| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Code for type-checking closure expressions. |
| |
| use super::{check_fn, Expectation, FnCtxt, GeneratorTypes}; |
| |
| use astconv::AstConv; |
| use rustc::hir::def_id::DefId; |
| use rustc::infer::{InferOk, InferResult}; |
| use rustc::infer::LateBoundRegionConversionTime; |
| use rustc::infer::type_variable::TypeVariableOrigin; |
| use rustc::traits::error_reporting::ArgKind; |
| use rustc::ty::{self, ToPolyTraitRef, Ty, GenericParamDefKind}; |
| use rustc::ty::fold::TypeFoldable; |
| use rustc::ty::subst::Substs; |
| use std::cmp; |
| use std::iter; |
| use rustc_target::spec::abi::Abi; |
| use syntax::source_map::Span; |
| use rustc::hir; |
| |
| /// What signature do we *expect* the closure to have from context? |
| #[derive(Debug)] |
| struct ExpectedSig<'tcx> { |
| /// Span that gave us this expectation, if we know that. |
| cause_span: Option<Span>, |
| sig: ty::FnSig<'tcx>, |
| } |
| |
| struct ClosureSignatures<'tcx> { |
| bound_sig: ty::PolyFnSig<'tcx>, |
| liberated_sig: ty::FnSig<'tcx>, |
| } |
| |
| impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { |
| pub fn check_expr_closure( |
| &self, |
| expr: &hir::Expr, |
| _capture: hir::CaptureClause, |
| decl: &'gcx hir::FnDecl, |
| body_id: hir::BodyId, |
| gen: Option<hir::GeneratorMovability>, |
| expected: Expectation<'tcx>, |
| ) -> Ty<'tcx> { |
| debug!( |
| "check_expr_closure(expr={:?},expected={:?})", |
| expr, expected |
| ); |
| |
| // It's always helpful for inference if we know the kind of |
| // closure sooner rather than later, so first examine the expected |
| // type, and see if can glean a closure kind from there. |
| let (expected_sig, expected_kind) = match expected.to_option(self) { |
| Some(ty) => self.deduce_expectations_from_expected_type(ty), |
| None => (None, None), |
| }; |
| let body = self.tcx.hir.body(body_id); |
| self.check_closure(expr, expected_kind, decl, body, gen, expected_sig) |
| } |
| |
| fn check_closure( |
| &self, |
| expr: &hir::Expr, |
| opt_kind: Option<ty::ClosureKind>, |
| decl: &'gcx hir::FnDecl, |
| body: &'gcx hir::Body, |
| gen: Option<hir::GeneratorMovability>, |
| expected_sig: Option<ExpectedSig<'tcx>>, |
| ) -> Ty<'tcx> { |
| debug!( |
| "check_closure(opt_kind={:?}, expected_sig={:?})", |
| opt_kind, expected_sig |
| ); |
| |
| let expr_def_id = self.tcx.hir.local_def_id(expr.id); |
| |
| let ClosureSignatures { |
| bound_sig, |
| liberated_sig, |
| } = self.sig_of_closure(expr_def_id, decl, body, expected_sig); |
| |
| debug!("check_closure: ty_of_closure returns {:?}", liberated_sig); |
| |
| let generator_types = check_fn( |
| self, |
| self.param_env, |
| liberated_sig, |
| decl, |
| expr.id, |
| body, |
| gen, |
| ).1; |
| |
| // Create type variables (for now) to represent the transformed |
| // types of upvars. These will be unified during the upvar |
| // inference phase (`upvar.rs`). |
| let base_substs = |
| Substs::identity_for_item(self.tcx, self.tcx.closure_base_def_id(expr_def_id)); |
| let substs = base_substs.extend_to(self.tcx,expr_def_id, |param, _| { |
| match param.kind { |
| GenericParamDefKind::Lifetime => { |
| span_bug!(expr.span, "closure has region param") |
| } |
| GenericParamDefKind::Type {..} => { |
| self.infcx |
| .next_ty_var(TypeVariableOrigin::ClosureSynthetic(expr.span)).into() |
| } |
| } |
| }); |
| if let Some(GeneratorTypes { yield_ty, interior, movability }) = generator_types { |
| let substs = ty::GeneratorSubsts { substs }; |
| self.demand_eqtype( |
| expr.span, |
| yield_ty, |
| substs.yield_ty(expr_def_id, self.tcx), |
| ); |
| self.demand_eqtype( |
| expr.span, |
| liberated_sig.output(), |
| substs.return_ty(expr_def_id, self.tcx), |
| ); |
| self.demand_eqtype( |
| expr.span, |
| interior, |
| substs.witness(expr_def_id, self.tcx), |
| ); |
| return self.tcx.mk_generator(expr_def_id, substs, movability); |
| } |
| |
| let substs = ty::ClosureSubsts { substs }; |
| let closure_type = self.tcx.mk_closure(expr_def_id, substs); |
| |
| debug!( |
| "check_closure: expr.id={:?} closure_type={:?}", |
| expr.id, closure_type |
| ); |
| |
| // Tuple up the arguments and insert the resulting function type into |
| // the `closures` table. |
| let sig = bound_sig.map_bound(|sig| { |
| self.tcx.mk_fn_sig( |
| iter::once(self.tcx.intern_tup(sig.inputs())), |
| sig.output(), |
| sig.variadic, |
| sig.unsafety, |
| sig.abi, |
| ) |
| }); |
| |
| debug!( |
| "check_closure: expr_def_id={:?}, sig={:?}, opt_kind={:?}", |
| expr_def_id, sig, opt_kind |
| ); |
| |
| let sig_fn_ptr_ty = self.tcx.mk_fn_ptr(sig); |
| self.demand_eqtype( |
| expr.span, |
| sig_fn_ptr_ty, |
| substs.closure_sig_ty(expr_def_id, self.tcx), |
| ); |
| |
| if let Some(kind) = opt_kind { |
| self.demand_eqtype( |
| expr.span, |
| kind.to_ty(self.tcx), |
| substs.closure_kind_ty(expr_def_id, self.tcx), |
| ); |
| } |
| |
| closure_type |
| } |
| |
| /// Given the expected type, figures out what it can about this closure we |
| /// are about to type check: |
| fn deduce_expectations_from_expected_type( |
| &self, |
| expected_ty: Ty<'tcx>, |
| ) -> (Option<ExpectedSig<'tcx>>, Option<ty::ClosureKind>) { |
| debug!( |
| "deduce_expectations_from_expected_type(expected_ty={:?})", |
| expected_ty |
| ); |
| |
| match expected_ty.sty { |
| ty::TyDynamic(ref object_type, ..) => { |
| let sig = object_type |
| .projection_bounds() |
| .filter_map(|pb| { |
| let pb = pb.with_self_ty(self.tcx, self.tcx.types.err); |
| self.deduce_sig_from_projection(None, &pb) |
| }) |
| .next(); |
| let kind = object_type |
| .principal() |
| .and_then(|p| self.tcx.lang_items().fn_trait_kind(p.def_id())); |
| (sig, kind) |
| } |
| ty::TyInfer(ty::TyVar(vid)) => self.deduce_expectations_from_obligations(vid), |
| ty::TyFnPtr(sig) => { |
| let expected_sig = ExpectedSig { |
| cause_span: None, |
| sig: sig.skip_binder().clone(), |
| }; |
| (Some(expected_sig), Some(ty::ClosureKind::Fn)) |
| } |
| _ => (None, None), |
| } |
| } |
| |
| fn deduce_expectations_from_obligations( |
| &self, |
| expected_vid: ty::TyVid, |
| ) -> (Option<ExpectedSig<'tcx>>, Option<ty::ClosureKind>) { |
| let fulfillment_cx = self.fulfillment_cx.borrow(); |
| // Here `expected_ty` is known to be a type inference variable. |
| |
| let expected_sig = fulfillment_cx |
| .pending_obligations() |
| .iter() |
| .filter_map(|obligation| { |
| debug!( |
| "deduce_expectations_from_obligations: obligation.predicate={:?}", |
| obligation.predicate |
| ); |
| |
| match obligation.predicate { |
| // Given a Projection predicate, we can potentially infer |
| // the complete signature. |
| ty::Predicate::Projection(ref proj_predicate) => { |
| let trait_ref = proj_predicate.to_poly_trait_ref(self.tcx); |
| self.self_type_matches_expected_vid(trait_ref, expected_vid) |
| .and_then(|_| { |
| self.deduce_sig_from_projection( |
| Some(obligation.cause.span), |
| proj_predicate, |
| ) |
| }) |
| } |
| _ => None, |
| } |
| }) |
| .next(); |
| |
| // Even if we can't infer the full signature, we may be able to |
| // infer the kind. This can occur if there is a trait-reference |
| // like `F : Fn<A>`. Note that due to subtyping we could encounter |
| // many viable options, so pick the most restrictive. |
| let expected_kind = fulfillment_cx |
| .pending_obligations() |
| .iter() |
| .filter_map(|obligation| { |
| let opt_trait_ref = match obligation.predicate { |
| ty::Predicate::Projection(ref data) => Some(data.to_poly_trait_ref(self.tcx)), |
| ty::Predicate::Trait(ref data) => Some(data.to_poly_trait_ref()), |
| ty::Predicate::Subtype(..) => None, |
| ty::Predicate::RegionOutlives(..) => None, |
| ty::Predicate::TypeOutlives(..) => None, |
| ty::Predicate::WellFormed(..) => None, |
| ty::Predicate::ObjectSafe(..) => None, |
| ty::Predicate::ConstEvaluatable(..) => None, |
| |
| // NB: This predicate is created by breaking down a |
| // `ClosureType: FnFoo()` predicate, where |
| // `ClosureType` represents some `TyClosure`. It can't |
| // possibly be referring to the current closure, |
| // because we haven't produced the `TyClosure` for |
| // this closure yet; this is exactly why the other |
| // code is looking for a self type of a unresolved |
| // inference variable. |
| ty::Predicate::ClosureKind(..) => None, |
| }; |
| opt_trait_ref |
| .and_then(|tr| self.self_type_matches_expected_vid(tr, expected_vid)) |
| .and_then(|tr| self.tcx.lang_items().fn_trait_kind(tr.def_id())) |
| }) |
| .fold(None, |best, cur| { |
| Some(best.map_or(cur, |best| cmp::min(best, cur))) |
| }); |
| |
| (expected_sig, expected_kind) |
| } |
| |
| /// Given a projection like "<F as Fn(X)>::Result == Y", we can deduce |
| /// everything we need to know about a closure. |
| /// |
| /// The `cause_span` should be the span that caused us to |
| /// have this expected signature, or `None` if we can't readily |
| /// know that. |
| fn deduce_sig_from_projection( |
| &self, |
| cause_span: Option<Span>, |
| projection: &ty::PolyProjectionPredicate<'tcx>, |
| ) -> Option<ExpectedSig<'tcx>> { |
| let tcx = self.tcx; |
| |
| debug!("deduce_sig_from_projection({:?})", projection); |
| |
| let trait_ref = projection.to_poly_trait_ref(tcx); |
| |
| if tcx.lang_items().fn_trait_kind(trait_ref.def_id()).is_none() { |
| return None; |
| } |
| |
| let arg_param_ty = trait_ref.skip_binder().substs.type_at(1); |
| let arg_param_ty = self.resolve_type_vars_if_possible(&arg_param_ty); |
| debug!( |
| "deduce_sig_from_projection: arg_param_ty {:?}", |
| arg_param_ty |
| ); |
| |
| let input_tys = match arg_param_ty.sty { |
| ty::TyTuple(tys) => tys.into_iter(), |
| _ => { |
| return None; |
| } |
| }; |
| |
| let ret_param_ty = projection.skip_binder().ty; |
| let ret_param_ty = self.resolve_type_vars_if_possible(&ret_param_ty); |
| debug!( |
| "deduce_sig_from_projection: ret_param_ty {:?}", |
| ret_param_ty |
| ); |
| |
| let sig = self.tcx.mk_fn_sig( |
| input_tys.cloned(), |
| ret_param_ty, |
| false, |
| hir::Unsafety::Normal, |
| Abi::Rust, |
| ); |
| debug!("deduce_sig_from_projection: sig {:?}", sig); |
| |
| Some(ExpectedSig { cause_span, sig }) |
| } |
| |
| fn self_type_matches_expected_vid( |
| &self, |
| trait_ref: ty::PolyTraitRef<'tcx>, |
| expected_vid: ty::TyVid, |
| ) -> Option<ty::PolyTraitRef<'tcx>> { |
| let self_ty = self.shallow_resolve(trait_ref.self_ty()); |
| debug!( |
| "self_type_matches_expected_vid(trait_ref={:?}, self_ty={:?})", |
| trait_ref, self_ty |
| ); |
| match self_ty.sty { |
| ty::TyInfer(ty::TyVar(v)) if expected_vid == v => Some(trait_ref), |
| _ => None, |
| } |
| } |
| |
| fn sig_of_closure( |
| &self, |
| expr_def_id: DefId, |
| decl: &hir::FnDecl, |
| body: &hir::Body, |
| expected_sig: Option<ExpectedSig<'tcx>>, |
| ) -> ClosureSignatures<'tcx> { |
| if let Some(e) = expected_sig { |
| self.sig_of_closure_with_expectation(expr_def_id, decl, body, e) |
| } else { |
| self.sig_of_closure_no_expectation(expr_def_id, decl, body) |
| } |
| } |
| |
| /// If there is no expected signature, then we will convert the |
| /// types that the user gave into a signature. |
| fn sig_of_closure_no_expectation( |
| &self, |
| expr_def_id: DefId, |
| decl: &hir::FnDecl, |
| body: &hir::Body, |
| ) -> ClosureSignatures<'tcx> { |
| debug!("sig_of_closure_no_expectation()"); |
| |
| let bound_sig = self.supplied_sig_of_closure(decl); |
| |
| self.closure_sigs(expr_def_id, body, bound_sig) |
| } |
| |
| /// Invoked to compute the signature of a closure expression. This |
| /// combines any user-provided type annotations (e.g., `|x: u32| |
| /// -> u32 { .. }`) with the expected signature. |
| /// |
| /// The approach is as follows: |
| /// |
| /// - Let `S` be the (higher-ranked) signature that we derive from the user's annotations. |
| /// - Let `E` be the (higher-ranked) signature that we derive from the expectations, if any. |
| /// - If we have no expectation `E`, then the signature of the closure is `S`. |
| /// - Otherwise, the signature of the closure is E. Moreover: |
| /// - Skolemize the late-bound regions in `E`, yielding `E'`. |
| /// - Instantiate all the late-bound regions bound in the closure within `S` |
| /// with fresh (existential) variables, yielding `S'` |
| /// - Require that `E' = S'` |
| /// - We could use some kind of subtyping relationship here, |
| /// I imagine, but equality is easier and works fine for |
| /// our purposes. |
| /// |
| /// The key intuition here is that the user's types must be valid |
| /// from "the inside" of the closure, but the expectation |
| /// ultimately drives the overall signature. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// fn with_closure<F>(_: F) |
| /// where F: Fn(&u32) -> &u32 { .. } |
| /// |
| /// with_closure(|x: &u32| { ... }) |
| /// ``` |
| /// |
| /// Here: |
| /// - E would be `fn(&u32) -> &u32`. |
| /// - S would be `fn(&u32) -> |
| /// - E' is `&'!0 u32 -> &'!0 u32` |
| /// - S' is `&'?0 u32 -> ?T` |
| /// |
| /// S' can be unified with E' with `['?0 = '!0, ?T = &'!10 u32]`. |
| /// |
| /// # Arguments |
| /// |
| /// - `expr_def_id`: the def-id of the closure expression |
| /// - `decl`: the HIR declaration of the closure |
| /// - `body`: the body of the closure |
| /// - `expected_sig`: the expected signature (if any). Note that |
| /// this is missing a binder: that is, there may be late-bound |
| /// regions with depth 1, which are bound then by the closure. |
| fn sig_of_closure_with_expectation( |
| &self, |
| expr_def_id: DefId, |
| decl: &hir::FnDecl, |
| body: &hir::Body, |
| expected_sig: ExpectedSig<'tcx>, |
| ) -> ClosureSignatures<'tcx> { |
| debug!( |
| "sig_of_closure_with_expectation(expected_sig={:?})", |
| expected_sig |
| ); |
| |
| // Watch out for some surprises and just ignore the |
| // expectation if things don't see to match up with what we |
| // expect. |
| if expected_sig.sig.variadic != decl.variadic { |
| return self.sig_of_closure_no_expectation(expr_def_id, decl, body); |
| } else if expected_sig.sig.inputs_and_output.len() != decl.inputs.len() + 1 { |
| return self.sig_of_closure_with_mismatched_number_of_arguments( |
| expr_def_id, |
| decl, |
| body, |
| expected_sig, |
| ); |
| } |
| |
| // Create a `PolyFnSig`. Note the oddity that late bound |
| // regions appearing free in `expected_sig` are now bound up |
| // in this binder we are creating. |
| assert!(!expected_sig.sig.has_regions_bound_above(ty::INNERMOST)); |
| let bound_sig = ty::Binder::bind(self.tcx.mk_fn_sig( |
| expected_sig.sig.inputs().iter().cloned(), |
| expected_sig.sig.output(), |
| decl.variadic, |
| hir::Unsafety::Normal, |
| Abi::RustCall, |
| )); |
| |
| // `deduce_expectations_from_expected_type` introduces |
| // late-bound lifetimes defined elsewhere, which we now |
| // anonymize away, so as not to confuse the user. |
| let bound_sig = self.tcx.anonymize_late_bound_regions(&bound_sig); |
| |
| let closure_sigs = self.closure_sigs(expr_def_id, body, bound_sig); |
| |
| // Up till this point, we have ignored the annotations that the user |
| // gave. This function will check that they unify successfully. |
| // Along the way, it also writes out entries for types that the user |
| // wrote into our tables, which are then later used by the privacy |
| // check. |
| match self.check_supplied_sig_against_expectation(decl, &closure_sigs) { |
| Ok(infer_ok) => self.register_infer_ok_obligations(infer_ok), |
| Err(_) => return self.sig_of_closure_no_expectation(expr_def_id, decl, body), |
| } |
| |
| closure_sigs |
| } |
| |
| fn sig_of_closure_with_mismatched_number_of_arguments( |
| &self, |
| expr_def_id: DefId, |
| decl: &hir::FnDecl, |
| body: &hir::Body, |
| expected_sig: ExpectedSig<'tcx>, |
| ) -> ClosureSignatures<'tcx> { |
| let expr_map_node = self.tcx.hir.get_if_local(expr_def_id).unwrap(); |
| let expected_args: Vec<_> = expected_sig |
| .sig |
| .inputs() |
| .iter() |
| .map(|ty| ArgKind::from_expected_ty(ty)) |
| .collect(); |
| let (closure_span, found_args) = self.get_fn_like_arguments(expr_map_node); |
| let expected_span = expected_sig.cause_span.unwrap_or(closure_span); |
| self.report_arg_count_mismatch( |
| expected_span, |
| Some(closure_span), |
| expected_args, |
| found_args, |
| true, |
| ).emit(); |
| |
| let error_sig = self.error_sig_of_closure(decl); |
| |
| self.closure_sigs(expr_def_id, body, error_sig) |
| } |
| |
| /// Enforce the user's types against the expectation. See |
| /// `sig_of_closure_with_expectation` for details on the overall |
| /// strategy. |
| fn check_supplied_sig_against_expectation( |
| &self, |
| decl: &hir::FnDecl, |
| expected_sigs: &ClosureSignatures<'tcx>, |
| ) -> InferResult<'tcx, ()> { |
| // Get the signature S that the user gave. |
| // |
| // (See comment on `sig_of_closure_with_expectation` for the |
| // meaning of these letters.) |
| let supplied_sig = self.supplied_sig_of_closure(decl); |
| |
| debug!( |
| "check_supplied_sig_against_expectation: supplied_sig={:?}", |
| supplied_sig |
| ); |
| |
| // FIXME(#45727): As discussed in [this comment][c1], naively |
| // forcing equality here actually results in suboptimal error |
| // messages in some cases. For now, if there would have been |
| // an obvious error, we fallback to declaring the type of the |
| // closure to be the one the user gave, which allows other |
| // error message code to trigger. |
| // |
| // However, I think [there is potential to do even better |
| // here][c2], since in *this* code we have the precise span of |
| // the type parameter in question in hand when we report the |
| // error. |
| // |
| // [c1]: https://github.com/rust-lang/rust/pull/45072#issuecomment-341089706 |
| // [c2]: https://github.com/rust-lang/rust/pull/45072#issuecomment-341096796 |
| self.infcx.commit_if_ok(|_| { |
| let mut all_obligations = vec![]; |
| |
| // The liberated version of this signature should be be a subtype |
| // of the liberated form of the expectation. |
| for ((hir_ty, &supplied_ty), expected_ty) in decl.inputs.iter() |
| .zip(*supplied_sig.inputs().skip_binder()) // binder moved to (*) below |
| .zip(expected_sigs.liberated_sig.inputs()) |
| // `liberated_sig` is E'. |
| { |
| // Instantiate (this part of..) S to S', i.e., with fresh variables. |
| let (supplied_ty, _) = self.infcx.replace_late_bound_regions_with_fresh_var( |
| hir_ty.span, |
| LateBoundRegionConversionTime::FnCall, |
| &ty::Binder::bind(supplied_ty), |
| ); // recreated from (*) above |
| |
| // Check that E' = S'. |
| let cause = &self.misc(hir_ty.span); |
| let InferOk { |
| value: (), |
| obligations, |
| } = self.at(cause, self.param_env) |
| .eq(*expected_ty, supplied_ty)?; |
| all_obligations.extend(obligations); |
| } |
| |
| let (supplied_output_ty, _) = self.infcx.replace_late_bound_regions_with_fresh_var( |
| decl.output.span(), |
| LateBoundRegionConversionTime::FnCall, |
| &supplied_sig.output(), |
| ); |
| let cause = &self.misc(decl.output.span()); |
| let InferOk { |
| value: (), |
| obligations, |
| } = self.at(cause, self.param_env) |
| .eq(expected_sigs.liberated_sig.output(), supplied_output_ty)?; |
| all_obligations.extend(obligations); |
| |
| Ok(InferOk { |
| value: (), |
| obligations: all_obligations, |
| }) |
| }) |
| } |
| |
| /// If there is no expected signature, then we will convert the |
| /// types that the user gave into a signature. |
| fn supplied_sig_of_closure(&self, decl: &hir::FnDecl) -> ty::PolyFnSig<'tcx> { |
| let astconv: &dyn AstConv = self; |
| |
| // First, convert the types that the user supplied (if any). |
| let supplied_arguments = decl.inputs.iter().map(|a| astconv.ast_ty_to_ty(a)); |
| let supplied_return = match decl.output { |
| hir::Return(ref output) => astconv.ast_ty_to_ty(&output), |
| hir::DefaultReturn(_) => astconv.ty_infer(decl.output.span()), |
| }; |
| |
| let result = ty::Binder::bind(self.tcx.mk_fn_sig( |
| supplied_arguments, |
| supplied_return, |
| decl.variadic, |
| hir::Unsafety::Normal, |
| Abi::RustCall, |
| )); |
| |
| debug!("supplied_sig_of_closure: result={:?}", result); |
| |
| result |
| } |
| |
| /// Converts the types that the user supplied, in case that doing |
| /// so should yield an error, but returns back a signature where |
| /// all parameters are of type `TyErr`. |
| fn error_sig_of_closure(&self, decl: &hir::FnDecl) -> ty::PolyFnSig<'tcx> { |
| let astconv: &dyn AstConv = self; |
| |
| let supplied_arguments = decl.inputs.iter().map(|a| { |
| // Convert the types that the user supplied (if any), but ignore them. |
| astconv.ast_ty_to_ty(a); |
| self.tcx.types.err |
| }); |
| |
| match decl.output { |
| hir::Return(ref output) => { |
| astconv.ast_ty_to_ty(&output); |
| } |
| hir::DefaultReturn(_) => {} |
| } |
| |
| let result = ty::Binder::bind(self.tcx.mk_fn_sig( |
| supplied_arguments, |
| self.tcx.types.err, |
| decl.variadic, |
| hir::Unsafety::Normal, |
| Abi::RustCall, |
| )); |
| |
| debug!("supplied_sig_of_closure: result={:?}", result); |
| |
| result |
| } |
| |
| fn closure_sigs( |
| &self, |
| expr_def_id: DefId, |
| body: &hir::Body, |
| bound_sig: ty::PolyFnSig<'tcx>, |
| ) -> ClosureSignatures<'tcx> { |
| let liberated_sig = self.tcx() |
| .liberate_late_bound_regions(expr_def_id, &bound_sig); |
| let liberated_sig = self.inh.normalize_associated_types_in( |
| body.value.span, |
| body.value.id, |
| self.param_env, |
| &liberated_sig, |
| ); |
| ClosureSignatures { |
| bound_sig, |
| liberated_sig, |
| } |
| } |
| } |