path: root/include/clang/AST/Type.h

//===--- Type.h - C Language Family Type Representation ---------*- 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 Type interface and subclasses.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_TYPE_H
#define LLVM_CLANG_AST_TYPE_H

#include "llvm/Support/Casting.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/Bitcode/SerializationFwd.h"

using llvm::isa;
using llvm::cast;
using llvm::cast_or_null;
using llvm::dyn_cast;
using llvm::dyn_cast_or_null;

namespace clang {
  class ASTContext;
  class Type;
  class TypedefDecl;
  class TagDecl;
  class RecordDecl;
  class EnumDecl;
  class FieldDecl;
  class ObjCInterfaceDecl;
  class ObjCProtocolDecl;
  class ObjCMethodDecl;
  class Expr;
  class SourceLocation;
  class PointerType;
  class ReferenceType;
  class VectorType;
  class ArrayType;
  class ConstantArrayType;
  class VariableArrayType;
  class RecordType;
  class ComplexType;
  class TagType;
  class FunctionType;
  class OCUVectorType;
  class BuiltinType;
  class ObjCQualifiedInterfaceType;
  class StmtIteratorBase;
  
/// QualType - For efficiency, we don't store CVR-qualified types as nodes on
/// their own: instead each reference to a type stores the qualifiers.  This
/// greatly reduces the number of nodes we need to allocate for types (for
/// example we only need one for 'int', 'const int', 'volatile int',
/// 'const volatile int', etc).
///
/// As an added efficiency bonus, instead of making this a pair, we just store
/// the three bits we care about in the low bits of the pointer.  To handle the
/// packing/unpacking, we make QualType be a simple wrapper class that acts like
/// a smart pointer.
class QualType {
  uintptr_t ThePtr;
public:
  enum TQ {   // NOTE: These flags must be kept in sync with DeclSpec::TQ.
    Const    = 0x1,
    Restrict = 0x2,
    Volatile = 0x4,
    CVRFlags = Const|Restrict|Volatile
  };
  
  QualType() : ThePtr(0) {}
  
  QualType(Type *Ptr, unsigned Quals) {
    assert((Quals & ~CVRFlags) == 0 && "Invalid type qualifiers!");
    ThePtr = reinterpret_cast<uintptr_t>(Ptr);
    assert((ThePtr & CVRFlags) == 0 && "Type pointer not 8-byte aligned?");
    ThePtr |= Quals;
  }

  static QualType getFromOpaquePtr(void *Ptr) {
    QualType T;
    T.ThePtr = reinterpret_cast<uintptr_t>(Ptr);
    return T;
  }
  
  unsigned getQualifiers() const {
    return ThePtr & CVRFlags;
  }
  Type *getTypePtr() const {
    return reinterpret_cast<Type*>(ThePtr & ~CVRFlags);
  }
  
  void *getAsOpaquePtr() const {
    return reinterpret_cast<void*>(ThePtr);
  }
  
  Type &operator*() const {
    return *getTypePtr();
  }

  Type *operator->() const {
    return getTypePtr();
  }
  
  /// isNull - Return true if this QualType doesn't point to a type yet.
  bool isNull() const {
    return ThePtr == 0;
  }

  bool isConstQualified() const {
    return (ThePtr & Const) ? true : false;
  }
  bool isVolatileQualified() const {
    return (ThePtr & Volatile) ? true : false;
  }
  bool isRestrictQualified() const {
    return (ThePtr & Restrict) ? true : false;
  }
  
  /// addConst/addVolatile/addRestrict - add the specified type qual to this
  /// QualType.
  void addConst()    { ThePtr |= Const; }
  void addVolatile() { ThePtr |= Volatile; }
  void addRestrict() { ThePtr |= Restrict; }

  QualType getQualifiedType(unsigned TQs) const {
    return QualType(getTypePtr(), TQs);
  }
  
  QualType getUnqualifiedType() const {
    return QualType(getTypePtr(), 0);
  }
  
  /// operator==/!= - Indicate whether the specified types and qualifiers are
  /// identical.