lib/Bitcode/Writer/BitcodeWriter.cpp - fp2-dev/platform/external/llvm - Gitiles

 //===--- Bitcode/Writer/Writer.cpp - Bitcode Writer -----------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by Chris Lattner and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Bitcode writer implementation.
 //
 //===----------------------------------------------------------------------===//

 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
 #include "ValueEnumerator.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Module.h"
 #include "llvm/TypeSymbolTable.h"
 #include "llvm/Support/MathExtras.h"
 using namespace llvm;

 static const unsigned CurVersion = 0;

 static void WriteStringRecord(unsigned Code, const std::string &Str,
                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
   SmallVector<unsigned, 64> Vals;

   // Code: [strlen, strchar x N]
   Vals.push_back(Str.size());
   for (unsigned i = 0, e = Str.size(); i != e; ++i)
     Vals.push_back(Str[i]);

   // Emit the finished record.
   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 }


 /// WriteTypeTable - Write out the type table for a module.
 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
   const ValueEnumerator::TypeList &TypeList = VE.getTypes();

   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
   SmallVector<uint64_t, 64> TypeVals;

   // FIXME: Set up abbrevs now that we know the width of the type fields, etc.

   // Emit an entry count so the reader can reserve space.
   TypeVals.push_back(TypeList.size());
   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
   TypeVals.clear();

   // Loop over all of the types, emitting each in turn.
   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
     const Type *T = TypeList[i].first;
     int AbbrevToUse = 0;
     unsigned Code = 0;

     switch (T->getTypeID()) {
     case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
     default: assert(0 && "Unknown type!");
     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
     case Type::IntegerTyID:
       // INTEGER: [width]
       Code = bitc::TYPE_CODE_INTEGER;
       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
       break;
     case Type::PointerTyID:
       // POINTER: [pointee type]
       Code = bitc::TYPE_CODE_POINTER;
       TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType()));
       break;

     case Type::FunctionTyID: {
       const FunctionType *FT = cast<FunctionType>(T);
       // FUNCTION: [isvararg, #pararms, paramty x N]
       Code = bitc::TYPE_CODE_FUNCTION;
       TypeVals.push_back(FT->isVarArg());
       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
       // FIXME: PARAM ATTR ID!
       TypeVals.push_back(FT->getNumParams());
       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
       break;
     }
     case Type::StructTyID: {
       const StructType *ST = cast<StructType>(T);
       // STRUCT: [ispacked, #elts, eltty x N]
       Code = bitc::TYPE_CODE_STRUCT;
       TypeVals.push_back(ST->isPacked());
       TypeVals.push_back(ST->getNumElements());
       // Output all of the element types...
       for (StructType::element_iterator I = ST->element_begin(),
            E = ST->element_end(); I != E; ++I)
         TypeVals.push_back(VE.getTypeID(*I));
       break;
     }
     case Type::ArrayTyID: {
       const ArrayType *AT = cast<ArrayType>(T);
       // ARRAY: [numelts, eltty]
       Code = bitc::TYPE_CODE_ARRAY;
       TypeVals.push_back(AT->getNumElements());
       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
       break;
     }
     case Type::VectorTyID: {
       const VectorType *VT = cast<VectorType>(T);
       // VECTOR [numelts, eltty]
       Code = bitc::TYPE_CODE_VECTOR;
       TypeVals.push_back(VT->getNumElements());
       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
       break;
     }
     }

     // Emit the finished record.
     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
     TypeVals.clear();
   }

   Stream.ExitBlock();
 }

 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
                                  const ValueEnumerator &VE,
                                  BitstreamWriter &Stream) {
   if (TST.empty()) return;

   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);

   // FIXME: Set up the abbrev, we know how many types there are!
   // FIXME: We know if the type names can use 7-bit ascii.

   SmallVector<unsigned, 64> NameVals;

   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
        TI != TE; ++TI) {
     unsigned AbbrevToUse = 0;

     // TST_ENTRY: [typeid, namelen, namechar x N]
     NameVals.push_back(VE.getTypeID(TI->second));

     const std::string &Str = TI->first;
     NameVals.push_back(Str.size());
     for (unsigned i = 0, e = Str.size(); i != e; ++i)
       NameVals.push_back(Str[i]);

     // Emit the finished record.
     Stream.EmitRecord(bitc::TST_ENTRY_CODE, NameVals, AbbrevToUse);
     NameVals.clear();
   }

   Stream.ExitBlock();
 }

 static unsigned getEncodedLinkage(const GlobalValue *GV) {
   switch (GV->getLinkage()) {
   default: assert(0 && "Invalid linkage!");
   case GlobalValue::ExternalLinkage:     return 0;
   case GlobalValue::WeakLinkage:         return 1;
   case GlobalValue::AppendingLinkage:    return 2;
   case GlobalValue::InternalLinkage:     return 3;
   case GlobalValue::LinkOnceLinkage:     return 4;
   case GlobalValue::DLLImportLinkage:    return 5;
   case GlobalValue::DLLExportLinkage:    return 6;
   case GlobalValue::ExternalWeakLinkage: return 7;
   }
 }

 static unsigned getEncodedVisibility(const GlobalValue *GV) {
   switch (GV->getVisibility()) {
   default: assert(0 && "Invalid visibility!");
   case GlobalValue::DefaultVisibility: return 0;
   case GlobalValue::HiddenVisibility:  return 1;
   }
 }

 // Emit top-level description of module, including target triple, inline asm,
 // descriptors for global variables, and function prototype info.
 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
                             BitstreamWriter &Stream) {
   // Emit the list of dependent libraries for the Module.
   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);

   // Emit various pieces of data attached to a module.
   if (!M->getTargetTriple().empty())
     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
                       0/*TODO*/, Stream);
   if (!M->getDataLayout().empty())
     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
                       0/*TODO*/, Stream);
   if (!M->getModuleInlineAsm().empty())
     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
                       0/*TODO*/, Stream);

   // Emit information about sections, computing how many there are.  Also
   // compute the maximum alignment value.
   std::map<std::string, unsigned> SectionMap;
   unsigned MaxAlignment = 0;
   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
        GV != E; ++GV) {
     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());

     if (!GV->hasSection()) continue;
     // Give section names unique ID's.
     unsigned &Entry = SectionMap[GV->getSection()];
     if (Entry != 0) continue;
     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
                       0/*TODO*/, Stream);
     Entry = SectionMap.size();
   }
   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
     if (!F->hasSection()) continue;
     // Give section names unique ID's.
     unsigned &Entry = SectionMap[F->getSection()];
     if (Entry != 0) continue;
     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
                       0/*TODO*/, Stream);
     Entry = SectionMap.size();
   }

   // Emit abbrev for globals, now that we know # sections and max alignment.
   unsigned SimpleGVarAbbrev = 0;
   if (!M->global_empty() && 0) {
     // Add an abbrev for common globals with no visibility or thread localness.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 1)); // Constant.
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 3)); // Linkage.
     if (MaxAlignment == 0)                                     // Alignment.
       Abbv->Add(BitCodeAbbrevOp(0));
     else {
       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
                                Log2_32_Ceil(MaxEncAlignment)));
     }
     if (SectionMap.empty())                                    // Section.
       Abbv->Add(BitCodeAbbrevOp(0));
     else
       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
                                Log2_32_Ceil(SectionMap.size())));
     // Don't bother emitting vis + thread local.
     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
   }

   // Emit the global variable information.
   SmallVector<unsigned, 64> Vals;
   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
        GV != E; ++GV) {
     unsigned AbbrevToUse = 0;

     // GLOBALVAR: [type, isconst, initid,
     //             linkage, alignment, section, visibility, threadlocal]
     Vals.push_back(VE.getTypeID(GV->getType()));
     Vals.push_back(GV->isConstant());
     Vals.push_back(GV->isDeclaration() ? 0 :
                    (VE.getValueID(GV->getInitializer()) + 1));
     Vals.push_back(getEncodedLinkage(GV));
     Vals.push_back(Log2_32(GV->getAlignment())+1);
     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
     if (GV->isThreadLocal() ||
         GV->getVisibility() != GlobalValue::DefaultVisibility) {
       Vals.push_back(getEncodedVisibility(GV));
       Vals.push_back(GV->isThreadLocal());
     } else {
       AbbrevToUse = SimpleGVarAbbrev;
     }

     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
     Vals.clear();
   }

   // Emit the function proto information.
   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
     // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
     //             visibility]
     Vals.push_back(VE.getTypeID(F->getType()));
     Vals.push_back(F->getCallingConv());
     Vals.push_back(F->isDeclaration());
     Vals.push_back(getEncodedLinkage(F));
     Vals.push_back(Log2_32(F->getAlignment())+1);
     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
     Vals.push_back(getEncodedVisibility(F));

     unsigned AbbrevToUse = 0;
     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
     Vals.clear();
   }
 }


 /// WriteModule - Emit the specified module to the bitstream.
 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 2);

   // Emit the version number if it is non-zero.
   if (CurVersion) {
     SmallVector<unsigned, 1> VersionVals;
     VersionVals.push_back(CurVersion);
     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, VersionVals);
   }

   // Analyze the module, enumerating globals, functions, etc.
   ValueEnumerator VE(M);

   // Emit information describing all of the types in the module.
   WriteTypeTable(VE, Stream);

   // FIXME: Emit constants.

   // Emit top-level description of module, including target triple, inline asm,
   // descriptors for global variables, and function prototype info.
   WriteModuleInfo(M, VE, Stream);

   // Emit the type symbol table information.
   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
   Stream.ExitBlock();
 }

 /// WriteBitcodeToFile - Write the specified module to the specified output
 /// stream.
 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
   std::vector<unsigned char> Buffer;
   BitstreamWriter Stream(Buffer);

   Buffer.reserve(256*1024);

   // Emit the file header.
   Stream.Emit((unsigned)'B', 8);
   Stream.Emit((unsigned)'C', 8);
   Stream.Emit(0x0, 4);
   Stream.Emit(0xC, 4);
   Stream.Emit(0xE, 4);
   Stream.Emit(0xD, 4);

   // Emit the module.
   WriteModule(M, Stream);

   // Write the generated bitstream to "Out".
   Out.write((char*)&Buffer.front(), Buffer.size());
 }
	//===--- Bitcode/Writer/Writer.cpp - Bitcode Writer -----------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file was developed by Chris Lattner and is distributed under
	// the University of Illinois Open Source License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// Bitcode writer implementation.
	//
	//===----------------------------------------------------------------------===//

	#include "llvm/Bitcode/ReaderWriter.h"
	#include "llvm/Bitcode/BitstreamWriter.h"
	#include "llvm/Bitcode/LLVMBitCodes.h"
	#include "ValueEnumerator.h"
	#include "llvm/DerivedTypes.h"
	#include "llvm/Module.h"
	#include "llvm/TypeSymbolTable.h"
	#include "llvm/Support/MathExtras.h"
	using namespace llvm;

	static const unsigned CurVersion = 0;

	static void WriteStringRecord(unsigned Code, const std::string &Str,
	unsigned AbbrevToUse, BitstreamWriter &Stream) {
	SmallVector<unsigned, 64> Vals;

	// Code: [strlen, strchar x N]
	Vals.push_back(Str.size());
	for (unsigned i = 0, e = Str.size(); i != e; ++i)
	Vals.push_back(Str[i]);

	// Emit the finished record.
	Stream.EmitRecord(Code, Vals, AbbrevToUse);
	}


	/// WriteTypeTable - Write out the type table for a module.
	static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
	const ValueEnumerator::TypeList &TypeList = VE.getTypes();

	Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /count from # abbrevs /);
	SmallVector<uint64_t, 64> TypeVals;

	// FIXME: Set up abbrevs now that we know the width of the type fields, etc.

	// Emit an entry count so the reader can reserve space.
	TypeVals.push_back(TypeList.size());
	Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
	TypeVals.clear();

	// Loop over all of the types, emitting each in turn.
	for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
	const Type *T = TypeList[i].first;
	int AbbrevToUse = 0;
	unsigned Code = 0;

	switch (T->getTypeID()) {
	case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
	default: assert(0 && "Unknown type!");
	case Type::VoidTyID: Code = bitc::TYPE_CODE_VOID; break;
	case Type::FloatTyID: Code = bitc::TYPE_CODE_FLOAT; break;
	case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
	case Type::LabelTyID: Code = bitc::TYPE_CODE_LABEL; break;
	case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
	case Type::IntegerTyID:
	// INTEGER: [width]
	Code = bitc::TYPE_CODE_INTEGER;
	TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
	break;
	case Type::PointerTyID:
	// POINTER: [pointee type]
	Code = bitc::TYPE_CODE_POINTER;
	TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType()));
	break;

	case Type::FunctionTyID: {
	const FunctionType *FT = cast<FunctionType>(T);
	// FUNCTION: [isvararg, #pararms, paramty x N]
	Code = bitc::TYPE_CODE_FUNCTION;
	TypeVals.push_back(FT->isVarArg());
	TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
	// FIXME: PARAM ATTR ID!
	TypeVals.push_back(FT->getNumParams());
	for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
	TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
	break;
	}
	case Type::StructTyID: {
	const StructType *ST = cast<StructType>(T);
	// STRUCT: [ispacked, #elts, eltty x N]
	Code = bitc::TYPE_CODE_STRUCT;
	TypeVals.push_back(ST->isPacked());
	TypeVals.push_back(ST->getNumElements());
	// Output all of the element types...
	for (StructType::element_iterator I = ST->element_begin(),
	E = ST->element_end(); I != E; ++I)
	TypeVals.push_back(VE.getTypeID(*I));
	break;
	}
	case Type::ArrayTyID: {
	const ArrayType *AT = cast<ArrayType>(T);
	// ARRAY: [numelts, eltty]
	Code = bitc::TYPE_CODE_ARRAY;
	TypeVals.push_back(AT->getNumElements());
	TypeVals.push_back(VE.getTypeID(AT->getElementType()));
	break;
	}
	case Type::VectorTyID: {
	const VectorType *VT = cast<VectorType>(T);
	// VECTOR [numelts, eltty]
	Code = bitc::TYPE_CODE_VECTOR;
	TypeVals.push_back(VT->getNumElements());
	TypeVals.push_back(VE.getTypeID(VT->getElementType()));
	break;
	}
	}

	// Emit the finished record.
	Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
	TypeVals.clear();
	}

	Stream.ExitBlock();
	}

	/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
	static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
	const ValueEnumerator &VE,
	BitstreamWriter &Stream) {
	if (TST.empty()) return;

	Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);

	// FIXME: Set up the abbrev, we know how many types there are!
	// FIXME: We know if the type names can use 7-bit ascii.

	SmallVector<unsigned, 64> NameVals;

	for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
	TI != TE; ++TI) {
	unsigned AbbrevToUse = 0;

	// TST_ENTRY: [typeid, namelen, namechar x N]
	NameVals.push_back(VE.getTypeID(TI->second));

	const std::string &Str = TI->first;
	NameVals.push_back(Str.size());
	for (unsigned i = 0, e = Str.size(); i != e; ++i)
	NameVals.push_back(Str[i]);

	// Emit the finished record.
	Stream.EmitRecord(bitc::TST_ENTRY_CODE, NameVals, AbbrevToUse);
	NameVals.clear();
	}

	Stream.ExitBlock();
	}

	static unsigned getEncodedLinkage(const GlobalValue *GV) {
	switch (GV->getLinkage()) {
	default: assert(0 && "Invalid linkage!");
	case GlobalValue::ExternalLinkage: return 0;
	case GlobalValue::WeakLinkage: return 1;
	case GlobalValue::AppendingLinkage: return 2;
	case GlobalValue::InternalLinkage: return 3;
	case GlobalValue::LinkOnceLinkage: return 4;
	case GlobalValue::DLLImportLinkage: return 5;
	case GlobalValue::DLLExportLinkage: return 6;
	case GlobalValue::ExternalWeakLinkage: return 7;
	}
	}

	static unsigned getEncodedVisibility(const GlobalValue *GV) {
	switch (GV->getVisibility()) {
	default: assert(0 && "Invalid visibility!");
	case GlobalValue::DefaultVisibility: return 0;
	case GlobalValue::HiddenVisibility: return 1;
	}
	}

	// Emit top-level description of module, including target triple, inline asm,
	// descriptors for global variables, and function prototype info.
	static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
	BitstreamWriter &Stream) {
	// Emit the list of dependent libraries for the Module.
	for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
	WriteStringRecord(bitc::MODULE_CODE_DEPLIB, I, 0/TODO*/, Stream);

	// Emit various pieces of data attached to a module.
	if (!M->getTargetTriple().empty())
	WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
	0/TODO/, Stream);
	if (!M->getDataLayout().empty())
	WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
	0/TODO/, Stream);
	if (!M->getModuleInlineAsm().empty())
	WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
	0/TODO/, Stream);

	// Emit information about sections, computing how many there are. Also
	// compute the maximum alignment value.
	std::map<std::string, unsigned> SectionMap;
	unsigned MaxAlignment = 0;
	for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
	GV != E; ++GV) {
	MaxAlignment = std::max(MaxAlignment, GV->getAlignment());

	if (!GV->hasSection()) continue;
	// Give section names unique ID's.
	unsigned &Entry = SectionMap[GV->getSection()];
	if (Entry != 0) continue;
	WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
	0/TODO/, Stream);
	Entry = SectionMap.size();
	}
	for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
	MaxAlignment = std::max(MaxAlignment, F->getAlignment());
	if (!F->hasSection()) continue;
	// Give section names unique ID's.
	unsigned &Entry = SectionMap[F->getSection()];
	if (Entry != 0) continue;
	WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
	0/TODO/, Stream);
	Entry = SectionMap.size();
	}

	// Emit abbrev for globals, now that we know # sections and max alignment.
	unsigned SimpleGVarAbbrev = 0;
	if (!M->global_empty() && 0) {
	// Add an abbrev for common globals with no visibility or thread localness.
	BitCodeAbbrev *Abbv = new BitCodeAbbrev();
	Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
	Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 1)); // Constant.
	Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Initializer.
	Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 3)); // Linkage.
	if (MaxAlignment == 0) // Alignment.
	Abbv->Add(BitCodeAbbrevOp(0));
	else {
	unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
	Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
	Log2_32_Ceil(MaxEncAlignment)));
	}
	if (SectionMap.empty()) // Section.
	Abbv->Add(BitCodeAbbrevOp(0));
	else
	Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
	Log2_32_Ceil(SectionMap.size())));
	// Don't bother emitting vis + thread local.
	SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
	}

	// Emit the global variable information.
	SmallVector<unsigned, 64> Vals;
	for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
	GV != E; ++GV) {
	unsigned AbbrevToUse = 0;

	// GLOBALVAR: [type, isconst, initid,
	// linkage, alignment, section, visibility, threadlocal]
	Vals.push_back(VE.getTypeID(GV->getType()));
	Vals.push_back(GV->isConstant());
	Vals.push_back(GV->isDeclaration() ? 0 :
	(VE.getValueID(GV->getInitializer()) + 1));
	Vals.push_back(getEncodedLinkage(GV));
	Vals.push_back(Log2_32(GV->getAlignment())+1);
	Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
	if (GV->isThreadLocal() \|\|
	GV->getVisibility() != GlobalValue::DefaultVisibility) {
	Vals.push_back(getEncodedVisibility(GV));
	Vals.push_back(GV->isThreadLocal());
	} else {
	AbbrevToUse = SimpleGVarAbbrev;
	}

	Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
	Vals.clear();
	}

	// Emit the function proto information.
	for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
	// FUNCTION: [type, callingconv, isproto, linkage, alignment, section,
	// visibility]
	Vals.push_back(VE.getTypeID(F->getType()));
	Vals.push_back(F->getCallingConv());
	Vals.push_back(F->isDeclaration());
	Vals.push_back(getEncodedLinkage(F));
	Vals.push_back(Log2_32(F->getAlignment())+1);
	Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
	Vals.push_back(getEncodedVisibility(F));

	unsigned AbbrevToUse = 0;
	Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
	Vals.clear();
	}
	}


	/// WriteModule - Emit the specified module to the bitstream.
	static void WriteModule(const Module *M, BitstreamWriter &Stream) {
	Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 2);

	// Emit the version number if it is non-zero.
	if (CurVersion) {
	SmallVector<unsigned, 1> VersionVals;
	VersionVals.push_back(CurVersion);
	Stream.EmitRecord(bitc::MODULE_CODE_VERSION, VersionVals);
	}

	// Analyze the module, enumerating globals, functions, etc.
	ValueEnumerator VE(M);

	// Emit information describing all of the types in the module.
	WriteTypeTable(VE, Stream);

	// FIXME: Emit constants.

	// Emit top-level description of module, including target triple, inline asm,
	// descriptors for global variables, and function prototype info.
	WriteModuleInfo(M, VE, Stream);

	// Emit the type symbol table information.
	WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
	Stream.ExitBlock();
	}

	/// WriteBitcodeToFile - Write the specified module to the specified output
	/// stream.
	void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
	std::vector<unsigned char> Buffer;
	BitstreamWriter Stream(Buffer);

	Buffer.reserve(256*1024);

	// Emit the file header.
	Stream.Emit((unsigned)'B', 8);
	Stream.Emit((unsigned)'C', 8);
	Stream.Emit(0x0, 4);
	Stream.Emit(0xC, 4);
	Stream.Emit(0xE, 4);
	Stream.Emit(0xD, 4);

	// Emit the module.
	WriteModule(M, Stream);

	// Write the generated bitstream to "Out".
	Out.write((char*)&Buffer.front(), Buffer.size());
	}