llvm/lib/CodeGen/AsmPrinter/DIE.h - toolchain/llvm-project - Gitiles

 //===--- lib/CodeGen/DIE.h - DWARF Info Entries -----------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Data structures for DWARF info entries.
 //
 //===----------------------------------------------------------------------===//

 #ifndef CODEGEN_ASMPRINTER_DIE_H__
 #define CODEGEN_ASMPRINTER_DIE_H__

 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/MC/MCExpr.h"
 #include <vector>

 namespace llvm {
   class AsmPrinter;
   class MCSymbol;
   class MCSymbolRefExpr;
   class raw_ostream;

   //===--------------------------------------------------------------------===//
   /// DIEAbbrevData - Dwarf abbreviation data, describes one attribute of a
   /// Dwarf abbreviation.
   class DIEAbbrevData {
     /// Attribute - Dwarf attribute code.
     ///
     dwarf::Attribute Attribute;

     /// Form - Dwarf form code.
     ///
     dwarf::Form Form;
   public:
     DIEAbbrevData(dwarf::Attribute A, dwarf::Form F) : Attribute(A), Form(F) {}

     // Accessors.
     dwarf::Attribute getAttribute() const { return Attribute; }
     dwarf::Form getForm() const { return Form; }

     /// Profile - Used to gather unique data for the abbreviation folding set.
     ///
     void Profile(FoldingSetNodeID &ID) const;
   };

   //===--------------------------------------------------------------------===//
   /// DIEAbbrev - Dwarf abbreviation, describes the organization of a debug
   /// information object.
   class DIEAbbrev : public FoldingSetNode {
     /// Tag - Dwarf tag code.
     ///
     dwarf::Tag Tag;

     /// ChildrenFlag - Dwarf children flag.
     ///
     uint16_t ChildrenFlag;

     /// Unique number for node.
     ///
     unsigned Number;

     /// Data - Raw data bytes for abbreviation.
     ///
     SmallVector<DIEAbbrevData, 12> Data;

   public:
     DIEAbbrev(dwarf::Tag T, uint16_t C) : Tag(T), ChildrenFlag(C), Data() {}

     // Accessors.
     dwarf::Tag getTag() const { return Tag; }
     unsigned getNumber() const { return Number; }
     uint16_t getChildrenFlag() const { return ChildrenFlag; }
     const SmallVectorImpl<DIEAbbrevData> &getData() const { return Data; }
     void setChildrenFlag(uint16_t CF) { ChildrenFlag = CF; }
     void setNumber(unsigned N) { Number = N; }

     /// AddAttribute - Adds another set of attribute information to the
     /// abbreviation.
     void AddAttribute(dwarf::Attribute Attribute, dwarf::Form Form) {
       Data.push_back(DIEAbbrevData(Attribute, Form));
     }

     /// Profile - Used to gather unique data for the abbreviation folding set.
     ///
     void Profile(FoldingSetNodeID &ID) const;

     /// Emit - Print the abbreviation using the specified asm printer.
     ///
     void Emit(AsmPrinter *AP) const;

 #ifndef NDEBUG
     void print(raw_ostream &O);
     void dump();
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIE - A structured debug information entry.  Has an abbreviation which
   /// describes its organization.
   class DIEValue;

   class DIE {
   protected:
     /// Offset - Offset in debug info section.
     ///
     unsigned Offset;

     /// Size - Size of instance + children.
     ///
     unsigned Size;

     /// Abbrev - Buffer for constructing abbreviation.
     ///
     DIEAbbrev Abbrev;

     /// Children DIEs.
     ///
     std::vector<DIE *> Children;

     DIE *Parent;

     /// Attribute values.
     ///
     SmallVector<DIEValue*, 12> Values;

   public:
     explicit DIE(unsigned Tag)
         : Offset(0), Size(0), Abbrev((dwarf::Tag)Tag, dwarf::DW_CHILDREN_no),
           Parent(0) {}
     ~DIE();

     // Accessors.
     DIEAbbrev &getAbbrev() { return Abbrev; }
     const DIEAbbrev &getAbbrev() const { return Abbrev; }
     unsigned getAbbrevNumber() const { return Abbrev.getNumber(); }
     dwarf::Tag getTag() const { return Abbrev.getTag(); }
     unsigned getOffset() const { return Offset; }
     unsigned getSize() const { return Size; }
     const std::vector<DIE *> &getChildren() const { return Children; }
     const SmallVectorImpl<DIEValue*> &getValues() const { return Values; }
     DIE *getParent() const { return Parent; }
     /// Climb up the parent chain to get the compile or type unit DIE this DIE
     /// belongs to.
     const DIE *getUnit() const;
     /// Similar to getUnit, returns null when DIE is not added to an
     /// owner yet.
     const DIE *getUnitOrNull() const;
     void setOffset(unsigned O) { Offset = O; }
     void setSize(unsigned S) { Size = S; }

     /// addValue - Add a value and attributes to a DIE.
     ///
     void addValue(dwarf::Attribute Attribute, dwarf::Form Form,
                   DIEValue *Value) {
       Abbrev.AddAttribute(Attribute, Form);
       Values.push_back(Value);
     }

     /// addChild - Add a child to the DIE.
     ///
     void addChild(DIE *Child) {
       assert(!Child->getParent());
       Abbrev.setChildrenFlag(dwarf::DW_CHILDREN_yes);
       Children.push_back(Child);
       Child->Parent = this;
     }

     /// findAttribute - Find a value in the DIE with the attribute given,
     /// returns NULL if no such attribute exists.
     DIEValue *findAttribute(uint16_t Attribute) const;

 #ifndef NDEBUG
     void print(raw_ostream &O, unsigned IndentCount = 0) const;
     void dump();
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEValue - A debug information entry value.
   ///
   class DIEValue {
     virtual void anchor();
   public:
     enum {
       isInteger,
       isString,
       isExpr,
       isLabel,
       isDelta,
       isEntry,
       isBlock
     };
   protected:
     /// Type - Type of data stored in the value.
     ///
     unsigned Type;
   public:
     explicit DIEValue(unsigned T) : Type(T) {}
     virtual ~DIEValue() {}

     // Accessors
     unsigned getType()  const { return Type; }

     /// EmitValue - Emit value via the Dwarf writer.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const = 0;

     /// SizeOf - Return the size of a value in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const = 0;

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const = 0;
     void dump() const;
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEInteger - An integer value DIE.
   ///
   class DIEInteger : public DIEValue {
     uint64_t Integer;
   public:
     explicit DIEInteger(uint64_t I) : DIEValue(isInteger), Integer(I) {}

     /// BestForm - Choose the best form for integer.
     ///
     static dwarf::Form BestForm(bool IsSigned, uint64_t Int) {
       if (IsSigned) {
         const int64_t SignedInt = Int;
         if ((char)Int == SignedInt)     return dwarf::DW_FORM_data1;
         if ((short)Int == SignedInt)    return dwarf::DW_FORM_data2;
         if ((int)Int == SignedInt)      return dwarf::DW_FORM_data4;
       } else {
         if ((unsigned char)Int == Int)  return dwarf::DW_FORM_data1;
         if ((unsigned short)Int == Int) return dwarf::DW_FORM_data2;
         if ((unsigned int)Int == Int)   return dwarf::DW_FORM_data4;
       }
       return dwarf::DW_FORM_data8;
     }

     /// EmitValue - Emit integer of appropriate size.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     uint64_t getValue() const { return Integer; }

     /// SizeOf - Determine size of integer value in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *I) { return I->getType() == isInteger; }

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEExpr - An expression DIE.
   //
   class DIEExpr : public DIEValue {
     const MCExpr *Expr;
   public:
     explicit DIEExpr(const MCExpr *E) : DIEValue(isExpr), Expr(E) {}

     /// EmitValue - Emit expression value.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     /// getValue - Get MCExpr.
     ///
     const MCExpr *getValue() const { return Expr; }

     /// SizeOf - Determine size of expression value in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *E) { return E->getType() == isExpr; }

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIELabel - A label DIE.
   //
   class DIELabel : public DIEValue {
     const MCSymbol *Label;
   public:
     explicit DIELabel(const MCSymbol *L) : DIEValue(isLabel), Label(L) {}

     /// EmitValue - Emit label value.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     /// getValue - Get MCSymbol.
     ///
     const MCSymbol *getValue() const { return Label; }

     /// SizeOf - Determine size of label value in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *L) { return L->getType() == isLabel; }

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEDelta - A simple label difference DIE.
   ///
   class DIEDelta : public DIEValue {
     const MCSymbol *LabelHi;
     const MCSymbol *LabelLo;
   public:
     DIEDelta(const MCSymbol *Hi, const MCSymbol *Lo)
       : DIEValue(isDelta), LabelHi(Hi), LabelLo(Lo) {}

     /// EmitValue - Emit delta value.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     /// SizeOf - Determine size of delta value in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *D) { return D->getType() == isDelta; }

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEString - A container for string values.
   ///
   class DIEString : public DIEValue {
     const DIEValue *Access;
     const StringRef Str;

   public:
     DIEString(const DIEValue *Acc, const StringRef S)
         : DIEValue(isString), Access(Acc), Str(S) {}

     /// getString - Grab the string out of the object.
     StringRef getString() const { return Str; }

     /// EmitValue - Emit delta value.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     /// SizeOf - Determine size of delta value in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *D) { return D->getType() == isString; }

   #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
   #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEEntry - A pointer to another debug information entry.  An instance of
   /// this class can also be used as a proxy for a debug information entry not
   /// yet defined (ie. types.)
   class DIEEntry : public DIEValue {
     DIE *const Entry;
   public:
     explicit DIEEntry(DIE *E) : DIEValue(isEntry), Entry(E) {
       assert(E && "Cannot construct a DIEEntry with a null DIE");
     }

     DIE *getEntry() const { return Entry; }

     /// EmitValue - Emit debug information entry offset.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     /// SizeOf - Determine size of debug information entry in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const {
       return Form == dwarf::DW_FORM_ref_addr ? getRefAddrSize(AP)
                                              : sizeof(int32_t);
     }

     /// Returns size of a ref_addr entry.
     static unsigned getRefAddrSize(AsmPrinter *AP);

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *E) { return E->getType() == isEntry; }

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
 #endif
   };

   //===--------------------------------------------------------------------===//
   /// DIEBlock - A block of values.  Primarily used for location expressions.
   //
   class DIEBlock : public DIEValue, public DIE {
     unsigned Size;                // Size in bytes excluding size header.
   public:
     DIEBlock() : DIEValue(isBlock), DIE(0), Size(0) {}

     /// ComputeSize - calculate the size of the block.
     ///
     unsigned ComputeSize(AsmPrinter *AP);

     /// BestForm - Choose the best form for data.
     ///
     dwarf::Form BestForm() const {
       if ((unsigned char)Size == Size)  return dwarf::DW_FORM_block1;
       if ((unsigned short)Size == Size) return dwarf::DW_FORM_block2;
       if ((unsigned int)Size == Size)   return dwarf::DW_FORM_block4;
       return dwarf::DW_FORM_block;
     }

     /// EmitValue - Emit block data.
     ///
     virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

     /// SizeOf - Determine size of block data in bytes.
     ///
     virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *E) { return E->getType() == isBlock; }

 #ifndef NDEBUG
     virtual void print(raw_ostream &O) const;
 #endif
   };

 } // end llvm namespace

 #endif
	//===--- lib/CodeGen/DIE.h - DWARF Info Entries ------------------ C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// Data structures for DWARF info entries.
	//
	//===----------------------------------------------------------------------===//

	#ifndef CODEGEN_ASMPRINTER_DIE_H__
	#define CODEGEN_ASMPRINTER_DIE_H__

	#include "llvm/ADT/FoldingSet.h"
	#include "llvm/ADT/SmallVector.h"
	#include "llvm/Support/Compiler.h"
	#include "llvm/Support/Dwarf.h"
	#include "llvm/MC/MCExpr.h"
	#include <vector>

	namespace llvm {
	class AsmPrinter;
	class MCSymbol;
	class MCSymbolRefExpr;
	class raw_ostream;

	//===--------------------------------------------------------------------===//
	/// DIEAbbrevData - Dwarf abbreviation data, describes one attribute of a
	/// Dwarf abbreviation.
	class DIEAbbrevData {
	/// Attribute - Dwarf attribute code.
	///
	dwarf::Attribute Attribute;

	/// Form - Dwarf form code.
	///
	dwarf::Form Form;
	public:
	DIEAbbrevData(dwarf::Attribute A, dwarf::Form F) : Attribute(A), Form(F) {}

	// Accessors.
	dwarf::Attribute getAttribute() const { return Attribute; }
	dwarf::Form getForm() const { return Form; }

	/// Profile - Used to gather unique data for the abbreviation folding set.
	///
	void Profile(FoldingSetNodeID &ID) const;
	};

	//===--------------------------------------------------------------------===//
	/// DIEAbbrev - Dwarf abbreviation, describes the organization of a debug
	/// information object.
	class DIEAbbrev : public FoldingSetNode {
	/// Tag - Dwarf tag code.
	///
	dwarf::Tag Tag;

	/// ChildrenFlag - Dwarf children flag.
	///
	uint16_t ChildrenFlag;

	/// Unique number for node.
	///
	unsigned Number;

	/// Data - Raw data bytes for abbreviation.
	///
	SmallVector<DIEAbbrevData, 12> Data;

	public:
	DIEAbbrev(dwarf::Tag T, uint16_t C) : Tag(T), ChildrenFlag(C), Data() {}

	// Accessors.
	dwarf::Tag getTag() const { return Tag; }
	unsigned getNumber() const { return Number; }
	uint16_t getChildrenFlag() const { return ChildrenFlag; }
	const SmallVectorImpl<DIEAbbrevData> &getData() const { return Data; }
	void setChildrenFlag(uint16_t CF) { ChildrenFlag = CF; }
	void setNumber(unsigned N) { Number = N; }

	/// AddAttribute - Adds another set of attribute information to the
	/// abbreviation.
	void AddAttribute(dwarf::Attribute Attribute, dwarf::Form Form) {
	Data.push_back(DIEAbbrevData(Attribute, Form));
	}

	/// Profile - Used to gather unique data for the abbreviation folding set.
	///
	void Profile(FoldingSetNodeID &ID) const;

	/// Emit - Print the abbreviation using the specified asm printer.
	///
	void Emit(AsmPrinter *AP) const;

	#ifndef NDEBUG
	void print(raw_ostream &O);
	void dump();
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIE - A structured debug information entry. Has an abbreviation which
	/// describes its organization.
	class DIEValue;

	class DIE {
	protected:
	/// Offset - Offset in debug info section.
	///
	unsigned Offset;

	/// Size - Size of instance + children.
	///
	unsigned Size;

	/// Abbrev - Buffer for constructing abbreviation.
	///
	DIEAbbrev Abbrev;

	/// Children DIEs.
	///
	std::vector<DIE *> Children;

	DIE *Parent;

	/// Attribute values.
	///
	SmallVector<DIEValue*, 12> Values;

	public:
	explicit DIE(unsigned Tag)
	: Offset(0), Size(0), Abbrev((dwarf::Tag)Tag, dwarf::DW_CHILDREN_no),
	Parent(0) {}
	~DIE();

	// Accessors.
	DIEAbbrev &getAbbrev() { return Abbrev; }
	const DIEAbbrev &getAbbrev() const { return Abbrev; }
	unsigned getAbbrevNumber() const { return Abbrev.getNumber(); }
	dwarf::Tag getTag() const { return Abbrev.getTag(); }
	unsigned getOffset() const { return Offset; }
	unsigned getSize() const { return Size; }
	const std::vector<DIE *> &getChildren() const { return Children; }
	const SmallVectorImpl<DIEValue*> &getValues() const { return Values; }
	DIE *getParent() const { return Parent; }
	/// Climb up the parent chain to get the compile or type unit DIE this DIE
	/// belongs to.
	const DIE *getUnit() const;
	/// Similar to getUnit, returns null when DIE is not added to an
	/// owner yet.
	const DIE *getUnitOrNull() const;
	void setOffset(unsigned O) { Offset = O; }
	void setSize(unsigned S) { Size = S; }

	/// addValue - Add a value and attributes to a DIE.
	///
	void addValue(dwarf::Attribute Attribute, dwarf::Form Form,
	DIEValue *Value) {
	Abbrev.AddAttribute(Attribute, Form);
	Values.push_back(Value);
	}

	/// addChild - Add a child to the DIE.
	///
	void addChild(DIE *Child) {
	assert(!Child->getParent());
	Abbrev.setChildrenFlag(dwarf::DW_CHILDREN_yes);
	Children.push_back(Child);
	Child->Parent = this;
	}

	/// findAttribute - Find a value in the DIE with the attribute given,
	/// returns NULL if no such attribute exists.
	DIEValue *findAttribute(uint16_t Attribute) const;

	#ifndef NDEBUG
	void print(raw_ostream &O, unsigned IndentCount = 0) const;
	void dump();
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEValue - A debug information entry value.
	///
	class DIEValue {
	virtual void anchor();
	public:
	enum {
	isInteger,
	isString,
	isExpr,
	isLabel,
	isDelta,
	isEntry,
	isBlock
	};
	protected:
	/// Type - Type of data stored in the value.
	///
	unsigned Type;
	public:
	explicit DIEValue(unsigned T) : Type(T) {}
	virtual ~DIEValue() {}

	// Accessors
	unsigned getType() const { return Type; }

	/// EmitValue - Emit value via the Dwarf writer.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const = 0;

	/// SizeOf - Return the size of a value in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const = 0;

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const = 0;
	void dump() const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEInteger - An integer value DIE.
	///
	class DIEInteger : public DIEValue {
	uint64_t Integer;
	public:
	explicit DIEInteger(uint64_t I) : DIEValue(isInteger), Integer(I) {}

	/// BestForm - Choose the best form for integer.
	///
	static dwarf::Form BestForm(bool IsSigned, uint64_t Int) {
	if (IsSigned) {
	const int64_t SignedInt = Int;
	if ((char)Int == SignedInt) return dwarf::DW_FORM_data1;
	if ((short)Int == SignedInt) return dwarf::DW_FORM_data2;
	if ((int)Int == SignedInt) return dwarf::DW_FORM_data4;
	} else {
	if ((unsigned char)Int == Int) return dwarf::DW_FORM_data1;
	if ((unsigned short)Int == Int) return dwarf::DW_FORM_data2;
	if ((unsigned int)Int == Int) return dwarf::DW_FORM_data4;
	}
	return dwarf::DW_FORM_data8;
	}

	/// EmitValue - Emit integer of appropriate size.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	uint64_t getValue() const { return Integer; }

	/// SizeOf - Determine size of integer value in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *I) { return I->getType() == isInteger; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEExpr - An expression DIE.
	//
	class DIEExpr : public DIEValue {
	const MCExpr *Expr;
	public:
	explicit DIEExpr(const MCExpr *E) : DIEValue(isExpr), Expr(E) {}

	/// EmitValue - Emit expression value.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	/// getValue - Get MCExpr.
	///
	const MCExpr *getValue() const { return Expr; }

	/// SizeOf - Determine size of expression value in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *E) { return E->getType() == isExpr; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIELabel - A label DIE.
	//
	class DIELabel : public DIEValue {
	const MCSymbol *Label;
	public:
	explicit DIELabel(const MCSymbol *L) : DIEValue(isLabel), Label(L) {}

	/// EmitValue - Emit label value.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	/// getValue - Get MCSymbol.
	///
	const MCSymbol *getValue() const { return Label; }

	/// SizeOf - Determine size of label value in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *L) { return L->getType() == isLabel; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEDelta - A simple label difference DIE.
	///
	class DIEDelta : public DIEValue {
	const MCSymbol *LabelHi;
	const MCSymbol *LabelLo;
	public:
	DIEDelta(const MCSymbol Hi, const MCSymbol Lo)
	: DIEValue(isDelta), LabelHi(Hi), LabelLo(Lo) {}

	/// EmitValue - Emit delta value.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	/// SizeOf - Determine size of delta value in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *D) { return D->getType() == isDelta; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEString - A container for string values.
	///
	class DIEString : public DIEValue {
	const DIEValue *Access;
	const StringRef Str;

	public:
	DIEString(const DIEValue *Acc, const StringRef S)
	: DIEValue(isString), Access(Acc), Str(S) {}

	/// getString - Grab the string out of the object.
	StringRef getString() const { return Str; }

	/// EmitValue - Emit delta value.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	/// SizeOf - Determine size of delta value in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *D) { return D->getType() == isString; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEEntry - A pointer to another debug information entry. An instance of
	/// this class can also be used as a proxy for a debug information entry not
	/// yet defined (ie. types.)
	class DIEEntry : public DIEValue {
	DIE *const Entry;
	public:
	explicit DIEEntry(DIE *E) : DIEValue(isEntry), Entry(E) {
	assert(E && "Cannot construct a DIEEntry with a null DIE");
	}

	DIE *getEntry() const { return Entry; }

	/// EmitValue - Emit debug information entry offset.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	/// SizeOf - Determine size of debug information entry in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const {
	return Form == dwarf::DW_FORM_ref_addr ? getRefAddrSize(AP)
	: sizeof(int32_t);
	}

	/// Returns size of a ref_addr entry.
	static unsigned getRefAddrSize(AsmPrinter *AP);

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *E) { return E->getType() == isEntry; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	//===--------------------------------------------------------------------===//
	/// DIEBlock - A block of values. Primarily used for location expressions.
	//
	class DIEBlock : public DIEValue, public DIE {
	unsigned Size; // Size in bytes excluding size header.
	public:
	DIEBlock() : DIEValue(isBlock), DIE(0), Size(0) {}

	/// ComputeSize - calculate the size of the block.
	///
	unsigned ComputeSize(AsmPrinter *AP);

	/// BestForm - Choose the best form for data.
	///
	dwarf::Form BestForm() const {
	if ((unsigned char)Size == Size) return dwarf::DW_FORM_block1;
	if ((unsigned short)Size == Size) return dwarf::DW_FORM_block2;
	if ((unsigned int)Size == Size) return dwarf::DW_FORM_block4;
	return dwarf::DW_FORM_block;
	}

	/// EmitValue - Emit block data.
	///
	virtual void EmitValue(AsmPrinter *AP, dwarf::Form Form) const;

	/// SizeOf - Determine size of block data in bytes.
	///
	virtual unsigned SizeOf(AsmPrinter *AP, dwarf::Form Form) const;

	// Implement isa/cast/dyncast.
	static bool classof(const DIEValue *E) { return E->getType() == isBlock; }

	#ifndef NDEBUG
	virtual void print(raw_ostream &O) const;
	#endif
	};

	} // end llvm namespace

	#endif