[LLVMdev] LLVM segmentation fault / need use Instruction instead of Instruction*

[Stephen McGruer]

I may be mistaken as I just took a quick look, but in ilist_node the
function "getPrevNode()" actually calls a method on the previous node:

NodeTy *getPrevNode() {
  NodeTy *Prev = this->getPrev();

  // Check for sentinel.
  if (!Prev->getNext())
    return 0;

  return Prev;
}

http://llvm.org/docs/doxygen/html/ilist__node_8h_source.html#l00058

Try checking if current->getPrev() is null before calling
current->getPrevNode().

Stephen


On 20 December 2012 10:42, Alexandru Ionut Diaconescu <
alexandruionutdiaconescu at gmail.com> wrote:

> Hello John,
>
> I was following your procedures and I isolated the problem. The problem
> are represented by the basic blocks with only one element.
>
>
> for (Function::iterator II = F.begin(), EE = F.end(); II != EE; ++II,
> ++ii)
> {
> BasicBlock* BB=II;
>
>
> if (BB->getTerminator())
>     {
>         Instruction* current = BB->getTerminator();
>
>         Instruction* previous;
>
>         errs()<<"AAA\n";
>         if(*current->getPrevNode()*)
>         {
>             errs()<<"BBB\n";
>             previous = current->getPrevNode();
>             ok=1;
>         }
>
>         if (ok){
>            errs()<<"CCC\n";
>               ........
>
>
> It does print AAA, but then I have the segfault. So when I am evaluating
> the *current->getPrevNode() *condition, I got the segfault.
> Do you know how can I solve this?
>
> Thank you
> Alex
>
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