| //=== UndefResultChecker.cpp ------------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This defines UndefResultChecker, a builtin check in ExprEngine that |
| // performs checks for undefined results of non-assignment binary operators. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ExprEngineInternalChecks.h" |
| #include "clang/GR/BugReporter/BugType.h" |
| #include "clang/GR/PathSensitive/CheckerVisitor.h" |
| #include "clang/GR/PathSensitive/ExprEngine.h" |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace { |
| class UndefResultChecker |
| : public CheckerVisitor<UndefResultChecker> { |
| |
| BugType *BT; |
| |
| public: |
| UndefResultChecker() : BT(0) {} |
| static void *getTag() { static int tag = 0; return &tag; } |
| void PostVisitBinaryOperator(CheckerContext &C, const BinaryOperator *B); |
| }; |
| } // end anonymous namespace |
| |
| void ento::RegisterUndefResultChecker(ExprEngine &Eng) { |
| Eng.registerCheck(new UndefResultChecker()); |
| } |
| |
| void UndefResultChecker::PostVisitBinaryOperator(CheckerContext &C, |
| const BinaryOperator *B) { |
| const GRState *state = C.getState(); |
| if (state->getSVal(B).isUndef()) { |
| // Generate an error node. |
| ExplodedNode *N = C.generateSink(); |
| if (!N) |
| return; |
| |
| if (!BT) |
| BT = new BuiltinBug("Result of operation is garbage or undefined"); |
| |
| llvm::SmallString<256> sbuf; |
| llvm::raw_svector_ostream OS(sbuf); |
| const Expr *Ex = NULL; |
| bool isLeft = true; |
| |
| if (state->getSVal(B->getLHS()).isUndef()) { |
| Ex = B->getLHS()->IgnoreParenCasts(); |
| isLeft = true; |
| } |
| else if (state->getSVal(B->getRHS()).isUndef()) { |
| Ex = B->getRHS()->IgnoreParenCasts(); |
| isLeft = false; |
| } |
| |
| if (Ex) { |
| OS << "The " << (isLeft ? "left" : "right") |
| << " operand of '" |
| << BinaryOperator::getOpcodeStr(B->getOpcode()) |
| << "' is a garbage value"; |
| } |
| else { |
| // Neither operand was undefined, but the result is undefined. |
| OS << "The result of the '" |
| << BinaryOperator::getOpcodeStr(B->getOpcode()) |
| << "' expression is undefined"; |
| } |
| EnhancedBugReport *report = new EnhancedBugReport(*BT, OS.str(), N); |
| if (Ex) { |
| report->addRange(Ex->getSourceRange()); |
| report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, Ex); |
| } |
| else |
| report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, B); |
| C.EmitReport(report); |
| } |
| } |