tripleCC added inline comments.
================
Comment at:
clang/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp:151-164
+ auto ArgSVal = C.getSVal(E).getAs<DefinedOrUnknownSVal>();
+ if (!ArgSVal)
+ return;
+
+ ProgramStateRef StNonNull, StNull;
+ std::tie(StNonNull, StNull) = State->assume(*ArgSVal);
+
----------------
steakhal wrote:
> steakhal wrote:
> > This means that we would raise an issue if `ArgSVal` might be null. We
> > usually warn if we are sure there is a bug, aka. if it must be null.
> > Consequently, the condition should be rather `StNull && !StNonNull` instead
> > of just `StNull`.
> Ah I see now. My bad, thats the whole point of this :D
Not exactly, this meas that if ArgSVal might be null, we dispatch an "implicit"
null event to NullabilityChecker. NullabilityChecker would emit a warning if
the pointer is nullable in `checkEvent` function:
```c++
/// This callback triggers when a pointer is dereferenced and the analyzer does
/// not know anything about the value of that pointer. When that pointer is
/// nullable, this code emits a warning.
void NullabilityChecker::checkEvent(ImplicitNullDerefEvent Event) const {
if (Event.SinkNode->getState()->get<InvariantViolated>())
return;
const MemRegion *Region =
getTrackRegion(Event.Location, /*CheckSuperRegion=*/true);
if (!Region)
return;
ProgramStateRef State = Event.SinkNode->getState();
const NullabilityState *TrackedNullability =
State->get<NullabilityMap>(Region);
if (!TrackedNullability)
return;
if (ChecksEnabled[CK_NullableDereferenced] &&
TrackedNullability->getValue() == Nullability::Nullable) {
BugReporter &BR = *Event.BR;
// Do not suppress errors on defensive code paths, because dereferencing
// a nullable pointer is always an error.
if (Event.IsDirectDereference)
reportBug("Nullable pointer is dereferenced",
ErrorKind::NullableDereferenced, CK_NullableDereferenced,
Event.SinkNode, Region, BR);
else {
reportBug("Nullable pointer is passed to a callee that requires a "
"non-null",
ErrorKind::NullablePassedToNonnull, CK_NullableDereferenced,
Event.SinkNode, Region, BR);
}
}
}
```
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D152269/new/
https://reviews.llvm.org/D152269
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