C++ ASTContext::Allocate方法代码示例

void ObjCClassDecl::setClassList(ASTContext &C, ObjCInterfaceDecl*const*List,
                                 const SourceLocation *Locs, unsigned Num) {
  ForwardDecls = (ObjCClassRef*) C.Allocate(sizeof(ObjCClassRef)*Num,
                                            llvm::alignOf<ObjCClassRef>());
  for (unsigned i = 0; i < Num; ++i)
    new (&ForwardDecls[i]) ObjCClassRef(List[i], Locs[i]);
  
  NumDecls = Num;
}

void BlockDecl::setParams(ASTContext& C, ParmVarDecl **NewParamInfo,
                          unsigned NParms) {
  assert(ParamInfo == 0 && "Already has param info!");

  // Zero params -> null pointer.
  if (NParms) {
    NumParams = NParms;
    void *Mem = C.Allocate(sizeof(ParmVarDecl*)*NumParams);
    ParamInfo = new (Mem) ParmVarDecl*[NumParams];
    memcpy(ParamInfo, NewParamInfo, sizeof(ParmVarDecl*)*NumParams);
  }
}

void OverloadExpr::initializeResults(ASTContext &C,
                                     UnresolvedSetIterator Begin,
                                     UnresolvedSetIterator End) {
  assert(Results == 0 && "Results already initialized!");
  NumResults = End - Begin;
  if (NumResults) {
     Results = static_cast<DeclAccessPair *>(
                               C.Allocate(sizeof(DeclAccessPair) * NumResults,
 
                                          llvm::alignOf<DeclAccessPair>()));
     memcpy(Results, &*Begin.getIterator(), 
            NumResults * sizeof(DeclAccessPair));
  }
}

void ObjCMethodDecl::setParamsAndSelLocs(ASTContext &C,
                                         ArrayRef<ParmVarDecl*> Params,
                                         ArrayRef<SourceLocation> SelLocs) {
  ParamsAndSelLocs = 0;
  NumParams = Params.size();
  if (Params.empty() && SelLocs.empty())
    return;

  unsigned Size = sizeof(ParmVarDecl *) * NumParams +
                  sizeof(SourceLocation) * SelLocs.size();
  ParamsAndSelLocs = C.Allocate(Size);
  std::copy(Params.begin(), Params.end(), getParams());
  std::copy(SelLocs.begin(), SelLocs.end(), getStoredSelLocs());
}

NestedNameSpecifierLoc 
NestedNameSpecifierLocBuilder::getWithLocInContext(ASTContext &Context) const {
  if (!Representation)
    return NestedNameSpecifierLoc();
  
  // If we adopted our data pointer from elsewhere in the AST context, there's
  // no need to copy the memory.
  if (BufferCapacity == 0)
    return NestedNameSpecifierLoc(Representation, Buffer);
  
  // FIXME: After copying the source-location information, should we free
  // our (temporary) buffer and adopt the ASTContext-allocated memory?
  // Doing so would optimize repeated calls to getWithLocInContext().
  void *Mem = Context.Allocate(BufferSize, llvm::alignOf<void *>());
  memcpy(Mem, Buffer, BufferSize);
  return NestedNameSpecifierLoc(Representation, Mem);
}

TemplateArgument::TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value,
                                   QualType Type) {
  Integer.Kind = Integral;
  // Copy the APSInt value into our decomposed form.
  Integer.BitWidth = Value.getBitWidth();
  Integer.IsUnsigned = Value.isUnsigned();
  // If the value is large, we have to get additional memory from the ASTContext
  unsigned NumWords = Value.getNumWords();
  if (NumWords > 1) {
    void *Mem = Ctx.Allocate(NumWords * sizeof(uint64_t));
    std::memcpy(Mem, Value.getRawData(), NumWords * sizeof(uint64_t));
    Integer.pVal = static_cast<uint64_t *>(Mem);
  } else {
    Integer.VAL = Value.getZExtValue();
  }

  Integer.Type = Type.getAsOpaquePtr();
}

void ScriptDefn::setCaptures(ASTContext &Context,
                            const Capture *begin,
                            const Capture *end) {
  if (begin == end) {
    NumCaptures = 0;
    Captures = 0;
    return;
  }

  NumCaptures = end - begin;

  // Avoid new Capture[] because we don't want to provide a default
  // constructor.
  size_t allocationSize = NumCaptures * sizeof(Capture);
  void *buffer = Context.Allocate(allocationSize, /*alignment*/sizeof(void*));
  memcpy(buffer, begin, allocationSize);
  Captures = static_cast<Capture*>(buffer);
}

FullExpr FullExpr::Create(ASTContext &Context, Expr *SubExpr,
                          CXXTemporary **Temporaries, unsigned NumTemporaries) {
  FullExpr E;

  if (!NumTemporaries) {
      E.SubExpr = SubExpr;
      return E;
  }

  unsigned Size = sizeof(FullExpr) 
      + sizeof(CXXTemporary *) * NumTemporaries;

  unsigned Align = llvm::AlignOf<ExprAndTemporaries>::Alignment;
  ExprAndTemporaries *ET = 
      static_cast<ExprAndTemporaries *>(Context.Allocate(Size, Align));

  ET->SubExpr = SubExpr;
  std::copy(Temporaries, Temporaries + NumTemporaries, ET->temps_begin());
    
  return E;
}

OverloadExpr::OverloadExpr(StmtClass K, ASTContext &C, 
                           NestedNameSpecifierLoc QualifierLoc,
                           const DeclarationNameInfo &NameInfo,
                           const TemplateArgumentListInfo *TemplateArgs,
                           UnresolvedSetIterator Begin, 
                           UnresolvedSetIterator End,
                           bool KnownDependent,
                           bool KnownInstantiationDependent,
                           bool KnownContainsUnexpandedParameterPack)
  : Expr(K, C.OverloadTy, VK_LValue, OK_Ordinary, KnownDependent, 
         KnownDependent,
         (KnownInstantiationDependent ||
          NameInfo.isInstantiationDependent() ||
          (QualifierLoc &&
           QualifierLoc.getNestedNameSpecifier()->isInstantiationDependent())),
         (KnownContainsUnexpandedParameterPack ||
          NameInfo.containsUnexpandedParameterPack() ||
          (QualifierLoc && 
           QualifierLoc.getNestedNameSpecifier()
                                      ->containsUnexpandedParameterPack()))),
    Results(0), NumResults(End - Begin), NameInfo(NameInfo), 
    QualifierLoc(QualifierLoc), HasExplicitTemplateArgs(TemplateArgs != 0)
{
  NumResults = End - Begin;
  if (NumResults) {
    // Determine whether this expression is type-dependent.
    for (UnresolvedSetImpl::const_iterator I = Begin; I != End; ++I) {
      if ((*I)->getDeclContext()->isDependentContext() ||
          isa<UnresolvedUsingValueDecl>(*I)) {
        ExprBits.TypeDependent = true;
        ExprBits.ValueDependent = true;
      }
    }

    Results = static_cast<DeclAccessPair *>(
                                C.Allocate(sizeof(DeclAccessPair) * NumResults, 
                                           llvm::alignOf<DeclAccessPair>()));
    memcpy(Results, &*Begin.getIterator(), 
           NumResults * sizeof(DeclAccessPair));
  }

  // If we have explicit template arguments, check for dependent
  // template arguments and whether they contain any unexpanded pack
  // expansions.
  if (TemplateArgs) {
    bool Dependent = false;
    bool InstantiationDependent = false;
    bool ContainsUnexpandedParameterPack = false;
    getExplicitTemplateArgs().initializeFrom(*TemplateArgs, Dependent,
                                             InstantiationDependent,
                                             ContainsUnexpandedParameterPack);

    if (Dependent) {
      ExprBits.TypeDependent = true;
      ExprBits.ValueDependent = true;
    }
    if (InstantiationDependent)
      ExprBits.InstantiationDependent = true;
    if (ContainsUnexpandedParameterPack)
      ExprBits.ContainsUnexpandedParameterPack = true;
  }

  if (isTypeDependent())
    setType(C.DependentTy);
}