pub struct EverInitializedPlaces<'a, 'tcx> {
    tcx: TyCtxt<'tcx>,
    body: &'a Body<'tcx>,
    mdpe: &'a MoveDataParamEnv<'tcx>,
}
Expand description

EverInitializedPlaces tracks all places that might have ever been initialized upon reaching a particular point in the control flow for a function, without an intervening StorageDead.

This dataflow is used to determine if an immutable local variable may be assigned to.

For example, in code like the following, we have corresponding dataflow information shown in the right-hand comments.

struct S;
fn foo(pred: bool) {                        // ever-init:
                                            // {          }
    let a = S; let mut b = S; let c; let d; // {a, b      }

    if pred {
        drop(a);                            // {a, b,     }
        b = S;                              // {a, b,     }

    } else {
        drop(b);                            // {a, b,      }
        d = S;                              // {a, b,    d }

    }                                       // {a, b,    d }

    c = S;                                  // {a, b, c, d }
}

Fields§

§tcx: TyCtxt<'tcx>§body: &'a Body<'tcx>§mdpe: &'a MoveDataParamEnv<'tcx>

Implementations§

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impl<'a, 'tcx> EverInitializedPlaces<'a, 'tcx>

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pub fn new(
    tcx: TyCtxt<'tcx>,
    body: &'a Body<'tcx>,
    mdpe: &'a MoveDataParamEnv<'tcx>
) -> Self

Trait Implementations§

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impl<'tcx> AnalysisDomain<'tcx> for EverInitializedPlaces<'_, 'tcx>

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type Domain = ChunkedBitSet<InitIndex>

The type that holds the dataflow state at any given point in the program.
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const NAME: &'static str = "ever_init"

A descriptive name for this analysis. Used only for debugging. Read more
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fn bottom_value(&self, _: &Body<'tcx>) -> Self::Domain

Returns the initial value of the dataflow state upon entry to each basic block.
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fn initialize_start_block(&self, body: &Body<'tcx>, state: &mut Self::Domain)

Mutates the initial value of the dataflow state upon entry to the START_BLOCK. Read more
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type Direction = Forward

The direction of this analysis. Either Forward or Backward.
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impl<'tcx> GenKillAnalysis<'tcx> for EverInitializedPlaces<'_, 'tcx>

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type Idx = InitIndex

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fn statement_effect(
    &self,
    trans: &mut impl GenKill<Self::Idx>,
    stmt: &Statement<'tcx>,
    location: Location
)

See Analysis::apply_statement_effect.
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fn terminator_effect(
    &self,
    trans: &mut impl GenKill<Self::Idx>,
    _terminator: &Terminator<'tcx>,
    location: Location
)

See Analysis::apply_terminator_effect.
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fn call_return_effect(
    &self,
    trans: &mut impl GenKill<Self::Idx>,
    block: BasicBlock,
    _return_places: CallReturnPlaces<'_, 'tcx>
)

See Analysis::apply_call_return_effect.
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fn before_statement_effect(
    &self,
    _trans: &mut impl GenKill<Self::Idx>,
    _statement: &Statement<'tcx>,
    _location: Location
)

See Analysis::apply_before_statement_effect.
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fn before_terminator_effect(
    &self,
    _trans: &mut impl GenKill<Self::Idx>,
    _terminator: &Terminator<'tcx>,
    _location: Location
)

See Analysis::apply_before_terminator_effect.
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fn yield_resume_effect(
    &self,
    _trans: &mut impl GenKill<Self::Idx>,
    _resume_block: BasicBlock,
    _resume_place: Place<'tcx>
)

See Analysis::apply_yield_resume_effect.
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fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
    &self,
    _block: BasicBlock,
    _discr: &Operand<'tcx>,
    _edge_effects: &mut impl SwitchIntEdgeEffects<G>
)

See Analysis::apply_switch_int_edge_effects.
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impl<'a, 'tcx> HasMoveData<'tcx> for EverInitializedPlaces<'a, 'tcx>

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fn move_data(&self) -> &MoveData<'tcx>

Auto Trait Implementations§

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impl<'a, 'tcx> !RefUnwindSafe for EverInitializedPlaces<'a, 'tcx>

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impl<'a, 'tcx> !Send for EverInitializedPlaces<'a, 'tcx>

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impl<'a, 'tcx> !Sync for EverInitializedPlaces<'a, 'tcx>

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impl<'a, 'tcx> Unpin for EverInitializedPlaces<'a, 'tcx>where
    'tcx: 'a,

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impl<'a, 'tcx> !UnwindSafe for EverInitializedPlaces<'a, 'tcx>

Blanket Implementations§

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impl<T> Any for Twhere
    T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere
    T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere
    T: ?Sized,

const: unstable · source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere
    U: From<T>,

const: unstable · source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere
    U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

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: 24 bytes