Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/infer/closure.rs')
| -rw-r--r-- | crates/hir-ty/src/infer/closure.rs | 266 |
1 files changed, 185 insertions, 81 deletions
diff --git a/crates/hir-ty/src/infer/closure.rs b/crates/hir-ty/src/infer/closure.rs index ce99016470..2cb936fec3 100644 --- a/crates/hir-ty/src/infer/closure.rs +++ b/crates/hir-ty/src/infer/closure.rs @@ -6,7 +6,7 @@ use std::{iter, mem, ops::ControlFlow}; use hir_def::{ TraitId, - hir::{ClosureKind, ExprId, PatId}, + hir::{ClosureKind, CoroutineSource, ExprId, PatId}, type_ref::TypeRefId, }; use rustc_type_ir::{ @@ -19,11 +19,11 @@ use tracing::debug; use crate::{ FnAbi, - db::{InternedClosure, InternedCoroutine}, + db::{InternedClosure, InternedClosureId, InternedCoroutineClosureId, InternedCoroutineId}, infer::{BreakableKind, Diverges, coerce::CoerceMany}, next_solver::{ AliasTy, Binder, ClauseKind, DbInterner, ErrorGuaranteed, FnSig, GenericArgs, PolyFnSig, - PolyProjectionPredicate, Predicate, PredicateKind, SolverDefId, Ty, TyKind, + PolyProjectionPredicate, Predicate, PredicateKind, SolverDefId, Ty, TyKind, Tys, abi::Safety, infer::{ BoundRegionConversionTime, InferOk, InferResult, @@ -54,52 +54,47 @@ impl<'db> InferenceContext<'_, 'db> { ret_type: Option<TypeRefId>, arg_types: &[Option<TypeRefId>], closure_kind: ClosureKind, - tgt_expr: ExprId, + closure_expr: ExprId, expected: &Expectation<'db>, ) -> Ty<'db> { assert_eq!(args.len(), arg_types.len()); let interner = self.interner(); + // 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(&mut self.table) { - Some(expected_ty) => self.deduce_closure_signature(expected_ty, closure_kind), + Some(ty) => { + let ty = self.table.try_structurally_resolve_type(ty); + self.deduce_closure_signature(ty, closure_kind) + } None => (None, None), }; - let ClosureSignatures { bound_sig, liberated_sig } = + let ClosureSignatures { bound_sig, mut liberated_sig } = self.sig_of_closure(arg_types, ret_type, expected_sig); - let body_ret_ty = bound_sig.output().skip_binder(); - let parent_args = GenericArgs::identity_for_item(interner, self.generic_def.into()); - // FIXME: Make this an infer var and infer it later. - let tupled_upvars_ty = self.types.types.unit; - let (id, ty, resume_yield_tys) = match closure_kind { - ClosureKind::Coroutine(_) => { - let yield_ty = self.table.next_ty_var(); - let resume_ty = - liberated_sig.inputs().first().copied().unwrap_or(self.types.types.unit); + debug!(?bound_sig, ?liberated_sig); - // FIXME: Infer the upvars later. - let parts = CoroutineArgsParts { - parent_args: parent_args.as_slice(), - kind_ty: self.types.types.unit, - resume_ty, - yield_ty, - return_ty: body_ret_ty, - tupled_upvars_ty, - }; + let parent_args = GenericArgs::identity_for_item(interner, self.generic_def.into()); - let coroutine_id = - self.db.intern_coroutine(InternedCoroutine(self.owner, tgt_expr)).into(); - let coroutine_ty = Ty::new_coroutine( - interner, - coroutine_id, - CoroutineArgs::new(interner, parts).args, - ); + // FIXME: Do this when we infer closures correctly: + // let tupled_upvars_ty = self.table.next_ty_var(); + let tupled_upvars_ty = self.types.types.unit; - (None, coroutine_ty, Some((resume_ty, yield_ty))) - } + let mut current_closure_id = None; + // FIXME: We could probably actually just unify this further -- + // instead of having a `FnSig` and a `Option<CoroutineTypes>`, + // we can have a `ClosureSignature { Coroutine { .. }, Closure { .. } }`, + // similar to how `ty::GenSig` is a distinct data structure. + let (closure_ty, resume_yield_tys) = match closure_kind { ClosureKind::Closure => { - let closure_id = self.db.intern_closure(InternedClosure(self.owner, tgt_expr)); + let closure_id = + InternedClosureId::new(self.db, InternedClosure(self.owner, closure_expr)); + current_closure_id = Some(closure_id); + self.deferred_closures.entry(closure_id).or_default(); + self.add_current_closure_dependency(closure_id); + match expected_kind { Some(kind) => { self.result.closure_info.insert( @@ -116,6 +111,9 @@ impl<'db> InferenceContext<'_, 'db> { } None => {} }; + + // Tuple up the arguments and insert the resulting function type into + // the `closures` table. let sig = bound_sig.map_bound(|sig| { interner.mk_fn_sig( [Ty::new_tup(interner, sig.inputs())], @@ -125,52 +123,101 @@ impl<'db> InferenceContext<'_, 'db> { sig.abi, ) }); - let sig_ty = Ty::new_fn_ptr(interner, sig); - // FIXME: Infer the kind later if needed. - let parts = ClosureArgsParts { - parent_args: parent_args.as_slice(), - closure_kind_ty: Ty::from_closure_kind( - interner, - expected_kind.unwrap_or(rustc_type_ir::ClosureKind::Fn), - ), - closure_sig_as_fn_ptr_ty: sig_ty, - tupled_upvars_ty, + + debug!(?sig, ?expected_kind); + + let closure_kind_ty = match expected_kind { + Some(kind) => Ty::from_closure_kind(interner, kind), + // Create a type variable (for now) to represent the closure kind. + // It will be unified during the upvar inference phase (`upvar.rs`) + // FIXME: This too should be the next line: + // None => self.table.next_ty_var(), + None => self.types.types.i8, }; - let closure_ty = Ty::new_closure( + + let closure_args = ClosureArgs::new( interner, - closure_id.into(), - ClosureArgs::new(interner, parts).args, + ClosureArgsParts { + parent_args: parent_args.as_slice(), + closure_kind_ty, + closure_sig_as_fn_ptr_ty: Ty::new_fn_ptr(interner, sig), + tupled_upvars_ty, + }, ); - self.deferred_closures.entry(closure_id).or_default(); - self.add_current_closure_dependency(closure_id); - (Some(closure_id), closure_ty, None) + + (Ty::new_closure(interner, closure_id.into(), closure_args.args), None) } - ClosureKind::Async => { - // async closures always return the type ascribed after the `->` (if present), - // and yield `()`. - let bound_return_ty = bound_sig.skip_binder().output(); - let bound_yield_ty = self.types.types.unit; - // rustc uses a special lang item type for the resume ty. I don't believe this can cause us problems. - let resume_ty = self.types.types.unit; + ClosureKind::Coroutine(_) | ClosureKind::AsyncBlock { .. } => { + let yield_ty = match closure_kind { + ClosureKind::Coroutine(_) => self.table.next_ty_var(), + ClosureKind::AsyncBlock { .. } => self.types.types.unit, + _ => unreachable!(), + }; + + // Resume type defaults to `()` if the coroutine has no argument. + let resume_ty = + liberated_sig.inputs().first().copied().unwrap_or(self.types.types.unit); - // FIXME: Infer the kind later if needed. - let closure_kind_ty = Ty::from_closure_kind( + // Coroutines that come from coroutine closures have not yet determined + // their kind ty, so make a fresh infer var which will be constrained + // later during upvar analysis. Regular coroutines always have the kind + // ty of `().` + let kind_ty = match closure_kind { + ClosureKind::AsyncBlock { source: CoroutineSource::Closure } => { + self.table.next_ty_var() + } + _ => self.types.types.unit, + }; + + let coroutine_args = CoroutineArgs::new( interner, - expected_kind.unwrap_or(rustc_type_ir::ClosureKind::Fn), + CoroutineArgsParts { + parent_args: parent_args.as_slice(), + kind_ty, + resume_ty, + yield_ty, + return_ty: liberated_sig.output(), + tupled_upvars_ty, + }, ); - // FIXME: Infer captures later. - // `for<'env> fn() -> ()`, for no captures. + let coroutine_id = + InternedCoroutineId::new(self.db, InternedClosure(self.owner, closure_expr)); + + ( + Ty::new_coroutine(interner, coroutine_id.into(), coroutine_args.args), + Some((resume_ty, yield_ty)), + ) + } + ClosureKind::AsyncClosure => { + // async closures always return the type ascribed after the `->` (if present), + // and yield `()`. + let (bound_return_ty, bound_yield_ty) = + (bound_sig.skip_binder().output(), self.types.types.unit); + // Compute all of the variables that will be used to populate the coroutine. + let resume_ty = self.table.next_ty_var(); + + let closure_kind_ty = match expected_kind { + Some(kind) => Ty::from_closure_kind(interner, kind), + + // Create a type variable (for now) to represent the closure kind. + // It will be unified during the upvar inference phase (`upvar.rs`) + // FIXME: Here again the next line should be active. + // None => self.table.next_ty_var(), + None => self.types.types.i8, + }; + + // FIXME: Another line that should be enabled. + // let coroutine_captures_by_ref_ty = self.table.next_ty_var(); let coroutine_captures_by_ref_ty = Ty::new_fn_ptr( interner, Binder::bind_with_vars( - interner.mk_fn_sig( - [], - self.types.types.unit, - false, - Safety::Safe, - FnAbi::Rust, - ), + FnSig { + inputs_and_output: Tys::new_from_slice(&[self.types.types.unit]), + c_variadic: false, + safety: Safety::Safe, + abi: FnAbi::Rust, + }, self.types.coroutine_captures_by_ref_bound_var_kinds, ), ); @@ -183,7 +230,13 @@ impl<'db> InferenceContext<'_, 'db> { interner, bound_sig.map_bound(|sig| { interner.mk_fn_sig( - [resume_ty, Ty::new_tup(interner, sig.inputs())], + [ + resume_ty, + Ty::new_tup_from_iter( + interner, + sig.inputs().iter().copied(), + ), + ], Ty::new_tup(interner, &[bound_yield_ty, bound_return_ty]), sig.c_variadic, sig.safety, @@ -196,9 +249,57 @@ impl<'db> InferenceContext<'_, 'db> { }, ); - let coroutine_id = - self.db.intern_coroutine(InternedCoroutine(self.owner, tgt_expr)).into(); - (None, Ty::new_coroutine_closure(interner, coroutine_id, closure_args.args), None) + let coroutine_kind_ty = match expected_kind { + Some(kind) => Ty::from_coroutine_closure_kind(interner, kind), + + // Create a type variable (for now) to represent the closure kind. + // It will be unified during the upvar inference phase (`upvar.rs`) + // FIXME: And here again. + // None => self.table.next_ty_var(), + None => self.types.types.i16, + }; + + let coroutine_upvars_ty = self.table.next_ty_var(); + + let coroutine_closure_id = InternedCoroutineClosureId::new( + self.db, + InternedClosure(self.owner, closure_expr), + ); + + // We need to turn the liberated signature that we got from HIR, which + // looks something like `|Args...| -> T`, into a signature that is suitable + // for type checking the inner body of the closure, which always returns a + // coroutine. To do so, we use the `CoroutineClosureSignature` to compute + // the coroutine type, filling in the tupled_upvars_ty and kind_ty with infer + // vars which will get constrained during upvar analysis. + let coroutine_output_ty = closure_args + .coroutine_closure_sig() + .map_bound(|sig| { + sig.to_coroutine( + interner, + parent_args.as_slice(), + coroutine_kind_ty, + interner.coroutine_for_closure(coroutine_closure_id.into()), + coroutine_upvars_ty, + ) + }) + .skip_binder(); + liberated_sig = interner.mk_fn_sig( + liberated_sig.inputs().iter().copied(), + coroutine_output_ty, + liberated_sig.c_variadic, + liberated_sig.safety, + liberated_sig.abi, + ); + + ( + Ty::new_coroutine_closure( + interner, + coroutine_closure_id.into(), + closure_args.args, + ), + None, + ) } }; @@ -209,9 +310,10 @@ impl<'db> InferenceContext<'_, 'db> { // FIXME: lift these out into a struct let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe); - let prev_closure = mem::replace(&mut self.current_closure, id); - let prev_ret_ty = mem::replace(&mut self.return_ty, body_ret_ty); - let prev_ret_coercion = self.return_coercion.replace(CoerceMany::new(body_ret_ty)); + let prev_closure = mem::replace(&mut self.current_closure, current_closure_id); + let prev_ret_ty = mem::replace(&mut self.return_ty, liberated_sig.output()); + let prev_ret_coercion = + self.return_coercion.replace(CoerceMany::new(liberated_sig.output())); let prev_resume_yield_tys = mem::replace(&mut self.resume_yield_tys, resume_yield_tys); self.with_breakable_ctx(BreakableKind::Border, None, None, |this| { @@ -224,7 +326,7 @@ impl<'db> InferenceContext<'_, 'db> { self.current_closure = prev_closure; self.resume_yield_tys = prev_resume_yield_tys; - ty + closure_ty } fn fn_trait_kind_from_def_id(&self, trait_id: TraitId) -> Option<rustc_type_ir::ClosureKind> { @@ -293,7 +395,9 @@ impl<'db> InferenceContext<'_, 'db> { let expected_sig = sig_tys.with(hdr); (Some(expected_sig), Some(rustc_type_ir::ClosureKind::Fn)) } - ClosureKind::Coroutine(_) | ClosureKind::Async => (None, None), + ClosureKind::Coroutine(_) + | ClosureKind::AsyncClosure + | ClosureKind::AsyncBlock { .. } => (None, None), }, _ => (None, None), } @@ -406,7 +510,7 @@ impl<'db> InferenceContext<'_, 'db> { if let Some(trait_def_id) = trait_def_id { let found_kind = match closure_kind { ClosureKind::Closure => self.fn_trait_kind_from_def_id(trait_def_id), - ClosureKind::Async => self + ClosureKind::AsyncClosure => self .async_fn_trait_kind_from_def_id(trait_def_id) .or_else(|| self.fn_trait_kind_from_def_id(trait_def_id)), _ => None, @@ -452,13 +556,13 @@ impl<'db> InferenceContext<'_, 'db> { ClosureKind::Closure if Some(def_id) == self.lang_items.FnOnceOutput => { self.extract_sig_from_projection(projection) } - ClosureKind::Async if Some(def_id) == self.lang_items.AsyncFnOnceOutput => { + ClosureKind::AsyncClosure if Some(def_id) == self.lang_items.AsyncFnOnceOutput => { self.extract_sig_from_projection(projection) } // It's possible we've passed the closure to a (somewhat out-of-fashion) // `F: FnOnce() -> Fut, Fut: Future<Output = T>` style bound. Let's still // guide inference here, since it's beneficial for the user. - ClosureKind::Async if Some(def_id) == self.lang_items.FnOnceOutput => { + ClosureKind::AsyncClosure if Some(def_id) == self.lang_items.FnOnceOutput => { self.extract_sig_from_projection_and_future_bound(projection) } _ => None, |