diff --git a/crates/hir-ty/src/autoderef.rs b/crates/hir-ty/src/autoderef.rs index 344036dd81..02332ea80d 100644 --- a/crates/hir-ty/src/autoderef.rs +++ b/crates/hir-ty/src/autoderef.rs @@ -123,13 +123,14 @@ fn deref_by_trait(table: &mut InferenceTable<'_>, ty: Ty) -> Option { let target = db.trait_data(deref_trait).associated_type_by_name(&name![Target])?; let projection = { - let b = TyBuilder::assoc_type_projection(db, target); + let b = TyBuilder::subst_for_def(db, deref_trait, None); if b.remaining() != 1 { // the Target type + Deref trait should only have one generic parameter, // namely Deref's Self type return None; } - b.push(ty).build() + let deref_subst = b.push(ty).build(); + TyBuilder::assoc_type_projection(db, target, Some(deref_subst)).build() }; // Check that the type implements Deref at all diff --git a/crates/hir-ty/src/chalk_db.rs b/crates/hir-ty/src/chalk_db.rs index c5cf6729d1..3f3f8f7d0f 100644 --- a/crates/hir-ty/src/chalk_db.rs +++ b/crates/hir-ty/src/chalk_db.rs @@ -382,13 +382,12 @@ impl<'a> chalk_solve::RustIrDatabase for ChalkContext<'a> { // `resume_type`, `yield_type`, and `return_type` of the generator in question. let subst = TyBuilder::subst_for_generator(self.db, parent).fill_with_unknown().build(); - let len = subst.len(Interner); let input_output = rust_ir::GeneratorInputOutputDatum { - resume_type: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, len - 3)) + resume_type: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)) .intern(Interner), - yield_type: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, len - 2)) + yield_type: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 1)) .intern(Interner), - return_type: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, len - 1)) + return_type: TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 2)) .intern(Interner), // FIXME: calculate upvars upvars: vec![], @@ -476,10 +475,15 @@ pub(crate) fn associated_ty_data_query( let resolver = hir_def::resolver::HasResolver::resolver(type_alias, db.upcast()); let ctx = crate::TyLoweringContext::new(db, &resolver) .with_type_param_mode(crate::lower::ParamLoweringMode::Variable); - let pro_ty = TyBuilder::assoc_type_projection(db, type_alias) + + let trait_subst = TyBuilder::subst_for_def(db, trait_, None) + .fill_with_bound_vars(crate::DebruijnIndex::INNERMOST, generic_params.len_self()) + .build(); + let pro_ty = TyBuilder::assoc_type_projection(db, type_alias, Some(trait_subst)) .fill_with_bound_vars(crate::DebruijnIndex::INNERMOST, 0) .build(); let self_ty = TyKind::Alias(AliasTy::Projection(pro_ty)).intern(Interner); + let mut bounds: Vec<_> = type_alias_data .bounds .iter() diff --git a/crates/hir-ty/src/display.rs b/crates/hir-ty/src/display.rs index a5058f71a4..7f0baf49da 100644 --- a/crates/hir-ty/src/display.rs +++ b/crates/hir-ty/src/display.rs @@ -27,7 +27,7 @@ use crate::{ db::HirDatabase, from_assoc_type_id, from_foreign_def_id, from_placeholder_idx, lt_from_placeholder_idx, mapping::from_chalk, - primitive, subst_prefix, to_assoc_type_id, + primitive, to_assoc_type_id, utils::{self, generics}, AdtId, AliasEq, AliasTy, Binders, CallableDefId, CallableSig, Const, ConstValue, DomainGoal, GenericArg, ImplTraitId, Interner, Lifetime, LifetimeData, LifetimeOutlives, Mutability, @@ -506,8 +506,15 @@ impl HirDisplay for Ty { let total_len = parent_params + self_param + type_params + const_params; // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self? if total_len > 0 { + // `parameters` are in the order of fn's params (including impl traits), + // parent's params (those from enclosing impl or trait, if any). + let parameters = parameters.as_slice(Interner); + let fn_params_len = self_param + type_params + const_params; + let fn_params = parameters.get(..fn_params_len); + let parent_params = parameters.get(parameters.len() - parent_params..); + let params = parent_params.into_iter().chain(fn_params).flatten(); write!(f, "<")?; - f.write_joined(¶meters.as_slice(Interner)[..total_len], ", ")?; + f.write_joined(params, ", ")?; write!(f, ">")?; } } @@ -579,9 +586,8 @@ impl HirDisplay for Ty { Some(x) => x, None => return true, }; - let actual_default = default_parameter - .clone() - .substitute(Interner, &subst_prefix(parameters, i)); + let actual_default = + default_parameter.clone().substitute(Interner, ¶meters); parameter != &actual_default } let mut default_from = 0; diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs index 25179afaca..31e56dec62 100644 --- a/crates/hir-ty/src/infer.rs +++ b/crates/hir-ty/src/infer.rs @@ -26,8 +26,8 @@ use hir_def::{ path::{path, Path}, resolver::{HasResolver, ResolveValueResult, Resolver, TypeNs, ValueNs}, type_ref::TypeRef, - AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId, FunctionId, HasModule, Lookup, - TraitId, TypeAliasId, VariantId, + AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId, FunctionId, HasModule, + ItemContainerId, Lookup, TraitId, TypeAliasId, VariantId, }; use hir_expand::name::{name, Name}; use itertools::Either; @@ -713,6 +713,8 @@ impl<'a> InferenceContext<'a> { &mut self, inner_ty: Ty, assoc_ty: Option, + // FIXME(GATs): these are args for the trait ref, args for assoc type itself should be + // handled when we support them. params: &[GenericArg], ) -> Ty { match assoc_ty { @@ -804,7 +806,18 @@ impl<'a> InferenceContext<'a> { self.resolve_variant_on_alias(ty, unresolved, path) } TypeNs::TypeAliasId(it) => { - let ty = TyBuilder::def_ty(self.db, it.into()) + let container = it.lookup(self.db.upcast()).container; + let parent_subst = match container { + ItemContainerId::TraitId(id) => { + let subst = TyBuilder::subst_for_def(self.db, id, None) + .fill_with_inference_vars(&mut self.table) + .build(); + Some(subst) + } + // Type aliases do not exist in impls. + _ => None, + }; + let ty = TyBuilder::def_ty(self.db, it.into(), parent_subst) .fill_with_inference_vars(&mut self.table) .build(); self.resolve_variant_on_alias(ty, unresolved, path) diff --git a/crates/hir-ty/src/infer/expr.rs b/crates/hir-ty/src/infer/expr.rs index 2643baf8a3..f56108b26c 100644 --- a/crates/hir-ty/src/infer/expr.rs +++ b/crates/hir-ty/src/infer/expr.rs @@ -987,11 +987,13 @@ impl<'a> InferenceContext<'a> { let lhs_ty = self.infer_expr(lhs, &lhs_expectation); let rhs_ty = self.table.new_type_var(); - let func = lang_names_for_bin_op(op).and_then(|(name, lang_item)| { - self.db.trait_data(self.resolve_lang_item(lang_item)?.as_trait()?).method_by_name(&name) + let trait_func = lang_names_for_bin_op(op).and_then(|(name, lang_item)| { + let trait_id = self.resolve_lang_item(lang_item)?.as_trait()?; + let func = self.db.trait_data(trait_id).method_by_name(&name)?; + Some((trait_id, func)) }); - let func = match func { - Some(func) => func, + let (trait_, func) = match trait_func { + Some(it) => it, None => { let rhs_ty = self.builtin_binary_op_rhs_expectation(op, lhs_ty.clone()); let rhs_ty = self.infer_expr_coerce(rhs, &Expectation::from_option(rhs_ty)); @@ -1001,7 +1003,9 @@ impl<'a> InferenceContext<'a> { } }; - let subst = TyBuilder::subst_for_def(self.db, func) + // HACK: We can use this substitution for the function because the function itself doesn't + // have its own generic parameters. + let subst = TyBuilder::subst_for_def(self.db, trait_, None) .push(lhs_ty.clone()) .push(rhs_ty.clone()) .build(); @@ -1280,19 +1284,7 @@ impl<'a> InferenceContext<'a> { assert_eq!(self_params, 0); // method shouldn't have another Self param let total_len = parent_params + type_params + const_params + impl_trait_params; let mut substs = Vec::with_capacity(total_len); - // Parent arguments are unknown - for (id, param) in def_generics.iter_parent() { - match param { - TypeOrConstParamData::TypeParamData(_) => { - substs.push(GenericArgData::Ty(self.table.new_type_var()).intern(Interner)); - } - TypeOrConstParamData::ConstParamData(_) => { - let ty = self.db.const_param_ty(ConstParamId::from_unchecked(id)); - substs - .push(GenericArgData::Const(self.table.new_const_var(ty)).intern(Interner)); - } - } - } + // handle provided arguments if let Some(generic_args) = generic_args { // if args are provided, it should be all of them, but we can't rely on that @@ -1301,7 +1293,7 @@ impl<'a> InferenceContext<'a> { .iter() .filter(|arg| !matches!(arg, GenericArg::Lifetime(_))) .take(type_params + const_params) - .zip(def_generics.iter_id().skip(parent_params)) + .zip(def_generics.iter_id()) { if let Some(g) = generic_arg_to_chalk( self.db, @@ -1325,6 +1317,9 @@ impl<'a> InferenceContext<'a> { } } }; + + // Handle everything else as unknown. This also handles generic arguments for the method's + // parent (impl or trait), which should come after those for the method. for (id, data) in def_generics.iter().skip(substs.len()) { match data { TypeOrConstParamData::TypeParamData(_) => { @@ -1362,9 +1357,13 @@ impl<'a> InferenceContext<'a> { CallableDefId::FunctionId(f) => { if let ItemContainerId::TraitId(trait_) = f.lookup(self.db.upcast()).container { // construct a TraitRef - let substs = crate::subst_prefix( - &*parameters, - generics(self.db.upcast(), trait_.into()).len(), + let params_len = parameters.len(Interner); + let trait_params_len = generics(self.db.upcast(), trait_.into()).len(); + let substs = Substitution::from_iter( + Interner, + // The generic parameters for the trait come after those for the + // function. + ¶meters.as_slice(Interner)[params_len - trait_params_len..], ); self.push_obligation( TraitRef { trait_id: to_chalk_trait_id(trait_), substitution: substs } diff --git a/crates/hir-ty/src/infer/path.rs b/crates/hir-ty/src/infer/path.rs index 7bb79b519e..7a4754cdc7 100644 --- a/crates/hir-ty/src/infer/path.rs +++ b/crates/hir-ty/src/infer/path.rs @@ -12,6 +12,7 @@ use crate::{ builder::ParamKind, consteval, method_resolution::{self, VisibleFromModule}, + utils::generics, Interner, Substitution, TraitRefExt, Ty, TyBuilder, TyExt, TyKind, ValueTyDefId, }; @@ -95,12 +96,18 @@ impl<'a> InferenceContext<'a> { ValueNs::GenericParam(it) => return Some(self.db.const_param_ty(it)), }; - let parent_substs = self_subst.unwrap_or_else(|| Substitution::empty(Interner)); let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver); let substs = ctx.substs_from_path(path, typable, true); - let mut it = substs.as_slice(Interner)[parent_substs.len(Interner)..].iter().cloned(); - let ty = TyBuilder::value_ty(self.db, typable) - .use_parent_substs(&parent_substs) + let substs = substs.as_slice(Interner); + let parent_substs = self_subst.or_else(|| { + let generics = generics(self.db.upcast(), typable.to_generic_def_id()?); + let parent_params_len = generics.parent_generics()?.len(); + let parent_args = &substs[substs.len() - parent_params_len..]; + Some(Substitution::from_iter(Interner, parent_args)) + }); + let parent_substs_len = parent_substs.as_ref().map_or(0, |s| s.len(Interner)); + let mut it = substs.iter().take(substs.len() - parent_substs_len).cloned(); + let ty = TyBuilder::value_ty(self.db, typable, parent_substs) .fill(|x| { it.next().unwrap_or_else(|| match x { ParamKind::Type => TyKind::Error.intern(Interner).cast(Interner), @@ -246,7 +253,7 @@ impl<'a> InferenceContext<'a> { }; let substs = match container { ItemContainerId::ImplId(impl_id) => { - let impl_substs = TyBuilder::subst_for_def(self.db, impl_id) + let impl_substs = TyBuilder::subst_for_def(self.db, impl_id, None) .fill_with_inference_vars(&mut self.table) .build(); let impl_self_ty = diff --git a/crates/hir-ty/src/infer/unify.rs b/crates/hir-ty/src/infer/unify.rs index e77b55670b..6ccd0b215c 100644 --- a/crates/hir-ty/src/infer/unify.rs +++ b/crates/hir-ty/src/infer/unify.rs @@ -598,11 +598,14 @@ impl<'a> InferenceTable<'a> { .build(); let projection = { - let b = TyBuilder::assoc_type_projection(self.db, output_assoc_type); + let b = TyBuilder::subst_for_def(self.db, fn_once_trait, None); if b.remaining() != 2 { return None; } - b.push(ty.clone()).push(arg_ty).build() + let fn_once_subst = b.push(ty.clone()).push(arg_ty).build(); + + TyBuilder::assoc_type_projection(self.db, output_assoc_type, Some(fn_once_subst)) + .build() }; let trait_env = self.trait_env.env.clone(); diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs index 82128ae658..0a4b1dfda1 100644 --- a/crates/hir-ty/src/lower.rs +++ b/crates/hir-ty/src/lower.rs @@ -306,7 +306,7 @@ impl<'a> TyLoweringContext<'a> { // FIXME we're probably doing something wrong here self.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16); let ( - parent_params, + _parent_params, self_params, list_params, const_params, @@ -319,7 +319,7 @@ impl<'a> TyLoweringContext<'a> { }; TyKind::BoundVar(BoundVar::new( self.in_binders, - idx as usize + parent_params + self_params + list_params + const_params, + idx as usize + self_params + list_params + const_params, )) .intern(Interner) } @@ -499,14 +499,31 @@ impl<'a> TyLoweringContext<'a> { .intern(Interner) } TypeNs::SelfType(impl_id) => { - let generics = generics(self.db.upcast(), impl_id.into()); - let substs = match self.type_param_mode { - ParamLoweringMode::Placeholder => generics.placeholder_subst(self.db), - ParamLoweringMode::Variable => { - generics.bound_vars_subst(self.db, self.in_binders) + let def = + self.resolver.generic_def().expect("impl should have generic param scope"); + let generics = generics(self.db.upcast(), def); + + match self.type_param_mode { + ParamLoweringMode::Placeholder => { + // `def` can be either impl itself or item within, and we need impl itself + // now. + let generics = generics.parent_generics().unwrap_or(&generics); + let subst = generics.placeholder_subst(self.db); + self.db.impl_self_ty(impl_id).substitute(Interner, &subst) } - }; - self.db.impl_self_ty(impl_id).substitute(Interner, &substs) + ParamLoweringMode::Variable => { + let starting_from = match def { + GenericDefId::ImplId(_) => 0, + // `def` is an item within impl. We need to substitute `BoundVar`s but + // remember that they are for parent (i.e. impl) generic params so they + // come after our own params. + _ => generics.len_self(), + }; + TyBuilder::impl_self_ty(self.db, impl_id) + .fill_with_bound_vars(self.in_binders, starting_from) + .build() + } + } } TypeNs::AdtSelfType(adt) => { let generics = generics(self.db.upcast(), adt.into()); @@ -636,13 +653,9 @@ impl<'a> TyLoweringContext<'a> { infer_args: bool, ) -> Substitution { let last = path.segments().last().expect("path should have at least one segment"); - let (segment, generic_def) = match resolved { - ValueTyDefId::FunctionId(it) => (last, Some(it.into())), - ValueTyDefId::StructId(it) => (last, Some(it.into())), - ValueTyDefId::UnionId(it) => (last, Some(it.into())), - ValueTyDefId::ConstId(it) => (last, Some(it.into())), - ValueTyDefId::StaticId(_) => (last, None), - ValueTyDefId::EnumVariantId(var) => { + let generic_def = resolved.to_generic_def_id(); + let segment = match resolved { + ValueTyDefId::EnumVariantId(_) => { // the generic args for an enum variant may be either specified // on the segment referring to the enum, or on the segment // referring to the variant. So `Option::::None` and @@ -650,12 +663,12 @@ impl<'a> TyLoweringContext<'a> { // preferred). See also `def_ids_for_path_segments` in rustc. let len = path.segments().len(); let penultimate = len.checked_sub(2).and_then(|idx| path.segments().get(idx)); - let segment = match penultimate { + match penultimate { Some(segment) if segment.args_and_bindings.is_some() => segment, _ => last, - }; - (segment, Some(var.parent.into())) + } } + _ => last, }; self.substs_from_path_segment(segment, generic_def, infer_args, None) } @@ -663,36 +676,27 @@ impl<'a> TyLoweringContext<'a> { fn substs_from_path_segment( &self, segment: PathSegment<'_>, - def_generic: Option, + def: Option, infer_args: bool, explicit_self_ty: Option, ) -> Substitution { + // Remember that the item's own generic args come before its parent's. let mut substs = Vec::new(); - let def_generics = if let Some(def) = def_generic { - generics(self.db.upcast(), def) + let def = if let Some(d) = def { + d } else { return Substitution::empty(Interner); }; + let def_generics = generics(self.db.upcast(), def); let (parent_params, self_params, type_params, const_params, impl_trait_params) = def_generics.provenance_split(); - let total_len = - parent_params + self_params + type_params + const_params + impl_trait_params; + let item_len = self_params + type_params + const_params + impl_trait_params; + let total_len = parent_params + item_len; let ty_error = TyKind::Error.intern(Interner).cast(Interner); let mut def_generic_iter = def_generics.iter_id(); - for _ in 0..parent_params { - if let Some(eid) = def_generic_iter.next() { - match eid { - Either::Left(_) => substs.push(ty_error.clone()), - Either::Right(x) => { - substs.push(unknown_const_as_generic(self.db.const_param_ty(x))) - } - } - } - } - let fill_self_params = || { for x in explicit_self_ty .into_iter() @@ -757,37 +761,40 @@ impl<'a> TyLoweringContext<'a> { fill_self_params(); } + // These params include those of parent. + let remaining_params: SmallVec<[_; 2]> = def_generic_iter + .map(|eid| match eid { + Either::Left(_) => ty_error.clone(), + Either::Right(x) => unknown_const_as_generic(self.db.const_param_ty(x)), + }) + .collect(); + assert_eq!(remaining_params.len() + substs.len(), total_len); + // handle defaults. In expression or pattern path segments without // explicitly specified type arguments, missing type arguments are inferred // (i.e. defaults aren't used). if !infer_args || had_explicit_args { - if let Some(def_generic) = def_generic { - let defaults = self.db.generic_defaults(def_generic); - assert_eq!(total_len, defaults.len()); + let defaults = self.db.generic_defaults(def); + assert_eq!(total_len, defaults.len()); + let parent_from = item_len - substs.len(); - for default_ty in defaults.iter().skip(substs.len()) { - // each default can depend on the previous parameters - let substs_so_far = Substitution::from_iter(Interner, substs.clone()); - if let Some(_id) = def_generic_iter.next() { - substs.push(default_ty.clone().substitute(Interner, &substs_so_far)); - } - } + for (idx, default_ty) in defaults[substs.len()..item_len].iter().enumerate() { + // each default can depend on the previous parameters + let substs_so_far = Substitution::from_iter( + Interner, + substs.iter().cloned().chain(remaining_params[idx..].iter().cloned()), + ); + substs.push(default_ty.clone().substitute(Interner, &substs_so_far)); } + + // Keep parent's params as unknown. + let mut remaining_params = remaining_params; + substs.extend(remaining_params.drain(parent_from..)); + } else { + substs.extend(remaining_params); } - // add placeholders for args that were not provided - // FIXME: emit diagnostics in contexts where this is not allowed - for eid in def_generic_iter { - match eid { - Either::Left(_) => substs.push(ty_error.clone()), - Either::Right(x) => { - substs.push(unknown_const_as_generic(self.db.const_param_ty(x))) - } - } - } - // If this assert fails, it means you pushed into subst but didn't call .next() of def_generic_iter assert_eq!(substs.len(), total_len); - Substitution::from_iter(Interner, substs) } @@ -1168,10 +1175,18 @@ fn named_associated_type_shorthand_candidates( } // Handle `Self::Type` referring to own associated type in trait definitions if let GenericDefId::TraitId(trait_id) = param_id.parent() { - let generics = generics(db.upcast(), trait_id.into()); - if generics.params.type_or_consts[param_id.local_id()].is_trait_self() { + let trait_generics = generics(db.upcast(), trait_id.into()); + if trait_generics.params.type_or_consts[param_id.local_id()].is_trait_self() { + let def_generics = generics(db.upcast(), def); + let starting_idx = match def { + GenericDefId::TraitId(_) => 0, + // `def` is an item within trait. We need to substitute `BoundVar`s but + // remember that they are for parent (i.e. trait) generic params so they + // come after our own params. + _ => def_generics.len_self(), + }; let trait_ref = TyBuilder::trait_ref(db, trait_id) - .fill_with_bound_vars(DebruijnIndex::INNERMOST, 0) + .fill_with_bound_vars(DebruijnIndex::INNERMOST, starting_idx) .build(); return search(trait_ref); } @@ -1413,6 +1428,7 @@ pub(crate) fn generic_defaults_query( let ctx = TyLoweringContext::new(db, &resolver).with_type_param_mode(ParamLoweringMode::Variable); let generic_params = generics(db.upcast(), def); + let parent_start_idx = generic_params.len_self(); let defaults = generic_params .iter() @@ -1425,19 +1441,17 @@ pub(crate) fn generic_defaults_query( let val = unknown_const_as_generic( db.const_param_ty(ConstParamId::from_unchecked(id)), ); - return crate::make_binders_with_count(db, idx, &generic_params, val); + return make_binders(db, &generic_params, val); } }; let mut ty = p.default.as_ref().map_or(TyKind::Error.intern(Interner), |t| ctx.lower_ty(t)); // Each default can only refer to previous parameters. - // type variable default referring to parameter coming - // after it. This is forbidden (FIXME: report - // diagnostic) - ty = fallback_bound_vars(ty, idx); - let val = GenericArgData::Ty(ty).intern(Interner); - crate::make_binders_with_count(db, idx, &generic_params, val) + // Type variable default referring to parameter coming + // after it is forbidden (FIXME: report diagnostic) + ty = fallback_bound_vars(ty, idx, parent_start_idx); + crate::make_binders(db, &generic_params, ty.cast(Interner)) }) .collect(); @@ -1454,15 +1468,14 @@ pub(crate) fn generic_defaults_recover( // we still need one default per parameter let defaults = generic_params .iter_id() - .enumerate() - .map(|(count, id)| { + .map(|id| { let val = match id { itertools::Either::Left(_) => { GenericArgData::Ty(TyKind::Error.intern(Interner)).intern(Interner) } itertools::Either::Right(id) => unknown_const_as_generic(db.const_param_ty(id)), }; - crate::make_binders_with_count(db, count, &generic_params, val) + crate::make_binders(db, &generic_params, val) }) .collect(); @@ -1837,26 +1850,48 @@ pub(crate) fn const_or_path_to_chalk( } } -/// This replaces any 'free' Bound vars in `s` (i.e. those with indices past -/// num_vars_to_keep) by `TyKind::Unknown`. +/// Replaces any 'free' `BoundVar`s in `s` by `TyKind::Error` from the perspective of generic +/// parameter whose index is `param_index`. A `BoundVar` is free when it is or (syntactically) +/// appears after the generic parameter of `param_index`. fn fallback_bound_vars + HasInterner>( s: T, - num_vars_to_keep: usize, + param_index: usize, + parent_start: usize, ) -> T { + // Keep in mind that parent generic parameters, if any, come *after* those of the item in + // question. In the diagrams below, `c*` and `p*` represent generic parameters of the item and + // its parent respectively. + let is_allowed = |index| { + if param_index < parent_start { + // The parameter of `param_index` is one from the item in question. Any parent generic + // parameters or the item's generic parameters that come before `param_index` is + // allowed. + // [c1, .., cj, .., ck, p1, .., pl] where cj is `param_index` + // ^^^^^^ ^^^^^^^^^^ these are allowed + !(param_index..parent_start).contains(&index) + } else { + // The parameter of `param_index` is one from the parent generics. Only parent generic + // parameters that come before `param_index` are allowed. + // [c1, .., ck, p1, .., pj, .., pl] where pj is `param_index` + // ^^^^^^ these are allowed + (parent_start..param_index).contains(&index) + } + }; + crate::fold_free_vars( s, |bound, binders| { - if bound.index >= num_vars_to_keep && bound.debruijn == DebruijnIndex::INNERMOST { - TyKind::Error.intern(Interner) - } else { + if bound.index_if_innermost().map_or(true, is_allowed) { bound.shifted_in_from(binders).to_ty(Interner) + } else { + TyKind::Error.intern(Interner) } }, |ty, bound, binders| { - if bound.index >= num_vars_to_keep && bound.debruijn == DebruijnIndex::INNERMOST { - unknown_const(ty.clone()) - } else { + if bound.index_if_innermost().map_or(true, is_allowed) { bound.shifted_in_from(binders).to_const(Interner, ty) + } else { + unknown_const(ty.clone()) } }, ) diff --git a/crates/hir-ty/src/method_resolution.rs b/crates/hir-ty/src/method_resolution.rs index 41fcef73d9..5998680dcd 100644 --- a/crates/hir-ty/src/method_resolution.rs +++ b/crates/hir-ty/src/method_resolution.rs @@ -654,7 +654,7 @@ fn find_matching_impl( let r = table.run_in_snapshot(|table| { let impl_data = db.impl_data(impl_); let substs = - TyBuilder::subst_for_def(db, impl_).fill_with_inference_vars(table).build(); + TyBuilder::subst_for_def(db, impl_, None).fill_with_inference_vars(table).build(); let impl_ty = db.impl_self_ty(impl_).substitute(Interner, &substs); table @@ -1147,10 +1147,9 @@ fn is_valid_candidate( })); if let ItemContainerId::ImplId(impl_id) = c.lookup(db.upcast()).container { let self_ty_matches = table.run_in_snapshot(|table| { - let subst = - TyBuilder::subst_for_def(db, c).fill_with_inference_vars(table).build(); - let expected_self_ty = - subst.apply(db.impl_self_ty(impl_id).skip_binders().clone(), Interner); + let expected_self_ty = TyBuilder::impl_self_ty(db, impl_id) + .fill_with_inference_vars(table) + .build(); table.unify(&expected_self_ty, &self_ty) }); if !self_ty_matches { @@ -1186,31 +1185,26 @@ fn is_valid_fn_candidate( table.run_in_snapshot(|table| { let container = fn_id.lookup(db.upcast()).container; - let impl_subst = match container { + let (impl_subst, expect_self_ty) = match container { ItemContainerId::ImplId(it) => { - TyBuilder::subst_for_def(db, it).fill_with_inference_vars(table).build() + let subst = + TyBuilder::subst_for_def(db, it, None).fill_with_inference_vars(table).build(); + let self_ty = db.impl_self_ty(it).substitute(Interner, &subst); + (subst, self_ty) } ItemContainerId::TraitId(it) => { - TyBuilder::subst_for_def(db, it).fill_with_inference_vars(table).build() + let subst = + TyBuilder::subst_for_def(db, it, None).fill_with_inference_vars(table).build(); + let self_ty = subst.at(Interner, 0).assert_ty_ref(Interner).clone(); + (subst, self_ty) } _ => unreachable!(), }; - let fn_subst = TyBuilder::subst_for_def(db, fn_id) - .use_parent_substs(&impl_subst) + let fn_subst = TyBuilder::subst_for_def(db, fn_id, Some(impl_subst.clone())) .fill_with_inference_vars(table) .build(); - let expect_self_ty = match container { - ItemContainerId::TraitId(_) => fn_subst.at(Interner, 0).assert_ty_ref(Interner).clone(), - ItemContainerId::ImplId(impl_id) => { - fn_subst.apply(db.impl_self_ty(impl_id).skip_binders().clone(), Interner) - } - // We should only get called for associated items (impl/trait) - ItemContainerId::ModuleId(_) | ItemContainerId::ExternBlockId(_) => { - unreachable!() - } - }; check_that!(table.unify(&expect_self_ty, self_ty)); if let Some(receiver_ty) = receiver_ty { diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs index d1c8fa59ae..e08dd8dade 100644 --- a/crates/hir/src/lib.rs +++ b/crates/hir/src/lib.rs @@ -61,7 +61,6 @@ use hir_ty::{ diagnostics::BodyValidationDiagnostic, method_resolution::{self, TyFingerprint}, primitive::UintTy, - subst_prefix, traits::FnTrait, AliasTy, CallableDefId, CallableSig, Canonical, CanonicalVarKinds, Cast, ClosureId, GenericArgData, Interner, ParamKind, QuantifiedWhereClause, Scalar, Substitution, @@ -1090,7 +1089,7 @@ impl Adt { pub fn ty_with_args(self, db: &dyn HirDatabase, args: &[Type]) -> Type { let id = AdtId::from(self); let mut it = args.iter().map(|t| t.ty.clone()); - let ty = TyBuilder::def_ty(db, id.into()) + let ty = TyBuilder::def_ty(db, id.into(), None) .fill(|x| { let r = it.next().unwrap_or_else(|| TyKind::Error.intern(Interner)); match x { @@ -2547,7 +2546,7 @@ impl TypeParam { let resolver = self.id.parent().resolver(db.upcast()); let ty = params.get(local_idx)?.clone(); let subst = TyBuilder::placeholder_subst(db, self.id.parent()); - let ty = ty.substitute(Interner, &subst_prefix(&subst, local_idx)); + let ty = ty.substitute(Interner, &subst); match ty.data(Interner) { GenericArgData::Ty(x) => Some(Type::new_with_resolver_inner(db, &resolver, x.clone())), _ => None, @@ -2801,7 +2800,18 @@ impl Type { } fn from_def(db: &dyn HirDatabase, def: impl HasResolver + Into) -> Type { - let ty = TyBuilder::def_ty(db, def.into()).fill_with_unknown().build(); + let ty_def = def.into(); + let parent_subst = match ty_def { + TyDefId::TypeAliasId(id) => match id.lookup(db.upcast()).container { + ItemContainerId::TraitId(id) => { + let subst = TyBuilder::subst_for_def(db, id, None).fill_with_unknown().build(); + Some(subst) + } + _ => None, + }, + _ => None, + }; + let ty = TyBuilder::def_ty(db, ty_def, parent_subst).fill_with_unknown().build(); Type::new(db, def, ty) } @@ -2941,7 +2951,11 @@ impl Type { alias: TypeAlias, ) -> Option { let mut args = args.iter(); - let projection = TyBuilder::assoc_type_projection(db, alias.id) + let trait_id = match alias.id.lookup(db.upcast()).container { + ItemContainerId::TraitId(id) => id, + _ => unreachable!("non assoc type alias reached in normalize_trait_assoc_type()"), + }; + let parent_subst = TyBuilder::subst_for_def(db, trait_id, None) .push(self.ty.clone()) .fill(|x| { // FIXME: this code is not covered in tests. @@ -2953,6 +2967,8 @@ impl Type { } }) .build(); + // FIXME: We don't handle GATs yet. + let projection = TyBuilder::assoc_type_projection(db, alias.id, Some(parent_subst)).build(); let ty = db.normalize_projection(projection, self.env.clone()); if ty.is_unknown() { diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs index 342912b678..07bae2b38c 100644 --- a/crates/hir/src/source_analyzer.rs +++ b/crates/hir/src/source_analyzer.rs @@ -22,7 +22,7 @@ use hir_def::{ resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs}, type_ref::Mutability, AsMacroCall, AssocItemId, DefWithBodyId, FieldId, FunctionId, ItemContainerId, LocalFieldId, - Lookup, ModuleDefId, VariantId, + Lookup, ModuleDefId, TraitId, VariantId, }; use hir_expand::{ builtin_fn_macro::BuiltinFnLikeExpander, @@ -302,10 +302,15 @@ impl SourceAnalyzer { } } + let future_trait = db + .lang_item(self.resolver.krate(), hir_expand::name![future_trait].to_smol_str())? + .as_trait()?; let poll_fn = db .lang_item(self.resolver.krate(), hir_expand::name![poll].to_smol_str())? .as_function()?; - let substs = hir_ty::TyBuilder::subst_for_def(db, poll_fn).push(ty.clone()).build(); + // HACK: subst for `poll()` coincides with that for `Future` because `poll()` itself + // doesn't have any generic parameters, so we skip building another subst for `poll()`. + let substs = hir_ty::TyBuilder::subst_for_def(db, future_trait, None).push(ty).build(); Some(self.resolve_impl_method_or_trait_def(db, poll_fn, &substs)) } @@ -321,8 +326,10 @@ impl SourceAnalyzer { }; let ty = self.ty_of_expr(db, &prefix_expr.expr()?.into())?; - let op_fn = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?; - let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn).push(ty.clone()).build(); + let (op_trait, op_fn) = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?; + // HACK: subst for all methods coincides with that for their trait because the methods + // don't have any generic parameters, so we skip building another subst for the methods. + let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None).push(ty.clone()).build(); Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs)) } @@ -337,8 +344,10 @@ impl SourceAnalyzer { let lang_item_name = name![index]; - let op_fn = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?; - let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn) + let (op_trait, op_fn) = self.lang_trait_fn(db, &lang_item_name, &lang_item_name)?; + // HACK: subst for all methods coincides with that for their trait because the methods + // don't have any generic parameters, so we skip building another subst for the methods. + let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None) .push(base_ty.clone()) .push(index_ty.clone()) .build(); @@ -354,10 +363,14 @@ impl SourceAnalyzer { let lhs = self.ty_of_expr(db, &binop_expr.lhs()?.into())?; let rhs = self.ty_of_expr(db, &binop_expr.rhs()?.into())?; - let op_fn = lang_names_for_bin_op(op) + let (op_trait, op_fn) = lang_names_for_bin_op(op) .and_then(|(name, lang_item)| self.lang_trait_fn(db, &lang_item, &name))?; - let substs = - hir_ty::TyBuilder::subst_for_def(db, op_fn).push(lhs.clone()).push(rhs.clone()).build(); + // HACK: subst for `index()` coincides with that for `Index` because `index()` itself + // doesn't have any generic parameters, so we skip building another subst for `index()`. + let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None) + .push(lhs.clone()) + .push(rhs.clone()) + .build(); Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs)) } @@ -371,7 +384,13 @@ impl SourceAnalyzer { let op_fn = db.lang_item(self.resolver.krate(), name![branch].to_smol_str())?.as_function()?; - let substs = hir_ty::TyBuilder::subst_for_def(db, op_fn).push(ty.clone()).build(); + let op_trait = match op_fn.lookup(db.upcast()).container { + ItemContainerId::TraitId(id) => id, + _ => return None, + }; + // HACK: subst for `branch()` coincides with that for `Try` because `branch()` itself + // doesn't have any generic parameters, so we skip building another subst for `branch()`. + let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None).push(ty.clone()).build(); Some(self.resolve_impl_method_or_trait_def(db, op_fn, &substs)) } @@ -799,9 +818,10 @@ impl SourceAnalyzer { db: &dyn HirDatabase, lang_trait: &Name, method_name: &Name, - ) -> Option { - db.trait_data(db.lang_item(self.resolver.krate(), lang_trait.to_smol_str())?.as_trait()?) - .method_by_name(method_name) + ) -> Option<(TraitId, FunctionId)> { + let trait_id = db.lang_item(self.resolver.krate(), lang_trait.to_smol_str())?.as_trait()?; + let fn_id = db.trait_data(trait_id).method_by_name(method_name)?; + Some((trait_id, fn_id)) } fn ty_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<&Ty> {