| //== BoolAssignmentChecker.cpp - Boolean assignment checker -----*- C++ -*--==// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This defines BoolAssignmentChecker, a builtin check in ExprEngine that |
| // performs checks for assignment of non-Boolean values to Boolean variables. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" |
| #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" |
| #include "clang/StaticAnalyzer/Core/Checker.h" |
| #include "clang/StaticAnalyzer/Core/CheckerManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace { |
| class BoolAssignmentChecker : public Checker< check::Bind > { |
| mutable std::unique_ptr<BuiltinBug> BT; |
| void emitReport(ProgramStateRef state, CheckerContext &C) const; |
| public: |
| void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const; |
| }; |
| } // end anonymous namespace |
| |
| void BoolAssignmentChecker::emitReport(ProgramStateRef state, |
| CheckerContext &C) const { |
| if (ExplodedNode *N = C.generateNonFatalErrorNode(state)) { |
| if (!BT) |
| BT.reset(new BuiltinBug(this, "Assignment of a non-Boolean value")); |
| |
| C.emitReport( |
| std::make_unique<PathSensitiveBugReport>(*BT, BT->getDescription(), N)); |
| } |
| } |
| |
| static bool isBooleanType(QualType Ty) { |
| if (Ty->isBooleanType()) // C++ or C99 |
| return true; |
| |
| if (const TypedefType *TT = Ty->getAs<TypedefType>()) |
| return TT->getDecl()->getName() == "BOOL" || // Objective-C |
| TT->getDecl()->getName() == "_Bool" || // stdbool.h < C99 |
| TT->getDecl()->getName() == "Boolean"; // MacTypes.h |
| |
| return false; |
| } |
| |
| void BoolAssignmentChecker::checkBind(SVal loc, SVal val, const Stmt *S, |
| CheckerContext &C) const { |
| |
| // We are only interested in stores into Booleans. |
| const TypedValueRegion *TR = |
| dyn_cast_or_null<TypedValueRegion>(loc.getAsRegion()); |
| |
| if (!TR) |
| return; |
| |
| QualType valTy = TR->getValueType(); |
| |
| if (!isBooleanType(valTy)) |
| return; |
| |
| // Get the value of the right-hand side. We only care about values |
| // that are defined (UnknownVals and UndefinedVals are handled by other |
| // checkers). |
| Optional<NonLoc> NV = val.getAs<NonLoc>(); |
| if (!NV) |
| return; |
| |
| // Check if the assigned value meets our criteria for correctness. It must |
| // be a value that is either 0 or 1. One way to check this is to see if |
| // the value is possibly < 0 (for a negative value) or greater than 1. |
| ProgramStateRef state = C.getState(); |
| SValBuilder &svalBuilder = C.getSValBuilder(); |
| BasicValueFactory &BVF = svalBuilder.getBasicValueFactory(); |
| ConstraintManager &CM = C.getConstraintManager(); |
| |
| llvm::APSInt Zero = BVF.getValue(0, valTy); |
| llvm::APSInt One = BVF.getValue(1, valTy); |
| |
| ProgramStateRef StIn, StOut; |
| std::tie(StIn, StOut) = CM.assumeInclusiveRangeDual(state, *NV, Zero, One); |
| |
| if (!StIn) |
| emitReport(StOut, C); |
| } |
| |
| void ento::registerBoolAssignmentChecker(CheckerManager &mgr) { |
| mgr.registerChecker<BoolAssignmentChecker>(); |
| } |
| |
| bool ento::shouldRegisterBoolAssignmentChecker(const CheckerManager &mgr) { |
| return true; |
| } |