[CFLAA] Check for pointer type when adding landingpad and vaarg instructions to CFLGraph

[grievejia]

Summary

CFLGraphBuilder::addNode() contains an assertion that will fail if the added node is not of pointer type. This may happen for landingpad instruction. I'm not sure if va_arg instruction could also have non-pointer type. To be safe I added a check there as well.

[george.burgess.iv]

Yay for assertions!

LGTM; thanks for the patch. :)

lib/Analysis/CFLGraph.h

void visitVAArgInst(VAArgInst &Inst) {
       // We can't fully model va_arg here. For *Ptr = Inst.getOperand(0), it
       // does
       // two things:
       //  1. Loads a value from *((T*)*Ptr).
       //  2. Increments (stores to) *Ptr by some target-specific amount.
       // For now, we'll handle this like a landingpad instruction (by placing
       // the
       // result in its own group, and having that group alias externals).
+      if (Inst.getType()->isPointerTy())
         addNode(&Inst, getAttrUnknown());
     }
 
     static bool isFunctionExternal(Function *Fn) {
       return !Fn->hasExactDefinition();
     }
 
     bool tryInterproceduralAnalysis(CallSite CS,
                                     const SmallVectorImpl<Function *> &Fns) {
void visitInsertElementInst(InsertElementInst &Inst) {
       addAssignEdge(Vec, &Inst);
       addStoreEdge(Val, &Inst);
     }
 
     void visitLandingPadInst(LandingPadInst &Inst) {
       // Exceptions come from "nowhere", from our analysis' perspective.
       // So we place the instruction its own group, noting that said group may
       // alias externals
+      if (Inst.getType()->isPointerTy())
         addNode(&Inst, getAttrUnknown());
     }
 
     void visitInsertValueInst(InsertValueInst &Inst) {
       auto *Agg = Inst.getOperand(0);
       auto *Val = Inst.getOperand(1);
       addAssignEdge(Agg, &Inst);
       addStoreEdge(Val, &Inst);
     }