[cfe-dev] acquiring all the ancestors or descendants of a matched node

[Himanshu via cfe-dev]

I believe by all the ancestors you mean: if a callExpr is encountered, then
you want all the functions that calls the callExpr, as well as each
function that calls the wrapping function in which the call was found?

In that case, you may need to do multiple passes using a loop such as:
while new calling functions were found, explore those functions).

--
Himanshu

On Wed, Jul 13, 2016 at 3:45 PM, Farzad Sadeghi <thabogre at gmail.com> wrote:

> Hi Himanshu,
> thank you for the answer but what i need is exactly what i asked for.
> i need to exactly know all the ancestors or descendants of a matched
> node.
>
> On 7/13/16, Himanshu <himanshu at utexas.edu> wrote:
> > Hi Farzad,
> >
> > If all you are looking for is finding a functionDecl wrapping a callExpr,
> > then following is what you want.
> >
> > const clang::FunctionDecl* getParentFunctionDecl(ASTContext
> *context,const
> > clang::Stmt& stmt){
> >         auto it = context->getParents(stmt).begin();
> >         if(it == context->getParents(stmt).end())
> >              return nullptr;
> >
> >         const clang::FunctionDecl *fDecl =
> it->get<clang::FunctionDecl>();
> >
> >         if(fDecl)
> >               return fDecl;
> >
> >         const clang::Stmt *aStmt = it->get<clang::Stmt>();
> >
> >         if(aStmt)
> >              return getParentFunctionDecl(context,*aStmt);
> >
> >        //nothing worked
> >        return nullptr;
> > }
> >
> > --
> > Himanshu
> >
> > On Wed, Jul 13, 2016 at 6:34 AM, Farzad Sadeghi via cfe-dev <
> > cfe-dev at lists.llvm.org> wrote:
> >
> >> Hi,
> >> I need to travel through all the ancestors or descendants of a matched
> >> AST node to later use that info to moodify parts of the input source
> >> code. I tried to look for ways to do that. I looked at the getParents
> >> member function of the ASTContext class. I could use that to just go
> >> up the AST hierarchy to visit all the ancestor nodes of my
> >> currently-matched node. but the problem with that is, when i get the
> >> parent node, i no longer have the context for that node to try and get
> >> its parent. I could try to rebuild the ASTContext for the new node but
> >> that seems to be another big task on its own, if possible. the lowest
> >> NodeKind (lowest in the C hierarchy) I'm looking for is a callExpr and
> >> the highest I'm looking for is a functionDecl. How can I obtain all
> >> the ancestors or descendants of a matched AST node after the match
> >> returns the control to run in MatchCallback?
> >>
> >>
> >> --
> >> Farzad Sadeghi
> >> _______________________________________________
> >> cfe-dev mailing list
> >> cfe-dev at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
> >>
> >
>
>
> --
> Farzad Sadeghi
>
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