1 //===- llvm/MC/WinCOFFObjectWriter.cpp ------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains an implementation of a Win32 COFF object file writer.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/ADT/DenseMap.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"
33 #include "llvm/MC/MCWinCOFFObjectWriter.h"
34 #include "llvm/MC/StringTableBuilder.h"
35 #include "llvm/Support/Casting.h"
36 #include "llvm/Support/Endian.h"
37 #include "llvm/Support/ErrorHandling.h"
38 #include "llvm/Support/JamCRC.h"
39 #include "llvm/Support/LEB128.h"
40 #include "llvm/Support/MathExtras.h"
41 #include "llvm/Support/raw_ostream.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;
53 using llvm::support::endian::write32le;
54
55 #define DEBUG_TYPE "WinCOFFObjectWriter"
56
57 namespace {
58
59 using name = SmallString<COFF::NameSize>;
60
61 enum AuxiliaryType {
62 ATWeakExternal,
63 ATFile,
64 ATSectionDefinition
65 };
66
67 struct AuxSymbol {
68 AuxiliaryType AuxType;
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
COFFSymbol(StringRef Name)88 COFFSymbol(StringRef Name) : Name(Name) {}
89
90 void set_name_offset(uint32_t Offset);
91
getIndex() const92 int64_t getIndex() const { return Index; }
setIndex(int Value)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 {
102 COFF::relocation Data;
103 COFFSymbol *Symb = nullptr;
104
105 COFFRelocation() = default;
106
size__anona09ca6930111::COFFRelocation107 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
COFFSection(StringRef Name)122 COFFSection(StringRef Name) : Name(Name) {}
123 };
124
125 class WinCOFFObjectWriter : public MCObjectWriter {
126 public:
127 support::endian::Writer W;
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 std::unique_ptr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
136
137 // Root level file contents.
138 COFF::header Header = {};
139 sections Sections;
140 symbols Symbols;
141 StringTableBuilder Strings{StringTableBuilder::WinCOFF};
142
143 // Maps used during object file creation.
144 section_map SectionMap;
145 symbol_map SymbolMap;
146
147 bool UseBigObj;
148
149 bool EmitAddrsigSection = false;
150 MCSectionCOFF *AddrsigSection;
151 std::vector<const MCSymbol *> AddrsigSyms;
152
153 WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
154 raw_pwrite_stream &OS);
155
reset()156 void reset() override {
157 memset(&Header, 0, sizeof(Header));
158 Header.Machine = TargetObjectWriter->getMachine();
159 Sections.clear();
160 Symbols.clear();
161 Strings.clear();
162 SectionMap.clear();
163 SymbolMap.clear();
164 MCObjectWriter::reset();
165 }
166
167 COFFSymbol *createSymbol(StringRef Name);
168 COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol *Symbol);
169 COFFSection *createSection(StringRef Name);
170
171 void defineSection(MCSectionCOFF const &Sec);
172
173 COFFSymbol *getLinkedSymbol(const MCSymbol &Symbol);
174 void DefineSymbol(const MCSymbol &Symbol, MCAssembler &Assembler,
175 const MCAsmLayout &Layout);
176
177 void SetSymbolName(COFFSymbol &S);
178 void SetSectionName(COFFSection &S);
179
180 bool IsPhysicalSection(COFFSection *S);
181
182 // Entity writing methods.
183
184 void WriteFileHeader(const COFF::header &Header);
185 void WriteSymbol(const COFFSymbol &S);
186 void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
187 void writeSectionHeaders();
188 void WriteRelocation(const COFF::relocation &R);
189 uint32_t writeSectionContents(MCAssembler &Asm, const MCAsmLayout &Layout,
190 const MCSection &MCSec);
191 void writeSection(MCAssembler &Asm, const MCAsmLayout &Layout,
192 const COFFSection &Sec, const MCSection &MCSec);
193
194 // MCObjectWriter interface implementation.
195
196 void executePostLayoutBinding(MCAssembler &Asm,
197 const MCAsmLayout &Layout) override;
198
199 bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
200 const MCSymbol &SymA,
201 const MCFragment &FB, bool InSet,
202 bool IsPCRel) const override;
203
204 void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
205 const MCFragment *Fragment, const MCFixup &Fixup,
206 MCValue Target, uint64_t &FixedValue) override;
207
208 void createFileSymbols(MCAssembler &Asm);
209 void assignSectionNumbers();
210 void assignFileOffsets(MCAssembler &Asm, const MCAsmLayout &Layout);
211
emitAddrsigSection()212 void emitAddrsigSection() override { EmitAddrsigSection = true; }
addAddrsigSymbol(const MCSymbol * Sym)213 void addAddrsigSymbol(const MCSymbol *Sym) override {
214 AddrsigSyms.push_back(Sym);
215 }
216
217 uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
218 };
219
220 } // end anonymous namespace
221
222 //------------------------------------------------------------------------------
223 // Symbol class implementation
224
225 // In the case that the name does not fit within 8 bytes, the offset
226 // into the string table is stored in the last 4 bytes instead, leaving
227 // the first 4 bytes as 0.
set_name_offset(uint32_t Offset)228 void COFFSymbol::set_name_offset(uint32_t Offset) {
229 write32le(Data.Name + 0, 0);
230 write32le(Data.Name + 4, Offset);
231 }
232
233 //------------------------------------------------------------------------------
234 // WinCOFFObjectWriter class implementation
235
WinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,raw_pwrite_stream & OS)236 WinCOFFObjectWriter::WinCOFFObjectWriter(
237 std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS)
238 : W(OS, support::little), TargetObjectWriter(std::move(MOTW)) {
239 Header.Machine = TargetObjectWriter->getMachine();
240 }
241
createSymbol(StringRef Name)242 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
243 Symbols.push_back(make_unique<COFFSymbol>(Name));
244 return Symbols.back().get();
245 }
246
GetOrCreateCOFFSymbol(const MCSymbol * Symbol)247 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol *Symbol) {
248 COFFSymbol *&Ret = SymbolMap[Symbol];
249 if (!Ret)
250 Ret = createSymbol(Symbol->getName());
251 return Ret;
252 }
253
createSection(StringRef Name)254 COFFSection *WinCOFFObjectWriter::createSection(StringRef Name) {
255 Sections.emplace_back(make_unique<COFFSection>(Name));
256 return Sections.back().get();
257 }
258
getAlignment(const MCSectionCOFF & Sec)259 static uint32_t getAlignment(const MCSectionCOFF &Sec) {
260 switch (Sec.getAlignment()) {
261 case 1:
262 return COFF::IMAGE_SCN_ALIGN_1BYTES;
263 case 2:
264 return COFF::IMAGE_SCN_ALIGN_2BYTES;
265 case 4:
266 return COFF::IMAGE_SCN_ALIGN_4BYTES;
267 case 8:
268 return COFF::IMAGE_SCN_ALIGN_8BYTES;
269 case 16:
270 return COFF::IMAGE_SCN_ALIGN_16BYTES;
271 case 32:
272 return COFF::IMAGE_SCN_ALIGN_32BYTES;
273 case 64:
274 return COFF::IMAGE_SCN_ALIGN_64BYTES;
275 case 128:
276 return COFF::IMAGE_SCN_ALIGN_128BYTES;
277 case 256:
278 return COFF::IMAGE_SCN_ALIGN_256BYTES;
279 case 512:
280 return COFF::IMAGE_SCN_ALIGN_512BYTES;
281 case 1024:
282 return COFF::IMAGE_SCN_ALIGN_1024BYTES;
283 case 2048:
284 return COFF::IMAGE_SCN_ALIGN_2048BYTES;
285 case 4096:
286 return COFF::IMAGE_SCN_ALIGN_4096BYTES;
287 case 8192:
288 return COFF::IMAGE_SCN_ALIGN_8192BYTES;
289 }
290 llvm_unreachable("unsupported section alignment");
291 }
292
293 /// This function takes a section data object from the assembler
294 /// and creates the associated COFF section staging object.
defineSection(const MCSectionCOFF & MCSec)295 void WinCOFFObjectWriter::defineSection(const MCSectionCOFF &MCSec) {
296 COFFSection *Section = createSection(MCSec.getSectionName());
297 COFFSymbol *Symbol = createSymbol(MCSec.getSectionName());
298 Section->Symbol = Symbol;
299 Symbol->Section = Section;
300 Symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
301
302 // Create a COMDAT symbol if needed.
303 if (MCSec.getSelection() != COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
304 if (const MCSymbol *S = MCSec.getCOMDATSymbol()) {
305 COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(S);
306 if (COMDATSymbol->Section)
307 report_fatal_error("two sections have the same comdat");
308 COMDATSymbol->Section = Section;
309 }
310 }
311
312 // In this case the auxiliary symbol is a Section Definition.
313 Symbol->Aux.resize(1);
314 Symbol->Aux[0] = {};
315 Symbol->Aux[0].AuxType = ATSectionDefinition;
316 Symbol->Aux[0].Aux.SectionDefinition.Selection = MCSec.getSelection();
317
318 // Set section alignment.
319 Section->Header.Characteristics = MCSec.getCharacteristics();
320 Section->Header.Characteristics |= getAlignment(MCSec);
321
322 // Bind internal COFF section to MC section.
323 Section->MCSection = &MCSec;
324 SectionMap[&MCSec] = Section;
325 }
326
getSymbolValue(const MCSymbol & Symbol,const MCAsmLayout & Layout)327 static uint64_t getSymbolValue(const MCSymbol &Symbol,
328 const MCAsmLayout &Layout) {
329 if (Symbol.isCommon() && Symbol.isExternal())
330 return Symbol.getCommonSize();
331
332 uint64_t Res;
333 if (!Layout.getSymbolOffset(Symbol, Res))
334 return 0;
335
336 return Res;
337 }
338
getLinkedSymbol(const MCSymbol & Symbol)339 COFFSymbol *WinCOFFObjectWriter::getLinkedSymbol(const MCSymbol &Symbol) {
340 if (!Symbol.isVariable())
341 return nullptr;
342
343 const MCSymbolRefExpr *SymRef =
344 dyn_cast<MCSymbolRefExpr>(Symbol.getVariableValue());
345 if (!SymRef)
346 return nullptr;
347
348 const MCSymbol &Aliasee = SymRef->getSymbol();
349 if (!Aliasee.isUndefined())
350 return nullptr;
351 return GetOrCreateCOFFSymbol(&Aliasee);
352 }
353
354 /// This function takes a symbol data object from the assembler
355 /// and creates the associated COFF symbol staging object.
DefineSymbol(const MCSymbol & MCSym,MCAssembler & Assembler,const MCAsmLayout & Layout)356 void WinCOFFObjectWriter::DefineSymbol(const MCSymbol &MCSym,
357 MCAssembler &Assembler,
358 const MCAsmLayout &Layout) {
359 COFFSymbol *Sym = GetOrCreateCOFFSymbol(&MCSym);
360 const MCSymbol *Base = Layout.getBaseSymbol(MCSym);
361 COFFSection *Sec = nullptr;
362 if (Base && Base->getFragment()) {
363 Sec = SectionMap[Base->getFragment()->getParent()];
364 if (Sym->Section && Sym->Section != Sec)
365 report_fatal_error("conflicting sections for symbol");
366 }
367
368 COFFSymbol *Local = nullptr;
369 if (cast<MCSymbolCOFF>(MCSym).isWeakExternal()) {
370 Sym->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
371
372 COFFSymbol *WeakDefault = getLinkedSymbol(MCSym);
373 if (!WeakDefault) {
374 std::string WeakName = (".weak." + MCSym.getName() + ".default").str();
375 WeakDefault = createSymbol(WeakName);
376 if (!Sec)
377 WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
378 else
379 WeakDefault->Section = Sec;
380 Local = WeakDefault;
381 }
382
383 Sym->Other = WeakDefault;
384
385 // Setup the Weak External auxiliary symbol.
386 Sym->Aux.resize(1);
387 memset(&Sym->Aux[0], 0, sizeof(Sym->Aux[0]));
388 Sym->Aux[0].AuxType = ATWeakExternal;
389 Sym->Aux[0].Aux.WeakExternal.TagIndex = 0;
390 Sym->Aux[0].Aux.WeakExternal.Characteristics =
391 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
392 } else {
393 if (!Base)
394 Sym->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
395 else
396 Sym->Section = Sec;
397 Local = Sym;
398 }
399
400 if (Local) {
401 Local->Data.Value = getSymbolValue(MCSym, Layout);
402
403 const MCSymbolCOFF &SymbolCOFF = cast<MCSymbolCOFF>(MCSym);
404 Local->Data.Type = SymbolCOFF.getType();
405 Local->Data.StorageClass = SymbolCOFF.getClass();
406
407 // If no storage class was specified in the streamer, define it here.
408 if (Local->Data.StorageClass == COFF::IMAGE_SYM_CLASS_NULL) {
409 bool IsExternal = MCSym.isExternal() ||
410 (!MCSym.getFragment() && !MCSym.isVariable());
411
412 Local->Data.StorageClass = IsExternal ? COFF::IMAGE_SYM_CLASS_EXTERNAL
413 : COFF::IMAGE_SYM_CLASS_STATIC;
414 }
415 }
416
417 Sym->MC = &MCSym;
418 }
419
420 // Maximum offsets for different string table entry encodings.
421 enum : unsigned { Max7DecimalOffset = 9999999U };
422 enum : uint64_t { MaxBase64Offset = 0xFFFFFFFFFULL }; // 64^6, including 0
423
424 // Encode a string table entry offset in base 64, padded to 6 chars, and
425 // prefixed with a double slash: '//AAAAAA', '//AAAAAB', ...
426 // Buffer must be at least 8 bytes large. No terminating null appended.
encodeBase64StringEntry(char * Buffer,uint64_t Value)427 static void encodeBase64StringEntry(char *Buffer, uint64_t Value) {
428 assert(Value > Max7DecimalOffset && Value <= MaxBase64Offset &&
429 "Illegal section name encoding for value");
430
431 static const char Alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
432 "abcdefghijklmnopqrstuvwxyz"
433 "0123456789+/";
434
435 Buffer[0] = '/';
436 Buffer[1] = '/';
437
438 char *Ptr = Buffer + 7;
439 for (unsigned i = 0; i < 6; ++i) {
440 unsigned Rem = Value % 64;
441 Value /= 64;
442 *(Ptr--) = Alphabet[Rem];
443 }
444 }
445
SetSectionName(COFFSection & S)446 void WinCOFFObjectWriter::SetSectionName(COFFSection &S) {
447 if (S.Name.size() <= COFF::NameSize) {
448 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
449 return;
450 }
451
452 uint64_t StringTableEntry = Strings.getOffset(S.Name);
453 if (StringTableEntry <= Max7DecimalOffset) {
454 SmallVector<char, COFF::NameSize> Buffer;
455 Twine('/').concat(Twine(StringTableEntry)).toVector(Buffer);
456 assert(Buffer.size() <= COFF::NameSize && Buffer.size() >= 2);
457 std::memcpy(S.Header.Name, Buffer.data(), Buffer.size());
458 return;
459 }
460 if (StringTableEntry <= MaxBase64Offset) {
461 // Starting with 10,000,000, offsets are encoded as base64.
462 encodeBase64StringEntry(S.Header.Name, StringTableEntry);
463 return;
464 }
465 report_fatal_error("COFF string table is greater than 64 GB.");
466 }
467
SetSymbolName(COFFSymbol & S)468 void WinCOFFObjectWriter::SetSymbolName(COFFSymbol &S) {
469 if (S.Name.size() > COFF::NameSize)
470 S.set_name_offset(Strings.getOffset(S.Name));
471 else
472 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
473 }
474
IsPhysicalSection(COFFSection * S)475 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
476 return (S->Header.Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) ==
477 0;
478 }
479
480 //------------------------------------------------------------------------------
481 // entity writing methods
482
WriteFileHeader(const COFF::header & Header)483 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
484 if (UseBigObj) {
485 W.write<uint16_t>(COFF::IMAGE_FILE_MACHINE_UNKNOWN);
486 W.write<uint16_t>(0xFFFF);
487 W.write<uint16_t>(COFF::BigObjHeader::MinBigObjectVersion);
488 W.write<uint16_t>(Header.Machine);
489 W.write<uint32_t>(Header.TimeDateStamp);
490 W.OS.write(COFF::BigObjMagic, sizeof(COFF::BigObjMagic));
491 W.write<uint32_t>(0);
492 W.write<uint32_t>(0);
493 W.write<uint32_t>(0);
494 W.write<uint32_t>(0);
495 W.write<uint32_t>(Header.NumberOfSections);
496 W.write<uint32_t>(Header.PointerToSymbolTable);
497 W.write<uint32_t>(Header.NumberOfSymbols);
498 } else {
499 W.write<uint16_t>(Header.Machine);
500 W.write<uint16_t>(static_cast<int16_t>(Header.NumberOfSections));
501 W.write<uint32_t>(Header.TimeDateStamp);
502 W.write<uint32_t>(Header.PointerToSymbolTable);
503 W.write<uint32_t>(Header.NumberOfSymbols);
504 W.write<uint16_t>(Header.SizeOfOptionalHeader);
505 W.write<uint16_t>(Header.Characteristics);
506 }
507 }
508
WriteSymbol(const COFFSymbol & S)509 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol &S) {
510 W.OS.write(S.Data.Name, COFF::NameSize);
511 W.write<uint32_t>(S.Data.Value);
512 if (UseBigObj)
513 W.write<uint32_t>(S.Data.SectionNumber);
514 else
515 W.write<uint16_t>(static_cast<int16_t>(S.Data.SectionNumber));
516 W.write<uint16_t>(S.Data.Type);
517 W.OS << char(S.Data.StorageClass);
518 W.OS << char(S.Data.NumberOfAuxSymbols);
519 WriteAuxiliarySymbols(S.Aux);
520 }
521
WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols & S)522 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
523 const COFFSymbol::AuxiliarySymbols &S) {
524 for (const AuxSymbol &i : S) {
525 switch (i.AuxType) {
526 case ATWeakExternal:
527 W.write<uint32_t>(i.Aux.WeakExternal.TagIndex);
528 W.write<uint32_t>(i.Aux.WeakExternal.Characteristics);
529 W.OS.write_zeros(sizeof(i.Aux.WeakExternal.unused));
530 if (UseBigObj)
531 W.OS.write_zeros(COFF::Symbol32Size - COFF::Symbol16Size);
532 break;
533 case ATFile:
534 W.OS.write(reinterpret_cast<const char *>(&i.Aux),
535 UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size);
536 break;
537 case ATSectionDefinition:
538 W.write<uint32_t>(i.Aux.SectionDefinition.Length);
539 W.write<uint16_t>(i.Aux.SectionDefinition.NumberOfRelocations);
540 W.write<uint16_t>(i.Aux.SectionDefinition.NumberOfLinenumbers);
541 W.write<uint32_t>(i.Aux.SectionDefinition.CheckSum);
542 W.write<uint16_t>(static_cast<int16_t>(i.Aux.SectionDefinition.Number));
543 W.OS << char(i.Aux.SectionDefinition.Selection);
544 W.OS.write_zeros(sizeof(i.Aux.SectionDefinition.unused));
545 W.write<uint16_t>(static_cast<int16_t>(i.Aux.SectionDefinition.Number >> 16));
546 if (UseBigObj)
547 W.OS.write_zeros(COFF::Symbol32Size - COFF::Symbol16Size);
548 break;
549 }
550 }
551 }
552
553 // Write the section header.
writeSectionHeaders()554 void WinCOFFObjectWriter::writeSectionHeaders() {
555 // Section numbers must be monotonically increasing in the section
556 // header, but our Sections array is not sorted by section number,
557 // so make a copy of Sections and sort it.
558 std::vector<COFFSection *> Arr;
559 for (auto &Section : Sections)
560 Arr.push_back(Section.get());
561 llvm::sort(Arr, [](const COFFSection *A, const COFFSection *B) {
562 return A->Number < B->Number;
563 });
564
565 for (auto &Section : Arr) {
566 if (Section->Number == -1)
567 continue;
568
569 COFF::section &S = Section->Header;
570 if (Section->Relocations.size() >= 0xffff)
571 S.Characteristics |= COFF::IMAGE_SCN_LNK_NRELOC_OVFL;
572 W.OS.write(S.Name, COFF::NameSize);
573 W.write<uint32_t>(S.VirtualSize);
574 W.write<uint32_t>(S.VirtualAddress);
575 W.write<uint32_t>(S.SizeOfRawData);
576 W.write<uint32_t>(S.PointerToRawData);
577 W.write<uint32_t>(S.PointerToRelocations);
578 W.write<uint32_t>(S.PointerToLineNumbers);
579 W.write<uint16_t>(S.NumberOfRelocations);
580 W.write<uint16_t>(S.NumberOfLineNumbers);
581 W.write<uint32_t>(S.Characteristics);
582 }
583 }
584
WriteRelocation(const COFF::relocation & R)585 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
586 W.write<uint32_t>(R.VirtualAddress);
587 W.write<uint32_t>(R.SymbolTableIndex);
588 W.write<uint16_t>(R.Type);
589 }
590
591 // Write MCSec's contents. What this function does is essentially
592 // "Asm.writeSectionData(&MCSec, Layout)", but it's a bit complicated
593 // because it needs to compute a CRC.
writeSectionContents(MCAssembler & Asm,const MCAsmLayout & Layout,const MCSection & MCSec)594 uint32_t WinCOFFObjectWriter::writeSectionContents(MCAssembler &Asm,
595 const MCAsmLayout &Layout,
596 const MCSection &MCSec) {
597 // Save the contents of the section to a temporary buffer, we need this
598 // to CRC the data before we dump it into the object file.
599 SmallVector<char, 128> Buf;
600 raw_svector_ostream VecOS(Buf);
601 Asm.writeSectionData(VecOS, &MCSec, Layout);
602
603 // Write the section contents to the object file.
604 W.OS << Buf;
605
606 // Calculate our CRC with an initial value of '0', this is not how
607 // JamCRC is specified but it aligns with the expected output.
608 JamCRC JC(/*Init=*/0);
609 JC.update(Buf);
610 return JC.getCRC();
611 }
612
writeSection(MCAssembler & Asm,const MCAsmLayout & Layout,const COFFSection & Sec,const MCSection & MCSec)613 void WinCOFFObjectWriter::writeSection(MCAssembler &Asm,
614 const MCAsmLayout &Layout,
615 const COFFSection &Sec,
616 const MCSection &MCSec) {
617 if (Sec.Number == -1)
618 return;
619
620 // Write the section contents.
621 if (Sec.Header.PointerToRawData != 0) {
622 assert(W.OS.tell() == Sec.Header.PointerToRawData &&
623 "Section::PointerToRawData is insane!");
624
625 uint32_t CRC = writeSectionContents(Asm, Layout, MCSec);
626
627 // Update the section definition auxiliary symbol to record the CRC.
628 COFFSection *Sec = SectionMap[&MCSec];
629 COFFSymbol::AuxiliarySymbols &AuxSyms = Sec->Symbol->Aux;
630 assert(AuxSyms.size() == 1 && AuxSyms[0].AuxType == ATSectionDefinition);
631 AuxSymbol &SecDef = AuxSyms[0];
632 SecDef.Aux.SectionDefinition.CheckSum = CRC;
633 }
634
635 // Write relocations for this section.
636 if (Sec.Relocations.empty()) {
637 assert(Sec.Header.PointerToRelocations == 0 &&
638 "Section::PointerToRelocations is insane!");
639 return;
640 }
641
642 assert(W.OS.tell() == Sec.Header.PointerToRelocations &&
643 "Section::PointerToRelocations is insane!");
644
645 if (Sec.Relocations.size() >= 0xffff) {
646 // In case of overflow, write actual relocation count as first
647 // relocation. Including the synthetic reloc itself (+ 1).
648 COFF::relocation R;
649 R.VirtualAddress = Sec.Relocations.size() + 1;
650 R.SymbolTableIndex = 0;
651 R.Type = 0;
652 WriteRelocation(R);
653 }
654
655 for (const auto &Relocation : Sec.Relocations)
656 WriteRelocation(Relocation.Data);
657 }
658
659 ////////////////////////////////////////////////////////////////////////////////
660 // MCObjectWriter interface implementations
661
executePostLayoutBinding(MCAssembler & Asm,const MCAsmLayout & Layout)662 void WinCOFFObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
663 const MCAsmLayout &Layout) {
664 if (EmitAddrsigSection) {
665 AddrsigSection = Asm.getContext().getCOFFSection(
666 ".llvm_addrsig", COFF::IMAGE_SCN_LNK_REMOVE,
667 SectionKind::getMetadata());
668 Asm.registerSection(*AddrsigSection);
669 }
670
671 // "Define" each section & symbol. This creates section & symbol
672 // entries in the staging area.
673 for (const auto &Section : Asm)
674 defineSection(static_cast<const MCSectionCOFF &>(Section));
675
676 for (const MCSymbol &Symbol : Asm.symbols())
677 if (!Symbol.isTemporary())
678 DefineSymbol(Symbol, Asm, Layout);
679 }
680
isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler & Asm,const MCSymbol & SymA,const MCFragment & FB,bool InSet,bool IsPCRel) const681 bool WinCOFFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
682 const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
683 bool InSet, bool IsPCRel) const {
684 // Don't drop relocations between functions, even if they are in the same text
685 // section. Multiple Visual C++ linker features depend on having the
686 // relocations present. The /INCREMENTAL flag will cause these relocations to
687 // point to thunks, and the /GUARD:CF flag assumes that it can use relocations
688 // to approximate the set of all address taken functions. LLD's implementation
689 // of /GUARD:CF also relies on the existance of these relocations.
690 uint16_t Type = cast<MCSymbolCOFF>(SymA).getType();
691 if ((Type >> COFF::SCT_COMPLEX_TYPE_SHIFT) == COFF::IMAGE_SYM_DTYPE_FUNCTION)
692 return false;
693 return MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(Asm, SymA, FB,
694 InSet, IsPCRel);
695 }
696
recordRelocation(MCAssembler & Asm,const MCAsmLayout & Layout,const MCFragment * Fragment,const MCFixup & Fixup,MCValue Target,uint64_t & FixedValue)697 void WinCOFFObjectWriter::recordRelocation(MCAssembler &Asm,
698 const MCAsmLayout &Layout,
699 const MCFragment *Fragment,
700 const MCFixup &Fixup, MCValue Target,
701 uint64_t &FixedValue) {
702 assert(Target.getSymA() && "Relocation must reference a symbol!");
703
704 const MCSymbol &A = Target.getSymA()->getSymbol();
705 if (!A.isRegistered()) {
706 Asm.getContext().reportError(Fixup.getLoc(),
707 Twine("symbol '") + A.getName() +
708 "' can not be undefined");
709 return;
710 }
711 if (A.isTemporary() && A.isUndefined()) {
712 Asm.getContext().reportError(Fixup.getLoc(),
713 Twine("assembler label '") + A.getName() +
714 "' can not be undefined");
715 return;
716 }
717
718 MCSection *MCSec = Fragment->getParent();
719
720 // Mark this symbol as requiring an entry in the symbol table.
721 assert(SectionMap.find(MCSec) != SectionMap.end() &&
722 "Section must already have been defined in executePostLayoutBinding!");
723
724 COFFSection *Sec = SectionMap[MCSec];
725 const MCSymbolRefExpr *SymB = Target.getSymB();
726
727 if (SymB) {
728 const MCSymbol *B = &SymB->getSymbol();
729 if (!B->getFragment()) {
730 Asm.getContext().reportError(
731 Fixup.getLoc(),
732 Twine("symbol '") + B->getName() +
733 "' can not be undefined in a subtraction expression");
734 return;
735 }
736
737 // Offset of the symbol in the section
738 int64_t OffsetOfB = Layout.getSymbolOffset(*B);
739
740 // Offset of the relocation in the section
741 int64_t OffsetOfRelocation =
742 Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
743
744 FixedValue = (OffsetOfRelocation - OffsetOfB) + Target.getConstant();
745 } else {
746 FixedValue = Target.getConstant();
747 }
748
749 COFFRelocation Reloc;
750
751 Reloc.Data.SymbolTableIndex = 0;
752 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
753
754 // Turn relocations for temporary symbols into section relocations.
755 if (A.isTemporary()) {
756 MCSection *TargetSection = &A.getSection();
757 assert(
758 SectionMap.find(TargetSection) != SectionMap.end() &&
759 "Section must already have been defined in executePostLayoutBinding!");
760 Reloc.Symb = SectionMap[TargetSection]->Symbol;
761 FixedValue += Layout.getSymbolOffset(A);
762 } else {
763 assert(
764 SymbolMap.find(&A) != SymbolMap.end() &&
765 "Symbol must already have been defined in executePostLayoutBinding!");
766 Reloc.Symb = SymbolMap[&A];
767 }
768
769 ++Reloc.Symb->Relocations;
770
771 Reloc.Data.VirtualAddress += Fixup.getOffset();
772 Reloc.Data.Type = TargetObjectWriter->getRelocType(
773 Asm.getContext(), Target, Fixup, SymB, Asm.getBackend());
774
775 // FIXME: Can anyone explain what this does other than adjust for the size
776 // of the offset?
777 if ((Header.Machine == COFF::IMAGE_FILE_MACHINE_AMD64 &&
778 Reloc.Data.Type == COFF::IMAGE_REL_AMD64_REL32) ||
779 (Header.Machine == COFF::IMAGE_FILE_MACHINE_I386 &&
780 Reloc.Data.Type == COFF::IMAGE_REL_I386_REL32))
781 FixedValue += 4;
782
783 if (Header.Machine == COFF::IMAGE_FILE_MACHINE_ARMNT) {
784 switch (Reloc.Data.Type) {
785 case COFF::IMAGE_REL_ARM_ABSOLUTE:
786 case COFF::IMAGE_REL_ARM_ADDR32:
787 case COFF::IMAGE_REL_ARM_ADDR32NB:
788 case COFF::IMAGE_REL_ARM_TOKEN:
789 case COFF::IMAGE_REL_ARM_SECTION:
790 case COFF::IMAGE_REL_ARM_SECREL:
791 break;
792 case COFF::IMAGE_REL_ARM_BRANCH11:
793 case COFF::IMAGE_REL_ARM_BLX11:
794 // IMAGE_REL_ARM_BRANCH11 and IMAGE_REL_ARM_BLX11 are only used for
795 // pre-ARMv7, which implicitly rules it out of ARMNT (it would be valid
796 // for Windows CE).
797 case COFF::IMAGE_REL_ARM_BRANCH24:
798 case COFF::IMAGE_REL_ARM_BLX24:
799 case COFF::IMAGE_REL_ARM_MOV32A:
800 // IMAGE_REL_ARM_BRANCH24, IMAGE_REL_ARM_BLX24, IMAGE_REL_ARM_MOV32A are
801 // only used for ARM mode code, which is documented as being unsupported
802 // by Windows on ARM. Empirical proof indicates that masm is able to
803 // generate the relocations however the rest of the MSVC toolchain is
804 // unable to handle it.
805 llvm_unreachable("unsupported relocation");
806 break;
807 case COFF::IMAGE_REL_ARM_MOV32T:
808 break;
809 case COFF::IMAGE_REL_ARM_BRANCH20T:
810 case COFF::IMAGE_REL_ARM_BRANCH24T:
811 case COFF::IMAGE_REL_ARM_BLX23T:
812 // IMAGE_REL_BRANCH20T, IMAGE_REL_ARM_BRANCH24T, IMAGE_REL_ARM_BLX23T all
813 // perform a 4 byte adjustment to the relocation. Relative branches are
814 // offset by 4 on ARM, however, because there is no RELA relocations, all
815 // branches are offset by 4.
816 FixedValue = FixedValue + 4;
817 break;
818 }
819 }
820
821 // The fixed value never makes sense for section indices, ignore it.
822 if (Fixup.getKind() == FK_SecRel_2)
823 FixedValue = 0;
824
825 if (TargetObjectWriter->recordRelocation(Fixup))
826 Sec->Relocations.push_back(Reloc);
827 }
828
getTime()829 static std::time_t getTime() {
830 std::time_t Now = time(nullptr);
831 if (Now < 0 || !isUInt<32>(Now))
832 return UINT32_MAX;
833 return Now;
834 }
835
836 // Create .file symbols.
createFileSymbols(MCAssembler & Asm)837 void WinCOFFObjectWriter::createFileSymbols(MCAssembler &Asm) {
838 for (const std::string &Name : Asm.getFileNames()) {
839 // round up to calculate the number of auxiliary symbols required
840 unsigned SymbolSize = UseBigObj ? COFF::Symbol32Size : COFF::Symbol16Size;
841 unsigned Count = (Name.size() + SymbolSize - 1) / SymbolSize;
842
843 COFFSymbol *File = createSymbol(".file");
844 File->Data.SectionNumber = COFF::IMAGE_SYM_DEBUG;
845 File->Data.StorageClass = COFF::IMAGE_SYM_CLASS_FILE;
846 File->Aux.resize(Count);
847
848 unsigned Offset = 0;
849 unsigned Length = Name.size();
850 for (auto &Aux : File->Aux) {
851 Aux.AuxType = ATFile;
852
853 if (Length > SymbolSize) {
854 memcpy(&Aux.Aux, Name.c_str() + Offset, SymbolSize);
855 Length = Length - SymbolSize;
856 } else {
857 memcpy(&Aux.Aux, Name.c_str() + Offset, Length);
858 memset((char *)&Aux.Aux + Length, 0, SymbolSize - Length);
859 break;
860 }
861
862 Offset += SymbolSize;
863 }
864 }
865 }
866
isAssociative(const COFFSection & Section)867 static bool isAssociative(const COFFSection &Section) {
868 return Section.Symbol->Aux[0].Aux.SectionDefinition.Selection ==
869 COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
870 }
871
assignSectionNumbers()872 void WinCOFFObjectWriter::assignSectionNumbers() {
873 size_t I = 1;
874 auto Assign = [&](COFFSection &Section) {
875 Section.Number = I;
876 Section.Symbol->Data.SectionNumber = I;
877 Section.Symbol->Aux[0].Aux.SectionDefinition.Number = I;
878 ++I;
879 };
880
881 // Although it is not explicitly requested by the Microsoft COFF spec,
882 // we should avoid emitting forward associative section references,
883 // because MSVC link.exe as of 2017 cannot handle that.
884 for (const std::unique_ptr<COFFSection> &Section : Sections)
885 if (!isAssociative(*Section))
886 Assign(*Section);
887 for (const std::unique_ptr<COFFSection> &Section : Sections)
888 if (isAssociative(*Section))
889 Assign(*Section);
890 }
891
892 // Assign file offsets to COFF object file structures.
assignFileOffsets(MCAssembler & Asm,const MCAsmLayout & Layout)893 void WinCOFFObjectWriter::assignFileOffsets(MCAssembler &Asm,
894 const MCAsmLayout &Layout) {
895 unsigned Offset = W.OS.tell();
896
897 Offset += UseBigObj ? COFF::Header32Size : COFF::Header16Size;
898 Offset += COFF::SectionSize * Header.NumberOfSections;
899
900 for (const auto &Section : Asm) {
901 COFFSection *Sec = SectionMap[&Section];
902
903 if (Sec->Number == -1)
904 continue;
905
906 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(&Section);
907
908 if (IsPhysicalSection(Sec)) {
909 Sec->Header.PointerToRawData = Offset;
910 Offset += Sec->Header.SizeOfRawData;
911 }
912
913 if (!Sec->Relocations.empty()) {
914 bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
915
916 if (RelocationsOverflow) {
917 // Signal overflow by setting NumberOfRelocations to max value. Actual
918 // size is found in reloc #0. Microsoft tools understand this.
919 Sec->Header.NumberOfRelocations = 0xffff;
920 } else {
921 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
922 }
923 Sec->Header.PointerToRelocations = Offset;
924
925 if (RelocationsOverflow) {
926 // Reloc #0 will contain actual count, so make room for it.
927 Offset += COFF::RelocationSize;
928 }
929
930 Offset += COFF::RelocationSize * Sec->Relocations.size();
931
932 for (auto &Relocation : Sec->Relocations) {
933 assert(Relocation.Symb->getIndex() != -1);
934 Relocation.Data.SymbolTableIndex = Relocation.Symb->getIndex();
935 }
936 }
937
938 assert(Sec->Symbol->Aux.size() == 1 &&
939 "Section's symbol must have one aux!");
940 AuxSymbol &Aux = Sec->Symbol->Aux[0];
941 assert(Aux.AuxType == ATSectionDefinition &&
942 "Section's symbol's aux symbol must be a Section Definition!");
943 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
944 Aux.Aux.SectionDefinition.NumberOfRelocations =
945 Sec->Header.NumberOfRelocations;
946 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
947 Sec->Header.NumberOfLineNumbers;
948 }
949
950 Header.PointerToSymbolTable = Offset;
951 }
952
writeObject(MCAssembler & Asm,const MCAsmLayout & Layout)953 uint64_t WinCOFFObjectWriter::writeObject(MCAssembler &Asm,
954 const MCAsmLayout &Layout) {
955 uint64_t StartOffset = W.OS.tell();
956
957 if (Sections.size() > INT32_MAX)
958 report_fatal_error(
959 "PE COFF object files can't have more than 2147483647 sections");
960
961 UseBigObj = Sections.size() > COFF::MaxNumberOfSections16;
962 Header.NumberOfSections = Sections.size();
963 Header.NumberOfSymbols = 0;
964
965 assignSectionNumbers();
966 createFileSymbols(Asm);
967
968 for (auto &Symbol : Symbols) {
969 // Update section number & offset for symbols that have them.
970 if (Symbol->Section)
971 Symbol->Data.SectionNumber = Symbol->Section->Number;
972 Symbol->setIndex(Header.NumberOfSymbols++);
973 // Update auxiliary symbol info.
974 Symbol->Data.NumberOfAuxSymbols = Symbol->Aux.size();
975 Header.NumberOfSymbols += Symbol->Data.NumberOfAuxSymbols;
976 }
977
978 // Build string table.
979 for (const auto &S : Sections)
980 if (S->Name.size() > COFF::NameSize)
981 Strings.add(S->Name);
982 for (const auto &S : Symbols)
983 if (S->Name.size() > COFF::NameSize)
984 Strings.add(S->Name);
985 Strings.finalize();
986
987 // Set names.
988 for (const auto &S : Sections)
989 SetSectionName(*S);
990 for (auto &S : Symbols)
991 SetSymbolName(*S);
992
993 // Fixup weak external references.
994 for (auto &Symbol : Symbols) {
995 if (Symbol->Other) {
996 assert(Symbol->getIndex() != -1);
997 assert(Symbol->Aux.size() == 1 && "Symbol must contain one aux symbol!");
998 assert(Symbol->Aux[0].AuxType == ATWeakExternal &&
999 "Symbol's aux symbol must be a Weak External!");
1000 Symbol->Aux[0].Aux.WeakExternal.TagIndex = Symbol->Other->getIndex();
1001 }
1002 }
1003
1004 // Fixup associative COMDAT sections.
1005 for (auto &Section : Sections) {
1006 if (Section->Symbol->Aux[0].Aux.SectionDefinition.Selection !=
1007 COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
1008 continue;
1009
1010 const MCSectionCOFF &MCSec = *Section->MCSection;
1011 const MCSymbol *AssocMCSym = MCSec.getCOMDATSymbol();
1012 assert(AssocMCSym);
1013
1014 // It's an error to try to associate with an undefined symbol or a symbol
1015 // without a section.
1016 if (!AssocMCSym->isInSection()) {
1017 Asm.getContext().reportError(
1018 SMLoc(), Twine("cannot make section ") + MCSec.getSectionName() +
1019 Twine(" associative with sectionless symbol ") +
1020 AssocMCSym->getName());
1021 continue;
1022 }
1023
1024 const auto *AssocMCSec = cast<MCSectionCOFF>(&AssocMCSym->getSection());
1025 assert(SectionMap.count(AssocMCSec));
1026 COFFSection *AssocSec = SectionMap[AssocMCSec];
1027
1028 // Skip this section if the associated section is unused.
1029 if (AssocSec->Number == -1)
1030 continue;
1031
1032 Section->Symbol->Aux[0].Aux.SectionDefinition.Number = AssocSec->Number;
1033 }
1034
1035 // Create the contents of the .llvm_addrsig section.
1036 if (EmitAddrsigSection) {
1037 auto Frag = new MCDataFragment(AddrsigSection);
1038 Frag->setLayoutOrder(0);
1039 raw_svector_ostream OS(Frag->getContents());
1040 for (const MCSymbol *S : AddrsigSyms) {
1041 if (!S->isTemporary()) {
1042 encodeULEB128(S->getIndex(), OS);
1043 continue;
1044 }
1045
1046 MCSection *TargetSection = &S->getSection();
1047 assert(SectionMap.find(TargetSection) != SectionMap.end() &&
1048 "Section must already have been defined in "
1049 "executePostLayoutBinding!");
1050 encodeULEB128(SectionMap[TargetSection]->Symbol->getIndex(), OS);
1051 }
1052 }
1053
1054 assignFileOffsets(Asm, Layout);
1055
1056 // MS LINK expects to be able to use this timestamp to implement their
1057 // /INCREMENTAL feature.
1058 if (Asm.isIncrementalLinkerCompatible()) {
1059 Header.TimeDateStamp = getTime();
1060 } else {
1061 // Have deterministic output if /INCREMENTAL isn't needed. Also matches GNU.
1062 Header.TimeDateStamp = 0;
1063 }
1064
1065 // Write it all to disk...
1066 WriteFileHeader(Header);
1067 writeSectionHeaders();
1068
1069 // Write section contents.
1070 sections::iterator I = Sections.begin();
1071 sections::iterator IE = Sections.end();
1072 MCAssembler::iterator J = Asm.begin();
1073 MCAssembler::iterator JE = Asm.end();
1074 for (; I != IE && J != JE; ++I, ++J)
1075 writeSection(Asm, Layout, **I, *J);
1076
1077 assert(W.OS.tell() == Header.PointerToSymbolTable &&
1078 "Header::PointerToSymbolTable is insane!");
1079
1080 // Write a symbol table.
1081 for (auto &Symbol : Symbols)
1082 if (Symbol->getIndex() != -1)
1083 WriteSymbol(*Symbol);
1084
1085 // Write a string table, which completes the entire COFF file.
1086 Strings.write(W.OS);
1087
1088 return W.OS.tell() - StartOffset;
1089 }
1090
MCWinCOFFObjectTargetWriter(unsigned Machine_)1091 MCWinCOFFObjectTargetWriter::MCWinCOFFObjectTargetWriter(unsigned Machine_)
1092 : Machine(Machine_) {}
1093
1094 // Pin the vtable to this file.
anchor()1095 void MCWinCOFFObjectTargetWriter::anchor() {}
1096
1097 //------------------------------------------------------------------------------
1098 // WinCOFFObjectWriter factory function
1099
createWinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,raw_pwrite_stream & OS)1100 std::unique_ptr<MCObjectWriter> llvm::createWinCOFFObjectWriter(
1101 std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW, raw_pwrite_stream &OS) {
1102 return llvm::make_unique<WinCOFFObjectWriter>(std::move(MOTW), OS);
1103 }
1104