lib/CodeGen/CGRtti.cpp - fp2-dev/platform/external/clang - Gitiles

 //===--- CGCXXRtti.cpp - Emit LLVM Code for C++ RTTI descriptors ----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This contains code dealing with C++ code generation of RTTI descriptors.
 //
 //===----------------------------------------------------------------------===//

 #include "clang/AST/Type.h"
 #include "clang/AST/RecordLayout.h"
 #include "CodeGenModule.h"
 using namespace clang;
 using namespace CodeGen;

 class RttiBuilder {
   CodeGenModule &CGM;  // Per-module state.
   llvm::LLVMContext &VMContext;
   const llvm::Type *Int8PtrTy;
   llvm::SmallSet<const CXXRecordDecl *, 16> SeenVBase;
   llvm::SmallSet<const CXXRecordDecl *, 32> SeenBase;
 public:
   RttiBuilder(CodeGenModule &cgm)
     : CGM(cgm), VMContext(cgm.getModule().getContext()),
       Int8PtrTy(llvm::Type::getInt8PtrTy(VMContext)) { }

   /// BuildVtableRef - Build a reference to a vtable.
   llvm::Constant *BuildVtableRef(const char *Name) {
     // Build a descriptor for Name
     llvm::Constant *GV = CGM.getModule().getGlobalVariable(Name);
     if (GV)
       GV = llvm::ConstantExpr::getBitCast(GV,
                                           llvm::PointerType::get(Int8PtrTy, 0));
     else {
       llvm::GlobalVariable::LinkageTypes linktype;
       linktype = llvm::GlobalValue::ExternalLinkage;
       GV = new llvm::GlobalVariable(CGM.getModule(), Int8PtrTy,
                                     true, linktype, 0, Name);
     }
     llvm::Constant *C;
     C = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), 2);
     C = llvm::ConstantExpr::getInBoundsGetElementPtr(GV, &C, 1);
     return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
   }

   llvm::Constant *BuildName(QualType Ty, bool Hidden, bool Extern) {
     llvm::SmallString<256> OutName;
     CGM.getMangleContext().mangleCXXRttiName(Ty, OutName);
     llvm::StringRef Name = OutName.str();

     llvm::GlobalVariable::LinkageTypes linktype;
     linktype = llvm::GlobalValue::LinkOnceODRLinkage;
     if (!Extern)
       linktype = llvm::GlobalValue::InternalLinkage;

     llvm::GlobalVariable *GV;
     GV = CGM.getModule().getGlobalVariable(Name);
     if (GV && !GV->isDeclaration())
       return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

     llvm::Constant *C;
     C = llvm::ConstantArray::get(VMContext, Name.substr(4));

     llvm::GlobalVariable *OGV = GV;
     GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, linktype,
                                   C, Name);
     if (OGV) {
       GV->takeName(OGV);
       llvm::Constant *NewPtr = llvm::ConstantExpr::getBitCast(GV,
                                                               OGV->getType());
       OGV->replaceAllUsesWith(NewPtr);
       OGV->eraseFromParent();
     }
     if (Hidden)
       GV->setVisibility(llvm::GlobalVariable::HiddenVisibility);
     return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
   };

   /// - BuildFlags - Build a psABI __flags value for __vmi_class_type_info.
   llvm::Constant *BuildFlags(int f) {
     return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), f);
   }

   /// BuildBaseCount - Build a psABI __base_count value for
   /// __vmi_class_type_info.
   llvm::Constant *BuildBaseCount(unsigned c) {
     return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), c);
   }

   llvm::Constant *BuildTypeRef(QualType Ty) {
     llvm::Constant *C;

     if (!CGM.getContext().getLangOptions().Rtti)
       return llvm::Constant::getNullValue(Int8PtrTy);

     llvm::SmallString<256> OutName;
     CGM.getMangleContext().mangleCXXRtti(Ty, OutName);
     llvm::StringRef Name = OutName.str();

     C = CGM.getModule().getGlobalVariable(Name);
     if (C)
       return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);

     llvm::GlobalVariable::LinkageTypes linktype;
     linktype = llvm::GlobalValue::ExternalLinkage;;

     C = new llvm::GlobalVariable(CGM.getModule(), Int8PtrTy, true, linktype,
                                  0, Name);
     return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
   }

   llvm::Constant *Buildclass_type_infoRef(const CXXRecordDecl *RD) {
     return BuildTypeRef(CGM.getContext().getTagDeclType(RD));
   }

   /// CalculateFlags - Calculate the flags for the __vmi_class_type_info
   /// datastructure.  1 for non-diamond repeated inheritance, 2 for a dimond
   /// shaped class.
   int CalculateFlags(const CXXRecordDecl*RD) {
     int flags = 0;
     if (SeenBase.count(RD))
       flags |= 1;
     else
       SeenBase.insert(RD);
     for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
            e = RD->bases_end(); i != e; ++i) {
       const CXXRecordDecl *Base =
         cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
       if (i->isVirtual()) {
         if (SeenVBase.count(Base))
           flags |= 2;
         else
           SeenVBase.insert(Base);
       }
       flags |= CalculateFlags(Base);
     }
     return flags;
   }

   bool SimpleInheritance(const CXXRecordDecl *RD) {
     if (RD->getNumBases() != 1)
       return false;
     CXXRecordDecl::base_class_const_iterator i = RD->bases_begin();
     if (i->isVirtual())
       return false;
     if (i->getAccessSpecifier() != AS_public)
       return false;

     const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
     const CXXRecordDecl *Base =
       cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
     if (Layout.getBaseClassOffset(Base) != 0)
       return false;
     return true;
   }

   llvm::Constant *finish(std::vector<llvm::Constant *> &info,
                          llvm::GlobalVariable *GV,
                          llvm::StringRef Name, bool Hidden, bool Extern) {
     llvm::GlobalVariable::LinkageTypes linktype;
     linktype = llvm::GlobalValue::LinkOnceODRLinkage;
     if (!Extern)
       linktype = llvm::GlobalValue::InternalLinkage;

     llvm::Constant *C;
     C = llvm::ConstantStruct::get(VMContext, &info[0], info.size(), false);

     llvm::GlobalVariable *OGV = GV;
     GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, linktype,
                                   C, Name);
     if (OGV) {
       GV->takeName(OGV);
       llvm::Constant *NewPtr = llvm::ConstantExpr::getBitCast(GV,
                                                               OGV->getType());
       OGV->replaceAllUsesWith(NewPtr);
       OGV->eraseFromParent();
     }
     if (Hidden)
       GV->setVisibility(llvm::GlobalVariable::HiddenVisibility);
     return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
   }


   llvm::Constant *Buildclass_type_info(const CXXRecordDecl *RD) {
     if (!CGM.getContext().getLangOptions().Rtti)
       return llvm::Constant::getNullValue(Int8PtrTy);

     llvm::Constant *C;

     llvm::SmallString<256> OutName;
     CGM.getMangleContext().mangleCXXRtti(CGM.getContext().getTagDeclType(RD),
                                          OutName);
     llvm::StringRef Name = OutName.str();

     llvm::GlobalVariable *GV;
     GV = CGM.getModule().getGlobalVariable(Name);
     if (GV && !GV->isDeclaration())
       return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

     std::vector<llvm::Constant *> info;

     bool Hidden = CGM.getDeclVisibilityMode(RD) == LangOptions::Hidden;
     bool Extern = !RD->isInAnonymousNamespace();

     bool simple = false;
     if (RD->getNumBases() == 0)
       C = BuildVtableRef("_ZTVN10__cxxabiv117__class_type_infoE");
     else if (SimpleInheritance(RD)) {
       simple = true;
       C = BuildVtableRef("_ZTVN10__cxxabiv120__si_class_type_infoE");
     } else
       C = BuildVtableRef("_ZTVN10__cxxabiv121__vmi_class_type_infoE");
     info.push_back(C);
     info.push_back(BuildName(CGM.getContext().getTagDeclType(RD), Hidden,
                              Extern));

     // If we have no bases, there are no more fields.
     if (RD->getNumBases()) {
       if (!simple) {
         info.push_back(BuildFlags(CalculateFlags(RD)));
         info.push_back(BuildBaseCount(RD->getNumBases()));
       }

       const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
       for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
              e = RD->bases_end(); i != e; ++i) {
         const CXXRecordDecl *Base =
           cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
         info.push_back(CGM.GenerateRttiRef(Base));
         if (simple)
           break;
         int64_t offset;
         if (!i->isVirtual())
           offset = Layout.getBaseClassOffset(Base)/8;
         else
           offset = CGM.getVtableInfo().getVirtualBaseOffsetIndex(RD, Base);
         offset <<= 8;
         // Now set the flags.
         offset += i->isVirtual() ? 1 : 0;;
         offset += i->getAccessSpecifier() == AS_public ? 2 : 0;
         const llvm::Type *LongTy =
           CGM.getTypes().ConvertType(CGM.getContext().LongTy);
         C = llvm::ConstantInt::get(LongTy, offset);
         info.push_back(C);
       }
     }

     return finish(info, GV, Name, Hidden, Extern);
   }

   /// - BuildFlags - Build a __flags value for __pbase_type_info.
   llvm::Constant *BuildInt(int f) {
     return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), f);
   }

   bool DecideExtern(QualType Ty) {
     // For this type, see if all components are never in an anonymous namespace.
     if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>())
       return (DecideExtern(MPT->getPointeeType())
               && DecideExtern(QualType(MPT->getClass(), 0)));
     if (const PointerType *PT = Ty->getAs<PointerType>())
       return DecideExtern(PT->getPointeeType());
     if (const RecordType *RT = Ty->getAs<RecordType>())
       if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
         return !RD->isInAnonymousNamespace();
     return true;
   }

   bool DecideHidden(QualType Ty) {
     // For this type, see if all components are never hidden.
     if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>())
       return (DecideHidden(MPT->getPointeeType())
               && DecideHidden(QualType(MPT->getClass(), 0)));
     if (const PointerType *PT = Ty->getAs<PointerType>())
       return DecideHidden(PT->getPointeeType());
     if (const RecordType *RT = Ty->getAs<RecordType>())
       if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
         return CGM.getDeclVisibilityMode(RD) == LangOptions::Hidden;
     return false;
   }

   llvm::Constant *BuildPointerType(QualType Ty) {
     llvm::Constant *C;

     llvm::SmallString<256> OutName;
     CGM.getMangleContext().mangleCXXRtti(Ty, OutName);
     llvm::StringRef Name = OutName.str();

     llvm::GlobalVariable *GV;
     GV = CGM.getModule().getGlobalVariable(Name);
     if (GV && !GV->isDeclaration())
       return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

     std::vector<llvm::Constant *> info;

     bool Extern = DecideExtern(Ty);
     bool Hidden = DecideHidden(Ty);

     QualType PTy = Ty->getPointeeType();
     QualType BTy;
     bool PtrMem = false;
     if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(Ty)) {
       PtrMem = true;
       BTy = QualType(MPT->getClass(), 0);
       PTy = MPT->getPointeeType();
     }

     if (PtrMem)
       C = BuildVtableRef("_ZTVN10__cxxabiv129__pointer_to_member_type_infoE");
     else
       C = BuildVtableRef("_ZTVN10__cxxabiv119__pointer_type_infoE");
     info.push_back(C);
     info.push_back(BuildName(Ty, Hidden, Extern));
     Qualifiers Q = PTy.getQualifiers();
     PTy = CGM.getContext().getCanonicalType(PTy).getUnqualifiedType();
     int flags = 0;
     flags += Q.hasConst() ? 0x1 : 0;
     flags += Q.hasVolatile() ? 0x2 : 0;
     flags += Q.hasRestrict() ? 0x4 : 0;
     flags += Ty.getTypePtr()->isIncompleteType() ? 0x8 : 0;
     if (PtrMem && BTy.getTypePtr()->isIncompleteType())
       flags += 0x10;

     info.push_back(BuildInt(flags));
     info.push_back(BuildInt(0));
     info.push_back(BuildType(PTy));

     if (PtrMem)
       info.push_back(BuildType(BTy));

     // We always generate these as hidden, only the name isn't hidden.
     return finish(info, GV, Name, true, Extern);
   }

   llvm::Constant *BuildSimpleType(QualType Ty, const char *vtbl) {
     llvm::Constant *C;

     llvm::SmallString<256> OutName;
     CGM.getMangleContext().mangleCXXRtti(Ty, OutName);
     llvm::StringRef Name = OutName.str();

     llvm::GlobalVariable *GV;
     GV = CGM.getModule().getGlobalVariable(Name);
     if (GV && !GV->isDeclaration())
       return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

     std::vector<llvm::Constant *> info;

     bool Extern = DecideExtern(Ty);
     bool Hidden = DecideHidden(Ty);

     C = BuildVtableRef(vtbl);
     info.push_back(C);
     info.push_back(BuildName(Ty, Hidden, Extern));

     // We always generate these as hidden, only the name isn't hidden.
     return finish(info, GV, Name, true, Extern);
   }

   llvm::Constant *BuildType(QualType Ty) {
     const clang::Type &Type
       = *CGM.getContext().getCanonicalType(Ty).getTypePtr();

     if (const RecordType *RT = Ty.getTypePtr()->getAs<RecordType>())
       if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()))
         return Buildclass_type_info(RD);

     switch (Type.getTypeClass()) {
     default: {
       assert(0 && "typeid expression");
       return llvm::Constant::getNullValue(Int8PtrTy);
     }

     case Type::Builtin: {
       // We expect all type_info objects for builtin types to be in the library.
       return BuildTypeRef(Ty);
     }

     case Type::Pointer: {
       QualType PTy = Ty->getPointeeType();
       Qualifiers Q = PTy.getQualifiers();
       Q.removeConst();
       // T* and const T* for all builtin types T are expected in the library.
       if (isa<BuiltinType>(PTy) && Q.empty())
         return BuildTypeRef(Ty);

       return BuildPointerType(Ty);
     }
     case Type::MemberPointer:
       return BuildPointerType(Ty);
     case Type::FunctionProto:
     case Type::FunctionNoProto:
       return BuildSimpleType(Ty, "_ZTVN10__cxxabiv120__function_type_infoE");
     case Type::ConstantArray:
     case Type::IncompleteArray:
     case Type::VariableArray:
     case Type::Vector:
     case Type::ExtVector:
       return BuildSimpleType(Ty, "_ZTVN10__cxxabiv117__array_type_infoE");
     case Type::Enum:
       return BuildSimpleType(Ty, "_ZTVN10__cxxabiv116__enum_type_infoE");
     }
   }
 };

 llvm::Constant *CodeGenModule::GenerateRttiRef(const CXXRecordDecl *RD) {
   RttiBuilder b(*this);

   return b.Buildclass_type_infoRef(RD);
 }

 llvm::Constant *CodeGenModule::GenerateRtti(const CXXRecordDecl *RD) {
   RttiBuilder b(*this);

   return b.Buildclass_type_info(RD);
 }

 llvm::Constant *CodeGenModule::GenerateRtti(QualType Ty) {
   RttiBuilder b(*this);

   return b.BuildType(Ty);
 }
	//===--- CGCXXRtti.cpp - Emit LLVM Code for C++ RTTI descriptors ----------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This contains code dealing with C++ code generation of RTTI descriptors.
	//
	//===----------------------------------------------------------------------===//

	#include "clang/AST/Type.h"
	#include "clang/AST/RecordLayout.h"
	#include "CodeGenModule.h"
	using namespace clang;
	using namespace CodeGen;

	class RttiBuilder {
	CodeGenModule &CGM; // Per-module state.
	llvm::LLVMContext &VMContext;
	const llvm::Type *Int8PtrTy;
	llvm::SmallSet<const CXXRecordDecl *, 16> SeenVBase;
	llvm::SmallSet<const CXXRecordDecl *, 32> SeenBase;
	public:
	RttiBuilder(CodeGenModule &cgm)
	: CGM(cgm), VMContext(cgm.getModule().getContext()),
	Int8PtrTy(llvm::Type::getInt8PtrTy(VMContext)) { }

	/// BuildVtableRef - Build a reference to a vtable.
	llvm::Constant BuildVtableRef(const char Name) {
	// Build a descriptor for Name
	llvm::Constant *GV = CGM.getModule().getGlobalVariable(Name);
	if (GV)
	GV = llvm::ConstantExpr::getBitCast(GV,
	llvm::PointerType::get(Int8PtrTy, 0));
	else {
	llvm::GlobalVariable::LinkageTypes linktype;
	linktype = llvm::GlobalValue::ExternalLinkage;
	GV = new llvm::GlobalVariable(CGM.getModule(), Int8PtrTy,
	true, linktype, 0, Name);
	}
	llvm::Constant *C;
	C = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), 2);
	C = llvm::ConstantExpr::getInBoundsGetElementPtr(GV, &C, 1);
	return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
	}

	llvm::Constant *BuildName(QualType Ty, bool Hidden, bool Extern) {
	llvm::SmallString<256> OutName;
	CGM.getMangleContext().mangleCXXRttiName(Ty, OutName);
	llvm::StringRef Name = OutName.str();

	llvm::GlobalVariable::LinkageTypes linktype;
	linktype = llvm::GlobalValue::LinkOnceODRLinkage;
	if (!Extern)
	linktype = llvm::GlobalValue::InternalLinkage;

	llvm::GlobalVariable *GV;
	GV = CGM.getModule().getGlobalVariable(Name);
	if (GV && !GV->isDeclaration())
	return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

	llvm::Constant *C;
	C = llvm::ConstantArray::get(VMContext, Name.substr(4));

	llvm::GlobalVariable *OGV = GV;
	GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, linktype,
	C, Name);
	if (OGV) {
	GV->takeName(OGV);
	llvm::Constant *NewPtr = llvm::ConstantExpr::getBitCast(GV,
	OGV->getType());
	OGV->replaceAllUsesWith(NewPtr);
	OGV->eraseFromParent();
	}
	if (Hidden)
	GV->setVisibility(llvm::GlobalVariable::HiddenVisibility);
	return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
	};

	/// - BuildFlags - Build a psABI __flags value for __vmi_class_type_info.
	llvm::Constant *BuildFlags(int f) {
	return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), f);
	}

	/// BuildBaseCount - Build a psABI __base_count value for
	/// __vmi_class_type_info.
	llvm::Constant *BuildBaseCount(unsigned c) {
	return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), c);
	}

	llvm::Constant *BuildTypeRef(QualType Ty) {
	llvm::Constant *C;

	if (!CGM.getContext().getLangOptions().Rtti)
	return llvm::Constant::getNullValue(Int8PtrTy);

	llvm::SmallString<256> OutName;
	CGM.getMangleContext().mangleCXXRtti(Ty, OutName);
	llvm::StringRef Name = OutName.str();

	C = CGM.getModule().getGlobalVariable(Name);
	if (C)
	return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);

	llvm::GlobalVariable::LinkageTypes linktype;
	linktype = llvm::GlobalValue::ExternalLinkage;;

	C = new llvm::GlobalVariable(CGM.getModule(), Int8PtrTy, true, linktype,
	0, Name);
	return llvm::ConstantExpr::getBitCast(C, Int8PtrTy);
	}

	llvm::Constant Buildclass_type_infoRef(const CXXRecordDecl RD) {
	return BuildTypeRef(CGM.getContext().getTagDeclType(RD));
	}

	/// CalculateFlags - Calculate the flags for the __vmi_class_type_info
	/// datastructure. 1 for non-diamond repeated inheritance, 2 for a dimond
	/// shaped class.
	int CalculateFlags(const CXXRecordDecl*RD) {
	int flags = 0;
	if (SeenBase.count(RD))
	flags \|= 1;
	else
	SeenBase.insert(RD);
	for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
	e = RD->bases_end(); i != e; ++i) {
	const CXXRecordDecl *Base =
	cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
	if (i->isVirtual()) {
	if (SeenVBase.count(Base))
	flags \|= 2;
	else
	SeenVBase.insert(Base);
	}
	flags \|= CalculateFlags(Base);
	}
	return flags;
	}

	bool SimpleInheritance(const CXXRecordDecl *RD) {
	if (RD->getNumBases() != 1)
	return false;
	CXXRecordDecl::base_class_const_iterator i = RD->bases_begin();
	if (i->isVirtual())
	return false;
	if (i->getAccessSpecifier() != AS_public)
	return false;

	const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
	const CXXRecordDecl *Base =
	cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
	if (Layout.getBaseClassOffset(Base) != 0)
	return false;
	return true;
	}

	llvm::Constant finish(std::vector<llvm::Constant > &info,
	llvm::GlobalVariable *GV,
	llvm::StringRef Name, bool Hidden, bool Extern) {
	llvm::GlobalVariable::LinkageTypes linktype;
	linktype = llvm::GlobalValue::LinkOnceODRLinkage;
	if (!Extern)
	linktype = llvm::GlobalValue::InternalLinkage;

	llvm::Constant *C;
	C = llvm::ConstantStruct::get(VMContext, &info[0], info.size(), false);

	llvm::GlobalVariable *OGV = GV;
	GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true, linktype,
	C, Name);
	if (OGV) {
	GV->takeName(OGV);
	llvm::Constant *NewPtr = llvm::ConstantExpr::getBitCast(GV,
	OGV->getType());
	OGV->replaceAllUsesWith(NewPtr);
	OGV->eraseFromParent();
	}
	if (Hidden)
	GV->setVisibility(llvm::GlobalVariable::HiddenVisibility);
	return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
	}


	llvm::Constant Buildclass_type_info(const CXXRecordDecl RD) {
	if (!CGM.getContext().getLangOptions().Rtti)
	return llvm::Constant::getNullValue(Int8PtrTy);

	llvm::Constant *C;

	llvm::SmallString<256> OutName;
	CGM.getMangleContext().mangleCXXRtti(CGM.getContext().getTagDeclType(RD),
	OutName);
	llvm::StringRef Name = OutName.str();

	llvm::GlobalVariable *GV;
	GV = CGM.getModule().getGlobalVariable(Name);
	if (GV && !GV->isDeclaration())
	return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

	std::vector<llvm::Constant *> info;

	bool Hidden = CGM.getDeclVisibilityMode(RD) == LangOptions::Hidden;
	bool Extern = !RD->isInAnonymousNamespace();

	bool simple = false;
	if (RD->getNumBases() == 0)
	C = BuildVtableRef("_ZTVN10__cxxabiv117__class_type_infoE");
	else if (SimpleInheritance(RD)) {
	simple = true;
	C = BuildVtableRef("_ZTVN10__cxxabiv120__si_class_type_infoE");
	} else
	C = BuildVtableRef("_ZTVN10__cxxabiv121__vmi_class_type_infoE");
	info.push_back(C);
	info.push_back(BuildName(CGM.getContext().getTagDeclType(RD), Hidden,
	Extern));

	// If we have no bases, there are no more fields.
	if (RD->getNumBases()) {
	if (!simple) {
	info.push_back(BuildFlags(CalculateFlags(RD)));
	info.push_back(BuildBaseCount(RD->getNumBases()));
	}

	const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
	for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
	e = RD->bases_end(); i != e; ++i) {
	const CXXRecordDecl *Base =
	cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
	info.push_back(CGM.GenerateRttiRef(Base));
	if (simple)
	break;
	int64_t offset;
	if (!i->isVirtual())
	offset = Layout.getBaseClassOffset(Base)/8;
	else
	offset = CGM.getVtableInfo().getVirtualBaseOffsetIndex(RD, Base);
	offset <<= 8;
	// Now set the flags.
	offset += i->isVirtual() ? 1 : 0;;
	offset += i->getAccessSpecifier() == AS_public ? 2 : 0;
	const llvm::Type *LongTy =
	CGM.getTypes().ConvertType(CGM.getContext().LongTy);
	C = llvm::ConstantInt::get(LongTy, offset);
	info.push_back(C);
	}
	}

	return finish(info, GV, Name, Hidden, Extern);
	}

	/// - BuildFlags - Build a __flags value for __pbase_type_info.
	llvm::Constant *BuildInt(int f) {
	return llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), f);
	}

	bool DecideExtern(QualType Ty) {
	// For this type, see if all components are never in an anonymous namespace.
	if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>())
	return (DecideExtern(MPT->getPointeeType())
	&& DecideExtern(QualType(MPT->getClass(), 0)));
	if (const PointerType *PT = Ty->getAs<PointerType>())
	return DecideExtern(PT->getPointeeType());
	if (const RecordType *RT = Ty->getAs<RecordType>())
	if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
	return !RD->isInAnonymousNamespace();
	return true;
	}

	bool DecideHidden(QualType Ty) {
	// For this type, see if all components are never hidden.
	if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>())
	return (DecideHidden(MPT->getPointeeType())
	&& DecideHidden(QualType(MPT->getClass(), 0)));
	if (const PointerType *PT = Ty->getAs<PointerType>())
	return DecideHidden(PT->getPointeeType());
	if (const RecordType *RT = Ty->getAs<RecordType>())
	if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
	return CGM.getDeclVisibilityMode(RD) == LangOptions::Hidden;
	return false;
	}

	llvm::Constant *BuildPointerType(QualType Ty) {
	llvm::Constant *C;

	llvm::SmallString<256> OutName;
	CGM.getMangleContext().mangleCXXRtti(Ty, OutName);
	llvm::StringRef Name = OutName.str();

	llvm::GlobalVariable *GV;
	GV = CGM.getModule().getGlobalVariable(Name);
	if (GV && !GV->isDeclaration())
	return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

	std::vector<llvm::Constant *> info;

	bool Extern = DecideExtern(Ty);
	bool Hidden = DecideHidden(Ty);

	QualType PTy = Ty->getPointeeType();
	QualType BTy;
	bool PtrMem = false;
	if (const MemberPointerType *MPT = dyn_cast<MemberPointerType>(Ty)) {
	PtrMem = true;
	BTy = QualType(MPT->getClass(), 0);
	PTy = MPT->getPointeeType();
	}

	if (PtrMem)
	C = BuildVtableRef("_ZTVN10__cxxabiv129__pointer_to_member_type_infoE");
	else
	C = BuildVtableRef("_ZTVN10__cxxabiv119__pointer_type_infoE");
	info.push_back(C);
	info.push_back(BuildName(Ty, Hidden, Extern));
	Qualifiers Q = PTy.getQualifiers();
	PTy = CGM.getContext().getCanonicalType(PTy).getUnqualifiedType();
	int flags = 0;
	flags += Q.hasConst() ? 0x1 : 0;
	flags += Q.hasVolatile() ? 0x2 : 0;
	flags += Q.hasRestrict() ? 0x4 : 0;
	flags += Ty.getTypePtr()->isIncompleteType() ? 0x8 : 0;
	if (PtrMem && BTy.getTypePtr()->isIncompleteType())
	flags += 0x10;

	info.push_back(BuildInt(flags));
	info.push_back(BuildInt(0));
	info.push_back(BuildType(PTy));

	if (PtrMem)
	info.push_back(BuildType(BTy));

	// We always generate these as hidden, only the name isn't hidden.
	return finish(info, GV, Name, true, Extern);
	}

	llvm::Constant BuildSimpleType(QualType Ty, const char vtbl) {
	llvm::Constant *C;

	llvm::SmallString<256> OutName;
	CGM.getMangleContext().mangleCXXRtti(Ty, OutName);
	llvm::StringRef Name = OutName.str();

	llvm::GlobalVariable *GV;
	GV = CGM.getModule().getGlobalVariable(Name);
	if (GV && !GV->isDeclaration())
	return llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);

	std::vector<llvm::Constant *> info;

	bool Extern = DecideExtern(Ty);
	bool Hidden = DecideHidden(Ty);

	C = BuildVtableRef(vtbl);
	info.push_back(C);
	info.push_back(BuildName(Ty, Hidden, Extern));

	// We always generate these as hidden, only the name isn't hidden.
	return finish(info, GV, Name, true, Extern);
	}

	llvm::Constant *BuildType(QualType Ty) {
	const clang::Type &Type
	= *CGM.getContext().getCanonicalType(Ty).getTypePtr();

	if (const RecordType *RT = Ty.getTypePtr()->getAs<RecordType>())
	if (const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()))
	return Buildclass_type_info(RD);

	switch (Type.getTypeClass()) {
	default: {
	assert(0 && "typeid expression");
	return llvm::Constant::getNullValue(Int8PtrTy);
	}

	case Type::Builtin: {
	// We expect all type_info objects for builtin types to be in the library.
	return BuildTypeRef(Ty);
	}

	case Type::Pointer: {
	QualType PTy = Ty->getPointeeType();
	Qualifiers Q = PTy.getQualifiers();
	Q.removeConst();
	// T* and const T* for all builtin types T are expected in the library.
	if (isa<BuiltinType>(PTy) && Q.empty())
	return BuildTypeRef(Ty);

	return BuildPointerType(Ty);
	}
	case Type::MemberPointer:
	return BuildPointerType(Ty);
	case Type::FunctionProto:
	case Type::FunctionNoProto:
	return BuildSimpleType(Ty, "_ZTVN10__cxxabiv120__function_type_infoE");
	case Type::ConstantArray:
	case Type::IncompleteArray:
	case Type::VariableArray:
	case Type::Vector:
	case Type::ExtVector:
	return BuildSimpleType(Ty, "_ZTVN10__cxxabiv117__array_type_infoE");
	case Type::Enum:
	return BuildSimpleType(Ty, "_ZTVN10__cxxabiv116__enum_type_infoE");
	}
	}
	};

	llvm::Constant CodeGenModule::GenerateRttiRef(const CXXRecordDecl RD) {
	RttiBuilder b(*this);

	return b.Buildclass_type_infoRef(RD);
	}

	llvm::Constant CodeGenModule::GenerateRtti(const CXXRecordDecl RD) {
	RttiBuilder b(*this);

	return b.Buildclass_type_info(RD);
	}

	llvm::Constant *CodeGenModule::GenerateRtti(QualType Ty) {
	RttiBuilder b(*this);

	return b.BuildType(Ty);
	}