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/MCObjectWriter.h"
17 #include "llvm/MC/MCSection.h"
18 #include "llvm/MC/MCContext.h"
19 #include "llvm/MC/MCSymbol.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCValue.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCAsmLayout.h"
24 #include "llvm/MC/MCSectionCOFF.h"
26 #include "llvm/ADT/DenseMap.h"
27 #include "llvm/ADT/StringMap.h"
28 #include "llvm/ADT/StringRef.h"
30 #include "llvm/Support/COFF.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/TimeValue.h"
36 #include "../Target/X86/X86FixupKinds.h"
43 typedef llvm::SmallString<COFF::NameSize> name;
54 AuxiliaryType AuxType;
65 typedef llvm::SmallVector<AuxSymbol, 1> AuxiliarySymbols;
74 MCSymbolData const *MCData;
76 COFFSymbol(llvm::StringRef name);
78 void set_name_offset(uint32_t Offset);
80 bool should_keep() const;
83 // This class contains staging data for a COFF relocation entry.
84 struct COFFRelocation {
85 COFF::relocation Data;
88 COFFRelocation() : Symb(NULL) {}
89 static size_t size() { return COFF::RelocationSize; }
92 typedef std::vector<COFFRelocation> relocations;
100 MCSectionData const *MCData;
102 relocations Relocations;
104 COFFSection(llvm::StringRef name);
105 static size_t size();
108 // This class holds the COFF string table.
110 typedef llvm::StringMap<size_t> map;
113 void update_length();
115 std::vector<char> Data;
119 size_t insert(llvm::StringRef String);
122 class WinCOFFObjectWriter : public MCObjectWriter {
125 typedef std::vector<COFFSymbol*> symbols;
126 typedef std::vector<COFFSection*> sections;
128 typedef DenseMap<MCSymbol const *, COFFSymbol *> symbol_map;
129 typedef DenseMap<MCSection const *, COFFSection *> section_map;
131 // Root level file contents.
138 // Maps used during object file creation.
139 section_map SectionMap;
140 symbol_map SymbolMap;
142 WinCOFFObjectWriter(raw_ostream &OS, bool is64Bit);
143 ~WinCOFFObjectWriter();
145 COFFSymbol *createSymbol(StringRef Name);
146 COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol * Symbol);
147 COFFSection *createSection(StringRef Name);
149 template <typename object_t, typename list_t>
150 object_t *createCOFFEntity(llvm::StringRef Name, list_t &List);
152 void DefineSection(MCSectionData const &SectionData);
153 void DefineSymbol(MCSymbolData const &SymbolData, MCAssembler &Assembler);
155 void MakeSymbolReal(COFFSymbol &S, size_t Index);
156 void MakeSectionReal(COFFSection &S, size_t Number);
158 bool ExportSection(COFFSection const *S);
159 bool ExportSymbol(MCSymbolData const &SymbolData, MCAssembler &Asm);
161 bool IsPhysicalSection(COFFSection *S);
163 // Entity writing methods.
165 void WriteFileHeader(const COFF::header &Header);
166 void WriteSymbol(const COFFSymbol *S);
167 void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
168 void WriteSectionHeader(const COFF::section &S);
169 void WriteRelocation(const COFF::relocation &R);
171 // MCObjectWriter interface implementation.
173 void ExecutePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout);
175 void RecordRelocation(const MCAssembler &Asm,
176 const MCAsmLayout &Layout,
177 const MCFragment *Fragment,
178 const MCFixup &Fixup,
180 uint64_t &FixedValue);
183 IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
184 const MCSymbolData &DataA,
185 const MCFragment &FB,
189 void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
193 static inline void write_uint32_le(void *Data, uint32_t const &Value) {
194 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
195 Ptr[0] = (Value & 0x000000FF) >> 0;
196 Ptr[1] = (Value & 0x0000FF00) >> 8;
197 Ptr[2] = (Value & 0x00FF0000) >> 16;
198 Ptr[3] = (Value & 0xFF000000) >> 24;
201 static inline void write_uint16_le(void *Data, uint16_t const &Value) {
202 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
203 Ptr[0] = (Value & 0x00FF) >> 0;
204 Ptr[1] = (Value & 0xFF00) >> 8;
207 static inline void write_uint8_le(void *Data, uint8_t const &Value) {
208 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
209 Ptr[0] = (Value & 0xFF) >> 0;
212 //------------------------------------------------------------------------------
213 // Symbol class implementation
215 COFFSymbol::COFFSymbol(llvm::StringRef name)
216 : Name(name.begin(), name.end())
221 memset(&Data, 0, sizeof(Data));
224 size_t COFFSymbol::size() const {
225 return COFF::SymbolSize + (Data.NumberOfAuxSymbols * COFF::SymbolSize);
228 // In the case that the name does not fit within 8 bytes, the offset
229 // into the string table is stored in the last 4 bytes instead, leaving
230 // the first 4 bytes as 0.
231 void COFFSymbol::set_name_offset(uint32_t Offset) {
232 write_uint32_le(Data.Name + 0, 0);
233 write_uint32_le(Data.Name + 4, Offset);
236 /// logic to decide if the symbol should be reported in the symbol table
237 bool COFFSymbol::should_keep() const {
238 // no section means its external, keep it
242 // if it has relocations pointing at it, keep it
243 if (Relocations > 0) {
244 assert(Section->Number != -1 && "Sections with relocations must be real!");
248 // if the section its in is being droped, drop it
249 if (Section->Number == -1)
252 // if it is the section symbol, keep it
253 if (Section->Symbol == this)
256 // if its temporary, drop it
257 if (MCData && MCData->getSymbol().isTemporary())
260 // otherwise, keep it
264 //------------------------------------------------------------------------------
265 // Section class implementation
267 COFFSection::COFFSection(llvm::StringRef name)
271 memset(&Header, 0, sizeof(Header));
274 size_t COFFSection::size() {
275 return COFF::SectionSize;
278 //------------------------------------------------------------------------------
279 // StringTable class implementation
281 /// Write the length of the string table into Data.
282 /// The length of the string table includes uint32 length header.
283 void StringTable::update_length() {
284 write_uint32_le(&Data.front(), Data.size());
287 StringTable::StringTable() {
288 // The string table data begins with the length of the entire string table
289 // including the length header. Allocate space for this header.
293 size_t StringTable::size() const {
297 /// Add String to the table iff it is not already there.
298 /// @returns the index into the string table where the string is now located.
299 size_t StringTable::insert(llvm::StringRef String) {
300 map::iterator i = Map.find(String);
305 size_t Offset = Data.size();
307 // Insert string data into string table.
308 Data.insert(Data.end(), String.begin(), String.end());
309 Data.push_back('\0');
311 // Put a reference to it in the map.
312 Map[String] = Offset;
314 // Update the internal length field.
320 //------------------------------------------------------------------------------
321 // WinCOFFObjectWriter class implementation
323 WinCOFFObjectWriter::WinCOFFObjectWriter(raw_ostream &OS, bool is64Bit)
324 : MCObjectWriter(OS, true)
326 memset(&Header, 0, sizeof(Header));
328 Is64Bit ? Header.Machine = COFF::IMAGE_FILE_MACHINE_AMD64
329 : Header.Machine = COFF::IMAGE_FILE_MACHINE_I386;
332 WinCOFFObjectWriter::~WinCOFFObjectWriter() {
333 for (symbols::iterator I = Symbols.begin(), E = Symbols.end(); I != E; ++I)
335 for (sections::iterator I = Sections.begin(), E = Sections.end(); I != E; ++I)
339 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
340 return createCOFFEntity<COFFSymbol>(Name, Symbols);
343 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol * Symbol){
344 symbol_map::iterator i = SymbolMap.find(Symbol);
345 if (i != SymbolMap.end())
347 COFFSymbol *RetSymbol
348 = createCOFFEntity<COFFSymbol>(Symbol->getName(), Symbols);
349 SymbolMap[Symbol] = RetSymbol;
353 COFFSection *WinCOFFObjectWriter::createSection(llvm::StringRef Name) {
354 return createCOFFEntity<COFFSection>(Name, Sections);
357 /// A template used to lookup or create a symbol/section, and initialize it if
359 template <typename object_t, typename list_t>
360 object_t *WinCOFFObjectWriter::createCOFFEntity(llvm::StringRef Name,
362 object_t *Object = new object_t(Name);
364 List.push_back(Object);
369 /// This function takes a section data object from the assembler
370 /// and creates the associated COFF section staging object.
371 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
372 assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
373 && "Got non COFF section in the COFF backend!");
374 // FIXME: Not sure how to verify this (at least in a debug build).
375 MCSectionCOFF const &Sec =
376 static_cast<MCSectionCOFF const &>(SectionData.getSection());
378 COFFSection *coff_section = createSection(Sec.getSectionName());
379 COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
381 coff_section->Symbol = coff_symbol;
382 coff_symbol->Section = coff_section;
383 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
385 // In this case the auxiliary symbol is a Section Definition.
386 coff_symbol->Aux.resize(1);
387 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
388 coff_symbol->Aux[0].AuxType = ATSectionDefinition;
389 coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
391 coff_section->Header.Characteristics = Sec.getCharacteristics();
393 uint32_t &Characteristics = coff_section->Header.Characteristics;
394 switch (SectionData.getAlignment()) {
395 case 1: Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES; break;
396 case 2: Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES; break;
397 case 4: Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES; break;
398 case 8: Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES; break;
399 case 16: Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES; break;
400 case 32: Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES; break;
401 case 64: Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES; break;
402 case 128: Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES; break;
403 case 256: Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES; break;
404 case 512: Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES; break;
405 case 1024: Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES; break;
406 case 2048: Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES; break;
407 case 4096: Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES; break;
408 case 8192: Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES; break;
410 llvm_unreachable("unsupported section alignment");
413 // Bind internal COFF section to MC section.
414 coff_section->MCData = &SectionData;
415 SectionMap[&SectionData.getSection()] = coff_section;
418 /// This function takes a section data object from the assembler
419 /// and creates the associated COFF symbol staging object.
420 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
421 MCAssembler &Assembler) {
422 COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&SymbolData.getSymbol());
424 coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
425 coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
427 if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
428 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
430 if (SymbolData.getSymbol().isVariable()) {
431 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
432 const MCExpr *Value = SymbolData.getSymbol().getVariableValue();
434 // FIXME: This assert message isn't very good.
435 assert(Value->getKind() == MCExpr::SymbolRef &&
436 "Value must be a SymbolRef!");
438 const MCSymbolRefExpr *SymbolRef =
439 static_cast<const MCSymbolRefExpr *>(Value);
440 coff_symbol->Other = GetOrCreateCOFFSymbol(&SymbolRef->getSymbol());
442 std::string WeakName = std::string(".weak.")
443 + SymbolData.getSymbol().getName().str()
445 COFFSymbol *WeakDefault = createSymbol(WeakName);
446 WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
447 WeakDefault->Data.StorageClass = COFF::IMAGE_SYM_CLASS_EXTERNAL;
448 WeakDefault->Data.Type = 0;
449 WeakDefault->Data.Value = 0;
450 coff_symbol->Other = WeakDefault;
453 // Setup the Weak External auxiliary symbol.
454 coff_symbol->Aux.resize(1);
455 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
456 coff_symbol->Aux[0].AuxType = ATWeakExternal;
457 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
458 coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
459 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
462 // If no storage class was specified in the streamer, define it here.
463 if (coff_symbol->Data.StorageClass == 0) {
464 bool external = SymbolData.isExternal() || (SymbolData.Fragment == NULL);
466 coff_symbol->Data.StorageClass =
467 external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
470 if (SymbolData.Fragment != NULL)
471 coff_symbol->Section =
472 SectionMap[&SymbolData.Fragment->getParent()->getSection()];
474 // Bind internal COFF symbol to MC symbol.
475 coff_symbol->MCData = &SymbolData;
476 SymbolMap[&SymbolData.getSymbol()] = coff_symbol;
479 /// making a section real involves assigned it a number and putting
480 /// name into the string table if needed
481 void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
482 if (S.Name.size() > COFF::NameSize) {
483 size_t StringTableEntry = Strings.insert(S.Name.c_str());
485 // FIXME: Why is this number 999999? This number is never mentioned in the
486 // spec. I'm assuming this is due to the printed value needing to fit into
487 // the S.Header.Name field. In which case why not 9999999 (7 9's instead of
488 // 6)? The spec does not state if this entry should be null terminated in
489 // this case, and thus this seems to be the best way to do it. I think I
490 // just solved my own FIXME...
491 if (StringTableEntry > 999999)
492 report_fatal_error("COFF string table is greater than 999999 bytes.");
494 std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
496 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
499 S.Symbol->Data.SectionNumber = S.Number;
500 S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
503 void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
504 if (S.Name.size() > COFF::NameSize) {
505 size_t StringTableEntry = Strings.insert(S.Name.c_str());
507 S.set_name_offset(StringTableEntry);
509 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
513 bool WinCOFFObjectWriter::ExportSection(COFFSection const *S) {
514 return !S->MCData->getFragmentList().empty();
517 bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
519 // This doesn't seem to be right. Strings referred to from the .data section
520 // need symbols so they can be linked to code in the .text section right?
522 // return Asm.isSymbolLinkerVisible (&SymbolData);
524 // For now, all non-variable symbols are exported,
525 // the linker will sort the rest out for us.
526 return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
529 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
530 return (S->Header.Characteristics
531 & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
534 //------------------------------------------------------------------------------
535 // entity writing methods
537 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
538 WriteLE16(Header.Machine);
539 WriteLE16(Header.NumberOfSections);
540 WriteLE32(Header.TimeDateStamp);
541 WriteLE32(Header.PointerToSymbolTable);
542 WriteLE32(Header.NumberOfSymbols);
543 WriteLE16(Header.SizeOfOptionalHeader);
544 WriteLE16(Header.Characteristics);
547 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
548 WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
549 WriteLE32(S->Data.Value);
550 WriteLE16(S->Data.SectionNumber);
551 WriteLE16(S->Data.Type);
552 Write8(S->Data.StorageClass);
553 Write8(S->Data.NumberOfAuxSymbols);
554 WriteAuxiliarySymbols(S->Aux);
557 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
558 const COFFSymbol::AuxiliarySymbols &S) {
559 for(COFFSymbol::AuxiliarySymbols::const_iterator i = S.begin(), e = S.end();
562 case ATFunctionDefinition:
563 WriteLE32(i->Aux.FunctionDefinition.TagIndex);
564 WriteLE32(i->Aux.FunctionDefinition.TotalSize);
565 WriteLE32(i->Aux.FunctionDefinition.PointerToLinenumber);
566 WriteLE32(i->Aux.FunctionDefinition.PointerToNextFunction);
567 WriteZeros(sizeof(i->Aux.FunctionDefinition.unused));
569 case ATbfAndefSymbol:
570 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused1));
571 WriteLE16(i->Aux.bfAndefSymbol.Linenumber);
572 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused2));
573 WriteLE32(i->Aux.bfAndefSymbol.PointerToNextFunction);
574 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused3));
577 WriteLE32(i->Aux.WeakExternal.TagIndex);
578 WriteLE32(i->Aux.WeakExternal.Characteristics);
579 WriteZeros(sizeof(i->Aux.WeakExternal.unused));
582 WriteBytes(StringRef(reinterpret_cast<const char *>(i->Aux.File.FileName),
583 sizeof(i->Aux.File.FileName)));
585 case ATSectionDefinition:
586 WriteLE32(i->Aux.SectionDefinition.Length);
587 WriteLE16(i->Aux.SectionDefinition.NumberOfRelocations);
588 WriteLE16(i->Aux.SectionDefinition.NumberOfLinenumbers);
589 WriteLE32(i->Aux.SectionDefinition.CheckSum);
590 WriteLE16(i->Aux.SectionDefinition.Number);
591 Write8(i->Aux.SectionDefinition.Selection);
592 WriteZeros(sizeof(i->Aux.SectionDefinition.unused));
598 void WinCOFFObjectWriter::WriteSectionHeader(const COFF::section &S) {
599 WriteBytes(StringRef(S.Name, COFF::NameSize));
601 WriteLE32(S.VirtualSize);
602 WriteLE32(S.VirtualAddress);
603 WriteLE32(S.SizeOfRawData);
604 WriteLE32(S.PointerToRawData);
605 WriteLE32(S.PointerToRelocations);
606 WriteLE32(S.PointerToLineNumbers);
607 WriteLE16(S.NumberOfRelocations);
608 WriteLE16(S.NumberOfLineNumbers);
609 WriteLE32(S.Characteristics);
612 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
613 WriteLE32(R.VirtualAddress);
614 WriteLE32(R.SymbolTableIndex);
618 ////////////////////////////////////////////////////////////////////////////////
619 // MCObjectWriter interface implementations
621 void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
622 const MCAsmLayout &Layout) {
623 // "Define" each section & symbol. This creates section & symbol
624 // entries in the staging area.
626 for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
629 for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
630 e = Asm.symbol_end(); i != e; i++) {
631 if (ExportSymbol(*i, Asm))
632 DefineSymbol(*i, Asm);
636 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
637 const MCAsmLayout &Layout,
638 const MCFragment *Fragment,
639 const MCFixup &Fixup,
641 uint64_t &FixedValue) {
642 assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
644 const MCSymbol *A = &Target.getSymA()->getSymbol();
645 MCSymbolData &A_SD = Asm.getSymbolData(*A);
647 MCSectionData const *SectionData = Fragment->getParent();
649 // Mark this symbol as requiring an entry in the symbol table.
650 assert(SectionMap.find(&SectionData->getSection()) != SectionMap.end() &&
651 "Section must already have been defined in ExecutePostLayoutBinding!");
652 assert(SymbolMap.find(&A_SD.getSymbol()) != SymbolMap.end() &&
653 "Symbol must already have been defined in ExecutePostLayoutBinding!");
655 COFFSection *coff_section = SectionMap[&SectionData->getSection()];
656 COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
658 if (Target.getSymB()) {
659 if (&Target.getSymA()->getSymbol().getSection()
660 != &Target.getSymB()->getSymbol().getSection()) {
661 llvm_unreachable("Symbol relative relocations are only allowed between "
662 "symbols in the same section");
664 const MCSymbol *B = &Target.getSymB()->getSymbol();
665 MCSymbolData &B_SD = Asm.getSymbolData(*B);
667 FixedValue = Layout.getSymbolOffset(&A_SD) - Layout.getSymbolOffset(&B_SD);
669 // In the case where we have SymbA and SymB, we just need to store the delta
670 // between the two symbols. Update FixedValue to account for the delta, and
671 // skip recording the relocation.
674 FixedValue = Target.getConstant();
677 COFFRelocation Reloc;
679 Reloc.Data.SymbolTableIndex = 0;
680 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
682 // Turn relocations for temporary symbols into section relocations.
683 if (coff_symbol->MCData->getSymbol().isTemporary()) {
684 Reloc.Symb = coff_symbol->Section->Symbol;
685 FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
686 + coff_symbol->MCData->getOffset();
688 Reloc.Symb = coff_symbol;
690 ++Reloc.Symb->Relocations;
692 Reloc.Data.VirtualAddress += Fixup.getOffset();
694 switch ((unsigned)Fixup.getKind()) {
696 case X86::reloc_riprel_4byte:
697 case X86::reloc_riprel_4byte_movq_load:
698 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_REL32
699 : COFF::IMAGE_REL_I386_REL32;
700 // FIXME: Can anyone explain what this does other than adjust for the size
705 case X86::reloc_signed_4byte:
706 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_ADDR32
707 : COFF::IMAGE_REL_I386_DIR32;
711 Reloc.Data.Type = COFF::IMAGE_REL_AMD64_ADDR64;
713 llvm_unreachable("unsupported relocation type");
716 llvm_unreachable("unsupported relocation type");
719 coff_section->Relocations.push_back(Reloc);
723 WinCOFFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
724 const MCAssembler &Asm,
725 const MCSymbolData &DataA,
726 const MCFragment &FB,
728 bool IsPCRel) const {
729 const MCSection &SecA = DataA.getSymbol().AliasedSymbol().getSection();
730 const MCSection &SecB = FB.getParent()->getSection();
731 // On COFF A - B is absolute if A and B are in the same section.
732 return &SecA == &SecB;
735 void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
736 const MCAsmLayout &Layout) {
737 // Assign symbol and section indexes and offsets.
738 Header.NumberOfSections = 0;
740 for (sections::iterator i = Sections.begin(),
741 e = Sections.end(); i != e; i++) {
742 if (Layout.getSectionAddressSize((*i)->MCData) > 0) {
743 MakeSectionReal(**i, ++Header.NumberOfSections);
749 Header.NumberOfSymbols = 0;
751 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
752 COFFSymbol *coff_symbol = *i;
753 MCSymbolData const *SymbolData = coff_symbol->MCData;
755 // Update section number & offset for symbols that have them.
756 if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
757 assert(coff_symbol->Section != NULL);
759 coff_symbol->Data.SectionNumber = coff_symbol->Section->Number;
760 coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
761 + SymbolData->Offset;
764 if (coff_symbol->should_keep()) {
765 MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++);
767 // Update auxiliary symbol info.
768 coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
769 Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
771 coff_symbol->Index = -1;
774 // Fixup weak external references.
775 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
776 COFFSymbol *coff_symbol = *i;
777 if (coff_symbol->Other != NULL) {
778 assert(coff_symbol->Index != -1);
779 assert(coff_symbol->Aux.size() == 1 &&
780 "Symbol must contain one aux symbol!");
781 assert(coff_symbol->Aux[0].AuxType == ATWeakExternal &&
782 "Symbol's aux symbol must be a Weak External!");
783 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index;
787 // Assign file offsets to COFF object file structures.
791 offset += COFF::HeaderSize;
792 offset += COFF::SectionSize * Header.NumberOfSections;
794 for (MCAssembler::const_iterator i = Asm.begin(),
797 COFFSection *Sec = SectionMap[&i->getSection()];
799 if (Sec->Number == -1)
802 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
804 if (IsPhysicalSection(Sec)) {
805 Sec->Header.PointerToRawData = offset;
807 offset += Sec->Header.SizeOfRawData;
810 if (Sec->Relocations.size() > 0) {
811 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
812 Sec->Header.PointerToRelocations = offset;
814 offset += COFF::RelocationSize * Sec->Relocations.size();
816 for (relocations::iterator cr = Sec->Relocations.begin(),
817 er = Sec->Relocations.end();
819 assert((*cr).Symb->Index != -1);
820 (*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
824 assert(Sec->Symbol->Aux.size() == 1
825 && "Section's symbol must have one aux!");
826 AuxSymbol &Aux = Sec->Symbol->Aux[0];
827 assert(Aux.AuxType == ATSectionDefinition &&
828 "Section's symbol's aux symbol must be a Section Definition!");
829 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
830 Aux.Aux.SectionDefinition.NumberOfRelocations =
831 Sec->Header.NumberOfRelocations;
832 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
833 Sec->Header.NumberOfLineNumbers;
836 Header.PointerToSymbolTable = offset;
838 Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
840 // Write it all to disk...
841 WriteFileHeader(Header);
844 sections::iterator i, ie;
845 MCAssembler::const_iterator j, je;
847 for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
848 if ((*i)->Number != -1)
849 WriteSectionHeader((*i)->Header);
851 for (i = Sections.begin(), ie = Sections.end(),
852 j = Asm.begin(), je = Asm.end();
853 (i != ie) && (j != je); ++i, ++j) {
855 if ((*i)->Number == -1)
858 if ((*i)->Header.PointerToRawData != 0) {
859 assert(OS.tell() == (*i)->Header.PointerToRawData &&
860 "Section::PointerToRawData is insane!");
862 Asm.WriteSectionData(j, Layout);
865 if ((*i)->Relocations.size() > 0) {
866 assert(OS.tell() == (*i)->Header.PointerToRelocations &&
867 "Section::PointerToRelocations is insane!");
869 for (relocations::const_iterator k = (*i)->Relocations.begin(),
870 ke = (*i)->Relocations.end();
872 WriteRelocation(k->Data);
875 assert((*i)->Header.PointerToRelocations == 0 &&
876 "Section::PointerToRelocations is insane!");
880 assert(OS.tell() == Header.PointerToSymbolTable &&
881 "Header::PointerToSymbolTable is insane!");
883 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
884 if ((*i)->Index != -1)
887 OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
890 //------------------------------------------------------------------------------
891 // WinCOFFObjectWriter factory function
894 MCObjectWriter *createWinCOFFObjectWriter(raw_ostream &OS, bool is64Bit) {
895 return new WinCOFFObjectWriter(OS, is64Bit);