path: root/lib/Sema/SemaInit.h

//===--- SemaInit.h - Semantic Analysis for Initializers --------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides supporting data types for initialization of objects.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_SEMA_INIT_H
#define LLVM_CLANG_SEMA_INIT_H

#include "SemaOverload.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Parse/Action.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/SmallVector.h"
#include <cassert>

namespace clang {
  
class CXXBaseSpecifier;
class DeclaratorDecl;
class DeclaratorInfo;
class FieldDecl;
class FunctionDecl;
class ParmVarDecl;
class Sema;
class TypeLoc;
class VarDecl;
  
/// \brief Describes an entity that is being initialized.
class InitializedEntity {
public:
  /// \brief Specifies the kind of entity being initialized.
  enum EntityKind {
    /// \brief The entity being initialized is a variable.
    EK_Variable,
    /// \brief The entity being initialized is a function parameter.
    EK_Parameter,
    /// \brief The entity being initialized is the result of a function call.
    EK_Result,
    /// \brief The entity being initialized is an exception object that
    /// is being thrown.
    EK_Exception,
    /// \brief The entity being initialized is a temporary object.
    EK_Temporary,
    /// \brief The entity being initialized is a base member subobject.
    EK_Base,
    /// \brief The entity being initialized is a non-static data member 
    /// subobject.
    EK_Member
  };
  
private:
  /// \brief The kind of entity being initialized.
  EntityKind Kind;

  /// \brief The type of the object or reference being initialized along with 
  /// its location information.
  TypeLoc TL;
  
  union {
    /// \brief When Kind == EK_Variable, EK_Parameter, or EK_Member, 
    /// the VarDecl, ParmVarDecl, or FieldDecl, respectively.
    DeclaratorDecl *VariableOrMember;
    
    /// \brief When Kind == EK_Result or EK_Exception, the location of the 
    /// 'return' or 'throw' keyword, respectively. When Kind == EK_Temporary,
    /// the location where the temporary is being created.
    unsigned Location;
    
    /// \brief When Kind == EK_Base, the base specifier that provides the 
    /// base class.
    CXXBaseSpecifier *Base;
  };

  InitializedEntity() { }

  /// \brief Create the initialization entity for a variable.
  InitializedEntity(VarDecl *Var)
    : Kind(EK_Variable), 
      VariableOrMember(reinterpret_cast<DeclaratorDecl*>(Var)) 
  {
    InitDeclLoc();
  }
  
  /// \brief Create the initialization entity for a parameter.
  InitializedEntity(ParmVarDecl *Parm)
    : Kind(EK_Parameter), 
      VariableOrMember(reinterpret_cast<DeclaratorDecl*>(Parm)) 
  { 
    InitDeclLoc();
  }
  
  /// \brief Create the initialization entity for the result of a function,
  /// throwing an object, or performing an explicit cast.
  InitializedEntity(EntityKind Kind, SourceLocation Loc, TypeLoc TL)
    : Kind(Kind), TL(TL), Location(Loc.getRawEncoding()) { }
  
  /// \brief Create the initialization entity for a member subobject.
  InitializedEntity(FieldDecl *Member) 
    : Kind(EK_Member), 
      VariableOrMember(reinterpret_cast<DeclaratorDecl*>(Member))
  { 
    InitDeclLoc();
  }
  
  /// \brief Initialize type-location information from a declaration.
  void InitDeclLoc();
  
public:
  /// \brief Create the initialization entity for a variable.
  static InitializedEntity InitializeVariable(VarDecl *Var) {
    return InitializedEntity(Var);
  }
  
  /// \brief Create the initialization entity for a parameter.
  static InitializedEntity InitializeParameter(ParmVarDecl *Parm) {
    return InitializedEntity(Parm);
  }

  /// \brief Create the initialization entity for the result of a function.
  static InitializedEntity InitializeResult(SourceLocation ReturnLoc,
                                            TypeLoc TL) {
    return InitializedEntity(EK_Result, ReturnLoc, TL);
  }

  /// \brief Create the initialization entity for an exception object.
  static InitializedEntity InitializeException(SourceLocation ThrowLoc,
                                               TypeLoc TL) {
    return InitializedEntity(EK_Exception, ThrowLoc, TL);
  }
  
  /// \brief Create the initialization entity for a temporary.
  static InitializedEntity InitializeTemporary(EntityKind Kind, TypeLoc TL) {
    return InitializedEntity(Kind, SourceLocation(), TL);
  }
  
  /// \brief Create the initialization entity for a base class subobject.
  static InitializedEntity InitializeBase(ASTContext &Context,
                                          CXXBaseSpecifier *Base);
  
  /// \brief Create the initialize entity for a member subobject.
  static InitializedEntity InitializeMember(FieldDecl *Member) {
    return InitializedEntity(Member);
  }
  
  /// \brief Determine the kind of initialization.
  EntityKind getKind() const { return Kind; }
  
  /// \brief Retrieve type being initialized.
  TypeLoc getType() const { return TL; }
  
  /// \brief Determine the location of the 'return' keyword when initializing
  /// the result of a function call.
  SourceLocation getReturnLoc() const {
    assert(getKind() == EK_Result && "No 'return' location!");
    return SourceLocation::getFromRawEncoding(Location);
  }
  
  /// \brief Determine the location of the 'throw' keyword when initializing
  /// an exception object.
  SourceLocation getThrowLoc() const {
    assert(getKind() == EK_Exception && "No 'throw' location!");
    return SourceLocation::getFromRawEncoding(Location);
  }
};
  
/// \brief Describes the kind of initialization being performed, along with 
/// location information for tokens related to the initialization (equal sign,
/// parentheses).
class InitializationKind {
public:
  /// \brief The kind of initialization being performed.
  enum InitKind {
    IK_Direct,  ///< Direct initialization
    IK_Copy,    ///< Copy initialization
    IK_Default, ///< Default initialization
    IK_Value    ///< Value initialization
  };
  
private:
  /// \brief The kind of initialization that we're storing.
  enum StoredInitKind {
    SIK_Direct = IK_Direct,   ///< Direct initialization
    SIK_Copy = IK_Copy,       ///< Copy initialization
    SIK_Default = IK_Default, ///< Default initialization
    SIK_Value = IK_Value,     ///< Value initialization
    SIK_DirectCast,  ///< Direct initialization due to a cast
    /// \brief Direct initialization due to a C-style or functional cast.
    SIK_DirectCStyleOrFunctionalCast
  };
  
  /// \brief The kind of initialization being performed.
  StoredInitKind Kind;
  
  /// \brief The source locations involved in the initialization.
  SourceLocation Locations[3];
  
  InitializationKind(StoredInitKind Kind, SourceLocation Loc1, 
                     SourceLocation Loc2, SourceLocation Loc3)
    : Kind(Kind) 
  {
    Locations[0] = Loc1;
    Locations[1] = Loc2;
    Locations[2] = Loc3;
  }
  
public:
  /// \brief Create a direct initialization.
  static InitializationKind CreateDirect(SourceLocation InitLoc,
                                         SourceLocation LParenLoc,
                                         SourceLocation RParenLoc) {
    return InitializationKind(SIK_Direct, InitLoc, LParenLoc, RParenLoc);
  }

  /// \brief Create a direct initialization due to a cast.
  static InitializationKind CreateCast(SourceRange TypeRange,
                                       bool IsCStyleCast) {
    return InitializationKind(IsCStyleCast? SIK_DirectCStyleOrFunctionalCast
                                          : SIK_DirectCast,
                              TypeRange.getBegin(), TypeRange.getBegin(), 
                              TypeRange.getEnd());
  }
  
  /// \brief Create a copy initialization.
  static InitializationKind CreateCopy(SourceLocation InitLoc,
                                       SourceLocation EqualLoc) {
    return InitializationKind(SIK_Copy, InitLoc, EqualLoc, EqualLoc);
  }
  
  /// \brief Create a default initialization.
  static InitializationKind CreateDefault(SourceLocation InitLoc) {
    return InitializationKind(SIK_Default, InitLoc, InitLoc, InitLoc);
  }
  
  /// \brief Create a value initialization.
  static InitializationKind CreateValue(SourceLocation InitLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation RParenLoc) {
    return InitializationKind(SIK_Value, InitLoc, LParenLoc, RParenLoc);
  }
  
  /// \brief Determine the initialization kind.
  InitKind getKind() const {
    if (Kind > SIK_Value)
      return IK_Direct;
    
    return (InitKind)Kind;
  }
  
  /// \brief Determine whether this initialization is an explicit cast.
  bool isExplicitCast() const {
    return Kind == SIK_DirectCast || Kind == SIK_DirectCStyleOrFunctionalCast;
  }
  
  /// \brief Determine whether this initialization is a C-style cast.
  bool isCStyleOrFunctionalCast() const { 
    return Kind == SIK_DirectCStyleOrFunctionalCast; 
  }
  
  /// \brief Retrieve the location at which initialization is occurring.
  SourceLocation getLocation() const { return Locations[0]; }
  
  /// \brief Retrieve the source range that covers the initialization.
  SourceRange getRange() const { 
    return SourceRange(Loc