Example #1
0
void GRTransferFuncs::EvalBinOpNN(GRStateSet& OStates,
                                  GRExprEngine& Eng,
                                  const GRState *St, Expr* Ex,
                                  BinaryOperator::Opcode Op,
                                  NonLoc L, NonLoc R, QualType T) {
  
  OStates.Add(Eng.getStateManager().BindExpr(St, Ex,
                                          DetermEvalBinOpNN(Eng, Op, L, R, T)));
}
Example #2
0
void UndefBranchChecker::VisitBranchCondition(GRBranchNodeBuilder &Builder, 
                                              GRExprEngine &Eng,
                                              Stmt *Condition, void *tag) {
  const GRState *state = Builder.getState();
  SVal X = state->getSVal(Condition);
  if (X.isUndef()) {
    ExplodedNode *N = Builder.generateNode(state, true);
    if (N) {
      N->markAsSink();
      if (!BT)
        BT = new BuiltinBug("Branch condition evaluates to a garbage value");

      // What's going on here: we want to highlight the subexpression of the
      // condition that is the most likely source of the "uninitialized
      // branch condition."  We do a recursive walk of the condition's
      // subexpressions and roughly look for the most nested subexpression
      // that binds to Undefined.  We then highlight that expression's range.
      BlockEdge B = cast<BlockEdge>(N->getLocation());
      Expr* Ex = cast<Expr>(B.getSrc()->getTerminatorCondition());
      assert (Ex && "Block must have a terminator.");

      // Get the predecessor node and check if is a PostStmt with the Stmt
      // being the terminator condition.  We want to inspect the state
      // of that node instead because it will contain main information about
      // the subexpressions.
      assert (!N->pred_empty());

      // Note: any predecessor will do.  They should have identical state,
      // since all the BlockEdge did was act as an error sink since the value
      // had to already be undefined.
      ExplodedNode *PrevN = *N->pred_begin();
      ProgramPoint P = PrevN->getLocation();
      const GRState* St = N->getState();

      if (PostStmt* PS = dyn_cast<PostStmt>(&P))
        if (PS->getStmt() == Ex)
          St = PrevN->getState();

      FindUndefExpr FindIt(Eng.getStateManager(), St);
      Ex = FindIt.FindExpr(Ex);

      // Emit the bug report.
      EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getDescription(),N);
      R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, Ex);
      R->addRange(Ex->getSourceRange());

      Eng.getBugReporter().EmitReport(R);
    }

    Builder.markInfeasible(true);
    Builder.markInfeasible(false);
  }
}
void GRSimpleVals::EvalObjCMessageExpr(ExplodedNodeSet<GRState>& Dst,
                                       GRExprEngine& Eng,
                                       GRStmtNodeBuilder<GRState>& Builder,
                                       ObjCMessageExpr* ME,
                                       ExplodedNode<GRState>* Pred) {
  
  
  // The basic transfer function logic for message expressions does nothing.
  // We just invalidate all arguments passed in by references.
  
  GRStateManager& StateMgr = Eng.getStateManager();
  const GRState* St = Builder.GetState(Pred);
  
  for (ObjCMessageExpr::arg_iterator I = ME->arg_begin(), E = ME->arg_end();
       I != E; ++I) {
    
    SVal V = StateMgr.GetSVal(St, *I);
    
    if (isa<Loc>(V))
      St = StateMgr.BindLoc(St, cast<Loc>(V), UnknownVal());
  }
  
  Builder.MakeNode(Dst, ME, Pred, St);
}
void GRSimpleVals::EvalCall(ExplodedNodeSet<GRState>& Dst,
                            GRExprEngine& Eng,
                            GRStmtNodeBuilder<GRState>& Builder,
                            CallExpr* CE, SVal L,
                            ExplodedNode<GRState>* Pred) {
  
  GRStateManager& StateMgr = Eng.getStateManager();
  const GRState* St = Builder.GetState(Pred);
  
  // Invalidate all arguments passed in by reference (Locs).

  for (CallExpr::arg_iterator I = CE->arg_begin(), E = CE->arg_end();
        I != E; ++I) {

    SVal V = StateMgr.GetSVal(St, *I);
    
    if (isa<loc::MemRegionVal>(V))
      St = StateMgr.BindLoc(St, cast<Loc>(V), UnknownVal());
    else if (isa<nonloc::LocAsInteger>(V))
      St = StateMgr.BindLoc(St, cast<nonloc::LocAsInteger>(V).getLoc(),
                            UnknownVal());
    
  }
  
  // Make up a symbol for the return value of this function.  
  // FIXME: We eventually should handle structs and other compound types
  // that are returned by value.
  QualType T = CE->getType();  
  if (Loc::IsLocType(T) || (T->isIntegerType() && T->isScalarType())) {    
    unsigned Count = Builder.getCurrentBlockCount();
    SVal X = Eng.getValueManager().getConjuredSymbolVal(CE, Count);
    St = StateMgr.BindExpr(St, CE, X, Eng.getCFG().isBlkExpr(CE), false);
  }  
    
  Builder.MakeNode(Dst, CE, Pred, St);
}