//===-- DeclarationName.cpp - Declaration names implementation --*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the DeclarationName and DeclarationNameTable
// classes.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/DeclarationName.h"
#include "clang/AST/Type.h"
#include "clang/AST/Decl.h"
#include "clang/Basic/IdentifierTable.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
using namespace clang;

namespace clang {
/// CXXSpecialName - Records the type associated with one of the
/// "special" kinds of declaration names in C++, e.g., constructors,
/// destructors, and conversion functions.
class CXXSpecialName 
  : public DeclarationNameExtra, public llvm::FoldingSetNode {
public:
  /// Type - The type associated with this declaration name.
  QualType Type;

  /// FETokenInfo - Extra information associated with this declaration
  /// name that can be used by the front end.
  void *FETokenInfo;

  void Profile(llvm::FoldingSetNodeID &ID) {
    ID.AddInteger(ExtraKindOrNumArgs);
    ID.AddPointer(Type.getAsOpaquePtr());
  }
};

/// CXXOperatorIdName - Contains extra information for the name of an
/// overloaded operator in C++, such as "operator+. 
class CXXOperatorIdName : public DeclarationNameExtra {
public:
  /// FETokenInfo - Extra information associated with this operator
  /// name that can be used by the front end.
  void *FETokenInfo;
};

bool operator<(DeclarationName LHS, DeclarationName RHS) {
  if (IdentifierInfo *LhsId = LHS.getAsIdentifierInfo())
    if (IdentifierInfo *RhsId = RHS.getAsIdentifierInfo())
      return strcmp(LhsId->getName(), RhsId->getName()) < 0;

  return LHS.getAsOpaqueInteger() < RHS.getAsOpaqueInteger();
}

} // end namespace clang

DeclarationName::DeclarationName(Selector Sel) {
  if (!Sel.getAsOpaquePtr()) {
    Ptr = StoredObjCZeroArgSelector;
    return;
  }

  switch (Sel.getNumArgs()) {
  case 0:
    Ptr = reinterpret_cast<uintptr_t>(Sel.getAsIdentifierInfo());
    assert((Ptr & PtrMask) == 0 && "Improperly aligned IdentifierInfo");
    Ptr |= StoredObjCZeroArgSelector;
    break;

  case 1:
    Ptr = reinterpret_cast<uintptr_t>(Sel.getAsIdentifierInfo());
    assert((Ptr & PtrMask) == 0 && "Improperly aligned IdentifierInfo");
    Ptr |= StoredObjCOneArgSelector;
    break;

  default:
    Ptr = Sel.InfoPtr & ~Selector::ArgFlags;
    assert((Ptr & PtrMask) == 0 && "Improperly aligned MultiKeywordSelector");
    Ptr |= StoredDeclarationNameExtra;
    break;
  }
}

DeclarationName::NameKind DeclarationName::getNameKind() const {
  switch (getStoredNameKind()) {
  case StoredIdentifier:          return Identifier;
  case StoredObjCZeroArgSelector: return ObjCZeroArgSelector;
  case StoredObjCOneArgSelector:  return ObjCOneArgSelector;

  case StoredDeclarationNameExtra:
    switch (getExtra()->ExtraKindOrNumArgs) {
    case DeclarationNameExtra::CXXConstructor: 
      return CXXConstructorName;

    case DeclarationNameExtra::CXXDestructor: 
      return CXXDestructorName;

    case DeclarationNameExtra::CXXConversionFunction: 
      return CXXConversionFunctionName;

    case DeclarationNameExtra::CXXUsingDirective:
      return CXXUsingDirective;

    default:
      // Check if we have one of the CXXOperator* enumeration values.
      if (getExtra()->ExtraKindOrNumArgs < 
            DeclarationNameExtra::CXXUsingDirective)
        return CXXOperatorName;

      return ObjCMultiArgSelector;
    }
    break;
  }

  // Can't actually get here.
  assert(0 && "This should be unreachable!");
  return Identifier;
}

std::string DeclarationName::getAsString() const {
  switch (getNameKind()) {
  case Identifier:
    if (const IdentifierInfo *II = getAsIdentifierInfo())
      return II->getName();
    return "";

  case ObjCZeroArgSelector:
  case ObjCOneArgSelector:
  case ObjCMultiArgSelector:
    return getObjCSelector().getAsString();

  case CXXConstructorName: {
    QualType ClassType = getCXXNameType();
    if (const RecordType *ClassRec = ClassType->getAs<RecordType>())
      return ClassRec->getDecl()->getNameAsString();
    return ClassType.getAsString();
  }

  case CXXDestructorName: {
    std::string Result = "~";
    QualType Type = getCXXNameType();
    if (const RecordType *Rec = Type->getAs<RecordType>())
      Result += Rec->getDecl()->getNameAsString();
    else
      Result += Type.getAsString();
    return Result;
  }

  case CXXOperatorName: {
    static const char *OperatorNames[NUM_OVERLOADED_OPERATORS] = {
      0,
#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
      Spelling,
#include "clang/Basic/OperatorKinds.def"
    };
    const char *OpName = OperatorNames[getCXXOverloadedOperator()];
    assert(OpName && "not an overloaded operator");
      
    std::string Result = "operator";
    if (OpName[0] >= 'a' && OpName[0] <= 'z')
      Result += ' ';
    Result += OpName;
    return Result;
  }

  case CXXConversionFunctionName: {
    std::string Result = "operator ";
    QualType Type = getCXXNameType();
    if (const RecordType *Rec = Type->getAs<RecordType>())
      Result += Rec->getDecl()->getNameAsString();
    else
      Result += Type.getAsString();
    return Result;
  }
  case CXXUsingDirective:
    return "<using-directive>";
  }

  assert(false && "Unexpected declaration name kind");
  return "";
}

QualType DeclarationName::getCXXNameType() const {
  if (CXXSpecialName *CXXName = getAsCXXSpecialName())
    return CXXName->Type;
  else
    return QualType();
}

OverloadedOperatorKind DeclarationName::getCXXOverloadedOperator() const {
  if (CXXOperatorIdName *CXXOp = getAsCXXOperatorIdName()) {
    unsigned value 
      = CXXOp->ExtraKindOrNumArgs - DeclarationNameExtra::CXXConversionFunction;
    return static_cast<OverloadedOperatorKind>(value);
  } else {
    return OO_None;
  }
}

Selector DeclarationName::getObjCSelector() const {
  switch (getNameKind()) {
  case ObjCZeroArgSelector:
    return Selector(reinterpret_cast<IdentifierInfo *>(Ptr & ~PtrMask), 0);

  case ObjCOneArgSelector:
    return Selector(reinterpret_cast<IdentifierInfo *>(Ptr & ~PtrMask), 1);

  case ObjCMultiArgSelector:
    return Selector(reinterpret_cast<MultiKeywordSelector *>(Ptr & ~PtrMask));

  default:
    break;
  }

  return Selector();
}

void *DeclarationName::getFETokenInfoAsVoid() const {
  switch (getNameKind()) {
  case Identifier:
    return getAsIdentifierInfo()->getFETokenInfo<void>();

  case CXXConstructorName:
  case CXXDestructorName:
  case CXXConversionFunctionName:
    return getAsCXXSpecialName()->FETokenInfo;

  case CXXOperatorName:
    return getAsCXXOperatorIdName()->FETokenInfo;

  default:
    assert(false && "Declaration name has no FETokenInfo");
  }
  return 0;
}

void DeclarationName::setFETokenInfo(void *T) {
  switch (getNameKind()) {
  case Identifier:
    getAsIdentifierInfo()->setFETokenInfo(T);
    break;

  case CXXConstructorName:
  case CXXDestructorName:
  case CXXConversionFunctionName:
    getAsCXXSpecialName()->FETokenInfo = T;
    break;

  case CXXOperatorName:
    getAsCXXOperatorIdName()->FETokenInfo = T;
    break;

  default:
    assert(false && "Declaration name has no FETokenInfo");
  }
}

DeclarationName DeclarationName::getUsingDirectiveName() {
  // Single instance of DeclarationNameExtra for using-directive
  static DeclarationNameExtra UDirExtra =
    { DeclarationNameExtra::CXXUsingDirective };

  uintptr_t Ptr = reinterpret_cast<uintptr_t>(&UDirExtra);
  Ptr |= StoredDeclarationNameExtra;

  return DeclarationName(Ptr);
}

DeclarationNameTable::DeclarationNameTable() {
  CXXSpecialNamesImpl = new llvm::FoldingSet<CXXSpecialName>;

  // Initialize the overloaded operator names.
  CXXOperatorNames = new CXXOperatorIdName[NUM_OVERLOADED_OPERATORS];
  for (unsigned Op = 0; Op < NUM_OVERLOADED_OPERATORS; ++Op) {
    CXXOperatorNames[Op].ExtraKindOrNumArgs 
      = Op + DeclarationNameExtra::CXXConversionFunction;
    CXXOperatorNames[Op].FETokenInfo = 0;
  }
}

DeclarationNameTable::~DeclarationNameTable() {
  llvm::FoldingSet<CXXSpecialName> *set =
    static_cast<llvm::FoldingSet<CXXSpecialName>*>(CXXSpecialNamesImpl);
  llvm::FoldingSetIterator<CXXSpecialName> I = set->begin(), E = set->end();

  while (I != E) {
    CXXSpecialName *n = &*I++;
    delete n;
  }

  delete set;
  delete [] CXXOperatorNames;
}

DeclarationName 
DeclarationNameTable::getCXXSpecialName(DeclarationName::NameKind Kind, 
                                        QualType Ty) {
  assert(Kind >= DeclarationName::CXXConstructorName &&
         Kind <= DeclarationName::CXXConversionFunctionName &&
         "Kind must be a C++ special name kind");
  assert(Ty->isCanonical() && 
         "Can only build C++ special names from canonical types");
  llvm::FoldingSet<CXXSpecialName> *SpecialNames 
    = static_cast<llvm::FoldingSet<CXXSpecialName>*>(CXXSpecialNamesImpl);

  DeclarationNameExtra::ExtraKind EKind;
  switch (Kind) {
  case DeclarationName::CXXConstructorName: 
    EKind = DeclarationNameExtra::CXXConstructor;
    assert(Ty.getCVRQualifiers() == 0 &&"Constructor type must be unqualified");
    break;
  case DeclarationName::CXXDestructorName:
    EKind = DeclarationNameExtra::CXXDestructor;
    assert(Ty.getCVRQualifiers() == 0 && "Destructor type must be unqualified");
    break;
  case DeclarationName::CXXConversionFunctionName:
    EKind = DeclarationNameExtra::CXXConversionFunction;
    break;
  default:
    return DeclarationName();
  }

  // Unique selector, to guarantee there is one per name.
  llvm::FoldingSetNodeID ID;
  ID.AddInteger(EKind);
  ID.AddPointer(Ty.getAsOpaquePtr());

  void *InsertPos = 0;
  if (CXXSpecialName *Name = SpecialNames->FindNodeOrInsertPos(ID, InsertPos))
    return DeclarationName(Name);

  CXXSpecialName *SpecialName = new CXXSpecialName;
  SpecialName->ExtraKindOrNumArgs = EKind;
  SpecialName->Type = Ty;
  SpecialName->FETokenInfo = 0;

  SpecialNames->InsertNode(SpecialName, InsertPos);
  return DeclarationName(SpecialName);
}

DeclarationName 
DeclarationNameTable::getCXXOperatorName(OverloadedOperatorKind Op) {
  return DeclarationName(&CXXOperatorNames[(unsigned)Op]);
}

unsigned 
llvm::DenseMapInfo<clang::DeclarationName>::
getHashValue(clang::DeclarationName N) {
  return DenseMapInfo<void*>::getHashValue(N.getAsOpaquePtr());
}