89 files changed, 3612 insertions, 3260 deletions

diff --git a/Cargo.lock b/Cargo.lock
index e47b87964..5066d5f0f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -216,20 +216,6 @@ dependencies = [
  "petgraph",
  "rustc-hash",
  "tracing",
- "tracing-subscriber",
- "tracing-tree",
-]
-
-[[package]]
-name = "chrono"
-version = "0.4.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
-dependencies = [
- "libc",
- "num-integer",
- "num-traits",
- "winapi",
 ]
 
 [[package]]
@@ -591,6 +577,7 @@ dependencies = [
  "ide_assists",
  "ide_completion",
  "ide_db",
+ "ide_diagnostics",
  "ide_ssr",
  "indexmap",
  "itertools",
@@ -669,6 +656,25 @@ dependencies = [
 ]
 
 [[package]]
+name = "ide_diagnostics"
+version = "0.0.0"
+dependencies = [
+ "cfg",
+ "cov-mark",
+ "either",
+ "expect-test",
+ "hir",
+ "ide_db",
+ "itertools",
+ "profile",
+ "rustc-hash",
+ "stdx",
+ "syntax",
+ "test_utils",
+ "text_edit",
+]
+
+[[package]]
 name = "ide_ssr"
 version = "0.0.0"
 dependencies = [
@@ -955,25 +961,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "num-integer"
-version = "0.1.44"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
-dependencies = [
- "autocfg",
- "num-traits",
-]
-
-[[package]]
-name = "num-traits"
-version = "0.2.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
-dependencies = [
- "autocfg",
-]
-
-[[package]]
 name = "num_cpus"
 version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1742,35 +1729,18 @@ dependencies = [
 ]
 
 [[package]]
-name = "tracing-serde"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb65ea441fbb84f9f6748fd496cf7f63ec9af5bca94dd86456978d055e8eb28b"
-dependencies = [
- "serde",
- "tracing-core",
-]
-
-[[package]]
 name = "tracing-subscriber"
 version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "aa5553bf0883ba7c9cbe493b085c29926bd41b66afc31ff72cf17ff4fb60dcd5"
 dependencies = [
- "ansi_term",
- "chrono",
  "lazy_static",
  "matchers",
  "regex",
- "serde",
- "serde_json",
  "sharded-slab",
- "smallvec",
  "thread_local",
  "tracing",
  "tracing-core",
- "tracing-log",
- "tracing-serde",
 ]
 
 [[package]]
diff --git a/crates/base_db/src/fixture.rs b/crates/base_db/src/fixture.rs
index da4afb5eb..d56b20b83 100644
--- a/crates/base_db/src/fixture.rs
+++ b/crates/base_db/src/fixture.rs
@@ -9,8 +9,8 @@ use test_utils::{
 use vfs::{file_set::FileSet, VfsPath};
 
 use crate::{
-    input::CrateName, Change, CrateGraph, CrateId, Edition, Env, FileId, FilePosition, FileRange,
-    SourceDatabaseExt, SourceRoot, SourceRootId,
+    input::CrateName, Change, CrateDisplayName, CrateGraph, CrateId, Edition, Env, FileId,
+    FilePosition, FileRange, SourceDatabaseExt, SourceRoot, SourceRootId,
 };
 
 pub const WORKSPACE: SourceRootId = SourceRootId(0);
@@ -24,6 +24,14 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
         (db, fixture.files[0])
     }
 
+    fn with_many_files(ra_fixture: &str) -> (Self, Vec<FileId>) {
+        let fixture = ChangeFixture::parse(ra_fixture);
+        let mut db = Self::default();
+        fixture.change.apply(&mut db);
+        assert!(fixture.file_position.is_none());
+        (db, fixture.files)
+    }
+
     fn with_files(ra_fixture: &str) -> Self {
         let fixture = ChangeFixture::parse(ra_fixture);
         let mut db = Self::default();
@@ -73,7 +81,7 @@ pub struct ChangeFixture {
 
 impl ChangeFixture {
     pub fn parse(ra_fixture: &str) -> ChangeFixture {
-        let fixture = Fixture::parse(ra_fixture);
+        let (mini_core, fixture) = Fixture::parse(ra_fixture);
         let mut change = Change::new();
 
         let mut files = Vec::new();
@@ -158,6 +166,31 @@ impl ChangeFixture {
             }
         }
 
+        if let Some(mini_core) = mini_core {
+            let core_file = file_id;
+            file_id.0 += 1;
+
+            let mut fs = FileSet::default();
+            fs.insert(core_file, VfsPath::new_virtual_path("/sysroot/core/lib.rs".to_string()));
+            roots.push(SourceRoot::new_library(fs));
+
+            change.change_file(core_file, Some(Arc::new(mini_core.source_code())));
+
+            let all_crates = crate_graph.crates_in_topological_order();
+
+            let core_crate = crate_graph.add_crate_root(
+                core_file,
+                Edition::Edition2021,
+                Some(CrateDisplayName::from_canonical_name("core".to_string())),
+                CfgOptions::default(),
+                Env::default(),
+                Vec::new(),
+            );
+
+            for krate in all_crates {
+                crate_graph.add_dep(krate, CrateName::new("core").unwrap(), core_crate).unwrap();
+            }
+        }
         roots.push(SourceRoot::new_local(mem::take(&mut file_set)));
         change.set_roots(roots);
         change.set_crate_graph(crate_graph);
diff --git a/crates/hir/src/has_source.rs b/crates/hir/src/has_source.rs
index dc10a4d0f..197149c5e 100644
--- a/crates/hir/src/has_source.rs
+++ b/crates/hir/src/has_source.rs
@@ -127,7 +127,7 @@ impl HasSource for Impl {
 }
 
 impl HasSource for TypeParam {
-    type Ast = Either<ast::Trait, ast::TypeParam>;
+    type Ast = Either<ast::TypeParam, ast::Trait>;
     fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
         let child_source = self.id.parent.child_source(db.upcast());
         Some(child_source.map(|it| it[self.id.local_id].clone()))
diff --git a/crates/hir_def/src/generics.rs b/crates/hir_def/src/generics.rs
index 6933f6e3c..0f04b2bae 100644
--- a/crates/hir_def/src/generics.rs
+++ b/crates/hir_def/src/generics.rs
@@ -92,7 +92,7 @@ pub enum WherePredicateTypeTarget {
 
 #[derive(Default)]
 pub(crate) struct SourceMap {
-    pub(crate) type_params: ArenaMap<LocalTypeParamId, Either<ast::Trait, ast::TypeParam>>,
+    pub(crate) type_params: ArenaMap<LocalTypeParamId, Either<ast::TypeParam, ast::Trait>>,
     lifetime_params: ArenaMap<LocalLifetimeParamId, ast::LifetimeParam>,
     const_params: ArenaMap<LocalConstParamId, ast::ConstParam>,
 }
@@ -199,7 +199,7 @@ impl GenericParams {
                     default: None,
                     provenance: TypeParamProvenance::TraitSelf,
                 });
-                sm.type_params.insert(self_param_id, Either::Left(src.value.clone()));
+                sm.type_params.insert(self_param_id, Either::Right(src.value.clone()));
                 // add super traits as bounds on Self
                 // i.e., trait Foo: Bar is equivalent to trait Foo where Self: Bar
                 let self_param = TypeRef::Path(name![Self].into());
@@ -277,7 +277,7 @@ impl GenericParams {
                 provenance: TypeParamProvenance::TypeParamList,
             };
             let param_id = self.types.alloc(param);
-            sm.type_params.insert(param_id, Either::Right(type_param.clone()));
+            sm.type_params.insert(param_id, Either::Left(type_param.clone()));
 
             let type_ref = TypeRef::Path(name.into());
             self.fill_bounds(lower_ctx, &type_param, Either::Left(type_ref));
@@ -413,7 +413,7 @@ impl GenericParams {
 }
 
 impl HasChildSource<LocalTypeParamId> for GenericDefId {
-    type Value = Either<ast::Trait, ast::TypeParam>;
+    type Value = Either<ast::TypeParam, ast::Trait>;
     fn child_source(
         &self,
         db: &dyn DefDatabase,
@@ -449,7 +449,7 @@ impl ChildBySource for GenericDefId {
         let sm = sm.as_ref();
         for (local_id, src) in sm.value.type_params.iter() {
             let id = TypeParamId { parent: *self, local_id };
-            if let Either::Right(type_param) = src {
+            if let Either::Left(type_param) = src {
                 res[keys::TYPE_PARAM].insert(sm.with_value(type_param.clone()), id)
             }
         }
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 3f90bda74..5b1386406 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -674,7 +674,7 @@ impl<'a> Ctx<'a> {
                     default: None,
                     provenance: TypeParamProvenance::TraitSelf,
                 });
-                sm.type_params.insert(self_param_id, Either::Left(trait_def.clone()));
+                sm.type_params.insert(self_param_id, Either::Right(trait_def.clone()));
                 // add super traits as bounds on Self
                 // i.e., trait Foo: Bar is equivalent to trait Foo where Self: Bar
                 let self_param = TypeRef::Path(name![Self].into());
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 6fab58f15..fc2c50fb8 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -1992,8 +1992,8 @@ mod tests {
         collector.def_map
     }
 
-    fn do_resolve(code: &str) -> DefMap {
-        let (db, _file_id) = TestDB::with_single_file(code);
+    fn do_resolve(not_ra_fixture: &str) -> DefMap {
+        let (db, _file_id) = TestDB::with_single_file(not_ra_fixture);
         let krate = db.test_crate();
 
         let edition = db.crate_graph()[krate].edition;
@@ -2005,24 +2005,37 @@ mod tests {
     fn test_macro_expand_will_stop_1() {
         do_resolve(
             r#"
-        macro_rules! foo {
-            ($($ty:ty)*) => { foo!($($ty)*); }
-        }
-        foo!(KABOOM);
-        "#,
+macro_rules! foo {
+    ($($ty:ty)*) => { foo!($($ty)*); }
+}
+foo!(KABOOM);
+"#,
+        );
+        do_resolve(
+            r#"
+macro_rules! foo {
+    ($($ty:ty)*) => { foo!(() $($ty)*); }
+}
+foo!(KABOOM);
+"#,
         );
     }
 
-    #[ignore] // this test does succeed, but takes quite a while :/
+    #[ignore]
     #[test]
     fn test_macro_expand_will_stop_2() {
+        // FIXME: this test does succeed, but takes quite a while: 90 seconds in
+        // the release mode. That's why the argument is not an ra_fixture --
+        // otherwise injection highlighting gets stuck.
+        //
+        // We need to find a way to fail this faster.
         do_resolve(
             r#"
-        macro_rules! foo {
-            ($($ty:ty)*) => { foo!($($ty)* $($ty)*); }
-        }
-        foo!(KABOOM);
-        "#,
+macro_rules! foo {
+    ($($ty:ty)*) => { foo!($($ty)* $($ty)*); }
+}
+foo!(KABOOM);
+"#,
         );
     }
 }
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index a1894e8d8..74129eb21 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -20,7 +20,7 @@ rustc-hash = "1.1.0"
 scoped-tls = "1"
 chalk-solve = { version = "0.68", default-features = false }
 chalk-ir = "0.68"
-chalk-recursive = "0.68"
+chalk-recursive = { version = "0.68", default-features = false }
 la-arena = { version = "0.2.0", path = "../../lib/arena" }
 once_cell = { version = "1.5.0" }
 
diff --git a/crates/hir_ty/src/tests/coercion.rs b/crates/hir_ty/src/tests/coercion.rs
index 71047703d..713b74165 100644
--- a/crates/hir_ty/src/tests/coercion.rs
+++ b/crates/hir_ty/src/tests/coercion.rs
@@ -23,38 +23,29 @@ fn infer_block_expr_type_mismatch() {
 fn coerce_places() {
     check_infer(
         r#"
-        struct S<T> { a: T }
+//- minicore: coerce_unsized
+struct S<T> { a: T }
 
-        fn f<T>(_: &[T]) -> T { loop {} }
-        fn g<T>(_: S<&[T]>) -> T { loop {} }
+fn f<T>(_: &[T]) -> T { loop {} }
+fn g<T>(_: S<&[T]>) -> T { loop {} }
 
-        fn gen<T>() -> *mut [T; 2] { loop {} }
-        fn test1<U>() -> *mut [U] {
-            gen()
-        }
-
-        fn test2() {
-            let arr: &[u8; 1] = &[1];
-
-            let a: &[_] = arr;
-            let b = f(arr);
-            let c: &[_] = { arr };
-            let d = g(S { a: arr });
-            let e: [&[_]; 1] = [arr];
-            let f: [&[_]; 2] = [arr; 2];
-            let g: (&[_], &[_]) = (arr, arr);
-        }
+fn gen<T>() -> *mut [T; 2] { loop {} }
+fn test1<U>() -> *mut [U] {
+    gen()
+}
 
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T: ?Sized> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
+fn test2() {
+    let arr: &[u8; 1] = &[1];
 
-        impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
-        impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
-        "#,
+    let a: &[_] = arr;
+    let b = f(arr);
+    let c: &[_] = { arr };
+    let d = g(S { a: arr });
+    let e: [&[_]; 1] = [arr];
+    let f: [&[_]; 2] = [arr; 2];
+    let g: (&[_], &[_]) = (arr, arr);
+}
+"#,
         expect![[r#"
             30..31 '_': &[T]
             44..55 '{ loop {} }': T
@@ -131,60 +122,52 @@ fn infer_let_stmt_coerce() {
 fn infer_custom_coerce_unsized() {
     check_infer(
         r#"
-        struct A<T: ?Sized>(*const T);
-        struct B<T: ?Sized>(*const T);
-        struct C<T: ?Sized> { inner: *const T }
+//- minicore: coerce_unsized
+use core::{marker::Unsize, ops::CoerceUnsized};
 
-        impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<B<U>> for B<T> {}
-        impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<C<U>> for C<T> {}
+struct A<T: ?Sized>(*const T);
+struct B<T: ?Sized>(*const T);
+struct C<T: ?Sized> { inner: *const T }
 
-        fn foo1<T>(x: A<[T]>) -> A<[T]> { x }
-        fn foo2<T>(x: B<[T]>) -> B<[T]> { x }
-        fn foo3<T>(x: C<[T]>) -> C<[T]> { x }
+impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<B<U>> for B<T> {}
+impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<C<U>> for C<T> {}
 
-        fn test(a: A<[u8; 2]>, b: B<[u8; 2]>, c: C<[u8; 2]>) {
-            let d = foo1(a);
-            let e = foo2(b);
-            let f = foo3(c);
-        }
-
-
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T: ?Sized> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
+fn foo1<T>(x: A<[T]>) -> A<[T]> { x }
+fn foo2<T>(x: B<[T]>) -> B<[T]> { x }
+fn foo3<T>(x: C<[T]>) -> C<[T]> { x }
 
-        impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
-        impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
-        "#,
+fn test(a: A<[u8; 2]>, b: B<[u8; 2]>, c: C<[u8; 2]>) {
+    let d = foo1(a);
+    let e = foo2(b);
+    let f = foo3(c);
+}
+"#,
         expect![[r#"
-            257..258 'x': A<[T]>
-            278..283 '{ x }': A<[T]>
-            280..281 'x': A<[T]>
-            295..296 'x': B<[T]>
-            316..321 '{ x }': B<[T]>
-            318..319 'x': B<[T]>
-            333..334 'x': C<[T]>
-            354..359 '{ x }': C<[T]>
-            356..357 'x': C<[T]>
-            369..370 'a': A<[u8; 2]>
-            384..385 'b': B<[u8; 2]>
-            399..400 'c': C<[u8; 2]>
-            414..480 '{     ...(c); }': ()
-            424..425 'd': A<[{unknown}]>
-            428..432 'foo1': fn foo1<{unknown}>(A<[{unknown}]>) -> A<[{unknown}]>
-            428..435 'foo1(a)': A<[{unknown}]>
-            433..434 'a': A<[u8; 2]>
-            445..446 'e': B<[u8]>
-            449..453 'foo2': fn foo2<u8>(B<[u8]>) -> B<[u8]>
-            449..456 'foo2(b)': B<[u8]>
-            454..455 'b': B<[u8; 2]>
-            466..467 'f': C<[u8]>
-            470..474 'foo3': fn foo3<u8>(C<[u8]>) -> C<[u8]>
-            470..477 'foo3(c)': C<[u8]>
-            475..476 'c': C<[u8; 2]>
+            306..307 'x': A<[T]>
+            327..332 '{ x }': A<[T]>
+            329..330 'x': A<[T]>
+            344..345 'x': B<[T]>
+            365..370 '{ x }': B<[T]>
+            367..368 'x': B<[T]>
+            382..383 'x': C<[T]>
+            403..408 '{ x }': C<[T]>
+            405..406 'x': C<[T]>
+            418..419 'a': A<[u8; 2]>
+            433..434 'b': B<[u8; 2]>
+            448..449 'c': C<[u8; 2]>
+            463..529 '{     ...(c); }': ()
+            473..474 'd': A<[{unknown}]>
+            477..481 'foo1': fn foo1<{unknown}>(A<[{unknown}]>) -> A<[{unknown}]>
+            477..484 'foo1(a)': A<[{unknown}]>
+            482..483 'a': A<[u8; 2]>
+            494..495 'e': B<[u8]>
+            498..502 'foo2': fn foo2<u8>(B<[u8]>) -> B<[u8]>
+            498..505 'foo2(b)': B<[u8]>
+            503..504 'b': B<[u8; 2]>
+            515..516 'f': C<[u8]>
+            519..523 'foo3': fn foo3<u8>(C<[u8]>) -> C<[u8]>
+            519..526 'foo3(c)': C<[u8]>
+            524..525 'c': C<[u8; 2]>
         "#]],
     );
 }
@@ -193,21 +176,16 @@ fn infer_custom_coerce_unsized() {
 fn infer_if_coerce() {
     check_infer(
         r#"
-        fn foo<T>(x: &[T]) -> &[T] { loop {} }
-        fn test() {
-            let x = if true {
-                foo(&[1])
-            } else {
-                &[1]
-            };
-        }
-
-
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T: ?Sized> {}
-        "#,
+//- minicore: unsize
+fn foo<T>(x: &[T]) -> &[T] { loop {} }
+fn test() {
+    let x = if true {
+        foo(&[1])
+    } else {
+        &[1]
+    };
+}
+"#,
         expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
@@ -235,25 +213,16 @@ fn infer_if_coerce() {
 fn infer_if_else_coerce() {
     check_infer(
         r#"
-        fn foo<T>(x: &[T]) -> &[T] { loop {} }
-        fn test() {
-            let x = if true {
-                &[1]
-            } else {
-                foo(&[1])
-            };
-        }
-
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T: ?Sized> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
-        impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
-        "#,
+//- minicore: coerce_unsized
+fn foo<T>(x: &[T]) -> &[T] { loop {} }
+fn test() {
+    let x = if true {
+        &[1]
+    } else {
+        foo(&[1])
+    };
+}
+"#,
         expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
@@ -281,20 +250,16 @@ fn infer_if_else_coerce() {
 fn infer_match_first_coerce() {
     check_infer(
         r#"
-        fn foo<T>(x: &[T]) -> &[T] { loop {} }
-        fn test(i: i32) {
-            let x = match i {
-                2 => foo(&[2]),
-                1 => &[1],
-                _ => &[3],
-            };
-        }
-
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T: ?Sized> {}
-        "#,
+//- minicore: unsize
+fn foo<T>(x: &[T]) -> &[T] { loop {} }
+fn test(i: i32) {
+    let x = match i {
+        2 => foo(&[2]),
+        1 => &[1],
+        _ => &[3],
+    };
+}
+"#,
         expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
@@ -329,25 +294,16 @@ fn infer_match_first_coerce() {
 fn infer_match_second_coerce() {
     check_infer(
         r#"
-        fn foo<T>(x: &[T]) -> &[T] { loop {} }
-        fn test(i: i32) {
-            let x = match i {
-                1 => &[1],
-                2 => foo(&[2]),
-                _ => &[3],
-            };
-        }
-
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T: ?Sized> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<'a, 'b: 'a, T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<&'a U> for &'b T {}
-        impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<*mut U> for *mut T {}
-        "#,
+//- minicore: coerce_unsized
+fn foo<T>(x: &[T]) -> &[T] { loop {} }
+fn test(i: i32) {
+    let x = match i {
+        1 => &[1],
+        2 => foo(&[2]),
+        _ => &[3],
+    };
+}
+"#,
         expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
@@ -470,15 +426,15 @@ fn coerce_autoderef() {
 #[test]
 fn coerce_autoderef_generic() {
     check_infer_with_mismatches(
-        r"
-        struct Foo;
-        fn takes_ref<T>(x: &T) -> T { *x }
-        fn test() {
-            takes_ref(&Foo);
-            takes_ref(&&Foo);
-            takes_ref(&&&Foo);
-        }
-        ",
+        r#"
+struct Foo;
+fn takes_ref<T>(x: &T) -> T { *x }
+fn test() {
+    takes_ref(&Foo);
+    takes_ref(&&Foo);
+    takes_ref(&&&Foo);
+}
+"#,
         expect![[r"
             28..29 'x': &T
             40..46 '{ *x }': T
@@ -508,30 +464,29 @@ fn coerce_autoderef_generic() {
 fn coerce_autoderef_block() {
     check_infer_with_mismatches(
         r#"
-        struct String {}
-        #[lang = "deref"]
-        trait Deref { type Target; }
-        impl Deref for String { type Target = str; }
-        fn takes_ref_str(x: &str) {}
-        fn returns_string() -> String { loop {} }
-        fn test() {
-            takes_ref_str(&{ returns_string() });
-        }
-        "#,
-        expect![[r"
-            126..127 'x': &str
-            135..137 '{}': ()
-            168..179 '{ loop {} }': String
-            170..177 'loop {}': !
-            175..177 '{}': ()
-            190..235 '{     ... }); }': ()
-            196..209 'takes_ref_str': fn takes_ref_str(&str)
-            196..232 'takes_...g() })': ()
-            210..231 '&{ ret...ng() }': &String
-            211..231 '{ retu...ng() }': String
-            213..227 'returns_string': fn returns_string() -> String
-            213..229 'return...ring()': String
-        "]],
+//- minicore: deref
+struct String {}
+impl core::ops::Deref for String { type Target = str; }
+fn takes_ref_str(x: &str) {}
+fn returns_string() -> String { loop {} }
+fn test() {
+    takes_ref_str(&{ returns_string() });
+}
+"#,
+        expect![[r#"
+            90..91 'x': &str
+            99..101 '{}': ()
+            132..143 '{ loop {} }': String
+            134..141 'loop {}': !
+            139..141 '{}': ()
+            154..199 '{     ... }); }': ()
+            160..173 'takes_ref_str': fn takes_ref_str(&str)
+            160..196 'takes_...g() })': ()
+            174..195 '&{ ret...ng() }': &String
+            175..195 '{ retu...ng() }': String
+            177..191 'returns_string': fn returns_string() -> String
+            177..193 'return...ring()': String
+        "#]],
     );
 }
 
@@ -674,25 +629,19 @@ fn coerce_placeholder_ref() {
 fn coerce_unsize_array() {
     check_infer_with_mismatches(
         r#"
-        #[lang = "unsize"]
-        pub trait Unsize<T> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
-
-        fn test() {
-            let f: &[usize] = &[1, 2, 3];
-        }
+//- minicore: coerce_unsized
+fn test() {
+    let f: &[usize] = &[1, 2, 3];
+}
         "#,
         expect![[r#"
-            161..198 '{     ... 3]; }': ()
-            171..172 'f': &[usize]
-            185..195 '&[1, 2, 3]': &[usize; 3]
-            186..195 '[1, 2, 3]': [usize; 3]
-            187..188 '1': usize
-            190..191 '2': usize
-            193..194 '3': usize
+            10..47 '{     ... 3]; }': ()
+            20..21 'f': &[usize]
+            34..44 '&[1, 2, 3]': &[usize; 3]
+            35..44 '[1, 2, 3]': [usize; 3]
+            36..37 '1': usize
+            39..40 '2': usize
+            42..43 '3': usize
         "#]],
     );
 }
@@ -701,93 +650,94 @@ fn coerce_unsize_array() {
 fn coerce_unsize_trait_object_simple() {
     check_infer_with_mismatches(
         r#"
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
-
-        trait Foo<T, U> {}
-        trait Bar<U, T, X>: Foo<T, U> {}
-        trait Baz<T, X>: Bar<usize, T, X> {}
-
-        struct S<T, X>;
-        impl<T, X> Foo<T, usize> for S<T, X> {}
-        impl<T, X> Bar<usize, T, X> for S<T, X> {}
-        impl<T, X> Baz<T, X> for S<T, X> {}
-
-        fn test() {
-            let obj: &dyn Baz<i8, i16> = &S;
-            let obj: &dyn Bar<_, i8, i16> = &S;
-            let obj: &dyn Foo<i8, _> = &S;
-        }
-        "#,
-        expect![[r"
-            424..539 '{     ... &S; }': ()
-            434..437 'obj': &dyn Baz<i8, i16>
-            459..461 '&S': &S<i8, i16>
-            460..461 'S': S<i8, i16>
-            471..474 'obj': &dyn Bar<usize, i8, i16>
-            499..501 '&S': &S<i8, i16>
-            500..501 'S': S<i8, i16>
-            511..514 'obj': &dyn Foo<i8, usize>
-            534..536 '&S': &S<i8, {unknown}>
-            535..536 'S': S<i8, {unknown}>
-        "]],
+//- minicore: coerce_unsized
+trait Foo<T, U> {}
+trait Bar<U, T, X>: Foo<T, U> {}
+trait Baz<T, X>: Bar<usize, T, X> {}
+
+struct S<T, X>;
+impl<T, X> Foo<T, usize> for S<T, X> {}
+impl<T, X> Bar<usize, T, X> for S<T, X> {}
+impl<T, X> Baz<T, X> for S<T, X> {}
+
+fn test() {
+    let obj: &dyn Baz<i8, i16> = &S;
+    let obj: &dyn Bar<_, i8, i16> = &S;
+    let obj: &dyn Foo<i8, _> = &S;
+}
+"#,
+        expect![[r#"
+            236..351 '{     ... &S; }': ()
+            246..249 'obj': &dyn Baz<i8, i16>
+            271..273 '&S': &S<i8, i16>
+            272..273 'S': S<i8, i16>
+            283..286 'obj': &dyn Bar<usize, i8, i16>
+            311..313 '&S': &S<i8, i16>
+            312..313 'S': S<i8, i16>
+            323..326 'obj': &dyn Foo<i8, usize>
+            346..348 '&S': &S<i8, {unknown}>
+            347..348 'S': S<i8, {unknown}>
+        "#]],
     );
 }
 
 #[test]
-// The rust reference says this should be possible, but rustc doesn't implement
-// it. We used to support it, but Chalk doesn't.
-#[ignore]
 fn coerce_unsize_trait_object_to_trait_object() {
+    // FIXME: The rust reference says this should be possible, but rustc doesn't
+    // implement it. We used to support it, but Chalk doesn't. Here's the
+    // correct expect:
+    //
+    //     424..609 '{     ...bj2; }': ()
+    //     434..437 'obj': &dyn Baz<i8, i16>
+    //     459..461 '&S': &S<i8, i16>
+    //     460..461 'S': S<i8, i16>
+    //     471..474 'obj': &dyn Bar<usize, i8, i16>
+    //     496..499 'obj': &dyn Baz<i8, i16>
+    //     509..512 'obj': &dyn Foo<i8, usize>
+    //     531..534 'obj': &dyn Bar<usize, i8, i16>
+    //     544..548 'obj2': &dyn Baz<i8, i16>
+    //     570..572 '&S': &S<i8, i16>
+    //     571..572 'S': S<i8, i16>
+    //     582..583 '_': &dyn Foo<i8, usize>
+    //     602..606 'obj2': &dyn Baz<i8, i16>
     check_infer_with_mismatches(
         r#"
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
-
-        trait Foo<T, U> {}
-        trait Bar<U, T, X>: Foo<T, U> {}
-        trait Baz<T, X>: Bar<usize, T, X> {}
-
-        struct S<T, X>;
-        impl<T, X> Foo<T, usize> for S<T, X> {}
-        impl<T, X> Bar<usize, T, X> for S<T, X> {}
-        impl<T, X> Baz<T, X> for S<T, X> {}
-
-        fn test() {
-            let obj: &dyn Baz<i8, i16> = &S;
-            let obj: &dyn Bar<_, _, _> = obj;
-            let obj: &dyn Foo<_, _> = obj;
-            let obj2: &dyn Baz<i8, i16> = &S;
-            let _: &dyn Foo<_, _> = obj2;
-        }
-        "#,
-        expect![[r"
-            424..609 '{     ...bj2; }': ()
-            434..437 'obj': &dyn Baz<i8, i16>
-            459..461 '&S': &S<i8, i16>
-            460..461 'S': S<i8, i16>
-            471..474 'obj': &dyn Bar<usize, i8, i16>
-            496..499 'obj': &dyn Baz<i8, i16>
-            509..512 'obj': &dyn Foo<i8, usize>
-            531..534 'obj': &dyn Bar<usize, i8, i16>
-            544..548 'obj2': &dyn Baz<i8, i16>
-            570..572 '&S': &S<i8, i16>
-            571..572 'S': S<i8, i16>
-            582..583 '_': &dyn Foo<i8, usize>
-            602..606 'obj2': &dyn Baz<i8, i16>
-        "]],
+//- minicore: coerce_unsized
+trait Foo<T, U> {}
+trait Bar<U, T, X>: Foo<T, U> {}
+trait Baz<T, X>: Bar<usize, T, X> {}
+
+struct S<T, X>;
+impl<T, X> Foo<T, usize> for S<T, X> {}
+impl<T, X> Bar<usize, T, X> for S<T, X> {}
+impl<T, X> Baz<T, X> for S<T, X> {}
+
+fn test() {
+    let obj: &dyn Baz<i8, i16> = &S;
+    let obj: &dyn Bar<_, _, _> = obj;
+    let obj: &dyn Foo<_, _> = obj;
+    let obj2: &dyn Baz<i8, i16> = &S;
+    let _: &dyn Foo<_, _> = obj2;
+}
+"#,
+        expect![[r#"
+            236..421 '{     ...bj2; }': ()
+            246..249 'obj': &dyn Baz<i8, i16>
+            271..273 '&S': &S<i8, i16>
+            272..273 'S': S<i8, i16>
+            283..286 'obj': &dyn Bar<{unknown}, {unknown}, {unknown}>
+            308..311 'obj': &dyn Baz<i8, i16>
+            321..324 'obj': &dyn Foo<{unknown}, {unknown}>
+            343..346 'obj': &dyn Bar<{unknown}, {unknown}, {unknown}>
+            356..360 'obj2': &dyn Baz<i8, i16>
+            382..384 '&S': &S<i8, i16>
+            383..384 'S': S<i8, i16>
+            394..395 '_': &dyn Foo<{unknown}, {unknown}>
+            414..418 'obj2': &dyn Baz<i8, i16>
+            308..311: expected &dyn Bar<{unknown}, {unknown}, {unknown}>, got &dyn Baz<i8, i16>
+            343..346: expected &dyn Foo<{unknown}, {unknown}>, got &dyn Bar<{unknown}, {unknown}, {unknown}>
+            414..418: expected &dyn Foo<{unknown}, {unknown}>, got &dyn Baz<i8, i16>
+        "#]],
     );
 }
 
@@ -795,40 +745,32 @@ fn coerce_unsize_trait_object_to_trait_object() {
 fn coerce_unsize_super_trait_cycle() {
     check_infer_with_mismatches(
         r#"
-        #[lang = "sized"]
-        pub trait Sized {}
-        #[lang = "unsize"]
-        pub trait Unsize<T> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
-
-        trait A {}
-        trait B: C + A {}
-        trait C: B {}
-        trait D: C
-
-        struct S;
-        impl A for S {}
-        impl B for S {}
-        impl C for S {}
-        impl D for S {}
-
-        fn test() {
-            let obj: &dyn D = &S;
-            let obj: &dyn A = &S;
-        }
-        "#,
-        expect![[r"
-            328..383 '{     ... &S; }': ()
-            338..341 'obj': &dyn D
-            352..354 '&S': &S
-            353..354 'S': S
-            364..367 'obj': &dyn A
-            378..380 '&S': &S
-            379..380 'S': S
-        "]],
+//- minicore: coerce_unsized
+trait A {}
+trait B: C + A {}
+trait C: B {}
+trait D: C
+
+struct S;
+impl A for S {}
+impl B for S {}
+impl C for S {}
+impl D for S {}
+
+fn test() {
+    let obj: &dyn D = &S;
+    let obj: &dyn A = &S;
+}
+"#,
+        expect![[r#"
+            140..195 '{     ... &S; }': ()
+            150..153 'obj': &dyn D
+            164..166 '&S': &S
+            165..166 'S': S
+            176..179 'obj': &dyn A
+            190..192 '&S': &S
+            191..192 'S': S
+        "#]],
     );
 }
 
@@ -837,41 +779,35 @@ fn coerce_unsize_generic() {
     // FIXME: fix the type mismatches here
     check_infer_with_mismatches(
         r#"
-        #[lang = "unsize"]
-        pub trait Unsize<T> {}
-        #[lang = "coerce_unsized"]
-        pub trait CoerceUnsized<T> {}
-
-        impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
+//- minicore: coerce_unsized
+struct Foo<T> { t: T };
+struct Bar<T>(Foo<T>);
 
-        struct Foo<T> { t: T };
-        struct Bar<T>(Foo<T>);
-
-        fn test() {
-            let _: &Foo<[usize]> = &Foo { t: [1, 2, 3] };
-            let _: &Bar<[usize]> = &Bar(Foo { t: [1, 2, 3] });
-        }
-        "#,
+fn test() {
+    let _: &Foo<[usize]> = &Foo { t: [1, 2, 3] };
+    let _: &Bar<[usize]> = &Bar(Foo { t: [1, 2, 3] });
+}
+"#,
         expect![[r#"
-            209..317 '{     ... }); }': ()
-            219..220 '_': &Foo<[usize]>
-            238..259 '&Foo {..., 3] }': &Foo<[usize]>
-            239..259 'Foo { ..., 3] }': Foo<[usize]>
-            248..257 '[1, 2, 3]': [usize; 3]
-            249..250 '1': usize
-            252..253 '2': usize
-            255..256 '3': usize
-            269..270 '_': &Bar<[usize]>
-            288..314 '&Bar(F... 3] })': &Bar<[i32; 3]>
-            289..292 'Bar': Bar<[i32; 3]>(Foo<[i32; 3]>) -> Bar<[i32; 3]>
-            289..314 'Bar(Fo... 3] })': Bar<[i32; 3]>
-            293..313 'Foo { ..., 3] }': Foo<[i32; 3]>
-            302..311 '[1, 2, 3]': [i32; 3]
-            303..304 '1': i32
-            306..307 '2': i32
-            309..310 '3': i32
-            248..257: expected [usize], got [usize; 3]
-            288..314: expected &Bar<[usize]>, got &Bar<[i32; 3]>
+            58..166 '{     ... }); }': ()
+            68..69 '_': &Foo<[usize]>
+            87..108 '&Foo {..., 3] }': &Foo<[usize]>
+            88..108 'Foo { ..., 3] }': Foo<[usize]>
+            97..106 '[1, 2, 3]': [usize; 3]
+            98..99 '1': usize
+            101..102 '2': usize
+            104..105 '3': usize
+            118..119 '_': &Bar<[usize]>
+            137..163 '&Bar(F... 3] })': &Bar<[i32; 3]>
+            138..141 'Bar': Bar<[i32; 3]>(Foo<[i32; 3]>) -> Bar<[i32; 3]>
+            138..163 'Bar(Fo... 3] })': Bar<[i32; 3]>
+            142..162 'Foo { ..., 3] }': Foo<[i32; 3]>
+            151..160 '[1, 2, 3]': [i32; 3]
+            152..153 '1': i32
+            155..156 '2': i32
+            158..159 '3': i32
+            97..106: expected [usize], got [usize; 3]
+            137..163: expected &Bar<[usize]>, got &Bar<[i32; 3]>
         "#]],
     );
 }
@@ -881,15 +817,7 @@ fn coerce_unsize_apit() {
     // FIXME: #8984
     check_infer_with_mismatches(
         r#"
-#[lang = "sized"]
-pub trait Sized {}
-#[lang = "unsize"]
-pub trait Unsize<T> {}
-#[lang = "coerce_unsized"]
-pub trait CoerceUnsized<T> {}
-
-impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
-
+//- minicore: coerce_unsized
 trait Foo {}
 
 fn test(f: impl Foo) {
@@ -897,12 +825,12 @@ fn test(f: impl Foo) {
 }
         "#,
         expect![[r#"
-            210..211 'f': impl Foo
-            223..252 '{     ... &f; }': ()
-            233..234 '_': &dyn Foo
-            247..249 '&f': &impl Foo
-            248..249 'f': impl Foo
-            247..249: expected &dyn Foo, got &impl Foo
+            22..23 'f': impl Foo
+            35..64 '{     ... &f; }': ()
+            45..46 '_': &dyn Foo
+            59..61 '&f': &impl Foo
+            60..61 'f': impl Foo
+            59..61: expected &dyn Foo, got &impl Foo
         "#]],
     );
 }
@@ -998,15 +926,7 @@ fn main() {
 fn coerce_unsize_expected_type() {
     check_no_mismatches(
         r#"
-#[lang = "sized"]
-pub trait Sized {}
-#[lang = "unsize"]
-pub trait Unsize<T> {}
-#[lang = "coerce_unsized"]
-pub trait CoerceUnsized<T> {}
-
-impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
-
+//- minicore: coerce_unsized
 fn main() {
     let foo: &[u32] = &[1, 2];
     let foo: &[u32] = match true {
diff --git a/crates/hir_ty/src/tests/method_resolution.rs b/crates/hir_ty/src/tests/method_resolution.rs
index f26b2c8a7..d9b5ee9cf 100644
--- a/crates/hir_ty/src/tests/method_resolution.rs
+++ b/crates/hir_ty/src/tests/method_resolution.rs
@@ -780,10 +780,7 @@ fn test() { (&S).foo(); }
 fn method_resolution_unsize_array() {
     check_types(
         r#"
-#[lang = "slice"]
-impl<T> [T] {
-    fn len(&self) -> usize { loop {} }
-}
+//- minicore: slice
 fn test() {
     let a = [1, 2, 3];
     a.len();
@@ -1178,11 +1175,7 @@ fn main() {
 fn autoderef_visibility_field() {
     check_infer(
         r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
+//- minicore: deref
 mod a {
     pub struct Foo(pub char);
     pub struct Bar(i32);
@@ -1191,7 +1184,7 @@ mod a {
             Self(0)
         }
     }
-    impl super::Deref for Bar {
+    impl core::ops::Deref for Bar {
         type Target = Foo;
         fn deref(&self) -> &Foo {
             &Foo('z')
@@ -1205,22 +1198,21 @@ mod b {
 }
         "#,
         expect![[r#"
-            67..71 'self': &Self
-            200..231 '{     ...     }': Bar
-            214..218 'Self': Bar(i32) -> Bar
-            214..221 'Self(0)': Bar
-            219..220 '0': i32
-            315..319 'self': &Bar
-            329..362 '{     ...     }': &Foo
-            343..352 '&Foo('z')': &Foo
-            344..347 'Foo': Foo(char) -> Foo
-            344..352 'Foo('z')': Foo
-            348..351 ''z'': char
-            392..439 '{     ...     }': ()
-            406..407 'x': char
-            410..428 'super:...r::new': fn new() -> Bar
-            410..430 'super:...:new()': Bar
-            410..432 'super:...ew().0': char
+            107..138 '{     ...     }': Bar
+            121..125 'Self': Bar(i32) -> Bar
+            121..128 'Self(0)': Bar
+            126..127 '0': i32
+            226..230 'self': &Bar
+            240..273 '{     ...     }': &Foo
+            254..263 '&Foo('z')': &Foo
+            255..258 'Foo': Foo(char) -> Foo
+            255..263 'Foo('z')': Foo
+            259..262 ''z'': char
+            303..350 '{     ...     }': ()
+            317..318 'x': char
+            321..339 'super:...r::new': fn new() -> Bar
+            321..341 'super:...:new()': Bar
+            321..343 'super:...ew().0': char
         "#]],
     )
 }
@@ -1230,11 +1222,7 @@ fn autoderef_visibility_method() {
     cov_mark::check!(autoderef_candidate_not_visible);
     check_infer(
         r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
+//- minicore: deref
 mod a {
     pub struct Foo(pub char);
     impl Foo {
@@ -1251,7 +1239,7 @@ mod a {
             self.0
         }
     }
-    impl super::Deref for Bar {
+    impl core::ops::Deref for Bar {
         type Target = Foo;
         fn deref(&self) -> &Foo {
             &Foo('z')
@@ -1265,30 +1253,29 @@ mod b {
 }
         "#,
         expect![[r#"
-            67..71 'self': &Self
-            168..172 'self': &Foo
-            182..212 '{     ...     }': char
-            196..200 'self': &Foo
-            196..202 'self.0': char
-            288..319 '{     ...     }': Bar
-            302..306 'Self': Bar(i32) -> Bar
-            302..309 'Self(0)': Bar
-            307..308 '0': i32
-            338..342 'self': &Bar
-            351..381 '{     ...     }': i32
-            365..369 'self': &Bar
-            365..371 'self.0': i32
-            465..469 'self': &Bar
-            479..512 '{     ...     }': &Foo
-            493..502 '&Foo('z')': &Foo
-            494..497 'Foo': Foo(char) -> Foo
-            494..502 'Foo('z')': Foo
-            498..501 ''z'': char
-            542..595 '{     ...     }': ()
-            556..557 'x': char
-            560..578 'super:...r::new': fn new() -> Bar
-            560..580 'super:...:new()': Bar
-            560..588 'super:...ango()': char
+            75..79 'self': &Foo
+            89..119 '{     ...     }': char
+            103..107 'self': &Foo
+            103..109 'self.0': char
+            195..226 '{     ...     }': Bar
+            209..213 'Self': Bar(i32) -> Bar
+            209..216 'Self(0)': Bar
+            214..215 '0': i32
+            245..249 'self': &Bar
+            258..288 '{     ...     }': i32
+            272..276 'self': &Bar
+            272..278 'self.0': i32
+            376..380 'self': &Bar
+            390..423 '{     ...     }': &Foo
+            404..413 '&Foo('z')': &Foo
+            405..408 'Foo': Foo(char) -> Foo
+            405..413 'Foo('z')': Foo
+            409..412 ''z'': char
+            453..506 '{     ...     }': ()
+            467..468 'x': char
+            471..489 'super:...r::new': fn new() -> Bar
+            471..491 'super:...:new()': Bar
+            471..499 'super:...ango()': char
         "#]],
     )
 }
diff --git a/crates/hir_ty/src/tests/regression.rs b/crates/hir_ty/src/tests/regression.rs
index 1019e783b..abd9c385a 100644
--- a/crates/hir_ty/src/tests/regression.rs
+++ b/crates/hir_ty/src/tests/regression.rs
@@ -927,35 +927,33 @@ fn issue_6628() {
 fn issue_6852() {
     check_infer(
         r#"
-        #[lang = "deref"]
-        pub trait Deref {
-            type Target;
-        }
+//- minicore: deref
+use core::ops::Deref;
 
-        struct BufWriter {}
+struct BufWriter {}
 
-        struct Mutex<T> {}
-        struct MutexGuard<'a, T> {}
-        impl<T> Mutex<T> {
-            fn lock(&self) -> MutexGuard<'_, T> {}
-        }
-        impl<'a, T: 'a> Deref for MutexGuard<'a, T> {
-            type Target = T;
-        }
-        fn flush(&self) {
-            let w: &Mutex<BufWriter>;
-            *(w.lock());
-        }
-        "#,
+struct Mutex<T> {}
+struct MutexGuard<'a, T> {}
+impl<T> Mutex<T> {
+    fn lock(&self) -> MutexGuard<'_, T> {}
+}
+impl<'a, T: 'a> Deref for MutexGuard<'a, T> {
+    type Target = T;
+}
+fn flush(&self) {
+    let w: &Mutex<BufWriter>;
+    *(w.lock());
+}
+"#,
         expect![[r#"
-            156..160 'self': &Mutex<T>
-            183..185 '{}': ()
-            267..271 'self': &{unknown}
-            273..323 '{     ...()); }': ()
-            283..284 'w': &Mutex<BufWriter>
-            309..320 '*(w.lock())': BufWriter
-            311..312 'w': &Mutex<BufWriter>
-            311..319 'w.lock()': MutexGuard<BufWriter>
+            123..127 'self': &Mutex<T>
+            150..152 '{}': ()
+            234..238 'self': &{unknown}
+            240..290 '{     ...()); }': ()
+            250..251 'w': &Mutex<BufWriter>
+            276..287 '*(w.lock())': BufWriter
+            278..279 'w': &Mutex<BufWriter>
+            278..286 'w.lock()': MutexGuard<BufWriter>
         "#]],
     );
 }
@@ -977,37 +975,33 @@ fn param_overrides_fn() {
 fn lifetime_from_chalk_during_deref() {
     check_types(
         r#"
-        #[lang = "deref"]
-        pub trait Deref {
-            type Target;
-        }
-
-        struct Box<T: ?Sized> {}
-        impl<T> Deref for Box<T> {
-            type Target = T;
+//- minicore: deref
+struct Box<T: ?Sized> {}
+impl<T> core::ops::Deref for Box<T> {
+    type Target = T;
 
-            fn deref(&self) -> &Self::Target {
-                loop {}
-            }
-        }
+    fn deref(&self) -> &Self::Target {
+        loop {}
+    }
+}
 
-        trait Iterator {
-            type Item;
-        }
+trait Iterator {
+    type Item;
+}
 
-        pub struct Iter<'a, T: 'a> {
-            inner: Box<dyn IterTrait<'a, T, Item = &'a T> + 'a>,
-        }
+pub struct Iter<'a, T: 'a> {
+    inner: Box<dyn IterTrait<'a, T, Item = &'a T> + 'a>,
+}
 
-        trait IterTrait<'a, T: 'a>: Iterator<Item = &'a T> {
-            fn clone_box(&self);
-        }
+trait IterTrait<'a, T: 'a>: Iterator<Item = &'a T> {
+    fn clone_box(&self);
+}
 
-        fn clone_iter<T>(s: Iter<T>) {
-            s.inner.clone_box();
-          //^^^^^^^^^^^^^^^^^^^ ()
-        }
-        "#,
+fn clone_iter<T>(s: Iter<T>) {
+    s.inner.clone_box();
+    //^^^^^^^^^^^^^^^^^^^ ()
+}
+"#,
     )
 }
 
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 3418ed21e..68776f3c0 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -113,7 +113,7 @@ fn type_alias_in_struct_lit() {
 fn infer_ranges() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
+//- minicore: range
 fn test() {
     let a = ..;
     let b = 1..;
@@ -125,32 +125,6 @@ fn test() {
     let t = (a, b, c, d, e, f);
     t;
 } //^ (RangeFull, RangeFrom<i32>, RangeTo<u32>, Range<usize>, RangeToInclusive<i32>, RangeInclusive<char>)
-
-//- /core.rs crate:core
-#[prelude_import] use prelude::*;
-mod prelude {}
-
-pub mod ops {
-    pub struct Range<Idx> {
-        pub start: Idx,
-        pub end: Idx,
-    }
-    pub struct RangeFrom<Idx> {
-        pub start: Idx,
-    }
-    struct RangeFull;
-    pub struct RangeInclusive<Idx> {
-        start: Idx,
-        end: Idx,
-        is_empty: u8,
-    }
-    pub struct RangeTo<Idx> {
-        pub end: Idx,
-    }
-    pub struct RangeToInclusive<Idx> {
-        pub end: Idx,
-    }
-}
 "#,
     );
 }
@@ -175,16 +149,17 @@ fn test() {
 fn infer_basics() {
     check_infer(
         r#"
-        fn test(a: u32, b: isize, c: !, d: &str) {
-            a;
-            b;
-            c;
-            d;
-            1usize;
-            1isize;
-            "test";
-            1.0f32;
-        }"#,
+fn test(a: u32, b: isize, c: !, d: &str) {
+    a;
+    b;
+    c;
+    d;
+    1usize;
+    1isize;
+    "test";
+    1.0f32;
+}
+"#,
         expect![[r#"
             8..9 'a': u32
             16..17 'b': isize
@@ -207,15 +182,15 @@ fn infer_basics() {
 fn infer_let() {
     check_infer(
         r#"
-        fn test() {
-            let a = 1isize;
-            let b: usize = 1;
-            let c = b;
-            let d: u32;
-            let e;
-            let f: i32 = e;
-        }
-        "#,
+fn test() {
+    let a = 1isize;
+    let b: usize = 1;
+    let c = b;
+    let d: u32;
+    let e;
+    let f: i32 = e;
+}
+"#,
         expect![[r#"
             10..117 '{     ...= e; }': ()
             20..21 'a': isize
@@ -236,17 +211,17 @@ fn infer_let() {
 fn infer_paths() {
     check_infer(
         r#"
-        fn a() -> u32 { 1 }
+fn a() -> u32 { 1 }
 
-        mod b {
-            fn c() -> u32 { 1 }
-        }
+mod b {
+    fn c() -> u32 { 1 }
+}
 
-        fn test() {
-            a();
-            b::c();
-        }
-        "#,
+fn test() {
+    a();
+    b::c();
+}
+"#,
         expect![[r#"
             14..19 '{ 1 }': u32
             16..17 '1': u32
@@ -265,17 +240,17 @@ fn infer_paths() {
 fn infer_path_type() {
     check_infer(
         r#"
-        struct S;
+struct S;
 
-        impl S {
-            fn foo() -> i32 { 1 }
-        }
+impl S {
+    fn foo() -> i32 { 1 }
+}
 
-        fn test() {
-            S::foo();
-            <S>::foo();
-        }
-        "#,
+fn test() {
+    S::foo();
+    <S>::foo();
+}
+"#,
         expect![[r#"
             40..45 '{ 1 }': i32
             42..43 '1': i32
@@ -292,21 +267,21 @@ fn infer_path_type() {
 fn infer_struct() {
     check_infer(
         r#"
-        struct A {
-            b: B,
-            c: C,
-        }
-        struct B;
-        struct C(usize);
+struct A {
+    b: B,
+    c: C,
+}
+struct B;
+struct C(usize);
 
-        fn test() {
-            let c = C(1);
-            B;
-            let a: A = A { b: B, c: C(1) };
-            a.b;
-            a.c;
-        }
-        "#,
+fn test() {
+    let c = C(1);
+    B;
+    let a: A = A { b: B, c: C(1) };
+    a.b;
+    a.c;
+}
+"#,
         expect![[r#"
             71..153 '{     ...a.c; }': ()
             81..82 'c': C
@@ -332,14 +307,15 @@ fn infer_struct() {
 fn infer_enum() {
     check_infer(
         r#"
-        enum E {
-            V1 { field: u32 },
-            V2
-        }
-        fn test() {
-            E::V1 { field: 1 };
-            E::V2;
-        }"#,
+enum E {
+    V1 { field: u32 },
+    V2
+}
+fn test() {
+    E::V1 { field: 1 };
+    E::V2;
+}
+"#,
         expect![[r#"
             51..89 '{     ...:V2; }': ()
             57..75 'E::V1 ...d: 1 }': E
@@ -353,23 +329,23 @@ fn infer_enum() {
 fn infer_union() {
     check_infer(
         r#"
-        union MyUnion {
-            foo: u32,
-            bar: f32,
-        }
+union MyUnion {
+    foo: u32,
+    bar: f32,
+}
 
-        fn test() {
-            let u = MyUnion { foo: 0 };
-            unsafe { baz(u); }
-            let u = MyUnion { bar: 0.0 };
-            unsafe { baz(u); }
-        }
+fn test() {
+    let u = MyUnion { foo: 0 };
+    unsafe { baz(u); }
+    let u = MyUnion { bar: 0.0 };
+    unsafe { baz(u); }
+}
 
-        unsafe fn baz(u: MyUnion) {
-            let inner = u.foo;
-            let inner = u.bar;
-        }
-        "#,
+unsafe fn baz(u: MyUnion) {
+    let inner = u.foo;
+    let inner = u.bar;
+}
+"#,
         expect![[r#"
             57..172 '{     ...); } }': ()
             67..68 'u': MyUnion
@@ -404,19 +380,19 @@ fn infer_union() {
 fn infer_refs() {
     check_infer(
         r#"
-        fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
-            a;
-            *a;
-            &a;
-            &mut a;
-            b;
-            *b;
-            &b;
-            c;
-            *c;
-            d;
-            *d;
-        }
+fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
+    a;
+    *a;
+    &a;
+    &mut a;
+    b;
+    *b;
+    &b;
+    c;
+    *c;
+    d;
+    *d;
+}
         "#,
         expect![[r#"
             8..9 'a': &u32
@@ -450,11 +426,11 @@ fn infer_refs() {
 fn infer_raw_ref() {
     check_infer(
         r#"
-        fn test(a: i32) {
-            &raw mut a;
-            &raw const a;
-        }
-        "#,
+fn test(a: i32) {
+    &raw mut a;
+    &raw const a;
+}
+"#,
         expect![[r#"
             8..9 'a': i32
             16..53 '{     ...t a; }': ()
@@ -524,26 +500,26 @@ h";
 fn infer_unary_op() {
     check_infer(
         r#"
-        enum SomeType {}
-
-        fn test(x: SomeType) {
-            let b = false;
-            let c = !b;
-            let a = 100;
-            let d: i128 = -a;
-            let e = -100;
-            let f = !!!true;
-            let g = !42;
-            let h = !10u32;
-            let j = !a;
-            -3.14;
-            !3;
-            -x;
-            !x;
-            -"hello";
-            !"hello";
-        }
-        "#,
+enum SomeType {}
+
+fn test(x: SomeType) {
+    let b = false;
+    let c = !b;
+    let a = 100;
+    let d: i128 = -a;
+    let e = -100;
+    let f = !!!true;
+    let g = !42;
+    let h = !10u32;
+    let j = !a;
+    -3.14;
+    !3;
+    -x;
+    !x;
+    -"hello";
+    !"hello";
+}
+"#,
         expect![[r#"
             26..27 'x': SomeType
             39..271 '{     ...lo"; }': ()
@@ -594,19 +570,19 @@ fn infer_unary_op() {
 fn infer_backwards() {
     check_infer(
         r#"
-        fn takes_u32(x: u32) {}
+fn takes_u32(x: u32) {}
 
-        struct S { i32_field: i32 }
+struct S { i32_field: i32 }
 
-        fn test() -> &mut &f64 {
-            let a = unknown_function();
-            takes_u32(a);
-            let b = unknown_function();
-            S { i32_field: b };
-            let c = unknown_function();
-            &mut &c
-        }
-        "#,
+fn test() -> &mut &f64 {
+    let a = unknown_function();
+    takes_u32(a);
+    let b = unknown_function();
+    S { i32_field: b };
+    let c = unknown_function();
+    &mut &c
+}
+"#,
         expect![[r#"
             13..14 'x': u32
             21..23 '{}': ()
@@ -636,23 +612,23 @@ fn infer_backwards() {
 fn infer_self() {
     check_infer(
         r#"
-        struct S;
+struct S;
 
-        impl S {
-            fn test(&self) {
-                self;
-            }
-            fn test2(self: &Self) {
-                self;
-            }
-            fn test3() -> Self {
-                S {}
-            }
-            fn test4() -> Self {
-                Self {}
-            }
-        }
-        "#,
+impl S {
+    fn test(&self) {
+        self;
+    }
+    fn test2(self: &Self) {
+        self;
+    }
+    fn test3() -> Self {
+        S {}
+    }
+    fn test4() -> Self {
+        Self {}
+    }
+}
+"#,
         expect![[r#"
             33..37 'self': &S
             39..60 '{     ...     }': ()
@@ -672,30 +648,30 @@ fn infer_self() {
 fn infer_self_as_path() {
     check_infer(
         r#"
-        struct S1;
-        struct S2(isize);
-        enum E {
-            V1,
-            V2(u32),
-        }
+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);
-            }
-        }
-        "#,
+impl S1 {
+    fn test() {
+        Self;
+    }
+}
+impl S2 {
+    fn test() {
+        Self(1);
+    }
+}
+impl E {
+    fn test() {
+        Self::V1;
+        Self::V2(1);
+    }
+}
+"#,
         expect![[r#"
             86..107 '{     ...     }': ()
             96..100 'Self': S1
@@ -716,26 +692,26 @@ fn infer_self_as_path() {
 fn infer_binary_op() {
     check_infer(
         r#"
-        fn f(x: bool) -> i32 {
-            0i32
-        }
+fn f(x: bool) -> i32 {
+    0i32
+}
 
-        fn test() -> bool {
-            let x = a && b;
-            let y = true || false;
-            let z = x == y;
-            let t = x != y;
-            let minus_forty: isize = -40isize;
-            let h = minus_forty <= CONST_2;
-            let c = f(z || y) + 5;
-            let d = b;
-            let g = minus_forty ^= i;
-            let ten: usize = 10;
-            let ten_is_eleven = ten == some_num;
-
-            ten < 3
-        }
-        "#,
+fn test() -> bool {
+    let x = a && b;
+    let y = true || false;
+    let z = x == y;
+    let t = x != y;
+    let minus_forty: isize = -40isize;
+    let h = minus_forty <= CONST_2;
+    let c = f(z || y) + 5;
+    let d = b;
+    let g = minus_forty ^= i;
+    let ten: usize = 10;
+    let ten_is_eleven = ten == some_num;
+
+    ten < 3
+}
+"#,
         expect![[r#"
             5..6 'x': bool
             21..33 '{     0i32 }': i32
@@ -795,11 +771,11 @@ fn infer_binary_op() {
 fn infer_shift_op() {
     check_infer(
         r#"
-        fn test() {
-            1u32 << 5u8;
-            1u32 >> 5u8;
-        }
-        "#,
+fn test() {
+    1u32 << 5u8;
+    1u32 >> 5u8;
+}
+"#,
         expect![[r#"
             10..47 '{     ...5u8; }': ()
             16..20 '1u32': u32
@@ -816,29 +792,29 @@ fn infer_shift_op() {
 fn infer_field_autoderef() {
     check_infer(
         r#"
-        struct A {
-            b: B,
-        }
-        struct B;
-
-        fn test1(a: A) {
-            let a1 = a;
-            a1.b;
-            let a2 = &a;
-            a2.b;
-            let a3 = &mut a;
-            a3.b;
-            let a4 = &&&&&&&a;
-            a4.b;
-            let a5 = &mut &&mut &&mut a;
-            a5.b;
-        }
+struct A {
+    b: B,
+}
+struct B;
 
-        fn test2(a1: *const A, a2: *mut A) {
-            a1.b;
-            a2.b;
-        }
-        "#,
+fn test1(a: A) {
+    let a1 = a;
+    a1.b;
+    let a2 = &a;
+    a2.b;
+    let a3 = &mut a;
+    a3.b;
+    let a4 = &&&&&&&a;
+    a4.b;
+    let a5 = &mut &&mut &&mut a;
+    a5.b;
+}
+
+fn test2(a1: *const A, a2: *mut A) {
+    a1.b;
+    a2.b;
+}
+"#,
         expect![[r#"
             43..44 'a': A
             49..212 '{     ...5.b; }': ()
@@ -891,58 +867,53 @@ fn infer_field_autoderef() {
 fn infer_argument_autoderef() {
     check_infer(
         r#"
-        #[lang = "deref"]
-        pub trait Deref {
-            type Target;
-            fn deref(&self) -> &Self::Target;
-        }
-
-        struct A<T>(T);
+//- minicore: deref
+use core::ops::Deref;
+struct A<T>(T);
 
-        impl<T> A<T> {
-            fn foo(&self) -> &T {
-                &self.0
-            }
-        }
+impl<T> A<T> {
+    fn foo(&self) -> &T {
+        &self.0
+    }
+}
 
-        struct B<T>(T);
+struct B<T>(T);
 
-        impl<T> Deref for B<T> {
-            type Target = T;
-            fn deref(&self) -> &Self::Target {
-                &self.0
-            }
-        }
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
 
-        fn test() {
-            let t = A::foo(&&B(B(A(42))));
-        }
-        "#,
+fn test() {
+    let t = A::foo(&&B(B(A(42))));
+}
+"#,
         expect![[r#"
-            67..71 'self': &Self
-            138..142 'self': &A<T>
-            150..173 '{     ...     }': &T
-            160..167 '&self.0': &T
-            161..165 'self': &A<T>
-            161..167 'self.0': T
-            254..258 'self': &B<T>
-            277..300 '{     ...     }': &T
-            287..294 '&self.0': &T
-            288..292 'self': &B<T>
-            288..294 'self.0': T
-            314..352 '{     ...))); }': ()
-            324..325 't': &i32
-            328..334 'A::foo': fn foo<i32>(&A<i32>) -> &i32
-            328..349 'A::foo...42))))': &i32
-            335..348 '&&B(B(A(42)))': &&B<B<A<i32>>>
-            336..348 '&B(B(A(42)))': &B<B<A<i32>>>
-            337..338 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
-            337..348 'B(B(A(42)))': B<B<A<i32>>>
-            339..340 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
-            339..347 'B(A(42))': B<A<i32>>
-            341..342 'A': A<i32>(i32) -> A<i32>
-            341..346 'A(42)': A<i32>
-            343..345 '42': i32
+            66..70 'self': &A<T>
+            78..101 '{     ...     }': &T
+            88..95 '&self.0': &T
+            89..93 'self': &A<T>
+            89..95 'self.0': T
+            182..186 'self': &B<T>
+            205..228 '{     ...     }': &T
+            215..222 '&self.0': &T
+            216..220 'self': &B<T>
+            216..222 'self.0': T
+            242..280 '{     ...))); }': ()
+            252..253 't': &i32
+            256..262 'A::foo': fn foo<i32>(&A<i32>) -> &i32
+            256..277 'A::foo...42))))': &i32
+            263..276 '&&B(B(A(42)))': &&B<B<A<i32>>>
+            264..276 '&B(B(A(42)))': &B<B<A<i32>>>
+            265..266 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
+            265..276 'B(B(A(42)))': B<B<A<i32>>>
+            267..268 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
+            267..275 'B(A(42))': B<A<i32>>
+            269..270 'A': A<i32>(i32) -> A<i32>
+            269..274 'A(42)': A<i32>
+            271..273 '42': i32
         "#]],
     );
 }
@@ -951,62 +922,57 @@ fn infer_argument_autoderef() {
 fn infer_method_argument_autoderef() {
     check_infer(
         r#"
-        #[lang = "deref"]
-        pub trait Deref {
-            type Target;
-            fn deref(&self) -> &Self::Target;
-        }
+//- minicore: deref
+use core::ops::Deref;
+struct A<T>(*mut T);
 
-        struct A<T>(*mut T);
-
-        impl<T> A<T> {
-            fn foo(&self, x: &A<T>) -> &T {
-                &*x.0
-            }
-        }
+impl<T> A<T> {
+    fn foo(&self, x: &A<T>) -> &T {
+        &*x.0
+    }
+}
 
-        struct B<T>(T);
+struct B<T>(T);
 
-        impl<T> Deref for B<T> {
-            type Target = T;
-            fn deref(&self) -> &Self::Target {
-                &self.0
-            }
-        }
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
 
-        fn test(a: A<i32>) {
-            let t = A(0 as *mut _).foo(&&B(B(a)));
-        }
-        "#,
+fn test(a: A<i32>) {
+    let t = A(0 as *mut _).foo(&&B(B(a)));
+}
+"#,
         expect![[r#"
-            67..71 'self': &Self
-            143..147 'self': &A<T>
-            149..150 'x': &A<T>
-            165..186 '{     ...     }': &T
-            175..180 '&*x.0': &T
-            176..180 '*x.0': T
-            177..178 'x': &A<T>
-            177..180 'x.0': *mut T
-            267..271 'self': &B<T>
-            290..313 '{     ...     }': &T
-            300..307 '&self.0': &T
-            301..305 'self': &B<T>
-            301..307 'self.0': T
-            325..326 'a': A<i32>
-            336..382 '{     ...))); }': ()
-            346..347 't': &i32
-            350..351 'A': A<i32>(*mut i32) -> A<i32>
-            350..364 'A(0 as *mut _)': A<i32>
-            350..379 'A(0 as...B(a)))': &i32
-            352..353 '0': i32
-            352..363 '0 as *mut _': *mut i32
-            369..378 '&&B(B(a))': &&B<B<A<i32>>>
-            370..378 '&B(B(a))': &B<B<A<i32>>>
-            371..372 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
-            371..378 'B(B(a))': B<B<A<i32>>>
-            373..374 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
-            373..377 'B(a)': B<A<i32>>
-            375..376 'a': A<i32>
+            71..75 'self': &A<T>
+            77..78 'x': &A<T>
+            93..114 '{     ...     }': &T
+            103..108 '&*x.0': &T
+            104..108 '*x.0': T
+            105..106 'x': &A<T>
+            105..108 'x.0': *mut T
+            195..199 'self': &B<T>
+            218..241 '{     ...     }': &T
+            228..235 '&self.0': &T
+            229..233 'self': &B<T>
+            229..235 'self.0': T
+            253..254 'a': A<i32>
+            264..310 '{     ...))); }': ()
+            274..275 't': &i32
+            278..279 'A': A<i32>(*mut i32) -> A<i32>
+            278..292 'A(0 as *mut _)': A<i32>
+            278..307 'A(0 as...B(a)))': &i32
+            280..281 '0': i32
+            280..291 '0 as *mut _': *mut i32
+            297..306 '&&B(B(a))': &&B<B<A<i32>>>
+            298..306 '&B(B(a))': &B<B<A<i32>>>
+            299..300 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
+            299..306 'B(B(a))': B<B<A<i32>>>
+            301..302 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
+            301..305 'B(a)': B<A<i32>>
+            303..304 'a': A<i32>
         "#]],
     );
 }
@@ -1015,15 +981,15 @@ fn infer_method_argument_autoderef() {
 fn infer_in_elseif() {
     check_infer(
         r#"
-        struct Foo { field: i32 }
-        fn main(foo: Foo) {
-            if true {
+struct Foo { field: i32 }
+fn main(foo: Foo) {
+    if true {
 
-            } else if false {
-                foo.field
-            }
-        }
-        "#,
+    } else if false {
+        foo.field
+    }
+}
+"#,
         expect![[r#"
             34..37 'foo': Foo
             44..108 '{     ...   } }': ()
@@ -1043,28 +1009,29 @@ fn infer_in_elseif() {
 fn infer_if_match_with_return() {
     check_infer(
         r#"
-        fn foo() {
-            let _x1 = if true {
-                1
-            } else {
-                return;
-            };
-            let _x2 = if true {
-                2
-            } else {
-                return
-            };
-            let _x3 = match true {
-                true => 3,
-                _ => {
-                    return;
-                }
-            };
-            let _x4 = match true {
-                true => 4,
-                _ => return
-            };
-        }"#,
+fn foo() {
+    let _x1 = if true {
+        1
+    } else {
+        return;
+    };
+    let _x2 = if true {
+        2
+    } else {
+        return
+    };
+    let _x3 = match true {
+        true => 3,
+        _ => {
+            return;
+        }
+    };
+    let _x4 = match true {
+        true => 4,
+        _ => return
+    };
+}
+"#,
         expect![[r#"
             9..322 '{     ...  }; }': ()
             19..22 '_x1': i32
@@ -2639,11 +2606,8 @@ fn f() {
 fn infer_boxed_self_receiver() {
     check_infer(
         r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
+//- minicore: deref
+use core::ops::Deref;
 
 struct Box<T>(T);
 
@@ -2675,40 +2639,39 @@ fn main() {
 }
         "#,
         expect![[r#"
-            67..71 'self': &Self
-            175..179 'self': &Box<T>
-            259..263 'self': &Box<Foo<T>>
-            289..291 '{}': ()
-            313..317 'self': &Box<Foo<T>>
-            346..348 '{}': ()
-            368..372 'self': Box<Foo<T>>
-            393..395 '{}': ()
-            409..630 '{     ...r(); }': ()
-            419..424 'boxed': Box<Foo<i32>>
-            427..430 'Box': Box<Foo<i32>>(Foo<i32>) -> Box<Foo<i32>>
-            427..442 'Box(Foo(0_i32))': Box<Foo<i32>>
-            431..434 'Foo': Foo<i32>(i32) -> Foo<i32>
-            431..441 'Foo(0_i32)': Foo<i32>
-            435..440 '0_i32': i32
-            453..457 'bad1': &i32
-            460..465 'boxed': Box<Foo<i32>>
-            460..477 'boxed....nner()': &i32
-            487..492 'good1': &i32
-            495..509 'Foo::get_inner': fn get_inner<i32>(&Box<Foo<i32>>) -> &i32
-            495..517 'Foo::g...boxed)': &i32
-            510..516 '&boxed': &Box<Foo<i32>>
-            511..516 'boxed': Box<Foo<i32>>
-            528..532 'bad2': &Foo<i32>
-            535..540 'boxed': Box<Foo<i32>>
-            535..551 'boxed....self()': &Foo<i32>
-            561..566 'good2': &Foo<i32>
-            569..582 'Foo::get_self': fn get_self<i32>(&Box<Foo<i32>>) -> &Foo<i32>
-            569..590 'Foo::g...boxed)': &Foo<i32>
-            583..589 '&boxed': &Box<Foo<i32>>
-            584..589 'boxed': Box<Foo<i32>>
-            601..606 'inner': Foo<i32>
-            609..614 'boxed': Box<Foo<i32>>
-            609..627 'boxed....nner()': Foo<i32>
+            104..108 'self': &Box<T>
+            188..192 'self': &Box<Foo<T>>
+            218..220 '{}': ()
+            242..246 'self': &Box<Foo<T>>
+            275..277 '{}': ()
+            297..301 'self': Box<Foo<T>>
+            322..324 '{}': ()
+            338..559 '{     ...r(); }': ()
+            348..353 'boxed': Box<Foo<i32>>
+            356..359 'Box': Box<Foo<i32>>(Foo<i32>) -> Box<Foo<i32>>
+            356..371 'Box(Foo(0_i32))': Box<Foo<i32>>
+            360..363 'Foo': Foo<i32>(i32) -> Foo<i32>
+            360..370 'Foo(0_i32)': Foo<i32>
+            364..369 '0_i32': i32
+            382..386 'bad1': &i32
+            389..394 'boxed': Box<Foo<i32>>
+            389..406 'boxed....nner()': &i32
+            416..421 'good1': &i32
+            424..438 'Foo::get_inner': fn get_inner<i32>(&Box<Foo<i32>>) -> &i32
+            424..446 'Foo::g...boxed)': &i32
+            439..445 '&boxed': &Box<Foo<i32>>
+            440..445 'boxed': Box<Foo<i32>>
+            457..461 'bad2': &Foo<i32>
+            464..469 'boxed': Box<Foo<i32>>
+            464..480 'boxed....self()': &Foo<i32>
+            490..495 'good2': &Foo<i32>
+            498..511 'Foo::get_self': fn get_self<i32>(&Box<Foo<i32>>) -> &Foo<i32>
+            498..519 'Foo::g...boxed)': &Foo<i32>
+            512..518 '&boxed': &Box<Foo<i32>>
+            513..518 'boxed': Box<Foo<i32>>
+            530..535 'inner': Foo<i32>
+            538..543 'boxed': Box<Foo<i32>>
+            538..556 'boxed....nner()': Foo<i32>
         "#]],
     );
 }
diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index 6bcede4c4..65fed02d2 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -6,10 +6,10 @@ use super::{check_infer, check_infer_with_mismatches, check_types};
 fn infer_await() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
+//- minicore: future
 struct IntFuture;
 
-impl Future for IntFuture {
+impl core::future::Future for IntFuture {
     type Output = u64;
 }
 
@@ -18,16 +18,6 @@ fn test() {
     let v = r.await;
     v;
 } //^ u64
-
-//- /core.rs crate:core
-pub mod prelude {
-    pub mod rust_2018 {
-        #[lang = "future_trait"]
-        pub trait Future {
-            type Output;
-        }
-    }
-}
 "#,
     );
 }
@@ -36,25 +26,14 @@ pub mod prelude {
 fn infer_async() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
-async fn foo() -> u64 {
-            128
-}
+//- minicore: future
+async fn foo() -> u64 { 128 }
 
 fn test() {
     let r = foo();
     let v = r.await;
     v;
 } //^ u64
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    #[lang = "future_trait"]
-    trait Future {
-        type Output;
-    }
-}
 "#,
     );
 }
@@ -63,24 +42,13 @@ mod future {
 fn infer_desugar_async() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
-async fn foo() -> u64 {
-            128
-}
+//- minicore: future
+async fn foo() -> u64 { 128 }
 
 fn test() {
     let r = foo();
     r;
 } //^ impl Future<Output = u64>
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    trait Future {
-        type Output;
-    }
-}
-
 "#,
     );
 }
@@ -89,7 +57,7 @@ mod future {
 fn infer_async_block() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
+//- minicore: future, option
 async fn test() {
     let a = async { 42 };
     a;
@@ -101,7 +69,7 @@ async fn test() {
     b;
 //  ^ ()
     let c = async {
-        let y = Option::None;
+        let y = None;
         y
     //  ^ Option<u64>
     };
@@ -109,18 +77,6 @@ async fn test() {
     c;
 //  ^ impl Future<Output = Option<u64>>
 }
-
-enum Option<T> { None, Some(T) }
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    #[lang = "future_trait"]
-    trait Future {
-        type Output;
-    }
-}
-
 "#,
     );
 }
@@ -704,14 +660,9 @@ mod ops {
 fn deref_trait() {
     check_types(
         r#"
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
+//- minicore: deref
 struct Arc<T>;
-impl<T> Deref for Arc<T> {
+impl<T> core::ops::Deref for Arc<T> {
     type Target = T;
 }
 
@@ -731,16 +682,10 @@ fn test(s: Arc<S>) {
 fn deref_trait_with_inference_var() {
     check_types(
         r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
+//- minicore: deref
 struct Arc<T>;
 fn new_arc<T>() -> Arc<T> {}
-impl<T> Deref for Arc<T> {
+impl<T> core::ops::Deref for Arc<T> {
     type Target = T;
 }
 
@@ -761,15 +706,10 @@ fn test() {
 fn deref_trait_infinite_recursion() {
     check_types(
         r#"
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
+//- minicore: deref
 struct S;
 
-impl Deref for S {
+impl core::ops::Deref for S {
     type Target = S;
 }
 
@@ -784,14 +724,9 @@ fn test(s: S) {
 fn deref_trait_with_question_mark_size() {
     check_types(
         r#"
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
+//- minicore: deref
 struct Arc<T>;
-impl<T> Deref for Arc<T> {
+impl<T: ?Sized> core::ops::Deref for Arc<T> {
     type Target = T;
 }
 
@@ -1475,7 +1410,6 @@ fn test(
 }
 
 #[test]
-#[ignore]
 fn error_bound_chalk() {
     check_types(
         r#"
@@ -2626,12 +2560,9 @@ fn test<T: Trait>() {
 fn dyn_trait_through_chalk() {
     check_types(
         r#"
+//- minicore: deref
 struct Box<T> {}
-#[lang = "deref"]
-trait Deref {
-    type Target;
-}
-impl<T> Deref for Box<T> {
+impl<T> core::ops::Deref for Box<T> {
     type Target = T;
 }
 trait Trait {
@@ -3696,16 +3627,7 @@ impl foo::Foo for u32 {
 fn infer_async_ret_type() {
     check_types(
         r#"
-//- /main.rs crate:main deps:core
-
-enum Result<T, E> {
-    Ok(T),
-    Err(E),
-}
-
-use Result::*;
-
-
+//- minicore: future, result
 struct Fooey;
 
 impl Fooey {
@@ -3728,15 +3650,6 @@ async fn get_accounts() -> Result<u32, ()> {
     //                      ^ u32
     Ok(ret)
 }
-
-//- /core.rs crate:core
-#[prelude_import] use future::*;
-mod future {
-    #[lang = "future_trait"]
-    trait Future {
-        type Output;
-    }
-}
 "#,
     );
 }
diff --git a/crates/ide/Cargo.toml b/crates/ide/Cargo.toml
index f12928225..0e8447394 100644
--- a/crates/ide/Cargo.toml
+++ b/crates/ide/Cargo.toml
@@ -29,6 +29,7 @@ ide_db = { path = "../ide_db", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 ide_assists = { path = "../ide_assists", version = "0.0.0" }
+ide_diagnostics = { path = "../ide_diagnostics", version = "0.0.0" }
 ide_ssr = { path = "../ide_ssr", version = "0.0.0" }
 ide_completion = { path = "../ide_completion", version = "0.0.0" }
 
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
deleted file mode 100644
index 815a633e5..000000000
--- a/crates/ide/src/diagnostics.rs
+++ /dev/null
@@ -1,498 +0,0 @@
-//! Collects diagnostics & fixits  for a single file.
-//!
-//! The tricky bit here is that diagnostics are produced by hir in terms of
-//! macro-expanded files, but we need to present them to the users in terms of
-//! original files. So we need to map the ranges.
-
-mod break_outside_of_loop;
-mod inactive_code;
-mod incorrect_case;
-mod macro_error;
-mod mismatched_arg_count;
-mod missing_fields;
-mod missing_match_arms;
-mod missing_ok_or_some_in_tail_expr;
-mod missing_unsafe;
-mod no_such_field;
-mod remove_this_semicolon;
-mod replace_filter_map_next_with_find_map;
-mod unimplemented_builtin_macro;
-mod unlinked_file;
-mod unresolved_extern_crate;
-mod unresolved_import;
-mod unresolved_macro_call;
-mod unresolved_module;
-mod unresolved_proc_macro;
-
-mod field_shorthand;
-
-use hir::{diagnostics::AnyDiagnostic, Semantics};
-use ide_assists::AssistResolveStrategy;
-use ide_db::{base_db::SourceDatabase, RootDatabase};
-use itertools::Itertools;
-use rustc_hash::FxHashSet;
-use syntax::{
-    ast::{self, AstNode},
-    SyntaxNode, TextRange,
-};
-use text_edit::TextEdit;
-use unlinked_file::UnlinkedFile;
-
-use crate::{Assist, AssistId, AssistKind, FileId, Label, SourceChange};
-
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub struct DiagnosticCode(pub &'static str);
-
-impl DiagnosticCode {
-    pub fn as_str(&self) -> &str {
-        self.0
-    }
-}
-
-#[derive(Debug)]
-pub struct Diagnostic {
-    pub code: DiagnosticCode,
-    pub message: String,
-    pub range: TextRange,
-    pub severity: Severity,
-    pub unused: bool,
-    pub experimental: bool,
-    pub fixes: Option<Vec<Assist>>,
-}
-
-impl Diagnostic {
-    fn new(code: &'static str, message: impl Into<String>, range: TextRange) -> Diagnostic {
-        let message = message.into();
-        Diagnostic {
-            code: DiagnosticCode(code),
-            message,
-            range,
-            severity: Severity::Error,
-            unused: false,
-            experimental: false,
-            fixes: None,
-        }
-    }
-
-    fn experimental(mut self) -> Diagnostic {
-        self.experimental = true;
-        self
-    }
-
-    fn severity(mut self, severity: Severity) -> Diagnostic {
-        self.severity = severity;
-        self
-    }
-
-    fn with_fixes(mut self, fixes: Option<Vec<Assist>>) -> Diagnostic {
-        self.fixes = fixes;
-        self
-    }
-
-    fn with_unused(mut self, unused: bool) -> Diagnostic {
-        self.unused = unused;
-        self
-    }
-}
-
-#[derive(Debug, Copy, Clone)]
-pub enum Severity {
-    Error,
-    WeakWarning,
-}
-
-#[derive(Default, Debug, Clone)]
-pub struct DiagnosticsConfig {
-    pub disable_experimental: bool,
-    pub disabled: FxHashSet<String>,
-}
-
-struct DiagnosticsContext<'a> {
-    config: &'a DiagnosticsConfig,
-    sema: Semantics<'a, RootDatabase>,
-    resolve: &'a AssistResolveStrategy,
-}
-
-pub(crate) fn diagnostics(
-    db: &RootDatabase,
-    config: &DiagnosticsConfig,
-    resolve: &AssistResolveStrategy,
-    file_id: FileId,
-) -> Vec<Diagnostic> {
-    let _p = profile::span("diagnostics");
-    let sema = Semantics::new(db);
-    let parse = db.parse(file_id);
-    let mut res = Vec::new();
-
-    // [#34344] Only take first 128 errors to prevent slowing down editor/ide, the number 128 is chosen arbitrarily.
-    res.extend(
-        parse.errors().iter().take(128).map(|err| {
-            Diagnostic::new("syntax-error", format!("Syntax Error: {}", err), err.range())
-        }),
-    );
-
-    for node in parse.tree().syntax().descendants() {
-        check_unnecessary_braces_in_use_statement(&mut res, file_id, &node);
-        field_shorthand::check(&mut res, file_id, &node);
-    }
-
-    let mut diags = Vec::new();
-    let module = sema.to_module_def(file_id);
-    if let Some(m) = module {
-        m.diagnostics(db, &mut diags)
-    }
-
-    let ctx = DiagnosticsContext { config, sema, resolve };
-    if module.is_none() {
-        let d = UnlinkedFile { file: file_id };
-        let d = unlinked_file::unlinked_file(&ctx, &d);
-        res.push(d)
-    }
-
-    for diag in diags {
-        #[rustfmt::skip]
-        let d = match diag {
-            AnyDiagnostic::BreakOutsideOfLoop(d) => break_outside_of_loop::break_outside_of_loop(&ctx, &d),
-            AnyDiagnostic::IncorrectCase(d) => incorrect_case::incorrect_case(&ctx, &d),
-            AnyDiagnostic::MacroError(d) => macro_error::macro_error(&ctx, &d),
-            AnyDiagnostic::MismatchedArgCount(d) => mismatched_arg_count::mismatched_arg_count(&ctx, &d),
-            AnyDiagnostic::MissingFields(d) => missing_fields::missing_fields(&ctx, &d),
-            AnyDiagnostic::MissingMatchArms(d) => missing_match_arms::missing_match_arms(&ctx, &d),
-            AnyDiagnostic::MissingOkOrSomeInTailExpr(d) => missing_ok_or_some_in_tail_expr::missing_ok_or_some_in_tail_expr(&ctx, &d),
-            AnyDiagnostic::MissingUnsafe(d) => missing_unsafe::missing_unsafe(&ctx, &d),
-            AnyDiagnostic::NoSuchField(d) => no_such_field::no_such_field(&ctx, &d),
-            AnyDiagnostic::RemoveThisSemicolon(d) => remove_this_semicolon::remove_this_semicolon(&ctx, &d),
-            AnyDiagnostic::ReplaceFilterMapNextWithFindMap(d) => replace_filter_map_next_with_find_map::replace_filter_map_next_with_find_map(&ctx, &d),
-            AnyDiagnostic::UnimplementedBuiltinMacro(d) => unimplemented_builtin_macro::unimplemented_builtin_macro(&ctx, &d),
-            AnyDiagnostic::UnresolvedExternCrate(d) => unresolved_extern_crate::unresolved_extern_crate(&ctx, &d),
-            AnyDiagnostic::UnresolvedImport(d) => unresolved_import::unresolved_import(&ctx, &d),
-            AnyDiagnostic::UnresolvedMacroCall(d) => unresolved_macro_call::unresolved_macro_call(&ctx, &d),
-            AnyDiagnostic::UnresolvedModule(d) => unresolved_module::unresolved_module(&ctx, &d),
-            AnyDiagnostic::UnresolvedProcMacro(d) => unresolved_proc_macro::unresolved_proc_macro(&ctx, &d),
-
-            AnyDiagnostic::InactiveCode(d) => match inactive_code::inactive_code(&ctx, &d) {
-                Some(it) => it,
-                None => continue,
-            }
-        };
-        res.push(d)
-    }
-
-    res.retain(|d| {
-        !ctx.config.disabled.contains(d.code.as_str())
-            && !(ctx.config.disable_experimental && d.experimental)
-    });
-
-    res
-}
-
-fn check_unnecessary_braces_in_use_statement(
-    acc: &mut Vec<Diagnostic>,
-    file_id: FileId,
-    node: &SyntaxNode,
-) -> Option<()> {
-    let use_tree_list = ast::UseTreeList::cast(node.clone())?;
-    if let Some((single_use_tree,)) = use_tree_list.use_trees().collect_tuple() {
-        // If there is a comment inside the bracketed `use`,
-        // assume it is a commented out module path and don't show diagnostic.
-        if use_tree_list.has_inner_comment() {
-            return Some(());
-        }
-
-        let use_range = use_tree_list.syntax().text_range();
-        let edit =
-            text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(&single_use_tree)
-                .unwrap_or_else(|| {
-                    let to_replace = single_use_tree.syntax().text().to_string();
-                    let mut edit_builder = TextEdit::builder();
-                    edit_builder.delete(use_range);
-                    edit_builder.insert(use_range.start(), to_replace);
-                    edit_builder.finish()
-                });
-
-        acc.push(
-            Diagnostic::new(
-                "unnecessary-braces",
-                "Unnecessary braces in use statement".to_string(),
-                use_range,
-            )
-            .severity(Severity::WeakWarning)
-            .with_fixes(Some(vec![fix(
-                "remove_braces",
-                "Remove unnecessary braces",
-                SourceChange::from_text_edit(file_id, edit),
-                use_range,
-            )])),
-        );
-    }
-
-    Some(())
-}
-
-fn text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(
-    single_use_tree: &ast::UseTree,
-) -> Option<TextEdit> {
-    let use_tree_list_node = single_use_tree.syntax().parent()?;
-    if single_use_tree.path()?.segment()?.self_token().is_some() {
-        let start = use_tree_list_node.prev_sibling_or_token()?.text_range().start();
-        let end = use_tree_list_node.text_range().end();
-        return Some(TextEdit::delete(TextRange::new(start, end)));
-    }
-    None
-}
-
-fn fix(id: &'static str, label: &str, source_change: SourceChange, target: TextRange) -> Assist {
-    let mut res = unresolved_fix(id, label, target);
-    res.source_change = Some(source_change);
-    res
-}
-
-fn unresolved_fix(id: &'static str, label: &str, target: TextRange) -> Assist {
-    assert!(!id.contains(' '));
-    Assist {
-        id: AssistId(id, AssistKind::QuickFix),
-        label: Label::new(label),
-        group: None,
-        target,
-        source_change: None,
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use expect_test::Expect;
-    use ide_assists::AssistResolveStrategy;
-    use stdx::trim_indent;
-    use test_utils::{assert_eq_text, extract_annotations};
-
-    use crate::{fixture, DiagnosticsConfig};
-
-    /// Takes a multi-file input fixture with annotated cursor positions,
-    /// and checks that:
-    ///  * a diagnostic is produced
-    ///  * the first diagnostic fix trigger range touches the input cursor position
-    ///  * that the contents of the file containing the cursor match `after` after the diagnostic fix is applied
-    #[track_caller]
-    pub(crate) fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
-        check_nth_fix(0, ra_fixture_before, ra_fixture_after);
-    }
-    /// Takes a multi-file input fixture with annotated cursor positions,
-    /// and checks that:
-    ///  * a diagnostic is produced
-    ///  * every diagnostic fixes trigger range touches the input cursor position
-    ///  * that the contents of the file containing the cursor match `after` after each diagnostic fix is applied
-    pub(crate) fn check_fixes(ra_fixture_before: &str, ra_fixtures_after: Vec<&str>) {
-        for (i, ra_fixture_after) in ra_fixtures_after.iter().enumerate() {
-            check_nth_fix(i, ra_fixture_before, ra_fixture_after)
-        }
-    }
-
-    #[track_caller]
-    fn check_nth_fix(nth: usize, ra_fixture_before: &str, ra_fixture_after: &str) {
-        let after = trim_indent(ra_fixture_after);
-
-        let (analysis, file_position) = fixture::position(ra_fixture_before);
-        let diagnostic = analysis
-            .diagnostics(
-                &DiagnosticsConfig::default(),
-                AssistResolveStrategy::All,
-                file_position.file_id,
-            )
-            .unwrap()
-            .pop()
-            .expect("no diagnostics");
-        let fix = &diagnostic.fixes.expect("diagnostic misses fixes")[nth];
-        let actual = {
-            let source_change = fix.source_change.as_ref().unwrap();
-            let file_id = *source_change.source_file_edits.keys().next().unwrap();
-            let mut actual = analysis.file_text(file_id).unwrap().to_string();
-
-            for edit in source_change.source_file_edits.values() {
-                edit.apply(&mut actual);
-            }
-            actual
-        };
-
-        assert_eq_text!(&after, &actual);
-        assert!(
-            fix.target.contains_inclusive(file_position.offset),
-            "diagnostic fix range {:?} does not touch cursor position {:?}",
-            fix.target,
-            file_position.offset
-        );
-    }
-
-    /// Checks that there's a diagnostic *without* fix at `$0`.
-    pub(crate) fn check_no_fix(ra_fixture: &str) {
-        let (analysis, file_position) = fixture::position(ra_fixture);
-        let diagnostic = analysis
-            .diagnostics(
-                &DiagnosticsConfig::default(),
-                AssistResolveStrategy::All,
-                file_position.file_id,
-            )
-            .unwrap()
-            .pop()
-            .unwrap();
-        assert!(diagnostic.fixes.is_none(), "got a fix when none was expected: {:?}", diagnostic);
-    }
-
-    pub(crate) fn check_expect(ra_fixture: &str, expect: Expect) {
-        let (analysis, file_id) = fixture::file(ra_fixture);
-        let diagnostics = analysis
-            .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
-            .unwrap();
-        expect.assert_debug_eq(&diagnostics)
-    }
-
-    #[track_caller]
-    pub(crate) fn check_diagnostics(ra_fixture: &str) {
-        let mut config = DiagnosticsConfig::default();
-        config.disabled.insert("inactive-code".to_string());
-        check_diagnostics_with_config(config, ra_fixture)
-    }
-
-    #[track_caller]
-    pub(crate) fn check_diagnostics_with_config(config: DiagnosticsConfig, ra_fixture: &str) {
-        let (analysis, files) = fixture::files(ra_fixture);
-        for file_id in files {
-            let diagnostics =
-                analysis.diagnostics(&config, AssistResolveStrategy::All, file_id).unwrap();
-
-            let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
-            let mut actual =
-                diagnostics.into_iter().map(|d| (d.range, d.message)).collect::<Vec<_>>();
-            actual.sort_by_key(|(range, _)| range.start());
-            assert_eq!(expected, actual);
-        }
-    }
-
-    #[test]
-    fn test_check_unnecessary_braces_in_use_statement() {
-        check_diagnostics(
-            r#"
-use a;
-use a::{c, d::e};
-
-mod a {
-    mod c {}
-    mod d {
-        mod e {}
-    }
-}
-"#,
-        );
-        check_diagnostics(
-            r#"
-use a;
-use a::{
-    c,
-    // d::e
-};
-
-mod a {
-    mod c {}
-    mod d {
-        mod e {}
-    }
-}
-"#,
-        );
-        check_fix(
-            r"
-            mod b {}
-            use {$0b};
-            ",
-            r"
-            mod b {}
-            use b;
-            ",
-        );
-        check_fix(
-            r"
-            mod b {}
-            use {b$0};
-            ",
-            r"
-            mod b {}
-            use b;
-            ",
-        );
-        check_fix(
-            r"
-            mod a { mod c {} }
-            use a::{c$0};
-            ",
-            r"
-            mod a { mod c {} }
-            use a::c;
-            ",
-        );
-        check_fix(
-            r"
-            mod a {}
-            use a::{self$0};
-            ",
-            r"
-            mod a {}
-            use a;
-            ",
-        );
-        check_fix(
-            r"
-            mod a { mod c {} mod d { mod e {} } }
-            use a::{c, d::{e$0}};
-            ",
-            r"
-            mod a { mod c {} mod d { mod e {} } }
-            use a::{c, d::e};
-            ",
-        );
-    }
-
-    #[test]
-    fn test_disabled_diagnostics() {
-        let mut config = DiagnosticsConfig::default();
-        config.disabled.insert("unresolved-module".into());
-
-        let (analysis, file_id) = fixture::file(r#"mod foo;"#);
-
-        let diagnostics =
-            analysis.diagnostics(&config, AssistResolveStrategy::All, file_id).unwrap();
-        assert!(diagnostics.is_empty());
-
-        let diagnostics = analysis
-            .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
-            .unwrap();
-        assert!(!diagnostics.is_empty());
-    }
-
-    #[test]
-    fn import_extern_crate_clash_with_inner_item() {
-        // This is more of a resolver test, but doesn't really work with the hir_def testsuite.
-
-        check_diagnostics(
-            r#"
-//- /lib.rs crate:lib deps:jwt
-mod permissions;
-
-use permissions::jwt;
-
-fn f() {
-    fn inner() {}
-    jwt::Claims {}; // should resolve to the local one with 0 fields, and not get a diagnostic
-}
-
-//- /permissions.rs
-pub mod jwt  {
-    pub struct Claims {}
-}
-
-//- /jwt/lib.rs crate:jwt
-pub struct Claims {
-    field: u8,
-}
-        "#,
-        );
-    }
-}
diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
index b75ec411c..455b32456 100644
--- a/crates/ide/src/display/navigation_target.rs
+++ b/crates/ide/src/display/navigation_target.rs
@@ -442,10 +442,10 @@ impl TryToNav for hir::TypeParam {
     fn try_to_nav(&self, db: &RootDatabase) -> Option<NavigationTarget> {
         let src = self.source(db)?;
         let full_range = match &src.value {
-            Either::Left(it) => it
+            Either::Left(type_param) => type_param.syntax().text_range(),
+            Either::Right(trait_) => trait_
                 .name()
-                .map_or_else(|| it.syntax().text_range(), |name| name.syntax().text_range()),
-            Either::Right(it) => it.syntax().text_range(),
+                .map_or_else(|| trait_.syntax().text_range(), |name| name.syntax().text_range()),
         };
         let focus_range = match &src.value {
             Either::Left(it) => it.name(),
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index 57ae9455b..7ac0118fe 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -241,6 +241,10 @@ fn get_doc_link(db: &RootDatabase, definition: Definition) -> Option<String> {
         Definition::ModuleDef(ModuleDef::Module(module)) => module.krate(),
         _ => definition.module(db)?.krate(),
     };
+    // FIXME: using import map doesn't make sense here. What we want here is
+    // canonical path. What import map returns is the shortest path suitable for
+    // import. See this test:
+    cov_mark::hit!(test_reexport_order);
     let import_map = db.import_map(krate.into());
 
     let mut base = krate.display_name(db)?.to_string();
@@ -642,13 +646,15 @@ pub mod foo {
         )
     }
 
-    // FIXME: ImportMap will return re-export paths instead of public module
-    // paths. The correct path to documentation will never be a re-export.
-    // This problem stops us from resolving stdlib items included in the prelude
-    // such as `Option::Some` correctly.
-    #[ignore = "ImportMap may return re-exports"]
     #[test]
     fn test_reexport_order() {
+        cov_mark::check!(test_reexport_order);
+        // FIXME: This should return
+        //
+        //    https://docs.rs/test/*/test/wrapper/modulestruct.Item.html
+        //
+        // That is, we should point inside the module, rather than at the
+        // re-export.
         check(
             r#"
 pub mod wrapper {
@@ -663,7 +669,7 @@ fn foo() {
     let bar: wrapper::It$0em;
 }
         "#,
-            expect![[r#"https://docs.rs/test/*/test/wrapper/module/struct.Item.html"#]],
+            expect![[r#"https://docs.rs/test/*/test/wrapper/struct.Item.html"#]],
         )
     }
 }
diff --git a/crates/ide/src/fixture.rs b/crates/ide/src/fixture.rs
index 38e2e866b..cf679edd3 100644
--- a/crates/ide/src/fixture.rs
+++ b/crates/ide/src/fixture.rs
@@ -12,14 +12,6 @@ pub(crate) fn file(ra_fixture: &str) -> (Analysis, FileId) {
     (host.analysis(), change_fixture.files[0])
 }
 
-/// Creates analysis for many files.
-pub(crate) fn files(ra_fixture: &str) -> (Analysis, Vec<FileId>) {
-    let mut host = AnalysisHost::default();
-    let change_fixture = ChangeFixture::parse(ra_fixture);
-    host.db.apply_change(change_fixture.change);
-    (host.analysis(), change_fixture.files)
-}
-
 /// Creates analysis from a multi-file fixture, returns positions marked with $0.
 pub(crate) fn position(ra_fixture: &str) -> (Analysis, FilePosition) {
     let mut host = AnalysisHost::default();
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index 8dd643a0f..d8e0dc4d5 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -1130,15 +1130,15 @@ fn foo<'foobar>(_: &'foobar ()) {
     }
 
     #[test]
-    #[ignore] // requires the HIR to somehow track these hrtb lifetimes
     fn goto_lifetime_hrtb() {
-        check(
+        // FIXME: requires the HIR to somehow track these hrtb lifetimes
+        check_unresolved(
             r#"trait Foo<T> {}
 fn foo<T>() where for<'a> T: Foo<&'a$0 (u8, u16)>, {}
                     //^^
 "#,
         );
-        check(
+        check_unresolved(
             r#"trait Foo<T> {}
 fn foo<T>() where for<'a$0> T: Foo<&'a (u8, u16)>, {}
                     //^^
@@ -1147,9 +1147,9 @@ fn foo<T>() where for<'a$0> T: Foo<&'a (u8, u16)>, {}
     }
 
     #[test]
-    #[ignore] // requires ForTypes to be implemented
     fn goto_lifetime_hrtb_for_type() {
-        check(
+        // FIXME: requires ForTypes to be implemented
+        check_unresolved(
             r#"trait Foo<T> {}
 fn foo<T>() where T: for<'a> Foo<&'a$0 (u8, u16)>, {}
                        //^^
diff --git a/crates/ide/src/goto_type_definition.rs b/crates/ide/src/goto_type_definition.rs
index 004d9cb68..ca3c02bf6 100644
--- a/crates/ide/src/goto_type_definition.rs
+++ b/crates/ide/src/goto_type_definition.rs
@@ -25,7 +25,7 @@ pub(crate) fn goto_type_definition(
     let token: SyntaxToken = pick_best(file.syntax().token_at_offset(position.offset))?;
     let token: SyntaxToken = sema.descend_into_macros(token);
 
-    let (ty, node) = sema.token_ancestors_with_macros(token).find_map(|node| {
+    let (ty, node) = sema.token_ancestors_with_macros(token.clone()).find_map(|node| {
         let ty = match_ast! {
             match node {
                 ast::Expr(it) => sema.type_of_expr(&it)?,
@@ -33,13 +33,23 @@ pub(crate) fn goto_type_definition(
                 ast::SelfParam(it) => sema.type_of_self(&it)?,
                 ast::Type(it) => sema.resolve_type(&it)?,
                 ast::RecordField(it) => sema.to_def(&it).map(|d| d.ty(db.upcast()))?,
+                ast::RecordField(it) => sema.to_def(&it).map(|d| d.ty(db.upcast()))?,
+                // can't match on RecordExprField directly as `ast::Expr` will match an iteration too early otherwise
+                ast::NameRef(it) => {
+                    if let Some(record_field) = ast::RecordExprField::for_name_ref(&it) {
+                        let (_, _, ty) = sema.resolve_record_field(&record_field)?;
+                        ty
+                    } else {
+                        let record_field = ast::RecordPatField::for_field_name_ref(&it)?;
+                        sema.resolve_record_pat_field(&record_field)?.ty(db)
+                    }
+                },
                 _ => return None,
             }
         };
 
         Some((ty, node))
     })?;
-
     let adt_def = ty.autoderef(db).filter_map(|ty| ty.as_adt()).last()?;
 
     let nav = adt_def.try_to_nav(db)?;
@@ -88,6 +98,54 @@ fn foo() {
     }
 
     #[test]
+    fn goto_type_definition_record_expr_field() {
+        check(
+            r#"
+struct Bar;
+    // ^^^
+struct Foo { foo: Bar }
+fn foo() {
+    Foo { foo$0 }
+}
+"#,
+        );
+        check(
+            r#"
+struct Bar;
+    // ^^^
+struct Foo { foo: Bar }
+fn foo() {
+    Foo { foo$0: Bar }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_type_definition_record_pat_field() {
+        check(
+            r#"
+struct Bar;
+    // ^^^
+struct Foo { foo: Bar }
+fn foo() {
+    let Foo { foo$0 };
+}
+"#,
+        );
+        check(
+            r#"
+struct Bar;
+    // ^^^
+struct Foo { foo: Bar }
+fn foo() {
+    let Foo { foo$0: bar };
+}
+"#,
+        );
+    }
+
+    #[test]
     fn goto_type_definition_works_simple_ref() {
         check(
             r#"
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index c08516805..14cf94d60 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1821,9 +1821,10 @@ pub struct B$0ar
         );
     }
 
-    #[ignore = "path based links currently only support documentation on ModuleDef items"]
     #[test]
     fn test_hover_path_link_field() {
+        // FIXME: Should be
+        //  [Foo](https://docs.rs/test/*/test/struct.Foo.html)
         check(
             r#"
 pub struct Foo;
@@ -1845,7 +1846,7 @@ pub struct Bar {
 
                 ---
 
-                [Foo](https://docs.rs/test/*/test/struct.Foo.html)
+                [Foo](struct.Foo.html)
             "#]],
         );
     }
@@ -2999,29 +3000,24 @@ fn foo(ar$0g: &impl Foo + Bar<S>) {}
     fn test_hover_async_block_impl_trait_has_goto_type_action() {
         check_actions(
             r#"
+//- minicore: future
 struct S;
 fn foo() {
     let fo$0o = async { S };
 }
-
-#[prelude_import] use future::*;
-mod future {
-    #[lang = "future_trait"]
-    pub trait Future { type Output; }
-}
 "#,
             expect![[r#"
                 [
                     GoToType(
                         [
                             HoverGotoTypeData {
-                                mod_path: "test::future::Future",
+                                mod_path: "core::future::Future",
                                 nav: NavigationTarget {
                                     file_id: FileId(
-                                        0,
+                                        1,
                                     ),
-                                    full_range: 101..163,
-                                    focus_range: 140..146,
+                                    full_range: 244..426,
+                                    focus_range: 283..289,
                                     name: "Future",
                                     kind: Trait,
                                     description: "pub trait Future",
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 0511efae3..4bd073cc3 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -24,7 +24,6 @@ mod display;
 
 mod annotations;
 mod call_hierarchy;
-mod diagnostics;
 mod expand_macro;
 mod extend_selection;
 mod file_structure;
@@ -40,6 +39,7 @@ mod matching_brace;
 mod move_item;
 mod parent_module;
 mod references;
+mod rename;
 mod fn_references;
 mod runnables;
 mod ssr;
@@ -71,7 +71,6 @@ use crate::display::ToNav;
 pub use crate::{
     annotations::{Annotation, AnnotationConfig, AnnotationKind},
     call_hierarchy::CallItem,
-    diagnostics::{Diagnostic, DiagnosticsConfig, Severity},
     display::navigation_target::NavigationTarget,
     expand_macro::ExpandedMacro,
     file_structure::{StructureNode, StructureNodeKind},
@@ -81,7 +80,8 @@ pub use crate::{
     markup::Markup,
     move_item::Direction,
     prime_caches::PrimeCachesProgress,
-    references::{rename::RenameError, ReferenceSearchResult},
+    references::ReferenceSearchResult,
+    rename::RenameError,
     runnables::{Runnable, RunnableKind, TestId},
     syntax_highlighting::{
         tags::{Highlight, HlMod, HlMods, HlOperator, HlPunct, HlTag},
@@ -109,6 +109,7 @@ pub use ide_db::{
     symbol_index::Query,
     RootDatabase, SymbolKind,
 };
+pub use ide_diagnostics::{Diagnostic, DiagnosticsConfig, Severity};
 pub use ide_ssr::SsrError;
 pub use syntax::{TextRange, TextSize};
 pub use text_edit::{Indel, TextEdit};
@@ -536,7 +537,7 @@ impl Analysis {
     ) -> Cancellable<Vec<Assist>> {
         self.with_db(|db| {
             let ssr_assists = ssr::ssr_assists(db, &resolve, frange);
-            let mut acc = Assist::get(db, config, resolve, frange);
+            let mut acc = ide_assists::assists(db, config, resolve, frange);
             acc.extend(ssr_assists.into_iter());
             acc
         })
@@ -549,7 +550,7 @@ impl Analysis {
         resolve: AssistResolveStrategy,
         file_id: FileId,
     ) -> Cancellable<Vec<Diagnostic>> {
-        self.with_db(|db| diagnostics::diagnostics(db, config, &resolve, file_id))
+        self.with_db(|db| ide_diagnostics::diagnost