168 lines
6.0 KiB
Rust
168 lines
6.0 KiB
Rust
use super::callee::DeferredCallResolution;
|
|
use super::MaybeInProgressTables;
|
|
|
|
use rustc_data_structures::fx::FxHashMap;
|
|
use rustc_hir as hir;
|
|
use rustc_hir::def_id::{DefIdMap, LocalDefId};
|
|
use rustc_hir::HirIdMap;
|
|
use rustc_infer::infer;
|
|
use rustc_infer::infer::{InferCtxt, InferOk, TyCtxtInferExt};
|
|
use rustc_middle::ty::fold::TypeFoldable;
|
|
use rustc_middle::ty::{self, Ty, TyCtxt};
|
|
use rustc_span::{self, Span};
|
|
use rustc_trait_selection::infer::InferCtxtExt as _;
|
|
use rustc_trait_selection::opaque_types::OpaqueTypeDecl;
|
|
use rustc_trait_selection::traits::{self, TraitEngine, TraitEngineExt};
|
|
|
|
use std::cell::RefCell;
|
|
use std::ops::Deref;
|
|
|
|
/// Closures defined within the function. For example:
|
|
///
|
|
/// fn foo() {
|
|
/// bar(move|| { ... })
|
|
/// }
|
|
///
|
|
/// Here, the function `foo()` and the closure passed to
|
|
/// `bar()` will each have their own `FnCtxt`, but they will
|
|
/// share the inherited fields.
|
|
pub struct Inherited<'a, 'tcx> {
|
|
pub(super) infcx: InferCtxt<'a, 'tcx>,
|
|
|
|
pub(super) typeck_results: super::MaybeInProgressTables<'a, 'tcx>,
|
|
|
|
pub(super) locals: RefCell<HirIdMap<super::LocalTy<'tcx>>>,
|
|
|
|
pub(super) fulfillment_cx: RefCell<Box<dyn TraitEngine<'tcx>>>,
|
|
|
|
// Some additional `Sized` obligations badly affect type inference.
|
|
// These obligations are added in a later stage of typeck.
|
|
pub(super) deferred_sized_obligations:
|
|
RefCell<Vec<(Ty<'tcx>, Span, traits::ObligationCauseCode<'tcx>)>>,
|
|
|
|
// When we process a call like `c()` where `c` is a closure type,
|
|
// we may not have decided yet whether `c` is a `Fn`, `FnMut`, or
|
|
// `FnOnce` closure. In that case, we defer full resolution of the
|
|
// call until upvar inference can kick in and make the
|
|
// decision. We keep these deferred resolutions grouped by the
|
|
// def-id of the closure, so that once we decide, we can easily go
|
|
// back and process them.
|
|
pub(super) deferred_call_resolutions: RefCell<DefIdMap<Vec<DeferredCallResolution<'tcx>>>>,
|
|
|
|
pub(super) deferred_cast_checks: RefCell<Vec<super::cast::CastCheck<'tcx>>>,
|
|
|
|
pub(super) deferred_generator_interiors:
|
|
RefCell<Vec<(hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>,
|
|
|
|
// Opaque types found in explicit return types and their
|
|
// associated fresh inference variable. Writeback resolves these
|
|
// variables to get the concrete type, which can be used to
|
|
// 'de-opaque' OpaqueTypeDecl, after typeck is done with all functions.
|
|
pub(super) opaque_types: RefCell<DefIdMap<OpaqueTypeDecl<'tcx>>>,
|
|
|
|
/// A map from inference variables created from opaque
|
|
/// type instantiations (`ty::Infer`) to the actual opaque
|
|
/// type (`ty::Opaque`). Used during fallback to map unconstrained
|
|
/// opaque type inference variables to their corresponding
|
|
/// opaque type.
|
|
pub(super) opaque_types_vars: RefCell<FxHashMap<Ty<'tcx>, Ty<'tcx>>>,
|
|
|
|
pub(super) body_id: Option<hir::BodyId>,
|
|
}
|
|
|
|
impl<'a, 'tcx> Deref for Inherited<'a, 'tcx> {
|
|
type Target = InferCtxt<'a, 'tcx>;
|
|
fn deref(&self) -> &Self::Target {
|
|
&self.infcx
|
|
}
|
|
}
|
|
|
|
/// Helper type of a temporary returned by `Inherited::build(...)`.
|
|
/// Necessary because we can't write the following bound:
|
|
/// `F: for<'b, 'tcx> where 'tcx FnOnce(Inherited<'b, 'tcx>)`.
|
|
pub struct InheritedBuilder<'tcx> {
|
|
infcx: infer::InferCtxtBuilder<'tcx>,
|
|
def_id: LocalDefId,
|
|
}
|
|
|
|
impl Inherited<'_, 'tcx> {
|
|
pub fn build(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> InheritedBuilder<'tcx> {
|
|
let hir_owner = tcx.hir().local_def_id_to_hir_id(def_id).owner;
|
|
|
|
InheritedBuilder {
|
|
infcx: tcx.infer_ctxt().with_fresh_in_progress_typeck_results(hir_owner),
|
|
def_id,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> InheritedBuilder<'tcx> {
|
|
pub fn enter<F, R>(&mut self, f: F) -> R
|
|
where
|
|
F: for<'a> FnOnce(Inherited<'a, 'tcx>) -> R,
|
|
{
|
|
let def_id = self.def_id;
|
|
self.infcx.enter(|infcx| f(Inherited::new(infcx, def_id)))
|
|
}
|
|
}
|
|
|
|
impl Inherited<'a, 'tcx> {
|
|
pub(super) fn new(infcx: InferCtxt<'a, 'tcx>, def_id: LocalDefId) -> Self {
|
|
let tcx = infcx.tcx;
|
|
let item_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
|
let body_id = tcx.hir().maybe_body_owned_by(item_id);
|
|
|
|
Inherited {
|
|
typeck_results: MaybeInProgressTables {
|
|
maybe_typeck_results: infcx.in_progress_typeck_results,
|
|
},
|
|
infcx,
|
|
fulfillment_cx: RefCell::new(<dyn TraitEngine<'_>>::new(tcx)),
|
|
locals: RefCell::new(Default::default()),
|
|
deferred_sized_obligations: RefCell::new(Vec::new()),
|
|
deferred_call_resolutions: RefCell::new(Default::default()),
|
|
deferred_cast_checks: RefCell::new(Vec::new()),
|
|
deferred_generator_interiors: RefCell::new(Vec::new()),
|
|
opaque_types: RefCell::new(Default::default()),
|
|
opaque_types_vars: RefCell::new(Default::default()),
|
|
body_id,
|
|
}
|
|
}
|
|
|
|
pub(super) fn register_predicate(&self, obligation: traits::PredicateObligation<'tcx>) {
|
|
debug!("register_predicate({:?})", obligation);
|
|
if obligation.has_escaping_bound_vars() {
|
|
span_bug!(obligation.cause.span, "escaping bound vars in predicate {:?}", obligation);
|
|
}
|
|
self.fulfillment_cx.borrow_mut().register_predicate_obligation(self, obligation);
|
|
}
|
|
|
|
pub(super) fn register_predicates<I>(&self, obligations: I)
|
|
where
|
|
I: IntoIterator<Item = traits::PredicateObligation<'tcx>>,
|
|
{
|
|
for obligation in obligations {
|
|
self.register_predicate(obligation);
|
|
}
|
|
}
|
|
|
|
pub(super) fn register_infer_ok_obligations<T>(&self, infer_ok: InferOk<'tcx, T>) -> T {
|
|
self.register_predicates(infer_ok.obligations);
|
|
infer_ok.value
|
|
}
|
|
|
|
pub(super) fn normalize_associated_types_in<T>(
|
|
&self,
|
|
span: Span,
|
|
body_id: hir::HirId,
|
|
param_env: ty::ParamEnv<'tcx>,
|
|
value: T,
|
|
) -> T
|
|
where
|
|
T: TypeFoldable<'tcx>,
|
|
{
|
|
let ok = self.partially_normalize_associated_types_in(span, body_id, param_env, value);
|
|
self.register_infer_ok_obligations(ok)
|
|
}
|
|
}
|