lib/MC/WinCOFFStreamer.cpp - platform/external/llvm - Git at Google

 //===-- llvm/MC/WinCOFFStreamer.cpp -----------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains an implementation of a Win32 COFF object file streamer.
 //
 //===----------------------------------------------------------------------===//

 #define DEBUG_TYPE "WinCOFFStreamer"

 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAsmLayout.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/MC/MCWin64EH.h"
 #include "llvm/Support/COFF.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"

 using namespace llvm;

 namespace {
 class WinCOFFStreamer : public MCObjectStreamer {
 public:
   MCSymbol const *CurSymbol;

   WinCOFFStreamer(MCContext &Context,
                   MCAsmBackend &MAB,
                   MCCodeEmitter &CE,
                   raw_ostream &OS);

   void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                        unsigned ByteAlignment, bool External);

   // MCStreamer interface

   virtual void InitSections();
   virtual void InitToTextSection();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitDebugLabel(MCSymbol *Symbol);
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
   virtual void EmitThumbFunc(MCSymbol *Func);
   virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
   virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
   virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
   virtual void EmitCOFFSymbolStorageClass(int StorageClass);
   virtual void EmitCOFFSymbolType(int Type);
   virtual void EndCOFFSymbolDef();
   virtual void EmitCOFFSecRel32(MCSymbol const *Symbol);
   virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
   virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                 unsigned ByteAlignment);
   virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                      unsigned ByteAlignment);
   virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
                             uint64_t Size,unsigned ByteAlignment);
   virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
                               uint64_t Size, unsigned ByteAlignment);
   virtual void EmitFileDirective(StringRef Filename);
   virtual void EmitWin64EHHandlerData();
   virtual void FinishImpl();

   static bool classof(const MCStreamer *S) {
     return S->getKind() == SK_WinCOFFStreamer;
   }

 private:
   virtual void EmitInstToData(const MCInst &Inst) {
     MCDataFragment *DF = getOrCreateDataFragment();

     SmallVector<MCFixup, 4> Fixups;
     SmallString<256> Code;
     raw_svector_ostream VecOS(Code);
     getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
     VecOS.flush();

     // Add the fixups and data.
     for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
       Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
       DF->getFixups().push_back(Fixups[i]);
     }
     DF->getContents().append(Code.begin(), Code.end());
   }

   void SetSection(StringRef Section,
                   unsigned Characteristics,
                   SectionKind Kind) {
     SwitchSection(getContext().getCOFFSection(Section, Characteristics, Kind));
   }

   void SetSectionText() {
     SetSection(".text",
                COFF::IMAGE_SCN_CNT_CODE
              | COFF::IMAGE_SCN_MEM_EXECUTE
              | COFF::IMAGE_SCN_MEM_READ,
                SectionKind::getText());
     EmitCodeAlignment(4, 0);
   }

   void SetSectionData() {
     SetSection(".data",
                COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
              | COFF::IMAGE_SCN_MEM_READ
              | COFF::IMAGE_SCN_MEM_WRITE,
                SectionKind::getDataRel());
     EmitCodeAlignment(4, 0);
   }

   void SetSectionBSS() {
     SetSection(".bss",
                COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA
              | COFF::IMAGE_SCN_MEM_READ
              | COFF::IMAGE_SCN_MEM_WRITE,
                SectionKind::getBSS());
     EmitCodeAlignment(4, 0);
   }
 };
 } // end anonymous namespace.

 WinCOFFStreamer::WinCOFFStreamer(MCContext &Context, MCAsmBackend &MAB,
                                  MCCodeEmitter &CE, raw_ostream &OS)
     : MCObjectStreamer(SK_WinCOFFStreamer, Context, MAB, OS, &CE),
       CurSymbol(NULL) {}

 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                       unsigned ByteAlignment, bool External) {
   assert(!Symbol->isInSection() && "Symbol must not already have a section!");

   std::string SectionName(".bss$linkonce");
   SectionName.append(Symbol->getName().begin(), Symbol->getName().end());

   MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);

   unsigned Characteristics =
     COFF::IMAGE_SCN_LNK_COMDAT |
     COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
     COFF::IMAGE_SCN_MEM_READ |
     COFF::IMAGE_SCN_MEM_WRITE;

   int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;

   const MCSection *Section = MCStreamer::getContext().getCOFFSection(
     SectionName, Characteristics, Selection, SectionKind::getBSS());

   MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);

   if (SectionData.getAlignment() < ByteAlignment)
     SectionData.setAlignment(ByteAlignment);

   SymbolData.setExternal(External);

   Symbol->setSection(*Section);

   if (ByteAlignment != 1)
       new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);

   SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
 }

 // MCStreamer interface

 void WinCOFFStreamer::InitToTextSection() {
   SetSectionText();
 }

 void WinCOFFStreamer::InitSections() {
   SetSectionText();
   SetSectionData();
   SetSectionBSS();
   SetSectionText();
 }

 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
   assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
   MCObjectStreamer::EmitLabel(Symbol);
 }

 void WinCOFFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
   EmitLabel(Symbol);
 }
 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
   llvm_unreachable("not implemented");
 }

 void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
   llvm_unreachable("not implemented");
 }

 void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
                                           MCSymbolAttr Attribute) {
   assert(Symbol && "Symbol must be non-null!");
   assert((Symbol->isInSection()
          ? Symbol->getSection().getVariant() == MCSection::SV_COFF
          : true) && "Got non COFF section in the COFF backend!");
   switch (Attribute) {
   case MCSA_WeakReference:
   case MCSA_Weak: {
       MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
       SD.modifyFlags(COFF::SF_WeakExternal, COFF::SF_WeakExternal);
       SD.setExternal(true);
     }
     break;

   case MCSA_Global:
     getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
     break;

   default:
     llvm_unreachable("unsupported attribute");
   }
 }

 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
   llvm_unreachable("not implemented");
 }

 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
   assert((Symbol->isInSection()
          ? Symbol->getSection().getVariant() == MCSection::SV_COFF
          : true) && "Got non COFF section in the COFF backend!");
   assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
                               "to BeginCOFFSymbolDef!");
   CurSymbol = Symbol;
 }

 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
   assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
   assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
                                         "the first byte!");

   getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
     StorageClass << COFF::SF_ClassShift,
     COFF::SF_ClassMask);
 }

 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
   assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
   assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
                                   "bytes");

   getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
     Type << COFF::SF_TypeShift,
     COFF::SF_TypeMask);
 }

 void WinCOFFStreamer::EndCOFFSymbolDef() {
   assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
   CurSymbol = NULL;
 }

 void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol)
 {
   MCDataFragment *DF = getOrCreateDataFragment();

   DF->getFixups().push_back(
       MCFixup::Create(DF->getContents().size(),
                       MCSymbolRefExpr::Create (Symbol, getContext ()),
                       FK_SecRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }

 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
   llvm_unreachable("not implemented");
 }

 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                        unsigned ByteAlignment) {
   assert((Symbol->isInSection()
          ? Symbol->getSection().getVariant() == MCSection::SV_COFF
          : true) && "Got non COFF section in the COFF backend!");
   AddCommonSymbol(Symbol, Size, ByteAlignment, true);
 }

 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                             unsigned ByteAlignment) {
   assert((Symbol->isInSection()
          ? Symbol->getSection().getVariant() == MCSection::SV_COFF
          : true) && "Got non COFF section in the COFF backend!");
   AddCommonSymbol(Symbol, Size, ByteAlignment, false);
 }

 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
                                    uint64_t Size,unsigned ByteAlignment) {
   llvm_unreachable("not implemented");
 }

 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
                                      uint64_t Size, unsigned ByteAlignment) {
   llvm_unreachable("not implemented");
 }

 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
   // Ignore for now, linkers don't care, and proper debug
   // info will be a much large effort.
 }

 void WinCOFFStreamer::EmitWin64EHHandlerData() {
   MCStreamer::EmitWin64EHHandlerData();

   // We have to emit the unwind info now, because this directive
   // actually switches to the .xdata section!
   MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo());
 }

 void WinCOFFStreamer::FinishImpl() {
   EmitW64Tables();
   MCObjectStreamer::FinishImpl();
 }

 namespace llvm
 {
   MCStreamer *createWinCOFFStreamer(MCContext &Context,
                                     MCAsmBackend &MAB,
                                     MCCodeEmitter &CE,
                                     raw_ostream &OS,
                                     bool RelaxAll) {
     WinCOFFStreamer *S = new WinCOFFStreamer(Context, MAB, CE, OS);
     S->getAssembler().setRelaxAll(RelaxAll);
     return S;
   }
 }
	//===-- llvm/MC/WinCOFFStreamer.cpp ------------------------------ C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file contains an implementation of a Win32 COFF object file streamer.
	//
	//===----------------------------------------------------------------------===//

	#define DEBUG_TYPE "WinCOFFStreamer"

	#include "llvm/MC/MCStreamer.h"
	#include "llvm/MC/MCAsmBackend.h"
	#include "llvm/MC/MCAsmLayout.h"
	#include "llvm/MC/MCAssembler.h"
	#include "llvm/MC/MCCodeEmitter.h"
	#include "llvm/MC/MCContext.h"
	#include "llvm/MC/MCExpr.h"
	#include "llvm/MC/MCObjectStreamer.h"
	#include "llvm/MC/MCSection.h"
	#include "llvm/MC/MCSectionCOFF.h"
	#include "llvm/MC/MCSymbol.h"
	#include "llvm/MC/MCValue.h"
	#include "llvm/MC/MCWin64EH.h"
	#include "llvm/Support/COFF.h"
	#include "llvm/Support/Debug.h"
	#include "llvm/Support/ErrorHandling.h"
	#include "llvm/Support/TargetRegistry.h"
	#include "llvm/Support/raw_ostream.h"

	using namespace llvm;

	namespace {
	class WinCOFFStreamer : public MCObjectStreamer {
	public:
	MCSymbol const *CurSymbol;

	WinCOFFStreamer(MCContext &Context,
	MCAsmBackend &MAB,
	MCCodeEmitter &CE,
	raw_ostream &OS);

	void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
	unsigned ByteAlignment, bool External);

	// MCStreamer interface

	virtual void InitSections();
	virtual void InitToTextSection();
	virtual void EmitLabel(MCSymbol *Symbol);
	virtual void EmitDebugLabel(MCSymbol *Symbol);
	virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
	virtual void EmitThumbFunc(MCSymbol *Func);
	virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
	virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
	virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
	virtual void EmitCOFFSymbolStorageClass(int StorageClass);
	virtual void EmitCOFFSymbolType(int Type);
	virtual void EndCOFFSymbolDef();
	virtual void EmitCOFFSecRel32(MCSymbol const *Symbol);
	virtual void EmitELFSize(MCSymbol Symbol, const MCExpr Value);
	virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
	unsigned ByteAlignment);
	virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
	unsigned ByteAlignment);
	virtual void EmitZerofill(const MCSection Section, MCSymbol Symbol,
	uint64_t Size,unsigned ByteAlignment);
	virtual void EmitTBSSSymbol(const MCSection Section, MCSymbol Symbol,
	uint64_t Size, unsigned ByteAlignment);
	virtual void EmitFileDirective(StringRef Filename);
	virtual void EmitWin64EHHandlerData();
	virtual void FinishImpl();

	static bool classof(const MCStreamer *S) {
	return S->getKind() == SK_WinCOFFStreamer;
	}

	private:
	virtual void EmitInstToData(const MCInst &Inst) {
	MCDataFragment *DF = getOrCreateDataFragment();

	SmallVector<MCFixup, 4> Fixups;
	SmallString<256> Code;
	raw_svector_ostream VecOS(Code);
	getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
	VecOS.flush();

	// Add the fixups and data.
	for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
	Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
	DF->getFixups().push_back(Fixups[i]);
	}
	DF->getContents().append(Code.begin(), Code.end());
	}

	void SetSection(StringRef Section,
	unsigned Characteristics,
	SectionKind Kind) {
	SwitchSection(getContext().getCOFFSection(Section, Characteristics, Kind));
	}

	void SetSectionText() {
	SetSection(".text",
	COFF::IMAGE_SCN_CNT_CODE
	\| COFF::IMAGE_SCN_MEM_EXECUTE
	\| COFF::IMAGE_SCN_MEM_READ,
	SectionKind::getText());
	EmitCodeAlignment(4, 0);
	}

	void SetSectionData() {
	SetSection(".data",
	COFF::IMAGE_SCN_CNT_INITIALIZED_DATA
	\| COFF::IMAGE_SCN_MEM_READ
	\| COFF::IMAGE_SCN_MEM_WRITE,
	SectionKind::getDataRel());
	EmitCodeAlignment(4, 0);
	}

	void SetSectionBSS() {
	SetSection(".bss",
	COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA
	\| COFF::IMAGE_SCN_MEM_READ
	\| COFF::IMAGE_SCN_MEM_WRITE,
	SectionKind::getBSS());
	EmitCodeAlignment(4, 0);
	}
	};
	} // end anonymous namespace.

	WinCOFFStreamer::WinCOFFStreamer(MCContext &Context, MCAsmBackend &MAB,
	MCCodeEmitter &CE, raw_ostream &OS)
	: MCObjectStreamer(SK_WinCOFFStreamer, Context, MAB, OS, &CE),
	CurSymbol(NULL) {}

	void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
	unsigned ByteAlignment, bool External) {
	assert(!Symbol->isInSection() && "Symbol must not already have a section!");

	std::string SectionName(".bss$linkonce");
	SectionName.append(Symbol->getName().begin(), Symbol->getName().end());

	MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);

	unsigned Characteristics =
	COFF::IMAGE_SCN_LNK_COMDAT \|
	COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA \|
	COFF::IMAGE_SCN_MEM_READ \|
	COFF::IMAGE_SCN_MEM_WRITE;

	int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;

	const MCSection *Section = MCStreamer::getContext().getCOFFSection(
	SectionName, Characteristics, Selection, SectionKind::getBSS());

	MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);

	if (SectionData.getAlignment() < ByteAlignment)
	SectionData.setAlignment(ByteAlignment);

	SymbolData.setExternal(External);

	Symbol->setSection(*Section);

	if (ByteAlignment != 1)
	new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);

	SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
	}

	// MCStreamer interface

	void WinCOFFStreamer::InitToTextSection() {
	SetSectionText();
	}

	void WinCOFFStreamer::InitSections() {
	SetSectionText();
	SetSectionData();
	SetSectionBSS();
	SetSectionText();
	}

	void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
	assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
	MCObjectStreamer::EmitLabel(Symbol);
	}

	void WinCOFFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
	EmitLabel(Symbol);
	}
	void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
	llvm_unreachable("not implemented");
	}

	void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
	llvm_unreachable("not implemented");
	}

	void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
	MCSymbolAttr Attribute) {
	assert(Symbol && "Symbol must be non-null!");
	assert((Symbol->isInSection()
	? Symbol->getSection().getVariant() == MCSection::SV_COFF
	: true) && "Got non COFF section in the COFF backend!");
	switch (Attribute) {
	case MCSA_WeakReference:
	case MCSA_Weak: {
	MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
	SD.modifyFlags(COFF::SF_WeakExternal, COFF::SF_WeakExternal);
	SD.setExternal(true);
	}
	break;

	case MCSA_Global:
	getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
	break;

	default:
	llvm_unreachable("unsupported attribute");
	}
	}

	void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
	llvm_unreachable("not implemented");
	}

	void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
	assert((Symbol->isInSection()
	? Symbol->getSection().getVariant() == MCSection::SV_COFF
	: true) && "Got non COFF section in the COFF backend!");
	assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
	"to BeginCOFFSymbolDef!");
	CurSymbol = Symbol;
	}

	void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
	assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
	assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
	"the first byte!");

	getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
	StorageClass << COFF::SF_ClassShift,
	COFF::SF_ClassMask);
	}

	void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
	assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
	assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
	"bytes");

	getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
	Type << COFF::SF_TypeShift,
	COFF::SF_TypeMask);
	}

	void WinCOFFStreamer::EndCOFFSymbolDef() {
	assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
	CurSymbol = NULL;
	}

	void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol)
	{
	MCDataFragment *DF = getOrCreateDataFragment();

	DF->getFixups().push_back(
	MCFixup::Create(DF->getContents().size(),
	MCSymbolRefExpr::Create (Symbol, getContext ()),
	FK_SecRel_4));
	DF->getContents().resize(DF->getContents().size() + 4, 0);
	}

	void WinCOFFStreamer::EmitELFSize(MCSymbol Symbol, const MCExpr Value) {
	llvm_unreachable("not implemented");
	}

	void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
	unsigned ByteAlignment) {
	assert((Symbol->isInSection()
	? Symbol->getSection().getVariant() == MCSection::SV_COFF
	: true) && "Got non COFF section in the COFF backend!");
	AddCommonSymbol(Symbol, Size, ByteAlignment, true);
	}

	void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
	unsigned ByteAlignment) {
	assert((Symbol->isInSection()
	? Symbol->getSection().getVariant() == MCSection::SV_COFF
	: true) && "Got non COFF section in the COFF backend!");
	AddCommonSymbol(Symbol, Size, ByteAlignment, false);
	}

	void WinCOFFStreamer::EmitZerofill(const MCSection Section, MCSymbol Symbol,
	uint64_t Size,unsigned ByteAlignment) {
	llvm_unreachable("not implemented");
	}

	void WinCOFFStreamer::EmitTBSSSymbol(const MCSection Section, MCSymbol Symbol,
	uint64_t Size, unsigned ByteAlignment) {
	llvm_unreachable("not implemented");
	}

	void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
	// Ignore for now, linkers don't care, and proper debug
	// info will be a much large effort.
	}

	void WinCOFFStreamer::EmitWin64EHHandlerData() {
	MCStreamer::EmitWin64EHHandlerData();

	// We have to emit the unwind info now, because this directive
	// actually switches to the .xdata section!
	MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo());
	}

	void WinCOFFStreamer::FinishImpl() {
	EmitW64Tables();
	MCObjectStreamer::FinishImpl();
	}

	namespace llvm
	{
	MCStreamer *createWinCOFFStreamer(MCContext &Context,
	MCAsmBackend &MAB,
	MCCodeEmitter &CE,
	raw_ostream &OS,
	bool RelaxAll) {
	WinCOFFStreamer *S = new WinCOFFStreamer(Context, MAB, CE, OS);
	S->getAssembler().setRelaxAll(RelaxAll);
	return S;
	}
	}