Use lower_nextsolver::callable_item_signature instead of lower::callable_item_signature

Author: jackh726

crates/hir-ty/src/db.rs

@@ -16,8 +16,8 @@ use smallvec::SmallVec;
 use triomphe::Arc;
 
 use crate::{
-    Binders, Const, ImplTraitId, ImplTraits, InferenceResult, PolyFnSig, Substitution,
-    TraitEnvironment, TraitRef, Ty, TyDefId, ValueTyDefId, chalk_db,
+    Binders, Const, ImplTraitId, ImplTraits, InferenceResult, Substitution, TraitEnvironment,
+    TraitRef, Ty, TyDefId, ValueTyDefId, chalk_db,
     consteval::ConstEvalError,
     drop::DropGlue,
     dyn_compatibility::DynCompatibilityViolation,
@@ -167,8 +167,11 @@ pub trait HirDatabase: DefDatabase + std::fmt::Debug {
     #[salsa::transparent]
     fn field_types(&self, var: VariantId) -> Arc<ArenaMap<LocalFieldId, Binders<Ty>>>;
 
-    #[salsa::invoke(crate::lower::callable_item_signature_query)]
-    fn callable_item_signature(&self, def: CallableDefId) -> PolyFnSig;
+    #[salsa::invoke(crate::lower_nextsolver::callable_item_signature_query)]
+    fn callable_item_signature<'db>(
+        &'db self,
+        def: CallableDefId,
+    ) -> crate::next_solver::EarlyBinder<'db, crate::next_solver::PolyFnSig<'db>>;
 
     #[salsa::invoke(crate::lower::return_type_impl_traits)]
     fn return_type_impl_traits(&self, def: FunctionId) -> Option<Arc<Binders<ImplTraits>>>;
@@ -354,12 +357,6 @@ pub trait HirDatabase: DefDatabase + std::fmt::Debug {
         ArenaMap<LocalFieldId, crate::next_solver::EarlyBinder<'db, crate::next_solver::Ty<'db>>>,
     >;
 
-    #[salsa::invoke(crate::lower_nextsolver::callable_item_signature_query)]
-    fn callable_item_signature_ns<'db>(
-        &'db self,
-        def: CallableDefId,
-    ) -> crate::next_solver::EarlyBinder<'db, crate::next_solver::PolyFnSig<'db>>;
-
     #[salsa::invoke(crate::lower_nextsolver::return_type_impl_traits)]
     fn return_type_impl_traits_ns<'db>(
         &'db self,

crates/hir-ty/src/display.rs

@@ -46,8 +46,8 @@ use span::Edition;
 use stdx::never;
 use triomphe::Arc;
 
-use crate::next_solver::infer::DbInternerInferExt;
 use crate::next_solver::infer::traits::ObligationCause;
+use crate::next_solver::{infer::DbInternerInferExt, mapping::NextSolverToChalk};
 use crate::{
     AliasEq, AliasTy, Binders, CallableDefId, CallableSig, ConcreteConst, Const, ConstScalar,
     ConstValue, DomainGoal, FnAbi, GenericArg, ImplTraitId, Interner, Lifetime, LifetimeData,
@@ -1298,7 +1298,9 @@ impl<'db> HirDisplay for crate::next_solver::Ty<'db> {
                 let def = def.0;
                 let sig = db
                     .callable_item_signature(def)
-                    .substitute(Interner, &convert_args_for_result(interner, args.as_slice()));
+                    .instantiate(interner, args)
+                    .skip_binder()
+                    .to_chalk(interner);
 
                 if f.display_kind.is_source_code() {
                     // `FnDef` is anonymous and there's no surface syntax for it. Show it as a

crates/hir-ty/src/dyn_compatibility.rs

@@ -329,7 +329,7 @@ where
         cb(MethodViolationCode::AsyncFn)?;
     }
 
-    let sig = db.callable_item_signature_ns(func.into());
+    let sig = db.callable_item_signature(func.into());
     if sig
         .skip_binder()
         .inputs()

crates/hir-ty/src/lib.rs

@@ -578,8 +578,10 @@ impl CallableSig {
 
     pub fn from_def(db: &dyn HirDatabase, def: FnDefId, substs: &Substitution) -> CallableSig {
         let callable_def = ToChalk::from_chalk(db, def);
+        let interner = DbInterner::new_with(db, None, None);
+        let args: crate::next_solver::GenericArgs<'_> = substs.to_nextsolver(interner);
         let sig = db.callable_item_signature(callable_def);
-        sig.substitute(Interner, substs)
+        sig.instantiate(interner, args).skip_binder().to_chalk(interner)
     }
     pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
         CallableSig {

crates/hir-ty/src/lower.rs

@@ -24,9 +24,9 @@ use chalk_ir::{
 
 use either::Either;
 use hir_def::{
-    AdtId, AssocItemId, CallableDefId, ConstId, ConstParamId, EnumId, EnumVariantId, FunctionId,
-    GenericDefId, GenericParamId, ImplId, ItemContainerId, LocalFieldId, Lookup, StaticId,
-    StructId, TypeAliasId, TypeOrConstParamId, UnionId, VariantId,
+    AdtId, AssocItemId, ConstId, ConstParamId, EnumId, EnumVariantId, FunctionId, GenericDefId,
+    GenericParamId, ImplId, ItemContainerId, LocalFieldId, Lookup, StaticId, StructId, TypeAliasId,
+    TypeOrConstParamId, UnionId, VariantId,
     builtin_type::BuiltinType,
     expr_store::{ExpressionStore, path::Path},
     hir::generics::{GenericParamDataRef, TypeOrConstParamData, WherePredicate},
@@ -45,10 +45,10 @@ use stdx::{impl_from, never};
 use triomphe::{Arc, ThinArc};
 
 use crate::{
-    AliasTy, Binders, BoundVar, CallableSig, Const, DebruijnIndex, DynTy, FnAbi, FnPointer, FnSig,
-    FnSubst, ImplTrait, ImplTraitId, ImplTraits, Interner, Lifetime, LifetimeData,
-    LifetimeOutlives, PolyFnSig, QuantifiedWhereClause, QuantifiedWhereClauses, Substitution,
-    TraitRef, TraitRefExt, Ty, TyBuilder, TyKind, WhereClause, all_super_traits,
+    AliasTy, Binders, BoundVar, Const, DebruijnIndex, DynTy, FnAbi, FnPointer, FnSig, FnSubst,
+    ImplTrait, ImplTraitId, ImplTraits, Interner, Lifetime, LifetimeData, LifetimeOutlives,
+    QuantifiedWhereClause, QuantifiedWhereClauses, Substitution, TraitRef, TraitRefExt, Ty,
+    TyBuilder, TyKind, WhereClause, all_super_traits,
     consteval::{intern_const_ref, path_to_const, unknown_const, unknown_const_as_generic},
     db::HirDatabase,
     error_lifetime,
@@ -824,15 +824,6 @@ impl<'a> TyLoweringContext<'a> {
     }
 }
 
-/// Build the signature of a callable item (function, struct or enum variant).
-pub(crate) fn callable_item_signature_query(db: &dyn HirDatabase, def: CallableDefId) -> PolyFnSig {
-    match def {
-        CallableDefId::FunctionId(f) => fn_sig_for_fn(db, f),
-        CallableDefId::StructId(s) => fn_sig_for_struct_constructor(db, s),
-        CallableDefId::EnumVariantId(e) => fn_sig_for_enum_variant_constructor(db, e),
-    }
-}
-
 fn named_associated_type_shorthand_candidates<R>(
     db: &dyn HirDatabase,
     // If the type parameter is defined in an impl and we're in a method, there
@@ -1312,73 +1303,6 @@ pub(crate) fn generic_defaults_with_diagnostics_cycle_result(
     (GenericDefaults(None), None)
 }
 
-fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
-    let data = db.function_signature(def);
-    let resolver = def.resolver(db);
-    let mut ctx_params = TyLoweringContext::new(
-        db,
-        &resolver,
-        &data.store,
-        def.into(),
-        LifetimeElisionKind::for_fn_params(&data),
-    )
-    .with_type_param_mode(ParamLoweringMode::Variable);
-    let params = data.params.iter().map(|&tr| ctx_params.lower_ty(tr));
-
-    let ret = match data.ret_type {
-        Some(ret_type) => {
-            let mut ctx_ret = TyLoweringContext::new(
-                db,
-                &resolver,
-                &data.store,
-                def.into(),
-                LifetimeElisionKind::for_fn_ret(),
-            )
-            .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
-            .with_type_param_mode(ParamLoweringMode::Variable);
-            ctx_ret.lower_ty(ret_type)
-        }
-        None => TyKind::Tuple(0, Substitution::empty(Interner)).intern(Interner),
-    };
-    let generics = generics(db, def.into());
-    let sig = CallableSig::from_params_and_return(
-        params,
-        ret,
-        data.is_varargs(),
-        if data.is_unsafe() { Safety::Unsafe } else { Safety::Safe },
-        data.abi.as_ref().map_or(FnAbi::Rust, FnAbi::from_symbol),
-    );
-    make_binders(db, &generics, sig)
-}
-
-fn fn_sig_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> PolyFnSig {
-    let field_tys = db.field_types(def.into());
-    let params = field_tys.iter().map(|(_, ty)| ty.skip_binders().clone());
-    let (ret, binders) = type_for_adt(db, def.into()).into_value_and_skipped_binders();
-    Binders::new(
-        binders,
-        CallableSig::from_params_and_return(params, ret, false, Safety::Safe, FnAbi::RustCall),
-    )
-}
-
-fn fn_sig_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId) -> PolyFnSig {
-    let field_tys = db.field_types(def.into());
-    let params = field_tys.iter().map(|(_, ty)| ty.skip_binders().clone());
-    let parent = def.lookup(db).parent;
-    let (ret, binders) = type_for_adt(db, parent.into()).into_value_and_skipped_binders();
-    Binders::new(
-        binders,
-        CallableSig::from_params_and_return(params, ret, false, Safety::Safe, FnAbi::RustCall),
-    )
-}
-
-fn type_for_adt(db: &dyn HirDatabase, adt: AdtId) -> Binders<Ty> {
-    let generics = generics(db, adt.into());
-    let subst = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);
-    let ty = TyKind::Adt(crate::AdtId(adt), subst).intern(Interner);
-    make_binders(db, &generics, ty)
-}
-
 pub(crate) fn type_for_type_alias_with_diagnostics_query(
     db: &dyn HirDatabase,
     t: TypeAliasId,

crates/hir-ty/src/method_resolution.rs

@@ -1746,9 +1746,13 @@ fn is_valid_trait_method_candidate(
                         .fill_with_inference_vars(table)
                         .build();
 
+                    let args: crate::next_solver::GenericArgs<'_> =
+                        fn_subst.to_nextsolver(table.interner);
                     let sig = db.callable_item_signature(fn_id.into());
-                    let expected_receiver =
-                        sig.map(|s| s.params()[0].clone()).substitute(Interner, &fn_subst);
+                    let expected_receiver = sig
+                        .map_bound(|s| s.skip_binder().inputs_and_output.as_slice()[0])
+                        .instantiate(table.interner, args)
+                        .to_chalk(table.interner);
 
                     // FIXME: Clean up this mess with some context struct like rustc's `ProbeContext`
                     let variance = match mode {
@@ -1833,9 +1837,12 @@ fn is_valid_impl_fn_candidate(
             let fn_subst: crate::Substitution =
                 table.infer_ctxt.fresh_args_for_item(fn_id.into()).to_chalk(table.interner);
 
+            let args: crate::next_solver::GenericArgs<'_> = fn_subst.to_nextsolver(table.interner);
             let sig = db.callable_item_signature(fn_id.into());
-            let expected_receiver =
-                sig.map(|s| s.params()[0].clone()).substitute(Interner, &fn_subst);
+            let expected_receiver = sig
+                .map_bound(|s| s.skip_binder().inputs_and_output.as_slice()[0])
+                .instantiate(table.interner, args)
+                .to_chalk(table.interner);
 
             check_that!(table.unify(receiver_ty, &expected_receiver));
         }

crates/hir-ty/src/mir/lower.rs

@@ -43,7 +43,10 @@ use crate::{
         Terminator, TerminatorKind, TupleFieldId, Ty, UnOp, VariantId, intern_const_scalar,
         return_slot,
     },
-    next_solver::{DbInterner, mapping::ChalkToNextSolver},
+    next_solver::{
+        DbInterner,
+        mapping::{ChalkToNextSolver, NextSolverToChalk},
+    },
     static_lifetime,
     traits::FnTrait,
     utils::ClosureSubst,
@@ -2207,8 +2210,13 @@ pub fn lower_to_mir(
             // otherwise it's an inline const, and has no parameter
             if let DefWithBodyId::FunctionId(fid) = owner {
                 let substs = TyBuilder::placeholder_subst(db, fid);
-                let callable_sig =
-                    db.callable_item_signature(fid.into()).substitute(Interner, &substs);
+                let interner = DbInterner::new_with(db, None, None);
+                let args: crate::next_solver::GenericArgs<'_> = substs.to_nextsolver(interner);
+                let callable_sig = db
+                    .callable_item_signature(fid.into())
+                    .instantiate(interner, args)
+                    .skip_binder()
+                    .to_chalk(interner);
                 let mut params = callable_sig.params().iter();
                 let self_param = body.self_param.and_then(|id| Some((id, params.next()?.clone())));
                 break 'b ctx.lower_params_and_bindings(

crates/hir-ty/src/next_solver/interner.rs

@@ -1225,7 +1225,7 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> {
         self,
         def_id: Self::FunctionId,
     ) -> EarlyBinder<Self, rustc_type_ir::Binder<Self, rustc_type_ir::FnSig<Self>>> {
-        self.db().callable_item_signature_ns(def_id.0)
+        self.db().callable_item_signature(def_id.0)
     }
 
     fn coroutine_movability(self, def_id: Self::CoroutineId) -> rustc_ast_ir::Movability {

crates/hir-ty/src/next_solver/mapping.rs

@@ -575,6 +575,17 @@ impl<
     }
 }
 
+impl<'db, T: NextSolverToChalk<'db, U>, U: HasInterner<Interner = Interner>>
+    NextSolverToChalk<'db, chalk_ir::Binders<U>> for rustc_type_ir::Binder<DbInterner<'db>, T>
+{
+    fn to_chalk(self, interner: DbInterner<'db>) -> chalk_ir::Binders<U> {
+        chalk_ir::Binders::new(
+            self.bound_vars().to_chalk(interner),
+            self.skip_binder().to_chalk(interner),
+        )
+    }
+}
+
 impl<'db> ChalkToNextSolver<'db, BoundVarKinds> for chalk_ir::VariableKinds<Interner> {
     fn to_nextsolver(&self, interner: DbInterner<'db>) -> BoundVarKinds {
         BoundVarKinds::new_from_iter(
@@ -584,6 +595,12 @@ impl<'db> ChalkToNextSolver<'db, BoundVarKinds> for chalk_ir::VariableKinds<Inte
     }
 }
 
+impl<'db> NextSolverToChalk<'db, chalk_ir::VariableKinds<Interner>> for BoundVarKinds {
+    fn to_chalk(self, interner: DbInterner<'db>) -> chalk_ir::VariableKinds<Interner> {
+        chalk_ir::VariableKinds::from_iter(Interner, self.iter().map(|v| v.to_chalk(interner)))
+    }
+}
+
 impl<'db> ChalkToNextSolver<'db, BoundVarKind> for chalk_ir::VariableKind<Interner> {
     fn to_nextsolver(&self, interner: DbInterner<'db>) -> BoundVarKind {
         match self {
@@ -594,6 +611,18 @@ impl<'db> ChalkToNextSolver<'db, BoundVarKind> for chalk_ir::VariableKind<Intern
     }
 }
 
+impl<'db> NextSolverToChalk<'db, chalk_ir::VariableKind<Interner>> for BoundVarKind {
+    fn to_chalk(self, interner: DbInterner<'db>) -> chalk_ir::VariableKind<Interner> {
+        match self {
+            BoundVarKind::Ty(_) => chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General),
+            BoundVarKind::Region(_) => chalk_ir::VariableKind::Lifetime,
+            BoundVarKind::Const => {
+                chalk_ir::VariableKind::Const(chalk_ir::TyKind::Error.intern(Interner))
+            }
+        }
+    }
+}
+
 impl<'db> ChalkToNextSolver<'db, GenericArg<'db>> for chalk_ir::GenericArg<Interner> {
     fn to_nextsolver(&self, interner: DbInterner<'db>) -> GenericArg<'db> {
         match self.data(Interner) {
@@ -1233,6 +1262,22 @@ where
     }
 }
 
+impl<'db> NextSolverToChalk<'db, crate::CallableSig> for rustc_type_ir::FnSig<DbInterner<'db>> {
+    fn to_chalk(self, interner: DbInterner<'db>) -> crate::CallableSig {
+        crate::CallableSig {
+            abi: self.abi,
+            is_varargs: self.c_variadic,
+            safety: match self.safety {
+                super::abi::Safety::Safe => chalk_ir::Safety::Safe,
+                super::abi::Safety::Unsafe => chalk_ir::Safety::Unsafe,
+            },
+            params_and_return: triomphe::Arc::from_iter(
+                self.inputs_and_output.iter().map(|ty| convert_ty_for_result(interner, ty)),
+            ),
+        }
+    }
+}
+
 pub fn convert_canonical_args_for_result<'db>(
     interner: DbInterner<'db>,
     args: Canonical<'db, Vec<GenericArg<'db>>>,

crates/hir-ty/src/tests/method_resolution.rs

@@ -2053,7 +2053,7 @@ impl dyn Error + Send {
                                // ^^^^ expected Box<dyn Error + '?>, got Box<dyn Error + Send + '?>
                                // FIXME, type mismatch should not occur
         <dyn Error>::downcast(err).map_err(|_| loop {})
-      //^^^^^^^^^^^^^^^^^^^^^ type: fn downcast<{unknown}>(Box<dyn Error + 'static>) -> Result<Box<{unknown}>, Box<dyn Error + '?>>
+      //^^^^^^^^^^^^^^^^^^^^^ type: fn downcast<{unknown}>(Box<dyn Error + 'static>) -> Result<Box<{unknown}>, Box<dyn Error + 'static>>
     }
 }
 "#,