void UndefBranchChecker::VisitBranchCondition(GRBranchNodeBuilder &Builder,
GRExprEngine &Eng,
Stmt *Condition, void *tag) {
const GRState *state = Builder.getState();
SVal X = state->getSVal(Condition);
if (X.isUndef()) {
ExplodedNode *N = Builder.generateNode(state, true);
if (N) {
N->markAsSink();
if (!BT)
BT = new BuiltinBug("Branch condition evaluates to a garbage value");
// What's going on here: we want to highlight the subexpression of the
// condition that is the most likely source of the "uninitialized
// branch condition." We do a recursive walk of the condition's
// subexpressions and roughly look for the most nested subexpression
// that binds to Undefined. We then highlight that expression's range.
BlockEdge B = cast<BlockEdge>(N->getLocation());
Expr* Ex = cast<Expr>(B.getSrc()->getTerminatorCondition());
assert (Ex && "Block must have a terminator.");
// Get the predecessor node and check if is a PostStmt with the Stmt
// being the terminator condition. We want to inspect the state
// of that node instead because it will contain main information about
// the subexpressions.
assert (!N->pred_empty());
// Note: any predecessor will do. They should have identical state,
// since all the BlockEdge did was act as an error sink since the value
// had to already be undefined.
ExplodedNode *PrevN = *N->pred_begin();
ProgramPoint P = PrevN->getLocation();
const GRState* St = N->getState();
if (PostStmt* PS = dyn_cast<PostStmt>(&P))
if (PS->getStmt() == Ex)
St = PrevN->getState();
FindUndefExpr FindIt(Eng.getStateManager(), St);
Ex = FindIt.FindExpr(Ex);
// Emit the bug report.
EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getDescription(),N);
R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, Ex);
R->addRange(Ex->getSourceRange());
Eng.getBugReporter().EmitReport(R);
}
Builder.markInfeasible(true);
Builder.markInfeasible(false);
}
}
void clang::RegisterAppleChecks(GRExprEngine& Eng, const Decl &D) {
ASTContext& Ctx = Eng.getContext();
BugReporter &BR = Eng.getBugReporter();
Eng.AddCheck(CreateBasicObjCFoundationChecks(Ctx, BR),
Stmt::ObjCMessageExprClass);
Eng.AddCheck(CreateAuditCFNumberCreate(Ctx, BR), Stmt::CallExprClass);
Eng.AddCheck(CreateAuditCFRetainRelease(Ctx, BR), Stmt::CallExprClass);
RegisterNSErrorChecks(BR, Eng, D);
RegisterNSAutoreleasePoolChecks(Eng);
Eng.registerCheck(new ClassReleaseChecker(Ctx));
}