LLVM  12.0.0git
WinCOFFObjectWriter.cpp
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1 //===- llvm/MC/WinCOFFObjectWriter.cpp ------------------------------------===//
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 // This file contains an implementation of a Win32 COFF object file writer.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/DenseMap.h"
14 #include "llvm/ADT/DenseSet.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/BinaryFormat/COFF.h"
21 #include "llvm/MC/MCAsmLayout.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCContext.h"
24 #include "llvm/MC/MCExpr.h"
25 #include "llvm/MC/MCFixup.h"
26 #include "llvm/MC/MCFragment.h"
27 #include "llvm/MC/MCObjectWriter.h"
28 #include "llvm/MC/MCSection.h"
29 #include "llvm/MC/MCSectionCOFF.h"
30 #include "llvm/MC/MCSymbol.h"
31 #include "llvm/MC/MCSymbolCOFF.h"
32 #include "llvm/MC/MCValue.h"
35 #include "llvm/Support/CRC.h"
36 #include "llvm/Support/Casting.h"
39 #include "llvm/Support/LEB128.h"
42 #include <algorithm>
43 #include <cassert>
44 #include <cstddef>
45 #include <cstdint>
46 #include <cstring>
47 #include <ctime>
48 #include <memory>
49 #include <string>
50 #include <vector>
51 
52 using namespace llvm;
54 
55 #define DEBUG_TYPE "WinCOFFObjectWriter"
56 
57 namespace {
58 
60 
62  ATWeakExternal,
63  ATFile,
64  ATSectionDefinition
65 };
66 
67 struct AuxSymbol {
69  COFF::Auxiliary Aux;
70 };
71 
72 class COFFSection;
73 
74 class COFFSymbol {
75 public:
76  COFF::symbol Data = {};
77 
78  using AuxiliarySymbols = SmallVector<AuxSymbol, 1>;
79 
80  name Name;
81  int Index;
82  AuxiliarySymbols Aux;
83  COFFSymbol *Other = nullptr;
84  COFFSection *Section = nullptr;
85  int Relocations = 0;
86  const MCSymbol *MC = nullptr;
87 
88  COFFSymbol(StringRef Name) : Name(Name) {}
89 
90  void set_name_offset(uint32_t Offset);
91 
92  int64_t getIndex() const { return Index; }
93  void setIndex(int Value) {
94  Index = Value;
95  if (MC)
96  MC->setIndex(static_cast<uint32_t>(Value));
97  }
98 };
99 
100 // This class contains staging data for a COFF relocation entry.
101 struct COFFRelocation {
103  COFFSymbol *Symb = nullptr;
104 
105  COFFRelocation() = default;
106 
107  static size_t size() { return COFF::RelocationSize; }
108 };
109 
110 using relocations = std::vector<COFFRelocation>;
111 
112 class COFFSection {
113 public:
114  COFF::section Header = {};
115 
116  std::string Name;
117  int Number;
118  MCSectionCOFF const *MCSection = nullptr;
119  COFFSymbol *Symbol = nullptr;
120  relocations Relocations;
121 
122  COFFSection(StringRef Name) : Name(std::string(Name)) {}
123 };
124 
125 class WinCOFFObjectWriter : public MCObjectWriter {
126 public:
128 
129  using symbols = std::vector<std::unique_ptr<COFFSymbol>>;
130  using sections = std::vector<std::unique_ptr<COFFSection>>;
131 
132  using symbol_map = DenseMap<MCSymbol const *, COFFSymbol *>;
133  using section_map = DenseMap<MCSection const *, COFFSection *>;
134 
135  using symbol_list = DenseSet<COFFSymbol *>;
136 
137  std::unique_ptr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
138 
139  // Root level file contents.
140  COFF::header Header = {};
141  sections Sections;
142  symbols Symbols;
144 
145  // Maps used during object file creation.
146  section_map SectionMap;
147  symbol_map SymbolMap;
148 
149  symbol_list WeakDefaults;
150 
151  bool UseBigObj;
152 
153  bool EmitAddrsigSection = false;
154  MCSectionCOFF *AddrsigSection;
155  std::vector<const MCSymbol *> AddrsigSyms;
156 
157  MCSectionCOFF *CGProfileSection = nullptr;
158 
159  WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
160  raw_pwrite_stream &OS);
161 
162  void reset() override {
163  memset(&Header, 0, sizeof(Header));
164  Header.Machine = TargetObjectWriter->getMachine();
165  Sections.clear();
166  Symbols.clear();
167  Strings.clear();
168  SectionMap.clear();
169  SymbolMap.clear();
171  }
172 
173  COFFSymbol *createSymbol(StringRef Name);
174  COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol *Symbol);
175  COFFSection *createSection(StringRef Name);
176 
177  void defineSection(MCSectionCOFF const &Sec);
178 
179  COFFSymbol *getLinkedSymbol(const MCSymbol &Symbol);
180  void DefineSymbol(const MCSymbol &Symbol, MCAssembler &Assembler,
181  const MCAsmLayout &Layout);
182 
183  void SetSymbolName(COFFSymbol &S);
184  void SetSectionName(COFFSection &S);
185 
186  bool IsPhysicalSection(COFFSection *S);
187 
188  // Entity writing methods.
189 
190  void WriteFileHeader(const COFF::header &Header);
191  void WriteSymbol(const COFFSymbol &S);
192  void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
193  void writeSectionHeaders();
194  void WriteRelocation(const COFF::relocation &R);
195  uint32_t writeSectionContents(MCAssembler &Asm, const MCAsmLayout &Layout,
196  const MCSection &MCSec);
197  void writeSection(MCAssembler &Asm, const MCAsmLayout &Layout,
198  const COFFSection &Sec, const MCSection &MCSec);
199 
200  // MCObjectWriter interface implementation.
201 
202  void executePostLayoutBinding(MCAssembler &Asm,
203  const MCAsmLayout &Layout) override;
204 
205  bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
206  const MCSymbol &SymA,
207  const MCFragment &FB, bool InSet,
208  bool IsPCRel) const override;
209 
210  void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
211  const MCFragment *Fragment, const MCFixup &Fixup,
212  MCValue Target, uint64_t &FixedValue) override;
213 
214  void createFileSymbols(MCAssembler &Asm);
215  void setWeakDefaultNames();
216  void assignSectionNumbers();
217  void assignFileOffsets(MCAssembler &Asm, const MCAsmLayout &Layout);
218 
219  void emitAddrsigSection() override { EmitAddrsigSection = true; }
220  void addAddrsigSymbol(const MCSymbol *Sym) override {
221  AddrsigSyms.push_back(Sym);
222  }
223 
224  uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
225 };
226 
227 } // end anonymous namespace
228 
229 //------------------------------------------------------------------------------
230 // Symbol class implementation
231 
232 // In the case that the name does not fit within 8 bytes, the offset
233 // into the string table is stored in the last 4 bytes instead, leaving
234 // the first 4 bytes as 0.
235 void COFFSymbol::set_name_offset(uint32_t Offset) {
236  write32le(Data.Name + 0, 0);
237  write32le(Data.Name + 4, Offset);
238 }
239 
240 //------------------------------------------------------------------------------
241 // WinCOFFObjectWriter class implementation
242 
243 WinCOFFObjectWriter::WinCOFFObjectWriter(
244  std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS)
245  : W(OS, support::little), TargetObjectWriter(std::move(MOTW)) {
246  Header.Machine = TargetObjectWriter->getMachine();
247 }
248 
249 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
250  Symbols.push_back(std::make_unique<COFFSymbol>(Name));
251  return Symbols.back().get();
252 }
253 
254 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol *Symbol) {
255  COFFSymbol *&Ret = SymbolMap[Symbol];
256  if (!Ret)
257  Ret = createSymbol(Symbol->getName());
258  return Ret;
259 }
260 
261 COFFSection *WinCOFFObjectWriter::createSection(StringRef Name) {
262  Sections.emplace_back(std::make_unique<COFFSection>(Name));
263  return Sections.back().get();
264 }
265 
266 static uint32_t getAlignment(const MCSectionCOFF &Sec) {
267  switch (Sec.getAlignment()) {
268  case 1:
270  case 2:
272  case 4:
274  case 8:
276  case 16:
278  case 32:
280  case 64:
282  case 128:
284  case 256:
286  case 512:
288  case 1024:
290  case 2048:
292  case 4096:
294  case 8192:
296  }
297  llvm_unreachable("unsupported section alignment");
298 }
299 
300 /// This function takes a section data object from the assembler
301 /// and creates the associated COFF section staging object.
302 void WinCOFFObjectWriter::defineSection(const MCSectionCOFF &MCSec) {
303  COFFSection *Section = createSection(MCSec.getName());
304  COFFSymbol *Symbol = createSymbol(MCSec.getName());
305  Section->Symbol = Symbol;
306  Symbol->Section = Section;
307  Symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
308 
309  // Create a COMDAT symbol if needed.
311  if (const MCSymbol *S = MCSec.getCOMDATSymbol()) {
312  COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(S);
313  if (COMDATSymbol->Section)
314  report_fatal_error("two sections have the same comdat");
315  COMDATSymbol->Section = Section;
316  }
317  }
318 
319  // In this case the auxiliary symbol is a Section Definition.
320  Symbol->Aux.resize(1);
321  Symbol->Aux[0] = {};
322  Symbol->Aux[0].AuxType = ATSectionDefinition;
323  Symbol->Aux[0].Aux.SectionDefinition.Selection = MCSec.getSelection();
324 
325  // Set section alignment.
326  Section->Header.Characteristics = MCSec.getCharacteristics();
327  Section->Header.Characteristics |= getAlignment(MCSec);
328 
329  // Bind internal COFF section to MC section.
330  Section->MCSection = &MCSec;
331  SectionMap[&MCSec] = Section;
332 }
333 
334 static uint64_t getSymbolValue(const MCSymbol &Symbol,
335  const MCAsmLayout &Layout) {
336  if (Symbol.isCommon() && Symbol.isExternal())
337  return Symbol.getCommonSize();
338 
339  uint64_t Res;
340  if (!Layout.getSymbolOffset(Symbol, Res))
341  return 0;
342 
343  return Res;
344 }
345 
346 COFFSymbol *WinCOFFObjectWriter::getLinkedSymbol(const MCSymbol &Symbol) {
347  if (!Symbol.isVariable())
348  return nullptr;
349 
350  const MCSymbolRefExpr *SymRef =
352  if (!SymRef)
353  return nullptr;
354 
355  const MCSymbol &Aliasee = SymRef->getSymbol();
356  if (!Aliasee.isUndefined())
357  return nullptr;
358  return GetOrCreateCOFFSymbol(&Aliasee);
359 }
360 
361 /// This function takes a symbol data object from the assembler
362 /// and creates the associated COFF symbol staging object.
363 void WinCOFFObjectWriter::DefineSymbol(const MCSymbol &MCSym,
364  MCAssembler &Assembler,
365  const MCAsmLayout &Layout) {
366  COFFSymbol *Sym = GetOrCreateCOFFSymbol(&MCSym);
367  const MCSymbol *Base = Layout.getBaseSymbol(MCSym);
368  COFFSection *Sec = nullptr;
369  if (Base && Base->getFragment()) {
370  Sec = SectionMap[Base->getFragment()->getParent()];
371  if (Sym->Section && Sym->Section != Sec)
372  report_fatal_error("conflicting sections for symbol");
373  }
374 
375  COFFSymbol *Local = nullptr;
376  if (cast<MCSymbolCOFF>(MCSym).isWeakExternal()) {
377  Sym->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
378 
379  COFFSymbol *WeakDefault = getLinkedSymbol(MCSym);
380  if (!WeakDefault) {
381  std::string WeakName = (".weak." + MCSym.getName() + ".default").str();
382  WeakDefault = createSymbol(WeakName);
383  if (!Sec)
384  WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
385  else
386  WeakDefault->Section = Sec;
387  WeakDefaults.insert(WeakDefault);
388  Local = WeakDefault;
389  }
390 
391  Sym->Other = WeakDefault;
392 
393  // Setup the Weak External auxiliary symbol.
394  Sym->Aux.resize(1);
395  memset(&Sym->Aux[0], 0, sizeof(Sym->Aux[0]));
396  Sym->Aux[0].AuxType = ATWeakExternal;
397  Sym->Aux[0].Aux.WeakExternal.TagIndex = 0;
398  Sym->Aux[0].Aux.WeakExternal.Characteristics =
400  } else {
401  if (!Base)
402  Sym->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
403  else
404  Sym->Section = Sec;
405  Local = Sym;
406  }
407 
408  if (Local) {
409  Local->Data.Value = getSymbolValue(MCSym, Layout);
410 
411  const MCSymbolCOFF &SymbolCOFF = cast<MCSymbolCOFF>(MCSym);
412  Local->Data.Type = SymbolCOFF.getType();
413  Local->Data.StorageClass = SymbolCOFF.getClass();
414 
415  // If no storage class was specified in the streamer, define it here.
416  if (Local->Data.StorageClass == COFF::IMAGE_SYM_CLASS_NULL) {
417  bool IsExternal = MCSym.isExternal() ||
418  (!MCSym.getFragment() && !MCSym.isVariable());
419 
420  Local->Data.StorageClass = IsExternal ? COFF::IMAGE_SYM_CLASS_EXTERNAL
422  }
423  }
424 
425  Sym->MC = &MCSym;
426 }
427 
428 // Maximum offsets for different string table entry encodings.
429 enum : unsigned { Max7DecimalOffset = 9999999U };
430 enum : uint64_t { MaxBase64Offset = 0xFFFFFFFFFULL }; // 64^6, including 0
431 
432 // Encode a string table entry offset in base 64, padded to 6 chars, and
433 // prefixed with a double slash: '//AAAAAA', '//AAAAAB', ...
434 // Buffer must be at least 8 bytes large. No terminating null appended.
435 static void encodeBase64StringEntry(char *Buffer, uint64_t Value) {
436  assert(Value > Max7DecimalOffset && Value <= MaxBase64Offset &&
437  "Illegal section name encoding for value");
438 
439  static const char Alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
440  "abcdefghijklmnopqrstuvwxyz"
441  "0123456789+/";
442 
443  Buffer[0] = '/';
444  Buffer[1] = '/';
445 
446  char *Ptr = Buffer + 7;
447  for (unsigned i = 0; i < 6; ++i) {
448  unsigned Rem = Value % 64;
449  Value /= 64;
450  *(Ptr--) = Alphabet[Rem];
451  }
452 }
453 
454 void WinCOFFObjectWriter::SetSectionName(COFFSection &S) {
455  if (S.Name.size() <= COFF::NameSize) {
456  std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
457  return;
458  }
459 
460  uint64_t StringTableEntry = Strings.getOffset(S.Name);
461  if (StringTableEntry <= Max7DecimalOffset) {
463  Twine('/').concat(Twine(StringTableEntry)).toVector(Buffer);
464  assert(Buffer.size() <= COFF::NameSize && Buffer.size() >= 2);
465  std::memcpy(S.Header.Name, Buffer.data(), Buffer.size());
466  return;
467  }
468  if (StringTableEntry <= MaxBase64Offset) {
469  // Starting with 10,000,000, offsets are encoded as base64.
470  encodeBase64StringEntry(S.Header.Name, StringTableEntry);
471  return;
472  }
473  report_fatal_error("COFF string table is greater than 64 GB.");
474 }
475 
476 void WinCOFFObjectWriter::SetSymbolName(COFFSymbol &S) {
477  if (S.Name.size() > COFF::NameSize)
478  S.set_name_offset(Strings.getOffset(S.Name));
479  else
480  std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
481 }
482 
483 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
484  return (S->Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) ==
485  0;
486 }
487 
488 //------------------------------------------------------------------------------
489 // entity writing methods
490 
491 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
492  if (UseBigObj) {
494  W.write<uint16_t>(0xFFFF);
496  W.write<uint16_t>(Header.Machine);
497  W.write<uint32_t>(Header.TimeDateStamp);
498  W.OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
499  W.write<uint32_t>(0);
500  W.write<uint32_t>(0);
501  W.write<uint32_t>(0);
502  W.write<uint32_t>(0);
503  W.write<uint32_t>(Header.NumberOfSections);
504  W.write<uint32_t>(Header.PointerToSymbolTable);
505  W.write<uint32_t>(Header.NumberOfSymbols);
506  } else {
507  W.write<uint16_t>(Header.Machine);
508  W.write<uint16_t>(static_cast<int16_t>(Header.NumberOfSections));
509  W.write<uint32_t>(Header.TimeDateStamp);
510  W.write<uint32_t>(Header.PointerToSymbolTable);
511  W.write<uint32_t>(Header.NumberOfSymbols);
512  W.write<uint16_t>(Header.SizeOfOptionalHeader);
513  W.write<uint16_t>(Header.Characteristics);
514  }
515 }
516 
517 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol &S) {
518  W.OS.write(S.Data.Name, COFF::NameSize);
519  W.write<uint32_t>(S.Data.Value);
520  if (UseBigObj)
521  W.write<uint32_t>(S.Data.SectionNumber);
522  else
523  W.write<uint16_t>(static_cast<int16_t>(S.Data.SectionNumber));
524  W.write<uint16_t>(S.Data.Type);
525  W.OS << char(S.Data.StorageClass);
526  W.OS << char(S.Data.NumberOfAuxSymbols);
527  WriteAuxiliarySymbols(S.Aux);
528 }
529 
530 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
531  const COFFSymbol::AuxiliarySymbols &S) {
532  for (const AuxSymbol &i : S) {
533  switch (i.AuxType) {
534  case ATWeakExternal:
535  W.write<uint32_t>(i.Aux.WeakExternal.TagIndex);
536  W.write<uint32_t>(i.Aux.WeakExternal.Characteristics);
537  W.OS.write_zeros(sizeof(i.Aux.WeakExternal.unused));
538  if (UseBigObj)
539  W.OS.write_zeros(COFF::Symbol32Size - COFF::Symbol16Size);
540  break;
541  case ATFile:
542  W.OS.write(reinterpret_cast<const char *>(&i.Aux),
543  UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size);
544  break;
545  case ATSectionDefinition:
546  W.write<uint32_t>(i.Aux.SectionDefinition.Length);
547  W.write<uint16_t>(i.Aux.SectionDefinition.NumberOfRelocations);
548  W.write<uint16_t>(i.Aux.SectionDefinition.NumberOfLinenumbers);
549  W.write<uint32_t>(i.Aux.SectionDefinition.CheckSum);
550  W.write<uint16_t>(static_cast<int16_t>(i.Aux.SectionDefinition.Number));
551  W.OS << char(i.Aux.SectionDefinition.Selection);
552  W.OS.write_zeros(sizeof(i.Aux.SectionDefinition.unused));
553  W.write<uint16_t>(static_cast<int16_t>(i.Aux.SectionDefinition.Number >> 16));
554  if (UseBigObj)
555  W.OS.write_zeros(COFF::Symbol32Size - COFF::Symbol16Size);
556  break;
557  }
558  }
559 }
560 
561 // Write the section header.
562 void WinCOFFObjectWriter::writeSectionHeaders() {
563  // Section numbers must be monotonically increasing in the section
564  // header, but our Sections array is not sorted by section number,
565  // so make a copy of Sections and sort it.
566  std::vector<COFFSection *> Arr;
567  for (auto &Section : Sections)
568  Arr.push_back(Section.get());
569  llvm::sort(Arr, [](const COFFSection *A, const COFFSection *B) {
570  return A->Number < B->Number;
571  });
572 
573  for (auto &Section : Arr) {
574  if (Section->Number == -1)
575  continue;
576 
577  COFF::section &S = Section->Header;
578  if (Section->Relocations.size() >= 0xffff)
580  W.OS.write(S.Name, COFF::NameSize);
581  W.write<uint32_t>(S.VirtualSize);
582  W.write<uint32_t>(S.VirtualAddress);
583  W.write<uint32_t>(S.SizeOfRawData);
584  W.write<uint32_t>(S.PointerToRawData);
585  W.write<uint32_t>(S.PointerToRelocations);
586  W.write<uint32_t>(S.PointerToLineNumbers);
587  W.write<uint16_t>(S.NumberOfRelocations);
588  W.write<uint16_t>(S.NumberOfLineNumbers);
589  W.write<uint32_t>(S.Characteristics);
590  }
591 }
592 
593 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
594  W.write<uint32_t>(R.VirtualAddress);
595  W.write<uint32_t>(R.SymbolTableIndex);
596  W.write<uint16_t>(R.Type);
597 }
598 
599 // Write MCSec's contents. What this function does is essentially
600 // "Asm.writeSectionData(&MCSec, Layout)", but it's a bit complicated
601 // because it needs to compute a CRC.
602 uint32_t WinCOFFObjectWriter::writeSectionContents(MCAssembler &Asm,
603  const MCAsmLayout &Layout,
604  const MCSection &MCSec) {
605  // Save the contents of the section to a temporary buffer, we need this
606  // to CRC the data before we dump it into the object file.
608  raw_svector_ostream VecOS(Buf);
609  Asm.writeSectionData(VecOS, &MCSec, Layout);
610 
611  // Write the section contents to the object file.
612  W.OS << Buf;
613 
614  // Calculate our CRC with an initial value of '0', this is not how
615  // JamCRC is specified but it aligns with the expected output.
616  JamCRC JC(/*Init=*/0);
617  JC.update(makeArrayRef(reinterpret_cast<uint8_t*>(Buf.data()), Buf.size()));
618  return JC.getCRC();
619 }
620 
621 void WinCOFFObjectWriter::writeSection(MCAssembler &Asm,
622  const MCAsmLayout &Layout,
623  const COFFSection &Sec,
624  const MCSection &MCSec) {
625  if (Sec.Number == -1)
626  return;
627 
628  // Write the section contents.
629  if (Sec.Header.PointerToRawData != 0) {
630  assert(W.OS.tell() == Sec.Header.PointerToRawData &&
631  "Section::PointerToRawData is insane!");
632 
633  uint32_t CRC = writeSectionContents(Asm, Layout, MCSec);
634 
635  // Update the section definition auxiliary symbol to record the CRC.
636  COFFSection *Sec = SectionMap[&MCSec];
637  COFFSymbol::AuxiliarySymbols &AuxSyms = Sec->Symbol->Aux;
638  assert(AuxSyms.size() == 1 && AuxSyms[0].AuxType == ATSectionDefinition);
639  AuxSymbol &SecDef = AuxSyms[0];
640  SecDef.Aux.SectionDefinition.CheckSum = CRC;
641  }
642 
643  // Write relocations for this section.
644  if (Sec.Relocations.empty()) {
645  assert(Sec.Header.PointerToRelocations == 0 &&
646  "Section::PointerToRelocations is insane!");
647  return;
648  }
649 
650  assert(W.OS.tell() == Sec.Header.PointerToRelocations &&
651  "Section::PointerToRelocations is insane!");
652 
653  if (Sec.Relocations.size() >= 0xffff) {
654  // In case of overflow, write actual relocation count as first
655  // relocation. Including the synthetic reloc itself (+ 1).
657  R.VirtualAddress = Sec.Relocations.size() + 1;
658  R.SymbolTableIndex = 0;
659  R.Type = 0;
660  WriteRelocation(R);
661  }
662 
663  for (const auto &Relocation : Sec.Relocations)
664  WriteRelocation(Relocation.Data);
665 }
666 
667 ////////////////////////////////////////////////////////////////////////////////
668 // MCObjectWriter interface implementations
669 
670 void WinCOFFObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
671  const MCAsmLayout &Layout) {
672  if (EmitAddrsigSection) {
673  AddrsigSection = Asm.getContext().getCOFFSection(
674  ".llvm_addrsig", COFF::IMAGE_SCN_LNK_REMOVE,
676  Asm.registerSection(*AddrsigSection);
677  }
678 
679  if (!Asm.CGProfile.empty()) {
680  CGProfileSection = Asm.getContext().getCOFFSection(
681  ".llvm.call-graph-profile", COFF::IMAGE_SCN_LNK_REMOVE,
683  Asm.registerSection(*CGProfileSection);
684  }
685 
686  // "Define" each section & symbol. This creates section & symbol
687  // entries in the staging area.
688  for (const auto &Section : Asm)
689  defineSection(static_cast<const MCSectionCOFF &>(Section));
690 
691  for (const MCSymbol &Symbol : Asm.symbols())
692  if (!Symbol.isTemporary())
693  DefineSymbol(Symbol, Asm, Layout);
694 }
695 
696 bool WinCOFFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
697  const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
698  bool InSet, bool IsPCRel) const {
699  // Don't drop relocations between functions, even if they are in the same text
700  // section. Multiple Visual C++ linker features depend on having the
701  // relocations present. The /INCREMENTAL flag will cause these relocations to
702  // point to thunks, and the /GUARD:CF flag assumes that it can use relocations
703  // to approximate the set of all address taken functions. LLD's implementation
704  // of /GUARD:CF also relies on the existance of these relocations.
705  uint16_t Type = cast<MCSymbolCOFF>(SymA).getType();
707  return false;
709  InSet, IsPCRel);
710 }
711 
712 void WinCOFFObjectWriter::recordRelocation(MCAssembler &Asm,
713  const MCAsmLayout &Layout,
714  const MCFragment *Fragment,
715  const MCFixup &Fixup, MCValue Target,
716  uint64_t &FixedValue) {
717  assert(Target.getSymA() && "Relocation must reference a symbol!");
718 
719  const MCSymbol &A = Target.getSymA()->getSymbol();
720  if (!A.isRegistered()) {
721  Asm.getContext().reportError(Fixup.getLoc(),
722  Twine("symbol '") + A.getName() +
723  "' can not be undefined");
724  return;
725  }
726  if (A.isTemporary() && A.isUndefined()) {
727  Asm.getContext().reportError(Fixup.getLoc(),
728  Twine("assembler label '") + A.getName() +
729  "' can not be undefined");
730  return;
731  }
732 
733  MCSection *MCSec = Fragment->getParent();
734 
735  // Mark this symbol as requiring an entry in the symbol table.
736  assert(SectionMap.find(MCSec) != SectionMap.end() &&
737  "Section must already have been defined in executePostLayoutBinding!");
738 
739  COFFSection *Sec = SectionMap[MCSec];
740  const MCSymbolRefExpr *SymB = Target.getSymB();
741 
742  if (SymB) {
743  const MCSymbol *B = &SymB->getSymbol();
744  if (!B->getFragment()) {
745  Asm.getContext().reportError(
746  Fixup.getLoc(),
747  Twine("symbol '") + B->getName() +
748  "' can not be undefined in a subtraction expression");
749  return;
750  }
751 
752  // Offset of the symbol in the section
753  int64_t OffsetOfB = Layout.getSymbolOffset(*B);
754 
755  // Offset of the relocation in the section
756  int64_t OffsetOfRelocation =
757  Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
758 
759  FixedValue = (OffsetOfRelocation - OffsetOfB) + Target.getConstant();
760  } else {
761  FixedValue = Target.getConstant();
762  }
763 
764  COFFRelocation Reloc;
765 
766  Reloc.Data.SymbolTableIndex = 0;
767  Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
768 
769  // Turn relocations for temporary symbols into section relocations.
770  if (A.isTemporary()) {
771  MCSection *TargetSection = &A.getSection();
772  assert(
773  SectionMap.find(TargetSection) != SectionMap.end() &&
774  "Section must already have been defined in executePostLayoutBinding!");
775  Reloc.Symb = SectionMap[TargetSection]->Symbol;
776  FixedValue += Layout.getSymbolOffset(A);
777  } else {
778  assert(
779  SymbolMap.find(&A) != SymbolMap.end() &&
780  "Symbol must already have been defined in executePostLayoutBinding!");
781  Reloc.Symb = SymbolMap[&A];
782  }
783 
784  ++Reloc.Symb->Relocations;
785 
786  Reloc.Data.VirtualAddress += Fixup.getOffset();
787  Reloc.Data.Type = TargetObjectWriter->getRelocType(
788  Asm.getContext(), Target, Fixup, SymB, Asm.getBackend());
789 
790  // FIXME: Can anyone explain what this does other than adjust for the size
791  // of the offset?
792  if ((Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64 &&
793  Reloc.Data.Type == COFF::IMAGE_REL_AMD64_REL32) ||
795  Reloc.Data.Type == COFF::IMAGE_REL_I386_REL32))
796  FixedValue += 4;
797 
798  if (Header.Machine == COFF::IMAGE_FILE_MACHINE_ARMNT) {
799  switch (Reloc.Data.Type) {
806  break;
809  // IMAGE_REL_ARM_BRANCH11 and IMAGE_REL_ARM_BLX11 are only used for
810  // pre-ARMv7, which implicitly rules it out of ARMNT (it would be valid
811  // for Windows CE).
815  // IMAGE_REL_ARM_BRANCH24, IMAGE_REL_ARM_BLX24, IMAGE_REL_ARM_MOV32A are
816  // only used for ARM mode code, which is documented as being unsupported
817  // by Windows on ARM. Empirical proof indicates that masm is able to
818  // generate the relocations however the rest of the MSVC toolchain is
819  // unable to handle it.
820  llvm_unreachable("unsupported relocation");
821  break;
823  break;
827  // IMAGE_REL_BRANCH20T, IMAGE_REL_ARM_BRANCH24T, IMAGE_REL_ARM_BLX23T all
828  // perform a 4 byte adjustment to the relocation. Relative branches are
829  // offset by 4 on ARM, however, because there is no RELA relocations, all
830  // branches are offset by 4.
831  FixedValue = FixedValue + 4;
832  break;
833  }
834  }
835 
836  // The fixed value never makes sense for section indices, ignore it.
837  if (Fixup.getKind() == FK_SecRel_2)
838  FixedValue = 0;
839 
840  if (TargetObjectWriter->recordRelocation(Fixup))
841  Sec->Relocations.push_back(Reloc);
842 }
843 
844 static std::time_t getTime() {
845  std::time_t Now = time(nullptr);
846  if (Now < 0 || !isUInt<32>(Now))
847  return UINT32_MAX;
848  return Now;
849 }
850 
851 // Create .file symbols.
852 void WinCOFFObjectWriter::createFileSymbols(MCAssembler &Asm) {
853  for (const std::string &Name : Asm.getFileNames()) {
854  // round up to calculate the number of auxiliary symbols required
855  unsigned SymbolSize = UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size;
856  unsigned Count = (Name.size() + SymbolSize - 1) / SymbolSize;
857 
858  COFFSymbol *File = createSymbol(".file");
859  File->Data.SectionNumber = COFF::IMAGE_SYM_DEBUG;
860  File->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
861  File->Aux.resize(Count);
862 
863  unsigned Offset = 0;
864  unsigned Length = Name.size();
865  for (auto &Aux : File->Aux) {
866  Aux.AuxType = ATFile;
867 
868  if (Length > SymbolSize) {
869  memcpy(&Aux.Aux, Name.c_str() + Offset, SymbolSize);
870  Length = Length - SymbolSize;
871  } else {
872  memcpy(&Aux.Aux, Name.c_str() + Offset, Length);
873  memset((char *)&Aux.Aux + Length, 0, SymbolSize - Length);
874  break;
875  }
876 
877  Offset += SymbolSize;
878  }
879  }
880 }
881 
882 void WinCOFFObjectWriter::setWeakDefaultNames() {
883  if (WeakDefaults.empty())
884  return;
885 
886  // If multiple object files use a weak symbol (either with a regular
887  // defined default, or an absolute zero symbol as default), the defaults
888  // cause duplicate definitions unless their names are made unique. Look
889  // for a defined extern symbol, that isn't comdat - that should be unique
890  // unless there are other duplicate definitions. And if none is found,
891  // allow picking a comdat symbol, as that's still better than nothing.
892 
893  COFFSymbol *Unique = nullptr;
894  for (bool AllowComdat : {false, true}) {
895  for (auto &Sym : Symbols) {
896  // Don't include the names of the defaults themselves
897  if (WeakDefaults.count(Sym.get()))
898  continue;
899  // Only consider external symbols
900  if (Sym->Data.StorageClass != COFF::IMAGE_SYM_CLASS_EXTERNAL)
901  continue;
902  // Only consider symbols defined in a section or that are absolute
903  if (!Sym->Section && Sym->Data.SectionNumber != COFF::IMAGE_SYM_ABSOLUTE)
904  continue;
905  if (!AllowComdat && Sym->Section &&
906  Sym->Section->Header.Characteristics & COFF::IMAGE_SCN_LNK_COMDAT)
907  continue;
908  Unique = Sym.get();
909  break;
910  }
911  if (Unique)
912  break;
913  }
914  // If we didn't find any unique symbol to use for the names, just skip this.
915  if (!Unique)
916  return;
917  for (auto *Sym : WeakDefaults) {
918  Sym->Name.append(".");
919  Sym->Name.append(Unique->Name);
920  }
921 }
922 
923 static bool isAssociative(const COFFSection &Section) {
924  return Section.Symbol->Aux[0].Aux.SectionDefinition.Selection ==
926 }
927 
928 void WinCOFFObjectWriter::assignSectionNumbers() {
929  size_t I = 1;
930  auto Assign = [&](COFFSection &Section) {
931  Section.Number = I;
932  Section.Symbol->Data.SectionNumber = I;
933  Section.Symbol->Aux[0].Aux.SectionDefinition.Number = I;
934  ++I;
935  };
936 
937  // Although it is not explicitly requested by the Microsoft COFF spec,
938  // we should avoid emitting forward associative section references,
939  // because MSVC link.exe as of 2017 cannot handle that.
940  for (const std::unique_ptr<COFFSection> &Section : Sections)
941  if (!isAssociative(*Section))
942  Assign(*Section);
943  for (const std::unique_ptr<COFFSection> &Section : Sections)
944  if (isAssociative(*Section))
945  Assign(*Section);
946 }
947 
948 // Assign file offsets to COFF object file structures.
949 void WinCOFFObjectWriter::assignFileOffsets(MCAssembler &Asm,
950  const MCAsmLayout &Layout) {
951  unsigned Offset = W.OS.tell();
952 
953  Offset += UseBigObj ? COFF::Header32Size : COFF::Header16Size;
954  Offset += COFF::SectionSize * Header.NumberOfSections;
955 
956  for (const auto &Section : Asm) {
957  COFFSection *Sec = SectionMap[&Section];
958 
959  if (Sec->Number == -1)
960  continue;
961 
962  Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
963 
964  if (IsPhysicalSection(Sec)) {
965  Sec->Header.PointerToRawData = Offset;
966  Offset += Sec->Header.SizeOfRawData;
967  }
968 
969  if (!Sec->Relocations.empty()) {
970  bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
971 
972  if (RelocationsOverflow) {
973  // Signal overflow by setting NumberOfRelocations to max value. Actual
974  // size is found in reloc #0. Microsoft tools understand this.
975  Sec->Header.NumberOfRelocations = 0xffff;
976  } else {
977  Sec->Header.NumberOfRelocations = Sec->Relocations.size();
978  }
979  Sec->Header.PointerToRelocations = Offset;
980 
981  if (RelocationsOverflow) {
982  // Reloc #0 will contain actual count, so make room for it.
983  Offset += COFF::RelocationSize;
984  }
985 
986  Offset += COFF::RelocationSize * Sec->Relocations.size();
987 
988  for (auto &Relocation : Sec->Relocations) {
989  assert(Relocation.Symb->getIndex() != -1);
990  Relocation.Data.SymbolTableIndex = Relocation.Symb->getIndex();
991  }
992  }
993 
994  assert(Sec->Symbol->Aux.size() == 1 &&
995  "Section's symbol must have one aux!");
996  AuxSymbol &Aux = Sec->Symbol->Aux[0];
997  assert(Aux.AuxType == ATSectionDefinition &&
998  "Section's symbol's aux symbol must be a Section Definition!");
999  Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
1000  Aux.Aux.SectionDefinition.NumberOfRelocations =
1001  Sec->Header.NumberOfRelocations;
1002  Aux.Aux.SectionDefinition.NumberOfLinenumbers =
1003  Sec->Header.NumberOfLineNumbers;
1004  }
1005 
1006  Header.PointerToSymbolTable = Offset;
1007 }
1008 
1009 uint64_t WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
1010  const MCAsmLayout &Layout) {
1011  uint64_t StartOffset = W.OS.tell();
1012 
1013  if (Sections.size() > INT32_MAX)
1015  "PE COFF object files can't have more than 2147483647 sections");
1016 
1017  UseBigObj = Sections.size() > COFF::MaxNumberOfSections16;
1018  Header.NumberOfSections = Sections.size();
1019  Header.NumberOfSymbols = 0;
1020 
1021  setWeakDefaultNames();
1022  assignSectionNumbers();
1023  createFileSymbols(Asm);
1024 
1025  for (auto &Symbol : Symbols) {
1026  // Update section number & offset for symbols that have them.
1027  if (Symbol->Section)
1028  Symbol->Data.SectionNumber = Symbol->Section->Number;
1029  Symbol->setIndex(Header.NumberOfSymbols++);
1030  // Update auxiliary symbol info.
1031  Symbol->Data.NumberOfAuxSymbols = Symbol->Aux.size();
1032  Header.NumberOfSymbols += Symbol->Data.NumberOfAuxSymbols;
1033  }
1034 
1035  // Build string table.
1036  for (const auto &S : Sections)
1037  if (S->Name.size() > COFF::NameSize)
1038  Strings.add(S->Name);
1039  for (const auto &S : Symbols)
1040  if (S->Name.size() > COFF::NameSize)
1041  Strings.add(S->Name);
1042  Strings.finalize();
1043 
1044  // Set names.
1045  for (const auto &S : Sections)
1046  SetSectionName(*S);
1047  for (auto &S : Symbols)
1048  SetSymbolName(*S);
1049 
1050  // Fixup weak external references.
1051  for (auto &Symbol : Symbols) {
1052  if (Symbol->Other) {
1053  assert(Symbol->getIndex() != -1);
1054  assert(Symbol->Aux.size() == 1 && "Symbol must contain one aux symbol!");
1055  assert(Symbol->Aux[0].AuxType == ATWeakExternal &&
1056  "Symbol's aux symbol must be a Weak External!");
1057  Symbol->Aux[0].Aux.WeakExternal.TagIndex = Symbol->Other->getIndex();
1058  }
1059  }
1060 
1061  // Fixup associative COMDAT sections.
1062  for (auto &Section : Sections) {
1063  if (Section->Symbol->Aux[0].Aux.SectionDefinition.Selection !=
1065  continue;
1066 
1067  const MCSectionCOFF &MCSec = *Section->MCSection;
1068  const MCSymbol *AssocMCSym = MCSec.getCOMDATSymbol();
1069  assert(AssocMCSym);
1070 
1071  // It's an error to try to associate with an undefined symbol or a symbol
1072  // without a section.
1073  if (!AssocMCSym->isInSection()) {
1074  Asm.getContext().reportError(
1075  SMLoc(), Twine("cannot make section ") + MCSec.getName() +
1076  Twine(" associative with sectionless symbol ") +
1077  AssocMCSym->getName());
1078  continue;
1079  }
1080 
1081  const auto *AssocMCSec = cast<MCSectionCOFF>(&AssocMCSym->getSection());
1082  assert(SectionMap.count(AssocMCSec));
1083  COFFSection *AssocSec = SectionMap[AssocMCSec];
1084 
1085  // Skip this section if the associated section is unused.
1086  if (AssocSec->Number == -1)
1087  continue;
1088 
1089  Section->Symbol->Aux[0].Aux.SectionDefinition.Number = AssocSec->Number;
1090  }
1091 
1092  // Create the contents of the .llvm_addrsig section.
1093  if (EmitAddrsigSection) {
1094  auto Frag = new MCDataFragment(AddrsigSection);
1095  Frag->setLayoutOrder(0);
1096  raw_svector_ostream OS(Frag->getContents());
1097  for (const MCSymbol *S : AddrsigSyms) {
1098  if (!S->isTemporary()) {
1099  encodeULEB128(S->getIndex(), OS);
1100  continue;
1101  }
1102 
1103  MCSection *TargetSection = &S->getSection();
1104  assert(SectionMap.find(TargetSection) != SectionMap.end() &&
1105  "Section must already have been defined in "
1106  "executePostLayoutBinding!");
1107  encodeULEB128(SectionMap[TargetSection]->Symbol->getIndex(), OS);
1108  }
1109  }
1110 
1111  // Create the contents of the .llvm.call-graph-profile section.
1112  if (CGProfileSection) {
1113  auto *Frag = new MCDataFragment(CGProfileSection);
1114  Frag->setLayoutOrder(0);
1115  raw_svector_ostream OS(Frag->getContents());
1116  for (const MCAssembler::CGProfileEntry &CGPE : Asm.CGProfile) {
1117  uint32_t FromIndex = CGPE.From->getSymbol().getIndex();
1118  uint32_t ToIndex = CGPE.To->getSymbol().getIndex();
1119  support::endian::write(OS, FromIndex, W.Endian);
1120  support::endian::write(OS, ToIndex, W.Endian);
1121  support::endian::write(OS, CGPE.Count, W.Endian);
1122  }
1123  }
1124 
1125  assignFileOffsets(Asm, Layout);
1126 
1127  // MS LINK expects to be able to use this timestamp to implement their
1128  // /INCREMENTAL feature.
1129  if (Asm.isIncrementalLinkerCompatible()) {
1130  Header.TimeDateStamp = getTime();
1131  } else {
1132  // Have deterministic output if /INCREMENTAL isn't needed. Also matches GNU.
1133  Header.TimeDateStamp = 0;
1134  }
1135 
1136  // Write it all to disk...
1137  WriteFileHeader(Header);
1138  writeSectionHeaders();
1139 
1140  // Write section contents.
1141  sections::iterator I = Sections.begin();
1142  sections::iterator IE = Sections.end();
1143  MCAssembler::iterator J = Asm.begin();
1144  MCAssembler::iterator JE = Asm.end();
1145  for (; I != IE && J != JE; ++I, ++J)
1146  writeSection(Asm, Layout, **I, *J);
1147 
1148  assert(W.OS.tell() == Header.PointerToSymbolTable &&
1149  "Header::PointerToSymbolTable is insane!");
1150 
1151  // Write a symbol table.
1152  for (auto &Symbol : Symbols)
1153  if (Symbol->getIndex() != -1)
1154  WriteSymbol(*Symbol);
1155 
1156  // Write a string table, which completes the entire COFF file.
1157  Strings.write(W.OS);
1158 
1159  return W.OS.tell() - StartOffset;
1160 }
1161 
1163  : Machine(Machine_) {}
1164 
1165 // Pin the vtable to this file.
1166 void MCWinCOFFObjectTargetWriter::anchor() {}
1167 
1168 //------------------------------------------------------------------------------
1169 // WinCOFFObjectWriter factory function
1170 
1171 std::unique_ptr<MCObjectWriter> llvm::createWinCOFFObjectWriter(
1172  std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS) {
1173  return std::make_unique<WinCOFFObjectWriter>(std::move(MOTW), OS);
1174 }
constexpr bool isUInt< 32 >(uint64_t x)
Definition: MathExtras.h:412
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:39
uint32_t getCRC() const
Definition: CRC.h:52
static uint64_t getSymbolValue(const MCSymbol &Symbol, const MCAsmLayout &Layout)
LLVM_NODISCARD std::enable_if_t< !is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type > dyn_cast(const Y &Val)
Definition: Casting.h:334
uint32_t getIndex() const
Get the (implementation defined) index.
Definition: MCSymbol.h:305
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:140
This class represents lattice values for constants.
Definition: AllocatorList.h:23
bool isVariable() const
isVariable - Check if this is a variable symbol.
Definition: MCSymbol.h:289
This represents an "assembler immediate".
Definition: MCValue.h:37
uint64_t getSectionAddressSize(const MCSection *Sec) const
Get the address space size of the given section, as it effects layout.
Definition: MCFragment.cpp:194
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
uint32_t SizeOfRawData
Definition: COFF.h:274
iterator begin()
Definition: MCAssembler.h:336
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
Implements a dense probed hash-table based set.
Definition: DenseSet.h:255
char Name[NameSize]
Definition: COFF.h:271
static void encodeBase64StringEntry(char *Buffer, uint64_t Value)
static std::time_t getTime()
A raw_ostream that writes to an SmallVector or SmallString.
Definition: raw_ostream.h:550
void write32le(void *P, uint32_t V)
Definition: Endian.h:416
static const char * name
bool isCommon() const
Is this a &#39;common&#39; symbol.
Definition: MCSymbol.h:378
Defines the object file and target independent interfaces used by the assembler backend to write nati...
uint16_t Machine
Definition: COFF.h:66
static const char BigObjMagic[]
Definition: COFF.h:38
MCSectionCOFF * getCOFFSection(StringRef Section, unsigned Characteristics, SectionKind Kind, StringRef COMDATSymName, int Selection, unsigned UniqueID=GenericSectionID, const char *BeginSymName=nullptr)
Definition: MCContext.cpp:549
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:82
unsigned getAlignment() const
Definition: MCSection.h:131
This represents a section on Windows.
Definition: MCSectionCOFF.h:26
MCContext & getContext() const
Definition: MCAssembler.h:284
int64_t getConstant() const
Definition: MCValue.h:44
const MCSymbolRefExpr * getSymB() const
Definition: MCValue.h:46
static uint32_t getAlignment(const MCSectionCOFF &Sec)
uint16_t Characteristics
Definition: COFF.h:72
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:80
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:458
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:28
const MCSymbolRefExpr * From
Definition: MCAssembler.h:429
bool isInSection() const
isInSection - Check if this symbol is defined in some section (i.e., it is defined but not absolute)...
Definition: MCSymbol.h:245
bool registerSection(MCSection &Section)
uint32_t PointerToSymbolTable
Definition: COFF.h:69
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:192
const int32_t MaxNumberOfSections16
Definition: COFF.h:33
ArrayRef< std::string > getFileNames()
Definition: MCAssembler.h:442
Utility for building string tables with deduplicated suffixes.
A two-byte section relative fixup.
Definition: MCFixup.h:42
unsigned getCharacteristics() const
Definition: MCSectionCOFF.h:66
LLVM_NODISCARD size_t size() const
size - Get the string size.
Definition: StringRef.h:160
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:25
COFF::MachineTypes Machine
Definition: COFFYAML.cpp:365
const MCSymbolRefExpr * To
Definition: MCAssembler.h:430
Type is formed as (base + (derived << SCT_COMPLEX_TYPE_SHIFT))
Definition: COFF.h:265
iterator end()
Definition: MCAssembler.h:339
iterator find(const_arg_type_t< KeyT > Val)
Definition: DenseMap.h:150
void write(void *memory, value_type value, endianness endian)
Write a value to memory with a particular endianness.
Definition: Endian.h:97
uint16_t SizeOfOptionalHeader
Definition: COFF.h:71
uint32_t SymbolTableIndex
Definition: COFF.h:326
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
Instrumentation for Order File
virtual void reset()
lifetime management
StringRef getName() const
Definition: MCSection.h:115
bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const
Get the offset of the given symbol, as computed in the current layout.
Definition: MCFragment.cpp:148
bool isTemporary() const
isTemporary - Check if this is an assembler temporary symbol.
Definition: MCSymbol.h:213
const MCSymbolRefExpr * getSymA() const
Definition: MCValue.h:45
uint64_t getCommonSize() const
Return the size of a &#39;common&#39; symbol.
Definition: MCSymbol.h:331
void reportError(SMLoc L, const Twine &Msg)
Definition: MCContext.cpp:811
DenseMap< SymbolStringPtr, JITEvaluatedSymbol > SymbolMap
A map from symbol names (as SymbolStringPtrs) to JITSymbols (address/flags pairs).
Definition: Core.h:51
uint32_t getOffset() const
Definition: MCFixup.h:135
void writeSectionData(raw_ostream &OS, const MCSection *Section, const MCAsmLayout &Layout) const
Emit the section contents to OS.
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1433
void toVector(SmallVectorImpl< char > &Out) const
Append the concatenated string into the given SmallString or SmallVector.
Definition: Twine.cpp:32
bool isExternal() const
Definition: MCSymbol.h:397
static wasm::ValType getType(const TargetRegisterClass *RC)
uint16_t NumberOfLineNumbers
Definition: COFF.h:279
uint32_t VirtualAddress
Definition: COFF.h:273
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
std::unique_ptr< MCObjectWriter > createWinCOFFObjectWriter(std::unique_ptr< MCWinCOFFObjectTargetWriter > MOTW, raw_pwrite_stream &OS)
Construct a new Win COFF writer instance.
uint32_t TimeDateStamp
Definition: COFF.h:68
uint64_t getFragmentOffset(const MCFragment *F) const
Get the offset of the given fragment inside its containing section.
Definition: MCFragment.cpp:96
PowerPC TLS Dynamic Call Fixup
SMLoc getLoc() const
Definition: MCFixup.h:202
COFFYAML::AuxSymbolType AuxType
Definition: COFFYAML.cpp:347
uint32_t PointerToRelocations
Definition: COFF.h:276
MCAsmBackend & getBackend() const
Definition: MCAssembler.h:292
MCSymbol * getCOMDATSymbol() const
Definition: MCSectionCOFF.h:67
unsigned encodeULEB128(uint64_t Value, raw_ostream &OS, unsigned PadTo=0)
Utility function to encode a ULEB128 value to an output stream.
Definition: LEB128.h:80
const MCSymbol & getSymbol() const
Definition: MCExpr.h:397
bool isUndefined(bool SetUsed=true) const
isUndefined - Check if this symbol undefined (i.e., implicitly defined).
Definition: MCSymbol.h:250
MCFragment * getFragment(bool SetUsed=true) const
Definition: MCSymbol.h:388
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:883
An iterator type that allows iterating over the pointees via some other iterator. ...
Definition: iterator.h:286
static SectionKind getMetadata()
Definition: SectionKind.h:178
uint32_t PointerToRawData
Definition: COFF.h:275
uint32_t VirtualSize
Definition: COFF.h:272
auto size(R &&Range, std::enable_if_t< std::is_same< typename std::iterator_traits< decltype(Range.begin())>::iterator_category, std::random_access_iterator_tag >::value, void > *=nullptr)
Get the size of a range.
Definition: STLExtras.h:1473
Target - Wrapper for Target specific information.
MCSection * getParent() const
Definition: MCFragment.h:90
int getSelection() const
Definition: MCSectionCOFF.h:68
MCSection & getSection() const
Get the section associated with a defined, non-absolute symbol.
Definition: MCSymbol.h:260
std::vector< CGProfileEntry > CGProfile
Definition: MCAssembler.h:433
uint32_t NumberOfSymbols
Definition: COFF.h:70
virtual bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B, bool InSet) const
Adapter to write values to a stream in a particular byte order.
Definition: EndianStream.h:51
void update(ArrayRef< uint8_t > Data)
Definition: CRC.cpp:103
pointer data()
Return a pointer to the vector&#39;s buffer, even if empty().
Definition: SmallVector.h:171
int32_t NumberOfSections
Definition: COFF.h:67
#define I(x, y, z)
Definition: MD5.cpp:59
iterator end()
Definition: DenseMap.h:83
uint16_t getClass() const
Definition: MCSymbolCOFF.h:40
StringRef getName() const
getName - Get the symbol name.
Definition: MCSymbol.h:196
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:383
Fragment for data and encoded instructions.
Definition: MCFragment.h:232
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
uint16_t NumberOfRelocations
Definition: COFF.h:278
bool isIncrementalLinkerCompatible() const
Definition: MCAssembler.h:313
const MCExpr * getVariableValue(bool SetUsed=true) const
getVariableValue - Get the value for variable symbols.
Definition: MCSymbol.h:294
LLVM Value Representation.
Definition: Value.h:74
uint32_t PointerToLineNumbers
Definition: COFF.h:277
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:57
uint16_t getType() const
Definition: MCSymbolCOFF.h:33
Represents a location in source code.
Definition: SMLoc.h:23
static bool isAssociative(const COFFSection &Section)
uint32_t Characteristics
Definition: COFF.h:280
void setIndex(uint32_t Value) const
Set the (implementation defined) index.
Definition: MCSymbol.h:310
Twine concat(const Twine &Suffix) const
Definition: Twine.h:488
const MCSymbol * getBaseSymbol(const MCSymbol &Symbol) const
If this symbol is equivalent to A + Constant, return A.
Definition: MCFragment.cpp:158
uint32_t VirtualAddress
Definition: COFF.h:325
A function that returns a base type.
Definition: COFF.h:261