pub struct MaybeUninitializedPlaces<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
body: &'a Body<'tcx>,
mdpe: &'a MoveDataParamEnv<'tcx>,
mark_inactive_variants_as_uninit: bool,
skip_unreachable_unwind: BitSet<BasicBlock>,
}
Expand description
MaybeUninitializedPlaces
tracks all places that might be
uninitialized upon reaching a particular point in the control flow
for a function.
For example, in code like the following, we have corresponding dataflow information shown in the right-hand comments.
struct S;
fn foo(pred: bool) { // maybe-uninit:
// {a, b, c, d}
let a = S; let mut b = S; let c; let d; // { c, d}
if pred {
drop(a); // {a, c, d}
b = S; // {a, c, d}
} else {
drop(b); // { b, c, d}
d = S; // { b, c }
} // {a, b, c, d}
c = S; // {a, b, d}
}
To determine whether a place must be uninitialized at a
particular control-flow point, one can take the set-difference
between this data and the data from MaybeInitializedPlaces
at the
corresponding control-flow point.
Similarly, at a given drop
statement, the set-intersection
between this data and MaybeInitializedPlaces
yields the set of
places that would require a dynamic drop-flag at that statement.
Fields§
§tcx: TyCtxt<'tcx>
§body: &'a Body<'tcx>
§mdpe: &'a MoveDataParamEnv<'tcx>
§mark_inactive_variants_as_uninit: bool
§skip_unreachable_unwind: BitSet<BasicBlock>
Implementations§
source§impl<'a, 'tcx> MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> MaybeUninitializedPlaces<'a, 'tcx>
pub fn new( tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, mdpe: &'a MoveDataParamEnv<'tcx> ) -> Self
sourcepub fn mark_inactive_variants_as_uninit(self) -> Self
pub fn mark_inactive_variants_as_uninit(self) -> Self
Causes inactive enum variants to be marked as “maybe uninitialized” after a switch on an enum discriminant.
This is correct in a vacuum but is not the default because it causes problems in the borrow
checker, where this information gets propagated along FakeEdge
s.
pub fn skipping_unreachable_unwind( self, unreachable_unwind: BitSet<BasicBlock> ) -> Self
source§impl<'a, 'tcx> MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> MaybeUninitializedPlaces<'a, 'tcx>
fn update_bits( trans: &mut impl GenKill<MovePathIndex>, path: MovePathIndex, state: DropFlagState )
Trait Implementations§
source§impl<'tcx> AnalysisDomain<'tcx> for MaybeUninitializedPlaces<'_, 'tcx>
impl<'tcx> AnalysisDomain<'tcx> for MaybeUninitializedPlaces<'_, 'tcx>
§type Domain = ChunkedBitSet<MovePathIndex>
type Domain = ChunkedBitSet<MovePathIndex>
source§const NAME: &'static str = "maybe_uninit"
const NAME: &'static str = "maybe_uninit"
source§fn bottom_value(&self, _: &Body<'tcx>) -> Self::Domain
fn bottom_value(&self, _: &Body<'tcx>) -> Self::Domain
source§impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx>
impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx>
type Idx = MovePathIndex
fn domain_size(&self, _: &Body<'tcx>) -> usize
source§fn statement_effect(
&mut self,
trans: &mut impl GenKill<Self::Idx>,
_statement: &Statement<'tcx>,
location: Location
)
fn statement_effect( &mut self, trans: &mut impl GenKill<Self::Idx>, _statement: &Statement<'tcx>, location: Location )
Analysis::apply_statement_effect
.source§fn terminator_effect<'mir>(
&mut self,
trans: &mut Self::Domain,
terminator: &'mir Terminator<'tcx>,
location: Location
) -> TerminatorEdges<'mir, 'tcx>
fn terminator_effect<'mir>( &mut self, trans: &mut Self::Domain, terminator: &'mir Terminator<'tcx>, location: Location ) -> TerminatorEdges<'mir, 'tcx>
Analysis::apply_terminator_effect
.source§fn call_return_effect(
&mut self,
trans: &mut impl GenKill<Self::Idx>,
_block: BasicBlock,
return_places: CallReturnPlaces<'_, 'tcx>
)
fn call_return_effect( &mut self, trans: &mut impl GenKill<Self::Idx>, _block: BasicBlock, return_places: CallReturnPlaces<'_, 'tcx> )
Analysis::apply_call_return_effect
.source§fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
&mut self,
block: BasicBlock,
discr: &Operand<'tcx>,
edge_effects: &mut impl SwitchIntEdgeEffects<G>
)
fn switch_int_edge_effects<G: GenKill<Self::Idx>>( &mut self, block: BasicBlock, discr: &Operand<'tcx>, edge_effects: &mut impl SwitchIntEdgeEffects<G> )
Analysis::apply_switch_int_edge_effects
.source§fn before_statement_effect(
&mut self,
_trans: &mut impl GenKill<Self::Idx>,
_statement: &Statement<'tcx>,
_location: Location
)
fn before_statement_effect( &mut self, _trans: &mut impl GenKill<Self::Idx>, _statement: &Statement<'tcx>, _location: Location )
Analysis::apply_before_statement_effect
.source§fn before_terminator_effect(
&mut self,
_trans: &mut impl GenKill<Self::Idx>,
_terminator: &Terminator<'tcx>,
_location: Location
)
fn before_terminator_effect( &mut self, _trans: &mut impl GenKill<Self::Idx>, _terminator: &Terminator<'tcx>, _location: Location )
Analysis::apply_before_terminator_effect
.source§impl<'a, 'tcx> HasMoveData<'tcx> for MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> HasMoveData<'tcx> for MaybeUninitializedPlaces<'a, 'tcx>
Auto Trait Implementations§
impl<'a, 'tcx> !RefUnwindSafe for MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> !Send for MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> !Sync for MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> Unpin for MaybeUninitializedPlaces<'a, 'tcx>
impl<'a, 'tcx> !UnwindSafe for MaybeUninitializedPlaces<'a, 'tcx>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<'tcx, A, D> RustcPeekAt<'tcx> for Awhere
A: Analysis<'tcx, Domain = D> + HasMoveData<'tcx>,
D: JoinSemiLattice + Clone + BitSetExt<MovePathIndex>,
impl<'tcx, A, D> RustcPeekAt<'tcx> for Awhere A: Analysis<'tcx, Domain = D> + HasMoveData<'tcx>, D: JoinSemiLattice + Clone + BitSetExt<MovePathIndex>,
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: 64 bytes