/// Insert a diagnostic piece at function exit
/// if a function parameter is annotated as "os_consumed",
/// but it does not actually consume the reference.
static std::shared_ptr<PathDiagnosticEventPiece>
annotateConsumedSummaryMismatch(const ExplodedNode *N,
CallExitBegin &CallExitLoc,
const SourceManager &SM,
CallEventManager &CEMgr) {
const ExplodedNode *CN = getCalleeNode(N);
if (!CN)
return nullptr;
CallEventRef<> Call = CEMgr.getCaller(N->getStackFrame(), N->getState());
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
ArrayRef<const ParmVarDecl *> Parameters = Call->parameters();
for (unsigned I=0; I < Call->getNumArgs() && I < Parameters.size(); ++I) {
const ParmVarDecl *PVD = Parameters[I];
if (!PVD->hasAttr<OSConsumedAttr>())
continue;
if (SymbolRef SR = Call->getArgSVal(I).getAsLocSymbol()) {
const RefVal *CountBeforeCall = getRefBinding(CN->getState(), SR);
const RefVal *CountAtExit = getRefBinding(N->getState(), SR);
if (!CountBeforeCall || !CountAtExit)
continue;
unsigned CountBefore = CountBeforeCall->getCount();
unsigned CountAfter = CountAtExit->getCount();
bool AsExpected = CountBefore > 0 && CountAfter == CountBefore - 1;
if (!AsExpected) {
os << "Parameter '";
PVD->getNameForDiagnostic(os, PVD->getASTContext().getPrintingPolicy(),
/*Qualified=*/false);
os << "' is marked as consuming, but the function did not consume "
<< "the reference\n";
}
}
}
if (os.str().empty())
return nullptr;
// FIXME: remove the code duplication with NoStoreFuncVisitor.
PathDiagnosticLocation L;
if (const ReturnStmt *RS = CallExitLoc.getReturnStmt()) {
L = PathDiagnosticLocation::createBegin(RS, SM, N->getLocationContext());
} else {
L = PathDiagnosticLocation(
Call->getRuntimeDefinition().getDecl()->getSourceRange().getEnd(), SM);
}
return std::make_shared<PathDiagnosticEventPiece>(L, os.str());
}
PathDiagnosticPiece *
UndefOrNullArgVisitor::VisitNode(const ExplodedNode *N,
const ExplodedNode *PrevN,
BugReporterContext &BRC,
BugReport &BR) {
ProgramStateRef State = N->getState();
ProgramPoint ProgLoc = N->getLocation();
// We are only interested in visiting CallEnter nodes.
Optional<CallEnter> CEnter = ProgLoc.getAs<CallEnter>();
if (!CEnter)
return 0;
// Check if one of the arguments is the region the visitor is tracking.
CallEventManager &CEMgr = BRC.getStateManager().getCallEventManager();
CallEventRef<> Call = CEMgr.getCaller(CEnter->getCalleeContext(), State);
unsigned Idx = 0;
for (CallEvent::param_iterator I = Call->param_begin(),
E = Call->param_end(); I != E; ++I, ++Idx) {
const MemRegion *ArgReg = Call->getArgSVal(Idx).getAsRegion();
// Are we tracking the argument or its subregion?
if ( !ArgReg || (ArgReg != R && !R->isSubRegionOf(ArgReg->StripCasts())))
continue;
// Check the function parameter type.
const ParmVarDecl *ParamDecl = *I;
assert(ParamDecl && "Formal parameter has no decl?");
QualType T = ParamDecl->getType();
if (!(T->isAnyPointerType() || T->isReferenceType())) {
// Function can only change the value passed in by address.
continue;
}
// If it is a const pointer value, the function does not intend to
// change the value.
if (T->getPointeeType().isConstQualified())
continue;
// Mark the call site (LocationContext) as interesting if the value of the
// argument is undefined or '0'/'NULL'.
SVal BoundVal = State->getSVal(R);
if (BoundVal.isUndef() || BoundVal.isZeroConstant()) {
BR.markInteresting(CEnter->getCalleeContext());
return 0;
}
}
return 0;
}
