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);
182 virtual bool IsFixupFullyResolved(const MCAssembler &Asm,
183 const MCValue Target,
185 const MCFragment *DF) const;
187 void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
191 static inline void write_uint32_le(void *Data, uint32_t const &Value) {
192 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
193 Ptr[0] = (Value & 0x000000FF) >> 0;
194 Ptr[1] = (Value & 0x0000FF00) >> 8;
195 Ptr[2] = (Value & 0x00FF0000) >> 16;
196 Ptr[3] = (Value & 0xFF000000) >> 24;
199 static inline void write_uint16_le(void *Data, uint16_t const &Value) {
200 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
201 Ptr[0] = (Value & 0x00FF) >> 0;
202 Ptr[1] = (Value & 0xFF00) >> 8;
205 static inline void write_uint8_le(void *Data, uint8_t const &Value) {
206 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
207 Ptr[0] = (Value & 0xFF) >> 0;
210 //------------------------------------------------------------------------------
211 // Symbol class implementation
213 COFFSymbol::COFFSymbol(llvm::StringRef name)
214 : Name(name.begin(), name.end())
219 memset(&Data, 0, sizeof(Data));
222 size_t COFFSymbol::size() const {
223 return COFF::SymbolSize + (Data.NumberOfAuxSymbols * COFF::SymbolSize);
226 // In the case that the name does not fit within 8 bytes, the offset
227 // into the string table is stored in the last 4 bytes instead, leaving
228 // the first 4 bytes as 0.
229 void COFFSymbol::set_name_offset(uint32_t Offset) {
230 write_uint32_le(Data.Name + 0, 0);
231 write_uint32_le(Data.Name + 4, Offset);
234 /// logic to decide if the symbol should be reported in the symbol table
235 bool COFFSymbol::should_keep() const {
236 // no section means its external, keep it
240 // if it has relocations pointing at it, keep it
241 if (Relocations > 0) {
242 assert(Section->Number != -1 && "Sections with relocations must be real!");
246 // if the section its in is being droped, drop it
247 if (Section->Number == -1)
250 // if it is the section symbol, keep it
251 if (Section->Symbol == this)
254 // if its temporary, drop it
255 if (MCData && MCData->getSymbol().isTemporary())
258 // otherwise, keep it
262 //------------------------------------------------------------------------------
263 // Section class implementation
265 COFFSection::COFFSection(llvm::StringRef name)
269 memset(&Header, 0, sizeof(Header));
272 size_t COFFSection::size() {
273 return COFF::SectionSize;
276 //------------------------------------------------------------------------------
277 // StringTable class implementation
279 /// Write the length of the string table into Data.
280 /// The length of the string table includes uint32 length header.
281 void StringTable::update_length() {
282 write_uint32_le(&Data.front(), Data.size());
285 StringTable::StringTable() {
286 // The string table data begins with the length of the entire string table
287 // including the length header. Allocate space for this header.
291 size_t StringTable::size() const {
295 /// Add String to the table iff it is not already there.
296 /// @returns the index into the string table where the string is now located.
297 size_t StringTable::insert(llvm::StringRef String) {
298 map::iterator i = Map.find(String);
303 size_t Offset = Data.size();
305 // Insert string data into string table.
306 Data.insert(Data.end(), String.begin(), String.end());
307 Data.push_back('\0');
309 // Put a reference to it in the map.
310 Map[String] = Offset;
312 // Update the internal length field.
318 //------------------------------------------------------------------------------
319 // WinCOFFObjectWriter class implementation
321 WinCOFFObjectWriter::WinCOFFObjectWriter(raw_ostream &OS, bool is64Bit)
322 : MCObjectWriter(OS, true)
324 memset(&Header, 0, sizeof(Header));
326 Is64Bit ? Header.Machine = COFF::IMAGE_FILE_MACHINE_AMD64
327 : Header.Machine = COFF::IMAGE_FILE_MACHINE_I386;
330 WinCOFFObjectWriter::~WinCOFFObjectWriter() {
331 for (symbols::iterator I = Symbols.begin(), E = Symbols.end(); I != E; ++I)
333 for (sections::iterator I = Sections.begin(), E = Sections.end(); I != E; ++I)
337 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
338 return createCOFFEntity<COFFSymbol>(Name, Symbols);
341 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol * Symbol){
342 symbol_map::iterator i = SymbolMap.find(Symbol);
343 if (i != SymbolMap.end())
345 COFFSymbol *RetSymbol
346 = createCOFFEntity<COFFSymbol>(Symbol->getName(), Symbols);
347 SymbolMap[Symbol] = RetSymbol;
351 COFFSection *WinCOFFObjectWriter::createSection(llvm::StringRef Name) {
352 return createCOFFEntity<COFFSection>(Name, Sections);
355 /// A template used to lookup or create a symbol/section, and initialize it if
357 template <typename object_t, typename list_t>
358 object_t *WinCOFFObjectWriter::createCOFFEntity(llvm::StringRef Name,
360 object_t *Object = new object_t(Name);
362 List.push_back(Object);
367 /// This function takes a section data object from the assembler
368 /// and creates the associated COFF section staging object.
369 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
370 assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
371 && "Got non COFF section in the COFF backend!");
372 // FIXME: Not sure how to verify this (at least in a debug build).
373 MCSectionCOFF const &Sec =
374 static_cast<MCSectionCOFF const &>(SectionData.getSection());
376 COFFSection *coff_section = createSection(Sec.getSectionName());
377 COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
379 coff_section->Symbol = coff_symbol;
380 coff_symbol->Section = coff_section;
381 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
383 // In this case the auxiliary symbol is a Section Definition.
384 coff_symbol->Aux.resize(1);
385 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
386 coff_symbol->Aux[0].AuxType = ATSectionDefinition;
387 coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
389 coff_section->Header.Characteristics = Sec.getCharacteristics();
391 uint32_t &Characteristics = coff_section->Header.Characteristics;
392 switch (SectionData.getAlignment()) {
393 case 1: Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES; break;
394 case 2: Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES; break;
395 case 4: Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES; break;
396 case 8: Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES; break;
397 case 16: Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES; break;
398 case 32: Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES; break;
399 case 64: Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES; break;
400 case 128: Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES; break;
401 case 256: Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES; break;
402 case 512: Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES; break;
403 case 1024: Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES; break;
404 case 2048: Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES; break;
405 case 4096: Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES; break;
406 case 8192: Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES; break;
408 llvm_unreachable("unsupported section alignment");
411 // Bind internal COFF section to MC section.
412 coff_section->MCData = &SectionData;
413 SectionMap[&SectionData.getSection()] = coff_section;
416 /// This function takes a section data object from the assembler
417 /// and creates the associated COFF symbol staging object.
418 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
419 MCAssembler &Assembler) {
420 COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&SymbolData.getSymbol());
422 coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
423 coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
425 if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
426 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
428 if (SymbolData.getSymbol().isVariable()) {
429 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
430 const MCExpr *Value = SymbolData.getSymbol().getVariableValue();
432 // FIXME: This assert message isn't very good.
433 assert(Value->getKind() == MCExpr::SymbolRef &&
434 "Value must be a SymbolRef!");
436 const MCSymbolRefExpr *SymbolRef =
437 static_cast<const MCSymbolRefExpr *>(Value);
438 coff_symbol->Other = GetOrCreateCOFFSymbol(&SymbolRef->getSymbol());
440 std::string WeakName = std::string(".weak.")
441 + SymbolData.getSymbol().getName().str()
443 COFFSymbol *WeakDefault = createSymbol(WeakName);
444 WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
445 WeakDefault->Data.StorageClass = COFF::IMAGE_SYM_CLASS_EXTERNAL;
446 WeakDefault->Data.Type = 0;
447 WeakDefault->Data.Value = 0;
448 coff_symbol->Other = WeakDefault;
451 // Setup the Weak External auxiliary symbol.
452 coff_symbol->Aux.resize(1);
453 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
454 coff_symbol->Aux[0].AuxType = ATWeakExternal;
455 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
456 coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
457 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
460 // If no storage class was specified in the streamer, define it here.
461 if (coff_symbol->Data.StorageClass == 0) {
462 bool external = SymbolData.isExternal() || (SymbolData.Fragment == NULL);
464 coff_symbol->Data.StorageClass =
465 external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
468 if (SymbolData.Fragment != NULL)
469 coff_symbol->Section =
470 SectionMap[&SymbolData.Fragment->getParent()->getSection()];
472 // Bind internal COFF symbol to MC symbol.
473 coff_symbol->MCData = &SymbolData;
474 SymbolMap[&SymbolData.getSymbol()] = coff_symbol;
477 /// making a section real involves assigned it a number and putting
478 /// name into the string table if needed
479 void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
480 if (S.Name.size() > COFF::NameSize) {
481 size_t StringTableEntry = Strings.insert(S.Name.c_str());
483 // FIXME: Why is this number 999999? This number is never mentioned in the
484 // spec. I'm assuming this is due to the printed value needing to fit into
485 // the S.Header.Name field. In which case why not 9999999 (7 9's instead of
486 // 6)? The spec does not state if this entry should be null terminated in
487 // this case, and thus this seems to be the best way to do it. I think I
488 // just solved my own FIXME...
489 if (StringTableEntry > 999999)
490 report_fatal_error("COFF string table is greater than 999999 bytes.");
492 std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
494 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
497 S.Symbol->Data.SectionNumber = S.Number;
498 S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
501 void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
502 if (S.Name.size() > COFF::NameSize) {
503 size_t StringTableEntry = Strings.insert(S.Name.c_str());
505 S.set_name_offset(StringTableEntry);
507 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
511 bool WinCOFFObjectWriter::ExportSection(COFFSection const *S) {
512 return !S->MCData->getFragmentList().empty();
515 bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
517 // This doesn't seem to be right. Strings referred to from the .data section
518 // need symbols so they can be linked to code in the .text section right?
520 // return Asm.isSymbolLinkerVisible (&SymbolData);
522 // For now, all non-variable symbols are exported,
523 // the linker will sort the rest out for us.
524 return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
527 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
528 return (S->Header.Characteristics
529 & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
532 //------------------------------------------------------------------------------
533 // entity writing methods
535 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
536 WriteLE16(Header.Machine);
537 WriteLE16(Header.NumberOfSections);
538 WriteLE32(Header.TimeDateStamp);
539 WriteLE32(Header.PointerToSymbolTable);
540 WriteLE32(Header.NumberOfSymbols);
541 WriteLE16(Header.SizeOfOptionalHeader);
542 WriteLE16(Header.Characteristics);
545 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
546 WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
547 WriteLE32(S->Data.Value);
548 WriteLE16(S->Data.SectionNumber);
549 WriteLE16(S->Data.Type);
550 Write8(S->Data.StorageClass);
551 Write8(S->Data.NumberOfAuxSymbols);
552 WriteAuxiliarySymbols(S->Aux);
555 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
556 const COFFSymbol::AuxiliarySymbols &S) {
557 for(COFFSymbol::AuxiliarySymbols::const_iterator i = S.begin(), e = S.end();
560 case ATFunctionDefinition:
561 WriteLE32(i->Aux.FunctionDefinition.TagIndex);
562 WriteLE32(i->Aux.FunctionDefinition.TotalSize);
563 WriteLE32(i->Aux.FunctionDefinition.PointerToLinenumber);
564 WriteLE32(i->Aux.FunctionDefinition.PointerToNextFunction);
565 WriteZeros(sizeof(i->Aux.FunctionDefinition.unused));
567 case ATbfAndefSymbol:
568 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused1));
569 WriteLE16(i->Aux.bfAndefSymbol.Linenumber);
570 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused2));
571 WriteLE32(i->Aux.bfAndefSymbol.PointerToNextFunction);
572 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused3));
575 WriteLE32(i->Aux.WeakExternal.TagIndex);
576 WriteLE32(i->Aux.WeakExternal.Characteristics);
577 WriteZeros(sizeof(i->Aux.WeakExternal.unused));
580 WriteBytes(StringRef(reinterpret_cast<const char *>(i->Aux.File.FileName),
581 sizeof(i->Aux.File.FileName)));
583 case ATSectionDefinition:
584 WriteLE32(i->Aux.SectionDefinition.Length);
585 WriteLE16(i->Aux.SectionDefinition.NumberOfRelocations);
586 WriteLE16(i->Aux.SectionDefinition.NumberOfLinenumbers);
587 WriteLE32(i->Aux.SectionDefinition.CheckSum);
588 WriteLE16(i->Aux.SectionDefinition.Number);
589 Write8(i->Aux.SectionDefinition.Selection);
590 WriteZeros(sizeof(i->Aux.SectionDefinition.unused));
596 void WinCOFFObjectWriter::WriteSectionHeader(const COFF::section &S) {
597 WriteBytes(StringRef(S.Name, COFF::NameSize));
599 WriteLE32(S.VirtualSize);
600 WriteLE32(S.VirtualAddress);
601 WriteLE32(S.SizeOfRawData);
602 WriteLE32(S.PointerToRawData);
603 WriteLE32(S.PointerToRelocations);
604 WriteLE32(S.PointerToLineNumbers);
605 WriteLE16(S.NumberOfRelocations);
606 WriteLE16(S.NumberOfLineNumbers);
607 WriteLE32(S.Characteristics);
610 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
611 WriteLE32(R.VirtualAddress);
612 WriteLE32(R.SymbolTableIndex);
616 ////////////////////////////////////////////////////////////////////////////////
617 // MCObjectWriter interface implementations
619 void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
620 const MCAsmLayout &Layout) {
621 // "Define" each section & symbol. This creates section & symbol
622 // entries in the staging area.
624 for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
627 for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
628 e = Asm.symbol_end(); i != e; i++) {
629 if (ExportSymbol(*i, Asm))
630 DefineSymbol(*i, Asm);
634 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
635 const MCAsmLayout &Layout,
636 const MCFragment *Fragment,
637 const MCFixup &Fixup,
639 uint64_t &FixedValue) {
640 assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
642 const MCSymbol *A = &Target.getSymA()->getSymbol();
643 MCSymbolData &A_SD = Asm.getSymbolData(*A);
645 MCSectionData const *SectionData = Fragment->getParent();
647 // Mark this symbol as requiring an entry in the symbol table.
648 assert(SectionMap.find(&SectionData->getSection()) != SectionMap.end() &&
649 "Section must already have been defined in ExecutePostLayoutBinding!");
650 assert(SymbolMap.find(&A_SD.getSymbol()) != SymbolMap.end() &&
651 "Symbol must already have been defined in ExecutePostLayoutBinding!");
653 COFFSection *coff_section = SectionMap[&SectionData->getSection()];
654 COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
656 if (Target.getSymB()) {
657 if (&Target.getSymA()->getSymbol().getSection()
658 != &Target.getSymB()->getSymbol().getSection()) {
659 llvm_unreachable("Symbol relative relocations are only allowed between "
660 "symbols in the same section");
662 const MCSymbol *B = &Target.getSymB()->getSymbol();
663 MCSymbolData &B_SD = Asm.getSymbolData(*B);
665 FixedValue = Layout.getSymbolOffset(&A_SD) - Layout.getSymbolOffset(&B_SD);
667 // In the case where we have SymbA and SymB, we just need to store the delta
668 // between the two symbols. Update FixedValue to account for the delta, and
669 // skip recording the relocation.
672 FixedValue = Target.getConstant();
675 COFFRelocation Reloc;
677 Reloc.Data.SymbolTableIndex = 0;
678 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
680 // Turn relocations for temporary symbols into section relocations.
681 if (coff_symbol->MCData->getSymbol().isTemporary()) {
682 Reloc.Symb = coff_symbol->Section->Symbol;
683 FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
684 + coff_symbol->MCData->getOffset();
686 Reloc.Symb = coff_symbol;
688 ++Reloc.Symb->Relocations;
690 Reloc.Data.VirtualAddress += Fixup.getOffset();
692 switch ((unsigned)Fixup.getKind()) {
694 case X86::reloc_riprel_4byte:
695 case X86::reloc_riprel_4byte_movq_load:
696 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_REL32
697 : COFF::IMAGE_REL_I386_REL32;
698 // FIXME: Can anyone explain what this does other than adjust for the size
703 case X86::reloc_signed_4byte:
704 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_ADDR32
705 : COFF::IMAGE_REL_I386_DIR32;
709 Reloc.Data.Type = COFF::IMAGE_REL_AMD64_ADDR64;
711 llvm_unreachable("unsupported relocation type");
714 llvm_unreachable("unsupported relocation type");
717 coff_section->Relocations.push_back(Reloc);
720 bool WinCOFFObjectWriter::IsFixupFullyResolved(const MCAssembler &Asm,
721 const MCValue Target,
723 const MCFragment *DF) const {
724 // If this is a PCrel relocation, find the section this fixup value is
726 const MCSection *BaseSection = 0;
728 BaseSection = &DF->getParent()->getSection();
732 const MCSection *SectionA = 0;
733 const MCSymbol *SymbolA = 0;
734 if (const MCSymbolRefExpr *A = Target.getSymA()) {
735 SymbolA = &A->getSymbol();
736 SectionA = &SymbolA->getSection();
739 const MCSection *SectionB = 0;
740 if (const MCSymbolRefExpr *B = Target.getSymB()) {
741 SectionB = &B->getSymbol().getSection();
745 return SectionA == SectionB;
747 return !SectionB && BaseSection == SectionA;
750 void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
751 const MCAsmLayout &Layout) {
752 // Assign symbol and section indexes and offsets.
753 Header.NumberOfSections = 0;
755 for (sections::iterator i = Sections.begin(),
756 e = Sections.end(); i != e; i++) {
757 if (Layout.getSectionAddressSize((*i)->MCData) > 0) {
758 MakeSectionReal(**i, ++Header.NumberOfSections);
764 Header.NumberOfSymbols = 0;
766 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
767 COFFSymbol *coff_symbol = *i;
768 MCSymbolData const *SymbolData = coff_symbol->MCData;
770 // Update section number & offset for symbols that have them.
771 if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
772 assert(coff_symbol->Section != NULL);
774 coff_symbol->Data.SectionNumber = coff_symbol->Section->Number;
775 coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
776 + SymbolData->Offset;
779 if (coff_symbol->should_keep()) {
780 MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++);
782 // Update auxiliary symbol info.
783 coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
784 Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
786 coff_symbol->Index = -1;
789 // Fixup weak external references.
790 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
791 COFFSymbol *coff_symbol = *i;
792 if (coff_symbol->Other != NULL) {
793 assert(coff_symbol->Index != -1);
794 assert(coff_symbol->Aux.size() == 1 &&
795 "Symbol must contain one aux symbol!");
796 assert(coff_symbol->Aux[0].AuxType == ATWeakExternal &&
797 "Symbol's aux symbol must be a Weak External!");
798 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index;
802 // Assign file offsets to COFF object file structures.
806 offset += COFF::HeaderSize;
807 offset += COFF::SectionSize * Header.NumberOfSections;
809 for (MCAssembler::const_iterator i = Asm.begin(),
812 COFFSection *Sec = SectionMap[&i->getSection()];
814 if (Sec->Number == -1)
817 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
819 if (IsPhysicalSection(Sec)) {
820 Sec->Header.PointerToRawData = offset;
822 offset += Sec->Header.SizeOfRawData;
825 if (Sec->Relocations.size() > 0) {
826 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
827 Sec->Header.PointerToRelocations = offset;
829 offset += COFF::RelocationSize * Sec->Relocations.size();
831 for (relocations::iterator cr = Sec->Relocations.begin(),
832 er = Sec->Relocations.end();
834 assert((*cr).Symb->Index != -1);
835 (*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
839 assert(Sec->Symbol->Aux.size() == 1
840 && "Section's symbol must have one aux!");
841 AuxSymbol &Aux = Sec->Symbol->Aux[0];
842 assert(Aux.AuxType == ATSectionDefinition &&
843 "Section's symbol's aux symbol must be a Section Definition!");
844 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
845 Aux.Aux.SectionDefinition.NumberOfRelocations =
846 Sec->Header.NumberOfRelocations;
847 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
848 Sec->Header.NumberOfLineNumbers;
851 Header.PointerToSymbolTable = offset;
853 Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
855 // Write it all to disk...
856 WriteFileHeader(Header);
859 sections::iterator i, ie;
860 MCAssembler::const_iterator j, je;
862 for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
863 if ((*i)->Number != -1)
864 WriteSectionHeader((*i)->Header);
866 for (i = Sections.begin(), ie = Sections.end(),
867 j = Asm.begin(), je = Asm.end();
868 (i != ie) && (j != je); ++i, ++j) {
870 if ((*i)->Number == -1)
873 if ((*i)->Header.PointerToRawData != 0) {
874 assert(OS.tell() == (*i)->Header.PointerToRawData &&
875 "Section::PointerToRawData is insane!");
877 Asm.WriteSectionData(j, Layout, this);
880 if ((*i)->Relocations.size() > 0) {
881 assert(OS.tell() == (*i)->Header.PointerToRelocations &&
882 "Section::PointerToRelocations is insane!");
884 for (relocations::const_iterator k = (*i)->Relocations.begin(),
885 ke = (*i)->Relocations.end();
887 WriteRelocation(k->Data);
890 assert((*i)->Header.PointerToRelocations == 0 &&
891 "Section::PointerToRelocations is insane!");
895 assert(OS.tell() == Header.PointerToSymbolTable &&
896 "Header::PointerToSymbolTable is insane!");
898 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
899 if ((*i)->Index != -1)
902 OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
905 //------------------------------------------------------------------------------
906 // WinCOFFObjectWriter factory function
909 MCObjectWriter *createWinCOFFObjectWriter(raw_ostream &OS, bool is64Bit) {
910 return new WinCOFFObjectWriter(OS, is64Bit);