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 IsSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
184 const MCSymbolRefExpr *A,
185 const MCSymbolRefExpr *B) const {
186 // FIXME: Implement this!
190 virtual bool isAbsolute(bool IsSet, const MCSymbol &A,
191 const MCSymbol &B) const {
192 // On COFF A - B is absolute if A and B are in the same section.
193 return &A.getSection() == &B.getSection();
196 virtual bool IsFixupFullyResolved(const MCAssembler &Asm,
197 const MCValue Target,
199 const MCFragment *DF) const;
201 void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
205 static inline void write_uint32_le(void *Data, uint32_t const &Value) {
206 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
207 Ptr[0] = (Value & 0x000000FF) >> 0;
208 Ptr[1] = (Value & 0x0000FF00) >> 8;
209 Ptr[2] = (Value & 0x00FF0000) >> 16;
210 Ptr[3] = (Value & 0xFF000000) >> 24;
213 static inline void write_uint16_le(void *Data, uint16_t const &Value) {
214 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
215 Ptr[0] = (Value & 0x00FF) >> 0;
216 Ptr[1] = (Value & 0xFF00) >> 8;
219 static inline void write_uint8_le(void *Data, uint8_t const &Value) {
220 uint8_t *Ptr = reinterpret_cast<uint8_t *>(Data);
221 Ptr[0] = (Value & 0xFF) >> 0;
224 //------------------------------------------------------------------------------
225 // Symbol class implementation
227 COFFSymbol::COFFSymbol(llvm::StringRef name)
228 : Name(name.begin(), name.end())
233 memset(&Data, 0, sizeof(Data));
236 size_t COFFSymbol::size() const {
237 return COFF::SymbolSize + (Data.NumberOfAuxSymbols * COFF::SymbolSize);
240 // In the case that the name does not fit within 8 bytes, the offset
241 // into the string table is stored in the last 4 bytes instead, leaving
242 // the first 4 bytes as 0.
243 void COFFSymbol::set_name_offset(uint32_t Offset) {
244 write_uint32_le(Data.Name + 0, 0);
245 write_uint32_le(Data.Name + 4, Offset);
248 /// logic to decide if the symbol should be reported in the symbol table
249 bool COFFSymbol::should_keep() const {
250 // no section means its external, keep it
254 // if it has relocations pointing at it, keep it
255 if (Relocations > 0) {
256 assert(Section->Number != -1 && "Sections with relocations must be real!");
260 // if the section its in is being droped, drop it
261 if (Section->Number == -1)
264 // if it is the section symbol, keep it
265 if (Section->Symbol == this)
268 // if its temporary, drop it
269 if (MCData && MCData->getSymbol().isTemporary())
272 // otherwise, keep it
276 //------------------------------------------------------------------------------
277 // Section class implementation
279 COFFSection::COFFSection(llvm::StringRef name)
283 memset(&Header, 0, sizeof(Header));
286 size_t COFFSection::size() {
287 return COFF::SectionSize;
290 //------------------------------------------------------------------------------
291 // StringTable class implementation
293 /// Write the length of the string table into Data.
294 /// The length of the string table includes uint32 length header.
295 void StringTable::update_length() {
296 write_uint32_le(&Data.front(), Data.size());
299 StringTable::StringTable() {
300 // The string table data begins with the length of the entire string table
301 // including the length header. Allocate space for this header.
305 size_t StringTable::size() const {
309 /// Add String to the table iff it is not already there.
310 /// @returns the index into the string table where the string is now located.
311 size_t StringTable::insert(llvm::StringRef String) {
312 map::iterator i = Map.find(String);
317 size_t Offset = Data.size();
319 // Insert string data into string table.
320 Data.insert(Data.end(), String.begin(), String.end());
321 Data.push_back('\0');
323 // Put a reference to it in the map.
324 Map[String] = Offset;
326 // Update the internal length field.
332 //------------------------------------------------------------------------------
333 // WinCOFFObjectWriter class implementation
335 WinCOFFObjectWriter::WinCOFFObjectWriter(raw_ostream &OS, bool is64Bit)
336 : MCObjectWriter(OS, true)
338 memset(&Header, 0, sizeof(Header));
340 Is64Bit ? Header.Machine = COFF::IMAGE_FILE_MACHINE_AMD64
341 : Header.Machine = COFF::IMAGE_FILE_MACHINE_I386;
344 WinCOFFObjectWriter::~WinCOFFObjectWriter() {
345 for (symbols::iterator I = Symbols.begin(), E = Symbols.end(); I != E; ++I)
347 for (sections::iterator I = Sections.begin(), E = Sections.end(); I != E; ++I)
351 COFFSymbol *WinCOFFObjectWriter::createSymbol(StringRef Name) {
352 return createCOFFEntity<COFFSymbol>(Name, Symbols);
355 COFFSymbol *WinCOFFObjectWriter::GetOrCreateCOFFSymbol(const MCSymbol * Symbol){
356 symbol_map::iterator i = SymbolMap.find(Symbol);
357 if (i != SymbolMap.end())
359 COFFSymbol *RetSymbol
360 = createCOFFEntity<COFFSymbol>(Symbol->getName(), Symbols);
361 SymbolMap[Symbol] = RetSymbol;
365 COFFSection *WinCOFFObjectWriter::createSection(llvm::StringRef Name) {
366 return createCOFFEntity<COFFSection>(Name, Sections);
369 /// A template used to lookup or create a symbol/section, and initialize it if
371 template <typename object_t, typename list_t>
372 object_t *WinCOFFObjectWriter::createCOFFEntity(llvm::StringRef Name,
374 object_t *Object = new object_t(Name);
376 List.push_back(Object);
381 /// This function takes a section data object from the assembler
382 /// and creates the associated COFF section staging object.
383 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
384 assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
385 && "Got non COFF section in the COFF backend!");
386 // FIXME: Not sure how to verify this (at least in a debug build).
387 MCSectionCOFF const &Sec =
388 static_cast<MCSectionCOFF const &>(SectionData.getSection());
390 COFFSection *coff_section = createSection(Sec.getSectionName());
391 COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
393 coff_section->Symbol = coff_symbol;
394 coff_symbol->Section = coff_section;
395 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
397 // In this case the auxiliary symbol is a Section Definition.
398 coff_symbol->Aux.resize(1);
399 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
400 coff_symbol->Aux[0].AuxType = ATSectionDefinition;
401 coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
403 coff_section->Header.Characteristics = Sec.getCharacteristics();
405 uint32_t &Characteristics = coff_section->Header.Characteristics;
406 switch (SectionData.getAlignment()) {
407 case 1: Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES; break;
408 case 2: Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES; break;
409 case 4: Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES; break;
410 case 8: Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES; break;
411 case 16: Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES; break;
412 case 32: Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES; break;
413 case 64: Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES; break;
414 case 128: Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES; break;
415 case 256: Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES; break;
416 case 512: Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES; break;
417 case 1024: Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES; break;
418 case 2048: Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES; break;
419 case 4096: Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES; break;
420 case 8192: Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES; break;
422 llvm_unreachable("unsupported section alignment");
425 // Bind internal COFF section to MC section.
426 coff_section->MCData = &SectionData;
427 SectionMap[&SectionData.getSection()] = coff_section;
430 /// This function takes a section data object from the assembler
431 /// and creates the associated COFF symbol staging object.
432 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
433 MCAssembler &Assembler) {
434 COFFSymbol *coff_symbol = GetOrCreateCOFFSymbol(&SymbolData.getSymbol());
436 coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
437 coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
439 if (SymbolData.getFlags() & COFF::SF_WeakExternal) {
440 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
442 if (SymbolData.getSymbol().isVariable()) {
443 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL;
444 const MCExpr *Value = SymbolData.getSymbol().getVariableValue();
446 // FIXME: This assert message isn't very good.
447 assert(Value->getKind() == MCExpr::SymbolRef &&
448 "Value must be a SymbolRef!");
450 const MCSymbolRefExpr *SymbolRef =
451 static_cast<const MCSymbolRefExpr *>(Value);
452 coff_symbol->Other = GetOrCreateCOFFSymbol(&SymbolRef->getSymbol());
454 std::string WeakName = std::string(".weak.")
455 + SymbolData.getSymbol().getName().str()
457 COFFSymbol *WeakDefault = createSymbol(WeakName);
458 WeakDefault->Data.SectionNumber = COFF::IMAGE_SYM_ABSOLUTE;
459 WeakDefault->Data.StorageClass = COFF::IMAGE_SYM_CLASS_EXTERNAL;
460 WeakDefault->Data.Type = 0;
461 WeakDefault->Data.Value = 0;
462 coff_symbol->Other = WeakDefault;
465 // Setup the Weak External auxiliary symbol.
466 coff_symbol->Aux.resize(1);
467 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
468 coff_symbol->Aux[0].AuxType = ATWeakExternal;
469 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
470 coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
471 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
474 // If no storage class was specified in the streamer, define it here.
475 if (coff_symbol->Data.StorageClass == 0) {
476 bool external = SymbolData.isExternal() || (SymbolData.Fragment == NULL);
478 coff_symbol->Data.StorageClass =
479 external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
482 if (SymbolData.Fragment != NULL)
483 coff_symbol->Section =
484 SectionMap[&SymbolData.Fragment->getParent()->getSection()];
486 // Bind internal COFF symbol to MC symbol.
487 coff_symbol->MCData = &SymbolData;
488 SymbolMap[&SymbolData.getSymbol()] = coff_symbol;
491 /// making a section real involves assigned it a number and putting
492 /// name into the string table if needed
493 void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
494 if (S.Name.size() > COFF::NameSize) {
495 size_t StringTableEntry = Strings.insert(S.Name.c_str());
497 // FIXME: Why is this number 999999? This number is never mentioned in the
498 // spec. I'm assuming this is due to the printed value needing to fit into
499 // the S.Header.Name field. In which case why not 9999999 (7 9's instead of
500 // 6)? The spec does not state if this entry should be null terminated in
501 // this case, and thus this seems to be the best way to do it. I think I
502 // just solved my own FIXME...
503 if (StringTableEntry > 999999)
504 report_fatal_error("COFF string table is greater than 999999 bytes.");
506 std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
508 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
511 S.Symbol->Data.SectionNumber = S.Number;
512 S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
515 void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
516 if (S.Name.size() > COFF::NameSize) {
517 size_t StringTableEntry = Strings.insert(S.Name.c_str());
519 S.set_name_offset(StringTableEntry);
521 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
525 bool WinCOFFObjectWriter::ExportSection(COFFSection const *S) {
526 return !S->MCData->getFragmentList().empty();
529 bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
531 // This doesn't seem to be right. Strings referred to from the .data section
532 // need symbols so they can be linked to code in the .text section right?
534 // return Asm.isSymbolLinkerVisible (&SymbolData);
536 // For now, all non-variable symbols are exported,
537 // the linker will sort the rest out for us.
538 return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
541 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
542 return (S->Header.Characteristics
543 & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
546 //------------------------------------------------------------------------------
547 // entity writing methods
549 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
550 WriteLE16(Header.Machine);
551 WriteLE16(Header.NumberOfSections);
552 WriteLE32(Header.TimeDateStamp);
553 WriteLE32(Header.PointerToSymbolTable);
554 WriteLE32(Header.NumberOfSymbols);
555 WriteLE16(Header.SizeOfOptionalHeader);
556 WriteLE16(Header.Characteristics);
559 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
560 WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
561 WriteLE32(S->Data.Value);
562 WriteLE16(S->Data.SectionNumber);
563 WriteLE16(S->Data.Type);
564 Write8(S->Data.StorageClass);
565 Write8(S->Data.NumberOfAuxSymbols);
566 WriteAuxiliarySymbols(S->Aux);
569 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
570 const COFFSymbol::AuxiliarySymbols &S) {
571 for(COFFSymbol::AuxiliarySymbols::const_iterator i = S.begin(), e = S.end();
574 case ATFunctionDefinition:
575 WriteLE32(i->Aux.FunctionDefinition.TagIndex);
576 WriteLE32(i->Aux.FunctionDefinition.TotalSize);
577 WriteLE32(i->Aux.FunctionDefinition.PointerToLinenumber);
578 WriteLE32(i->Aux.FunctionDefinition.PointerToNextFunction);
579 WriteZeros(sizeof(i->Aux.FunctionDefinition.unused));
581 case ATbfAndefSymbol:
582 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused1));
583 WriteLE16(i->Aux.bfAndefSymbol.Linenumber);
584 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused2));
585 WriteLE32(i->Aux.bfAndefSymbol.PointerToNextFunction);
586 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused3));
589 WriteLE32(i->Aux.WeakExternal.TagIndex);
590 WriteLE32(i->Aux.WeakExternal.Characteristics);
591 WriteZeros(sizeof(i->Aux.WeakExternal.unused));
594 WriteBytes(StringRef(reinterpret_cast<const char *>(i->Aux.File.FileName),
595 sizeof(i->Aux.File.FileName)));
597 case ATSectionDefinition:
598 WriteLE32(i->Aux.SectionDefinition.Length);
599 WriteLE16(i->Aux.SectionDefinition.NumberOfRelocations);
600 WriteLE16(i->Aux.SectionDefinition.NumberOfLinenumbers);
601 WriteLE32(i->Aux.SectionDefinition.CheckSum);
602 WriteLE16(i->Aux.SectionDefinition.Number);
603 Write8(i->Aux.SectionDefinition.Selection);
604 WriteZeros(sizeof(i->Aux.SectionDefinition.unused));
610 void WinCOFFObjectWriter::WriteSectionHeader(const COFF::section &S) {
611 WriteBytes(StringRef(S.Name, COFF::NameSize));
613 WriteLE32(S.VirtualSize);
614 WriteLE32(S.VirtualAddress);
615 WriteLE32(S.SizeOfRawData);
616 WriteLE32(S.PointerToRawData);
617 WriteLE32(S.PointerToRelocations);
618 WriteLE32(S.PointerToLineNumbers);
619 WriteLE16(S.NumberOfRelocations);
620 WriteLE16(S.NumberOfLineNumbers);
621 WriteLE32(S.Characteristics);
624 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
625 WriteLE32(R.VirtualAddress);
626 WriteLE32(R.SymbolTableIndex);
630 ////////////////////////////////////////////////////////////////////////////////
631 // MCObjectWriter interface implementations
633 void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
634 const MCAsmLayout &Layout) {
635 // "Define" each section & symbol. This creates section & symbol
636 // entries in the staging area.
638 for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
641 for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
642 e = Asm.symbol_end(); i != e; i++) {
643 if (ExportSymbol(*i, Asm))
644 DefineSymbol(*i, Asm);
648 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
649 const MCAsmLayout &Layout,
650 const MCFragment *Fragment,
651 const MCFixup &Fixup,
653 uint64_t &FixedValue) {
654 assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
656 const MCSymbol *A = &Target.getSymA()->getSymbol();
657 MCSymbolData &A_SD = Asm.getSymbolData(*A);
659 MCSectionData const *SectionData = Fragment->getParent();
661 // Mark this symbol as requiring an entry in the symbol table.
662 assert(SectionMap.find(&SectionData->getSection()) != SectionMap.end() &&
663 "Section must already have been defined in ExecutePostLayoutBinding!");
664 assert(SymbolMap.find(&A_SD.getSymbol()) != SymbolMap.end() &&
665 "Symbol must already have been defined in ExecutePostLayoutBinding!");
667 COFFSection *coff_section = SectionMap[&SectionData->getSection()];
668 COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
670 if (Target.getSymB()) {
671 if (&Target.getSymA()->getSymbol().getSection()
672 != &Target.getSymB()->getSymbol().getSection()) {
673 llvm_unreachable("Symbol relative relocations are only allowed between "
674 "symbols in the same section");
676 const MCSymbol *B = &Target.getSymB()->getSymbol();
677 MCSymbolData &B_SD = Asm.getSymbolData(*B);
679 FixedValue = Layout.getSymbolOffset(&A_SD) - Layout.getSymbolOffset(&B_SD);
681 // In the case where we have SymbA and SymB, we just need to store the delta
682 // between the two symbols. Update FixedValue to account for the delta, and
683 // skip recording the relocation.
686 FixedValue = Target.getConstant();
689 COFFRelocation Reloc;
691 Reloc.Data.SymbolTableIndex = 0;
692 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
694 // Turn relocations for temporary symbols into section relocations.
695 if (coff_symbol->MCData->getSymbol().isTemporary()) {
696 Reloc.Symb = coff_symbol->Section->Symbol;
697 FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
698 + coff_symbol->MCData->getOffset();
700 Reloc.Symb = coff_symbol;
702 ++Reloc.Symb->Relocations;
704 Reloc.Data.VirtualAddress += Fixup.getOffset();
706 switch ((unsigned)Fixup.getKind()) {
708 case X86::reloc_riprel_4byte:
709 case X86::reloc_riprel_4byte_movq_load:
710 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_REL32
711 : COFF::IMAGE_REL_I386_REL32;
712 // FIXME: Can anyone explain what this does other than adjust for the size
717 case X86::reloc_signed_4byte:
718 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_ADDR32
719 : COFF::IMAGE_REL_I386_DIR32;
723 Reloc.Data.Type = COFF::IMAGE_REL_AMD64_ADDR64;
725 llvm_unreachable("unsupported relocation type");
728 llvm_unreachable("unsupported relocation type");
731 coff_section->Relocations.push_back(Reloc);
734 bool WinCOFFObjectWriter::IsFixupFullyResolved(const MCAssembler &Asm,
735 const MCValue Target,
737 const MCFragment *DF) const {
738 // If this is a PCrel relocation, find the section this fixup value is
740 const MCSection *BaseSection = 0;
742 BaseSection = &DF->getParent()->getSection();
746 const MCSection *SectionA = 0;
747 const MCSymbol *SymbolA = 0;
748 if (const MCSymbolRefExpr *A = Target.getSymA()) {
749 SymbolA = &A->getSymbol();
750 SectionA = &SymbolA->getSection();
753 const MCSection *SectionB = 0;
754 if (const MCSymbolRefExpr *B = Target.getSymB()) {
755 SectionB = &B->getSymbol().getSection();
759 return SectionA == SectionB;
761 return !SectionB && BaseSection == SectionA;
764 void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
765 const MCAsmLayout &Layout) {
766 // Assign symbol and section indexes and offsets.
767 Header.NumberOfSections = 0;
769 for (sections::iterator i = Sections.begin(),
770 e = Sections.end(); i != e; i++) {
771 if (Layout.getSectionAddressSize((*i)->MCData) > 0) {
772 MakeSectionReal(**i, ++Header.NumberOfSections);
778 Header.NumberOfSymbols = 0;
780 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
781 COFFSymbol *coff_symbol = *i;
782 MCSymbolData const *SymbolData = coff_symbol->MCData;
784 // Update section number & offset for symbols that have them.
785 if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
786 assert(coff_symbol->Section != NULL);
788 coff_symbol->Data.SectionNumber = coff_symbol->Section->Number;
789 coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
790 + SymbolData->Offset;
793 if (coff_symbol->should_keep()) {
794 MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++);
796 // Update auxiliary symbol info.
797 coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
798 Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
800 coff_symbol->Index = -1;
803 // Fixup weak external references.
804 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
805 COFFSymbol *coff_symbol = *i;
806 if (coff_symbol->Other != NULL) {
807 assert(coff_symbol->Index != -1);
808 assert(coff_symbol->Aux.size() == 1 &&
809 "Symbol must contain one aux symbol!");
810 assert(coff_symbol->Aux[0].AuxType == ATWeakExternal &&
811 "Symbol's aux symbol must be a Weak External!");
812 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index;
816 // Assign file offsets to COFF object file structures.
820 offset += COFF::HeaderSize;
821 offset += COFF::SectionSize * Header.NumberOfSections;
823 for (MCAssembler::const_iterator i = Asm.begin(),
826 COFFSection *Sec = SectionMap[&i->getSection()];
828 if (Sec->Number == -1)
831 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
833 if (IsPhysicalSection(Sec)) {
834 Sec->Header.PointerToRawData = offset;
836 offset += Sec->Header.SizeOfRawData;
839 if (Sec->Relocations.size() > 0) {
840 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
841 Sec->Header.PointerToRelocations = offset;
843 offset += COFF::RelocationSize * Sec->Relocations.size();
845 for (relocations::iterator cr = Sec->Relocations.begin(),
846 er = Sec->Relocations.end();
848 assert((*cr).Symb->Index != -1);
849 (*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
853 assert(Sec->Symbol->Aux.size() == 1
854 && "Section's symbol must have one aux!");
855 AuxSymbol &Aux = Sec->Symbol->Aux[0];
856 assert(Aux.AuxType == ATSectionDefinition &&
857 "Section's symbol's aux symbol must be a Section Definition!");
858 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
859 Aux.Aux.SectionDefinition.NumberOfRelocations =
860 Sec->Header.NumberOfRelocations;
861 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
862 Sec->Header.NumberOfLineNumbers;
865 Header.PointerToSymbolTable = offset;
867 Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
869 // Write it all to disk...
870 WriteFileHeader(Header);
873 sections::iterator i, ie;
874 MCAssembler::const_iterator j, je;
876 for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
877 if ((*i)->Number != -1)
878 WriteSectionHeader((*i)->Header);
880 for (i = Sections.begin(), ie = Sections.end(),
881 j = Asm.begin(), je = Asm.end();
882 (i != ie) && (j != je); ++i, ++j) {
884 if ((*i)->Number == -1)
887 if ((*i)->Header.PointerToRawData != 0) {
888 assert(OS.tell() == (*i)->Header.PointerToRawData &&
889 "Section::PointerToRawData is insane!");
891 Asm.WriteSectionData(j, Layout);
894 if ((*i)->Relocations.size() > 0) {
895 assert(OS.tell() == (*i)->Header.PointerToRelocations &&
896 "Section::PointerToRelocations is insane!");
898 for (relocations::const_iterator k = (*i)->Relocations.begin(),
899 ke = (*i)->Relocations.end();
901 WriteRelocation(k->Data);
904 assert((*i)->Header.PointerToRelocations == 0 &&
905 "Section::PointerToRelocations is insane!");
909 assert(OS.tell() == Header.PointerToSymbolTable &&
910 "Header::PointerToSymbolTable is insane!");
912 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
913 if ((*i)->Index != -1)
916 OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
919 //------------------------------------------------------------------------------
920 // WinCOFFObjectWriter factory function
923 MCObjectWriter *createWinCOFFObjectWriter(raw_ostream &OS, bool is64Bit) {
924 return new WinCOFFObjectWriter(OS, is64Bit);