diff options
Diffstat (limited to 'compiler/rustc_traits/src/chalk/db.rs')
| -rw-r--r-- | compiler/rustc_traits/src/chalk/db.rs | 796 |
1 files changed, 796 insertions, 0 deletions
diff --git a/compiler/rustc_traits/src/chalk/db.rs b/compiler/rustc_traits/src/chalk/db.rs new file mode 100644 index 000000000..ff5ca0cbc --- /dev/null +++ b/compiler/rustc_traits/src/chalk/db.rs @@ -0,0 +1,796 @@ +//! Provides the `RustIrDatabase` implementation for `chalk-solve` +//! +//! The purpose of the `chalk_solve::RustIrDatabase` is to get data about +//! specific types, such as bounds, where clauses, or fields. This file contains +//! the minimal logic to assemble the types for `chalk-solve` by calling out to +//! either the `TyCtxt` (for information about types) or +//! `crate::chalk::lowering` (to lower rustc types into Chalk types). + +use rustc_middle::traits::ChalkRustInterner as RustInterner; +use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef}; +use rustc_middle::ty::{self, AssocKind, EarlyBinder, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable}; + +use rustc_ast::ast; +use rustc_attr as attr; + +use rustc_hir::def_id::DefId; + +use rustc_span::symbol::sym; + +use std::fmt; +use std::sync::Arc; + +use crate::chalk::lowering::LowerInto; + +pub struct RustIrDatabase<'tcx> { + pub(crate) interner: RustInterner<'tcx>, +} + +impl fmt::Debug for RustIrDatabase<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "RustIrDatabase") + } +} + +impl<'tcx> RustIrDatabase<'tcx> { + fn where_clauses_for( + &self, + def_id: DefId, + bound_vars: SubstsRef<'tcx>, + ) -> Vec<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> { + let predicates = self.interner.tcx.predicates_defined_on(def_id).predicates; + predicates + .iter() + .map(|(wc, _)| EarlyBinder(*wc).subst(self.interner.tcx, bound_vars)) + .filter_map(|wc| LowerInto::< + Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> + >::lower_into(wc, self.interner)).collect() + } + + fn bounds_for<T>(&self, def_id: DefId, bound_vars: SubstsRef<'tcx>) -> Vec<T> + where + ty::Predicate<'tcx>: LowerInto<'tcx, std::option::Option<T>>, + { + let bounds = self.interner.tcx.bound_explicit_item_bounds(def_id); + bounds + .0 + .iter() + .map(|(bound, _)| bounds.rebind(*bound).subst(self.interner.tcx, &bound_vars)) + .filter_map(|bound| LowerInto::<Option<_>>::lower_into(bound, self.interner)) + .collect() + } +} + +impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'tcx> { + fn interner(&self) -> RustInterner<'tcx> { + self.interner + } + + fn associated_ty_data( + &self, + assoc_type_id: chalk_ir::AssocTypeId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::AssociatedTyDatum<RustInterner<'tcx>>> { + let def_id = assoc_type_id.0; + let assoc_item = self.interner.tcx.associated_item(def_id); + let Some(trait_def_id) = assoc_item.trait_container(self.interner.tcx) else { + unimplemented!("Not possible??"); + }; + match assoc_item.kind { + AssocKind::Type => {} + _ => unimplemented!("Not possible??"), + } + let bound_vars = bound_vars_for_item(self.interner.tcx, def_id); + let binders = binders_for(self.interner, bound_vars); + + let where_clauses = self.where_clauses_for(def_id, bound_vars); + let bounds = self.bounds_for(def_id, bound_vars); + + Arc::new(chalk_solve::rust_ir::AssociatedTyDatum { + trait_id: chalk_ir::TraitId(trait_def_id), + id: assoc_type_id, + name: (), + binders: chalk_ir::Binders::new( + binders, + chalk_solve::rust_ir::AssociatedTyDatumBound { bounds, where_clauses }, + ), + }) + } + + fn trait_datum( + &self, + trait_id: chalk_ir::TraitId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::TraitDatum<RustInterner<'tcx>>> { + use chalk_solve::rust_ir::WellKnownTrait::*; + + let def_id = trait_id.0; + let trait_def = self.interner.tcx.trait_def(def_id); + + let bound_vars = bound_vars_for_item(self.interner.tcx, def_id); + let binders = binders_for(self.interner, bound_vars); + + let where_clauses = self.where_clauses_for(def_id, bound_vars); + + let associated_ty_ids: Vec<_> = self + .interner + .tcx + .associated_items(def_id) + .in_definition_order() + .filter(|i| i.kind == AssocKind::Type) + .map(|i| chalk_ir::AssocTypeId(i.def_id)) + .collect(); + + let lang_items = self.interner.tcx.lang_items(); + let well_known = if lang_items.sized_trait() == Some(def_id) { + Some(Sized) + } else if lang_items.copy_trait() == Some(def_id) { + Some(Copy) + } else if lang_items.clone_trait() == Some(def_id) { + Some(Clone) + } else if lang_items.drop_trait() == Some(def_id) { + Some(Drop) + } else if lang_items.fn_trait() == Some(def_id) { + Some(Fn) + } else if lang_items.fn_once_trait() == Some(def_id) { + Some(FnOnce) + } else if lang_items.fn_mut_trait() == Some(def_id) { + Some(FnMut) + } else if lang_items.unsize_trait() == Some(def_id) { + Some(Unsize) + } else if lang_items.unpin_trait() == Some(def_id) { + Some(Unpin) + } else if lang_items.coerce_unsized_trait() == Some(def_id) { + Some(CoerceUnsized) + } else if lang_items.dispatch_from_dyn_trait() == Some(def_id) { + Some(DispatchFromDyn) + } else { + None + }; + Arc::new(chalk_solve::rust_ir::TraitDatum { + id: trait_id, + binders: chalk_ir::Binders::new( + binders, + chalk_solve::rust_ir::TraitDatumBound { where_clauses }, + ), + flags: chalk_solve::rust_ir::TraitFlags { + auto: trait_def.has_auto_impl, + marker: trait_def.is_marker, + upstream: !def_id.is_local(), + fundamental: self.interner.tcx.has_attr(def_id, sym::fundamental), + non_enumerable: true, + coinductive: false, + }, + associated_ty_ids, + well_known, + }) + } + + fn adt_datum( + &self, + adt_id: chalk_ir::AdtId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::AdtDatum<RustInterner<'tcx>>> { + let adt_def = adt_id.0; + + let bound_vars = bound_vars_for_item(self.interner.tcx, adt_def.did()); + let binders = binders_for(self.interner, bound_vars); + + let where_clauses = self.where_clauses_for(adt_def.did(), bound_vars); + + let variants: Vec<_> = adt_def + .variants() + .iter() + .map(|variant| chalk_solve::rust_ir::AdtVariantDatum { + fields: variant + .fields + .iter() + .map(|field| field.ty(self.interner.tcx, bound_vars).lower_into(self.interner)) + .collect(), + }) + .collect(); + Arc::new(chalk_solve::rust_ir::AdtDatum { + id: adt_id, + binders: chalk_ir::Binders::new( + binders, + chalk_solve::rust_ir::AdtDatumBound { variants, where_clauses }, + ), + flags: chalk_solve::rust_ir::AdtFlags { + upstream: !adt_def.did().is_local(), + fundamental: adt_def.is_fundamental(), + phantom_data: adt_def.is_phantom_data(), + }, + kind: match adt_def.adt_kind() { + ty::AdtKind::Struct => chalk_solve::rust_ir::AdtKind::Struct, + ty::AdtKind::Union => chalk_solve::rust_ir::AdtKind::Union, + ty::AdtKind::Enum => chalk_solve::rust_ir::AdtKind::Enum, + }, + }) + } + + fn adt_repr( + &self, + adt_id: chalk_ir::AdtId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::AdtRepr<RustInterner<'tcx>>> { + let adt_def = adt_id.0; + let int = |i| chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Int(i)).intern(self.interner); + let uint = |i| chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Uint(i)).intern(self.interner); + Arc::new(chalk_solve::rust_ir::AdtRepr { + c: adt_def.repr().c(), + packed: adt_def.repr().packed(), + int: adt_def.repr().int.map(|i| match i { + attr::IntType::SignedInt(ty) => match ty { + ast::IntTy::Isize => int(chalk_ir::IntTy::Isize), + ast::IntTy::I8 => int(chalk_ir::IntTy::I8), + ast::IntTy::I16 => int(chalk_ir::IntTy::I16), + ast::IntTy::I32 => int(chalk_ir::IntTy::I32), + ast::IntTy::I64 => int(chalk_ir::IntTy::I64), + ast::IntTy::I128 => int(chalk_ir::IntTy::I128), + }, + attr::IntType::UnsignedInt(ty) => match ty { + ast::UintTy::Usize => uint(chalk_ir::UintTy::Usize), + ast::UintTy::U8 => uint(chalk_ir::UintTy::U8), + ast::UintTy::U16 => uint(chalk_ir::UintTy::U16), + ast::UintTy::U32 => uint(chalk_ir::UintTy::U32), + ast::UintTy::U64 => uint(chalk_ir::UintTy::U64), + ast::UintTy::U128 => uint(chalk_ir::UintTy::U128), + }, + }), + }) + } + + fn adt_size_align( + &self, + adt_id: chalk_ir::AdtId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::AdtSizeAlign> { + let tcx = self.interner.tcx; + let did = adt_id.0.did(); + + // Grab the ADT and the param we might need to calculate its layout + let param_env = tcx.param_env(did); + let adt_ty = tcx.type_of(did); + + // The ADT is a 1-zst if it's a ZST and its alignment is 1. + // Mark the ADT as _not_ a 1-zst if there was a layout error. + let one_zst = if let Ok(layout) = tcx.layout_of(param_env.and(adt_ty)) { + layout.is_zst() && layout.align.abi.bytes() == 1 + } else { + false + }; + + Arc::new(chalk_solve::rust_ir::AdtSizeAlign::from_one_zst(one_zst)) + } + + fn fn_def_datum( + &self, + fn_def_id: chalk_ir::FnDefId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::FnDefDatum<RustInterner<'tcx>>> { + let def_id = fn_def_id.0; + let bound_vars = bound_vars_for_item(self.interner.tcx, def_id); + let binders = binders_for(self.interner, bound_vars); + + let where_clauses = self.where_clauses_for(def_id, bound_vars); + + let sig = self.interner.tcx.bound_fn_sig(def_id); + let (inputs_and_output, iobinders, _) = crate::chalk::lowering::collect_bound_vars( + self.interner, + self.interner.tcx, + sig.map_bound(|s| s.inputs_and_output()).subst(self.interner.tcx, bound_vars), + ); + + let argument_types = inputs_and_output[..inputs_and_output.len() - 1] + .iter() + .map(|t| sig.rebind(*t).subst(self.interner.tcx, &bound_vars).lower_into(self.interner)) + .collect(); + + let return_type = sig + .rebind(inputs_and_output[inputs_and_output.len() - 1]) + .subst(self.interner.tcx, &bound_vars) + .lower_into(self.interner); + + let bound = chalk_solve::rust_ir::FnDefDatumBound { + inputs_and_output: chalk_ir::Binders::new( + iobinders, + chalk_solve::rust_ir::FnDefInputsAndOutputDatum { argument_types, return_type }, + ), + where_clauses, + }; + Arc::new(chalk_solve::rust_ir::FnDefDatum { + id: fn_def_id, + sig: sig.0.lower_into(self.interner), + binders: chalk_ir::Binders::new(binders, bound), + }) + } + + fn impl_datum( + &self, + impl_id: chalk_ir::ImplId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::ImplDatum<RustInterner<'tcx>>> { + let def_id = impl_id.0; + let bound_vars = bound_vars_for_item(self.interner.tcx, def_id); + let binders = binders_for(self.interner, bound_vars); + + let trait_ref = self.interner.tcx.bound_impl_trait_ref(def_id).expect("not an impl"); + let trait_ref = trait_ref.subst(self.interner.tcx, bound_vars); + + let where_clauses = self.where_clauses_for(def_id, bound_vars); + + let value = chalk_solve::rust_ir::ImplDatumBound { + trait_ref: trait_ref.lower_into(self.interner), + where_clauses, + }; + + let associated_ty_value_ids: Vec<_> = self + .interner + .tcx + .associated_items(def_id) + .in_definition_order() + .filter(|i| i.kind == AssocKind::Type) + .map(|i| chalk_solve::rust_ir::AssociatedTyValueId(i.def_id)) + .collect(); + + Arc::new(chalk_solve::rust_ir::ImplDatum { + polarity: self.interner.tcx.impl_polarity(def_id).lower_into(self.interner), + binders: chalk_ir::Binders::new(binders, value), + impl_type: chalk_solve::rust_ir::ImplType::Local, + associated_ty_value_ids, + }) + } + + fn impls_for_trait( + &self, + trait_id: chalk_ir::TraitId<RustInterner<'tcx>>, + parameters: &[chalk_ir::GenericArg<RustInterner<'tcx>>], + _binders: &chalk_ir::CanonicalVarKinds<RustInterner<'tcx>>, + ) -> Vec<chalk_ir::ImplId<RustInterner<'tcx>>> { + let def_id = trait_id.0; + + // FIXME(chalk): use TraitDef::for_each_relevant_impl, but that will + // require us to be able to interconvert `Ty<'tcx>`, and we're + // not there yet. + + let all_impls = self.interner.tcx.all_impls(def_id); + let matched_impls = all_impls.filter(|impl_def_id| { + use chalk_ir::could_match::CouldMatch; + let trait_ref = self.interner.tcx.bound_impl_trait_ref(*impl_def_id).unwrap(); + let bound_vars = bound_vars_for_item(self.interner.tcx, *impl_def_id); + + let self_ty = trait_ref.map_bound(|t| t.self_ty()); + let self_ty = self_ty.subst(self.interner.tcx, bound_vars); + let lowered_ty = self_ty.lower_into(self.interner); + + parameters[0].assert_ty_ref(self.interner).could_match( + self.interner, + self.unification_database(), + &lowered_ty, + ) + }); + + let impls = matched_impls.map(chalk_ir::ImplId).collect(); + impls + } + + fn impl_provided_for( + &self, + auto_trait_id: chalk_ir::TraitId<RustInterner<'tcx>>, + chalk_ty: &chalk_ir::TyKind<RustInterner<'tcx>>, + ) -> bool { + use chalk_ir::Scalar::*; + use chalk_ir::TyKind::*; + + let trait_def_id = auto_trait_id.0; + let all_impls = self.interner.tcx.all_impls(trait_def_id); + for impl_def_id in all_impls { + let trait_ref = self.interner.tcx.impl_trait_ref(impl_def_id).unwrap(); + let self_ty = trait_ref.self_ty(); + let provides = match (self_ty.kind(), chalk_ty) { + (&ty::Adt(impl_adt_def, ..), Adt(id, ..)) => impl_adt_def.did() == id.0.did(), + (_, AssociatedType(_ty_id, ..)) => { + // FIXME(chalk): See https://github.com/rust-lang/rust/pull/77152#discussion_r494484774 + false + } + (ty::Bool, Scalar(Bool)) => true, + (ty::Char, Scalar(Char)) => true, + (ty::Int(ty1), Scalar(Int(ty2))) => matches!( + (ty1, ty2), + (ty::IntTy::Isize, chalk_ir::IntTy::Isize) + | (ty::IntTy::I8, chalk_ir::IntTy::I8) + | (ty::IntTy::I16, chalk_ir::IntTy::I16) + | (ty::IntTy::I32, chalk_ir::IntTy::I32) + | (ty::IntTy::I64, chalk_ir::IntTy::I64) + | (ty::IntTy::I128, chalk_ir::IntTy::I128) + ), + (ty::Uint(ty1), Scalar(Uint(ty2))) => matches!( + (ty1, ty2), + (ty::UintTy::Usize, chalk_ir::UintTy::Usize) + | (ty::UintTy::U8, chalk_ir::UintTy::U8) + | (ty::UintTy::U16, chalk_ir::UintTy::U16) + | (ty::UintTy::U32, chalk_ir::UintTy::U32) + | (ty::UintTy::U64, chalk_ir::UintTy::U64) + | (ty::UintTy::U128, chalk_ir::UintTy::U128) + ), + (ty::Float(ty1), Scalar(Float(ty2))) => matches!( + (ty1, ty2), + (ty::FloatTy::F32, chalk_ir::FloatTy::F32) + | (ty::FloatTy::F64, chalk_ir::FloatTy::F64) + ), + (&ty::Tuple(substs), Tuple(len, _)) => substs.len() == *len, + (&ty::Array(..), Array(..)) => true, + (&ty::Slice(..), Slice(..)) => true, + (&ty::RawPtr(type_and_mut), Raw(mutability, _)) => { + match (type_and_mut.mutbl, mutability) { + (ast::Mutability::Mut, chalk_ir::Mutability::Mut) => true, + (ast::Mutability::Mut, chalk_ir::Mutability::Not) => false, + (ast::Mutability::Not, chalk_ir::Mutability::Mut) => false, + (ast::Mutability::Not, chalk_ir::Mutability::Not) => true, + } + } + (&ty::Ref(.., mutability1), Ref(mutability2, ..)) => { + match (mutability1, mutability2) { + (ast::Mutability::Mut, chalk_ir::Mutability::Mut) => true, + (ast::Mutability::Mut, chalk_ir::Mutability::Not) => false, + (ast::Mutability::Not, chalk_ir::Mutability::Mut) => false, + (ast::Mutability::Not, chalk_ir::Mutability::Not) => true, + } + } + (&ty::Opaque(def_id, ..), OpaqueType(opaque_ty_id, ..)) => def_id == opaque_ty_id.0, + (&ty::FnDef(def_id, ..), FnDef(fn_def_id, ..)) => def_id == fn_def_id.0, + (&ty::Str, Str) => true, + (&ty::Never, Never) => true, + (&ty::Closure(def_id, ..), Closure(closure_id, _)) => def_id == closure_id.0, + (&ty::Foreign(def_id), Foreign(foreign_def_id)) => def_id == foreign_def_id.0, + (&ty::Error(..), Error) => false, + _ => false, + }; + if provides { + return true; + } + } + false + } + + fn associated_ty_value( + &self, + associated_ty_id: chalk_solve::rust_ir::AssociatedTyValueId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::AssociatedTyValue<RustInterner<'tcx>>> { + let def_id = associated_ty_id.0; + let assoc_item = self.interner.tcx.associated_item(def_id); + let impl_id = assoc_item.container_id(self.interner.tcx); + match assoc_item.kind { + AssocKind::Type => {} + _ => unimplemented!("Not possible??"), + } + + let trait_item_id = assoc_item.trait_item_def_id.expect("assoc_ty with no trait version"); + let bound_vars = bound_vars_for_item(self.interner.tcx, def_id); + let binders = binders_for(self.interner, bound_vars); + let ty = self + .interner + .tcx + .bound_type_of(def_id) + .subst(self.interner.tcx, bound_vars) + .lower_into(self.interner); + + Arc::new(chalk_solve::rust_ir::AssociatedTyValue { + impl_id: chalk_ir::ImplId(impl_id), + associated_ty_id: chalk_ir::AssocTypeId(trait_item_id), + value: chalk_ir::Binders::new( + binders, + chalk_solve::rust_ir::AssociatedTyValueBound { ty }, + ), + }) + } + + fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<RustInterner<'tcx>>> { + vec![] + } + + fn local_impls_to_coherence_check( + &self, + _trait_id: chalk_ir::TraitId<RustInterner<'tcx>>, + ) -> Vec<chalk_ir::ImplId<RustInterner<'tcx>>> { + unimplemented!() + } + + fn opaque_ty_data( + &self, + opaque_ty_id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::OpaqueTyDatum<RustInterner<'tcx>>> { + let bound_vars = ty::fold::shift_vars( + self.interner.tcx, + bound_vars_for_item(self.interner.tcx, opaque_ty_id.0), + 1, + ); + let where_clauses = self.where_clauses_for(opaque_ty_id.0, bound_vars); + + let identity_substs = InternalSubsts::identity_for_item(self.interner.tcx, opaque_ty_id.0); + + let explicit_item_bounds = self.interner.tcx.bound_explicit_item_bounds(opaque_ty_id.0); + let bounds = + explicit_item_bounds + .0 + .iter() + .map(|(bound, _)| { + explicit_item_bounds.rebind(*bound).subst(self.interner.tcx, &bound_vars) + }) + .map(|bound| { + bound.fold_with(&mut ReplaceOpaqueTyFolder { + tcx: self.interner.tcx, + opaque_ty_id, + identity_substs, + binder_index: ty::INNERMOST, + }) + }) + .filter_map(|bound| { + LowerInto::< + Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> + >::lower_into(bound, self.interner) + }) + .collect(); + + // Binder for the bound variable representing the concrete impl Trait type. + let existential_binder = chalk_ir::VariableKinds::from1( + self.interner, + chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General), + ); + + let value = chalk_solve::rust_ir::OpaqueTyDatumBound { + bounds: chalk_ir::Binders::new(existential_binder.clone(), bounds), + where_clauses: chalk_ir::Binders::new(existential_binder, where_clauses), + }; + + let binders = binders_for(self.interner, bound_vars); + Arc::new(chalk_solve::rust_ir::OpaqueTyDatum { + opaque_ty_id, + bound: chalk_ir::Binders::new(binders, value), + }) + } + + fn program_clauses_for_env( + &self, + environment: &chalk_ir::Environment<RustInterner<'tcx>>, + ) -> chalk_ir::ProgramClauses<RustInterner<'tcx>> { + chalk_solve::program_clauses_for_env(self, environment) + } + + fn well_known_trait_id( + &self, + well_known_trait: chalk_solve::rust_ir::WellKnownTrait, + ) -> Option<chalk_ir::TraitId<RustInterner<'tcx>>> { + use chalk_solve::rust_ir::WellKnownTrait::*; + let lang_items = self.interner.tcx.lang_items(); + let def_id = match well_known_trait { + Sized => lang_items.sized_trait(), + Copy => lang_items.copy_trait(), + Clone => lang_items.clone_trait(), + Drop => lang_items.drop_trait(), + Fn => lang_items.fn_trait(), + FnMut => lang_items.fn_mut_trait(), + FnOnce => lang_items.fn_once_trait(), + Generator => lang_items.gen_trait(), + Unsize => lang_items.unsize_trait(), + Unpin => lang_items.unpin_trait(), + CoerceUnsized => lang_items.coerce_unsized_trait(), + DiscriminantKind => lang_items.discriminant_kind_trait(), + DispatchFromDyn => lang_items.dispatch_from_dyn_trait(), + }; + def_id.map(chalk_ir::TraitId) + } + + fn is_object_safe(&self, trait_id: chalk_ir::TraitId<RustInterner<'tcx>>) -> bool { + self.interner.tcx.is_object_safe(trait_id.0) + } + + fn hidden_opaque_type( + &self, + _id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>, + ) -> chalk_ir::Ty<RustInterner<'tcx>> { + // FIXME(chalk): actually get hidden ty + self.interner + .tcx + .mk_ty(ty::Tuple(self.interner.tcx.intern_type_list(&[]))) + .lower_into(self.interner) + } + + fn closure_kind( + &self, + _closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>, + substs: &chalk_ir::Substitution<RustInterner<'tcx>>, + ) -> chalk_solve::rust_ir::ClosureKind { + let kind = &substs.as_slice(self.interner)[substs.len(self.interner) - 3]; + match kind.assert_ty_ref(self.interner).kind(self.interner) { + chalk_ir::TyKind::Scalar(chalk_ir::Scalar::Int(int_ty)) => match int_ty { + chalk_ir::IntTy::I8 => chalk_solve::rust_ir::ClosureKind::Fn, + chalk_ir::IntTy::I16 => chalk_solve::rust_ir::ClosureKind::FnMut, + chalk_ir::IntTy::I32 => chalk_solve::rust_ir::ClosureKind::FnOnce, + _ => bug!("bad closure kind"), + }, + _ => bug!("bad closure kind"), + } + } + + fn closure_inputs_and_output( + &self, + _closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>, + substs: &chalk_ir::Substitution<RustInterner<'tcx>>, + ) -> chalk_ir::Binders<chalk_solve::rust_ir::FnDefInputsAndOutputDatum<RustInterner<'tcx>>> + { + let sig = &substs.as_slice(self.interner)[substs.len(self.interner) - 2]; + match sig.assert_ty_ref(self.interner).kind(self.interner) { + chalk_ir::TyKind::Function(f) => { + let substitution = f.substitution.0.as_slice(self.interner); + let return_type = substitution.last().unwrap().assert_ty_ref(self.interner).clone(); + // Closure arguments are tupled + let argument_tuple = substitution[0].assert_ty_ref(self.interner); + let argument_types = match argument_tuple.kind(self.interner) { + chalk_ir::TyKind::Tuple(_len, substitution) => substitution + .iter(self.interner) + .map(|arg| arg.assert_ty_ref(self.interner)) + .cloned() + .collect(), + _ => bug!("Expecting closure FnSig args to be tupled."), + }; + + chalk_ir::Binders::new( + chalk_ir::VariableKinds::from_iter( + self.interner, + (0..f.num_binders).map(|_| chalk_ir::VariableKind::Lifetime), + ), + chalk_solve::rust_ir::FnDefInputsAndOutputDatum { argument_types, return_type }, + ) + } + _ => panic!("Invalid sig."), + } + } + + fn closure_upvars( + &self, + _closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>, + substs: &chalk_ir::Substitution<RustInterner<'tcx>>, + ) -> chalk_ir::Binders<chalk_ir::Ty<RustInterner<'tcx>>> { + let inputs_and_output = self.closure_inputs_and_output(_closure_id, substs); + let tuple = substs.as_slice(self.interner).last().unwrap().assert_ty_ref(self.interner); + inputs_and_output.map_ref(|_| tuple.clone()) + } + + fn closure_fn_substitution( + &self, + _closure_id: chalk_ir::ClosureId<RustInterner<'tcx>>, + substs: &chalk_ir::Substitution<RustInterner<'tcx>>, + ) -> chalk_ir::Substitution<RustInterner<'tcx>> { + let substitution = &substs.as_slice(self.interner)[0..substs.len(self.interner) - 3]; + chalk_ir::Substitution::from_iter(self.interner, substitution) + } + + fn generator_datum( + &self, + _generator_id: chalk_ir::GeneratorId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::GeneratorDatum<RustInterner<'tcx>>> { + unimplemented!() + } + + fn generator_witness_datum( + &self, + _generator_id: chalk_ir::GeneratorId<RustInterner<'tcx>>, + ) -> Arc<chalk_solve::rust_ir::GeneratorWitnessDatum<RustInterner<'tcx>>> { + unimplemented!() + } + + fn unification_database(&self) -> &dyn chalk_ir::UnificationDatabase<RustInterner<'tcx>> { + self + } + + fn discriminant_type( + &self, + _: chalk_ir::Ty<RustInterner<'tcx>>, + ) -> chalk_ir::Ty<RustInterner<'tcx>> { + unimplemented!() + } +} + +impl<'tcx> chalk_ir::UnificationDatabase<RustInterner<'tcx>> for RustIrDatabase<'tcx> { + fn fn_def_variance( + &self, + def_id: chalk_ir::FnDefId<RustInterner<'tcx>>, + ) -> chalk_ir::Variances<RustInterner<'tcx>> { + let variances = self.interner.tcx.variances_of(def_id.0); + chalk_ir::Variances::from_iter( + self.interner, + variances.iter().map(|v| v.lower_into(self.interner)), + ) + } + + fn adt_variance( + &self, + adt_id: chalk_ir::AdtId<RustInterner<'tcx>>, + ) -> chalk_ir::Variances<RustInterner<'tcx>> { + let variances = self.interner.tcx.variances_of(adt_id.0.did()); + chalk_ir::Variances::from_iter( + self.interner, + variances.iter().map(|v| v.lower_into(self.interner)), + ) + } +} + +/// Creates an `InternalSubsts` that maps each generic parameter to a higher-ranked +/// var bound at index `0`. For types, we use a `BoundVar` index equal to +/// the type parameter index. For regions, we use the `BoundRegionKind::BrNamed` +/// variant (which has a `DefId`). +fn bound_vars_for_item<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> SubstsRef<'tcx> { + InternalSubsts::for_item(tcx, def_id, |param, substs| match param.kind { + ty::GenericParamDefKind::Type { .. } => tcx + .mk_ty(ty::Bound( + ty::INNERMOST, + ty::BoundTy { + var: ty::BoundVar::from(param.index), + kind: ty::BoundTyKind::Param(param.name), + }, + )) + .into(), + + ty::GenericParamDefKind::Lifetime => { + let br = ty::BoundRegion { + var: ty::BoundVar::from_usize(substs.len()), + kind: ty::BrAnon(substs.len() as u32), + }; + tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)).into() + } + + ty::GenericParamDefKind::Const { .. } => tcx + .mk_const(ty::ConstS { + kind: ty::ConstKind::Bound(ty::INNERMOST, ty::BoundVar::from(param.index)), + ty: tcx.type_of(param.def_id), + }) + .into(), + }) +} + +fn binders_for<'tcx>( + interner: RustInterner<'tcx>, + bound_vars: SubstsRef<'tcx>, +) -> chalk_ir::VariableKinds<RustInterner<'tcx>> { + chalk_ir::VariableKinds::from_iter( + interner, + bound_vars.iter().map(|arg| match arg.unpack() { + ty::subst::GenericArgKind::Lifetime(_re) => chalk_ir::VariableKind::Lifetime, + ty::subst::GenericArgKind::Type(_ty) => { + chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General) + } + ty::subst::GenericArgKind::Const(c) => { + chalk_ir::VariableKind::Const(c.ty().lower_into(interner)) + } + }), + ) +} + +struct ReplaceOpaqueTyFolder<'tcx> { + tcx: TyCtxt<'tcx>, + opaque_ty_id: chalk_ir::OpaqueTyId<RustInterner<'tcx>>, + identity_substs: SubstsRef<'tcx>, + binder_index: ty::DebruijnIndex, +} + +impl<'tcx> ty::TypeFolder<'tcx> for ReplaceOpaqueTyFolder<'tcx> { + fn tcx<'b>(&'b self) -> TyCtxt<'tcx> { + self.tcx + } + + fn fold_binder<T: TypeFoldable<'tcx>>( + &mut self, + t: ty::Binder<'tcx, T>, + ) -> ty::Binder<'tcx, T> { + self.binder_index.shift_in(1); + let t = t.super_fold_with(self); + self.binder_index.shift_out(1); + t + } + + fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> { + if let ty::Opaque(def_id, substs) = *ty.kind() { + if def_id == self.opaque_ty_id.0 && substs == self.identity_substs { + return self.tcx.mk_ty(ty::Bound( + self.binder_index, + ty::BoundTy::from(ty::BoundVar::from_u32(0)), + )); + } + } + ty + } +} |