C++ CheckerContext::blockCount方法代码示例

void StreamChecker::OpenFileAux(CheckerContext &C, const CallExpr *CE) const {
  ProgramStateRef state = C.getState();
  SValBuilder &svalBuilder = C.getSValBuilder();
  const LocationContext *LCtx = C.getPredecessor()->getLocationContext();
  DefinedSVal RetVal = svalBuilder.conjureSymbolVal(nullptr, CE, LCtx,
                                                    C.blockCount())
      .castAs<DefinedSVal>();
  state = state->BindExpr(CE, C.getLocationContext(), RetVal);

  ConstraintManager &CM = C.getConstraintManager();
  // Bifurcate the state into two: one with a valid FILE* pointer, the other
  // with a NULL.
  ProgramStateRef stateNotNull, stateNull;
  std::tie(stateNotNull, stateNull) = CM.assumeDual(state, RetVal);

  if (SymbolRef Sym = RetVal.getAsSymbol()) {
    // if RetVal is not NULL, set the symbol's state to Opened.
    stateNotNull =
      stateNotNull->set<StreamMap>(Sym,StreamState::getOpened(CE));
    stateNull =
      stateNull->set<StreamMap>(Sym, StreamState::getOpenFailed(CE));

    C.addTransition(stateNotNull);
    C.addTransition(stateNull);
  }
}

void IteratorChecker::assignToContainer(CheckerContext &C, const Expr *CE,
                                        const SVal &RetVal,
                                        const MemRegion *Cont) const {
  while (const auto *CBOR = Cont->getAs<CXXBaseObjectRegion>()) {
    Cont = CBOR->getSuperRegion();
  }

  auto State = C.getState();
  auto &SymMgr = C.getSymbolManager();
  auto Sym = SymMgr.conjureSymbol(CE, C.getLocationContext(),
                                  C.getASTContext().LongTy, C.blockCount());
  State = setIteratorPosition(State, RetVal,
                              IteratorPosition::getPosition(Cont, Sym));
  C.addTransition(State);
}

bool BuiltinFunctionChecker::evalCall(const CallExpr *CE,
                                      CheckerContext &C) const {
  ProgramStateRef state = C.getState();
  const FunctionDecl *FD = C.getCalleeDecl(CE);
  const LocationContext *LCtx = C.getLocationContext();
  if (!FD)
    return false;

  unsigned id = FD->getBuiltinID();

  if (!id)
    return false;

  switch (id) {
  case Builtin::BI__builtin_expect: {
    // For __builtin_expect, just return the value of the subexpression.
    assert (CE->arg_begin() != CE->arg_end());
    SVal X = state->getSVal(*(CE->arg_begin()), LCtx);
    C.addTransition(state->BindExpr(CE, LCtx, X));
    return true;
  }

  case Builtin::BI__builtin_alloca: {
    // FIXME: Refactor into StoreManager itself?
    MemRegionManager& RM = C.getStoreManager().getRegionManager();
    const AllocaRegion* R =
      RM.getAllocaRegion(CE, C.blockCount(), C.getLocationContext());

    // Set the extent of the region in bytes. This enables us to use the
    // SVal of the argument directly. If we save the extent in bits, we
    // cannot represent values like symbol*8.
    DefinedOrUnknownSVal Size =
        state->getSVal(*(CE->arg_begin()), LCtx).castAs<DefinedOrUnknownSVal>();

    SValBuilder& svalBuilder = C.getSValBuilder();
    DefinedOrUnknownSVal Extent = R->getExtent(svalBuilder);
    DefinedOrUnknownSVal extentMatchesSizeArg =
      svalBuilder.evalEQ(state, Extent, Size);
    state = state->assume(extentMatchesSizeArg, true);
    assert(state && "The region should not have any previous constraints");

    C.addTransition(state->BindExpr(CE, LCtx, loc::MemRegionVal(R)));
    return true;
  }
  }

  return false;
}

void IteratorChecker::handleEnd(CheckerContext &C, const Expr *CE,
                                const SVal &RetVal, const SVal &Cont) const {
  const auto *ContReg = Cont.getAsRegion();
  if (!ContReg)
    return;

  while (const auto *CBOR = ContReg->getAs<CXXBaseObjectRegion>()) {
    ContReg = CBOR->getSuperRegion();
  }

  // If the container already has an end symbol then use it. Otherwise first
  // create a new one.
  auto State = C.getState();
  auto EndSym = getContainerEnd(State, ContReg);
  if (!EndSym) {
    auto &SymMgr = C.getSymbolManager();
    EndSym = SymMgr.conjureSymbol(CE, C.getLocationContext(),
                                  C.getASTContext().LongTy, C.blockCount());
    State = createContainerEnd(State, ContReg, EndSym);
  }
  State = setIteratorPosition(State, RetVal,
                              IteratorPosition::getPosition(ContReg, EndSym));
  C.addTransition(State);
}

bool BuiltinFunctionChecker::evalCall(const CallExpr *CE,
                                      CheckerContext &C) const {
  ProgramStateRef state = C.getState();
  const FunctionDecl *FD = C.getCalleeDecl(CE);
  const LocationContext *LCtx = C.getLocationContext();
  if (!FD)
    return false;

  switch (FD->getBuiltinID()) {
  default:
    return false;

  case Builtin::BI__builtin_unpredictable:
  case Builtin::BI__builtin_expect:
  case Builtin::BI__builtin_assume_aligned:
  case Builtin::BI__builtin_addressof: {
    // For __builtin_unpredictable, __builtin_expect, and
    // __builtin_assume_aligned, just return the value of the subexpression.
    // __builtin_addressof is going from a reference to a pointer, but those
    // are represented the same way in the analyzer.
    assert (CE->arg_begin() != CE->arg_end());
    SVal X = state->getSVal(*(CE->arg_begin()), LCtx);
    C.addTransition(state->BindExpr(CE, LCtx, X));
    return true;
  }

  case Builtin::BI__builtin_alloca_with_align:
  case Builtin::BI__builtin_alloca: {
    // FIXME: Refactor into StoreManager itself?
    MemRegionManager& RM = C.getStoreManager().getRegionManager();
    const AllocaRegion* R =
      RM.getAllocaRegion(CE, C.blockCount(), C.getLocationContext());

    // Set the extent of the region in bytes. This enables us to use the
    // SVal of the argument directly. If we save the extent in bits, we
    // cannot represent values like symbol*8.
    DefinedOrUnknownSVal Size =
        state->getSVal(*(CE->arg_begin()), LCtx).castAs<DefinedOrUnknownSVal>();

    SValBuilder& svalBuilder = C.getSValBuilder();
    DefinedOrUnknownSVal Extent = R->getExtent(svalBuilder);
    DefinedOrUnknownSVal extentMatchesSizeArg =
      svalBuilder.evalEQ(state, Extent, Size);
    state = state->assume(extentMatchesSizeArg, true);
    assert(state && "The region should not have any previous constraints");

    C.addTransition(state->BindExpr(CE, LCtx, loc::MemRegionVal(R)));
    return true;
  }

  case Builtin::BI__builtin_object_size: {
    // This must be resolvable at compile time, so we defer to the constant
    // evaluator for a value.
    SVal V = UnknownVal();
    llvm::APSInt Result;
    if (CE->EvaluateAsInt(Result, C.getASTContext(), Expr::SE_NoSideEffects)) {
      // Make sure the result has the correct type.
      SValBuilder &SVB = C.getSValBuilder();
      BasicValueFactory &BVF = SVB.getBasicValueFactory();
      BVF.getAPSIntType(CE->getType()).apply(Result);
      V = SVB.makeIntVal(Result);
    }

    C.addTransition(state->BindExpr(CE, LCtx, V));
    return true;
  }
  }
}