lib/CodeGen/CodeGenModule.h - clang - Git at Google

 //===--- CodeGenModule.h - Per-Module state for LLVM CodeGen ----*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This is the internal per-translation-unit state used for llvm translation.
 //
 //===----------------------------------------------------------------------===//

 #ifndef CLANG_CODEGEN_CODEGENMODULE_H
 #define CLANG_CODEGEN_CODEGENMODULE_H

 #include "clang/Basic/LangOptions.h"
 #include "clang/AST/Attr.h"
 #include "clang/AST/DeclCXX.h"
 #include "CGBlocks.h"
 #include "CGCall.h"
 #include "CGCXX.h"
 #include "CodeGenTypes.h"
 #include "llvm/Module.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/ValueHandle.h"
 #include <list>

 namespace llvm {
   class Module;
   class Constant;
   class Function;
   class GlobalValue;
   class TargetData;
   class FunctionType;
   class LLVMContext;
 }

 namespace clang {
   class ASTContext;
   class FunctionDecl;
   class IdentifierInfo;
   class ObjCMethodDecl;
   class ObjCImplementationDecl;
   class ObjCCategoryImplDecl;
   class ObjCProtocolDecl;
   class ObjCEncodeExpr;
   class BlockExpr;
   class Decl;
   class Expr;
   class Stmt;
   class StringLiteral;
   class NamedDecl;
   class ValueDecl;
   class VarDecl;
   class LangOptions;
   class CompileOptions;
   class Diagnostic;
   class AnnotateAttr;
   class CXXDestructorDecl;

 namespace CodeGen {

   class CodeGenFunction;
   class CGDebugInfo;
   class CGObjCRuntime;

 /// GlobalDecl - represents a global declaration. This can either be a
 /// CXXConstructorDecl and the constructor type (Base, Complete).
 /// a CXXDestructorDecl and the destructor type (Base, Complete) or
 // a regular VarDecl or a FunctionDecl.
 class GlobalDecl {
   llvm::PointerIntPair<const ValueDecl*, 2> Value;

 public:
   GlobalDecl() {}

   explicit GlobalDecl(const ValueDecl *VD) : Value(VD, 0) {
     assert(!isa<CXXConstructorDecl>(VD) && "Use other ctor with ctor decls!");
     assert(!isa<CXXDestructorDecl>(VD) && "Use other ctor with dtor decls!");
   }
   GlobalDecl(const CXXConstructorDecl *D, CXXCtorType Type)
   : Value(D, Type) {}
   GlobalDecl(const CXXDestructorDecl *D, CXXDtorType Type)
   : Value(D, Type) {}

   const ValueDecl *getDecl() const { return Value.getPointer(); }

   CXXCtorType getCtorType() const {
     assert(isa<CXXConstructorDecl>(getDecl()) && "Decl is not a ctor!");
     return static_cast<CXXCtorType>(Value.getInt());
   }

   CXXDtorType getDtorType() const {
     assert(isa<CXXDestructorDecl>(getDecl()) && "Decl is not a dtor!");
     return static_cast<CXXDtorType>(Value.getInt());
   }
 };

 /// CodeGenModule - This class organizes the cross-function state that is used
 /// while generating LLVM code.
 class CodeGenModule : public BlockModule {
   CodeGenModule(const CodeGenModule&);  // DO NOT IMPLEMENT
   void operator=(const CodeGenModule&); // DO NOT IMPLEMENT

   typedef std::vector< std::pair<llvm::Constant*, int> > CtorList;

   ASTContext &Context;
   const LangOptions &Features;
   const CompileOptions &CompileOpts;
   llvm::Module &TheModule;
   const llvm::TargetData &TheTargetData;
   Diagnostic &Diags;
   CodeGenTypes Types;
   CGObjCRuntime* Runtime;
   CGDebugInfo* DebugInfo;

   llvm::Function *MemCpyFn;
   llvm::Function *MemMoveFn;
   llvm::Function *MemSetFn;

   /// GlobalDeclMap - Mapping of decl names (represented as unique
   /// character pointers from either the identifier table or the set
   /// of mangled names) to global variables we have already
   /// emitted. Note that the entries in this map are the actual
   /// globals and therefore may not be of the same type as the decl,
   /// they should be bitcasted on retrieval. Also note that the
   /// globals are keyed on their source mangled name, not the global name
   /// (which may change with attributes such as asm-labels).  The key
   /// to this map should be generated using getMangledName().
   ///
   /// Note that this map always lines up exactly with the contents of the LLVM
   /// IR symbol table, but this is quicker to query since it is doing uniqued
   /// pointer lookups instead of full string lookups.
   llvm::DenseMap<const char*, llvm::GlobalValue*> GlobalDeclMap;

   /// \brief Contains the strings used for mangled names.
   ///
   /// FIXME: Eventually, this should map from the semantic/canonical
   /// declaration for each global entity to its mangled name (if it
   /// has one).
   llvm::StringSet<> MangledNames;

   /// DeferredDecls - This contains all the decls which have definitions but
   /// which are deferred for emission and therefore should only be output if
   /// they are actually used.  If a decl is in this, then it is known to have
   /// not been referenced yet.  The key to this map is a uniqued mangled name.
   llvm::DenseMap<const char*, GlobalDecl> DeferredDecls;

   /// DeferredDeclsToEmit - This is a list of deferred decls which we have seen
   /// that *are* actually referenced.  These get code generated when the module
   /// is done.
   std::vector<GlobalDecl> DeferredDeclsToEmit;

   /// LLVMUsed - List of global values which are required to be
   /// present in the object file; bitcast to i8*. This is used for
   /// forcing visibility of symbols which may otherwise be optimized
   /// out.
   std::vector<llvm::WeakVH> LLVMUsed;

   /// GlobalCtors - Store the list of global constructors and their respective
   /// priorities to be emitted when the translation unit is complete.
   CtorList GlobalCtors;

   /// GlobalDtors - Store the list of global destructors and their respective
   /// priorities to be emitted when the translation unit is complete.
   CtorList GlobalDtors;

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

   llvm::StringMap<llvm::Constant*> CFConstantStringMap;
   llvm::StringMap<llvm::Constant*> ConstantStringMap;

   /// CXXGlobalInits - Variables with global initializers that need to run
   /// before main.
   std::vector<const VarDecl*> CXXGlobalInits;

   /// CFConstantStringClassRef - Cached reference to the class for constant
   /// strings. This value has type int * but is actually an Obj-C class pointer.
   llvm::Constant *CFConstantStringClassRef;

   llvm::LLVMContext &VMContext;
 public:
   CodeGenModule(ASTContext &C, const CompileOptions &CompileOpts,
                 llvm::Module &M, const llvm::TargetData &TD, Diagnostic &Diags);

   ~CodeGenModule();

   /// Release - Finalize LLVM code generation.
   void Release();

   /// getObjCRuntime() - Return a reference to the configured
   /// Objective-C runtime.
   CGObjCRuntime &getObjCRuntime() {
     assert(Runtime && "No Objective-C runtime has been configured.");
     return *Runtime;
   }

   /// hasObjCRuntime() - Return true iff an Objective-C runtime has
   /// been configured.
   bool hasObjCRuntime() { return !!Runtime; }

   CGDebugInfo *getDebugInfo() { return DebugInfo; }
   ASTContext &getContext() const { return Context; }
   const CompileOptions &getCompileOpts() const { return CompileOpts; }
   const LangOptions &getLangOptions() const { return Features; }
   llvm::Module &getModule() const { return TheModule; }
   CodeGenTypes &getTypes() { return Types; }
   Diagnostic &getDiags() const { return Diags; }
   const llvm::TargetData &getTargetData() const { return TheTargetData; }
   llvm::LLVMContext &getLLVMContext() { return VMContext; }

   /// getDeclVisibilityMode - Compute the visibility of the decl \arg D.
   LangOptions::VisibilityMode getDeclVisibilityMode(const Decl *D) const;

   /// setGlobalVisibility - Set the visibility for the given LLVM
   /// GlobalValue.
   void setGlobalVisibility(llvm::GlobalValue *GV, const Decl *D) const;

   /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
   /// given global variable.  If Ty is non-null and if the global doesn't exist,
   /// then it will be greated with the specified type instead of whatever the
   /// normal requested type would be.
   llvm::Constant *GetAddrOfGlobalVar(const VarDecl *D,
                                      const llvm::Type *Ty = 0);

   /// GetAddrOfFunction - Return the address of the given function.  If Ty is
   /// non-null, then this function will use the specified type if it has to
   /// create it.
   llvm::Constant *GetAddrOfFunction(GlobalDecl GD,
                                     const llvm::Type *Ty = 0);

   /// GenerateRtti - Generate the rtti information for the given type.
   llvm::Constant *GenerateRtti(const CXXRecordDecl *RD);

   /// GetStringForStringLiteral - Return the appropriate bytes for a string
   /// literal, properly padded to match the literal type. If only the address of
   /// a constant is needed consider using GetAddrOfConstantStringLiteral.
   std::string GetStringForStringLiteral(const StringLiteral *E);

   /// GetAddrOfConstantCFString - Return a pointer to a constant CFString object
   /// for the given string.
   llvm::Constant *GetAddrOfConstantCFString(const StringLiteral *Literal);

   /// GetAddrOfConstantStringFromLiteral - Return a pointer to a constant array
   /// for the given string literal.
   llvm::Constant *GetAddrOfConstantStringFromLiteral(const StringLiteral *S);

   /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
   /// array for the given ObjCEncodeExpr node.
   llvm::Constant *GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *);

   /// GetAddrOfConstantString - Returns a pointer to a character array
   /// containing the literal. This contents are exactly that of the given
   /// string, i.e. it will not be null terminated automatically; see
   /// GetAddrOfConstantCString. Note that whether the result is actually a
   /// pointer to an LLVM constant depends on Feature.WriteableStrings.
   ///
   /// The result has pointer to array type.
   ///
   /// \param GlobalName If provided, the name to use for the global
   /// (if one is created).
   llvm::Constant *GetAddrOfConstantString(const std::string& str,
                                           const char *GlobalName=0);

   /// GetAddrOfConstantCString - Returns a pointer to a character array
   /// containing the literal and a terminating '\0' character. The result has
   /// pointer to array type.
   ///
   /// \param GlobalName If provided, the name to use for the global (if one is
   /// created).
   llvm::Constant *GetAddrOfConstantCString(const std::string &str,
                                            const char *GlobalName=0);

   /// GetAddrOfCXXConstructor - Return the address of the constructor of the
   /// given type.
   llvm::Function *GetAddrOfCXXConstructor(const CXXConstructorDecl *D,
                                           CXXCtorType Type);

   /// GetAddrOfCXXDestructor - Return the address of the constructor of the
   /// given type.
   llvm::Function *GetAddrOfCXXDestructor(const CXXDestructorDecl *D,
                                          CXXDtorType Type);

   /// getBuiltinLibFunction - Given a builtin id for a function like
   /// "__builtin_fabsf", return a Function* for "fabsf".
   llvm::Value *getBuiltinLibFunction(unsigned BuiltinID);

   llvm::Function *getMemCpyFn();
   llvm::Function *getMemMoveFn();
   llvm::Function *getMemSetFn();
   llvm::Function *getIntrinsic(unsigned IID, const llvm::Type **Tys = 0,
                                unsigned NumTys = 0);

   /// EmitTopLevelDecl - Emit code for a single top level declaration.
   void EmitTopLevelDecl(Decl *D);

   /// AddUsedGlobal - Add a global which should be forced to be
   /// present in the object file; these are emitted to the llvm.used
   /// metadata global.
   void AddUsedGlobal(llvm::GlobalValue *GV);

   void AddAnnotation(llvm::Constant *C) { Annotations.push_back(C); }

   /// CreateRuntimeFunction - Create a new runtime function with the specified
   /// type and name.
   llvm::Constant *CreateRuntimeFunction(const llvm::FunctionType *Ty,
                                         const char *Name);
   /// CreateRuntimeVariable - Create a new runtime global variable with the
   /// specified type and name.
   llvm::Constant *CreateRuntimeVariable(const llvm::Type *Ty,
                                         const char *Name);

   void UpdateCompletedType(const TagDecl *TD) {
     // Make sure that this type is translated.
     Types.UpdateCompletedType(TD);
   }

   /// EmitConstantExpr - Try to emit the given expression as a
   /// constant; returns 0 if the expression cannot be emitted as a
   /// constant.
   llvm::Constant *EmitConstantExpr(const Expr *E, QualType DestType,
                                    CodeGenFunction *CGF = 0);

   /// EmitNullConstant - Return the result of value-initializing the given
   /// type, i.e. a null expression of the given type.  This is usually,
   /// but not always, an LLVM null constant.
   llvm::Constant *EmitNullConstant(QualType T);

   llvm::Constant *EmitAnnotateAttr(llvm::GlobalValue *GV,
                                    const AnnotateAttr *AA, unsigned LineNo);

   /// ErrorUnsupported - Print out an error that codegen doesn't support the
   /// specified stmt yet.
   /// \param OmitOnError - If true, then this error should only be emitted if no
   /// other errors have been reported.
   void ErrorUnsupported(const Stmt *S, const char *Type,
                         bool OmitOnError=false);

   /// ErrorUnsupported - Print out an error that codegen doesn't support the
   /// specified decl yet.
   /// \param OmitOnError - If true, then this error should only be emitted if no
   /// other errors have been reported.
   void ErrorUnsupported(const Decl *D, const char *Type,
                         bool OmitOnError=false);

   /// SetInternalFunctionAttributes - Set the attributes on the LLVM
   /// function for the given decl and function info. This applies
   /// attributes necessary for handling the ABI as well as user
   /// specified attributes like section.
   void SetInternalFunctionAttributes(const Decl *D, llvm::Function *F,
                                      const CGFunctionInfo &FI);

   /// SetLLVMFunctionAttributes - Set the LLVM function attributes
   /// (sext, zext, etc).
   void SetLLVMFunctionAttributes(const Decl *D,
                                  const CGFunctionInfo &Info,
                                  llvm::Function *F);

   /// SetLLVMFunctionAttributesForDefinition - Set the LLVM function attributes
   /// which only apply to a function definintion.
   void SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F);

   /// ReturnTypeUsesSret - Return true iff the given type uses 'sret' when used
   /// as a return type.
   bool ReturnTypeUsesSret(const CGFunctionInfo &FI);

   void ConstructAttributeList(const CGFunctionInfo &Info,
                               const Decl *TargetDecl,
                               AttributeListType &PAL);

   const char *getMangledName(const GlobalDecl &D);

   const char *getMangledName(const NamedDecl *ND);
   const char *getMangledCXXCtorName(const CXXConstructorDecl *D,
                                     CXXCtorType Type);
   const char *getMangledCXXDtorName(const CXXDestructorDecl *D,
                                     CXXDtorType Type);

   void EmitTentativeDefinition(const VarDecl *D);

   enum GVALinkage {
     GVA_Internal,
     GVA_C99Inline,
     GVA_CXXInline,
     GVA_StrongExternal,
     GVA_TemplateInstantiation
   };

 private:
   /// UniqueMangledName - Unique a name by (if necessary) inserting it into the
   /// MangledNames string map.
   const char *UniqueMangledName(const char *NameStart, const char *NameEnd);

   llvm::Constant *GetOrCreateLLVMFunction(const char *MangledName,
                                           const llvm::Type *Ty,
                                           GlobalDecl D);
   llvm::Constant *GetOrCreateLLVMGlobal(const char *MangledName,
                                         const llvm::PointerType *PTy,
                                         const VarDecl *D);
   void DeferredCopyConstructorToEmit(GlobalDecl D);
   void DeferredCopyAssignmentToEmit(GlobalDecl D);
   void DeferredDestructorToEmit(GlobalDecl D);

   /// SetCommonAttributes - Set attributes which are common to any
   /// form of a global definition (alias, Objective-C method,
   /// function, global variable).
   ///
   /// NOTE: This should only be called for definitions.
   void SetCommonAttributes(const Decl *D, llvm::GlobalValue *GV);

   /// SetFunctionDefinitionAttributes - Set attributes for a global definition.
   void SetFunctionDefinitionAttributes(const FunctionDecl *D,
                                        llvm::GlobalValue *GV);

   /// SetFunctionAttributes - Set function attributes for a function
   /// declaration.
   void SetFunctionAttributes(const FunctionDecl *FD,
                              llvm::Function *F,
                              bool IsIncompleteFunction);

   /// EmitGlobal - Emit code for a singal global function or var decl. Forward
   /// declarations are emitted lazily.
   void EmitGlobal(GlobalDecl D);

   void EmitGlobalDefinition(GlobalDecl D);

   void EmitGlobalFunctionDefinition(GlobalDecl GD);
   void EmitGlobalVarDefinition(const VarDecl *D);
   void EmitAliasDefinition(const ValueDecl *D);
   void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);

   // C++ related functions.

   void EmitNamespace(const NamespaceDecl *D);
   void EmitLinkageSpec(const LinkageSpecDecl *D);

   /// EmitCXXConstructors - Emit constructors (base, complete) from a
   /// C++ constructor Decl.
   void EmitCXXConstructors(const CXXConstructorDecl *D);

   /// EmitCXXConstructor - Emit a single constructor with the given type from
   /// a C++ constructor Decl.
   void EmitCXXConstructor(const CXXConstructorDecl *D, CXXCtorType Type);

   /// EmitCXXDestructors - Emit destructors (base, complete) from a
   /// C++ destructor Decl.
   void EmitCXXDestructors(const CXXDestructorDecl *D);

   /// EmitCXXDestructor - Emit a single destructor with the given type from
   /// a C++ destructor Decl.
   void EmitCXXDestructor(const CXXDestructorDecl *D, CXXDtorType Type);

   /// EmitCXXGlobalInitFunc - Emit a function that initializes C++ globals.
   void EmitCXXGlobalInitFunc();

   // FIXME: Hardcoding priority here is gross.
   void AddGlobalCtor(llvm::Function *Ctor, int Priority=65535);
   void AddGlobalDtor(llvm::Function *Dtor, int Priority=65535);

   /// EmitCtorList - Generates a global array of functions and priorities using
   /// the given list and name. This array will have appending linkage and is
   /// suitable for use as a LLVM constructor or destructor array.
   void EmitCtorList(const CtorList &Fns, const char *GlobalName);

   void EmitAnnotations(void);

   /// EmitDeferred - Emit any needed decls for which code generation
   /// was deferred.
   void EmitDeferred(void);

   /// EmitLLVMUsed - Emit the llvm.used metadata used to force
   /// references to global which may otherwise be optimized out.
   void EmitLLVMUsed(void);

   /// MayDeferGeneration - Determine if the given decl can be emitted
   /// lazily; this is only relevant for definitions. The given decl
   /// must be either a function or var decl.
   bool MayDeferGeneration(const ValueDecl *D);
 };
 }  // end namespace CodeGen
 }  // end namespace clang

 #endif
	//===--- CodeGenModule.h - Per-Module state for LLVM CodeGen ----- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This is the internal per-translation-unit state used for llvm translation.
	//
	//===----------------------------------------------------------------------===//

	#ifndef CLANG_CODEGEN_CODEGENMODULE_H
	#define CLANG_CODEGEN_CODEGENMODULE_H

	#include "clang/Basic/LangOptions.h"
	#include "clang/AST/Attr.h"
	#include "clang/AST/DeclCXX.h"
	#include "CGBlocks.h"
	#include "CGCall.h"
	#include "CGCXX.h"
	#include "CodeGenTypes.h"
	#include "llvm/Module.h"
	#include "llvm/ADT/DenseMap.h"
	#include "llvm/ADT/StringMap.h"
	#include "llvm/ADT/StringSet.h"
	#include "llvm/Support/ValueHandle.h"
	#include <list>

	namespace llvm {
	class Module;
	class Constant;
	class Function;
	class GlobalValue;
	class TargetData;
	class FunctionType;
	class LLVMContext;
	}

	namespace clang {
	class ASTContext;
	class FunctionDecl;
	class IdentifierInfo;
	class ObjCMethodDecl;
	class ObjCImplementationDecl;
	class ObjCCategoryImplDecl;
	class ObjCProtocolDecl;
	class ObjCEncodeExpr;
	class BlockExpr;
	class Decl;
	class Expr;
	class Stmt;
	class StringLiteral;
	class NamedDecl;
	class ValueDecl;
	class VarDecl;
	class LangOptions;
	class CompileOptions;
	class Diagnostic;
	class AnnotateAttr;
	class CXXDestructorDecl;

	namespace CodeGen {

	class CodeGenFunction;
	class CGDebugInfo;
	class CGObjCRuntime;

	/// GlobalDecl - represents a global declaration. This can either be a
	/// CXXConstructorDecl and the constructor type (Base, Complete).
	/// a CXXDestructorDecl and the destructor type (Base, Complete) or
	// a regular VarDecl or a FunctionDecl.
	class GlobalDecl {
	llvm::PointerIntPair<const ValueDecl*, 2> Value;

	public:
	GlobalDecl() {}

	explicit GlobalDecl(const ValueDecl *VD) : Value(VD, 0) {
	assert(!isa<CXXConstructorDecl>(VD) && "Use other ctor with ctor decls!");
	assert(!isa<CXXDestructorDecl>(VD) && "Use other ctor with dtor decls!");
	}
	GlobalDecl(const CXXConstructorDecl *D, CXXCtorType Type)
	: Value(D, Type) {}
	GlobalDecl(const CXXDestructorDecl *D, CXXDtorType Type)
	: Value(D, Type) {}

	const ValueDecl *getDecl() const { return Value.getPointer(); }

	CXXCtorType getCtorType() const {
	assert(isa<CXXConstructorDecl>(getDecl()) && "Decl is not a ctor!");
	return static_cast<CXXCtorType>(Value.getInt());
	}

	CXXDtorType getDtorType() const {
	assert(isa<CXXDestructorDecl>(getDecl()) && "Decl is not a dtor!");
	return static_cast<CXXDtorType>(Value.getInt());
	}
	};

	/// CodeGenModule - This class organizes the cross-function state that is used
	/// while generating LLVM code.
	class CodeGenModule : public BlockModule {
	CodeGenModule(const CodeGenModule&); // DO NOT IMPLEMENT
	void operator=(const CodeGenModule&); // DO NOT IMPLEMENT

	typedef std::vector< std::pair<llvm::Constant*, int> > CtorList;

	ASTContext &Context;
	const LangOptions &Features;
	const CompileOptions &CompileOpts;
	llvm::Module &TheModule;
	const llvm::TargetData &TheTargetData;
	Diagnostic &Diags;
	CodeGenTypes Types;
	CGObjCRuntime* Runtime;
	CGDebugInfo* DebugInfo;

	llvm::Function *MemCpyFn;
	llvm::Function *MemMoveFn;
	llvm::Function *MemSetFn;

	/// GlobalDeclMap - Mapping of decl names (represented as unique
	/// character pointers from either the identifier table or the set
	/// of mangled names) to global variables we have already
	/// emitted. Note that the entries in this map are the actual
	/// globals and therefore may not be of the same type as the decl,
	/// they should be bitcasted on retrieval. Also note that the
	/// globals are keyed on their source mangled name, not the global name
	/// (which may change with attributes such as asm-labels). The key
	/// to this map should be generated using getMangledName().
	///
	/// Note that this map always lines up exactly with the contents of the LLVM
	/// IR symbol table, but this is quicker to query since it is doing uniqued
	/// pointer lookups instead of full string lookups.
	llvm::DenseMap<const char, llvm::GlobalValue> GlobalDeclMap;

	/// \brief Contains the strings used for mangled names.
	///
	/// FIXME: Eventually, this should map from the semantic/canonical
	/// declaration for each global entity to its mangled name (if it
	/// has one).
	llvm::StringSet<> MangledNames;

	/// DeferredDecls - This contains all the decls which have definitions but
	/// which are deferred for emission and therefore should only be output if
	/// they are actually used. If a decl is in this, then it is known to have
	/// not been referenced yet. The key to this map is a uniqued mangled name.
	llvm::DenseMap<const char*, GlobalDecl> DeferredDecls;

	/// DeferredDeclsToEmit - This is a list of deferred decls which we have seen
	/// that are actually referenced. These get code generated when the module
	/// is done.
	std::vector<GlobalDecl> DeferredDeclsToEmit;

	/// LLVMUsed - List of global values which are required to be
	/// present in the object file; bitcast to i8*. This is used for
	/// forcing visibility of symbols which may otherwise be optimized
	/// out.
	std::vector<llvm::WeakVH> LLVMUsed;

	/// GlobalCtors - Store the list of global constructors and their respective
	/// priorities to be emitted when the translation unit is complete.
	CtorList GlobalCtors;

	/// GlobalDtors - Store the list of global destructors and their respective
	/// priorities to be emitted when the translation unit is complete.
	CtorList GlobalDtors;

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

	llvm::StringMap<llvm::Constant*> CFConstantStringMap;
	llvm::StringMap<llvm::Constant*> ConstantStringMap;

	/// CXXGlobalInits - Variables with global initializers that need to run
	/// before main.
	std::vector<const VarDecl*> CXXGlobalInits;

	/// CFConstantStringClassRef - Cached reference to the class for constant
	/// strings. This value has type int * but is actually an Obj-C class pointer.
	llvm::Constant *CFConstantStringClassRef;

	llvm::LLVMContext &VMContext;
	public:
	CodeGenModule(ASTContext &C, const CompileOptions &CompileOpts,
	llvm::Module &M, const llvm::TargetData &TD, Diagnostic &Diags);

	~CodeGenModule();

	/// Release - Finalize LLVM code generation.
	void Release();

	/// getObjCRuntime() - Return a reference to the configured
	/// Objective-C runtime.
	CGObjCRuntime &getObjCRuntime() {
	assert(Runtime && "No Objective-C runtime has been configured.");
	return *Runtime;
	}

	/// hasObjCRuntime() - Return true iff an Objective-C runtime has
	/// been configured.
	bool hasObjCRuntime() { return !!Runtime; }

	CGDebugInfo *getDebugInfo() { return DebugInfo; }
	ASTContext &getContext() const { return Context; }
	const CompileOptions &getCompileOpts() const { return CompileOpts; }
	const LangOptions &getLangOptions() const { return Features; }
	llvm::Module &getModule() const { return TheModule; }
	CodeGenTypes &getTypes() { return Types; }
	Diagnostic &getDiags() const { return Diags; }
	const llvm::TargetData &getTargetData() const { return TheTargetData; }
	llvm::LLVMContext &getLLVMContext() { return VMContext; }

	/// getDeclVisibilityMode - Compute the visibility of the decl \arg D.
	LangOptions::VisibilityMode getDeclVisibilityMode(const Decl *D) const;

	/// setGlobalVisibility - Set the visibility for the given LLVM
	/// GlobalValue.
	void setGlobalVisibility(llvm::GlobalValue GV, const Decl D) const;

	/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
	/// given global variable. If Ty is non-null and if the global doesn't exist,
	/// then it will be greated with the specified type instead of whatever the
	/// normal requested type would be.
	llvm::Constant GetAddrOfGlobalVar(const VarDecl D,
	const llvm::Type *Ty = 0);

	/// GetAddrOfFunction - Return the address of the given function. If Ty is
	/// non-null, then this function will use the specified type if it has to
	/// create it.
	llvm::Constant *GetAddrOfFunction(GlobalDecl GD,
	const llvm::Type *Ty = 0);

	/// GenerateRtti - Generate the rtti information for the given type.
	llvm::Constant GenerateRtti(const CXXRecordDecl RD);

	/// GetStringForStringLiteral - Return the appropriate bytes for a string
	/// literal, properly padded to match the literal type. If only the address of
	/// a constant is needed consider using GetAddrOfConstantStringLiteral.
	std::string GetStringForStringLiteral(const StringLiteral *E);

	/// GetAddrOfConstantCFString - Return a pointer to a constant CFString object
	/// for the given string.
	llvm::Constant GetAddrOfConstantCFString(const StringLiteral Literal);

	/// GetAddrOfConstantStringFromLiteral - Return a pointer to a constant array
	/// for the given string literal.
	llvm::Constant GetAddrOfConstantStringFromLiteral(const StringLiteral S);

	/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
	/// array for the given ObjCEncodeExpr node.
	llvm::Constant GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr );

	/// GetAddrOfConstantString - Returns a pointer to a character array
	/// containing the literal. This contents are exactly that of the given
	/// string, i.e. it will not be null terminated automatically; see
	/// GetAddrOfConstantCString. Note that whether the result is actually a
	/// pointer to an LLVM constant depends on Feature.WriteableStrings.
	///
	/// The result has pointer to array type.
	///
	/// \param GlobalName If provided, the name to use for the global
	/// (if one is created).
	llvm::Constant *GetAddrOfConstantString(const std::string& str,
	const char *GlobalName=0);

	/// GetAddrOfConstantCString - Returns a pointer to a character array
	/// containing the literal and a terminating '\0' character. The result has
	/// pointer to array type.
	///
	/// \param GlobalName If provided, the name to use for the global (if one is
	/// created).
	llvm::Constant *GetAddrOfConstantCString(const std::string &str,
	const char *GlobalName=0);

	/// GetAddrOfCXXConstructor - Return the address of the constructor of the
	/// given type.
	llvm::Function GetAddrOfCXXConstructor(const CXXConstructorDecl D,
	CXXCtorType Type);

	/// GetAddrOfCXXDestructor - Return the address of the constructor of the
	/// given type.
	llvm::Function GetAddrOfCXXDestructor(const CXXDestructorDecl D,
	CXXDtorType Type);

	/// getBuiltinLibFunction - Given a builtin id for a function like
	/// "__builtin_fabsf", return a Function* for "fabsf".
	llvm::Value *getBuiltinLibFunction(unsigned BuiltinID);

	llvm::Function *getMemCpyFn();
	llvm::Function *getMemMoveFn();
	llvm::Function *getMemSetFn();
	llvm::Function getIntrinsic(unsigned IID, const llvm::Type *Tys = 0,
	unsigned NumTys = 0);

	/// EmitTopLevelDecl - Emit code for a single top level declaration.
	void EmitTopLevelDecl(Decl *D);

	/// AddUsedGlobal - Add a global which should be forced to be
	/// present in the object file; these are emitted to the llvm.used
	/// metadata global.
	void AddUsedGlobal(llvm::GlobalValue *GV);

	void AddAnnotation(llvm::Constant *C) { Annotations.push_back(C); }

	/// CreateRuntimeFunction - Create a new runtime function with the specified
	/// type and name.
	llvm::Constant CreateRuntimeFunction(const llvm::FunctionType Ty,
	const char *Name);
	/// CreateRuntimeVariable - Create a new runtime global variable with the
	/// specified type and name.
	llvm::Constant CreateRuntimeVariable(const llvm::Type Ty,
	const char *Name);

	void UpdateCompletedType(const TagDecl *TD) {
	// Make sure that this type is translated.
	Types.UpdateCompletedType(TD);
	}

	/// EmitConstantExpr - Try to emit the given expression as a
	/// constant; returns 0 if the expression cannot be emitted as a
	/// constant.
	llvm::Constant EmitConstantExpr(const Expr E, QualType DestType,
	CodeGenFunction *CGF = 0);

	/// EmitNullConstant - Return the result of value-initializing the given
	/// type, i.e. a null expression of the given type. This is usually,
	/// but not always, an LLVM null constant.
	llvm::Constant *EmitNullConstant(QualType T);

	llvm::Constant EmitAnnotateAttr(llvm::GlobalValue GV,
	const AnnotateAttr *AA, unsigned LineNo);

	/// ErrorUnsupported - Print out an error that codegen doesn't support the
	/// specified stmt yet.
	/// \param OmitOnError - If true, then this error should only be emitted if no
	/// other errors have been reported.
	void ErrorUnsupported(const Stmt S, const char Type,
	bool OmitOnError=false);

	/// ErrorUnsupported - Print out an error that codegen doesn't support the
	/// specified decl yet.
	/// \param OmitOnError - If true, then this error should only be emitted if no
	/// other errors have been reported.
	void ErrorUnsupported(const Decl D, const char Type,
	bool OmitOnError=false);

	/// SetInternalFunctionAttributes - Set the attributes on the LLVM
	/// function for the given decl and function info. This applies
	/// attributes necessary for handling the ABI as well as user
	/// specified attributes like section.
	void SetInternalFunctionAttributes(const Decl D, llvm::Function F,
	const CGFunctionInfo &FI);

	/// SetLLVMFunctionAttributes - Set the LLVM function attributes
	/// (sext, zext, etc).
	void SetLLVMFunctionAttributes(const Decl *D,
	const CGFunctionInfo &Info,
	llvm::Function *F);

	/// SetLLVMFunctionAttributesForDefinition - Set the LLVM function attributes
	/// which only apply to a function definintion.
	void SetLLVMFunctionAttributesForDefinition(const Decl D, llvm::Function F);

	/// ReturnTypeUsesSret - Return true iff the given type uses 'sret' when used
	/// as a return type.
	bool ReturnTypeUsesSret(const CGFunctionInfo &FI);

	void ConstructAttributeList(const CGFunctionInfo &Info,
	const Decl *TargetDecl,
	AttributeListType &PAL);

	const char *getMangledName(const GlobalDecl &D);

	const char getMangledName(const NamedDecl ND);
	const char getMangledCXXCtorName(const CXXConstructorDecl D,
	CXXCtorType Type);
	const char getMangledCXXDtorName(const CXXDestructorDecl D,
	CXXDtorType Type);

	void EmitTentativeDefinition(const VarDecl *D);

	enum GVALinkage {
	GVA_Internal,
	GVA_C99Inline,
	GVA_CXXInline,
	GVA_StrongExternal,
	GVA_TemplateInstantiation
	};

	private:
	/// UniqueMangledName - Unique a name by (if necessary) inserting it into the
	/// MangledNames string map.
	const char UniqueMangledName(const char NameStart, const char *NameEnd);

	llvm::Constant GetOrCreateLLVMFunction(const char MangledName,
	const llvm::Type *Ty,
	GlobalDecl D);
	llvm::Constant GetOrCreateLLVMGlobal(const char MangledName,
	const llvm::PointerType *PTy,
	const VarDecl *D);
	void DeferredCopyConstructorToEmit(GlobalDecl D);
	void DeferredCopyAssignmentToEmit(GlobalDecl D);
	void DeferredDestructorToEmit(GlobalDecl D);

	/// SetCommonAttributes - Set attributes which are common to any
	/// form of a global definition (alias, Objective-C method,
	/// function, global variable).
	///
	/// NOTE: This should only be called for definitions.
	void SetCommonAttributes(const Decl D, llvm::GlobalValue GV);

	/// SetFunctionDefinitionAttributes - Set attributes for a global definition.
	void SetFunctionDefinitionAttributes(const FunctionDecl *D,
	llvm::GlobalValue *GV);

	/// SetFunctionAttributes - Set function attributes for a function
	/// declaration.
	void SetFunctionAttributes(const FunctionDecl *FD,
	llvm::Function *F,
	bool IsIncompleteFunction);

	/// EmitGlobal - Emit code for a singal global function or var decl. Forward
	/// declarations are emitted lazily.
	void EmitGlobal(GlobalDecl D);

	void EmitGlobalDefinition(GlobalDecl D);

	void EmitGlobalFunctionDefinition(GlobalDecl GD);
	void EmitGlobalVarDefinition(const VarDecl *D);
	void EmitAliasDefinition(const ValueDecl *D);
	void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);

	// C++ related functions.

	void EmitNamespace(const NamespaceDecl *D);
	void EmitLinkageSpec(const LinkageSpecDecl *D);

	/// EmitCXXConstructors - Emit constructors (base, complete) from a
	/// C++ constructor Decl.
	void EmitCXXConstructors(const CXXConstructorDecl *D);

	/// EmitCXXConstructor - Emit a single constructor with the given type from
	/// a C++ constructor Decl.
	void EmitCXXConstructor(const CXXConstructorDecl *D, CXXCtorType Type);

	/// EmitCXXDestructors - Emit destructors (base, complete) from a
	/// C++ destructor Decl.
	void EmitCXXDestructors(const CXXDestructorDecl *D);

	/// EmitCXXDestructor - Emit a single destructor with the given type from
	/// a C++ destructor Decl.
	void EmitCXXDestructor(const CXXDestructorDecl *D, CXXDtorType Type);

	/// EmitCXXGlobalInitFunc - Emit a function that initializes C++ globals.
	void EmitCXXGlobalInitFunc();

	// FIXME: Hardcoding priority here is gross.
	void AddGlobalCtor(llvm::Function *Ctor, int Priority=65535);
	void AddGlobalDtor(llvm::Function *Dtor, int Priority=65535);

	/// EmitCtorList - Generates a global array of functions and priorities using
	/// the given list and name. This array will have appending linkage and is
	/// suitable for use as a LLVM constructor or destructor array.
	void EmitCtorList(const CtorList &Fns, const char *GlobalName);

	void EmitAnnotations(void);

	/// EmitDeferred - Emit any needed decls for which code generation
	/// was deferred.
	void EmitDeferred(void);

	/// EmitLLVMUsed - Emit the llvm.used metadata used to force
	/// references to global which may otherwise be optimized out.
	void EmitLLVMUsed(void);

	/// MayDeferGeneration - Determine if the given decl can be emitted
	/// lazily; this is only relevant for definitions. The given decl
	/// must be either a function or var decl.
	bool MayDeferGeneration(const ValueDecl *D);
	};
	} // end namespace CodeGen
	} // end namespace clang

	#endif