safecode/tools/clang/include/clang/AST/RecursiveASTVisitor.h - llvm-archive - Git at Google

 //===--- RecursiveASTVisitor.h - Recursive AST Visitor ----------*- 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 RecursiveASTVisitor interface, which recursively
 //  traverses the entire AST.
 //
 //===----------------------------------------------------------------------===//
 #ifndef LLVM_CLANG_AST_RECURSIVEASTVISITOR_H
 #define LLVM_CLANG_AST_RECURSIVEASTVISITOR_H

 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclFriend.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclOpenMP.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExprObjC.h"
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/StmtCXX.h"
 #include "clang/AST/StmtObjC.h"
 #include "clang/AST/TemplateBase.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/AST/Type.h"
 #include "clang/AST/TypeLoc.h"

 // The following three macros are used for meta programming.  The code
 // using them is responsible for defining macro OPERATOR().

 // All unary operators.
 #define UNARYOP_LIST()                          \
   OPERATOR(PostInc)   OPERATOR(PostDec)         \
   OPERATOR(PreInc)    OPERATOR(PreDec)          \
   OPERATOR(AddrOf)    OPERATOR(Deref)           \
   OPERATOR(Plus)      OPERATOR(Minus)           \
   OPERATOR(Not)       OPERATOR(LNot)            \
   OPERATOR(Real)      OPERATOR(Imag)            \
   OPERATOR(Extension)

 // All binary operators (excluding compound assign operators).
 #define BINOP_LIST() \
   OPERATOR(PtrMemD)              OPERATOR(PtrMemI)    \
   OPERATOR(Mul)   OPERATOR(Div)  OPERATOR(Rem)        \
   OPERATOR(Add)   OPERATOR(Sub)  OPERATOR(Shl)        \
   OPERATOR(Shr)                                       \
                                                       \
   OPERATOR(LT)    OPERATOR(GT)   OPERATOR(LE)         \
   OPERATOR(GE)    OPERATOR(EQ)   OPERATOR(NE)         \
   OPERATOR(And)   OPERATOR(Xor)  OPERATOR(Or)         \
   OPERATOR(LAnd)  OPERATOR(LOr)                       \
                                                       \
   OPERATOR(Assign)                                    \
   OPERATOR(Comma)

 // All compound assign operators.
 #define CAO_LIST()                                                      \
   OPERATOR(Mul) OPERATOR(Div) OPERATOR(Rem) OPERATOR(Add) OPERATOR(Sub) \
   OPERATOR(Shl) OPERATOR(Shr) OPERATOR(And) OPERATOR(Or)  OPERATOR(Xor)

 namespace clang {

 // A helper macro to implement short-circuiting when recursing.  It
 // invokes CALL_EXPR, which must be a method call, on the derived
 // object (s.t. a user of RecursiveASTVisitor can override the method
 // in CALL_EXPR).
 #define TRY_TO(CALL_EXPR) \
   do { if (!getDerived().CALL_EXPR) return false; } while (0)

 /// \brief A class that does preorder depth-first traversal on the
 /// entire Clang AST and visits each node.
 ///
 /// This class performs three distinct tasks:
 ///   1. traverse the AST (i.e. go to each node);
 ///   2. at a given node, walk up the class hierarchy, starting from
 ///      the node's dynamic type, until the top-most class (e.g. Stmt,
 ///      Decl, or Type) is reached.
 ///   3. given a (node, class) combination, where 'class' is some base
 ///      class of the dynamic type of 'node', call a user-overridable
 ///      function to actually visit the node.
 ///
 /// These tasks are done by three groups of methods, respectively:
 ///   1. TraverseDecl(Decl *x) does task #1.  It is the entry point
 ///      for traversing an AST rooted at x.  This method simply
 ///      dispatches (i.e. forwards) to TraverseFoo(Foo *x) where Foo
 ///      is the dynamic type of *x, which calls WalkUpFromFoo(x) and
 ///      then recursively visits the child nodes of x.
 ///      TraverseStmt(Stmt *x) and TraverseType(QualType x) work
 ///      similarly.
 ///   2. WalkUpFromFoo(Foo *x) does task #2.  It does not try to visit
 ///      any child node of x.  Instead, it first calls WalkUpFromBar(x)
 ///      where Bar is the direct parent class of Foo (unless Foo has
 ///      no parent), and then calls VisitFoo(x) (see the next list item).
 ///   3. VisitFoo(Foo *x) does task #3.
 ///
 /// These three method groups are tiered (Traverse* > WalkUpFrom* >
 /// Visit*).  A method (e.g. Traverse*) may call methods from the same
 /// tier (e.g. other Traverse*) or one tier lower (e.g. WalkUpFrom*).
 /// It may not call methods from a higher tier.
 ///
 /// Note that since WalkUpFromFoo() calls WalkUpFromBar() (where Bar
 /// is Foo's super class) before calling VisitFoo(), the result is
 /// that the Visit*() methods for a given node are called in the
 /// top-down order (e.g. for a node of type NamedDecl, the order will
 /// be VisitDecl(), VisitNamedDecl(), and then VisitNamespaceDecl()).
 ///
 /// This scheme guarantees that all Visit*() calls for the same AST
 /// node are grouped together.  In other words, Visit*() methods for
 /// different nodes are never interleaved.
 ///
 /// Clients of this visitor should subclass the visitor (providing
 /// themselves as the template argument, using the curiously recurring
 /// template pattern) and override any of the Traverse*, WalkUpFrom*,
 /// and Visit* methods for declarations, types, statements,
 /// expressions, or other AST nodes where the visitor should customize
 /// behavior.  Most users only need to override Visit*.  Advanced
 /// users may override Traverse* and WalkUpFrom* to implement custom
 /// traversal strategies.  Returning false from one of these overridden
 /// functions will abort the entire traversal.
 ///
 /// By default, this visitor tries to visit every part of the explicit
 /// source code exactly once.  The default policy towards templates
 /// is to descend into the 'pattern' class or function body, not any
 /// explicit or implicit instantiations.  Explicit specializations
 /// are still visited, and the patterns of partial specializations
 /// are visited separately.  This behavior can be changed by
 /// overriding shouldVisitTemplateInstantiations() in the derived class
 /// to return true, in which case all known implicit and explicit
 /// instantiations will be visited at the same time as the pattern
 /// from which they were produced.
 template<typename Derived>
 class RecursiveASTVisitor {
 public:
   /// \brief Return a reference to the derived class.
   Derived &getDerived() { return *static_cast<Derived*>(this); }

   /// \brief Return whether this visitor should recurse into
   /// template instantiations.
   bool shouldVisitTemplateInstantiations() const { return false; }

   /// \brief Return whether this visitor should recurse into the types of
   /// TypeLocs.
   bool shouldWalkTypesOfTypeLocs() const { return true; }

   /// \brief Return whether this visitor should recurse into implicit
   /// code, e.g., implicit constructors and destructors.
   bool shouldVisitImplicitCode() const { return false; }

   /// \brief Return whether \param S should be traversed using data recursion
   /// to avoid a stack overflow with extreme cases.
   bool shouldUseDataRecursionFor(Stmt *S) const {
     return isa<BinaryOperator>(S) || isa<UnaryOperator>(S) ||
            isa<CaseStmt>(S) || isa<CXXOperatorCallExpr>(S);
   }

   /// \brief Recursively visit a statement or expression, by
   /// dispatching to Traverse*() based on the argument's dynamic type.
   ///
   /// \returns false if the visitation was terminated early, true
   /// otherwise (including when the argument is NULL).
   bool TraverseStmt(Stmt *S);

   /// \brief Recursively visit a type, by dispatching to
   /// Traverse*Type() based on the argument's getTypeClass() property.
   ///
   /// \returns false if the visitation was terminated early, true
   /// otherwise (including when the argument is a Null type).
   bool TraverseType(QualType T);

   /// \brief Recursively visit a type with location, by dispatching to
   /// Traverse*TypeLoc() based on the argument type's getTypeClass() property.
   ///
   /// \returns false if the visitation was terminated early, true
   /// otherwise (including when the argument is a Null type location).
   bool TraverseTypeLoc(TypeLoc TL);

   /// \brief Recursively visit a declaration, by dispatching to
   /// Traverse*Decl() based on the argument's dynamic type.
   ///
   /// \returns false if the visitation was terminated early, true
   /// otherwise (including when the argument is NULL).
   bool TraverseDecl(Decl *D);

   /// \brief Recursively visit a C++ nested-name-specifier.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseNestedNameSpecifier(NestedNameSpecifier *NNS);

   /// \brief Recursively visit a C++ nested-name-specifier with location
   /// information.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS);

   /// \brief Recursively visit a name with its location information.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseDeclarationNameInfo(DeclarationNameInfo NameInfo);

   /// \brief Recursively visit a template name and dispatch to the
   /// appropriate method.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseTemplateName(TemplateName Template);

   /// \brief Recursively visit a template argument and dispatch to the
   /// appropriate method for the argument type.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   // FIXME: migrate callers to TemplateArgumentLoc instead.
   bool TraverseTemplateArgument(const TemplateArgument &Arg);

   /// \brief Recursively visit a template argument location and dispatch to the
   /// appropriate method for the argument type.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc);

   /// \brief Recursively visit a set of template arguments.
   /// This can be overridden by a subclass, but it's not expected that
   /// will be needed -- this visitor always dispatches to another.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   // FIXME: take a TemplateArgumentLoc* (or TemplateArgumentListInfo) instead.
   bool TraverseTemplateArguments(const TemplateArgument *Args,
                                  unsigned NumArgs);

   /// \brief Recursively visit a constructor initializer.  This
   /// automatically dispatches to another visitor for the initializer
   /// expression, but not for the name of the initializer, so may
   /// be overridden for clients that need access to the name.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseConstructorInitializer(CXXCtorInitializer *Init);

   /// \brief Recursively visit a lambda capture.
   ///
   /// \returns false if the visitation was terminated early, true otherwise.
   bool TraverseLambdaCapture(LambdaExpr::Capture C);

   // ---- Methods on Stmts ----

   // Declare Traverse*() for all concrete Stmt classes.
 #define ABSTRACT_STMT(STMT)
 #define STMT(CLASS, PARENT)                                     \
   bool Traverse##CLASS(CLASS *S);
 #include "clang/AST/StmtNodes.inc"
   // The above header #undefs ABSTRACT_STMT and STMT upon exit.

   // Define WalkUpFrom*() and empty Visit*() for all Stmt classes.
   bool WalkUpFromStmt(Stmt *S) { return getDerived().VisitStmt(S); }
   bool VisitStmt(Stmt *S) { return true; }
 #define STMT(CLASS, PARENT)                                     \
   bool WalkUpFrom##CLASS(CLASS *S) {                            \
     TRY_TO(WalkUpFrom##PARENT(S));                              \
     TRY_TO(Visit##CLASS(S));                                    \
     return true;                                                \
   }                                                             \
   bool Visit##CLASS(CLASS *S) { return true; }
 #include "clang/AST/StmtNodes.inc"

   // Define Traverse*(), WalkUpFrom*(), and Visit*() for unary
   // operator methods.  Unary operators are not classes in themselves
   // (they're all opcodes in UnaryOperator) but do have visitors.
 #define OPERATOR(NAME)                                           \
   bool TraverseUnary##NAME(UnaryOperator *S) {                  \
     TRY_TO(WalkUpFromUnary##NAME(S));                           \
     TRY_TO(TraverseStmt(S->getSubExpr()));                      \
     return true;                                                \
   }                                                             \
   bool WalkUpFromUnary##NAME(UnaryOperator *S) {                \
     TRY_TO(WalkUpFromUnaryOperator(S));                         \
     TRY_TO(VisitUnary##NAME(S));                                \
     return true;                                                \
   }                                                             \
   bool VisitUnary##NAME(UnaryOperator *S) { return true; }

   UNARYOP_LIST()
 #undef OPERATOR

   // Define Traverse*(), WalkUpFrom*(), and Visit*() for binary
   // operator methods.  Binary operators are not classes in themselves
   // (they're all opcodes in BinaryOperator) but do have visitors.
 #define GENERAL_BINOP_FALLBACK(NAME, BINOP_TYPE)                \
   bool TraverseBin##NAME(BINOP_TYPE *S) {                       \
     TRY_TO(WalkUpFromBin##NAME(S));                             \
     TRY_TO(TraverseStmt(S->getLHS()));                          \
     TRY_TO(TraverseStmt(S->getRHS()));                          \
     return true;                                                \
   }                                                             \
   bool WalkUpFromBin##NAME(BINOP_TYPE *S) {                     \
     TRY_TO(WalkUpFrom##BINOP_TYPE(S));                          \
     TRY_TO(VisitBin##NAME(S));                                  \
     return true;                                                \
   }                                                             \
   bool VisitBin##NAME(BINOP_TYPE *S) { return true; }

 #define OPERATOR(NAME) GENERAL_BINOP_FALLBACK(NAME, BinaryOperator)
   BINOP_LIST()
 #undef OPERATOR

   // Define Traverse*(), WalkUpFrom*(), and Visit*() for compound
   // assignment methods.  Compound assignment operators are not
   // classes in themselves (they're all opcodes in
   // CompoundAssignOperator) but do have visitors.
 #define OPERATOR(NAME) \
   GENERAL_BINOP_FALLBACK(NAME##Assign, CompoundAssignOperator)

   CAO_LIST()
 #undef OPERATOR
 #undef GENERAL_BINOP_FALLBACK

   // ---- Methods on Types ----
   // FIXME: revamp to take TypeLoc's rather than Types.

   // Declare Traverse*() for all concrete Type classes.
 #define ABSTRACT_TYPE(CLASS, BASE)
 #define TYPE(CLASS, BASE) \
   bool Traverse##CLASS##Type(CLASS##Type *T);
 #include "clang/AST/TypeNodes.def"
   // The above header #undefs ABSTRACT_TYPE and TYPE upon exit.

   // Define WalkUpFrom*() and empty Visit*() for all Type classes.
   bool WalkUpFromType(Type *T) { return getDerived().VisitType(T); }
   bool VisitType(Type *T) { return true; }
 #define TYPE(CLASS, BASE)                                       \
   bool WalkUpFrom##CLASS##Type(CLASS##Type *T) {                \
     TRY_TO(WalkUpFrom##BASE(T));                                \
     TRY_TO(Visit##CLASS##Type(T));                              \
     return true;                                                \
   }                                                             \
   bool Visit##CLASS##Type(CLASS##Type *T) { return true; }
 #include "clang/AST/TypeNodes.def"

   // ---- Methods on TypeLocs ----
   // FIXME: this currently just calls the matching Type methods

   // Declare Traverse*() for all concrete Type classes.
 #define ABSTRACT_TYPELOC(CLASS, BASE)
 #define TYPELOC(CLASS, BASE) \
   bool Traverse##CLASS##TypeLoc(CLASS##TypeLoc TL);
 #include "clang/AST/TypeLocNodes.def"
   // The above header #undefs ABSTRACT_TYPELOC and TYPELOC upon exit.

   // Define WalkUpFrom*() and empty Visit*() for all TypeLoc classes.
   bool WalkUpFromTypeLoc(TypeLoc TL) { return getDerived().VisitTypeLoc(TL); }
   bool VisitTypeLoc(TypeLoc TL) { return true; }

   // QualifiedTypeLoc and UnqualTypeLoc are not declared in
   // TypeNodes.def and thus need to be handled specially.
   bool WalkUpFromQualifiedTypeLoc(QualifiedTypeLoc TL) {
     return getDerived().VisitUnqualTypeLoc(TL.getUnqualifiedLoc());
   }
   bool VisitQualifiedTypeLoc(QualifiedTypeLoc TL) { return true; }
   bool WalkUpFromUnqualTypeLoc(UnqualTypeLoc TL) {
     return getDerived().VisitUnqualTypeLoc(TL.getUnqualifiedLoc());
   }
   bool VisitUnqualTypeLoc(UnqualTypeLoc TL) { return true; }

   // Note that BASE includes trailing 'Type' which CLASS doesn't.
 #define TYPE(CLASS, BASE)                                       \
   bool WalkUpFrom##CLASS##TypeLoc(CLASS##TypeLoc TL) {          \
     TRY_TO(WalkUpFrom##BASE##Loc(TL));                          \
     TRY_TO(Visit##CLASS##TypeLoc(TL));                          \
     return true;                                                \
   }                                                             \
   bool Visit##CLASS##TypeLoc(CLASS##TypeLoc TL) { return true; }
 #include "clang/AST/TypeNodes.def"

   // ---- Methods on Decls ----

   // Declare Traverse*() for all concrete Decl classes.
 #define ABSTRACT_DECL(DECL)
 #define DECL(CLASS, BASE) \
   bool Traverse##CLASS##Decl(CLASS##Decl *D);
 #include "clang/AST/DeclNodes.inc"
   // The above header #undefs ABSTRACT_DECL and DECL upon exit.

   // Define WalkUpFrom*() and empty Visit*() for all Decl classes.
   bool WalkUpFromDecl(Decl *D) { return getDerived().VisitDecl(D); }
   bool VisitDecl(Decl *D) { return true; }
 #define DECL(CLASS, BASE)                                       \
   bool WalkUpFrom##CLASS##Decl(CLASS##Decl *D) {                \
     TRY_TO(WalkUpFrom##BASE(D));                                \
     TRY_TO(Visit##CLASS##Decl(D));                              \
     return true;                                                \
   }                                                             \
   bool Visit##CLASS##Decl(CLASS##Decl *D) { return true; }
 #include "clang/AST/DeclNodes.inc"

 private:
   // These are helper methods used by more than one Traverse* method.
   bool TraverseTemplateParameterListHelper(TemplateParameterList *TPL);
   bool TraverseClassInstantiations(ClassTemplateDecl *D);
   bool TraverseFunctionInstantiations(FunctionTemplateDecl *D) ;
   bool TraverseTemplateArgumentLocsHelper(const TemplateArgumentLoc *TAL,
                                           unsigned Count);
   bool TraverseArrayTypeLocHelper(ArrayTypeLoc TL);
   bool TraverseRecordHelper(RecordDecl *D);
   bool TraverseCXXRecordHelper(CXXRecordDecl *D);
   bool TraverseDeclaratorHelper(DeclaratorDecl *D);
   bool TraverseDeclContextHelper(DeclContext *DC);
   bool TraverseFunctionHelper(FunctionDecl *D);
   bool TraverseVarHelper(VarDecl *D);

   struct EnqueueJob {
     Stmt *S;
     Stmt::child_iterator StmtIt;

     EnqueueJob(Stmt *S) : S(S), StmtIt() {}
   };
   bool dataTraverse(Stmt *S);
   bool dataTraverseNode(Stmt *S, bool &EnqueueChildren);
 };

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::dataTraverse(Stmt *S) {

   SmallVector<EnqueueJob, 16> Queue;
   Queue.push_back(S);

   while (!Queue.empty()) {
     EnqueueJob &job = Queue.back();
     Stmt *CurrS = job.S;
     if (!CurrS) {
       Queue.pop_back();
       continue;
     }

     if (getDerived().shouldUseDataRecursionFor(CurrS)) {
       if (job.StmtIt == Stmt::child_iterator()) {
         bool EnqueueChildren = true;
         if (!dataTraverseNode(CurrS, EnqueueChildren)) return false;
         if (!EnqueueChildren) {
           Queue.pop_back();
           continue;
         }
         job.StmtIt = CurrS->child_begin();
       } else {
         ++job.StmtIt;
       }

       if (job.StmtIt != CurrS->child_end())
         Queue.push_back(*job.StmtIt);
       else
         Queue.pop_back();
       continue;
     }

     Queue.pop_back();
     TRY_TO(TraverseStmt(CurrS));
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::dataTraverseNode(Stmt *S,
                                                     bool &EnqueueChildren) {

   // Dispatch to the corresponding WalkUpFrom* function only if the derived
   // class didn't override Traverse* (and thus the traversal is trivial).
 #define DISPATCH_WALK(NAME, CLASS, VAR) \
   { \
     bool (Derived::*DerivedFn)(CLASS*) = &Derived::Traverse##NAME; \
     bool (Derived::*BaseFn)(CLASS*) = &RecursiveASTVisitor::Traverse##NAME; \
     if (DerivedFn == BaseFn) \
       return getDerived().WalkUpFrom##NAME(static_cast<CLASS*>(VAR)); \
   } \
   EnqueueChildren = false; \
   return getDerived().Traverse##NAME(static_cast<CLASS*>(VAR));

   if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(S)) {
     switch (BinOp->getOpcode()) {
 #define OPERATOR(NAME) \
     case BO_##NAME: DISPATCH_WALK(Bin##NAME, BinaryOperator, S);

     BINOP_LIST()
 #undef OPERATOR

 #define OPERATOR(NAME)                                          \
     case BO_##NAME##Assign:                          \
     DISPATCH_WALK(Bin##NAME##Assign, CompoundAssignOperator, S);

     CAO_LIST()
 #undef OPERATOR
     }
   } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(S)) {
     switch (UnOp->getOpcode()) {
 #define OPERATOR(NAME)                                                  \
     case UO_##NAME: DISPATCH_WALK(Unary##NAME, UnaryOperator, S);

     UNARYOP_LIST()
 #undef OPERATOR
     }
   }

   // Top switch stmt: dispatch to TraverseFooStmt for each concrete FooStmt.
   switch (S->getStmtClass()) {
   case Stmt::NoStmtClass: break;
 #define ABSTRACT_STMT(STMT)
 #define STMT(CLASS, PARENT) \
   case Stmt::CLASS##Class: DISPATCH_WALK(CLASS, CLASS, S);
 #include "clang/AST/StmtNodes.inc"
   }

 #undef DISPATCH_WALK

   return true;
 }

 #define DISPATCH(NAME, CLASS, VAR) \
   return getDerived().Traverse##NAME(static_cast<CLASS*>(VAR))

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseStmt(Stmt *S) {
   if (!S)
     return true;

   if (getDerived().shouldUseDataRecursionFor(S))
     return dataTraverse(S);

   // If we have a binary expr, dispatch to the subcode of the binop.  A smart
   // optimizer (e.g. LLVM) will fold this comparison into the switch stmt
   // below.
   if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(S)) {
     switch (BinOp->getOpcode()) {
 #define OPERATOR(NAME) \
     case BO_##NAME: DISPATCH(Bin##NAME, BinaryOperator, S);

     BINOP_LIST()
 #undef OPERATOR
 #undef BINOP_LIST

 #define OPERATOR(NAME)                                          \
     case BO_##NAME##Assign:                          \
       DISPATCH(Bin##NAME##Assign, CompoundAssignOperator, S);

     CAO_LIST()
 #undef OPERATOR
 #undef CAO_LIST
     }
   } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(S)) {
     switch (UnOp->getOpcode()) {
 #define OPERATOR(NAME)                                                  \
     case UO_##NAME: DISPATCH(Unary##NAME, UnaryOperator, S);

     UNARYOP_LIST()
 #undef OPERATOR
 #undef UNARYOP_LIST
     }
   }

   // Top switch stmt: dispatch to TraverseFooStmt for each concrete FooStmt.
   switch (S->getStmtClass()) {
   case Stmt::NoStmtClass: break;
 #define ABSTRACT_STMT(STMT)
 #define STMT(CLASS, PARENT) \
   case Stmt::CLASS##Class: DISPATCH(CLASS, CLASS, S);
 #include "clang/AST/StmtNodes.inc"
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseType(QualType T) {
   if (T.isNull())
     return true;

   switch (T->getTypeClass()) {
 #define ABSTRACT_TYPE(CLASS, BASE)
 #define TYPE(CLASS, BASE) \
   case Type::CLASS: DISPATCH(CLASS##Type, CLASS##Type, \
                              const_cast<Type*>(T.getTypePtr()));
 #include "clang/AST/TypeNodes.def"
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTypeLoc(TypeLoc TL) {
   if (TL.isNull())
     return true;

   switch (TL.getTypeLocClass()) {
 #define ABSTRACT_TYPELOC(CLASS, BASE)
 #define TYPELOC(CLASS, BASE) \
   case TypeLoc::CLASS: \
     return getDerived().Traverse##CLASS##TypeLoc(TL.castAs<CLASS##TypeLoc>());
 #include "clang/AST/TypeLocNodes.def"
   }

   return true;
 }


 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseDecl(Decl *D) {
   if (!D)
     return true;

   // As a syntax visitor, by default we want to ignore declarations for
   // implicit declarations (ones not typed explicitly by the user).
   if (!getDerived().shouldVisitImplicitCode() && D->isImplicit())
     return true;

   switch (D->getKind()) {
 #define ABSTRACT_DECL(DECL)
 #define DECL(CLASS, BASE) \
   case Decl::CLASS: DISPATCH(CLASS##Decl, CLASS##Decl, D);
 #include "clang/AST/DeclNodes.inc"
  }

   return true;
 }

 #undef DISPATCH

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseNestedNameSpecifier(
                                                     NestedNameSpecifier *NNS) {
   if (!NNS)
     return true;

   if (NNS->getPrefix())
     TRY_TO(TraverseNestedNameSpecifier(NNS->getPrefix()));

   switch (NNS->getKind()) {
   case NestedNameSpecifier::Identifier:
   case NestedNameSpecifier::Namespace:
   case NestedNameSpecifier::NamespaceAlias:
   case NestedNameSpecifier::Global:
     return true;

   case NestedNameSpecifier::TypeSpec:
   case NestedNameSpecifier::TypeSpecWithTemplate:
     TRY_TO(TraverseType(QualType(NNS->getAsType(), 0)));
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseNestedNameSpecifierLoc(
                                                   NestedNameSpecifierLoc NNS) {
   if (!NNS)
     return true;

    if (NestedNameSpecifierLoc Prefix = NNS.getPrefix())
      TRY_TO(TraverseNestedNameSpecifierLoc(Prefix));

   switch (NNS.getNestedNameSpecifier()->getKind()) {
   case NestedNameSpecifier::Identifier:
   case NestedNameSpecifier::Namespace:
   case NestedNameSpecifier::NamespaceAlias:
   case NestedNameSpecifier::Global:
     return true;

   case NestedNameSpecifier::TypeSpec:
   case NestedNameSpecifier::TypeSpecWithTemplate:
     TRY_TO(TraverseTypeLoc(NNS.getTypeLoc()));
     break;
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseDeclarationNameInfo(
                                                  DeclarationNameInfo NameInfo) {
   switch (NameInfo.getName().getNameKind()) {
   case DeclarationName::CXXConstructorName:
   case DeclarationName::CXXDestructorName:
   case DeclarationName::CXXConversionFunctionName:
     if (TypeSourceInfo *TSInfo = NameInfo.getNamedTypeInfo())
       TRY_TO(TraverseTypeLoc(TSInfo->getTypeLoc()));

     break;

   case DeclarationName::Identifier:
   case DeclarationName::ObjCZeroArgSelector:
   case DeclarationName::ObjCOneArgSelector:
   case DeclarationName::ObjCMultiArgSelector:
   case DeclarationName::CXXOperatorName:
   case DeclarationName::CXXLiteralOperatorName:
   case DeclarationName::CXXUsingDirective:
     break;
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateName(TemplateName Template) {
   if (DependentTemplateName *DTN = Template.getAsDependentTemplateName())
     TRY_TO(TraverseNestedNameSpecifier(DTN->getQualifier()));
   else if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
     TRY_TO(TraverseNestedNameSpecifier(QTN->getQualifier()));

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateArgument(
                                                 const TemplateArgument &Arg) {
   switch (Arg.getKind()) {
   case TemplateArgument::Null:
   case TemplateArgument::Declaration:
   case TemplateArgument::Integral:
   case TemplateArgument::NullPtr:
     return true;

   case TemplateArgument::Type:
     return getDerived().TraverseType(Arg.getAsType());

   case TemplateArgument::Template:
   case TemplateArgument::TemplateExpansion:
     return getDerived().TraverseTemplateName(
                                           Arg.getAsTemplateOrTemplatePattern());

   case TemplateArgument::Expression:
     return getDerived().TraverseStmt(Arg.getAsExpr());

   case TemplateArgument::Pack:
     return getDerived().TraverseTemplateArguments(Arg.pack_begin(),
                                                   Arg.pack_size());
   }

   return true;
 }

 // FIXME: no template name location?
 // FIXME: no source locations for a template argument pack?
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateArgumentLoc(
                                            const TemplateArgumentLoc &ArgLoc) {
   const TemplateArgument &Arg = ArgLoc.getArgument();

   switch (Arg.getKind()) {
   case TemplateArgument::Null:
   case TemplateArgument::Declaration:
   case TemplateArgument::Integral:
   case TemplateArgument::NullPtr:
     return true;

   case TemplateArgument::Type: {
     // FIXME: how can TSI ever be NULL?
     if (TypeSourceInfo *TSI = ArgLoc.getTypeSourceInfo())
       return getDerived().TraverseTypeLoc(TSI->getTypeLoc());
     else
       return getDerived().TraverseType(Arg.getAsType());
   }

   case TemplateArgument::Template:
   case TemplateArgument::TemplateExpansion:
     if (ArgLoc.getTemplateQualifierLoc())
       TRY_TO(getDerived().TraverseNestedNameSpecifierLoc(
                                             ArgLoc.getTemplateQualifierLoc()));
     return getDerived().TraverseTemplateName(
                                          Arg.getAsTemplateOrTemplatePattern());

   case TemplateArgument::Expression:
     return getDerived().TraverseStmt(ArgLoc.getSourceExpression());

   case TemplateArgument::Pack:
     return getDerived().TraverseTemplateArguments(Arg.pack_begin(),
                                                   Arg.pack_size());
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateArguments(
                                                   const TemplateArgument *Args,
                                                             unsigned NumArgs) {
   for (unsigned I = 0; I != NumArgs; ++I) {
     TRY_TO(TraverseTemplateArgument(Args[I]));
   }

   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseConstructorInitializer(
                                                      CXXCtorInitializer *Init) {
   if (TypeSourceInfo *TInfo = Init->getTypeSourceInfo())
     TRY_TO(TraverseTypeLoc(TInfo->getTypeLoc()));

   if (Init->isWritten() || getDerived().shouldVisitImplicitCode())
     TRY_TO(TraverseStmt(Init->getInit()));
   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseLambdaCapture(LambdaExpr::Capture C){
   return true;
 }

 // ----------------- Type traversal -----------------

 // This macro makes available a variable T, the passed-in type.
 #define DEF_TRAVERSE_TYPE(TYPE, CODE)                     \
   template<typename Derived>                                           \
   bool RecursiveASTVisitor<Derived>::Traverse##TYPE (TYPE *T) {        \
     TRY_TO(WalkUpFrom##TYPE (T));                                      \
     { CODE; }                                                          \
     return true;                                                       \
   }

 DEF_TRAVERSE_TYPE(BuiltinType, { })

 DEF_TRAVERSE_TYPE(ComplexType, {
     TRY_TO(TraverseType(T->getElementType()));
   })

 DEF_TRAVERSE_TYPE(PointerType, {
     TRY_TO(TraverseType(T->getPointeeType()));
   })

 DEF_TRAVERSE_TYPE(BlockPointerType, {
     TRY_TO(TraverseType(T->getPointeeType()));
   })

 DEF_TRAVERSE_TYPE(LValueReferenceType, {
     TRY_TO(TraverseType(T->getPointeeType()));
   })

 DEF_TRAVERSE_TYPE(RValueReferenceType, {
     TRY_TO(TraverseType(T->getPointeeType()));
   })

 DEF_TRAVERSE_TYPE(MemberPointerType, {
     TRY_TO(TraverseType(QualType(T->getClass(), 0)));
     TRY_TO(TraverseType(T->getPointeeType()));
   })

 DEF_TRAVERSE_TYPE(ConstantArrayType, {
     TRY_TO(TraverseType(T->getElementType()));
   })

 DEF_TRAVERSE_TYPE(IncompleteArrayType, {
     TRY_TO(TraverseType(T->getElementType()));
   })

 DEF_TRAVERSE_TYPE(VariableArrayType, {
     TRY_TO(TraverseType(T->getElementType()));
     TRY_TO(TraverseStmt(T->getSizeExpr()));
   })

 DEF_TRAVERSE_TYPE(DependentSizedArrayType, {
     TRY_TO(TraverseType(T->getElementType()));
     if (T->getSizeExpr())
       TRY_TO(TraverseStmt(T->getSizeExpr()));
   })

 DEF_TRAVERSE_TYPE(DependentSizedExtVectorType, {
     if (T->getSizeExpr())
       TRY_TO(TraverseStmt(T->getSizeExpr()));
     TRY_TO(TraverseType(T->getElementType()));
   })

 DEF_TRAVERSE_TYPE(VectorType, {
     TRY_TO(TraverseType(T->getElementType()));
   })

 DEF_TRAVERSE_TYPE(ExtVectorType, {
     TRY_TO(TraverseType(T->getElementType()));
   })

 DEF_TRAVERSE_TYPE(FunctionNoProtoType, {
     TRY_TO(TraverseType(T->getResultType()));
   })

 DEF_TRAVERSE_TYPE(FunctionProtoType, {
     TRY_TO(TraverseType(T->getResultType()));

     for (FunctionProtoType::arg_type_iterator A = T->arg_type_begin(),
                                            AEnd = T->arg_type_end();
          A != AEnd; ++A) {
       TRY_TO(TraverseType(*A));
     }

     for (FunctionProtoType::exception_iterator E = T->exception_begin(),
                                             EEnd = T->exception_end();
          E != EEnd; ++E) {
       TRY_TO(TraverseType(*E));
     }
   })

 DEF_TRAVERSE_TYPE(UnresolvedUsingType, { })
 DEF_TRAVERSE_TYPE(TypedefType, { })

 DEF_TRAVERSE_TYPE(TypeOfExprType, {
     TRY_TO(TraverseStmt(T->getUnderlyingExpr()));
   })

 DEF_TRAVERSE_TYPE(TypeOfType, {
     TRY_TO(TraverseType(T->getUnderlyingType()));
   })

 DEF_TRAVERSE_TYPE(DecltypeType, {
     TRY_TO(TraverseStmt(T->getUnderlyingExpr()));
   })

 DEF_TRAVERSE_TYPE(UnaryTransformType, {
     TRY_TO(TraverseType(T->getBaseType()));
     TRY_TO(TraverseType(T->getUnderlyingType()));
     })

 DEF_TRAVERSE_TYPE(AutoType, {
     TRY_TO(TraverseType(T->getDeducedType()));
   })

 DEF_TRAVERSE_TYPE(RecordType, { })
 DEF_TRAVERSE_TYPE(EnumType, { })
 DEF_TRAVERSE_TYPE(TemplateTypeParmType, { })
 DEF_TRAVERSE_TYPE(SubstTemplateTypeParmType, { })
 DEF_TRAVERSE_TYPE(SubstTemplateTypeParmPackType, { })

 DEF_TRAVERSE_TYPE(TemplateSpecializationType, {
     TRY_TO(TraverseTemplateName(T->getTemplateName()));
     TRY_TO(TraverseTemplateArguments(T->getArgs(), T->getNumArgs()));
   })

 DEF_TRAVERSE_TYPE(InjectedClassNameType, { })

 DEF_TRAVERSE_TYPE(AttributedType, {
     TRY_TO(TraverseType(T->getModifiedType()));
   })

 DEF_TRAVERSE_TYPE(ParenType, {
     TRY_TO(TraverseType(T->getInnerType()));
   })

 DEF_TRAVERSE_TYPE(ElaboratedType, {
     if (T->getQualifier()) {
       TRY_TO(TraverseNestedNameSpecifier(T->getQualifier()));
     }
     TRY_TO(TraverseType(T->getNamedType()));
   })

 DEF_TRAVERSE_TYPE(DependentNameType, {
     TRY_TO(TraverseNestedNameSpecifier(T->getQualifier()));
   })

 DEF_TRAVERSE_TYPE(DependentTemplateSpecializationType, {
     TRY_TO(TraverseNestedNameSpecifier(T->getQualifier()));
     TRY_TO(TraverseTemplateArguments(T->getArgs(), T->getNumArgs()));
   })

 DEF_TRAVERSE_TYPE(PackExpansionType, {
     TRY_TO(TraverseType(T->getPattern()));
   })

 DEF_TRAVERSE_TYPE(ObjCInterfaceType, { })

 DEF_TRAVERSE_TYPE(ObjCObjectType, {
     // We have to watch out here because an ObjCInterfaceType's base
     // type is itself.
     if (T->getBaseType().getTypePtr() != T)
       TRY_TO(TraverseType(T->getBaseType()));
   })

 DEF_TRAVERSE_TYPE(ObjCObjectPointerType, {
     TRY_TO(TraverseType(T->getPointeeType()));
   })

 DEF_TRAVERSE_TYPE(AtomicType, {
     TRY_TO(TraverseType(T->getValueType()));
   })

 #undef DEF_TRAVERSE_TYPE

 // ----------------- TypeLoc traversal -----------------

 // This macro makes available a variable TL, the passed-in TypeLoc.
 // If requested, it calls WalkUpFrom* for the Type in the given TypeLoc,
 // in addition to WalkUpFrom* for the TypeLoc itself, such that existing
 // clients that override the WalkUpFrom*Type() and/or Visit*Type() methods
 // continue to work.
 #define DEF_TRAVERSE_TYPELOC(TYPE, CODE)                                \
   template<typename Derived>                                            \
   bool RecursiveASTVisitor<Derived>::Traverse##TYPE##Loc(TYPE##Loc TL) { \
     if (getDerived().shouldWalkTypesOfTypeLocs())                       \
       TRY_TO(WalkUpFrom##TYPE(const_cast<TYPE*>(TL.getTypePtr())));     \
     TRY_TO(WalkUpFrom##TYPE##Loc(TL));                                  \
     { CODE; }                                                           \
     return true;                                                        \
   }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseQualifiedTypeLoc(
     QualifiedTypeLoc TL) {
   // Move this over to the 'main' typeloc tree.  Note that this is a
   // move -- we pretend that we were really looking at the unqualified
   // typeloc all along -- rather than a recursion, so we don't follow
   // the normal CRTP plan of going through
   // getDerived().TraverseTypeLoc.  If we did, we'd be traversing
   // twice for the same type (once as a QualifiedTypeLoc version of
   // the type, once as an UnqualifiedTypeLoc version of the type),
   // which in effect means we'd call VisitTypeLoc twice with the
   // 'same' type.  This solves that problem, at the cost of never
   // seeing the qualified version of the type (unless the client
   // subclasses TraverseQualifiedTypeLoc themselves).  It's not a
   // perfect solution.  A perfect solution probably requires making
   // QualifiedTypeLoc a wrapper around TypeLoc -- like QualType is a
   // wrapper around Type* -- rather than being its own class in the
   // type hierarchy.
   return TraverseTypeLoc(TL.getUnqualifiedLoc());
 }

 DEF_TRAVERSE_TYPELOC(BuiltinType, { })

 // FIXME: ComplexTypeLoc is unfinished
 DEF_TRAVERSE_TYPELOC(ComplexType, {
     TRY_TO(TraverseType(TL.getTypePtr()->getElementType()));
   })

 DEF_TRAVERSE_TYPELOC(PointerType, {
     TRY_TO(TraverseTypeLoc(TL.getPointeeLoc()));
   })

 DEF_TRAVERSE_TYPELOC(BlockPointerType, {
     TRY_TO(TraverseTypeLoc(TL.getPointeeLoc()));
   })

 DEF_TRAVERSE_TYPELOC(LValueReferenceType, {
     TRY_TO(TraverseTypeLoc(TL.getPointeeLoc()));
   })

 DEF_TRAVERSE_TYPELOC(RValueReferenceType, {
     TRY_TO(TraverseTypeLoc(TL.getPointeeLoc()));
   })

 // FIXME: location of base class?
 // We traverse this in the type case as well, but how is it not reached through
 // the pointee type?
 DEF_TRAVERSE_TYPELOC(MemberPointerType, {
     TRY_TO(TraverseType(QualType(TL.getTypePtr()->getClass(), 0)));
     TRY_TO(TraverseTypeLoc(TL.getPointeeLoc()));
   })

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseArrayTypeLocHelper(ArrayTypeLoc TL) {
   // This isn't available for ArrayType, but is for the ArrayTypeLoc.
   TRY_TO(TraverseStmt(TL.getSizeExpr()));
   return true;
 }

 DEF_TRAVERSE_TYPELOC(ConstantArrayType, {
     TRY_TO(TraverseTypeLoc(TL.getElementLoc()));
     return TraverseArrayTypeLocHelper(TL);
   })

 DEF_TRAVERSE_TYPELOC(IncompleteArrayType, {
     TRY_TO(TraverseTypeLoc(TL.getElementLoc()));
     return TraverseArrayTypeLocHelper(TL);
   })

 DEF_TRAVERSE_TYPELOC(VariableArrayType, {
     TRY_TO(TraverseTypeLoc(TL.getElementLoc()));
     return TraverseArrayTypeLocHelper(TL);
   })

 DEF_TRAVERSE_TYPELOC(DependentSizedArrayType, {
     TRY_TO(TraverseTypeLoc(TL.getElementLoc()));
     return TraverseArrayTypeLocHelper(TL);
   })

 // FIXME: order? why not size expr first?
 // FIXME: base VectorTypeLoc is unfinished
 DEF_TRAVERSE_TYPELOC(DependentSizedExtVectorType, {
     if (TL.getTypePtr()->getSizeExpr())
       TRY_TO(TraverseStmt(TL.getTypePtr()->getSizeExpr()));
     TRY_TO(TraverseType(TL.getTypePtr()->getElementType()));
   })

 // FIXME: VectorTypeLoc is unfinished
 DEF_TRAVERSE_TYPELOC(VectorType, {
     TRY_TO(TraverseType(TL.getTypePtr()->getElementType()));
   })

 // FIXME: size and attributes
 // FIXME: base VectorTypeLoc is unfinished
 DEF_TRAVERSE_TYPELOC(ExtVectorType, {
     TRY_TO(TraverseType(TL.getTypePtr()->getElementType()));
   })

 DEF_TRAVERSE_TYPELOC(FunctionNoProtoType, {
     TRY_TO(TraverseTypeLoc(TL.getResultLoc()));
   })

 // FIXME: location of exception specifications (attributes?)
 DEF_TRAVERSE_TYPELOC(FunctionProtoType, {
     TRY_TO(TraverseTypeLoc(TL.getResultLoc()));

     const FunctionProtoType *T = TL.getTypePtr();

     for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
       if (TL.getArg(I)) {
         TRY_TO(TraverseDecl(TL.getArg(I)));
       } else if (I < T->getNumArgs()) {
         TRY_TO(TraverseType(T->getArgType(I)));
       }
     }

     for (FunctionProtoType::exception_iterator E = T->exception_begin(),
                                             EEnd = T->exception_end();
          E != EEnd; ++E) {
       TRY_TO(TraverseType(*E));
     }
   })

 DEF_TRAVERSE_TYPELOC(UnresolvedUsingType, { })
 DEF_TRAVERSE_TYPELOC(TypedefType, { })

 DEF_TRAVERSE_TYPELOC(TypeOfExprType, {
     TRY_TO(TraverseStmt(TL.getUnderlyingExpr()));
   })

 DEF_TRAVERSE_TYPELOC(TypeOfType, {
     TRY_TO(TraverseTypeLoc(TL.getUnderlyingTInfo()->getTypeLoc()));
   })

 // FIXME: location of underlying expr
 DEF_TRAVERSE_TYPELOC(DecltypeType, {
     TRY_TO(TraverseStmt(TL.getTypePtr()->getUnderlyingExpr()));
   })

 DEF_TRAVERSE_TYPELOC(UnaryTransformType, {
     TRY_TO(TraverseTypeLoc(TL.getUnderlyingTInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_TYPELOC(AutoType, {
     TRY_TO(TraverseType(TL.getTypePtr()->getDeducedType()));
   })

 DEF_TRAVERSE_TYPELOC(RecordType, { })
 DEF_TRAVERSE_TYPELOC(EnumType, { })
 DEF_TRAVERSE_TYPELOC(TemplateTypeParmType, { })
 DEF_TRAVERSE_TYPELOC(SubstTemplateTypeParmType, { })
 DEF_TRAVERSE_TYPELOC(SubstTemplateTypeParmPackType, { })

 // FIXME: use the loc for the template name?
 DEF_TRAVERSE_TYPELOC(TemplateSpecializationType, {
     TRY_TO(TraverseTemplateName(TL.getTypePtr()->getTemplateName()));
     for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
       TRY_TO(TraverseTemplateArgumentLoc(TL.getArgLoc(I)));
     }
   })

 DEF_TRAVERSE_TYPELOC(InjectedClassNameType, { })

 DEF_TRAVERSE_TYPELOC(ParenType, {
     TRY_TO(TraverseTypeLoc(TL.getInnerLoc()));
   })

 DEF_TRAVERSE_TYPELOC(AttributedType, {
     TRY_TO(TraverseTypeLoc(TL.getModifiedLoc()));
   })

 DEF_TRAVERSE_TYPELOC(ElaboratedType, {
     if (TL.getQualifierLoc()) {
       TRY_TO(TraverseNestedNameSpecifierLoc(TL.getQualifierLoc()));
     }
     TRY_TO(TraverseTypeLoc(TL.getNamedTypeLoc()));
   })

 DEF_TRAVERSE_TYPELOC(DependentNameType, {
     TRY_TO(TraverseNestedNameSpecifierLoc(TL.getQualifierLoc()));
   })

 DEF_TRAVERSE_TYPELOC(DependentTemplateSpecializationType, {
     if (TL.getQualifierLoc()) {
       TRY_TO(TraverseNestedNameSpecifierLoc(TL.getQualifierLoc()));
     }

     for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
       TRY_TO(TraverseTemplateArgumentLoc(TL.getArgLoc(I)));
     }
   })

 DEF_TRAVERSE_TYPELOC(PackExpansionType, {
     TRY_TO(TraverseTypeLoc(TL.getPatternLoc()));
   })

 DEF_TRAVERSE_TYPELOC(ObjCInterfaceType, { })

 DEF_TRAVERSE_TYPELOC(ObjCObjectType, {
     // We have to watch out here because an ObjCInterfaceType's base
     // type is itself.
     if (TL.getTypePtr()->getBaseType().getTypePtr() != TL.getTypePtr())
       TRY_TO(TraverseTypeLoc(TL.getBaseLoc()));
   })

 DEF_TRAVERSE_TYPELOC(ObjCObjectPointerType, {
     TRY_TO(TraverseTypeLoc(TL.getPointeeLoc()));
   })

 DEF_TRAVERSE_TYPELOC(AtomicType, {
     TRY_TO(TraverseTypeLoc(TL.getValueLoc()));
   })

 #undef DEF_TRAVERSE_TYPELOC

 // ----------------- Decl traversal -----------------
 //
 // For a Decl, we automate (in the DEF_TRAVERSE_DECL macro) traversing
 // the children that come from the DeclContext associated with it.
 // Therefore each Traverse* only needs to worry about children other
 // than those.

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseDeclContextHelper(DeclContext *DC) {
   if (!DC)
     return true;

   for (DeclContext::decl_iterator Child = DC->decls_begin(),
            ChildEnd = DC->decls_end();
        Child != ChildEnd; ++Child) {
     // BlockDecls and CapturedDecls are traversed through BlockExprs and
     // CapturedStmts respectively.
     if (!isa<BlockDecl>(*Child) && !isa<CapturedDecl>(*Child))
       TRY_TO(TraverseDecl(*Child));
   }

   return true;
 }

 // This macro makes available a variable D, the passed-in decl.
 #define DEF_TRAVERSE_DECL(DECL, CODE)                           \
 template<typename Derived>                                      \
 bool RecursiveASTVisitor<Derived>::Traverse##DECL (DECL *D) {   \
   TRY_TO(WalkUpFrom##DECL (D));                                 \
   { CODE; }                                                     \
   TRY_TO(TraverseDeclContextHelper(dyn_cast<DeclContext>(D)));  \
   return true;                                                  \
 }

 DEF_TRAVERSE_DECL(AccessSpecDecl, { })

 DEF_TRAVERSE_DECL(BlockDecl, {
     if (TypeSourceInfo *TInfo = D->getSignatureAsWritten())
       TRY_TO(TraverseTypeLoc(TInfo->getTypeLoc()));
     TRY_TO(TraverseStmt(D->getBody()));
     // This return statement makes sure the traversal of nodes in
     // decls_begin()/decls_end() (done in the DEF_TRAVERSE_DECL macro)
     // is skipped - don't remove it.
     return true;
   })

 DEF_TRAVERSE_DECL(CapturedDecl, {
     TRY_TO(TraverseStmt(D->getBody()));
     // This return statement makes sure the traversal of nodes in
     // decls_begin()/decls_end() (done in the DEF_TRAVERSE_DECL macro)
     // is skipped - don't remove it.
     return true;
   })

 DEF_TRAVERSE_DECL(EmptyDecl, { })

 DEF_TRAVERSE_DECL(FileScopeAsmDecl, {
     TRY_TO(TraverseStmt(D->getAsmString()));
   })

 DEF_TRAVERSE_DECL(ImportDecl, { })

 DEF_TRAVERSE_DECL(FriendDecl, {
     // Friend is either decl or a type.
     if (D->getFriendType())
       TRY_TO(TraverseTypeLoc(D->getFriendType()->getTypeLoc()));
     else
       TRY_TO(TraverseDecl(D->getFriendDecl()));
   })

 DEF_TRAVERSE_DECL(FriendTemplateDecl, {
     if (D->getFriendType())
       TRY_TO(TraverseTypeLoc(D->getFriendType()->getTypeLoc()));
     else
       TRY_TO(TraverseDecl(D->getFriendDecl()));
     for (unsigned I = 0, E = D->getNumTemplateParameters(); I < E; ++I) {
       TemplateParameterList *TPL = D->getTemplateParameterList(I);
       for (TemplateParameterList::iterator ITPL = TPL->begin(),
                                            ETPL = TPL->end();
            ITPL != ETPL; ++ITPL) {
         TRY_TO(TraverseDecl(*ITPL));
       }
     }
   })

 DEF_TRAVERSE_DECL(ClassScopeFunctionSpecializationDecl, {
     TRY_TO(TraverseDecl(D->getSpecialization()));

     if (D->hasExplicitTemplateArgs()) {
       const TemplateArgumentListInfo& args = D->templateArgs();
       TRY_TO(TraverseTemplateArgumentLocsHelper(
           args.getArgumentArray(), args.size()));
     }
  })

 DEF_TRAVERSE_DECL(LinkageSpecDecl, { })

 DEF_TRAVERSE_DECL(ObjCPropertyImplDecl, {
     // FIXME: implement this
   })

 DEF_TRAVERSE_DECL(StaticAssertDecl, {
     TRY_TO(TraverseStmt(D->getAssertExpr()));
     TRY_TO(TraverseStmt(D->getMessage()));
   })

 DEF_TRAVERSE_DECL(TranslationUnitDecl, {
     // Code in an unnamed namespace shows up automatically in
     // decls_begin()/decls_end().  Thus we don't need to recurse on
     // D->getAnonymousNamespace().
   })

 DEF_TRAVERSE_DECL(NamespaceAliasDecl, {
     // We shouldn't traverse an aliased namespace, since it will be
     // defined (and, therefore, traversed) somewhere else.
     //
     // This return statement makes sure the traversal of nodes in
     // decls_begin()/decls_end() (done in the DEF_TRAVERSE_DECL macro)
     // is skipped - don't remove it.
     return true;
   })

 DEF_TRAVERSE_DECL(LabelDecl, {
   // There is no code in a LabelDecl.
 })


 DEF_TRAVERSE_DECL(NamespaceDecl, {
     // Code in an unnamed namespace shows up automatically in
     // decls_begin()/decls_end().  Thus we don't need to recurse on
     // D->getAnonymousNamespace().
   })

 DEF_TRAVERSE_DECL(ObjCCompatibleAliasDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(ObjCCategoryDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(ObjCCategoryImplDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(ObjCImplementationDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(ObjCInterfaceDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(ObjCProtocolDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(ObjCMethodDecl, {
     if (D->getResultTypeSourceInfo()) {
       TRY_TO(TraverseTypeLoc(D->getResultTypeSourceInfo()->getTypeLoc()));
     }
     for (ObjCMethodDecl::param_iterator
            I = D->param_begin(), E = D->param_end(); I != E; ++I) {
       TRY_TO(TraverseDecl(*I));
     }
     if (D->isThisDeclarationADefinition()) {
       TRY_TO(TraverseStmt(D->getBody()));
     }
     return true;
   })

 DEF_TRAVERSE_DECL(ObjCPropertyDecl, {
     // FIXME: implement
   })

 DEF_TRAVERSE_DECL(UsingDecl, {
     TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(D->getNameInfo()));
   })

 DEF_TRAVERSE_DECL(UsingDirectiveDecl, {
     TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
   })

 DEF_TRAVERSE_DECL(UsingShadowDecl, { })

 DEF_TRAVERSE_DECL(OMPThreadPrivateDecl, {
     for (OMPThreadPrivateDecl::varlist_iterator I = D->varlist_begin(),
                                                 E = D->varlist_end();
          I != E; ++I) {
       TRY_TO(TraverseStmt(*I));
     }
   })

 // A helper method for TemplateDecl's children.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateParameterListHelper(
     TemplateParameterList *TPL) {
   if (TPL) {
     for (TemplateParameterList::iterator I = TPL->begin(), E = TPL->end();
          I != E; ++I) {
       TRY_TO(TraverseDecl(*I));
     }
   }
   return true;
 }

 // A helper method for traversing the implicit instantiations of a
 // class template.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseClassInstantiations(
     ClassTemplateDecl *D) {
   ClassTemplateDecl::spec_iterator end = D->spec_end();
   for (ClassTemplateDecl::spec_iterator it = D->spec_begin(); it != end; ++it) {
     ClassTemplateSpecializationDecl* SD = *it;

     switch (SD->getSpecializationKind()) {
     // Visit the implicit instantiations with the requested pattern.
     case TSK_Undeclared:
     case TSK_ImplicitInstantiation:
       TRY_TO(TraverseDecl(SD));
       break;

     // We don't need to do anything on an explicit instantiation
     // or explicit specialization because there will be an explicit
     // node for it elsewhere.
     case TSK_ExplicitInstantiationDeclaration:
     case TSK_ExplicitInstantiationDefinition:
     case TSK_ExplicitSpecialization:
       break;
     }
   }

   return true;
 }

 DEF_TRAVERSE_DECL(ClassTemplateDecl, {
     CXXRecordDecl* TempDecl = D->getTemplatedDecl();
     TRY_TO(TraverseDecl(TempDecl));
     TRY_TO(TraverseTemplateParameterListHelper(D->getTemplateParameters()));

     // By default, we do not traverse the instantiations of
     // class templates since they do not appear in the user code. The
     // following code optionally traverses them.
     //
     // We only traverse the class instantiations when we see the canonical
     // declaration of the template, to ensure we only visit them once.
     if (getDerived().shouldVisitTemplateInstantiations() &&
         D == D->getCanonicalDecl())
       TRY_TO(TraverseClassInstantiations(D));

     // Note that getInstantiatedFromMemberTemplate() is just a link
     // from a template instantiation back to the template from which
     // it was instantiated, and thus should not be traversed.
   })

 // A helper method for traversing the instantiations of a
 // function while skipping its specializations.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseFunctionInstantiations(
     FunctionTemplateDecl *D) {
   FunctionTemplateDecl::spec_iterator end = D->spec_end();
   for (FunctionTemplateDecl::spec_iterator it = D->spec_begin(); it != end;
        ++it) {
     FunctionDecl* FD = *it;
     switch (FD->getTemplateSpecializationKind()) {
     case TSK_Undeclared:
     case TSK_ImplicitInstantiation:
       // We don't know what kind of FunctionDecl this is.
       TRY_TO(TraverseDecl(FD));
       break;

     // FIXME: For now traverse explicit instantiations here. Change that
     // once they are represented as dedicated nodes in the AST.
     case TSK_ExplicitInstantiationDeclaration:
     case TSK_ExplicitInstantiationDefinition:
       TRY_TO(TraverseDecl(FD));
       break;

     case TSK_ExplicitSpecialization:
       break;
     }
   }

   return true;
 }

 DEF_TRAVERSE_DECL(FunctionTemplateDecl, {
     TRY_TO(TraverseDecl(D->getTemplatedDecl()));
     TRY_TO(TraverseTemplateParameterListHelper(D->getTemplateParameters()));

     // By default, we do not traverse the instantiations of
     // function templates since they do not appear in the user code. The
     // following code optionally traverses them.
     //
     // We only traverse the function instantiations when we see the canonical
     // declaration of the template, to ensure we only visit them once.
     if (getDerived().shouldVisitTemplateInstantiations() &&
         D == D->getCanonicalDecl())
       TRY_TO(TraverseFunctionInstantiations(D));
   })

 DEF_TRAVERSE_DECL(TemplateTemplateParmDecl, {
     // D is the "T" in something like
     //   template <template <typename> class T> class container { };
     TRY_TO(TraverseDecl(D->getTemplatedDecl()));
     if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
       TRY_TO(TraverseTemplateArgumentLoc(D->getDefaultArgument()));
     }
     TRY_TO(TraverseTemplateParameterListHelper(D->getTemplateParameters()));
   })

 DEF_TRAVERSE_DECL(TemplateTypeParmDecl, {
     // D is the "T" in something like "template<typename T> class vector;"
     if (D->getTypeForDecl())
       TRY_TO(TraverseType(QualType(D->getTypeForDecl(), 0)));
     if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited())
       TRY_TO(TraverseTypeLoc(D->getDefaultArgumentInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_DECL(TypedefDecl, {
     TRY_TO(TraverseTypeLoc(D->getTypeSourceInfo()->getTypeLoc()));
     // We shouldn't traverse D->getTypeForDecl(); it's a result of
     // declaring the typedef, not something that was written in the
     // source.
   })

 DEF_TRAVERSE_DECL(TypeAliasDecl, {
     TRY_TO(TraverseTypeLoc(D->getTypeSourceInfo()->getTypeLoc()));
     // We shouldn't traverse D->getTypeForDecl(); it's a result of
     // declaring the type alias, not something that was written in the
     // source.
   })

 DEF_TRAVERSE_DECL(TypeAliasTemplateDecl, {
     TRY_TO(TraverseDecl(D->getTemplatedDecl()));
     TRY_TO(TraverseTemplateParameterListHelper(D->getTemplateParameters()));
   })

 DEF_TRAVERSE_DECL(UnresolvedUsingTypenameDecl, {
     // A dependent using declaration which was marked with 'typename'.
     //   template<class T> class A : public B<T> { using typename B<T>::foo; };
     TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
     // We shouldn't traverse D->getTypeForDecl(); it's a result of
     // declaring the type, not something that was written in the
     // source.
   })

 DEF_TRAVERSE_DECL(EnumDecl, {
     if (D->getTypeForDecl())
       TRY_TO(TraverseType(QualType(D->getTypeForDecl(), 0)));

     TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
     // The enumerators are already traversed by
     // decls_begin()/decls_end().
   })


 // Helper methods for RecordDecl and its children.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseRecordHelper(
     RecordDecl *D) {
   // We shouldn't traverse D->getTypeForDecl(); it's a result of
   // declaring the type, not something that was written in the source.

   TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
   return true;
 }

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseCXXRecordHelper(
     CXXRecordDecl *D) {
   if (!TraverseRecordHelper(D))
     return false;
   if (D->isCompleteDefinition()) {
     for (CXXRecordDecl::base_class_iterator I = D->bases_begin(),
                                             E = D->bases_end();
          I != E; ++I) {
       TRY_TO(TraverseTypeLoc(I->getTypeSourceInfo()->getTypeLoc()));
     }
     // We don't traverse the friends or the conversions, as they are
     // already in decls_begin()/decls_end().
   }
   return true;
 }

 DEF_TRAVERSE_DECL(RecordDecl, {
     TRY_TO(TraverseRecordHelper(D));
   })

 DEF_TRAVERSE_DECL(CXXRecordDecl, {
     TRY_TO(TraverseCXXRecordHelper(D));
   })

 DEF_TRAVERSE_DECL(ClassTemplateSpecializationDecl, {
     // For implicit instantiations ("set<int> x;"), we don't want to
     // recurse at all, since the instatiated class isn't written in
     // the source code anywhere.  (Note the instatiated *type* --
     // set<int> -- is written, and will still get a callback of
     // TemplateSpecializationType).  For explicit instantiations
     // ("template set<int>;"), we do need a callback, since this
     // is the only callback that's made for this instantiation.
     // We use getTypeAsWritten() to distinguish.
     if (TypeSourceInfo *TSI = D->getTypeAsWritten())
       TRY_TO(TraverseTypeLoc(TSI->getTypeLoc()));

     if (!getDerived().shouldVisitTemplateInstantiations() &&
         D->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
       // Returning from here skips traversing the
       // declaration context of the ClassTemplateSpecializationDecl
       // (embedded in the DEF_TRAVERSE_DECL() macro)
       // which contains the instantiated members of the class.
       return true;
   })

 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateArgumentLocsHelper(
     const TemplateArgumentLoc *TAL, unsigned Count) {
   for (unsigned I = 0; I < Count; ++I) {
     TRY_TO(TraverseTemplateArgumentLoc(TAL[I]));
   }
   return true;
 }

 DEF_TRAVERSE_DECL(ClassTemplatePartialSpecializationDecl, {
     // The partial specialization.
     if (TemplateParameterList *TPL = D->getTemplateParameters()) {
       for (TemplateParameterList::iterator I = TPL->begin(), E = TPL->end();
            I != E; ++I) {
         TRY_TO(TraverseDecl(*I));
       }
     }
     // The args that remains unspecialized.
     TRY_TO(TraverseTemplateArgumentLocsHelper(
         D->getTemplateArgsAsWritten(), D->getNumTemplateArgsAsWritten()));

     // Don't need the ClassTemplatePartialSpecializationHelper, even
     // though that's our parent class -- we already visit all the
     // template args here.
     TRY_TO(TraverseCXXRecordHelper(D));

     // Instantiations will have been visited with the primary template.
   })

 DEF_TRAVERSE_DECL(EnumConstantDecl, {
     TRY_TO(TraverseStmt(D->getInitExpr()));
   })

 DEF_TRAVERSE_DECL(UnresolvedUsingValueDecl, {
     // Like UnresolvedUsingTypenameDecl, but without the 'typename':
     //    template <class T> Class A : public Base<T> { using Base<T>::foo; };
     TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(D->getNameInfo()));
   })

 DEF_TRAVERSE_DECL(IndirectFieldDecl, {})

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseDeclaratorHelper(DeclaratorDecl *D) {
   TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
   if (D->getTypeSourceInfo())
     TRY_TO(TraverseTypeLoc(D->getTypeSourceInfo()->getTypeLoc()));
   else
     TRY_TO(TraverseType(D->getType()));
   return true;
 }

 DEF_TRAVERSE_DECL(MSPropertyDecl, {
     TRY_TO(TraverseDeclaratorHelper(D));
   })

 DEF_TRAVERSE_DECL(FieldDecl, {
     TRY_TO(TraverseDeclaratorHelper(D));
     if (D->isBitField())
       TRY_TO(TraverseStmt(D->getBitWidth()));
     else if (D->hasInClassInitializer())
       TRY_TO(TraverseStmt(D->getInClassInitializer()));
   })

 DEF_TRAVERSE_DECL(ObjCAtDefsFieldDecl, {
     TRY_TO(TraverseDeclaratorHelper(D));
     if (D->isBitField())
       TRY_TO(TraverseStmt(D->getBitWidth()));
     // FIXME: implement the rest.
   })

 DEF_TRAVERSE_DECL(ObjCIvarDecl, {
     TRY_TO(TraverseDeclaratorHelper(D));
     if (D->isBitField())
       TRY_TO(TraverseStmt(D->getBitWidth()));
     // FIXME: implement the rest.
   })

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseFunctionHelper(FunctionDecl *D) {
   TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
   TRY_TO(TraverseDeclarationNameInfo(D->getNameInfo()));

   // If we're an explicit template specialization, iterate over the
   // template args that were explicitly specified.  If we were doing
   // this in typing order, we'd do it between the return type and
   // the function args, but both are handled by the FunctionTypeLoc
   // above, so we have to choose one side.  I've decided to do before.
   if (const FunctionTemplateSpecializationInfo *FTSI =
       D->getTemplateSpecializationInfo()) {
     if (FTSI->getTemplateSpecializationKind() != TSK_Undeclared &&
         FTSI->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) {
       // A specialization might not have explicit template arguments if it has
       // a templated return type and concrete arguments.
       if (const ASTTemplateArgumentListInfo *TALI =
           FTSI->TemplateArgumentsAsWritten) {
         TRY_TO(TraverseTemplateArgumentLocsHelper(TALI->getTemplateArgs(),
                                                   TALI->NumTemplateArgs));
       }
     }
   }

   // Visit the function type itself, which can be either
   // FunctionNoProtoType or FunctionProtoType, or a typedef.  This
   // also covers the return type and the function parameters,
   // including exception specifications.
   if (TypeSourceInfo *TSI = D->getTypeSourceInfo()) {
     TRY_TO(TraverseTypeLoc(TSI->getTypeLoc()));
   }

   if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(D)) {
     // Constructor initializers.
     for (CXXConstructorDecl::init_iterator I = Ctor->init_begin(),
                                            E = Ctor->init_end();
          I != E; ++I) {
       TRY_TO(TraverseConstructorInitializer(*I));
     }
   }

   if (D->isThisDeclarationADefinition()) {
     TRY_TO(TraverseStmt(D->getBody()));  // Function body.
   }
   return true;
 }

 DEF_TRAVERSE_DECL(FunctionDecl, {
     // We skip decls_begin/decls_end, which are already covered by
     // TraverseFunctionHelper().
     return TraverseFunctionHelper(D);
   })

 DEF_TRAVERSE_DECL(CXXMethodDecl, {
     // We skip decls_begin/decls_end, which are already covered by
     // TraverseFunctionHelper().
     return TraverseFunctionHelper(D);
   })

 DEF_TRAVERSE_DECL(CXXConstructorDecl, {
     // We skip decls_begin/decls_end, which are already covered by
     // TraverseFunctionHelper().
     return TraverseFunctionHelper(D);
   })

 // CXXConversionDecl is the declaration of a type conversion operator.
 // It's not a cast expression.
 DEF_TRAVERSE_DECL(CXXConversionDecl, {
     // We skip decls_begin/decls_end, which are already covered by
     // TraverseFunctionHelper().
     return TraverseFunctionHelper(D);
   })

 DEF_TRAVERSE_DECL(CXXDestructorDecl, {
     // We skip decls_begin/decls_end, which are already covered by
     // TraverseFunctionHelper().
     return TraverseFunctionHelper(D);
   })

 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseVarHelper(VarDecl *D) {
   TRY_TO(TraverseDeclaratorHelper(D));
   // Default params are taken care of when we traverse the ParmVarDecl.
   if (!isa<ParmVarDecl>(D) &&
       (!D->isCXXForRangeDecl() || getDerived().shouldVisitImplicitCode()))
     TRY_TO(TraverseStmt(D->getInit()));
   return true;
 }

 DEF_TRAVERSE_DECL(VarDecl, {
     TRY_TO(TraverseVarHelper(D));
   })

 DEF_TRAVERSE_DECL(ImplicitParamDecl, {
     TRY_TO(TraverseVarHelper(D));
   })

 DEF_TRAVERSE_DECL(NonTypeTemplateParmDecl, {
     // A non-type template parameter, e.g. "S" in template<int S> class Foo ...
     TRY_TO(TraverseDeclaratorHelper(D));
     if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited())
       TRY_TO(TraverseStmt(D->getDefaultArgument()));
   })

 DEF_TRAVERSE_DECL(ParmVarDecl, {
     TRY_TO(TraverseVarHelper(D));

     if (D->hasDefaultArg() &&
         D->hasUninstantiatedDefaultArg() &&
         !D->hasUnparsedDefaultArg())
       TRY_TO(TraverseStmt(D->getUninstantiatedDefaultArg()));

     if (D->hasDefaultArg() &&
         !D->hasUninstantiatedDefaultArg() &&
         !D->hasUnparsedDefaultArg())
       TRY_TO(TraverseStmt(D->getDefaultArg()));
   })

 #undef DEF_TRAVERSE_DECL

 // ----------------- Stmt traversal -----------------
 //
 // For stmts, we automate (in the DEF_TRAVERSE_STMT macro) iterating
 // over the children defined in children() (every stmt defines these,
 // though sometimes the range is empty).  Each individual Traverse*
 // method only needs to worry about children other than those.  To see
 // what children() does for a given class, see, e.g.,
 //   http://clang.llvm.org/doxygen/Stmt_8cpp_source.html

 // This macro makes available a variable S, the passed-in stmt.
 #define DEF_TRAVERSE_STMT(STMT, CODE)                                   \
 template<typename Derived>                                              \
 bool RecursiveASTVisitor<Derived>::Traverse##STMT (STMT *S) {           \
   TRY_TO(WalkUpFrom##STMT(S));                                          \
   { CODE; }                                                             \
   for (Stmt::child_range range = S->children(); range; ++range) {       \
     TRY_TO(TraverseStmt(*range));                                       \
   }                                                                     \
   return true;                                                          \
 }

 DEF_TRAVERSE_STMT(GCCAsmStmt, {
     TRY_TO(TraverseStmt(S->getAsmString()));
     for (unsigned I = 0, E = S->getNumInputs(); I < E; ++I) {
       TRY_TO(TraverseStmt(S->getInputConstraintLiteral(I)));
     }
     for (unsigned I = 0, E = S->getNumOutputs(); I < E; ++I) {
       TRY_TO(TraverseStmt(S->getOutputConstraintLiteral(I)));
     }
     for (unsigned I = 0, E = S->getNumClobbers(); I < E; ++I) {
       TRY_TO(TraverseStmt(S->getClobberStringLiteral(I)));
     }
     // children() iterates over inputExpr and outputExpr.
   })

 DEF_TRAVERSE_STMT(MSAsmStmt, {
     // FIXME: MS Asm doesn't currently parse Constraints, Clobbers, etc.  Once
     // added this needs to be implemented.
   })

 DEF_TRAVERSE_STMT(CXXCatchStmt, {
     TRY_TO(TraverseDecl(S->getExceptionDecl()));
     // children() iterates over the handler block.
   })

 DEF_TRAVERSE_STMT(DeclStmt, {
     for (DeclStmt::decl_iterator I = S->decl_begin(), E = S->decl_end();
          I != E; ++I) {
       TRY_TO(TraverseDecl(*I));
     }
     // Suppress the default iteration over children() by
     // returning.  Here's why: A DeclStmt looks like 'type var [=
     // initializer]'.  The decls above already traverse over the
     // initializers, so we don't have to do it again (which
     // children() would do).
     return true;
   })


 // These non-expr stmts (most of them), do not need any action except
 // iterating over the children.
 DEF_TRAVERSE_STMT(BreakStmt, { })
 DEF_TRAVERSE_STMT(CXXTryStmt, { })
 DEF_TRAVERSE_STMT(CaseStmt, { })
 DEF_TRAVERSE_STMT(CompoundStmt, { })
 DEF_TRAVERSE_STMT(ContinueStmt, { })
 DEF_TRAVERSE_STMT(DefaultStmt, { })
 DEF_TRAVERSE_STMT(DoStmt, { })
 DEF_TRAVERSE_STMT(ForStmt, { })
 DEF_TRAVERSE_STMT(GotoStmt, { })
 DEF_TRAVERSE_STMT(IfStmt, { })
 DEF_TRAVERSE_STMT(IndirectGotoStmt, { })
 DEF_TRAVERSE_STMT(LabelStmt, { })
 DEF_TRAVERSE_STMT(AttributedStmt, { })
 DEF_TRAVERSE_STMT(NullStmt, { })
 DEF_TRAVERSE_STMT(ObjCAtCatchStmt, { })
 DEF_TRAVERSE_STMT(ObjCAtFinallyStmt, { })
 DEF_TRAVERSE_STMT(ObjCAtSynchronizedStmt, { })
 DEF_TRAVERSE_STMT(ObjCAtThrowStmt, { })
 DEF_TRAVERSE_STMT(ObjCAtTryStmt, { })
 DEF_TRAVERSE_STMT(ObjCForCollectionStmt, { })
 DEF_TRAVERSE_STMT(ObjCAutoreleasePoolStmt, { })
 DEF_TRAVERSE_STMT(CXXForRangeStmt, {
   if (!getDerived().shouldVisitImplicitCode()) {
     TRY_TO(TraverseStmt(S->getLoopVarStmt()));
     TRY_TO(TraverseStmt(S->getRangeInit()));
     TRY_TO(TraverseStmt(S->getBody()));
     // Visit everything else only if shouldVisitImplicitCode().
     return true;
   }
 })
 DEF_TRAVERSE_STMT(MSDependentExistsStmt, {
     TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(S->getNameInfo()));
 })
 DEF_TRAVERSE_STMT(ReturnStmt, { })
 DEF_TRAVERSE_STMT(SwitchStmt, { })
 DEF_TRAVERSE_STMT(WhileStmt, { })


 DEF_TRAVERSE_STMT(CXXDependentScopeMemberExpr, {
     TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(S->getMemberNameInfo()));
     if (S->hasExplicitTemplateArgs()) {
       TRY_TO(TraverseTemplateArgumentLocsHelper(
           S->getTemplateArgs(), S->getNumTemplateArgs()));
     }
   })

 DEF_TRAVERSE_STMT(DeclRefExpr, {
     TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(S->getNameInfo()));
     TRY_TO(TraverseTemplateArgumentLocsHelper(
         S->getTemplateArgs(), S->getNumTemplateArgs()));
   })

 DEF_TRAVERSE_STMT(DependentScopeDeclRefExpr, {
     TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(S->getNameInfo()));
     if (S->hasExplicitTemplateArgs()) {
       TRY_TO(TraverseTemplateArgumentLocsHelper(
           S->getExplicitTemplateArgs().getTemplateArgs(),
           S->getNumTemplateArgs()));
     }
   })

 DEF_TRAVERSE_STMT(MemberExpr, {
     TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
     TRY_TO(TraverseDeclarationNameInfo(S->getMemberNameInfo()));
     TRY_TO(TraverseTemplateArgumentLocsHelper(
         S->getTemplateArgs(), S->getNumTemplateArgs()));
   })

 DEF_TRAVERSE_STMT(ImplicitCastExpr, {
     // We don't traverse the cast type, as it's not written in the
     // source code.
   })

 DEF_TRAVERSE_STMT(CStyleCastExpr, {
     TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXFunctionalCastExpr, {
     TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXConstCastExpr, {
     TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXDynamicCastExpr, {
     TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXReinterpretCastExpr, {
     TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXStaticCastExpr, {
     TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
   })

 // InitListExpr is a tricky one, because we want to do all our work on
 // the syntactic form of the listexpr, but this method takes the
 // semantic form by default.  We can't use the macro helper because it
 // calls WalkUp*() on the semantic form, before our code can convert
 // to the syntactic form.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseInitListExpr(InitListExpr *S) {
   if (InitListExpr *Syn = S->getSyntacticForm())
     S = Syn;
   TRY_TO(WalkUpFromInitListExpr(S));
   // All we need are the default actions.  FIXME: use a helper function.
   for (Stmt::child_range range = S->children(); range; ++range) {
     TRY_TO(TraverseStmt(*range));
   }
   return true;
 }

 // GenericSelectionExpr is a special case because the types and expressions
 // are interleaved.  We also need to watch out for null types (default
 // generic associations).
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::
 TraverseGenericSelectionExpr(GenericSelectionExpr *S) {
   TRY_TO(WalkUpFromGenericSelectionExpr(S));
   TRY_TO(TraverseStmt(S->getControllingExpr()));
   for (unsigned i = 0; i != S->getNumAssocs(); ++i) {
     if (TypeSourceInfo *TS = S->getAssocTypeSourceInfo(i))
       TRY_TO(TraverseTypeLoc(TS->getTypeLoc()));
     TRY_TO(TraverseStmt(S->getAssocExpr(i)));
   }
   return true;
 }

 // PseudoObjectExpr is a special case because of the wierdness with
 // syntactic expressions and opaque values.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::
 TraversePseudoObjectExpr(PseudoObjectExpr *S) {
   TRY_TO(WalkUpFromPseudoObjectExpr(S));
   TRY_TO(TraverseStmt(S->getSyntacticForm()));
   for (PseudoObjectExpr::semantics_iterator
          i = S->semantics_begin(), e = S->semantics_end(); i != e; ++i) {
     Expr *sub = *i;
     if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(sub))
       sub = OVE->getSourceExpr();
     TRY_TO(TraverseStmt(sub));
   }
   return true;
 }

 DEF_TRAVERSE_STMT(CXXScalarValueInitExpr, {
     // This is called for code like 'return T()' where T is a built-in
     // (i.e. non-class) type.
     TRY_TO(TraverseTypeLoc(S->getTypeSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXNewExpr, {
   // The child-iterator will pick up the other arguments.
   TRY_TO(TraverseTypeLoc(S->getAllocatedTypeSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(OffsetOfExpr, {
     // The child-iterator will pick up the expression representing
     // the field.
     // FIMXE: for code like offsetof(Foo, a.b.c), should we get
     // making a MemberExpr callbacks for Foo.a, Foo.a.b, and Foo.a.b.c?
     TRY_TO(TraverseTypeLoc(S->getTypeSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(UnaryExprOrTypeTraitExpr, {
     // The child-iterator will pick up the arg if it's an expression,
     // but not if it's a type.
     if (S->isArgumentType())
       TRY_TO(TraverseTypeLoc(S->getArgumentTypeInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXTypeidExpr, {
     // The child-iterator will pick up the arg if it's an expression,
     // but not if it's a type.
     if (S->isTypeOperand())
       TRY_TO(TraverseTypeLoc(S->getTypeOperandSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(MSPropertyRefExpr, {
   TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
 })

 DEF_TRAVERSE_STMT(CXXUuidofExpr, {
     // The child-iterator will pick up the arg if it's an expression,
     // but not if it's a type.
     if (S->isTypeOperand())
       TRY_TO(TraverseTypeLoc(S->getTypeOperandSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(UnaryTypeTraitExpr, {
     TRY_TO(TraverseTypeLoc(S->getQueriedTypeSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(BinaryTypeTraitExpr, {
     TRY_TO(TraverseTypeLoc(S->getLhsTypeSourceInfo()->getTypeLoc()));
     TRY_TO(TraverseTypeLoc(S->getRhsTypeSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(TypeTraitExpr, {
   for (unsigned I = 0, N = S->getNumArgs(); I != N; ++I)
     TRY_TO(TraverseTypeLoc(S->getArg(I)->getTypeLoc()));
 })

 DEF_TRAVERSE_STMT(ArrayTypeTraitExpr, {
     TRY_TO(TraverseTypeLoc(S->getQueriedTypeSourceInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(ExpressionTraitExpr, {
     TRY_TO(TraverseStmt(S->getQueriedExpression()));
   })

 DEF_TRAVERSE_STMT(VAArgExpr, {
     // The child-iterator will pick up the expression argument.
     TRY_TO(TraverseTypeLoc(S->getWrittenTypeInfo()->getTypeLoc()));
   })

 DEF_TRAVERSE_STMT(CXXTemporaryObjectExpr, {
     // This is called for code like 'return T()' where T is a class type.
     TRY_TO(TraverseTypeLoc(S->getTypeSourceInfo()->getTypeLoc()));
   })

 // Walk only the visible parts of lambda expressions.
 template<typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseLambdaExpr(LambdaExpr *S) {
   for (LambdaExpr::capture_iterator C = S->explicit_capture_begin(),
                                  CEnd = S->explicit_capture_end();
        C != CEnd; ++C) {
     TRY_TO(TraverseLambdaCapture(*C));
   }

   if (S->hasExplicitParameters() || S->hasExplicitResultType()) {
     TypeLoc TL = S->getCallOperator()->getTypeSourceInfo()->getTypeLoc();
     if (S->hasExplicitParameters() && S->hasExplicitResultType()) {
       // Visit the whole type.
       TRY_TO(TraverseTypeLoc(TL));
     } else if (FunctionProtoTypeLoc Proto = TL.getAs<FunctionProtoTypeLoc>()) {
       if (S->hasExplicitParameters()) {
         // Visit parameters.
         for (unsigned I = 0, N = Proto.getNumArgs(); I != N; ++I) {
           TRY_TO(TraverseDecl(Proto.getArg(I)));
         }
       } else {
         TRY_TO(TraverseTypeLoc(Proto.getResultLoc()));
       }
     }
   }

   TRY_TO(TraverseStmt(S->getBody()));
   return true;
 }

 DEF_TRAVERSE_STMT(CXXUnresolvedConstructExpr, {
     // This is called for code like 'T()', where T is a template argument.
     TRY_TO(TraverseTypeLoc(S->getTypeSourceInfo()->getTypeLoc()));
   })

 // These expressions all might take explicit template arguments.
 // We traverse those if so.  FIXME: implement these.
 DEF_TRAVERSE_STMT(CXXConstructExpr, { })
 DEF_TRAVERSE_STMT(CallExpr, { })
 DEF_TRAVERSE_STMT(CXXMemberCallExpr, { })

 // These exprs (most of them), do not need any action except iterating
 // over the children.
 DEF_TRAVERSE_STMT(AddrLabelExpr, { })
 DEF_TRAVERSE_STMT(ArraySubscriptExpr, { })
 DEF_TRAVERSE_STMT(BlockExpr, {
   TRY_TO(TraverseDecl(S->getBlockDecl()));
   return true; // no child statements to loop through.
 })
 DEF_TRAVERSE_STMT(ChooseExpr, { })
 DEF_TRAVERSE_STMT(CompoundLiteralExpr, {
   TRY_TO(TraverseTypeLoc(S->getTypeSourceInfo()->getTypeLoc()));
 })
 DEF_TRAVERSE_STMT(CXXBindTemporaryExpr, { })
 DEF_TRAVERSE_STMT(CXXBoolLiteralExpr, { })
 DEF_TRAVERSE_STMT(CXXDefaultArgExpr, { })
 DEF_TRAVERSE_STMT(CXXDefaultInitExpr, { })
 DEF_TRAVERSE_STMT(CXXDeleteExpr, { })
 DEF_TRAVERSE_STMT(ExprWithCleanups, { })
 DEF_TRAVERSE_STMT(CXXNullPtrLiteralExpr, { })
 DEF_TRAVERSE_STMT(CXXPseudoDestructorExpr, {
   TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
   if (TypeSourceInfo *ScopeInfo = S->getScopeTypeInfo())
     TRY_TO(TraverseTypeLoc(ScopeInfo->getTypeLoc()));
   if (TypeSourceInfo *DestroyedTypeInfo = S->getDestroyedTypeInfo())
     TRY_TO(TraverseTypeLoc(DestroyedTypeInfo->getTypeLoc()));
 })
 DEF_TRAVERSE_STMT(CXXThisExpr, { })
 DEF_TRAVERSE_STMT(CXXThrowExpr, { })
 DEF_TRAVERSE_STMT(UserDefinedLiteral, { })
 DEF_TRAVERSE_STMT(DesignatedInitExpr, { })
 DEF_TRAVERSE_STMT(ExtVectorElementExpr, { })
 DEF_TRAVERSE_STMT(GNUNullExpr, { })
 DEF_TRAVERSE_STMT(ImplicitValueInitExpr, { })
 DEF_TRAVERSE_STMT(ObjCBoolLiteralExpr, { })
 DEF_TRAVERSE_STMT(ObjCEncodeExpr, {
   if (TypeSourceInfo *TInfo = S->getEncodedTypeSourceInfo())
     TRY_TO(TraverseTypeLoc(TInfo->getTypeLoc()));
 })
 DEF_TRAVERSE_STMT(ObjCIsaExpr, { })
 DEF_TRAVERSE_STMT(ObjCIvarRefExpr, { })
 DEF_TRAVERSE_STMT(ObjCMessageExpr, {
   if (TypeSourceInfo *TInfo = S->getClassReceiverTypeInfo())
     TRY_TO(TraverseTypeLoc(TInfo->getTypeLoc()));
 })
 DEF_TRAVERSE_STMT(ObjCPropertyRefExpr, { })
 DEF_TRAVERSE_STMT(ObjCSubscriptRefExpr, { })
 DEF_TRAVERSE_STMT(ObjCProtocolExpr, { })
 DEF_TRAVERSE_STMT(ObjCSelectorExpr, { })
 DEF_TRAVERSE_STMT(ObjCIndirectCopyRestoreExpr, { })
 DEF_TRAVERSE_STMT(ObjCBridgedCastExpr, {
   TRY_TO(TraverseTypeLoc(S->getTypeInfoAsWritten()->getTypeLoc()));
 })
 DEF_TRAVERSE_STMT(ParenExpr, { })
 DEF_TRAVERSE_STMT(ParenListExpr, { })
 DEF_TRAVERSE_STMT(PredefinedExpr, { })
 DEF_TRAVERSE_STMT(ShuffleVectorExpr, { })
 DEF_TRAVERSE_STMT(StmtExpr, { })
 DEF_TRAVERSE_STMT(UnresolvedLookupExpr, {
   TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
   if (S->hasExplicitTemplateArgs()) {
     TRY_TO(TraverseTemplateArgumentLocsHelper(S->getTemplateArgs(),
                                               S->getNumTemplateArgs()));
   }
 })

 DEF_TRAVERSE_STMT(UnresolvedMemberExpr, {
   TRY_TO(TraverseNestedNameSpecifierLoc(S->getQualifierLoc()));
   if (S->hasExplicitTemplateArgs()) {
     TRY_TO(TraverseTemplateArgumentLocsHelper(S->getTemplateArgs(),
                                               S->getNumTemplateArgs()));
   }
 })

 DEF_TRAVERSE_STMT(SEHTryStmt, {})
 DEF_TRAVERSE_STMT(SEHExceptStmt, {})
 DEF_TRAVERSE_STMT(SEHFinallyStmt,{})
 DEF_TRAVERSE_STMT(CapturedStmt, {
   TRY_TO(TraverseDecl(S->getCapturedDecl()));
 })

 DEF_TRAVERSE_STMT(CXXOperatorCallExpr, { })
 DEF_TRAVERSE_STMT(OpaqueValueExpr, { })
 DEF_TRAVERSE_STMT(CUDAKernelCallExpr, { })

 // These operators (all of them) do not need any action except
 // iterating over the children.
 DEF_TRAVERSE_STMT(BinaryConditionalOperator, { })
 DEF_TRAVERSE_STMT(ConditionalOperator, { })
 DEF_TRAVERSE_STMT(UnaryOperator, { })
 DEF_TRAVERSE_STMT(BinaryOperator, { })
 DEF_TRAVERSE_STMT(CompoundAssignOperator, { })
 DEF_TRAVERSE_STMT(CXXNoexceptExpr, { })
 DEF_TRAVERSE_STMT(PackExpansionExpr, { })
 DEF_TRAVERSE_STMT(SizeOfPackExpr, { })
 DEF_TRAVERSE_STMT(SubstNonTypeTemplateParmPackExpr, { })
 DEF_TRAVERSE_STMT(SubstNonTypeTemplateParmExpr, { })
 DEF_TRAVERSE_STMT(FunctionParmPackExpr, { })
 DEF_TRAVERSE_STMT(MaterializeTemporaryExpr, { })
 DEF_TRAVERSE_STMT(AtomicExpr, { })

 // These literals (all of them) do not need any action.
 DEF_TRAVERSE_STMT(IntegerLiteral, { })
 DEF_TRAVERSE_STMT(CharacterLiteral, { })
 DEF_TRAVERSE_STMT(FloatingLiteral, { })
 DEF_TRAVERSE_STMT(ImaginaryLiteral, { })
 DEF_TRAVERSE_STMT(StringLiteral, { })
 DEF_TRAVERSE_STMT(ObjCStringLiteral, { })
 DEF_TRAVERSE_STMT(ObjCBoxedExpr, { })
 DEF_TRAVERSE_STMT(ObjCArrayLiteral, { })
 DEF_TRAVERSE_STMT(ObjCDictionaryLiteral, { })

 // Traverse OpenCL: AsType, Convert.
 DEF_TRAVERSE_STMT(AsTypeExpr, { })

 // FIXME: look at the following tricky-seeming exprs to see if we
 // need to recurse on anything.  These are ones that have methods
 // returning decls or qualtypes or nestednamespecifier -- though I'm
 // not sure if they own them -- or just seemed very complicated, or
 // had lots of sub-types to explore.
 //
 // VisitOverloadExpr and its children: recurse on template args? etc?

 // FIXME: go through all the stmts and exprs again, and see which of them
 // create new types, and recurse on the types (TypeLocs?) of those.
 // Candidates:
 //
 //    http://clang.llvm.org/doxygen/classclang_1_1CXXTypeidExpr.html
 //    http://clang.llvm.org/doxygen/classclang_1_1UnaryExprOrTypeTraitExpr.html
 //    http://clang.llvm.org/doxygen/classclang_1_1TypesCompatibleExpr.html
 //    Every class that has getQualifier.

 #undef DEF_TRAVERSE_STMT

 #undef TRY_TO

 } // end namespace clang

 #endif // LLVM_CLANG_AST_RECURSIVEASTVISITOR_H