template<typename Derived>
bool RecursiveASTVisitor<Derived>::TraverseQualifiedTypeLoc(
QualifiedTypeLoc TL) {
- // Move this over to the 'main' typeloc tree.
- return getDerived().TraverseTypeLoc(TL.getUnqualifiedLoc());
+ // 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, { })