diff options
Diffstat (limited to '')
-rw-r--r-- | compiler/rustc_hir_typeck/src/method/confirm.rs | 74 |
1 files changed, 59 insertions, 15 deletions
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs index 03d0e7926..372ea30eb 100644 --- a/compiler/rustc_hir_typeck/src/method/confirm.rs +++ b/compiler/rustc_hir_typeck/src/method/confirm.rs @@ -4,6 +4,9 @@ use crate::{callee, FnCtxt}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_hir::GenericArg; +use rustc_hir_analysis::astconv::generics::{ + check_generic_arg_count_for_call, create_substs_for_generic_args, +}; use rustc_hir_analysis::astconv::{AstConv, CreateSubstsForGenericArgsCtxt, IsMethodCall}; use rustc_infer::infer::{self, InferOk}; use rustc_middle::traits::{ObligationCauseCode, UnifyReceiverContext}; @@ -12,10 +15,10 @@ use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutabili use rustc_middle::ty::fold::TypeFoldable; use rustc_middle::ty::subst::{self, SubstsRef}; use rustc_middle::ty::{self, GenericParamDefKind, Ty}; -use rustc_span::Span; +use rustc_middle::ty::{InternalSubsts, UserSubsts, UserType}; +use rustc_span::{Span, DUMMY_SP}; use rustc_trait_selection::traits; -use std::iter; use std::ops::Deref; struct ConfirmContext<'a, 'tcx> { @@ -45,7 +48,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { self_expr: &'tcx hir::Expr<'tcx>, call_expr: &'tcx hir::Expr<'tcx>, unadjusted_self_ty: Ty<'tcx>, - pick: probe::Pick<'tcx>, + pick: &probe::Pick<'tcx>, segment: &hir::PathSegment<'_>, ) -> ConfirmResult<'tcx> { debug!( @@ -71,7 +74,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { fn confirm( &mut self, unadjusted_self_ty: Ty<'tcx>, - pick: probe::Pick<'tcx>, + pick: &probe::Pick<'tcx>, segment: &hir::PathSegment<'_>, ) -> ConfirmResult<'tcx> { // Adjust the self expression the user provided and obtain the adjusted type. @@ -89,7 +92,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { // 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`. + // See test `tests/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 @@ -97,7 +100,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { 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), + self.tcx.predicates_of(pick.item.def_id).instantiate(self.tcx, filler_substs), ); // Unify the (adjusted) self type with what the method expects. @@ -330,7 +333,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { // variables. let generics = self.tcx.generics_of(pick.item.def_id); - let arg_count_correct = <dyn AstConv<'_>>::check_generic_arg_count_for_call( + let arg_count_correct = check_generic_arg_count_for_call( self.tcx, self.span, pick.item.def_id, @@ -368,11 +371,10 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { ) -> subst::GenericArg<'tcx> { match (¶m.kind, arg) { (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => { - <dyn AstConv<'_>>::ast_region_to_region(self.cfcx.fcx, lt, Some(param)) - .into() + self.cfcx.fcx.astconv().ast_region_to_region(lt, Some(param)).into() } (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => { - self.cfcx.to_ty(ty).into() + self.cfcx.to_ty(ty).raw.into() } (GenericParamDefKind::Const { .. }, GenericArg::Const(ct)) => { self.cfcx.const_arg_to_const(&ct.value, param.def_id).into() @@ -397,7 +399,8 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { self.cfcx.var_for_def(self.cfcx.span, param) } } - <dyn AstConv<'_>>::create_substs_for_generic_args( + + let substs = create_substs_for_generic_args( self.tcx, pick.item.def_id, parent_substs, @@ -405,7 +408,47 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { None, &arg_count_correct, &mut MethodSubstsCtxt { cfcx: self, pick, seg }, - ) + ); + + // When the method is confirmed, the `substs` includes + // parameters from not just the method, but also the impl of + // the method -- in particular, the `Self` type will be fully + // resolved. However, those are not something that the "user + // specified" -- i.e., those types come from the inferred type + // of the receiver, not something the user wrote. So when we + // create the user-substs, we want to replace those earlier + // types with just the types that the user actually wrote -- + // that is, those that appear on the *method itself*. + // + // As an example, if the user wrote something like + // `foo.bar::<u32>(...)` -- the `Self` type here will be the + // type of `foo` (possibly adjusted), but we don't want to + // include that. We want just the `[_, u32]` part. + if !substs.is_empty() && !generics.params.is_empty() { + let user_type_annotation = self.probe(|_| { + let user_substs = UserSubsts { + substs: InternalSubsts::for_item(self.tcx, pick.item.def_id, |param, _| { + let i = param.index as usize; + if i < generics.parent_count { + self.fcx.var_for_def(DUMMY_SP, param) + } else { + substs[i] + } + }), + user_self_ty: None, // not relevant here + }; + + self.fcx.canonicalize_user_type_annotation(UserType::TypeOf( + pick.item.def_id, + user_substs, + )) + }); + + debug!("instantiate_method_substs: user_type_annotation={:?}", user_type_annotation); + self.fcx.write_user_type_annotation(self.call_expr.hir_id, user_type_annotation); + } + + self.normalize(self.span, substs) } fn unify_receivers( @@ -521,7 +564,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { fn predicates_require_illegal_sized_bound( &self, - predicates: &ty::InstantiatedPredicates<'tcx>, + predicates: ty::InstantiatedPredicates<'tcx>, ) -> Option<Span> { let sized_def_id = self.tcx.lang_items().sized_trait()?; @@ -531,10 +574,11 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> { ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) if trait_pred.def_id() == sized_def_id => { - let span = iter::zip(&predicates.predicates, &predicates.spans) + let span = predicates + .iter() .find_map( |(p, span)| { - if *p == obligation.predicate { Some(*span) } else { None } + if p == obligation.predicate { Some(span) } else { None } }, ) .unwrap_or(rustc_span::DUMMY_SP); |