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

Member predicate ConditionBlock::controls

Holds if basic block controlled is controlled by this basic block with conditional value s. That is, controlled can only be reached from the callable entry point by going via the s edge out of this basic block.

predicate controls(BasicBlock controlled, ConditionalSuccessor s)