Struct Borrows

pub struct Borrows<'a, 'tcx> {
    tcx: TyCtxt<'tcx>,
    body: &'a Body<'tcx>,
    borrow_set: &'a BorrowSet<'tcx>,
    borrows_out_of_scope_at_location: FxIndexMap<Location, Vec<BorrowIndex>>,
}

Borrows stores the data used in the analyses that track the flow of borrows.

It uniquely identifies every borrow (Rvalue::Ref) by a BorrowIndex, and maps each such index to a BorrowData describing the borrow. These indexes are used for representing the borrows in compact bitvectors.

Fields

tcx: TyCtxt<'tcx>

body: &'a Body<'tcx>

borrow_set: &'a BorrowSet<'tcx>

borrows_out_of_scope_at_location: FxIndexMap<Location, Vec<BorrowIndex>>

Implementations

impl<'a, 'tcx> Borrows<'a, 'tcx>

pub fn new( tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, regioncx: &RegionInferenceContext<'tcx>, borrow_set: &'a BorrowSet<'tcx>, ) -> Self

fn kill_loans_out_of_scope_at_location( &self, state: &mut BitSet<BorrowIndex>, location: Location, )

Add all borrows to the kill set, if those borrows are out of scope at location. That means they went out of a nonlexical scope

fn kill_borrows_on_place( &self, state: &mut BitSet<BorrowIndex>, place: Place<'tcx>, )

Kill any borrows that conflict with place.

Trait Implementations

impl<'tcx> Analysis<'tcx> for Borrows<'_, 'tcx>

Forward dataflow computation of the set of borrows that are in scope at a particular location.

• we gen the introduced loans
• we kill loans on locals going out of (regular) scope
• we kill the loans going out of their region’s NLL scope: in NLL terms, the frontier where a region stops containing the CFG points reachable from the issuing location.
• we also kill loans of conflicting places when overwriting a shared path: e.g. borrows of a.b.c when a is overwritten.

const NAME: &'static str = "borrows"

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

type Domain = BitSet<BorrowIndex>

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

fn bottom_value(&self, _: &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.

fn apply_early_statement_effect( &mut self, state: &mut Self::Domain, _statement: &Statement<'tcx>, location: Location, )

Updates the current dataflow state with an “early” effect, i.e. one that occurs immediately before the given statement.

fn apply_primary_statement_effect( &mut self, state: &mut Self::Domain, stmt: &Statement<'tcx>, location: Location, )

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

fn apply_early_terminator_effect( &mut 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_primary_terminator_effect<'mir>( &mut self, state: &mut Self::Domain, terminator: &'mir Terminator<'tcx>, _location: Location, ) -> TerminatorEdges<'mir, 'tcx>

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

type Direction = Forward

The direction of this analysis. Either Forward or Backward.

type SwitchIntData = !

Auxiliary data used for analyzing SwitchInt terminators, if necessary.

fn apply_call_return_effect( &mut self, _state: &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 get_switch_int_data( &mut self, _block: BasicBlock, _discr: &Operand<'tcx>, ) -> Option<Self::SwitchIntData>

Used to update the current dataflow state with the effect of taking a particular branch in a SwitchInt terminator.

fn apply_switch_int_edge_effect( &mut self, _data: &mut Self::SwitchIntData, _state: &mut Self::Domain, _edge: SwitchIntTarget, )

See comments on get_switch_int_data.

fn iterate_to_fixpoint<'mir>( self, tcx: TyCtxt<'tcx>, body: &'mir Body<'tcx>, pass_name: Option<&'static str>, ) -> Results<'tcx, Self>

where Self: Sized, Self::Domain: DebugWithContext<Self>,

Finds the fixpoint for this dataflow problem.

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: 80 bytes