[llvm-dev] Change function call name in a CallInst only in certain functions

[Dávid Bolvanský via llvm-dev]

Okey, setCalledFunction is useful. But I have a problem since my "a", "b",
"c" are functions from libc, not my defined ones in the module.

if (CallInst *call_inst = dyn_cast<CallInst>(&I)) {

          Function *fn = call_inst->getCalledFunction();
          if (fn->getName() == "a") {
            ValueToValueMapTy map;
            FN = CloneFunction(fn, map, nullptr);
            FN->setName("c");
            call_inst->setCalledFunction(FN);
          }
          ...
}


I get "Assertion `!NodePtr->isKnownSentinel()' failed."


2018-03-24 1:19 GMT+01:00 mayuyu.io <admin at mayuyu.io>:

>
> You are probably calling setName() on the called Function, which in-turned
> renamed the called Function instead of replacing the called function.
> Depending on your use-case, if you are certain that you only need to
> modify CallInsts, then you could simply call CallInst::setCalledFunction ,
> otherwise it’s probably wiser to use CallSite as a wrapper for both
> CallInst and InvokeInst. Do note, however, that no matter which solution
> you end up using, you’ll need to update the FunctionType as well
> Zhang
>
> > On 23 Mar 2018, at 23:07, Dávid Bolvanský via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
> >
> > Hello,
> >
> > In my module I have functions:
> >
> > a
> > b
> > c
> > f3 calls "a"
> > f2 calls "a"
> > f1 calls "b"
> >
> > I would like to modify a CallInst in the f2. Now it calls "a", but I
> want changed it to "c".
> >
> > When loop over the instructions of the  f2, I can get a CallInst to be
> modified, then I use "setName" to changed it to "c".
> >
> >
> > Problem is, since references are updated, "a" is changed to "c" even in
> f1.
> >
> > Any solution?
> >
> > Thanks
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
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