private void transferTaintToMutables(TaintMethodSummary methodSummary, Taint taint)
     throws RuntimeException {
   if (methodSummary == null || !methodSummary.hasMutableStackIndex()) {
     return;
   }
   int mutableStackIndex = methodSummary.getMutableStackIndex();
   try {
     Taint stackValue = getFrame().getStackValue(mutableStackIndex);
     // needed especially for constructors
     stackValue.setState(taint.getState());
     for (Location location : taint.getTaintedLocations()) {
       stackValue.addTaintLocation(location, true);
     }
     for (Location location : taint.getPossibleTaintedLocations()) {
       stackValue.addTaintLocation(location, false);
     }
     if (stackValue.hasValidLocalVariableIndex()) {
       int index = stackValue.getLocalVariableIndex();
       getFrame().setValue(index, taint);
     }
     // else we are not able to transfer taint to a local variable
   } catch (DataflowAnalysisException ex) {
     throw new RuntimeException("Bad mutable stack index specification", ex);
   }
 }
 private void visitInvoke(InvokeInstruction obj) {
   TaintMethodSummary methodSummary = getMethodSummary(obj);
   Taint taint = getMethodTaint(methodSummary);
   if (taint.getState() == Taint.State.UNKNOWN) {
     taint.addTaintLocation(getLocation(), false);
   }
   transferTaintToMutables(methodSummary, taint);
   modelInstruction(obj, getNumWordsConsumed(obj), getNumWordsProduced(obj), taint);
 }
 private Taint getMethodTaint(TaintMethodSummary methodSummary) {
   if (methodSummary == null) {
     return getDefaultValue();
   }
   if (methodSummary.hasConstantOutputTaint()) {
     Taint taint = new Taint(methodSummary.getOutputTaint());
     if (taint.getState() == Taint.State.TAINTED) {
       taint.addTaintLocation(getLocation(), true);
     }
     return taint;
   }
   if (methodSummary.hasTransferParameters()) {
     return mergeTransferParameters(methodSummary.getTransferParameters());
   }
   throw new IllegalStateException("invalid method summary");
 }