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/System/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 StringMap<COFFSymbol *> name_symbol_map;
129 typedef StringMap<COFFSection *> name_section_map;
131 typedef DenseMap<MCSymbolData const *, COFFSymbol *> symbol_map;
132 typedef DenseMap<MCSectionData const *, COFFSection *> section_map;
134 // Root level file contents.
141 // Maps used during object file creation.
142 section_map SectionMap;
143 symbol_map SymbolMap;
145 WinCOFFObjectWriter(raw_ostream &OS, bool is64Bit);
146 ~WinCOFFObjectWriter();
148 COFFSymbol *createSymbol(llvm::StringRef Name);
149 COFFSection *createSection(llvm::StringRef Name);
151 template <typename object_t, typename list_t>
152 object_t *createCOFFEntity(llvm::StringRef Name, list_t &List);
154 void DefineSection(MCSectionData const &SectionData);
155 void DefineSymbol(MCSymbolData const &SymbolData, MCAssembler &Assembler);
157 void MakeSymbolReal(COFFSymbol &S, size_t Index);
158 void MakeSectionReal(COFFSection &S, size_t Number);
160 bool ExportSection(COFFSection const *S);
161 bool ExportSymbol(MCSymbolData const &SymbolData, MCAssembler &Asm);
163 bool IsPhysicalSection(COFFSection *S);
165 // Entity writing methods.
167 void WriteFileHeader(const COFF::header &Header);
168 void WriteSymbol(const COFFSymbol *S);
169 void WriteAuxiliarySymbols(const COFFSymbol::AuxiliarySymbols &S);
170 void WriteSectionHeader(const COFF::section &S);
171 void WriteRelocation(const COFF::relocation &R);
173 // MCObjectWriter interface implementation.
175 void ExecutePostLayoutBinding(MCAssembler &Asm);
177 void RecordRelocation(const MCAssembler &Asm,
178 const MCAsmLayout &Layout,
179 const MCFragment *Fragment,
180 const MCFixup &Fixup,
182 uint64_t &FixedValue);
184 virtual bool IsFixupFullyResolved(const MCAssembler &Asm,
185 const MCValue Target,
187 const MCFragment *DF) const;
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(llvm::StringRef Name) {
340 return createCOFFEntity<COFFSymbol>(Name, Symbols);
343 COFFSection *WinCOFFObjectWriter::createSection(llvm::StringRef Name) {
344 return createCOFFEntity<COFFSection>(Name, Sections);
347 /// A template used to lookup or create a symbol/section, and initialize it if
349 template <typename object_t, typename list_t>
350 object_t *WinCOFFObjectWriter::createCOFFEntity(llvm::StringRef Name,
352 object_t *Object = new object_t(Name);
354 List.push_back(Object);
359 /// This function takes a section data object from the assembler
360 /// and creates the associated COFF section staging object.
361 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
362 assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
363 && "Got non COFF section in the COFF backend!");
364 // FIXME: Not sure how to verify this (at least in a debug build).
365 MCSectionCOFF const &Sec =
366 static_cast<MCSectionCOFF const &>(SectionData.getSection());
368 COFFSection *coff_section = createSection(Sec.getSectionName());
369 COFFSymbol *coff_symbol = createSymbol(Sec.getSectionName());
371 coff_section->Symbol = coff_symbol;
372 coff_symbol->Section = coff_section;
373 coff_symbol->Data.StorageClass = COFF::IMAGE_SYM_CLASS_STATIC;
375 // In this case the auxiliary symbol is a Section Definition.
376 coff_symbol->Aux.resize(1);
377 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
378 coff_symbol->Aux[0].AuxType = ATSectionDefinition;
379 coff_symbol->Aux[0].Aux.SectionDefinition.Selection = Sec.getSelection();
381 coff_section->Header.Characteristics = Sec.getCharacteristics();
383 uint32_t &Characteristics = coff_section->Header.Characteristics;
384 switch (SectionData.getAlignment()) {
385 case 1: Characteristics |= COFF::IMAGE_SCN_ALIGN_1BYTES; break;
386 case 2: Characteristics |= COFF::IMAGE_SCN_ALIGN_2BYTES; break;
387 case 4: Characteristics |= COFF::IMAGE_SCN_ALIGN_4BYTES; break;
388 case 8: Characteristics |= COFF::IMAGE_SCN_ALIGN_8BYTES; break;
389 case 16: Characteristics |= COFF::IMAGE_SCN_ALIGN_16BYTES; break;
390 case 32: Characteristics |= COFF::IMAGE_SCN_ALIGN_32BYTES; break;
391 case 64: Characteristics |= COFF::IMAGE_SCN_ALIGN_64BYTES; break;
392 case 128: Characteristics |= COFF::IMAGE_SCN_ALIGN_128BYTES; break;
393 case 256: Characteristics |= COFF::IMAGE_SCN_ALIGN_256BYTES; break;
394 case 512: Characteristics |= COFF::IMAGE_SCN_ALIGN_512BYTES; break;
395 case 1024: Characteristics |= COFF::IMAGE_SCN_ALIGN_1024BYTES; break;
396 case 2048: Characteristics |= COFF::IMAGE_SCN_ALIGN_2048BYTES; break;
397 case 4096: Characteristics |= COFF::IMAGE_SCN_ALIGN_4096BYTES; break;
398 case 8192: Characteristics |= COFF::IMAGE_SCN_ALIGN_8192BYTES; break;
400 llvm_unreachable("unsupported section alignment");
403 // Bind internal COFF section to MC section.
404 coff_section->MCData = &SectionData;
405 SectionMap[&SectionData] = coff_section;
408 /// This function takes a section data object from the assembler
409 /// and creates the associated COFF symbol staging object.
410 void WinCOFFObjectWriter::DefineSymbol(MCSymbolData const &SymbolData,
411 MCAssembler &Assembler) {
412 assert(!SymbolData.getSymbol().isVariable()
413 && "Cannot define a symbol that is a variable!");
414 COFFSymbol *coff_symbol = createSymbol(SymbolData.getSymbol().getName());
416 coff_symbol->Data.Type = (SymbolData.getFlags() & 0x0000FFFF) >> 0;
417 coff_symbol->Data.StorageClass = (SymbolData.getFlags() & 0x00FF0000) >> 16;
419 // If no storage class was specified in the streamer, define it here.
420 if (coff_symbol->Data.StorageClass == 0) {
421 bool external = SymbolData.isExternal() || (SymbolData.Fragment == NULL);
423 coff_symbol->Data.StorageClass =
424 external ? COFF::IMAGE_SYM_CLASS_EXTERNAL : COFF::IMAGE_SYM_CLASS_STATIC;
427 if (SymbolData.getFlags() & COFF::SF_WeakReference) {
428 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);
439 const MCSymbolData &OtherSymbolData =
440 Assembler.getSymbolData(SymbolRef->getSymbol());
442 // FIXME: This assert message isn't very good.
443 assert(SymbolMap.find(&OtherSymbolData) != SymbolMap.end() &&
444 "OtherSymbolData must be in the symbol map!");
446 coff_symbol->Other = SymbolMap[&OtherSymbolData];
448 // Setup the Weak External auxiliary symbol.
449 coff_symbol->Aux.resize(1);
450 memset(&coff_symbol->Aux[0], 0, sizeof(coff_symbol->Aux[0]));
451 coff_symbol->Aux[0].AuxType = ATWeakExternal;
452 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = 0;
453 coff_symbol->Aux[0].Aux.WeakExternal.Characteristics =
454 COFF::IMAGE_WEAK_EXTERN_SEARCH_LIBRARY;
457 if (SymbolData.Fragment != NULL)
458 coff_symbol->Section = SectionMap[SymbolData.Fragment->getParent()];
460 // Bind internal COFF symbol to MC symbol.
461 coff_symbol->MCData = &SymbolData;
462 SymbolMap[&SymbolData] = coff_symbol;
465 /// making a section real involves assigned it a number and putting
466 /// name into the string table if needed
467 void WinCOFFObjectWriter::MakeSectionReal(COFFSection &S, size_t Number) {
468 if (S.Name.size() > COFF::NameSize) {
469 size_t StringTableEntry = Strings.insert(S.Name.c_str());
471 // FIXME: Why is this number 999999? This number is never mentioned in the
472 // spec. I'm assuming this is due to the printed value needing to fit into
473 // the S.Header.Name field. In which case why not 9999999 (7 9's instead of
474 // 6)? The spec does not state if this entry should be null terminated in
475 // this case, and thus this seems to be the best way to do it. I think I
476 // just solved my own FIXME...
477 if (StringTableEntry > 999999)
478 report_fatal_error("COFF string table is greater than 999999 bytes.");
480 std::sprintf(S.Header.Name, "/%d", unsigned(StringTableEntry));
482 std::memcpy(S.Header.Name, S.Name.c_str(), S.Name.size());
485 S.Symbol->Data.SectionNumber = S.Number;
486 S.Symbol->Aux[0].Aux.SectionDefinition.Number = S.Number;
489 void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
490 if (S.Name.size() > COFF::NameSize) {
491 size_t StringTableEntry = Strings.insert(S.Name.c_str());
493 S.set_name_offset(StringTableEntry);
495 std::memcpy(S.Data.Name, S.Name.c_str(), S.Name.size());
499 bool WinCOFFObjectWriter::ExportSection(COFFSection const *S) {
500 return !S->MCData->getFragmentList().empty();
503 bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
505 // This doesn't seem to be right. Strings referred to from the .data section
506 // need symbols so they can be linked to code in the .text section right?
508 // return Asm.isSymbolLinkerVisible (&SymbolData);
510 // For now, all non-variable symbols are exported,
511 // the linker will sort the rest out for us.
512 return !SymbolData.getSymbol().isVariable();
515 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
516 return (S->Header.Characteristics
517 & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
520 //------------------------------------------------------------------------------
521 // entity writing methods
523 void WinCOFFObjectWriter::WriteFileHeader(const COFF::header &Header) {
524 WriteLE16(Header.Machine);
525 WriteLE16(Header.NumberOfSections);
526 WriteLE32(Header.TimeDateStamp);
527 WriteLE32(Header.PointerToSymbolTable);
528 WriteLE32(Header.NumberOfSymbols);
529 WriteLE16(Header.SizeOfOptionalHeader);
530 WriteLE16(Header.Characteristics);
533 void WinCOFFObjectWriter::WriteSymbol(const COFFSymbol *S) {
534 WriteBytes(StringRef(S->Data.Name, COFF::NameSize));
535 WriteLE32(S->Data.Value);
536 WriteLE16(S->Data.SectionNumber);
537 WriteLE16(S->Data.Type);
538 Write8(S->Data.StorageClass);
539 Write8(S->Data.NumberOfAuxSymbols);
540 WriteAuxiliarySymbols(S->Aux);
543 void WinCOFFObjectWriter::WriteAuxiliarySymbols(
544 const COFFSymbol::AuxiliarySymbols &S) {
545 for(COFFSymbol::AuxiliarySymbols::const_iterator i = S.begin(), e = S.end();
548 case ATFunctionDefinition:
549 WriteLE32(i->Aux.FunctionDefinition.TagIndex);
550 WriteLE32(i->Aux.FunctionDefinition.TotalSize);
551 WriteLE32(i->Aux.FunctionDefinition.PointerToLinenumber);
552 WriteLE32(i->Aux.FunctionDefinition.PointerToNextFunction);
553 WriteZeros(sizeof(i->Aux.FunctionDefinition.unused));
555 case ATbfAndefSymbol:
556 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused1));
557 WriteLE16(i->Aux.bfAndefSymbol.Linenumber);
558 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused2));
559 WriteLE32(i->Aux.bfAndefSymbol.PointerToNextFunction);
560 WriteZeros(sizeof(i->Aux.bfAndefSymbol.unused3));
563 WriteLE32(i->Aux.WeakExternal.TagIndex);
564 WriteLE32(i->Aux.WeakExternal.Characteristics);
565 WriteZeros(sizeof(i->Aux.WeakExternal.unused));
568 WriteBytes(StringRef(reinterpret_cast<const char *>(i->Aux.File.FileName),
569 sizeof(i->Aux.File.FileName)));
571 case ATSectionDefinition:
572 WriteLE32(i->Aux.SectionDefinition.Length);
573 WriteLE16(i->Aux.SectionDefinition.NumberOfRelocations);
574 WriteLE16(i->Aux.SectionDefinition.NumberOfLinenumbers);
575 WriteLE32(i->Aux.SectionDefinition.CheckSum);
576 WriteLE16(i->Aux.SectionDefinition.Number);
577 Write8(i->Aux.SectionDefinition.Selection);
578 WriteZeros(sizeof(i->Aux.SectionDefinition.unused));
584 void WinCOFFObjectWriter::WriteSectionHeader(const COFF::section &S) {
585 WriteBytes(StringRef(S.Name, COFF::NameSize));
587 WriteLE32(S.VirtualSize);
588 WriteLE32(S.VirtualAddress);
589 WriteLE32(S.SizeOfRawData);
590 WriteLE32(S.PointerToRawData);
591 WriteLE32(S.PointerToRelocations);
592 WriteLE32(S.PointerToLineNumbers);
593 WriteLE16(S.NumberOfRelocations);
594 WriteLE16(S.NumberOfLineNumbers);
595 WriteLE32(S.Characteristics);
598 void WinCOFFObjectWriter::WriteRelocation(const COFF::relocation &R) {
599 WriteLE32(R.VirtualAddress);
600 WriteLE32(R.SymbolTableIndex);
604 ////////////////////////////////////////////////////////////////////////////////
605 // MCObjectWriter interface implementations
607 void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm) {
608 // "Define" each section & symbol. This creates section & symbol
609 // entries in the staging area.
611 for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++)
614 for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
615 e = Asm.symbol_end(); i != e; i++) {
616 if (ExportSymbol(*i, Asm))
617 DefineSymbol(*i, Asm);
621 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
622 const MCAsmLayout &Layout,
623 const MCFragment *Fragment,
624 const MCFixup &Fixup,
626 uint64_t &FixedValue) {
627 assert(Target.getSymA() != NULL && "Relocation must reference a symbol!");
629 const MCSymbol *A = &Target.getSymA()->getSymbol();
630 MCSymbolData &A_SD = Asm.getSymbolData(*A);
632 MCSectionData const *SectionData = Fragment->getParent();
634 // Mark this symbol as requiring an entry in the symbol table.
635 assert(SectionMap.find(SectionData) != SectionMap.end() &&
636 "Section must already have been defined in ExecutePostLayoutBinding!");
637 assert(SymbolMap.find(&A_SD) != SymbolMap.end() &&
638 "Symbol must already have been defined in ExecutePostLayoutBinding!");
640 COFFSection *coff_section = SectionMap[SectionData];
641 COFFSymbol *coff_symbol = SymbolMap[&A_SD];
643 if (Target.getSymB()) {
644 if (&Target.getSymA()->getSymbol().getSection()
645 != &Target.getSymB()->getSymbol().getSection()) {
646 llvm_unreachable("Symbol relative relocations are only allowed between "
647 "symbols in the same section");
649 const MCSymbol *B = &Target.getSymB()->getSymbol();
650 MCSymbolData &B_SD = Asm.getSymbolData(*B);
652 FixedValue = Layout.getSymbolAddress(&A_SD) - Layout.getSymbolAddress(&B_SD);
654 // In the case where we have SymbA and SymB, we just need to store the delta
655 // between the two symbols. Update FixedValue to account for the delta, and
656 // skip recording the relocation.
659 FixedValue = Target.getConstant();
662 COFFRelocation Reloc;
664 Reloc.Data.SymbolTableIndex = 0;
665 Reloc.Data.VirtualAddress = Layout.getFragmentOffset(Fragment);
667 // Turn relocations for temporary symbols into section relocations.
668 if (coff_symbol->MCData->getSymbol().isTemporary()) {
669 Reloc.Symb = coff_symbol->Section->Symbol;
670 FixedValue += Layout.getFragmentOffset(coff_symbol->MCData->Fragment)
671 + coff_symbol->MCData->getOffset();
673 Reloc.Symb = coff_symbol;
675 ++Reloc.Symb->Relocations;
677 Reloc.Data.VirtualAddress += Fixup.getOffset();
679 switch (Fixup.getKind()) {
680 case X86::reloc_pcrel_4byte:
681 case X86::reloc_riprel_4byte:
682 case X86::reloc_riprel_4byte_movq_load:
683 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_REL32
684 : COFF::IMAGE_REL_I386_REL32;
685 // FIXME: Can anyone explain what this does other than adjust for the size
690 case X86::reloc_signed_4byte:
691 Reloc.Data.Type = Is64Bit ? COFF::IMAGE_REL_AMD64_ADDR32
692 : COFF::IMAGE_REL_I386_DIR32;
696 Reloc.Data.Type = COFF::IMAGE_REL_AMD64_ADDR64;
698 llvm_unreachable("unsupported relocation type");
701 llvm_unreachable("unsupported relocation type");
704 coff_section->Relocations.push_back(Reloc);
707 bool WinCOFFObjectWriter::IsFixupFullyResolved(const MCAssembler &Asm,
708 const MCValue Target,
710 const MCFragment *DF) const {
711 // If this is a PCrel relocation, find the section this fixup value is
713 const MCSection *BaseSection = 0;
715 BaseSection = &DF->getParent()->getSection();
719 const MCSection *SectionA = 0;
720 const MCSymbol *SymbolA = 0;
721 if (const MCSymbolRefExpr *A = Target.getSymA()) {
722 SymbolA = &A->getSymbol();
723 SectionA = &SymbolA->getSection();
726 const MCSection *SectionB = 0;
727 if (const MCSymbolRefExpr *B = Target.getSymB()) {
728 SectionB = &B->getSymbol().getSection();
732 return SectionA == SectionB;
734 return !SectionB && BaseSection == SectionA;
737 void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
738 const MCAsmLayout &Layout) {
739 // Assign symbol and section indexes and offsets.
740 Header.NumberOfSections = 0;
742 for (sections::iterator i = Sections.begin(),
743 e = Sections.end(); i != e; i++) {
744 if (Layout.getSectionSize((*i)->MCData) > 0) {
745 MakeSectionReal(**i, ++Header.NumberOfSections);
751 Header.NumberOfSymbols = 0;
753 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
754 COFFSymbol *coff_symbol = *i;
755 MCSymbolData const *SymbolData = coff_symbol->MCData;
757 // Update section number & offset for symbols that have them.
758 if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) {
759 assert(coff_symbol->Section != NULL);
761 coff_symbol->Data.SectionNumber = coff_symbol->Section->Number;
762 coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment)
763 + SymbolData->Offset;
766 if (coff_symbol->should_keep()) {
767 MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++);
769 // Update auxiliary symbol info.
770 coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size();
771 Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols;
773 coff_symbol->Index = -1;
776 // Fixup weak external references.
777 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) {
778 COFFSymbol *coff_symbol = *i;
779 if (coff_symbol->Other != NULL) {
780 assert(coff_symbol->Index != -1);
781 assert(coff_symbol->Aux.size() == 1 &&
782 "Symbol must contain one aux symbol!");
783 assert(coff_symbol->Aux[0].AuxType == ATWeakExternal &&
784 "Symbol's aux symbol must be a Weak External!");
785 coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index;
789 // Assign file offsets to COFF object file structures.
793 offset += COFF::HeaderSize;
794 offset += COFF::SectionSize * Header.NumberOfSections;
796 for (MCAssembler::const_iterator i = Asm.begin(),
799 COFFSection *Sec = SectionMap[i];
801 if (Sec->Number == -1)
804 Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i);
806 if (IsPhysicalSection(Sec)) {
807 Sec->Header.PointerToRawData = offset;
809 offset += Sec->Header.SizeOfRawData;
812 if (Sec->Relocations.size() > 0) {
813 Sec->Header.NumberOfRelocations = Sec->Relocations.size();
814 Sec->Header.PointerToRelocations = offset;
816 offset += COFF::RelocationSize * Sec->Relocations.size();
818 for (relocations::iterator cr = Sec->Relocations.begin(),
819 er = Sec->Relocations.end();
821 assert((*cr).Symb->Index != -1);
822 (*cr).Data.SymbolTableIndex = (*cr).Symb->Index;
826 assert(Sec->Symbol->Aux.size() == 1
827 && "Section's symbol must have one aux!");
828 AuxSymbol &Aux = Sec->Symbol->Aux[0];
829 assert(Aux.AuxType == ATSectionDefinition &&
830 "Section's symbol's aux symbol must be a Section Definition!");
831 Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData;
832 Aux.Aux.SectionDefinition.NumberOfRelocations =
833 Sec->Header.NumberOfRelocations;
834 Aux.Aux.SectionDefinition.NumberOfLinenumbers =
835 Sec->Header.NumberOfLineNumbers;
838 Header.PointerToSymbolTable = offset;
840 Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
842 // Write it all to disk...
843 WriteFileHeader(Header);
846 sections::iterator i, ie;
847 MCAssembler::const_iterator j, je;
849 for (i = Sections.begin(), ie = Sections.end(); i != ie; i++)
850 if ((*i)->Number != -1)
851 WriteSectionHeader((*i)->Header);
853 for (i = Sections.begin(), ie = Sections.end(),
854 j = Asm.begin(), je = Asm.end();
855 (i != ie) && (j != je); ++i, ++j) {
857 if ((*i)->Number == -1)
860 if ((*i)->Header.PointerToRawData != 0) {
861 assert(OS.tell() == (*i)->Header.PointerToRawData &&
862 "Section::PointerToRawData is insane!");
864 Asm.WriteSectionData(j, Layout, this);
867 if ((*i)->Relocations.size() > 0) {
868 assert(OS.tell() == (*i)->Header.PointerToRelocations &&
869 "Section::PointerToRelocations is insane!");
871 for (relocations::const_iterator k = (*i)->Relocations.begin(),
872 ke = (*i)->Relocations.end();
874 WriteRelocation(k->Data);
877 assert((*i)->Header.PointerToRelocations == 0 &&
878 "Section::PointerToRelocations is insane!");
882 assert(OS.tell() == Header.PointerToSymbolTable &&
883 "Header::PointerToSymbolTable is insane!");
885 for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++)
886 if ((*i)->Index != -1)
889 OS.write((char const *)&Strings.Data.front(), Strings.Data.size());
892 //------------------------------------------------------------------------------
893 // WinCOFFObjectWriter factory function
896 MCObjectWriter *createWinCOFFObjectWriter(raw_ostream &OS, bool is64Bit) {
897 return new WinCOFFObjectWriter(OS, is64Bit);