text: //===- llvm/TableGen/Record.h - Classes for Table Records -------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file defines the main TableGen data structures, including the TableGen
  // types, values, and high-level data structures.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_TABLEGEN_RECORD_H
  #define LLVM_TABLEGEN_RECORD_H
  
  #include "llvm/ADT/ArrayRef.h"
  #include "llvm/ADT/FoldingSet.h"
  #include "llvm/Support/Allocator.h"
  #include "llvm/Support/SourceMgr.h"
  #include "llvm/Support/DataTypes.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/raw_ostream.h"
  #include <map>
  
  namespace llvm {
  class raw_ostream;
  
  // RecTy subclasses.
  class BitRecTy;
  class BitsRecTy;
  class IntRecTy;
  class StringRecTy;
  class ListRecTy;
  class DagRecTy;
  class RecordRecTy;
  
  // Init subclasses.
  class Init;
  class UnsetInit;
  class BitInit;
  class BitsInit;
  class IntInit;
  class StringInit;
  class ListInit;
  class UnOpInit;
  class BinOpInit;
  class TernOpInit;
  class DefInit;
  class DagInit;
  class TypedInit;
  class VarInit;
  class FieldInit;
  class VarBitInit;
  class VarListElementInit;
  
  // Other classes.
  class Record;
  class RecordVal;
  struct MultiClass;
  class RecordKeeper;
  
  //===----------------------------------------------------------------------===//
  //  Type Classes
  //===----------------------------------------------------------------------===//
  
  class RecTy {
    ListRecTy *ListTy;
    virtual void anchor();
  public:
    RecTy() : ListTy(0) {}
    virtual ~RecTy() {}
  
    virtual std::string getAsString() const = 0;
    void print(raw_ostream &OS) const { OS << getAsString(); }
    void dump() const;
  
    /// typeIsConvertibleTo - Return true if all values of 'this' type can be
    /// converted to the specified type.
    virtual bool typeIsConvertibleTo(const RecTy *RHS) const = 0;
  
    /// getListTy - Returns the type representing list<this>.
    ListRecTy *getListTy();
  
  public:   // These methods should only be called from subclasses of Init
    virtual Init *convertValue( UnsetInit *UI) { return 0; }
    virtual Init *convertValue(   BitInit *BI) { return 0; }
    virtual Init *convertValue(  BitsInit *BI) { return 0; }
    virtual Init *convertValue(   IntInit *II) { return 0; }
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue( UnOpInit *UI) {
      return convertValue((TypedInit*)UI);
    }
    virtual Init *convertValue( BinOpInit *UI) {
      return convertValue((TypedInit*)UI);
    }
    virtual Init *convertValue( TernOpInit *UI) {
      return convertValue((TypedInit*)UI);
    }
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( TypedInit *TI) { return 0; }
    virtual Init *convertValue(   VarInit *VI) {
      return convertValue((TypedInit*)VI);
    }
    virtual Init *convertValue( FieldInit *FI) {
      return convertValue((TypedInit*)FI);
    }
  
  public:   // These methods should only be called by subclasses of RecTy.
    // baseClassOf - These virtual methods should be overloaded to return true iff
    // all values of type 'RHS' can be converted to the 'this' type.
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  };
  
  inline raw_ostream &operator<<(raw_ostream &OS, const RecTy &Ty) {
    Ty.print(OS);
    return OS;
  }
  
  
  /// BitRecTy - 'bit' - Represent a single bit
  ///
  class BitRecTy : public RecTy {
    static BitRecTy Shared;
    BitRecTy() {}
  public:
    static BitRecTy *get() { return &Shared; }
  
    virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
    virtual Init *convertValue(   BitInit *BI) { return (Init*)BI; }
    virtual Init *convertValue(  BitsInit *BI);
    virtual Init *convertValue(   IntInit *II);
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue(VarBitInit *VB) { return (Init*)VB; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TypedInit *TI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const { return "bit"; }
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return true; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const;
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return true; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  
  };
  
  
  // BitsRecTy - 'bits<n>' - Represent a fixed number of bits
  /// BitsRecTy - 'bits&lt;n&gt;' - Represent a fixed number of bits
  ///
  class BitsRecTy : public RecTy {
    unsigned Size;
    explicit BitsRecTy(unsigned Sz) : Size(Sz) {}
  public:
    static BitsRecTy *get(unsigned Sz);
  
    unsigned getNumBits() const { return Size; }
  
    virtual Init *convertValue( UnsetInit *UI);
    virtual Init *convertValue(   BitInit *UI);
    virtual Init *convertValue(  BitsInit *BI);
    virtual Init *convertValue(   IntInit *II);
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TypedInit *TI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const;
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return Size == 1; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const {
      return RHS->Size == Size;
    }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return true; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  
  };
  
  
  /// IntRecTy - 'int' - Represent an integer value of no particular size
  ///
  class IntRecTy : public RecTy {
    static IntRecTy Shared;
    IntRecTy() {}
  public:
    static IntRecTy *get() { return &Shared; }
  
    virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
    virtual Init *convertValue(   BitInit *BI);
    virtual Init *convertValue(  BitsInit *BI);
    virtual Init *convertValue(   IntInit *II) { return (Init*)II; }
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TypedInit *TI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const { return "int"; }
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
  
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return true; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const { return true; }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return true; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  
  };
  
  /// StringRecTy - 'string' - Represent an string value
  ///
  class StringRecTy : public RecTy {
    static StringRecTy Shared;
    StringRecTy() {}
  public:
    static StringRecTy *get() { return &Shared; }
  
    virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
    virtual Init *convertValue(   BitInit *BI) { return 0; }
    virtual Init *convertValue(  BitsInit *BI) { return 0; }
    virtual Init *convertValue(   IntInit *II) { return 0; }
    virtual Init *convertValue(StringInit *SI) { return (Init*)SI; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue( UnOpInit *BO);
    virtual Init *convertValue( BinOpInit *BO);
    virtual Init *convertValue( TernOpInit *BO) { return RecTy::convertValue(BO);}
  
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( TypedInit *TI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const { return "string"; }
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
  
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return true; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  };
  
  // ListRecTy - 'list<Ty>' - Represent a list of values, all of which must be of
  // the specified type.
  /// ListRecTy - 'list&lt;Ty&gt;' - Represent a list of values, all of which must
  /// be of the specified type.
  ///
  class ListRecTy : public RecTy {
    RecTy *Ty;
    explicit ListRecTy(RecTy *T) : Ty(T) {}
    friend ListRecTy *RecTy::getListTy();
  public:
    static ListRecTy *get(RecTy *T) { return T->getListTy(); }
    RecTy *getElementType() const { return Ty; }
  
    virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
    virtual Init *convertValue(   BitInit *BI) { return 0; }
    virtual Init *convertValue(  BitsInit *BI) { return 0; }
    virtual Init *convertValue(   IntInit *II) { return 0; }
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI);
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TypedInit *TI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const;
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
  
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const {
      return RHS->getElementType()->typeIsConvertibleTo(Ty);
    }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  };
  
  /// DagRecTy - 'dag' - Represent a dag fragment
  ///
  class DagRecTy : public RecTy {
    static DagRecTy Shared;
    DagRecTy() {}
  public:
    static DagRecTy *get() { return &Shared; }
  
    virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
    virtual Init *convertValue(   BitInit *BI) { return 0; }
    virtual Init *convertValue(  BitsInit *BI) { return 0; }
    virtual Init *convertValue(   IntInit *II) { return 0; }
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue(   DefInit *DI) { return 0; }
    virtual Init *convertValue( UnOpInit *BO);
    virtual Init *convertValue( BinOpInit *BO);
    virtual Init *convertValue( TernOpInit *BO) { return RecTy::convertValue(BO);}
    virtual Init *convertValue(   DagInit *CI) { return (Init*)CI; }
    virtual Init *convertValue( TypedInit *TI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const { return "dag"; }
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
  
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return true; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const { return false; }
  };
  
  
  /// RecordRecTy - '[classname]' - Represent an instance of a class, such as:
  /// (R32 X = EAX).
  ///
  class RecordRecTy : public RecTy {
    Record *Rec;
    explicit RecordRecTy(Record *R) : Rec(R) {}
    friend class Record;
  public:
    static RecordRecTy *get(Record *R);
  
    Record *getRecord() const { return Rec; }
  
    virtual Init *convertValue( UnsetInit *UI) { return (Init*)UI; }
    virtual Init *convertValue(   BitInit *BI) { return 0; }
    virtual Init *convertValue(  BitsInit *BI) { return 0; }
    virtual Init *convertValue(   IntInit *II) { return 0; }
    virtual Init *convertValue(StringInit *SI) { return 0; }
    virtual Init *convertValue(  ListInit *LI) { return 0; }
    virtual Init *convertValue(VarBitInit *VB) { return 0; }
    virtual Init *convertValue( UnOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( BinOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue( TernOpInit *UI) { return RecTy::convertValue(UI);}
    virtual Init *convertValue(   DefInit *DI);
    virtual Init *convertValue(   DagInit *DI) { return 0; }
    virtual Init *convertValue( TypedInit *VI);
    virtual Init *convertValue(   VarInit *VI) { return RecTy::convertValue(VI);}
    virtual Init *convertValue( FieldInit *FI) { return RecTy::convertValue(FI);}
  
    std::string getAsString() const;
  
    bool typeIsConvertibleTo(const RecTy *RHS) const {
      return RHS->baseClassOf(this);
    }
    virtual bool baseClassOf(const BitRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const BitsRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const IntRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const StringRecTy *RHS) const { return false; }
    virtual bool baseClassOf(const ListRecTy   *RHS) const { return false; }
    virtual bool baseClassOf(const DagRecTy    *RHS) const { return false; }
    virtual bool baseClassOf(const RecordRecTy *RHS) const;
  };
  
  /// resolveTypes - Find a common type that T1 and T2 convert to.
  /// Return 0 if no such type exists.
  ///
  RecTy *resolveTypes(RecTy *T1, RecTy *T2);
  
  //===----------------------------------------------------------------------===//
  //  Initializer Classes
  //===----------------------------------------------------------------------===//
  
  class Init {
    Init(const Init &);  // Do not define.
    Init &operator=(const Init &);  // Do not define.
    virtual void anchor();
  
  protected:
    Init(void) {}
  
  public:
    virtual ~Init() {}
  
    /// isComplete - This virtual method should be overridden by values that may
    /// not be completely specified yet.
    virtual bool isComplete() const { return true; }
  
    /// print - Print out this value.
    void print(raw_ostream &OS) const { OS << getAsString(); }
  
    /// getAsString - Convert this value to a string form.
    virtual std::string getAsString() const = 0;
    /// getAsUnquotedString - Convert this value to a string form,
    /// without adding quote markers.  This primaruly affects
    /// StringInits where we will not surround the string value with
    /// quotes.
    virtual std::string getAsUnquotedString() const { return getAsString(); }
  
    /// dump - Debugging method that may be called through a debugger, just
    /// invokes print on stderr.
    void dump() const;
  
    /// convertInitializerTo - This virtual function is a simple call-back
    /// function that should be overridden to call the appropriate
    /// RecTy::convertValue method.
    ///
    virtual Init *convertInitializerTo(RecTy *Ty) const = 0;
  
    /// convertInitializerBitRange - This method is used to implement the bitrange
    /// selection operator.  Given an initializer, it selects the specified bits
    /// out, returning them as a new init of bits type.  If it is not legal to use
    /// the bit subscript operator on this initializer, return null.
    ///
    virtual Init *
    convertInitializerBitRange(const std::vector<unsigned> &Bits) const {
      return 0;
    }
  
    /// convertInitListSlice - This method is used to implement the list slice
    /// selection operator.  Given an initializer, it selects the specified list
    /// elements, returning them as a new init of list type.  If it is not legal
    /// to take a slice of this, return null.
    ///
    virtual Init *
    convertInitListSlice(const std::vector<unsigned> &Elements) const {
      return 0;
    }
  
    /// getFieldType - This method is used to implement the FieldInit class.
    /// Implementors of this method should return the type of the named field if
    /// they are of record type.
    ///
    virtual RecTy *getFieldType(const std::string &FieldName) const { return 0; }
  
    /// getFieldInit - This method complements getFieldType to return the
    /// initializer for the specified field.  If getFieldType returns non-null
    /// this method should return non-null, otherwise it returns null.
    ///
    virtual Init *getFieldInit(Record &R, const RecordVal *RV,
                               const std::string &FieldName) const {
      return 0;
    }
  
    /// resolveReferences - This method is used by classes that refer to other
    /// variables which may not be defined at the time the expression is formed.
    /// If a value is set for the variable later, this method will be called on
    /// users of the value to allow the value to propagate out.
    ///
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const {
      return const_cast<Init *>(this);
    }
  };
  
  inline raw_ostream &operator<<(raw_ostream &OS, const Init &I) {
    I.print(OS); return OS;
  }
  
  /// TypedInit - This is the common super-class of types that have a specific,
  /// explicit, type.
  ///
  class TypedInit : public Init {
    RecTy *Ty;
  
    TypedInit(const TypedInit &Other);  // Do not define.
    TypedInit &operator=(const TypedInit &Other);  // Do not define.
  
  protected:
    explicit TypedInit(RecTy *T) : Ty(T) {}
  
  public:
    RecTy *getType() const { return Ty; }
  
    virtual Init *
    convertInitializerBitRange(const std::vector<unsigned> &Bits) const;
    virtual Init *
    convertInitListSlice(const std::vector<unsigned> &Elements) const;
  
    /// getFieldType - This method is used to implement the FieldInit class.
    /// Implementors of this method should return the type of the named field if
    /// they are of record type.
    ///
    virtual RecTy *getFieldType(const std::string &FieldName) const;
  
    /// resolveBitReference - This method is used to implement
    /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
    /// simply return the resolved value, otherwise we return null.
    ///
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const = 0;
  
    /// resolveListElementReference - This method is used to implement
    /// VarListElementInit::resolveReferences.  If the list element is resolvable
    /// now, we return the resolved value, otherwise we return null.
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const = 0;
  };
  
  
  /// UnsetInit - ? - Represents an uninitialized value
  ///
  class UnsetInit : public Init {
    UnsetInit() : Init() {}
    UnsetInit(const UnsetInit &);  // Do not define.
    UnsetInit &operator=(const UnsetInit &Other);  // Do not define.
    virtual void anchor();
  
  public:
    static UnsetInit *get();
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<UnsetInit *>(this));
    }
  
    virtual bool isComplete() const { return false; }
    virtual std::string getAsString() const { return "?"; }
  };
  
  
  /// BitInit - true/false - Represent a concrete initializer for a bit.
  ///
  class BitInit : public Init {
    bool Value;
  
    explicit BitInit(bool V) : Value(V) {}
    BitInit(const BitInit &Other);  // Do not define.
    BitInit &operator=(BitInit &Other);  // Do not define.
    virtual void anchor();
  
  public:
    static BitInit *get(bool V);
  
    bool getValue() const { return Value; }
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<BitInit *>(this));
    }
  
    virtual std::string getAsString() const { return Value ? "1" : "0"; }
  };
  
  /// BitsInit - { a, b, c } - Represents an initializer for a BitsRecTy value.
  /// It contains a vector of bits, whose size is determined by the type.
  ///
  class BitsInit : public Init, public FoldingSetNode {
    std::vector<Init*> Bits;
  
    BitsInit(ArrayRef<Init *> Range) : Bits(Range.begin(), Range.end()) {}
  
    BitsInit(const BitsInit &Other);  // Do not define.
    BitsInit &operator=(const BitsInit &Other);  // Do not define.
  
  public:
    static BitsInit *get(ArrayRef<Init *> Range);
  
    void Profile(FoldingSetNodeID &ID) const;
  
    unsigned getNumBits() const { return Bits.size(); }
  
    Init *getBit(unsigned Bit) const {
      assert(Bit < Bits.size() && "Bit index out of range!");
      return Bits[Bit];
    }
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<BitsInit *>(this));
    }
    virtual Init *
    convertInitializerBitRange(const std::vector<unsigned> &Bits) const;
  
    virtual bool isComplete() const {
      for (unsigned i = 0; i != getNumBits(); ++i)
        if (!getBit(i)->isComplete()) return false;
      return true;
    }
    bool allInComplete() const {
      for (unsigned i = 0; i != getNumBits(); ++i)
        if (getBit(i)->isComplete()) return false;
      return true;
    }
    virtual std::string getAsString() const;
  
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  };
  
  
  /// IntInit - 7 - Represent an initalization by a literal integer value.
  ///
  class IntInit : public TypedInit {
    int64_t Value;
  
    explicit IntInit(int64_t V) : TypedInit(IntRecTy::get()), Value(V) {}
  
    IntInit(const IntInit &Other);  // Do not define.
    IntInit &operator=(const IntInit &Other);  // Do note define.
  
  public:
    static IntInit *get(int64_t V);
  
    int64_t getValue() const { return Value; }
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<IntInit *>(this));
    }
    virtual Init *
    convertInitializerBitRange(const std::vector<unsigned> &Bits) const;
  
    virtual std::string getAsString() const;
  
    /// resolveBitReference - This method is used to implement
    /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
    /// simply return the resolved value, otherwise we return null.
    ///
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const {
      llvm_unreachable("Illegal bit reference off int");
    }
  
    /// resolveListElementReference - This method is used to implement
    /// VarListElementInit::resolveReferences.  If the list element is resolvable
    /// now, we return the resolved value, otherwise we return null.
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const {
      llvm_unreachable("Illegal element reference off int");
    }
  };
  
  
  /// StringInit - "foo" - Represent an initialization by a string value.
  ///
  class StringInit : public TypedInit {
    std::string Value;
  
    explicit StringInit(const std::string &V)
      : TypedInit(StringRecTy::get()), Value(V) {}
  
    StringInit(const StringInit &Other);  // Do not define.
    StringInit &operator=(const StringInit &Other);  // Do not define.
    virtual void anchor();
  
  public:
    static StringInit *get(StringRef);
  
    const std::string &getValue() const { return Value; }
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<StringInit *>(this));
    }
  
    virtual std::string getAsString() const { return "\"" + Value + "\""; }
    virtual std::string getAsUnquotedString() const { return Value; }
  
    /// resolveBitReference - This method is used to implement
    /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
    /// simply return the resolved value, otherwise we return null.
    ///
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const {
      llvm_unreachable("Illegal bit reference off string");
    }
  
    /// resolveListElementReference - This method is used to implement
    /// VarListElementInit::resolveReferences.  If the list element is resolvable
    /// now, we return the resolved value, otherwise we return null.
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const {
      llvm_unreachable("Illegal element reference off string");
    }
  };
  
  /// ListInit - [AL, AH, CL] - Represent a list of defs
  ///
  class ListInit : public TypedInit, public FoldingSetNode {
    std::vector<Init*> Values;
  public:
    typedef std::vector<Init*>::const_iterator const_iterator;
  
  private:
    explicit ListInit(ArrayRef<Init *> Range, RecTy *EltTy)
        : TypedInit(ListRecTy::get(EltTy)), Values(Range.begin(), Range.end()) {}
  
    ListInit(const ListInit &Other);  // Do not define.
    ListInit &operator=(const ListInit &Other);  // Do not define.
  
  public:
    static ListInit *get(ArrayRef<Init *> Range, RecTy *EltTy);
  
    void Profile(FoldingSetNodeID &ID) const;
  
    unsigned getSize() const { return Values.size(); }
    Init *getElement(unsigned i) const {
      assert(i < Values.size() && "List element index out of range!");
      return Values[i];
    }
  
    Record *getElementAsRecord(unsigned i) const;
  
    Init *convertInitListSlice(const std::vector<unsigned> &Elements) const;
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<ListInit *>(this));
    }
  
    /// resolveReferences - This method is used by classes that refer to other
    /// variables which may not be defined at the time they expression is formed.
    /// If a value is set for the variable later, this method will be called on
    /// users of the value to allow the value to propagate out.
    ///
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const;
  
    ArrayRef<Init*> getValues() const { return Values; }
  
    inline const_iterator begin() const { return Values.begin(); }
    inline const_iterator end  () const { return Values.end();   }
  
    inline size_t         size () const { return Values.size();  }
    inline bool           empty() const { return Values.empty(); }
  
    /// resolveBitReference - This method is used to implement
    /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
    /// simply return the resolved value, otherwise we return null.
    ///
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const {
      llvm_unreachable("Illegal bit reference off list");
    }
  
    /// resolveListElementReference - This method is used to implement
    /// VarListElementInit::resolveReferences.  If the list element is resolvable
    /// now, we return the resolved value, otherwise we return null.
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const;
  };
  
  
  /// OpInit - Base class for operators
  ///
  class OpInit : public TypedInit {
    OpInit(const OpInit &Other);  // Do not define.
    OpInit &operator=(OpInit &Other);  // Do not define.
  
  protected:
    explicit OpInit(RecTy *Type) : TypedInit(Type) {}
  
  public:
    // Clone - Clone this operator, replacing arguments with the new list
    virtual OpInit *clone(std::vector<Init *> &Operands) const = 0;
  
    virtual int getNumOperands() const = 0;
    virtual Init *getOperand(int i) const = 0;
  
    // Fold - If possible, fold this to a simpler init.  Return this if not
    // possible to fold.
    virtual Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const = 0;
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<OpInit *>(this));
    }
  
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const;
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const;
  };
  
  
  /// UnOpInit - !op (X) - Transform an init.
  ///
  class UnOpInit : public OpInit {
  public:
    enum UnaryOp { CAST, HEAD, TAIL, EMPTY };
  private:
    UnaryOp Opc;
    Init *LHS;
  
    UnOpInit(UnaryOp opc, Init *lhs, RecTy *Type)
        : OpInit(Type), Opc(opc), LHS(lhs) {}
  
    UnOpInit(const UnOpInit &Other);  // Do not define.
    UnOpInit &operator=(const UnOpInit &Other);  // Do not define.
  
  public:
    static UnOpInit *get(UnaryOp opc, Init *lhs, RecTy *Type);
  
    // Clone - Clone this operator, replacing arguments with the new list
    virtual OpInit *clone(std::vector<Init *> &Operands) const {
      assert(Operands.size() == 1 &&
             "Wrong number of operands for unary operation");
      return UnOpInit::get(getOpcode(), *Operands.begin(), getType());
    }
  
    int getNumOperands() const { return 1; }
    Init *getOperand(int i) const {
      assert(i == 0 && "Invalid operand id for unary operator");
      return getOperand();
    }
  
    UnaryOp getOpcode() const { return Opc; }
    Init *getOperand() const { return LHS; }
  
    // Fold - If possible, fold this to a simpler init.  Return this if not
    // possible to fold.
    Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const;
  
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const;
  };
  
  /// BinOpInit - !op (X, Y) - Combine two inits.
  ///
  class BinOpInit : public OpInit {
  public:
    enum BinaryOp { SHL, SRA, SRL, STRCONCAT, CONCAT, EQ };
  private:
    BinaryOp Opc;
    Init *LHS, *RHS;
  
    BinOpInit(BinaryOp opc, Init *lhs, Init *rhs, RecTy *Type) :
        OpInit(Type), Opc(opc), LHS(lhs), RHS(rhs) {}
  
    BinOpInit(const BinOpInit &Other);  // Do not define.
    BinOpInit &operator=(const BinOpInit &Other);  // Do not define.
  
  public:
    static BinOpInit *get(BinaryOp opc, Init *lhs, Init *rhs,
                          RecTy *Type);
  
    // Clone - Clone this operator, replacing arguments with the new list
    virtual OpInit *clone(std::vector<Init *> &Operands) const {
      assert(Operands.size() == 2 &&
             "Wrong number of operands for binary operation");
      return BinOpInit::get(getOpcode(), Operands[0], Operands[1], getType());
    }
  
    int getNumOperands() const { return 2; }
    Init *getOperand(int i) const {
      assert((i == 0 || i == 1) && "Invalid operand id for binary operator");
      if (i == 0) {
        return getLHS();
      } else {
        return getRHS();
      }
    }
  
    BinaryOp getOpcode() const { return Opc; }
    Init *getLHS() const { return LHS; }
    Init *getRHS() const { return RHS; }
  
    // Fold - If possible, fold this to a simpler init.  Return this if not
    // possible to fold.
    Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const;
  
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const;
  };
  
  /// TernOpInit - !op (X, Y, Z) - Combine two inits.
  ///
  class TernOpInit : public OpInit {
  public:
    enum TernaryOp { SUBST, FOREACH, IF };
  private:
    TernaryOp Opc;
    Init *LHS, *MHS, *RHS;
  
    TernOpInit(TernaryOp opc, Init *lhs, Init *mhs, Init *rhs,
               RecTy *Type) :
        OpInit(Type), Opc(opc), LHS(lhs), MHS(mhs), RHS(rhs) {}
  
    TernOpInit(const TernOpInit &Other);  // Do not define.
    TernOpInit &operator=(const TernOpInit &Other);  // Do not define.
  
  public:
    static TernOpInit *get(TernaryOp opc, Init *lhs,
                           Init *mhs, Init *rhs,
                           RecTy *Type);
  
    // Clone - Clone this operator, replacing arguments with the new list
    virtual OpInit *clone(std::vector<Init *> &Operands) const {
      assert(Operands.size() == 3 &&
             "Wrong number of operands for ternary operation");
      return TernOpInit::get(getOpcode(), Operands[0], Operands[1], Operands[2],
                             getType());
    }
  
    int getNumOperands() const { return 3; }
    Init *getOperand(int i) const {
      assert((i == 0 || i == 1 || i == 2) &&
             "Invalid operand id for ternary operator");
      if (i == 0) {
        return getLHS();
      } else if (i == 1) {
        return getMHS();
      } else {
        return getRHS();
      }
    }
  
    TernaryOp getOpcode() const { return Opc; }
    Init *getLHS() const { return LHS; }
    Init *getMHS() const { return MHS; }
    Init *getRHS() const { return RHS; }
  
    // Fold - If possible, fold this to a simpler init.  Return this if not
    // possible to fold.
    Init *Fold(Record *CurRec, MultiClass *CurMultiClass) const;
  
    virtual bool isComplete() const { return false; }
  
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const;
  };
  
  
  /// VarInit - 'Opcode' - Represent a reference to an entire variable object.
  ///
  class VarInit : public TypedInit {
    Init *VarName;
  
    explicit VarInit(const std::string &VN, RecTy *T)
        : TypedInit(T), VarName(StringInit::get(VN)) {}
    explicit VarInit(Init *VN, RecTy *T)
        : TypedInit(T), VarName(VN) {}
  
    VarInit(const VarInit &Other);  // Do not define.
    VarInit &operator=(const VarInit &Other);  // Do not define.
  
  public:
    static VarInit *get(const std::string &VN, RecTy *T);
    static VarInit *get(Init *VN, RecTy *T);
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<VarInit *>(this));
    }
  
    const std::string &getName() const;
    Init *getNameInit() const { return VarName; }
    std::string getNameInitAsString() const {
      return getNameInit()->getAsUnquotedString();
    }
  
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const;
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const;
  
    virtual RecTy *getFieldType(const std::string &FieldName) const;
    virtual Init *getFieldInit(Record &R, const RecordVal *RV,
                               const std::string &FieldName) const;
  
    /// resolveReferences - This method is used by classes that refer to other
    /// variables which may not be defined at the time they expression is formed.
    /// If a value is set for the variable later, this method will be called on
    /// users of the value to allow the value to propagate out.
    ///
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const { return getName(); }
  };
  
  
  /// VarBitInit - Opcode{0} - Represent access to one bit of a variable or field.
  ///
  class VarBitInit : public Init {
    TypedInit *TI;
    unsigned Bit;
  
    VarBitInit(TypedInit *T, unsigned B) : TI(T), Bit(B) {
      assert(T->getType() && dynamic_cast<BitsRecTy*>(T->getType()) &&
             ((BitsRecTy*)T->getType())->getNumBits() > B &&
             "Illegal VarBitInit expression!");
    }
  
    VarBitInit(const VarBitInit &Other);  // Do not define.
    VarBitInit &operator=(const VarBitInit &Other);  // Do not define.
  
  public:
    static VarBitInit *get(TypedInit *T, unsigned B);
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<VarBitInit *>(this));
    }
  
    TypedInit *getVariable() const { return TI; }
    unsigned getBitNum() const { return Bit; }
  
    virtual std::string getAsString() const;
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  };
  
  /// VarListElementInit - List[4] - Represent access to one element of a var or
  /// field.
  class VarListElementInit : public TypedInit {
    TypedInit *TI;
    unsigned Element;
  
    VarListElementInit(TypedInit *T, unsigned E)
        : TypedInit(dynamic_cast<ListRecTy*>(T->getType())->getElementType()),
            TI(T), Element(E) {
      assert(T->getType() && dynamic_cast<ListRecTy*>(T->getType()) &&
             "Illegal VarBitInit expression!");
    }
  
    VarListElementInit(const VarListElementInit &Other);  // Do not define.
    VarListElementInit &operator=(const VarListElementInit &Other);  // Do
                                                                     // not
                                                                     // define.
  
  public:
    static VarListElementInit *get(TypedInit *T, unsigned E);
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<VarListElementInit *>(this));
    }
  
    TypedInit *getVariable() const { return TI; }
    unsigned getElementNum() const { return Element; }
  
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const;
  
    /// resolveListElementReference - This method is used to implement
    /// VarListElementInit::resolveReferences.  If the list element is resolvable
    /// now, we return the resolved value, otherwise we return null.
    virtual Init *resolveListElementReference(Record &R,
                                              const RecordVal *RV,
                                              unsigned Elt) const;
  
    virtual std::string getAsString() const;
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  };
  
  /// DefInit - AL - Represent a reference to a 'def' in the description
  ///
  class DefInit : public TypedInit {
    Record *Def;
  
    DefInit(Record *D, RecordRecTy *T) : TypedInit(T), Def(D) {}
    friend class Record;
  
    DefInit(const DefInit &Other);  // Do not define.
    DefInit &operator=(const DefInit &Other);  // Do not define.
  
  public:
    static DefInit *get(Record*);
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<DefInit *>(this));
    }
  
    Record *getDef() const { return Def; }
  
    //virtual Init *convertInitializerBitRange(const std::vector<unsigned> &Bits);
  
    virtual RecTy *getFieldType(const std::string &FieldName) const;
    virtual Init *getFieldInit(Record &R, const RecordVal *RV,
                               const std::string &FieldName) const;
  
    virtual std::string getAsString() const;
  
    /// resolveBitReference - This method is used to implement
    /// VarBitInit::resolveReferences.  If the bit is able to be resolved, we
    /// simply return the resolved value, otherwise we return null.
    ///
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const {
      llvm_unreachable("Illegal bit reference off def");
    }
  
    /// resolveListElementReference - This method is used to implement
    /// VarListElementInit::resolveReferences.  If the list element is resolvable
    /// now, we return the resolved value, otherwise we return null.
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const {
      llvm_unreachable("Illegal element reference off def");
    }
  };
  
  
  /// FieldInit - X.Y - Represent a reference to a subfield of a variable
  ///
  class FieldInit : public TypedInit {
    Init *Rec;                // Record we are referring to
    std::string FieldName;    // Field we are accessing
  
    FieldInit(Init *R, const std::string &FN)
        : TypedInit(R->getFieldType(FN)), Rec(R), FieldName(FN) {
      assert(getType() && "FieldInit with non-record type!");
    }
  
    FieldInit(const FieldInit &Other);  // Do not define.
    FieldInit &operator=(const FieldInit &Other);  // Do not define.
  
  public:
    static FieldInit *get(Init *R, const std::string &FN);
    static FieldInit *get(Init *R, const Init *FN);
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<FieldInit *>(this));
    }
  
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const;
    virtual Init *resolveListElementReference(Record &R,
                                              const RecordVal *RV,
                                              unsigned Elt) const;
  
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const {
      return Rec->getAsString() + "." + FieldName;
    }
  };
  
  /// DagInit - (v a, b) - Represent a DAG tree value.  DAG inits are required
  /// to have at least one value then a (possibly empty) list of arguments.  Each
  /// argument can have a name associated with it.
  ///
  class DagInit : public TypedInit, public FoldingSetNode {
    Init *Val;
    std::string ValName;
    std::vector<Init*> Args;
    std::vector<std::string> ArgNames;
  
    DagInit(Init *V, const std::string &VN,
            ArrayRef<Init *> ArgRange,
            ArrayRef<std::string> NameRange)
        : TypedInit(DagRecTy::get()), Val(V), ValName(VN),
            Args(ArgRange.begin(), ArgRange.end()),
            ArgNames(NameRange.begin(), NameRange.end()) {}
  
    DagInit(const DagInit &Other);  // Do not define.
    DagInit &operator=(const DagInit &Other);  // Do not define.
  
  public:
    static DagInit *get(Init *V, const std::string &VN,
                        ArrayRef<Init *> ArgRange,
                        ArrayRef<std::string> NameRange);
    static DagInit *get(Init *V, const std::string &VN,
                        const std::vector<
                          std::pair<Init*, std::string> > &args);
  
    void Profile(FoldingSetNodeID &ID) const;
  
    virtual Init *convertInitializerTo(RecTy *Ty) const {
      return Ty->convertValue(const_cast<DagInit *>(this));
    }
  
    Init *getOperator() const { return Val; }
  
    const std::string &getName() const { return ValName; }
  
    unsigned getNumArgs() const { return Args.size(); }
    Init *getArg(unsigned Num) const {
      assert(Num < Args.size() && "Arg number out of range!");
      return Args[Num];
    }
    const std::string &getArgName(unsigned Num) const {
      assert(Num < ArgNames.size() && "Arg number out of range!");
      return ArgNames[Num];
    }
  
    virtual Init *resolveReferences(Record &R, const RecordVal *RV) const;
  
    virtual std::string getAsString() const;
  
    typedef std::vector<Init*>::const_iterator       const_arg_iterator;
    typedef std::vector<std::string>::const_iterator const_name_iterator;
  
    inline const_arg_iterator  arg_begin() const { return Args.begin(); }
    inline const_arg_iterator  arg_end  () const { return Args.end();   }
  
    inline size_t              arg_size () const { return Args.size();  }
    inline bool                arg_empty() const { return Args.empty(); }
  
    inline const_name_iterator name_begin() const { return ArgNames.begin(); }
    inline const_name_iterator name_end  () const { return ArgNames.end();   }
  
    inline size_t              name_size () const { return ArgNames.size();  }
    inline bool                name_empty() const { return ArgNames.empty(); }
  
    virtual Init *resolveBitReference(Record &R, const RecordVal *RV,
                                      unsigned Bit) const {
      llvm_unreachable("Illegal bit reference off dag");
    }
  
    virtual Init *resolveListElementReference(Record &R, const RecordVal *RV,
                                              unsigned Elt) const {
      llvm_unreachable("Illegal element reference off dag");
    }
  };
  
  //===----------------------------------------------------------------------===//
  //  High-Level Classes
  //===----------------------------------------------------------------------===//
  
  class RecordVal {
    Init *Name;
    RecTy *Ty;
    unsigned Prefix;
    Init *Value;
  public:
    RecordVal(Init *N, RecTy *T, unsigned P);
    RecordVal(const std::string &N, RecTy *T, unsigned P);
  
    const std::string &getName() const;
    const Init *getNameInit() const { return Name; }
    std::string getNameInitAsString() const {
      return getNameInit()->getAsUnquotedString();
    }
  
    unsigned getPrefix() const { return Prefix; }
    RecTy *getType() const { return Ty; }
    Init *getValue() const { return Value; }
  
    bool setValue(Init *V) {
      if (V) {
        Value = V->convertInitializerTo(Ty);
        return Value == 0;
      }
      Value = 0;
      return false;
    }
  
    void dump() const;
    void print(raw_ostream &OS, bool PrintSem = true) const;
  };
  
  inline raw_ostream &operator<<(raw_ostream &OS, const RecordVal &RV) {
    RV.print(OS << "  ");
    return OS;
  }
  
  class Record {
    static unsigned LastID;
  
    // Unique record ID.
    unsigned ID;
    Init *Name;
    SMLoc Loc;
    std::vector<Init *> TemplateArgs;
    std::vector<RecordVal> Values;
    std::vector<Record*> SuperClasses;
  
    // Tracks Record instances. Not owned by Record.
    RecordKeeper &TrackedRecords;
  
    DefInit *TheInit;
  
    void init();
    void checkName();
  
  public:
  
    // Constructs a record.
    explicit Record(const std::string &N, SMLoc loc, RecordKeeper &records) :
      ID(LastID++), Name(StringInit::get(N)), Loc(loc), TrackedRecords(records),
        TheInit(0) {
      init();
    }
    explicit Record(Init *N, SMLoc loc, RecordKeeper &records) :
      ID(LastID++), Name(N), Loc(loc), TrackedRecords(records), TheInit(0) {
      init();
    }
    ~Record() {}
  
  
    static unsigned getNewUID() { return LastID++; }
  
  
    unsigned getID() const { return ID; }
  
    const std::string &getName() const;
    Init *getNameInit() const {
      return Name;
    }
    const std::string getNameInitAsString() const {
      return getNameInit()->getAsUnquotedString();
    }
  
    void setName(Init *Name);               // Also updates RecordKeeper.
    void setName(const std::string &Name);  // Also updates RecordKeeper.
  
    SMLoc getLoc() const { return Loc; }
  
    /// get the corresponding DefInit.
    DefInit *getDefInit();
  
    const std::vector<Init *> &getTemplateArgs() const {
      return TemplateArgs;
    }
    const std::vector<RecordVal> &getValues() const { return Values; }
    const std::vector<Record*>   &getSuperClasses() const { return SuperClasses; }
  
    bool isTemplateArg(Init *Name) const {
      for (unsigned i = 0, e = TemplateArgs.size(); i != e; ++i)
        if (TemplateArgs[i] == Name) return true;
      return false;
    }
    bool isTemplateArg(StringRef Name) const {
      return isTemplateArg(StringInit::get(Name.str()));
    }
  
    const RecordVal *getValue(const Init *Name) const {
      for (unsigned i = 0, e = Values.size(); i != e; ++i)
        if (Values[i].getNameInit() == Name) return &Values[i];
      return 0;
    }
    const RecordVal *getValue(StringRef Name) const {
      return getValue(StringInit::get(Name));
    }
    RecordVal *getValue(const Init *Name) {
      for (unsigned i = 0, e = Values.size(); i != e; ++i)
        if (Values[i].getNameInit() == Name) return &Values[i];
      return 0;
    }
    RecordVal *getValue(StringRef Name) {
      return getValue(StringInit::get(Name));
    }
  
    void addTemplateArg(Init *Name) {
      assert(!isTemplateArg(Name) && "Template arg already defined!");
      TemplateArgs.push_back(Name);
    }
    void addTemplateArg(StringRef Name) {
      addTemplateArg(StringInit::get(Name.str()));
    }
  
    void addValue(const RecordVal &RV) {
      assert(getValue(RV.getNameInit()) == 0 && "Value already added!");
      Values.push_back(RV);
      if (Values.size() > 1)
        // Keep NAME at the end of the list.  It makes record dumps a
        // bit prettier and allows TableGen tests to be written more
        // naturally.  Tests can use CHECK-NEXT to look for Record
        // fields they expect to see after a def.  They can't do that if
        // NAME is the first Record field.
        std::swap(Values[Values.size() - 2], Values[Values.size() - 1]);
    }
  
    void removeValue(Init *Name) {
      for (unsigned i = 0, e = Values.size(); i != e; ++i)
        if (Values[i].getNameInit() == Name) {
          Values.erase(Values.begin()+i);
          return;
        }
      llvm_unreachable("Cannot remove an entry that does not exist!");
    }
  
    void removeValue(StringRef Name) {
      removeValue(StringInit::get(Name.str()));
    }
  
    bool isSubClassOf(const Record *R) const {
      for (unsigned i = 0, e = SuperClasses.size(); i != e; ++i)
        if (SuperClasses[i] == R)
          return true;
      return false;
    }
  
    bool isSubClassOf(StringRef Name) const {
      for (unsigned i = 0, e = SuperClasses.size(); i != e; ++i)
        if (SuperClasses[i]->getNameInitAsString() == Name)
          return true;
      return false;
    }
  
    void addSuperClass(Record *R) {
      assert(!isSubClassOf(R) && "Already subclassing record!");
      SuperClasses.push_back(R);
    }
  
    /// resolveReferences - If there are any field references that refer to fields
    /// that have been filled in, we can propagate the values now.
    ///
    void resolveReferences() { resolveReferencesTo(0); }
  
    /// resolveReferencesTo - If anything in this record refers to RV, replace the
    /// reference to RV with the RHS of RV.  If RV is null, we resolve all
    /// possible references.
    void resolveReferencesTo(const RecordVal *RV);
  
    RecordKeeper &getRecords() const {
      return TrackedRecords;
    }
  
    void dump() const;
  
    //===--------------------------------------------------------------------===//
    // High-level methods useful to tablegen back-ends
    //
  
    /// getValueInit - Return the initializer for a value with the specified name,
    /// or throw an exception if the field does not exist.
    ///
    Init *getValueInit(StringRef FieldName) const;
  
    /// getValueAsString - This method looks up the specified field and returns
    /// its value as a string, throwing an exception if the field does not exist
    /// or if the value is not a string.
    ///
    std::string getValueAsString(StringRef FieldName) const;
  
    /// getValueAsBitsInit - This method looks up the specified field and returns
    /// its value as a BitsInit, throwing an exception if the field does not exist
    /// or if the value is not the right type.
    ///
    BitsInit *getValueAsBitsInit(StringRef FieldName) const;
  
    /// getValueAsListInit - This method looks up the specified field and returns
    /// its value as a ListInit, throwing an exception if the field does not exist
    /// or if the value is not the right type.
    ///
    ListInit *getValueAsListInit(StringRef FieldName) const;
  
    /// getValueAsListOfDefs - This method looks up the specified field and
    /// returns its value as a vector of records, throwing an exception if the
    /// field does not exist or if the value is not the right type.
    ///
    std::vector<Record*> getValueAsListOfDefs(StringRef FieldName) const;
  
    /// getValueAsListOfInts - This method looks up the specified field and
    /// returns its value as a vector of integers, throwing an exception if the
    /// field does not exist or if the value is not the right type.
    ///
    std::vector<int64_t> getValueAsListOfInts(StringRef FieldName) const;
  
    /// getValueAsListOfStrings - This method looks up the specified field and
    /// returns its value as a vector of strings, throwing an exception if the
    /// field does not exist or if the value is not the right type.
    ///
    std::vector<std::string> getValueAsListOfStrings(StringRef FieldName) const;
  
    /// getValueAsDef - This method looks up the specified field and returns its
    /// value as a Record, throwing an exception if the field does not exist or if
    /// the value is not the right type.
    ///
    Record *getValueAsDef(StringRef FieldName) const;
  
    /// getValueAsBit - This method looks up the specified field and returns its
    /// value as a bit, throwing an exception if the field does not exist or if
    /// the value is not the right type.
    ///
    bool getValueAsBit(StringRef FieldName) const;
  
    /// getValueAsInt - This method looks up the specified field and returns its
    /// value as an int64_t, throwing an exception if the field does not exist or
    /// if the value is not the right type.
    ///
    int64_t getValueAsInt(StringRef FieldName) const;
  
    /// getValueAsDag - This method looks up the specified field and returns its
    /// value as an Dag, throwing an exception if the field does not exist or if
    /// the value is not the right type.
    ///
    DagInit *getValueAsDag(StringRef FieldName) const;
  };
  
  raw_ostream &operator<<(raw_ostream &OS, const Record &R);
  
  struct MultiClass {
    Record Rec;  // Placeholder for template args and Name.
    typedef std::vector<Record*> RecordVector;
    RecordVector DefPrototypes;
  
    void dump() const;
  
    MultiClass(const std::string &Name, SMLoc Loc, RecordKeeper &Records) :
      Rec(Name, Loc, Records) {}
  };
  
  class RecordKeeper {
    std::map<std::string, Record*> Classes, Defs;
  
  public:
    ~RecordKeeper() {
      for (std::map<std::string, Record*>::iterator I = Classes.begin(),
             E = Classes.end(); I != E; ++I)
        delete I->second;
      for (std::map<std::string, Record*>::iterator I = Defs.begin(),
             E = Defs.end(); I != E; ++I)
        delete I->second;
    }
  
    const std::map<std::string, Record*> &getClasses() const { return Classes; }
    const std::map<std::string, Record*> &getDefs() const { return Defs; }
  
    Record *getClass(const std::string &Name) const {
      std::map<std::string, Record*>::const_iterator I = Classes.find(Name);
      return I == Classes.end() ? 0 : I->second;
    }
    Record *getDef(const std::string &Name) const {
      std::map<std::string, Record*>::const_iterator I = Defs.find(Name);
      return I == Defs.end() ? 0 : I->second;
    }
    void addClass(Record *R) {
      assert(getClass(R->getNameInitAsString()) == 0 && "Class already exists!");
      Classes.insert(std::make_pair(R->getNameInitAsString(), R));
    }
    void addDef(Record *R) {
      assert(getDef(R->getNameInitAsString()) == 0 && "Def already exists!");
      Defs.insert(std::make_pair(R->getNameInitAsString(), R));
    }
  
    /// removeClass - Remove, but do not delete, the specified record.
    ///
    void removeClass(const std::string &Name) {
      assert(Classes.count(Name) && "Class does not exist!");
      Classes.erase(Name);
    }
    /// removeDef - Remove, but do not delete, the specified record.
    ///
    void removeDef(const std::string &Name) {
      assert(Defs.count(Name) && "Def does not exist!");
      Defs.erase(Name);
    }
  
    //===--------------------------------------------------------------------===//
    // High-level helper methods, useful for tablegen backends...
  
    /// getAllDerivedDefinitions - This method returns all concrete definitions
    /// that derive from the specified class name.  If a class with the specified
    /// name does not exist, an exception is thrown.
    std::vector<Record*>
    getAllDerivedDefinitions(const std::string &ClassName) const;
  
    void dump() const;
  };
  
  /// LessRecord - Sorting predicate to sort record pointers by name.
  ///
  struct LessRecord {
    bool operator()(const Record *Rec1, const Record *Rec2) const {
      return StringRef(Rec1->getName()).compare_numeric(Rec2->getName()) < 0;
    }
  };
  
  /// LessRecordFieldName - Sorting predicate to sort record pointers by their
  /// name field.
  ///
  struct LessRecordFieldName {
    bool operator()(const Record *Rec1, const Record *Rec2) const {
      return Rec1->getValueAsString("Name") < Rec2->getValueAsString("Name");
    }
  };
  
  raw_ostream &operator<<(raw_ostream &OS, const RecordKeeper &RK);
  
  /// QualifyName - Return an Init with a qualifier prefix referring
  /// to CurRec's name.
  Init *QualifyName(Record &CurRec, MultiClass *CurMultiClass,
                    Init *Name, const std::string &Scoper);
  
  /// QualifyName - Return an Init with a qualifier prefix referring
  /// to CurRec's name.
  Init *QualifyName(Record &CurRec, MultiClass *CurMultiClass,
                    const std::string &Name, const std::string &Scoper);
  
  } // End llvm namespace
  
  #endif
  