Merging upstream version 1.76.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

39 files changed, 1083 insertions, 607 deletions

diff --git a/src/tools/rust-analyzer/crates/hir-ty/Cargo.toml b/src/tools/rust-analyzer/crates/hir-ty/Cargo.toml
index b95ae05cc..bbcb76a43 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/Cargo.toml
+++ b/src/tools/rust-analyzer/crates/hir-ty/Cargo.toml
@@ -13,27 +13,27 @@ doctest = false
 
 [dependencies]
 cov-mark = "2.0.0-pre.1"
-itertools = "0.10.5"
+itertools.workspace = true
 arrayvec = "0.7.2"
-bitflags = "2.1.0"
+bitflags.workspace = true
 smallvec.workspace = true
 ena = "0.14.0"
-either = "1.7.0"
+either.workspace = true
 oorandom = "11.1.3"
-tracing = "0.1.35"
+tracing.workspace = true
 rustc-hash = "1.1.0"
 scoped-tls = "1.0.0"
-chalk-solve = { version = "0.92.0", default-features = false }
-chalk-ir = "0.92.0"
-chalk-recursive = { version = "0.92.0", default-features = false }
-chalk-derive = "0.92.0"
+chalk-solve = { version = "0.95.0", default-features = false }
+chalk-ir = "0.95.0"
+chalk-recursive = { version = "0.95.0", default-features = false }
+chalk-derive = "0.95.0"
 la-arena.workspace = true
 once_cell = "1.17.0"
 triomphe.workspace = true
 nohash-hasher.workspace = true
 typed-arena = "2.0.1"
 
-rustc_index.workspace = true
+rustc-dependencies.workspace = true
 
 # local deps
 stdx.workspace = true
@@ -47,12 +47,13 @@ limit.workspace = true
 
 [dev-dependencies]
 expect-test = "1.4.0"
-tracing = "0.1.35"
-tracing-subscriber = { version = "0.3.16", default-features = false, features = [
-    "registry",
-] }
-tracing-tree = "0.2.1"
+tracing.workspace = true
+tracing-subscriber.workspace = true
+tracing-tree.workspace = true
 project-model = { path = "../project-model" }
 
 # local deps
 test-utils.workspace = true
+
+[features]
+in-rust-tree = ["rustc-dependencies/in-rust-tree"]
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs b/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs
index c0b243ea2..c9ab35685 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs
@@ -28,6 +28,7 @@ pub trait TyExt {
     fn is_unknown(&self) -> bool;
     fn contains_unknown(&self) -> bool;
     fn is_ty_var(&self) -> bool;
+    fn is_union(&self) -> bool;
 
     fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)>;
     fn as_builtin(&self) -> Option<BuiltinType>;
@@ -96,6 +97,10 @@ impl TyExt for Ty {
         matches!(self.kind(Interner), TyKind::InferenceVar(_, _))
     }
 
+    fn is_union(&self) -> bool {
+        matches!(self.adt_id(Interner), Some(AdtId(hir_def::AdtId::UnionId(_))))
+    }
+
     fn as_adt(&self) -> Option<(hir_def::AdtId, &Substitution)> {
         match self.kind(Interner) {
             TyKind::Adt(AdtId(adt), parameters) => Some((*adt, parameters)),
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/consteval.rs b/src/tools/rust-analyzer/crates/hir-ty/src/consteval.rs
index 0348680e5..9792d945e 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/consteval.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/consteval.rs
@@ -1,9 +1,10 @@
 //! Constant evaluation details
 
-use base_db::CrateId;
+use base_db::{salsa::Cycle, CrateId};
 use chalk_ir::{cast::Cast, BoundVar, DebruijnIndex};
 use hir_def::{
-    hir::Expr,
+    body::Body,
+    hir::{Expr, ExprId},
     path::Path,
     resolver::{Resolver, ValueNs},
     type_ref::LiteralConstRef,
@@ -136,7 +137,7 @@ pub fn intern_const_ref(
     ty: Ty,
     krate: CrateId,
 ) -> Const {
-    let layout = db.layout_of_ty(ty.clone(), Arc::new(TraitEnvironment::empty(krate)));
+    let layout = db.layout_of_ty(ty.clone(), TraitEnvironment::empty(krate));
     let bytes = match value {
         LiteralConstRef::Int(i) => {
             // FIXME: We should handle failure of layout better.
@@ -184,7 +185,7 @@ pub fn try_const_usize(db: &dyn HirDatabase, c: &Const) -> Option<u128> {
 
 pub(crate) fn const_eval_recover(
     _: &dyn HirDatabase,
-    _: &[String],
+    _: &Cycle,
     _: &GeneralConstId,
     _: &Substitution,
     _: &Option<Arc<TraitEnvironment>>,
@@ -194,7 +195,7 @@ pub(crate) fn const_eval_recover(
 
 pub(crate) fn const_eval_static_recover(
     _: &dyn HirDatabase,
-    _: &[String],
+    _: &Cycle,
     _: &StaticId,
 ) -> Result<Const, ConstEvalError> {
     Err(ConstEvalError::MirLowerError(MirLowerError::Loop))
@@ -202,7 +203,7 @@ pub(crate) fn const_eval_static_recover(
 
 pub(crate) fn const_eval_discriminant_recover(
     _: &dyn HirDatabase,
-    _: &[String],
+    _: &Cycle,
     _: &EnumVariantId,
 ) -> Result<i128, ConstEvalError> {
     Err(ConstEvalError::MirLowerError(MirLowerError::Loop))
@@ -280,7 +281,7 @@ pub(crate) fn const_eval_discriminant_variant(
 // get an `InferenceResult` instead of an `InferenceContext`. And we should remove `ctx.clone().resolve_all()` here
 // and make this function private. See the fixme comment on `InferenceContext::resolve_all`.
 pub(crate) fn eval_to_const(
-    expr: Idx<Expr>,
+    expr: ExprId,
     mode: ParamLoweringMode,
     ctx: &mut InferenceContext<'_>,
     args: impl FnOnce() -> Generics,
@@ -288,13 +289,24 @@ pub(crate) fn eval_to_const(
 ) -> Const {
     let db = ctx.db;
     let infer = ctx.clone().resolve_all();
+    fn has_closure(body: &Body, expr: ExprId) -> bool {
+        if matches!(body[expr], Expr::Closure { .. }) {
+            return true;
+        }
+        let mut r = false;
+        body[expr].walk_child_exprs(|idx| r |= has_closure(body, idx));
+        r
+    }
+    if has_closure(&ctx.body, expr) {
+        // Type checking clousres need an isolated body (See the above FIXME). Bail out early to prevent panic.
+        return unknown_const(infer[expr].clone());
+    }
     if let Expr::Path(p) = &ctx.body.exprs[expr] {
         let resolver = &ctx.resolver;
         if let Some(c) = path_to_const(db, resolver, p, mode, args, debruijn, infer[expr].clone()) {
             return c;
         }
     }
-    let infer = ctx.clone().resolve_all();
     if let Ok(mir_body) = lower_to_mir(ctx.db, ctx.owner, &ctx.body, &infer, expr) {
         if let Ok(result) = interpret_mir(db, Arc::new(mir_body), true, None).0 {
             return result;
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/consteval/tests.rs b/src/tools/rust-analyzer/crates/hir-ty/src/consteval/tests.rs
index 7ad3659a4..b395e7f4a 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/consteval/tests.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/consteval/tests.rs
@@ -1159,6 +1159,20 @@ fn pattern_matching_slice() {
         "#,
         33213,
     );
+    check_number(
+        r#"
+    //- minicore: slice, index, coerce_unsized, copy
+    const fn f(mut slice: &[u32]) -> usize {
+        slice = match slice {
+            [0, rest @ ..] | rest => rest,
+        };
+        slice.len()
+    }
+    const GOAL: usize = f(&[]) + f(&[10]) + f(&[0, 100])
+        + f(&[1000, 1000, 1000]) + f(&[0, 57, 34, 46, 10000, 10000]);
+        "#,
+        10,
+    );
 }
 
 #[test]
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/db.rs b/src/tools/rust-analyzer/crates/hir-ty/src/db.rs
index 9c96b5ab8..410bcbf03 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/db.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/db.rs
@@ -20,8 +20,8 @@ use crate::{
     method_resolution::{InherentImpls, TraitImpls, TyFingerprint},
     mir::{BorrowckResult, MirBody, MirLowerError},
     Binders, CallableDefId, ClosureId, Const, FnDefId, GenericArg, ImplTraitId, InferenceResult,
-    Interner, PolyFnSig, QuantifiedWhereClause, ReturnTypeImplTraits, Substitution, TraitRef, Ty,
-    TyDefId, ValueTyDefId,
+    Interner, PolyFnSig, QuantifiedWhereClause, ReturnTypeImplTraits, Substitution,
+    TraitEnvironment, TraitRef, Ty, TyDefId, ValueTyDefId,
 };
 use hir_expand::name::Name;
 
@@ -47,7 +47,7 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         &self,
         def: DefWithBodyId,
         subst: Substitution,
-        env: Arc<crate::TraitEnvironment>,
+        env: Arc<TraitEnvironment>,
     ) -> Result<Arc<MirBody>, MirLowerError>;
 
     #[salsa::invoke(crate::mir::monomorphized_mir_body_for_closure_query)]
@@ -55,7 +55,7 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         &self,
         def: ClosureId,
         subst: Substitution,
-        env: Arc<crate::TraitEnvironment>,
+        env: Arc<TraitEnvironment>,
     ) -> Result<Arc<MirBody>, MirLowerError>;
 
     #[salsa::invoke(crate::mir::borrowck_query)]
@@ -81,7 +81,7 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         &self,
         def: GeneralConstId,
         subst: Substitution,
-        trait_env: Option<Arc<crate::TraitEnvironment>>,
+        trait_env: Option<Arc<TraitEnvironment>>,
     ) -> Result<Const, ConstEvalError>;
 
     #[salsa::invoke(crate::consteval::const_eval_static_query)]
@@ -104,16 +104,12 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         &self,
         def: AdtId,
         subst: Substitution,
-        env: Arc<crate::TraitEnvironment>,
+        env: Arc<TraitEnvironment>,
     ) -> Result<Arc<Layout>, LayoutError>;
 
     #[salsa::invoke(crate::layout::layout_of_ty_query)]
     #[salsa::cycle(crate::layout::layout_of_ty_recover)]
-    fn layout_of_ty(
-        &self,
-        ty: Ty,
-        env: Arc<crate::TraitEnvironment>,
-    ) -> Result<Arc<Layout>, LayoutError>;
+    fn layout_of_ty(&self, ty: Ty, env: Arc<TraitEnvironment>) -> Result<Arc<Layout>, LayoutError>;
 
     #[salsa::invoke(crate::layout::target_data_layout_query)]
     fn target_data_layout(&self, krate: CrateId) -> Option<Arc<TargetDataLayout>>;
@@ -121,7 +117,7 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     #[salsa::invoke(crate::method_resolution::lookup_impl_method_query)]
     fn lookup_impl_method(
         &self,
-        env: Arc<crate::TraitEnvironment>,
+        env: Arc<TraitEnvironment>,
         func: FunctionId,
         fn_subst: Substitution,
     ) -> (FunctionId, Substitution);
@@ -149,10 +145,10 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
 
     #[salsa::invoke(crate::lower::trait_environment_for_body_query)]
     #[salsa::transparent]
-    fn trait_environment_for_body(&self, def: DefWithBodyId) -> Arc<crate::TraitEnvironment>;
+    fn trait_environment_for_body(&self, def: DefWithBodyId) -> Arc<TraitEnvironment>;
 
     #[salsa::invoke(crate::lower::trait_environment_query)]
-    fn trait_environment(&self, def: GenericDefId) -> Arc<crate::TraitEnvironment>;
+    fn trait_environment(&self, def: GenericDefId) -> Arc<TraitEnvironment>;
 
     #[salsa::invoke(crate::lower::generic_defaults_query)]
     #[salsa::cycle(crate::lower::generic_defaults_recover)]
@@ -249,7 +245,7 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     fn normalize_projection(
         &self,
         projection: crate::ProjectionTy,
-        env: Arc<crate::TraitEnvironment>,
+        env: Arc<TraitEnvironment>,
     ) -> Ty;
 
     #[salsa::invoke(trait_solve_wait)]
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics.rs b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics.rs
index ef43ed5c4..c1b361900 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics.rs
@@ -11,9 +11,3 @@ pub use crate::diagnostics::{
     },
     unsafe_check::{missing_unsafe, unsafe_expressions, UnsafeExpr},
 };
-
-#[derive(Debug, PartialEq, Eq)]
-pub struct IncoherentImpl {
-    pub file_id: hir_expand::HirFileId,
-    pub impl_: syntax::AstPtr<syntax::ast::Impl>,
-}
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check.rs b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check.rs
index 36d69edf9..51a044d8e 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check.rs
@@ -9,6 +9,7 @@
 //! - constants (e.g. `const FOO: u8 = 10;`)
 //! - static items (e.g. `static FOO: u8 = 10;`)
 //! - match arm bindings (e.g. `foo @ Some(_)`)
+//! - modules (e.g. `mod foo { ... }` or `mod foo;`)
 
 mod case_conv;
 
@@ -18,12 +19,12 @@ use hir_def::{
     data::adt::VariantData,
     hir::{Pat, PatId},
     src::HasSource,
-    AdtId, AttrDefId, ConstId, DefWithBodyId, EnumId, EnumVariantId, FunctionId, ItemContainerId,
-    Lookup, ModuleDefId, StaticId, StructId,
+    AdtId, AttrDefId, ConstId, EnumId, FunctionId, ItemContainerId, Lookup, ModuleDefId, ModuleId,
+    StaticId, StructId,
 };
 use hir_expand::{
     name::{AsName, Name},
-    HirFileId,
+    HirFileId, MacroFileIdExt,
 };
 use stdx::{always, never};
 use syntax::{
@@ -83,6 +84,7 @@ pub enum IdentType {
     Structure,
     Variable,
     Variant,
+    Module,
 }
 
 impl fmt::Display for IdentType {
@@ -97,6 +99,7 @@ impl fmt::Display for IdentType {
             IdentType::Structure => "Structure",
             IdentType::Variable => "Variable",
             IdentType::Variant => "Variant",
+            IdentType::Module => "Module",
         };
 
         repr.fmt(f)
@@ -132,6 +135,7 @@ impl<'a> DeclValidator<'a> {
 
     pub(super) fn validate_item(&mut self, item: ModuleDefId) {
         match item {
+            ModuleDefId::ModuleId(module_id) => self.validate_module(module_id),
             ModuleDefId::FunctionId(func) => self.validate_func(func),
             ModuleDefId::AdtId(adt) => self.validate_adt(adt),
             ModuleDefId::ConstId(const_id) => self.validate_const(const_id),
@@ -192,7 +196,7 @@ impl<'a> DeclValidator<'a> {
                 AttrDefId::GenericParamId(_) => None,
             }
             .map_or(false, |file_id| {
-                file_id.is_custom_derive(db.upcast()) || file_id.is_builtin_derive(db.upcast())
+                matches!(file_id.macro_file(), Some(file_id) if file_id.is_custom_derive(db.upcast()) || file_id.is_builtin_derive(db.upcast()))
             })
         };
 
@@ -230,6 +234,55 @@ impl<'a> DeclValidator<'a> {
             || parent()
     }
 
+    fn validate_module(&mut self, module_id: ModuleId) {
+        // Check whether non-snake case identifiers are allowed for this module.
+        if self.allowed(module_id.into(), allow::NON_SNAKE_CASE, false) {
+            return;
+        }
+
+        // Check the module name.
+        let Some(module_name) = module_id.name(self.db.upcast()) else { return };
+        let module_name_replacement =
+            module_name.as_str().and_then(to_lower_snake_case).map(|new_name| Replacement {
+                current_name: module_name,
+                suggested_text: new_name,
+                expected_case: CaseType::LowerSnakeCase,
+            });
+
+        if let Some(module_name_replacement) = module_name_replacement {
+            let module_data = &module_id.def_map(self.db.upcast())[module_id.local_id];
+            let module_src = module_data.declaration_source(self.db.upcast());
+
+            if let Some(module_src) = module_src {
+                let ast_ptr = match module_src.value.name() {
+                    Some(name) => name,
+                    None => {
+                        never!(
+                            "Replacement ({:?}) was generated for a module without a name: {:?}",
+                            module_name_replacement,
+                            module_src
+                        );
+                        return;
+                    }
+                };
+
+                let diagnostic = IncorrectCase {
+                    file: module_src.file_id,
+                    ident_type: IdentType::Module,
+                    ident: AstPtr::new(&ast_ptr),
+                    expected_case: module_name_replacement.expected_case,
+                    ident_text: module_name_replacement
+                        .current_name
+                        .display(self.db.upcast())
+                        .to_string(),
+                    suggested_text: module_name_replacement.suggested_text,
+                };
+
+                self.sink.push(diagnostic);
+            }
+        }
+    }
+
     fn validate_func(&mut self, func: FunctionId) {
         let data = self.db.function_data(func);
         if matches!(func.lookup(self.db.upcast()).container, ItemContainerId::ExternBlockId(_)) {
@@ -237,8 +290,6 @@ impl<'a> DeclValidator<'a> {
             return;
         }
 
-        self.validate_body_inner_items(func.into());
-
         // Check whether non-snake case identifiers are allowed for this function.
         if self.allowed(func.into(), allow::NON_SNAKE_CASE, false) {
             return;
@@ -336,48 +387,44 @@ impl<'a> DeclValidator<'a> {
 
         for (id, replacement) in pats_replacements {
             if let Ok(source_ptr) = source_map.pat_syntax(id) {
-                if let Some(expr) = source_ptr.value.as_ref().left() {
+                if let Some(ptr) = source_ptr.value.clone().cast::<ast::IdentPat>() {
                     let root = source_ptr.file_syntax(self.db.upcast());
-                    if let ast::Pat::IdentPat(ident_pat) = expr.to_node(&root) {
-                        let parent = match ident_pat.syntax().parent() {
-                            Some(parent) => parent,
-                            None => continue,
-                        };
-                        let name_ast = match ident_pat.name() {
-                            Some(name_ast) => name_ast,
-                            None => continue,
-                        };
+                    let ident_pat = ptr.to_node(&root);
+                    let parent = match ident_pat.syntax().parent() {
+                        Some(parent) => parent,
+                        None => continue,
+                    };
+                    let name_ast = match ident_pat.name() {
+                        Some(name_ast) => name_ast,
+                        None => continue,
+                    };
+
+                    let is_param = ast::Param::can_cast(parent.kind());
+
+                    // We have to check that it's either `let var = ...` or `var @ Variant(_)` statement,
+                    // because e.g. match arms are patterns as well.
+                    // In other words, we check that it's a named variable binding.
+                    let is_binding = ast::LetStmt::can_cast(parent.kind())
+                        || (ast::MatchArm::can_cast(parent.kind())
+                            && ident_pat.at_token().is_some());
+                    if !(is_param || is_binding) {
+                        // This pattern is not an actual variable declaration, e.g. `Some(val) => {..}` match arm.
+                        continue;
+                    }
 
-                        let is_param = ast::Param::can_cast(parent.kind());
-
-                        // We have to check that it's either `let var = ...` or `var @ Variant(_)` statement,
-                        // because e.g. match arms are patterns as well.
-                        // In other words, we check that it's a named variable binding.
-                        let is_binding = ast::LetStmt::can_cast(parent.kind())
-                            || (ast::MatchArm::can_cast(parent.kind())
-                                && ident_pat.at_token().is_some());
-                        if !(is_param || is_binding) {
-                            // This pattern is not an actual variable declaration, e.g. `Some(val) => {..}` match arm.
-                            continue;
-                        }
+                    let ident_type =
+                        if is_param { IdentType::Parameter } else { IdentType::Variable };
 
-                        let ident_type =
-                            if is_param { IdentType::Parameter } else { IdentType::Variable };
-
-                        let diagnostic = IncorrectCase {
-                            file: source_ptr.file_id,
-                            ident_type,
-                            ident: AstPtr::new(&name_ast),
-                            expected_case: replacement.expected_case,
-                            ident_text: replacement
-                                .current_name
-                                .display(self.db.upcast())
-                                .to_string(),
-                            suggested_text: replacement.suggested_text,
-                        };
+                    let diagnostic = IncorrectCase {
+                        file: source_ptr.file_id,
+                        ident_type,
+                        ident: AstPtr::new(&name_ast),
+                        expected_case: replacement.expected_case,
+                        ident_text: replacement.current_name.display(self.db.upcast()).to_string(),
+                        suggested_text: replacement.suggested_text,
+                    };
 
-                        self.sink.push(diagnostic);
-                    }
+                    self.sink.push(diagnostic);
                 }
             }
         }
@@ -519,11 +566,6 @@ impl<'a> DeclValidator<'a> {
     fn validate_enum(&mut self, enum_id: EnumId) {
         let data = self.db.enum_data(enum_id);
 
-        for (local_id, _) in data.variants.iter() {
-            let variant_id = EnumVariantId { parent: enum_id, local_id };
-            self.validate_body_inner_items(variant_id.into());
-        }
-
         // Check whether non-camel case names are allowed for this enum.
         if self.allowed(enum_id.into(), allow::NON_CAMEL_CASE_TYPES, false) {
             return;
@@ -648,8 +690,6 @@ impl<'a> DeclValidator<'a> {
     fn validate_const(&mut self, const_id: ConstId) {
         let data = self.db.const_data(const_id);
 
-        self.validate_body_inner_items(const_id.into());
-
         if self.allowed(const_id.into(), allow::NON_UPPER_CASE_GLOBAL, false) {
             return;
         }
@@ -698,8 +738,6 @@ impl<'a> DeclValidator<'a> {
             return;
         }
 
-        self.validate_body_inner_items(static_id.into());
-
         if self.allowed(static_id.into(), allow::NON_UPPER_CASE_GLOBAL, false) {
             return;
         }
@@ -737,17 +775,4 @@ impl<'a> DeclValidator<'a> {
 
         self.sink.push(diagnostic);
     }
-
-    // FIXME: We don't currently validate names within `DefWithBodyId::InTypeConstId`.
-    /// Recursively validates inner scope items, such as static variables and constants.
-    fn validate_body_inner_items(&mut self, body_id: DefWithBodyId) {
-        let body = self.db.body(body_id);
-        for (_, block_def_map) in body.blocks(self.db.upcast()) {
-            for (_, module) in block_def_map.modules() {
-                for def_id in module.scope.declarations() {
-                    self.validate_item(def_id);
-                }
-            }
-        }
-    }
 }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check/case_conv.rs b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check/case_conv.rs
index 2c1368962..cbe1af157 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check/case_conv.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/decl_check/case_conv.rs
@@ -11,50 +11,7 @@ pub(crate) fn to_camel_case(ident: &str) -> Option<String> {
         return None;
     }
 
-    // Taken from rustc.
-    let ret = ident
-        .trim_matches('_')
-        .split('_')
-        .filter(|component| !component.is_empty())
-        .map(|component| {
-            let mut camel_cased_component = String::with_capacity(component.len());
-
-            let mut new_word = true;
-            let mut prev_is_lower_case = true;
-
-            for c in component.chars() {
-                // Preserve the case if an uppercase letter follows a lowercase letter, so that
-                // `camelCase` is converted to `CamelCase`.
-                if prev_is_lower_case && c.is_uppercase() {
-                    new_word = true;
-                }
-
-                if new_word {
-                    camel_cased_component.extend(c.to_uppercase());
-                } else {
-                    camel_cased_component.extend(c.to_lowercase());
-                }
-
-                prev_is_lower_case = c.is_lowercase();
-                new_word = false;
-            }
-
-            camel_cased_component
-        })
-        .fold((String::new(), None), |(acc, prev): (_, Option<String>), next| {
-            // separate two components with an underscore if their boundary cannot
-            // be distinguished using an uppercase/lowercase case distinction
-            let join = prev
-                .and_then(|prev| {
-                    let f = next.chars().next()?;
-                    let l = prev.chars().last()?;
-                    Some(!char_has_case(l) && !char_has_case(f))
-                })
-                .unwrap_or(false);
-            (acc + if join { "_" } else { "" } + &next, Some(next))
-        })
-        .0;
-    Some(ret)
+    Some(stdx::to_camel_case(ident))
 }
 
 /// Converts an identifier to a lower_snake_case form.
@@ -97,7 +54,9 @@ fn is_camel_case(name: &str) -> bool {
         && !name.chars().any(|snd| {
             let ret = match fst {
                 None => false,
-                Some(fst) => char_has_case(fst) && snd == '_' || char_has_case(snd) && fst == '_',
+                Some(fst) => {
+                    stdx::char_has_case(fst) && snd == '_' || stdx::char_has_case(snd) && fst == '_'
+                }
             };
             fst = Some(snd);
 
@@ -135,11 +94,6 @@ fn is_snake_case<F: Fn(char) -> bool>(ident: &str, wrong_case: F) -> bool {
     })
 }
 
-// Taken from rustc.
-fn char_has_case(c: char) -> bool {
-    c.is_lowercase() || c.is_uppercase()
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/match_check.rs b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/match_check.rs
index f8cdeaa5e..2e04bbfee 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/match_check.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/diagnostics/match_check.rs
@@ -147,7 +147,7 @@ impl<'a> PatCtxt<'a> {
             }
 
             hir_def::hir::Pat::Bind { id, subpat, .. } => {
-                let bm = self.infer.binding_modes[id];
+                let bm = self.infer.binding_modes[pat];
                 ty = &self.infer[id];
                 let name = &self.body.bindings[id].name;
                 match (bm, ty.kind(Interner)) {
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/display.rs b/src/tools/rust-analyzer/crates/hir-ty/src/display.rs
index f6d6b00d7..d81926f7c 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/display.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/display.rs
@@ -23,7 +23,7 @@ use hir_def::{
     EnumVariantId, HasModule, ItemContainerId, LocalFieldId, Lookup, ModuleDefId, ModuleId,
     TraitId,
 };
-use hir_expand::{hygiene::Hygiene, name::Name};
+use hir_expand::name::Name;
 use intern::{Internable, Interned};
 use itertools::Itertools;
 use la_arena::ArenaMap;
@@ -448,9 +448,8 @@ fn render_const_scalar(
 ) -> Result<(), HirDisplayError> {
     // FIXME: We need to get krate from the final callers of the hir display
     // infrastructure and have it here as a field on `f`.
-    let trait_env = Arc::new(TraitEnvironment::empty(
-        *f.db.crate_graph().crates_in_topological_order().last().unwrap(),
-    ));
+    let trait_env =
+        TraitEnvironment::empty(*f.db.crate_graph().crates_in_topological_order().last().unwrap());
     match ty.kind(Interner) {
         TyKind::Scalar(s) => match s {
             Scalar::Bool => write!(f, "{}", if b[0] == 0 { false } else { true }),
@@ -945,6 +944,7 @@ impl HirDisplay for Ty {
                             ItemInNs::Types((*def_id).into()),
                             module_id,
                             false,
+                            true,
                         ) {
                             write!(f, "{}", path.display(f.db.upcast()))?;
                         } else {
@@ -1731,13 +1731,13 @@ impl HirDisplay for TypeRef {
                 f.write_joined(bounds, " + ")?;
             }
             TypeRef::Macro(macro_call) => {
-                let macro_call = macro_call.to_node(f.db.upcast());
-                let ctx = hir_def::lower::LowerCtx::with_hygiene(
+                let ctx = hir_def::lower::LowerCtx::with_span_map(
                     f.db.upcast(),
-                    &Hygiene::new_unhygienic(),
+                    f.db.span_map(macro_call.file_id),
                 );
+                let macro_call = macro_call.to_node(f.db.upcast());
                 match macro_call.path() {
-                    Some(path) => match Path::from_src(path, &ctx) {
+                    Some(path) => match Path::from_src(&ctx, path) {
                         Some(path) => path.hir_fmt(f)?,
                         None => write!(f, "{{macro}}")?,
                     },
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs
index 78d3c667a..6f724e458 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer.rs
@@ -113,7 +113,7 @@ pub(crate) fn infer_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<Infer
             // FIXME(const-generic-body): We should not get the return type in this way.
             ctx.return_ty = c
                 .lookup(db.upcast())
-                .thing
+                .expected_ty
                 .box_any()
                 .downcast::<InTypeConstIdMetadata>()
                 .unwrap()
@@ -420,7 +420,19 @@ pub struct InferenceResult {
     standard_types: InternedStandardTypes,
     /// Stores the types which were implicitly dereferenced in pattern binding modes.
     pub pat_adjustments: FxHashMap<PatId, Vec<Ty>>,
-    pub binding_modes: ArenaMap<BindingId, BindingMode>,
+    /// Stores the binding mode (`ref` in `let ref x = 2`) of bindings.
+    ///
+    /// This one is tied to the `PatId` instead of `BindingId`, because in some rare cases, a binding in an
+    /// or pattern can have multiple binding modes. For example:
+    /// ```
+    /// fn foo(mut slice: &[u32]) -> usize {
+    ///    slice = match slice {
+    ///        [0, rest @ ..] | rest => rest,
+    ///    };
+    /// }
+    /// ```
+    /// the first `rest` has implicit `ref` binding mode, but the second `rest` binding mode is `move`.
+    pub binding_modes: ArenaMap<PatId, BindingMode>,
     pub expr_adjustments: FxHashMap<ExprId, Vec<Adjustment>>,
     pub(crate) closure_info: FxHashMap<ClosureId, (Vec<CapturedItem>, FnTrait)>,
     // FIXME: remove this field
@@ -1140,20 +1152,15 @@ impl<'a> InferenceContext<'a> {
                 (ty, variant)
             }
             TypeNs::TypeAliasId(it) => {
-                let container = it.lookup(self.db.upcast()).container;
-                let parent_subst = match container {
-                    ItemContainerId::TraitId(id) => {
-                        let subst = TyBuilder::subst_for_def(self.db, id, None)
-                            .fill_with_inference_vars(&mut self.table)
-                            .build();
-                        Some(subst)
-                    }
-                    // Type aliases do not exist in impls.
-                    _ => None,
+                let resolved_seg = match unresolved {
+                    None => path.segments().last().unwrap(),
+                    Some(n) => path.segments().get(path.segments().len() - n - 1).unwrap(),
                 };
-                let ty = TyBuilder::def_ty(self.db, it.into(), parent_subst)
-                    .fill_with_inference_vars(&mut self.table)
-                    .build();
+                let substs =
+                    ctx.substs_from_path_segment(resolved_seg, Some(it.into()), true, None);
+                let ty = self.db.ty(it.into());
+                let ty = self.insert_type_vars(ty.substitute(Interner, &substs));
+
                 self.resolve_variant_on_alias(ty, unresolved, mod_path)
             }
             TypeNs::AdtSelfType(_) => {
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer/closure.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer/closure.rs
index 13d6b5643..af74df103 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer/closure.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer/closure.rs
@@ -679,7 +679,7 @@ impl InferenceContext<'_> {
             | Pat::Range { .. } => {
                 update_result(CaptureKind::ByRef(BorrowKind::Shared));
             }
-            Pat::Bind { id, .. } => match self.result.binding_modes[*id] {
+            Pat::Bind { id, .. } => match self.result.binding_modes[p] {
                 crate::BindingMode::Move => {
                     if self.is_ty_copy(self.result.type_of_binding[*id].clone()) {
                         update_result(CaptureKind::ByRef(BorrowKind::Shared));
@@ -735,6 +735,32 @@ impl InferenceContext<'_> {
         self.walk_expr(expr);
     }
 
+    fn restrict_precision_for_unsafe(&mut self) {
+        for capture in &mut self.current_captures {
+            let mut ty = self.table.resolve_completely(self.result[capture.place.local].clone());
+            if ty.as_raw_ptr().is_some() || ty.is_union() {
+                capture.kind = CaptureKind::ByRef(BorrowKind::Shared);
+                capture.place.projections.truncate(0);
+                continue;
+            }
+            for (i, p) in capture.place.projections.iter().enumerate() {
+                ty = p.projected_ty(
+                    ty,
+                    self.db,
+                    |_, _, _| {
+                        unreachable!("Closure field only happens in MIR");
+                    },
+                    self.owner.module(self.db.upcast()).krate(),
+                );
+                if ty.as_raw_ptr().is_some() || ty.is_union() {
+                    capture.kind = CaptureKind::ByRef(BorrowKind::Shared);
+                    capture.place.projections.truncate(i + 1);
+                    break;
+                }
+            }
+        }
+    }
+
     fn adjust_for_move_closure(&mut self) {
         for capture in &mut self.current_captures {
             if let Some(first_deref) =
@@ -838,8 +864,8 @@ impl InferenceContext<'_> {
             | Pat::ConstBlock(_)
             | Pat::Path(_)
             | Pat::Lit(_) => self.consume_place(place, pat.into()),
-            Pat::Bind { id, subpat: _ } => {
-                let mode = self.result.binding_modes[*id];
+            Pat::Bind { id: _, subpat: _ } => {
+                let mode = self.result.binding_modes[pat];
                 let capture_kind = match mode {
                     BindingMode::Move => {
                         self.consume_place(place, pat.into());
@@ -924,6 +950,7 @@ impl InferenceContext<'_> {
                 self.result.mutated_bindings_in_closure.insert(item.place.local);
             }
         }
+        self.restrict_precision_for_unsafe();
         // closure_kind should be done before adjust_for_move_closure
         let closure_kind = self.closure_kind();
         match capture_by {
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer/expr.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer/expr.rs
index 0c3c725a7..a5e77a12d 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer/expr.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer/expr.rs
@@ -18,7 +18,6 @@ use hir_def::{
 use hir_expand::name::{name, Name};
 use stdx::always;
 use syntax::ast::RangeOp;
-use triomphe::Arc;
 
 use crate::{
     autoderef::{builtin_deref, deref_by_trait, Autoderef},
@@ -40,7 +39,8 @@ use crate::{
     traits::FnTrait,
     utils::{generics, Generics},
     Adjust, Adjustment, AdtId, AutoBorrow, Binders, CallableDefId, FnPointer, FnSig, FnSubst,
-    Interner, Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyExt, TyKind,
+    Interner, Rawness, Scalar, Substitution, TraitEnvironment, TraitRef, Ty, TyBuilder, TyExt,
+    TyKind,
 };
 
 use super::{
@@ -579,7 +579,7 @@ impl InferenceContext<'_> {
                 }
                 ty
             }
-            Expr::Field { expr, name } => self.infer_field_access(tgt_expr, *expr, name),
+            Expr::Field { expr, name } => self.infer_field_access(tgt_expr, *expr, name, expected),
             Expr::Await { expr } => {
                 let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 self.resolve_associated_type(inner_ty, self.resolve_future_future_output())
@@ -1291,7 +1291,7 @@ impl InferenceContext<'_> {
         let g = self.resolver.update_to_inner_scope(self.db.upcast(), self.owner, expr);
         let prev_env = block_id.map(|block_id| {
             let prev_env = self.table.trait_env.clone();
-            Arc::make_mut(&mut self.table.trait_env).block = Some(block_id);
+            TraitEnvironment::with_block(&mut self.table.trait_env, block_id);
             prev_env
         });
 
@@ -1456,7 +1456,13 @@ impl InferenceContext<'_> {
         })
     }
 
-    fn infer_field_access(&mut self, tgt_expr: ExprId, receiver: ExprId, name: &Name) -> Ty {
+    fn infer_field_access(
+        &mut self,
+        tgt_expr: ExprId,
+        receiver: ExprId,
+        name: &Name,
+        expected: &Expectation,
+    ) -> Ty {
         let receiver_ty = self.infer_expr_inner(receiver, &Expectation::none());
 
         if name.is_missing() {
@@ -1482,28 +1488,42 @@ impl InferenceContext<'_> {
                 ty
             }
             None => {
-                // no field found,
-                let method_with_same_name_exists = {
-                    self.get_traits_in_scope();
-
-                    let canonicalized_receiver = self.canonicalize(receiver_ty.clone());
-                    method_resolution::lookup_method(
-                        self.db,
-                        &canonicalized_receiver.value,
-                        self.table.trait_env.clone(),
-                        self.get_traits_in_scope().as_ref().left_or_else(|&it| it),
-                        VisibleFromModule::Filter(self.resolver.module()),
-                        name,
-                    )
-                    .is_some()
-                };
+                // no field found, lets attempt to resolve it like a function so that IDE things
+                // work out while people are typing
+                let canonicalized_receiver = self.canonicalize(receiver_ty.clone());
+                let resolved = method_resolution::lookup_method(
+                    self.db,
+                    &canonicalized_receiver.value,
+                    self.table.trait_env.clone(),
+                    self.get_traits_in_scope().as_ref().left_or_else(|&it| it),
+                    VisibleFromModule::Filter(self.resolver.module()),
+                    name,
+                );
                 self.result.diagnostics.push(InferenceDiagnostic::UnresolvedField {
                     expr: tgt_expr,
-                    receiver: receiver_ty,
+                    receiver: receiver_ty.clone(),
                     name: name.clone(),
-                    method_with_same_name_exists,
+                    method_with_same_name_exists: resolved.is_some(),
                 });
-                self.err_ty()
+                match resolved {
+                    Some((adjust, func, _)) => {
+                        let (ty, adjustments) = adjust.apply(&mut self.table, receiver_ty);
+                        let generics = generics(self.db.upcast(), func.into());
+                        let substs = self.substs_for_method_call(generics, None);
+                        self.write_expr_adj(receiver, adjustments);
+                        self.write_method_resolution(tgt_expr, func, substs.clone());
+
+                        self.check_method_call(
+                            tgt_expr,
+                            &[],
+                            self.db.value_ty(func.into()),
+                            substs,
+                            ty,
+                            expected,
+                        )
+                    }
+                    None => self.err_ty(),
+                }
             }
         }
     }
@@ -1517,7 +1537,7 @@ impl InferenceContext<'_> {
         generic_args: Option<&GenericArgs>,
         expected: &Expectation,
     ) -> Ty {
-        let receiver_ty = self.infer_expr(receiver, &Expectation::none());
+        let receiver_ty = self.infer_expr_inner(receiver, &Expectation::none());
         let canonicalized_receiver = self.canonicalize(receiver_ty.clone());
 
         let resolved = method_resolution::lookup_method(
@@ -1568,23 +1588,32 @@ impl InferenceContext<'_> {
                 )
             }
         };
+        self.check_method_call(tgt_expr, args, method_ty, substs, receiver_ty, expected)
+    }
+
+    fn check_method_call(
+        &mut self,
+        tgt_expr: ExprId,
+        args: &[ExprId],
+        method_ty: Binders<Ty>,
+        substs: Substitution,
+        receiver_ty: Ty,
+        expected: &Expectation,
+    ) -> Ty {
         let method_ty = method_ty.substitute(Interner, &substs);
         self.register_obligations_for_call(&method_ty);
-        let (formal_receiver_ty, param_tys, ret_ty, is_varargs) =
+        let ((formal_receiver_ty, param_tys), ret_ty, is_varargs) =
             match method_ty.callable_sig(self.db) {
-                Some(sig) => {
+                Some(sig) => (
                     if !sig.params().is_empty() {
-                        (
-                            sig.params()[0].clone(),
-                            sig.params()[1..].to_vec(),
-                            sig.ret().clone(),
-                            sig.is_varargs,
-                        )
+                        (sig.params()[0].clone(), sig.params()[1..].to_vec())
                     } else {
-                        (self.err_ty(), Vec::new(), sig.ret().clone(), sig.is_varargs)
-                    }
-                }
-                None => (self.err_ty(), Vec::new(), self.err_ty(), true),
+                        (self.err_ty(), Vec::new())
+                    },
+                    sig.ret().clone(),
+                    sig.is_varargs,
+                ),
+                None => ((self.err_ty(), Vec::new()), self.err_ty(), true),
             };
         self.unify(&formal_receiver_ty, &receiver_ty);
 
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer/pat.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer/pat.rs
index 4e28ec060..acdb54028 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer/pat.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer/pat.rs
@@ -262,7 +262,7 @@ impl InferenceContext<'_> {
     fn infer_pat(&mut self, pat: PatId, expected: &Ty, mut default_bm: BindingMode) -> Ty {
         let mut expected = self.resolve_ty_shallow(expected);
 
-        if is_non_ref_pat(self.body, pat) {
+        if self.is_non_ref_pat(self.body, pat) {
             let mut pat_adjustments = Vec::new();
             while let Some((inner, _lifetime, mutability)) = expected.as_reference() {
                 pat_adjustments.push(expected.clone());
@@ -421,7 +421,7 @@ impl InferenceContext<'_> {
         } else {
             BindingMode::convert(mode)
         };
-        self.result.binding_modes.insert(binding, mode);
+        self.result.binding_modes.insert(pat, mode);
 
         let inner_ty = match subpat {
             Some(subpat) => self.infer_pat(subpat, &expected, default_bm),
@@ -496,24 +496,28 @@ impl InferenceContext<'_> {
 
         self.infer_expr(expr, &Expectation::has_type(expected.clone()))
     }
-}
 
-fn is_non_ref_pat(body: &hir_def::body::Body, pat: PatId) -> bool {
-    match &body[pat] {
-        Pat::Tuple { .. }
-        | Pat::TupleStruct { .. }
-        | Pat::Record { .. }
-        | Pat::Range { .. }
-        | Pat::Slice { .. } => true,
-        Pat::Or(pats) => pats.iter().all(|p| is_non_ref_pat(body, *p)),
-        // FIXME: ConstBlock/Path/Lit might actually evaluate to ref, but inference is unimplemented.
-        Pat::Path(..) => true,
-        Pat::ConstBlock(..) => true,
-        Pat::Lit(expr) => !matches!(
-            body[*expr],
-            Expr::Literal(Literal::String(..) | Literal::CString(..) | Literal::ByteString(..))
-        ),
-        Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Box { .. } | Pat::Missing => false,
+    fn is_non_ref_pat(&mut self, body: &hir_def::body::Body, pat: PatId) -> bool {
+        match &body[pat] {
+            Pat::Tuple { .. }
+            | Pat::TupleStruct { .. }
+            | Pat::Record { .. }
+            | Pat::Range { .. }
+            | Pat::Slice { .. } => true,
+            Pat::Or(pats) => pats.iter().all(|p| self.is_non_ref_pat(body, *p)),
+            Pat::Path(p) => {
+                let v = self.resolve_value_path_inner(p, pat.into());
+                v.is_some_and(|x| !matches!(x.0, hir_def::resolver::ValueNs::ConstId(_)))
+            }
+            Pat::ConstBlock(..) => false,
+            Pat::Lit(expr) => !matches!(
+                body[*expr],
+                Expr::Literal(Literal::String(..) | Literal::CString(..) | Literal::ByteString(..))
+            ),
+            Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Box { .. } | Pat::Missing => {
+                false
+            }
+        }
     }
 }
 
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer/path.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer/path.rs
index c6bbf2f61..49fb78f67 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer/path.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer/path.rs
@@ -40,33 +40,7 @@ impl InferenceContext<'_> {
     }
 
     fn resolve_value_path(&mut self, path: &Path, id: ExprOrPatId) -> Option<ValuePathResolution> {
-        let (value, self_subst) = if let Some(type_ref) = path.type_anchor() {
-            let last = path.segments().last()?;
-
-            // Don't use `self.make_ty()` here as we need `orig_ns`.
-            let ctx =
-                crate::lower::TyLoweringContext::new(self.db, &self.resolver, self.owner.into());
-            let (ty, orig_ns) = ctx.lower_ty_ext(type_ref);
-            let ty = self.table.insert_type_vars(ty);
-            let ty = self.table.normalize_associated_types_in(ty);
-
-            let remaining_segments_for_ty = path.segments().take(path.segments().len() - 1);
-            let (ty, _) = ctx.lower_ty_relative_path(ty, orig_ns, remaining_segments_for_ty);
-            let ty = self.table.insert_type_vars(ty);
-            let ty = self.table.normalize_associated_types_in(ty);
-            self.resolve_ty_assoc_item(ty, last.name, id).map(|(it, substs)| (it, Some(substs)))?
-        } else {
-            // FIXME: report error, unresolved first path segment
-            let value_or_partial =
-                self.resolver.resolve_path_in_value_ns(self.db.upcast(), path)?;
-
-            match value_or_partial {
-                ResolveValueResult::ValueNs(it, _) => (it, None),
-                ResolveValueResult::Partial(def, remaining_index, _) => self
-                    .resolve_assoc_item(def, path, remaining_index, id)
-                    .map(|(it, substs)| (it, Some(substs)))?,
-            }
-        };
+        let (value, self_subst) = self.resolve_value_path_inner(path, id)?;
 
         let value_def = match value {
             ValueNs::LocalBinding(pat) => match self.result.type_of_binding.get(pat) {
@@ -144,6 +118,41 @@ impl InferenceContext<'_> {
         Some(ValuePathResolution::GenericDef(value_def, generic_def, substs))
     }
 
+    pub(super) fn resolve_value_path_inner(
+        &mut self,
+        path: &Path,
+        id: ExprOrPatId,
+    ) -> Option<(ValueNs, Option<chalk_ir::Substitution<Interner>>)> {
+        let (value, self_subst) = if let Some(type_ref) = path.type_anchor() {
+            let last = path.segments().last()?;
+
+            // Don't use `self.make_ty()` here as we need `orig_ns`.
+            let ctx =
+                crate::lower::TyLoweringContext::new(self.db, &self.resolver, self.owner.into());
+            let (ty, orig_ns) = ctx.lower_ty_ext(type_ref);
+            let ty = self.table.insert_type_vars(ty);
+            let ty = self.table.normalize_associated_types_in(ty);
+
+            let remaining_segments_for_ty = path.segments().take(path.segments().len() - 1);
+            let (ty, _) = ctx.lower_ty_relative_path(ty, orig_ns, remaining_segments_for_ty);
+            let ty = self.table.insert_type_vars(ty);
+            let ty = self.table.normalize_associated_types_in(ty);
+            self.resolve_ty_assoc_item(ty, last.name, id).map(|(it, substs)| (it, Some(substs)))?
+        } else {
+            // FIXME: report error, unresolved first path segment
+            let value_or_partial =
+                self.resolver.resolve_path_in_value_ns(self.db.upcast(), path)?;
+
+            match value_or_partial {
+                ResolveValueResult::ValueNs(it, _) => (it, None),
+                ResolveValueResult::Partial(def, remaining_index, _) => self
+                    .resolve_assoc_item(def, path, remaining_index, id)
+                    .map(|(it, substs)| (it, Some(substs)))?,
+            }
+        };
+        Some((value, self_subst))
+    }
+
     fn add_required_obligations_for_value_path(&mut self, def: GenericDefId, subst: &Substitution) {
         let predicates = self.db.generic_predicates(def);
         for predicate in predicates.iter() {
@@ -390,6 +399,7 @@ impl InferenceContext<'_> {
     }
 }
 
+#[derive(Debug)]
 enum ValuePathResolution {
     // It's awkward to wrap a single ID in two enums, but we need both and this saves fallible
     // conversion between them + `unwrap()`.
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/infer/unify.rs b/src/tools/rust-analyzer/crates/hir-ty/src/infer/unify.rs
index 0a68a9f3b..ac39bdf5b 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/infer/unify.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/infer/unify.rs
@@ -43,7 +43,7 @@ where
 }
 
 impl<T: HasInterner<Interner = Interner>> Canonicalized<T> {
-    pub(super) fn apply_solution(
+    pub(crate) fn apply_solution(
         &self,
         ctx: &mut InferenceTable<'_>,
         solution: Canonical<Substitution>,
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs b/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs
index 1a6106c02..bfc4f1383 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs
@@ -1,5 +1,8 @@
 //! Compute the binary representation of a type
 
+use std::fmt;
+
+use base_db::salsa::Cycle;
 use chalk_ir::{AdtId, FloatTy, IntTy, TyKind, UintTy};
 use hir_def::{
     layout::{
@@ -9,6 +12,10 @@ use hir_def::{
     LocalEnumVariantId, LocalFieldId, StructId,
 };
 use la_arena::{Idx, RawIdx};
+use rustc_dependencies::{
+    abi::AddressSpace,
+    index::{IndexSlice, IndexVec},
+};
 use stdx::never;
 use triomphe::Arc;
 
@@ -22,19 +29,13 @@ pub use self::{
     target::target_data_layout_query,
 };
 
-macro_rules! user_error {
-    ($it: expr) => {
-        return Err(LayoutError::UserError(format!($it).into()))
-    };
-}
-
 mod adt;
 mod target;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct RustcEnumVariantIdx(pub LocalEnumVariantId);
 
-impl rustc_index::vec::Idx for RustcEnumVariantIdx {
+impl rustc_dependencies::index::Idx for RustcEnumVariantIdx {
     fn new(idx: usize) -> Self {
         RustcEnumVariantIdx(Idx::from_raw(RawIdx::from(idx as u32)))
     }
@@ -44,19 +45,63 @@ impl rustc_index::vec::Idx for RustcEnumVariantIdx {
     }
 }
 
-pub type Layout = LayoutS<RustcEnumVariantIdx>;
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct RustcFieldIdx(pub LocalFieldId);
+
+impl RustcFieldIdx {
+    pub fn new(idx: usize) -> Self {
+        RustcFieldIdx(Idx::from_raw(RawIdx::from(idx as u32)))
+    }
+}
+
+impl rustc_dependencies::index::Idx for RustcFieldIdx {
+    fn new(idx: usize) -> Self {
+        RustcFieldIdx(Idx::from_raw(RawIdx::from(idx as u32)))
+    }
+
+    fn index(self) -> usize {
+        u32::from(self.0.into_raw()) as usize
+    }
+}
+
+pub type Layout = LayoutS<RustcFieldIdx, RustcEnumVariantIdx>;
 pub type TagEncoding = hir_def::layout::TagEncoding<RustcEnumVariantIdx>;
-pub type Variants = hir_def::layout::Variants<RustcEnumVariantIdx>;
+pub type Variants = hir_def::layout::Variants<RustcFieldIdx, RustcEnumVariantIdx>;
 
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum LayoutError {
-    UserError(Box<str>),
-    SizeOverflow,
-    TargetLayoutNotAvailable,
-    HasPlaceholder,
+    HasErrorConst,
     HasErrorType,
+    HasPlaceholder,
+    InvalidSimdType,
     NotImplemented,
+    RecursiveTypeWithoutIndirection,
+    SizeOverflow,
+    TargetLayoutNotAvailable,
     Unknown,
+    UserReprTooSmall,
+}
+
+impl std::error::Error for LayoutError {}
+impl fmt::Display for LayoutError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            LayoutError::HasErrorConst => write!(f, "type contains an unevaluatable const"),
+            LayoutError::HasErrorType => write!(f, "type contains an error"),
+            LayoutError::HasPlaceholder => write!(f, "type contains placeholders"),
+            LayoutError::InvalidSimdType => write!(f, "invalid simd type definition"),
+            LayoutError::NotImplemented => write!(f, "not implemented"),
+            LayoutError::RecursiveTypeWithoutIndirection => {
+                write!(f, "recursive type without indirection")
+            }
+            LayoutError::SizeOverflow => write!(f, "size overflow"),
+            LayoutError::TargetLayoutNotAvailable => write!(f, "target layout not available"),
+            LayoutError::Unknown => write!(f, "unknown"),
+            LayoutError::UserReprTooSmall => {
+                write!(f, "the `#[repr]` hint is too small to hold the discriminants of the enum")
+            }
+        }
+    }
 }
 
 struct LayoutCx<'a> {
@@ -66,7 +111,7 @@ struct LayoutCx<'a> {
 impl<'a> LayoutCalculator for LayoutCx<'a> {
     type TargetDataLayoutRef = &'a TargetDataLayout;
 
-    fn delay_bug(&self, txt: &str) {
+    fn delayed_bug(&self, txt: String) {
         never!("{}", txt);
     }
 
@@ -95,9 +140,7 @@ fn layout_of_simd_ty(
 
     let f0_ty = match fields.iter().next() {
         Some(it) => it.1.clone().substitute(Interner, subst),
-        None => {
-            user_error!("simd type with zero fields");
-        }
+        None => return Err(LayoutError::InvalidSimdType),
     };
 
     // The element type and number of elements of the SIMD vector
@@ -111,7 +154,7 @@ fn layout_of_simd_ty(
         // Extract the number of elements from the layout of the array field:
         let FieldsShape::Array { count, .. } = db.layout_of_ty(f0_ty.clone(), env.clone())?.fields
         else {
-            user_error!("Array with non array layout");
+            return Err(LayoutError::Unknown);
         };
 
         (e_ty.clone(), count, true)
@@ -123,7 +166,7 @@ fn layout_of_simd_ty(
     // Compute the ABI of the element type:
     let e_ly = db.layout_of_ty(e_ty, env.clone())?;
     let Abi::Scalar(e_abi) = e_ly.abi else {
-        user_error!("simd type with inner non scalar type");
+        return Err(LayoutError::Unknown);
     };
 
     // Compute the size and alignment of the vector:
@@ -145,6 +188,8 @@ fn layout_of_simd_ty(
         largest_niche: e_ly.largest_niche,
         size,
         align,
+        max_repr_align: None,
+        unadjusted_abi_align: align.abi,
     }))
 }
 
@@ -230,13 +275,11 @@ pub fn layout_of_ty_query(
                 .map(|k| db.layout_of_ty(k.assert_ty_ref(Interner).clone(), trait_env.clone()))
                 .collect::<Result<Vec<_>, _>>()?;
             let fields = fields.iter().map(|it| &**it).collect::<Vec<_>>();
-            let fields = fields.iter().collect::<Vec<_>>();
+            let fields = fields.iter().collect::<IndexVec<_, _>>();
             cx.univariant(dl, &fields, &ReprOptions::default(), kind).ok_or(LayoutError::Unknown)?
         }
         TyKind::Array(element, count) => {
-            let count = try_const_usize(db, &count).ok_or(LayoutError::UserError(Box::from(
-                "unevaluated or mistyped const generic parameter",
-            )))? as u64;
+            let count = try_const_usize(db, &count).ok_or(LayoutError::HasErrorConst)? as u64;
             let element = db.layout_of_ty(element.clone(), trait_env.clone())?;
             let size = element.size.checked_mul(count, dl).ok_or(LayoutError::SizeOverflow)?;
 
@@ -255,6 +298,8 @@ pub fn layout_of_ty_query(
                 largest_niche,
                 align: element.align,
                 size,
+                max_repr_align: None,
+                unadjusted_abi_align: element.align.abi,
             }
         }
         TyKind::Slice(element) => {
@@ -266,11 +311,23 @@ pub fn layout_of_ty_query(
                 largest_niche: None,
                 align: element.align,
                 size: Size::ZERO,
+                max_repr_align: None,
+                unadjusted_abi_align: element.align.abi,
             }
         }
+        TyKind::Str => Layout {
+            variants: Variants::Single { index: struct_variant_idx() },
+            fields: FieldsShape::Array { stride: Size::from_bytes(1), count: 0 },
+            abi: Abi::Aggregate { sized: false },
+            largest_niche: None,
+            align: dl.i8_align,
+            size: Size::ZERO,
+            max_repr_align: None,
+            unadjusted_abi_align: dl.i8_align.abi,
+        },
         // Potentially-wide pointers.
         TyKind::Ref(_, _, pointee) | TyKind::Raw(_, pointee) => {
-            let mut data_ptr = scalar_unit(dl, Primitive::Pointer);
+            let mut data_ptr = scalar_unit(dl, Primitive::Pointer(AddressSpace::DATA));
             if matches!(ty.kind(Interner), TyKind::Ref(..)) {
                 data_ptr.valid_range_mut().start = 1;
             }
@@ -294,7 +351,7 @@ pub fn layout_of_ty_query(
                     scalar_unit(dl, Primitive::Int(dl.ptr_sized_integer(), false))
                 }
                 TyKind::Dyn(..) => {
-                    let mut vtable = scalar_unit(dl, Primitive::Pointer);
+                    let mut vtable = scalar_unit(dl, Primitive::Pointer(AddressSpace::DATA));
                     vtable.valid_range_mut().start = 1;
                     vtable
                 }
@@ -308,32 +365,17 @@ pub fn layout_of_ty_query(
             cx.scalar_pair(data_ptr, metadata)
         }
         TyKind::FnDef(_, _) => layout_of_unit(&cx, dl)?,
-        TyKind::Str => Layout {
-            variants: Variants::Single { index: struct_variant_idx() },
-            fields: FieldsShape::Array { stride: Size::from_bytes(1), count: 0 },
-            abi: Abi::Aggregate { sized: false },
-            largest_niche: None,
-            align: dl.i8_align,
-            size: Size::ZERO,
-        },
-        TyKind::Never => Layout {
-            variants: Variants::Single { index: struct_variant_idx() },
-            fields: FieldsShape::Primitive,
-            abi: Abi::Uninhabited,
-            largest_niche: None,
-            align: dl.i8_align,
-            size: Size::ZERO,
-        },
+        TyKind::Never => cx.layout_of_never_type(),
         TyKind::Dyn(_) | TyKind::Foreign(_) => {
             let mut unit = layout_of_unit(&cx, dl)?;
             match unit.abi {
                 Abi::Aggregate { ref mut sized } => *sized = false,
-                _ => user_error!("bug"),
+                _ => return Err(LayoutError::Unknown),
             }
             unit
         }
         TyKind::Function(_) => {
-            let mut ptr = scalar_unit(dl, Primitive::Pointer);
+            let mut ptr = scalar_unit(dl, Primitive::Pointer(dl.instruction_address_space));
             ptr.valid_range_mut().start = 1;
             Layout::scalar(dl, ptr)
         }
@@ -363,7 +405,7 @@ pub fn layout_of_ty_query(
                 })
                 .collect::<Result<Vec<_>, _>>()?;
             let fields = fields.iter().map(|it| &**it).collect::<Vec<_>>();
-            let fields = fields.iter().collect::<Vec<_>>();
+            let fields = fields.iter().collect::<IndexVec<_, _>>();
             cx.univariant(dl, &fields, &ReprOptions::default(), StructKind::AlwaysSized)
                 .ok_or(LayoutError::Unknown)?
         }
@@ -390,17 +432,17 @@ pub fn layout_of_ty_query(
 
 pub fn layout_of_ty_recover(
     _: &dyn HirDatabase,
-    _: &[String],
+    _: &Cycle,
     _: &Ty,
     _: &Arc<TraitEnvironment>,
 ) -> Result<Arc<Layout>, LayoutError> {
-    user_error!("infinite sized recursive type");
+    Err(LayoutError::RecursiveTypeWithoutIndirection)
 }
 
 fn layout_of_unit(cx: &LayoutCx<'_>, dl: &TargetDataLayout) -> Result<Layout, LayoutError> {
-    cx.univariant::<RustcEnumVariantIdx, &&Layout>(
+    cx.univariant::<RustcFieldIdx, RustcEnumVariantIdx, &&Layout>(
         dl,
-        &[],
+        IndexSlice::empty(),
         &ReprOptions::default(),
         StructKind::AlwaysSized,
     )
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/layout/adt.rs b/src/tools/rust-analyzer/crates/hir-ty/src/layout/adt.rs
index 85ef649b8..39788a950 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/layout/adt.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/layout/adt.rs
@@ -2,12 +2,14 @@
 
 use std::{cmp, ops::Bound};
 
+use base_db::salsa::Cycle;
 use hir_def::{
     data::adt::VariantData,
     layout::{Integer, LayoutCalculator, ReprOptions, TargetDataLayout},
     AdtId, EnumVariantId, LocalEnumVariantId, VariantId,
 };
 use la_arena::RawIdx;
+use rustc_dependencies::index::IndexVec;
 use smallvec::SmallVec;
 use triomphe::Arc;
 
@@ -20,8 +22,8 @@ use crate::{
 
 use super::LayoutCx;
 
-pub(crate) fn struct_variant_idx() -> RustcEnumVariantIdx {
-    RustcEnumVariantIdx(LocalEnumVariantId::from_raw(RawIdx::from(0)))
+pub(crate) const fn struct_variant_idx() -> RustcEnumVariantIdx {
+    RustcEnumVariantIdx(LocalEnumVariantId::from_raw(RawIdx::from_u32(0)))
 }
 
 pub fn layout_of_adt_query(
@@ -74,7 +76,7 @@ pub fn layout_of_adt_query(
         .iter()
         .map(|it| it.iter().map(|it| &**it).collect::<Vec<_>>())
         .collect::<SmallVec<[_; 1]>>();
-    let variants = variants.iter().map(|it| it.iter().collect()).collect();
+    let variants = variants.iter().map(|it| it.iter().collect()).collect::<IndexVec<_, _>>();
     let result = if matches!(def, AdtId::UnionId(..)) {
         cx.layout_of_union(&repr, &variants).ok_or(LayoutError::Unknown)?
     } else {
@@ -105,7 +107,7 @@ pub fn layout_of_adt_query(
                 && variants
                     .iter()
                     .next()
-                    .and_then(|it| it.last().map(|it| !it.is_unsized()))
+                    .and_then(|it| it.iter().last().map(|it| !it.is_unsized()))
                     .unwrap_or(true),
         )
         .ok_or(LayoutError::SizeOverflow)?
@@ -119,7 +121,15 @@ fn layout_scalar_valid_range(db: &dyn HirDatabase, def: AdtId) -> (Bound<u128>,
         let attr = attrs.by_key(name).tt_values();
         for tree in attr {
             if let Some(it) = tree.token_trees.first() {
-                if let Ok(it) = it.to_string().parse() {
+                let text = it.to_string().replace('_', "");
+                let (text, base) = match text.as_bytes() {
+                    [b'0', b'x', ..] => (&text[2..], 16),
+                    [b'0', b'o', ..] => (&text[2..], 8),
+                    [b'0', b'b', ..] => (&text[2..], 2),
+                    _ => (&*text, 10),
+                };
+
+                if let Ok(it) = u128::from_str_radix(text, base) {
                     return Bound::Included(it);
                 }
             }
@@ -131,12 +141,12 @@ fn layout_scalar_valid_range(db: &dyn HirDatabase, def: AdtId) -> (Bound<u128>,
 
 pub fn layout_of_adt_recover(
     _: &dyn HirDatabase,
-    _: &[String],
+    _: &Cycle,
     _: &AdtId,
     _: &Substitution,
     _: &Arc<TraitEnvironment>,
 ) -> Result<Arc<Layout>, LayoutError> {
-    user_error!("infinite sized recursive type");
+    Err(LayoutError::RecursiveTypeWithoutIndirection)
 }
 
 /// Finds the appropriate Integer type and signedness for the given
@@ -160,11 +170,7 @@ fn repr_discr(
         let discr = Integer::from_attr(dl, ity);
         let fit = if ity.is_signed() { signed_fit } else { unsigned_fit };
         if discr < fit {
-            return Err(LayoutError::UserError(
-                "Integer::repr_discr: `#[repr]` hint too small for \
-                      discriminant range of enum "
-                    .into(),
-            ));
+            return Err(LayoutError::UserReprTooSmall);
         }
         return Ok((discr, ity.is_signed()));
     }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests.rs b/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests.rs
index ffdbb9de9..5e3a86c80 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests.rs
@@ -210,16 +210,13 @@ fn recursive() {
         struct BoxLike<T: ?Sized>(*mut T);
         struct Goal(BoxLike<Goal>);
     }
-    check_fail(
-        r#"struct Goal(Goal);"#,
-        LayoutError::UserError("infinite sized recursive type".into()),
-    );
+    check_fail(r#"struct Goal(Goal);"#, LayoutError::RecursiveTypeWithoutIndirection);
     check_fail(
         r#"
         struct Foo<T>(Foo<T>);
         struct Goal(Foo<i32>);
         "#,
-        LayoutError::UserError("infinite sized recursive type".into()),
+        LayoutError::RecursiveTypeWithoutIndirection,
     );
 }
 
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests/closure.rs b/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests/closure.rs
index bbe855a14..939025461 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests/closure.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/layout/tests/closure.rs
@@ -186,9 +186,9 @@ fn capture_specific_fields() {
 fn match_pattern() {
     size_and_align_expr! {
         struct X(i64, i32, (u8, i128));
-        let y: X = X(2, 5, (7, 3));
+        let _y: X = X(2, 5, (7, 3));
         move |x: i64| {
-            match y {
+            match _y {
                 _ => x,
             }
         }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
index 405bb001b..cf174feed 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
@@ -1,6 +1,7 @@
 //! The type system. We currently use this to infer types for completion, hover
 //! information and various assists.
-#![warn(rust_2018_idioms, unused_lifetimes, semicolon_in_expressions_from_macros)]
+#![warn(rust_2018_idioms, unused_lifetimes)]
+#![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
 
 #[allow(unused)]
 macro_rules! eprintln {
@@ -72,14 +73,15 @@ pub use infer::{
 };
 pub use interner::Interner;
 pub use lower::{
-    associated_type_shorthand_candidates, CallableDefId, ImplTraitLoweringMode, TyDefId,
-    TyLoweringContext, ValueTyDefId,
+    associated_type_shorthand_candidates, CallableDefId, ImplTraitLoweringMode, ParamLoweringMode,
+    TyDefId, TyLoweringContext, ValueTyDefId,
 };
 pub use mapping::{
     from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
     lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,
     to_placeholder_idx,
 };
+pub use method_resolution::check_orphan_rules;
 pub use traits::TraitEnvironment;
 pub use utils::{all_super_traits, is_fn_unsafe_to_call};
 
@@ -120,7 +122,7 @@ pub type TyKind = chalk_ir::TyKind<Interner>;
 pub type TypeFlags = chalk_ir::TypeFlags;
 pub type DynTy = chalk_ir::DynTy<Interner>;
 pub type FnPointer = chalk_ir::FnPointer<Interner>;
-// pub type FnSubst = chalk_ir::FnSubst<Interner>;
+// pub type FnSubst = chalk_ir::FnSubst<Interner>; // a re-export so we don't lose the tuple constructor
 pub use chalk_ir::FnSubst;
 pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
 pub type AliasTy = chalk_ir::AliasTy<Interner>;
@@ -320,8 +322,7 @@ impl CallableSig {
     pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
         CallableSig {
             // FIXME: what to do about lifetime params? -> return PolyFnSig
-            // FIXME: use `Arc::from_iter` when it becomes available
-            params_and_return: Arc::from(
+            params_and_return: Arc::from_iter(
                 fn_ptr
                     .substitution
                     .clone()
@@ -330,8 +331,7 @@ impl CallableSig {
                     .0
                     .as_slice(Interner)
                     .iter()
-                    .map(|arg| arg.assert_ty_ref(Interner).clone())
-                    .collect::<Vec<_>>(),
+                    .map(|arg| arg.assert_ty_ref(Interner).clone()),
             ),
             is_varargs: fn_ptr.sig.variadic,
             safety: fn_ptr.sig.safety,
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/lower.rs b/src/tools/rust-analyzer/crates/hir-ty/src/lower.rs
index 9a61f1535..97c4a741f 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/lower.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/lower.rs
@@ -10,7 +10,7 @@ use std::{
     iter,
 };
 
-use base_db::CrateId;
+use base_db::{salsa::Cycle, CrateId};
 use chalk_ir::{
     cast::Cast, fold::Shift, fold::TypeFoldable, interner::HasInterner, Mutability, Safety,
 };
@@ -113,7 +113,9 @@ pub struct TyLoweringContext<'a> {
     pub db: &'a dyn HirDatabase,
     resolver: &'a Resolver,
     in_binders: DebruijnIndex,
-    owner: TypeOwnerId,
+    // FIXME: Should not be an `Option` but `Resolver` currently does not return owners in all cases
+    // where expected
+    owner: Option<TypeOwnerId>,
     /// Note: Conceptually, it's thinkable that we could be in a location where
     /// some type params should be represented as placeholders, and others
     /// should be converted to variables. I think in practice, this isn't
@@ -127,6 +129,14 @@ pub struct TyLoweringContext<'a> {
 
 impl<'a> TyLoweringContext<'a> {
     pub fn new(db: &'a dyn HirDatabase, resolver: &'a Resolver, owner: TypeOwnerId) -> Self {
+        Self::new_maybe_unowned(db, resolver, Some(owner))
+    }
+
+    pub fn new_maybe_unowned(
+        db: &'a dyn HirDatabase,
+        resolver: &'a Resolver,
+        owner: Option<TypeOwnerId>,
+    ) -> Self {
         let impl_trait_mode = ImplTraitLoweringState::Disallowed;
         let type_param_mode = ParamLoweringMode::Placeholder;
         let in_binders = DebruijnIndex::INNERMOST;
@@ -213,10 +223,11 @@ impl<'a> TyLoweringContext<'a> {
     }
 
     pub fn lower_const(&self, const_ref: &ConstRef, const_type: Ty) -> Const {
+        let Some(owner) = self.owner else { return unknown_const(const_type) };
         const_or_path_to_chalk(
             self.db,
             self.resolver,
-            self.owner,
+            owner,
             const_type,
             const_ref,
             self.type_param_mode,
@@ -407,11 +418,7 @@ impl<'a> TyLoweringContext<'a> {
                             drop(expander);
                             let ty = self.lower_ty(&type_ref);
 
-                            self.expander
-                                .borrow_mut()
-                                .as_mut()
-                                .unwrap()
-                                .exit(self.db.upcast(), mark);
+                            self.expander.borrow_mut().as_mut().unwrap().exit(mark);
                             Some(ty)
                         }
                         _ => {
@@ -768,7 +775,7 @@ impl<'a> TyLoweringContext<'a> {
         }
     }
 
-    fn substs_from_path_segment(
+    pub(super) fn substs_from_path_segment(
         &self,
         segment: PathSegment<'_>,
         def: Option<GenericDefId>,
@@ -1097,10 +1104,25 @@ impl<'a> TyLoweringContext<'a> {
                     binding.type_ref.as_ref().map_or(0, |_| 1) + binding.bounds.len(),
                 );
                 if let Some(type_ref) = &binding.type_ref {
-                    let ty = self.lower_ty(type_ref);
-                    let alias_eq =
-                        AliasEq { alias: AliasTy::Projection(projection_ty.clone()), ty };
-                    predicates.push(crate::wrap_empty_binders(WhereClause::AliasEq(alias_eq)));
+                    if let (TypeRef::ImplTrait(bounds), ImplTraitLoweringState::Disallowed) =
+                        (type_ref, &self.impl_trait_mode)
+                    {
+                        for bound in bounds {
+                            predicates.extend(
+                                self.lower_type_bound(
+                                    bound,
+                                    TyKind::Alias(AliasTy::Projection(projection_ty.clone()))
+                                        .intern(Interner),
+                                    false,
+                                ),
+                            );
+                        }
+                    } else {
+                        let ty = self.lower_ty(type_ref);
+                        let alias_eq =
+                            AliasEq { alias: AliasTy::Projection(projection_ty.clone()), ty };
+                        predicates.push(crate::wrap_empty_binders(WhereClause::AliasEq(alias_eq)));
+                    }
                 }
                 for bound in binding.bounds.iter() {
                     predicates.extend(self.lower_type_bound(
@@ -1383,51 +1405,50 @@ pub(crate) fn generic_predicates_for_param_query(
     let ctx = TyLoweringContext::new(db, &resolver, def.into())
         .with_type_param_mode(ParamLoweringMode::Variable);
     let generics = generics(db.upcast(), def);
-    let mut predicates: Vec<_> = resolver
-        .where_predicates_in_scope()
-        // we have to filter out all other predicates *first*, before attempting to lower them
-        .filter(|pred| match pred {
-            WherePredicate::ForLifetime { target, bound, .. }
-            | WherePredicate::TypeBound { target, bound, .. } => {
-                match target {
-                    WherePredicateTypeTarget::TypeRef(type_ref) => {
-                        if ctx.lower_ty_only_param(type_ref) != Some(param_id) {
-                            return false;
-                        }
-                    }
-                    &WherePredicateTypeTarget::TypeOrConstParam(local_id) => {
-                        let target_id = TypeOrConstParamId { parent: def, local_id };
-                        if target_id != param_id {
-                            return false;
-                        }
-                    }
-                };
 
-                match &**bound {
-                    TypeBound::ForLifetime(_, path) | TypeBound::Path(path, _) => {
-                        // Only lower the bound if the trait could possibly define the associated
-                        // type we're looking for.
+    // we have to filter out all other predicates *first*, before attempting to lower them
+    let predicate = |pred: &&_| match pred {
+        WherePredicate::ForLifetime { target, bound, .. }
+        | WherePredicate::TypeBound { target, bound, .. } => {
+            let invalid_target = match target {
+                WherePredicateTypeTarget::TypeRef(type_ref) => {
+                    ctx.lower_ty_only_param(type_ref) != Some(param_id)
+                }
+                &WherePredicateTypeTarget::TypeOrConstParam(local_id) => {
+                    let target_id = TypeOrConstParamId { parent: def, local_id };
+                    target_id != param_id
+                }
+            };
+            if invalid_target {
+                return false;
+            }
+
+            match &**bound {
+                TypeBound::ForLifetime(_, path) | TypeBound::Path(path, _) => {
+                    // Only lower the bound if the trait could possibly define the associated
+                    // type we're looking for.
 
-                        let assoc_name = match &assoc_name {
-                            Some(it) => it,
-                            None => return true,
-                        };
-                        let tr = match resolver.resolve_path_in_type_ns_fully(db.upcast(), path) {
-                            Some(TypeNs::TraitId(tr)) => tr,
-                            _ => return false,
-                        };
+                    let Some(assoc_name) = &assoc_name else { return true };
+                    let Some(TypeNs::TraitId(tr)) =
+                        resolver.resolve_path_in_type_ns_fully(db.upcast(), path)
+                    else {
+                        return false;
+                    };
 
-                        all_super_traits(db.upcast(), tr).iter().any(|tr| {
-                            db.trait_data(*tr).items.iter().any(|(name, item)| {
-                                matches!(item, AssocItemId::TypeAliasId(_)) && name == assoc_name
-                            })
+                    all_super_traits(db.upcast(), tr).iter().any(|tr| {
+                        db.trait_data(*tr).items.iter().any(|(name, item)| {
+                            matches!(item, AssocItemId::TypeAliasId(_)) && name == assoc_name
                         })
-                    }
-                    TypeBound::Lifetime(_) | TypeBound::Error => false,
+                    })
                 }
+                TypeBound::Lifetime(_) | TypeBound::Error => false,
             }
-            WherePredicate::Lifetime { .. } => false,
-        })
+        }
+        WherePredicate::Lifetime { .. } => false,
+    };
+    let mut predicates: Vec<_> = resolver
+        .where_predicates_in_scope()
+        .filter(predicate)
         .flat_map(|pred| {
             ctx.lower_where_predicate(pred, true).map(|p| make_binders(db, &generics, p))
         })
@@ -1444,13 +1465,12 @@ pub(crate) fn generic_predicates_for_param_query(
 
 pub(crate) fn generic_predicates_for_param_recover(
     _db: &dyn HirDatabase,
-    _cycle: &[String],
+    _cycle: &Cycle,
     _def: &GenericDefId,
     _param_id: &TypeOrConstParamId,
     _assoc_name: &Option<Name>,
 ) -> Arc<[Binders<QuantifiedWhereClause>]> {
-    // FIXME: use `Arc::from_iter` when it becomes available
-    Arc::from(vec![])
+    Arc::from_iter(None)
 }
 
 pub(crate) fn trait_environment_for_body_query(
@@ -1459,7 +1479,7 @@ pub(crate) fn trait_environment_for_body_query(
 ) -> Arc<TraitEnvironment> {
     let Some(def) = def.as_generic_def_id() else {
         let krate = def.module(db.upcast()).krate();
-        return Arc::new(TraitEnvironment::empty(krate));
+        return TraitEnvironment::empty(krate);
     };
     db.trait_environment(def)
 }
@@ -1519,7 +1539,7 @@ pub(crate) fn trait_environment_query(
 
     let env = chalk_ir::Environment::new(Interner).add_clauses(Interner, clauses);
 
-    Arc::new(TraitEnvironment { krate, block: None, traits_from_clauses: traits_in_scope, env })
+    TraitEnvironment::new(krate, None, traits_in_scope.into_boxed_slice(), env)
 }
 
 /// Resolve the where clause(s) of an item with generics.
@@ -1588,69 +1608,54 @@ pub(crate) fn generic_defaults_query(
     let generic_params = generics(db.upcast(), def);
     let parent_start_idx = generic_params.len_self();
 
-    let defaults = Arc::from(
-        generic_params
-            .iter()
-            .enumerate()
-            .map(|(idx, (id, p))| {
-                match p {
-                    TypeOrConstParamData::TypeParamData(p) => {
-                        let mut ty = p
-                            .default
-                            .as_ref()
-                            .map_or(TyKind::Error.intern(Interner), |t| ctx.lower_ty(t));
-                        // Each default can only refer to previous parameters.
-                        // Type variable default referring to parameter coming
-                        // after it is forbidden (FIXME: report diagnostic)
-                        ty = fallback_bound_vars(ty, idx, parent_start_idx);
-                        crate::make_binders(db, &generic_params, ty.cast(Interner))
-                    }
-                    TypeOrConstParamData::ConstParamData(p) => {
-                        let mut val = p.default.as_ref().map_or_else(
-                            || {
-                                unknown_const_as_generic(
-                                    db.const_param_ty(ConstParamId::from_unchecked(id)),
-                                )
-                            },
-                            |c| {
-                                let c = ctx.lower_const(c, ctx.lower_ty(&p.ty));
-                                c.cast(Interner)
-                            },
-                        );
-                        // Each default can only refer to previous parameters, see above.
-                        val = fallback_bound_vars(val, idx, parent_start_idx);
-                        make_binders(db, &generic_params, val)
-                    }
-                }
-            })
-            // FIXME: use `Arc::from_iter` when it becomes available
-            .collect::<Vec<_>>(),
-    );
+    let defaults = Arc::from_iter(generic_params.iter().enumerate().map(|(idx, (id, p))| {
+        match p {
+            TypeOrConstParamData::TypeParamData(p) => {
+                let mut ty =
+                    p.default.as_ref().map_or(TyKind::Error.intern(Interner), |t| ctx.lower_ty(t));
+                // Each default can only refer to previous parameters.
+                // Type variable default referring to parameter coming
+                // after it is forbidden (FIXME: report diagnostic)
+                ty = fallback_bound_vars(ty, idx, parent_start_idx);
+                crate::make_binders(db, &generic_params, ty.cast(Interner))
+            }
+            TypeOrConstParamData::ConstParamData(p) => {
+                let mut val = p.default.as_ref().map_or_else(
+                    || {
+                        unknown_const_as_generic(
+                            db.const_param_ty(ConstParamId::from_unchecked(id)),
+                        )
+                    },
+                    |c| {
+                        let c = ctx.lower_const(c, ctx.lower_ty(&p.ty));
+                        c.cast(Interner)
+                    },
+                );
+                // Each default can only refer to previous parameters, see above.
+                val = fallback_bound_vars(val, idx, parent_start_idx);
+                make_binders(db, &generic_params, val)
+            }
+        }
+    }));
 
     defaults
 }
 
 pub(crate) fn generic_defaults_recover(
     db: &dyn HirDatabase,
-    _cycle: &[String],
+    _cycle: &Cycle,
     def: &GenericDefId,
 ) -> Arc<[Binders<crate::GenericArg>]> {
     let generic_params = generics(db.upcast(), *def);
     // FIXME: this code is not covered in tests.
     // we still need one default per parameter
-    let defaults = Arc::from(
-        generic_params
-            .iter_id()
-            .map(|id| {
-                let val = match id {
-                    Either::Left(_) => TyKind::Error.intern(Interner).cast(Interner),
-                    Either::Right(id) => unknown_const_as_generic(db.const_param_ty(id)),
-                };
-                crate::make_binders(db, &generic_params, val)
-            })
-            // FIXME: use `Arc::from_iter` when it becomes available
-            .collect::<Vec<_>>(),
-    );
+    let defaults = Arc::from_iter(generic_params.iter_id().map(|id| {
+        let val = match id {
+            Either::Left(_) => TyKind::Error.intern(Interner).cast(Interner),
+            Either::Right(id) => unknown_const_as_generic(db.const_param_ty(id)),
+        };
+        crate::make_binders(db, &generic_params, val)
+    }));
 
     defaults
 }
@@ -1774,10 +1779,11 @@ fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
     let resolver = t.resolver(db.upcast());
     let ctx = TyLoweringContext::new(db, &resolver, t.into())
         .with_type_param_mode(ParamLoweringMode::Variable);
-    if db.type_alias_data(t).is_extern {
+    let type_alias_data = db.type_alias_data(t);
+    if type_alias_data.is_extern {
         Binders::empty(Interner, TyKind::Foreign(crate::to_foreign_def_id(t)).intern(Interner))
     } else {
-        let type_ref = &db.type_alias_data(t).type_ref;
+        let type_ref = &type_alias_data.type_ref;
         let inner = ctx.lower_ty(type_ref.as_deref().unwrap_or(&TypeRef::Error));
         make_binders(db, &generics, inner)
     }
@@ -1866,7 +1872,7 @@ pub(crate) fn ty_query(db: &dyn HirDatabase, def: TyDefId) -> Binders<Ty> {
     }
 }
 
-pub(crate) fn ty_recover(db: &dyn HirDatabase, _cycle: &[String], def: &TyDefId) -> Binders<Ty> {
+pub(crate) fn ty_recover(db: &dyn HirDatabase, _cycle: &Cycle, def: &TyDefId) -> Binders<Ty> {
     let generics = match *def {
         TyDefId::BuiltinType(_) => return Binders::empty(Interner, TyKind::Error.intern(Interner)),
         TyDefId::AdtId(it) => generics(db.upcast(), it.into()),
@@ -1916,7 +1922,7 @@ pub(crate) fn const_param_ty_query(db: &dyn HirDatabase, def: ConstParamId) -> T
 
 pub(crate) fn impl_self_ty_recover(
     db: &dyn HirDatabase,
-    _cycle: &[String],
+    _cycle: &Cycle,
     impl_id: &ImplId,
 ) -> Binders<Ty> {
     let generics = generics(db.upcast(), (*impl_id).into());
@@ -2048,7 +2054,7 @@ pub(crate) fn const_or_path_to_chalk(
                 .intern_in_type_const(InTypeConstLoc {
                     id: it,
                     owner,
-                    thing: Box::new(InTypeConstIdMetadata(expected_ty.clone())),
+                    expected_ty: Box::new(InTypeConstIdMetadata(expected_ty.clone())),
                 })
                 .into();
             intern_const_scalar(
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs b/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs
index f3a5f69b2..041d61c1b 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/method_resolution.rs
@@ -27,8 +27,9 @@ use crate::{
     primitive::{FloatTy, IntTy, UintTy},
     static_lifetime, to_chalk_trait_id,
     utils::all_super_traits,
-    AdtId, Canonical, CanonicalVarKinds, DebruijnIndex, DynTyExt, ForeignDefId, InEnvironment,
-    Interner, Scalar, Substitution, TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder, TyExt,
+    AdtId, Canonical, CanonicalVarKinds, DebruijnIndex, DynTyExt, ForeignDefId, Goal, Guidance,
+    InEnvironment, Interner, Scalar, Solution, Substitution, TraitEnvironment, TraitRef,
+    TraitRefExt, Ty, TyBuilder, TyExt,
 };
 
 /// This is used as a key for indexing impls.
@@ -167,12 +168,9 @@ impl TraitImpls {
     ) -> Arc<[Arc<Self>]> {
         let _p = profile::span("trait_impls_in_deps_query").detail(|| format!("{krate:?}"));
         let crate_graph = db.crate_graph();
-        // FIXME: use `Arc::from_iter` when it becomes available
-        Arc::from(
-            crate_graph
-                .transitive_deps(krate)
-                .map(|krate| db.trait_impls_in_crate(krate))
-                .collect::<Vec<_>>(),
+
+        Arc::from_iter(
+            crate_graph.transitive_deps(krate).map(|krate| db.trait_impls_in_crate(krate)),
         )
     }
 
@@ -862,6 +860,62 @@ fn is_inherent_impl_coherent(
     }
 }
 
+/// Checks whether the impl satisfies the orphan rules.
+///
+/// Given `impl<P1..=Pn> Trait<T1..=Tn> for T0`, an `impl`` is valid only if at least one of the following is true:
+/// - Trait is a local trait
+/// - All of
+///   - At least one of the types `T0..=Tn`` must be a local type. Let `Ti`` be the first such type.
+///   - No uncovered type parameters `P1..=Pn` may appear in `T0..Ti`` (excluding `Ti`)
+pub fn check_orphan_rules(db: &dyn HirDatabase, impl_: ImplId) -> bool {
+    let substs = TyBuilder::placeholder_subst(db, impl_);
+    let Some(impl_trait) = db.impl_trait(impl_) else {
+        // not a trait impl
+        return true;
+    };
+
+    let local_crate = impl_.lookup(db.upcast()).container.krate();
+    let is_local = |tgt_crate| tgt_crate == local_crate;
+
+    let trait_ref = impl_trait.substitute(Interner, &substs);
+    let trait_id = from_chalk_trait_id(trait_ref.trait_id);
+    if is_local(trait_id.module(db.upcast()).krate()) {
+        // trait to be implemented is local
+        return true;
+    }
+
+    let unwrap_fundamental = |ty: Ty| match ty.kind(Interner) {
+        TyKind::Ref(_, _, referenced) => referenced.clone(),
+        &TyKind::Adt(AdtId(hir_def::AdtId::StructId(s)), ref subs) => {
+            let struct_data = db.struct_data(s);
+            if struct_data.flags.contains(StructFlags::IS_FUNDAMENTAL) {
+                let next = subs.type_parameters(Interner).next();
+                match next {
+                    Some(ty) => ty,
+                    None => ty,
+                }
+            } else {
+                ty
+            }
+        }
+        _ => ty,
+    };
+    //   - At least one of the types `T0..=Tn`` must be a local type. Let `Ti`` be the first such type.
+    let is_not_orphan = trait_ref.substitution.type_parameters(Interner).any(|ty| {
+        match unwrap_fundamental(ty).kind(Interner) {
+            &TyKind::Adt(AdtId(id), _) => is_local(id.module(db.upcast()).krate()),
+            TyKind::Error => true,
+            TyKind::Dyn(it) => it.principal().map_or(false, |trait_ref| {
+                is_local(from_chalk_trait_id(trait_ref.trait_id).module(db.upcast()).krate())
+            }),
+            _ => false,
+        }
+    });
+    // FIXME: param coverage
+    //   - No uncovered type parameters `P1..=Pn` may appear in `T0..Ti`` (excluding `Ti`)
+    is_not_orphan
+}
+
 pub fn iterate_path_candidates(
     ty: &Canonical<Ty>,
     db: &dyn HirDatabase,
@@ -1422,26 +1476,52 @@ fn is_valid_fn_candidate(
             // We need to consider the bounds on the impl to distinguish functions of the same name
             // for a type.
             let predicates = db.generic_predicates(impl_id.into());
-            let valid = predicates
-                .iter()
-                .map(|predicate| {
-                    let (p, b) = predicate
-                        .clone()
-                        .substitute(Interner, &impl_subst)
-                        // Skipping the inner binders is ok, as we don't handle quantified where
-                        // clauses yet.
-                        .into_value_and_skipped_binders();
-                    stdx::always!(b.len(Interner) == 0);
-                    p
-                })
-                // It's ok to get ambiguity here, as we may not have enough information to prove
-                // obligations. We'll check if the user is calling the selected method properly
-                // later anyway.
-                .all(|p| table.try_obligation(p.cast(Interner)).is_some());
-            match valid {
-                true => IsValidCandidate::Yes,
-                false => IsValidCandidate::No,
+            let goals = predicates.iter().map(|p| {
+                let (p, b) = p
+                    .clone()
+                    .substitute(Interner, &impl_subst)
+                    // Skipping the inner binders is ok, as we don't handle quantified where
+                    // clauses yet.
+                    .into_value_and_skipped_binders();
+                stdx::always!(b.len(Interner) == 0);
+
+                p.cast::<Goal>(Interner)
+            });
+
+            for goal in goals.clone() {
+                let in_env = InEnvironment::new(&table.trait_env.env, goal);
+                let canonicalized = table.canonicalize(in_env);
+                let solution = table.db.trait_solve(
+                    table.trait_env.krate,
+                    table.trait_env.block,
+                    canonicalized.value.clone(),
+                );
+
+                match solution {
+                    Some(Solution::Unique(canonical_subst)) => {
+                        canonicalized.apply_solution(
+                            table,
+                            Canonical {
+                                binders: canonical_subst.binders,
+                                value: canonical_subst.value.subst,
+                            },
+                        );
+                    }
+                    Some(Solution::Ambig(Guidance::Definite(substs))) => {
+                        canonicalized.apply_solution(table, substs);
+                    }
+                    Some(_) => (),
+                    None => return IsValidCandidate::No,
+                }
             }
+
+            for goal in goals {
+                if table.try_obligation(goal).is_none() {
+                    return IsValidCandidate::No;
+                }
+            }
+
+            IsValidCandidate::Yes
         } else {
             // For `ItemContainerId::TraitId`, we check if `self_ty` implements the trait in
             // `iterate_trait_method_candidates()`.
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir.rs
index e953058cc..f1795e71d 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir.rs
@@ -40,7 +40,6 @@ pub use monomorphization::{
 use rustc_hash::FxHashMap;
 use smallvec::{smallvec, SmallVec};
 use stdx::{impl_from, never};
-use triomphe::Arc;
 
 use super::consteval::{intern_const_scalar, try_const_usize};
 
@@ -147,7 +146,7 @@ impl<V, T> ProjectionElem<V, T> {
             base = normalize(
                 db,
                 // FIXME: we should get this from caller
-                Arc::new(TraitEnvironment::empty(krate)),
+                TraitEnvironment::empty(krate),
                 base,
             );
         }
@@ -243,16 +242,16 @@ impl Default for ProjectionStore {
 }
 
 impl ProjectionStore {
-    fn shrink_to_fit(&mut self) {
+    pub fn shrink_to_fit(&mut self) {
         self.id_to_proj.shrink_to_fit();
         self.proj_to_id.shrink_to_fit();
     }
 
-    fn intern_if_exist(&self, projection: &[PlaceElem]) -> Option<ProjectionId> {
+    pub fn intern_if_exist(&self, projection: &[PlaceElem]) -> Option<ProjectionId> {
         self.proj_to_id.get(projection).copied()
     }
 
-    fn intern(&mut self, projection: Box<[PlaceElem]>) -> ProjectionId {
+    pub fn intern(&mut self, projection: Box<[PlaceElem]>) -> ProjectionId {
         let new_id = ProjectionId(self.proj_to_id.len() as u32);
         match self.proj_to_id.entry(projection) {
             Entry::Occupied(id) => *id.get(),
@@ -267,20 +266,24 @@ impl ProjectionStore {
 }
 
 impl ProjectionId {
-    const EMPTY: ProjectionId = ProjectionId(0);
+    pub const EMPTY: ProjectionId = ProjectionId(0);
+
+    pub fn is_empty(self) -> bool {
+        self == ProjectionId::EMPTY
+    }
 
-    fn lookup(self, store: &ProjectionStore) -> &[PlaceElem] {
+    pub fn lookup(self, store: &ProjectionStore) -> &[PlaceElem] {
         store.id_to_proj.get(&self).unwrap()
     }
 
-    fn project(self, projection: PlaceElem, store: &mut ProjectionStore) -> ProjectionId {
+    pub fn project(self, projection: PlaceElem, store: &mut ProjectionStore) -> ProjectionId {
         let mut current = self.lookup(store).to_vec();
         current.push(projection);
         store.intern(current.into())
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Place {
     pub local: LocalId,
     pub projection: ProjectionId,
@@ -1007,7 +1010,7 @@ pub enum Rvalue {
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum StatementKind {
     Assign(Place, Rvalue),
-    //FakeRead(Box<(FakeReadCause, Place)>),
+    FakeRead(Place),
     //SetDiscriminant {
     //    place: Box<Place>,
     //    variant_index: VariantIdx,
@@ -1069,6 +1072,10 @@ pub struct MirBody {
 }
 
 impl MirBody {
+    pub fn local_to_binding_map(&self) -> ArenaMap<LocalId, BindingId> {
+        self.binding_locals.iter().map(|(it, y)| (*y, it)).collect()
+    }
+
     fn walk_places(&mut self, mut f: impl FnMut(&mut Place, &mut ProjectionStore)) {
         fn for_operand(
             op: &mut Operand,
@@ -1109,7 +1116,9 @@ impl MirBody {
                             }
                         }
                     }
-                    StatementKind::Deinit(p) => f(p, &mut self.projection_store),
+                    StatementKind::FakeRead(p) | StatementKind::Deinit(p) => {
+                        f(p, &mut self.projection_store)
+                    }
                     StatementKind::StorageLive(_)
                     | StatementKind::StorageDead(_)
                     | StatementKind::Nop => (),
@@ -1186,3 +1195,9 @@ pub enum MirSpan {
 }
 
 impl_from!(ExprId, PatId for MirSpan);
+
+impl From<&ExprId> for MirSpan {
+    fn from(value: &ExprId) -> Self {
+        (*value).into()
+    }
+}
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/borrowck.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/borrowck.rs
index 41fb12965..74c5efd6c 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/borrowck.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/borrowck.rs
@@ -24,6 +24,7 @@ use super::{
 pub enum MutabilityReason {
     Mut { spans: Vec<MirSpan> },
     Not,
+    Unused,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -144,7 +145,8 @@ fn moved_out_of_ref(db: &dyn HirDatabase, body: &MirBody) -> Vec<MovedOutOfRef>
                         }
                     }
                 },
-                StatementKind::Deinit(_)
+                StatementKind::FakeRead(_)
+                | StatementKind::Deinit(_)
                 | StatementKind::StorageLive(_)
                 | StatementKind::StorageDead(_)
                 | StatementKind::Nop => (),
@@ -264,7 +266,10 @@ fn ever_initialized_map(
                         is_ever_initialized = false;
                     }
                 }
-                StatementKind::Deinit(_) | StatementKind::Nop | StatementKind::StorageLive(_) => (),
+                StatementKind::Deinit(_)
+                | StatementKind::FakeRead(_)
+                | StatementKind::Nop
+                | StatementKind::StorageLive(_) => (),
             }
         }
         let Some(terminator) = &block.terminator else {
@@ -331,16 +336,37 @@ fn ever_initialized_map(
     result
 }
 
+fn push_mut_span(local: LocalId, span: MirSpan, result: &mut ArenaMap<LocalId, MutabilityReason>) {
+    match &mut result[local] {
+        MutabilityReason::Mut { spans } => spans.push(span),
+        it @ (MutabilityReason::Not | MutabilityReason::Unused) => {
+            *it = MutabilityReason::Mut { spans: vec![span] }
+        }
+    };
+}
+
+fn record_usage(local: LocalId, result: &mut ArenaMap<LocalId, MutabilityReason>) {
+    match &mut result[local] {
+        it @ MutabilityReason::Unused => {
+            *it = MutabilityReason::Not;
+        }
+        _ => (),
+    };
+}
+
+fn record_usage_for_operand(arg: &Operand, result: &mut ArenaMap<LocalId, MutabilityReason>) {
+    if let Operand::Copy(p) | Operand::Move(p) = arg {
+        record_usage(p.local, result);
+    }
+}
+
 fn mutability_of_locals(
     db: &dyn HirDatabase,
     body: &MirBody,
 ) -> ArenaMap<LocalId, MutabilityReason> {
     let mut result: ArenaMap<LocalId, MutabilityReason> =
-        body.locals.iter().map(|it| (it.0, MutabilityReason::Not)).collect();
-    let mut push_mut_span = |local, span| match &mut result[local] {
-        MutabilityReason::Mut { spans } => spans.push(span),
-        it @ MutabilityReason::Not => *it = MutabilityReason::Mut { spans: vec![span] },
-    };
+        body.locals.iter().map(|it| (it.0, MutabilityReason::Unused)).collect();
+
     let ever_init_maps = ever_initialized_map(db, body);
     for (block_id, mut ever_init_map) in ever_init_maps.into_iter() {
         let block = &body.basic_blocks[block_id];
@@ -350,23 +376,51 @@ fn mutability_of_locals(
                     match place_case(db, body, place) {
                         ProjectionCase::Direct => {
                             if ever_init_map.get(place.local).copied().unwrap_or_default() {
-                                push_mut_span(place.local, statement.span);
+                                push_mut_span(place.local, statement.span, &mut result);
                             } else {
                                 ever_init_map.insert(place.local, true);
                             }
                         }
                         ProjectionCase::DirectPart => {
                             // Partial initialization is not supported, so it is definitely `mut`
-                            push_mut_span(place.local, statement.span);
+                            push_mut_span(place.local, statement.span, &mut result);
+                        }
+                        ProjectionCase::Indirect => {
+                            record_usage(place.local, &mut result);
                         }
-                        ProjectionCase::Indirect => (),
+                    }
+                    match value {
+                        Rvalue::CopyForDeref(p)
+                        | Rvalue::Discriminant(p)
+                        | Rvalue::Len(p)
+                        | Rvalue::Ref(_, p) => {
+                            record_usage(p.local, &mut result);
+                        }
+                        Rvalue::Use(o)
+                        | Rvalue::Repeat(o, _)
+                        | Rvalue::Cast(_, o, _)
+                        | Rvalue::UnaryOp(_, o) => record_usage_for_operand(o, &mut result),
+                        Rvalue::CheckedBinaryOp(_, o1, o2) => {
+                            for o in [o1, o2] {
+                                record_usage_for_operand(o, &mut result);
+                            }
+                        }
+                        Rvalue::Aggregate(_, args) => {
+                            for arg in args.iter() {
+                                record_usage_for_operand(arg, &mut result);
+                            }
+                        }
+                        Rvalue::ShallowInitBox(_, _) | Rvalue::ShallowInitBoxWithAlloc(_) => (),
                     }
                     if let Rvalue::Ref(BorrowKind::Mut { .. }, p) = value {
                         if place_case(db, body, p) != ProjectionCase::Indirect {
-                            push_mut_span(p.local, statement.span);
+                            push_mut_span(p.local, statement.span, &mut result);
                         }
                     }
                 }
+                StatementKind::FakeRead(p) => {
+                    record_usage(p.local, &mut result);
+                }
                 StatementKind::StorageDead(p) => {
                     ever_init_map.insert(*p, false);
                 }
@@ -386,15 +440,21 @@ fn mutability_of_locals(
             | TerminatorKind::FalseEdge { .. }
             | TerminatorKind::FalseUnwind { .. }
             | TerminatorKind::GeneratorDrop
-            | TerminatorKind::SwitchInt { .. }
             | TerminatorKind::Drop { .. }
             | TerminatorKind::DropAndReplace { .. }
             | TerminatorKind::Assert { .. }
             | TerminatorKind::Yield { .. } => (),
-            TerminatorKind::Call { destination, .. } => {
+            TerminatorKind::SwitchInt { discr, targets: _ } => {
+                record_usage_for_operand(discr, &mut result);
+            }
+            TerminatorKind::Call { destination, args, func, .. } => {
+                record_usage_for_operand(func, &mut result);
+                for arg in args.iter() {
+                    record_usage_for_operand(arg, &mut result);
+                }
                 if destination.projection.lookup(&body.projection_store).len() == 0 {
                     if ever_init_map.get(destination.local).copied().unwrap_or_default() {
-                        push_mut_span(destination.local, MirSpan::Unknown);
+                        push_mut_span(destination.local, MirSpan::Unknown, &mut result);
                     } else {
                         ever_init_map.insert(destination.local, true);
                     }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval.rs
index 4364e0d32..fbfb6ff8c 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval.rs
@@ -21,7 +21,7 @@ use hir_def::{
     AdtId, ConstId, DefWithBodyId, EnumVariantId, FunctionId, HasModule, ItemContainerId, Lookup,
     StaticId, VariantId,
 };
-use hir_expand::{mod_path::ModPath, InFile};
+use hir_expand::{mod_path::ModPath, HirFileIdExt, InFile};
 use intern::Interned;
 use la_arena::ArenaMap;
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -162,7 +162,7 @@ pub struct Evaluator<'a> {
     not_special_fn_cache: RefCell<FxHashSet<FunctionId>>,
     mir_or_dyn_index_cache: RefCell<FxHashMap<(FunctionId, Substitution), MirOrDynIndex>>,
     /// Constantly dropping and creating `Locals` is very costly. We store
-    /// old locals that we normaly want to drop here, to reuse their allocations
+    /// old locals that we normally want to drop here, to reuse their allocations
     /// later.
     unused_locals_store: RefCell<FxHashMap<DefWithBodyId, Vec<Locals>>>,
     cached_ptr_size: usize,
@@ -375,10 +375,7 @@ impl MirEvalError {
                         Err(_) => continue,
                     },
                     MirSpan::PatId(p) => match source_map.pat_syntax(*p) {
-                        Ok(s) => s.map(|it| match it {
-                            Either::Left(e) => e.into(),
-                            Either::Right(e) => e.into(),
-                        }),
+                        Ok(s) => s.map(|it| it.syntax_node_ptr()),
                         Err(_) => continue,
                     },
                     MirSpan::Unknown => continue,
@@ -842,6 +839,7 @@ impl Evaluator<'_> {
                             }
                             StatementKind::Deinit(_) => not_supported!("de-init statement"),
                             StatementKind::StorageLive(_)
+                            | StatementKind::FakeRead(_)
                             | StatementKind::StorageDead(_)
                             | StatementKind::Nop => (),
                         }
@@ -2301,7 +2299,7 @@ impl Evaluator<'_> {
         match self.get_mir_or_dyn_index(def, generic_args.clone(), locals, span)? {
             MirOrDynIndex::Dyn(self_ty_idx) => {
                 // In the layout of current possible receiver, which at the moment of writing this code is one of
-                // `&T`, `&mut T`, `Box<T>`, `Rc<T>`, `Arc<T>`, and `Pin<P>` where `P` is one of possible recievers,
+                // `&T`, `&mut T`, `Box<T>`, `Rc<T>`, `Arc<T>`, and `Pin<P>` where `P` is one of possible receivers,
                 // the vtable is exactly in the `[ptr_size..2*ptr_size]` bytes. So we can use it without branching on
                 // the type.
                 let first_arg = arg_bytes.clone().next().unwrap();
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs
index 803ef631f..2de99e416 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs
@@ -1045,7 +1045,7 @@ impl Evaluator<'_> {
             }
             "transmute" => {
                 let [arg] = args else {
-                    return Err(MirEvalError::TypeError("trasmute arg is not provided"));
+                    return Err(MirEvalError::TypeError("transmute arg is not provided"));
                 };
                 destination.write_from_interval(self, arg.interval)
             }
@@ -1065,7 +1065,7 @@ impl Evaluator<'_> {
             }
             "ctlz" | "ctlz_nonzero" => {
                 let [arg] = args else {
-                    return Err(MirEvalError::TypeError("cttz arg is not provided"));
+                    return Err(MirEvalError::TypeError("ctlz arg is not provided"));
                 };
                 let result =
                     u128::from_le_bytes(pad16(arg.get(self)?, false)).leading_zeros() as usize;
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower.rs
index dd2dba717..639fabc19 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower.rs
@@ -2,7 +2,7 @@
 
 use std::{fmt::Write, iter, mem};
 
-use base_db::FileId;
+use base_db::{salsa::Cycle, FileId};
 use chalk_ir::{BoundVar, ConstData, DebruijnIndex, TyKind};
 use hir_def::{
     body::Body,
@@ -105,9 +105,14 @@ pub enum MirLowerError {
 /// A token to ensuring that each drop scope is popped at most once, thanks to the compiler that checks moves.
 struct DropScopeToken;
 impl DropScopeToken {
-    fn pop_and_drop(self, ctx: &mut MirLowerCtx<'_>, current: BasicBlockId) -> BasicBlockId {
+    fn pop_and_drop(
+        self,
+        ctx: &mut MirLowerCtx<'_>,
+        current: BasicBlockId,
+        span: MirSpan,
+    ) -> BasicBlockId {
         std::mem::forget(self);
-        ctx.pop_drop_scope_internal(current)
+        ctx.pop_drop_scope_internal(current, span)
     }
 
     /// It is useful when we want a drop scope is syntaxically closed, but we don't want to execute any drop
@@ -529,6 +534,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
                 else {
                     return Ok(None);
                 };
+                self.push_fake_read(current, cond_place, expr_id.into());
                 let (then_target, else_target) =
                     self.pattern_match(current, None, cond_place, *pat)?;
                 self.write_bytes_to_place(
@@ -581,7 +587,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
                 self.lower_loop(current, place, *label, expr_id.into(), |this, begin| {
                     let scope = this.push_drop_scope();
                     if let Some((_, mut current)) = this.lower_expr_as_place(begin, *body, true)? {
-                        current = scope.pop_and_drop(this, current);
+                        current = scope.pop_and_drop(this, current, body.into());
                         this.set_goto(current, begin, expr_id.into());
                     } else {
                         scope.pop_assume_dropped(this);
@@ -668,6 +674,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
                 else {
                     return Ok(None);
                 };
+                self.push_fake_read(current, cond_place, expr_id.into());
                 let mut end = None;
                 for MatchArm { pat, guard, expr } in arms.iter() {
                     let (then, mut otherwise) =
@@ -718,7 +725,8 @@ impl<'ctx> MirLowerCtx<'ctx> {
                         .ok_or(MirLowerError::ContinueWithoutLoop)?,
                 };
                 let begin = loop_data.begin;
-                current = self.drop_until_scope(loop_data.drop_scope_index, current);
+                current =
+                    self.drop_until_scope(loop_data.drop_scope_index, current, expr_id.into());
                 self.set_goto(current, begin, expr_id.into());
                 Ok(None)
             }
@@ -757,7 +765,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
                         self.current_loop_blocks.as_ref().unwrap().drop_scope_index,
                     ),
                 };
-                current = self.drop_until_scope(drop_scope, current);
+                current = self.drop_until_scope(drop_scope, current, expr_id.into());
                 self.set_goto(current, end, expr_id.into());
                 Ok(None)
             }
@@ -771,7 +779,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
                         return Ok(None);
                     }
                 }
-                current = self.drop_until_scope(0, current);
+                current = self.drop_until_scope(0, current, expr_id.into());
                 self.set_terminator(current, TerminatorKind::Return, expr_id.into());
                 Ok(None)
             }
@@ -1299,6 +1307,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
             return Ok(None);
         };
         if matches!(&self.body.exprs[lhs], Expr::Underscore) {
+            self.push_fake_read_for_operand(current, rhs_op, span);
             return Ok(Some(current));
         }
         if matches!(
@@ -1575,6 +1584,16 @@ impl<'ctx> MirLowerCtx<'ctx> {
         self.result.basic_blocks[block].statements.push(statement);
     }
 
+    fn push_fake_read(&mut self, block: BasicBlockId, p: Place, span: MirSpan) {
+        self.push_statement(block, StatementKind::FakeRead(p).with_span(span));
+    }
+
+    fn push_fake_read_for_operand(&mut self, block: BasicBlockId, operand: Operand, span: MirSpan) {
+        if let Operand::Move(p) | Operand::Copy(p) = operand {
+            self.push_fake_read(block, p, span);
+        }
+    }
+
     fn push_assignment(
         &mut self,
         block: BasicBlockId,
@@ -1733,6 +1752,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
                             return Ok(None);
                         };
                         current = c;
+                        self.push_fake_read(current, init_place, span);
                         (current, else_block) =
                             self.pattern_match(current, None, init_place, *pat)?;
                         match (else_block, else_branch) {
@@ -1760,14 +1780,15 @@ impl<'ctx> MirLowerCtx<'ctx> {
                         }
                     }
                 }
-                hir_def::hir::Statement::Expr { expr, has_semi: _ } => {
+                &hir_def::hir::Statement::Expr { expr, has_semi: _ } => {
                     let scope2 = self.push_drop_scope();
-                    let Some((_, c)) = self.lower_expr_as_place(current, *expr, true)? else {
+                    let Some((p, c)) = self.lower_expr_as_place(current, expr, true)? else {
                         scope2.pop_assume_dropped(self);
                         scope.pop_assume_dropped(self);
                         return Ok(None);
                     };
-                    current = scope2.pop_and_drop(self, c);
+                    self.push_fake_read(c, p, expr.into());
+                    current = scope2.pop_and_drop(self, c, expr.into());
                 }
             }
         }
@@ -1778,7 +1799,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
             };
             current = c;
         }
-        current = scope.pop_and_drop(self, current);
+        current = scope.pop_and_drop(self, current, span);
         Ok(Some(current))
     }
 
@@ -1858,9 +1879,14 @@ impl<'ctx> MirLowerCtx<'ctx> {
         }
     }
 
-    fn drop_until_scope(&mut self, scope_index: usize, mut current: BasicBlockId) -> BasicBlockId {
+    fn drop_until_scope(
+        &mut self,
+        scope_index: usize,
+        mut current: BasicBlockId,
+        span: MirSpan,
+    ) -> BasicBlockId {
         for scope in self.drop_scopes[scope_index..].to_vec().iter().rev() {
-            self.emit_drop_and_storage_dead_for_scope(scope, &mut current);
+            self.emit_drop_and_storage_dead_for_scope(scope, &mut current, span);
         }
         current
     }
@@ -1876,17 +1902,22 @@ impl<'ctx> MirLowerCtx<'ctx> {
     }
 
     /// Don't call directly
-    fn pop_drop_scope_internal(&mut self, mut current: BasicBlockId) -> BasicBlockId {
+    fn pop_drop_scope_internal(
+        &mut self,
+        mut current: BasicBlockId,
+        span: MirSpan,
+    ) -> BasicBlockId {
         let scope = self.drop_scopes.pop().unwrap();
-        self.emit_drop_and_storage_dead_for_scope(&scope, &mut current);
+        self.emit_drop_and_storage_dead_for_scope(&scope, &mut current, span);
         current
     }
 
     fn pop_drop_scope_assert_finished(
         &mut self,
         mut current: BasicBlockId,
+        span: MirSpan,
     ) -> Result<BasicBlockId> {
-        current = self.pop_drop_scope_internal(current);
+        current = self.pop_drop_scope_internal(current, span);
         if !self.drop_scopes.is_empty() {
             implementation_error!("Mismatched count between drop scope push and pops");
         }
@@ -1897,6 +1928,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
         &mut self,
         scope: &DropScope,
         current: &mut Idx<BasicBlock>,
+        span: MirSpan,
     ) {
         for &l in scope.locals.iter().rev() {
             if !self.result.locals[l].ty.clone().is_copy(self.db, self.owner) {
@@ -1904,13 +1936,10 @@ impl<'ctx> MirLowerCtx<'ctx> {
                 self.set_terminator(
                     prev,
                     TerminatorKind::Drop { place: l.into(), target: *current, unwind: None },
-                    MirSpan::Unknown,
+                    span,
                 );
             }
-            self.push_statement(
-                *current,
-                StatementKind::StorageDead(l).with_span(MirSpan::Unknown),
-            );
+            self.push_statement(*current, StatementKind::StorageDead(l).with_span(span));
         }
     }
 }
@@ -1987,7 +2016,7 @@ pub fn mir_body_for_closure_query(
         |_| true,
     )?;
     if let Some(current) = ctx.lower_expr_to_place(*root, return_slot().into(), current)? {
-        let current = ctx.pop_drop_scope_assert_finished(current)?;
+        let current = ctx.pop_drop_scope_assert_finished(current, root.into())?;
         ctx.set_terminator(current, TerminatorKind::Return, (*root).into());
     }
     let mut upvar_map: FxHashMap<LocalId, Vec<(&CapturedItem, usize)>> = FxHashMap::default();
@@ -2081,7 +2110,7 @@ pub fn mir_body_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Result<Arc<Mi
 
 pub fn mir_body_recover(
     _db: &dyn HirDatabase,
-    _cycle: &[String],
+    _cycle: &Cycle,
     _def: &DefWithBodyId,
 ) -> Result<Arc<MirBody>> {
     Err(MirLowerError::Loop)
@@ -2131,7 +2160,7 @@ pub fn lower_to_mir(
         ctx.lower_params_and_bindings([].into_iter(), binding_picker)?
     };
     if let Some(current) = ctx.lower_expr_to_place(root_expr, return_slot().into(), current)? {
-        let current = ctx.pop_drop_scope_assert_finished(current)?;
+        let current = ctx.pop_drop_scope_assert_finished(current, root_expr.into())?;
         ctx.set_terminator(current, TerminatorKind::Return, root_expr.into());
     }
     Ok(ctx.result)
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower/pattern_matching.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower/pattern_matching.rs
index 270f75ad9..1120bb1c1 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower/pattern_matching.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/lower/pattern_matching.rs
@@ -284,6 +284,7 @@ impl MirLowerCtx<'_> {
                             );
                             (current, current_else) = self.pattern_match_binding(
                                 id,
+                                *slice,
                                 next_place,
                                 (*slice).into(),
                                 current,
@@ -395,6 +396,7 @@ impl MirLowerCtx<'_> {
                 if mode == MatchingMode::Bind {
                     self.pattern_match_binding(
                         *id,
+                        pattern,
                         cond_place,
                         pattern.into(),
                         current,
@@ -431,13 +433,14 @@ impl MirLowerCtx<'_> {
     fn pattern_match_binding(
         &mut self,
         id: BindingId,
+        pat: PatId,
         cond_place: Place,
         span: MirSpan,
         current: BasicBlockId,
         current_else: Option<BasicBlockId>,
     ) -> Result<(BasicBlockId, Option<BasicBlockId>)> {
         let target_place = self.binding_local(id)?;
-        let mode = self.infer.binding_modes[id];
+        let mode = self.infer.binding_modes[pat];
         self.push_storage_live(id, current)?;
         self.push_assignment(
             current,
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/monomorphization.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/monomorphization.rs
index df16d0d82..8da03eef2 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/monomorphization.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/monomorphization.rs
@@ -9,6 +9,7 @@
 
 use std::mem;
 
+use base_db::salsa::Cycle;
 use chalk_ir::{
     fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable},
     ConstData, DebruijnIndex,
@@ -248,6 +249,7 @@ impl Filler<'_> {
                         | Rvalue::CopyForDeref(_) => (),
                     },
                     StatementKind::Deinit(_)
+                    | StatementKind::FakeRead(_)
                     | StatementKind::StorageLive(_)
                     | StatementKind::StorageDead(_)
                     | StatementKind::Nop => (),
@@ -299,7 +301,7 @@ pub fn monomorphized_mir_body_query(
 
 pub fn monomorphized_mir_body_recover(
     _: &dyn HirDatabase,
-    _: &[String],
+    _: &Cycle,
     _: &DefWithBodyId,
     _: &Substitution,
     _: &Arc<crate::TraitEnvironment>,
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/pretty.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/pretty.rs
index 0108859ff..a91f90bc2 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/pretty.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/pretty.rs
@@ -145,7 +145,7 @@ impl<'a> MirPrettyCtx<'a> {
         let indent = mem::take(&mut self.indent);
         let mut ctx = MirPrettyCtx {
             body: &body,
-            local_to_binding: body.binding_locals.iter().map(|(it, y)| (*y, it)).collect(),
+            local_to_binding: body.local_to_binding_map(),
             result,
             indent,
             ..*self
@@ -167,7 +167,7 @@ impl<'a> MirPrettyCtx<'a> {
     }
 
     fn new(body: &'a MirBody, hir_body: &'a Body, db: &'a dyn HirDatabase) -> Self {
-        let local_to_binding = body.binding_locals.iter().map(|(it, y)| (*y, it)).collect();
+        let local_to_binding = body.local_to_binding_map();
         MirPrettyCtx {
             body,
             db,
@@ -233,6 +233,11 @@ impl<'a> MirPrettyCtx<'a> {
                             this.place(p);
                             wln!(this, ");");
                         }
+                        StatementKind::FakeRead(p) => {
+                            w!(this, "FakeRead(");
+                            this.place(p);
+                            wln!(this, ");");
+                        }
                         StatementKind::Nop => wln!(this, "Nop;"),
                     }
                 }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/test_db.rs b/src/tools/rust-analyzer/crates/hir-ty/src/test_db.rs
index 7d19e0a19..6f4aef22d 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/test_db.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/test_db.rs
@@ -30,6 +30,7 @@ pub(crate) struct TestDB {
 impl Default for TestDB {
     fn default() -> Self {
         let mut this = Self { storage: Default::default(), events: Default::default() };
+        this.setup_syntax_context_root();
         this.set_expand_proc_attr_macros_with_durability(true, Durability::HIGH);
         this
     }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests.rs
index d22d0d85c..1446e83fa 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests.rs
@@ -269,12 +269,7 @@ fn pat_node(
     Some(match body_source_map.pat_syntax(pat) {
         Ok(sp) => {
             let root = db.parse_or_expand(sp.file_id);
-            sp.map(|ptr| {
-                ptr.either(
-                    |it| it.to_node(&root).syntax().clone(),
-                    |it| it.to_node(&root).syntax().clone(),
-                )
-            })
+            sp.map(|ptr| ptr.to_node(&root).syntax().clone())
         }
         Err(SyntheticSyntax) => return None,
     })
@@ -303,12 +298,7 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
             let syntax_ptr = match body_source_map.pat_syntax(pat) {
                 Ok(sp) => {
                     let root = db.parse_or_expand(sp.file_id);
-                    sp.map(|ptr| {
-                        ptr.either(
-                            |it| it.to_node(&root).syntax().clone(),
-                            |it| it.to_node(&root).syntax().clone(),
-                        )
-                    })
+                    sp.map(|ptr| ptr.to_node(&root).syntax().clone())
                 }
                 Err(SyntheticSyntax) => continue,
             };
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests/incremental.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests/incremental.rs
index bb15ca8c4..28e84e480 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests/incremental.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests/incremental.rs
@@ -9,11 +9,10 @@ use super::visit_module;
 fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
     let (mut db, pos) = TestDB::with_position(
         "
-        //- /lib.rs
-        fn foo() -> i32 {
-            $01 + 1
-        }
-    ",
+//- /lib.rs
+fn foo() -> i32 {
+    $01 + 1
+}",
     );
     {
         let events = db.log_executed(|| {
@@ -27,12 +26,11 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
     }
 
     let new_text = "
-        fn foo() -> i32 {
-            1
-            +
-            1
-        }
-    ";
+fn foo() -> i32 {
+    1
+    +
+    1
+}";
 
     db.set_file_text(pos.file_id, Arc::from(new_text));
 
@@ -47,3 +45,55 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
         assert!(!format!("{events:?}").contains("infer"), "{events:#?}")
     }
 }
+
+#[test]
+fn typing_inside_a_function_should_not_invalidate_types_in_another() {
+    let (mut db, pos) = TestDB::with_position(
+        "
+//- /lib.rs
+fn foo() -> f32 {
+    1.0 + 2.0
+}
+fn bar() -> i32 {
+    $01 + 1
+}
+fn baz() -> i32 {
+    1 + 1
+}",
+    );
+    {
+        let events = db.log_executed(|| {
+            let module = db.module_for_file(pos.file_id);
+            let crate_def_map = module.def_map(&db);
+            visit_module(&db, &crate_def_map, module.local_id, &mut |def| {
+                db.infer(def);
+            });
+        });
+        assert!(format!("{events:?}").contains("infer"))
+    }
+
+    let new_text = "
+fn foo() -> f32 {
+    1.0 + 2.0
+}
+fn bar() -> i32 {
+    53
+}
+fn baz() -> i32 {
+    1 + 1
+}
+";
+
+    db.set_file_text(pos.file_id, Arc::from(new_text));
+
+    {
+        let events = db.log_executed(|| {
+            let module = db.module_for_file(pos.file_id);
+            let crate_def_map = module.def_map(&db);
+            visit_module(&db, &crate_def_map, module.local_id, &mut |def| {
+                db.infer(def);
+            });
+        });
+        assert!(format!("{events:?}").matches("infer").count() == 1, "{events:#?}")
+    }
+}
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests/macros.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests/macros.rs
index 1e6e946a1..d16e0eb01 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests/macros.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests/macros.rs
@@ -684,8 +684,7 @@ fn infer_builtin_macros_line() {
         }
         "#,
         expect![[r#"
-            !0..1 '0': i32
-            !0..6 '0asu32': u32
+            !0..4 '0u32': u32
             63..87 '{     ...!(); }': ()
             73..74 'x': u32
         "#]],
@@ -723,8 +722,7 @@ fn infer_builtin_macros_column() {
         }
         "#,
         expect![[r#"
-            !0..1 '0': i32
-            !0..6 '0asu32': u32
+            !0..4 '0u32': u32
             65..91 '{     ...!(); }': ()
             75..76 'x': u32
         "#]],
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests/patterns.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests/patterns.rs
index 0f5a3e175..7234af2d6 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests/patterns.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests/patterns.rs
@@ -1129,3 +1129,65 @@ fn foo() {
 "#,
     );
 }
+
+#[test]
+fn generic_alias() {
+    check_types(
+        r#"
+type Wrap<T> = T;
+
+enum X {
+    A { cool: u32, stuff: u32 },
+    B,
+}
+
+fn main() {
+    let wrapped = Wrap::<X>::A {
+        cool: 100,
+        stuff: 100,
+    };
+
+    if let Wrap::<X>::A { cool, ..} = &wrapped {}
+                        //^^^^ &u32
+}
+"#,
+    );
+}
+
+#[test]
+fn type_mismatch_pat_const_reference() {
+    check_no_mismatches(
+        r#"
+const TEST_STR: &'static str = "abcd";
+
+fn main() {
+    let s = "abcd";
+    match s {
+        TEST_STR => (),
+        _ => (),
+    }
+}
+
+            "#,
+    );
+    check(
+        r#"
+struct Foo<T>(T);
+
+impl<T> Foo<T> {
+    const TEST_I32_REF: &'static i32 = &3;
+    const TEST_I32: i32 = 3;
+}
+
+fn main() {
+    match &6 {
+        Foo::<i32>::TEST_I32_REF => (),
+        Foo::<i32>::TEST_I32 => (),
+      //^^^^^^^^^^^^^^^^^^^^ expected &i32, got i32
+        _ => (),
+    }
+}
+
+            "#,
+    );
+}
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests/regression.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests/regression.rs
index 6ea059065..35079e709 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests/regression.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests/regression.rs
@@ -2000,3 +2000,15 @@ fn test() {
 "#,
     );
 }
+
+#[test]
+fn rustc_test_issue_52437() {
+    check_types(
+        r#"
+    fn main() {
+        let x = [(); &(&'static: loop { |x| {}; }) as *const _ as usize]
+          //^ [(); _]
+    }
+    "#,
+    );
+}
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/tests/traits.rs b/src/tools/rust-analyzer/crates/hir-ty/src/tests/traits.rs
index d36b885ec..003ae60e8 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/tests/traits.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/tests/traits.rs
@@ -2598,6 +2598,34 @@ fn test<T: Trait>() {
 }
 
 #[test]
+fn associated_type_in_type_bound() {
+    check_types(
+        r#"
+//- minicore: deref
+fn fb(f: Foo<&u8>) {
+    f.foobar();
+  //^^^^^^^^^^ u8
+}
+trait Bar {
+    fn bar(&self) -> u8;
+}
+impl Bar for u8 {
+    fn bar(&self) -> u8 { *self }
+}
+
+struct Foo<F> {
+    foo: F,
+}
+impl<F: core::ops::Deref<Target = impl Bar>> Foo<F> {
+    fn foobar(&self) -> u8 {
+        self.foo.deref().bar()
+    }
+}
+"#,
+    )
+}
+
+#[test]
 fn dyn_trait_through_chalk() {
     check_types(
         r#"
@@ -4439,42 +4467,42 @@ fn test(v: S<i32>) {
 fn associated_type_in_argument() {
     check(
         r#"
-    trait A {
-        fn m(&self) -> i32;
-    }
+trait A {
+    fn m(&self) -> i32;
+}
 
-    fn x<T: B>(k: &<T as B>::Ty) {
-        k.m();
-    }
+fn x<T: B>(k: &<T as B>::Ty) {
+    k.m();
+}
 
-    struct X;
-    struct Y;
+struct X;
+struct Y;
 
-    impl A for X {
-        fn m(&self) -> i32 {
-            8
-        }
+impl A for X {
+    fn m(&self) -> i32 {
+        8
     }
+}
 
-    impl A for Y {
-        fn m(&self) -> i32 {
-            32
-        }
+impl A for Y {
+    fn m(&self) -> i32 {
+        32
     }
+}
 
-    trait B {
-        type Ty: A;
-    }
+trait B {
+    type Ty: A;
+}
 
-    impl B for u16 {
-        type Ty = X;
-    }
+impl B for u16 {
+    type Ty = X;
+}
 
-    fn ttt() {
-        let inp = Y;
-        x::<u16>(&inp);
-               //^^^^ expected &X, got &Y
-    }
-    "#,
+fn ttt() {
+    let inp = Y;
+    x::<u16>(&inp);
+           //^^^^ expected &X, got &Y
+}
+"#,
     );
 }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/traits.rs b/src/tools/rust-analyzer/crates/hir-ty/src/traits.rs
index 3c7cfbaed..b6bc76bc9 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/traits.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/traits.rs
@@ -48,18 +48,32 @@ pub struct TraitEnvironment {
     pub krate: CrateId,
     pub block: Option<BlockId>,
     // FIXME make this a BTreeMap
-    pub(crate) traits_from_clauses: Vec<(Ty, TraitId)>,
+    traits_from_clauses: Box<[(Ty, TraitId)]>,
     pub env: chalk_ir::Environment<Interner>,
 }
 
 impl TraitEnvironment {
-    pub fn empty(krate: CrateId) -> Self {
-        TraitEnvironment {
+    pub fn empty(krate: CrateId) -> Arc<Self> {
+        Arc::new(TraitEnvironment {
             krate,
             block: None,
-            traits_from_clauses: Vec::new(),
+            traits_from_clauses: Box::default(),
             env: chalk_ir::Environment::new(Interner),
-        }
+        })
+    }
+
+    pub fn new(
+        krate: CrateId,
+        block: Option<BlockId>,
+        traits_from_clauses: Box<[(Ty, TraitId)]>,
+        env: chalk_ir::Environment<Interner>,
+    ) -> Arc<Self> {
+        Arc::new(TraitEnvironment { krate, block, traits_from_clauses, env })
+    }
+
+    // pub fn with_block(self: &mut Arc<Self>, block: BlockId) {
+    pub fn with_block(this: &mut Arc<Self>, block: BlockId) {
+        Arc::make_mut(this).block = Some(block);
     }
 
     pub fn traits_in_scope_from_clauses(&self, ty: Ty) -> impl Iterator<Item = TraitId> + '_ {