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

Member predicate Guard::controlsNode

Holds if cfn is guarded by this expression having value v, where sub is a sub expression of this expression that is structurally equal to the expression belonging to cfn.

In case cfn or sub access an SSA variable in their left-most qualifier, then so must the other (accessing the same SSA variable).

predicate controlsNode(ElementNode cfn, AccessOrCallExpr sub, AbstractValue v)