12 files changed, 175 insertions, 56 deletions

diff --git a/crates/hir_ty/src/db.rs b/crates/hir_ty/src/db.rs
index f3567c49e..b3af82444 100644
--- a/crates/hir_ty/src/db.rs
+++ b/crates/hir_ty/src/db.rs
@@ -2,12 +2,12 @@
 
 use std::sync::Arc;
 
-use arena::map::ArenaMap;
 use base_db::{impl_intern_key, salsa, CrateId, Upcast};
 use hir_def::{
     db::DefDatabase, expr::ExprId, ConstParamId, DefWithBodyId, FunctionId, GenericDefId, ImplId,
     LocalFieldId, TypeParamId, VariantId,
 };
+use la_arena::ArenaMap;
 
 use crate::{
     method_resolution::{InherentImpls, TraitImpls},
diff --git a/crates/hir_ty/src/diagnostics.rs b/crates/hir_ty/src/diagnostics.rs
index 14e18f5a1..c67a289f2 100644
--- a/crates/hir_ty/src/diagnostics.rs
+++ b/crates/hir_ty/src/diagnostics.rs
@@ -186,9 +186,10 @@ impl Diagnostic for MissingMatchArms {
     }
 }
 
-// Diagnostic: missing-ok-in-tail-expr
+// Diagnostic: missing-ok-or-some-in-tail-expr
 //
-// This diagnostic is triggered if block that should return `Result` returns a value not wrapped in `Ok`.
+// This diagnostic is triggered if a block that should return `Result` returns a value not wrapped in `Ok`,
+// or if a block that should return `Option` returns a value not wrapped in `Some`.
 //
 // Example:
 //
@@ -198,17 +199,19 @@ impl Diagnostic for MissingMatchArms {
 // }
 // ```
 #[derive(Debug)]
-pub struct MissingOkInTailExpr {
+pub struct MissingOkOrSomeInTailExpr {
     pub file: HirFileId,
     pub expr: AstPtr<ast::Expr>,
+    // `Some` or `Ok` depending on whether the return type is Result or Option
+    pub required: String,
 }
 
-impl Diagnostic for MissingOkInTailExpr {
+impl Diagnostic for MissingOkOrSomeInTailExpr {
     fn code(&self) -> DiagnosticCode {
-        DiagnosticCode("missing-ok-in-tail-expr")
+        DiagnosticCode("missing-ok-or-some-in-tail-expr")
     }
     fn message(&self) -> String {
-        "wrap return expression in Ok".to_string()
+        format!("wrap return expression in {}", self.required)
     }
     fn display_source(&self) -> InFile<SyntaxNodePtr> {
         InFile { file_id: self.file, value: self.expr.clone().into() }
diff --git a/crates/hir_ty/src/diagnostics/expr.rs b/crates/hir_ty/src/diagnostics/expr.rs
index b4e453411..107417c27 100644
--- a/crates/hir_ty/src/diagnostics/expr.rs
+++ b/crates/hir_ty/src/diagnostics/expr.rs
@@ -11,8 +11,8 @@ use crate::{
     db::HirDatabase,
     diagnostics::{
         match_check::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
-        MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, MissingPatFields,
-        RemoveThisSemicolon,
+        MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkOrSomeInTailExpr,
+        MissingPatFields, RemoveThisSemicolon,
     },
     utils::variant_data,
     ApplicationTy, InferenceResult, Ty, TypeCtor,
@@ -306,27 +306,40 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         };
 
         let core_result_path = path![core::result::Result];
+        let core_option_path = path![core::option::Option];
 
         let resolver = self.owner.resolver(db.upcast());
         let core_result_enum = match resolver.resolve_known_enum(db.upcast(), &core_result_path) {
             Some(it) => it,
             _ => return,
         };
+        let core_option_enum = match resolver.resolve_known_enum(db.upcast(), &core_option_path) {
+            Some(it) => it,
+            _ => return,
+        };
 
         let core_result_ctor = TypeCtor::Adt(AdtId::EnumId(core_result_enum));
-        let params = match &mismatch.expected {
+        let core_option_ctor = TypeCtor::Adt(AdtId::EnumId(core_option_enum));
+
+        let (params, required) = match &mismatch.expected {
             Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_result_ctor => {
-                parameters
+                (parameters, "Ok".to_string())
+            }
+            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_option_ctor => {
+                (parameters, "Some".to_string())
             }
             _ => return,
         };
 
-        if params.len() == 2 && params[0] == mismatch.actual {
+        if params.len() > 0 && params[0] == mismatch.actual {
             let (_, source_map) = db.body_with_source_map(self.owner.into());
 
             if let Ok(source_ptr) = source_map.expr_syntax(id) {
-                self.sink
-                    .push(MissingOkInTailExpr { file: source_ptr.file_id, expr: source_ptr.value });
+                self.sink.push(MissingOkOrSomeInTailExpr {
+                    file: source_ptr.file_id,
+                    expr: source_ptr.value,
+                    required,
+                });
             }
         }
     }
@@ -366,7 +379,7 @@ pub fn record_literal_missing_fields(
     id: ExprId,
     expr: &Expr,
 ) -> Option<(VariantId, Vec<LocalFieldId>, /*exhaustive*/ bool)> {
-    let (fields, exhausitve) = match expr {
+    let (fields, exhaustive) = match expr {
         Expr::RecordLit { path: _, fields, spread } => (fields, spread.is_none()),
         _ => return None,
     };
@@ -387,7 +400,7 @@ pub fn record_literal_missing_fields(
     if missed_fields.is_empty() {
         return None;
     }
-    Some((variant_def, missed_fields, exhausitve))
+    Some((variant_def, missed_fields, exhaustive))
 }
 
 pub fn record_pattern_missing_fields(
diff --git a/crates/hir_ty/src/diagnostics/match_check.rs b/crates/hir_ty/src/diagnostics/match_check.rs
index 62c329731..fbe760c39 100644
--- a/crates/hir_ty/src/diagnostics/match_check.rs
+++ b/crates/hir_ty/src/diagnostics/match_check.rs
@@ -14,7 +14,7 @@
 //! The algorithm implemented here is a modified version of the one described in
 //! <http://moscova.inria.fr/~maranget/papers/warn/index.html>.
 //! However, to save future implementors from reading the original paper, we
-//! summarise the algorithm here to hopefully save time and be a little clearer
+//! summarize the algorithm here to hopefully save time and be a little clearer
 //! (without being so rigorous).
 //!
 //! The core of the algorithm revolves about a "usefulness" check. In particular, we
@@ -132,7 +132,7 @@
 //! The algorithm is inductive (on the number of columns: i.e., components of tuple patterns).
 //! That means we're going to check the components from left-to-right, so the algorithm
 //! operates principally on the first component of the matrix and new pattern-stack `p`.
-//! This algorithm is realised in the `is_useful` function.
+//! This algorithm is realized in the `is_useful` function.
 //!
 //! Base case (`n = 0`, i.e., an empty tuple pattern):
 //! - If `P` already contains an empty pattern (i.e., if the number of patterns `m > 0`), then
@@ -218,13 +218,13 @@
 //!   ```
 use std::{iter, sync::Arc};
 
-use arena::Idx;
 use hir_def::{
     adt::VariantData,
     body::Body,
     expr::{Expr, Literal, Pat, PatId},
     AdtId, EnumVariantId, StructId, VariantId,
 };
+use la_arena::Idx;
 use smallvec::{smallvec, SmallVec};
 
 use crate::{db::HirDatabase, ApplicationTy, InferenceResult, Ty, TypeCtor};
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index e9e949c47..d2f1b4014 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -1,14 +1,15 @@
 //! FIXME: write short doc here
 
-use std::fmt;
+use std::{borrow::Cow, fmt};
 
 use crate::{
     db::HirDatabase, utils::generics, ApplicationTy, CallableDefId, FnSig, GenericPredicate,
-    Lifetime, Obligation, OpaqueTyId, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
+    Lifetime, Obligation, OpaqueTy, OpaqueTyId, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
 };
+use arrayvec::ArrayVec;
 use hir_def::{
-    find_path, generics::TypeParamProvenance, item_scope::ItemInNs, AdtId, AssocContainerId,
-    Lookup, ModuleId,
+    db::DefDatabase, find_path, generics::TypeParamProvenance, item_scope::ItemInNs, AdtId,
+    AssocContainerId, HasModule, Lookup, ModuleId, TraitId,
 };
 use hir_expand::name::Name;
 
@@ -257,25 +258,45 @@ impl HirDisplay for ApplicationTy {
                 t.hir_fmt(f)?;
                 write!(f, "; _]")?;
             }
-            TypeCtor::RawPtr(m) => {
+            TypeCtor::RawPtr(m) | TypeCtor::Ref(m) => {
                 let t = self.parameters.as_single();
+                let ty_display =
+                    t.into_displayable(f.db, f.max_size, f.omit_verbose_types, f.display_target);
 
-                write!(f, "*{}", m.as_keyword_for_ptr())?;
-                if matches!(t, Ty::Dyn(predicates) if predicates.len() > 1) {
-                    write!(f, "(")?;
-                    t.hir_fmt(f)?;
-                    write!(f, ")")?;
+                if matches!(self.ctor, TypeCtor::RawPtr(_)) {
+                    write!(f, "*{}", m.as_keyword_for_ptr())?;
                 } else {
-                    t.hir_fmt(f)?;
+                    write!(f, "&{}", m.as_keyword_for_ref())?;
+                }
+
+                let datas;
+                let predicates = match t {
+                    Ty::Dyn(predicates) if predicates.len() > 1 => {
+                        Cow::Borrowed(predicates.as_ref())
+                    }
+                    &Ty::Opaque(OpaqueTy {
+                        opaque_ty_id: OpaqueTyId::ReturnTypeImplTrait(func, idx),
+                        ref parameters,
+                    }) => {
+                        datas =
+                            f.db.return_type_impl_traits(func).expect("impl trait id without data");
+                        let data = (*datas)
+                            .as_ref()
+                            .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                        let bounds = data.subst(parameters);
+                        Cow::Owned(bounds.value)
+                    }
+                    _ => Cow::Borrowed(&[][..]),
+                };
+
+                if let [GenericPredicate::Implemented(trait_ref), _] = predicates.as_ref() {
+                    let trait_ = trait_ref.trait_;
+                    if fn_traits(f.db.upcast(), trait_).any(|it| it == trait_) {
+                        return write!(f, "{}", ty_display);
+                    }
                 }
-            }
-            TypeCtor::Ref(m) => {
-                let t = self.parameters.as_single();
-                let ty_display =
-                    t.into_displayable(f.db, f.max_size, f.omit_verbose_types, f.display_target);
 
-                write!(f, "&{}", m.as_keyword_for_ref())?;
-                if matches!(t, Ty::Dyn(predicates) if predicates.len() > 1) {
+                if predicates.len() > 1 {
                     write!(f, "(")?;
                     write!(f, "{}", ty_display)?;
                     write!(f, ")")?;
@@ -595,6 +616,17 @@ impl HirDisplay for FnSig {
     }
 }
 
+fn fn_traits(db: &dyn DefDatabase, trait_: TraitId) -> impl Iterator<Item = TraitId> {
+    let krate = trait_.lookup(db).container.module(db).krate;
+    let fn_traits = [
+        db.lang_item(krate, "fn".into()),
+        db.lang_item(krate, "fn_mut".into()),
+        db.lang_item(krate, "fn_once".into()),
+    ];
+    // FIXME: Replace ArrayVec when into_iter is a thing on arrays
+    ArrayVec::from(fn_traits).into_iter().flatten().flat_map(|it| it.as_trait())
+}
+
 pub fn write_bounds_like_dyn_trait(
     predicates: &[GenericPredicate],
     f: &mut HirFormatter,
@@ -607,10 +639,15 @@ pub fn write_bounds_like_dyn_trait(
     // predicate for that trait).
     let mut first = true;
     let mut angle_open = false;
+    let mut is_fn_trait = false;
     for p in predicates.iter() {
         match p {
             GenericPredicate::Implemented(trait_ref) => {
-                if angle_open {
+                let trait_ = trait_ref.trait_;
+                if !is_fn_trait {
+                    is_fn_trait = fn_traits(f.db.upcast(), trait_).any(|it| it == trait_);
+                }
+                if !is_fn_trait && angle_open {
                     write!(f, ">")?;
                     angle_open = false;
                 }
@@ -620,14 +657,27 @@ pub fn write_bounds_like_dyn_trait(
                 // We assume that the self type is $0 (i.e. the
                 // existential) here, which is the only thing that's
                 // possible in actual Rust, and hence don't print it
-                write!(f, "{}", f.db.trait_data(trait_ref.trait_).name)?;
-                if trait_ref.substs.len() > 1 {
-                    write!(f, "<")?;
-                    f.write_joined(&trait_ref.substs[1..], ", ")?;
-                    // there might be assoc type bindings, so we leave the angle brackets open
-                    angle_open = true;
+                write!(f, "{}", f.db.trait_data(trait_).name)?;
+                if let [_, params @ ..] = &*trait_ref.substs.0 {
+                    if is_fn_trait {
+                        if let Some(args) = params.first().and_then(|it| it.as_tuple()) {
+                            write!(f, "(")?;
+                            f.write_joined(&*args.0, ", ")?;
+                            write!(f, ")")?;
+                        }
+                    } else if !params.is_empty() {
+                        write!(f, "<")?;
+                        f.write_joined(params, ", ")?;
+                        // there might be assoc type bindings, so we leave the angle brackets open
+                        angle_open = true;
+                    }
                 }
             }
+            GenericPredicate::Projection(projection_pred) if is_fn_trait => {
+                is_fn_trait = false;
+                write!(f, " -> ")?;
+                projection_pred.ty.hir_fmt(f)?;
+            }
             GenericPredicate::Projection(projection_pred) => {
                 // in types in actual Rust, these will always come
                 // after the corresponding Implemented predicate
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index a14d67c06..d08867c70 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -18,7 +18,6 @@ use std::mem;
 use std::ops::Index;
 use std::sync::Arc;
 
-use arena::map::ArenaMap;
 use hir_def::{
     body::Body,
     data::{ConstData, FunctionData, StaticData},
@@ -31,6 +30,7 @@ use hir_def::{
     TypeAliasId, VariantId,
 };
 use hir_expand::{diagnostics::DiagnosticSink, name::name};
+use la_arena::ArenaMap;
 use rustc_hash::FxHashMap;
 use stdx::impl_from;
 use syntax::SmolStr;
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index f2fc69b2f..9bf3b51b0 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -367,6 +367,13 @@ impl<'a> InferenceContext<'a> {
                 }
                 Ty::simple(TypeCtor::Never)
             }
+            Expr::Yield { expr } => {
+                // FIXME: track yield type for coercion
+                if let Some(expr) = expr {
+                    self.infer_expr(*expr, &Expectation::none());
+                }
+                Ty::simple(TypeCtor::Never)
+            }
             Expr::RecordLit { path, fields, spread } => {
                 let (ty, def_id) = self.resolve_variant(path.as_ref());
                 if let Some(variant) = def_id {
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 222f61a11..7a734c8b9 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -7,7 +7,6 @@
 //! This usually involves resolving names, collecting generic arguments etc.
 use std::{iter, sync::Arc};
 
-use arena::map::ArenaMap;
 use base_db::CrateId;
 use hir_def::{
     adt::StructKind,
@@ -21,6 +20,7 @@ use hir_def::{
     TypeAliasId, TypeParamId, UnionId, VariantId,
 };
 use hir_expand::name::Name;
+use la_arena::ArenaMap;
 use smallvec::SmallVec;
 use stdx::impl_from;
 use test_utils::mark;
@@ -491,16 +491,16 @@ impl Ty {
     fn from_hir_path_inner(
         ctx: &TyLoweringContext<'_>,
         segment: PathSegment<'_>,
-        typable: TyDefId,
+        typeable: TyDefId,
         infer_args: bool,
     ) -> Ty {
-        let generic_def = match typable {
+        let generic_def = match typeable {
             TyDefId::BuiltinType(_) => None,
             TyDefId::AdtId(it) => Some(it.into()),
             TyDefId::TypeAliasId(it) => Some(it.into()),
         };
         let substs = substs_from_path_segment(ctx, segment, generic_def, infer_args);
-        ctx.db.ty(typable).subst(&substs)
+        ctx.db.ty(typeable).subst(&substs)
     }
 
     /// Collect generic arguments from a path into a `Substs`. See also
diff --git a/crates/hir_ty/src/tests.rs b/crates/hir_ty/src/tests.rs
index 0a400cb70..5ff755321 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -26,7 +26,7 @@ use once_cell::race::OnceBool;
 use stdx::format_to;
 use syntax::{
     algo,
-    ast::{self, AstNode},
+    ast::{self, AstNode, NameOwner},
     SyntaxNode,
 };
 use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
@@ -153,7 +153,7 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
         });
         for (node, ty) in &types {
             let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.value.clone()) {
-                (self_param.self_token().unwrap().text_range(), "self".to_string())
+                (self_param.name().unwrap().syntax().text_range(), "self".to_string())
             } else {
                 (node.value.text_range(), node.value.text().to_string().replace("\n", " "))
             };
@@ -314,7 +314,7 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
         "
         //- /lib.rs
         fn foo() -> i32 {
-            <|>1 + 1
+            $01 + 1
         }
     ",
     );
diff --git a/crates/hir_ty/src/tests/display_source_code.rs b/crates/hir_ty/src/tests/display_source_code.rs
index b502135d8..3d29021aa 100644
--- a/crates/hir_ty/src/tests/display_source_code.rs
+++ b/crates/hir_ty/src/tests/display_source_code.rs
@@ -39,3 +39,18 @@ fn main() {
 "#,
     );
 }
+
+#[test]
+fn render_raw_ptr_impl_ty() {
+    check_types_source_code(
+        r#"
+trait Sized {}
+trait Unpin {}
+fn foo() -> *const (impl Unpin + Sized) { loop {} }
+fn main() {
+    let foo = foo();
+    foo;
+}   //^ *const (impl Unpin + Sized)
+"#,
+    );
+}
diff --git a/crates/hir_ty/src/tests/macros.rs b/crates/hir_ty/src/tests/macros.rs
index 1953da7be..c64f0b5b5 100644
--- a/crates/hir_ty/src/tests/macros.rs
+++ b/crates/hir_ty/src/tests/macros.rs
@@ -371,6 +371,37 @@ expand!();
 }
 
 #[test]
+fn infer_macro_with_dollar_crate_in_def_site() {
+    check_types(
+        r#"
+//- /main.rs crate:main deps:foo
+use foo::expand;
+
+macro_rules! list {
+    ($($tt:tt)*) => { $($tt)* }
+}
+
+fn test() {
+    let r = expand!();
+    r;
+  //^ u128
+}
+
+//- /lib.rs crate:foo
+#[macro_export]
+macro_rules! expand {
+    () => { list!($crate::m!()) };
+}
+
+#[macro_export]
+macro_rules! m {
+    () => { 0u128 };
+}
+"#,
+    );
+}
+
+#[test]
 fn infer_type_value_non_legacy_macro_use_as() {
     check_infer(
         r#"
diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index 41d097519..e5a3f95a6 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -3038,16 +3038,16 @@ fn infer_box_fn_arg() {
             406..417 '&self.inner': &*mut T
             407..411 'self': &Box<T>
             407..417 'self.inner': *mut T
-            478..575 '{     ...(&s) }': FnOnce::Output<dyn FnOnce<(&Option<i32>,)>, (&Option<i32>,)>
+            478..575 '{     ...(&s) }': FnOnce::Output<dyn FnOnce(&Option<i32>), (&Option<i32>,)>
             488..489 's': Option<i32>
             492..504 'Option::None': Option<i32>
-            514..515 'f': Box<dyn FnOnce<(&Option<i32>,)>>
+            514..515 'f': Box<dyn FnOnce(&Option<i32>)>
             549..562 'box (|ps| {})': Box<|{unknown}| -> ()>
             554..561 '|ps| {}': |{unknown}| -> ()
             555..557 'ps': {unknown}
             559..561 '{}': ()
-            568..569 'f': Box<dyn FnOnce<(&Option<i32>,)>>
-            568..573 'f(&s)': FnOnce::Output<dyn FnOnce<(&Option<i32>,)>, (&Option<i32>,)>
+            568..569 'f': Box<dyn FnOnce(&Option<i32>)>
+            568..573 'f(&s)': FnOnce::Output<dyn FnOnce(&Option<i32>), (&Option<i32>,)>
             570..572 '&s': &Option<i32>
             571..572 's': Option<i32>
         "#]],