C++ TemplateArgumentLoc::getArgument方法代码示例

bool Sema::DiagnoseUnexpandedParameterPack(TemplateArgumentLoc Arg,
                                         UnexpandedParameterPackContext UPPC) {
  if (Arg.getArgument().isNull() ||
      !Arg.getArgument().containsUnexpandedParameterPack())
    return false;

  SmallVector<UnexpandedParameterPack, 2> Unexpanded;
  CollectUnexpandedParameterPacksVisitor(Unexpanded)
    .TraverseTemplateArgumentLoc(Arg);
  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
  return DiagnoseUnexpandedParameterPacks(Arg.getLocation(), UPPC, Unexpanded);
}

bool ReduceClassTemplateParameter::isValidForReduction(
       const ClassTemplatePartialSpecializationDecl *PartialD)
{
  const ASTTemplateArgumentListInfo *ArgList = 
    PartialD->getTemplateArgsAsWritten();
  
  unsigned NumArgsAsWritten = ArgList->NumTemplateArgs;
  unsigned NumArgs = PartialD->getTemplateInstantiationArgs().size();

  if ((NumArgsAsWritten > 0) && 
      (TheParameterIndex >= NumArgsAsWritten) && 
      hasDefaultArg &&
      ((NumArgsAsWritten + 1) == NumArgs))  {

    return true;
  }

  if (NumArgsAsWritten != NumArgs)
    return false;

  const TemplateArgumentLoc *ArgLocs = ArgList->getTemplateArgs();
  for (unsigned AI = 0; AI < NumArgsAsWritten; ++AI) {
    if (AI == TheParameterIndex)
      continue;
    const TemplateArgumentLoc ArgLoc = ArgLocs[AI];
    TemplateArgument Arg = ArgLoc.getArgument();
    if (!referToAParameter(PartialD, Arg))
      return false;
  }

  return true;
}

void TemplateTemplateParmDecl::setDefaultArgument(
    const ASTContext &C, const TemplateArgumentLoc &DefArg) {
  if (DefArg.getArgument().isNull())
    DefaultArgument.set(nullptr);
  else
    DefaultArgument.set(new (C) TemplateArgumentLoc(DefArg));
}

TemplateArgumentLoc
Sema::getTemplateArgumentPackExpansionPattern(
      TemplateArgumentLoc OrigLoc,
      SourceLocation &Ellipsis, Optional<unsigned> &NumExpansions) const {
  const TemplateArgument &Argument = OrigLoc.getArgument();
  assert(Argument.isPackExpansion());
  switch (Argument.getKind()) {
  case TemplateArgument::Type: {
    // FIXME: We shouldn't ever have to worry about missing
    // type-source info!
    TypeSourceInfo *ExpansionTSInfo = OrigLoc.getTypeSourceInfo();
    if (!ExpansionTSInfo)
      ExpansionTSInfo = Context.getTrivialTypeSourceInfo(Argument.getAsType(),
                                                         Ellipsis);
    PackExpansionTypeLoc Expansion =
        ExpansionTSInfo->getTypeLoc().castAs<PackExpansionTypeLoc>();
    Ellipsis = Expansion.getEllipsisLoc();

    TypeLoc Pattern = Expansion.getPatternLoc();
    NumExpansions = Expansion.getTypePtr()->getNumExpansions();

    // We need to copy the TypeLoc because TemplateArgumentLocs store a
    // TypeSourceInfo.
    // FIXME: Find some way to avoid the copy?
    TypeLocBuilder TLB;
    TLB.pushFullCopy(Pattern);
    TypeSourceInfo *PatternTSInfo =
        TLB.getTypeSourceInfo(Context, Pattern.getType());
    return TemplateArgumentLoc(TemplateArgument(Pattern.getType()),
                               PatternTSInfo);
  }

  case TemplateArgument::Expression: {
    PackExpansionExpr *Expansion
      = cast<PackExpansionExpr>(Argument.getAsExpr());
    Expr *Pattern = Expansion->getPattern();
    Ellipsis = Expansion->getEllipsisLoc();
    NumExpansions = Expansion->getNumExpansions();
    return TemplateArgumentLoc(Pattern, Pattern);
  }

  case TemplateArgument::TemplateExpansion:
    Ellipsis = OrigLoc.getTemplateEllipsisLoc();
    NumExpansions = Argument.getNumTemplateExpansions();
    return TemplateArgumentLoc(Argument.getPackExpansionPattern(),
                               OrigLoc.getTemplateQualifierLoc(),
                               OrigLoc.getTemplateNameLoc());

  case TemplateArgument::Declaration:
  case TemplateArgument::NullPtr:
  case TemplateArgument::Template:
  case TemplateArgument::Integral:
  case TemplateArgument::Pack:
  case TemplateArgument::Null:
    return TemplateArgumentLoc();
  }

  llvm_unreachable("Invalid TemplateArgument Kind!");
}

// ISSUE: The transformation is known to go wrong in the following case:
// template<typename T1, typename T2> struct S;
// template<typename T1, typename T2> struct S<T2, T1>;
void ReduceClassTemplateParameter::removeParameterFromPartialSpecs()
{
  SmallVector<ClassTemplatePartialSpecializationDecl *, 10> PartialDecls;
  TheClassTemplateDecl->getPartialSpecializations(PartialDecls);

  for (SmallVector<ClassTemplatePartialSpecializationDecl *, 10>::iterator 
         I = PartialDecls.begin(), E = PartialDecls.end(); I != E; ++I) {
    const ClassTemplatePartialSpecializationDecl *PartialD = (*I);
    
    const ASTTemplateArgumentListInfo *ArgList = 
      PartialD->getTemplateArgsAsWritten();
    const TemplateArgumentLoc *ArgLocs = ArgList->getTemplateArgs();
    unsigned NumArgs = ArgList->NumTemplateArgs;
    
    if (!ArgLocs)
      continue;

    // handle a special case where we could reduce a partial specialization
    // to a class template definition, e.g.:
    //   template<typename T1, typename T2> struct A;
    //   template<typename T1> struct A<T1, int> { };
    // ==>
    //   template<typename T1> struct A;
    //   template<typename T1> struct A { };
    if (reducePartialSpec(PartialD))
      continue;

    if ((TheParameterIndex >= NumArgs) && hasDefaultArg)
      return;

    TransAssert((TheParameterIndex < NumArgs) && 
                 "Bad NumArgs from partial template decl!");
    TemplateArgumentLoc ArgLoc = ArgLocs[TheParameterIndex];

    TemplateArgument Arg = ArgLoc.getArgument();
    removeOneParameterFromPartialDecl(PartialD, Arg);
     
    SourceRange Range = ArgLoc.getSourceRange();

    if (NumArgs == 1) {
      SourceLocation StartLoc = Range.getBegin();
      SourceLocation EndLoc = 
        RewriteHelper->getEndLocationUntil(Range, '>');
      EndLoc = EndLoc.getLocWithOffset(-1);
      TheRewriter.RemoveText(SourceRange(StartLoc, EndLoc));
    }
    else if ((TheParameterIndex + 1) == NumArgs) {
      // Seems there is no getRAngleLoc() utility for 
      // template arguments from a partial specialization
      SourceLocation EndLoc = 
        RewriteHelper->getEndLocationUntil(Range, '>');
      EndLoc = EndLoc.getLocWithOffset(-1);
      RewriteHelper->removeTextFromLeftAt(Range, ',', EndLoc);
    }
    else {
      RewriteHelper->removeTextUntil(Range, ',');
    }
  }
}

  bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
    std::string ArgStr;
    llvm::raw_string_ostream Stream(ArgStr);
    const TemplateArgument &Arg = ArgLoc.getArgument();

    Arg.print(Context->getPrintingPolicy(), Stream);
    Match(Stream.str(), ArgLoc.getLocation());
    return ExpectedLocationVisitor<TemplateArgumentLocTraverser>::
      TraverseTemplateArgumentLoc(ArgLoc);
  }

void TemplateArgToInt::handleOneTemplateArgumentLoc(
       const TemplateArgumentLoc &ArgLoc)
{
  if (ArgLoc.getLocation().isInvalid())
    return;
  const TemplateArgument &Arg = ArgLoc.getArgument();

  if (Arg.getKind() != TemplateArgument::Type)
    return;
  const Type *Ty = Arg.getAsType().getTypePtr();
  if (!Ty->getAsCXXRecordDecl() && !Ty->getPointeeCXXRecordDecl())
    return;

  ValidInstanceNum++;
  if (ValidInstanceNum == TransformationCounter)
    TheTypeSourceInfo = ArgLoc.getTypeSourceInfo();
}

void TemplateNonTypeArgToInt::handleOneTemplateArgumentLoc(
       const TemplateArgumentLoc &ArgLoc)
{
  if (ArgLoc.getLocation().isInvalid())
    return;
  const TemplateArgument &Arg = ArgLoc.getArgument();

  if (!isValidTemplateArgument(Arg))
    return;

  ValidInstanceNum++;
  if (ValidInstanceNum == TransformationCounter) {
    TheExpr = ArgLoc.getLocInfo().getAsExpr();
    llvm::APSInt Result;
    if (!TheExpr->isValueDependent() &&
        TheExpr->EvaluateAsInt(Result, *Context)) {
      IntString = Result.toString(10);
    }
  }
}

void ReduceClassTemplateParameter::removeOneParameterByArgType(
       const ClassTemplatePartialSpecializationDecl *PartialD,
       const TemplateArgument &Arg)
{
  TransAssert((Arg.getKind() == TemplateArgument::Type) && 
              "Arg is not TemplateArgument::Type!");
  llvm::DenseMap<const Type *, unsigned> TypeToVisitsCount;
  llvm::DenseMap<const Type *, const NamedDecl *> TypeToNamedDecl;
  llvm::DenseMap<const Type *, unsigned> TypeToIndex;

  // retrieve all TemplateTypeParmType
  const TemplateParameterList *TPList = PartialD->getTemplateParameters();
  unsigned Idx = 0;
  for (TemplateParameterList::const_iterator I = TPList->begin(),
       E = TPList->end(); I != E; ++I) {
    const NamedDecl *ND = (*I);
    const TemplateTypeParmDecl *TypeD = dyn_cast<TemplateTypeParmDecl>(ND);
    if (!TypeD) {
      Idx++;
      continue;
    }
    const Type *ParmTy = TypeD->getTypeForDecl();
    TypeToVisitsCount[ParmTy] = 0;
    TypeToNamedDecl[ParmTy] = ND;
    TypeToIndex[ParmTy] = Idx;
  }

  QualType QTy = Arg.getAsType();
  ArgumentDependencyVisitor V(TypeToVisitsCount);
  // collect TemplateTypeParmType being used by Arg
  V.TraverseType(QTy);

  llvm::DenseMap<const Type *, unsigned> DependentTypeToVisitsCount;
  for (llvm::DenseMap<const Type *, unsigned>::iterator 
         I = TypeToVisitsCount.begin(), E = TypeToVisitsCount.end();
       I != E; ++I) {
    if ((*I).second > 0)
      DependentTypeToVisitsCount[(*I).first] = 1;
  }

  // check if the used TemplateTypeParmType[s] have dependencies
  // on other Args. If yes, we cannot remove it from the parameter list.
  // For example:
  //   template <typename T>
  //   struct S <T*, T&> {};
  // removing either of the arguments needs to keep the template 
  // parameter
  ArgumentDependencyVisitor AccumV(DependentTypeToVisitsCount);
  
  const ASTTemplateArgumentListInfo *ArgList = 
    PartialD->getTemplateArgsAsWritten();
  
  const TemplateArgumentLoc *ArgLocs = ArgList->getTemplateArgs();
  unsigned NumArgs = ArgList->NumTemplateArgs;
  TransAssert((TheParameterIndex < NumArgs) && 
               "Bad NumArgs from partial template decl!");
  for (unsigned I = 0; I < NumArgs; ++I) {
    if (I == TheParameterIndex)
      continue;
    
    const TemplateArgumentLoc ArgLoc = ArgLocs[I];
    TemplateArgument OtherArg = ArgLoc.getArgument();
    if (OtherArg.isInstantiationDependent() && 
        (OtherArg.getKind() == TemplateArgument::Type)) {
      QualType QTy = OtherArg.getAsType();
      AccumV.TraverseType(QTy);
    }
  }

  for (llvm::DenseMap<const Type *, unsigned>::iterator 
         I = DependentTypeToVisitsCount.begin(), 
         E = DependentTypeToVisitsCount.end();
       I != E; ++I) {
    if ((*I).second != 1)
      continue;

    const NamedDecl *Param = TypeToNamedDecl[(*I).first];
    TransAssert(Param && "NULL Parameter!");
    SourceRange Range = Param->getSourceRange();
    removeParameterByRange(Range, TPList, TypeToIndex[(*I).first]);
  }
}

void ASTDumper::dumpTemplateArgumentLoc(const TemplateArgumentLoc &A) {
  dumpTemplateArgument(A.getArgument(), A.getSourceRange());
}