20 files changed, 381 insertions, 139 deletions

diff --git a/crates/hir_def/src/find_path.rs b/crates/hir_def/src/find_path.rs
index 858e88038..ee52794aa 100644
--- a/crates/hir_def/src/find_path.rs
+++ b/crates/hir_def/src/find_path.rs
@@ -5,10 +5,10 @@ use std::iter;
 use hir_expand::name::{known, AsName, Name};
 use rustc_hash::FxHashSet;
 
-use crate::nameres::DefMap;
 use crate::{
     db::DefDatabase,
     item_scope::ItemInNs,
+    nameres::DefMap,
     path::{ModPath, PathKind},
     visibility::Visibility,
     ModuleDefId, ModuleId,
@@ -134,7 +134,16 @@ fn find_path_inner(
     for (name, def_id) in root_def_map.extern_prelude() {
         if item == ItemInNs::Types(*def_id) {
             let name = scope_name.unwrap_or_else(|| name.clone());
-            return Some(ModPath::from_segments(PathKind::Plain, vec![name]));
+
+            let name_already_occupied_in_type_ns = def_map
+                .with_ancestor_maps(db, from.local_id, &mut |def_map, local_id| {
+                    def_map[local_id].scope.get(&name).take_types().filter(|&id| id != *def_id)
+                })
+                .is_some();
+            return Some(ModPath::from_segments(
+                if name_already_occupied_in_type_ns { PathKind::Abs } else { PathKind::Plain },
+                vec![name],
+            ));
         }
     }
 
diff --git a/crates/hir_ty/src/consts.rs b/crates/hir_ty/src/consts.rs
new file mode 100644
index 000000000..0044b1cff
--- /dev/null
+++ b/crates/hir_ty/src/consts.rs
@@ -0,0 +1,21 @@
+//! Handling of concrete const values
+
+/// A concrete constant value
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum ConstScalar {
+    // for now, we only support the trivial case of constant evaluating the length of an array
+    // Note that this is u64 because the target usize may be bigger than our usize
+    Usize(u64),
+
+    /// Case of an unknown value that rustc might know but we don't
+    Unknown,
+}
+
+impl std::fmt::Display for ConstScalar {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        match self {
+            ConstScalar::Usize(us) => write!(fmt, "{}", us),
+            ConstScalar::Unknown => write!(fmt, "_"),
+        }
+    }
+}
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index 1f6edf7a2..8a4296697 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -308,7 +308,7 @@ impl HirDisplay for Const {
                 let param_data = &generics.params.consts[id.local_id];
                 write!(f, "{}", param_data.name)
             }
-            ConstValue::Concrete(_) => write!(f, "_"),
+            ConstValue::Concrete(c) => write!(f, "{}", c.interned),
         }
     }
 }
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 9476e6297..2178ffd07 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -3,7 +3,7 @@
 use std::iter::{repeat, repeat_with};
 use std::{mem, sync::Arc};
 
-use chalk_ir::{cast::Cast, fold::Shift, Mutability, TyVariableKind};
+use chalk_ir::{cast::Cast, fold::Shift, ConstData, Mutability, TyVariableKind};
 use hir_def::{
     expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
     path::{GenericArg, GenericArgs},
@@ -15,7 +15,9 @@ use stdx::always;
 use syntax::ast::RangeOp;
 
 use crate::{
-    autoderef, dummy_usize_const,
+    autoderef,
+    consts::ConstScalar,
+    dummy_usize_const,
     lower::lower_to_chalk_mutability,
     mapping::from_chalk,
     method_resolution, op,
@@ -23,7 +25,7 @@ use crate::{
     static_lifetime, to_chalk_trait_id,
     traits::FnTrait,
     utils::{generics, Generics},
-    AdtId, Binders, CallableDefId, FnPointer, FnSig, FnSubst, InEnvironment, Interner,
+    AdtId, Binders, CallableDefId, ConstValue, FnPointer, FnSig, FnSubst, InEnvironment, Interner,
     ProjectionTyExt, Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyExt, TyKind,
 };
 
@@ -717,11 +719,12 @@ impl<'a> InferenceContext<'a> {
                     _ => self.table.new_type_var(),
                 };
 
-                match array {
+                let len = match array {
                     Array::ElementList(items) => {
                         for expr in items.iter() {
                             self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone()));
                         }
+                        Some(items.len())
                     }
                     Array::Repeat { initializer, repeat } => {
                         self.infer_expr_coerce(
@@ -734,10 +737,20 @@ impl<'a> InferenceContext<'a> {
                                 TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner),
                             ),
                         );
+                        // FIXME: support length for Repeat array expressions
+                        None
                     }
-                }
+                };
 
-                TyKind::Array(elem_ty, dummy_usize_const()).intern(&Interner)
+                let cd = ConstData {
+                    ty: TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner),
+                    value: ConstValue::Concrete(chalk_ir::ConcreteConst {
+                        interned: len
+                            .map(|len| ConstScalar::Usize(len as u64))
+                            .unwrap_or(ConstScalar::Unknown),
+                    }),
+                };
+                TyKind::Array(elem_ty, cd.intern(&Interner)).intern(&Interner)
             }
             Expr::Literal(lit) => match lit {
                 Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner),
@@ -747,6 +760,7 @@ impl<'a> InferenceContext<'a> {
                 }
                 Literal::ByteString(..) => {
                     let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(&Interner);
+
                     let array_type =
                         TyKind::Array(byte_type, dummy_usize_const()).intern(&Interner);
                     TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(&Interner)
diff --git a/crates/hir_ty/src/interner.rs b/crates/hir_ty/src/interner.rs
index a1656115d..4cbc9cd4f 100644
--- a/crates/hir_ty/src/interner.rs
+++ b/crates/hir_ty/src/interner.rs
@@ -1,7 +1,7 @@
 //! Implementation of the Chalk `Interner` trait, which allows customizing the
 //! representation of the various objects Chalk deals with (types, goals etc.).
 
-use crate::{chalk_db, tls, GenericArg};
+use crate::{chalk_db, consts::ConstScalar, tls, GenericArg};
 use base_db::salsa::InternId;
 use chalk_ir::{Goal, GoalData};
 use hir_def::{
@@ -31,6 +31,7 @@ impl_internable!(
     InternedWrapper<chalk_ir::TyData<Interner>>,
     InternedWrapper<chalk_ir::LifetimeData<Interner>>,
     InternedWrapper<chalk_ir::ConstData<Interner>>,
+    InternedWrapper<ConstScalar>,
     InternedWrapper<Vec<chalk_ir::CanonicalVarKind<Interner>>>,
     InternedWrapper<Vec<chalk_ir::ProgramClause<Interner>>>,
     InternedWrapper<Vec<chalk_ir::QuantifiedWhereClause<Interner>>>,
@@ -41,7 +42,7 @@ impl chalk_ir::interner::Interner for Interner {
     type InternedType = Interned<InternedWrapper<chalk_ir::TyData<Interner>>>;
     type InternedLifetime = Interned<InternedWrapper<chalk_ir::LifetimeData<Self>>>;
     type InternedConst = Interned<InternedWrapper<chalk_ir::ConstData<Self>>>;
-    type InternedConcreteConst = ();
+    type InternedConcreteConst = ConstScalar;
     type InternedGenericArg = chalk_ir::GenericArgData<Self>;
     type InternedGoal = Arc<GoalData<Self>>;
     type InternedGoals = Vec<Goal<Self>>;
@@ -245,10 +246,15 @@ impl chalk_ir::interner::Interner for Interner {
     fn const_eq(
         &self,
         _ty: &Self::InternedType,
-        _c1: &Self::InternedConcreteConst,
-        _c2: &Self::InternedConcreteConst,
+        c1: &Self::InternedConcreteConst,
+        c2: &Self::InternedConcreteConst,
     ) -> bool {
-        true
+        match (c1, c2) {
+            (&ConstScalar::Usize(a), &ConstScalar::Usize(b)) => a == b,
+            // we were previously assuming this to be true, I'm not whether true or false on
+            // unknown values is safer.
+            (_, _) => true,
+        }
     }
 
     fn intern_generic_arg(
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 0505fa4ae..d23eff513 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -12,6 +12,7 @@ mod chalk_db;
 mod chalk_ext;
 mod infer;
 mod interner;
+mod consts;
 mod lower;
 mod mapping;
 mod op;
@@ -39,7 +40,7 @@ use chalk_ir::{
 };
 use hir_def::{expr::ExprId, type_ref::Rawness, TypeParamId};
 
-use crate::{db::HirDatabase, display::HirDisplay, utils::generics};
+use crate::{consts::ConstScalar, db::HirDatabase, display::HirDisplay, utils::generics};
 
 pub use autoderef::autoderef;
 pub use builder::TyBuilder;
@@ -250,7 +251,9 @@ pub fn dummy_usize_const() -> Const {
     let usize_ty = chalk_ir::TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner);
     chalk_ir::ConstData {
         ty: usize_ty,
-        value: chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst { interned: () }),
+        value: chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst {
+            interned: ConstScalar::Unknown,
+        }),
     }
     .intern(&Interner)
 }
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index c99dd8d0a..9751b45e4 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -174,6 +174,8 @@ impl<'a> TyLoweringContext<'a> {
             }
             TypeRef::Array(inner) => {
                 let inner_ty = self.lower_ty(inner);
+                // FIXME: we don't have length info here because we don't store an expression for
+                // the length
                 TyKind::Array(inner_ty, dummy_usize_const()).intern(&Interner)
             }
             TypeRef::Slice(inner) => {
diff --git a/crates/hir_ty/src/tests/coercion.rs b/crates/hir_ty/src/tests/coercion.rs
index 63d9d4e0b..aad3d610e 100644
--- a/crates/hir_ty/src/tests/coercion.rs
+++ b/crates/hir_ty/src/tests/coercion.rs
@@ -55,7 +55,7 @@ fn coerce_places() {
         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 {}
         "#,
-        expect![[r"
+        expect![[r#"
             30..31 '_': &[T]
             44..55 '{ loop {} }': T
             46..53 'loop {}': !
@@ -72,8 +72,8 @@ fn coerce_places() {
             165..170 'gen()': *mut [U; _]
             185..419 '{     ...rr); }': ()
             195..198 'arr': &[u8; _]
-            211..215 '&[1]': &[u8; _]
-            212..215 '[1]': [u8; _]
+            211..215 '&[1]': &[u8; 1]
+            212..215 '[1]': [u8; 1]
             213..214 '1': u8
             226..227 'a': &[u8]
             236..239 'arr': &[u8; _]
@@ -90,7 +90,7 @@ fn coerce_places() {
             302..314 'S { a: arr }': S<&[u8]>
             309..312 'arr': &[u8; _]
             325..326 'e': [&[u8]; _]
-            340..345 '[arr]': [&[u8]; _]
+            340..345 '[arr]': [&[u8]; 1]
             341..344 'arr': &[u8; _]
             355..356 'f': [&[u8]; _]
             370..378 '[arr; 2]': [&[u8]; _]
@@ -100,7 +100,7 @@ fn coerce_places() {
             406..416 '(arr, arr)': (&[u8], &[u8])
             407..410 'arr': &[u8; _]
             412..415 'arr': &[u8; _]
-        "]],
+        "#]],
     );
 }
 
@@ -113,17 +113,17 @@ fn infer_let_stmt_coerce() {
             let x: *const [isize] = &[1];
         }
         ",
-        expect![[r"
+        expect![[r#"
             10..75 '{     ...[1]; }': ()
             20..21 'x': &[isize]
-            34..38 '&[1]': &[isize; _]
-            35..38 '[1]': [isize; _]
+            34..38 '&[1]': &[isize; 1]
+            35..38 '[1]': [isize; 1]
             36..37 '1': isize
             48..49 'x': *const [isize]
-            68..72 '&[1]': &[isize; _]
-            69..72 '[1]': [isize; _]
+            68..72 '&[1]': &[isize; 1]
+            69..72 '[1]': [isize; 1]
             70..71 '1': isize
-        "]],
+        "#]],
     );
 }
 
@@ -208,7 +208,7 @@ fn infer_if_coerce() {
         #[lang = "unsize"]
         pub trait Unsize<T: ?Sized> {}
         "#,
-        expect![[r"
+        expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
             29..36 'loop {}': !
@@ -220,14 +220,14 @@ fn infer_if_coerce() {
             71..96 '{     ...     }': &[i32]
             81..84 'foo': fn foo<i32>(&[i32]) -> &[i32]
             81..90 'foo(&[1])': &[i32]
-            85..89 '&[1]': &[i32; _]
-            86..89 '[1]': [i32; _]
+            85..89 '&[1]': &[i32; 1]
+            86..89 '[1]': [i32; 1]
             87..88 '1': i32
-            102..122 '{     ...     }': &[i32; _]
-            112..116 '&[1]': &[i32; _]
-            113..116 '[1]': [i32; _]
+            102..122 '{     ...     }': &[i32; 1]
+            112..116 '&[1]': &[i32; 1]
+            113..116 '[1]': [i32; 1]
             114..115 '1': i32
-        "]],
+        "#]],
     );
 }
 
@@ -254,7 +254,7 @@ fn infer_if_else_coerce() {
         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 {}
         "#,
-        expect![[r"
+        expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
             29..36 'loop {}': !
@@ -263,17 +263,17 @@ fn infer_if_else_coerce() {
             59..60 'x': &[i32]
             63..122 'if tru...     }': &[i32]
             66..70 'true': bool
-            71..91 '{     ...     }': &[i32; _]
-            81..85 '&[1]': &[i32; _]
-            82..85 '[1]': [i32; _]
+            71..91 '{     ...     }': &[i32; 1]
+            81..85 '&[1]': &[i32; 1]
+            82..85 '[1]': [i32; 1]
             83..84 '1': i32
             97..122 '{     ...     }': &[i32]
             107..110 'foo': fn foo<i32>(&[i32]) -> &[i32]
             107..116 'foo(&[1])': &[i32]
-            111..115 '&[1]': &[i32; _]
-            112..115 '[1]': [i32; _]
+            111..115 '&[1]': &[i32; 1]
+            112..115 '[1]': [i32; 1]
             113..114 '1': i32
-        "]],
+        "#]],
     )
 }
 
@@ -295,7 +295,7 @@ fn infer_match_first_coerce() {
         #[lang = "unsize"]
         pub trait Unsize<T: ?Sized> {}
         "#,
-        expect![[r"
+        expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
             29..36 'loop {}': !
@@ -309,19 +309,19 @@ fn infer_match_first_coerce() {
             87..88 '2': i32
             92..95 'foo': fn foo<i32>(&[i32]) -> &[i32]
             92..101 'foo(&[2])': &[i32]
-            96..100 '&[2]': &[i32; _]
-            97..100 '[2]': [i32; _]
+            96..100 '&[2]': &[i32; 1]
+            97..100 '[2]': [i32; 1]
             98..99 '2': i32
             111..112 '1': i32
             111..112 '1': i32
-            116..120 '&[1]': &[i32; _]
-            117..120 '[1]': [i32; _]
+            116..120 '&[1]': &[i32; 1]
+            117..120 '[1]': [i32; 1]
             118..119 '1': i32
             130..131 '_': i32
-            135..139 '&[3]': &[i32; _]
-            136..139 '[3]': [i32; _]
+            135..139 '&[3]': &[i32; 1]
+            136..139 '[3]': [i32; 1]
             137..138 '3': i32
-    "]],
+        "#]],
     );
 }
 
@@ -348,7 +348,7 @@ fn infer_match_second_coerce() {
         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 {}
         "#,
-        expect![[r"
+        expect![[r#"
             10..11 'x': &[T]
             27..38 '{ loop {} }': &[T]
             29..36 'loop {}': !
@@ -360,21 +360,21 @@ fn infer_match_second_coerce() {
             75..76 'i': i32
             87..88 '1': i32
             87..88 '1': i32
-            92..96 '&[1]': &[i32; _]
-            93..96 '[1]': [i32; _]
+            92..96 '&[1]': &[i32; 1]
+            93..96 '[1]': [i32; 1]
             94..95 '1': i32
             106..107 '2': i32
             106..107 '2': i32
             111..114 'foo': fn foo<i32>(&[i32]) -> &[i32]
             111..120 'foo(&[2])': &[i32]
-            115..119 '&[2]': &[i32; _]
-            116..119 '[2]': [i32; _]
+            115..119 '&[2]': &[i32; 1]
+            116..119 '[2]': [i32; 1]
             117..118 '2': i32
             130..131 '_': i32
-            135..139 '&[3]': &[i32; _]
-            136..139 '[3]': [i32; _]
+            135..139 '&[3]': &[i32; 1]
+            136..139 '[3]': [i32; 1]
             137..138 '3': i32
-    "]],
+        "#]],
     );
 }
 
@@ -685,15 +685,15 @@ fn coerce_unsize_array() {
             let f: &[usize] = &[1, 2, 3];
         }
         "#,
-        expect![[r"
+        expect![[r#"
             161..198 '{     ... 3]; }': ()
             171..172 'f': &[usize]
-            185..195 '&[1, 2, 3]': &[usize; _]
-            186..195 '[1, 2, 3]': [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
-        "]],
+        "#]],
     );
 }
 
diff --git a/crates/hir_ty/src/tests/patterns.rs b/crates/hir_ty/src/tests/patterns.rs
index f514b3efe..33305f208 100644
--- a/crates/hir_ty/src/tests/patterns.rs
+++ b/crates/hir_ty/src/tests/patterns.rs
@@ -243,8 +243,8 @@ fn infer_pattern_match_slice() {
         expect![[r#"
             10..209 '{     ...   } }': ()
             20..25 'slice': &[f64]
-            36..42 '&[0.0]': &[f64; _]
-            37..42 '[0.0]': [f64; _]
+            36..42 '&[0.0]': &[f64; 1]
+            37..42 '[0.0]': [f64; 1]
             38..41 '0.0': f64
             48..207 'match ...     }': ()
             54..59 'slice': &[f64]
@@ -346,7 +346,7 @@ fn infer_pattern_match_arr() {
         expect![[r#"
             10..179 '{     ...   } }': ()
             20..23 'arr': [f64; _]
-            36..46 '[0.0, 1.0]': [f64; _]
+            36..46 '[0.0, 1.0]': [f64; 2]
             37..40 '0.0': f64
             42..45 '1.0': f64
             52..177 'match ...     }': ()
diff --git a/crates/hir_ty/src/tests/regression.rs b/crates/hir_ty/src/tests/regression.rs
index e23bd4da9..431861712 100644
--- a/crates/hir_ty/src/tests/regression.rs
+++ b/crates/hir_ty/src/tests/regression.rs
@@ -99,7 +99,7 @@ fn recursive_vars() {
             10..47 '{     ...&y]; }': ()
             20..21 'y': &{unknown}
             24..31 'unknown': &{unknown}
-            37..44 '[y, &y]': [&&{unknown}; _]
+            37..44 '[y, &y]': [&&{unknown}; 2]
             38..39 'y': &{unknown}
             41..43 '&y': &&{unknown}
             42..43 'y': &{unknown}
@@ -123,7 +123,7 @@ fn recursive_vars_2() {
             24..31 'unknown': &&{unknown}
             41..42 'y': &&{unknown}
             45..52 'unknown': &&{unknown}
-            58..76 '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown}); _]
+            58..76 '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown}); 2]
             59..65 '(x, y)': (&&&{unknown}, &&&{unknown})
             60..61 'x': &&{unknown}
             63..64 'y': &&{unknown}
@@ -175,8 +175,8 @@ fn infer_std_crash_2() {
         "#,
         expect![[r#"
             22..52 '{     ...n']; }': ()
-            28..49 '&[0, b...b'\n']': &[u8; _]
-            29..49 '[0, b'...b'\n']': [u8; _]
+            28..49 '&[0, b...b'\n']': &[u8; 4]
+            29..49 '[0, b'...b'\n']': [u8; 4]
             30..31 '0': u8
             33..38 'b'\n'': u8
             40..41 '1': u8
@@ -336,8 +336,8 @@ fn infer_array_macro_call() {
         expect![[r#"
             !0..4 '0u32': u32
             44..69 '{     ...()]; }': ()
-            54..55 'a': [u32; _]
-            58..66 '[bar!()]': [u32; _]
+            54..55 'a': [u32; 1]
+            58..66 '[bar!()]': [u32; 1]
         "#]],
     );
 }
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 0eefd70f2..8b09f2e4a 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -11,7 +11,7 @@ fn test() {
     let x = box 1;
     let t = (x, box x, box &1, box [1]);
     t;
-} //^ (Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32; _]>)
+} //^ (Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32; 1]>)
 
 //- /std.rs crate:std
 #[prelude_import] use prelude::*;
@@ -36,7 +36,7 @@ fn test() {
     let x = box 1;
     let t = (x, box x, box &1, box [1]);
     t;
-} //^ (Box<i32, {unknown}>, Box<Box<i32, {unknown}>, {unknown}>, Box<&i32, {unknown}>, Box<[i32; _], {unknown}>)
+} //^ (Box<i32, {unknown}>, Box<Box<i32, {unknown}>, {unknown}>, Box<&i32, {unknown}>, Box<[i32; 1], {unknown}>)
 
 //- /std.rs crate:std
 #[prelude_import] use prelude::*;
@@ -1266,55 +1266,55 @@ fn infer_array() {
             8..9 'x': &str
             17..18 'y': isize
             27..292 '{     ... []; }': ()
-            37..38 'a': [&str; _]
-            41..44 '[x]': [&str; _]
+            37..38 'a': [&str; 1]
+            41..44 '[x]': [&str; 1]
             42..43 'x': &str
-            54..55 'b': [[&str; _]; _]
-            58..64 '[a, a]': [[&str; _]; _]
-            59..60 'a': [&str; _]
-            62..63 'a': [&str; _]
-            74..75 'c': [[[&str; _]; _]; _]
-            78..84 '[b, b]': [[[&str; _]; _]; _]
-            79..80 'b': [[&str; _]; _]
-            82..83 'b': [[&str; _]; _]
-            95..96 'd': [isize; _]
-            99..111 '[y, 1, 2, 3]': [isize; _]
+            54..55 'b': [[&str; 1]; 2]
+            58..64 '[a, a]': [[&str; 1]; 2]
+            59..60 'a': [&str; 1]
+            62..63 'a': [&str; 1]
+            74..75 'c': [[[&str; 1]; 2]; 2]
+            78..84 '[b, b]': [[[&str; 1]; 2]; 2]
+            79..80 'b': [[&str; 1]; 2]
+            82..83 'b': [[&str; 1]; 2]
+            95..96 'd': [isize; 4]
+            99..111 '[y, 1, 2, 3]': [isize; 4]
             100..101 'y': isize
             103..104 '1': isize
             106..107 '2': isize
             109..110 '3': isize
-            121..122 'd': [isize; _]
-            125..137 '[1, y, 2, 3]': [isize; _]
+            121..122 'd': [isize; 4]
+            125..137 '[1, y, 2, 3]': [isize; 4]
             126..127 '1': isize
             129..130 'y': isize
             132..133 '2': isize
             135..136 '3': isize
-            147..148 'e': [isize; _]
-            151..154 '[y]': [isize; _]
+            147..148 'e': [isize; 1]
+            151..154 '[y]': [isize; 1]
             152..153 'y': isize
-            164..165 'f': [[isize; _]; _]
-            168..174 '[d, d]': [[isize; _]; _]
-            169..170 'd': [isize; _]
-            172..173 'd': [isize; _]
-            184..185 'g': [[isize; _]; _]
-            188..194 '[e, e]': [[isize; _]; _]
-            189..190 'e': [isize; _]
-            192..193 'e': [isize; _]
-            205..206 'h': [i32; _]
-            209..215 '[1, 2]': [i32; _]
+            164..165 'f': [[isize; 4]; 2]
+            168..174 '[d, d]': [[isize; 4]; 2]
+            169..170 'd': [isize; 4]
+            172..173 'd': [isize; 4]
+            184..185 'g': [[isize; 1]; 2]
+            188..194 '[e, e]': [[isize; 1]; 2]
+            189..190 'e': [isize; 1]
+            192..193 'e': [isize; 1]
+            205..206 'h': [i32; 2]
+            209..215 '[1, 2]': [i32; 2]
             210..211 '1': i32
             213..214 '2': i32
-            225..226 'i': [&str; _]
-            229..239 '["a", "b"]': [&str; _]
+            225..226 'i': [&str; 2]
+            229..239 '["a", "b"]': [&str; 2]
             230..233 '"a"': &str
             235..238 '"b"': &str
-            250..251 'b': [[&str; _]; _]
-            254..264 '[a, ["b"]]': [[&str; _]; _]
-            255..256 'a': [&str; _]
-            258..263 '["b"]': [&str; _]
+            250..251 'b': [[&str; 1]; 2]
+            254..264 '[a, ["b"]]': [[&str; 1]; 2]
+            255..256 'a': [&str; 1]
+            258..263 '["b"]': [&str; 1]
             259..262 '"b"': &str
             274..275 'x': [u8; _]
-            287..289 '[]': [u8; _]
+            287..289 '[]': [u8; 0]
         "#]],
     );
 }
@@ -2429,20 +2429,20 @@ fn infer_operator_overload() {
             394..395 '1': i32
             406..408 'V2': V2([f32; _]) -> V2
             406..416 'V2([x, y])': V2
-            409..415 '[x, y]': [f32; _]
+            409..415 '[x, y]': [f32; 2]
             410..411 'x': f32
             413..414 'y': f32
             436..519 '{     ... vb; }': ()
             446..448 'va': V2
             451..453 'V2': V2([f32; _]) -> V2
             451..465 'V2([0.0, 1.0])': V2
-            454..464 '[0.0, 1.0]': [f32; _]
+            454..464 '[0.0, 1.0]': [f32; 2]
             455..458 '0.0': f32
             460..463 '1.0': f32
             475..477 'vb': V2
             480..482 'V2': V2([f32; _]) -> V2
             480..494 'V2([0.0, 1.0])': V2
-            483..493 '[0.0, 1.0]': [f32; _]
+            483..493 '[0.0, 1.0]': [f32; 2]
             484..487 '0.0': f32
             489..492 '1.0': f32
             505..506 'r': V2
@@ -2593,8 +2593,8 @@ fn test() {
             658..661 'vec': Vec<i32, Global>
             664..679 '<[_]>::into_vec': fn into_vec<i32, Global>(Box<[i32], Global>) -> Vec<i32, Global>
             664..691 '<[_]>:...1i32])': Vec<i32, Global>
-            680..690 'box [1i32]': Box<[i32; _], Global>
-            684..690 '[1i32]': [i32; _]
+            680..690 'box [1i32]': Box<[i32; 1], Global>
+            684..690 '[1i32]': [i32; 1]
             685..689 '1i32': i32
         "#]],
     )
diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index ffc7c8ef4..47a1455fd 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -531,7 +531,7 @@ fn indexing_arrays() {
         expect![[r#"
             10..26 '{ &mut...[2]; }': ()
             12..23 '&mut [9][2]': &mut {unknown}
-            17..20 '[9]': [i32; _]
+            17..20 '[9]': [i32; 1]
             17..23 '[9][2]': {unknown}
             18..19 '9': i32
             21..22 '2': i32
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index cb5a8e19a..320694a17 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -29,7 +29,8 @@ pub(crate) type DocumentationLink = String;
 /// Rewrite documentation links in markdown to point to an online host (e.g. docs.rs)
 pub(crate) fn rewrite_links(db: &RootDatabase, markdown: &str, definition: &Definition) -> String {
     let mut cb = broken_link_clone_cb;
-    let doc = Parser::new_with_broken_link_callback(markdown, Options::empty(), Some(&mut cb));
+    let doc =
+        Parser::new_with_broken_link_callback(markdown, Options::ENABLE_TASKLISTS, Some(&mut cb));
 
     let doc = map_links(doc, |target, title: &str| {
         // This check is imperfect, there's some overlap between valid intra-doc links
@@ -64,8 +65,7 @@ pub(crate) fn rewrite_links(db: &RootDatabase, markdown: &str, definition: &Defi
 pub(crate) fn remove_links(markdown: &str) -> String {
     let mut drop_link = false;
 
-    let mut opts = Options::empty();
-    opts.insert(Options::ENABLE_FOOTNOTES);
+    let opts = Options::ENABLE_TASKLISTS | Options::ENABLE_FOOTNOTES;
 
     let mut cb = |_: BrokenLink| {
         let empty = InlineStr::try_from("").unwrap();
@@ -123,7 +123,7 @@ pub(crate) fn extract_definitions_from_markdown(
 ) -> Vec<(TextRange, String, Option<hir::Namespace>)> {
     Parser::new_with_broken_link_callback(
         markdown,
-        Options::empty(),
+        Options::ENABLE_TASKLISTS,
         Some(&mut broken_link_clone_cb),
     )
     .into_offset_iter()
diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs
index e0bf660c4..960d169f4 100644
--- a/crates/ide/src/inlay_hints.rs
+++ b/crates/ide/src/inlay_hints.rs
@@ -1126,7 +1126,7 @@ fn main() {
             r#"
 fn main() {
     let data = &[1i32, 2, 3];
-      //^^^^ &[i32; _]
+      //^^^^ &[i32; 3]
     for i
 }"#,
         );
diff --git a/crates/ide_assists/src/handlers/auto_import.rs b/crates/ide_assists/src/handlers/auto_import.rs
index a454a2af3..506cc292c 100644
--- a/crates/ide_assists/src/handlers/auto_import.rs
+++ b/crates/ide_assists/src/handlers/auto_import.rs
@@ -969,4 +969,30 @@ mod bar {
 "#,
         );
     }
+
+    #[test]
+    fn uses_abs_path_with_extern_crate_clash() {
+        check_assist(
+            auto_import,
+            r#"
+//- /main.rs crate:main deps:foo
+mod foo {}
+
+const _: () = {
+    Foo$0
+};
+//- /foo.rs crate:foo
+pub struct Foo
+"#,
+            r#"
+use ::foo::Foo;
+
+mod foo {}
+
+const _: () = {
+    Foo
+};
+"#,
+        );
+    }
 }
diff --git a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
index 66f274fa7..8e2178391 100644
--- a/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
+++ b/crates/ide_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -151,20 +151,37 @@ fn create_struct_def(
     field_list: &Either<ast::RecordFieldList, ast::TupleFieldList>,
     visibility: Option<ast::Visibility>,
 ) -> ast::Struct {
-    let pub_vis = Some(make::visibility_pub());
+    let pub_vis = make::visibility_pub();
+
+    let insert_pub = |node: &'_ SyntaxNode| {
+        let pub_vis = pub_vis.clone_for_update();
+        ted::insert(ted::Position::before(node), pub_vis.syntax());
+    };
+
+    // for fields without any existing visibility, use pub visibility
     let field_list = match field_list {
         Either::Left(field_list) => {
-            make::record_field_list(field_list.fields().flat_map(|field| {
-                Some(make::record_field(pub_vis.clone(), field.name()?, field.ty()?))
-            }))
-            .into()
+            let field_list = field_list.clone_for_update();
+
+            field_list
+                .fields()
+                .filter(|field| field.visibility().is_none())
+                .filter_map(|field| field.name())
+                .for_each(|it| insert_pub(it.syntax()));
+
+            field_list.into()
         }
-        Either::Right(field_list) => make::tuple_field_list(
+        Either::Right(field_list) => {
+            let field_list = field_list.clone_for_update();
+
             field_list
                 .fields()
-                .flat_map(|field| Some(make::tuple_field(pub_vis.clone(), field.ty()?))),
-        )
-        .into(),
+                .filter(|field| field.visibility().is_none())
+                .filter_map(|field| field.ty())
+                .for_each(|it| insert_pub(it.syntax()));
+
+            field_list.into()
+        }
     };
 
     make::struct_(visibility, variant_name, None, field_list).clone_for_update()
@@ -295,6 +312,106 @@ enum A { One(One) }"#,
     }
 
     #[test]
+    fn test_extract_struct_keep_comments_and_attrs_one_field_named() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"
+enum A {
+    $0One {
+        // leading comment
+        /// doc comment
+        #[an_attr]
+        foo: u32
+        // trailing comment
+    }
+}"#,
+            r#"
+struct One{
+        // leading comment
+        /// doc comment
+        #[an_attr]
+        pub foo: u32
+        // trailing comment
+    }
+
+enum A {
+    One(One)
+}"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_keep_comments_and_attrs_several_fields_named() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"
+enum A {
+    $0One {
+        // comment
+        /// doc
+        #[attr]
+        foo: u32,
+        // comment
+        #[attr]
+        /// doc
+        bar: u32
+    }
+}"#,
+            r#"
+struct One{
+        // comment
+        /// doc
+        #[attr]
+        pub foo: u32,
+        // comment
+        #[attr]
+        /// doc
+        pub bar: u32
+    }
+
+enum A {
+    One(One)
+}"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_keep_comments_and_attrs_several_fields_tuple() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { $0One(/* comment */ #[attr] u32, /* another */ u32 /* tail */) }",
+            r#"
+struct One(/* comment */ #[attr] pub u32, /* another */ pub u32 /* tail */);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_keep_existing_visibility_named() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { $0One{ pub a: u32, pub(crate) b: u32, pub(super) c: u32, d: u32 } }",
+            r#"
+struct One{ pub a: u32, pub(crate) b: u32, pub(super) c: u32, pub d: u32 }
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_keep_existing_visibility_tuple() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { $0One(pub u32, pub(crate) u32, pub(super) u32, u32) }",
+            r#"
+struct One(pub u32, pub(crate) u32, pub(super) u32, pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
     fn test_extract_enum_variant_name_value_namespace() {
         check_assist(
             extract_struct_from_enum_variant,
diff --git a/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs b/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
index 0fec961b4..a3bfa221c 100644
--- a/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
+++ b/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
@@ -17,7 +17,7 @@ use ide_db::ty_filter::TryEnum;
 
 // Assist: replace_unwrap_with_match
 //
-// Replaces `unwrap` a `match` expression. Works for Result and Option.
+// Replaces `unwrap` with a `match` expression. Works for Result and Option.
 //
 // ```
 // enum Result<T, E> { Ok(T), Err(E) }
diff --git a/crates/project_model/src/cargo_workspace.rs b/crates/project_model/src/cargo_workspace.rs
index b18699b77..4a4996cf4 100644
--- a/crates/project_model/src/cargo_workspace.rs
+++ b/crates/project_model/src/cargo_workspace.rs
@@ -119,6 +119,32 @@ pub struct RustAnalyzerPackageMetaData {
 pub struct PackageDependency {
     pub pkg: Package,
     pub name: String,
+    pub kind: DepKind,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum DepKind {
+    /// Available to the library, binary, and dev targets in the package (but not the build script).
+    Normal,
+    /// Available only to test and bench targets (and the library target, when built with `cfg(test)`).
+    Dev,
+    /// Available only to the build script target.
+    Build,
+}
+
+impl DepKind {
+    fn new(list: &[cargo_metadata::DepKindInfo]) -> Self {
+        for info in list {
+            match info.kind {
+                cargo_metadata::DependencyKind::Normal => return Self::Normal,
+                cargo_metadata::DependencyKind::Development => return Self::Dev,
+                cargo_metadata::DependencyKind::Build => return Self::Build,
+                cargo_metadata::DependencyKind::Unknown => continue,
+            }
+        }
+
+        Self::Normal
+    }
 }
 
 /// Information associated with a package's target
@@ -144,6 +170,7 @@ pub enum TargetKind {
     Example,
     Test,
     Bench,
+    BuildScript,
     Other,
 }
 
@@ -155,6 +182,7 @@ impl TargetKind {
                 "test" => TargetKind::Test,
                 "bench" => TargetKind::Bench,
                 "example" => TargetKind::Example,
+                "custom-build" => TargetKind::BuildScript,
                 "proc-macro" => TargetKind::Lib,
                 _ if kind.contains("lib") => TargetKind::Lib,
                 _ => continue,
@@ -301,7 +329,11 @@ impl CargoWorkspace {
                         continue;
                     }
                 };
-                let dep = PackageDependency { name: dep_node.name, pkg };
+                let dep = PackageDependency {
+                    name: dep_node.name,
+                    pkg,
+                    kind: DepKind::new(&dep_node.dep_kinds),
+                };
                 packages[source].dependencies.push(dep);
             }
             packages[source].active_features.extend(node.features);
diff --git a/crates/project_model/src/workspace.rs b/crates/project_model/src/workspace.rs
index 761fbb3ab..607e62ea5 100644
--- a/crates/project_model/src/workspace.rs
+++ b/crates/project_model/src/workspace.rs
@@ -6,6 +6,7 @@ use std::{collections::VecDeque, fmt, fs, path::Path, process::Command};
 
 use anyhow::{Context, Result};
 use base_db::{CrateDisplayName, CrateGraph, CrateId, CrateName, Edition, Env, FileId, ProcMacro};
+use cargo_workspace::DepKind;
 use cfg::CfgOptions;
 use paths::{AbsPath, AbsPathBuf};
 use proc_macro_api::ProcMacroClient;
@@ -407,23 +408,25 @@ fn cargo_to_crate_graph(
                     }
                 }
 
-                pkg_crates.entry(pkg).or_insert_with(Vec::new).push(crate_id);
+                pkg_crates.entry(pkg).or_insert_with(Vec::new).push((crate_id, cargo[tgt].kind));
             }
         }
 
         // Set deps to the core, std and to the lib target of the current package
-        for &from in pkg_crates.get(&pkg).into_iter().flatten() {
+        for (from, kind) in pkg_crates.get(&pkg).into_iter().flatten() {
             if let Some((to, name)) = lib_tgt.clone() {
-                if to != from {
+                if to != *from && *kind != TargetKind::BuildScript {
+                    // (build script can not depend on its library target)
+
                     // For root projects with dashes in their name,
                     // cargo metadata does not do any normalization,
                     // so we do it ourselves currently
                     let name = CrateName::normalize_dashes(&name);
-                    add_dep(&mut crate_graph, from, name, to);
+                    add_dep(&mut crate_graph, *from, name, to);
                 }
             }
             for (name, krate) in public_deps.iter() {
-                add_dep(&mut crate_graph, from, name.clone(), *krate);
+                add_dep(&mut crate_graph, *from, name.clone(), *krate);
             }
         }
     }
@@ -434,8 +437,17 @@ fn cargo_to_crate_graph(
         for dep in cargo[pkg].dependencies.iter() {
             let name = CrateName::new(&dep.name).unwrap();
             if let Some(&to) = pkg_to_lib_crate.get(&dep.pkg) {
-                for &from in pkg_crates.get(&pkg).into_iter().flatten() {
-                    add_dep(&mut crate_graph, from, name.clone(), to)
+                for (from, kind) in pkg_crates.get(&pkg).into_iter().flatten() {
+                    if dep.kind == DepKind::Build && *kind != TargetKind::BuildScript {
+                        // Only build scripts may depend on build dependencies.
+                        continue;
+                    }
+                    if dep.kind != DepKind::Build && *kind == TargetKind::BuildScript {
+                        // Build scripts may only depend on build dependencies.
+                        continue;
+                    }
+
+                    add_dep(&mut crate_graph, *from, name.clone(), to)
                 }
             }
         }
@@ -472,7 +484,7 @@ fn handle_rustc_crates(
     pkg_to_lib_crate: &mut FxHashMap<la_arena::Idx<crate::PackageData>, CrateId>,
     public_deps: &[(CrateName, CrateId)],
     cargo: &CargoWorkspace,
-    pkg_crates: &FxHashMap<la_arena::Idx<crate::PackageData>, Vec<CrateId>>,
+    pkg_crates: &FxHashMap<la_arena::Idx<crate::PackageData>, Vec<(CrateId, TargetKind)>>,
 ) {
     let mut rustc_pkg_crates = FxHashMap::default();
     // The root package of the rustc-dev component is rustc_driver, so we match that
@@ -541,13 +553,13 @@ fn handle_rustc_crates(
                 if !package.metadata.rustc_private {
                     continue;
                 }
-                for &from in pkg_crates.get(&pkg).into_iter().flatten() {
+                for (from, _) in pkg_crates.get(&pkg).into_iter().flatten() {
                     // Avoid creating duplicate dependencies
                     // This avoids the situation where `from` depends on e.g. `arrayvec`, but
                     // `rust_analyzer` thinks that it should use the one from the `rustcSource`
                     // instead of the one from `crates.io`
-                    if !crate_graph[from].dependencies.iter().any(|d| d.name == name) {
-                        add_dep(crate_graph, from, name.clone(), to);
+                    if !crate_graph[*from].dependencies.iter().any(|d| d.name == name) {
+                        add_dep(crate_graph, *from, name.clone(), to);
                     }
                 }
             }
diff --git a/crates/rust-analyzer/src/cargo_target_spec.rs b/crates/rust-analyzer/src/cargo_target_spec.rs
index 909c21532..f4cd43448 100644
--- a/crates/rust-analyzer/src/cargo_target_spec.rs
+++ b/crates/rust-analyzer/src/cargo_target_spec.rs
@@ -159,7 +159,7 @@ impl CargoTargetSpec {
             TargetKind::Lib => {
                 buf.push("--lib".to_string());
             }
-            TargetKind::Other => (),
+            TargetKind::Other | TargetKind::BuildScript => (),
         }
     }
 }