xref: /external/clang/include/clang/AST/DeclObjC.h

//===--- DeclObjC.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 DeclObjC interface and subclasses.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_DECLOBJC_H
#define LLVM_CLANG_AST_DECLOBJC_H

#include "clang/AST/Decl.h"
#include "clang/Basic/IdentifierTable.h"

namespace clang {
class Expr;
class Stmt;
class FunctionDecl;
class AttributeList;
class ObjCIvarDecl;
class ObjCMethodDecl;
class ObjCProtocolDecl;
class ObjCCategoryDecl;
class ObjCPropertyDecl;

/// ObjCMethodDecl - Represents an instance or class method declaration.
/// ObjC methods can be declared within 4 contexts: class interfaces,
/// categories, protocols, and class implementations. While C++ member
/// functions leverage C syntax, Objective-C method syntax is modeled after
/// Smalltalk (using colons to specify argument types/expressions).
/// Here are some brief examples:
///
/// Setter/getter instance methods:
/// - (void)setMenu:(NSMenu *)menu;
/// - (NSMenu *)menu;
///
/// Instance method that takes 2 NSView arguments:
/// - (void)replaceSubview:(NSView *)oldView with:(NSView *)newView;
///
/// Getter class method:
/// + (NSMenu *)defaultMenu;
///
/// A selector represents a unique name for a method. The selector names for
/// the above methods are setMenu:, menu, replaceSubview:with:, and defaultMenu.
///
class ObjCMethodDecl : public Decl, public DeclContext {
public:
  enum ImplementationControl { None, Required, Optional };
private:
  /// Bitfields must be first fields in this class so they pack with those
  /// declared in class Decl.
  /// instance (true) or class (false) method.
  bool IsInstance : 1;
  bool IsVariadic : 1;

  // NOTE: VC++ treats enums as signed, avoid using ImplementationControl enum
  /// @required/@optional
  unsigned DeclImplementation : 2;

  // NOTE: VC++ treats enums as signed, avoid using the ObjCDeclQualifier enum
  /// in, inout, etc.
  unsigned objcDeclQualifier : 6;

  // Context this method is declared in.
  NamedDecl *MethodContext;

  // A unigue name for this method.
  Selector SelName;

  // Type of this method.
  QualType MethodDeclType;
  /// ParamInfo - new[]'d array of pointers to VarDecls for the formal
  /// parameters of this Method.  This is null if there are no formals.
  ParmVarDecl **ParamInfo;
  unsigned NumMethodParams;

  /// List of attributes for this method declaration.
  AttributeList *MethodAttrs;

  SourceLocation EndLoc; // the location of the ';' or '{'.

  // The following are only used for method definitions, null otherwise.
  // FIXME: space savings opportunity, consider a sub-class.
  Stmt *Body;
  ParmVarDecl *SelfDecl;

  ObjCMethodDecl(SourceLocation beginLoc, SourceLocation endLoc,
                 Selector SelInfo, QualType T,
                 Decl *contextDecl,
                 AttributeList *M = 0, bool isInstance = true,
                 bool isVariadic = false,
                 ImplementationControl impControl = None)
  : Decl(ObjCMethod, beginLoc),
    DeclContext(ObjCMethod),
    IsInstance(isInstance), IsVariadic(isVariadic),
    DeclImplementation(impControl), objcDeclQualifier(OBJC_TQ_None),
    MethodContext(static_cast<NamedDecl*>(contextDecl)),
    SelName(SelInfo), MethodDeclType(T),
    ParamInfo(0), NumMethodParams(0),
    MethodAttrs(M), EndLoc(endLoc), Body(0), SelfDecl(0) {}
  virtual ~ObjCMethodDecl();
public:

  static ObjCMethodDecl *Create(ASTContext &C,
                                SourceLocation beginLoc,
                                SourceLocation endLoc, Selector SelInfo,
                                QualType T, Decl *contextDecl,
                                AttributeList *M = 0, bool isInstance = true,
                                bool isVariadic = false,
                                ImplementationControl impControl = None);

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

  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const { return getLocation(); }
  SourceLocation getLocEnd() const { return EndLoc; }

  NamedDecl *getMethodContext() const { return MethodContext; }

  const ObjCInterfaceDecl *getClassInterface() const;
  ObjCInterfaceDecl *getClassInterface() {
    return (ObjCInterfaceDecl*)((ObjCMethodDecl*)this)->getClassInterface();
  }

  Selector getSelector() const { return SelName; }
  unsigned getSynthesizedMethodSize() const;
  QualType getResultType() const { return MethodDeclType; }

  // Iterator access to formal parameters.
  unsigned param_size() const { return NumMethodParams; }
  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 { return NumMethodParams; }
  ParmVarDecl *getParamDecl(unsigned i) const {
    assert(i < getNumParams() && "Illegal param #");
    return ParamInfo[i];
  }
  void setParamDecl(int i, ParmVarDecl *pDecl) {
    ParamInfo[i] = pDecl;
  }
  void setMethodParams(ParmVarDecl **NewParamInfo, unsigned NumParams);

  AttributeList *getMethodAttrs() const {return MethodAttrs;}
  bool isInstance() const { return IsInstance; }
  bool isVariadic() const { return IsVariadic; }

  // Related to protocols declared in  @protocol
  void setDeclImplementation(ImplementationControl ic) {
    DeclImplementation = ic;
  }
  ImplementationControl getImplementationControl() const {
    return ImplementationControl(DeclImplementation);
  }
  Stmt *getBody() { return Body; }
  const Stmt *getBody() const { return Body; }
  void setBody(Stmt *B) { Body = B; }

  const ParmVarDecl *getSelfDecl() const { return SelfDecl; }
  ParmVarDecl *getSelfDecl() { return SelfDecl; }
  void setSelfDecl(ParmVarDecl *PVD) { SelfDecl = PVD; }

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

/// ObjCInterfaceDecl - Represents an ObjC class declaration. For example:
///
///   // MostPrimitive declares no super class (not particularly useful).
///   @interface MostPrimitive
///     // no instance variables or methods.
///   @end
///
///   // NSResponder inherits from NSObject & implements NSCoding (a protocol).
///   @interface NSResponder : NSObject <NSCoding>
///   { // instance variables are represented by ObjCIvarDecl.
///     id nextResponder; // nextResponder instance variable.
///   }
///   - (NSResponder *)nextResponder; // return a pointer to NSResponder.
///   - (void)mouseMoved:(NSEvent *)theEvent; // return void, takes a pointer
///   @end                                    // to an NSEvent.
///
///   Unlike C/C++, forward class declarations are accomplished with @class.
///   Unlike C/C++, @class allows for a list of classes to be forward declared.
///   Unlike C++, ObjC is a single-rooted class model. In Cocoa, classes
///   typically inherit from NSObject (an exception is NSProxy).
///
class ObjCInterfaceDecl : public NamedDecl, public DeclContext {
  /// TypeForDecl - This indicates the Type object that represents this
  /// TypeDecl.  It is a cache maintained by ASTContext::getObjCInterfaceType
  Type *TypeForDecl;
  friend class ASTContext;

  /// Class's super class.
  ObjCInterfaceDecl *SuperClass;

  /// Protocols referenced in interface header declaration
  ObjCProtocolDecl **ReferencedProtocols;  // Null if none
  unsigned NumReferencedProtocols;  // 0 if none

  /// Ivars/NumIvars - This is a new[]'d array of pointers to Decls.
  ObjCIvarDecl **Ivars;   // Null if not defined.
  unsigned NumIvars;      // 0 if none.

  /// instance methods
  ObjCMethodDecl **InstanceMethods;  // Null if not defined
  unsigned NumInstanceMethods;  // 0 if none.

  /// class methods
  ObjCMethodDecl **ClassMethods;  // Null if not defined
  unsigned NumClassMethods;  // 0 if none

  /// List of categories defined for this class.
  ObjCCategoryDecl *CategoryList;

  /// class properties
  ObjCPropertyDecl **PropertyDecl;  // Null if no property
  unsigned NumPropertyDecl;  // 0 if none.

  bool ForwardDecl:1; // declared with @class.
  bool InternalInterface:1; // true - no @interface for @implementation

  SourceLocation EndLoc; // marks the '>', '}', or identifier.
  SourceLocation AtEndLoc; // marks the end of the entire interface.

  ObjCInterfaceDecl(SourceLocation atLoc,
                    unsigned numRefProtos,
                    IdentifierInfo *Id, bool FD, bool isInternal)
    : NamedDecl(ObjCInterface, atLoc, Id), DeclContext(ObjCInterface),
      TypeForDecl(0), SuperClass(0),
      ReferencedProtocols(0), NumReferencedProtocols(0), Ivars(0),
      NumIvars(0),
      InstanceMethods(0), NumInstanceMethods(0),
      ClassMethods(0), NumClassMethods(0),
      CategoryList(0), PropertyDecl(0), NumPropertyDecl(0),
      ForwardDecl(FD), InternalInterface(isInternal) {
        AllocIntfRefProtocols(numRefProtos);
      }
public:

  static ObjCInterfaceDecl *Create(ASTContext &C,
                                   SourceLocation atLoc,
                                   unsigned numRefProtos, IdentifierInfo *Id,
                                   bool ForwardDecl = false,
                                   bool isInternal = false);

  // This is necessary when converting a forward declaration to a definition.
  void AllocIntfRefProtocols(unsigned numRefProtos) {
    if (numRefProtos) {
      ReferencedProtocols = new ObjCProtocolDecl*[numRefProtos];
      memset(ReferencedProtocols, '\0',
             numRefProtos*sizeof(ObjCProtocolDecl*));
      NumReferencedProtocols = numRefProtos;
    }
  }

  ObjCProtocolDecl **getReferencedProtocols() const {
    return ReferencedProtocols;
  }
  unsigned getNumIntfRefProtocols() const { return NumReferencedProtocols; }

  typedef ObjCIvarDecl * const *ivar_iterator;
  ivar_iterator ivar_begin() const { return Ivars; }
  ivar_iterator ivar_end() const { return Ivars + ivar_size();}
  unsigned ivar_size() const { return NumIvars; }

  unsigned getNumInstanceMethods() const { return NumInstanceMethods; }
  unsigned getNumClassMethods() const { return NumClassMethods; }

  typedef ObjCMethodDecl * const * instmeth_iterator;
  instmeth_iterator instmeth_begin() const { return InstanceMethods; }
  instmeth_iterator instmeth_end() const {
    return InstanceMethods+NumInstanceMethods;
  }

  typedef ObjCMethodDecl * const * classmeth_iterator;
  classmeth_iterator classmeth_begin() const { return ClassMethods; }
  classmeth_iterator classmeth_end() const {
    return ClassMethods+NumClassMethods;
  }

  void addInstanceVariablesToClass(ObjCIvarDecl **ivars, unsigned numIvars,
                                   SourceLocation RBracLoc);

  void addMethods(ObjCMethodDecl **insMethods, unsigned numInsMembers,
                  ObjCMethodDecl **clsMethods, unsigned numClsMembers,
                  SourceLocation AtEnd);

  void addProperties(ObjCPropertyDecl **Properties, unsigned NumProperties);


  bool isForwardDecl() const { return ForwardDecl; }
  void setForwardDecl(bool val) { ForwardDecl = val; }

  void setIntfRefProtocols(unsigned idx, ObjCProtocolDecl *OID) {
    assert((idx < NumReferencedProtocols) && "index out of range");
    ReferencedProtocols[idx] = OID;
  }

  ObjCInterfaceDecl *getSuperClass() const { return SuperClass; }
  void setSuperClass(ObjCInterfaceDecl * superCls) { SuperClass = superCls; }

  ObjCCategoryDecl* getCategoryList() const { return CategoryList; }
  void setCategoryList(ObjCCategoryDecl *category) {
         CategoryList = category;
  }
  ObjCIvarDecl *lookupInstanceVariable(IdentifierInfo *ivarName,
                                       ObjCInterfaceDecl *&clsDeclared);

  // Get the local instance method declared in this interface.
  ObjCMethodDecl *getInstanceMethod(Selector &Sel) {
    for (instmeth_iterator I = instmeth_begin(), E = instmeth_end();
         I != E; ++I) {
      if ((*I)->getSelector() == Sel)
        return *I;
    }
    return 0;
  }
  // Get the local class method declared in this interface.
  ObjCMethodDecl *getClassMethod(Selector &Sel) {
    for (classmeth_iterator I = classmeth_begin(), E = classmeth_end();
         I != E; ++I) {
      if ((*I)->getSelector() == Sel)
        return *I;
    }
    return 0;
  }
  // Lookup a method. First, we search locally. If a method isn't
  // found, we search referenced protocols and class categories.
  ObjCMethodDecl *lookupInstanceMethod(Selector Sel);
  ObjCMethodDecl *lookupClassMethod(Selector Sel);

  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const { return getLocation(); } // '@'interface
  SourceLocation getLocEnd() const { return EndLoc; }
  void setLocEnd(SourceLocation LE) { EndLoc = LE; };

  // We also need to record the @end location.
  SourceLocation getAtEndLoc() const { return AtEndLoc; }

  unsigned getNumPropertyDecl() const { return NumPropertyDecl; }

  ObjCPropertyDecl * const * getPropertyDecl() const { return PropertyDecl; }
  ObjCPropertyDecl **getPropertyDecl() { return PropertyDecl; }

  /// ImplicitInterfaceDecl - check that this is an implicitely declared
  /// ObjCInterfaceDecl node. This is for legacy objective-c @implementation
  /// declaration without an @interface declaration.
  bool ImplicitInterfaceDecl() const { return InternalInterface; }

  static bool classof(const Decl *D) { return D->getKind() == ObjCInterface; }
  static bool classof(const ObjCInterfaceDecl *D) { return true; }
};

/// ObjCIvarDecl - Represents an ObjC instance variable. In general, ObjC
/// instance variables are identical to C. The only exception is Objective-C
/// supports C++ style access control. For example:
///
///   @interface IvarExample : NSObject
///   {
///     id defaultToPrivate; // same as C++.
///   @public:
///     id canBePublic; // same as C++.
///   @protected:
///     id canBeProtected; // same as C++.
///   @package:
///     id canBePackage; // framework visibility (not available in C++).
///   }
///
class ObjCIvarDecl : public FieldDecl {
  ObjCIvarDecl(SourceLocation L, IdentifierInfo *Id, QualType T)
    : FieldDecl(ObjCIvar, L, Id, T) {}
public:
  static ObjCIvarDecl *Create(ASTContext &C, SourceLocation L,
                              IdentifierInfo *Id, QualType T);

  enum AccessControl {
    None, Private, Protected, Public, Package
  };
  void setAccessControl(AccessControl ac) { DeclAccess = ac; }
  AccessControl getAccessControl() const { return AccessControl(DeclAccess); }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return D->getKind() == ObjCIvar; }
  static bool classof(const ObjCIvarDecl *D) { return true; }
private:
  // NOTE: VC++ treats enums as signed, avoid using the AccessControl enum
  unsigned DeclAccess : 3;
};


/// ObjCProtocolDecl - Represents a protocol declaration. ObjC protocols
/// declare a pure abstract type (i.e no instance variables are permitted).
/// Protocols orginally drew inspiration from C++ pure virtual functions (a C++
/// feature with nice semantics and lousy syntax:-). Here is an example:
///
/// @protocol NSDraggingInfo
/// - (NSWindow *)draggingDestinationWindow;
/// - (NSImage *)draggedImage;
/// @end
///
/// @interface ImplementsNSDraggingInfo : NSObject <NSDraggingInfo>
/// @end
///
/// ObjC protocols inspired Java interfaces. Unlike Java, ObjC classes and
/// protocols are in distinct namespaces. For example, Cocoa defines both
/// an NSObject protocol and class (which isn't allowed in Java). As a result,
/// protocols are referenced using angle brackets as follows:
///
/// id <NSDraggingInfo> anyObjectThatImplementsNSDraggingInfo;
///
class ObjCProtocolDecl : public NamedDecl {
  /// referenced protocols
  ObjCProtocolDecl **ReferencedProtocols;  // Null if none
  unsigned NumReferencedProtocols;  // 0 if none

  /// protocol instance methods
  ObjCMethodDecl **InstanceMethods;  // Null if not defined
  unsigned NumInstanceMethods;  // 0 if none

  /// protocol class methods
  ObjCMethodDecl **ClassMethods;  // Null if not defined
  unsigned NumClassMethods;  // 0 if none

  bool isForwardProtoDecl; // declared with @protocol.

  SourceLocation EndLoc; // marks the '>' or identifier.
  SourceLocation AtEndLoc; // marks the end of the entire interface.

  ObjCProtocolDecl(SourceLocation L, unsigned numRefProtos, IdentifierInfo *Id)
    : NamedDecl(ObjCProtocol, L, Id),
      ReferencedProtocols(0), NumReferencedProtocols(0),
      InstanceMethods(0), NumInstanceMethods(0),
      ClassMethods(0), NumClassMethods(0),
      isForwardProtoDecl(true) {
    AllocReferencedProtocols(numRefProtos);
  }
public:
  static ObjCProtocolDecl *Create(ASTContext &C, SourceLocation L,
                                  unsigned numRefProtos, IdentifierInfo *Id);

  void AllocReferencedProtocols(unsigned numRefProtos) {
    if (numRefProtos) {
      ReferencedProtocols = new ObjCProtocolDecl*[numRefProtos];
      memset(ReferencedProtocols, '\0',
             numRefProtos*sizeof(ObjCProtocolDecl*));
      NumReferencedProtocols = numRefProtos;
    }
  }
  void addMethods(ObjCMethodDecl **insMethods, unsigned numInsMembers,
                  ObjCMethodDecl **clsMethods, unsigned numClsMembers,
                  SourceLocation AtEndLoc);

  void setReferencedProtocols(unsigned idx, ObjCProtocolDecl *OID) {
    assert((idx < NumReferencedProtocols) && "index out of range");
    ReferencedProtocols[idx] = OID;
  }

  ObjCProtocolDecl** getReferencedProtocols() const {
    return ReferencedProtocols;
  }
  unsigned getNumReferencedProtocols() const { return NumReferencedProtocols; }
  unsigned getNumInstanceMethods() const { return NumInstanceMethods; }
  unsigned getNumClassMethods() const { return NumClassMethods; }

  typedef ObjCMethodDecl * const * instmeth_iterator;
  instmeth_iterator instmeth_begin() const { return InstanceMethods; }
  instmeth_iterator instmeth_end() const {
    return InstanceMethods+NumInstanceMethods;
  }

  typedef ObjCMethodDecl * const * classmeth_iterator;
  classmeth_iterator classmeth_begin() const { return ClassMethods; }
  classmeth_iterator classmeth_end() const {
    return ClassMethods+NumClassMethods;
  }

  // Get the local instance method declared in this interface.
  ObjCMethodDecl *getInstanceMethod(Selector Sel) {
    for (instmeth_iterator I = instmeth_begin(), E = instmeth_end();
         I != E; ++I) {
      if ((*I)->getSelector() == Sel)
        return *I;
    }
    return 0;
  }
  // Get the local class method declared in this interface.
  ObjCMethodDecl *getClassMethod(Selector Sel) {
    for (classmeth_iterator I = classmeth_begin(), E = classmeth_end();
         I != E; ++I) {
      if ((*I)->getSelector() == Sel)
        return *I;
    }
    return 0;
  }

  // Lookup a method. First, we search locally. If a method isn't
  // found, we search referenced protocols and class categories.
  ObjCMethodDecl *lookupInstanceMethod(Selector Sel);
  ObjCMethodDecl *lookupClassMethod(Selector Sel);

  bool isForwardDecl() const { return isForwardProtoDecl; }
  void setForwardDecl(bool val) { isForwardProtoDecl = val; }

  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const { return getLocation(); } // '@'protocol
  SourceLocation getLocEnd() const { return EndLoc; }
  void setLocEnd(SourceLocation LE) { EndLoc = LE; };

  // We also need to record the @end location.
  SourceLocation getAtEndLoc() const { return AtEndLoc; }

  static bool classof(const Decl *D) { return D->getKind() == ObjCProtocol; }
  static bool classof(const ObjCProtocolDecl *D) { return true; }
};

/// ObjCClassDecl - Specifies a list of forward class declarations. For example:
///
/// @class NSCursor, NSImage, NSPasteboard, NSWindow;
///
class ObjCClassDecl : public Decl {
  ObjCInterfaceDecl **ForwardDecls;
  unsigned NumForwardDecls;

  ObjCClassDecl(SourceLocation L, ObjCInterfaceDecl **Elts, unsigned nElts)
    : Decl(ObjCClass, L) {
    if (nElts) {
      ForwardDecls = new ObjCInterfaceDecl*[nElts];
      memcpy(ForwardDecls, Elts, nElts*sizeof(ObjCInterfaceDecl*));
    } else {
      ForwardDecls = 0;
    }
    NumForwardDecls = nElts;
  }
public:
  static ObjCClassDecl *Create(ASTContext &C, SourceLocation L,
                               ObjCInterfaceDecl **Elts, unsigned nElts);

  void setInterfaceDecl(unsigned idx, ObjCInterfaceDecl *OID) {
    assert(idx < NumForwardDecls && "index out of range");
    ForwardDecls[idx] = OID;
  }
  ObjCInterfaceDecl** getForwardDecls() const { return ForwardDecls; }
  int getNumForwardDecls() const { return NumForwardDecls; }

  static bool classof(const Decl *D) { return D->getKind() == ObjCClass; }
  static bool classof(const ObjCClassDecl *D) { return true; }
};

/// ObjCForwardProtocolDecl - Specifies a list of forward protocol declarations.
/// For example:
///
/// @protocol NSTextInput, NSChangeSpelling, NSDraggingInfo;
///
class ObjCForwardProtocolDecl : public Decl {
  ObjCProtocolDecl **ReferencedProtocols;
  unsigned NumReferencedProtocols;

  ObjCForwardProtocolDecl(SourceLocation L,
                          ObjCProtocolDecl **Elts, unsigned nElts)
  : Decl(ObjCForwardProtocol, L) {
    NumReferencedProtocols = nElts;
    if (nElts) {
      ReferencedProtocols = new ObjCProtocolDecl*[nElts];
      memcpy(ReferencedProtocols, Elts, nElts*sizeof(ObjCProtocolDecl*));
    } else {
      ReferencedProtocols = 0;
    }
  }
public:
  static ObjCForwardProtocolDecl *Create(ASTContext &C, SourceLocation L,
                                         ObjCProtocolDecl **Elts, unsigned Num);


  void setForwardProtocolDecl(unsigned idx, ObjCProtocolDecl *OID) {
    assert(idx < NumReferencedProtocols && "index out of range");
    ReferencedProtocols[idx] = OID;
  }

  unsigned getNumForwardDecls() const { return NumReferencedProtocols; }

  ObjCProtocolDecl *getForwardProtocolDecl(unsigned idx) {
    assert(idx < NumReferencedProtocols && "index out of range");
    return ReferencedProtocols[idx];
  }
  const ObjCProtocolDecl *getForwardProtocolDecl(unsigned idx) const {
    assert(idx < NumReferencedProtocols && "index out of range");
    return ReferencedProtocols[idx];
  }

  static bool classof(const Decl *D) {
    return D->getKind() == ObjCForwardProtocol;
  }
  static bool classof(const ObjCForwardProtocolDecl *D) { return true; }
};

/// ObjCCategoryDecl - Represents a category declaration. A category allows
/// you to add methods to an existing class (without subclassing or modifying
/// the original class interface or implementation:-). Categories don't allow
/// you to add instance data. The following example adds "myMethod" to all
/// NSView's within a process:
///
/// @interface NSView (MyViewMethods)
/// - myMethod;
/// @end
///
/// Cateogries also allow you to split the implementation of a class across
/// several files (a feature more naturally supported in C++).
///
/// Categories were originally inspired by dynamic languages such as Common
/// Lisp and Smalltalk.  More traditional class-based languages (C++, Java)
/// don't support this level of dynamism, which is both powerful and dangerous.
///
class ObjCCategoryDecl : public NamedDecl {
  /// Interface belonging to this category
  ObjCInterfaceDecl *ClassInterface;

  /// referenced protocols in this category.
  ObjCProtocolDecl **ReferencedProtocols;  // Null if none
  unsigned NumReferencedProtocols;  // 0 if none

  /// category instance methods
  ObjCMethodDecl **InstanceMethods;  // Null if not defined
  unsigned NumInstanceMethods;  // 0 if none

  /// category class methods
  ObjCMethodDecl **ClassMethods;  // Null if not defined
  unsigned NumClassMethods;  // 0 if not defined

  /// Next category belonging to this class
  ObjCCategoryDecl *NextClassCategory;

  SourceLocation EndLoc; // marks the '>' or identifier.
  SourceLocation AtEndLoc; // marks the end of the entire interface.

  ObjCCategoryDecl(SourceLocation L, IdentifierInfo *Id)
    : NamedDecl(ObjCCategory, L, Id),
      ClassInterface(0), ReferencedProtocols(0), NumReferencedProtocols(0),
      InstanceMethods(0), NumInstanceMethods(0),
      ClassMethods(0), NumClassMethods(0),
      NextClassCategory(0) {
  }
public:

  static ObjCCategoryDecl *Create(ASTContext &C,
                                  SourceLocation L, IdentifierInfo *Id);

  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
  void setClassInterface(ObjCInterfaceDecl *IDecl) { ClassInterface = IDecl; }

  void setReferencedProtocolList(ObjCProtocolDecl **List, unsigned NumRPs);

  void setCatReferencedProtocols(unsigned idx, ObjCProtocolDecl *OID) {
    assert((idx < NumReferencedProtocols) && "index out of range");
    ReferencedProtocols[idx] = OID;
  }

  ObjCProtocolDecl **getReferencedProtocols() const {
    return ReferencedProtocols;
  }
  unsigned getNumReferencedProtocols() const { return NumReferencedProtocols; }
  unsigned getNumInstanceMethods() const { return NumInstanceMethods; }
  unsigned getNumClassMethods() const { return NumClassMethods; }

  typedef ObjCMethodDecl * const * instmeth_iterator;
  instmeth_iterator instmeth_begin() const { return InstanceMethods; }
  instmeth_iterator instmeth_end() const {
    return InstanceMethods+NumInstanceMethods;
  }

  typedef ObjCMethodDecl * const * classmeth_iterator;
  classmeth_iterator classmeth_begin() const { return ClassMethods; }
  classmeth_iterator classmeth_end() const {
    return ClassMethods+NumClassMethods;
  }

  // Get the local instance method declared in this interface.
  ObjCMethodDecl *getInstanceMethod(Selector Sel) {
    for (instmeth_iterator I = instmeth_begin(), E = instmeth_end();
         I != E; ++I) {
      if ((*I)->getSelector() == Sel)
        return *I;
    }
    return 0;
  }
  // Get the local class method declared in this interface.
  ObjCMethodDecl *getClassMethod(Selector Sel) {
    for (classmeth_iterator I = classmeth_begin(), E = classmeth_end();
         I != E; ++I) {
      if ((*I)->getSelector() == Sel)
        return *I;
    }
    return 0;
  }

  void addMethods(ObjCMethodDecl **insMethods, unsigned numInsMembers,
                  ObjCMethodDecl **clsMethods, unsigned numClsMembers,
                  SourceLocation AtEndLoc);

  ObjCCategoryDecl *getNextClassCategory() const { return NextClassCategory; }
  void insertNextClassCategory() {
    NextClassCategory = ClassInterface->getCategoryList();
    ClassInterface->setCategoryList(this);
  }
  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const { return getLocation(); } // '@'interface
  SourceLocation getLocEnd() const { return EndLoc; }
  void setLocEnd(SourceLocation LE) { EndLoc = LE; };

  // We also need to record the @end location.
  SourceLocation getAtEndLoc() const { return AtEndLoc; }

  static bool classof(const Decl *D) { return D->getKind() == ObjCCategory; }
  static bool classof(const ObjCCategoryDecl *D) { return true; }
};

/// ObjCCategoryImplDecl - An object of this class encapsulates a category
/// @implementation declaration.
class ObjCCategoryImplDecl : public NamedDecl {
  /// Class interface for this category implementation
  ObjCInterfaceDecl *ClassInterface;

  /// implemented instance methods
  llvm::SmallVector<ObjCMethodDecl*, 32> InstanceMethods;

  /// implemented class methods
  llvm::SmallVector<ObjCMethodDecl*, 32> ClassMethods;

  SourceLocation EndLoc;

  ObjCCategoryImplDecl(SourceLocation L, IdentifierInfo *Id,
                       ObjCInterfaceDecl *classInterface)
    : NamedDecl(ObjCCategoryImpl, L, Id), ClassInterface(classInterface) {}
public:
  static ObjCCategoryImplDecl *Create(ASTContext &C,
                                      SourceLocation L, IdentifierInfo *Id,
                                      ObjCInterfaceDecl *classInterface);

  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }

  unsigned getNumInstanceMethods() const { return InstanceMethods.size(); }
  unsigned getNumClassMethods() const { return ClassMethods.size(); }

  void addInstanceMethod(ObjCMethodDecl *method) {
    InstanceMethods.push_back(method);
  }
  void addClassMethod(ObjCMethodDecl *method) {
    ClassMethods.push_back(method);
  }
  // Get the instance method definition for this implementation.
  ObjCMethodDecl *getInstanceMethod(Selector Sel);

  // Get the class method definition for this implementation.
  ObjCMethodDecl *getClassMethod(Selector Sel);

  typedef llvm::SmallVector<ObjCMethodDecl*, 32>::const_iterator
    instmeth_iterator;
  instmeth_iterator instmeth_begin() const { return InstanceMethods.begin(); }
  instmeth_iterator instmeth_end() const { return InstanceMethods.end(); }

  typedef llvm::SmallVector<ObjCMethodDecl*, 32>::const_iterator
    classmeth_iterator;
  classmeth_iterator classmeth_begin() const { return ClassMethods.begin(); }
  classmeth_iterator classmeth_end() const { return ClassMethods.end(); }


  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const { return getLocation(); }
  SourceLocation getLocEnd() const { return EndLoc; }
  void setLocEnd(SourceLocation LE) { EndLoc = LE; };

  static bool classof(const Decl *D) { return D->getKind() == ObjCCategoryImpl;}
  static bool classof(const ObjCCategoryImplDecl *D) { return true; }
};

/// ObjCImplementationDecl - Represents a class definition - this is where
/// method definitions are specified. For example:
///
/// @implementation MyClass
/// - (void)myMethod { /* do something */ }
/// @end
///
/// Typically, instance variables are specified in the class interface,
/// *not* in the implemenentation. Nevertheless (for legacy reasons), we
/// allow instance variables to be specified in the implementation. When
/// specified, they need to be *identical* to the interface. Now that we
/// have support for non-fragile ivars in ObjC 2.0, we can consider removing
/// the legacy semantics and allow developers to move private ivar declarations
/// from the class interface to the class implementation (but I digress:-)
///
class ObjCImplementationDecl : public NamedDecl {
  /// Class interface for this category implementation
  ObjCInterfaceDecl *ClassInterface;

  /// Implementation Class's super class.
  ObjCInterfaceDecl *SuperClass;

  /// Optional Ivars/NumIvars - This is a new[]'d array of pointers to Decls.
  ObjCIvarDecl **Ivars;   // Null if not specified
  unsigned NumIvars;      // 0 if none.

  /// implemented instance methods
  llvm::SmallVector<ObjCMethodDecl*, 32> InstanceMethods;

  /// implemented class methods
  llvm::SmallVector<ObjCMethodDecl*, 32> ClassMethods;

  SourceLocation EndLoc;

  ObjCImplementationDecl(SourceLocation L, IdentifierInfo *Id,
                         ObjCInterfaceDecl *classInterface,
                         ObjCInterfaceDecl *superDecl)
    : NamedDecl(ObjCImplementation, L, Id),
      ClassInterface(classInterface), SuperClass(superDecl),
      Ivars(0), NumIvars(0) {}
public:
  static ObjCImplementationDecl *Create(ASTContext &C,
                                        SourceLocation L, IdentifierInfo *Id,
                                        ObjCInterfaceDecl *classInterface,
                                        ObjCInterfaceDecl *superDecl);


  void ObjCAddInstanceVariablesToClassImpl(ObjCIvarDecl **ivars,
                                           unsigned numIvars);

  void addInstanceMethod(ObjCMethodDecl *method) {
    InstanceMethods.push_back(method);
  }
  void addClassMethod(ObjCMethodDecl *method) {
    ClassMethods.push_back(method);
  }
  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const { return getLocation(); }
  SourceLocation getLocEnd() const { return EndLoc; }
  void setLocEnd(SourceLocation LE) { EndLoc = LE; };

  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
  const ObjCInterfaceDecl *getSuperClass() const { return SuperClass; }
  ObjCInterfaceDecl *getSuperClass() { return SuperClass; }

  void setSuperClass(ObjCInterfaceDecl * superCls) { SuperClass = superCls; }

  unsigned getNumInstanceMethods() const { return InstanceMethods.size(); }
  unsigned getNumClassMethods() const { return ClassMethods.size(); }

  typedef llvm::SmallVector<ObjCMethodDecl*, 32>::const_iterator
       instmeth_iterator;
  instmeth_iterator instmeth_begin() const { return InstanceMethods.begin(); }
  instmeth_iterator instmeth_end() const { return InstanceMethods.end(); }

  typedef llvm::SmallVector<ObjCMethodDecl*, 32>::const_iterator
    classmeth_iterator;
  classmeth_iterator classmeth_begin() const { return ClassMethods.begin(); }
  classmeth_iterator classmeth_end() const { return ClassMethods.end(); }

  // Get the instance method definition for this implementation.
  ObjCMethodDecl *getInstanceMethod(Selector Sel);

  // Get the class method definition for this implementation.
  ObjCMethodDecl *getClassMethod(Selector Sel);

  typedef ObjCIvarDecl * const *ivar_iterator;
  ivar_iterator ivar_begin() const { return Ivars; }
  ivar_iterator ivar_end() const { return Ivars+NumIvars; }
  unsigned ivar_size() const { return NumIvars; }
  bool ivar_empty() const { return NumIvars == 0; }

  static bool classof(const Decl *D) {
    return D->getKind() == ObjCImplementation;
  }
  static bool classof(const ObjCImplementationDecl *D) { return true; }
};

/// ObjCCompatibleAliasDecl - Represents alias of a class. This alias is
/// declared as @compatibility_alias alias class.
class ObjCCompatibleAliasDecl : public NamedDecl {
  /// Class that this is an alias of.
  ObjCInterfaceDecl *AliasedClass;

  ObjCCompatibleAliasDecl(SourceLocation L, IdentifierInfo *Id,
                          ObjCInterfaceDecl* aliasedClass)
    : NamedDecl(ObjCCompatibleAlias, L, Id), AliasedClass(aliasedClass) {}
public:
  static ObjCCompatibleAliasDecl *Create(ASTContext &C,
                                         SourceLocation L, IdentifierInfo *Id,
                                         ObjCInterfaceDecl* aliasedClass);

  const ObjCInterfaceDecl *getClassInterface() const { return AliasedClass; }
  ObjCInterfaceDecl *getClassInterface() { return AliasedClass; }

  static bool classof(const Decl *D) {
    return D->getKind() == ObjCCompatibleAlias;
  }
  static bool classof(const ObjCCompatibleAliasDecl *D) { return true; }

};

class ObjCPropertyDecl : public Decl {
public:
  enum PropertyAttributeKind {
    OBJC_PR_noattr    = 0x00,
    OBJC_PR_readonly  = 0x01,
    OBJC_PR_getter    = 0x02,
    OBJC_PR_assign    = 0x04,
    OBJC_PR_readwrite = 0x08,
    OBJC_PR_retain    = 0x10,
    OBJC_PR_copy      = 0x20,
    OBJC_PR_nonatomic = 0x40,
    OBJC_PR_setter    = 0x80
  };
private:
  // List of property name declarations
  // FIXME: Property is not an ivar.
  ObjCIvarDecl **PropertyDecls;
  unsigned NumPropertyDecls;
  unsigned PropertyAttributes : 8;

  IdentifierInfo *GetterName;    // getter name of NULL if no getter
  IdentifierInfo *SetterName;    // setter name of NULL if no setter

  ObjCPropertyDecl(SourceLocation L)
    : Decl(PropertyDecl, L), PropertyDecls(0), NumPropertyDecls(0),
      PropertyAttributes(OBJC_PR_noattr), GetterName(0), SetterName(0) {}
public:
  static ObjCPropertyDecl *Create(ASTContext &C, SourceLocation L);

  typedef ObjCIvarDecl * const *propdecl_iterator;
  propdecl_iterator propdecl_begin() const { return PropertyDecls; }
  propdecl_iterator propdecl_end() const {
    return PropertyDecls+NumPropertyDecls;
  }
  unsigned propdecl_size() const { return NumPropertyDecls; }
  bool propdecl_empty() const { return NumPropertyDecls == 0; }

  /// setPropertyDeclLists - Set the property decl list to the specified array
  /// of decls.
  void setPropertyDeclLists(ObjCIvarDecl **Properties, unsigned NumProp);

  PropertyAttributeKind getPropertyAttributes() const {
    return PropertyAttributeKind(PropertyAttributes);
  }
  void setPropertyAttributes(PropertyAttributeKind PRVal) {
    PropertyAttributes |= PRVal;
  }

  IdentifierInfo *getGetterName() const { return GetterName; }
  void setGetterName(IdentifierInfo *Id) { GetterName = Id; }

  IdentifierInfo *getSetterName() const { return SetterName; }
  void setSetterName(IdentifierInfo *Id) { SetterName = Id; }

  static bool classof(const Decl *D) {
    return D->getKind() == PropertyDecl;
  }
  static bool classof(const ObjCPropertyDecl *D) { return true; }
};

}  // end namespace clang
#endif