CodeQL library for C#
codeql/csharp-all 1.0.3-dev (changelog, source)

Member predicate DereferenceableExpr::getANullCheck

Gets an expression that tests whether this expression is null.

If the returned expression has abstract value v, then this expression is guaranteed to be null if isNull is true, and non-null if isNull is false.

For example, if the expression x != null evaluates to true then the expression x is guaranteed to be non-null.

Expr getANullCheck(AbstractValue v, boolean isNull)