Module Nullness

Provides classes and predicates for nullness analysis.

Local variables that may be null are tracked to see if they might reach a dereference and cause a NullPointerException. Assertions are assumed to hold, so results guarded by, for example, assert x != null; or if (x == null) { assert false; } are excluded.

Import path

import semmle.code.java.dataflow.Nullness

Imports

java	Provides all default Java QL imports.

Predicates

alwaysNullDeref	A dereference of a variable that is always `null`.
dereference	An expression that is being dereferenced. These are the points where `NullPointerException`s can occur.
nullDeref	Holds if the dereference of `v` at `va` might be `null`.
nullExpr	Gets an expression that may be `null`.