struct LivenessContext<'a, 'typeck, 'tcx> {
typeck: &'a mut TypeChecker<'typeck, 'tcx>,
location_map: &'a DenseLocationMap,
move_data: &'a MoveData<'tcx>,
drop_data: FxIndexMap<Ty<'tcx>, DropData<'tcx>>,
flow_inits: Option<ResultsCursor<'a, 'tcx, MaybeInitializedPlaces<'a, 'tcx>>>,
local_use_map: &'a LocalUseMap,
}
Expand description
Contextual state for the type-liveness coroutine.
Fields§
§typeck: &'a mut TypeChecker<'typeck, 'tcx>
Current type-checker, giving us our inference context etc.
This also stores the body we’re currently analyzing.
location_map: &'a DenseLocationMap
Defines the PointIndex
mapping
move_data: &'a MoveData<'tcx>
Mapping to/from the various indices used for initialization tracking.
drop_data: FxIndexMap<Ty<'tcx>, DropData<'tcx>>
Cache for the results of dropck_outlives
query.
flow_inits: Option<ResultsCursor<'a, 'tcx, MaybeInitializedPlaces<'a, 'tcx>>>
Results of dataflow tracking which variables (and paths) have been initialized. Computed lazily when needed by drop-liveness.
local_use_map: &'a LocalUseMap
Index indicating where each variable is assigned, used, or dropped.
Implementations§
Source§impl<'a, 'typeck, 'tcx> LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> LivenessContext<'a, 'typeck, 'tcx>
Sourcefn flow_inits(
&mut self,
) -> &mut ResultsCursor<'a, 'tcx, MaybeInitializedPlaces<'a, 'tcx>>
fn flow_inits( &mut self, ) -> &mut ResultsCursor<'a, 'tcx, MaybeInitializedPlaces<'a, 'tcx>>
Computes the MaybeInitializedPlaces
dataflow analysis if it hasn’t been done already.
In practice, the results of this dataflow analysis are rarely needed but can be expensive to compute on big functions, so we compute them lazily as a fast path when:
- there are relevant live locals
- there are drop points for these relevant live locals.
This happens as part of the drop-liveness computation: it’s the only place checking for
maybe-initializedness of MovePathIndex
es.
Source§impl<'tcx> LivenessContext<'_, '_, 'tcx>
impl<'tcx> LivenessContext<'_, '_, 'tcx>
fn body(&self) -> &Body<'tcx>
Sourcefn initialized_at_curr_loc(&mut self, mpi: MovePathIndex) -> bool
fn initialized_at_curr_loc(&mut self, mpi: MovePathIndex) -> bool
Returns true
if the local variable (or some part of it) is initialized at the current
cursor position. Callers should call one of the seek
methods immediately before to point
the cursor to the desired location.
Sourcefn initialized_at_terminator(
&mut self,
block: BasicBlock,
mpi: MovePathIndex,
) -> bool
fn initialized_at_terminator( &mut self, block: BasicBlock, mpi: MovePathIndex, ) -> bool
Returns true
if the local variable (or some part of it) is initialized in
the terminator of block
. We need to check this to determine if a
DROP of some local variable will have an effect – note that
drops, as they may unwind, are always terminators.
Sourcefn initialized_at_exit(&mut self, block: BasicBlock, mpi: MovePathIndex) -> bool
fn initialized_at_exit(&mut self, block: BasicBlock, mpi: MovePathIndex) -> bool
Returns true
if the path mpi
(or some part of it) is initialized at
the exit of block
.
Warning: Does not account for the result of Call
instructions.
Sourcefn add_use_live_facts_for(
&mut self,
value: Ty<'tcx>,
live_at: &IntervalSet<PointIndex>,
)
fn add_use_live_facts_for( &mut self, value: Ty<'tcx>, live_at: &IntervalSet<PointIndex>, )
Stores the result that all regions in value
are live for the
points live_at
.
Sourcefn add_drop_live_facts_for(
&mut self,
dropped_local: Local,
dropped_ty: Ty<'tcx>,
drop_locations: &[Location],
live_at: &IntervalSet<PointIndex>,
)
fn add_drop_live_facts_for( &mut self, dropped_local: Local, dropped_ty: Ty<'tcx>, drop_locations: &[Location], live_at: &IntervalSet<PointIndex>, )
Some variable with type live_ty
is “drop live” at location
– i.e., it may be dropped later. This means that some of
the regions in its type must be live at location
. The
precise set will depend on the dropck constraints, and in
particular this takes #[may_dangle]
into account.
fn make_all_regions_live( location_map: &DenseLocationMap, typeck: &mut TypeChecker<'_, 'tcx>, value: impl TypeVisitable<TyCtxt<'tcx>> + Relate<TyCtxt<'tcx>>, live_at: &IntervalSet<PointIndex>, )
fn compute_drop_data( typeck: &TypeChecker<'_, 'tcx>, dropped_ty: Ty<'tcx>, span: Span, ) -> DropData<'tcx>
Auto Trait Implementations§
impl<'a, 'typeck, 'tcx> !DynSend for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> !DynSync for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> Freeze for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> !RefUnwindSafe for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> !Send for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> !Sync for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> Unpin for LivenessContext<'a, 'typeck, 'tcx>
impl<'a, 'typeck, 'tcx> !UnwindSafe for LivenessContext<'a, 'typeck, 'tcx>
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T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
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fn borrow_mut(&mut self) -> &mut T
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impl<T, R> CollectAndApply<T, R> for T
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impl<T> Filterable for T
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self,
filter_name: &'static str,
) -> RequestFilterDataProvider<T, fn(DataRequest<'_>) -> bool>
fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(DataRequest<'_>) -> bool>
Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
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impl<T> IntoEither for T
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fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
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self
into a Left
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if into_left(&self)
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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: 224 bytes