struct TransferFunction<'a, 'mir, 'tcx, Q> {
    ccx: &'a ConstCx<'mir, 'tcx>,
    state: &'a mut State,
    _qualif: PhantomData<Q>,
}
Expand description

A Visitor that propagates qualifs between locals. This defines the transfer function of FlowSensitiveAnalysis.

To account for indirect assignments, data flow conservatively assumes that local becomes qualified immediately after it is borrowed or its address escapes. The borrow must allow for mutation, which includes shared borrows of places with interior mutability. The type of borrowed place must contain the qualif.

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§ccx: &'a ConstCx<'mir, 'tcx>§state: &'a mut State§_qualif: PhantomData<Q>

Implementations§

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impl<'a, 'mir, 'tcx, Q> TransferFunction<'a, 'mir, 'tcx, Q>where Q: Qualif,

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fn new(ccx: &'a ConstCx<'mir, 'tcx>, state: &'a mut State) -> Self

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fn initialize_state(&mut self)

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fn assign_qualif_direct(&mut self, place: &Place<'tcx>, value: bool)

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fn apply_call_return_effect( &mut self, _block: BasicBlock, return_places: CallReturnPlaces<'_, 'tcx> )

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fn address_of_allows_mutation( &self, _mt: Mutability, _place: Place<'tcx> ) -> bool

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fn ref_allows_mutation(&self, kind: BorrowKind, place: Place<'tcx>) -> bool

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fn shared_borrow_allows_mutation(&self, place: Place<'tcx>) -> bool

& only allow mutation if the borrowed place is !Freeze.

This assumes that it is UB to take the address of a struct field whose type is Freeze, then use pointer arithmetic to derive a pointer to a different field of that same struct whose type is !Freeze. If we decide that this is not UB, we will have to check the type of the borrowed local instead of the borrowed place below. See rust-lang/unsafe-code-guidelines#134.

Trait Implementations§

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impl<'tcx, Q> Visitor<'tcx> for TransferFunction<'_, '_, 'tcx, Q>where Q: Qualif,

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fn visit_operand(&mut self, operand: &Operand<'tcx>, location: Location)

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fn visit_assign( &mut self, place: &Place<'tcx>, rvalue: &Rvalue<'tcx>, location: Location )

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fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location)

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fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location)

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fn visit_terminator( &mut self, terminator: &Terminator<'tcx>, location: Location )

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fn visit_body(&mut self, body: &Body<'tcx>)

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fn visit_basic_block_data( &mut self, block: BasicBlock, data: &BasicBlockData<'tcx> )

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fn visit_source_scope_data(&mut self, scope_data: &SourceScopeData<'tcx>)

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fn visit_assert_message( &mut self, msg: &AssertKind<Operand<'tcx>>, location: Location )

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fn visit_ascribe_user_ty( &mut self, place: &Place<'tcx>, variance: Variance, user_ty: &UserTypeProjection, location: Location )

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fn visit_coverage(&mut self, coverage: &Coverage, location: Location)

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fn visit_retag( &mut self, kind: RetagKind, place: &Place<'tcx>, location: Location )

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fn visit_place( &mut self, place: &Place<'tcx>, context: PlaceContext, location: Location )

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fn visit_projection( &mut self, place_ref: PlaceRef<'tcx>, context: PlaceContext, location: Location )

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fn visit_projection_elem( &mut self, place_ref: PlaceRef<'tcx>, elem: ProjectionElem<Local, Ty<'tcx>>, context: PlaceContext, location: Location )

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fn super_place( &mut self, place: &Place<'tcx>, context: PlaceContext, location: Location )

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fn super_projection( &mut self, place_ref: PlaceRef<'tcx>, context: PlaceContext, location: Location )

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fn super_projection_elem( &mut self, _place_ref: PlaceRef<'tcx>, elem: ProjectionElem<Local, Ty<'tcx>>, _context: PlaceContext, location: Location )

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fn visit_constant(&mut self, constant: &ConstOperand<'tcx>, location: Location)

This is called for every constant in the MIR body and every required_consts (i.e., including consts that have been dead-code-eliminated).
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fn visit_ty_const(&mut self, ct: Const<'tcx>, location: Location)

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fn visit_span(&mut self, span: Span)

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fn visit_source_info(&mut self, source_info: &SourceInfo)

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fn visit_ty(&mut self, ty: Ty<'tcx>, _: TyContext)

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fn visit_user_type_projection(&mut self, ty: &UserTypeProjection)

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fn visit_user_type_annotation( &mut self, index: UserTypeAnnotationIndex, ty: &CanonicalUserTypeAnnotation<'tcx> )

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fn visit_region(&mut self, region: Region<'tcx>, _: Location)

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fn visit_args(&mut self, args: &&'tcx List<GenericArg<'tcx>>, _: Location)

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fn visit_local_decl(&mut self, local: Local, local_decl: &LocalDecl<'tcx>)

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fn visit_var_debug_info(&mut self, var_debug_info: &VarDebugInfo<'tcx>)

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fn visit_local( &mut self, _local: Local, _context: PlaceContext, _location: Location )

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fn visit_source_scope(&mut self, scope: SourceScope)

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fn super_body(&mut self, body: &Body<'tcx>)

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fn super_basic_block_data( &mut self, block: BasicBlock, data: &BasicBlockData<'tcx> )

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fn super_source_scope_data(&mut self, scope_data: &SourceScopeData<'tcx>)

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fn super_statement(&mut self, statement: &Statement<'tcx>, location: Location)

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fn super_assign( &mut self, place: &Place<'tcx>, rvalue: &Rvalue<'tcx>, location: Location )

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fn super_terminator( &mut self, terminator: &Terminator<'tcx>, location: Location )

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fn super_assert_message( &mut self, msg: &AssertKind<Operand<'tcx>>, location: Location )

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fn super_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location)

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fn super_operand(&mut self, operand: &Operand<'tcx>, location: Location)

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fn super_ascribe_user_ty( &mut self, place: &Place<'tcx>, variance: Variance, user_ty: &UserTypeProjection, location: Location )

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fn super_coverage(&mut self, _coverage: &Coverage, _location: Location)

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fn super_retag( &mut self, _kind: RetagKind, place: &Place<'tcx>, location: Location )

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fn super_local_decl(&mut self, local: Local, local_decl: &LocalDecl<'tcx>)

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fn super_var_debug_info(&mut self, var_debug_info: &VarDebugInfo<'tcx>)

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fn super_source_scope(&mut self, _scope: SourceScope)

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fn super_constant(&mut self, constant: &ConstOperand<'tcx>, location: Location)

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fn super_ty_const(&mut self, _ct: Const<'tcx>, _location: Location)

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fn super_span(&mut self, _span: Span)

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fn super_source_info(&mut self, source_info: &SourceInfo)

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fn super_user_type_projection(&mut self, _ty: &UserTypeProjection)

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fn super_user_type_annotation( &mut self, _index: UserTypeAnnotationIndex, ty: &CanonicalUserTypeAnnotation<'tcx> )

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fn super_ty(&mut self, _ty: Ty<'tcx>)

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fn super_region(&mut self, _region: Region<'tcx>)

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fn super_args(&mut self, _args: &&'tcx List<GenericArg<'tcx>>)

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fn visit_location(&mut self, body: &Body<'tcx>, location: Location)

Auto Trait Implementations§

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impl<'a, 'mir, 'tcx, Q> !RefUnwindSafe for TransferFunction<'a, 'mir, 'tcx, Q>

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impl<'a, 'mir, 'tcx, Q> !Send for TransferFunction<'a, 'mir, 'tcx, Q>

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impl<'a, 'mir, 'tcx, Q> !Sync for TransferFunction<'a, 'mir, 'tcx, Q>

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impl<'a, 'mir, 'tcx, Q> Unpin for TransferFunction<'a, 'mir, 'tcx, Q>where Q: Unpin,

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impl<'a, 'mir, 'tcx, Q> !UnwindSafe for TransferFunction<'a, 'mir, 'tcx, Q>

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,

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fn borrow(&self) -> &T

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

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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

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fn from(t: T) -> T

Returns the argument unchanged.

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

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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.
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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.
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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: 16 bytes