clang/AST/Decl.h

//===--- Decl.h - Classes for representing declarations ---------*- 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 Decl subclasses.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_DECL_H
#define LLVM_CLANG_AST_DECL_H

#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/DeclBase.h"
#include "clang/Parse/AccessSpecifier.h"
#include "llvm/ADT/SmallVector.h"

namespace clang {
class Expr;
class Stmt;
class CompoundStmt;
class StringLiteral;

/// TranslationUnitDecl - The top declaration context.
/// FIXME: The TranslationUnit class should probably be modified to serve as
/// the top decl context. It would have ownership of the top decls so that the
/// AST is self-contained and easily de/serializable.
/// FIXME: TranslationUnitDecl isn't really a Decl (!)
class TranslationUnitDecl : public Decl, public DeclContext {
  TranslationUnitDecl()
    : Decl(TranslationUnit, 0, SourceLocation()),
      DeclContext(TranslationUnit) {}
public:
  static TranslationUnitDecl *Create(ASTContext &C);
  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == TranslationUnit; }
  static bool classof(const TranslationUnitDecl *D) { return true; }
  static DeclContext *castToDeclContext(const TranslationUnitDecl *D) {
    return static_cast<DeclContext *>(const_cast<TranslationUnitDecl*>(D));
  }
  static TranslationUnitDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<TranslationUnitDecl *>(const_cast<DeclContext*>(DC));
  }

protected:
  /// EmitImpl - Serialize this TranslationUnitDecl. Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a TranslationUnitDecl.  Called by Decl::Create.
  static TranslationUnitDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

/// NamedDecl - This represents a decl with a name.  Many decls have names such
/// as ObjCMethodDecl, but not @class, etc.
class NamedDecl : public Decl {
  /// Name - The name of this declaration, which is typically a normal
  /// identifier but may also be a special kind of name (C++
  /// constructor, Objective-C selector, etc.)
  DeclarationName Name;

protected:
  NamedDecl(Kind DK, DeclContext *DC, SourceLocation L, DeclarationName N)
    : Decl(DK, DC, L), Name(N) {}

  NamedDecl(Kind DK, DeclContext *DC, SourceLocation L, IdentifierInfo *Id)
    : Decl(DK, DC, L), Name(Id) {}

public:
  /// getIdentifier - Get the identifier that names this declaration,
  /// if there is one. This will return NULL if this declaration has
  /// no name (e.g., for an unnamed class) or if the name is a special
  /// name (C++ constructor, Objective-C selector, etc.).
  IdentifierInfo *getIdentifier() const { return Name.getAsIdentifierInfo(); }

  /// getNameAsCString - Get the name of identifier for this declaration as a
  /// C string (const char*).  This requires that the declaration have a name
  /// and that it be a simple identifier.
  const char *getNameAsCString() const {
    assert(getIdentifier() && "Name is not a simple identifier");
    return getIdentifier()->getName();
  }

  /// getDeclName - Get the actual, stored name of the declaration,
  /// which may be a special name.
  DeclarationName getDeclName() const { return Name; }

  /// getNameAsString - Get a human-readable name for the declaration, even if
  /// it is one of the special kinds of names (C++ constructor, Objective-C
  /// selector, etc).  Creating this name requires expensive string
  /// manipulation, so it should be called only when performance doesn't matter.
  /// For simple declarations, getNameAsCString() should suffice.
  std::string getNameAsString() const { return Name.getAsString(); }

  /// declarationReplaces - Determine whether this declaration, if
  /// known to be well-formed within its context, will replace the
  /// declaration OldD if introduced into scope. A declaration will
  /// replace another declaration if, for example, it is a
  /// redeclaration of the same variable or function, but not if it is
  /// a declaration of a different kind (function vs. class) or an
  /// overloaded function.
  bool declarationReplaces(NamedDecl *OldD) const;

  static bool classof(const Decl *D) {
    return D->getKind() >= NamedFirst && D->getKind() <= NamedLast;
  }
  static bool classof(const NamedDecl *D) { return true; }

protected:
  void EmitInRec(llvm::Serializer& S) const;
  void ReadInRec(llvm::Deserializer& D, ASTContext& C);
};

/// NamespaceDecl - Represent a C++ namespace.
class NamespaceDecl : public NamedDecl, public DeclContext {
  SourceLocation LBracLoc, RBracLoc;

  // For extended namespace definitions:
  //
  // namespace A { int x; }
  // namespace A { int y; }
  //
  // there will be one NamespaceDecl for each declaration.
  // NextDeclarator points to the next extended declaration.
  // OrigNamespace points to the original namespace declaration.
  // OrigNamespace of the first namespace decl points to itself.

  NamespaceDecl *OrigNamespace;

  NamespaceDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id)
    : NamedDecl(Namespace, DC, L, Id), DeclContext(Namespace) {
      OrigNamespace = this;
  }
public:
  static NamespaceDecl *Create(ASTContext &C, DeclContext *DC,
                               SourceLocation L, IdentifierInfo *Id);

  virtual void Destroy(ASTContext& C);

  NamespaceDecl *getNextNamespace() {
    return cast_or_null<NamespaceDecl>(getNextDeclarator());
  }
  const NamespaceDecl *getNextNamespace() const {
    return cast_or_null<NamespaceDecl>(getNextDeclarator());
  }
  void setNextNamespace(NamespaceDecl *ND) { setNextDeclarator(ND); }

  NamespaceDecl *getOriginalNamespace() const {
    return OrigNamespace;
  }
  void setOriginalNamespace(NamespaceDecl *ND) { OrigNamespace = ND; }

  SourceRange getSourceRange() const {
    return SourceRange(LBracLoc, RBracLoc);
  }

  SourceLocation getLBracLoc() const { return LBracLoc; }
  SourceLocation getRBracLoc() const { return RBracLoc; }
  void setLBracLoc(SourceLocation LBrace) { LBracLoc = LBrace; }
  void setRBracLoc(SourceLocation RBrace) { RBracLoc = RBrace; }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == Namespace; }
  static bool classof(const NamespaceDecl *D) { return true; }
  static DeclContext *castToDeclContext(const NamespaceDecl *D) {
    return static_cast<DeclContext *>(const_cast<NamespaceDecl*>(D));
  }
  static NamespaceDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<NamespaceDecl *>(const_cast<DeclContext*>(DC));
  }

protected:
  /// EmitImpl - Serialize this NamespaceDecl. Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a NamespaceDecl.  Called by Decl::Create.
  static NamespaceDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

/// ValueDecl - Represent the declaration of a variable (in which case it is
/// an lvalue) a function (in which case it is a function designator) or
/// an enum constant.
class ValueDecl : public NamedDecl {
  QualType DeclType;

protected:
  ValueDecl(Kind DK, DeclContext *DC, SourceLocation L,
            DeclarationName N, QualType T)
    : NamedDecl(DK, DC, L, N), DeclType(T) {}
public:
  QualType getType() const { return DeclType; }
  void setType(QualType newType) { DeclType = newType; }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return D->getKind() >= ValueFirst && D->getKind() <= ValueLast;
  }
  static bool classof(const ValueDecl *D) { return true; }

protected:
  void EmitInRec(llvm::Serializer& S) const;
  void ReadInRec(llvm::Deserializer& D, ASTContext& C);
};

/// VarDecl - An instance of this class is created to represent a variable
/// declaration or definition.
class VarDecl : public ValueDecl {
public:
  enum StorageClass {
    None, Auto, Register, Extern, Static, PrivateExtern
  };
private:
  Stmt *Init;
  // FIXME: This can be packed into the bitfields in Decl.
  unsigned SClass : 3;
  bool ThreadSpecified : 1;
  bool HasCXXDirectInit : 1;

  /// DeclaredInCondition - Whether this variable was declared in a
  /// condition, e.g., if (int x = foo()) { ... }.
  bool DeclaredInCondition : 1;

  // Move to DeclGroup when it is implemented.
  SourceLocation TypeSpecStartLoc;
  friend class StmtIteratorBase;
protected:
  VarDecl(Kind DK, DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
          QualType T, StorageClass SC, SourceLocation TSSL = SourceLocation())
    : ValueDecl(DK, DC, L, Id, T), Init(0),
          ThreadSpecified(false), HasCXXDirectInit(false),
          DeclaredInCondition(false), TypeSpecStartLoc(TSSL) {
    SClass = SC;
  }
public:
  static VarDecl *Create(ASTContext &C, DeclContext *DC,
                         SourceLocation L, IdentifierInfo *Id,
                         QualType T, StorageClass S,
                         SourceLocation TypeSpecStartLoc = SourceLocation());

  virtual ~VarDecl();
  virtual void Destroy(ASTContext& C);

  StorageClass getStorageClass() const { return (StorageClass)SClass; }

  SourceLocation getTypeSpecStartLoc() const { return TypeSpecStartLoc; }

  const Expr *getInit() const { return (const Expr*) Init; }
  Expr *getInit() { return (Expr*) Init; }
  void setInit(Expr *I) { Init = (Stmt*) I; }

  void setThreadSpecified(bool T) { ThreadSpecified = T; }
  bool isThreadSpecified() const {
    return ThreadSpecified;
  }

  void setCXXDirectInitializer(bool T) { HasCXXDirectInit = T; }

  /// hasCXXDirectInitializer - If true, the initializer was a direct
  /// initializer, e.g: "int x(1);". The Init expression will be the expression
  /// inside the parens or a "ClassType(a,b,c)" class constructor expression for
  /// class types. Clients can distinguish between "int x(1);" and "int x=1;"
  /// by checking hasCXXDirectInitializer.
  ///
  bool hasCXXDirectInitializer() const {
    return HasCXXDirectInit;
  }

  /// isDeclaredInCondition - Whether this variable was declared as
  /// part of a condition in an if/switch/while statement, e.g.,
  /// @code
  /// if (int x = foo()) { ... }
  /// @endcode
  bool isDeclaredInCondition() const {
    return DeclaredInCondition;
  }
  void setDeclaredInCondition(bool InCondition) {
    DeclaredInCondition = InCondition;
  }

  /// hasLocalStorage - Returns true if a variable with function scope
  ///  is a non-static local variable.
  bool hasLocalStorage() const {
    if (getStorageClass() == None)
      return !isFileVarDecl();

    // Return true for:  Auto, Register.
    // Return false for: Extern, Static, PrivateExtern.

    return getStorageClass() <= Register;
  }

  /// hasGlobalStorage - Returns true for all variables that do not
  ///  have local storage.  This includs all global variables as well
  ///  as static variables declared within a function.
  bool hasGlobalStorage() const { return !hasLocalStorage(); }

  /// isBlockVarDecl - Returns true for local variable declarations.  Note that
  /// this includes static variables inside of functions.
  ///
  ///   void foo() { int x; static int y; extern int z; }
  ///
  bool isBlockVarDecl() const {
    if (getKind() != Decl::Var)
      return false;
    if (const DeclContext *DC = getDeclContext())
      return DC->getLookupContext()->isFunctionOrMethod();
    return false;
  }

  /// isFileVarDecl - Returns true for file scoped variable declaration.
  bool isFileVarDecl() const {
    if (getKind() != Decl::Var)
      return false;
    if (const DeclContext *Ctx = getDeclContext()) {
      Ctx = Ctx->getLookupContext();
      if (isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx) )
        return true;
    }
    return false;
  }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return D->getKind() >= VarFirst && D->getKind() <= VarLast;
  }
  static bool classof(const VarDecl *D) { return true; }

protected:
  void EmitInRec(llvm::Serializer& S) const;
  void ReadInRec(llvm::Deserializer& D, ASTContext& C);

  void EmitOutRec(llvm::Serializer& S) const;
  void ReadOutRec(llvm::Deserializer& D, ASTContext& C);

  /// EmitImpl - Serialize this VarDecl. Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// ReadImpl - Deserialize this VarDecl. Called by subclasses.
  virtual void ReadImpl(llvm::Deserializer& D, ASTContext& C);

  /// CreateImpl - Deserialize a VarDecl.  Called by Decl::Create.
  static VarDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);
};

class ImplicitParamDecl : public VarDecl {
protected:
  ImplicitParamDecl(Kind DK, DeclContext *DC, SourceLocation L,
            IdentifierInfo *Id, QualType Tw)
    : VarDecl(DK, DC, L, Id, Tw, VarDecl::None) {}
public:
  static ImplicitParamDecl *Create(ASTContext &C, DeclContext *DC,
                         SourceLocation L, IdentifierInfo *Id,
                         QualType T);
  // Implement isa/cast/dyncast/etc.
  static bool classof(const ImplicitParamDecl *D) { return true; }
  static bool classof(const Decl *D) { return D->getKind() == ImplicitParam; }
};

/// ParmVarDecl - Represent a parameter to a function.
class ParmVarDecl : public VarDecl {
  // NOTE: VC++ treats enums as signed, avoid using the ObjCDeclQualifier enum
  /// FIXME: Also can be paced into the bitfields in Decl.
  /// in, inout, etc.
  unsigned objcDeclQualifier : 6;

  /// Default argument, if any.  [C++ Only]
  Expr *DefaultArg;
protected:
  ParmVarDecl(Kind DK, DeclContext *DC, SourceLocation L,
              IdentifierInfo *Id, QualType T, StorageClass S,
              Expr *DefArg)
    : VarDecl(DK, DC, L, Id, T, S),
      objcDeclQualifier(OBJC_TQ_None), DefaultArg(DefArg) {}

public:
  static ParmVarDecl *Create(ASTContext &C, DeclContext *DC,
                             SourceLocation L,IdentifierInfo *Id,
                             QualType T, StorageClass S, Expr *DefArg);

  ObjCDeclQualifier getObjCDeclQualifier() const {
    return ObjCDeclQualifier(objcDeclQualifier);
  }
  void setObjCDeclQualifier(ObjCDeclQualifier QTVal) {
    objcDeclQualifier = QTVal;
  }

  const Expr *getDefaultArg() const { return DefaultArg; }
  Expr *getDefaultArg() { return DefaultArg; }
  void setDefaultArg(Expr *defarg) { DefaultArg = defarg; }

  /// hasUnparsedDefaultArg - Determines whether this parameter has a
  /// default argument that has not yet been parsed. This will occur
  /// during the processing of a C++ class whose member functions have
  /// default arguments, e.g.,
  /// @code
  ///   class X {
  ///   public:
  ///     void f(int x = 17); // x has an unparsed default argument now
  ///   }; // x has a regular default argument now
  /// @endcode
  bool hasUnparsedDefaultArg() const {
    return DefaultArg == reinterpret_cast<Expr *>(-1);
  }

  /// setUnparsedDefaultArg - Specify that this parameter has an
  /// unparsed default argument. The argument will be replaced with a
  /// real default argument via setDefaultArg when the class
  /// definition enclosing the function declaration that owns this
  /// default argument is completed.
  void setUnparsedDefaultArg() { DefaultArg = reinterpret_cast<Expr *>(-1); }

  QualType getOriginalType() const;

  /// setOwningFunction - Sets the function declaration that owns this
  /// ParmVarDecl. Since ParmVarDecls are often created before the
  /// FunctionDecls that own them, this routine is required to update
  /// the DeclContext appropriately.
  void setOwningFunction(DeclContext *FD) { setDeclContext(FD); }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return (D->getKind() == ParmVar ||
            D->getKind() == OriginalParmVar);
  }
  static bool classof(const ParmVarDecl *D) { return true; }

protected:
  /// EmitImpl - Serialize this ParmVarDecl. Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a ParmVarDecl.  Called by Decl::Create.
  static ParmVarDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

/// OriginalParmVarDecl - Represent a parameter to a function, when
/// the type of the parameter has been promoted. This node represents the
/// parameter to the function with its original type.
///
class OriginalParmVarDecl : public ParmVarDecl {
  friend class ParmVarDecl;
protected:
  QualType OriginalType;
private:
  OriginalParmVarDecl(DeclContext *DC, SourceLocation L,
                              IdentifierInfo *Id, QualType T,
                              QualType OT, StorageClass S,
                              Expr *DefArg)
  : ParmVarDecl(OriginalParmVar, DC, L, Id, T, S, DefArg), OriginalType(OT) {}
public:
    static OriginalParmVarDecl *Create(ASTContext &C, DeclContext *DC,
                               SourceLocation L,IdentifierInfo *Id,
                               QualType T, QualType OT,
                               StorageClass S, Expr *DefArg);

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == OriginalParmVar; }
  static bool classof(const OriginalParmVarDecl *D) { return true; }

protected:
  /// EmitImpl - Serialize this OriginalParmVarDecl.
  /// Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a OriginalParmVarDecl.
  /// Called by Decl::Create.
  static OriginalParmVarDecl* CreateImpl(llvm::Deserializer& D,
                                                 ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

/// FunctionDecl - An instance of this class is created to represent a
/// function declaration or definition.
///
/// Since a given function can be declared several times in a program,
/// there may be several FunctionDecls that correspond to that
/// function. Only one of those FunctionDecls will be found when
/// traversing the list of declarations in the context of the
/// FunctionDecl (e.g., the translation unit); this FunctionDecl
/// contains all of the information known about the function. Other,
/// previous declarations of the function are available via the
/// getPreviousDeclaration() chain.
class FunctionDecl : public ValueDecl, public DeclContext {
public:
  enum StorageClass {
    None, Extern, Static, PrivateExtern
  };
private:
  /// ParamInfo - new[]'d array of pointers to VarDecls for the formal
  /// parameters of this function.  This is null if a prototype or if there are
  /// no formals.  TODO: we could allocate this space immediately after the
  /// FunctionDecl object to save an allocation like FunctionType does.
  ParmVarDecl **ParamInfo;

  Stmt *Body;  // Null if a prototype.

  /// PreviousDeclaration - A link to the previous declaration of this
  /// same function, NULL if this is the first declaration. For
  /// example, in the following code, the PreviousDeclaration can be
  /// traversed several times to see all three declarations of the
  /// function "f", the last of which is also a definition.
  ///
  ///   int f(int x, int y = 1);
  ///   int f(int x = 0, int y);
  ///   int f(int x, int y) { return x + y; }
  FunctionDecl *PreviousDeclaration;

  // NOTE: VC++ treats enums as signed, avoid using the StorageClass enum
  unsigned SClass : 2;
  bool IsInline : 1;
  bool IsVirtual : 1;
  bool IsPure : 1;

  // Move to DeclGroup when it is implemented.
  SourceLocation TypeSpecStartLoc;
protected:
  FunctionDecl(Kind DK, DeclContext *DC, SourceLocation L,
               DeclarationName N, QualType T,
               StorageClass S, bool isInline,
               SourceLocation TSSL = SourceLocation())
    : ValueDecl(DK, DC, L, N, T),
      DeclContext(DK),
      ParamInfo(0), Body(0), PreviousDeclaration(0),
      SClass(S), IsInline(isInline), IsVirtual(false), IsPure(false),
      TypeSpecStartLoc(TSSL) {}

  virtual ~FunctionDecl() {}
  virtual void Destroy(ASTContext& C);

public:
  static FunctionDecl *Create(ASTContext &C, DeclContext *DC, SourceLocation L,
                              DeclarationName N, QualType T,
                              StorageClass S = None, bool isInline = false,
                              SourceLocation TSStartLoc = SourceLocation());

  SourceLocation getTypeSpecStartLoc() const { return TypeSpecStartLoc; }

  /// getBody - Retrieve the body (definition) of the function. The
  /// function body might be in any of the (re-)declarations of this
  /// function. The variant that accepts a FunctionDecl pointer will
  /// set that function declaration to the actual declaration
  /// containing the body (if there is one).
  Stmt *getBody(const FunctionDecl *&Definition) const;

  virtual Stmt *getBody() const {
    const FunctionDecl* Definition;
    return getBody(Definition);
  }

  /// isThisDeclarationADefinition - Returns whether this specific
  /// declaration of the function is also a definition. This does not
  /// determine whether the function has been defined (e.g., in a
  /// previous definition); for that information, use getBody.
  bool isThisDeclarationADefinition() const { return Body != 0; }

  void setBody(Stmt *B) { Body = B; }

  /// Whether this function is virtual, either by explicit marking, or by
  /// overriding a virtual function. Only valid on C++ member functions.
  bool isVirtual() { return IsVirtual; }
  void setVirtual() { IsVirtual = true; }

  /// Whether this virtual function is pure, i.e. makes the containing class
  /// abstract.
  bool isPure() { return IsPure; }
  void setPure() { IsPure = true; }

  /// getPreviousDeclaration - Return the previous declaration of this
  /// function.
  const FunctionDecl *getPreviousDeclaration() const {
    return PreviousDeclaration;
  }

  void setPreviousDeclaration(FunctionDecl * PrevDecl) {
    PreviousDeclaration = PrevDecl;
  }

  // Iterator access to formal parameters.
  unsigned param_size() const { return getNumParams(); }
  typedef ParmVarDecl **param_iterator;
  typedef ParmVarDecl * const *param_const_iterator;

  param_iterator param_begin() { return ParamInfo; }
  param_iterator param_end()   { return ParamInfo+param_size(); }

  param_const_iterator param_begin() const { return ParamInfo; }
  param_const_iterator param_end() const   { return ParamInfo+param_size(); }

  unsigned getNumParams() const;
  const ParmVarDecl *getParamDecl(unsigned i) const {
    assert(i < getNumParams() && "Illegal param #");
    return ParamInfo[i];
  }
  ParmVarDecl *getParamDecl(unsigned i) {
    assert(i < getNumParams() && "Illegal param #");
    return ParamInfo[i];
  }
  void setParams(ASTContext& C, ParmVarDecl **NewParamInfo, unsigned NumParams);

  /// getMinRequiredArguments - Returns the minimum number of arguments
  /// needed to call this function. This may be fewer than the number of
  /// function parameters, if some of the parameters have default
  /// arguments (in C++).
  unsigned getMinRequiredArguments() const;

  QualType getResultType() const {
    return getType()->getAsFunctionType()->getResultType();
  }
  StorageClass getStorageClass() const { return StorageClass(SClass); }
  bool isInline() const { return IsInline; }

  /// isOverloadedOperator - Whether this function declaration
  /// represents an C++ overloaded operator, e.g., "operator+".
  bool isOverloadedOperator() const {
    return getOverloadedOperator() != OO_None;
  };

  OverloadedOperatorKind getOverloadedOperator() const;

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return D->getKind() >= FunctionFirst && D->getKind() <= FunctionLast;
  }
  static bool classof(const FunctionDecl *D) { return true; }
  static DeclContext *castToDeclContext(const FunctionDecl *D) {
    return static_cast<DeclContext *>(const_cast<FunctionDecl*>(D));
  }
  static FunctionDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<FunctionDecl *>(const_cast<DeclContext*>(DC));
  }

protected:
  /// EmitImpl - Serialize this FunctionDecl.  Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a FunctionDecl.  Called by Decl::Create.
  static FunctionDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
  friend class CXXRecordDecl;
};


/// FieldDecl - An instance of this class is created by Sema::ActOnField to
/// represent a member of a struct/union/class.
class FieldDecl : public NamedDecl {
  bool Mutable : 1;
  QualType DeclType;
  Expr *BitWidth;
protected:
  FieldDecl(Kind DK, DeclContext *DC, SourceLocation L,
            IdentifierInfo *Id, QualType T, Expr *BW, bool Mutable)
    : NamedDecl(DK, DC, L, Id), Mutable(Mutable), DeclType(T),
      BitWidth(BW)
      { }

public:
  static FieldDecl *Create(ASTContext &C, DeclContext *DC, SourceLocation L,
                           IdentifierInfo *Id, QualType T, Expr *BW,
                           bool Mutable);

  QualType getType() const { return DeclType; }

  /// isMutable - Determines whether this field is mutable (C++ only).
  bool isMutable() const { return Mutable; }

  /// isBitfield - Determines whether this field is a bitfield.
  bool isBitField() const { return BitWidth != NULL; }

  /// @brief Determines whether this is an unnamed bitfield.
  bool isUnnamedBitfield() const { return BitWidth != NULL && !getDeclName(); }

  /// isAnonymousStructOrUnion - Determines whether this field is a
  /// representative for an anonymous struct or union. Such fields are
  /// unnamed and are implicitly generated by the implementation to
  /// store the data for the anonymous union or struct.
  bool isAnonymousStructOrUnion() const;

  Expr *getBitWidth() const { return BitWidth; }
  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return D->getKind() >= FieldFirst && D->getKind() <= FieldLast;
  }
  static bool classof(const FieldDecl *D) { return true; }

protected:
  /// EmitImpl - Serialize this FieldDecl.  Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a FieldDecl.  Called by Decl::Create.
  static FieldDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

/// EnumConstantDecl - An instance of this object exists for each enum constant
/// that is defined.  For example, in "enum X {a,b}", each of a/b are
/// EnumConstantDecl's, X is an instance of EnumDecl, and the type of a/b is a
/// TagType for the X EnumDecl.
class EnumConstantDecl : public ValueDecl {
  Stmt *Init; // an integer constant expression
  llvm::APSInt Val; // The value.
protected:
  EnumConstantDecl(DeclContext *DC, SourceLocation L,
                   IdentifierInfo *Id, QualType T, Expr *E,
                   const llvm::APSInt &V)
    : ValueDecl(EnumConstant, DC, L, Id, T), Init((Stmt*)E), Val(V) {}

  virtual ~EnumConstantDecl() {}
public:

  static EnumConstantDecl *Create(ASTContext &C, EnumDecl *DC,
                                  SourceLocation L, IdentifierInfo *Id,
                                  QualType T, Expr *E,
                                  const llvm::APSInt &V);

  virtual void Destroy(ASTContext& C);

  const Expr *getInitExpr() const { return (const Expr*) Init; }
  Expr *getInitExpr() { return (Expr*) Init; }
  const llvm::APSInt &getInitVal() const { return Val; }

  void setInitExpr(Expr *E) { Init = (Stmt*) E; }
  void setInitVal(const llvm::APSInt &V) { Val = V; }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == EnumConstant; }
  static bool classof(const EnumConstantDecl *D) { return true; }

  friend class StmtIteratorBase;

protected:
  /// EmitImpl - Serialize this EnumConstantDecl.  Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a EnumConstantDecl.  Called by Decl::Create.
  static EnumConstantDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};


/// TypeDecl - Represents a declaration of a type.
///
class TypeDecl : public NamedDecl {
  /// TypeForDecl - This indicates the Type object that represents this
  /// TypeDecl.  It is a cache maintained by ASTContext::getTypedefType,
  /// ASTContext::getTagDeclType, and ASTContext::getTemplateTypeParmType.
  Type *TypeForDecl;
  friend class ASTContext;
  friend class DeclContext;
  friend class TagDecl;

protected:
  TypeDecl(Kind DK, DeclContext *DC, SourceLocation L,
           IdentifierInfo *Id)
    : NamedDecl(DK, DC, L, Id), TypeForDecl(0) {}

public:
  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return D->getKind() >= TypeFirst && D->getKind() <= TypeLast;
  }
  static bool classof(const TypeDecl *D) { return true; }
};


class TypedefDecl : public TypeDecl {
  /// UnderlyingType - This is the type the typedef is set to.
  QualType UnderlyingType;
  TypedefDecl(DeclContext *DC, SourceLocation L,
              IdentifierInfo *Id, QualType T)
    : TypeDecl(Typedef, DC, L, Id), UnderlyingType(T) {}

  virtual ~TypedefDecl() {}
public:

  static TypedefDecl *Create(ASTContext &C, DeclContext *DC,
                             SourceLocation L,IdentifierInfo *Id,
                             QualType T);

  QualType getUnderlyingType() const { return UnderlyingType; }
  void setUnderlyingType(QualType newType) { UnderlyingType = newType; }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == Typedef; }
  static bool classof(const TypedefDecl *D) { return true; }

protected:
  /// EmitImpl - Serialize this TypedefDecl.  Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a TypedefDecl.  Called by Decl::Create.
  static TypedefDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};


/// TagDecl - Represents the declaration of a struct/union/class/enum.
class TagDecl : public TypeDecl, public DeclContext {
public:
  enum TagKind {
    TK_struct,
    TK_union,
    TK_class,
    TK_enum
  };

private:
  /// TagDeclKind - The TagKind enum.
  unsigned TagDeclKind : 2;

  /// IsDefinition - True if this is a definition ("struct foo {};"), false if
  /// it is a declaration ("struct foo;").
  bool IsDefinition : 1;
protected:
  TagDecl(Kind DK, TagKind TK, DeclContext *DC, SourceLocation L,
          IdentifierInfo *Id)
    : TypeDecl(DK, DC, L, Id), DeclContext(DK) {
    assert((DK != Enum || TK == TK_enum) &&"EnumDecl not matched with TK_enum");
    TagDeclKind = TK;
    IsDefinition = false;
  }
public:

  /// isDefinition - Return true if this decl has its body specified.
  bool isDefinition() const {
    return IsDefinition;
  }

  /// @brief Starts the definition of this tag declaration.
  ///
  /// This method should be invoked at the beginning of the definition
  /// of this tag declaration. It will set the tag type into a state
  /// where it is in the process of being defined.
  void startDefinition();

  /// @brief Completes the definition of this tag declaration.
  void completeDefinition();

  /// getDefinition - Returns the TagDecl that actually defines this
  ///  struct/union/class/enum.  When determining whether or not a
  ///  struct/union/class/enum is completely defined, one should use this method
  ///  as opposed to 'isDefinition'.  'isDefinition' indicates whether or not a
  ///  specific TagDecl is defining declaration, not whether or not the
  ///  struct/union/class/enum type is defined.  This method returns NULL if
  ///  there is no TagDecl that defines the struct/union/class/enum.
  TagDecl* getDefinition(ASTContext& C) const;

  const char *getKindName() const {
    switch (getTagKind()) {
    default: assert(0 && "Unknown TagKind!");
    case TK_struct: return "struct";
    case TK_union:  return "union";
    case TK_class:  return "class";
    case TK_enum:   return "enum";
    }
  }

  TagKind getTagKind() const {
    return TagKind(TagDeclKind);
  }

  bool isStruct() const { return getTagKind() == TK_struct; }
  bool isClass()  const { return getTagKind() == TK_class; }
  bool isUnion()  const { return getTagKind() == TK_union; }
  bool isEnum()   const { return getTagKind() == TK_enum; }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) {
    return D->getKind() >= TagFirst && D->getKind() <= TagLast;
  }
  static bool classof(const TagDecl *D) { return true; }

  static DeclContext *castToDeclContext(const TagDecl *D) {
    return static_cast<DeclContext *>(const_cast<TagDecl*>(D));
  }
  static TagDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<TagDecl *>(const_cast<DeclContext*>(DC));
  }

protected:
  void setDefinition(bool V) { IsDefinition = V; }
};

/// EnumDecl - Represents an enum.  As an extension, we allow forward-declared
/// enums.
class EnumDecl : public TagDecl {
  /// IntegerType - This represent the integer type that the enum corresponds
  /// to for code generation purposes.  Note that the enumerator constants may
  /// have a different type than this does.
  QualType IntegerType;

  EnumDecl(DeclContext *DC, SourceLocation L,
           IdentifierInfo *Id)
    : TagDecl(Enum, TK_enum, DC, L, Id) {
      IntegerType = QualType();
    }
public:
  static EnumDecl *Create(ASTContext &C, DeclContext *DC,
                          SourceLocation L, IdentifierInfo *Id,
                          EnumDecl *PrevDecl);

  virtual void Destroy(ASTContext& C);

  /// completeDefinition - When created, the EnumDecl corresponds to a
  /// forward-declared enum. This method is used to mark the
  /// declaration as being defined; it's enumerators have already been
  /// added (via DeclContext::addDecl). NewType is the new underlying
  /// type of the enumeration type.
  void completeDefinition(ASTContext &C, QualType NewType);

  // enumerator_iterator - Iterates through the enumerators of this
  // enumeration.
  typedef specific_decl_iterator<EnumConstantDecl> enumerator_iterator;

  enumerator_iterator enumerator_begin() const {
    return enumerator_iterator(this->decls_begin());
  }

  enumerator_iterator enumerator_end() const {
    return enumerator_iterator(this->decls_end());
  }

  /// getIntegerType - Return the integer type this enum decl corresponds to.
  /// This returns a null qualtype for an enum forward definition.
  QualType getIntegerType() const { return IntegerType; }

  static bool classof(const Decl *D) { return D->getKind() == Enum; }
  static bool classof(const EnumDecl *D) { return true; }
  static DeclContext *castToDeclContext(const EnumDecl *D) {
    return static_cast<DeclContext *>(const_cast<EnumDecl*>(D));
  }
  static EnumDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<EnumDecl *>(const_cast<DeclContext*>(DC));
  }

protected:
  /// EmitImpl - Serialize this EnumDecl.  Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a EnumDecl.  Called by Decl::Create.
  static EnumDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};


/// RecordDecl - Represents a struct/union/class.  For example:
///   struct X;                  // Forward declaration, no "body".
///   union Y { int A, B; };     // Has body with members A and B (FieldDecls).
/// This decl will be marked invalid if *any* members are invalid.
///
class RecordDecl : public TagDecl {
  /// HasFlexibleArrayMember - This is true if this struct ends with a flexible
  /// array member (e.g. int X[]) or if this union contains a struct that does.
  /// If so, this cannot be contained in arrays or other structs as a member.
  bool HasFlexibleArrayMember : 1;

  /// AnonymousStructOrUnion - Whether this is the type of an
  /// anonymous struct or union.
  bool AnonymousStructOrUnion : 1;

protected:
  RecordDecl(Kind DK, TagKind TK, DeclContext *DC,
             SourceLocation L, IdentifierInfo *Id);
  virtual ~RecordDecl();

public:
  static RecordDecl *Create(ASTContext &C, TagKind TK, DeclContext *DC,
                            SourceLocation L, IdentifierInfo *Id,
                            RecordDecl* PrevDecl = 0);

  virtual void Destroy(ASTContext& C);

  bool hasFlexibleArrayMember() const { return HasFlexibleArrayMember; }
  void setHasFlexibleArrayMember(bool V) { HasFlexibleArrayMember = V; }

  /// isAnonymousStructOrUnion - Whether this is an anonymous struct
  /// or union. To be an anonymous struct or union, it must have been
  /// declared without a name and there must be no objects of this
  /// type declared, e.g.,
  /// @code
  ///   union { int i; float f; };
  /// @endcode
  /// is an anonymous union but neither of the following are:
  /// @code
  ///  union X { int i; float f; };
  ///  union { int i; float f; } obj;
  /// @endcode
  bool isAnonymousStructOrUnion() const { return AnonymousStructOrUnion; }
  void setAnonymousStructOrUnion(bool Anon) {
    AnonymousStructOrUnion = Anon;
  }

  /// getDefinition - Returns the RecordDecl that actually defines this
  ///  struct/union/class.  When determining whether or not a struct/union/class
  ///  is completely defined, one should use this method as opposed to
  ///  'isDefinition'.  'isDefinition' indicates whether or not a specific
  ///  RecordDecl is defining declaration, not whether or not the record
  ///  type is defined.  This method returns NULL if there is no RecordDecl
  ///  that defines the struct/union/tag.
  RecordDecl* getDefinition(ASTContext& C) const {
    return cast_or_null<RecordDecl>(TagDecl::getDefinition(C));
  }

  // Iterator access to field members. The field iterator only visits
  // the non-static data members of this class, ignoring any static
  // data members, functions, constructors, destructors, etc.
  typedef specific_decl_iterator<FieldDecl> field_iterator;

  field_iterator field_begin() const {
    return field_iterator(decls_begin());
  }
  field_iterator field_end() const {
    return field_iterator(decls_end());
  }

  // field_empty - Whether there are any fields (non-static data
  // members) in this record.
  bool field_empty() const { return field_begin() == field_end(); }

  /// completeDefinition - Notes that the definition of this type is
  /// now complete.
  void completeDefinition(ASTContext& C);

  static bool classof(const Decl *D) {
    return D->getKind() >= RecordFirst && D->getKind() <= RecordLast;
  }
  static bool classof(const RecordDecl *D) { return true; }
  static DeclContext *castToDeclContext(const RecordDecl *D) {
    return static_cast<DeclContext *>(const_cast<RecordDecl*>(D));
  }
  static RecordDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<RecordDecl *>(const_cast<DeclContext*>(DC));
  }
protected:
  /// EmitImpl - Serialize this RecordDecl.  Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a RecordDecl.  Called by Decl::Create.
  static RecordDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

class FileScopeAsmDecl : public Decl {
  StringLiteral *AsmString;
  FileScopeAsmDecl(DeclContext *DC, SourceLocation L, StringLiteral *asmstring)
    : Decl(FileScopeAsm, DC, L), AsmString(asmstring) {}
public:
  static FileScopeAsmDecl *Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation L, StringLiteral *Str);

  const StringLiteral *getAsmString() const { return AsmString; }
  StringLiteral *getAsmString() { return AsmString; }
  static bool classof(const Decl *D) {
    return D->getKind() == FileScopeAsm;
  }
  static bool classof(const FileScopeAsmDecl *D) { return true; }
protected:
  /// EmitImpl - Serialize this FileScopeAsmDecl. Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a FileScopeAsmDecl.  Called by Decl::Create.
  static FileScopeAsmDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

/// BlockDecl - This represents a block literal declaration, which is like an
/// unnamed FunctionDecl.  For example:
/// ^{ statement-body }   or   ^(int arg1, float arg2){ statement-body }
///
class BlockDecl : public Decl, public DeclContext {
  llvm::SmallVector<ParmVarDecl*, 8> Args;
  Stmt *Body;

protected:
  BlockDecl(DeclContext *DC, SourceLocation CaretLoc)
    : Decl(Block, DC, CaretLoc), DeclContext(Block), Body(0) {}

  virtual ~BlockDecl();
  virtual void Destroy(ASTContext& C);

public:
  static BlockDecl *Create(ASTContext &C, DeclContext *DC, SourceLocation L);

  SourceLocation getCaretLocation() const { return getLocation(); }

  Stmt *getBody() const { return Body; }
  void setBody(Stmt *B) { Body = B; }

  void setArgs(ParmVarDecl **args, unsigned numargs) {
    Args.clear();
    Args.insert(Args.begin(), args, args+numargs);
  }

  /// arg_iterator - Iterate over the ParmVarDecl's for this block.
  typedef llvm::SmallVector<ParmVarDecl*, 8>::const_iterator param_iterator;
  bool param_empty() const { return Args.empty(); }
  param_iterator param_begin() const { return Args.begin(); }
  param_iterator param_end() const { return Args.end(); }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == Block; }
  static bool classof(const BlockDecl *D) { return true; }
  static DeclContext *castToDeclContext(const BlockDecl *D) {
    return static_cast<DeclContext *>(const_cast<BlockDecl*>(D));
  }
  static BlockDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<BlockDecl *>(const_cast<DeclContext*>(DC));
  }

protected:
  /// EmitImpl - Serialize this BlockDecl. Called by Decl::Emit.
  virtual void EmitImpl(llvm::Serializer& S) const;

  /// CreateImpl - Deserialize a BlockDecl.  Called by Decl::Create.
  static BlockDecl* CreateImpl(llvm::Deserializer& D, ASTContext& C);

  friend Decl* Decl::Create(llvm::Deserializer& D, ASTContext& C);
};

}  // end namespace clang

#endif