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RuntimeDyldELF.cpp
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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 #include "RuntimeDyldELF.h"
15 #include "RuntimeDyldCheckerImpl.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/BinaryFormat/ELF.h"
22 #include "llvm/Object/ObjectFile.h"
23 #include "llvm/Support/Endian.h"
25 
26 using namespace llvm;
27 using namespace llvm::object;
28 using namespace llvm::support::endian;
29 
30 #define DEBUG_TYPE "dyld"
31 
32 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
33 
34 static void or32AArch64Imm(void *L, uint64_t Imm) {
35  or32le(L, (Imm & 0xFFF) << 10);
36 }
37 
38 template <class T> static void write(bool isBE, void *P, T V) {
39  isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V);
40 }
41 
42 static void write32AArch64Addr(void *L, uint64_t Imm) {
43  uint32_t ImmLo = (Imm & 0x3) << 29;
44  uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
45  uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
46  write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi);
47 }
48 
49 // Return the bits [Start, End] from Val shifted Start bits.
50 // For instance, getBits(0xF0, 4, 8) returns 0xF.
51 static uint64_t getBits(uint64_t Val, int Start, int End) {
52  uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1;
53  return (Val >> Start) & Mask;
54 }
55 
56 namespace {
57 
58 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
60 
61  typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
62  typedef Elf_Sym_Impl<ELFT> Elf_Sym;
63  typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
64  typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
65 
66  typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
67 
68  typedef typename ELFT::uint addr_type;
69 
70  DyldELFObject(ELFObjectFile<ELFT> &&Obj);
71 
72 public:
74  create(MemoryBufferRef Wrapper);
75 
76  void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
77 
78  void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
79 
80  // Methods for type inquiry through isa, cast and dyn_cast
81  static bool classof(const Binary *v) {
82  return (isa<ELFObjectFile<ELFT>>(v) &&
83  classof(cast<ELFObjectFile<ELFT>>(v)));
84  }
85  static bool classof(const ELFObjectFile<ELFT> *v) {
86  return v->isDyldType();
87  }
88 };
89 
90 
91 
92 // The MemoryBuffer passed into this constructor is just a wrapper around the
93 // actual memory. Ultimately, the Binary parent class will take ownership of
94 // this MemoryBuffer object but not the underlying memory.
95 template <class ELFT>
96 DyldELFObject<ELFT>::DyldELFObject(ELFObjectFile<ELFT> &&Obj)
97  : ELFObjectFile<ELFT>(std::move(Obj)) {
98  this->isDyldELFObject = true;
99 }
100 
101 template <class ELFT>
103 DyldELFObject<ELFT>::create(MemoryBufferRef Wrapper) {
104  auto Obj = ELFObjectFile<ELFT>::create(Wrapper);
105  if (auto E = Obj.takeError())
106  return std::move(E);
107  std::unique_ptr<DyldELFObject<ELFT>> Ret(
108  new DyldELFObject<ELFT>(std::move(*Obj)));
109  return std::move(Ret);
110 }
111 
112 template <class ELFT>
113 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
114  uint64_t Addr) {
115  DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
116  Elf_Shdr *shdr =
117  const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
118 
119  // This assumes the address passed in matches the target address bitness
120  // The template-based type cast handles everything else.
121  shdr->sh_addr = static_cast<addr_type>(Addr);
122 }
123 
124 template <class ELFT>
125 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
126  uint64_t Addr) {
127 
128  Elf_Sym *sym = const_cast<Elf_Sym *>(
130 
131  // This assumes the address passed in matches the target address bitness
132  // The template-based type cast handles everything else.
133  sym->st_value = static_cast<addr_type>(Addr);
134 }
135 
136 class LoadedELFObjectInfo final
137  : public LoadedObjectInfoHelper<LoadedELFObjectInfo,
138  RuntimeDyld::LoadedObjectInfo> {
139 public:
140  LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap)
141  : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
142 
144  getObjectForDebug(const ObjectFile &Obj) const override;
145 };
146 
147 template <typename ELFT>
149 createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject,
150  const LoadedELFObjectInfo &L) {
151  typedef typename ELFT::Shdr Elf_Shdr;
152  typedef typename ELFT::uint addr_type;
153 
155  DyldELFObject<ELFT>::create(Buffer);
156  if (Error E = ObjOrErr.takeError())
157  return std::move(E);
158 
159  std::unique_ptr<DyldELFObject<ELFT>> Obj = std::move(*ObjOrErr);
160 
161  // Iterate over all sections in the object.
162  auto SI = SourceObject.section_begin();
163  for (const auto &Sec : Obj->sections()) {
165  Sec.getName(SectionName);
166  if (SectionName != "") {
167  DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
168  Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
169  reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
170 
171  if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) {
172  // This assumes that the address passed in matches the target address
173  // bitness. The template-based type cast handles everything else.
174  shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
175  }
176  }
177  ++SI;
178  }
179 
180  return std::move(Obj);
181 }
182 
184 createELFDebugObject(const ObjectFile &Obj, const LoadedELFObjectInfo &L) {
185  assert(Obj.isELF() && "Not an ELF object file.");
186 
187  std::unique_ptr<MemoryBuffer> Buffer =
189 
190  Expected<std::unique_ptr<ObjectFile>> DebugObj(nullptr);
191  handleAllErrors(DebugObj.takeError());
192  if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian())
193  DebugObj =
194  createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L);
195  else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian())
196  DebugObj =
197  createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L);
198  else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian())
199  DebugObj =
200  createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L);
201  else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian())
202  DebugObj =
203  createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L);
204  else
205  llvm_unreachable("Unexpected ELF format");
206 
207  handleAllErrors(DebugObj.takeError());
208  return OwningBinary<ObjectFile>(std::move(*DebugObj), std::move(Buffer));
209 }
210 
212 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
213  return createELFDebugObject(Obj, *this);
214 }
215 
216 } // anonymous namespace
217 
218 namespace llvm {
219 
222  : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
224 
226  for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
227  SID EHFrameSID = UnregisteredEHFrameSections[i];
228  uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
229  uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
230  size_t EHFrameSize = Sections[EHFrameSID].getSize();
231  MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
232  }
233  UnregisteredEHFrameSections.clear();
234 }
235 
236 std::unique_ptr<RuntimeDyldELF>
240  switch (Arch) {
241  default:
242  return make_unique<RuntimeDyldELF>(MemMgr, Resolver);
243  case Triple::mips:
244  case Triple::mipsel:
245  case Triple::mips64:
246  case Triple::mips64el:
247  return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
248  }
249 }
250 
251 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
253  if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
254  return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
255  else {
256  HasError = true;
257  raw_string_ostream ErrStream(ErrorStr);
258  logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream);
259  return nullptr;
260  }
261 }
262 
263 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
264  uint64_t Offset, uint64_t Value,
265  uint32_t Type, int64_t Addend,
266  uint64_t SymOffset) {
267  switch (Type) {
268  default:
269  llvm_unreachable("Relocation type not implemented yet!");
270  break;
271  case ELF::R_X86_64_NONE:
272  break;
273  case ELF::R_X86_64_64: {
275  Value + Addend;
276  LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
277  << format("%p\n", Section.getAddressWithOffset(Offset)));
278  break;
279  }
280  case ELF::R_X86_64_32:
281  case ELF::R_X86_64_32S: {
282  Value += Addend;
283  assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
284  (Type == ELF::R_X86_64_32S &&
285  ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
286  uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
288  TruncatedAddr;
289  LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
290  << format("%p\n", Section.getAddressWithOffset(Offset)));
291  break;
292  }
293  case ELF::R_X86_64_PC8: {
294  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
295  int64_t RealOffset = Value + Addend - FinalAddress;
296  assert(isInt<8>(RealOffset));
297  int8_t TruncOffset = (RealOffset & 0xFF);
298  Section.getAddress()[Offset] = TruncOffset;
299  break;
300  }
301  case ELF::R_X86_64_PC32: {
302  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
303  int64_t RealOffset = Value + Addend - FinalAddress;
304  assert(isInt<32>(RealOffset));
305  int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
307  TruncOffset;
308  break;
309  }
310  case ELF::R_X86_64_PC64: {
311  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
312  int64_t RealOffset = Value + Addend - FinalAddress;
314  RealOffset;
315  LLVM_DEBUG(dbgs() << "Writing " << format("%p", RealOffset) << " at "
316  << format("%p\n", FinalAddress));
317  break;
318  }
319  case ELF::R_X86_64_GOTOFF64: {
320  // Compute Value - GOTBase.
321  uint64_t GOTBase = 0;
322  for (const auto &Section : Sections) {
323  if (Section.getName() == ".got") {
324  GOTBase = Section.getLoadAddressWithOffset(0);
325  break;
326  }
327  }
328  assert(GOTBase != 0 && "missing GOT");
329  int64_t GOTOffset = Value - GOTBase + Addend;
330  support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = GOTOffset;
331  break;
332  }
333  }
334 }
335 
336 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
337  uint64_t Offset, uint32_t Value,
338  uint32_t Type, int32_t Addend) {
339  switch (Type) {
340  case ELF::R_386_32: {
342  Value + Addend;
343  break;
344  }
345  // Handle R_386_PLT32 like R_386_PC32 since it should be able to
346  // reach any 32 bit address.
347  case ELF::R_386_PLT32:
348  case ELF::R_386_PC32: {
349  uint32_t FinalAddress =
350  Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
351  uint32_t RealOffset = Value + Addend - FinalAddress;
353  RealOffset;
354  break;
355  }
356  default:
357  // There are other relocation types, but it appears these are the
358  // only ones currently used by the LLVM ELF object writer
359  llvm_unreachable("Relocation type not implemented yet!");
360  break;
361  }
362 }
363 
364 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
365  uint64_t Offset, uint64_t Value,
366  uint32_t Type, int64_t Addend) {
367  uint32_t *TargetPtr =
368  reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
369  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
370  // Data should use target endian. Code should always use little endian.
371  bool isBE = Arch == Triple::aarch64_be;
372 
373  LLVM_DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
374  << format("%llx", Section.getAddressWithOffset(Offset))
375  << " FinalAddress: 0x" << format("%llx", FinalAddress)
376  << " Value: 0x" << format("%llx", Value) << " Type: 0x"
377  << format("%x", Type) << " Addend: 0x"
378  << format("%llx", Addend) << "\n");
379 
380  switch (Type) {
381  default:
382  llvm_unreachable("Relocation type not implemented yet!");
383  break;
384  case ELF::R_AARCH64_ABS16: {
385  uint64_t Result = Value + Addend;
386  assert(static_cast<int64_t>(Result) >= INT16_MIN && Result < UINT16_MAX);
387  write(isBE, TargetPtr, static_cast<uint16_t>(Result & 0xffffU));
388  break;
389  }
390  case ELF::R_AARCH64_ABS32: {
391  uint64_t Result = Value + Addend;
392  assert(static_cast<int64_t>(Result) >= INT32_MIN && Result < UINT32_MAX);
393  write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
394  break;
395  }
396  case ELF::R_AARCH64_ABS64:
397  write(isBE, TargetPtr, Value + Addend);
398  break;
399  case ELF::R_AARCH64_PREL32: {
400  uint64_t Result = Value + Addend - FinalAddress;
401  assert(static_cast<int64_t>(Result) >= INT32_MIN &&
402  static_cast<int64_t>(Result) <= UINT32_MAX);
403  write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
404  break;
405  }
406  case ELF::R_AARCH64_PREL64:
407  write(isBE, TargetPtr, Value + Addend - FinalAddress);
408  break;
409  case ELF::R_AARCH64_CALL26: // fallthrough
410  case ELF::R_AARCH64_JUMP26: {
411  // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
412  // calculation.
413  uint64_t BranchImm = Value + Addend - FinalAddress;
414 
415  // "Check that -2^27 <= result < 2^27".
416  assert(isInt<28>(BranchImm));
417  or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
418  break;
419  }
420  case ELF::R_AARCH64_MOVW_UABS_G3:
421  or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
422  break;
423  case ELF::R_AARCH64_MOVW_UABS_G2_NC:
424  or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
425  break;
426  case ELF::R_AARCH64_MOVW_UABS_G1_NC:
427  or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
428  break;
429  case ELF::R_AARCH64_MOVW_UABS_G0_NC:
430  or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
431  break;
432  case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
433  // Operation: Page(S+A) - Page(P)
434  uint64_t Result =
435  ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
436 
437  // Check that -2^32 <= X < 2^32
438  assert(isInt<33>(Result) && "overflow check failed for relocation");
439 
440  // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
441  // from bits 32:12 of X.
442  write32AArch64Addr(TargetPtr, Result >> 12);
443  break;
444  }
445  case ELF::R_AARCH64_ADD_ABS_LO12_NC:
446  // Operation: S + A
447  // Immediate goes in bits 21:10 of LD/ST instruction, taken
448  // from bits 11:0 of X
449  or32AArch64Imm(TargetPtr, Value + Addend);
450  break;
451  case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
452  // Operation: S + A
453  // Immediate goes in bits 21:10 of LD/ST instruction, taken
454  // from bits 11:0 of X
455  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11));
456  break;
457  case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
458  // Operation: S + A
459  // Immediate goes in bits 21:10 of LD/ST instruction, taken
460  // from bits 11:1 of X
461  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11));
462  break;
463  case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
464  // Operation: S + A
465  // Immediate goes in bits 21:10 of LD/ST instruction, taken
466  // from bits 11:2 of X
467  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11));
468  break;
469  case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
470  // Operation: S + A
471  // Immediate goes in bits 21:10 of LD/ST instruction, taken
472  // from bits 11:3 of X
473  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11));
474  break;
475  case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
476  // Operation: S + A
477  // Immediate goes in bits 21:10 of LD/ST instruction, taken
478  // from bits 11:4 of X
479  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 4, 11));
480  break;
481  }
482 }
483 
484 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
485  uint64_t Offset, uint32_t Value,
486  uint32_t Type, int32_t Addend) {
487  // TODO: Add Thumb relocations.
488  uint32_t *TargetPtr =
489  reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
490  uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
491  Value += Addend;
492 
493  LLVM_DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
494  << Section.getAddressWithOffset(Offset)
495  << " FinalAddress: " << format("%p", FinalAddress)
496  << " Value: " << format("%x", Value)
497  << " Type: " << format("%x", Type)
498  << " Addend: " << format("%x", Addend) << "\n");
499 
500  switch (Type) {
501  default:
502  llvm_unreachable("Not implemented relocation type!");
503 
504  case ELF::R_ARM_NONE:
505  break;
506  // Write a 31bit signed offset
507  case ELF::R_ARM_PREL31:
508  support::ulittle32_t::ref{TargetPtr} =
509  (support::ulittle32_t::ref{TargetPtr} & 0x80000000) |
510  ((Value - FinalAddress) & ~0x80000000);
511  break;
512  case ELF::R_ARM_TARGET1:
513  case ELF::R_ARM_ABS32:
514  support::ulittle32_t::ref{TargetPtr} = Value;
515  break;
516  // Write first 16 bit of 32 bit value to the mov instruction.
517  // Last 4 bit should be shifted.
518  case ELF::R_ARM_MOVW_ABS_NC:
519  case ELF::R_ARM_MOVT_ABS:
520  if (Type == ELF::R_ARM_MOVW_ABS_NC)
521  Value = Value & 0xFFFF;
522  else if (Type == ELF::R_ARM_MOVT_ABS)
523  Value = (Value >> 16) & 0xFFFF;
524  support::ulittle32_t::ref{TargetPtr} =
525  (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) |
526  (((Value >> 12) & 0xF) << 16);
527  break;
528  // Write 24 bit relative value to the branch instruction.
529  case ELF::R_ARM_PC24: // Fall through.
530  case ELF::R_ARM_CALL: // Fall through.
531  case ELF::R_ARM_JUMP24:
532  int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
533  RelValue = (RelValue & 0x03FFFFFC) >> 2;
534  assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE);
535  support::ulittle32_t::ref{TargetPtr} =
536  (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue;
537  break;
538  }
539 }
540 
541 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
542  if (Arch == Triple::UnknownArch ||
543  !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
544  IsMipsO32ABI = false;
545  IsMipsN32ABI = false;
546  IsMipsN64ABI = false;
547  return;
548  }
549  if (auto *E = dyn_cast<ELFObjectFileBase>(&Obj)) {
550  unsigned AbiVariant = E->getPlatformFlags();
551  IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
552  IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2;
553  }
554  IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
555 }
556 
557 // Return the .TOC. section and offset.
558 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
559  ObjSectionToIDMap &LocalSections,
560  RelocationValueRef &Rel) {
561  // Set a default SectionID in case we do not find a TOC section below.
562  // This may happen for references to TOC base base (sym@toc, .odp
563  // relocation) without a .toc directive. In this case just use the
564  // first section (which is usually the .odp) since the code won't
565  // reference the .toc base directly.
566  Rel.SymbolName = nullptr;
567  Rel.SectionID = 0;
568 
569  // The TOC consists of sections .got, .toc, .tocbss, .plt in that
570  // order. The TOC starts where the first of these sections starts.
571  for (auto &Section: Obj.sections()) {
573  if (auto EC = Section.getName(SectionName))
574  return errorCodeToError(EC);
575 
576  if (SectionName == ".got"
577  || SectionName == ".toc"
578  || SectionName == ".tocbss"
579  || SectionName == ".plt") {
580  if (auto SectionIDOrErr =
581  findOrEmitSection(Obj, Section, false, LocalSections))
582  Rel.SectionID = *SectionIDOrErr;
583  else
584  return SectionIDOrErr.takeError();
585  break;
586  }
587  }
588 
589  // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
590  // thus permitting a full 64 Kbytes segment.
591  Rel.Addend = 0x8000;
592 
593  return Error::success();
594 }
595 
596 // Returns the sections and offset associated with the ODP entry referenced
597 // by Symbol.
598 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
599  ObjSectionToIDMap &LocalSections,
600  RelocationValueRef &Rel) {
601  // Get the ELF symbol value (st_value) to compare with Relocation offset in
602  // .opd entries
603  for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
604  si != se; ++si) {
605  section_iterator RelSecI = si->getRelocatedSection();
606  if (RelSecI == Obj.section_end())
607  continue;
608 
609  StringRef RelSectionName;
610  if (auto EC = RelSecI->getName(RelSectionName))
611  return errorCodeToError(EC);
612 
613  if (RelSectionName != ".opd")
614  continue;
615 
616  for (elf_relocation_iterator i = si->relocation_begin(),
617  e = si->relocation_end();
618  i != e;) {
619  // The R_PPC64_ADDR64 relocation indicates the first field
620  // of a .opd entry
621  uint64_t TypeFunc = i->getType();
622  if (TypeFunc != ELF::R_PPC64_ADDR64) {
623  ++i;
624  continue;
625  }
626 
627  uint64_t TargetSymbolOffset = i->getOffset();
628  symbol_iterator TargetSymbol = i->getSymbol();
629  int64_t Addend;
630  if (auto AddendOrErr = i->getAddend())
631  Addend = *AddendOrErr;
632  else
633  return AddendOrErr.takeError();
634 
635  ++i;
636  if (i == e)
637  break;
638 
639  // Just check if following relocation is a R_PPC64_TOC
640  uint64_t TypeTOC = i->getType();
641  if (TypeTOC != ELF::R_PPC64_TOC)
642  continue;
643 
644  // Finally compares the Symbol value and the target symbol offset
645  // to check if this .opd entry refers to the symbol the relocation
646  // points to.
647  if (Rel.Addend != (int64_t)TargetSymbolOffset)
648  continue;
649 
650  section_iterator TSI = Obj.section_end();
651  if (auto TSIOrErr = TargetSymbol->getSection())
652  TSI = *TSIOrErr;
653  else
654  return TSIOrErr.takeError();
655  assert(TSI != Obj.section_end() && "TSI should refer to a valid section");
656 
657  bool IsCode = TSI->isText();
658  if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode,
659  LocalSections))
660  Rel.SectionID = *SectionIDOrErr;
661  else
662  return SectionIDOrErr.takeError();
663  Rel.Addend = (intptr_t)Addend;
664  return Error::success();
665  }
666  }
667  llvm_unreachable("Attempting to get address of ODP entry!");
668 }
669 
670 // Relocation masks following the #lo(value), #hi(value), #ha(value),
671 // #higher(value), #highera(value), #highest(value), and #highesta(value)
672 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
673 // document.
674 
675 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
676 
677 static inline uint16_t applyPPChi(uint64_t value) {
678  return (value >> 16) & 0xffff;
679 }
680 
681 static inline uint16_t applyPPCha (uint64_t value) {
682  return ((value + 0x8000) >> 16) & 0xffff;
683 }
684 
685 static inline uint16_t applyPPChigher(uint64_t value) {
686  return (value >> 32) & 0xffff;
687 }
688 
689 static inline uint16_t applyPPChighera (uint64_t value) {
690  return ((value + 0x8000) >> 32) & 0xffff;
691 }
692 
693 static inline uint16_t applyPPChighest(uint64_t value) {
694  return (value >> 48) & 0xffff;
695 }
696 
697 static inline uint16_t applyPPChighesta (uint64_t value) {
698  return ((value + 0x8000) >> 48) & 0xffff;
699 }
700 
701 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section,
702  uint64_t Offset, uint64_t Value,
703  uint32_t Type, int64_t Addend) {
704  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
705  switch (Type) {
706  default:
707  llvm_unreachable("Relocation type not implemented yet!");
708  break;
709  case ELF::R_PPC_ADDR16_LO:
710  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
711  break;
712  case ELF::R_PPC_ADDR16_HI:
713  writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
714  break;
715  case ELF::R_PPC_ADDR16_HA:
716  writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
717  break;
718  }
719 }
720 
721 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
722  uint64_t Offset, uint64_t Value,
723  uint32_t Type, int64_t Addend) {
724  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
725  switch (Type) {
726  default:
727  llvm_unreachable("Relocation type not implemented yet!");
728  break;
729  case ELF::R_PPC64_ADDR16:
730  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
731  break;
732  case ELF::R_PPC64_ADDR16_DS:
733  writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
734  break;
735  case ELF::R_PPC64_ADDR16_LO:
736  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
737  break;
738  case ELF::R_PPC64_ADDR16_LO_DS:
739  writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
740  break;
741  case ELF::R_PPC64_ADDR16_HI:
742  case ELF::R_PPC64_ADDR16_HIGH:
743  writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
744  break;
745  case ELF::R_PPC64_ADDR16_HA:
746  case ELF::R_PPC64_ADDR16_HIGHA:
747  writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
748  break;
749  case ELF::R_PPC64_ADDR16_HIGHER:
750  writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
751  break;
752  case ELF::R_PPC64_ADDR16_HIGHERA:
753  writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
754  break;
755  case ELF::R_PPC64_ADDR16_HIGHEST:
756  writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
757  break;
758  case ELF::R_PPC64_ADDR16_HIGHESTA:
759  writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
760  break;
761  case ELF::R_PPC64_ADDR14: {
762  assert(((Value + Addend) & 3) == 0);
763  // Preserve the AA/LK bits in the branch instruction
764  uint8_t aalk = *(LocalAddress + 3);
765  writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
766  } break;
767  case ELF::R_PPC64_REL16_LO: {
768  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
769  uint64_t Delta = Value - FinalAddress + Addend;
770  writeInt16BE(LocalAddress, applyPPClo(Delta));
771  } break;
772  case ELF::R_PPC64_REL16_HI: {
773  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
774  uint64_t Delta = Value - FinalAddress + Addend;
775  writeInt16BE(LocalAddress, applyPPChi(Delta));
776  } break;
777  case ELF::R_PPC64_REL16_HA: {
778  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
779  uint64_t Delta = Value - FinalAddress + Addend;
780  writeInt16BE(LocalAddress, applyPPCha(Delta));
781  } break;
782  case ELF::R_PPC64_ADDR32: {
783  int64_t Result = static_cast<int64_t>(Value + Addend);
784  if (SignExtend64<32>(Result) != Result)
785  llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
786  writeInt32BE(LocalAddress, Result);
787  } break;
788  case ELF::R_PPC64_REL24: {
789  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
790  int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
791  if (SignExtend64<26>(delta) != delta)
792  llvm_unreachable("Relocation R_PPC64_REL24 overflow");
793  // We preserve bits other than LI field, i.e. PO and AA/LK fields.
794  uint32_t Inst = readBytesUnaligned(LocalAddress, 4);
795  writeInt32BE(LocalAddress, (Inst & 0xFC000003) | (delta & 0x03FFFFFC));
796  } break;
797  case ELF::R_PPC64_REL32: {
798  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
799  int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
800  if (SignExtend64<32>(delta) != delta)
801  llvm_unreachable("Relocation R_PPC64_REL32 overflow");
802  writeInt32BE(LocalAddress, delta);
803  } break;
804  case ELF::R_PPC64_REL64: {
805  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
806  uint64_t Delta = Value - FinalAddress + Addend;
807  writeInt64BE(LocalAddress, Delta);
808  } break;
809  case ELF::R_PPC64_ADDR64:
810  writeInt64BE(LocalAddress, Value + Addend);
811  break;
812  }
813 }
814 
815 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
816  uint64_t Offset, uint64_t Value,
817  uint32_t Type, int64_t Addend) {
818  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
819  switch (Type) {
820  default:
821  llvm_unreachable("Relocation type not implemented yet!");
822  break;
823  case ELF::R_390_PC16DBL:
824  case ELF::R_390_PLT16DBL: {
825  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
826  assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
827  writeInt16BE(LocalAddress, Delta / 2);
828  break;
829  }
830  case ELF::R_390_PC32DBL:
831  case ELF::R_390_PLT32DBL: {
832  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
833  assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
834  writeInt32BE(LocalAddress, Delta / 2);
835  break;
836  }
837  case ELF::R_390_PC16: {
838  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
839  assert(int16_t(Delta) == Delta && "R_390_PC16 overflow");
840  writeInt16BE(LocalAddress, Delta);
841  break;
842  }
843  case ELF::R_390_PC32: {
844  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
845  assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
846  writeInt32BE(LocalAddress, Delta);
847  break;
848  }
849  case ELF::R_390_PC64: {
850  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
851  writeInt64BE(LocalAddress, Delta);
852  break;
853  }
854  case ELF::R_390_8:
855  *LocalAddress = (uint8_t)(Value + Addend);
856  break;
857  case ELF::R_390_16:
858  writeInt16BE(LocalAddress, Value + Addend);
859  break;
860  case ELF::R_390_32:
861  writeInt32BE(LocalAddress, Value + Addend);
862  break;
863  case ELF::R_390_64:
864  writeInt64BE(LocalAddress, Value + Addend);
865  break;
866  }
867 }
868 
869 void RuntimeDyldELF::resolveBPFRelocation(const SectionEntry &Section,
870  uint64_t Offset, uint64_t Value,
871  uint32_t Type, int64_t Addend) {
872  bool isBE = Arch == Triple::bpfeb;
873 
874  switch (Type) {
875  default:
876  llvm_unreachable("Relocation type not implemented yet!");
877  break;
878  case ELF::R_BPF_NONE:
879  break;
880  case ELF::R_BPF_64_64: {
881  write(isBE, Section.getAddressWithOffset(Offset), Value + Addend);
882  LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
883  << format("%p\n", Section.getAddressWithOffset(Offset)));
884  break;
885  }
886  case ELF::R_BPF_64_32: {
887  Value += Addend;
888  assert(Value <= UINT32_MAX);
889  write(isBE, Section.getAddressWithOffset(Offset), static_cast<uint32_t>(Value));
890  LLVM_DEBUG(dbgs() << "Writing " << format("%p", Value) << " at "
891  << format("%p\n", Section.getAddressWithOffset(Offset)));
892  break;
893  }
894  }
895 }
896 
897 // The target location for the relocation is described by RE.SectionID and
898 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
899 // SectionEntry has three members describing its location.
900 // SectionEntry::Address is the address at which the section has been loaded
901 // into memory in the current (host) process. SectionEntry::LoadAddress is the
902 // address that the section will have in the target process.
903 // SectionEntry::ObjAddress is the address of the bits for this section in the
904 // original emitted object image (also in the current address space).
905 //
906 // Relocations will be applied as if the section were loaded at
907 // SectionEntry::LoadAddress, but they will be applied at an address based
908 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
909 // Target memory contents if they are required for value calculations.
910 //
911 // The Value parameter here is the load address of the symbol for the
912 // relocation to be applied. For relocations which refer to symbols in the
913 // current object Value will be the LoadAddress of the section in which
914 // the symbol resides (RE.Addend provides additional information about the
915 // symbol location). For external symbols, Value will be the address of the
916 // symbol in the target address space.
917 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
918  uint64_t Value) {
919  const SectionEntry &Section = Sections[RE.SectionID];
920  return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
921  RE.SymOffset, RE.SectionID);
922 }
923 
924 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
925  uint64_t Offset, uint64_t Value,
926  uint32_t Type, int64_t Addend,
927  uint64_t SymOffset, SID SectionID) {
928  switch (Arch) {
929  case Triple::x86_64:
930  resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
931  break;
932  case Triple::x86:
933  resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
934  (uint32_t)(Addend & 0xffffffffL));
935  break;
936  case Triple::aarch64:
937  case Triple::aarch64_be:
938  resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
939  break;
940  case Triple::arm: // Fall through.
941  case Triple::armeb:
942  case Triple::thumb:
943  case Triple::thumbeb:
944  resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
945  (uint32_t)(Addend & 0xffffffffL));
946  break;
947  case Triple::ppc:
948  resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
949  break;
950  case Triple::ppc64: // Fall through.
951  case Triple::ppc64le:
952  resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
953  break;
954  case Triple::systemz:
955  resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
956  break;
957  case Triple::bpfel:
958  case Triple::bpfeb:
959  resolveBPFRelocation(Section, Offset, Value, Type, Addend);
960  break;
961  default:
962  llvm_unreachable("Unsupported CPU type!");
963  }
964 }
965 
966 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
967  return (void *)(Sections[SectionID].getObjAddress() + Offset);
968 }
969 
970 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
971  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
972  if (Value.SymbolName)
974  else
976 }
977 
978 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType,
979  bool IsLocal) const {
980  switch (RelType) {
981  case ELF::R_MICROMIPS_GOT16:
982  if (IsLocal)
983  return ELF::R_MICROMIPS_LO16;
984  break;
985  case ELF::R_MICROMIPS_HI16:
986  return ELF::R_MICROMIPS_LO16;
987  case ELF::R_MIPS_GOT16:
988  if (IsLocal)
989  return ELF::R_MIPS_LO16;
990  break;
991  case ELF::R_MIPS_HI16:
992  return ELF::R_MIPS_LO16;
993  case ELF::R_MIPS_PCHI16:
994  return ELF::R_MIPS_PCLO16;
995  default:
996  break;
997  }
998  return ELF::R_MIPS_NONE;
999 }
1000 
1001 // Sometimes we don't need to create thunk for a branch.
1002 // This typically happens when branch target is located
1003 // in the same object file. In such case target is either
1004 // a weak symbol or symbol in a different executable section.
1005 // This function checks if branch target is located in the
1006 // same object file and if distance between source and target
1007 // fits R_AARCH64_CALL26 relocation. If both conditions are
1008 // met, it emits direct jump to the target and returns true.
1009 // Otherwise false is returned and thunk is created.
1010 bool RuntimeDyldELF::resolveAArch64ShortBranch(
1011  unsigned SectionID, relocation_iterator RelI,
1012  const RelocationValueRef &Value) {
1013  uint64_t Address;
1014  if (Value.SymbolName) {
1015  auto Loc = GlobalSymbolTable.find(Value.SymbolName);
1016 
1017  // Don't create direct branch for external symbols.
1018  if (Loc == GlobalSymbolTable.end())
1019  return false;
1020 
1021  const auto &SymInfo = Loc->second;
1022  Address =
1023  uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset(
1024  SymInfo.getOffset()));
1025  } else {
1026  Address = uint64_t(Sections[Value.SectionID].getLoadAddress());
1027  }
1028  uint64_t Offset = RelI->getOffset();
1029  uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset);
1030 
1031  // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27
1032  // If distance between source and target is out of range then we should
1033  // create thunk.
1034  if (!isInt<28>(Address + Value.Addend - SourceAddress))
1035  return false;
1036 
1037  resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(),
1038  Value.Addend);
1039 
1040  return true;
1041 }
1042 
1043 void RuntimeDyldELF::resolveAArch64Branch(unsigned SectionID,
1044  const RelocationValueRef &Value,
1045  relocation_iterator RelI,
1046  StubMap &Stubs) {
1047 
1048  LLVM_DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1049  SectionEntry &Section = Sections[SectionID];
1050 
1051  uint64_t Offset = RelI->getOffset();
1052  unsigned RelType = RelI->getType();
1053  // Look for an existing stub.
1054  StubMap::const_iterator i = Stubs.find(Value);
1055  if (i != Stubs.end()) {
1056  resolveRelocation(Section, Offset,
1057  (uint64_t)Section.getAddressWithOffset(i->second),
1058  RelType, 0);
1059  LLVM_DEBUG(dbgs() << " Stub function found\n");
1060  } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) {
1061  // Create a new stub function.
1062  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1063  Stubs[Value] = Section.getStubOffset();
1064  uint8_t *StubTargetAddr = createStubFunction(
1065  Section.getAddressWithOffset(Section.getStubOffset()));
1066 
1067  RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.getAddress(),
1068  ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1069  RelocationEntry REmovk_g2(SectionID,
1070  StubTargetAddr - Section.getAddress() + 4,
1071  ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1072  RelocationEntry REmovk_g1(SectionID,
1073  StubTargetAddr - Section.getAddress() + 8,
1074  ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1075  RelocationEntry REmovk_g0(SectionID,
1076  StubTargetAddr - Section.getAddress() + 12,
1077  ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1078 
1079  if (Value.SymbolName) {
1080  addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1081  addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1082  addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1083  addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1084  } else {
1085  addRelocationForSection(REmovz_g3, Value.SectionID);
1086  addRelocationForSection(REmovk_g2, Value.SectionID);
1087  addRelocationForSection(REmovk_g1, Value.SectionID);
1088  addRelocationForSection(REmovk_g0, Value.SectionID);
1089  }
1090  resolveRelocation(Section, Offset,
1091  reinterpret_cast<uint64_t>(Section.getAddressWithOffset(
1092  Section.getStubOffset())),
1093  RelType, 0);
1094  Section.advanceStubOffset(getMaxStubSize());
1095  }
1096 }
1097 
1100  unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
1101  ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
1102  const auto &Obj = cast<ELFObjectFileBase>(O);
1103  uint64_t RelType = RelI->getType();
1104  int64_t Addend = 0;
1105  if (Expected<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend())
1106  Addend = *AddendOrErr;
1107  else
1108  consumeError(AddendOrErr.takeError());
1109  elf_symbol_iterator Symbol = RelI->getSymbol();
1110 
1111  // Obtain the symbol name which is referenced in the relocation
1112  StringRef TargetName;
1113  if (Symbol != Obj.symbol_end()) {
1114  if (auto TargetNameOrErr = Symbol->getName())
1115  TargetName = *TargetNameOrErr;
1116  else
1117  return TargetNameOrErr.takeError();
1118  }
1119  LLVM_DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1120  << " TargetName: " << TargetName << "\n");
1121  RelocationValueRef Value;
1122  // First search for the symbol in the local symbol table
1123  SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1124 
1125  // Search for the symbol in the global symbol table
1127  if (Symbol != Obj.symbol_end()) {
1128  gsi = GlobalSymbolTable.find(TargetName.data());
1129  Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType();
1130  if (!SymTypeOrErr) {
1131  std::string Buf;
1132  raw_string_ostream OS(Buf);
1133  logAllUnhandledErrors(SymTypeOrErr.takeError(), OS);
1134  OS.flush();
1135  report_fatal_error(Buf);
1136  }
1137  SymType = *SymTypeOrErr;
1138  }
1139  if (gsi != GlobalSymbolTable.end()) {
1140  const auto &SymInfo = gsi->second;
1141  Value.SectionID = SymInfo.getSectionID();
1142  Value.Offset = SymInfo.getOffset();
1143  Value.Addend = SymInfo.getOffset() + Addend;
1144  } else {
1145  switch (SymType) {
1146  case SymbolRef::ST_Debug: {
1147  // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1148  // and can be changed by another developers. Maybe best way is add
1149  // a new symbol type ST_Section to SymbolRef and use it.
1150  auto SectionOrErr = Symbol->getSection();
1151  if (!SectionOrErr) {
1152  std::string Buf;
1153  raw_string_ostream OS(Buf);
1154  logAllUnhandledErrors(SectionOrErr.takeError(), OS);
1155  OS.flush();
1156  report_fatal_error(Buf);
1157  }
1158  section_iterator si = *SectionOrErr;
1159  if (si == Obj.section_end())
1160  llvm_unreachable("Symbol section not found, bad object file format!");
1161  LLVM_DEBUG(dbgs() << "\t\tThis is section symbol\n");
1162  bool isCode = si->isText();
1163  if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode,
1164  ObjSectionToID))
1165  Value.SectionID = *SectionIDOrErr;
1166  else
1167  return SectionIDOrErr.takeError();
1168  Value.Addend = Addend;
1169  break;
1170  }
1171  case SymbolRef::ST_Data:
1172  case SymbolRef::ST_Function:
1173  case SymbolRef::ST_Unknown: {
1174  Value.SymbolName = TargetName.data();
1175  Value.Addend = Addend;
1176 
1177  // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1178  // will manifest here as a NULL symbol name.
1179  // We can set this as a valid (but empty) symbol name, and rely
1180  // on addRelocationForSymbol to handle this.
1181  if (!Value.SymbolName)
1182  Value.SymbolName = "";
1183  break;
1184  }
1185  default:
1186  llvm_unreachable("Unresolved symbol type!");
1187  break;
1188  }
1189  }
1190 
1191  uint64_t Offset = RelI->getOffset();
1192 
1193  LLVM_DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1194  << "\n");
1195  if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be)) {
1196  if (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26) {
1197  resolveAArch64Branch(SectionID, Value, RelI, Stubs);
1198  } else if (RelType == ELF::R_AARCH64_ADR_GOT_PAGE) {
1199  // Craete new GOT entry or find existing one. If GOT entry is
1200  // to be created, then we also emit ABS64 relocation for it.
1201  uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1202  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1203  ELF::R_AARCH64_ADR_PREL_PG_HI21);
1204 
1205  } else if (RelType == ELF::R_AARCH64_LD64_GOT_LO12_NC) {
1206  uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1207  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1208  ELF::R_AARCH64_LDST64_ABS_LO12_NC);
1209  } else {
1210  processSimpleRelocation(SectionID, Offset, RelType, Value);
1211  }
1212  } else if (Arch == Triple::arm) {
1213  if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1214  RelType == ELF::R_ARM_JUMP24) {
1215  // This is an ARM branch relocation, need to use a stub function.
1216  LLVM_DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n");
1217  SectionEntry &Section = Sections[SectionID];
1218 
1219  // Look for an existing stub.
1220  StubMap::const_iterator i = Stubs.find(Value);
1221  if (i != Stubs.end()) {
1222  resolveRelocation(
1223  Section, Offset,
1224  reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)),
1225  RelType, 0);
1226  LLVM_DEBUG(dbgs() << " Stub function found\n");
1227  } else {
1228  // Create a new stub function.
1229  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1230  Stubs[Value] = Section.getStubOffset();
1231  uint8_t *StubTargetAddr = createStubFunction(
1232  Section.getAddressWithOffset(Section.getStubOffset()));
1233  RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1234  ELF::R_ARM_ABS32, Value.Addend);
1235  if (Value.SymbolName)
1237  else
1239 
1240  resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1241  Section.getAddressWithOffset(
1242  Section.getStubOffset())),
1243  RelType, 0);
1244  Section.advanceStubOffset(getMaxStubSize());
1245  }
1246  } else {
1247  uint32_t *Placeholder =
1248  reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1249  if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1250  RelType == ELF::R_ARM_ABS32) {
1251  Value.Addend += *Placeholder;
1252  } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1253  // See ELF for ARM documentation
1254  Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1255  }
1256  processSimpleRelocation(SectionID, Offset, RelType, Value);
1257  }
1258  } else if (IsMipsO32ABI) {
1259  uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1260  computePlaceholderAddress(SectionID, Offset));
1261  uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1262  if (RelType == ELF::R_MIPS_26) {
1263  // This is an Mips branch relocation, need to use a stub function.
1264  LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1265  SectionEntry &Section = Sections[SectionID];
1266 
1267  // Extract the addend from the instruction.
1268  // We shift up by two since the Value will be down shifted again
1269  // when applying the relocation.
1270  uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1271 
1272  Value.Addend += Addend;
1273 
1274  // Look up for existing stub.
1275  StubMap::const_iterator i = Stubs.find(Value);
1276  if (i != Stubs.end()) {
1277  RelocationEntry RE(SectionID, Offset, RelType, i->second);
1278  addRelocationForSection(RE, SectionID);
1279  LLVM_DEBUG(dbgs() << " Stub function found\n");
1280  } else {
1281  // Create a new stub function.
1282  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1283  Stubs[Value] = Section.getStubOffset();
1284 
1285  unsigned AbiVariant = Obj.getPlatformFlags();
1286 
1287  uint8_t *StubTargetAddr = createStubFunction(
1288  Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1289 
1290  // Creating Hi and Lo relocations for the filled stub instructions.
1291  RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1292  ELF::R_MIPS_HI16, Value.Addend);
1293  RelocationEntry RELo(SectionID,
1294  StubTargetAddr - Section.getAddress() + 4,
1295  ELF::R_MIPS_LO16, Value.Addend);
1296 
1297  if (Value.SymbolName) {
1298  addRelocationForSymbol(REHi, Value.SymbolName);
1299  addRelocationForSymbol(RELo, Value.SymbolName);
1300  } else {
1301  addRelocationForSection(REHi, Value.SectionID);
1302  addRelocationForSection(RELo, Value.SectionID);
1303  }
1304 
1305  RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1306  addRelocationForSection(RE, SectionID);
1307  Section.advanceStubOffset(getMaxStubSize());
1308  }
1309  } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) {
1310  int64_t Addend = (Opcode & 0x0000ffff) << 16;
1311  RelocationEntry RE(SectionID, Offset, RelType, Addend);
1312  PendingRelocs.push_back(std::make_pair(Value, RE));
1313  } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) {
1314  int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff);
1315  for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) {
1316  const RelocationValueRef &MatchingValue = I->first;
1317  RelocationEntry &Reloc = I->second;
1318  if (MatchingValue == Value &&
1319  RelType == getMatchingLoRelocation(Reloc.RelType) &&
1320  SectionID == Reloc.SectionID) {
1321  Reloc.Addend += Addend;
1322  if (Value.SymbolName)
1323  addRelocationForSymbol(Reloc, Value.SymbolName);
1324  else
1325  addRelocationForSection(Reloc, Value.SectionID);
1326  I = PendingRelocs.erase(I);
1327  } else
1328  ++I;
1329  }
1330  RelocationEntry RE(SectionID, Offset, RelType, Addend);
1331  if (Value.SymbolName)
1333  else
1335  } else {
1336  if (RelType == ELF::R_MIPS_32)
1337  Value.Addend += Opcode;
1338  else if (RelType == ELF::R_MIPS_PC16)
1339  Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1340  else if (RelType == ELF::R_MIPS_PC19_S2)
1341  Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1342  else if (RelType == ELF::R_MIPS_PC21_S2)
1343  Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1344  else if (RelType == ELF::R_MIPS_PC26_S2)
1345  Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1346  processSimpleRelocation(SectionID, Offset, RelType, Value);
1347  }
1348  } else if (IsMipsN32ABI || IsMipsN64ABI) {
1349  uint32_t r_type = RelType & 0xff;
1350  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1351  if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1352  || r_type == ELF::R_MIPS_GOT_DISP) {
1353  StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1354  if (i != GOTSymbolOffsets.end())
1355  RE.SymOffset = i->second;
1356  else {
1357  RE.SymOffset = allocateGOTEntries(1);
1358  GOTSymbolOffsets[TargetName] = RE.SymOffset;
1359  }
1360  if (Value.SymbolName)
1362  else
1364  } else if (RelType == ELF::R_MIPS_26) {
1365  // This is an Mips branch relocation, need to use a stub function.
1366  LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1367  SectionEntry &Section = Sections[SectionID];
1368 
1369  // Look up for existing stub.
1370  StubMap::const_iterator i = Stubs.find(Value);
1371  if (i != Stubs.end()) {
1372  RelocationEntry RE(SectionID, Offset, RelType, i->second);
1373  addRelocationForSection(RE, SectionID);
1374  LLVM_DEBUG(dbgs() << " Stub function found\n");
1375  } else {
1376  // Create a new stub function.
1377  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1378  Stubs[Value] = Section.getStubOffset();
1379 
1380  unsigned AbiVariant = Obj.getPlatformFlags();
1381 
1382  uint8_t *StubTargetAddr = createStubFunction(
1383  Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1384 
1385  if (IsMipsN32ABI) {
1386  // Creating Hi and Lo relocations for the filled stub instructions.
1387  RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1388  ELF::R_MIPS_HI16, Value.Addend);
1389  RelocationEntry RELo(SectionID,
1390  StubTargetAddr - Section.getAddress() + 4,
1391  ELF::R_MIPS_LO16, Value.Addend);
1392  if (Value.SymbolName) {
1393  addRelocationForSymbol(REHi, Value.SymbolName);
1394  addRelocationForSymbol(RELo, Value.SymbolName);
1395  } else {
1396  addRelocationForSection(REHi, Value.SectionID);
1397  addRelocationForSection(RELo, Value.SectionID);
1398  }
1399  } else {
1400  // Creating Highest, Higher, Hi and Lo relocations for the filled stub
1401  // instructions.
1402  RelocationEntry REHighest(SectionID,
1403  StubTargetAddr - Section.getAddress(),
1404  ELF::R_MIPS_HIGHEST, Value.Addend);
1405  RelocationEntry REHigher(SectionID,
1406  StubTargetAddr - Section.getAddress() + 4,
1407  ELF::R_MIPS_HIGHER, Value.Addend);
1408  RelocationEntry REHi(SectionID,
1409  StubTargetAddr - Section.getAddress() + 12,
1410  ELF::R_MIPS_HI16, Value.Addend);
1411  RelocationEntry RELo(SectionID,
1412  StubTargetAddr - Section.getAddress() + 20,
1413  ELF::R_MIPS_LO16, Value.Addend);
1414  if (Value.SymbolName) {
1415  addRelocationForSymbol(REHighest, Value.SymbolName);
1416  addRelocationForSymbol(REHigher, Value.SymbolName);
1417  addRelocationForSymbol(REHi, Value.SymbolName);
1418  addRelocationForSymbol(RELo, Value.SymbolName);
1419  } else {
1420  addRelocationForSection(REHighest, Value.SectionID);
1421  addRelocationForSection(REHigher, Value.SectionID);
1422  addRelocationForSection(REHi, Value.SectionID);
1423  addRelocationForSection(RELo, Value.SectionID);
1424  }
1425  }
1426  RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1427  addRelocationForSection(RE, SectionID);
1428  Section.advanceStubOffset(getMaxStubSize());
1429  }
1430  } else {
1431  processSimpleRelocation(SectionID, Offset, RelType, Value);
1432  }
1433 
1434  } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1435  if (RelType == ELF::R_PPC64_REL24) {
1436  // Determine ABI variant in use for this object.
1437  unsigned AbiVariant = Obj.getPlatformFlags();
1438  AbiVariant &= ELF::EF_PPC64_ABI;
1439  // A PPC branch relocation will need a stub function if the target is
1440  // an external symbol (either Value.SymbolName is set, or SymType is
1441  // Symbol::ST_Unknown) or if the target address is not within the
1442  // signed 24-bits branch address.
1443  SectionEntry &Section = Sections[SectionID];
1444  uint8_t *Target = Section.getAddressWithOffset(Offset);
1445  bool RangeOverflow = false;
1446  bool IsExtern = Value.SymbolName || SymType == SymbolRef::ST_Unknown;
1447  if (!IsExtern) {
1448  if (AbiVariant != 2) {
1449  // In the ELFv1 ABI, a function call may point to the .opd entry,
1450  // so the final symbol value is calculated based on the relocation
1451  // values in the .opd section.
1452  if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
1453  return std::move(Err);
1454  } else {
1455  // In the ELFv2 ABI, a function symbol may provide a local entry
1456  // point, which must be used for direct calls.
1457  if (Value.SectionID == SectionID){
1458  uint8_t SymOther = Symbol->getOther();
1459  Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1460  }
1461  }
1462  uint8_t *RelocTarget =
1463  Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
1464  int64_t delta = static_cast<int64_t>(Target - RelocTarget);
1465  // If it is within 26-bits branch range, just set the branch target
1466  if (SignExtend64<26>(delta) != delta) {
1467  RangeOverflow = true;
1468  } else if ((AbiVariant != 2) ||
1469  (AbiVariant == 2 && Value.SectionID == SectionID)) {
1470  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1472  }
1473  }
1474  if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID) ||
1475  RangeOverflow) {
1476  // It is an external symbol (either Value.SymbolName is set, or
1477  // SymType is SymbolRef::ST_Unknown) or out of range.
1478  StubMap::const_iterator i = Stubs.find(Value);
1479  if (i != Stubs.end()) {
1480  // Symbol function stub already created, just relocate to it
1481  resolveRelocation(Section, Offset,
1482  reinterpret_cast<uint64_t>(
1483  Section.getAddressWithOffset(i->second)),
1484  RelType, 0);
1485  LLVM_DEBUG(dbgs() << " Stub function found\n");
1486  } else {
1487  // Create a new stub function.
1488  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1489  Stubs[Value] = Section.getStubOffset();
1490  uint8_t *StubTargetAddr = createStubFunction(
1491  Section.getAddressWithOffset(Section.getStubOffset()),
1492  AbiVariant);
1493  RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1494  ELF::R_PPC64_ADDR64, Value.Addend);
1495 
1496  // Generates the 64-bits address loads as exemplified in section
1497  // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1498  // apply to the low part of the instructions, so we have to update
1499  // the offset according to the target endianness.
1500  uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress();
1501  if (!IsTargetLittleEndian)
1502  StubRelocOffset += 2;
1503 
1504  RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1505  ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1506  RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1507  ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1508  RelocationEntry REh(SectionID, StubRelocOffset + 12,
1509  ELF::R_PPC64_ADDR16_HI, Value.Addend);
1510  RelocationEntry REl(SectionID, StubRelocOffset + 16,
1511  ELF::R_PPC64_ADDR16_LO, Value.Addend);
1512 
1513  if (Value.SymbolName) {
1514  addRelocationForSymbol(REhst, Value.SymbolName);
1515  addRelocationForSymbol(REhr, Value.SymbolName);
1516  addRelocationForSymbol(REh, Value.SymbolName);
1517  addRelocationForSymbol(REl, Value.SymbolName);
1518  } else {
1519  addRelocationForSection(REhst, Value.SectionID);
1520  addRelocationForSection(REhr, Value.SectionID);
1521  addRelocationForSection(REh, Value.SectionID);
1522  addRelocationForSection(REl, Value.SectionID);
1523  }
1524 
1525  resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1526  Section.getAddressWithOffset(
1527  Section.getStubOffset())),
1528  RelType, 0);
1529  Section.advanceStubOffset(getMaxStubSize());
1530  }
1531  if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID)) {
1532  // Restore the TOC for external calls
1533  if (AbiVariant == 2)
1534  writeInt32BE(Target + 4, 0xE8410018); // ld r2,24(r1)
1535  else
1536  writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1537  }
1538  }
1539  } else if (RelType == ELF::R_PPC64_TOC16 ||
1540  RelType == ELF::R_PPC64_TOC16_DS ||
1541  RelType == ELF::R_PPC64_TOC16_LO ||
1542  RelType == ELF::R_PPC64_TOC16_LO_DS ||
1543  RelType == ELF::R_PPC64_TOC16_HI ||
1544  RelType == ELF::R_PPC64_TOC16_HA) {
1545  // These relocations are supposed to subtract the TOC address from
1546  // the final value. This does not fit cleanly into the RuntimeDyld
1547  // scheme, since there may be *two* sections involved in determining
1548  // the relocation value (the section of the symbol referred to by the
1549  // relocation, and the TOC section associated with the current module).
1550  //
1551  // Fortunately, these relocations are currently only ever generated
1552  // referring to symbols that themselves reside in the TOC, which means
1553  // that the two sections are actually the same. Thus they cancel out
1554  // and we can immediately resolve the relocation right now.
1555  switch (RelType) {
1556  case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1557  case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1558  case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1559  case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1560  case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1561  case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1562  default: llvm_unreachable("Wrong relocation type.");
1563  }
1564 
1565  RelocationValueRef TOCValue;
1566  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
1567  return std::move(Err);
1568  if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1569  llvm_unreachable("Unsupported TOC relocation.");
1570  Value.Addend -= TOCValue.Addend;
1571  resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1572  } else {
1573  // There are two ways to refer to the TOC address directly: either
1574  // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1575  // ignored), or via any relocation that refers to the magic ".TOC."
1576  // symbols (in which case the addend is respected).
1577  if (RelType == ELF::R_PPC64_TOC) {
1578  RelType = ELF::R_PPC64_ADDR64;
1579  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1580  return std::move(Err);
1581  } else if (TargetName == ".TOC.") {
1582  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1583  return std::move(Err);
1584  Value.Addend += Addend;
1585  }
1586 
1587  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1588 
1589  if (Value.SymbolName)
1591  else
1593  }
1594  } else if (Arch == Triple::systemz &&
1595  (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1596  // Create function stubs for both PLT and GOT references, regardless of
1597  // whether the GOT reference is to data or code. The stub contains the
1598  // full address of the symbol, as needed by GOT references, and the
1599  // executable part only adds an overhead of 8 bytes.
1600  //
1601  // We could try to conserve space by allocating the code and data
1602  // parts of the stub separately. However, as things stand, we allocate
1603  // a stub for every relocation, so using a GOT in JIT code should be
1604  // no less space efficient than using an explicit constant pool.
1605  LLVM_DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1606  SectionEntry &Section = Sections[SectionID];
1607 
1608  // Look for an existing stub.
1609  StubMap::const_iterator i = Stubs.find(Value);
1610  uintptr_t StubAddress;
1611  if (i != Stubs.end()) {
1612  StubAddress = uintptr_t(Section.getAddressWithOffset(i->second));
1613  LLVM_DEBUG(dbgs() << " Stub function found\n");
1614  } else {
1615  // Create a new stub function.
1616  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1617 
1618  uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1619  uintptr_t StubAlignment = getStubAlignment();
1620  StubAddress =
1621  (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1622  -StubAlignment;
1623  unsigned StubOffset = StubAddress - BaseAddress;
1624 
1625  Stubs[Value] = StubOffset;
1626  createStubFunction((uint8_t *)StubAddress);
1627  RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1628  Value.Offset);
1629  if (Value.SymbolName)
1631  else
1633  Section.advanceStubOffset(getMaxStubSize());
1634  }
1635 
1636  if (RelType == ELF::R_390_GOTENT)
1637  resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1638  Addend);
1639  else
1640  resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1641  } else if (Arch == Triple::x86_64) {
1642  if (RelType == ELF::R_X86_64_PLT32) {
1643  // The way the PLT relocations normally work is that the linker allocates
1644  // the
1645  // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1646  // entry will then jump to an address provided by the GOT. On first call,
1647  // the
1648  // GOT address will point back into PLT code that resolves the symbol. After
1649  // the first call, the GOT entry points to the actual function.
1650  //
1651  // For local functions we're ignoring all of that here and just replacing
1652  // the PLT32 relocation type with PC32, which will translate the relocation
1653  // into a PC-relative call directly to the function. For external symbols we
1654  // can't be sure the function will be within 2^32 bytes of the call site, so
1655  // we need to create a stub, which calls into the GOT. This case is
1656  // equivalent to the usual PLT implementation except that we use the stub
1657  // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1658  // rather than allocating a PLT section.
1659  if (Value.SymbolName) {
1660  // This is a call to an external function.
1661  // Look for an existing stub.
1662  SectionEntry &Section = Sections[SectionID];
1663  StubMap::const_iterator i = Stubs.find(Value);
1664  uintptr_t StubAddress;
1665  if (i != Stubs.end()) {
1666  StubAddress = uintptr_t(Section.getAddress()) + i->second;
1667  LLVM_DEBUG(dbgs() << " Stub function found\n");
1668  } else {
1669  // Create a new stub function (equivalent to a PLT entry).
1670  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1671 
1672  uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1673  uintptr_t StubAlignment = getStubAlignment();
1674  StubAddress =
1675  (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1676  -StubAlignment;
1677  unsigned StubOffset = StubAddress - BaseAddress;
1678  Stubs[Value] = StubOffset;
1679  createStubFunction((uint8_t *)StubAddress);
1680 
1681  // Bump our stub offset counter
1682  Section.advanceStubOffset(getMaxStubSize());
1683 
1684  // Allocate a GOT Entry
1685  uint64_t GOTOffset = allocateGOTEntries(1);
1686 
1687  // The load of the GOT address has an addend of -4
1688  resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4,
1689  ELF::R_X86_64_PC32);
1690 
1691  // Fill in the value of the symbol we're targeting into the GOT
1693  computeGOTOffsetRE(GOTOffset, 0, ELF::R_X86_64_64),
1694  Value.SymbolName);
1695  }
1696 
1697  // Make the target call a call into the stub table.
1698  resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1699  Addend);
1700  } else {
1701  RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1702  Value.Offset);
1704  }
1705  } else if (RelType == ELF::R_X86_64_GOTPCREL ||
1706  RelType == ELF::R_X86_64_GOTPCRELX ||
1707  RelType == ELF::R_X86_64_REX_GOTPCRELX) {
1708  uint64_t GOTOffset = allocateGOTEntries(1);
1709  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1710  ELF::R_X86_64_PC32);
1711 
1712  // Fill in the value of the symbol we're targeting into the GOT
1713  RelocationEntry RE =
1714  computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1715  if (Value.SymbolName)
1717  else
1719  } else if (RelType == ELF::R_X86_64_GOT64) {
1720  // Fill in a 64-bit GOT offset.
1721  uint64_t GOTOffset = allocateGOTEntries(1);
1722  resolveRelocation(Sections[SectionID], Offset, GOTOffset,
1723  ELF::R_X86_64_64, 0);
1724 
1725  // Fill in the value of the symbol we're targeting into the GOT
1726  RelocationEntry RE =
1727  computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1728  if (Value.SymbolName)
1730  else
1732  } else if (RelType == ELF::R_X86_64_GOTPC64) {
1733  // Materialize the address of the base of the GOT relative to the PC.
1734  // This doesn't create a GOT entry, but it does mean we need a GOT
1735  // section.
1736  (void)allocateGOTEntries(0);
1737  resolveGOTOffsetRelocation(SectionID, Offset, Addend, ELF::R_X86_64_PC64);
1738  } else if (RelType == ELF::R_X86_64_GOTOFF64) {
1739  // GOTOFF relocations ultimately require a section difference relocation.
1740  (void)allocateGOTEntries(0);
1741  processSimpleRelocation(SectionID, Offset, RelType, Value);
1742  } else if (RelType == ELF::R_X86_64_PC32) {
1743  Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1744  processSimpleRelocation(SectionID, Offset, RelType, Value);
1745  } else if (RelType == ELF::R_X86_64_PC64) {
1746  Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1747  processSimpleRelocation(SectionID, Offset, RelType, Value);
1748  } else {
1749  processSimpleRelocation(SectionID, Offset, RelType, Value);
1750  }
1751  } else {
1752  if (Arch == Triple::x86) {
1753  Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1754  }
1755  processSimpleRelocation(SectionID, Offset, RelType, Value);
1756  }
1757  return ++RelI;
1758 }
1759 
1761  // We don't use the GOT in all of these cases, but it's essentially free
1762  // to put them all here.
1763  size_t Result = 0;
1764  switch (Arch) {
1765  case Triple::x86_64:
1766  case Triple::aarch64:
1767  case Triple::aarch64_be:
1768  case Triple::ppc64:
1769  case Triple::ppc64le:
1770  case Triple::systemz:
1771  Result = sizeof(uint64_t);
1772  break;
1773  case Triple::x86:
1774  case Triple::arm:
1775  case Triple::thumb:
1776  Result = sizeof(uint32_t);
1777  break;
1778  case Triple::mips:
1779  case Triple::mipsel:
1780  case Triple::mips64:
1781  case Triple::mips64el:
1782  if (IsMipsO32ABI || IsMipsN32ABI)
1783  Result = sizeof(uint32_t);
1784  else if (IsMipsN64ABI)
1785  Result = sizeof(uint64_t);
1786  else
1787  llvm_unreachable("Mips ABI not handled");
1788  break;
1789  default:
1790  llvm_unreachable("Unsupported CPU type!");
1791  }
1792  return Result;
1793 }
1794 
1795 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned no) {
1796  if (GOTSectionID == 0) {
1797  GOTSectionID = Sections.size();
1798  // Reserve a section id. We'll allocate the section later
1799  // once we know the total size
1800  Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0));
1801  }
1802  uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1803  CurrentGOTIndex += no;
1804  return StartOffset;
1805 }
1806 
1807 uint64_t RuntimeDyldELF::findOrAllocGOTEntry(const RelocationValueRef &Value,
1808  unsigned GOTRelType) {
1809  auto E = GOTOffsetMap.insert({Value, 0});
1810  if (E.second) {
1811  uint64_t GOTOffset = allocateGOTEntries(1);
1812 
1813  // Create relocation for newly created GOT entry
1814  RelocationEntry RE =
1815  computeGOTOffsetRE(GOTOffset, Value.Offset, GOTRelType);
1816  if (Value.SymbolName)
1818  else
1820 
1821  E.first->second = GOTOffset;
1822  }
1823 
1824  return E.first->second;
1825 }
1826 
1827 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID,
1828  uint64_t Offset,
1829  uint64_t GOTOffset,
1830  uint32_t Type) {
1831  // Fill in the relative address of the GOT Entry into the stub
1832  RelocationEntry GOTRE(SectionID, Offset, Type, GOTOffset);
1833  addRelocationForSection(GOTRE, GOTSectionID);
1834 }
1835 
1836 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(uint64_t GOTOffset,
1837  uint64_t SymbolOffset,
1838  uint32_t Type) {
1839  return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1840 }
1841 
1843  ObjSectionToIDMap &SectionMap) {
1844  if (IsMipsO32ABI)
1845  if (!PendingRelocs.empty())
1846  return make_error<RuntimeDyldError>("Can't find matching LO16 reloc");
1847 
1848  // If necessary, allocate the global offset table
1849  if (GOTSectionID != 0) {
1850  // Allocate memory for the section
1851  size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1852  uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1853  GOTSectionID, ".got", false);
1854  if (!Addr)
1855  return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!");
1856 
1857  Sections[GOTSectionID] =
1858  SectionEntry(".got", Addr, TotalSize, TotalSize, 0);
1859 
1860  if (Checker)
1861  Checker->registerSection(Obj.getFileName(), GOTSectionID);
1862 
1863  // For now, initialize all GOT entries to zero. We'll fill them in as
1864  // needed when GOT-based relocations are applied.
1865  memset(Addr, 0, TotalSize);
1866  if (IsMipsN32ABI || IsMipsN64ABI) {
1867  // To correctly resolve Mips GOT relocations, we need a mapping from
1868  // object's sections to GOTs.
1869  for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1870  SI != SE; ++SI) {
1871  if (SI->relocation_begin() != SI->relocation_end()) {
1872  section_iterator RelocatedSection = SI->getRelocatedSection();
1873  ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1874  assert (i != SectionMap.end());
1875  SectionToGOTMap[i->second] = GOTSectionID;
1876  }
1877  }
1878  GOTSymbolOffsets.clear();
1879  }
1880  }
1881 
1882  // Look for and record the EH frame section.
1883  ObjSectionToIDMap::iterator i, e;
1884  for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1885  const SectionRef &Section = i->first;
1886  StringRef Name;
1887  Section.getName(Name);
1888  if (Name == ".eh_frame") {
1889  UnregisteredEHFrameSections.push_back(i->second);
1890  break;
1891  }
1892  }
1893 
1894  GOTSectionID = 0;
1895  CurrentGOTIndex = 0;
1896 
1897  return Error::success();
1898 }
1899 
1901  return Obj.isELF();
1902 }
1903 
1904 bool RuntimeDyldELF::relocationNeedsGot(const RelocationRef &R) const {
1905  unsigned RelTy = R.getType();
1907  return RelTy == ELF::R_AARCH64_ADR_GOT_PAGE ||
1908  RelTy == ELF::R_AARCH64_LD64_GOT_LO12_NC;
1909 
1910  if (Arch == Triple::x86_64)
1911  return RelTy == ELF::R_X86_64_GOTPCREL ||
1912  RelTy == ELF::R_X86_64_GOTPCRELX ||
1913  RelTy == ELF::R_X86_64_GOT64 ||
1914  RelTy == ELF::R_X86_64_REX_GOTPCRELX;
1915  return false;
1916 }
1917 
1918 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
1919  if (Arch != Triple::x86_64)
1920  return true; // Conservative answer
1921 
1922  switch (R.getType()) {
1923  default:
1924  return true; // Conservative answer
1925 
1926 
1927  case ELF::R_X86_64_GOTPCREL:
1928  case ELF::R_X86_64_GOTPCRELX:
1929  case ELF::R_X86_64_REX_GOTPCRELX:
1930  case ELF::R_X86_64_GOTPC64:
1931  case ELF::R_X86_64_GOT64:
1932  case ELF::R_X86_64_GOTOFF64:
1933  case ELF::R_X86_64_PC32:
1934  case ELF::R_X86_64_PC64:
1935  case ELF::R_X86_64_64:
1936  // We know that these reloation types won't need a stub function. This list
1937  // can be extended as needed.
1938  return false;
1939  }
1940 }
1941 
1942 } // namespace llvm
RelocationEntry - used to represent relocations internally in the dynamic linker. ...
static void or32AArch64Imm(void *L, uint64_t Imm)
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:139
This class represents lattice values for constants.
Definition: AllocatorList.h:24
void writeInt16BE(uint8_t *Addr, uint16_t Value)
StringRef getFileName() const
Definition: Binary.cpp:41
void push_back(const T &Elt)
Definition: SmallVector.h:218
uint64_t readBytesUnaligned(uint8_t *Src, unsigned Size) const
Endian-aware read Read the least significant Size bytes from Src.
uint64_t getLoadAddressWithOffset(unsigned OffsetBytes) const
Return the load address of this section with an offset.
RuntimeDyld::MemoryManager & MemMgr
format_object< Ts... > format(const char *Fmt, const Ts &... Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:124
size_t getGOTEntrySize() override
iterator find(StringRef Key)
Definition: StringMap.h:333
constexpr bool isInt< 8 >(int64_t x)
Definition: MathExtras.h:303
This class is the base class for all object file types.
Definition: ObjectFile.h:202
RuntimeDyldCheckerImpl * Checker
static uint16_t applyPPChigher(uint64_t value)
void write32le(void *P, uint32_t V)
Definition: Endian.h:404
static uint16_t applyPPChighesta(uint64_t value)
uint8_t * getAddress() const
Error takeError()
Take ownership of the stored error.
Definition: Error.h:553
static uint16_t applyPPChighera(uint64_t value)
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:128
static std::unique_ptr< RuntimeDyldELF > create(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
static int64_t decodePPC64LocalEntryOffset(unsigned Other)
Definition: ELF.h:393
unsigned SectionID
SectionID - the section this relocation points to.
amdgpu Simplify well known AMD library false Value Value const Twine & Name
amdgpu aa AMDGPU Address space based Alias Analysis Wrapper
DataRefImpl getRawDataRefImpl() const
Definition: SymbolicFile.h:205
This is a value type class that represents a single relocation in the list of relocations in the obje...
Definition: ObjectFile.h:52
std::unique_ptr< RuntimeDyld::LoadedObjectInfo > loadObject(const object::ObjectFile &O) override
std::map< RelocationValueRef, uintptr_t > StubMap
Tagged union holding either a T or a Error.
Definition: CachePruning.h:23
section_iterator_range sections() const
Definition: ObjectFile.h:292
Expected< relocation_iterator > processRelocationRef(unsigned SectionID, relocation_iterator RelI, const ObjectFile &Obj, ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) override
Parses one or more object file relocations (some object files use relocation pairs) and stores it to ...
static uint16_t applyPPChi(uint64_t value)
std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type cast(const Y &Val)
Definition: Casting.h:240
Expected< section_iterator > getSection() const
Get section this symbol is defined in reference to.
Definition: ObjectFile.h:379
const Elf_Sym * getSymbol(DataRefImpl Sym) const
#define P(N)
void addRelocationForSymbol(const RelocationEntry &RE, StringRef SymbolName)
virtual uint8_t getBytesInAddress() const =0
The number of bytes used to represent an address in this object file format.
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
void registerEHFrames() override
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
Error errorCodeToError(std::error_code EC)
Helper for converting an std::error_code to a Error.
Definition: Error.cpp:87
static uint64_t getBits(uint64_t Val, int Start, int End)
void addRelocationForSection(const RelocationEntry &RE, unsigned SectionID)
Interface for looking up the initializer for a variable name, used by Init::resolveReferences.
Definition: Record.h:1774
static StringRef getArchTypePrefix(ArchType Kind)
getArchTypePrefix - Get the "prefix" canonical name for the Kind architecture.
Definition: Triple.cpp:79
Expected< int64_t > getAddend() const
Symbol resolution interface.
Definition: JITSymbol.h:344
static uint16_t applyPPClo(uint64_t value)
virtual basic_symbol_iterator symbol_end() const =0
static Expected< ELFObjectFile< ELFT > > create(MemoryBufferRef Object)
void writeInt32BE(uint8_t *Addr, uint32_t Value)
Expected< unsigned > findOrEmitSection(const ObjectFile &Obj, const SectionRef &Section, bool IsCode, ObjSectionToIDMap &LocalSections)
Find Section in LocalSections.
bool isCompatibleFile(const object::ObjectFile &Obj) const override
DenseMap< SID, SID > SectionToGOTMap
static void write(bool isBE, void *P, T V)
virtual uint8_t * allocateDataSection(uintptr_t Size, unsigned Alignment, unsigned SectionID, StringRef SectionName, bool IsReadOnly)=0
Allocate a memory block of (at least) the given size suitable for data.
bool isELF() const
Definition: Binary.h:109
DataRefImpl getRawDataRefImpl() const
Definition: ObjectFile.h:486
void consumeError(Error Err)
Consume a Error without doing anything.
Definition: Error.h:982
size_t size() const
Definition: SmallVector.h:53
void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner={})
Log all errors (if any) in E to OS.
Definition: Error.cpp:61
uint64_t getType() const
Definition: ObjectFile.h:516
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
bool isLittleEndian() const
Definition: Binary.h:131
static uint16_t applyPPChighest(uint64_t value)
void handleAllErrors(Error E, HandlerTs &&... Handlers)
Behaves the same as handleErrors, except that by contract all errors must be handled by the given han...
Definition: Error.h:905
static ErrorSuccess success()
Create a success value.
Definition: Error.h:327
constexpr bool isInt< 32 >(int64_t x)
Definition: MathExtras.h:309
Error finalizeLoad(const ObjectFile &Obj, ObjSectionToIDMap &SectionMap) override
virtual section_iterator section_begin() const =0
Expected< SymbolRef::Type > getType() const
Definition: ObjectFile.h:383
int64_t Addend
Addend - the relocation addend encoded in the instruction itself.
std::error_code getName(StringRef &Result) const
Definition: ObjectFile.h:414
uint32_t RelType
RelType - relocation type.
JITSymbolResolver & Resolver
virtual unsigned getPlatformFlags() const =0
Returns platform-specific object flags, if any.
LLVM_NODISCARD bool isa(const Y &Val)
Definition: Casting.h:142
static void or32le(void *P, int32_t V)
uint8_t * createStubFunction(uint8_t *Addr, unsigned AbiVariant=0)
Emits long jump instruction to Addr.
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:133
StringMap - This is an unconventional map that is specialized for handling keys that are "strings"...
Definition: StringMap.h:220
Target - Wrapper for Target specific information.
static std::unique_ptr< MemoryBuffer > getMemBufferCopy(StringRef InputData, const Twine &BufferName="")
Open the specified memory range as a MemoryBuffer, copying the contents and taking ownership of it...
uintptr_t getStubOffset() const
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool equals(StringRef RHS) const
equals - Check for string equality, this is more efficient than compare() when the relative ordering ...
Definition: StringRef.h:169
This is a value type class that represents a single symbol in the list of symbols in the object file...
Definition: ObjectFile.h:141
Triple::ArchType Arch
uint64_t Offset
Offset - offset into the section.
virtual section_iterator section_end() const =0
std::map< SectionRef, unsigned > ObjSectionToIDMap
uint8_t * getAddressWithOffset(unsigned OffsetBytes) const
Return the address of this section with an offset.
#define I(x, y, z)
Definition: MD5.cpp:58
void writeInt64BE(uint8_t *Addr, uint64_t Value)
uint32_t read32le(const void *P)
Definition: Endian.h:369
StringRef getName() const
SymInfo contains information about symbol: it&#39;s address and section index which is -1LL for absolute ...
SectionEntry - represents a section emitted into memory by the dynamic linker.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:483
LLVM Value Representation.
Definition: Value.h:73
RTDyldSymbolTable GlobalSymbolTable
Lightweight error class with error context and mandatory checking.
Definition: Error.h:158
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:81
static void write32AArch64Addr(void *L, uint64_t Imm)
const char SectionName[]
Definition: AMDGPUPTNote.h:24
void advanceStubOffset(unsigned StubSize)
#define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
Definition: ELFTypes.h:104
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
virtual void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size)=0
Register the EH frames with the runtime so that c++ exceptions work.
Expected< ObjSectionToIDMap > loadObjectImpl(const object::ObjectFile &Obj)
static uint16_t applyPPCha(uint64_t value)
#define LLVM_DEBUG(X)
Definition: Debug.h:123
virtual StringRef getFileFormatName() const =0
StringRef getData() const
Definition: Binary.cpp:39
iterator end()
Definition: StringMap.h:318
This is a value type class that represents a single section in the list of sections in the object fil...
Definition: ObjectFile.h:81