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/MCTargetDesc/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 void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
186 static inline void write_uint32_le(void *Data, uint32_t const &Value) {
187 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
188 Ptr[0] = (Value & 0x000000FF) >> 0;
189 Ptr[1] = (Value & 0x0000FF00) >> 8;
190 Ptr[2] = (Value & 0x00FF0000) >> 16;
191 Ptr[3] = (Value & 0xFF000000) >> 24;
194 static inline void write_uint16_le(void *Data, uint16_t const &Value) {
195 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
196 Ptr[0] = (Value & 0x00FF) >> 0;
197 Ptr[1] = (Value & 0xFF00) >> 8;
200 static inline void write_uint8_le(void *Data, uint8_t const &Value) {
201 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
202 Ptr[0] = (Value & 0xFF) >> 0;
205 //------------------------------------------------------------------------------
206 // Symbol class implementation
208 COFFSymbol::COFFSymbol(llvm::StringRef name)
209 : Name(name.begin(), name.end())
214 memset(&Data, 0, sizeof(Data));
217 size_t COFFSymbol::size() const {
218 return COFF::SymbolSize + (Data.NumberOfAuxSymbols * COFF::SymbolSize);
221 // In the case that the name does not fit within 8 bytes, the offset
222 // into the string table is stored in the last 4 bytes instead, leaving
223 // the first 4 bytes as 0.
224 void COFFSymbol::set_name_offset(uint32_t Offset) {
225 write_uint32_le(Data.Name + 0, 0);
226 write_uint32_le(Data.Name + 4, Offset);
229 /// logic to decide if the symbol should be reported in the symbol table
230 bool COFFSymbol::should_keep() const {
231 // no section means its external, keep it
235 // if it has relocations pointing at it, keep it
236 if (Relocations > 0) {
237 assert(Section->Number != -1 && "Sections with relocations must be real!");
241 // if the section its in is being droped, drop it
242 if (Section->Number == -1)
245 // if it is the section symbol, keep it
246 if (Section->Symbol == this)
249 // if its temporary, drop it
250 if (MCData && MCData->getSymbol().isTemporary())
253 // otherwise, keep it
257 //------------------------------------------------------------------------------
258 // Section class implementation
260 COFFSection::COFFSection(llvm::StringRef name)
264 memset(&Header, 0, sizeof(Header));
267 size_t COFFSection::size() {
268 return COFF::SectionSize;
271 //------------------------------------------------------------------------------
272 // StringTable class implementation
274 /// Write the length of the string table into Data.
275 /// The length of the string table includes uint32 length header.
276 void StringTable::update_length() {
277 write_uint32_le(&Data.front(), Data.size());
280 StringTable::StringTable() {
281 // The string table data begins with the length of the entire string table
282 // including the length header. Allocate space for this header.
287 size_t StringTable::size() const {
291 /// Add String to the table iff it is not already there.
292 /// @returns the index into the string table where the string is now located.
293 size_t StringTable::insert(llvm::StringRef String) {
294 map::iterator i = Map.find(String);
299 size_t Offset = Data.size();
301 // Insert string data into string table.
302 Data.insert(Data.end(), String.begin(), String.end());
303 Data.push_back('\0');
305 // Put a reference to it in the map.
306 Map[String] = Offset;
308 // Update the internal length field.
314 //------------------------------------------------------------------------------
315 // WinCOFFObjectWriter class implementation
317 WinCOFFObjectWriter::WinCOFFObjectWriter(raw_ostream &OS, bool is64Bit)
318 : MCObjectWriter(OS, true)
320 memset(&Header, 0, sizeof(Header));
322 Is64Bit ? Header.Machine = COFF::IMAGE_FILE_MACHINE_AMD64
323 : Header.Machine = COFF::IMAGE_FILE_MACHINE_I386;
326 WinCOFFObjectWriter::~WinCOFFObjectWriter() {
327 for (symbols::iterator I = Symbols.begin(), E = Symbols.end(); I != E; ++I)
329 for (sections::iterator I = Sections.begin(), E = Sections.end(); I != E; ++I)
333 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
334 return createCOFFEntity<COFFSymbol>(Name, Symbols);
337 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol * Symbol){
338 symbol_map::iterator i = SymbolMap.find(Symbol);
339 if (i != SymbolMap.end())
341 COFFSymbol *RetSymbol
342 = createCOFFEntity<COFFSymbol>(Symbol->getName(), Symbols);
343 SymbolMap[Symbol] = RetSymbol;
347 COFFSection *WinCOFFObjectWriter::createSection(llvm::StringRef Name) {
348 return createCOFFEntity<COFFSection>(Name, Sections);
351 /// A template used to lookup or create a symbol/section, and initialize it if
353 template <typename object_t, typename list_t>
354 object_t *WinCOFFObjectWriter::createCOFFEntity(llvm::StringRef Name,
356 object_t *Object = new object_t(Name);
358 List.push_back(Object);
363 /// This function takes a section data object from the assembler
364 /// and creates the associated COFF section staging object.
365 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
366 assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
367 && "Got non COFF section in the COFF backend!");
368 // FIXME: Not sure how to verify this (at least in a debug build).
369 MCSectionCOFF const &Sec =
370 static_cast<MCSectionCOFF const &>(SectionData.getSection());
372 COFFSection *coff_section = createSection(Sec.getSectionName());
373 COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
375 coff_section->Symbol = coff_symbol;
376 coff_symbol->Section = coff_section;
377 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
379 // In this case the auxiliary symbol is a Section Definition.
380 coff_symbol->Aux.resize(1);
381 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
382 coff_symbol->Aux[0].AuxType = ATSectionDefinition;
383 coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
385 coff_section->Header.Characteristics = Sec.getCharacteristics();
387 uint32_t &Characteristics = coff_section->Header.Characteristics;
388 switch (SectionData.getAlignment()) {
389 case 1: Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES; break;
390 case 2: Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES; break;
391 case 4: Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES; break;
392 case 8: Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES; break;
393 case 16: Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES; break;
394 case 32: Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES; break;
395 case 64: Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES; break;
396 case 128: Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES; break;
397 case 256: Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES; break;
398 case 512: Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES; break;
399 case 1024: Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES; break;
400 case 2048: Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES; break;
401 case 4096: Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES; break;
402 case 8192: Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES; break;
404 llvm_unreachable("unsupported section alignment");
407 // Bind internal COFF section to MC section.
408 coff_section->MCData = &SectionData;
409 SectionMap[&SectionData.getSection()] = coff_section;
412 /// This function takes a section data object from the assembler
413 /// and creates the associated COFF symbol staging object.
414 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
415 MCAssembler &Assembler) {
416 COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&SymbolData.getSymbol());
418 coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
419 coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
421 if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
422 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
424 if (SymbolData.getSymbol().isVariable()) {
425 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
426 const MCExpr *Value = SymbolData.getSymbol().getVariableValue();
428 // FIXME: This assert message isn't very good.
429 assert(Value->getKind() == MCExpr::SymbolRef &&
430 "Value must be a SymbolRef!");
432 const MCSymbolRefExpr *SymbolRef =
433 static_cast<const MCSymbolRefExpr *>(Value);
434 coff_symbol->Other = GetOrCreateCOFFSymbol(&SymbolRef->getSymbol());
436 std::string WeakName = std::string(".weak.")
437 + SymbolData.getSymbol().getName().str()
439 COFFSymbol *WeakDefault = createSymbol(WeakName);
440 WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
441 WeakDefault->Data.StorageClass = COFF::IMAGE_SYM_CLASS_EXTERNAL;
442 WeakDefault->Data.Type = 0;
443 WeakDefault->Data.Value = 0;
444 coff_symbol->Other = WeakDefault;
447 // Setup the Weak External auxiliary symbol.
448 coff_symbol->Aux.resize(1);
449 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
450 coff_symbol->Aux[0].AuxType = ATWeakExternal;
451 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
452 coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
453 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
456 // If no storage class was specified in the streamer, define it here.
457 if (coff_symbol->Data.StorageClass == 0) {
458 bool external = SymbolData.isExternal() || (SymbolData.Fragment == NULL);
460 coff_symbol->Data.StorageClass =
461 external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
464 if (SymbolData.Fragment != NULL)
465 coff_symbol->Section =
466 SectionMap[&SymbolData.Fragment->getParent()->getSection()];
468 // Bind internal COFF symbol to MC symbol.
469 coff_symbol->MCData = &SymbolData;
470 SymbolMap[&SymbolData.getSymbol()] = coff_symbol;
473 /// making a section real involves assigned it a number and putting
474 /// name into the string table if needed
475 void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
476 if (S.Name.size() > COFF::NameSize) {
477 size_t StringTableEntry = Strings.insert(S.Name.c_str());
479 // FIXME: Why is this number 999999? This number is never mentioned in the
480 // spec. I'm assuming this is due to the printed value needing to fit into
481 // the S.Header.Name field. In which case why not 9999999 (7 9's instead of
482 // 6)? The spec does not state if this entry should be null terminated in
483 // this case, and thus this seems to be the best way to do it. I think I
484 // just solved my own FIXME...
485 if (StringTableEntry > 999999)
486 report_fatal_error("COFF string table is greater than 999999 bytes.");
488 std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
490 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
493 S.Symbol->Data.SectionNumber = S.Number;
494 S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
497 void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
498 if (S.Name.size() > COFF::NameSize) {
499 size_t StringTableEntry = Strings.insert(S.Name.c_str());
501 S.set_name_offset(StringTableEntry);
503 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
507 bool WinCOFFObjectWriter::ExportSection(COFFSection const *S) {
508 return !S->MCData->getFragmentList().empty();
511 bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
513 // This doesn't seem to be right. Strings referred to from the .data section
514 // need symbols so they can be linked to code in the .text section right?
516 // return Asm.isSymbolLinkerVisible (&SymbolData);
518 // For now, all non-variable symbols are exported,
519 // the linker will sort the rest out for us.
520 return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
523 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
524 return (S->Header.Characteristics
525 & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
528 //------------------------------------------------------------------------------
529 // entity writing methods
531 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
532 WriteLE16(Header.Machine);
533 WriteLE16(Header.NumberOfSections);
534 WriteLE32(Header.TimeDateStamp);
535 WriteLE32(Header.PointerToSymbolTable);
536 WriteLE32(Header.NumberOfSymbols);
537 WriteLE16(Header.SizeOfOptionalHeader);
538 WriteLE16(Header.Characteristics);
541 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
542 WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
543 WriteLE32(S->Data.Value);
544 WriteLE16(S->Data.SectionNumber);
545 WriteLE16(S->Data.Type);
546 Write8(S->Data.StorageClass);
547 Write8(S->Data.NumberOfAuxSymbols);
548 WriteAuxiliarySymbols(S->Aux);
551 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
552 const COFFSymbol::AuxiliarySymbols &S) {
553 for(COFFSymbol::AuxiliarySymbols::const_iterator i = S.begin(), e = S.end();
556 case ATFunctionDefinition:
557 WriteLE32(i->Aux.FunctionDefinition.TagIndex);
558 WriteLE32(i->Aux.FunctionDefinition.TotalSize);
559 WriteLE32(i->Aux.FunctionDefinition.PointerToLinenumber);
560 WriteLE32(i->Aux.FunctionDefinition.PointerToNextFunction);
561 WriteZeros(sizeof(i->Aux.FunctionDefinition.unused));
563 case ATbfAndefSymbol:
564 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused1));
565 WriteLE16(i->Aux.bfAndefSymbol.Linenumber);
566 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused2));
567 WriteLE32(i->Aux.bfAndefSymbol.PointerToNextFunction);
568 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused3));
571 WriteLE32(i->Aux.WeakExternal.TagIndex);
572 WriteLE32(i->Aux.WeakExternal.Characteristics);
573 WriteZeros(sizeof(i->Aux.WeakExternal.unused));
576 WriteBytes(StringRef(reinterpret_cast<const char *>(i->Aux.File.FileName),
577 sizeof(i->Aux.File.FileName)));
579 case ATSectionDefinition:
580 WriteLE32(i->Aux.SectionDefinition.Length);
581 WriteLE16(i->Aux.SectionDefinition.NumberOfRelocations);
582 WriteLE16(i->Aux.SectionDefinition.NumberOfLinenumbers);
583 WriteLE32(i->Aux.SectionDefinition.CheckSum);
584 WriteLE16(i->Aux.SectionDefinition.Number);
585 Write8(i->Aux.SectionDefinition.Selection);
586 WriteZeros(sizeof(i->Aux.SectionDefinition.unused));
592 void WinCOFFObjectWriter::WriteSectionHeader(const COFF::section &S) {
593 WriteBytes(StringRef(S.Name, COFF::NameSize));
595 WriteLE32(S.VirtualSize);
596 WriteLE32(S.VirtualAddress);
597 WriteLE32(S.SizeOfRawData);
598 WriteLE32(S.PointerToRawData);
599 WriteLE32(S.PointerToRelocations);
600 WriteLE32(S.PointerToLineNumbers);
601 WriteLE16(S.NumberOfRelocations);
602 WriteLE16(S.NumberOfLineNumbers);
603 WriteLE32(S.Characteristics);
606 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
607 WriteLE32(R.VirtualAddress);
608 WriteLE32(R.SymbolTableIndex);
612 ////////////////////////////////////////////////////////////////////////////////
613 // MCObjectWriter interface implementations
615 void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
616 const MCAsmLayout &Layout) {
617 // "Define" each section & symbol. This creates section & symbol
618 // entries in the staging area.
620 for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
623 for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
624 e = Asm.symbol_end(); i != e; i++) {
625 if (ExportSymbol(*i, Asm))
626 DefineSymbol(*i, Asm);
630 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
631 const MCAsmLayout &Layout,
632 const MCFragment *Fragment,
633 const MCFixup &Fixup,
635 uint64_t &FixedValue) {
636 assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
638 const MCSymbol *A = &Target.getSymA()->getSymbol();
639 MCSymbolData &A_SD = Asm.getSymbolData(*A);
641 MCSectionData const *SectionData = Fragment->getParent();
643 // Mark this symbol as requiring an entry in the symbol table.
644 assert(SectionMap.find(&SectionData->getSection()) != SectionMap.end() &&
645 "Section must already have been defined in ExecutePostLayoutBinding!");
646 assert(SymbolMap.find(&A_SD.getSymbol()) != SymbolMap.end() &&
647 "Symbol must already have been defined in ExecutePostLayoutBinding!");
649 COFFSection *coff_section = SectionMap[&SectionData->getSection()];
650 COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
651 const MCSymbolRefExpr *SymA = Target.getSymA();
652 const MCSymbolRefExpr *SymB = Target.getSymB();
653 const bool CrossSection = SymB &&
654 &SymA->getSymbol().getSection() != &SymB->getSymbol().getSection();
656 if (Target.getSymB()) {
657 const MCSymbol *B = &Target.getSymB()->getSymbol();
658 MCSymbolData &B_SD = Asm.getSymbolData(*B);
660 // Offset of the symbol in the section
661 int64_t a = Layout.getSymbolOffset(&B_SD);
663 // Ofeset of the relocation in the section
664 int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
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.
673 FixedValue = Target.getConstant();
676 COFFRelocation Reloc;
678 Reloc.Data.SymbolTableIndex = 0;
679 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
681 // Turn relocations for temporary symbols into section relocations.
682 if (coff_symbol->MCData->getSymbol().isTemporary() || CrossSection) {
683 Reloc.Symb = coff_symbol->Section->Symbol;
684 FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
685 + coff_symbol->MCData->getOffset();
687 Reloc.Symb = coff_symbol;
689 ++Reloc.Symb->Relocations;
691 Reloc.Data.VirtualAddress += Fixup.getOffset();
693 unsigned FixupKind = Fixup.getKind();
696 FixupKind = FK_PCRel_4;
700 case X86::reloc_riprel_4byte:
701 case X86::reloc_riprel_4byte_movq_load:
702 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_REL32
703 : COFF::IMAGE_REL_I386_REL32;
704 // FIXME: Can anyone explain what this does other than adjust for the size
709 case X86::reloc_signed_4byte:
710 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_ADDR32
711 : COFF::IMAGE_REL_I386_DIR32;
715 Reloc.Data.Type = COFF::IMAGE_REL_AMD64_ADDR64;
717 llvm_unreachable("unsupported relocation type");
720 llvm_unreachable("unsupported relocation type");
723 coff_section->Relocations.push_back(Reloc);
726 void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
727 const MCAsmLayout &Layout) {
728 // Assign symbol and section indexes and offsets.
729 Header.NumberOfSections = 0;
731 for (sections::iterator i = Sections.begin(),
732 e = Sections.end(); i != e; i++) {
733 if (Layout.getSectionAddressSize((*i)->MCData) > 0) {
734 MakeSectionReal(**i, ++Header.NumberOfSections);
740 Header.NumberOfSymbols = 0;
742 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
743 COFFSymbol *coff_symbol = *i;
744 MCSymbolData const *SymbolData = coff_symbol->MCData;
746 // Update section number & offset for symbols that have them.
747 if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
748 assert(coff_symbol->Section != NULL);
750 coff_symbol->Data.SectionNumber = coff_symbol->Section->Number;
751 coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
752 + SymbolData->Offset;
755 if (coff_symbol->should_keep()) {
756 MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++);
758 // Update auxiliary symbol info.
759 coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
760 Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
762 coff_symbol->Index = -1;
765 // Fixup weak external references.
766 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
767 COFFSymbol *coff_symbol = *i;
768 if (coff_symbol->Other != NULL) {
769 assert(coff_symbol->Index != -1);
770 assert(coff_symbol->Aux.size() == 1 &&
771 "Symbol must contain one aux symbol!");
772 assert(coff_symbol->Aux[0].AuxType == ATWeakExternal &&
773 "Symbol's aux symbol must be a Weak External!");
774 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index;
778 // Assign file offsets to COFF object file structures.
782 offset += COFF::HeaderSize;
783 offset += COFF::SectionSize * Header.NumberOfSections;
785 for (MCAssembler::const_iterator i = Asm.begin(),
788 COFFSection *Sec = SectionMap[&i->getSection()];
790 if (Sec->Number == -1)
793 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
795 if (IsPhysicalSection(Sec)) {
796 Sec->Header.PointerToRawData = offset;
798 offset += Sec->Header.SizeOfRawData;
801 if (Sec->Relocations.size() > 0) {
802 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
803 Sec->Header.PointerToRelocations = offset;
805 offset += COFF::RelocationSize * Sec->Relocations.size();
807 for (relocations::iterator cr = Sec->Relocations.begin(),
808 er = Sec->Relocations.end();
810 assert((*cr).Symb->Index != -1);
811 (*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
815 assert(Sec->Symbol->Aux.size() == 1
816 && "Section's symbol must have one aux!");
817 AuxSymbol &Aux = Sec->Symbol->Aux[0];
818 assert(Aux.AuxType == ATSectionDefinition &&
819 "Section's symbol's aux symbol must be a Section Definition!");
820 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
821 Aux.Aux.SectionDefinition.NumberOfRelocations =
822 Sec->Header.NumberOfRelocations;
823 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
824 Sec->Header.NumberOfLineNumbers;
827 Header.PointerToSymbolTable = offset;
829 Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
831 // Write it all to disk...
832 WriteFileHeader(Header);
835 sections::iterator i, ie;
836 MCAssembler::const_iterator j, je;
838 for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
839 if ((*i)->Number != -1)
840 WriteSectionHeader((*i)->Header);
842 for (i = Sections.begin(), ie = Sections.end(),
843 j = Asm.begin(), je = Asm.end();
844 (i != ie) && (j != je); ++i, ++j) {
846 if ((*i)->Number == -1)
849 if ((*i)->Header.PointerToRawData != 0) {
850 assert(OS.tell() == (*i)->Header.PointerToRawData &&
851 "Section::PointerToRawData is insane!");
853 Asm.writeSectionData(j, Layout);
856 if ((*i)->Relocations.size() > 0) {
857 assert(OS.tell() == (*i)->Header.PointerToRelocations &&
858 "Section::PointerToRelocations is insane!");
860 for (relocations::const_iterator k = (*i)->Relocations.begin(),
861 ke = (*i)->Relocations.end();
863 WriteRelocation(k->Data);
866 assert((*i)->Header.PointerToRelocations == 0 &&
867 "Section::PointerToRelocations is insane!");
871 assert(OS.tell() == Header.PointerToSymbolTable &&
872 "Header::PointerToSymbolTable is insane!");
874 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
875 if ((*i)->Index != -1)
878 OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
881 //------------------------------------------------------------------------------
882 // WinCOFFObjectWriter factory function
885 MCObjectWriter *createWinCOFFObjectWriter(raw_ostream &OS, bool is64Bit) {
886 return new WinCOFFObjectWriter(OS, is64Bit);