libnixt/lib/ParentMap.cpp

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#include "nixt/ParentMap.h"
 
namespace nixt {
 
ParentMap parentMap(const nix::Expr *Root) {
  ParentMap Ret;
  struct VisitorClass : RecursiveASTVisitor<VisitorClass> {
    // The parent before traverseExpr
    const nix::Expr *ParentExpr;
    ParentMap *CapturedRet;
 
    bool traverseExpr(const nix::Expr *E) {
      CapturedRet->insert({E, ParentExpr});
      const auto *OldParent = ParentExpr;
      ParentExpr = E; // Set the parent into the visitor, it should be the
                      // parent when we are traversing child nodes.
      if (!RecursiveASTVisitor<VisitorClass>::traverseExpr(E))
        return false;
 
      // After traversing on childrens finished, set parent expr to previous
      // parent.
      ParentExpr = OldParent;
      return true;
    }
 
  } Visitor;
 
  Visitor.ParentExpr = Root;
  Visitor.CapturedRet = &Ret;
 
  Visitor.traverseExpr(Root);
 
  return Ret;
}
 
} // namespace nixt