Struct rustc_mir_dataflow::impls::liveness::MaybeTransitiveLiveLocals

pub struct MaybeTransitiveLiveLocals<'a> {
    always_live: &'a BitSet<Local>,
}

Like MaybeLiveLocals, but does not mark locals as live if they are used in a dead assignment.

This is basically written for dead store elimination and nothing else.

All of the caveats of MaybeLiveLocals apply.

Fields

always_live: &'a BitSet<Local>

Implementations

impl<'a> MaybeTransitiveLiveLocals<'a>

pub fn new(always_live: &'a BitSet<Local>) -> Self

The always_alive set is the set of locals to which all stores should unconditionally be considered live.

This should include at least all locals that are ever borrowed.

Trait Implementations

impl<'a, 'tcx> Analysis<'tcx> for MaybeTransitiveLiveLocals<'a>

fn apply_statement_effect(
    &self,
    trans: &mut Self::Domain,
    statement: &Statement<'tcx>,
    location: Location
)

Updates the current dataflow state with the effect of evaluating a statement.

fn apply_terminator_effect(
    &self,
    trans: &mut Self::Domain,
    terminator: &Terminator<'tcx>,
    location: Location
)

Updates the current dataflow state with the effect of evaluating a terminator.

fn apply_call_return_effect(
    &self,
    trans: &mut Self::Domain,
    _block: BasicBlock,
    return_places: CallReturnPlaces<'_, 'tcx>
)

Updates the current dataflow state with the effect of a successful return from a Call terminator.

fn apply_yield_resume_effect(
    &self,
    trans: &mut Self::Domain,
    _resume_block: BasicBlock,
    resume_place: Place<'tcx>
)

Updates the current dataflow state with the effect of resuming from a Yield terminator.

fn apply_before_statement_effect(
    &self,
    _state: &mut Self::Domain,
    _statement: &Statement<'tcx>,
    _location: Location
)

Updates the current dataflow state with an effect that occurs immediately before the given statement.

fn apply_before_terminator_effect(
    &self,
    _state: &mut Self::Domain,
    _terminator: &Terminator<'tcx>,
    _location: Location
)

Updates the current dataflow state with an effect that occurs immediately before the given terminator.

fn apply_switch_int_edge_effects(
    &self,
    _block: BasicBlock,
    _discr: &Operand<'tcx>,
    _apply_edge_effects: &mut impl SwitchIntEdgeEffects<Self::Domain>
)

Updates the current dataflow state with the effect of taking a particular branch in a SwitchInt terminator.

fn into_engine<'mir>(
    self,
    tcx: TyCtxt<'tcx>,
    body: &'mir Body<'tcx>
) -> Engine<'mir, 'tcx, Self>where
    Self: Sized,

Creates an Engine to find the fixpoint for this dataflow problem.

impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeTransitiveLiveLocals<'a>

type Domain = ChunkedBitSet<Local>

The type that holds the dataflow state at any given point in the program.

type Direction = Backward

The direction of this analysis. Either Forward or Backward.

const NAME: &'static str = "transitive liveness"

A descriptive name for this analysis. Used only for debugging.

fn bottom_value(&self, body: &Body<'tcx>) -> Self::Domain

Returns the initial value of the dataflow state upon entry to each basic block.

fn initialize_start_block(&self, _: &Body<'tcx>, _: &mut Self::Domain)

Mutates the initial value of the dataflow state upon entry to the START_BLOCK.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 8 bytes