Parameter BackwardAnalysis.D

type t

States propagated by the dataflow analysis.

val join : t -> t -> t

Merges two states coming from different paths.

val widen : t -> t -> t option

widen v1 v2 must returns None if v2 is included in v1. Otherwise, over-approximates the join between v1 and v2 such that any sequence of successive widenings is ultimately stationary, i.e. …widen (widen (widen x0 x1) x2) x3… eventually returns None. Called on loop heads to ensure the analysis termination.

val transfer : vertex transition -> t -> t option

Transfer function for transitions: computes the state after the transition from the state before. Returns None if the end of the transition is not reachable from the given state.