1 //===-- llvm/MC/WinCOFFObjectWriter.cpp -------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains an implementation of a Win32 COFF object file writer.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "WinCOFFObjectWriter"
16 #include "llvm/MC/MCWinCOFFObjectWriter.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/OwningPtr.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/ADT/Twine.h"
22 #include "llvm/MC/MCAsmLayout.h"
23 #include "llvm/MC/MCAssembler.h"
24 #include "llvm/MC/MCContext.h"
25 #include "llvm/MC/MCExpr.h"
26 #include "llvm/MC/MCObjectWriter.h"
27 #include "llvm/MC/MCSection.h"
28 #include "llvm/MC/MCSectionCOFF.h"
29 #include "llvm/MC/MCSymbol.h"
30 #include "llvm/MC/MCValue.h"
31 #include "llvm/Support/COFF.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/TimeValue.h"
40 typedef SmallString<COFF::NameSize> name;
51 AuxiliaryType AuxType;
62 typedef SmallVector<AuxSymbol, 1> AuxiliarySymbols;
71 MCSymbolData const *MCData;
73 COFFSymbol(StringRef name);
75 void set_name_offset(uint32_t Offset);
77 bool should_keep() const;
80 // This class contains staging data for a COFF relocation entry.
81 struct COFFRelocation {
82 COFF::relocation Data;
85 COFFRelocation() : Symb(NULL) {}
86 static size_t size() { return COFF::RelocationSize; }
89 typedef std::vector<COFFRelocation> relocations;
97 MCSectionData const *MCData;
99 relocations Relocations;
101 COFFSection(StringRef name);
102 static size_t size();
105 // This class holds the COFF string table.
107 typedef StringMap<size_t> map;
110 void update_length();
112 std::vector<char> Data;
116 size_t insert(StringRef String);
119 class WinCOFFObjectWriter : public MCObjectWriter {
122 typedef std::vector<COFFSymbol*> symbols;
123 typedef std::vector<COFFSection*> sections;
125 typedef DenseMap<MCSymbol const *, COFFSymbol *> symbol_map;
126 typedef DenseMap<MCSection const *, COFFSection *> section_map;
128 llvm::OwningPtr<MCWinCOFFObjectTargetWriter> TargetObjectWriter;
130 // Root level file contents.
136 // Maps used during object file creation.
137 section_map SectionMap;
138 symbol_map SymbolMap;
140 WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW, raw_ostream &OS);
141 ~WinCOFFObjectWriter();
143 COFFSymbol *createSymbol(StringRef Name);
144 COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol * Symbol);
145 COFFSection *createSection(StringRef Name);
147 template <typename object_t, typename list_t>
148 object_t *createCOFFEntity(StringRef Name, list_t &List);
150 void DefineSection(MCSectionData const &SectionData);
151 void DefineSymbol(MCSymbolData const &SymbolData,
152 MCAssembler &Assembler);
154 void MakeSymbolReal(COFFSymbol &S, size_t Index);
155 void MakeSectionReal(COFFSection &S, size_t Number);
157 bool IsPhysicalSection(COFFSection *S);
159 // Entity writing methods.
161 void WriteFileHeader(const COFF::header &Header);
162 void WriteSymbol(const COFFSymbol *S);
163 void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
164 void WriteSectionHeader(const COFF::section &S);
165 void WriteRelocation(const COFF::relocation &R);
167 // MCObjectWriter interface implementation.
169 void ExecutePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout);
171 void RecordRelocation(const MCAssembler &Asm,
172 const MCAsmLayout &Layout,
173 const MCFragment *Fragment,
174 const MCFixup &Fixup,
176 uint64_t &FixedValue);
178 void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
182 static inline void write_uint32_le(void *Data, uint32_t const &Value) {
183 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
184 Ptr[0] = (Value & 0x000000FF) >> 0;
185 Ptr[1] = (Value & 0x0000FF00) >> 8;
186 Ptr[2] = (Value & 0x00FF0000) >> 16;
187 Ptr[3] = (Value & 0xFF000000) >> 24;
190 //------------------------------------------------------------------------------
191 // Symbol class implementation
193 COFFSymbol::COFFSymbol(StringRef name)
194 : Name(name.begin(), name.end())
199 memset(&Data, 0, sizeof(Data));
202 size_t COFFSymbol::size() const {
203 return COFF::SymbolSize + (Data.NumberOfAuxSymbols * COFF::SymbolSize);
206 // In the case that the name does not fit within 8 bytes, the offset
207 // into the string table is stored in the last 4 bytes instead, leaving
208 // the first 4 bytes as 0.
209 void COFFSymbol::set_name_offset(uint32_t Offset) {
210 write_uint32_le(Data.Name + 0, 0);
211 write_uint32_le(Data.Name + 4, Offset);
214 /// logic to decide if the symbol should be reported in the symbol table
215 bool COFFSymbol::should_keep() const {
216 // no section means its external, keep it
220 // if it has relocations pointing at it, keep it
221 if (Relocations > 0) {
222 assert(Section->Number != -1 && "Sections with relocations must be real!");
226 // if the section its in is being droped, drop it
227 if (Section->Number == -1)
230 // if it is the section symbol, keep it
231 if (Section->Symbol == this)
234 // if its temporary, drop it
235 if (MCData && MCData->getSymbol().isTemporary())
238 // otherwise, keep it
242 //------------------------------------------------------------------------------
243 // Section class implementation
245 COFFSection::COFFSection(StringRef name)
249 memset(&Header, 0, sizeof(Header));
252 size_t COFFSection::size() {
253 return COFF::SectionSize;
256 //------------------------------------------------------------------------------
257 // StringTable class implementation
259 /// Write the length of the string table into Data.
260 /// The length of the string table includes uint32 length header.
261 void StringTable::update_length() {
262 write_uint32_le(&Data.front(), Data.size());
265 StringTable::StringTable() {
266 // The string table data begins with the length of the entire string table
267 // including the length header. Allocate space for this header.
272 size_t StringTable::size() const {
276 /// Add String to the table iff it is not already there.
277 /// @returns the index into the string table where the string is now located.
278 size_t StringTable::insert(StringRef String) {
279 map::iterator i = Map.find(String);
284 size_t Offset = Data.size();
286 // Insert string data into string table.
287 Data.insert(Data.end(), String.begin(), String.end());
288 Data.push_back('\0');
290 // Put a reference to it in the map.
291 Map[String] = Offset;
293 // Update the internal length field.
299 //------------------------------------------------------------------------------
300 // WinCOFFObjectWriter class implementation
302 WinCOFFObjectWriter::WinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW,
304 : MCObjectWriter(OS, true)
305 , TargetObjectWriter(MOTW) {
306 memset(&Header, 0, sizeof(Header));
308 Header.Machine = TargetObjectWriter->getMachine();
311 WinCOFFObjectWriter::~WinCOFFObjectWriter() {
312 for (symbols::iterator I = Symbols.begin(), E = Symbols.end(); I != E; ++I)
314 for (sections::iterator I = Sections.begin(), E = Sections.end(); I != E; ++I)
318 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
319 return createCOFFEntity<COFFSymbol>(Name, Symbols);
322 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol * Symbol){
323 symbol_map::iterator i = SymbolMap.find(Symbol);
324 if (i != SymbolMap.end())
326 COFFSymbol *RetSymbol
327 = createCOFFEntity<COFFSymbol>(Symbol->getName(), Symbols);
328 SymbolMap[Symbol] = RetSymbol;
332 COFFSection *WinCOFFObjectWriter::createSection(StringRef Name) {
333 return createCOFFEntity<COFFSection>(Name, Sections);
336 /// A template used to lookup or create a symbol/section, and initialize it if
338 template <typename object_t, typename list_t>
339 object_t *WinCOFFObjectWriter::createCOFFEntity(StringRef Name,
341 object_t *Object = new object_t(Name);
343 List.push_back(Object);
348 /// This function takes a section data object from the assembler
349 /// and creates the associated COFF section staging object.
350 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
351 assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
352 && "Got non COFF section in the COFF backend!");
353 // FIXME: Not sure how to verify this (at least in a debug build).
354 MCSectionCOFF const &Sec =
355 static_cast<MCSectionCOFF const &>(SectionData.getSection());
357 COFFSection *coff_section = createSection(Sec.getSectionName());
358 COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
360 coff_section->Symbol = coff_symbol;
361 coff_symbol->Section = coff_section;
362 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
364 // In this case the auxiliary symbol is a Section Definition.
365 coff_symbol->Aux.resize(1);
366 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
367 coff_symbol->Aux[0].AuxType = ATSectionDefinition;
368 coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
370 coff_section->Header.Characteristics = Sec.getCharacteristics();
372 uint32_t &Characteristics = coff_section->Header.Characteristics;
373 switch (SectionData.getAlignment()) {
374 case 1: Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES; break;
375 case 2: Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES; break;
376 case 4: Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES; break;
377 case 8: Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES; break;
378 case 16: Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES; break;
379 case 32: Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES; break;
380 case 64: Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES; break;
381 case 128: Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES; break;
382 case 256: Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES; break;
383 case 512: Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES; break;
384 case 1024: Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES; break;
385 case 2048: Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES; break;
386 case 4096: Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES; break;
387 case 8192: Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES; break;
389 llvm_unreachable("unsupported section alignment");
392 // Bind internal COFF section to MC section.
393 coff_section->MCData = &SectionData;
394 SectionMap[&SectionData.getSection()] = coff_section;
397 /// This function takes a section data object from the assembler
398 /// and creates the associated COFF symbol staging object.
399 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
400 MCAssembler &Assembler) {
401 MCSymbol const &Symbol = SymbolData.getSymbol();
402 COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&Symbol);
403 SymbolMap[&Symbol] = coff_symbol;
405 if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
406 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
408 if (Symbol.isVariable()) {
409 const MCSymbolRefExpr *SymRef =
410 dyn_cast<MCSymbolRefExpr>(Symbol.getVariableValue());
413 report_fatal_error("Weak externals may only alias symbols");
415 coff_symbol->Other = GetOrCreateCOFFSymbol(&SymRef->getSymbol());
417 std::string WeakName = std::string(".weak.")
418 + Symbol.getName().str()
420 COFFSymbol *WeakDefault = createSymbol(WeakName);
421 WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
422 WeakDefault->Data.StorageClass = COFF::IMAGE_SYM_CLASS_EXTERNAL;
423 WeakDefault->Data.Type = 0;
424 WeakDefault->Data.Value = 0;
425 coff_symbol->Other = WeakDefault;
428 // Setup the Weak External auxiliary symbol.
429 coff_symbol->Aux.resize(1);
430 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
431 coff_symbol->Aux[0].AuxType = ATWeakExternal;
432 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
433 coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
434 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
436 coff_symbol->MCData = &SymbolData;
438 const MCSymbolData &ResSymData =
439 Assembler.getSymbolData(Symbol.AliasedSymbol());
441 coff_symbol->Data.Type = (ResSymData.getFlags() & 0x0000FFFF) >> 0;
442 coff_symbol->Data.StorageClass = (ResSymData.getFlags() & 0x00FF0000) >> 16;
444 // If no storage class was specified in the streamer, define it here.
445 if (coff_symbol->Data.StorageClass == 0) {
446 bool external = ResSymData.isExternal() || (ResSymData.Fragment == NULL);
448 coff_symbol->Data.StorageClass =
449 external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
452 if (ResSymData.Fragment != NULL)
453 coff_symbol->Section =
454 SectionMap[&ResSymData.Fragment->getParent()->getSection()];
456 coff_symbol->MCData = &ResSymData;
460 /// making a section real involves assigned it a number and putting
461 /// name into the string table if needed
462 void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
463 if (S.Name.size() > COFF::NameSize) {
464 const unsigned Max6DecimalSize = 999999;
465 const unsigned Max7DecimalSize = 9999999;
466 uint64_t StringTableEntry = Strings.insert(S.Name.c_str());
468 if (StringTableEntry <= Max6DecimalSize) {
469 std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
470 } else if (StringTableEntry <= Max7DecimalSize) {
471 // With seven digits, we have to skip the terminating null. Because
472 // sprintf always appends it, we use a larger temporary buffer.
473 char buffer[9] = { };
474 std::sprintf(buffer, "/%d", unsigned(StringTableEntry));
475 std::memcpy(S.Header.Name, buffer, 8);
477 report_fatal_error("COFF string table is greater than 9,999,999 bytes.");
480 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
483 S.Symbol->Data.SectionNumber = S.Number;
484 S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
487 void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
488 if (S.Name.size() > COFF::NameSize) {
489 size_t StringTableEntry = Strings.insert(S.Name.c_str());
491 S.set_name_offset(StringTableEntry);
493 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
497 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
498 return (S->Header.Characteristics
499 & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
502 //------------------------------------------------------------------------------
503 // entity writing methods
505 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
506 WriteLE16(Header.Machine);
507 WriteLE16(Header.NumberOfSections);
508 WriteLE32(Header.TimeDateStamp);
509 WriteLE32(Header.PointerToSymbolTable);
510 WriteLE32(Header.NumberOfSymbols);
511 WriteLE16(Header.SizeOfOptionalHeader);
512 WriteLE16(Header.Characteristics);
515 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
516 WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
517 WriteLE32(S->Data.Value);
518 WriteLE16(S->Data.SectionNumber);
519 WriteLE16(S->Data.Type);
520 Write8(S->Data.StorageClass);
521 Write8(S->Data.NumberOfAuxSymbols);
522 WriteAuxiliarySymbols(S->Aux);
525 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
526 const COFFSymbol::AuxiliarySymbols &S) {
527 for(COFFSymbol::AuxiliarySymbols::const_iterator i = S.begin(), e = S.end();
530 case ATFunctionDefinition:
531 WriteLE32(i->Aux.FunctionDefinition.TagIndex);
532 WriteLE32(i->Aux.FunctionDefinition.TotalSize);
533 WriteLE32(i->Aux.FunctionDefinition.PointerToLinenumber);
534 WriteLE32(i->Aux.FunctionDefinition.PointerToNextFunction);
535 WriteZeros(sizeof(i->Aux.FunctionDefinition.unused));
537 case ATbfAndefSymbol:
538 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused1));
539 WriteLE16(i->Aux.bfAndefSymbol.Linenumber);
540 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused2));
541 WriteLE32(i->Aux.bfAndefSymbol.PointerToNextFunction);
542 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused3));
545 WriteLE32(i->Aux.WeakExternal.TagIndex);
546 WriteLE32(i->Aux.WeakExternal.Characteristics);
547 WriteZeros(sizeof(i->Aux.WeakExternal.unused));
550 WriteBytes(StringRef(reinterpret_cast<const char *>(i->Aux.File.FileName),
551 sizeof(i->Aux.File.FileName)));
553 case ATSectionDefinition:
554 WriteLE32(i->Aux.SectionDefinition.Length);
555 WriteLE16(i->Aux.SectionDefinition.NumberOfRelocations);
556 WriteLE16(i->Aux.SectionDefinition.NumberOfLinenumbers);
557 WriteLE32(i->Aux.SectionDefinition.CheckSum);
558 WriteLE16(i->Aux.SectionDefinition.Number);
559 Write8(i->Aux.SectionDefinition.Selection);
560 WriteZeros(sizeof(i->Aux.SectionDefinition.unused));
566 void WinCOFFObjectWriter::WriteSectionHeader(const COFF::section &S) {
567 WriteBytes(StringRef(S.Name, COFF::NameSize));
569 WriteLE32(S.VirtualSize);
570 WriteLE32(S.VirtualAddress);
571 WriteLE32(S.SizeOfRawData);
572 WriteLE32(S.PointerToRawData);
573 WriteLE32(S.PointerToRelocations);
574 WriteLE32(S.PointerToLineNumbers);
575 WriteLE16(S.NumberOfRelocations);
576 WriteLE16(S.NumberOfLineNumbers);
577 WriteLE32(S.Characteristics);
580 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
581 WriteLE32(R.VirtualAddress);
582 WriteLE32(R.SymbolTableIndex);
586 ////////////////////////////////////////////////////////////////////////////////
587 // MCObjectWriter interface implementations
589 void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
590 const MCAsmLayout &Layout) {
591 // "Define" each section & symbol. This creates section & symbol
592 // entries in the staging area.
594 for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
597 for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
598 e = Asm.symbol_end();
600 DefineSymbol(*i, Asm);
603 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
604 const MCAsmLayout &Layout,
605 const MCFragment *Fragment,
606 const MCFixup &Fixup,
608 uint64_t &FixedValue) {
609 assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
611 const MCSymbol &Symbol = Target.getSymA()->getSymbol();
612 const MCSymbol &A = Symbol.AliasedSymbol();
613 MCSymbolData &A_SD = Asm.getSymbolData(A);
615 MCSectionData const *SectionData = Fragment->getParent();
617 // Mark this symbol as requiring an entry in the symbol table.
618 assert(SectionMap.find(&SectionData->getSection()) != SectionMap.end() &&
619 "Section must already have been defined in ExecutePostLayoutBinding!");
620 assert(SymbolMap.find(&A_SD.getSymbol()) != SymbolMap.end() &&
621 "Symbol must already have been defined in ExecutePostLayoutBinding!");
623 COFFSection *coff_section = SectionMap[&SectionData->getSection()];
624 COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
625 const MCSymbolRefExpr *SymA = Target.getSymA();
626 const MCSymbolRefExpr *SymB = Target.getSymB();
627 const bool CrossSection = SymB &&
628 &SymA->getSymbol().getSection() != &SymB->getSymbol().getSection();
630 if (Target.getSymB()) {
631 const MCSymbol *B = &Target.getSymB()->getSymbol();
632 MCSymbolData &B_SD = Asm.getSymbolData(*B);
634 // Offset of the symbol in the section
635 int64_t a = Layout.getSymbolOffset(&B_SD);
637 // Ofeset of the relocation in the section
638 int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
641 // In the case where we have SymbA and SymB, we just need to store the delta
642 // between the two symbols. Update FixedValue to account for the delta, and
643 // skip recording the relocation.
647 FixedValue = Target.getConstant();
650 COFFRelocation Reloc;
652 Reloc.Data.SymbolTableIndex = 0;
653 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
655 // Turn relocations for temporary symbols into section relocations.
656 if (coff_symbol->MCData->getSymbol().isTemporary() || CrossSection) {
657 Reloc.Symb = coff_symbol->Section->Symbol;
658 FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
659 + coff_symbol->MCData->getOffset();
661 Reloc.Symb = coff_symbol;
663 ++Reloc.Symb->Relocations;
665 Reloc.Data.VirtualAddress += Fixup.getOffset();
666 Reloc.Data.Type = TargetObjectWriter->getRelocType(Target, Fixup,
669 // FIXME: Can anyone explain what this does other than adjust for the size
671 if (Reloc.Data.Type == COFF::IMAGE_REL_AMD64_REL32 ||
672 Reloc.Data.Type == COFF::IMAGE_REL_I386_REL32)
675 coff_section->Relocations.push_back(Reloc);
678 void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
679 const MCAsmLayout &Layout) {
680 // Assign symbol and section indexes and offsets.
681 Header.NumberOfSections = 0;
683 DenseMap<COFFSection *, uint16_t> SectionIndices;
684 for (sections::iterator i = Sections.begin(),
685 e = Sections.end(); i != e; i++) {
686 if (Layout.getSectionAddressSize((*i)->MCData) > 0) {
687 size_t Number = ++Header.NumberOfSections;
688 SectionIndices[*i] = Number;
689 MakeSectionReal(**i, Number);
695 Header.NumberOfSymbols = 0;
697 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
698 COFFSymbol *coff_symbol = *i;
699 MCSymbolData const *SymbolData = coff_symbol->MCData;
701 // Update section number & offset for symbols that have them.
702 if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
703 assert(coff_symbol->Section != NULL);
705 coff_symbol->Data.SectionNumber = coff_symbol->Section->Number;
706 coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
707 + SymbolData->Offset;
710 if (coff_symbol->should_keep()) {
711 MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++);
713 // Update auxiliary symbol info.
714 coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
715 Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
717 coff_symbol->Index = -1;
720 // Fixup weak external references.
721 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
722 COFFSymbol *coff_symbol = *i;
723 if (coff_symbol->Other != NULL) {
724 assert(coff_symbol->Index != -1);
725 assert(coff_symbol->Aux.size() == 1 &&
726 "Symbol must contain one aux symbol!");
727 assert(coff_symbol->Aux[0].AuxType == ATWeakExternal &&
728 "Symbol's aux symbol must be a Weak External!");
729 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index;
733 // Fixup associative COMDAT sections.
734 for (sections::iterator i = Sections.begin(),
735 e = Sections.end(); i != e; i++) {
736 if ((*i)->Symbol->Aux[0].Aux.SectionDefinition.Selection !=
737 COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE)
740 const MCSectionCOFF &MCSec = static_cast<const MCSectionCOFF &>(
741 (*i)->MCData->getSection());
743 COFFSection *Assoc = SectionMap.lookup(MCSec.getAssocSection());
745 report_fatal_error(Twine("Missing associated COMDAT section ") +
746 MCSec.getAssocSection()->getSectionName() +
747 " for section " + MCSec.getSectionName());
750 // Skip this section if the associated section is unused.
751 if (Assoc->Number == -1)
754 (*i)->Symbol->Aux[0].Aux.SectionDefinition.Number = SectionIndices[Assoc];
758 // Assign file offsets to COFF object file structures.
762 offset += COFF::HeaderSize;
763 offset += COFF::SectionSize * Header.NumberOfSections;
765 for (MCAssembler::const_iterator i = Asm.begin(),
768 COFFSection *Sec = SectionMap[&i->getSection()];
770 if (Sec->Number == -1)
773 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
775 if (IsPhysicalSection(Sec)) {
776 Sec->Header.PointerToRawData = offset;
778 offset += Sec->Header.SizeOfRawData;
781 if (Sec->Relocations.size() > 0) {
782 bool RelocationsOverflow = Sec->Relocations.size() >= 0xffff;
784 if (RelocationsOverflow) {
785 // Signal overflow by setting NumberOfSections to max value. Actual
786 // size is found in reloc #0. Microsoft tools understand this.
787 Sec->Header.NumberOfRelocations = 0xffff;
789 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
791 Sec->Header.PointerToRelocations = offset;
793 if (RelocationsOverflow) {
794 // Reloc #0 will contain actual count, so make room for it.
795 offset += COFF::RelocationSize;
798 offset += COFF::RelocationSize * Sec->Relocations.size();
800 for (relocations::iterator cr = Sec->Relocations.begin(),
801 er = Sec->Relocations.end();
803 assert((*cr).Symb->Index != -1);
804 (*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
808 assert(Sec->Symbol->Aux.size() == 1
809 && "Section's symbol must have one aux!");
810 AuxSymbol &Aux = Sec->Symbol->Aux[0];
811 assert(Aux.AuxType == ATSectionDefinition &&
812 "Section's symbol's aux symbol must be a Section Definition!");
813 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
814 Aux.Aux.SectionDefinition.NumberOfRelocations =
815 Sec->Header.NumberOfRelocations;
816 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
817 Sec->Header.NumberOfLineNumbers;
820 Header.PointerToSymbolTable = offset;
822 Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
824 // Write it all to disk...
825 WriteFileHeader(Header);
828 sections::iterator i, ie;
829 MCAssembler::const_iterator j, je;
831 for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
832 if ((*i)->Number != -1) {
833 if ((*i)->Relocations.size() >= 0xffff) {
834 (*i)->Header.Characteristics |= COFF::IMAGE_SCN_LNK_NRELOC_OVFL;
836 WriteSectionHeader((*i)->Header);
839 for (i = Sections.begin(), ie = Sections.end(),
840 j = Asm.begin(), je = Asm.end();
841 (i != ie) && (j != je); ++i, ++j) {
843 if ((*i)->Number == -1)
846 if ((*i)->Header.PointerToRawData != 0) {
847 assert(OS.tell() == (*i)->Header.PointerToRawData &&
848 "Section::PointerToRawData is insane!");
850 Asm.writeSectionData(j, Layout);
853 if ((*i)->Relocations.size() > 0) {
854 assert(OS.tell() == (*i)->Header.PointerToRelocations &&
855 "Section::PointerToRelocations is insane!");
857 if ((*i)->Relocations.size() >= 0xffff) {
858 // In case of overflow, write actual relocation count as first
859 // relocation. Including the synthetic reloc itself (+ 1).
861 r.VirtualAddress = (*i)->Relocations.size() + 1;
862 r.SymbolTableIndex = 0;
867 for (relocations::const_iterator k = (*i)->Relocations.begin(),
868 ke = (*i)->Relocations.end();
870 WriteRelocation(k->Data);
873 assert((*i)->Header.PointerToRelocations == 0 &&
874 "Section::PointerToRelocations is insane!");
878 assert(OS.tell() == Header.PointerToSymbolTable &&
879 "Header::PointerToSymbolTable is insane!");
881 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
882 if ((*i)->Index != -1)
885 OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
888 MCWinCOFFObjectTargetWriter::MCWinCOFFObjectTargetWriter(unsigned Machine_) :
892 //------------------------------------------------------------------------------
893 // WinCOFFObjectWriter factory function
896 MCObjectWriter *createWinCOFFObjectWriter(MCWinCOFFObjectTargetWriter *MOTW,
898 return new WinCOFFObjectWriter(MOTW, OS);