Module rustc_mir::dataflow::framework

A framework that can express both gen-kill and generic dataflow problems.

To actually use this framework, you must implement either the Analysis or the GenKillAnalysis trait. If your transfer function can be expressed with only gen/kill operations, prefer GenKillAnalysis since it will run faster while iterating to fixpoint. The impls module contains several examples of gen/kill dataflow analyses.

Create an Engine for your analysis using the into_engine method on the Analysis trait, then call iterate_to_fixpoint. From there, you can use a ResultsCursor to inspect the fixpoint solution to your dataflow problem, or implement the ResultsVisitor interface and use visit_results. The following example uses the ResultsCursor approach.

use rustc_mir::dataflow::Analysis; // Makes `into_engine` available.

fn do_my_analysis(tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>) {
    let analysis = MyAnalysis::new()
        .into_engine(tcx, body)
        .iterate_to_fixpoint()
        .into_results_cursor(body);

    // Print the dataflow state *after* each statement in the start block.
    for (_, statement_index) in body.block_data[START_BLOCK].statements.iter_enumerated() {
        cursor.seek_after(Location { block: START_BLOCK, statement_index });
        let state = cursor.get();
        println!("{:?}", state);
    }
}

Re-exports

pub use self::cursor::ResultsCursor;

pub use self::cursor::ResultsRefCursor;

pub use self::direction::Backward;

pub use self::direction::Direction;

pub use self::direction::Forward;

pub use self::engine::Engine;

pub use self::engine::Results;

pub use self::lattice::JoinSemiLattice;

pub use self::lattice::MeetSemiLattice;

pub use self::visitor::visit_results;

pub use self::visitor::ResultsVisitor;

pub use self::visitor::BorrowckFlowState;

pub use self::visitor::BorrowckResults;

Modules

cursor	Random access inspection of the results of a dataflow analysis.
direction
engine	A solver for dataflow problems.
fmt	Custom formatting traits used when outputting Graphviz diagrams with the results of a dataflow analysis.
graphviz	A helpful diagram for debugging dataflow problems.
lattice	Traits used to represent lattices for use as the domain of a dataflow analysis.
visitor

Structs

EffectIndex
GenKillSet	Stores a transfer function for a gen/kill problem.
SwitchIntTarget

Enums

Effect

Traits

Analysis	A dataflow problem with an arbitrarily complex transfer function.
AnalysisDomain	Define the domain of a dataflow problem.
GenKill	The legal operations for a transfer function in a gen/kill problem.
GenKillAnalysis	A gen/kill dataflow problem.
SwitchIntEdgeEffects	A type that records the edge-specific effects for a SwitchInt terminator.