C++ ExprEngine::getSValBuilder方法代码示例

bool OSAtomicChecker::evalOSAtomicCompareAndSwap(const CallExpr *CE,
                                                 ExprEngine &Eng,
                                                 ExplodedNode *Pred,
                                                 ExplodedNodeSet &Dst) const {
  // Not enough arguments to match OSAtomicCompareAndSwap?
  if (CE->getNumArgs() != 3)
    return false;

  ASTContext &Ctx = Eng.getContext();
  const Expr *oldValueExpr = CE->getArg(0);
  QualType oldValueType = Ctx.getCanonicalType(oldValueExpr->getType());

  const Expr *newValueExpr = CE->getArg(1);
  QualType newValueType = Ctx.getCanonicalType(newValueExpr->getType());

  // Do the types of 'oldValue' and 'newValue' match?
  if (oldValueType != newValueType)
    return false;

  const Expr *theValueExpr = CE->getArg(2);
  const PointerType *theValueType=theValueExpr->getType()->getAs<PointerType>();

  // theValueType not a pointer?
  if (!theValueType)
    return false;

  QualType theValueTypePointee =
    Ctx.getCanonicalType(theValueType->getPointeeType()).getUnqualifiedType();

  // The pointee must match newValueType and oldValueType.
  if (theValueTypePointee != newValueType)
    return false;

  static SimpleProgramPointTag OSAtomicLoadTag("OSAtomicChecker : Load");
  static SimpleProgramPointTag OSAtomicStoreTag("OSAtomicChecker : Store");
  
  // Load 'theValue'.
  ProgramStateRef state = Pred->getState();
  const LocationContext *LCtx = Pred->getLocationContext();
  ExplodedNodeSet Tmp;
  SVal location = state->getSVal(theValueExpr, LCtx);
  // Here we should use the value type of the region as the load type, because
  // we are simulating the semantics of the function, not the semantics of 
  // passing argument. So the type of theValue expr is not we are loading.
  // But usually the type of the varregion is not the type we want either,
  // we still need to do a CastRetrievedVal in store manager. So actually this
  // LoadTy specifying can be omitted. But we put it here to emphasize the 
  // semantics.
  QualType LoadTy;
  if (const TypedValueRegion *TR =
      dyn_cast_or_null<TypedValueRegion>(location.getAsRegion())) {
    LoadTy = TR->getValueType();
  }
  Eng.evalLoad(Tmp, CE, theValueExpr, Pred,
               state, location, &OSAtomicLoadTag, LoadTy);

  if (Tmp.empty()) {
    // If no nodes were generated, other checkers must have generated sinks. 
    // We return an empty Dst.
    return true;
  }
 
  for (ExplodedNodeSet::iterator I = Tmp.begin(), E = Tmp.end();
       I != E; ++I) {

    ExplodedNode *N = *I;
    ProgramStateRef stateLoad = N->getState();

    // Use direct bindings from the environment since we are forcing a load
    // from a location that the Environment would typically not be used
    // to bind a value.
    SVal theValueVal_untested = stateLoad->getSVal(theValueExpr, LCtx, true);

    SVal oldValueVal_untested = stateLoad->getSVal(oldValueExpr, LCtx);

    // FIXME: Issue an error.
    if (theValueVal_untested.isUndef() || oldValueVal_untested.isUndef()) {
      return false;
    }
    
    DefinedOrUnknownSVal theValueVal =
      cast<DefinedOrUnknownSVal>(theValueVal_untested);
    DefinedOrUnknownSVal oldValueVal =
      cast<DefinedOrUnknownSVal>(oldValueVal_untested);

    SValBuilder &svalBuilder = Eng.getSValBuilder();

    // Perform the comparison.
    DefinedOrUnknownSVal Cmp =
      svalBuilder.evalEQ(stateLoad,theValueVal,oldValueVal);

    ProgramStateRef stateEqual = stateLoad->assume(Cmp, true);

    // Were they equal?
    if (stateEqual) {
      // Perform the store.
      ExplodedNodeSet TmpStore;
      SVal val = stateEqual->getSVal(newValueExpr, LCtx);

      // Handle implicit value casts.
//.........这里部分代码省略.........