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

[Farzad Sadeghi via cfe-dev]

ok the fault is probably mine for not explaining more. my situation is
I'm looking for callEXprs that are inside functionCall. that part is
simple enough. but I need to know whether the callExpr is inside an
ifStmt, whileStmt, forStmt or SwitchStmt or inside a combination of
those fourand then i have to decide and deal differently for each
case. that's why I'm looking for the ancestors or descendants of a
matched node.

On 7/14/16, Himanshu <himanshu at utexas.edu> wrote:
> 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
>>
>


-- 
Farzad Sadeghi