       uint8_t *StubTargetAddr = createStubFunction(Section.Address +
 909                                                    Section.StubOffset);
 910
 911       // Creating Hi and Lo relocations for the filled stub instructions.
 912       RelocationEntry REHi(SectionID,
 913                            StubTargetAddr - Section.Address,
 914                            ELF::R_MIPS_HI16, Value.Addend);
 915       RelocationEntry RELo(SectionID,
 916                            StubTargetAddr - Section.Address + 4,
 917                            ELF::R_MIPS_LO16, Value.Addend);
 918
 919       if (Value.SymbolName) {
 920         addRelocationForSymbol(REHi, Value.SymbolName);
 921         addRelocationForSymbol(RELo, Value.SymbolName);
 922       } else {
 923         addRelocationForSection(REHi, Value.SectionID);
 924         addRelocationForSection(RELo, Value.SectionID);
 925       }
 926
 927       resolveRelocation(Section, Offset,
 928                         (uint64_t)Section.Address + Section.StubOffset,
 929                         RelType, 0);
 930       Section.StubOffset += getMaxStubSize();
 931     }
 932   } else if (Arch == Triple::ppc64) {
 933     if (RelType == ELF::R_PPC64_REL24) {
 934       // A PPC branch relocation will need a stub function if the target is
 935       // an external symbol (Symbol::ST_Unknown) or if the target address
 936       // is not within the signed 24-bits branch address.
 937       SectionEntry &Section = Sections[SectionID];
 938       uint8_t *Target = Section.Address + Offset;
 939       bool RangeOverflow = false;
 940       if (SymType != SymbolRef::ST_Unknown) {
 941         // A function call may points to the .opd entry, so the final symbol value
 942         // in calculated based in the relocation values in .opd section.
 943         findOPDEntrySection(Obj, ObjSectionToID, Value);
 944         uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
 945         int32_t delta = static_cast<int32_t>(Target - RelocTarget);
 946         // If it is within 24-bits branch range, just set the branch target
 947         if (SignExtend32<24>(delta) == delta) {
 948           RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
 949           if (Value.SymbolName)
 950             addRelocationForSymbol(RE, Value.SymbolName);
 951           else
 952             addRelocationForSection(RE, Value.SectionID);
 953         } else {
 954           RangeOverflow = true;
 955         }
 956       }
 957       if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
 958         // It is an external symbol (SymbolRef::ST_Unknown) or within a range
 959         // larger than 24-bits.
 960         StubMap::const_iterator i = Stubs.find(Value);
 961         if (i != Stubs.end()) {
 962           // Symbol function stub already created, just relocate to it
 963           resolveRelocation(Section, Offset,
 964                             (uint64_t)Section.Address + i->second, RelType, 0);
 965           DEBUG(dbgs() << " Stub function found\n");
 966         } else {
 967           // Create a new stub function.
 968           DEBUG(dbgs() << " Create a new stub function\n");
 969           Stubs[Value] = Section.StubOffset;
 970           uint8_t *StubTargetAddr = createStubFunction(Section.Address +
 971                                                        Section.StubOffset);
 972           RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
 973                              ELF::R_PPC64_ADDR64, Value.Addend);
 974
 975           // Generates the 64-bits address loads as exemplified in section
 976           // 4.5.1 in PPC64 ELF ABI.
 977           RelocationEntry REhst(SectionID,
 978                                 StubTargetAddr - Section.Address + 2,
 979                                 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
 980           RelocationEntry REhr(SectionID,
 981                                StubTargetAddr - Section.Address + 6,
 982                                ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
 983           RelocationEntry REh(SectionID,
 984                               StubTargetAddr - Section.Address + 14,
 985                               ELF::R_PPC64_ADDR16_HI, Value.Addend);
 986           RelocationEntry REl(SectionID,
 987                               StubTargetAddr - Section.Address + 18,
 988                               ELF::R_PPC64_ADDR16_LO, Value.Addend);
 989
 990           if (Value.SymbolName) {
 991             addRelocationForSymbol(REhst, Value.SymbolName);
 992             addRelocationForSymbol(REhr,  Value.SymbolName);
 993             addRelocationForSymbol(REh,   Value.SymbolName);
 994             addRelocationForSymbol(REl,   Value.SymbolName);
 995           } else {
 996             addRelocationForSection(REhst, Value.SectionID);
 997             addRelocationForSection(REhr,  Value.SectionID);
 998             addRelocationForSection(REh,   Value.SectionID);
 999             addRelocationForSection(REl,   Value.SectionID);
1000           }
1001
1002           resolveRelocation(Section, Offset,
1003                             (uint64_t)Section.Address + Section.StubOffset,
1004                             RelType, 0);
1005           if (SymType == SymbolRef::ST_Unknown)
1006             // Restore the TOC for external calls
1007             writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1)
1008           Section.StubOffset += getMaxStubSize();
1009         }
1010       }
1011     } else {
1012       RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1013       // Extra check to avoid relocation againt empty symbols (usually
1014       // the R_PPC64_TOC).
1015       if (Value.SymbolName && !TargetName.empty())
1016         addRelocationForSymbol(RE, Value.SymbolName);
1017       else
1018         addRelocationForSection(RE, Value.SectionID);
1019     }
1020   } else if (Arch == Triple::systemz &&
1021              (RelType == ELF::R_390_PLT32DBL ||
1022               RelType == ELF::R_390_GOTENT)) {
1023     // Create function stubs for both PLT and GOT references, regardless of
1024     // whether the GOT reference is to data or code.  The stub contains the
1025     // full address of the symbol, as needed by GOT references, and the
1026     // executable part only adds an overhead of 8 bytes.
1027     //
1028     // We could try to conserve space by allocating the code and data
1029     // parts of the stub separately.  However, as things stand, we allocate
1030     // a stub for every relocation, so using a GOT in JIT code should be
1031     // no less space efficient than using an explicit constant pool.
1032     DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1033     SectionEntry &Section = Sections[SectionID];
1034
1035     // Look for an existing stub.
1036     StubMap::const_iterator i = Stubs.find(Value);
1037     uintptr_t StubAddress;
1038     if (i != Stubs.end()) {
1039       StubAddress = uintptr_t(Section.Address) + i->second;
1040       DEBUG(dbgs() << " Stub function found\n");
1041     } else {
1042       // Create a new stub function.
1043       DEBUG(dbgs() << " Create a new stub function\n");
1044
1045       uintptr_t BaseAddress = uintptr_t(Section.Address);
1046       uintptr_t StubAlignment = getStubAlignment();
1047       StubAddress = (BaseAddress + Section.StubOffset +
1048                      StubAlignment - 1) & -StubAlignment;
1049       unsigned StubOffset = StubAddress - BaseAddress;
1050
1051       Stubs[Value] = StubOffset;
1052       createStubFunction((uint8_t *)StubAddress);
1053       RelocationEntry RE(SectionID, StubOffset + 8,
1054                          ELF::R_390_64, Value.Addend - Addend);
1055       if (Value.SymbolName)
1056         addRelocationForSymbol(RE, Value.SymbolName);
1057       else
1058         addRelocationForSection(RE, Value.SectionID);
1059       Section.StubOffset = StubOffset + getMaxStubSize();
1060     }
1061
1062     if (RelType == ELF::R_390_GOTENT)
1063       resolveRelocation(Section, Offset, StubAddress + 8,
1064                         ELF::R_390_PC32DBL, Addend);
1065     else
1066       resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1067   } else {
1068     RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1069     if (Value.SymbolName)
1070       addRelocationForSymbol(RE, Value.SymbolName);
1071     else
1072       addRelocationForSection(RE, Value.SectionID);
1073   }
1074 }
1075
1076 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1077   if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1078     return false;
1079   return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0;
1080 }
1081 } // namespace llvm