1 //== BoolAssignmentChecker.cpp - Boolean assignment checker -----*- C++ -*--==//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This defines BoolAssignmentChecker, a builtin check in ExprEngine that
10 // performs checks for assignment of non-Boolean values to Boolean variables.
12 //===----------------------------------------------------------------------===//
14 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
15 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
16 #include "clang/StaticAnalyzer/Core/Checker.h"
17 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
18 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
20 using namespace clang;
24 class BoolAssignmentChecker : public Checker< check::Bind > {
25 mutable std::unique_ptr<BuiltinBug> BT;
26 void emitReport(ProgramStateRef state, CheckerContext &C) const;
28 void checkBind(SVal loc, SVal val, const Stmt *S, CheckerContext &C) const;
30 } // end anonymous namespace
32 void BoolAssignmentChecker::emitReport(ProgramStateRef state,
33 CheckerContext &C) const {
34 if (ExplodedNode *N = C.generateNonFatalErrorNode(state)) {
36 BT.reset(new BuiltinBug(this, "Assignment of a non-Boolean value"));
39 std::make_unique<PathSensitiveBugReport>(*BT, BT->getDescription(), N));
43 static bool isBooleanType(QualType Ty) {
44 if (Ty->isBooleanType()) // C++ or C99
47 if (const TypedefType *TT = Ty->getAs<TypedefType>())
48 return TT->getDecl()->getName() == "BOOL" || // Objective-C
49 TT->getDecl()->getName() == "_Bool" || // stdbool.h < C99
50 TT->getDecl()->getName() == "Boolean"; // MacTypes.h
55 void BoolAssignmentChecker::checkBind(SVal loc, SVal val, const Stmt *S,
56 CheckerContext &C) const {
58 // We are only interested in stores into Booleans.
59 const TypedValueRegion *TR =
60 dyn_cast_or_null<TypedValueRegion>(loc.getAsRegion());
65 QualType valTy = TR->getValueType();
67 if (!isBooleanType(valTy))
70 // Get the value of the right-hand side. We only care about values
71 // that are defined (UnknownVals and UndefinedVals are handled by other
73 Optional<NonLoc> NV = val.getAs<NonLoc>();
77 // Check if the assigned value meets our criteria for correctness. It must
78 // be a value that is either 0 or 1. One way to check this is to see if
79 // the value is possibly < 0 (for a negative value) or greater than 1.
80 ProgramStateRef state = C.getState();
81 SValBuilder &svalBuilder = C.getSValBuilder();
82 BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
83 ConstraintManager &CM = C.getConstraintManager();
85 llvm::APSInt Zero = BVF.getValue(0, valTy);
86 llvm::APSInt One = BVF.getValue(1, valTy);
88 ProgramStateRef StIn, StOut;
89 std::tie(StIn, StOut) = CM.assumeInclusiveRangeDual(state, *NV, Zero, One);
95 void ento::registerBoolAssignmentChecker(CheckerManager &mgr) {
96 mgr.registerChecker<BoolAssignmentChecker>();
99 bool ento::shouldRegisterBoolAssignmentChecker(const CheckerManager &mgr) {