Struct rustc_mir_transform::coroutine::EnsureCoroutineFieldAssignmentsNeverAlias

struct EnsureCoroutineFieldAssignmentsNeverAlias<'a> {
    saved_locals: &'a CoroutineSavedLocals,
    storage_conflicts: &'a BitMatrix<CoroutineSavedLocal, CoroutineSavedLocal>,
    assigned_local: Option<CoroutineSavedLocal>,
}

Looks for any assignments between locals (e.g., _4 = _5) that will both be converted to fields in the coroutine state machine but whose storage is not marked as conflicting

Validation needs to happen immediately before TransformVisitor is invoked, not after.

This condition would arise when the assignment is the last use of _5 but the initial definition of _4 if we weren’t extra careful to mark all locals used inside a statement as conflicting. Non-conflicting coroutine saved locals may be stored at the same location within the coroutine state machine, which would result in ill-formed MIR: the left-hand and right-hand sides of an assignment may not alias. This caused a miscompilation in #73137.

Fields

saved_locals: &'a CoroutineSavedLocals

storage_conflicts: &'a BitMatrix<CoroutineSavedLocal, CoroutineSavedLocal>

assigned_local: Option<CoroutineSavedLocal>

Implementations

impl EnsureCoroutineFieldAssignmentsNeverAlias<'_>

fn saved_local_for_direct_place( &self, place: Place<'_>, ) -> Option<CoroutineSavedLocal>

fn check_assigned_place(&mut self, place: Place<'_>, f: impl FnOnce(&mut Self))

Trait Implementations

impl<'tcx> Visitor<'tcx> for EnsureCoroutineFieldAssignmentsNeverAlias<'_>

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

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

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

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

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

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

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

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

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

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

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

fn visit_coverage(&mut self, kind: &CoverageKind, location: Location)

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

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

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

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

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

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

fn visit_const_operand( &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).

fn visit_ty_const(&mut self, ct: Const<'tcx>, location: Location)

fn visit_span(&mut self, span: Span)

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

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

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

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

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

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

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

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

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

fn visit_source_scope(&mut self, scope: SourceScope)

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

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

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

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

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

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

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

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

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

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

fn super_coverage(&mut self, _kind: &CoverageKind, _location: Location)

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

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

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

fn super_source_scope(&mut self, _scope: SourceScope)

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

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

fn super_span(&mut self, _span: Span)

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

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

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

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

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

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

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

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