Struct rustc_resolve::late::lifetimes::LifetimeContext

pub(crate) struct LifetimeContext<'a, 'tcx> {
    pub(crate) tcx: TyCtxt<'tcx>,
    map: &'a mut NamedRegionMap,
    scope: &'a Scope<'a>,
    trait_definition_only: bool,
    xcrate_object_lifetime_defaults: DefIdMap<Vec<ObjectLifetimeDefault>>,
}

Fields

tcx: TyCtxt<'tcx>

map: &'a mut NamedRegionMap

scope: &'a Scope<'a>

trait_definition_only: bool

Indicates that we only care about the definition of a trait. This should be false if the Item we are resolving lifetimes for is not a trait or we eventually need lifetimes resolve for trait items.

xcrate_object_lifetime_defaults: DefIdMap<Vec<ObjectLifetimeDefault>>

Cache for cross-crate per-definition object lifetime defaults.

Implementations

impl<'a, 'tcx> LifetimeContext<'a, 'tcx>

fn poly_trait_ref_binder_info(
    &mut self
) -> (Vec<BoundVariableKind>, BinderScopeType)

Returns the binders in scope and the type of Binder that should be created for a poly trait ref.

impl<'a, 'tcx> LifetimeContext<'a, 'tcx>

fn with<F>(&mut self, wrap_scope: Scope<'_>, f: F) where
    F: for<'b> FnOnce(&mut LifetimeContext<'b, 'tcx>), 

fn visit_early_late<F>(
    &mut self,
    parent_id: Option<LocalDefId>,
    hir_id: HirId,
    generics: &'tcx Generics<'tcx>,
    walk: F
) where
    F: for<'b, 'c> FnOnce(&'b mut LifetimeContext<'c, 'tcx>), 

Visits self by adding a scope and handling recursive walk over the contents with walk.

Handles visiting fns and methods. These are a bit complicated because we must distinguish early- vs late-bound lifetime parameters. We do this by checking which lifetimes appear within type bounds; those are early bound lifetimes, and the rest are late bound.

For example:

fn foo<’a,’b,’c,T:Trait<’b>>(…)

Here 'a and 'c are late bound but 'b is early bound. Note that early- and late-bound lifetimes may be interspersed together.

If early bound lifetimes are present, we separate them into their own list (and likewise for late bound). They will be numbered sequentially, starting from the lowest index that is already in scope (for a fn item, that will be 0, but for a method it might not be). Late bound lifetimes are resolved by name and associated with a binder ID (binder_id), so the ordering is not important there.

fn next_early_index_helper(&self, only_opaque_type_parent: bool) -> u32

fn next_early_index(&self) -> u32

Returns the next index one would use for an early-bound-region if extending the current scope.

fn next_early_index_for_opaque_type(&self) -> u32

Returns the next index one would use for an impl Trait that is being converted into an opaque type alias impl Trait. This will be the next early index from the enclosing item, for the most part. See the opaque_type_parent field for more info.

fn resolve_lifetime_ref(
    &mut self,
    region_def_id: LocalDefId,
    lifetime_ref: &'tcx Lifetime
)

fn visit_segment_args(
    &mut self,
    res: Res,
    depth: usize,
    generic_args: &'tcx GenericArgs<'tcx>
)

fn supertrait_hrtb_lifetimes(
    tcx: TyCtxt<'tcx>,
    def_id: DefId,
    assoc_name: Ident
) -> Option<Vec<BoundVariableKind>>

Returns all the late-bound vars that come into scope from supertrait HRTBs, based on the associated type name and starting trait. For example, imagine we have

trait Foo<'a, 'b> {
  type As;
}
trait Bar<'b>: for<'a> Foo<'a, 'b> {}
trait Bar: for<'b> Bar<'b> {}

In this case, if we wanted to the supertrait HRTB lifetimes for As on the starting trait Bar, we would return Some(['b, 'a]).

fn visit_fn_like_elision(
    &mut self,
    inputs: &'tcx [Ty<'tcx>],
    output: Option<&'tcx Ty<'tcx>>,
    in_closure: bool
)

fn resolve_object_lifetime_default(&mut self, lifetime_ref: &'tcx Lifetime)

fn insert_lifetime(&mut self, lifetime_ref: &'tcx Lifetime, def: Region)

fn uninsert_lifetime_on_error(
    &mut self,
    lifetime_ref: &'tcx Lifetime,
    bad_def: Region
)

Sometimes we resolve a lifetime, but later find that it is an error (esp. around impl trait). In that case, we remove the entry into map.defs so as not to confuse later code.

Trait Implementations

impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx>

type NestedFilter = All

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.

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, _: ItemId)

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 on itemlikevisit::ItemLikeVisitor. 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_trait_item_ref(&mut self, ii: &'tcx TraitItemRef)

fn visit_nested_body(&mut self, body: BodyId)

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_expr(&mut self, e: &'tcx Expr<'tcx>)

fn visit_item(&mut self, item: &'tcx Item<'tcx>)

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

fn visit_foreign_item(&mut self, item: &'tcx ForeignItem<'tcx>)

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

fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>)

fn visit_impl_item(&mut self, impl_item: &'tcx ImplItem<'tcx>)

fn visit_lifetime(&mut self, lifetime_ref: &'tcx Lifetime)

fn visit_path(&mut self, path: &'tcx Path<'tcx>, _: HirId)

fn visit_fn(
    &mut self,
    fk: FnKind<'tcx>,
    fd: &'tcx FnDecl<'tcx>,
    body_id: BodyId,
    _: Span,
    _: HirId
)

fn visit_generics(&mut self, generics: &'tcx Generics<'tcx>)

fn visit_param_bound(&mut self, bound: &'tcx GenericBound<'tcx>)

fn visit_poly_trait_ref(
    &mut self,
    trait_ref: &'tcx PolyTraitRef<'tcx>,
    _modifier: TraitBoundModifier
)

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

fn visit_nested_trait_item(&mut self, id: TraitItemId)

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)

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)

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

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

fn visit_body(&mut self, b: &'v Body<'v>)

fn visit_id(&mut self, _hir_id: HirId)

fn visit_name(&mut self, _span: Span, _name: Symbol)

fn visit_ident(&mut self, ident: Ident)

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

fn visit_local(&mut self, l: &'v Local<'v>)

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

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

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

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

fn visit_array_length(&mut self, len: &'v ArrayLen)

fn visit_anon_const(&mut self, c: &'v AnonConst)

fn visit_let_expr(&mut self, lex: &'v Let<'v>)

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

fn visit_const_param_default(&mut self, _param: HirId, ct: &'v AnonConst)

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

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

fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId)

fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef)

fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef)

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

fn visit_variant_data(
    &mut self,
    s: &'v VariantData<'v>,
    Symbol,
    &'v Generics<'v>,
    _parent_id: HirId,
    Span
)

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

fn visit_enum_def(
    &mut self,
    enum_definition: &'v EnumDef<'v>,
    generics: &'v Generics<'v>,
    item_id: HirId,
    Span
)

fn visit_variant(
    &mut self,
    v: &'v Variant<'v>,
    g: &'v Generics<'v>,
    item_id: HirId
)

fn visit_label(&mut self, label: &'v Label)

fn visit_infer(&mut self, inf: &'v InferArg)

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

fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span)

fn visit_path_segment(
    &mut self,
    path_span: Span,
    path_segment: &'v PathSegment<'v>
)

fn visit_generic_args(
    &mut self,
    path_span: Span,
    generic_args: &'v GenericArgs<'v>
)

fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>)

fn visit_attribute(&mut self, _attr: &'v Attribute)

fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind)

fn visit_defaultness(&mut self, defaultness: &'v Defaultness)

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

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: 64 bytes