Struct RegionResolutionVisitor

struct RegionResolutionVisitor<'tcx> {
    tcx: TyCtxt<'tcx>,
    expr_and_pat_count: usize,
    pessimistic_yield: bool,
    fixup_scopes: Vec<Scope>,
    scope_tree: ScopeTree,
    cx: Context,
    terminating_scopes: FxHashSet<ItemLocalId>,
}

Fields

tcx: TyCtxt<'tcx>

expr_and_pat_count: usize

pessimistic_yield: bool

fixup_scopes: Vec<Scope>

scope_tree: ScopeTree

cx: Context

terminating_scopes: FxHashSet<ItemLocalId>

terminating_scopes is a set containing the ids of each statement, or conditional/repeating expression. These scopes are calling “terminating scopes” because, when attempting to find the scope of a temporary, by default we search up the enclosing scopes until we encounter the terminating scope. A conditional/repeating expression is one which is not guaranteed to execute exactly once upon entering the parent scope. This could be because the expression only executes conditionally, such as the expression b in a && b, or because the expression may execute many times, such as a loop body. The reason that we distinguish such expressions is that, upon exiting the parent scope, we cannot statically know how many times the expression executed, and thus if the expression creates temporaries we cannot know statically how many such temporaries we would have to cleanup. Therefore, we ensure that the temporaries never outlast the conditional/repeating expression, preventing the need for dynamic checks and/or arbitrary amounts of stack space. Terminating scopes end up being contained in a DestructionScope that contains the destructor’s execution.

Implementations

impl<'tcx> RegionResolutionVisitor<'tcx>

fn record_child_scope(&mut self, child_scope: Scope) -> ScopeDepth

Records the current parent (if any) as the parent of child_scope. Returns the depth of child_scope.

fn enter_scope(&mut self, child_scope: Scope)

Records the current parent (if any) as the parent of child_scope, and sets child_scope as the new current parent.

fn enter_node_scope_with_dtor(&mut self, id: ItemLocalId)

fn enter_body(&mut self, hir_id: HirId, f: impl FnOnce(&mut Self))

Trait Implementations

impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx>

fn visit_block(&mut self, b: &'tcx Block<'tcx>)

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

fn visit_arm(&mut self, a: &'tcx Arm<'tcx>)

fn visit_pat(&mut self, p: &'tcx Pat<'tcx>)

fn visit_stmt(&mut self, s: &'tcx Stmt<'tcx>)

fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>)

fn visit_local(&mut self, l: &'tcx LetStmt<'tcx>)

type Map = <Self::NestedFilter as NestedFilter<'v>>::Map

type NestedFilter = None

Override this type to control which nested HIR are visited; see [NestedFilter] for details. If you override this type, you must also override nested_visit_map.

type Result = ()

The result type of the visit_* methods. Can be either (), or ControlFlow<T>.

fn nested_visit_map(&mut self) -> Self::Map

If type NestedFilter is set to visit nested items, this method must also be overridden to provide a map to retrieve nested items.

fn visit_nested_item(&mut self, id: ItemId) -> Self::Result

Invoked when a nested item is encountered. By default, when Self::NestedFilter is nested_filter::None, this method does nothing. You probably don’t want to override this method – instead, override [Self::NestedFilter] or use the “shallow” or “deep” visit patterns described at [rustc_hir::intravisit]. The only reason to override this method is if you want a nested pattern but cannot supply a [Map]; see nested_visit_map for advice.

fn visit_nested_trait_item(&mut self, id: TraitItemId) -> Self::Result

Like visit_nested_item(), but for trait items. See visit_nested_item() for advice on when to override this method.

fn visit_nested_impl_item(&mut self, id: ImplItemId) -> Self::Result

Like visit_nested_item(), but for impl items. See visit_nested_item() for advice on when to override this method.

fn visit_nested_foreign_item(&mut self, id: ForeignItemId) -> Self::Result

Like visit_nested_item(), but for foreign items. See visit_nested_item() for advice on when to override this method.

fn visit_nested_body(&mut self, id: BodyId) -> Self::Result

Invoked to visit the body of a function, method or closure. Like visit_nested_item, does nothing by default unless you override Self::NestedFilter.

fn visit_param(&mut self, param: &'v Param<'v>) -> Self::Result

fn visit_item(&mut self, i: &'v Item<'v>) -> Self::Result

Visits the top-level item and (optionally) nested items / impl items. See visit_nested_item for details.

fn visit_id(&mut self, _hir_id: HirId) -> Self::Result

fn visit_name(&mut self, _name: Symbol) -> Self::Result

fn visit_ident(&mut self, ident: Ident) -> Self::Result

fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) -> Self::Result

fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) -> Self::Result

fn visit_pat_field(&mut self, f: &'v PatField<'v>) -> Self::Result

fn visit_array_length(&mut self, len: &'v ArrayLen<'v>) -> Self::Result

fn visit_anon_const(&mut self, c: &'v AnonConst) -> Self::Result

fn visit_inline_const(&mut self, c: &'v ConstBlock) -> Self::Result

fn visit_const_arg(&mut self, c: &'v ConstArg<'v>) -> Self::Result

fn visit_expr_field(&mut self, field: &'v ExprField<'v>) -> Self::Result

fn visit_ty(&mut self, t: &'v Ty<'v>) -> Self::Result

fn visit_pattern_type_pattern(&mut self, _p: &'v Pat<'v>)

fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) -> Self::Result

fn visit_const_param_default( &mut self, _param: HirId, ct: &'v ConstArg<'v>, ) -> Self::Result

fn visit_generics(&mut self, g: &'v Generics<'v>) -> Self::Result

fn visit_where_predicate( &mut self, predicate: &'v WherePredicate<'v>, ) -> Self::Result

fn visit_fn_ret_ty(&mut self, ret_ty: &'v FnRetTy<'v>) -> Self::Result

fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) -> Self::Result

fn visit_fn( &mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, _: Span, id: LocalDefId, ) -> Self::Result

fn visit_use( &mut self, path: &'v Path<'v, SmallVec<[Res; 3]>>, hir_id: HirId, ) -> Self::Result

fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) -> Self::Result

fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) -> Self::Result

fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) -> Self::Result

fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef) -> Self::Result

fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) -> Self::Result

fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) -> Self::Result

fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) -> Self::Result

fn visit_precise_capturing_arg( &mut self, arg: &'v PreciseCapturingArg<'v>, ) -> Self::Result

fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>) -> Self::Result

fn visit_opaque_ty(&mut self, opaque: &'v OpaqueTy<'v>) -> Self::Result

fn visit_variant_data(&mut self, s: &'v VariantData<'v>) -> Self::Result

fn visit_field_def(&mut self, s: &'v FieldDef<'v>) -> Self::Result

fn visit_enum_def( &mut self, enum_definition: &'v EnumDef<'v>, item_id: HirId, ) -> Self::Result

fn visit_variant(&mut self, v: &'v Variant<'v>) -> Self::Result

fn visit_label(&mut self, label: &'v Label) -> Self::Result

fn visit_infer(&mut self, inf: &'v InferArg) -> Self::Result

fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) -> Self::Result

fn visit_lifetime(&mut self, lifetime: &'v Lifetime) -> Self::Result

fn visit_qpath( &mut self, qpath: &'v QPath<'v>, id: HirId, _span: Span, ) -> Self::Result

fn visit_path(&mut self, path: &Path<'v>, _id: HirId) -> Self::Result

fn visit_path_segment( &mut self, path_segment: &'v PathSegment<'v>, ) -> Self::Result

fn visit_generic_args( &mut self, generic_args: &'v GenericArgs<'v>, ) -> Self::Result

fn visit_assoc_item_constraint( &mut self, constraint: &'v AssocItemConstraint<'v>, ) -> Self::Result

fn visit_attribute(&mut self, _attr: &'v Attribute) -> Self::Result

fn visit_associated_item_kind( &mut self, kind: &'v AssocItemKind, ) -> Self::Result

fn visit_defaultness(&mut self, defaultness: &'v Defaultness) -> Self::Result

fn visit_inline_asm( &mut self, asm: &'v InlineAsm<'v>, id: HirId, ) -> Self::Result

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: 312 bytes