Chris Lattner has strong opinions about directory
layout. :)
Rename the 'EntoSA' directories to 'StaticAnalyzer'.
Internally we will still use the 'ento' namespace
for the analyzer engine (unless there are further
sabre rattlings...).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122514 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp b/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp
new file mode 100644
index 0000000..8332af8
--- /dev/null
+++ b/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp
@@ -0,0 +1,86 @@
+//== 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 ExprEngine that performs
+// checks for division by zeros.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ExprEngineInternalChecks.h"
+#include "clang/StaticAnalyzer/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/PathSensitive/CheckerVisitor.h"
+
+using namespace clang;
+using namespace ento;
+
+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 ento::RegisterDivZeroChecker(ExprEngine &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 != BO_Div &&
+ Op != BO_Rem &&
+ Op != BO_DivAssign &&
+ Op != BO_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);
+}