Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 0 insertions, 594 deletions

diff --git a/compiler/rustc_typeck/src/check/method/confirm.rs b/compiler/rustc_typeck/src/check/method/confirm.rs
deleted file mode 100644
index 59fd5c315..000000000
--- a/compiler/rustc_typeck/src/check/method/confirm.rs
+++ /dev/null
@@ -1,594 +0,0 @@
-use super::{probe, MethodCallee};
-
-use crate::astconv::{AstConv, CreateSubstsForGenericArgsCtxt, IsMethodCall};
-use crate::check::{callee, FnCtxt};
-use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
-use rustc_hir::GenericArg;
-use rustc_infer::infer::{self, InferOk};
-use rustc_middle::traits::{ObligationCauseCode, UnifyReceiverContext};
-use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCast};
-use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutability};
-use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::subst::{self, Subst, SubstsRef};
-use rustc_middle::ty::{self, GenericParamDefKind, Ty};
-use rustc_span::Span;
-use rustc_trait_selection::traits;
-
-use std::iter;
-use std::ops::Deref;
-
-struct ConfirmContext<'a, 'tcx> {
-    fcx: &'a FnCtxt<'a, 'tcx>,
-    span: Span,
-    self_expr: &'tcx hir::Expr<'tcx>,
-    call_expr: &'tcx hir::Expr<'tcx>,
-}
-
-impl<'a, 'tcx> Deref for ConfirmContext<'a, 'tcx> {
-    type Target = FnCtxt<'a, 'tcx>;
-    fn deref(&self) -> &Self::Target {
-        self.fcx
-    }
-}
-
-#[derive(Debug)]
-pub struct ConfirmResult<'tcx> {
-    pub callee: MethodCallee<'tcx>,
-    pub illegal_sized_bound: Option<Span>,
-}
-
-impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn confirm_method(
-        &self,
-        span: Span,
-        self_expr: &'tcx hir::Expr<'tcx>,
-        call_expr: &'tcx hir::Expr<'tcx>,
-        unadjusted_self_ty: Ty<'tcx>,
-        pick: probe::Pick<'tcx>,
-        segment: &hir::PathSegment<'_>,
-    ) -> ConfirmResult<'tcx> {
-        debug!(
-            "confirm(unadjusted_self_ty={:?}, pick={:?}, generic_args={:?})",
-            unadjusted_self_ty, pick, segment.args,
-        );
-
-        let mut confirm_cx = ConfirmContext::new(self, span, self_expr, call_expr);
-        confirm_cx.confirm(unadjusted_self_ty, pick, segment)
-    }
-}
-
-impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
-    fn new(
-        fcx: &'a FnCtxt<'a, 'tcx>,
-        span: Span,
-        self_expr: &'tcx hir::Expr<'tcx>,
-        call_expr: &'tcx hir::Expr<'tcx>,
-    ) -> ConfirmContext<'a, 'tcx> {
-        ConfirmContext { fcx, span, self_expr, call_expr }
-    }
-
-    fn confirm(
-        &mut self,
-        unadjusted_self_ty: Ty<'tcx>,
-        pick: probe::Pick<'tcx>,
-        segment: &hir::PathSegment<'_>,
-    ) -> ConfirmResult<'tcx> {
-        // Adjust the self expression the user provided and obtain the adjusted type.
-        let self_ty = self.adjust_self_ty(unadjusted_self_ty, &pick);
-
-        // Create substitutions for the method's type parameters.
-        let rcvr_substs = self.fresh_receiver_substs(self_ty, &pick);
-        let all_substs = self.instantiate_method_substs(&pick, segment, rcvr_substs);
-
-        debug!("rcvr_substs={rcvr_substs:?}, all_substs={all_substs:?}");
-
-        // Create the final signature for the method, replacing late-bound regions.
-        let (method_sig, method_predicates) = self.instantiate_method_sig(&pick, all_substs);
-
-        // If there is a `Self: Sized` bound and `Self` is a trait object, it is possible that
-        // something which derefs to `Self` actually implements the trait and the caller
-        // wanted to make a static dispatch on it but forgot to import the trait.
-        // See test `src/test/ui/issue-35976.rs`.
-        //
-        // In that case, we'll error anyway, but we'll also re-run the search with all traits
-        // in scope, and if we find another method which can be used, we'll output an
-        // appropriate hint suggesting to import the trait.
-        let filler_substs = rcvr_substs
-            .extend_to(self.tcx, pick.item.def_id, |def, _| self.tcx.mk_param_from_def(def));
-        let illegal_sized_bound = self.predicates_require_illegal_sized_bound(
-            &self.tcx.predicates_of(pick.item.def_id).instantiate(self.tcx, filler_substs),
-        );
-
-        // Unify the (adjusted) self type with what the method expects.
-        //
-        // SUBTLE: if we want good error messages, because of "guessing" while matching
-        // traits, no trait system method can be called before this point because they
-        // could alter our Self-type, except for normalizing the receiver from the
-        // signature (which is also done during probing).
-        let method_sig_rcvr = self.normalize_associated_types_in(self.span, method_sig.inputs()[0]);
-        debug!(
-            "confirm: self_ty={:?} method_sig_rcvr={:?} method_sig={:?} method_predicates={:?}",
-            self_ty, method_sig_rcvr, method_sig, method_predicates
-        );
-        self.unify_receivers(self_ty, method_sig_rcvr, &pick, all_substs);
-
-        let (method_sig, method_predicates) =
-            self.normalize_associated_types_in(self.span, (method_sig, method_predicates));
-        let method_sig = ty::Binder::dummy(method_sig);
-
-        // Make sure nobody calls `drop()` explicitly.
-        self.enforce_illegal_method_limitations(&pick);
-
-        // Add any trait/regions obligations specified on the method's type parameters.
-        // We won't add these if we encountered an illegal sized bound, so that we can use
-        // a custom error in that case.
-        if illegal_sized_bound.is_none() {
-            self.add_obligations(
-                self.tcx.mk_fn_ptr(method_sig),
-                all_substs,
-                method_predicates,
-                pick.item.def_id,
-            );
-        }
-
-        // Create the final `MethodCallee`.
-        let callee = MethodCallee {
-            def_id: pick.item.def_id,
-            substs: all_substs,
-            sig: method_sig.skip_binder(),
-        };
-        ConfirmResult { callee, illegal_sized_bound }
-    }
-
-    ///////////////////////////////////////////////////////////////////////////
-    // ADJUSTMENTS
-
-    fn adjust_self_ty(
-        &mut self,
-        unadjusted_self_ty: Ty<'tcx>,
-        pick: &probe::Pick<'tcx>,
-    ) -> Ty<'tcx> {
-        // Commit the autoderefs by calling `autoderef` again, but this
-        // time writing the results into the various typeck results.
-        let mut autoderef =
-            self.autoderef_overloaded_span(self.span, unadjusted_self_ty, self.call_expr.span);
-        let Some((ty, n)) = autoderef.nth(pick.autoderefs) else {
-            return self.tcx.ty_error_with_message(
-                rustc_span::DUMMY_SP,
-                &format!("failed autoderef {}", pick.autoderefs),
-            );
-        };
-        assert_eq!(n, pick.autoderefs);
-
-        let mut adjustments = self.adjust_steps(&autoderef);
-        let mut target = self.structurally_resolved_type(autoderef.span(), ty);
-
-        match pick.autoref_or_ptr_adjustment {
-            Some(probe::AutorefOrPtrAdjustment::Autoref { mutbl, unsize }) => {
-                let region = self.next_region_var(infer::Autoref(self.span));
-                // Type we're wrapping in a reference, used later for unsizing
-                let base_ty = target;
-
-                target = self.tcx.mk_ref(region, ty::TypeAndMut { mutbl, ty: target });
-                let mutbl = match mutbl {
-                    hir::Mutability::Not => AutoBorrowMutability::Not,
-                    hir::Mutability::Mut => AutoBorrowMutability::Mut {
-                        // Method call receivers are the primary use case
-                        // for two-phase borrows.
-                        allow_two_phase_borrow: AllowTwoPhase::Yes,
-                    },
-                };
-                adjustments.push(Adjustment {
-                    kind: Adjust::Borrow(AutoBorrow::Ref(region, mutbl)),
-                    target,
-                });
-
-                if unsize {
-                    let unsized_ty = if let ty::Array(elem_ty, _) = base_ty.kind() {
-                        self.tcx.mk_slice(*elem_ty)
-                    } else {
-                        bug!(
-                            "AutorefOrPtrAdjustment's unsize flag should only be set for array ty, found {}",
-                            base_ty
-                        )
-                    };
-                    target = self
-                        .tcx
-                        .mk_ref(region, ty::TypeAndMut { mutbl: mutbl.into(), ty: unsized_ty });
-                    adjustments
-                        .push(Adjustment { kind: Adjust::Pointer(PointerCast::Unsize), target });
-                }
-            }
-            Some(probe::AutorefOrPtrAdjustment::ToConstPtr) => {
-                target = match target.kind() {
-                    &ty::RawPtr(ty::TypeAndMut { ty, mutbl }) => {
-                        assert_eq!(mutbl, hir::Mutability::Mut);
-                        self.tcx.mk_ptr(ty::TypeAndMut { mutbl: hir::Mutability::Not, ty })
-                    }
-                    other => panic!("Cannot adjust receiver type {:?} to const ptr", other),
-                };
-
-                adjustments.push(Adjustment {
-                    kind: Adjust::Pointer(PointerCast::MutToConstPointer),
-                    target,
-                });
-            }
-            None => {}
-        }
-
-        self.register_predicates(autoderef.into_obligations());
-
-        // Write out the final adjustments.
-        self.apply_adjustments(self.self_expr, adjustments);
-
-        target
-    }
-
-    /// Returns a set of substitutions for the method *receiver* where all type and region
-    /// parameters are instantiated with fresh variables. This substitution does not include any
-    /// parameters declared on the method itself.
-    ///
-    /// Note that this substitution may include late-bound regions from the impl level. If so,
-    /// these are instantiated later in the `instantiate_method_sig` routine.
-    fn fresh_receiver_substs(
-        &mut self,
-        self_ty: Ty<'tcx>,
-        pick: &probe::Pick<'tcx>,
-    ) -> SubstsRef<'tcx> {
-        match pick.kind {
-            probe::InherentImplPick => {
-                let impl_def_id = pick.item.container_id(self.tcx);
-                assert!(
-                    self.tcx.impl_trait_ref(impl_def_id).is_none(),
-                    "impl {:?} is not an inherent impl",
-                    impl_def_id
-                );
-                self.fresh_substs_for_item(self.span, impl_def_id)
-            }
-
-            probe::ObjectPick => {
-                let trait_def_id = pick.item.container_id(self.tcx);
-                self.extract_existential_trait_ref(self_ty, |this, object_ty, principal| {
-                    // The object data has no entry for the Self
-                    // Type. For the purposes of this method call, we
-                    // substitute the object type itself. This
-                    // wouldn't be a sound substitution in all cases,
-                    // since each instance of the object type is a
-                    // different existential and hence could match
-                    // distinct types (e.g., if `Self` appeared as an
-                    // argument type), but those cases have already
-                    // been ruled out when we deemed the trait to be
-                    // "object safe".
-                    let original_poly_trait_ref = principal.with_self_ty(this.tcx, object_ty);
-                    let upcast_poly_trait_ref = this.upcast(original_poly_trait_ref, trait_def_id);
-                    let upcast_trait_ref =
-                        this.replace_bound_vars_with_fresh_vars(upcast_poly_trait_ref);
-                    debug!(
-                        "original_poly_trait_ref={:?} upcast_trait_ref={:?} target_trait={:?}",
-                        original_poly_trait_ref, upcast_trait_ref, trait_def_id
-                    );
-                    upcast_trait_ref.substs
-                })
-            }
-
-            probe::TraitPick => {
-                let trait_def_id = pick.item.container_id(self.tcx);
-
-                // Make a trait reference `$0 : Trait<$1...$n>`
-                // consisting entirely of type variables. Later on in
-                // the process we will unify the transformed-self-type
-                // of the method with the actual type in order to
-                // unify some of these variables.
-                self.fresh_substs_for_item(self.span, trait_def_id)
-            }
-
-            probe::WhereClausePick(poly_trait_ref) => {
-                // Where clauses can have bound regions in them. We need to instantiate
-                // those to convert from a poly-trait-ref to a trait-ref.
-                self.replace_bound_vars_with_fresh_vars(poly_trait_ref).substs
-            }
-        }
-    }
-
-    fn extract_existential_trait_ref<R, F>(&mut self, self_ty: Ty<'tcx>, mut closure: F) -> R
-    where
-        F: FnMut(&mut ConfirmContext<'a, 'tcx>, Ty<'tcx>, ty::PolyExistentialTraitRef<'tcx>) -> R,
-    {
-        // If we specified that this is an object method, then the
-        // self-type ought to be something that can be dereferenced to
-        // yield an object-type (e.g., `&Object` or `Box<Object>`
-        // etc).
-
-        // FIXME: this feels, like, super dubious
-        self.fcx
-            .autoderef(self.span, self_ty)
-            .include_raw_pointers()
-            .find_map(|(ty, _)| match ty.kind() {
-                ty::Dynamic(data, ..) => Some(closure(
-                    self,
-                    ty,
-                    data.principal().unwrap_or_else(|| {
-                        span_bug!(self.span, "calling trait method on empty object?")
-                    }),
-                )),
-                _ => None,
-            })
-            .unwrap_or_else(|| {
-                span_bug!(
-                    self.span,
-                    "self-type `{}` for ObjectPick never dereferenced to an object",
-                    self_ty
-                )
-            })
-    }
-
-    fn instantiate_method_substs(
-        &mut self,
-        pick: &probe::Pick<'tcx>,
-        seg: &hir::PathSegment<'_>,
-        parent_substs: SubstsRef<'tcx>,
-    ) -> SubstsRef<'tcx> {
-        // Determine the values for the generic parameters of the method.
-        // If they were not explicitly supplied, just construct fresh
-        // variables.
-        let generics = self.tcx.generics_of(pick.item.def_id);
-
-        let arg_count_correct = <dyn AstConv<'_>>::check_generic_arg_count_for_call(
-            self.tcx,
-            self.span,
-            pick.item.def_id,
-            generics,
-            seg,
-            IsMethodCall::Yes,
-        );
-
-        // Create subst for early-bound lifetime parameters, combining
-        // parameters from the type and those from the method.
-        assert_eq!(generics.parent_count, parent_substs.len());
-
-        struct MethodSubstsCtxt<'a, 'tcx> {
-            cfcx: &'a ConfirmContext<'a, 'tcx>,
-            pick: &'a probe::Pick<'tcx>,
-            seg: &'a hir::PathSegment<'a>,
-        }
-        impl<'a, 'tcx> CreateSubstsForGenericArgsCtxt<'a, 'tcx> for MethodSubstsCtxt<'a, 'tcx> {
-            fn args_for_def_id(
-                &mut self,
-                def_id: DefId,
-            ) -> (Option<&'a hir::GenericArgs<'a>>, bool) {
-                if def_id == self.pick.item.def_id {
-                    if let Some(data) = self.seg.args {
-                        return (Some(data), false);
-                    }
-                }
-                (None, false)
-            }
-
-            fn provided_kind(
-                &mut self,
-                param: &ty::GenericParamDef,
-                arg: &GenericArg<'_>,
-            ) -> subst::GenericArg<'tcx> {
-                match (&param.kind, arg) {
-                    (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => {
-                        <dyn AstConv<'_>>::ast_region_to_region(self.cfcx.fcx, lt, Some(param))
-                            .into()
-                    }
-                    (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => {
-                        self.cfcx.to_ty(ty).into()
-                    }
-                    (GenericParamDefKind::Const { .. }, GenericArg::Const(ct)) => {
-                        self.cfcx.const_arg_to_const(&ct.value, param.def_id).into()
-                    }
-                    (GenericParamDefKind::Type { .. }, GenericArg::Infer(inf)) => {
-                        self.cfcx.ty_infer(Some(param), inf.span).into()
-                    }
-                    (GenericParamDefKind::Const { .. }, GenericArg::Infer(inf)) => {
-                        let tcx = self.cfcx.tcx();
-                        self.cfcx.ct_infer(tcx.type_of(param.def_id), Some(param), inf.span).into()
-                    }
-                    _ => unreachable!(),
-                }
-            }
-
-            fn inferred_kind(
-                &mut self,
-                _substs: Option<&[subst::GenericArg<'tcx>]>,
-                param: &ty::GenericParamDef,
-                _infer_args: bool,
-            ) -> subst::GenericArg<'tcx> {
-                self.cfcx.var_for_def(self.cfcx.span, param)
-            }
-        }
-        <dyn AstConv<'_>>::create_substs_for_generic_args(
-            self.tcx,
-            pick.item.def_id,
-            parent_substs,
-            false,
-            None,
-            &arg_count_correct,
-            &mut MethodSubstsCtxt { cfcx: self, pick, seg },
-        )
-    }
-
-    fn unify_receivers(
-        &mut self,
-        self_ty: Ty<'tcx>,
-        method_self_ty: Ty<'tcx>,
-        pick: &probe::Pick<'tcx>,
-        substs: SubstsRef<'tcx>,
-    ) {
-        debug!(
-            "unify_receivers: self_ty={:?} method_self_ty={:?} span={:?} pick={:?}",
-            self_ty, method_self_ty, self.span, pick
-        );
-        let cause = self.cause(
-            self.span,
-            ObligationCauseCode::UnifyReceiver(Box::new(UnifyReceiverContext {
-                assoc_item: pick.item,
-                param_env: self.param_env,
-                substs,
-            })),
-        );
-        match self.at(&cause, self.param_env).sup(method_self_ty, self_ty) {
-            Ok(InferOk { obligations, value: () }) => {
-                self.register_predicates(obligations);
-            }
-            Err(_) => {
-                span_bug!(
-                    self.span,
-                    "{} was a subtype of {} but now is not?",
-                    self_ty,
-                    method_self_ty
-                );
-            }
-        }
-    }
-
-    // NOTE: this returns the *unnormalized* predicates and method sig. Because of
-    // inference guessing, the predicates and method signature can't be normalized
-    // until we unify the `Self` type.
-    fn instantiate_method_sig(
-        &mut self,
-        pick: &probe::Pick<'tcx>,
-        all_substs: SubstsRef<'tcx>,
-    ) -> (ty::FnSig<'tcx>, ty::InstantiatedPredicates<'tcx>) {
-        debug!("instantiate_method_sig(pick={:?}, all_substs={:?})", pick, all_substs);
-
-        // Instantiate the bounds on the method with the
-        // type/early-bound-regions substitutions performed. There can
-        // be no late-bound regions appearing here.
-        let def_id = pick.item.def_id;
-        let method_predicates = self.tcx.predicates_of(def_id).instantiate(self.tcx, all_substs);
-
-        debug!("method_predicates after subst = {:?}", method_predicates);
-
-        let sig = self.tcx.bound_fn_sig(def_id);
-
-        let sig = sig.subst(self.tcx, all_substs);
-        debug!("type scheme substituted, sig={:?}", sig);
-
-        let sig = self.replace_bound_vars_with_fresh_vars(sig);
-        debug!("late-bound lifetimes from method instantiated, sig={:?}", sig);
-
-        (sig, method_predicates)
-    }
-
-    fn add_obligations(
-        &mut self,
-        fty: Ty<'tcx>,
-        all_substs: SubstsRef<'tcx>,
-        method_predicates: ty::InstantiatedPredicates<'tcx>,
-        def_id: DefId,
-    ) {
-        debug!(
-            "add_obligations: fty={:?} all_substs={:?} method_predicates={:?} def_id={:?}",
-            fty, all_substs, method_predicates, def_id
-        );
-
-        // FIXME: could replace with the following, but we already calculated `method_predicates`,
-        // so we just call `predicates_for_generics` directly to avoid redoing work.
-        // `self.add_required_obligations(self.span, def_id, &all_substs);`
-        for obligation in traits::predicates_for_generics(
-            |idx, span| {
-                let code = if span.is_dummy() {
-                    ObligationCauseCode::ExprItemObligation(def_id, self.call_expr.hir_id, idx)
-                } else {
-                    ObligationCauseCode::ExprBindingObligation(
-                        def_id,
-                        span,
-                        self.call_expr.hir_id,
-                        idx,
-                    )
-                };
-                traits::ObligationCause::new(self.span, self.body_id, code)
-            },
-            self.param_env,
-            method_predicates,
-        ) {
-            self.register_predicate(obligation);
-        }
-
-        // this is a projection from a trait reference, so we have to
-        // make sure that the trait reference inputs are well-formed.
-        self.add_wf_bounds(all_substs, self.call_expr);
-
-        // the function type must also be well-formed (this is not
-        // implied by the substs being well-formed because of inherent
-        // impls and late-bound regions - see issue #28609).
-        self.register_wf_obligation(fty.into(), self.span, traits::WellFormed(None));
-    }
-
-    ///////////////////////////////////////////////////////////////////////////
-    // MISCELLANY
-
-    fn predicates_require_illegal_sized_bound(
-        &self,
-        predicates: &ty::InstantiatedPredicates<'tcx>,
-    ) -> Option<Span> {
-        let sized_def_id = self.tcx.lang_items().sized_trait()?;
-
-        traits::elaborate_predicates(self.tcx, predicates.predicates.iter().copied())
-            // We don't care about regions here.
-            .filter_map(|obligation| match obligation.predicate.kind().skip_binder() {
-                ty::PredicateKind::Trait(trait_pred) if trait_pred.def_id() == sized_def_id => {
-                    let span = iter::zip(&predicates.predicates, &predicates.spans)
-                        .find_map(
-                            |(p, span)| {
-                                if *p == obligation.predicate { Some(*span) } else { None }
-                            },
-                        )
-                        .unwrap_or(rustc_span::DUMMY_SP);
-                    Some((trait_pred, span))
-                }
-                _ => None,
-            })
-            .find_map(|(trait_pred, span)| match trait_pred.self_ty().kind() {
-                ty::Dynamic(..) => Some(span),
-                _ => None,
-            })
-    }
-
-    fn enforce_illegal_method_limitations(&self, pick: &probe::Pick<'_>) {
-        // Disallow calls to the method `drop` defined in the `Drop` trait.
-        if let Some(trait_def_id) = pick.item.trait_container(self.tcx) {
-            callee::check_legal_trait_for_method_call(
-                self.tcx,
-                self.span,
-                Some(self.self_expr.span),
-                self.call_expr.span,
-                trait_def_id,
-            )
-        }
-    }
-
-    fn upcast(
-        &mut self,
-        source_trait_ref: ty::PolyTraitRef<'tcx>,
-        target_trait_def_id: DefId,
-    ) -> ty::PolyTraitRef<'tcx> {
-        let upcast_trait_refs =
-            traits::upcast_choices(self.tcx, source_trait_ref, target_trait_def_id);
-
-        // must be exactly one trait ref or we'd get an ambig error etc
-        if upcast_trait_refs.len() != 1 {
-            span_bug!(
-                self.span,
-                "cannot uniquely upcast `{:?}` to `{:?}`: `{:?}`",
-                source_trait_ref,
-                target_trait_def_id,
-                upcast_trait_refs
-            );
-        }
-
-        upcast_trait_refs.into_iter().next().unwrap()
-    }
-
-    fn replace_bound_vars_with_fresh_vars<T>(&self, value: ty::Binder<'tcx, T>) -> T
-    where
-        T: TypeFoldable<'tcx> + Copy,
-    {
-        self.fcx.replace_bound_vars_with_fresh_vars(self.span, infer::FnCall, value)
-    }
-}