Module wfcheck

Structs

CollectUsageSpans 🔒

Collect usages of the param_def_id and Res::SelfTyAlias in the HIR.

GATArgsCollector 🔒

TypeVisitor that looks for uses of GATs like <P0 as Trait<P1..Pn>>::GAT<Pn..Pm> and adds the arguments P0..Pm into the two vectors, regions and types (depending on their kind). For each parameter Pi also track the index i.

HasErrorDeep 🔒

Look for ErrorGuaranteed deeply within structs’ (unsubstituted) fields.

IsProbablyCyclical 🔒

Detects cases where an ADT/LTA is trivially cyclical – we want to detect this so we only mention that its parameters are used cyclically if the ADT/LTA is truly cyclical.

RedundantLifetimeArgsLint 🔒

WfCheckingCtxt 🔒

Enums

ArbitrarySelfTypesLevel 🔒

The arbitrary_self_types_pointers feature implies arbitrary_self_types.

ReceiverValidityError 🔒

Error cases which may be returned from receiver_is_valid. These error cases are generated in this function as they may be unearthed as we explore the autoderef chain, but they’re converted to diagnostics in the caller.

UnsizedHandling 🔒

Functions

augment_param_env 🔒

Add a new set of predicates to the caller_bounds of an existing param_env.

check_associated_item 🔒

check_associated_type_bounds 🔒

Checks all associated type defaults of trait trait_def_id.

check_dyn_incompatible_self_trait_by_name 🔒

Detect when a dyn-incompatible trait is referring to itself in one of its associated items.

check_fn_or_method 🔒

check_foreign_item 🔒

check_gat_where_clauses 🔒

Require that the user writes where clauses on GATs for the implicit outlives bounds involving trait parameters in trait functions and lifetimes passed as GAT args. See self-outlives-lint test.

check_impl 🔒

check_impl_item 🔒

check_item 🔒

Checks that the field types (in a struct def’n) or argument types (in an enum def’n) are well-formed, meaning that they do not require any constraints not declared in the struct definition itself. For example, this definition would be illegal:

check_item_fn 🔒

check_item_type 🔒

check_method_receiver 🔒

check_mod_type_wf 🔒

check_param_wf 🔒

check_trait 🔒

check_trait_item 🔒

check_type_defn 🔒

In a type definition, we check that to ensure that the types of the fields are well-formed.

check_variances_for_type_defn 🔒

check_well_formed 🔒

check_where_clauses 🔒

Checks where-clauses and inline bounds that are declared on def_id.

confirm_type_is_not_a_method_generic_param 🔒

Confirms that a type is not a type parameter referring to one of the method’s type params.

could_be_self 🔒

enter_wf_checking_ctxt 🔒

gather_gat_bounds 🔒

We use the following trait as an example throughout this function. Specifically, let’s assume that to_check here is the return type of into_iter, and the GAT we are checking this for is Iter.

legacy_receiver_is_implemented 🔒

lint_item_shadowing_supertrait_item 🔒

lint_redundant_lifetimes 🔒

provide

receiver_is_valid 🔒

Returns whether receiver_ty would be considered a valid receiver type for self_ty. If arbitrary_self_types is enabled, receiver_ty must transitively deref to self_ty, possibly through a *const/mut T raw pointer if arbitrary_self_types_pointers is also enabled. If neither feature is enabled, the requirements are more strict: receiver_ty must implement Receiver and directly implement Deref<Target = self_ty>.

region_known_to_outlive 🔒

Given a known param_env and a set of well formed types, can we prove that region_a outlives region_b

report_bivariance 🔒

test_region_obligations 🔒

Given a known param_env and a set of well formed types, set up an InferCtxt, call the passed function (to e.g. set up region constraints to be tested), then resolve region and return errors

ty_known_to_outlive 🔒

Given a known param_env and a set of well formed types, can we prove that ty outlives region.