From 001dd6a2000ce4adada0ab6e4ed8fd67cb8eb569 Mon Sep 17 00:00:00 2001
From: Florian Diebold <florian.diebold@freiheit.com>
Date: Fri, 14 Feb 2020 19:16:42 +0100
Subject: [PATCH] Make Self implement the trait inside trait default methods
---
crates/ra_hir_def/src/resolver.rs | 6 +---
crates/ra_hir_ty/src/lower.rs | 32 ++++++++++++++++---
crates/ra_hir_ty/src/marks.rs | 1 +
crates/ra_hir_ty/src/tests/traits.rs | 48 ++++++++++++++++++++++++++++
4 files changed, 78 insertions(+), 9 deletions(-)
diff --git a/crates/ra_hir_def/src/resolver.rs b/crates/ra_hir_def/src/resolver.rs
index 05cf4646a89..e2b228e80d3 100644
--- a/crates/ra_hir_def/src/resolver.rs
+++ b/crates/ra_hir_def/src/resolver.rs
@@ -542,11 +542,7 @@ impl Resolver {
fn push_generic_params_scope(self, db: &impl DefDatabase, def: GenericDefId) -> Resolver {
let params = db.generic_params(def);
- if params.types.is_empty() {
- self
- } else {
- self.push_scope(Scope::GenericParams { def, params })
- }
+ self.push_scope(Scope::GenericParams { def, params })
}
fn push_impl_block_scope(self, impl_block: ImplId) -> Resolver {
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index df24c16a3f8..6a2aded021c 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -14,9 +14,9 @@ use hir_def::{
path::{GenericArg, Path, PathSegment, PathSegments},
resolver::{HasResolver, Resolver, TypeNs},
type_ref::{TypeBound, TypeRef},
- AdtId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
- LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, TypeParamId, UnionId,
- VariantId,
+ AdtId, AssocContainerId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule,
+ ImplId, LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
+ UnionId, VariantId,
};
use ra_arena::map::ArenaMap;
use ra_db::CrateId;
@@ -672,11 +672,35 @@ impl TraitEnvironment {
pub fn lower(db: &impl HirDatabase, resolver: &Resolver) -> Arc<TraitEnvironment> {
let ctx = TyLoweringContext::new(db, &resolver)
.with_type_param_mode(TypeParamLoweringMode::Placeholder);
- let predicates = resolver
+ let mut predicates = resolver
.where_predicates_in_scope()
.flat_map(|pred| GenericPredicate::from_where_predicate(&ctx, pred))
.collect::<Vec<_>>();
+ if let Some(def) = resolver.generic_def() {
+ let container: Option<AssocContainerId> = match def {
+ // FIXME: is there a function for this?
+ GenericDefId::FunctionId(f) => Some(f.lookup(db).container),
+ GenericDefId::AdtId(_) => None,
+ GenericDefId::TraitId(_) => None,
+ GenericDefId::TypeAliasId(t) => Some(t.lookup(db).container),
+ GenericDefId::ImplId(_) => None,
+ GenericDefId::EnumVariantId(_) => None,
+ GenericDefId::ConstId(c) => Some(c.lookup(db).container),
+ };
+ if let Some(AssocContainerId::TraitId(trait_id)) = container {
+ // add `Self: Trait<T1, T2, ...>` to the environment in trait
+ // function default implementations (and hypothetical code
+ // inside consts or type aliases)
+ test_utils::tested_by!(trait_self_implements_self);
+ let substs = Substs::type_params(db, trait_id);
+ let trait_ref = TraitRef { trait_: trait_id, substs };
+ let pred = GenericPredicate::Implemented(trait_ref);
+
+ predicates.push(pred);
+ }
+ }
+
Arc::new(TraitEnvironment { predicates })
}
}
diff --git a/crates/ra_hir_ty/src/marks.rs b/crates/ra_hir_ty/src/marks.rs
index 0f754eb9c75..ae47855e958 100644
--- a/crates/ra_hir_ty/src/marks.rs
+++ b/crates/ra_hir_ty/src/marks.rs
@@ -6,4 +6,5 @@ test_utils::marks!(
type_var_resolves_to_int_var
match_ergonomics_ref
coerce_merge_fail_fallback
+ trait_self_implements_self
);
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 17611ddbfa4..aa2018944ce 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -299,6 +299,54 @@ fn test() {
);
}
+#[test]
+fn trait_default_method_self_bound_implements_trait() {
+ test_utils::covers!(trait_self_implements_self);
+ assert_snapshot!(
+ infer(r#"
+trait Trait {
+ fn foo(&self) -> i64;
+ fn bar(&self) -> {
+ let x = self.foo();
+ }
+}
+"#),
+ @r###"
+ [27; 31) 'self': &Self
+ [53; 57) 'self': &Self
+ [62; 97) '{ ... }': ()
+ [76; 77) 'x': i64
+ [80; 84) 'self': &Self
+ [80; 90) 'self.foo()': i64
+ "###
+ );
+}
+
+#[test]
+fn trait_default_method_self_bound_implements_super_trait() {
+ test_utils::covers!(trait_self_implements_self);
+ assert_snapshot!(
+ infer(r#"
+trait SuperTrait {
+ fn foo(&self) -> i64;
+}
+trait Trait: SuperTrait {
+ fn bar(&self) -> {
+ let x = self.foo();
+ }
+}
+"#),
+ @r###"
+ [32; 36) 'self': &Self
+ [86; 90) 'self': &Self
+ [95; 130) '{ ... }': ()
+ [109; 110) 'x': i64
+ [113; 117) 'self': &Self
+ [113; 123) 'self.foo()': i64
+ "###
+ );
+}
+
#[test]
fn infer_project_associated_type() {
// y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234