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RuntimeDyldELF.cpp
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1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "RuntimeDyldELF.h"
14 #include "RuntimeDyldCheckerImpl.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/BinaryFormat/ELF.h"
21 #include "llvm/Object/ObjectFile.h"
22 #include "llvm/Support/Endian.h"
24 
25 using namespace llvm;
26 using namespace llvm::object;
27 using namespace llvm::support::endian;
28 
29 #define DEBUG_TYPE "dyld"
30 
31 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
32 
33 static void or32AArch64Imm(void *L, uint64_t Imm) {
34  or32le(L, (Imm & 0xFFF) << 10);
35 }
36 
37 template <class T> static void write(bool isBE, void *P, T V) {
38  isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V);
39 }
40 
41 static void write32AArch64Addr(void *L, uint64_t Imm) {
42  uint32_t ImmLo = (Imm & 0x3) << 29;
43  uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
44  uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
45  write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi);
46 }
47 
48 // Return the bits [Start, End] from Val shifted Start bits.
49 // For instance, getBits(0xF0, 4, 8) returns 0xF.
50 static uint64_t getBits(uint64_t Val, int Start, int End) {
51  uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1;
52  return (Val >> Start) & Mask;
53 }
54 
55 namespace {
56 
57 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
59 
60  typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
61  typedef Elf_Sym_Impl<ELFT> Elf_Sym;
62  typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
63  typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
64 
65  typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
66 
67  typedef typename ELFT::uint addr_type;
68 
69  DyldELFObject(ELFObjectFile<ELFT> &&Obj);
70 
71 public:
73  create(MemoryBufferRef Wrapper);
74 
75  void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
76 
77  void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
78 
79  // Methods for type inquiry through isa, cast and dyn_cast
80  static bool classof(const Binary *v) {
81  return (isa<ELFObjectFile<ELFT>>(v) &&
82  classof(cast<ELFObjectFile<ELFT>>(v)));
83  }
84  static bool classof(const ELFObjectFile<ELFT> *v) {
85  return v->isDyldType();
86  }
87 };
88 
89 
90 
91 // The MemoryBuffer passed into this constructor is just a wrapper around the
92 // actual memory. Ultimately, the Binary parent class will take ownership of
93 // this MemoryBuffer object but not the underlying memory.
94 template <class ELFT>
95 DyldELFObject<ELFT>::DyldELFObject(ELFObjectFile<ELFT> &&Obj)
96  : ELFObjectFile<ELFT>(std::move(Obj)) {
97  this->isDyldELFObject = true;
98 }
99 
100 template <class ELFT>
102 DyldELFObject<ELFT>::create(MemoryBufferRef Wrapper) {
103  auto Obj = ELFObjectFile<ELFT>::create(Wrapper);
104  if (auto E = Obj.takeError())
105  return std::move(E);
106  std::unique_ptr<DyldELFObject<ELFT>> Ret(
107  new DyldELFObject<ELFT>(std::move(*Obj)));
108  return std::move(Ret);
109 }
110 
111 template <class ELFT>
112 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
113  uint64_t Addr) {
114  DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
115  Elf_Shdr *shdr =
116  const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
117 
118  // This assumes the address passed in matches the target address bitness
119  // The template-based type cast handles everything else.
120  shdr->sh_addr = static_cast<addr_type>(Addr);
121 }
122 
123 template <class ELFT>
124 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
125  uint64_t Addr) {
126 
127  Elf_Sym *sym = const_cast<Elf_Sym *>(
129 
130  // This assumes the address passed in matches the target address bitness
131  // The template-based type cast handles everything else.
132  sym->st_value = static_cast<addr_type>(Addr);
133 }
134 
135 class LoadedELFObjectInfo final
136  : public LoadedObjectInfoHelper<LoadedELFObjectInfo,
137  RuntimeDyld::LoadedObjectInfo> {
138 public:
139  LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap)
140  : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
141 
143  getObjectForDebug(const ObjectFile &Obj) const override;
144 };
145 
146 template <typename ELFT>
148 createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject,
149  const LoadedELFObjectInfo &L) {
150  typedef typename ELFT::Shdr Elf_Shdr;
151  typedef typename ELFT::uint addr_type;
152 
154  DyldELFObject<ELFT>::create(Buffer);
155  if (Error E = ObjOrErr.takeError())
156  return std::move(E);
157 
158  std::unique_ptr<DyldELFObject<ELFT>> Obj = std::move(*ObjOrErr);
159 
160  // Iterate over all sections in the object.
161  auto SI = SourceObject.section_begin();
162  for (const auto &Sec : Obj->sections()) {
163  Expected<StringRef> NameOrErr = Sec.getName();
164  if (!NameOrErr) {
165  consumeError(NameOrErr.takeError());
166  continue;
167  }
168 
169  if (*NameOrErr != "") {
170  DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
171  Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
172  reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
173 
174  if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) {
175  // This assumes that the address passed in matches the target address
176  // bitness. The template-based type cast handles everything else.
177  shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
178  }
179  }
180  ++SI;
181  }
182 
183  return std::move(Obj);
184 }
185 
187 createELFDebugObject(const ObjectFile &Obj, const LoadedELFObjectInfo &L) {
188  assert(Obj.isELF() && "Not an ELF object file.");
189 
190  std::unique_ptr<MemoryBuffer> Buffer =
192 
193  Expected<std::unique_ptr<ObjectFile>> DebugObj(nullptr);
194  handleAllErrors(DebugObj.takeError());
195  if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian())
196  DebugObj =
197  createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L);
198  else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian())
199  DebugObj =
200  createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L);
201  else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian())
202  DebugObj =
203  createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L);
204  else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian())
205  DebugObj =
206  createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L);
207  else
208  llvm_unreachable("Unexpected ELF format");
209 
210  handleAllErrors(DebugObj.takeError());
211  return OwningBinary<ObjectFile>(std::move(*DebugObj), std::move(Buffer));
212 }
213 
215 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
216  return createELFDebugObject(Obj, *this);
217 }
218 
219 } // anonymous namespace
220 
221 namespace llvm {
222 
225  : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
227 
229  for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
230  SID EHFrameSID = UnregisteredEHFrameSections[i];
231  uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
232  uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
233  size_t EHFrameSize = Sections[EHFrameSID].getSize();
234  MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
235  }
236  UnregisteredEHFrameSections.clear();
237 }
238 
239 std::unique_ptr<RuntimeDyldELF>
243  switch (Arch) {
244  default:
245  return std::make_unique<RuntimeDyldELF>(MemMgr, Resolver);
246  case Triple::mips:
247  case Triple::mipsel:
248  case Triple::mips64:
249  case Triple::mips64el:
250  return std::make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
251  }
252 }
253 
254 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
256  if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
257  return std::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
258  else {
259  HasError = true;
260  raw_string_ostream ErrStream(ErrorStr);
261  logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream);
262  return nullptr;
263  }
264 }
265 
266 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
267  uint64_t Offset, uint64_t Value,
268  uint32_t Type, int64_t Addend,
269  uint64_t SymOffset) {
270  switch (Type) {
271  default:
272  llvm_unreachable("Relocation type not implemented yet!");
273  break;
274  case ELF::R_X86_64_NONE:
275  break;
276  case ELF::R_X86_64_64: {
278  Value + Addend;
279  LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
280  << format("%p\n", Section.getAddressWithOffset(Offset)));
281  break;
282  }
283  case ELF::R_X86_64_32:
284  case ELF::R_X86_64_32S: {
285  Value += Addend;
286  assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
287  (Type == ELF::R_X86_64_32S &&
288  ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
289  uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
291  TruncatedAddr;
292  LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
293  << format("%p\n", Section.getAddressWithOffset(Offset)));
294  break;
295  }
296  case ELF::R_X86_64_PC8: {
297  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
298  int64_t RealOffset = Value + Addend - FinalAddress;
299  assert(isInt<8>(RealOffset));
300  int8_t TruncOffset = (RealOffset & 0xFF);
301  Section.getAddress()[Offset] = TruncOffset;
302  break;
303  }
304  case ELF::R_X86_64_PC32: {
305  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
306  int64_t RealOffset = Value + Addend - FinalAddress;
307  assert(isInt<32>(RealOffset));
308  int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
310  TruncOffset;
311  break;
312  }
313  case ELF::R_X86_64_PC64: {
314  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
315  int64_t RealOffset = Value + Addend - FinalAddress;
317  RealOffset;
318  LLVM_DEBUG(dbgs() << "Writing " << format("%p", RealOffset) << " at "
319  << format("%p\n", FinalAddress));
320  break;
321  }
322  case ELF::R_X86_64_GOTOFF64: {
323  // Compute Value - GOTBase.
324  uint64_t GOTBase = 0;
325  for (const auto &Section : Sections) {
326  if (Section.getName() == ".got") {
327  GOTBase = Section.getLoadAddressWithOffset(0);
328  break;
329  }
330  }
331  assert(GOTBase != 0 && "missing GOT");
332  int64_t GOTOffset = Value - GOTBase + Addend;
333  support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = GOTOffset;
334  break;
335  }
336  }
337 }
338 
339 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
340  uint64_t Offset, uint32_t Value,
341  uint32_t Type, int32_t Addend) {
342  switch (Type) {
343  case ELF::R_386_32: {
345  Value + Addend;
346  break;
347  }
348  // Handle R_386_PLT32 like R_386_PC32 since it should be able to
349  // reach any 32 bit address.
350  case ELF::R_386_PLT32:
351  case ELF::R_386_PC32: {
352  uint32_t FinalAddress =
353  Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
354  uint32_t RealOffset = Value + Addend - FinalAddress;
356  RealOffset;
357  break;
358  }
359  default:
360  // There are other relocation types, but it appears these are the
361  // only ones currently used by the LLVM ELF object writer
362  llvm_unreachable("Relocation type not implemented yet!");
363  break;
364  }
365 }
366 
367 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
368  uint64_t Offset, uint64_t Value,
369  uint32_t Type, int64_t Addend) {
370  uint32_t *TargetPtr =
371  reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
372  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
373  // Data should use target endian. Code should always use little endian.
374  bool isBE = Arch == Triple::aarch64_be;
375 
376  LLVM_DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
377  << format("%llx", Section.getAddressWithOffset(Offset))
378  << " FinalAddress: 0x" << format("%llx", FinalAddress)
379  << " Value: 0x" << format("%llx", Value) << " Type: 0x"
380  << format("%x", Type) << " Addend: 0x"
381  << format("%llx", Addend) << "\n");
382 
383  switch (Type) {
384  default:
385  llvm_unreachable("Relocation type not implemented yet!");
386  break;
387  case ELF::R_AARCH64_ABS16: {
388  uint64_t Result = Value + Addend;
389  assert(static_cast<int64_t>(Result) >= INT16_MIN && Result < UINT16_MAX);
390  write(isBE, TargetPtr, static_cast<uint16_t>(Result & 0xffffU));
391  break;
392  }
393  case ELF::R_AARCH64_ABS32: {
394  uint64_t Result = Value + Addend;
395  assert(static_cast<int64_t>(Result) >= INT32_MIN && Result < UINT32_MAX);
396  write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
397  break;
398  }
399  case ELF::R_AARCH64_ABS64:
400  write(isBE, TargetPtr, Value + Addend);
401  break;
402  case ELF::R_AARCH64_PREL32: {
403  uint64_t Result = Value + Addend - FinalAddress;
404  assert(static_cast<int64_t>(Result) >= INT32_MIN &&
405  static_cast<int64_t>(Result) <= UINT32_MAX);
406  write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
407  break;
408  }
409  case ELF::R_AARCH64_PREL64:
410  write(isBE, TargetPtr, Value + Addend - FinalAddress);
411  break;
412  case ELF::R_AARCH64_CALL26: // fallthrough
413  case ELF::R_AARCH64_JUMP26: {
414  // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
415  // calculation.
416  uint64_t BranchImm = Value + Addend - FinalAddress;
417 
418  // "Check that -2^27 <= result < 2^27".
419  assert(isInt<28>(BranchImm));
420  or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
421  break;
422  }
423  case ELF::R_AARCH64_MOVW_UABS_G3:
424  or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
425  break;
426  case ELF::R_AARCH64_MOVW_UABS_G2_NC:
427  or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
428  break;
429  case ELF::R_AARCH64_MOVW_UABS_G1_NC:
430  or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
431  break;
432  case ELF::R_AARCH64_MOVW_UABS_G0_NC:
433  or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
434  break;
435  case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
436  // Operation: Page(S+A) - Page(P)
437  uint64_t Result =
438  ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
439 
440  // Check that -2^32 <= X < 2^32
441  assert(isInt<33>(Result) && "overflow check failed for relocation");
442 
443  // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
444  // from bits 32:12 of X.
445  write32AArch64Addr(TargetPtr, Result >> 12);
446  break;
447  }
448  case ELF::R_AARCH64_ADD_ABS_LO12_NC:
449  // Operation: S + A
450  // Immediate goes in bits 21:10 of LD/ST instruction, taken
451  // from bits 11:0 of X
452  or32AArch64Imm(TargetPtr, Value + Addend);
453  break;
454  case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
455  // Operation: S + A
456  // Immediate goes in bits 21:10 of LD/ST instruction, taken
457  // from bits 11:0 of X
458  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11));
459  break;
460  case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
461  // Operation: S + A
462  // Immediate goes in bits 21:10 of LD/ST instruction, taken
463  // from bits 11:1 of X
464  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11));
465  break;
466  case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
467  // Operation: S + A
468  // Immediate goes in bits 21:10 of LD/ST instruction, taken
469  // from bits 11:2 of X
470  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11));
471  break;
472  case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
473  // Operation: S + A
474  // Immediate goes in bits 21:10 of LD/ST instruction, taken
475  // from bits 11:3 of X
476  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11));
477  break;
478  case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
479  // Operation: S + A
480  // Immediate goes in bits 21:10 of LD/ST instruction, taken
481  // from bits 11:4 of X
482  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 4, 11));
483  break;
484  }
485 }
486 
487 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
488  uint64_t Offset, uint32_t Value,
489  uint32_t Type, int32_t Addend) {
490  // TODO: Add Thumb relocations.
491  uint32_t *TargetPtr =
492  reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
493  uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
494  Value += Addend;
495 
496  LLVM_DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
497  << Section.getAddressWithOffset(Offset)
498  << " FinalAddress: " << format("%p", FinalAddress)
499  << " Value: " << format("%x", Value)
500  << " Type: " << format("%x", Type)
501  << " Addend: " << format("%x", Addend) << "\n");
502 
503  switch (Type) {
504  default:
505  llvm_unreachable("Not implemented relocation type!");
506 
507  case ELF::R_ARM_NONE:
508  break;
509  // Write a 31bit signed offset
510  case ELF::R_ARM_PREL31:
511  support::ulittle32_t::ref{TargetPtr} =
512  (support::ulittle32_t::ref{TargetPtr} & 0x80000000) |
513  ((Value - FinalAddress) & ~0x80000000);
514  break;
515  case ELF::R_ARM_TARGET1:
516  case ELF::R_ARM_ABS32:
517  support::ulittle32_t::ref{TargetPtr} = Value;
518  break;
519  // Write first 16 bit of 32 bit value to the mov instruction.
520  // Last 4 bit should be shifted.
521  case ELF::R_ARM_MOVW_ABS_NC:
522  case ELF::R_ARM_MOVT_ABS:
523  if (Type == ELF::R_ARM_MOVW_ABS_NC)
524  Value = Value & 0xFFFF;
525  else if (Type == ELF::R_ARM_MOVT_ABS)
526  Value = (Value >> 16) & 0xFFFF;
527  support::ulittle32_t::ref{TargetPtr} =
528  (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) |
529  (((Value >> 12) & 0xF) << 16);
530  break;
531  // Write 24 bit relative value to the branch instruction.
532  case ELF::R_ARM_PC24: // Fall through.
533  case ELF::R_ARM_CALL: // Fall through.
534  case ELF::R_ARM_JUMP24:
535  int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
536  RelValue = (RelValue & 0x03FFFFFC) >> 2;
537  assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE);
538  support::ulittle32_t::ref{TargetPtr} =
539  (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue;
540  break;
541  }
542 }
543 
544 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
545  if (Arch == Triple::UnknownArch ||
546  !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
547  IsMipsO32ABI = false;
548  IsMipsN32ABI = false;
549  IsMipsN64ABI = false;
550  return;
551  }
552  if (auto *E = dyn_cast<ELFObjectFileBase>(&Obj)) {
553  unsigned AbiVariant = E->getPlatformFlags();
554  IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
555  IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2;
556  }
557  IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
558 }
559 
560 // Return the .TOC. section and offset.
561 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
562  ObjSectionToIDMap &LocalSections,
563  RelocationValueRef &Rel) {
564  // Set a default SectionID in case we do not find a TOC section below.
565  // This may happen for references to TOC base base (sym@toc, .odp
566  // relocation) without a .toc directive. In this case just use the
567  // first section (which is usually the .odp) since the code won't
568  // reference the .toc base directly.
569  Rel.SymbolName = nullptr;
570  Rel.SectionID = 0;
571 
572  // The TOC consists of sections .got, .toc, .tocbss, .plt in that
573  // order. The TOC starts where the first of these sections starts.
574  for (auto &Section : Obj.sections()) {
575  Expected<StringRef> NameOrErr = Section.getName();
576  if (!NameOrErr)
577  return NameOrErr.takeError();
578  StringRef SectionName = *NameOrErr;
579 
580  if (SectionName == ".got"
581  || SectionName == ".toc"
582  || SectionName == ".tocbss"
583  || SectionName == ".plt") {
584  if (auto SectionIDOrErr =
585  findOrEmitSection(Obj, Section, false, LocalSections))
586  Rel.SectionID = *SectionIDOrErr;
587  else
588  return SectionIDOrErr.takeError();
589  break;
590  }
591  }
592 
593  // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
594  // thus permitting a full 64 Kbytes segment.
595  Rel.Addend = 0x8000;
596 
597  return Error::success();
598 }
599 
600 // Returns the sections and offset associated with the ODP entry referenced
601 // by Symbol.
602 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
603  ObjSectionToIDMap &LocalSections,
604  RelocationValueRef &Rel) {
605  // Get the ELF symbol value (st_value) to compare with Relocation offset in
606  // .opd entries
607  for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
608  si != se; ++si) {
609  section_iterator RelSecI = si->getRelocatedSection();
610  if (RelSecI == Obj.section_end())
611  continue;
612 
613  Expected<StringRef> NameOrErr = RelSecI->getName();
614  if (!NameOrErr)
615  return NameOrErr.takeError();
616  StringRef RelSectionName = *NameOrErr;
617 
618  if (RelSectionName != ".opd")
619  continue;
620 
621  for (elf_relocation_iterator i = si->relocation_begin(),
622  e = si->relocation_end();
623  i != e;) {
624  // The R_PPC64_ADDR64 relocation indicates the first field
625  // of a .opd entry
626  uint64_t TypeFunc = i->getType();
627  if (TypeFunc != ELF::R_PPC64_ADDR64) {
628  ++i;
629  continue;
630  }
631 
632  uint64_t TargetSymbolOffset = i->getOffset();
633  symbol_iterator TargetSymbol = i->getSymbol();
634  int64_t Addend;
635  if (auto AddendOrErr = i->getAddend())
636  Addend = *AddendOrErr;
637  else
638  return AddendOrErr.takeError();
639 
640  ++i;
641  if (i == e)
642  break;
643 
644  // Just check if following relocation is a R_PPC64_TOC
645  uint64_t TypeTOC = i->getType();
646  if (TypeTOC != ELF::R_PPC64_TOC)
647  continue;
648 
649  // Finally compares the Symbol value and the target symbol offset
650  // to check if this .opd entry refers to the symbol the relocation
651  // points to.
652  if (Rel.Addend != (int64_t)TargetSymbolOffset)
653  continue;
654 
655  section_iterator TSI = Obj.section_end();
656  if (auto TSIOrErr = TargetSymbol->getSection())
657  TSI = *TSIOrErr;
658  else
659  return TSIOrErr.takeError();
660  assert(TSI != Obj.section_end() && "TSI should refer to a valid section");
661 
662  bool IsCode = TSI->isText();
663  if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode,
664  LocalSections))
665  Rel.SectionID = *SectionIDOrErr;
666  else
667  return SectionIDOrErr.takeError();
668  Rel.Addend = (intptr_t)Addend;
669  return Error::success();
670  }
671  }
672  llvm_unreachable("Attempting to get address of ODP entry!");
673 }
674 
675 // Relocation masks following the #lo(value), #hi(value), #ha(value),
676 // #higher(value), #highera(value), #highest(value), and #highesta(value)
677 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
678 // document.
679 
680 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
681 
682 static inline uint16_t applyPPChi(uint64_t value) {
683  return (value >> 16) & 0xffff;
684 }
685 
686 static inline uint16_t applyPPCha (uint64_t value) {
687  return ((value + 0x8000) >> 16) & 0xffff;
688 }
689 
690 static inline uint16_t applyPPChigher(uint64_t value) {
691  return (value >> 32) & 0xffff;
692 }
693 
694 static inline uint16_t applyPPChighera (uint64_t value) {
695  return ((value + 0x8000) >> 32) & 0xffff;
696 }
697 
698 static inline uint16_t applyPPChighest(uint64_t value) {
699  return (value >> 48) & 0xffff;
700 }
701 
702 static inline uint16_t applyPPChighesta (uint64_t value) {
703  return ((value + 0x8000) >> 48) & 0xffff;
704 }
705 
706 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section,
707  uint64_t Offset, uint64_t Value,
708  uint32_t Type, int64_t Addend) {
709  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
710  switch (Type) {
711  default:
712  llvm_unreachable("Relocation type not implemented yet!");
713  break;
714  case ELF::R_PPC_ADDR16_LO:
715  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
716  break;
717  case ELF::R_PPC_ADDR16_HI:
718  writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
719  break;
720  case ELF::R_PPC_ADDR16_HA:
721  writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
722  break;
723  }
724 }
725 
726 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
727  uint64_t Offset, uint64_t Value,
728  uint32_t Type, int64_t Addend) {
729  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
730  switch (Type) {
731  default:
732  llvm_unreachable("Relocation type not implemented yet!");
733  break;
734  case ELF::R_PPC64_ADDR16:
735  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
736  break;
737  case ELF::R_PPC64_ADDR16_DS:
738  writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
739  break;
740  case ELF::R_PPC64_ADDR16_LO:
741  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
742  break;
743  case ELF::R_PPC64_ADDR16_LO_DS:
744  writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
745  break;
746  case ELF::R_PPC64_ADDR16_HI:
747  case ELF::R_PPC64_ADDR16_HIGH:
748  writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
749  break;
750  case ELF::R_PPC64_ADDR16_HA:
751  case ELF::R_PPC64_ADDR16_HIGHA:
752  writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
753  break;
754  case ELF::R_PPC64_ADDR16_HIGHER:
755  writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
756  break;
757  case ELF::R_PPC64_ADDR16_HIGHERA:
758  writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
759  break;
760  case ELF::R_PPC64_ADDR16_HIGHEST:
761  writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
762  break;
763  case ELF::R_PPC64_ADDR16_HIGHESTA:
764  writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
765  break;
766  case ELF::R_PPC64_ADDR14: {
767  assert(((Value + Addend) & 3) == 0);
768  // Preserve the AA/LK bits in the branch instruction
769  uint8_t aalk = *(LocalAddress + 3);
770  writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
771  } break;
772  case ELF::R_PPC64_REL16_LO: {
773  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
774  uint64_t Delta = Value - FinalAddress + Addend;
775  writeInt16BE(LocalAddress, applyPPClo(Delta));
776  } break;
777  case ELF::R_PPC64_REL16_HI: {
778  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
779  uint64_t Delta = Value - FinalAddress + Addend;
780  writeInt16BE(LocalAddress, applyPPChi(Delta));
781  } break;
782  case ELF::R_PPC64_REL16_HA: {
783  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
784  uint64_t Delta = Value - FinalAddress + Addend;
785  writeInt16BE(LocalAddress, applyPPCha(Delta));
786  } break;
787  case ELF::R_PPC64_ADDR32: {
788  int64_t Result = static_cast<int64_t>(Value + Addend);
789  if (SignExtend64<32>(Result) != Result)
790  llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
791  writeInt32BE(LocalAddress, Result);
792  } break;
793  case ELF::R_PPC64_REL24: {
794  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
795  int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
796  if (SignExtend64<26>(delta) != delta)
797  llvm_unreachable("Relocation R_PPC64_REL24 overflow");
798  // We preserve bits other than LI field, i.e. PO and AA/LK fields.
799  uint32_t Inst = readBytesUnaligned(LocalAddress, 4);
800  writeInt32BE(LocalAddress, (Inst & 0xFC000003) | (delta & 0x03FFFFFC));
801  } break;
802  case ELF::R_PPC64_REL32: {
803  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
804  int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
805  if (SignExtend64<32>(delta) != delta)
806  llvm_unreachable("Relocation R_PPC64_REL32 overflow");
807  writeInt32BE(LocalAddress, delta);
808  } break;
809  case ELF::R_PPC64_REL64: {
810  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
811  uint64_t Delta = Value - FinalAddress + Addend;
812  writeInt64BE(LocalAddress, Delta);
813  } break;
814  case ELF::R_PPC64_ADDR64:
815  writeInt64BE(LocalAddress, Value + Addend);
816  break;
817  }
818 }
819 
820 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
821  uint64_t Offset, uint64_t Value,
822  uint32_t Type, int64_t Addend) {
823  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
824  switch (Type) {
825  default:
826  llvm_unreachable("Relocation type not implemented yet!");
827  break;
828  case ELF::R_390_PC16DBL:
829  case ELF::R_390_PLT16DBL: {
830  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
831  assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
832  writeInt16BE(LocalAddress, Delta / 2);
833  break;
834  }
835  case ELF::R_390_PC32DBL:
836  case ELF::R_390_PLT32DBL: {
837  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
838  assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
839  writeInt32BE(LocalAddress, Delta / 2);
840  break;
841  }
842  case ELF::R_390_PC16: {
843  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
844  assert(int16_t(Delta) == Delta && "R_390_PC16 overflow");
845  writeInt16BE(LocalAddress, Delta);
846  break;
847  }
848  case ELF::R_390_PC32: {
849  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
850  assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
851  writeInt32BE(LocalAddress, Delta);
852  break;
853  }
854  case ELF::R_390_PC64: {
855  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
856  writeInt64BE(LocalAddress, Delta);
857  break;
858  }
859  case ELF::R_390_8:
860  *LocalAddress = (uint8_t)(Value + Addend);
861  break;
862  case ELF::R_390_16:
863  writeInt16BE(LocalAddress, Value + Addend);
864  break;
865  case ELF::R_390_32:
866  writeInt32BE(LocalAddress, Value + Addend);
867  break;
868  case ELF::R_390_64:
869  writeInt64BE(LocalAddress, Value + Addend);
870  break;
871  }
872 }
873 
874 void RuntimeDyldELF::resolveBPFRelocation(const SectionEntry &Section,
875  uint64_t Offset, uint64_t Value,
876  uint32_t Type, int64_t Addend) {
877  bool isBE = Arch == Triple::bpfeb;
878 
879  switch (Type) {
880  default:
881  llvm_unreachable("Relocation type not implemented yet!");
882  break;
883  case ELF::R_BPF_NONE:
884  break;
885  case ELF::R_BPF_64_64: {
886  write(isBE, Section.getAddressWithOffset(Offset), Value + Addend);
887  LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
888  << format("%p\n", Section.getAddressWithOffset(Offset)));
889  break;
890  }
891  case ELF::R_BPF_64_32: {
892  Value += Addend;
893  assert(Value <= UINT32_MAX);
894  write(isBE, Section.getAddressWithOffset(Offset), static_cast<uint32_t>(Value));
895  LLVM_DEBUG(dbgs() << "Writing " << format("%p", Value) << " at "
896  << format("%p\n", Section.getAddressWithOffset(Offset)));
897  break;
898  }
899  }
900 }
901 
902 // The target location for the relocation is described by RE.SectionID and
903 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
904 // SectionEntry has three members describing its location.
905 // SectionEntry::Address is the address at which the section has been loaded
906 // into memory in the current (host) process. SectionEntry::LoadAddress is the
907 // address that the section will have in the target process.
908 // SectionEntry::ObjAddress is the address of the bits for this section in the
909 // original emitted object image (also in the current address space).
910 //
911 // Relocations will be applied as if the section were loaded at
912 // SectionEntry::LoadAddress, but they will be applied at an address based
913 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
914 // Target memory contents if they are required for value calculations.
915 //
916 // The Value parameter here is the load address of the symbol for the
917 // relocation to be applied. For relocations which refer to symbols in the
918 // current object Value will be the LoadAddress of the section in which
919 // the symbol resides (RE.Addend provides additional information about the
920 // symbol location). For external symbols, Value will be the address of the
921 // symbol in the target address space.
922 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
923  uint64_t Value) {
924  const SectionEntry &Section = Sections[RE.SectionID];
925  return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
926  RE.SymOffset, RE.SectionID);
927 }
928 
929 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
930  uint64_t Offset, uint64_t Value,
931  uint32_t Type, int64_t Addend,
932  uint64_t SymOffset, SID SectionID) {
933  switch (Arch) {
934  case Triple::x86_64:
935  resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
936  break;
937  case Triple::x86:
938  resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
939  (uint32_t)(Addend & 0xffffffffL));
940  break;
941  case Triple::aarch64:
942  case Triple::aarch64_be:
943  resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
944  break;
945  case Triple::arm: // Fall through.
946  case Triple::armeb:
947  case Triple::thumb:
948  case Triple::thumbeb:
949  resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
950  (uint32_t)(Addend & 0xffffffffL));
951  break;
952  case Triple::ppc:
953  resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
954  break;
955  case Triple::ppc64: // Fall through.
956  case Triple::ppc64le:
957  resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
958  break;
959  case Triple::systemz:
960  resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
961  break;
962  case Triple::bpfel:
963  case Triple::bpfeb:
964  resolveBPFRelocation(Section, Offset, Value, Type, Addend);
965  break;
966  default:
967  llvm_unreachable("Unsupported CPU type!");
968  }
969 }
970 
971 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
972  return (void *)(Sections[SectionID].getObjAddress() + Offset);
973 }
974 
975 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
976  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
977  if (Value.SymbolName)
979  else
981 }
982 
983 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType,
984  bool IsLocal) const {
985  switch (RelType) {
986  case ELF::R_MICROMIPS_GOT16:
987  if (IsLocal)
988  return ELF::R_MICROMIPS_LO16;
989  break;
990  case ELF::R_MICROMIPS_HI16:
991  return ELF::R_MICROMIPS_LO16;
992  case ELF::R_MIPS_GOT16:
993  if (IsLocal)
994  return ELF::R_MIPS_LO16;
995  break;
996  case ELF::R_MIPS_HI16:
997  return ELF::R_MIPS_LO16;
998  case ELF::R_MIPS_PCHI16:
999  return ELF::R_MIPS_PCLO16;
1000  default:
1001  break;
1002  }
1003  return ELF::R_MIPS_NONE;
1004 }
1005 
1006 // Sometimes we don't need to create thunk for a branch.
1007 // This typically happens when branch target is located
1008 // in the same object file. In such case target is either
1009 // a weak symbol or symbol in a different executable section.
1010 // This function checks if branch target is located in the
1011 // same object file and if distance between source and target
1012 // fits R_AARCH64_CALL26 relocation. If both conditions are
1013 // met, it emits direct jump to the target and returns true.
1014 // Otherwise false is returned and thunk is created.
1015 bool RuntimeDyldELF::resolveAArch64ShortBranch(
1016  unsigned SectionID, relocation_iterator RelI,
1017  const RelocationValueRef &Value) {
1018  uint64_t Address;
1019  if (Value.SymbolName) {
1020  auto Loc = GlobalSymbolTable.find(Value.SymbolName);
1021 
1022  // Don't create direct branch for external symbols.
1023  if (Loc == GlobalSymbolTable.end())
1024  return false;
1025 
1026  const auto &SymInfo = Loc->second;
1027  Address =
1028  uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset(
1029  SymInfo.getOffset()));
1030  } else {
1031  Address = uint64_t(Sections[Value.SectionID].getLoadAddress());
1032  }
1033  uint64_t Offset = RelI->getOffset();
1034  uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset);
1035 
1036  // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27
1037  // If distance between source and target is out of range then we should
1038  // create thunk.
1039  if (!isInt<28>(Address + Value.Addend - SourceAddress))
1040  return false;
1041 
1042  resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(),
1043  Value.Addend);
1044 
1045  return true;
1046 }
1047 
1048 void RuntimeDyldELF::resolveAArch64Branch(unsigned SectionID,
1049  const RelocationValueRef &Value,
1050  relocation_iterator RelI,
1051  StubMap &Stubs) {
1052 
1053  LLVM_DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1054  SectionEntry &Section = Sections[SectionID];
1055 
1056  uint64_t Offset = RelI->getOffset();
1057  unsigned RelType = RelI->getType();
1058  // Look for an existing stub.
1059  StubMap::const_iterator i = Stubs.find(Value);
1060  if (i != Stubs.end()) {
1061  resolveRelocation(Section, Offset,
1062  (uint64_t)Section.getAddressWithOffset(i->second),
1063  RelType, 0);
1064  LLVM_DEBUG(dbgs() << " Stub function found\n");
1065  } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) {
1066  // Create a new stub function.
1067  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1068  Stubs[Value] = Section.getStubOffset();
1069  uint8_t *StubTargetAddr = createStubFunction(
1070  Section.getAddressWithOffset(Section.getStubOffset()));
1071 
1072  RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.getAddress(),
1073  ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1074  RelocationEntry REmovk_g2(SectionID,
1075  StubTargetAddr - Section.getAddress() + 4,
1076  ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1077  RelocationEntry REmovk_g1(SectionID,
1078  StubTargetAddr - Section.getAddress() + 8,
1079  ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1080  RelocationEntry REmovk_g0(SectionID,
1081  StubTargetAddr - Section.getAddress() + 12,
1082  ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1083 
1084  if (Value.SymbolName) {
1085  addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1086  addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1087  addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1088  addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1089  } else {
1090  addRelocationForSection(REmovz_g3, Value.SectionID);
1091  addRelocationForSection(REmovk_g2, Value.SectionID);
1092  addRelocationForSection(REmovk_g1, Value.SectionID);
1093  addRelocationForSection(REmovk_g0, Value.SectionID);
1094  }
1095  resolveRelocation(Section, Offset,
1096  reinterpret_cast<uint64_t>(Section.getAddressWithOffset(
1097  Section.getStubOffset())),
1098  RelType, 0);
1099  Section.advanceStubOffset(getMaxStubSize());
1100  }
1101 }
1102 
1105  unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
1106  ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
1107  const auto &Obj = cast<ELFObjectFileBase>(O);
1108  uint64_t RelType = RelI->getType();
1109  int64_t Addend = 0;
1110  if (Expected<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend())
1111  Addend = *AddendOrErr;
1112  else
1113  consumeError(AddendOrErr.takeError());
1114  elf_symbol_iterator Symbol = RelI->getSymbol();
1115 
1116  // Obtain the symbol name which is referenced in the relocation
1117  StringRef TargetName;
1118  if (Symbol != Obj.symbol_end()) {
1119  if (auto TargetNameOrErr = Symbol->getName())
1120  TargetName = *TargetNameOrErr;
1121  else
1122  return TargetNameOrErr.takeError();
1123  }
1124  LLVM_DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1125  << " TargetName: " << TargetName << "\n");
1127  // First search for the symbol in the local symbol table
1128  SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1129 
1130  // Search for the symbol in the global symbol table
1132  if (Symbol != Obj.symbol_end()) {
1133  gsi = GlobalSymbolTable.find(TargetName.data());
1134  Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType();
1135  if (!SymTypeOrErr) {
1136  std::string Buf;
1137  raw_string_ostream OS(Buf);
1138  logAllUnhandledErrors(SymTypeOrErr.takeError(), OS);
1139  OS.flush();
1140  report_fatal_error(Buf);
1141  }
1142  SymType = *SymTypeOrErr;
1143  }
1144  if (gsi != GlobalSymbolTable.end()) {
1145  const auto &SymInfo = gsi->second;
1146  Value.SectionID = SymInfo.getSectionID();
1147  Value.Offset = SymInfo.getOffset();
1148  Value.Addend = SymInfo.getOffset() + Addend;
1149  } else {
1150  switch (SymType) {
1151  case SymbolRef::ST_Debug: {
1152  // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1153  // and can be changed by another developers. Maybe best way is add
1154  // a new symbol type ST_Section to SymbolRef and use it.
1155  auto SectionOrErr = Symbol->getSection();
1156  if (!SectionOrErr) {
1157  std::string Buf;
1158  raw_string_ostream OS(Buf);
1159  logAllUnhandledErrors(SectionOrErr.takeError(), OS);
1160  OS.flush();
1161  report_fatal_error(Buf);
1162  }
1163  section_iterator si = *SectionOrErr;
1164  if (si == Obj.section_end())
1165  llvm_unreachable("Symbol section not found, bad object file format!");
1166  LLVM_DEBUG(dbgs() << "\t\tThis is section symbol\n");
1167  bool isCode = si->isText();
1168  if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode,
1169  ObjSectionToID))
1170  Value.SectionID = *SectionIDOrErr;
1171  else
1172  return SectionIDOrErr.takeError();
1173  Value.Addend = Addend;
1174  break;
1175  }
1176  case SymbolRef::ST_Data:
1177  case SymbolRef::ST_Function:
1178  case SymbolRef::ST_Unknown: {
1179  Value.SymbolName = TargetName.data();
1180  Value.Addend = Addend;
1181 
1182  // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1183  // will manifest here as a NULL symbol name.
1184  // We can set this as a valid (but empty) symbol name, and rely
1185  // on addRelocationForSymbol to handle this.
1186  if (!Value.SymbolName)
1187  Value.SymbolName = "";
1188  break;
1189  }
1190  default:
1191  llvm_unreachable("Unresolved symbol type!");
1192  break;
1193  }
1194  }
1195 
1196  uint64_t Offset = RelI->getOffset();
1197 
1198  LLVM_DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1199  << "\n");
1200  if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be)) {
1201  if (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26) {
1202  resolveAArch64Branch(SectionID, Value, RelI, Stubs);
1203  } else if (RelType == ELF::R_AARCH64_ADR_GOT_PAGE) {
1204  // Craete new GOT entry or find existing one. If GOT entry is
1205  // to be created, then we also emit ABS64 relocation for it.
1206  uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1207  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1208  ELF::R_AARCH64_ADR_PREL_PG_HI21);
1209 
1210  } else if (RelType == ELF::R_AARCH64_LD64_GOT_LO12_NC) {
1211  uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1212  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1213  ELF::R_AARCH64_LDST64_ABS_LO12_NC);
1214  } else {
1215  processSimpleRelocation(SectionID, Offset, RelType, Value);
1216  }
1217  } else if (Arch == Triple::arm) {
1218  if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1219  RelType == ELF::R_ARM_JUMP24) {
1220  // This is an ARM branch relocation, need to use a stub function.
1221  LLVM_DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n");
1222  SectionEntry &Section = Sections[SectionID];
1223 
1224  // Look for an existing stub.
1225  StubMap::const_iterator i = Stubs.find(Value);
1226  if (i != Stubs.end()) {
1227  resolveRelocation(
1228  Section, Offset,
1229  reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)),
1230  RelType, 0);
1231  LLVM_DEBUG(dbgs() << " Stub function found\n");
1232  } else {
1233  // Create a new stub function.
1234  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1235  Stubs[Value] = Section.getStubOffset();
1236  uint8_t *StubTargetAddr = createStubFunction(
1237  Section.getAddressWithOffset(Section.getStubOffset()));
1238  RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1239  ELF::R_ARM_ABS32, Value.Addend);
1240  if (Value.SymbolName)
1242  else
1244 
1245  resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1246  Section.getAddressWithOffset(
1247  Section.getStubOffset())),
1248  RelType, 0);
1249  Section.advanceStubOffset(getMaxStubSize());
1250  }
1251  } else {
1252  uint32_t *Placeholder =
1253  reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1254  if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1255  RelType == ELF::R_ARM_ABS32) {
1256  Value.Addend += *Placeholder;
1257  } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1258  // See ELF for ARM documentation
1259  Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1260  }
1261  processSimpleRelocation(SectionID, Offset, RelType, Value);
1262  }
1263  } else if (IsMipsO32ABI) {
1264  uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1265  computePlaceholderAddress(SectionID, Offset));
1266  uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1267  if (RelType == ELF::R_MIPS_26) {
1268  // This is an Mips branch relocation, need to use a stub function.
1269  LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1270  SectionEntry &Section = Sections[SectionID];
1271 
1272  // Extract the addend from the instruction.
1273  // We shift up by two since the Value will be down shifted again
1274  // when applying the relocation.
1275  uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1276 
1277  Value.Addend += Addend;
1278 
1279  // Look up for existing stub.
1280  StubMap::const_iterator i = Stubs.find(Value);
1281  if (i != Stubs.end()) {
1282  RelocationEntry RE(SectionID, Offset, RelType, i->second);
1283  addRelocationForSection(RE, SectionID);
1284  LLVM_DEBUG(dbgs() << " Stub function found\n");
1285  } else {
1286  // Create a new stub function.
1287  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1288  Stubs[Value] = Section.getStubOffset();
1289 
1290  unsigned AbiVariant = Obj.getPlatformFlags();
1291 
1292  uint8_t *StubTargetAddr = createStubFunction(
1293  Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1294 
1295  // Creating Hi and Lo relocations for the filled stub instructions.
1296  RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1297  ELF::R_MIPS_HI16, Value.Addend);
1298  RelocationEntry RELo(SectionID,
1299  StubTargetAddr - Section.getAddress() + 4,
1300  ELF::R_MIPS_LO16, Value.Addend);
1301 
1302  if (Value.SymbolName) {
1303  addRelocationForSymbol(REHi, Value.SymbolName);
1304  addRelocationForSymbol(RELo, Value.SymbolName);
1305  } else {
1306  addRelocationForSection(REHi, Value.SectionID);
1307  addRelocationForSection(RELo, Value.SectionID);
1308  }
1309 
1310  RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1311  addRelocationForSection(RE, SectionID);
1312  Section.advanceStubOffset(getMaxStubSize());
1313  }
1314  } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) {
1315  int64_t Addend = (Opcode & 0x0000ffff) << 16;
1316  RelocationEntry RE(SectionID, Offset, RelType, Addend);
1317  PendingRelocs.push_back(std::make_pair(Value, RE));
1318  } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) {
1319  int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff);
1320  for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) {
1321  const RelocationValueRef &MatchingValue = I->first;
1322  RelocationEntry &Reloc = I->second;
1323  if (MatchingValue == Value &&
1324  RelType == getMatchingLoRelocation(Reloc.RelType) &&
1325  SectionID == Reloc.SectionID) {
1326  Reloc.Addend += Addend;
1327  if (Value.SymbolName)
1328  addRelocationForSymbol(Reloc, Value.SymbolName);
1329  else
1330  addRelocationForSection(Reloc, Value.SectionID);
1331  I = PendingRelocs.erase(I);
1332  } else
1333  ++I;
1334  }
1335  RelocationEntry RE(SectionID, Offset, RelType, Addend);
1336  if (Value.SymbolName)
1338  else
1340  } else {
1341  if (RelType == ELF::R_MIPS_32)
1342  Value.Addend += Opcode;
1343  else if (RelType == ELF::R_MIPS_PC16)
1344  Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1345  else if (RelType == ELF::R_MIPS_PC19_S2)
1346  Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1347  else if (RelType == ELF::R_MIPS_PC21_S2)
1348  Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1349  else if (RelType == ELF::R_MIPS_PC26_S2)
1350  Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1351  processSimpleRelocation(SectionID, Offset, RelType, Value);
1352  }
1353  } else if (IsMipsN32ABI || IsMipsN64ABI) {
1354  uint32_t r_type = RelType & 0xff;
1355  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1356  if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1357  || r_type == ELF::R_MIPS_GOT_DISP) {
1358  StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1359  if (i != GOTSymbolOffsets.end())
1360  RE.SymOffset = i->second;
1361  else {
1362  RE.SymOffset = allocateGOTEntries(1);
1363  GOTSymbolOffsets[TargetName] = RE.SymOffset;
1364  }
1365  if (Value.SymbolName)
1367  else
1369  } else if (RelType == ELF::R_MIPS_26) {
1370  // This is an Mips branch relocation, need to use a stub function.
1371  LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1372  SectionEntry &Section = Sections[SectionID];
1373 
1374  // Look up for existing stub.
1375  StubMap::const_iterator i = Stubs.find(Value);
1376  if (i != Stubs.end()) {
1377  RelocationEntry RE(SectionID, Offset, RelType, i->second);
1378  addRelocationForSection(RE, SectionID);
1379  LLVM_DEBUG(dbgs() << " Stub function found\n");
1380  } else {
1381  // Create a new stub function.
1382  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1383  Stubs[Value] = Section.getStubOffset();
1384 
1385  unsigned AbiVariant = Obj.getPlatformFlags();
1386 
1387  uint8_t *StubTargetAddr = createStubFunction(
1388  Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1389 
1390  if (IsMipsN32ABI) {
1391  // Creating Hi and Lo relocations for the filled stub instructions.
1392  RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1393  ELF::R_MIPS_HI16, Value.Addend);
1394  RelocationEntry RELo(SectionID,
1395  StubTargetAddr - Section.getAddress() + 4,
1396  ELF::R_MIPS_LO16, Value.Addend);
1397  if (Value.SymbolName) {
1398  addRelocationForSymbol(REHi, Value.SymbolName);
1399  addRelocationForSymbol(RELo, Value.SymbolName);
1400  } else {
1401  addRelocationForSection(REHi, Value.SectionID);
1402  addRelocationForSection(RELo, Value.SectionID);
1403  }
1404  } else {
1405  // Creating Highest, Higher, Hi and Lo relocations for the filled stub
1406  // instructions.
1407  RelocationEntry REHighest(SectionID,
1408  StubTargetAddr - Section.getAddress(),
1409  ELF::R_MIPS_HIGHEST, Value.Addend);
1410  RelocationEntry REHigher(SectionID,
1411  StubTargetAddr - Section.getAddress() + 4,
1412  ELF::R_MIPS_HIGHER, Value.Addend);
1413  RelocationEntry REHi(SectionID,
1414  StubTargetAddr - Section.getAddress() + 12,
1415  ELF::R_MIPS_HI16, Value.Addend);
1416  RelocationEntry RELo(SectionID,
1417  StubTargetAddr - Section.getAddress() + 20,
1418  ELF::R_MIPS_LO16, Value.Addend);
1419  if (Value.SymbolName) {
1420  addRelocationForSymbol(REHighest, Value.SymbolName);
1421  addRelocationForSymbol(REHigher, Value.SymbolName);
1422  addRelocationForSymbol(REHi, Value.SymbolName);
1423  addRelocationForSymbol(RELo, Value.SymbolName);
1424  } else {
1425  addRelocationForSection(REHighest, Value.SectionID);
1426  addRelocationForSection(REHigher, Value.SectionID);
1427  addRelocationForSection(REHi, Value.SectionID);
1428  addRelocationForSection(RELo, Value.SectionID);
1429  }
1430  }
1431  RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1432  addRelocationForSection(RE, SectionID);
1433  Section.advanceStubOffset(getMaxStubSize());
1434  }
1435  } else {
1436  processSimpleRelocation(SectionID, Offset, RelType, Value);
1437  }
1438 
1439  } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1440  if (RelType == ELF::R_PPC64_REL24) {
1441  // Determine ABI variant in use for this object.
1442  unsigned AbiVariant = Obj.getPlatformFlags();
1443  AbiVariant &= ELF::EF_PPC64_ABI;
1444  // A PPC branch relocation will need a stub function if the target is
1445  // an external symbol (either Value.SymbolName is set, or SymType is
1446  // Symbol::ST_Unknown) or if the target address is not within the
1447  // signed 24-bits branch address.
1448  SectionEntry &Section = Sections[SectionID];
1449  uint8_t *Target = Section.getAddressWithOffset(Offset);
1450  bool RangeOverflow = false;
1451  bool IsExtern = Value.SymbolName || SymType == SymbolRef::ST_Unknown;
1452  if (!IsExtern) {
1453  if (AbiVariant != 2) {
1454  // In the ELFv1 ABI, a function call may point to the .opd entry,
1455  // so the final symbol value is calculated based on the relocation
1456  // values in the .opd section.
1457  if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
1458  return std::move(Err);
1459  } else {
1460  // In the ELFv2 ABI, a function symbol may provide a local entry
1461  // point, which must be used for direct calls.
1462  if (Value.SectionID == SectionID){
1463  uint8_t SymOther = Symbol->getOther();
1464  Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1465  }
1466  }
1467  uint8_t *RelocTarget =
1468  Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
1469  int64_t delta = static_cast<int64_t>(Target - RelocTarget);
1470  // If it is within 26-bits branch range, just set the branch target
1471  if (SignExtend64<26>(delta) != delta) {
1472  RangeOverflow = true;
1473  } else if ((AbiVariant != 2) ||
1474  (AbiVariant == 2 && Value.SectionID == SectionID)) {
1475  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1477  }
1478  }
1479  if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID) ||
1480  RangeOverflow) {
1481  // It is an external symbol (either Value.SymbolName is set, or
1482  // SymType is SymbolRef::ST_Unknown) or out of range.
1483  StubMap::const_iterator i = Stubs.find(Value);
1484  if (i != Stubs.end()) {
1485  // Symbol function stub already created, just relocate to it
1486  resolveRelocation(Section, Offset,
1487  reinterpret_cast<uint64_t>(
1488  Section.getAddressWithOffset(i->second)),
1489  RelType, 0);
1490  LLVM_DEBUG(dbgs() << " Stub function found\n");
1491  } else {
1492  // Create a new stub function.
1493  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1494  Stubs[Value] = Section.getStubOffset();
1495  uint8_t *StubTargetAddr = createStubFunction(
1496  Section.getAddressWithOffset(Section.getStubOffset()),
1497  AbiVariant);
1498  RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1499  ELF::R_PPC64_ADDR64, Value.Addend);
1500 
1501  // Generates the 64-bits address loads as exemplified in section
1502  // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1503  // apply to the low part of the instructions, so we have to update
1504  // the offset according to the target endianness.
1505  uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress();
1506  if (!IsTargetLittleEndian)
1507  StubRelocOffset += 2;
1508 
1509  RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1510  ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1511  RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1512  ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1513  RelocationEntry REh(SectionID, StubRelocOffset + 12,
1514  ELF::R_PPC64_ADDR16_HI, Value.Addend);
1515  RelocationEntry REl(SectionID, StubRelocOffset + 16,
1516  ELF::R_PPC64_ADDR16_LO, Value.Addend);
1517 
1518  if (Value.SymbolName) {
1519  addRelocationForSymbol(REhst, Value.SymbolName);
1520  addRelocationForSymbol(REhr, Value.SymbolName);
1521  addRelocationForSymbol(REh, Value.SymbolName);
1522  addRelocationForSymbol(REl, Value.SymbolName);
1523  } else {
1524  addRelocationForSection(REhst, Value.SectionID);
1525  addRelocationForSection(REhr, Value.SectionID);
1526  addRelocationForSection(REh, Value.SectionID);
1527  addRelocationForSection(REl, Value.SectionID);
1528  }
1529 
1530  resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1531  Section.getAddressWithOffset(
1532  Section.getStubOffset())),
1533  RelType, 0);
1534  Section.advanceStubOffset(getMaxStubSize());
1535  }
1536  if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID)) {
1537  // Restore the TOC for external calls
1538  if (AbiVariant == 2)
1539  writeInt32BE(Target + 4, 0xE8410018); // ld r2,24(r1)
1540  else
1541  writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1542  }
1543  }
1544  } else if (RelType == ELF::R_PPC64_TOC16 ||
1545  RelType == ELF::R_PPC64_TOC16_DS ||
1546  RelType == ELF::R_PPC64_TOC16_LO ||
1547  RelType == ELF::R_PPC64_TOC16_LO_DS ||
1548  RelType == ELF::R_PPC64_TOC16_HI ||
1549  RelType == ELF::R_PPC64_TOC16_HA) {
1550  // These relocations are supposed to subtract the TOC address from
1551  // the final value. This does not fit cleanly into the RuntimeDyld
1552  // scheme, since there may be *two* sections involved in determining
1553  // the relocation value (the section of the symbol referred to by the
1554  // relocation, and the TOC section associated with the current module).
1555  //
1556  // Fortunately, these relocations are currently only ever generated
1557  // referring to symbols that themselves reside in the TOC, which means
1558  // that the two sections are actually the same. Thus they cancel out
1559  // and we can immediately resolve the relocation right now.
1560  switch (RelType) {
1561  case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1562  case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1563  case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1564  case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1565  case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1566  case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1567  default: llvm_unreachable("Wrong relocation type.");
1568  }
1569 
1570  RelocationValueRef TOCValue;
1571  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
1572  return std::move(Err);
1573  if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1574  llvm_unreachable("Unsupported TOC relocation.");
1575  Value.Addend -= TOCValue.Addend;
1576  resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1577  } else {
1578  // There are two ways to refer to the TOC address directly: either
1579  // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1580  // ignored), or via any relocation that refers to the magic ".TOC."
1581  // symbols (in which case the addend is respected).
1582  if (RelType == ELF::R_PPC64_TOC) {
1583  RelType = ELF::R_PPC64_ADDR64;
1584  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1585  return std::move(Err);
1586  } else if (TargetName == ".TOC.") {
1587  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1588  return std::move(Err);
1589  Value.Addend += Addend;
1590  }
1591 
1592  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1593 
1594  if (Value.SymbolName)
1596  else
1598  }
1599  } else if (Arch == Triple::systemz &&
1600  (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1601  // Create function stubs for both PLT and GOT references, regardless of
1602  // whether the GOT reference is to data or code. The stub contains the
1603  // full address of the symbol, as needed by GOT references, and the
1604  // executable part only adds an overhead of 8 bytes.
1605  //
1606  // We could try to conserve space by allocating the code and data
1607  // parts of the stub separately. However, as things stand, we allocate
1608  // a stub for every relocation, so using a GOT in JIT code should be
1609  // no less space efficient than using an explicit constant pool.
1610  LLVM_DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1611  SectionEntry &Section = Sections[SectionID];
1612 
1613  // Look for an existing stub.
1614  StubMap::const_iterator i = Stubs.find(Value);
1615  uintptr_t StubAddress;
1616  if (i != Stubs.end()) {
1617  StubAddress = uintptr_t(Section.getAddressWithOffset(i->second));
1618  LLVM_DEBUG(dbgs() << " Stub function found\n");
1619  } else {
1620  // Create a new stub function.
1621  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1622 
1623  uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1624  uintptr_t StubAlignment = getStubAlignment();
1625  StubAddress =
1626  (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1627  -StubAlignment;
1628  unsigned StubOffset = StubAddress - BaseAddress;
1629 
1630  Stubs[Value] = StubOffset;
1631  createStubFunction((uint8_t *)StubAddress);
1632  RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1633  Value.Offset);
1634  if (Value.SymbolName)
1636  else
1638  Section.advanceStubOffset(getMaxStubSize());
1639  }
1640 
1641  if (RelType == ELF::R_390_GOTENT)
1642  resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1643  Addend);
1644  else
1645  resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1646  } else if (Arch == Triple::x86_64) {
1647  if (RelType == ELF::R_X86_64_PLT32) {
1648  // The way the PLT relocations normally work is that the linker allocates
1649  // the
1650  // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1651  // entry will then jump to an address provided by the GOT. On first call,
1652  // the
1653  // GOT address will point back into PLT code that resolves the symbol. After
1654  // the first call, the GOT entry points to the actual function.
1655  //
1656  // For local functions we're ignoring all of that here and just replacing
1657  // the PLT32 relocation type with PC32, which will translate the relocation
1658  // into a PC-relative call directly to the function. For external symbols we
1659  // can't be sure the function will be within 2^32 bytes of the call site, so
1660  // we need to create a stub, which calls into the GOT. This case is
1661  // equivalent to the usual PLT implementation except that we use the stub
1662  // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1663  // rather than allocating a PLT section.
1664  if (Value.SymbolName) {
1665  // This is a call to an external function.
1666  // Look for an existing stub.
1667  SectionEntry &Section = Sections[SectionID];
1668  StubMap::const_iterator i = Stubs.find(Value);
1669  uintptr_t StubAddress;
1670  if (i != Stubs.end()) {
1671  StubAddress = uintptr_t(Section.getAddress()) + i->second;
1672  LLVM_DEBUG(dbgs() << " Stub function found\n");
1673  } else {
1674  // Create a new stub function (equivalent to a PLT entry).
1675  LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1676 
1677  uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1678  uintptr_t StubAlignment = getStubAlignment();
1679  StubAddress =
1680  (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1681  -StubAlignment;
1682  unsigned StubOffset = StubAddress - BaseAddress;
1683  Stubs[Value] = StubOffset;
1684  createStubFunction((uint8_t *)StubAddress);
1685 
1686  // Bump our stub offset counter
1687  Section.advanceStubOffset(getMaxStubSize());
1688 
1689  // Allocate a GOT Entry
1690  uint64_t GOTOffset = allocateGOTEntries(1);
1691 
1692  // The load of the GOT address has an addend of -4
1693  resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4,
1694  ELF::R_X86_64_PC32);
1695 
1696  // Fill in the value of the symbol we're targeting into the GOT
1698  computeGOTOffsetRE(GOTOffset, 0, ELF::R_X86_64_64),
1699  Value.SymbolName);
1700  }
1701 
1702  // Make the target call a call into the stub table.
1703  resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1704  Addend);
1705  } else {
1706  RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1707  Value.Offset);
1709  }
1710  } else if (RelType == ELF::R_X86_64_GOTPCREL ||
1711  RelType == ELF::R_X86_64_GOTPCRELX ||
1712  RelType == ELF::R_X86_64_REX_GOTPCRELX) {
1713  uint64_t GOTOffset = allocateGOTEntries(1);
1714  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1715  ELF::R_X86_64_PC32);
1716 
1717  // Fill in the value of the symbol we're targeting into the GOT
1718  RelocationEntry RE =
1719  computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1720  if (Value.SymbolName)
1722  else
1724  } else if (RelType == ELF::R_X86_64_GOT64) {
1725  // Fill in a 64-bit GOT offset.
1726  uint64_t GOTOffset = allocateGOTEntries(1);
1727  resolveRelocation(Sections[SectionID], Offset, GOTOffset,
1728  ELF::R_X86_64_64, 0);
1729 
1730  // Fill in the value of the symbol we're targeting into the GOT
1731  RelocationEntry RE =
1732  computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1733  if (Value.SymbolName)
1735  else
1737  } else if (RelType == ELF::R_X86_64_GOTPC64) {
1738  // Materialize the address of the base of the GOT relative to the PC.
1739  // This doesn't create a GOT entry, but it does mean we need a GOT
1740  // section.
1741  (void)allocateGOTEntries(0);
1742  resolveGOTOffsetRelocation(SectionID, Offset, Addend, ELF::R_X86_64_PC64);
1743  } else if (RelType == ELF::R_X86_64_GOTOFF64) {
1744  // GOTOFF relocations ultimately require a section difference relocation.
1745  (void)allocateGOTEntries(0);
1746  processSimpleRelocation(SectionID, Offset, RelType, Value);
1747  } else if (RelType == ELF::R_X86_64_PC32) {
1748  Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1749  processSimpleRelocation(SectionID, Offset, RelType, Value);
1750  } else if (RelType == ELF::R_X86_64_PC64) {
1751  Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1752  processSimpleRelocation(SectionID, Offset, RelType, Value);
1753  } else {
1754  processSimpleRelocation(SectionID, Offset, RelType, Value);
1755  }
1756  } else {
1757  if (Arch == Triple::x86) {
1758  Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1759  }
1760  processSimpleRelocation(SectionID, Offset, RelType, Value);
1761  }
1762  return ++RelI;
1763 }
1764 
1766  // We don't use the GOT in all of these cases, but it's essentially free
1767  // to put them all here.
1768  size_t Result = 0;
1769  switch (Arch) {
1770  case Triple::x86_64:
1771  case Triple::aarch64:
1772  case Triple::aarch64_be:
1773  case Triple::ppc64:
1774  case Triple::ppc64le:
1775  case Triple::systemz:
1776  Result = sizeof(uint64_t);
1777  break;
1778  case Triple::x86:
1779  case Triple::arm:
1780  case Triple::thumb:
1781  Result = sizeof(uint32_t);
1782  break;
1783  case Triple::mips:
1784  case Triple::mipsel:
1785  case Triple::mips64:
1786  case Triple::mips64el:
1787  if (IsMipsO32ABI || IsMipsN32ABI)
1788  Result = sizeof(uint32_t);
1789  else if (IsMipsN64ABI)
1790  Result = sizeof(uint64_t);
1791  else
1792  llvm_unreachable("Mips ABI not handled");
1793  break;
1794  default:
1795  llvm_unreachable("Unsupported CPU type!");
1796  }
1797  return Result;
1798 }
1799 
1800 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned no) {
1801  if (GOTSectionID == 0) {
1802  GOTSectionID = Sections.size();
1803  // Reserve a section id. We'll allocate the section later
1804  // once we know the total size
1805  Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0));
1806  }
1807  uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1808  CurrentGOTIndex += no;
1809  return StartOffset;
1810 }
1811 
1812 uint64_t RuntimeDyldELF::findOrAllocGOTEntry(const RelocationValueRef &Value,
1813  unsigned GOTRelType) {
1814  auto E = GOTOffsetMap.insert({Value, 0});
1815  if (E.second) {
1816  uint64_t GOTOffset = allocateGOTEntries(1);
1817 
1818  // Create relocation for newly created GOT entry
1819  RelocationEntry RE =
1820  computeGOTOffsetRE(GOTOffset, Value.Offset, GOTRelType);
1821  if (Value.SymbolName)
1823  else
1825 
1826  E.first->second = GOTOffset;
1827  }
1828 
1829  return E.first->second;
1830 }
1831 
1832 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID,
1833  uint64_t Offset,
1834  uint64_t GOTOffset,
1835  uint32_t Type) {
1836  // Fill in the relative address of the GOT Entry into the stub
1837  RelocationEntry GOTRE(SectionID, Offset, Type, GOTOffset);
1838  addRelocationForSection(GOTRE, GOTSectionID);
1839 }
1840 
1841 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(uint64_t GOTOffset,
1842  uint64_t SymbolOffset,
1843  uint32_t Type) {
1844  return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1845 }
1846 
1848  ObjSectionToIDMap &SectionMap) {
1849  if (IsMipsO32ABI)
1850  if (!PendingRelocs.empty())
1851  return make_error<RuntimeDyldError>("Can't find matching LO16 reloc");
1852 
1853  // If necessary, allocate the global offset table
1854  if (GOTSectionID != 0) {
1855  // Allocate memory for the section
1856  size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1857  uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1858  GOTSectionID, ".got", false);
1859  if (!Addr)
1860  return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!");
1861 
1862  Sections[GOTSectionID] =
1863  SectionEntry(".got", Addr, TotalSize, TotalSize, 0);
1864 
1865  // For now, initialize all GOT entries to zero. We'll fill them in as
1866  // needed when GOT-based relocations are applied.
1867  memset(Addr, 0, TotalSize);
1868  if (IsMipsN32ABI || IsMipsN64ABI) {
1869  // To correctly resolve Mips GOT relocations, we need a mapping from
1870  // object's sections to GOTs.
1871  for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1872  SI != SE; ++SI) {
1873  if (SI->relocation_begin() != SI->relocation_end()) {
1874  section_iterator RelocatedSection = SI->getRelocatedSection();
1875  ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1876  assert (i != SectionMap.end());
1877  SectionToGOTMap[i->second] = GOTSectionID;
1878  }
1879  }
1880  GOTSymbolOffsets.clear();
1881  }
1882  }
1883 
1884  // Look for and record the EH frame section.
1885  ObjSectionToIDMap::iterator i, e;
1886  for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1887  const SectionRef &Section = i->first;
1888 
1889  StringRef Name;
1890  Expected<StringRef> NameOrErr = Section.getName();
1891  if (NameOrErr)
1892  Name = *NameOrErr;
1893  else
1894  consumeError(NameOrErr.takeError());
1895 
1896  if (Name == ".eh_frame") {
1897  UnregisteredEHFrameSections.push_back(i->second);
1898  break;
1899  }
1900  }
1901 
1902  GOTSectionID = 0;
1903  CurrentGOTIndex = 0;
1904 
1905  return Error::success();
1906 }
1907 
1909  return Obj.isELF();
1910 }
1911 
1912 bool RuntimeDyldELF::relocationNeedsGot(const RelocationRef &R) const {
1913  unsigned RelTy = R.getType();
1915  return RelTy == ELF::R_AARCH64_ADR_GOT_PAGE ||
1916  RelTy == ELF::R_AARCH64_LD64_GOT_LO12_NC;
1917 
1918  if (Arch == Triple::x86_64)
1919  return RelTy == ELF::R_X86_64_GOTPCREL ||
1920  RelTy == ELF::R_X86_64_GOTPCRELX ||
1921  RelTy == ELF::R_X86_64_GOT64 ||
1922  RelTy == ELF::R_X86_64_REX_GOTPCRELX;
1923  return false;
1924 }
1925 
1926 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
1927  if (Arch != Triple::x86_64)
1928  return true; // Conservative answer
1929 
1930  switch (R.getType()) {
1931  default:
1932  return true; // Conservative answer
1933 
1934 
1935  case ELF::R_X86_64_GOTPCREL:
1936  case ELF::R_X86_64_GOTPCRELX:
1937  case ELF::R_X86_64_REX_GOTPCRELX:
1938  case ELF::R_X86_64_GOTPC64:
1939  case ELF::R_X86_64_GOT64:
1940  case ELF::R_X86_64_GOTOFF64:
1941  case ELF::R_X86_64_PC32:
1942  case ELF::R_X86_64_PC64:
1943  case ELF::R_X86_64_64:
1944  // We know that these reloation types won't need a stub function. This list
1945  // can be extended as needed.
1946  return false;
1947  }
1948 }
1949 
1950 } // 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:23
void writeInt16BE(uint8_t *Addr, uint16_t Value)
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
StringRef getFileName() const
Definition: Binary.cpp:42
void push_back(const T &Elt)
Definition: SmallVector.h:211
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:332
constexpr bool isInt< 8 >(int64_t x)
Definition: MathExtras.h:302
This class is the base class for all object file types.
Definition: ObjectFile.h:221
static uint16_t applyPPChigher(uint64_t value)
void write32le(void *P, uint32_t V)
Definition: Endian.h:418
static uint16_t applyPPChighesta(uint64_t value)
uint8_t * getAddress() const
Error takeError()
Take ownership of the stored error.
Definition: Error.h:552
static uint16_t applyPPChighera(uint64_t value)
static std::unique_ptr< RuntimeDyldELF > create(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
static int64_t decodePPC64LocalEntryOffset(unsigned Other)
Definition: ELF.h:392
unsigned SectionID
SectionID - the section this relocation points to.
amdgpu aa AMDGPU Address space based Alias Analysis Wrapper
DataRefImpl getRawDataRefImpl() const
Definition: SymbolicFile.h:203
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: yaml2obj.h:21
section_iterator_range sections() const
Definition: ObjectFile.h:310
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:249
Expected< section_iterator > getSection() const
Get section this symbol is defined in reference to.
Definition: ObjectFile.h:395
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:45
void registerEHFrames() override
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
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:1863
static StringRef getArchTypePrefix(ArchType Kind)
getArchTypePrefix - Get the "prefix" canonical name for the Kind architecture.
Definition: Triple.cpp:78
Expected< int64_t > getAddend() const
Symbol resolution interface.
Definition: JITSymbol.h:325
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:118
DataRefImpl getRawDataRefImpl() const
Definition: ObjectFile.h:508
void consumeError(Error Err)
Consume a Error without doing anything.
Definition: Error.h:981
size_t size() const
Definition: SmallVector.h:52
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:538
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
bool isLittleEndian() const
Definition: Binary.h:146
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:904
static ErrorSuccess success()
Create a success value.
Definition: Error.h:326
constexpr bool isInt< 32 >(int64_t x)
Definition: MathExtras.h:308
Error finalizeLoad(const ObjectFile &Obj, ObjSectionToIDMap &SectionMap) override
virtual section_iterator section_begin() const =0
Expected< SymbolRef::Type > getType() const
Definition: ObjectFile.h:399
int64_t Addend
Addend - the relocation addend encoded in the instruction itself.
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:141
static void or32le(void *P, int32_t V)
uint8_t * createStubFunction(uint8_t *Addr, unsigned AbiVariant=0)
Emits long jump instruction to Addr.
Expected< StringRef > getName() const
Definition: ObjectFile.h:432
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
StringMap - This is an unconventional map that is specialized for handling keys that are "strings"...
Definition: StringMap.h:219
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
This is a value type class that represents a single symbol in the list of symbols in the object file...
Definition: ObjectFile.h:160
Triple::ArchType Arch
LLVM_NODISCARD bool equals(StringRef RHS) const
equals - Check for string equality, this is more efficient than compare() when the relative ordering ...
Definition: StringRef.h:174
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:383
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.
LLVM_NODISCARD const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:136
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:503
LLVM Value Representation.
Definition: Value.h:73
RTDyldSymbolTable GlobalSymbolTable
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
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:80
static void write32AArch64Addr(void *L, uint64_t Imm)
void advanceStubOffset(unsigned StubSize)
#define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
Definition: ELFTypes.h:103
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
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:122
virtual StringRef getFileFormatName() const =0
StringRef getData() const
Definition: Binary.cpp:40
iterator end()
Definition: StringMap.h:317
This is a value type class that represents a single section in the list of sections in the object fil...
Definition: ObjectFile.h:81