diff options
author | rdivacky <rdivacky@FreeBSD.org> | 2010-02-16 09:31:36 +0000 |
---|---|---|
committer | rdivacky <rdivacky@FreeBSD.org> | 2010-02-16 09:31:36 +0000 |
commit | fd035e6496665b1f1197868e21cb0a4594e8db6e (patch) | |
tree | 53010172e19c77ea447bcd89e117cda052ab52e0 /lib/Checker/DivZeroChecker.cpp | |
parent | 2fce988e86bc01829142e4362d4eff1af0925147 (diff) | |
download | FreeBSD-src-fd035e6496665b1f1197868e21cb0a4594e8db6e.zip FreeBSD-src-fd035e6496665b1f1197868e21cb0a4594e8db6e.tar.gz |
Update clang to r96341.
Diffstat (limited to 'lib/Checker/DivZeroChecker.cpp')
-rw-r--r-- | lib/Checker/DivZeroChecker.cpp | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/lib/Checker/DivZeroChecker.cpp b/lib/Checker/DivZeroChecker.cpp new file mode 100644 index 0000000..e1346e1 --- /dev/null +++ b/lib/Checker/DivZeroChecker.cpp @@ -0,0 +1,84 @@ +//== DivZeroChecker.cpp - Division by zero checker --------------*- C++ -*--==// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This defines DivZeroChecker, a builtin check in GRExprEngine that performs +// checks for division by zeros. +// +//===----------------------------------------------------------------------===// + +#include "clang/Checker/PathSensitive/CheckerVisitor.h" +#include "GRExprEngineInternalChecks.h" + +using namespace clang; + +namespace { +class DivZeroChecker : public CheckerVisitor<DivZeroChecker> { + BuiltinBug *BT; +public: + DivZeroChecker() : BT(0) {} + static void *getTag(); + void PreVisitBinaryOperator(CheckerContext &C, const BinaryOperator *B); +}; +} // end anonymous namespace + +void clang::RegisterDivZeroChecker(GRExprEngine &Eng) { + Eng.registerCheck(new DivZeroChecker()); +} + +void *DivZeroChecker::getTag() { + static int x; + return &x; +} + +void DivZeroChecker::PreVisitBinaryOperator(CheckerContext &C, + const BinaryOperator *B) { + BinaryOperator::Opcode Op = B->getOpcode(); + if (Op != BinaryOperator::Div && + Op != BinaryOperator::Rem && + Op != BinaryOperator::DivAssign && + Op != BinaryOperator::RemAssign) + return; + + if (!B->getRHS()->getType()->isIntegerType() || + !B->getRHS()->getType()->isScalarType()) + return; + + SVal Denom = C.getState()->getSVal(B->getRHS()); + const DefinedSVal *DV = dyn_cast<DefinedSVal>(&Denom); + + // Divide-by-undefined handled in the generic checking for uses of + // undefined values. + if (!DV) + return; + + // Check for divide by zero. + ConstraintManager &CM = C.getConstraintManager(); + const GRState *stateNotZero, *stateZero; + llvm::tie(stateNotZero, stateZero) = CM.AssumeDual(C.getState(), *DV); + + if (stateZero && !stateNotZero) { + if (ExplodedNode *N = C.GenerateSink(stateZero)) { + if (!BT) + BT = new BuiltinBug("Division by zero"); + + EnhancedBugReport *R = + new EnhancedBugReport(*BT, BT->getDescription(), N); + + R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, + bugreporter::GetDenomExpr(N)); + + C.EmitReport(R); + } + return; + } + + // If we get here, then the denom should not be zero. We abandon the implicit + // zero denom case for now. + C.addTransition(stateNotZero); +} |