Struct rustc_mir_dataflow::impls::liveness::MaybeLiveLocals
source · [−]pub struct MaybeLiveLocals;
Expand description
A live-variable dataflow analysis.
This analysis considers references as being used only at the point of the
borrow. In other words, this analysis does not track uses because of references that already
exist. See this mir-dataflow
test for an example. You almost never want to use
this analysis without also looking at the results of MaybeBorrowedLocals
.
Field-(in)sensitivity
As the name suggests, this analysis is field insensitive. If a projection of a variable x
is
assigned to (e.g. x.0 = 42
), it does not “define” x
as far as liveness is concerned. In fact,
such an assignment is currently marked as a “use” of x
in an attempt to be maximally
conservative.
Implementations
sourceimpl MaybeLiveLocals
impl MaybeLiveLocals
fn transfer_function<'a, T>(&self, trans: &'a mut T) -> TransferFunction<'a, T>
Trait Implementations
sourceimpl<'tcx> AnalysisDomain<'tcx> for MaybeLiveLocals
impl<'tcx> AnalysisDomain<'tcx> for MaybeLiveLocals
type Domain = ChunkedBitSet<Local>
type Domain = ChunkedBitSet<Local>
The type that holds the dataflow state at any given point in the program.
sourceconst NAME: &'static str = "liveness"
const NAME: &'static str = "liveness"
A descriptive name for this analysis. Used only for debugging. Read more
sourcefn bottom_value(&self, body: &Body<'tcx>) -> Self::Domain
fn bottom_value(&self, body: &Body<'tcx>) -> Self::Domain
The initial value of the dataflow state upon entry to each basic block.
sourcefn initialize_start_block(&self, _: &Body<'tcx>, _: &mut Self::Domain)
fn initialize_start_block(&self, _: &Body<'tcx>, _: &mut Self::Domain)
Mutates the initial value of the dataflow state upon entry to the START_BLOCK
. Read more
sourceimpl<'tcx> GenKillAnalysis<'tcx> for MaybeLiveLocals
impl<'tcx> GenKillAnalysis<'tcx> for MaybeLiveLocals
type Idx = Local
sourcefn statement_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
statement: &Statement<'tcx>,
location: Location
)
fn statement_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
statement: &Statement<'tcx>,
location: Location
)
See Analysis::apply_statement_effect
.
sourcefn terminator_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
terminator: &Terminator<'tcx>,
location: Location
)
fn terminator_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
terminator: &Terminator<'tcx>,
location: Location
)
See Analysis::apply_terminator_effect
.
sourcefn call_return_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
_block: BasicBlock,
return_places: CallReturnPlaces<'_, 'tcx>
)
fn call_return_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
_block: BasicBlock,
return_places: CallReturnPlaces<'_, 'tcx>
)
See Analysis::apply_call_return_effect
.
sourcefn yield_resume_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
_resume_block: BasicBlock,
resume_place: Place<'tcx>
)
fn yield_resume_effect(
&self,
trans: &mut impl GenKill<Self::Idx>,
_resume_block: BasicBlock,
resume_place: Place<'tcx>
)
See Analysis::apply_yield_resume_effect
.
sourcefn before_statement_effect(
&self,
_trans: &mut impl GenKill<Self::Idx>,
_statement: &Statement<'tcx>,
_location: Location
)
fn before_statement_effect(
&self,
_trans: &mut impl GenKill<Self::Idx>,
_statement: &Statement<'tcx>,
_location: Location
)
See Analysis::apply_before_statement_effect
.
sourcefn before_terminator_effect(
&self,
_trans: &mut impl GenKill<Self::Idx>,
_terminator: &Terminator<'tcx>,
_location: Location
)
fn before_terminator_effect(
&self,
_trans: &mut impl GenKill<Self::Idx>,
_terminator: &Terminator<'tcx>,
_location: Location
)
See Analysis::apply_before_terminator_effect
.
sourcefn switch_int_edge_effects<G: GenKill<Self::Idx>>(
&self,
_block: BasicBlock,
_discr: &Operand<'tcx>,
_edge_effects: &mut impl SwitchIntEdgeEffects<G>
)
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
.
sourceimpl<'tcx> RustcPeekAt<'tcx> for MaybeLiveLocals
impl<'tcx> RustcPeekAt<'tcx> for MaybeLiveLocals
Auto Trait Implementations
impl RefUnwindSafe for MaybeLiveLocals
impl Send for MaybeLiveLocals
impl Sync for MaybeLiveLocals
impl Unpin for MaybeLiveLocals
impl UnwindSafe for MaybeLiveLocals
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
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: 0 bytes