26 files changed, 1444 insertions, 254 deletions

diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 65db6d1b0..5fc0ec5e3 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -27,9 +27,9 @@ test_utils = { path = "../test_utils" }
 
 scoped-tls = "1"
 
-chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "2c072cc830d04af5f10b390e6643327f85108282" }
-chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "2c072cc830d04af5f10b390e6643327f85108282" }
-chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "2c072cc830d04af5f10b390e6643327f85108282" }
+chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "3e9c2503ae9c5277c2acb74624dc267876dd89b3" }
+chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "3e9c2503ae9c5277c2acb74624dc267876dd89b3" }
+chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "3e9c2503ae9c5277c2acb74624dc267876dd89b3" }
 
 [dev-dependencies]
 insta = "0.16.0"
diff --git a/crates/ra_hir_ty/src/_match.rs b/crates/ra_hir_ty/src/_match.rs
index 779e78574..3e6e1e333 100644
--- a/crates/ra_hir_ty/src/_match.rs
+++ b/crates/ra_hir_ty/src/_match.rs
@@ -573,14 +573,20 @@ pub(crate) fn is_useful(
     matrix: &Matrix,
     v: &PatStack,
 ) -> MatchCheckResult<Usefulness> {
-    // Handle the special case of enums with no variants. In that case, no match
-    // arm is useful.
-    if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(AdtId::EnumId(enum_id)), .. }) =
-        cx.infer[cx.match_expr].strip_references()
-    {
-        if cx.db.enum_data(*enum_id).variants.is_empty() {
+    // Handle two special cases:
+    // - enum with no variants
+    // - `!` type
+    // In those cases, no match arm is useful.
+    match cx.infer[cx.match_expr].strip_references() {
+        Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(AdtId::EnumId(enum_id)), .. }) => {
+            if cx.db.enum_data(*enum_id).variants.is_empty() {
+                return Ok(Usefulness::NotUseful);
+            }
+        }
+        Ty::Apply(ApplicationTy { ctor: TypeCtor::Never, .. }) => {
             return Ok(Usefulness::NotUseful);
         }
+        _ => (),
     }
 
     if v.is_empty() {
@@ -1918,6 +1924,17 @@ mod tests {
     }
 
     #[test]
+    fn type_never() {
+        let content = r"
+            fn test_fn(never: !) {
+                match never {}
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
     fn enum_never_ref() {
         let content = r"
             enum Never {}
@@ -1929,6 +1946,23 @@ mod tests {
 
         check_no_diagnostic(content);
     }
+
+    #[test]
+    fn expr_diverges_missing_arm() {
+        let content = r"
+            enum Either {
+                A,
+                B,
+            }
+            fn test_fn() {
+                match loop {} {
+                    Either::A => (),
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
 }
 
 #[cfg(test)]
@@ -1981,26 +2015,6 @@ mod false_negatives {
     }
 
     #[test]
-    fn expr_diverges_missing_arm() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match loop {} {
-                    Either::A => (),
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // Even though the match expression diverges, rustc fails
-        // to compile here since `Either::B` is missing.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
     fn expr_loop_missing_arm() {
         let content = r"
             enum Either {
@@ -2018,7 +2032,7 @@ mod false_negatives {
         // We currently infer the type of `loop { break Foo::A }` to `!`, which
         // causes us to skip the diagnostic since `Either::A` doesn't type check
         // with `!`.
-        check_no_diagnostic(content);
+        check_diagnostic(content);
     }
 
     #[test]
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index c8fd54861..41ac70272 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -131,3 +131,31 @@ impl AstDiagnostic for MissingOkInTailExpr {
         ast::Expr::cast(node).unwrap()
     }
 }
+
+#[derive(Debug)]
+pub struct BreakOutsideOfLoop {
+    pub file: HirFileId,
+    pub expr: AstPtr<ast::Expr>,
+}
+
+impl Diagnostic for BreakOutsideOfLoop {
+    fn message(&self) -> String {
+        "break outside of loop".to_string()
+    }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.expr.clone().into() }
+    }
+    fn as_any(&self) -> &(dyn Any + Send + 'static) {
+        self
+    }
+}
+
+impl AstDiagnostic for BreakOutsideOfLoop {
+    type AST = ast::Expr;
+
+    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
+        let root = db.parse_or_expand(self.file).unwrap();
+        let node = self.source().value.to_node(&root);
+        ast::Expr::cast(node).unwrap()
+    }
+}
diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index d03bbd5a7..b9c4d2e89 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -6,28 +6,42 @@ use crate::{
     db::HirDatabase, utils::generics, ApplicationTy, CallableDef, FnSig, GenericPredicate,
     Obligation, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
 };
-use hir_def::{generics::TypeParamProvenance, AdtId, AssocContainerId, Lookup};
+use hir_def::{
+    find_path, generics::TypeParamProvenance, item_scope::ItemInNs, AdtId, AssocContainerId,
+    Lookup, ModuleId,
+};
 use hir_expand::name::Name;
 
-pub struct HirFormatter<'a, 'b> {
+pub struct HirFormatter<'a> {
     pub db: &'a dyn HirDatabase,
-    fmt: &'a mut fmt::Formatter<'b>,
+    fmt: &'a mut dyn fmt::Write,
     buf: String,
     curr_size: usize,
     pub(crate) max_size: Option<usize>,
     omit_verbose_types: bool,
+    display_target: DisplayTarget,
 }
 
 pub trait HirDisplay {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result;
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError>;
 
+    /// Returns a `Display`able type that is human-readable.
+    /// Use this for showing types to the user (e.g. diagnostics)
     fn display<'a>(&'a self, db: &'a dyn HirDatabase) -> HirDisplayWrapper<'a, Self>
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, None, false)
+        HirDisplayWrapper {
+            db,
+            t: self,
+            max_size: None,
+            omit_verbose_types: false,
+            display_target: DisplayTarget::Diagnostics,
+        }
     }
 
+    /// Returns a `Display`able type that is human-readable and tries to be succinct.
+    /// Use this for showing types to the user where space is constrained (e.g. doc popups)
     fn display_truncated<'a>(
         &'a self,
         db: &'a dyn HirDatabase,
@@ -36,16 +50,46 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, max_size, true)
+        HirDisplayWrapper {
+            db,
+            t: self,
+            max_size,
+            omit_verbose_types: true,
+            display_target: DisplayTarget::Diagnostics,
+        }
+    }
+
+    /// Returns a String representation of `self` that can be inserted into the given module.
+    /// Use this when generating code (e.g. assists)
+    fn display_source_code<'a>(
+        &'a self,
+        db: &'a dyn HirDatabase,
+        module_id: ModuleId,
+    ) -> Result<String, DisplaySourceCodeError> {
+        let mut result = String::new();
+        match self.hir_fmt(&mut HirFormatter {
+            db,
+            fmt: &mut result,
+            buf: String::with_capacity(20),
+            curr_size: 0,
+            max_size: None,
+            omit_verbose_types: false,
+            display_target: DisplayTarget::SourceCode { module_id },
+        }) {
+            Ok(()) => {}
+            Err(HirDisplayError::FmtError) => panic!("Writing to String can't fail!"),
+            Err(HirDisplayError::DisplaySourceCodeError(e)) => return Err(e),
+        };
+        Ok(result)
     }
 }
 
-impl<'a, 'b> HirFormatter<'a, 'b> {
+impl<'a> HirFormatter<'a> {
     pub fn write_joined<T: HirDisplay>(
         &mut self,
         iter: impl IntoIterator<Item = T>,
         sep: &str,
-    ) -> fmt::Result {
+    ) -> Result<(), HirDisplayError> {
         let mut first = true;
         for e in iter {
             if !first {
@@ -58,14 +102,14 @@ impl<'a, 'b> HirFormatter<'a, 'b> {
     }
 
     /// This allows using the `write!` macro directly with a `HirFormatter`.
-    pub fn write_fmt(&mut self, args: fmt::Arguments) -> fmt::Result {
+    pub fn write_fmt(&mut self, args: fmt::Arguments) -> Result<(), HirDisplayError> {
         // We write to a buffer first to track output size
         self.buf.clear();
         fmt::write(&mut self.buf, args)?;
         self.curr_size += self.buf.len();
 
         // Then we write to the internal formatter from the buffer
-        self.fmt.write_str(&self.buf)
+        self.fmt.write_str(&self.buf).map_err(HirDisplayError::from)
     }
 
     pub fn should_truncate(&self) -> bool {
@@ -81,34 +125,82 @@ impl<'a, 'b> HirFormatter<'a, 'b> {
     }
 }
 
-pub struct HirDisplayWrapper<'a, T>(&'a dyn HirDatabase, &'a T, Option<usize>, bool);
+#[derive(Clone, Copy)]
+enum DisplayTarget {
+    /// Display types for inlays, doc popups, autocompletion, etc...
+    /// Showing `{unknown}` or not qualifying paths is fine here.
+    /// There's no reason for this to fail.
+    Diagnostics,
+    /// Display types for inserting them in source files.
+    /// The generated code should compile, so paths need to be qualified.
+    SourceCode { module_id: ModuleId },
+}
+
+impl DisplayTarget {
+    fn is_source_code(&self) -> bool {
+        matches!(self, Self::SourceCode {..})
+    }
+}
+
+#[derive(Debug)]
+pub enum DisplaySourceCodeError {
+    PathNotFound,
+}
+
+pub enum HirDisplayError {
+    /// Errors that can occur when generating source code
+    DisplaySourceCodeError(DisplaySourceCodeError),
+    /// `FmtError` is required to be compatible with std::fmt::Display
+    FmtError,
+}
+impl From<fmt::Error> for HirDisplayError {
+    fn from(_: fmt::Error) -> Self {
+        Self::FmtError
+    }
+}
+
+pub struct HirDisplayWrapper<'a, T> {
+    db: &'a dyn HirDatabase,
+    t: &'a T,
+    max_size: Option<usize>,
+    omit_verbose_types: bool,
+    display_target: DisplayTarget,
+}
 
 impl<'a, T> fmt::Display for HirDisplayWrapper<'a, T>
 where
     T: HirDisplay,
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.1.hir_fmt(&mut HirFormatter {
-            db: self.0,
+        match self.t.hir_fmt(&mut HirFormatter {
+            db: self.db,
             fmt: f,
             buf: String::with_capacity(20),
             curr_size: 0,
-            max_size: self.2,
-            omit_verbose_types: self.3,
-        })
+            max_size: self.max_size,
+            omit_verbose_types: self.omit_verbose_types,
+            display_target: self.display_target,
+        }) {
+            Ok(()) => Ok(()),
+            Err(HirDisplayError::FmtError) => Err(fmt::Error),
+            Err(HirDisplayError::DisplaySourceCodeError(_)) => {
+                // This should never happen
+                panic!("HirDisplay failed when calling Display::fmt!")
+            }
+        }
     }
 }
 
 const TYPE_HINT_TRUNCATION: &str = "…";
 
 impl HirDisplay for &Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         HirDisplay::hir_fmt(*self, f)
     }
 }
 
 impl HirDisplay for ApplicationTy {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
             return write!(f, "{}", TYPE_HINT_TRUNCATION);
         }
@@ -191,45 +283,66 @@ impl HirDisplay for ApplicationTy {
                 }
             }
             TypeCtor::Adt(def_id) => {
-                let name = match def_id {
-                    AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
-                    AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
-                    AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
-                };
-                write!(f, "{}", name)?;
+                match f.display_target {
+                    DisplayTarget::Diagnostics => {
+                        let name = match def_id {
+                            AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
+                            AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
+                            AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
+                        };
+                        write!(f, "{}", name)?;
+                    }
+                    DisplayTarget::SourceCode { module_id } => {
+                        if let Some(path) = find_path::find_path(
+                            f.db.upcast(),
+                            ItemInNs::Types(def_id.into()),
+                            module_id,
+                        ) {
+                            write!(f, "{}", path)?;
+                        } else {
+                            return Err(HirDisplayError::DisplaySourceCodeError(
+                                DisplaySourceCodeError::PathNotFound,
+                            ));
+                        }
+                    }
+                }
+
                 if self.parameters.len() > 0 {
                     let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
-                    let parameters_to_write = if f.omit_verbose_types() {
-                        match self
-                            .ctor
-                            .as_generic_def()
-                            .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
-                            .filter(|defaults| !defaults.is_empty())
-                        {
-                            None => self.parameters.0.as_ref(),
-                            Some(default_parameters) => {
-                                for (i, parameter) in self.parameters.iter().enumerate() {
-                                    match (parameter, default_parameters.get(i)) {
-                                        (&Ty::Unknown, _) | (_, None) => {
-                                            non_default_parameters.push(parameter.clone())
+                    let parameters_to_write =
+                        if f.display_target.is_source_code() || f.omit_verbose_types() {
+                            match self
+                                .ctor
+                                .as_generic_def()
+                                .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
+                                .filter(|defaults| !defaults.is_empty())
+                            {
+                                None => self.parameters.0.as_ref(),
+                                Some(default_parameters) => {
+                                    for (i, parameter) in self.parameters.iter().enumerate() {
+                                        match (parameter, default_parameters.get(i)) {
+                                            (&Ty::Unknown, _) | (_, None) => {
+                                                non_default_parameters.push(parameter.clone())
+                                            }
+                                            (_, Some(default_parameter))
+                                                if parameter != default_parameter =>
+                                            {
+                                                non_default_parameters.push(parameter.clone())
+                                            }
+                                            _ => (),
                                         }
-                                        (_, Some(default_parameter))
-                                            if parameter != default_parameter =>
-                                        {
-                                            non_default_parameters.push(parameter.clone())
-                                        }
-                                        _ => (),
                                     }
+                                    &non_default_parameters
                                 }
-                                &non_default_parameters
                             }
-                        }
-                    } else {
-                        self.parameters.0.as_ref()
-                    };
-                    write!(f, "<")?;
-                    f.write_joined(parameters_to_write, ", ")?;
-                    write!(f, ">")?;
+                        } else {
+                            self.parameters.0.as_ref()
+                        };
+                    if !parameters_to_write.is_empty() {
+                        write!(f, "<")?;
+                        f.write_joined(parameters_to_write, ", ")?;
+                        write!(f, ">")?;
+                    }
                 }
             }
             TypeCtor::AssociatedType(type_alias) => {
@@ -269,7 +382,7 @@ impl HirDisplay for ApplicationTy {
 }
 
 impl HirDisplay for ProjectionTy {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
             return write!(f, "{}", TYPE_HINT_TRUNCATION);
         }
@@ -287,7 +400,7 @@ impl HirDisplay for ProjectionTy {
 }
 
 impl HirDisplay for Ty {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
             return write!(f, "{}", TYPE_HINT_TRUNCATION);
         }
@@ -332,7 +445,7 @@ impl HirDisplay for Ty {
 fn write_bounds_like_dyn_trait(
     predicates: &[GenericPredicate],
     f: &mut HirFormatter,
-) -> fmt::Result {
+) -> Result<(), HirDisplayError> {
     // Note: This code is written to produce nice results (i.e.
     // corresponding to surface Rust) for types that can occur in
     // actual Rust. It will have weird results if the predicates
@@ -394,7 +507,7 @@ fn write_bounds_like_dyn_trait(
 }
 
 impl TraitRef {
-    fn hir_fmt_ext(&self, f: &mut HirFormatter, use_as: bool) -> fmt::Result {
+    fn hir_fmt_ext(&self, f: &mut HirFormatter, use_as: bool) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
             return write!(f, "{}", TYPE_HINT_TRUNCATION);
         }
@@ -416,19 +529,19 @@ impl TraitRef {
 }
 
 impl HirDisplay for TraitRef {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         self.hir_fmt_ext(f, false)
     }
 }
 
 impl HirDisplay for &GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         HirDisplay::hir_fmt(*self, f)
     }
 }
 
 impl HirDisplay for GenericPredicate {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
             return write!(f, "{}", TYPE_HINT_TRUNCATION);
         }
@@ -452,15 +565,15 @@ impl HirDisplay for GenericPredicate {
 }
 
 impl HirDisplay for Obligation {
-    fn hir_fmt(&self, f: &mut HirFormatter) -> fmt::Result {
-        match self {
-            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        Ok(match self {
+            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db))?,
             Obligation::Projection(proj) => write!(
                 f,
                 "Normalize({} => {})",
                 proj.projection_ty.display(f.db),
                 proj.ty.display(f.db)
-            ),
-        }
+            )?,
+        })
     }
 }
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index bd4ef69a0..957d6e0b5 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -22,13 +22,14 @@ use rustc_hash::FxHashMap;
 
 use hir_def::{
     body::Body,
-    data::{ConstData, FunctionData},
+    data::{ConstData, FunctionData, StaticData},
     expr::{BindingAnnotation, ExprId, PatId},
     lang_item::LangItemTarget,
     path::{path, Path},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{Mutability, TypeRef},
-    AdtId, AssocItemId, DefWithBodyId, FieldId, FunctionId, TraitId, TypeAliasId, VariantId,
+    AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId, FunctionId, TraitId, TypeAliasId,
+    VariantId,
 };
 use hir_expand::{diagnostics::DiagnosticSink, name::name};
 use ra_arena::map::ArenaMap;
@@ -71,7 +72,7 @@ pub(crate) fn infer_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<Infer
     match def {
         DefWithBodyId::ConstId(c) => ctx.collect_const(&db.const_data(c)),
         DefWithBodyId::FunctionId(f) => ctx.collect_fn(&db.function_data(f)),
-        DefWithBodyId::StaticId(s) => ctx.collect_const(&db.static_data(s)),
+        DefWithBodyId::StaticId(s) => ctx.collect_static(&db.static_data(s)),
     }
 
     ctx.infer_body();
@@ -210,6 +211,14 @@ struct InferenceContext<'a> {
     /// closures, but currently this is the only field that will change there,
     /// so it doesn't make sense.
     return_ty: Ty,
+    diverges: Diverges,
+    breakables: Vec<BreakableContext>,
+}
+
+#[derive(Clone, Debug)]
+struct BreakableContext {
+    pub may_break: bool,
+    pub break_ty: Ty,
 }
 
 impl<'a> InferenceContext<'a> {
@@ -224,6 +233,8 @@ impl<'a> InferenceContext<'a> {
             owner,
             body: db.body(owner),
             resolver,
+            diverges: Diverges::Maybe,
+            breakables: Vec::new(),
         }
     }
 
@@ -429,43 +440,95 @@ impl<'a> InferenceContext<'a> {
         let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver);
         // FIXME: this should resolve assoc items as well, see this example:
         // https://play.rust-lang.org/?gist=087992e9e22495446c01c0d4e2d69521
-        return match resolver.resolve_path_in_type_ns_fully(self.db.upcast(), path.mod_path()) {
-            Some(TypeNs::AdtId(AdtId::StructId(strukt))) => {
+        let (resolution, unresolved) =
+            match resolver.resolve_path_in_type_ns(self.db.upcast(), path.mod_path()) {
+                Some(it) => it,
+                None => return (Ty::Unknown, None),
+            };
+        return match resolution {
+            TypeNs::AdtId(AdtId::StructId(strukt)) => {
                 let substs = Ty::substs_from_path(&ctx, path, strukt.into());
                 let ty = self.db.ty(strukt.into());
                 let ty = self.insert_type_vars(ty.subst(&substs));
-                (ty, Some(strukt.into()))
+                forbid_unresolved_segments((ty, Some(strukt.into())), unresolved)
             }
-            Some(TypeNs::EnumVariantId(var)) => {
+            TypeNs::EnumVariantId(var) => {
                 let substs = Ty::substs_from_path(&ctx, path, var.into());
                 let ty = self.db.ty(var.parent.into());
                 let ty = self.insert_type_vars(ty.subst(&substs));
-                (ty, Some(var.into()))
+                forbid_unresolved_segments((ty, Some(var.into())), unresolved)
             }
-            Some(TypeNs::SelfType(impl_id)) => {
+            TypeNs::SelfType(impl_id) => {
                 let generics = crate::utils::generics(self.db.upcast(), impl_id.into());
                 let substs = Substs::type_params_for_generics(&generics);
                 let ty = self.db.impl_self_ty(impl_id).subst(&substs);
-                let variant = ty_variant(&ty);
-                (ty, variant)
+                match unresolved {
+                    None => {
+                        let variant = ty_variant(&ty);
+                        (ty, variant)
+                    }
+                    Some(1) => {
+                        let segment = path.mod_path().segments.last().unwrap();
+                        // this could be an enum variant or associated type
+                        if let Some((AdtId::EnumId(enum_id), _)) = ty.as_adt() {
+                            let enum_data = self.db.enum_data(enum_id);
+                            if let Some(local_id) = enum_data.variant(segment) {
+                                let variant = EnumVariantId { parent: enum_id, local_id };
+                                return (ty, Some(variant.into()));
+                            }
+                        }
+                        // FIXME potentially resolve assoc type
+                        (Ty::Unknown, None)
+                    }
+                    Some(_) => {
+                        // FIXME diagnostic
+                        (Ty::Unknown, None)
+                    }
+                }
             }
-            Some(TypeNs::TypeAliasId(it)) => {
+            TypeNs::TypeAliasId(it) => {
                 let substs = Substs::build_for_def(self.db, it)
                     .fill(std::iter::repeat_with(|| self.table.new_type_var()))
                     .build();
                 let ty = self.db.ty(it.into()).subst(&substs);
                 let variant = ty_variant(&ty);
-                (ty, variant)
+                forbid_unresolved_segments((ty, variant), unresolved)
+            }
+            TypeNs::AdtSelfType(_) => {
+                // FIXME this could happen in array size expressions, once we're checking them
+                (Ty::Unknown, None)
+            }
+            TypeNs::GenericParam(_) => {
+                // FIXME potentially resolve assoc type
+                (Ty::Unknown, None)
+            }
+            TypeNs::AdtId(AdtId::EnumId(_))
+            | TypeNs::AdtId(AdtId::UnionId(_))
+            | TypeNs::BuiltinType(_)
+            | TypeNs::TraitId(_) => {
+                // FIXME diagnostic
+                (Ty::Unknown, None)
             }
-            Some(_) | None => (Ty::Unknown, None),
         };
 
+        fn forbid_unresolved_segments(
+            result: (Ty, Option<VariantId>),
+            unresolved: Option<usize>,
+        ) -> (Ty, Option<VariantId>) {
+            if unresolved.is_none() {
+                result
+            } else {
+                // FIXME diagnostic
+                (Ty::Unknown, None)
+            }
+        }
+
         fn ty_variant(ty: &Ty) -> Option<VariantId> {
             ty.as_adt().and_then(|(adt_id, _)| match adt_id {
                 AdtId::StructId(s) => Some(VariantId::StructId(s)),
                 AdtId::UnionId(u) => Some(VariantId::UnionId(u)),
                 AdtId::EnumId(_) => {
-                    // Error E0071, expected struct, variant or union type, found enum `Foo`
+                    // FIXME Error E0071, expected struct, variant or union type, found enum `Foo`
                     None
                 }
             })
@@ -476,6 +539,10 @@ impl<'a> InferenceContext<'a> {
         self.return_ty = self.make_ty(&data.type_ref);
     }
 
+    fn collect_static(&mut self, data: &StaticData) {
+        self.return_ty = self.make_ty(&data.type_ref);
+    }
+
     fn collect_fn(&mut self, data: &FunctionData) {
         let body = Arc::clone(&self.body); // avoid borrow checker problem
         let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver)
@@ -666,15 +733,57 @@ impl Expectation {
     }
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+enum Diverges {
+    Maybe,
+    Always,
+}
+
+impl Diverges {
+    fn is_always(self) -> bool {
+        self == Diverges::Always
+    }
+}
+
+impl std::ops::BitAnd for Diverges {
+    type Output = Self;
+    fn bitand(self, other: Self) -> Self {
+        std::cmp::min(self, other)
+    }
+}
+
+impl std::ops::BitOr for Diverges {
+    type Output = Self;
+    fn bitor(self, other: Self) -> Self {
+        std::cmp::max(self, other)
+    }
+}
+
+impl std::ops::BitAndAssign for Diverges {
+    fn bitand_assign(&mut self, other: Self) {
+        *self = *self & other;
+    }
+}
+
+impl std::ops::BitOrAssign for Diverges {
+    fn bitor_assign(&mut self, other: Self) {
+        *self = *self | other;
+    }
+}
+
 mod diagnostics {
     use hir_def::{expr::ExprId, FunctionId};
     use hir_expand::diagnostics::DiagnosticSink;
 
-    use crate::{db::HirDatabase, diagnostics::NoSuchField};
+    use crate::{
+        db::HirDatabase,
+        diagnostics::{BreakOutsideOfLoop, NoSuchField},
+    };
 
     #[derive(Debug, PartialEq, Eq, Clone)]
     pub(super) enum InferenceDiagnostic {
         NoSuchField { expr: ExprId, field: usize },
+        BreakOutsideOfLoop { expr: ExprId },
     }
 
     impl InferenceDiagnostic {
@@ -690,6 +799,13 @@ mod diagnostics {
                     let field = source_map.field_syntax(*expr, *field);
                     sink.push(NoSuchField { file: field.file_id, field: field.value })
                 }
+                InferenceDiagnostic::BreakOutsideOfLoop { expr } => {
+                    let (_, source_map) = db.body_with_source_map(owner.into());
+                    let ptr = source_map
+                        .expr_syntax(*expr)
+                        .expect("break outside of loop in synthetic syntax");
+                    sink.push(BreakOutsideOfLoop { file: ptr.file_id, expr: ptr.value })
+                }
             }
         }
     }
diff --git a/crates/ra_hir_ty/src/infer/coerce.rs b/crates/ra_hir_ty/src/infer/coerce.rs
index 89200255a..2ee9adb16 100644
--- a/crates/ra_hir_ty/src/infer/coerce.rs
+++ b/crates/ra_hir_ty/src/infer/coerce.rs
@@ -5,7 +5,7 @@
 //! See: https://doc.rust-lang.org/nomicon/coercions.html
 
 use hir_def::{lang_item::LangItemTarget, type_ref::Mutability};
-use test_utils::tested_by;
+use test_utils::mark;
 
 use crate::{autoderef, traits::Solution, Obligation, Substs, TraitRef, Ty, TypeCtor};
 
@@ -20,21 +20,35 @@ impl<'a> InferenceContext<'a> {
         self.coerce_inner(from_ty, &to_ty)
     }
 
-    /// Merge two types from different branches, with possible implicit coerce.
+    /// Merge two types from different branches, with possible coercion.
     ///
-    /// Note that it is only possible that one type are coerced to another.
-    /// Coercing both types to another least upper bound type is not possible in rustc,
-    /// which will simply result in "incompatible types" error.
+    /// Mostly this means trying to coerce one to the other, but
+    ///  - if we have two function types for different functions, we need to
+    ///    coerce both to function pointers;
+    ///  - if we were concerned with lifetime subtyping, we'd need to look for a
+    ///    least upper bound.
     pub(super) fn coerce_merge_branch(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
         if self.coerce(ty1, ty2) {
             ty2.clone()
         } else if self.coerce(ty2, ty1) {
             ty1.clone()
         } else {
-            tested_by!(coerce_merge_fail_fallback);
-            // For incompatible types, we use the latter one as result
-            // to be better recovery for `if` without `else`.
-            ty2.clone()
+            if let (ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnDef(_))) = (ty1, ty2) {
+                mark::hit!(coerce_fn_reification);
+                // Special case: two function types. Try to coerce both to
+                // pointers to have a chance at getting a match. See
+                // https://github.com/rust-lang/rust/blob/7b805396bf46dce972692a6846ce2ad8481c5f85/src/librustc_typeck/check/coercion.rs#L877-L916
+                let sig1 = ty1.callable_sig(self.db).expect("FnDef without callable sig");
+                let sig2 = ty2.callable_sig(self.db).expect("FnDef without callable sig");
+                let ptr_ty1 = Ty::fn_ptr(sig1);
+                let ptr_ty2 = Ty::fn_ptr(sig2);
+                self.coerce_merge_branch(&ptr_ty1, &ptr_ty2)
+            } else {
+                mark::hit!(coerce_merge_fail_fallback);
+                // For incompatible types, we use the latter one as result
+                // to be better recovery for `if` without `else`.
+                ty2.clone()
+            }
         }
     }
 
@@ -84,9 +98,7 @@ impl<'a> InferenceContext<'a> {
                 match from_ty.callable_sig(self.db) {
                     None => return false,
                     Some(sig) => {
-                        let num_args = sig.params_and_return.len() as u16 - 1;
-                        from_ty =
-                            Ty::apply(TypeCtor::FnPtr { num_args }, Substs(sig.params_and_return));
+                        from_ty = Ty::fn_ptr(sig);
                     }
                 }
             }
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index efc60986b..b28724f0e 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -1,7 +1,7 @@
 //! Type inference for expressions.
 
 use std::iter::{repeat, repeat_with};
-use std::sync::Arc;
+use std::{mem, sync::Arc};
 
 use hir_def::{
     builtin_type::Signedness,
@@ -21,11 +21,18 @@ use crate::{
     Ty, TypeCtor, Uncertain,
 };
 
-use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
+use super::{
+    BindingMode, BreakableContext, Diverges, Expectation, InferenceContext, InferenceDiagnostic,
+    TypeMismatch,
+};
 
 impl<'a> InferenceContext<'a> {
     pub(super) fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
         let ty = self.infer_expr_inner(tgt_expr, expected);
+        if ty.is_never() {
+            // Any expression that produces a value of type `!` must have diverged
+            self.diverges = Diverges::Always;
+        }
         let could_unify = self.unify(&ty, &expected.ty);
         if !could_unify {
             self.result.type_mismatches.insert(
@@ -64,34 +71,68 @@ impl<'a> InferenceContext<'a> {
                 // if let is desugared to match, so this is always simple if
                 self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
 
+                let condition_diverges = mem::replace(&mut self.diverges, Diverges::Maybe);
+                let mut both_arms_diverge = Diverges::Always;
+
                 let then_ty = self.infer_expr_inner(*then_branch, &expected);
+                both_arms_diverge &= mem::replace(&mut self.diverges, Diverges::Maybe);
                 let else_ty = match else_branch {
                     Some(else_branch) => self.infer_expr_inner(*else_branch, &expected),
                     None => Ty::unit(),
                 };
+                both_arms_diverge &= self.diverges;
+
+                self.diverges = condition_diverges | both_arms_diverge;
 
                 self.coerce_merge_branch(&then_ty, &else_ty)
             }
             Expr::Block { statements, tail } => self.infer_block(statements, *tail, expected),
+            Expr::TryBlock { body } => {
+                let _inner = self.infer_expr(*body, expected);
+                // FIXME should be std::result::Result<{inner}, _>
+                Ty::Unknown
+            }
             Expr::Loop { body } => {
+                self.breakables.push(BreakableContext {
+                    may_break: false,
+                    break_ty: self.table.new_type_var(),
+                });
                 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
-                // FIXME handle break with value
-                Ty::simple(TypeCtor::Never)
+
+                let ctxt = self.breakables.pop().expect("breakable stack broken");
+                if ctxt.may_break {
+                    self.diverges = Diverges::Maybe;
+                }
+
+                if ctxt.may_break {
+                    ctxt.break_ty
+                } else {
+                    Ty::simple(TypeCtor::Never)
+                }
             }
             Expr::While { condition, body } => {
+                self.breakables.push(BreakableContext { may_break: false, break_ty: Ty::Unknown });
                 // while let is desugared to a match loop, so this is always simple while
                 self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
                 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
+                let _ctxt = self.breakables.pop().expect("breakable stack broken");
+                // the body may not run, so it diverging doesn't mean we diverge
+                self.diverges = Diverges::Maybe;
                 Ty::unit()
             }
             Expr::For { iterable, body, pat } => {
                 let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
 
+                self.breakables.push(BreakableContext { may_break: false, break_ty: Ty::Unknown });
                 let pat_ty =
                     self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
 
                 self.infer_pat(*pat, &pat_ty, BindingMode::default());
+
                 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
+                let _ctxt = self.breakables.pop().expect("breakable stack broken");
+                // the body may not run, so it diverging doesn't mean we diverge
+                self.diverges = Diverges::Maybe;
                 Ty::unit()
             }
             Expr::Lambda { body, args, ret_type, arg_types } => {
@@ -127,10 +168,12 @@ impl<'a> InferenceContext<'a> {
                 // infer the body.
                 self.coerce(&closure_ty, &expected.ty);
 
-                let prev_ret_ty = std::mem::replace(&mut self.return_ty, ret_ty.clone());
+                let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe);
+                let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone());
 
                 self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
 
+                self.diverges = prev_diverges;
                 self.return_ty = prev_ret_ty;
 
                 closure_ty
@@ -160,7 +203,11 @@ impl<'a> InferenceContext<'a> {
                     self.table.new_type_var()
                 };
 
+                let matchee_diverges = self.diverges;
+                let mut all_arms_diverge = Diverges::Always;
+
                 for arm in arms {
+                    self.diverges = Diverges::Maybe;
                     let _pat_ty = self.infer_pat(arm.pat, &input_ty, BindingMode::default());
                     if let Some(guard_expr) = arm.guard {
                         self.infer_expr(
@@ -170,9 +217,12 @@ impl<'a> InferenceContext<'a> {
                     }
 
                     let arm_ty = self.infer_expr_inner(arm.expr, &expected);
+                    all_arms_diverge &= self.diverges;
                     result_ty = self.coerce_merge_branch(&result_ty, &arm_ty);
                 }
 
+                self.diverges = matchee_diverges | all_arms_diverge;
+
                 result_ty
             }
             Expr::Path(p) => {
@@ -182,10 +232,29 @@ impl<'a> InferenceContext<'a> {
             }
             Expr::Continue => Ty::simple(TypeCtor::Never),
             Expr::Break { expr } => {
-                if let Some(expr) = expr {
-                    // FIXME handle break with value
-                    self.infer_expr(*expr, &Expectation::none());
+                let val_ty = if let Some(expr) = expr {
+                    self.infer_expr(*expr, &Expectation::none())
+                } else {
+                    Ty::unit()
+                };
+
+                let last_ty = if let Some(ctxt) = self.breakables.last() {
+                    ctxt.break_ty.clone()
+                } else {
+                    Ty::Unknown
+                };
+
+                let merged_type = self.coerce_merge_branch(&last_ty, &val_ty);
+
+                if let Some(ctxt) = self.breakables.last_mut() {
+                    ctxt.break_ty = merged_type;
+                    ctxt.may_break = true;
+                } else {
+                    self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop {
+                        expr: tgt_expr,
+                    });
                 }
+
                 Ty::simple(TypeCtor::Never)
             }
             Expr::Return { expr } => {
@@ -496,8 +565,8 @@ impl<'a> InferenceContext<'a> {
                 }
                 Literal::ByteString(..) => {
                     let byte_type = Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::u8())));
-                    let slice_type = Ty::apply_one(TypeCtor::Slice, byte_type);
-                    Ty::apply_one(TypeCtor::Ref(Mutability::Shared), slice_type)
+                    let array_type = Ty::apply_one(TypeCtor::Array, byte_type);
+                    Ty::apply_one(TypeCtor::Ref(Mutability::Shared), array_type)
                 }
                 Literal::Char(..) => Ty::simple(TypeCtor::Char),
                 Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int((*ty).into())),
@@ -517,7 +586,6 @@ impl<'a> InferenceContext<'a> {
         tail: Option<ExprId>,
         expected: &Expectation,
     ) -> Ty {
-        let mut diverges = false;
         for stmt in statements {
             match stmt {
                 Statement::Let { pat, type_ref, initializer } => {
@@ -539,9 +607,7 @@ impl<'a> InferenceContext<'a> {
                     self.infer_pat(*pat, &ty, BindingMode::default());
                 }
                 Statement::Expr(expr) => {
-                    if let ty_app!(TypeCtor::Never) = self.infer_expr(*expr, &Expectation::none()) {
-                        diverges = true;
-                    }
+                    self.infer_expr(*expr, &Expectation::none());
                 }
             }
         }
@@ -549,14 +615,22 @@ impl<'a> InferenceContext<'a> {
         let ty = if let Some(expr) = tail {
             self.infer_expr_coerce(expr, expected)
         } else {
-            self.coerce(&Ty::unit(), expected.coercion_target());
-            Ty::unit()
+            // Citing rustc: if there is no explicit tail expression,
+            // that is typically equivalent to a tail expression
+            // of `()` -- except if the block diverges. In that
+            // case, there is no value supplied from the tail
+            // expression (assuming there are no other breaks,
+            // this implies that the type of the block will be
+            // `!`).
+            if self.diverges.is_always() {
+                // we don't even make an attempt at coercion
+                self.table.new_maybe_never_type_var()
+            } else {
+                self.coerce(&Ty::unit(), expected.coercion_target());
+                Ty::unit()
+            }
         };
-        if diverges {
-            Ty::simple(TypeCtor::Never)
-        } else {
-            ty
-        }
+        ty
     }
 
     fn infer_method_call(
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 54ec870df..4006f595d 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -10,7 +10,7 @@ use hir_def::{
     FieldId,
 };
 use hir_expand::name::Name;
-use test_utils::tested_by;
+use test_utils::mark;
 
 use super::{BindingMode, Expectation, InferenceContext};
 use crate::{utils::variant_data, Substs, Ty, TypeCtor};
@@ -111,7 +111,7 @@ impl<'a> InferenceContext<'a> {
                 }
             }
         } else if let Pat::Ref { .. } = &body[pat] {
-            tested_by!(match_ergonomics_ref);
+            mark::hit!(match_ergonomics_ref);
             // When you encounter a `&pat` pattern, reset to Move.
             // This is so that `w` is by value: `let (_, &w) = &(1, &2);`
             default_bm = BindingMode::Move;
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 2b6bc0f79..1c2e56fb0 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -5,7 +5,7 @@ use std::iter;
 use hir_def::{
     path::{Path, PathSegment},
     resolver::{ResolveValueResult, Resolver, TypeNs, ValueNs},
-    AssocContainerId, AssocItemId, Lookup,
+    AdtId, AssocContainerId, AssocItemId, EnumVariantId, Lookup,
 };
 use hir_expand::name::Name;
 
@@ -77,6 +77,18 @@ impl<'a> InferenceContext<'a> {
 
                 it.into()
             }
+            ValueNs::ImplSelf(impl_id) => {
+                let generics = crate::utils::generics(self.db.upcast(), impl_id.into());
+                let substs = Substs::type_params_for_generics(&generics);
+                let ty = self.db.impl_self_ty(impl_id).subst(&substs);
+                if let Some((AdtId::StructId(struct_id), _)) = ty.as_adt() {
+                    let ty = self.db.value_ty(struct_id.into()).subst(&substs);
+                    return Some(ty);
+                } else {
+                    // FIXME: diagnostic, invalid Self reference
+                    return None;
+                }
+            }
         };
 
         let ty = self.db.value_ty(typable);
@@ -199,6 +211,10 @@ impl<'a> InferenceContext<'a> {
             return None;
         }
 
+        if let Some(result) = self.resolve_enum_variant_on_ty(&ty, name, id) {
+            return Some(result);
+        }
+
         let canonical_ty = self.canonicalizer().canonicalize_ty(ty.clone());
         let krate = self.resolver.krate()?;
         let traits_in_scope = self.resolver.traits_in_scope(self.db.upcast());
@@ -250,4 +266,21 @@ impl<'a> InferenceContext<'a> {
             },
         )
     }
+
+    fn resolve_enum_variant_on_ty(
+        &mut self,
+        ty: &Ty,
+        name: &Name,
+        id: ExprOrPatId,
+    ) -> Option<(ValueNs, Option<Substs>)> {
+        let (enum_id, subst) = match ty.as_adt() {
+            Some((AdtId::EnumId(e), subst)) => (e, subst),
+            _ => return None,
+        };
+        let enum_data = self.db.enum_data(enum_id);
+        let local_id = enum_data.variant(name)?;
+        let variant = EnumVariantId { parent: enum_id, local_id };
+        self.write_variant_resolution(id, variant.into());
+        Some((ValueNs::EnumVariantId(variant), Some(subst.clone())))
+    }
 }
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index ab0bc8b70..269495ca0 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -4,7 +4,7 @@ use std::borrow::Cow;
 
 use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
 
-use test_utils::tested_by;
+use test_utils::mark;
 
 use super::{InferenceContext, Obligation};
 use crate::{
@@ -313,7 +313,7 @@ impl InferenceTable {
         // more than once
         for i in 0..3 {
             if i > 0 {
-                tested_by!(type_var_resolves_to_int_var);
+                mark::hit!(type_var_resolves_to_int_var);
             }
             match &*ty {
                 Ty::Infer(tv) => {
@@ -342,7 +342,7 @@ impl InferenceTable {
             Ty::Infer(tv) => {
                 let inner = tv.to_inner();
                 if tv_stack.contains(&inner) {
-                    tested_by!(type_var_cycles_resolve_as_possible);
+                    mark::hit!(type_var_cycles_resolve_as_possible);
                     // recursive type
                     return tv.fallback_value();
                 }
@@ -369,7 +369,7 @@ impl InferenceTable {
             Ty::Infer(tv) => {
                 let inner = tv.to_inner();
                 if tv_stack.contains(&inner) {
-                    tested_by!(type_var_cycles_resolve_completely);
+                    mark::hit!(type_var_cycles_resolve_completely);
                     // recursive type
                     return tv.fallback_value();
                 }
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index a6f56c661..c87ee06ce 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -42,7 +42,6 @@ pub mod expr;
 mod tests;
 #[cfg(test)]
 mod test_db;
-mod marks;
 mod _match;
 
 use std::ops::Deref;
@@ -427,6 +426,11 @@ impl Substs {
     }
 }
 
+/// Return an index of a parameter in the generic type parameter list by it's id.
+pub fn param_idx(db: &dyn HirDatabase, id: TypeParamId) -> Option<usize> {
+    generics(db.upcast(), id.parent).param_idx(id)
+}
+
 #[derive(Debug, Clone)]
 pub struct SubstsBuilder {
     vec: Vec<Ty>,
@@ -683,6 +687,12 @@ impl Ty {
     pub fn unit() -> Self {
         Ty::apply(TypeCtor::Tuple { cardinality: 0 }, Substs::empty())
     }
+    pub fn fn_ptr(sig: FnSig) -> Self {
+        Ty::apply(
+            TypeCtor::FnPtr { num_args: sig.params().len() as u16 },
+            Substs(sig.params_and_return),
+        )
+    }
 
     pub fn as_reference(&self) -> Option<(&Ty, Mutability)> {
         match self {
@@ -730,6 +740,10 @@ impl Ty {
         }
     }
 
+    pub fn is_never(&self) -> bool {
+        matches!(self, Ty::Apply(ApplicationTy { ctor: TypeCtor::Never, .. }))
+    }
+
     /// If this is a `dyn Trait` type, this returns the `Trait` part.
     pub fn dyn_trait_ref(&self) -> Option<&TraitRef> {
         match self {
@@ -793,15 +807,13 @@ impl Ty {
         }
     }
 
-    /// If this is an `impl Trait` or `dyn Trait`, returns that trait.
-    pub fn inherent_trait(&self) -> Option<TraitId> {
+    /// If this is a `dyn Trait`, returns that trait.
+    pub fn dyn_trait(&self) -> Option<TraitId> {
         match self {
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                predicates.iter().find_map(|pred| match pred {
-                    GenericPredicate::Implemented(tr) => Some(tr.trait_),
-                    _ => None,
-                })
-            }
+            Ty::Dyn(predicates) => predicates.iter().find_map(|pred| match pred {
+                GenericPredicate::Implemented(tr) => Some(tr.trait_),
+                _ => None,
+            }),
             _ => None,
         }
     }
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index 9ad6dbe07..35ac86a46 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -812,7 +812,7 @@ impl TraitEnvironment {
                 // 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);
+                test_utils::mark::hit!(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);
diff --git a/crates/ra_hir_ty/src/marks.rs b/crates/ra_hir_ty/src/marks.rs
deleted file mode 100644
index de5cb1d6b..000000000
--- a/crates/ra_hir_ty/src/marks.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-//! See test_utils/src/marks.rs
-
-test_utils::marks!(
-    type_var_cycles_resolve_completely
-    type_var_cycles_resolve_as_possible
-    type_var_resolves_to_int_var
-    impl_self_type_match_without_receiver
-    match_ergonomics_ref
-    coerce_merge_fail_fallback
-    trait_self_implements_self
-);
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index 657284fd0..e19628fdf 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -408,8 +408,9 @@ fn iterate_trait_method_candidates<T>(
     receiver_ty: Option<&Canonical<Ty>>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    // if ty is `impl Trait` or `dyn Trait`, the trait doesn't need to be in scope
-    let inherent_trait = self_ty.value.inherent_trait().into_iter();
+    // if ty is `dyn Trait`, the trait doesn't need to be in scope
+    let inherent_trait =
+        self_ty.value.dyn_trait().into_iter().flat_map(|t| all_super_traits(db.upcast(), t));
     let env_traits = if let Ty::Placeholder(_) = self_ty.value {
         // if we have `T: Trait` in the param env, the trait doesn't need to be in scope
         env.trait_predicates_for_self_ty(&self_ty.value)
@@ -468,7 +469,7 @@ fn iterate_inherent_methods<T>(
                 // already happens in `is_valid_candidate` above; if not, we
                 // check it here
                 if receiver_ty.is_none() && inherent_impl_substs(db, impl_def, self_ty).is_none() {
-                    test_utils::tested_by!(impl_self_type_match_without_receiver);
+                    test_utils::mark::hit!(impl_self_type_match_without_receiver);
                     continue;
                 }
                 if let Some(result) = callback(&self_ty.value, item) {
@@ -601,11 +602,6 @@ pub fn implements_trait(
     krate: CrateId,
     trait_: TraitId,
 ) -> bool {
-    if ty.value.inherent_trait() == Some(trait_) {
-        // FIXME this is a bit of a hack, since Chalk should say the same thing
-        // anyway, but currently Chalk doesn't implement `dyn/impl Trait` yet
-        return true;
-    }
     let goal = generic_implements_goal(db, env, trait_, ty.clone());
     let solution = db.trait_solve(krate, goal);
 
diff --git a/crates/ra_hir_ty/src/op.rs b/crates/ra_hir_ty/src/op.rs
index 54e2bd05a..0870874fc 100644
--- a/crates/ra_hir_ty/src/op.rs
+++ b/crates/ra_hir_ty/src/op.rs
@@ -30,7 +30,8 @@ pub(super) fn binary_op_return_ty(op: BinaryOp, lhs_ty: Ty, rhs_ty: Ty) -> Ty {
 pub(super) fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
     match op {
         BinaryOp::LogicOp(..) => Ty::simple(TypeCtor::Bool),
-        BinaryOp::Assignment { op: None } | BinaryOp::CmpOp(CmpOp::Eq { .. }) => match lhs_ty {
+        BinaryOp::Assignment { op: None } => lhs_ty,
+        BinaryOp::CmpOp(CmpOp::Eq { .. }) => match lhs_ty {
             Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
                 TypeCtor::Int(..)
                 | TypeCtor::Float(..)
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index 588d81282..1fe05c70c 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -6,6 +6,7 @@ mod patterns;
 mod traits;
 mod method_resolution;
 mod macros;
+mod display_source_code;
 
 use std::sync::Arc;
 
@@ -16,7 +17,7 @@ use hir_def::{
     item_scope::ItemScope,
     keys,
     nameres::CrateDefMap,
-    AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
+    AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId, ModuleId,
 };
 use hir_expand::{db::AstDatabase, InFile};
 use insta::assert_snapshot;
@@ -37,6 +38,18 @@ use crate::{
 // update the snapshots.
 
 fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
+    type_at_pos_displayed(db, pos, |ty, _| ty.display(db).to_string())
+}
+
+fn displayed_source_at_pos(db: &TestDB, pos: FilePosition) -> String {
+    type_at_pos_displayed(db, pos, |ty, module_id| ty.display_source_code(db, module_id).unwrap())
+}
+
+fn type_at_pos_displayed(
+    db: &TestDB,
+    pos: FilePosition,
+    display_fn: impl FnOnce(&Ty, ModuleId) -> String,
+) -> String {
     let file = db.parse(pos.file_id).ok().unwrap();
     let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
     let fn_def = expr.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
@@ -49,7 +62,7 @@ fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
     if let Some(expr_id) = source_map.node_expr(InFile::new(pos.file_id.into(), &expr)) {
         let infer = db.infer(func.into());
         let ty = &infer[expr_id];
-        return ty.display(db).to_string();
+        return display_fn(ty, module);
     }
     panic!("Can't find expression")
 }
@@ -361,6 +374,33 @@ fn no_such_field_with_feature_flag_diagnostics() {
 }
 
 #[test]
+fn no_such_field_enum_with_feature_flag_diagnostics() {
+    let diagnostics = TestDB::with_files(
+        r#"
+        //- /lib.rs crate:foo cfg:feature=foo
+        enum Foo {
+            #[cfg(not(feature = "foo"))]
+            Buz,
+            #[cfg(feature = "foo")]
+            Bar,
+            Baz
+        }
+
+        fn test_fn(f: Foo) {
+            match f {
+                Foo::Bar => {},
+                Foo::Baz => {},
+            }
+        }
+        "#,
+    )
+    .diagnostics()
+    .0;
+
+    assert_snapshot!(diagnostics, @r###""###);
+}
+
+#[test]
 fn no_such_field_with_feature_flag_diagnostics_on_struct_lit() {
     let diagnostics = TestDB::with_files(
         r#"
@@ -491,3 +531,21 @@ fn missing_record_pat_field_no_diagnostic_if_not_exhaustive() {
 
     assert_snapshot!(diagnostics, @"");
 }
+
+#[test]
+fn break_outside_of_loop() {
+    let diagnostics = TestDB::with_files(
+        r"
+        //- /lib.rs
+        fn foo() {
+            break;
+        }
+        ",
+    )
+    .diagnostics()
+    .0;
+
+    assert_snapshot!(diagnostics, @r###""break": break outside of loop
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index e6fb3e123..2cc4f4bf9 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -1,6 +1,6 @@
 use super::infer_with_mismatches;
 use insta::assert_snapshot;
-use test_utils::covers;
+use test_utils::mark;
 
 // Infer with some common definitions and impls.
 fn infer(source: &str) -> String {
@@ -339,7 +339,7 @@ fn test(i: i32) {
 
 #[test]
 fn coerce_merge_one_by_one1() {
-    covers!(coerce_merge_fail_fallback);
+    mark::check!(coerce_merge_fail_fallback);
 
     assert_snapshot!(
         infer(r#"
@@ -384,7 +384,7 @@ fn foo() -> u32 {
 }
 "#, true),
         @r###"
-    17..40 '{     ...own; }': !
+    17..40 '{     ...own; }': u32
     23..37 'return unknown': !
     30..37 'unknown': u32
     "###
@@ -514,7 +514,7 @@ fn foo() {
     27..103 '{     ...     }': &u32
     37..82 'if tru...     }': ()
     40..44 'true': bool
-    45..82 '{     ...     }': !
+    45..82 '{     ...     }': ()
     59..71 'return &1u32': !
     66..71 '&1u32': &u32
     67..71 '1u32': u32
@@ -546,6 +546,48 @@ fn test() {
 }
 
 #[test]
+fn coerce_fn_items_in_match_arms() {
+    mark::check!(coerce_fn_reification);
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo1(x: u32) -> isize { 1 }
+fn foo2(x: u32) -> isize { 2 }
+fn foo3(x: u32) -> isize { 3 }
+fn test() {
+    let x = match 1 {
+        1 => foo1,
+        2 => foo2,
+        _ => foo3,
+    };
+}
+"#, true),
+        @r###"
+    9..10 'x': u32
+    26..31 '{ 1 }': isize
+    28..29 '1': isize
+    40..41 'x': u32
+    57..62 '{ 2 }': isize
+    59..60 '2': isize
+    71..72 'x': u32
+    88..93 '{ 3 }': isize
+    90..91 '3': isize
+    104..193 '{     ...  }; }': ()
+    114..115 'x': fn(u32) -> isize
+    118..190 'match ...     }': fn(u32) -> isize
+    124..125 '1': i32
+    136..137 '1': i32
+    136..137 '1': i32
+    141..145 'foo1': fn foo1(u32) -> isize
+    155..156 '2': i32
+    155..156 '2': i32
+    160..164 'foo2': fn foo2(u32) -> isize
+    174..175 '_': i32
+    179..183 'foo3': fn foo3(u32) -> isize
+    "###
+    );
+}
+
+#[test]
 fn coerce_closure_to_fn_ptr() {
     assert_snapshot!(
         infer_with_mismatches(r#"
diff --git a/crates/ra_hir_ty/src/tests/display_source_code.rs b/crates/ra_hir_ty/src/tests/display_source_code.rs
new file mode 100644
index 000000000..4088b1d22
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/display_source_code.rs
@@ -0,0 +1,50 @@
+use super::displayed_source_at_pos;
+use crate::test_db::TestDB;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn qualify_path_to_submodule() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs
+
+mod foo {
+    pub struct Foo;
+}
+
+fn bar() {
+    let foo: foo::Foo = foo::Foo;
+    foo<|>
+}
+
+"#,
+    );
+    assert_eq!("foo::Foo", displayed_source_at_pos(&db, pos));
+}
+
+#[test]
+fn omit_default_type_parameters() {
+    let (db, pos) = TestDB::with_position(
+        r"
+        //- /main.rs
+        struct Foo<T = u8> { t: T }
+        fn main() {
+            let foo = Foo { t: 5 };
+            foo<|>;
+        }
+        ",
+    );
+    assert_eq!("Foo", displayed_source_at_pos(&db, pos));
+
+    let (db, pos) = TestDB::with_position(
+        r"
+        //- /main.rs
+        struct Foo<K, T = u8> { k: K, t: T }
+        fn main() {
+            let foo = Foo { k: 400, t: 5 };
+            foo<|>;
+        }
+        ",
+    );
+    assert_eq!("Foo<i32>", displayed_source_at_pos(&db, pos));
+}
diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
index 1f796876d..4c6099aa2 100644
--- a/crates/ra_hir_ty/src/tests/macros.rs
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -197,7 +197,7 @@ fn spam() {
     !0..6 '1isize': isize
     !0..6 '1isize': isize
     !0..6 '1isize': isize
-    54..457 '{     ...!(); }': !
+    54..457 '{     ...!(); }': ()
     88..109 'spam!(...am!())': {unknown}
     115..134 'for _ ...!() {}': ()
     119..120 '_': {unknown}
@@ -269,7 +269,7 @@ fn test() { S.foo()<|>; }
 }
 
 #[test]
-fn infer_impl_items_generated_by_macros() {
+fn infer_assoc_items_generated_by_macros() {
     let t = type_at(
         r#"
 //- /main.rs
@@ -288,7 +288,7 @@ fn test() { S.foo()<|>; }
 }
 
 #[test]
-fn infer_impl_items_generated_by_macros_chain() {
+fn infer_assoc_items_generated_by_macros_chain() {
     let t = type_at(
         r#"
 //- /main.rs
@@ -428,6 +428,32 @@ fn main() {
 }
 
 #[test]
+fn infer_local_inner_macros() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo
+fn test() {
+    let x = foo::foo!(1);
+    x<|>;
+}
+
+//- /lib.rs crate:foo
+#[macro_export(local_inner_macros)]
+macro_rules! foo {
+    (1) => { bar!() };
+}
+
+#[macro_export]
+macro_rules! bar {
+    () => { 42 }
+}
+
+"#,
+    );
+    assert_eq!("i32", type_at_pos(&db, pos));
+}
+
+#[test]
 fn infer_builtin_macros_line() {
     assert_snapshot!(
         infer(r#"
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
index ab87f598a..558a70022 100644
--- a/crates/ra_hir_ty/src/tests/method_resolution.rs
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -17,8 +17,8 @@ impl<T> [T] {
 #[lang = "slice_alloc"]
 impl<T> [T] {}
 
-fn test() {
-    <[_]>::foo(b"foo");
+fn test(x: &[u8]) {
+    <[_]>::foo(x);
 }
 "#),
         @r###"
@@ -26,10 +26,11 @@ fn test() {
     56..79 '{     ...     }': T
     66..73 'loop {}': !
     71..73 '{}': ()
-    133..160 '{     ...o"); }': ()
-    139..149 '<[_]>::foo': fn foo<u8>(&[u8]) -> u8
-    139..157 '<[_]>:..."foo")': u8
-    150..156 'b"foo"': &[u8]
+    131..132 'x': &[u8]
+    141..163 '{     ...(x); }': ()
+    147..157 '<[_]>::foo': fn foo<u8>(&[u8]) -> u8
+    147..160 '<[_]>::foo(x)': u8
+    158..159 'x': &[u8]
     "###
     );
 }
@@ -983,7 +984,7 @@ fn test() { S2.into()<|>; }
 
 #[test]
 fn method_resolution_overloaded_method() {
-    test_utils::covers!(impl_self_type_match_without_receiver);
+    test_utils::mark::check!(impl_self_type_match_without_receiver);
     let t = type_at(
         r#"
 //- main.rs
@@ -1095,3 +1096,34 @@ fn test() { (S {}).method()<|>; }
     );
     assert_eq!(t, "()");
 }
+
+#[test]
+fn dyn_trait_super_trait_not_in_scope() {
+    assert_snapshot!(
+        infer(r#"
+mod m {
+    pub trait SuperTrait {
+        fn foo(&self) -> u32 { 0 }
+    }
+}
+trait Trait: m::SuperTrait {}
+
+struct S;
+impl m::SuperTrait for S {}
+impl Trait for S {}
+
+fn test(d: &dyn Trait) {
+    d.foo();
+}
+"#),
+        @r###"
+    52..56 'self': &Self
+    65..70 '{ 0 }': u32
+    67..68 '0': u32
+    177..178 'd': &dyn Trait
+    192..208 '{     ...o(); }': ()
+    198..199 'd': &dyn Trait
+    198..205 'd.foo()': u32
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/never_type.rs b/crates/ra_hir_ty/src/tests/never_type.rs
index a77209480..082c47208 100644
--- a/crates/ra_hir_ty/src/tests/never_type.rs
+++ b/crates/ra_hir_ty/src/tests/never_type.rs
@@ -1,4 +1,6 @@
-use super::type_at;
+use insta::assert_snapshot;
+
+use super::{infer_with_mismatches, type_at};
 
 #[test]
 fn infer_never1() {
@@ -261,3 +263,176 @@ fn test(a: i32) {
     );
     assert_eq!(t, "f64");
 }
+
+#[test]
+fn diverging_expression_1() {
+    let t = infer_with_mismatches(
+        r#"
+//- /main.rs
+fn test1() {
+    let x: u32 = return;
+}
+fn test2() {
+    let x: u32 = { return; };
+}
+fn test3() {
+    let x: u32 = loop {};
+}
+fn test4() {
+    let x: u32 = { loop {} };
+}
+fn test5() {
+    let x: u32 = { if true { loop {}; } else { loop {}; } };
+}
+fn test6() {
+    let x: u32 = { let y: u32 = { loop {}; }; };
+}
+"#,
+        true,
+    );
+    assert_snapshot!(t, @r###"
+    25..53 '{     ...urn; }': ()
+    35..36 'x': u32
+    44..50 'return': !
+    65..98 '{     ...; }; }': ()
+    75..76 'x': u32
+    84..95 '{ return; }': u32
+    86..92 'return': !
+    110..139 '{     ... {}; }': ()
+    120..121 'x': u32
+    129..136 'loop {}': !
+    134..136 '{}': ()
+    151..184 '{     ...} }; }': ()
+    161..162 'x': u32
+    170..181 '{ loop {} }': u32
+    172..179 'loop {}': !
+    177..179 '{}': ()
+    196..260 '{     ...} }; }': ()
+    206..207 'x': u32
+    215..257 '{ if t...}; } }': u32
+    217..255 'if tru... {}; }': u32
+    220..224 'true': bool
+    225..237 '{ loop {}; }': u32
+    227..234 'loop {}': !
+    232..234 '{}': ()
+    243..255 '{ loop {}; }': u32
+    245..252 'loop {}': !
+    250..252 '{}': ()
+    272..324 '{     ...; }; }': ()
+    282..283 'x': u32
+    291..321 '{ let ...; }; }': u32
+    297..298 'y': u32
+    306..318 '{ loop {}; }': u32
+    308..315 'loop {}': !
+    313..315 '{}': ()
+    "###);
+}
+
+#[test]
+fn diverging_expression_2() {
+    let t = infer_with_mismatches(
+        r#"
+//- /main.rs
+fn test1() {
+    // should give type mismatch
+    let x: u32 = { loop {}; "foo" };
+}
+"#,
+        true,
+    );
+    assert_snapshot!(t, @r###"
+    25..98 '{     ..." }; }': ()
+    68..69 'x': u32
+    77..95 '{ loop...foo" }': &str
+    79..86 'loop {}': !
+    84..86 '{}': ()
+    88..93 '"foo"': &str
+    77..95: expected u32, got &str
+    88..93: expected u32, got &str
+    "###);
+}
+
+#[test]
+fn diverging_expression_3_break() {
+    let t = infer_with_mismatches(
+        r#"
+//- /main.rs
+fn test1() {
+    // should give type mismatch
+    let x: u32 = { loop { break; } };
+}
+fn test2() {
+    // should give type mismatch
+    let x: u32 = { for a in b { break; }; };
+    // should give type mismatch as well
+    let x: u32 = { for a in b {}; };
+    // should give type mismatch as well
+    let x: u32 = { for a in b { return; }; };
+}
+fn test3() {
+    // should give type mismatch
+    let x: u32 = { while true { break; }; };
+    // should give type mismatch as well -- there's an implicit break, even if it's never hit
+    let x: u32 = { while true {}; };
+    // should give type mismatch as well
+    let x: u32 = { while true { return; }; };
+}
+"#,
+        true,
+    );
+    assert_snapshot!(t, @r###"
+    25..99 '{     ...} }; }': ()
+    68..69 'x': u32
+    77..96 '{ loop...k; } }': ()
+    79..94 'loop { break; }': ()
+    84..94 '{ break; }': ()
+    86..91 'break': !
+    77..96: expected u32, got ()
+    79..94: expected u32, got ()
+    111..357 '{     ...; }; }': ()
+    154..155 'x': u32
+    163..189 '{ for ...; }; }': ()
+    165..186 'for a ...eak; }': ()
+    169..170 'a': {unknown}
+    174..175 'b': {unknown}
+    176..186 '{ break; }': ()
+    178..183 'break': !
+    240..241 'x': u32
+    249..267 '{ for ... {}; }': ()
+    251..264 'for a in b {}': ()
+    255..256 'a': {unknown}
+    260..261 'b': {unknown}
+    262..264 '{}': ()
+    318..319 'x': u32
+    327..354 '{ for ...; }; }': ()
+    329..351 'for a ...urn; }': ()
+    333..334 'a': {unknown}
+    338..339 'b': {unknown}
+    340..351 '{ return; }': ()
+    342..348 'return': !
+    163..189: expected u32, got ()
+    249..267: expected u32, got ()
+    327..354: expected u32, got ()
+    369..668 '{     ...; }; }': ()
+    412..413 'x': u32
+    421..447 '{ whil...; }; }': ()
+    423..444 'while ...eak; }': ()
+    429..433 'true': bool
+    434..444 '{ break; }': ()
+    436..441 'break': !
+    551..552 'x': u32
+    560..578 '{ whil... {}; }': ()
+    562..575 'while true {}': ()
+    568..572 'true': bool
+    573..575 '{}': ()
+    629..630 'x': u32
+    638..665 '{ whil...; }; }': ()
+    640..662 'while ...urn; }': ()
+    646..650 'true': bool
+    651..662 '{ return; }': ()
+    653..659 'return': !
+    421..447: expected u32, got ()
+    560..578: expected u32, got ()
+    638..665: expected u32, got ()
+    "###);
+}
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
index af291092d..0c5f972a2 100644
--- a/crates/ra_hir_ty/src/tests/patterns.rs
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -1,5 +1,5 @@
 use insta::assert_snapshot;
-use test_utils::covers;
+use test_utils::mark;
 
 use super::{infer, infer_with_mismatches};
 
@@ -197,7 +197,7 @@ fn test() {
 
 #[test]
 fn infer_pattern_match_ergonomics_ref() {
-    covers!(match_ergonomics_ref);
+    mark::check!(match_ergonomics_ref);
     assert_snapshot!(
         infer(r#"
 fn test() {
@@ -369,6 +369,45 @@ fn test() {
 }
 
 #[test]
+fn enum_variant_through_self_in_pattern() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+    A { x: usize },
+    B(usize),
+    C
+}
+
+impl E {
+    fn test() {
+        match (loop {}) {
+            Self::A { x } => { x; },
+            Self::B(x) => { x; },
+            Self::C => {},
+        };
+    }
+}
+"#),
+        @r###"
+    76..218 '{     ...     }': ()
+    86..211 'match ...     }': ()
+    93..100 'loop {}': !
+    98..100 '{}': ()
+    116..129 'Self::A { x }': E
+    126..127 'x': usize
+    133..139 '{ x; }': ()
+    135..136 'x': usize
+    153..163 'Self::B(x)': E
+    161..162 'x': usize
+    167..173 '{ x; }': ()
+    169..170 'x': usize
+    187..194 'Self::C': E
+    198..200 '{}': ()
+    "###
+    );
+}
+
+#[test]
 fn infer_generics_in_patterns() {
     assert_snapshot!(
         infer(r#"
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 8a1292c7a..1f004bd63 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -1,9 +1,10 @@
 use insta::assert_snapshot;
-use test_utils::covers;
+use ra_db::fixture::WithFixture;
+use test_utils::mark;
 
-use super::infer;
 use crate::test_db::TestDB;
-use ra_db::fixture::WithFixture;
+
+use super::infer;
 
 #[test]
 fn bug_484() {
@@ -89,8 +90,8 @@ fn quux() {
 
 #[test]
 fn recursive_vars() {
-    covers!(type_var_cycles_resolve_completely);
-    covers!(type_var_cycles_resolve_as_possible);
+    mark::check!(type_var_cycles_resolve_completely);
+    mark::check!(type_var_cycles_resolve_as_possible);
     assert_snapshot!(
         infer(r#"
 fn test() {
@@ -112,8 +113,6 @@ fn test() {
 
 #[test]
 fn recursive_vars_2() {
-    covers!(type_var_cycles_resolve_completely);
-    covers!(type_var_cycles_resolve_as_possible);
     assert_snapshot!(
         infer(r#"
 fn test() {
@@ -170,7 +169,7 @@ fn write() {
 
 #[test]
 fn infer_std_crash_2() {
-    covers!(type_var_resolves_to_int_var);
+    mark::check!(type_var_resolves_to_int_var);
     // caused "equating two type variables, ...", taken from std
     assert_snapshot!(
         infer(r#"
@@ -535,6 +534,66 @@ fn foo(b: Bar) {
 }
 
 #[test]
+fn issue_4235_name_conflicts() {
+    assert_snapshot!(
+        infer(r#"
+struct FOO {}
+static FOO:FOO = FOO {};
+
+impl FOO {
+    fn foo(&self) {}
+}
+
+fn main() {
+    let a = &FOO;
+    a.foo();
+}
+"#), @r###"
+    32..38 'FOO {}': FOO
+    64..68 'self': &FOO
+    70..72 '{}': ()
+    86..120 '{     ...o(); }': ()
+    96..97 'a': &FOO
+    100..104 '&FOO': &FOO
+    101..104 'FOO': FOO
+    110..111 'a': &FOO
+    110..117 'a.foo()': ()
+"###
+    );
+}
+
+#[test]
+fn issue_4465_dollar_crate_at_type() {
+    assert_snapshot!(
+        infer(r#"
+pub struct Foo {}
+pub fn anything<T>() -> T {
+    loop {}
+}
+macro_rules! foo {
+    () => {{
+        let r: $crate::Foo = anything();
+        r
+    }};
+}
+fn main() {
+    let _a = foo!();
+}
+"#), @r###"
+    45..60 '{     loop {} }': T
+    51..58 'loop {}': !
+    56..58 '{}': ()
+    !0..31 '{letr:...g();r}': Foo
+    !4..5 'r': Foo
+    !18..26 'anything': fn anything<Foo>() -> Foo
+    !18..28 'anything()': Foo
+    !29..30 'r': Foo
+    164..188 '{     ...!(); }': ()
+    174..176 '_a': Foo
+"###);
+}
+
+#[test]
 fn issue_4053_diesel_where_clauses() {
     assert_snapshot!(
         infer(r#"
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index 56abc65b8..fd2208af2 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -179,7 +179,7 @@ fn test(a: u32, b: isize, c: !, d: &str) {
     17..18 'b': isize
     27..28 'c': !
     33..34 'd': &str
-    42..121 '{     ...f32; }': !
+    42..121 '{     ...f32; }': ()
     48..49 'a': u32
     55..56 'b': isize
     62..63 'c': !
@@ -414,7 +414,7 @@ fn test() {
     27..31 '5f32': f32
     37..41 '5f64': f64
     47..54 '"hello"': &str
-    60..68 'b"bytes"': &[u8]
+    60..68 'b"bytes"': &[u8; _]
     74..77 ''c'': char
     83..87 'b'b'': u8
     93..97 '3.14': f64
@@ -422,7 +422,7 @@ fn test() {
     113..118 'false': bool
     124..128 'true': bool
     134..202 'r#"   ...    "#': &str
-    208..218 'br#"yolo"#': &[u8]
+    208..218 'br#"yolo"#': &[u8; _]
     "###
     );
 }
@@ -576,6 +576,50 @@ impl S {
 }
 
 #[test]
+fn infer_self_as_path() {
+    assert_snapshot!(
+        infer(r#"
+struct S1;
+struct S2(isize);
+enum E {
+    V1,
+    V2(u32),
+}
+
+impl S1 {
+    fn test() {
+        Self;
+    }
+}
+impl S2 {
+    fn test() {
+        Self(1);
+    }
+}
+impl E {
+    fn test() {
+        Self::V1;
+        Self::V2(1);
+    }
+}
+"#),
+        @r###"
+    87..108 '{     ...     }': ()
+    97..101 'Self': S1
+    135..159 '{     ...     }': ()
+    145..149 'Self': S2(isize) -> S2
+    145..152 'Self(1)': S2
+    150..151 '1': isize
+    185..231 '{     ...     }': ()
+    195..203 'Self::V1': E
+    213..221 'Self::V2': V2(u32) -> E
+    213..224 'Self::V2(1)': E
+    222..223 '1': u32
+    "###
+    );
+}
+
+#[test]
 fn infer_binary_op() {
     assert_snapshot!(
         infer(r#"
@@ -935,7 +979,7 @@ fn foo() {
     29..33 'true': bool
     34..51 '{     ...     }': i32
     44..45 '1': i32
-    57..80 '{     ...     }': !
+    57..80 '{     ...     }': i32
     67..73 'return': !
     90..93 '_x2': i32
     96..149 'if tru...     }': i32
@@ -951,7 +995,7 @@ fn foo() {
     186..190 'true': bool
     194..195 '3': i32
     205..206 '_': bool
-    210..241 '{     ...     }': !
+    210..241 '{     ...     }': i32
     224..230 'return': !
     257..260 '_x4': i32
     263..320 'match ...     }': i32
@@ -1687,7 +1731,7 @@ fn foo() -> u32 {
     17..59 '{     ...; }; }': ()
     27..28 'x': || -> usize
     31..56 '|| -> ...n 1; }': || -> usize
-    43..56 '{ return 1; }': !
+    43..56 '{ return 1; }': usize
     45..53 'return 1': !
     52..53 '1': usize
     "###
@@ -1706,7 +1750,7 @@ fn foo() -> u32 {
     17..48 '{     ...; }; }': ()
     27..28 'x': || -> ()
     31..45 '|| { return; }': || -> ()
-    34..45 '{ return; }': !
+    34..45 '{ return; }': ()
     36..42 'return': !
     "###
     );
@@ -1755,3 +1799,127 @@ fn main() {
     "###
     );
 }
+
+#[test]
+fn effects_smoke_test() {
+    assert_snapshot!(
+        infer(r#"
+fn main() {
+    let x = unsafe { 92 };
+    let y = async { async { () }.await };
+    let z = try { () };
+    let t = 'a: { 92 };
+}
+"#),
+        @r###"
+    11..131 '{     ...2 }; }': ()
+    21..22 'x': i32
+    32..38 '{ 92 }': i32
+    34..36 '92': i32
+    48..49 'y': {unknown}
+    58..80 '{ asyn...wait }': {unknown}
+    60..78 'async ....await': {unknown}
+    66..72 '{ () }': ()
+    68..70 '()': ()
+    90..91 'z': {unknown}
+    94..104 'try { () }': {unknown}
+    98..104 '{ () }': ()
+    100..102 '()': ()
+    114..115 't': i32
+    122..128 '{ 92 }': i32
+    124..126 '92': i32
+    "###
+    )
+}
+
+#[test]
+fn infer_generic_from_later_assignment() {
+    assert_snapshot!(
+        infer(r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn test() {
+    let mut end = None;
+    loop {
+        end = Some(true);
+    }
+}
+"#),
+        @r###"
+    60..130 '{     ...   } }': ()
+    70..77 'mut end': Option<bool>
+    80..84 'None': Option<bool>
+    90..128 'loop {...     }': !
+    95..128 '{     ...     }': ()
+    105..108 'end': Option<bool>
+    105..121 'end = ...(true)': ()
+    111..115 'Some': Some<bool>(bool) -> Option<bool>
+    111..121 'Some(true)': Option<bool>
+    116..120 'true': bool
+    "###
+    );
+}
+
+#[test]
+fn infer_loop_break_with_val() {
+    assert_snapshot!(
+        infer(r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn test() {
+    let x = loop {
+        if false {
+            break None;
+        }
+
+        break Some(true);
+    };
+}
+"#),
+        @r###"
+    60..169 '{     ...  }; }': ()
+    70..71 'x': Option<bool>
+    74..166 'loop {...     }': Option<bool>
+    79..166 '{     ...     }': ()
+    89..133 'if fal...     }': ()
+    92..97 'false': bool
+    98..133 '{     ...     }': ()
+    112..122 'break None': !
+    118..122 'None': Option<bool>
+    143..159 'break ...(true)': !
+    149..153 'Some': Some<bool>(bool) -> Option<bool>
+    149..159 'Some(true)': Option<bool>
+    154..158 'true': bool
+    "###
+    );
+}
+
+#[test]
+fn infer_loop_break_without_val() {
+    assert_snapshot!(
+        infer(r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn test() {
+    let x = loop {
+        if false {
+            break;
+        }
+    };
+}
+"#),
+        @r###"
+    60..137 '{     ...  }; }': ()
+    70..71 'x': ()
+    74..134 'loop {...     }': ()
+    79..134 '{     ...     }': ()
+    89..128 'if fal...     }': ()
+    92..97 'false': bool
+    98..128 '{     ...     }': ()
+    112..117 'break': !
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index e555c879a..34f4b9039 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -1,10 +1,11 @@
 use insta::assert_snapshot;
-
 use ra_db::fixture::WithFixture;
+use test_utils::mark;
 
-use super::{infer, infer_with_mismatches, type_at, type_at_pos};
 use crate::test_db::TestDB;
 
+use super::{infer, infer_with_mismatches, type_at, type_at_pos};
+
 #[test]
 fn infer_await() {
     let (db, pos) = TestDB::with_position(
@@ -301,7 +302,7 @@ fn test() {
 
 #[test]
 fn trait_default_method_self_bound_implements_trait() {
-    test_utils::covers!(trait_self_implements_self);
+    mark::check!(trait_self_implements_self);
     assert_snapshot!(
         infer(r#"
 trait Trait {
@@ -324,7 +325,6 @@ trait Trait {
 
 #[test]
 fn trait_default_method_self_bound_implements_super_trait() {
-    test_utils::covers!(trait_self_implements_self);
     assert_snapshot!(
         infer(r#"
 trait SuperTrait {
@@ -1617,6 +1617,138 @@ fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
 }
 
 #[test]
+fn fn_ptr_and_item() {
+    assert_snapshot!(
+        infer(r#"
+#[lang="fn_once"]
+trait FnOnce<Args> {
+    type Output;
+
+    fn call_once(self, args: Args) -> Self::Output;
+}
+
+trait Foo<T> {
+    fn foo(&self) -> T;
+}
+
+struct Bar<T>(T);
+
+impl<A1, R, F: FnOnce(A1) -> R> Foo<(A1, R)> for Bar<F> {
+    fn foo(&self) -> (A1, R) {}
+}
+
+enum Opt<T> { None, Some(T) }
+impl<T> Opt<T> {
+    fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Opt<U> {}
+}
+
+fn test() {
+    let bar: Bar<fn(u8) -> u32>;
+    bar.foo();
+
+    let opt: Opt<u8>;
+    let f: fn(u8) -> u32;
+    opt.map(f);
+}
+"#),
+        @r###"
+75..79 'self': Self
+81..85 'args': Args
+140..144 'self': &Self
+244..248 'self': &Bar<F>
+261..263 '{}': ()
+347..351 'self': Opt<T>
+353..354 'f': F
+369..371 '{}': ()
+385..501 '{     ...(f); }': ()
+395..398 'bar': Bar<fn(u8) -> u32>
+424..427 'bar': Bar<fn(u8) -> u32>
+424..433 'bar.foo()': {unknown}
+444..447 'opt': Opt<u8>
+466..467 'f': fn(u8) -> u32
+488..491 'opt': Opt<u8>
+488..498 'opt.map(f)': Opt<FnOnce::Output<fn(u8) -> u32, (u8,)>>
+496..497 'f': fn(u8) -> u32
+"###
+    );
+}
+
+#[test]
+fn fn_trait_deref_with_ty_default() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+trait Deref {
+    type Target;
+
+    fn deref(&self) -> &Self::Target;
+}
+
+#[lang="fn_once"]
+trait FnOnce<Args> {
+    type Output;
+
+    fn call_once(self, args: Args) -> Self::Output;
+}
+
+struct Foo;
+
+impl Foo {
+    fn foo(&self) -> usize {}
+}
+
+struct Lazy<T, F = fn() -> T>(F);
+
+impl<T, F> Lazy<T, F> {
+    pub fn new(f: F) -> Lazy<T, F> {}
+}
+
+impl<T, F: FnOnce() -> T> Deref for Lazy<T, F> {
+    type Target = T;
+}
+
+fn test() {
+    let lazy1: Lazy<Foo, _> = Lazy::new(|| Foo);
+    let r1 = lazy1.foo();
+
+    fn make_foo_fn() -> Foo {}
+    let make_foo_fn_ptr: fn() -> Foo = make_foo_fn;
+    let lazy2: Lazy<Foo, _> = Lazy::new(make_foo_fn_ptr);
+    let r2 = lazy2.foo();
+}
+"#),
+        @r###"
+65..69 'self': &Self
+166..170 'self': Self
+172..176 'args': Args
+240..244 'self': &Foo
+255..257 '{}': ()
+335..336 'f': F
+355..357 '{}': ()
+444..690 '{     ...o(); }': ()
+454..459 'lazy1': Lazy<Foo, fn() -> T>
+476..485 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
+476..493 'Lazy::...| Foo)': Lazy<Foo, fn() -> T>
+486..492 '|| Foo': || -> T
+489..492 'Foo': Foo
+503..505 'r1': {unknown}
+508..513 'lazy1': Lazy<Foo, fn() -> T>
+508..519 'lazy1.foo()': {unknown}
+561..576 'make_foo_fn_ptr': fn() -> Foo
+592..603 'make_foo_fn': fn make_foo_fn() -> Foo
+613..618 'lazy2': Lazy<Foo, fn() -> T>
+635..644 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
+635..661 'Lazy::...n_ptr)': Lazy<Foo, fn() -> T>
+645..660 'make_foo_fn_ptr': fn() -> Foo
+671..673 'r2': {unknown}
+676..681 'lazy2': Lazy<Foo, fn() -> T>
+676..687 'lazy2.foo()': {unknown}
+550..552 '{}': ()
+"###
+    );
+}
+
+#[test]
 fn closure_1() {
     assert_snapshot!(
         infer(r#"
@@ -2055,7 +2187,7 @@ fn test<I: Iterator<Item: Iterator<Item = u32>>>() {
 #[test]
 fn proc_macro_server_types() {
     assert_snapshot!(
-        infer_with_mismatches(r#"
+        infer(r#"
 macro_rules! with_api {
     ($S:ident, $self:ident, $m:ident) => {
         $m! {
@@ -2069,9 +2201,9 @@ macro_rules! with_api {
 }
 macro_rules! associated_item {
     (type TokenStream) =>
-        (type TokenStream: 'static + Clone;);
+        (type TokenStream: 'static;);
     (type Group) =>
-        (type Group: 'static + Clone;);
+        (type Group: 'static;);
     ($($item:tt)*) => ($($item)*;)
 }
 macro_rules! declare_server_traits {
@@ -2083,21 +2215,23 @@ macro_rules! declare_server_traits {
         }
 
         $(pub trait $name: Types {
-            $(associated_item!(fn $method(&mut self, $($arg: $arg_ty),*) $(-> $ret_ty)?);)*
+            $(associated_item!(fn $method($($arg: $arg_ty),*) $(-> $ret_ty)?);)*
         })*
 
         pub trait Server: Types $(+ $name)* {}
         impl<S: Types $(+ $name)*> Server for S {}
     }
 }
+
 with_api!(Self, self_, declare_server_traits);
-struct Group {}
-struct TokenStream {}
+struct G {}
+struct T {}
 struct Rustc;
 impl Types for Rustc {
-    type TokenStream = TokenStream;
-    type Group = Group;
+    type TokenStream = T;
+    type Group = G;
 }
+
 fn make<T>() -> T { loop {} }
 impl TokenStream for Rustc {
     fn new() -> Self::TokenStream {
@@ -2105,17 +2239,17 @@ impl TokenStream for Rustc {
         make()
     }
 }
-"#, true),
+"#),
         @r###"
-    1115..1126 '{ loop {} }': T
-    1117..1124 'loop {}': !
-    1122..1124 '{}': ()
-    1190..1253 '{     ...     }': {unknown}
-    1204..1209 'group': {unknown}
-    1225..1229 'make': fn make<{unknown}>() -> {unknown}
-    1225..1231 'make()': {unknown}
-    1241..1245 'make': fn make<{unknown}>() -> {unknown}
-    1241..1247 'make()': {unknown}
+    1062..1073 '{ loop {} }': T
+    1064..1071 'loop {}': !
+    1069..1071 '{}': ()
+    1137..1200 '{     ...     }': T
+    1151..1156 'group': G
+    1172..1176 'make': fn make<G>() -> G
+    1172..1178 'make()': G
+    1188..1192 'make': fn make<T>() -> T
+    1188..1194 'make()': T
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 1ccb7c3b4..5870618a0 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -182,7 +182,10 @@ impl chalk_ir::interner::Interner for Interner {
         Arc::new(goal)
     }
 
-    fn intern_goals(&self, data: impl IntoIterator<Item = Goal<Self>>) -> Self::InternedGoals {
+    fn intern_goals<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<Goal<Self>, E>>,
+    ) -> Result<Self::InternedGoals, E> {
         data.into_iter().collect()
     }
 
@@ -222,10 +225,10 @@ impl chalk_ir::interner::Interner for Interner {
         clause
     }
 
-    fn intern_program_clauses(
+    fn intern_program_clauses<E>(
         &self,
-        data: impl IntoIterator<Item = chalk_ir::ProgramClause<Self>>,
-    ) -> Arc<[chalk_ir::ProgramClause<Self>]> {
+        data: impl IntoIterator<Item = Result<chalk_ir::ProgramClause<Self>, E>>,
+    ) -> Result<Arc<[chalk_ir::ProgramClause<Self>]>, E> {
         data.into_iter().collect()
     }
 
@@ -236,10 +239,10 @@ impl chalk_ir::interner::Interner for Interner {
         &clauses
     }
 
-    fn intern_quantified_where_clauses(
+    fn intern_quantified_where_clauses<E>(
         &self,
-        data: impl IntoIterator<Item = chalk_ir::QuantifiedWhereClause<Self>>,
-    ) -> Self::InternedQuantifiedWhereClauses {
+        data: impl IntoIterator<Item = Result<chalk_ir::QuantifiedWhereClause<Self>, E>>,
+    ) -> Result<Self::InternedQuantifiedWhereClauses, E> {
         data.into_iter().collect()
     }
 
@@ -250,10 +253,10 @@ impl chalk_ir::interner::Interner for Interner {
         clauses
     }
 
-    fn intern_parameter_kinds(
+    fn intern_parameter_kinds<E>(
         &self,
-        data: impl IntoIterator<Item = chalk_ir::ParameterKind<()>>,
-    ) -> Self::InternedParameterKinds {
+        data: impl IntoIterator<Item = Result<chalk_ir::ParameterKind<()>, E>>,
+    ) -> Result<Self::InternedParameterKinds, E> {
         data.into_iter().collect()
     }
 
@@ -264,10 +267,10 @@ impl chalk_ir::interner::Interner for Interner {
         &parameter_kinds
     }
 
-    fn intern_canonical_var_kinds(
+    fn intern_canonical_var_kinds<E>(
         &self,
-        data: impl IntoIterator<Item = chalk_ir::ParameterKind<UniverseIndex>>,
-    ) -> Self::InternedCanonicalVarKinds {
+        data: impl IntoIterator<Item = Result<chalk_ir::ParameterKind<UniverseIndex>, E>>,
+    ) -> Result<Self::InternedCanonicalVarKinds, E> {
         data.into_iter().collect()
     }
 
@@ -460,6 +463,14 @@ impl ToChalk for TypeCtor {
             TypeName::Struct(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
             TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
             TypeName::OpaqueType(_) => unreachable!(),
+
+            TypeName::Scalar(_) => unreachable!(),
+            TypeName::Tuple(_) => unreachable!(),
+            TypeName::Raw(_) => unreachable!(),
+            TypeName::Slice => unreachable!(),
+            TypeName::Ref(_) => unreachable!(),
+            TypeName::Str => unreachable!(),
+
             TypeName::Error => {
                 // this should not be reached, since we don't represent TypeName::Error with TypeCtor
                 unreachable!()
@@ -862,12 +873,6 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         // We don't do coherence checking (yet)
         unimplemented!()
     }
-    fn as_struct_id(&self, id: &TypeName<Interner>) -> Option<StructId> {
-        match id {
-            TypeName::Struct(struct_id) => Some(*struct_id),
-            _ => None,
-        }
-    }
     fn interner(&self) -> &Interner {
         &Interner
     }
@@ -892,6 +897,20 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     ) -> Arc<chalk_rust_ir::OpaqueTyDatum<Interner>> {
         unimplemented!()
     }
+
+    fn force_impl_for(
+        &self,
+        _well_known: chalk_rust_ir::WellKnownTrait,
+        _ty: &chalk_ir::TyData<Interner>,
+    ) -> Option<bool> {
+        // this method is mostly for rustc
+        None
+    }
+
+    fn is_object_safe(&self, _trait_id: chalk_ir::TraitId<Interner>) -> bool {
+        // FIXME: implement actual object safety
+        true
+    }
 }
 
 pub(crate) fn program_clauses_for_chalk_env_query(