Merging upstream version 1.76.0+dfsg1.

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

10 files changed, 986 insertions, 488 deletions

diff --git a/src/tools/rust-analyzer/crates/hir/Cargo.toml b/src/tools/rust-analyzer/crates/hir/Cargo.toml
index f860ee948..4c1dfbc29 100644
--- a/src/tools/rust-analyzer/crates/hir/Cargo.toml
+++ b/src/tools/rust-analyzer/crates/hir/Cargo.toml
@@ -13,9 +13,9 @@ doctest = false
 
 [dependencies]
 rustc-hash = "1.1.0"
-either = "1.7.0"
+either.workspace = true
 arrayvec = "0.7.2"
-itertools = "0.10.5"
+itertools.workspace = true
 smallvec.workspace = true
 triomphe.workspace = true
 once_cell = "1.17.1"
@@ -30,3 +30,6 @@ profile.workspace = true
 stdx.workspace = true
 syntax.workspace = true
 tt.workspace = true
+
+[features]
+in-rust-tree = []
diff --git a/src/tools/rust-analyzer/crates/hir/src/attrs.rs b/src/tools/rust-analyzer/crates/hir/src/attrs.rs
index 796490abd..185853353 100644
--- a/src/tools/rust-analyzer/crates/hir/src/attrs.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/attrs.rs
@@ -1,5 +1,6 @@
 //! Attributes & documentation for hir types.
 
+use base_db::FileId;
 use hir_def::{
     attr::AttrsWithOwner,
     item_scope::ItemInNs,
@@ -8,7 +9,10 @@ use hir_def::{
     resolver::{HasResolver, Resolver, TypeNs},
     AssocItemId, AttrDefId, ModuleDefId,
 };
-use hir_expand::{hygiene::Hygiene, name::Name};
+use hir_expand::{
+    name::Name,
+    span::{RealSpanMap, SpanMapRef},
+};
 use hir_ty::db::HirDatabase;
 use syntax::{ast, AstNode};
 
@@ -234,7 +238,11 @@ fn modpath_from_str(db: &dyn HirDatabase, link: &str) -> Option<ModPath> {
         if ast_path.syntax().text() != link {
             return None;
         }
-        ModPath::from_src(db.upcast(), ast_path, &Hygiene::new_unhygienic())
+        ModPath::from_src(
+            db.upcast(),
+            ast_path,
+            SpanMapRef::RealSpanMap(&RealSpanMap::absolute(FileId::BOGUS)),
+        )
     };
 
     let full = try_get_modpath(link);
diff --git a/src/tools/rust-analyzer/crates/hir/src/db.rs b/src/tools/rust-analyzer/crates/hir/src/db.rs
index 936581bfe..d98e3decd 100644
--- a/src/tools/rust-analyzer/crates/hir/src/db.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/db.rs
@@ -3,10 +3,27 @@
 //! we didn't do that.
 //!
 //! But we need this for at least LRU caching at the query level.
-pub use hir_def::db::*;
+pub use hir_def::db::{
+    AttrsQuery, BlockDefMapQuery, BlockItemTreeQueryQuery, BodyQuery, BodyWithSourceMapQuery,
+    ConstDataQuery, ConstVisibilityQuery, CrateDefMapQueryQuery, CrateLangItemsQuery,
+    CrateSupportsNoStdQuery, DefDatabase, DefDatabaseStorage, EnumDataQuery,
+    EnumDataWithDiagnosticsQuery, ExprScopesQuery, ExternCrateDeclDataQuery,
+    FieldVisibilitiesQuery, FieldsAttrsQuery, FieldsAttrsSourceMapQuery, FileItemTreeQuery,
+    FunctionDataQuery, FunctionVisibilityQuery, GenericParamsQuery, ImplDataQuery,
+    ImplDataWithDiagnosticsQuery, ImportMapQuery, InternAnonymousConstQuery, InternBlockQuery,
+    InternConstQuery, InternDatabase, InternDatabaseStorage, InternEnumQuery,
+    InternExternBlockQuery, InternExternCrateQuery, InternFunctionQuery, InternImplQuery,
+    InternInTypeConstQuery, InternMacro2Query, InternMacroRulesQuery, InternProcMacroQuery,
+    InternStaticQuery, InternStructQuery, InternTraitAliasQuery, InternTraitQuery,
+    InternTypeAliasQuery, InternUnionQuery, InternUseQuery, LangAttrQuery, LangItemQuery,
+    Macro2DataQuery, MacroRulesDataQuery, ProcMacroDataQuery, StaticDataQuery, StructDataQuery,
+    StructDataWithDiagnosticsQuery, TraitAliasDataQuery, TraitDataQuery,
+    TraitDataWithDiagnosticsQuery, TypeAliasDataQuery, UnionDataQuery,
+    UnionDataWithDiagnosticsQuery, VariantsAttrsQuery, VariantsAttrsSourceMapQuery,
+};
 pub use hir_expand::db::{
     AstIdMapQuery, DeclMacroExpanderQuery, ExpandDatabase, ExpandDatabaseStorage,
-    ExpandProcMacroQuery, HygieneFrameQuery, InternMacroCallQuery, MacroArgNodeQuery,
-    MacroExpandQuery, ParseMacroExpansionErrorQuery, ParseMacroExpansionQuery,
+    ExpandProcMacroQuery, InternMacroCallQuery, InternSyntaxContextQuery, MacroArgQuery,
+    ParseMacroExpansionErrorQuery, ParseMacroExpansionQuery, RealSpanMapQuery,
 };
 pub use hir_ty::db::*;
diff --git a/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs b/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
index 479138b67..1cb36f9b0 100644
--- a/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/diagnostics.rs
@@ -3,7 +3,7 @@
 //!
 //! This probably isn't the best way to do this -- ideally, diagnostics should
 //! be expressed in terms of hir types themselves.
-pub use hir_ty::diagnostics::{CaseType, IncoherentImpl, IncorrectCase};
+pub use hir_ty::diagnostics::{CaseType, IncorrectCase};
 
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
@@ -12,7 +12,7 @@ use hir_def::path::ModPath;
 use hir_expand::{name::Name, HirFileId, InFile};
 use syntax::{ast, AstPtr, SyntaxError, SyntaxNodePtr, TextRange};
 
-use crate::{AssocItem, Field, Local, MacroKind, Type};
+use crate::{AssocItem, Field, Local, MacroKind, Trait, Type};
 
 macro_rules! diagnostics {
     ($($diag:ident,)*) => {
@@ -53,6 +53,10 @@ diagnostics![
     PrivateAssocItem,
     PrivateField,
     ReplaceFilterMapNextWithFindMap,
+    TraitImplIncorrectSafety,
+    TraitImplMissingAssocItems,
+    TraitImplRedundantAssocItems,
+    TraitImplOrphan,
     TypedHole,
     TypeMismatch,
     UndeclaredLabel,
@@ -66,6 +70,7 @@ diagnostics![
     UnresolvedModule,
     UnresolvedProcMacro,
     UnusedMut,
+    UnusedVariable,
 ];
 
 #[derive(Debug)]
@@ -173,20 +178,19 @@ pub struct MalformedDerive {
 
 #[derive(Debug)]
 pub struct NoSuchField {
-    pub field: InFile<Either<AstPtr<ast::RecordExprField>, AstPtr<ast::RecordPatField>>>,
+    pub field: InFile<AstPtr<Either<ast::RecordExprField, ast::RecordPatField>>>,
     pub private: bool,
 }
 
 #[derive(Debug)]
 pub struct PrivateAssocItem {
-    pub expr_or_pat:
-        InFile<Either<AstPtr<ast::Expr>, Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>>>,
+    pub expr_or_pat: InFile<AstPtr<Either<ast::Expr, Either<ast::Pat, ast::SelfParam>>>>,
     pub item: AssocItem,
 }
 
 #[derive(Debug)]
 pub struct MismatchedTupleStructPatArgCount {
-    pub expr_or_pat: InFile<Either<AstPtr<ast::Expr>, AstPtr<ast::Pat>>>,
+    pub expr_or_pat: InFile<AstPtr<Either<ast::Expr, ast::Pat>>>,
     pub expected: usize,
     pub found: usize,
 }
@@ -227,7 +231,7 @@ pub struct MissingUnsafe {
 #[derive(Debug)]
 pub struct MissingFields {
     pub file: HirFileId,
-    pub field_list_parent: Either<AstPtr<ast::RecordExpr>, AstPtr<ast::RecordPat>>,
+    pub field_list_parent: AstPtr<Either<ast::RecordExpr, ast::RecordPat>>,
     pub field_list_parent_path: Option<AstPtr<ast::Path>>,
     pub missed_fields: Vec<Name>,
 }
@@ -254,7 +258,7 @@ pub struct MissingMatchArms {
 
 #[derive(Debug)]
 pub struct TypeMismatch {
-    pub expr_or_pat: Either<InFile<AstPtr<ast::Expr>>, InFile<AstPtr<ast::Pat>>>,
+    pub expr_or_pat: InFile<AstPtr<Either<ast::Expr, ast::Pat>>>,
     pub expected: Type,
     pub actual: Type,
 }
@@ -271,7 +275,47 @@ pub struct UnusedMut {
 }
 
 #[derive(Debug)]
+pub struct UnusedVariable {
+    pub local: Local,
+}
+
+#[derive(Debug)]
 pub struct MovedOutOfRef {
     pub ty: Type,
     pub span: InFile<SyntaxNodePtr>,
 }
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct IncoherentImpl {
+    pub file_id: HirFileId,
+    pub impl_: AstPtr<ast::Impl>,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TraitImplOrphan {
+    pub file_id: HirFileId,
+    pub impl_: AstPtr<ast::Impl>,
+}
+
+// FIXME: Split this off into the corresponding 4 rustc errors
+#[derive(Debug, PartialEq, Eq)]
+pub struct TraitImplIncorrectSafety {
+    pub file_id: HirFileId,
+    pub impl_: AstPtr<ast::Impl>,
+    pub should_be_safe: bool,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TraitImplMissingAssocItems {
+    pub file_id: HirFileId,
+    pub impl_: AstPtr<ast::Impl>,
+    pub missing: Vec<(Name, AssocItem)>,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TraitImplRedundantAssocItems {
+    pub file_id: HirFileId,
+    pub trait_: Trait,
+    pub impl_: AstPtr<ast::Impl>,
+    pub assoc_item: (Name, AssocItem),
+}
diff --git a/src/tools/rust-analyzer/crates/hir/src/display.rs b/src/tools/rust-analyzer/crates/hir/src/display.rs
index ac171026d..5847c8a9f 100644
--- a/src/tools/rust-analyzer/crates/hir/src/display.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/display.rs
@@ -1,6 +1,6 @@
 //! HirDisplay implementations for various hir types.
 use hir_def::{
-    data::adt::VariantData,
+    data::adt::{StructKind, VariantData},
     generics::{
         TypeOrConstParamData, TypeParamProvenance, WherePredicate, WherePredicateTypeTarget,
     },
@@ -163,7 +163,40 @@ impl HirDisplay for Struct {
         write!(f, "{}", self.name(f.db).display(f.db.upcast()))?;
         let def_id = GenericDefId::AdtId(AdtId::StructId(self.id));
         write_generic_params(def_id, f)?;
+
+        let variant_data = self.variant_data(f.db);
+        if let StructKind::Tuple = variant_data.kind() {
+            f.write_char('(')?;
+            let mut it = variant_data.fields().iter().peekable();
+
+            while let Some((id, _)) = it.next() {
+                let field = Field { parent: (*self).into(), id };
+                field.ty(f.db).hir_fmt(f)?;
+                if it.peek().is_some() {
+                    f.write_str(", ")?;
+                }
+            }
+
+            f.write_str(");")?;
+        }
+
         write_where_clause(def_id, f)?;
+
+        if let StructKind::Record = variant_data.kind() {
+            let fields = self.fields(f.db);
+            if fields.is_empty() {
+                f.write_str(" {}")?;
+            } else {
+                f.write_str(" {\n")?;
+                for field in self.fields(f.db) {
+                    f.write_str("    ")?;
+                    field.hir_fmt(f)?;
+                    f.write_str(",\n")?;
+                }
+                f.write_str("}")?;
+            }
+        }
+
         Ok(())
     }
 }
@@ -176,6 +209,18 @@ impl HirDisplay for Enum {
         let def_id = GenericDefId::AdtId(AdtId::EnumId(self.id));
         write_generic_params(def_id, f)?;
         write_where_clause(def_id, f)?;
+
+        let variants = self.variants(f.db);
+        if !variants.is_empty() {
+            f.write_str(" {\n")?;
+            for variant in variants {
+                f.write_str("    ")?;
+                variant.hir_fmt(f)?;
+                f.write_str(",\n")?;
+            }
+            f.write_str("}")?;
+        }
+
         Ok(())
     }
 }
@@ -188,6 +233,18 @@ impl HirDisplay for Union {
         let def_id = GenericDefId::AdtId(AdtId::UnionId(self.id));
         write_generic_params(def_id, f)?;
         write_where_clause(def_id, f)?;
+
+        let fields = self.fields(f.db);
+        if !fields.is_empty() {
+            f.write_str(" {\n")?;
+            for field in self.fields(f.db) {
+                f.write_str("    ")?;
+                field.hir_fmt(f)?;
+                f.write_str(",\n")?;
+            }
+            f.write_str("}")?;
+        }
+
         Ok(())
     }
 }
@@ -559,7 +616,7 @@ impl HirDisplay for TypeAlias {
         write_where_clause(def_id, f)?;
         if !data.bounds.is_empty() {
             f.write_str(": ")?;
-            f.write_joined(&data.bounds, " + ")?;
+            f.write_joined(data.bounds.iter(), " + ")?;
         }
         if let Some(ty) = &data.type_ref {
             f.write_str(" = ")?;
diff --git a/src/tools/rust-analyzer/crates/hir/src/lib.rs b/src/tools/rust-analyzer/crates/hir/src/lib.rs
index b215ed38f..e0230fa37 100644
--- a/src/tools/rust-analyzer/crates/hir/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/lib.rs
@@ -17,7 +17,8 @@
 //! from the ide with completions, hovers, etc. It is a (soft, internal) boundary:
 //! <https://www.tedinski.com/2018/02/06/system-boundaries.html>.
 
-#![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))]
 #![recursion_limit = "512"]
 
 mod semantics;
@@ -33,7 +34,7 @@ pub mod symbols;
 
 mod display;
 
-use std::{iter, ops::ControlFlow};
+use std::{iter, mem::discriminant, ops::ControlFlow};
 
 use arrayvec::ArrayVec;
 use base_db::{CrateDisplayName, CrateId, CrateOrigin, Edition, FileId, ProcMacroKind};
@@ -53,20 +54,20 @@ use hir_def::{
     resolver::{HasResolver, Resolver},
     src::HasSource as _,
     AssocItemId, AssocItemLoc, AttrDefId, ConstId, ConstParamId, CrateRootModuleId, DefWithBodyId,
-    EnumId, EnumVariantId, ExternCrateId, FunctionId, GenericDefId, HasModule, ImplId,
-    InTypeConstId, ItemContainerId, LifetimeParamId, LocalEnumVariantId, LocalFieldId, Lookup,
-    MacroExpander, MacroId, ModuleId, StaticId, StructId, TraitAliasId, TraitId, TypeAliasId,
-    TypeOrConstParamId, TypeParamId, UnionId,
+    EnumId, EnumVariantId, ExternCrateId, FunctionId, GenericDefId, GenericParamId, HasModule,
+    ImplId, InTypeConstId, ItemContainerId, LifetimeParamId, LocalEnumVariantId, LocalFieldId,
+    Lookup, MacroExpander, MacroId, ModuleId, StaticId, StructId, TraitAliasId, TraitId,
+    TypeAliasId, TypeOrConstParamId, TypeParamId, UnionId,
 };
-use hir_expand::{name::name, MacroCallKind};
+use hir_expand::{attrs::collect_attrs, name::name, MacroCallKind};
 use hir_ty::{
-    all_super_traits, autoderef,
+    all_super_traits, autoderef, check_orphan_rules,
     consteval::{try_const_usize, unknown_const_as_generic, ConstEvalError, ConstExt},
     diagnostics::BodyValidationDiagnostic,
     known_const_to_ast,
-    layout::{Layout as TyLayout, RustcEnumVariantIdx, TagEncoding},
+    layout::{Layout as TyLayout, RustcEnumVariantIdx, RustcFieldIdx, TagEncoding},
     method_resolution::{self, TyFingerprint},
-    mir::{self, interpret_mir},
+    mir::interpret_mir,
     primitive::UintTy,
     traits::FnTrait,
     AliasTy, CallableDefId, CallableSig, Canonical, CanonicalVarKinds, Cast, ClosureId, GenericArg,
@@ -80,7 +81,7 @@ use once_cell::unsync::Lazy;
 use rustc_hash::FxHashSet;
 use stdx::{impl_from, never};
 use syntax::{
-    ast::{self, HasAttrs as _, HasDocComments, HasName},
+    ast::{self, HasAttrs as _, HasName},
     AstNode, AstPtr, SmolStr, SyntaxNode, SyntaxNodePtr, TextRange, T,
 };
 use triomphe::Arc;
@@ -89,19 +90,11 @@ use crate::db::{DefDatabase, HirDatabase};
 
 pub use crate::{
     attrs::{resolve_doc_path_on, HasAttrs},
-    diagnostics::{
-        AnyDiagnostic, BreakOutsideOfLoop, CaseType, ExpectedFunction, InactiveCode,
-        IncoherentImpl, IncorrectCase, InvalidDeriveTarget, MacroDefError, MacroError,
-        MacroExpansionParseError, MalformedDerive, MismatchedArgCount,
-        MismatchedTupleStructPatArgCount, MissingFields, MissingMatchArms, MissingUnsafe,
-        MovedOutOfRef, NeedMut, NoSuchField, PrivateAssocItem, PrivateField,
-        ReplaceFilterMapNextWithFindMap, TypeMismatch, TypedHole, UndeclaredLabel,
-        UnimplementedBuiltinMacro, UnreachableLabel, UnresolvedExternCrate, UnresolvedField,
-        UnresolvedImport, UnresolvedMacroCall, UnresolvedMethodCall, UnresolvedModule,
-        UnresolvedProcMacro, UnusedMut,
-    },
+    diagnostics::*,
     has_source::HasSource,
-    semantics::{PathResolution, Semantics, SemanticsScope, TypeInfo, VisibleTraits},
+    semantics::{
+        DescendPreference, PathResolution, Semantics, SemanticsScope, TypeInfo, VisibleTraits,
+    },
 };
 
 // Be careful with these re-exports.
@@ -132,15 +125,18 @@ pub use {
     },
     hir_expand::{
         attrs::{Attr, AttrId},
+        hygiene::{marks_rev, SyntaxContextExt},
         name::{known, Name},
-        ExpandResult, HirFileId, InFile, MacroFile, Origin,
+        tt, ExpandResult, HirFileId, HirFileIdExt, InFile, InMacroFile, InRealFile, MacroFileId,
+        MacroFileIdExt,
     },
     hir_ty::{
         display::{ClosureStyle, HirDisplay, HirDisplayError, HirWrite},
         layout::LayoutError,
-        mir::MirEvalError,
         PointerCast, Safety,
     },
+    // FIXME: Properly encapsulate mir
+    hir_ty::{mir, Interner as ChalkTyInterner},
 };
 
 // These are negative re-exports: pub using these names is forbidden, they
@@ -148,7 +144,10 @@ pub use {
 #[allow(unused)]
 use {
     hir_def::path::Path,
-    hir_expand::{hygiene::Hygiene, name::AsName},
+    hir_expand::{
+        name::AsName,
+        span::{ExpansionSpanMap, RealSpanMap, SpanMap, SpanMapRef},
+    },
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -452,15 +451,7 @@ impl HasVisibility for ModuleDef {
 impl Module {
     /// Name of this module.
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        let def_map = self.id.def_map(db.upcast());
-        let parent = def_map[self.id.local_id].parent?;
-        def_map[parent].children.iter().find_map(|(name, module_id)| {
-            if *module_id == self.id.local_id {
-                Some(name.clone())
-            } else {
-                None
-            }
-        })
+        self.id.name(db.upcast())
     }
 
     /// Returns the crate this module is part of.
@@ -571,6 +562,7 @@ impl Module {
                     if def_map[m.id.local_id].origin.is_inline() {
                         m.diagnostics(db, acc)
                     }
+                    acc.extend(def.diagnostics(db))
                 }
                 ModuleDef::Trait(t) => {
                     for diag in db.trait_data_with_diagnostics(t.id).1.iter() {
@@ -610,29 +602,141 @@ impl Module {
 
         let inherent_impls = db.inherent_impls_in_crate(self.id.krate());
 
+        let mut impl_assoc_items_scratch = vec![];
         for impl_def in self.impl_defs(db) {
             let loc = impl_def.id.lookup(db.upcast());
             let tree = loc.id.item_tree(db.upcast());
             let node = &tree[loc.id.value];
             let file_id = loc.id.file_id();
-            if file_id.is_builtin_derive(db.upcast()) {
+            if file_id.macro_file().map_or(false, |it| it.is_builtin_derive(db.upcast())) {
                 // these expansion come from us, diagnosing them is a waste of resources
                 // FIXME: Once we diagnose the inputs to builtin derives, we should at least extract those diagnostics somehow
                 continue;
             }
+            let ast_id_map = db.ast_id_map(file_id);
 
             for diag in db.impl_data_with_diagnostics(impl_def.id).1.iter() {
                 emit_def_diagnostic(db, acc, diag);
             }
 
             if inherent_impls.invalid_impls().contains(&impl_def.id) {
-                let ast_id_map = db.ast_id_map(file_id);
-
                 acc.push(IncoherentImpl { impl_: ast_id_map.get(node.ast_id()), file_id }.into())
             }
 
-            for item in impl_def.items(db) {
-                let def: DefWithBody = match item {
+            if !impl_def.check_orphan_rules(db) {
+                acc.push(TraitImplOrphan { impl_: ast_id_map.get(node.ast_id()), file_id }.into())
+            }
+
+            let trait_ = impl_def.trait_(db);
+            let trait_is_unsafe = trait_.map_or(false, |t| t.is_unsafe(db));
+            let impl_is_negative = impl_def.is_negative(db);
+            let impl_is_unsafe = impl_def.is_unsafe(db);
+
+            let drop_maybe_dangle = (|| {
+                // FIXME: This can be simplified a lot by exposing hir-ty's utils.rs::Generics helper
+                let trait_ = trait_?;
+                let drop_trait = db.lang_item(self.krate().into(), LangItem::Drop)?.as_trait()?;
+                if drop_trait != trait_.into() {
+                    return None;
+                }
+                let parent = impl_def.id.into();
+                let generic_params = db.generic_params(parent);
+                let lifetime_params = generic_params.lifetimes.iter().map(|(local_id, _)| {
+                    GenericParamId::LifetimeParamId(LifetimeParamId { parent, local_id })
+                });
+                let type_params = generic_params
+                    .iter()
+                    .filter(|(_, it)| it.type_param().is_some())
+                    .map(|(local_id, _)| {
+                        GenericParamId::TypeParamId(TypeParamId::from_unchecked(
+                            TypeOrConstParamId { parent, local_id },
+                        ))
+                    });
+                let res = type_params
+                    .chain(lifetime_params)
+                    .any(|p| db.attrs(AttrDefId::GenericParamId(p)).by_key("may_dangle").exists());
+                Some(res)
+            })()
+            .unwrap_or(false);
+
+            match (impl_is_unsafe, trait_is_unsafe, impl_is_negative, drop_maybe_dangle) {
+                // unsafe negative impl
+                (true, _, true, _) |
+                // unsafe impl for safe trait
+                (true, false, _, false) => acc.push(TraitImplIncorrectSafety { impl_: ast_id_map.get(node.ast_id()), file_id, should_be_safe: true }.into()),
+                // safe impl for unsafe trait
+                (false, true, false, _) |
+                // safe impl of dangling drop
+                (false, false, _, true) => acc.push(TraitImplIncorrectSafety { impl_: ast_id_map.get(node.ast_id()), file_id, should_be_safe: false }.into()),
+                _ => (),
+            };
+
+            // Negative impls can't have items, don't emit missing items diagnostic for them
+            if let (false, Some(trait_)) = (impl_is_negative, trait_) {
+                let items = &db.trait_data(trait_.into()).items;
+                let required_items = items.iter().filter(|&(_, assoc)| match *assoc {
+                    AssocItemId::FunctionId(it) => !db.function_data(it).has_body(),
+                    AssocItemId::ConstId(id) => Const::from(id).value(db).is_none(),
+                    AssocItemId::TypeAliasId(it) => db.type_alias_data(it).type_ref.is_none(),
+                });
+                impl_assoc_items_scratch.extend(db.impl_data(impl_def.id).items.iter().filter_map(
+                    |&item| {
+                        Some((
+                            item,
+                            match item {
+                                AssocItemId::FunctionId(it) => db.function_data(it).name.clone(),
+                                AssocItemId::ConstId(it) => {
+                                    db.const_data(it).name.as_ref()?.clone()
+                                }
+                                AssocItemId::TypeAliasId(it) => db.type_alias_data(it).name.clone(),
+                            },
+                        ))
+                    },
+                ));
+
+                let redundant = impl_assoc_items_scratch
+                    .iter()
+                    .filter(|(id, name)| {
+                        !items.iter().any(|(impl_name, impl_item)| {
+                            discriminant(impl_item) == discriminant(id) && impl_name == name
+                        })
+                    })
+                    .map(|(item, name)| (name.clone(), AssocItem::from(*item)));
+                for (name, assoc_item) in redundant {
+                    acc.push(
+                        TraitImplRedundantAssocItems {
+                            trait_,
+                            file_id,
+                            impl_: ast_id_map.get(node.ast_id()),
+                            assoc_item: (name, assoc_item),
+                        }
+                        .into(),
+                    )
+                }
+
+                let missing: Vec<_> = required_items
+                    .filter(|(name, id)| {
+                        !impl_assoc_items_scratch.iter().any(|(impl_item, impl_name)| {
+                            discriminant(impl_item) == discriminant(id) && impl_name == name
+                        })
+                    })
+                    .map(|(name, item)| (name.clone(), AssocItem::from(*item)))
+                    .collect();
+                if !missing.is_empty() {
+                    acc.push(
+                        TraitImplMissingAssocItems {
+                            impl_: ast_id_map.get(node.ast_id()),
+                            file_id,
+                            missing,
+                        }
+                        .into(),
+                    )
+                }
+                impl_assoc_items_scratch.clear();
+            }
+
+            for &item in &db.impl_data(impl_def.id).items {
+                let def: DefWithBody = match AssocItem::from(item) {
                     AssocItem::Function(it) => it.into(),
                     AssocItem::Const(it) => it.into(),
                     AssocItem::TypeAlias(_) => continue,
@@ -671,8 +775,15 @@ impl Module {
         db: &dyn DefDatabase,
         item: impl Into<ItemInNs>,
         prefer_no_std: bool,
+        prefer_prelude: bool,
     ) -> Option<ModPath> {
-        hir_def::find_path::find_path(db, item.into().into(), self.into(), prefer_no_std)
+        hir_def::find_path::find_path(
+            db,
+            item.into().into(),
+            self.into(),
+            prefer_no_std,
+            prefer_prelude,
+        )
     }
 
     /// Finds a path that can be used to refer to the given item from within
@@ -683,6 +794,7 @@ impl Module {
         item: impl Into<ItemInNs>,
         prefix_kind: PrefixKind,
         prefer_no_std: bool,
+        prefer_prelude: bool,
     ) -> Option<ModPath> {
         hir_def::find_path::find_path_prefixed(
             db,
@@ -690,6 +802,7 @@ impl Module {
             self.into(),
             prefix_kind,
             prefer_no_std,
+            prefer_prelude,
         )
     }
 }
@@ -862,10 +975,9 @@ fn precise_macro_call_location(
             // Compute the precise location of the macro name's token in the derive
             // list.
             let token = (|| {
-                let derive_attr = node
-                    .doc_comments_and_attrs()
+                let derive_attr = collect_attrs(&node)
                     .nth(derive_attr_index.ast_index())
-                    .and_then(Either::left)?;
+                    .and_then(|x| Either::left(x.1))?;
                 let token_tree = derive_attr.meta()?.token_tree()?;
                 let group_by = token_tree
                     .syntax()
@@ -890,10 +1002,9 @@ fn precise_macro_call_location(
         }
         MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => {
             let node = ast_id.to_node(db.upcast());
-            let attr = node
-                .doc_comments_and_attrs()
+            let attr = collect_attrs(&node)
                 .nth(invoc_attr_index.ast_index())
-                .and_then(Either::left)
+                .and_then(|x| Either::left(x.1))
                 .unwrap_or_else(|| {
                     panic!("cannot find attribute #{}", invoc_attr_index.ast_index())
                 });
@@ -1453,9 +1564,7 @@ impl DefWithBody {
         let (body, source_map) = db.body_with_source_map(self.into());
 
         for (_, def_map) in body.blocks(db.upcast()) {
-            for diag in def_map.diagnostics() {
-                emit_def_diagnostic(db, acc, diag);
-            }
+            Module { id: def_map.module_id(DefMap::ROOT) }.diagnostics(db, acc);
         }
 
         for diag in source_map.diagnostics() {
@@ -1509,10 +1618,10 @@ impl DefWithBody {
                 &hir_ty::InferenceDiagnostic::NoSuchField { field: expr, private } => {
                     let expr_or_pat = match expr {
                         ExprOrPatId::ExprId(expr) => {
-                            source_map.field_syntax(expr).map(Either::Left)
+                            source_map.field_syntax(expr).map(AstPtr::wrap_left)
                         }
                         ExprOrPatId::PatId(pat) => {
-                            source_map.pat_field_syntax(pat).map(Either::Right)
+                            source_map.pat_field_syntax(pat).map(AstPtr::wrap_right)
                         }
                     };
                     acc.push(NoSuchField { field: expr_or_pat, private }.into())
@@ -1530,8 +1639,8 @@ impl DefWithBody {
                 }
                 &hir_ty::InferenceDiagnostic::PrivateAssocItem { id, item } => {
                     let expr_or_pat = match id {
-                        ExprOrPatId::ExprId(expr) => expr_syntax(expr).map(Either::Left),
-                        ExprOrPatId::PatId(pat) => pat_syntax(pat).map(Either::Right),
+                        ExprOrPatId::ExprId(expr) => expr_syntax(expr).map(AstPtr::wrap_left),
+                        ExprOrPatId::PatId(pat) => pat_syntax(pat).map(AstPtr::wrap_right),
                     };
                     let item = item.into();
                     acc.push(PrivateAssocItem { expr_or_pat, item }.into())
@@ -1609,12 +1718,17 @@ impl DefWithBody {
                     found,
                 } => {
                     let expr_or_pat = match pat {
-                        ExprOrPatId::ExprId(expr) => expr_syntax(expr).map(Either::Left),
-                        ExprOrPatId::PatId(pat) => source_map
-                            .pat_syntax(pat)
-                            .expect("unexpected synthetic")
-                            .map(|it| it.unwrap_left())
-                            .map(Either::Right),
+                        ExprOrPatId::ExprId(expr) => expr_syntax(expr).map(AstPtr::wrap_left),
+                        ExprOrPatId::PatId(pat) => {
+                            let InFile { file_id, value } =
+                                source_map.pat_syntax(pat).expect("unexpected synthetic");
+
+                            // cast from Either<Pat, SelfParam> -> Either<_, Pat>
+                            let Some(ptr) = AstPtr::try_from_raw(value.syntax_node_ptr()) else {
+                                continue;
+                            };
+                            InFile { file_id, value: ptr }
+                        }
                     };
                     acc.push(
                         MismatchedTupleStructPatArgCount { expr_or_pat, expected, found }.into(),
@@ -1628,11 +1742,15 @@ impl DefWithBody {
                 ExprOrPatId::PatId(pat) => source_map.pat_syntax(pat).map(Either::Right),
             };
             let expr_or_pat = match expr_or_pat {
-                Ok(Either::Left(expr)) => Either::Left(expr),
-                Ok(Either::Right(InFile { file_id, value: Either::Left(pat) })) => {
-                    Either::Right(InFile { file_id, value: pat })
+                Ok(Either::Left(expr)) => expr.map(AstPtr::wrap_left),
+                Ok(Either::Right(InFile { file_id, value: pat })) => {
+                    // cast from Either<Pat, SelfParam> -> Either<_, Pat>
+                    let Some(ptr) = AstPtr::try_from_raw(pat.syntax_node_ptr()) else {
+                        continue;
+                    };
+                    InFile { file_id, value: ptr }
                 }
-                Ok(Either::Right(_)) | Err(SyntheticSyntax) => continue,
+                Err(SyntheticSyntax) => continue,
             };
 
             acc.push(
@@ -1667,10 +1785,7 @@ impl DefWithBody {
                             Err(_) => continue,
                         },
                         mir::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.into()),
                             Err(_) => continue,
                         },
                         mir::MirSpan::Unknown => continue,
@@ -1697,9 +1812,20 @@ impl DefWithBody {
                         // Skip synthetic bindings
                         continue;
                     }
-                    let need_mut = &mol[local];
+                    let mut need_mut = &mol[local];
+                    if body[binding_id].name.as_str() == Some("self")
+                        && need_mut == &mir::MutabilityReason::Unused
+                    {
+                        need_mut = &mir::MutabilityReason::Not;
+                    }
                     let local = Local { parent: self.into(), binding_id };
                     match (need_mut, local.is_mut(db)) {
+                        (mir::MutabilityReason::Unused, _) => {
+                            let should_ignore = matches!(body[binding_id].name.as_str(), Some(it) if it.starts_with("_"));
+                            if !should_ignore {
+                                acc.push(UnusedVariable { local }.into())
+                            }
+                        }
                         (mir::MutabilityReason::Mut { .. }, true)
                         | (mir::MutabilityReason::Not, false) => (),
                         (mir::MutabilityReason::Mut { spans }, false) => {
@@ -1710,10 +1836,7 @@ impl DefWithBody {
                                         Err(_) => continue,
                                     },
                                     mir::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.into()),
                                         Err(_) => continue,
                                     },
                                     mir::MirSpan::Unknown => continue,
@@ -1752,18 +1875,18 @@ impl DefWithBody {
                             Ok(source_ptr) => {
                                 let root = source_ptr.file_syntax(db.upcast());
                                 if let ast::Expr::RecordExpr(record_expr) =
-                                    &source_ptr.value.to_node(&root)
+                                    source_ptr.value.to_node(&root)
                                 {
                                     if record_expr.record_expr_field_list().is_some() {
+                                        let field_list_parent_path =
+                                            record_expr.path().map(|path| AstPtr::new(&path));
                                         acc.push(
                                             MissingFields {
                                                 file: source_ptr.file_id,
-                                                field_list_parent: Either::Left(AstPtr::new(
+                                                field_list_parent: AstPtr::new(&Either::Left(
                                                     record_expr,
                                                 )),
-                                                field_list_parent_path: record_expr
-                                                    .path()
-                                                    .map(|path| AstPtr::new(&path)),
+                                                field_list_parent_path,
                                                 missed_fields,
                                             }
                                             .into(),
@@ -1775,24 +1898,24 @@ impl DefWithBody {
                         },
                         Either::Right(record_pat) => match source_map.pat_syntax(record_pat) {
                             Ok(source_ptr) => {
-                                if let Some(expr) = source_ptr.value.as_ref().left() {
+                                if let Some(ptr) = source_ptr.value.clone().cast::<ast::RecordPat>()
+                                {
                                     let root = source_ptr.file_syntax(db.upcast());
-                                    if let ast::Pat::RecordPat(record_pat) = expr.to_node(&root) {
-                                        if record_pat.record_pat_field_list().is_some() {
-                                            acc.push(
-                                                MissingFields {
-                                                    file: source_ptr.file_id,
-                                                    field_list_parent: Either::Right(AstPtr::new(
-                                                        &record_pat,
-                                                    )),
-                                                    field_list_parent_path: record_pat
-                                                        .path()
-                                                        .map(|path| AstPtr::new(&path)),
-                                                    missed_fields,
-                                                }
-                                                .into(),
-                                            )
-                                        }
+                                    let record_pat = ptr.to_node(&root);
+                                    if record_pat.record_pat_field_list().is_some() {
+                                        let field_list_parent_path =
+                                            record_pat.path().map(|path| AstPtr::new(&path));
+                                        acc.push(
+                                            MissingFields {
+                                                file: source_ptr.file_id,
+                                                field_list_parent: AstPtr::new(&Either::Right(
+                                                    record_pat,
+                                                )),
+                                                field_list_parent_path,
+                                                missed_fields,
+                                            }
+                                            .into(),
+                                        )
                                     }
                                 }
                             }
@@ -1818,17 +1941,20 @@ impl DefWithBody {
                             if let ast::Expr::MatchExpr(match_expr) =
                                 &source_ptr.value.to_node(&root)
                             {
-                                if let Some(scrut_expr) = match_expr.expr() {
-                                    acc.push(
-                                        MissingMatchArms {
-                                            scrutinee_expr: InFile::new(
-                                                source_ptr.file_id,
-                                                AstPtr::new(&scrut_expr),
-                                            ),
-                                            uncovered_patterns,
-                                        }
-                                        .into(),
-                                    );
+                                match match_expr.expr() {
+                                    Some(scrut_expr) if match_expr.match_arm_list().is_some() => {
+                                        acc.push(
+                                            MissingMatchArms {
+                                                scrutinee_expr: InFile::new(
+                                                    source_ptr.file_id,
+                                                    AstPtr::new(&scrut_expr),
+                                                ),
+                                                uncovered_patterns,
+                                            }
+                                            .into(),
+                                        );
+                                    }
+                                    _ => {}
                                 }
                             }
                         }
@@ -1960,6 +2086,17 @@ impl Function {
         db.function_data(self.id).attrs.is_test()
     }
 
+    /// is this a `fn main` or a function with an `export_name` of `main`?
+    pub fn is_main(self, db: &dyn HirDatabase) -> bool {
+        if !self.module(db).is_crate_root() {
+            return false;
+        }
+        let data = db.function_data(self.id);
+
+        data.name.to_smol_str() == "main"
+            || data.attrs.export_name().map(core::ops::Deref::deref) == Some("main")
+    }
+
     /// Does this function have the ignore attribute?
     pub fn is_ignore(self, db: &dyn HirDatabase) -> bool {
         db.function_data(self.id).attrs.is_ignore()
@@ -2926,10 +3063,10 @@ impl Local {
             .map(|&definition| {
                 let src = source_map.pat_syntax(definition).unwrap(); // Hmm...
                 let root = src.file_syntax(db.upcast());
-                src.map(|ast| match ast {
-                    // Suspicious unwrap
-                    Either::Left(it) => Either::Left(it.cast().unwrap().to_node(&root)),
-                    Either::Right(it) => Either::Right(it.to_node(&root)),
+                src.map(|ast| match ast.to_node(&root) {
+                    Either::Left(ast::Pat::IdentPat(it)) => Either::Left(it),
+                    Either::Left(_) => unreachable!("local with non ident-pattern"),
+                    Either::Right(it) => Either::Right(it),
                 })
             })
             .map(move |source| LocalSource { local: self, source })
@@ -3371,13 +3508,46 @@ impl Impl {
         db.impl_data(self.id).is_negative
     }
 
+    pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
+        db.impl_data(self.id).is_unsafe
+    }
+
     pub fn module(self, db: &dyn HirDatabase) -> Module {
         self.id.lookup(db.upcast()).container.into()
     }
 
-    pub fn as_builtin_derive(self, db: &dyn HirDatabase) -> Option<InFile<ast::Attr>> {
+    pub fn as_builtin_derive_path(self, db: &dyn HirDatabase) -> Option<InMacroFile<ast::Path>> {
         let src = self.source(db)?;
-        src.file_id.as_builtin_derive_attr_node(db.upcast())
+
+        let macro_file = src.file_id.macro_file()?;
+        let loc = db.lookup_intern_macro_call(macro_file.macro_call_id);
+        let (derive_attr, derive_index) = match loc.kind {
+            MacroCallKind::Derive { ast_id, derive_attr_index, derive_index } => {
+                let module_id = self.id.lookup(db.upcast()).container;
+                (
+                    db.crate_def_map(module_id.krate())[module_id.local_id]
+                        .scope
+                        .derive_macro_invoc(ast_id, derive_attr_index)?,
+                    derive_index,
+                )
+            }
+            _ => return None,
+        };
+        let file_id = MacroFileId { macro_call_id: derive_attr };
+        let path = db
+            .parse_macro_expansion(file_id)
+            .value
+            .0
+            .syntax_node()
+            .children()
+            .nth(derive_index as usize)
+            .and_then(<ast::Attr as AstNode>::cast)
+            .and_then(|it| it.path())?;
+        Some(InMacroFile { file_id, value: path })
+    }
+
+    pub fn check_orphan_rules(self, db: &dyn HirDatabase) -> bool {
+        check_orphan_rules(db, self.id)
     }
 }
 
@@ -3393,10 +3563,9 @@ impl TraitRef {
         resolver: &Resolver,
         trait_ref: hir_ty::TraitRef,
     ) -> TraitRef {
-        let env = resolver.generic_def().map_or_else(
-            || Arc::new(TraitEnvironment::empty(resolver.krate())),
-            |d| db.trait_environment(d),
-        );
+        let env = resolver
+            .generic_def()
+            .map_or_else(|| TraitEnvironment::empty(resolver.krate()), |d| db.trait_environment(d));
         TraitRef { env, trait_ref }
     }
 
@@ -3536,15 +3705,14 @@ impl Type {
         resolver: &Resolver,
         ty: Ty,
     ) -> Type {
-        let environment = resolver.generic_def().map_or_else(
-            || Arc::new(TraitEnvironment::empty(resolver.krate())),
-            |d| db.trait_environment(d),
-        );
+        let environment = resolver
+            .generic_def()
+            .map_or_else(|| TraitEnvironment::empty(resolver.krate()), |d| db.trait_environment(d));
         Type { env: environment, ty }
     }
 
     pub(crate) fn new_for_crate(krate: CrateId, ty: Ty) -> Type {
-        Type { env: Arc::new(TraitEnvironment::empty(krate)), ty }
+        Type { env: TraitEnvironment::empty(krate), ty }
     }
 
     pub fn reference(inner: &Type, m: Mutability) -> Type {
@@ -3560,10 +3728,9 @@ impl Type {
 
     fn new(db: &dyn HirDatabase, lexical_env: impl HasResolver, ty: Ty) -> Type {
         let resolver = lexical_env.resolver(db.upcast());
-        let environment = resolver.generic_def().map_or_else(
-            || Arc::new(TraitEnvironment::empty(resolver.krate())),
-            |d| db.trait_environment(d),
-        );
+        let environment = resolver
+            .generic_def()
+            .map_or_else(|| TraitEnvironment::empty(resolver.krate()), |d| db.trait_environment(d));
         Type { env: environment, ty }
     }
 
@@ -4133,10 +4300,10 @@ impl Type {
         let canonical = hir_ty::replace_errors_with_variables(&self.ty);
 
         let krate = scope.krate();
-        let environment = scope.resolver().generic_def().map_or_else(
-            || Arc::new(TraitEnvironment::empty(krate.id)),
-            |d| db.trait_environment(d),
-        );
+        let environment = scope
+            .resolver()
+            .generic_def()
+            .map_or_else(|| TraitEnvironment::empty(krate.id), |d| db.trait_environment(d));
 
         method_resolution::iterate_method_candidates_dyn(
             &canonical,
@@ -4190,10 +4357,10 @@ impl Type {
         let canonical = hir_ty::replace_errors_with_variables(&self.ty);
 
         let krate = scope.krate();
-        let environment = scope.resolver().generic_def().map_or_else(
-            || Arc::new(TraitEnvironment::empty(krate.id)),
-            |d| db.trait_environment(d),
-        );
+        let environment = scope
+            .resolver()
+            .generic_def()
+            .map_or_else(|| TraitEnvironment::empty(krate.id), |d| db.trait_environment(d));
 
         method_resolution::iterate_path_candidates(
             &canonical,
@@ -4515,15 +4682,31 @@ impl Layout {
         Some(self.0.largest_niche?.available(&*self.1))
     }
 
-    pub fn field_offset(&self, idx: usize) -> Option<u64> {
+    pub fn field_offset(&self, field: Field) -> Option<u64> {
         match self.0.fields {
             layout::FieldsShape::Primitive => None,
             layout::FieldsShape::Union(_) => Some(0),
             layout::FieldsShape::Array { stride, count } => {
-                let i = u64::try_from(idx).ok()?;
+                let i = u64::try_from(field.index()).ok()?;
                 (i < count).then_some((stride * i).bytes())
             }
-            layout::FieldsShape::Arbitrary { ref offsets, .. } => Some(offsets.get(idx)?.bytes()),
+            layout::FieldsShape::Arbitrary { ref offsets, .. } => {
+                Some(offsets.get(RustcFieldIdx(field.id))?.bytes())
+            }
+        }
+    }
+
+    pub fn tuple_field_offset(&self, field: usize) -> Option<u64> {
+        match self.0.fields {
+            layout::FieldsShape::Primitive => None,
+            layout::FieldsShape::Union(_) => Some(0),
+            layout::FieldsShape::Array { stride, count } => {
+                let i = u64::try_from(field).ok()?;
+                (i < count).then_some((stride * i).bytes())
+            }
+            layout::FieldsShape::Arbitrary { ref offsets, .. } => {
+                Some(offsets.get(RustcFieldIdx::new(field))?.bytes())
+            }
         }
     }
 
diff --git a/src/tools/rust-analyzer/crates/hir/src/semantics.rs b/src/tools/rust-analyzer/crates/hir/src/semantics.rs
index a42e0978b..a03ff2207 100644
--- a/src/tools/rust-analyzer/crates/hir/src/semantics.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/semantics.rs
@@ -2,7 +2,11 @@
 
 mod source_to_def;
 
-use std::{cell::RefCell, fmt, iter, mem, ops};
+use std::{
+    cell::RefCell,
+    fmt, iter, mem,
+    ops::{self, ControlFlow, Not},
+};
 
 use base_db::{FileId, FileRange};
 use either::Either;
@@ -13,16 +17,21 @@ use hir_def::{
     nameres::MacroSubNs,
     resolver::{self, HasResolver, Resolver, TypeNs},
     type_ref::Mutability,
-    AsMacroCall, DefWithBodyId, FieldId, FunctionId, MacroId, TraitId, VariantId,
+    AsMacroCall, DefWithBodyId, FunctionId, MacroId, TraitId, VariantId,
+};
+use hir_expand::{
+    attrs::collect_attrs, db::ExpandDatabase, files::InRealFile, name::AsName, ExpansionInfo,
+    InMacroFile, MacroCallId, MacroFileId, MacroFileIdExt,
 };
-use hir_expand::{db::ExpandDatabase, name::AsName, ExpansionInfo, MacroCallId};
 use itertools::Itertools;
 use rustc_hash::{FxHashMap, FxHashSet};
 use smallvec::{smallvec, SmallVec};
+use stdx::TupleExt;
 use syntax::{
     algo::skip_trivia_token,
-    ast::{self, HasAttrs as _, HasGenericParams, HasLoopBody},
-    match_ast, AstNode, Direction, SyntaxKind, SyntaxNode, SyntaxNodePtr, SyntaxToken, TextSize,
+    ast::{self, HasAttrs as _, HasGenericParams, HasLoopBody, IsString as _},
+    match_ast, AstNode, AstToken, Direction, SyntaxKind, SyntaxNode, SyntaxNodePtr, SyntaxToken,
+    TextRange, TextSize,
 };
 
 use crate::{
@@ -35,7 +44,13 @@ use crate::{
     TypeAlias, TypeParam, VariantDef,
 };
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum DescendPreference {
+    SameText,
+    SameKind,
+    None,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub enum PathResolution {
     /// An item
     Def(ModuleDef),
@@ -114,11 +129,12 @@ pub struct Semantics<'db, DB> {
 pub struct SemanticsImpl<'db> {
     pub db: &'db dyn HirDatabase,
     s2d_cache: RefCell<SourceToDefCache>,
-    expansion_info_cache: RefCell<FxHashMap<HirFileId, Option<ExpansionInfo>>>,
-    // Rootnode to HirFileId cache
+    /// Rootnode to HirFileId cache
     cache: RefCell<FxHashMap<SyntaxNode, HirFileId>>,
-    // MacroCall to its expansion's HirFileId cache
-    macro_call_cache: RefCell<FxHashMap<InFile<ast::MacroCall>, HirFileId>>,
+    // These 2 caches are mainly useful for semantic highlighting as nothing else descends a lot of tokens
+    expansion_info_cache: RefCell<FxHashMap<MacroFileId, ExpansionInfo>>,
+    /// MacroCall to its expansion's MacroFileId cache
+    macro_call_cache: RefCell<FxHashMap<InFile<ast::MacroCall>, MacroFileId>>,
 }
 
 impl<DB> fmt::Debug for Semantics<'_, DB> {
@@ -182,20 +198,6 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.descend_node_at_offset(node, offset).filter_map(|mut it| it.find_map(N::cast))
     }
 
-    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
-        self.imp.resolve_method_call(call).map(Function::from)
-    }
-
-    /// Attempts to resolve this call expression as a method call falling back to resolving it as a field.
-    pub fn resolve_method_call_field_fallback(
-        &self,
-        call: &ast::MethodCallExpr,
-    ) -> Option<Either<Function, Field>> {
-        self.imp
-            .resolve_method_call_fallback(call)
-            .map(|it| it.map_left(Function::from).map_right(Field::from))
-    }
-
     pub fn resolve_await_to_poll(&self, await_expr: &ast::AwaitExpr) -> Option<Function> {
         self.imp.resolve_await_to_poll(await_expr).map(Function::from)
     }
@@ -255,7 +257,7 @@ impl<'db> SemanticsImpl<'db> {
     pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
         let sa = self.analyze_no_infer(macro_call.syntax())?;
         let file_id = sa.expand(self.db, InFile::new(sa.file_id, macro_call))?;
-        let node = self.parse_or_expand(file_id);
+        let node = self.parse_or_expand(file_id.into());
         Some(node)
     }
 
@@ -388,11 +390,72 @@ impl<'db> SemanticsImpl<'db> {
         )
     }
 
+    pub fn as_format_args_parts(
+        &self,
+        string: &ast::String,
+    ) -> Option<Vec<(TextRange, Option<PathResolution>)>> {
+        if let Some(quote) = string.open_quote_text_range() {
+            return self
+                .descend_into_macros(DescendPreference::SameText, string.syntax().clone())
+                .into_iter()
+                .find_map(|token| {
+                    let string = ast::String::cast(token)?;
+                    let literal =
+                        string.syntax().parent().filter(|it| it.kind() == SyntaxKind::LITERAL)?;
+                    let format_args = ast::FormatArgsExpr::cast(literal.parent()?)?;
+                    let source_analyzer = self.analyze_no_infer(format_args.syntax())?;
+                    let format_args = self.wrap_node_infile(format_args);
+                    let res = source_analyzer
+                        .as_format_args_parts(self.db, format_args.as_ref())?
+                        .map(|(range, res)| (range + quote.end(), res))
+                        .collect();
+                    Some(res)
+                });
+        }
+        None
+    }
+
+    pub fn check_for_format_args_template(
+        &self,
+        original_token: SyntaxToken,
+        offset: TextSize,
+    ) -> Option<(TextRange, Option<PathResolution>)> {
+        if let Some(original_string) = ast::String::cast(original_token.clone()) {
+            if let Some(quote) = original_string.open_quote_text_range() {
+                return self
+                    .descend_into_macros(DescendPreference::SameText, original_token.clone())
+                    .into_iter()
+                    .find_map(|token| {
+                        self.resolve_offset_in_format_args(
+                            ast::String::cast(token)?,
+                            offset - quote.end(),
+                        )
+                    })
+                    .map(|(range, res)| (range + quote.end(), res));
+            }
+        }
+        None
+    }
+
+    fn resolve_offset_in_format_args(
+        &self,
+        string: ast::String,
+        offset: TextSize,
+    ) -> Option<(TextRange, Option<PathResolution>)> {
+        debug_assert!(offset <= string.syntax().text_range().len());
+        let literal = string.syntax().parent().filter(|it| it.kind() == SyntaxKind::LITERAL)?;
+        let format_args = ast::FormatArgsExpr::cast(literal.parent()?)?;
+        let source_analyzer = &self.analyze_no_infer(format_args.syntax())?;
+        let format_args = self.wrap_node_infile(format_args);
+        source_analyzer.resolve_offset_in_format_args(self.db, format_args.as_ref(), offset)
+    }
+
     /// Maps a node down by mapping its first and last token down.
     pub fn descend_node_into_attributes<N: AstNode>(&self, node: N) -> SmallVec<[N; 1]> {
         // This might not be the correct way to do this, but it works for now
         let mut res = smallvec![];
         let tokens = (|| {
+            // FIXME: the trivia skipping should not be necessary
             let first = skip_trivia_token(node.syntax().first_token()?, Direction::Next)?;
             let last = skip_trivia_token(node.syntax().last_token()?, Direction::Prev)?;
             Some((first, last))
@@ -403,24 +466,28 @@ impl<'db> SemanticsImpl<'db> {
         };
 
         if first == last {
-            self.descend_into_macros_impl(first, 0.into(), &mut |InFile { value, .. }| {
-                if let Some(node) = value.parent_ancestors().find_map(N::cast) {
+            // node is just the token, so descend the token
+            self.descend_into_macros_impl(first, &mut |InFile { value, .. }| {
+                if let Some(node) = value
+                    .parent_ancestors()
+                    .take_while(|it| it.text_range() == value.text_range())
+                    .find_map(N::cast)
+                {
                     res.push(node)
                 }
-                false
+                ControlFlow::Continue(())
             });
         } else {
             // Descend first and last token, then zip them to look for the node they belong to
             let mut scratch: SmallVec<[_; 1]> = smallvec![];
-            self.descend_into_macros_impl(first, 0.into(), &mut |token| {
+            self.descend_into_macros_impl(first, &mut |token| {
                 scratch.push(token);
-                false
+                ControlFlow::Continue(())
             });
 
             let mut scratch = scratch.into_iter();
             self.descend_into_macros_impl(
                 last,
-                0.into(),
                 &mut |InFile { value: last, file_id: last_fid }| {
                     if let Some(InFile { value: first, file_id: first_fid }) = scratch.next() {
                         if first_fid == last_fid {
@@ -437,7 +504,7 @@ impl<'db> SemanticsImpl<'db> {
                             }
                         }
                     }
-                    false
+                    ControlFlow::Continue(())
                 },
             );
         }
@@ -449,32 +516,42 @@ impl<'db> SemanticsImpl<'db> {
     /// be considered for the mapping in case of inline format args.
     pub fn descend_into_macros(
         &self,
+        mode: DescendPreference,
         token: SyntaxToken,
-        offset: TextSize,
-    ) -> SmallVec<[SyntaxToken; 1]> {
-        let mut res = smallvec![];
-        self.descend_into_macros_impl(token, offset, &mut |InFile { value, .. }| {
-            res.push(value);
-            false
-        });
-        res
-    }
-
-    /// Descend the token into macrocalls to all its mapped counterparts that have the same text as the input token.
-    ///
-    /// Returns the original non descended token if none of the mapped counterparts have the same text.
-    pub fn descend_into_macros_with_same_text(
-        &self,
-        token: SyntaxToken,
-        offset: TextSize,
     ) -> SmallVec<[SyntaxToken; 1]> {
-        let text = token.text();
+        enum Dp<'t> {
+            SameText(&'t str),
+            SameKind(SyntaxKind),
+            None,
+        }
+        let fetch_kind = |token: &SyntaxToken| match token.parent() {
+            Some(node) => match node.kind() {
+                kind @ (SyntaxKind::NAME | SyntaxKind::NAME_REF) => kind,
+                _ => token.kind(),
+            },
+            None => token.kind(),
+        };
+        let mode = match mode {
+            DescendPreference::SameText => Dp::SameText(token.text()),
+            DescendPreference::SameKind => Dp::SameKind(fetch_kind(&token)),
+            DescendPreference::None => Dp::None,
+        };
         let mut res = smallvec![];
-        self.descend_into_macros_impl(token.clone(), offset, &mut |InFile { value, .. }| {
-            if value.text() == text {
+        self.descend_into_macros_impl(token.clone(), &mut |InFile { value, .. }| {
+            let is_a_match = match mode {
+                Dp::SameText(text) => value.text() == text,
+                Dp::SameKind(preferred_kind) => {
+                    let kind = fetch_kind(&value);
+                    kind == preferred_kind
+                        // special case for derive macros
+                        || (preferred_kind == SyntaxKind::IDENT && kind == SyntaxKind::NAME_REF)
+                }
+                Dp::None => true,
+            };
+            if is_a_match {
                 res.push(value);
             }
-            false
+            ControlFlow::Continue(())
         });
         if res.is_empty() {
             res.push(token);
@@ -482,44 +559,46 @@ impl<'db> SemanticsImpl<'db> {
         res
     }
 
-    pub fn descend_into_macros_with_kind_preference(
+    pub fn descend_into_macros_single(
         &self,
+        mode: DescendPreference,
         token: SyntaxToken,
-        offset: TextSize,
     ) -> SyntaxToken {
+        enum Dp<'t> {
+            SameText(&'t str),
+            SameKind(SyntaxKind),
+            None,
+        }
         let fetch_kind = |token: &SyntaxToken| match token.parent() {
             Some(node) => match node.kind() {
-                kind @ (SyntaxKind::NAME | SyntaxKind::NAME_REF) => {
-                    node.parent().map_or(kind, |it| it.kind())
-                }
+                kind @ (SyntaxKind::NAME | SyntaxKind::NAME_REF) => kind,
                 _ => token.kind(),
             },
             None => token.kind(),
         };
-        let preferred_kind = fetch_kind(&token);
-        let mut res = None;
-        self.descend_into_macros_impl(token.clone(), offset, &mut |InFile { value, .. }| {
-            if fetch_kind(&value) == preferred_kind {
-                res = Some(value);
-                true
-            } else {
-                if let None = res {
-                    res = Some(value)
-                }
-                false
-            }
-        });
-        res.unwrap_or(token)
-    }
-
-    /// Descend the token into its macro call if it is part of one, returning the token in the
-    /// expansion that it is associated with. If `offset` points into the token's range, it will
-    /// be considered for the mapping in case of inline format args.
-    pub fn descend_into_macros_single(&self, token: SyntaxToken, offset: TextSize) -> SyntaxToken {
+        let mode = match mode {
+            DescendPreference::SameText => Dp::SameText(token.text()),
+            DescendPreference::SameKind => Dp::SameKind(fetch_kind(&token)),
+            DescendPreference::None => Dp::None,
+        };
         let mut res = token.clone();
-        self.descend_into_macros_impl(token, offset, &mut |InFile { value, .. }| {
+        self.descend_into_macros_impl(token.clone(), &mut |InFile { value, .. }| {
+            let is_a_match = match mode {
+                Dp::SameText(text) => value.text() == text,
+                Dp::SameKind(preferred_kind) => {
+                    let kind = fetch_kind(&value);
+                    kind == preferred_kind
+                        // special case for derive macros
+                        || (preferred_kind == SyntaxKind::IDENT && kind == SyntaxKind::NAME_REF)
+                }
+                Dp::None => true,
+            };
             res = value;
-            true
+            if is_a_match {
+                ControlFlow::Break(())
+            } else {
+                ControlFlow::Continue(())
+            }
         });
         res
     }
@@ -527,177 +606,204 @@ impl<'db> SemanticsImpl<'db> {
     fn descend_into_macros_impl(
         &self,
         token: SyntaxToken,
-        // FIXME: We might want this to be Option<TextSize> to be able to opt out of subrange
-        // mapping, specifically for node downmapping
-        offset: TextSize,
-        f: &mut dyn FnMut(InFile<SyntaxToken>) -> bool,
+        f: &mut dyn FnMut(InFile<SyntaxToken>) -> ControlFlow<()>,
     ) {
         let _p = profile::span("descend_into_macros");
-        let relative_token_offset = token.text_range().start().checked_sub(offset);
-        let parent = match token.parent() {
+        let sa = match token.parent().and_then(|parent| self.analyze_no_infer(&parent)) {
             Some(it) => it,
             None => return,
         };
-        let sa = match self.analyze_no_infer(&parent) {
-            Some(it) => it,
-            None => return,
+
+        let span = match sa.file_id.file_id() {
+            Some(file_id) => self.db.real_span_map(file_id).span_for_range(token.text_range()),
+            None => {
+                stdx::never!();
+                return;
+            }
         };
-        let def_map = sa.resolver.def_map();
 
-        let mut stack: SmallVec<[_; 4]> = smallvec![InFile::new(sa.file_id, token)];
         let mut cache = self.expansion_info_cache.borrow_mut();
         let mut mcache = self.macro_call_cache.borrow_mut();
+        let def_map = sa.resolver.def_map();
 
-        let mut process_expansion_for_token =
-            |stack: &mut SmallVec<_>, macro_file, item, token: InFile<&_>| {
-                let expansion_info = cache
-                    .entry(macro_file)
-                    .or_insert_with(|| macro_file.expansion_info(self.db.upcast()))
-                    .as_ref()?;
+        let mut process_expansion_for_token = |stack: &mut Vec<_>, macro_file| {
+            let expansion_info = cache
+                .entry(macro_file)
+                .or_insert_with(|| macro_file.expansion_info(self.db.upcast()));
 
-                {
-                    let InFile { file_id, value } = expansion_info.expanded();
-                    self.cache(value, file_id);
-                }
+            {
+                let InMacroFile { file_id, value } = expansion_info.expanded();
+                self.cache(value, file_id.into());
+            }
 
-                let mapped_tokens = expansion_info.map_token_down(
-                    self.db.upcast(),
-                    item,
-                    token,
-                    relative_token_offset,
-                )?;
-                let len = stack.len();
-
-                // requeue the tokens we got from mapping our current token down
-                stack.extend(mapped_tokens);
-                // if the length changed we have found a mapping for the token
-                (stack.len() != len).then_some(())
-            };
+            let InMacroFile { file_id, value: mapped_tokens } =
+                expansion_info.map_range_down(span)?;
+            let mapped_tokens: SmallVec<[_; 2]> = mapped_tokens.collect();
 
-        // Remap the next token in the queue into a macro call its in, if it is not being remapped
-        // either due to not being in a macro-call or because its unused push it into the result vec,
-        // otherwise push the remapped tokens back into the queue as they can potentially be remapped again.
-        while let Some(token) = stack.pop() {
-            self.db.unwind_if_cancelled();
-            let was_not_remapped = (|| {
-                // First expand into attribute invocations
-                let containing_attribute_macro_call = self.with_ctx(|ctx| {
-                    token.value.parent_ancestors().filter_map(ast::Item::cast).find_map(|item| {
-                        if item.attrs().next().is_none() {
-                            // Don't force populate the dyn cache for items that don't have an attribute anyways
-                            return None;
-                        }
-                        Some((ctx.item_to_macro_call(token.with_value(item.clone()))?, item))
-                    })
-                });
-                if let Some((call_id, item)) = containing_attribute_macro_call {
-                    let file_id = call_id.as_file();
-                    return process_expansion_for_token(
-                        &mut stack,
-                        file_id,
-                        Some(item),
-                        token.as_ref(),
-                    );
-                }
+            // if the length changed we have found a mapping for the token
+            let res = mapped_tokens.is_empty().not().then_some(());
+            // requeue the tokens we got from mapping our current token down
+            stack.push((HirFileId::from(file_id), mapped_tokens));
+            res
+        };
 
-                // Then check for token trees, that means we are either in a function-like macro or
-                // secondary attribute inputs
-                let tt = token.value.parent_ancestors().map_while(ast::TokenTree::cast).last()?;
-                let parent = tt.syntax().parent()?;
+        let mut stack: Vec<(_, SmallVec<[_; 2]>)> = vec![(sa.file_id, smallvec![token])];
+
+        while let Some((file_id, mut tokens)) = stack.pop() {
+            while let Some(token) = tokens.pop() {
+                let was_not_remapped = (|| {
+                    // First expand into attribute invocations
+                    let containing_attribute_macro_call = self.with_ctx(|ctx| {
+                        token.parent_ancestors().filter_map(ast::Item::cast).find_map(|item| {
+                            if item.attrs().next().is_none() {
+                                // Don't force populate the dyn cache for items that don't have an attribute anyways
+                                return None;
+                            }
+                            Some((
+                                ctx.item_to_macro_call(InFile::new(file_id, item.clone()))?,
+                                item,
+                            ))
+                        })
+                    });
+                    if let Some((call_id, item)) = containing_attribute_macro_call {
+                        let file_id = call_id.as_macro_file();
+                        let attr_id = match self.db.lookup_intern_macro_call(call_id).kind {
+                            hir_expand::MacroCallKind::Attr { invoc_attr_index, .. } => {
+                                invoc_attr_index.ast_index()
+                            }
+                            _ => 0,
+                        };
+                        // FIXME: here, the attribute's text range is used to strip away all
+                        // entries from the start of the attribute "list" up the the invoking
+                        // attribute. But in
+                        // ```
+                        // mod foo {
+                        //     #![inner]
+                        // }
+                        // ```
+                        // we don't wanna strip away stuff in the `mod foo {` range, that is
+                        // here if the id corresponds to an inner attribute we got strip all
+                        // text ranges of the outer ones, and then all of the inner ones up
+                        // to the invoking attribute so that the inbetween is ignored.
+                        let text_range = item.syntax().text_range();
+                        let start = collect_attrs(&item)
+                            .nth(attr_id)
+                            .map(|attr| match attr.1 {
+                                Either::Left(it) => it.syntax().text_range().start(),
+                                Either::Right(it) => it.syntax().text_range().start(),
+                            })
+                            .unwrap_or_else(|| text_range.start());
+                        let text_range = TextRange::new(start, text_range.end());
+                        // remove any other token in this macro input, all their mappings are the
+                        // same as this one
+                        tokens.retain(|t| !text_range.contains_range(t.text_range()));
+                        return process_expansion_for_token(&mut stack, file_id);
+                    }
 
-                if tt.left_delimiter_token().map_or(false, |it| it == token.value) {
-                    return None;
-                }
-                if tt.right_delimiter_token().map_or(false, |it| it == token.value) {
-                    return None;
-                }
+                    // Then check for token trees, that means we are either in a function-like macro or
+                    // secondary attribute inputs
+                    let tt = token.parent_ancestors().map_while(ast::TokenTree::cast).last()?;
+                    let parent = tt.syntax().parent()?;
 
-                if let Some(macro_call) = ast::MacroCall::cast(parent.clone()) {
-                    let mcall = token.with_value(macro_call);
-                    let file_id = match mcache.get(&mcall) {
-                        Some(&it) => it,
-                        None => {
-                            let it = sa.expand(self.db, mcall.as_ref())?;
-                            mcache.insert(mcall, it);
-                            it
-                        }
-                    };
-                    process_expansion_for_token(&mut stack, file_id, None, token.as_ref())
-                } else if let Some(meta) = ast::Meta::cast(parent) {
-                    // attribute we failed expansion for earlier, this might be a derive invocation
-                    // or derive helper attribute
-                    let attr = meta.parent_attr()?;
-
-                    let adt = if let Some(adt) = attr.syntax().parent().and_then(ast::Adt::cast) {
-                        // this might be a derive, or a derive helper on an ADT
-                        let derive_call = self.with_ctx(|ctx| {
-                            // so try downmapping the token into the pseudo derive expansion
-                            // see [hir_expand::builtin_attr_macro] for how the pseudo derive expansion works
-                            ctx.attr_to_derive_macro_call(
-                                token.with_value(&adt),
-                                token.with_value(attr.clone()),
-                            )
-                            .map(|(_, call_id, _)| call_id)
-                        });
-
-                        match derive_call {
-                            Some(call_id) => {
-                                // resolved to a derive
-                                let file_id = call_id.as_file();
-                                return process_expansion_for_token(
-                                    &mut stack,
-                                    file_id,
-                                    Some(adt.into()),
-                                    token.as_ref(),
-                                );
+                    if tt.left_delimiter_token().map_or(false, |it| it == token) {
+                        return None;
+                    }
+                    if tt.right_delimiter_token().map_or(false, |it| it == token) {
+                        return None;
+                    }
+
+                    if let Some(macro_call) = ast::MacroCall::cast(parent.clone()) {
+                        let mcall: hir_expand::files::InFileWrapper<HirFileId, ast::MacroCall> =
+                            InFile::new(file_id, macro_call);
+                        let file_id = match mcache.get(&mcall) {
+                            Some(&it) => it,
+                            None => {
+                                let it = sa.expand(self.db, mcall.as_ref())?;
+                                mcache.insert(mcall, it);
+                                it
                             }
-                            None => Some(adt),
-                        }
-                    } else {
-                        // Otherwise this could be a derive helper on a variant or field
-                        if let Some(field) = attr.syntax().parent().and_then(ast::RecordField::cast)
+                        };
+                        let text_range = tt.syntax().text_range();
+                        // remove any other token in this macro input, all their mappings are the
+                        // same as this one
+                        tokens.retain(|t| !text_range.contains_range(t.text_range()));
+                        process_expansion_for_token(&mut stack, file_id)
+                    } else if let Some(meta) = ast::Meta::cast(parent) {
+                        // attribute we failed expansion for earlier, this might be a derive invocation
+                        // or derive helper attribute
+                        let attr = meta.parent_attr()?;
+
+                        let adt = if let Some(adt) = attr.syntax().parent().and_then(ast::Adt::cast)
                         {
-                            field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
-                        } else if let Some(field) =
-                            attr.syntax().parent().and_then(ast::TupleField::cast)
-                        {
-                            field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
-                        } else if let Some(variant) =
-                            attr.syntax().parent().and_then(ast::Variant::cast)
-                        {
-                            variant.syntax().ancestors().nth(2).and_then(ast::Adt::cast)
+                            // this might be a derive, or a derive helper on an ADT
+                            let derive_call = self.with_ctx(|ctx| {
+                                // so try downmapping the token into the pseudo derive expansion
+                                // see [hir_expand::builtin_attr_macro] for how the pseudo derive expansion works
+                                ctx.attr_to_derive_macro_call(
+                                    InFile::new(file_id, &adt),
+                                    InFile::new(file_id, attr.clone()),
+                                )
+                                .map(|(_, call_id, _)| call_id)
+                            });
+
+                            match derive_call {
+                                Some(call_id) => {
+                                    // resolved to a derive
+                                    let file_id = call_id.as_macro_file();
+                                    let text_range = attr.syntax().text_range();
+                                    // remove any other token in this macro input, all their mappings are the
+                                    // same as this one
+                                    tokens.retain(|t| !text_range.contains_range(t.text_range()));
+                                    return process_expansion_for_token(&mut stack, file_id);
+                                }
+                                None => Some(adt),
+                            }
                         } else {
-                            None
+                            // Otherwise this could be a derive helper on a variant or field
+                            if let Some(field) =
+                                attr.syntax().parent().and_then(ast::RecordField::cast)
+                            {
+                                field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
+                            } else if let Some(field) =
+                                attr.syntax().parent().and_then(ast::TupleField::cast)
+                            {
+                                field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
+                            } else if let Some(variant) =
+                                attr.syntax().parent().and_then(ast::Variant::cast)
+                            {
+                                variant.syntax().ancestors().nth(2).and_then(ast::Adt::cast)
+                            } else {
+                                None
+                            }
+                        }?;
+                        if !self.with_ctx(|ctx| ctx.has_derives(InFile::new(file_id, &adt))) {
+                            return None;
                         }
-                    }?;
-                    if !self.with_ctx(|ctx| ctx.has_derives(InFile::new(token.file_id, &adt))) {
-                        return None;
-                    }
-                    // Not an attribute, nor a derive, so it's either a builtin or a derive helper
-                    // Try to resolve to a derive helper and downmap
-                    let attr_name = attr.path().and_then(|it| it.as_single_name_ref())?.as_name();
-                    let id = self.db.ast_id_map(token.file_id).ast_id(&adt);
-                    let helpers =
-                        def_map.derive_helpers_in_scope(InFile::new(token.file_id, id))?;
-                    let item = Some(adt.into());
-                    let mut res = None;
-                    for (.., derive) in helpers.iter().filter(|(helper, ..)| *helper == attr_name) {
-                        res = res.or(process_expansion_for_token(
-                            &mut stack,
-                            derive.as_file(),
-                            item.clone(),
-                            token.as_ref(),
-                        ));
+                        // Not an attribute, nor a derive, so it's either a builtin or a derive helper
+                        // Try to resolve to a derive helper and downmap
+                        let attr_name =
+                            attr.path().and_then(|it| it.as_single_name_ref())?.as_name();
+                        let id = self.db.ast_id_map(file_id).ast_id(&adt);
+                        let helpers = def_map.derive_helpers_in_scope(InFile::new(file_id, id))?;
+                        let mut res = None;
+                        for (.., derive) in
+                            helpers.iter().filter(|(helper, ..)| *helper == attr_name)
+                        {
+                            res = res.or(process_expansion_for_token(
+                                &mut stack,
+                                derive.as_macro_file(),
+                            ));
+                        }
+                        res
+                    } else {
+                        None
                     }
-                    res
-                } else {
-                    None
-                }
-            })()
-            .is_none();
+                })()
+                .is_none();
 
-            if was_not_remapped && f(token) {
-                break;
+                if was_not_remapped && f(InFile::new(file_id, token)).is_break() {
+                    break;
+                }
             }
         }
     }
@@ -712,7 +818,7 @@ impl<'db> SemanticsImpl<'db> {
         offset: TextSize,
     ) -> impl Iterator<Item = impl Iterator<Item = SyntaxNode> + '_> + '_ {
         node.token_at_offset(offset)
-            .map(move |token| self.descend_into_macros(token, offset))
+            .map(move |token| self.descend_into_macros(DescendPreference::None, token))
             .map(|descendants| {
                 descendants.into_iter().map(move |it| self.token_ancestors_with_macros(it))
             })
@@ -737,14 +843,16 @@ impl<'db> SemanticsImpl<'db> {
     pub fn original_range_opt(&self, node: &SyntaxNode) -> Option<FileRange> {
         let node = self.find_file(node);
         node.original_file_range_opt(self.db.upcast())
+            .filter(|(_, ctx)| ctx.is_root())
+            .map(TupleExt::head)
     }
 
     /// Attempts to map the node out of macro expanded files.
     /// This only work for attribute expansions, as other ones do not have nodes as input.
     pub fn original_ast_node<N: AstNode>(&self, node: N) -> Option<N> {
         self.wrap_node_infile(node).original_ast_node(self.db.upcast()).map(
-            |InFile { file_id, value }| {
-                self.cache(find_root(value.syntax()), file_id);
+            |InRealFile { file_id, value }| {
+                self.cache(find_root(value.syntax()), file_id.into());
                 value
             },
         )
@@ -755,8 +863,8 @@ impl<'db> SemanticsImpl<'db> {
     pub fn original_syntax_node(&self, node: &SyntaxNode) -> Option<SyntaxNode> {
         let InFile { file_id, .. } = self.find_file(node);
         InFile::new(file_id, node).original_syntax_node(self.db.upcast()).map(
-            |InFile { file_id, value }| {
-                self.cache(find_root(&value), file_id);
+            |InRealFile { file_id, value }| {
+                self.cache(find_root(&value), file_id.into());
                 value
             },
         )
@@ -787,7 +895,7 @@ impl<'db> SemanticsImpl<'db> {
                 Some(parent) => Some(InFile::new(file_id, parent)),
                 None => {
                     self.cache(value.clone(), file_id);
-                    file_id.call_node(db)
+                    Some(file_id.macro_file()?.call_node(db))
                 }
             }
         })
@@ -840,10 +948,10 @@ impl<'db> SemanticsImpl<'db> {
     pub fn resolve_type(&self, ty: &ast::Type) -> Option<Type> {
         let analyze = self.analyze(ty.syntax())?;
         let ctx = LowerCtx::with_file_id(self.db.upcast(), analyze.file_id);
-        let ty = hir_ty::TyLoweringContext::new(
+        let ty = hir_ty::TyLoweringContext::new_maybe_unowned(
             self.db,
             &analyze.resolver,
-            analyze.resolver.module().into(),
+            analyze.resolver.type_owner(),
         )
         .lower_ty(&crate::TypeRef::from_ast(&ctx, ty.clone()));
         Some(Type::new_with_resolver(self.db, &analyze.resolver, ty))
@@ -851,9 +959,9 @@ impl<'db> SemanticsImpl<'db> {
 
     pub fn resolve_trait(&self, path: &ast::Path) -> Option<Trait> {
         let analyze = self.analyze(path.syntax())?;
-        let hygiene = hir_expand::hygiene::Hygiene::new(self.db.upcast(), analyze.file_id);
-        let ctx = LowerCtx::with_hygiene(self.db.upcast(), &hygiene);
-        let hir_path = Path::from_src(path.clone(), &ctx)?;
+        let span_map = self.db.span_map(analyze.file_id);
+        let ctx = LowerCtx::with_span_map(self.db.upcast(), span_map);
+        let hir_path = Path::from_src(&ctx, path.clone())?;
         match analyze.resolver.resolve_path_in_type_ns_fully(self.db.upcast(), &hir_path)? {
             TypeNs::TraitId(id) => Some(Trait { id }),
             _ => None,
@@ -937,14 +1045,15 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(pat.syntax())?.binding_mode_of_pat(self.db, pat)
     }
 
-    fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<FunctionId> {
+    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
         self.analyze(call.syntax())?.resolve_method_call(self.db, call)
     }
 
-    fn resolve_method_call_fallback(
+    /// Attempts to resolve this call expression as a method call falling back to resolving it as a field.
+    pub fn resolve_method_call_fallback(
         &self,
         call: &ast::MethodCallExpr,
-    ) -> Option<Either<FunctionId, FieldId>> {
+    ) -> Option<Either<Function, Field>> {
         self.analyze(call.syntax())?.resolve_method_call_fallback(self.db, call)
     }
 
@@ -976,6 +1085,13 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(field.syntax())?.resolve_field(self.db, field)
     }
 
+    pub fn resolve_field_fallback(
+        &self,
+        field: &ast::FieldExpr,
+    ) -> Option<Either<Field, Function>> {
+        self.analyze(field.syntax())?.resolve_field_fallback(self.db, field)
+    }
+
     pub fn resolve_record_field(
         &self,
         field: &ast::RecordExprField,
@@ -1037,7 +1153,7 @@ impl<'db> SemanticsImpl<'db> {
 
     fn with_ctx<F: FnOnce(&mut SourceToDefCtx<'_, '_>) -> T, T>(&self, f: F) -> T {
         let mut cache = self.s2d_cache.borrow_mut();
-        let mut ctx = SourceToDefCtx { db: self.db, cache: &mut cache };
+        let mut ctx = SourceToDefCtx { db: self.db, dynmap_cache: &mut cache };
         f(&mut ctx)
     }
 
@@ -1187,7 +1303,7 @@ impl<'db> SemanticsImpl<'db> {
                     return None;
                 }
 
-                let func = self.resolve_method_call(method_call_expr).map(Function::from)?;
+                let func = self.resolve_method_call(method_call_expr)?;
                 let res = match func.self_param(self.db)?.access(self.db) {
                     Access::Shared | Access::Exclusive => true,
                     Access::Owned => false,
@@ -1451,7 +1567,7 @@ impl SemanticsScope<'_> {
     /// necessary a heuristic, as it doesn't take hygiene into account.
     pub fn speculative_resolve(&self, path: &ast::Path) -> Option<PathResolution> {
         let ctx = LowerCtx::with_file_id(self.db.upcast(), self.file_id);
-        let path = Path::from_src(path.clone(), &ctx)?;
+        let path = Path::from_src(&ctx, path.clone())?;
         resolve_hir_path(self.db, &self.resolver, &path)
     }
 
@@ -1478,6 +1594,10 @@ impl SemanticsScope<'_> {
     pub fn extern_crate_decls(&self) -> impl Iterator<Item = Name> + '_ {
         self.resolver.extern_crate_decls_in_scope(self.db.upcast())
     }
+
+    pub fn has_same_self_type(&self, other: &SemanticsScope<'_>) -> bool {
+        self.resolver.impl_def() == other.resolver.impl_def()
+    }
 }
 
 #[derive(Debug)]
diff --git a/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs b/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
index aabda3655..df8c1e904 100644
--- a/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/semantics/source_to_def.rs
@@ -97,7 +97,7 @@ use hir_def::{
     FunctionId, GenericDefId, GenericParamId, ImplId, LifetimeParamId, MacroId, ModuleId, StaticId,
     StructId, TraitAliasId, TraitId, TypeAliasId, TypeParamId, UnionId, UseId, VariantId,
 };
-use hir_expand::{attrs::AttrId, name::AsName, HirFileId, MacroCallId};
+use hir_expand::{attrs::AttrId, name::AsName, HirFileId, HirFileIdExt, MacroCallId};
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 use stdx::{impl_from, never};
@@ -112,7 +112,7 @@ pub(super) type SourceToDefCache = FxHashMap<(ChildContainer, HirFileId), DynMap
 
 pub(super) struct SourceToDefCtx<'a, 'b> {
     pub(super) db: &'b dyn HirDatabase,
-    pub(super) cache: &'a mut SourceToDefCache,
+    pub(super) dynmap_cache: &'a mut SourceToDefCache,
 }
 
 impl SourceToDefCtx<'_, '_> {
@@ -300,7 +300,7 @@ impl SourceToDefCtx<'_, '_> {
 
     fn cache_for(&mut self, container: ChildContainer, file_id: HirFileId) -> &DynMap {
         let db = self.db;
-        self.cache
+        self.dynmap_cache
             .entry((container, file_id))
             .or_insert_with(|| container.child_by_source(db, file_id))
     }
diff --git a/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs b/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
index f29fb1edf..d05118bbc 100644
--- a/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/source_analyzer.rs
@@ -26,11 +26,10 @@ use hir_def::{
 };
 use hir_expand::{
     builtin_fn_macro::BuiltinFnLikeExpander,
-    hygiene::Hygiene,
     mod_path::path,
     name,
     name::{AsName, Name},
-    HirFileId, InFile,
+    HirFileId, InFile, MacroFileId, MacroFileIdExt,
 };
 use hir_ty::{
     diagnostics::{
@@ -236,9 +235,9 @@ impl SourceAnalyzer {
         _db: &dyn HirDatabase,
         pat: &ast::IdentPat,
     ) -> Option<BindingMode> {
-        let binding_id = self.binding_id_of_pat(pat)?;
+        let id = self.pat_id(&pat.clone().into())?;
         let infer = self.infer.as_ref()?;
-        infer.binding_modes.get(binding_id).map(|bm| match bm {
+        infer.binding_modes.get(id).map(|bm| match bm {
             hir_ty::BindingMode::Move => BindingMode::Move,
             hir_ty::BindingMode::Ref(hir_ty::Mutability::Mut) => BindingMode::Ref(Mutability::Mut),
             hir_ty::BindingMode::Ref(hir_ty::Mutability::Not) => {
@@ -281,25 +280,49 @@ impl SourceAnalyzer {
         &self,
         db: &dyn HirDatabase,
         call: &ast::MethodCallExpr,
-    ) -> Option<FunctionId> {
+    ) -> Option<Function> {
         let expr_id = self.expr_id(db, &call.clone().into())?;
         let (f_in_trait, substs) = self.infer.as_ref()?.method_resolution(expr_id)?;
 
-        Some(self.resolve_impl_method_or_trait_def(db, f_in_trait, substs))
+        Some(self.resolve_impl_method_or_trait_def(db, f_in_trait, substs).into())
     }
 
     pub(crate) fn resolve_method_call_fallback(
         &self,
         db: &dyn HirDatabase,
         call: &ast::MethodCallExpr,
-    ) -> Option<Either<FunctionId, FieldId>> {
+    ) -> Option<Either<Function, Field>> {
         let expr_id = self.expr_id(db, &call.clone().into())?;
         let inference_result = self.infer.as_ref()?;
         match inference_result.method_resolution(expr_id) {
-            Some((f_in_trait, substs)) => {
-                Some(Either::Left(self.resolve_impl_method_or_trait_def(db, f_in_trait, substs)))
-            }
-            None => inference_result.field_resolution(expr_id).map(Either::Right),
+            Some((f_in_trait, substs)) => Some(Either::Left(
+                self.resolve_impl_method_or_trait_def(db, f_in_trait, substs).into(),
+            )),
+            None => inference_result.field_resolution(expr_id).map(Into::into).map(Either::Right),
+        }
+    }
+
+    pub(crate) fn resolve_field(
+        &self,
+        db: &dyn HirDatabase,
+        field: &ast::FieldExpr,
+    ) -> Option<Field> {
+        let expr_id = self.expr_id(db, &field.clone().into())?;
+        self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
+    }
+
+    pub(crate) fn resolve_field_fallback(
+        &self,
+        db: &dyn HirDatabase,
+        field: &ast::FieldExpr,
+    ) -> Option<Either<Field, Function>> {
+        let expr_id = self.expr_id(db, &field.clone().into())?;
+        let inference_result = self.infer.as_ref()?;
+        match inference_result.field_resolution(expr_id) {
+            Some(field) => Some(Either::Left(field.into())),
+            None => inference_result.method_resolution(expr_id).map(|(f, substs)| {
+                Either::Right(self.resolve_impl_method_or_trait_def(db, f, substs).into())
+            }),
         }
     }
 
@@ -418,15 +441,6 @@ impl SourceAnalyzer {
         Some(self.resolve_impl_method_or_trait_def(db, op_fn, substs))
     }
 
-    pub(crate) fn resolve_field(
-        &self,
-        db: &dyn HirDatabase,
-        field: &ast::FieldExpr,
-    ) -> Option<Field> {
-        let expr_id = self.expr_id(db, &field.clone().into())?;
-        self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
-    }
-
     pub(crate) fn resolve_record_field(
         &self,
         db: &dyn HirDatabase,
@@ -484,7 +498,7 @@ impl SourceAnalyzer {
         macro_call: InFile<&ast::MacroCall>,
     ) -> Option<Macro> {
         let ctx = LowerCtx::with_file_id(db.upcast(), macro_call.file_id);
-        let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &ctx))?;
+        let path = macro_call.value.path().and_then(|ast| Path::from_src(&ctx, ast))?;
         self.resolver
             .resolve_path_as_macro(db.upcast(), path.mod_path()?, Some(MacroSubNs::Bang))
             .map(|(it, _)| it.into())
@@ -596,9 +610,8 @@ impl SourceAnalyzer {
         }
 
         // This must be a normal source file rather than macro file.
-        let hygiene = Hygiene::new(db.upcast(), self.file_id);
-        let ctx = LowerCtx::with_hygiene(db.upcast(), &hygiene);
-        let hir_path = Path::from_src(path.clone(), &ctx)?;
+        let ctx = LowerCtx::with_span_map(db.upcast(), db.span_map(self.file_id));
+        let hir_path = Path::from_src(&ctx, path.clone())?;
 
         // Case where path is a qualifier of a use tree, e.g. foo::bar::{Baz, Qux} where we are
         // trying to resolve foo::bar.
@@ -755,14 +768,15 @@ impl SourceAnalyzer {
         &self,
         db: &dyn HirDatabase,
         macro_call: InFile<&ast::MacroCall>,
-    ) -> Option<HirFileId> {
+    ) -> Option<MacroFileId> {
         let krate = self.resolver.krate();
         let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
             self.resolver
                 .resolve_path_as_macro(db.upcast(), &path, Some(MacroSubNs::Bang))
                 .map(|(it, _)| macro_id_to_def_id(db.upcast(), it))
         })?;
-        Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
+        // why the 64?
+        Some(macro_call_id.as_macro_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
     }
 
     pub(crate) fn resolve_variant(
@@ -821,6 +835,52 @@ impl SourceAnalyzer {
         false
     }
 
+    pub(crate) fn resolve_offset_in_format_args(
+        &self,
+        db: &dyn HirDatabase,
+        format_args: InFile<&ast::FormatArgsExpr>,
+        offset: TextSize,
+    ) -> Option<(TextRange, Option<PathResolution>)> {
+        let implicits = self.body_source_map()?.implicit_format_args(format_args)?;
+        implicits.iter().find(|(range, _)| range.contains_inclusive(offset)).map(|(range, name)| {
+            (
+                *range,
+                resolve_hir_value_path(
+                    db,
+                    &self.resolver,
+                    self.resolver.body_owner(),
+                    &Path::from_known_path_with_no_generic(ModPath::from_segments(
+                        PathKind::Plain,
+                        Some(name.clone()),
+                    )),
+                ),
+            )
+        })
+    }
+
+    pub(crate) fn as_format_args_parts<'a>(
+        &'a self,
+        db: &'a dyn HirDatabase,
+        format_args: InFile<&ast::FormatArgsExpr>,
+    ) -> Option<impl Iterator<Item = (TextRange, Option<PathResolution>)> + 'a> {
+        Some(self.body_source_map()?.implicit_format_args(format_args)?.iter().map(
+            move |(range, name)| {
+                (
+                    *range,
+                    resolve_hir_value_path(
+                        db,
+                        &self.resolver,
+                        self.resolver.body_owner(),
+                        &Path::from_known_path_with_no_generic(ModPath::from_segments(
+                            PathKind::Plain,
+                            Some(name.clone()),
+                        )),
+                    ),
+                )
+            },
+        ))
+    }
+
     fn resolve_impl_method_or_trait_def(
         &self,
         db: &dyn HirDatabase,
@@ -888,17 +948,18 @@ fn scope_for_offset(
         .scope_by_expr()
         .iter()
         .filter_map(|(id, scope)| {
-            let InFile { file_id, value } = source_map.expr_syntax(*id).ok()?;
+            let InFile { file_id, value } = source_map.expr_syntax(id).ok()?;
             if from_file == file_id {
                 return Some((value.text_range(), scope));
             }
 
             // FIXME handle attribute expansion
-            let source = iter::successors(file_id.call_node(db.upcast()), |it| {
-                it.file_id.call_node(db.upcast())
-            })
-            .find(|it| it.file_id == from_file)
-            .filter(|it| it.value.kind() == SyntaxKind::MACRO_CALL)?;
+            let source =
+                iter::successors(file_id.macro_file().map(|it| it.call_node(db.upcast())), |it| {
+                    Some(it.file_id.macro_file()?.call_node(db.upcast()))
+                })
+                .find(|it| it.file_id == from_file)
+                .filter(|it| it.value.kind() == SyntaxKind::MACRO_CALL)?;
             Some((source.value.text_range(), scope))
         })
         .filter(|(expr_range, _scope)| expr_range.start() <= offset && offset <= expr_range.end())
@@ -923,7 +984,7 @@ fn adjust(
         .scope_by_expr()
         .iter()
         .filter_map(|(id, scope)| {
-            let source = source_map.expr_syntax(*id).ok()?;
+            let source = source_map.expr_syntax(id).ok()?;
             // FIXME: correctly handle macro expansion
             if source.file_id != from_file {
                 return None;
@@ -979,8 +1040,9 @@ fn resolve_hir_path_(
     let types = || {
         let (ty, unresolved) = match path.type_anchor() {
             Some(type_ref) => {
-                let (_, res) = TyLoweringContext::new(db, resolver, resolver.module().into())
-                    .lower_ty_ext(type_ref);
+                let (_, res) =
+                    TyLoweringContext::new_maybe_unowned(db, resolver, resolver.type_owner())
+                        .lower_ty_ext(type_ref);
                 res.map(|ty_ns| (ty_ns, path.segments().first()))
             }
             None => {
@@ -1039,24 +1101,7 @@ fn resolve_hir_path_(
     };
 
     let body_owner = resolver.body_owner();
-    let values = || {
-        resolver.resolve_path_in_value_ns_fully(db.upcast(), path).and_then(|val| {
-            let res = match val {
-                ValueNs::LocalBinding(binding_id) => {
-                    let var = Local { parent: body_owner?, binding_id };
-                    PathResolution::Local(var)
-                }
-                ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
-                ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
-                ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
-                ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
-                ValueNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
-                ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
-                ValueNs::GenericParam(id) => PathResolution::ConstParam(id.into()),
-            };
-            Some(res)
-        })
-    };
+    let values = || resolve_hir_value_path(db, resolver, body_owner, path);
 
     let items = || {
         resolver
@@ -1076,6 +1121,30 @@ fn resolve_hir_path_(
         .or_else(macros)
 }
 
+fn resolve_hir_value_path(
+    db: &dyn HirDatabase,
+    resolver: &Resolver,
+    body_owner: Option<DefWithBodyId>,
+    path: &Path,
+) -> Option<PathResolution> {
+    resolver.resolve_path_in_value_ns_fully(db.upcast(), path).and_then(|val| {
+        let res = match val {
+            ValueNs::LocalBinding(binding_id) => {
+                let var = Local { parent: body_owner?, binding_id };
+                PathResolution::Local(var)
+            }
+            ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
+            ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
+            ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
+            ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
+            ValueNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
+            ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
+            ValueNs::GenericParam(id) => PathResolution::ConstParam(id.into()),
+        };
+        Some(res)
+    })
+}
+
 /// Resolves a path where we know it is a qualifier of another path.
 ///
 /// For example, if we have:
diff --git a/src/tools/rust-analyzer/crates/hir/src/symbols.rs b/src/tools/rust-analyzer/crates/hir/src/symbols.rs
index ca7874c36..a2a30edeb 100644
--- a/src/tools/rust-analyzer/crates/hir/src/symbols.rs
+++ b/src/tools/rust-analyzer/crates/hir/src/symbols.rs
@@ -9,7 +9,7 @@ use hir_def::{
 };
 use hir_expand::{HirFileId, InFile};
 use hir_ty::db::HirDatabase;
-use syntax::{ast::HasName, AstNode, SmolStr, SyntaxNode, SyntaxNodePtr};
+use syntax::{ast::HasName, AstNode, AstPtr, SmolStr, SyntaxNode, SyntaxNodePtr};
 
 use crate::{Module, ModuleDef, Semantics};
 
@@ -23,6 +23,7 @@ pub struct FileSymbol {
     pub loc: DeclarationLocation,
     pub container_name: Option<SmolStr>,
     pub is_alias: bool,
+    pub is_assoc: bool,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -32,7 +33,7 @@ pub struct DeclarationLocation {
     /// This points to the whole syntax node of the declaration.
     pub ptr: SyntaxNodePtr,
     /// This points to the [`syntax::ast::Name`] identifier of the declaration.
-    pub name_ptr: SyntaxNodePtr,
+    pub name_ptr: AstPtr<syntax::ast::Name>,
 }
 
 impl DeclarationLocation {
@@ -49,15 +50,6 @@ impl DeclarationLocation {
         let node = resolve_node(db, self.hir_file_id, &self.ptr);
         node.as_ref().original_file_range(db.upcast())
     }
-
-    pub fn original_name_range(&self, db: &dyn HirDatabase) -> Option<FileRange> {
-        if let Some(file_id) = self.hir_file_id.file_id() {
-            // fast path to prevent parsing
-            return Some(FileRange { file_id, range: self.name_ptr.text_range() });
-        }
-        let node = resolve_node(db, self.hir_file_id, &self.name_ptr);
-        node.as_ref().original_file_range_opt(db.upcast())
-    }
 }
 
 fn resolve_node(
@@ -130,34 +122,34 @@ impl<'a> SymbolCollector<'a> {
             match module_def_id {
                 ModuleDefId::ModuleId(id) => self.push_module(id),
                 ModuleDefId::FunctionId(id) => {
-                    self.push_decl(id);
+                    self.push_decl(id, false);
                     self.collect_from_body(id);
                 }
-                ModuleDefId::AdtId(AdtId::StructId(id)) => self.push_decl(id),
-                ModuleDefId::AdtId(AdtId::EnumId(id)) => self.push_decl(id),
-                ModuleDefId::AdtId(AdtId::UnionId(id)) => self.push_decl(id),
+                ModuleDefId::AdtId(AdtId::StructId(id)) => self.push_decl(id, false),
+                ModuleDefId::AdtId(AdtId::EnumId(id)) => self.push_decl(id, false),
+                ModuleDefId::AdtId(AdtId::UnionId(id)) => self.push_decl(id, false),
                 ModuleDefId::ConstId(id) => {
-                    self.push_decl(id);
+                    self.push_decl(id, false);
                     self.collect_from_body(id);
                 }
                 ModuleDefId::StaticId(id) => {
-                    self.push_decl(id);
+                    self.push_decl(id, false);
                     self.collect_from_body(id);
                 }
                 ModuleDefId::TraitId(id) => {
-                    self.push_decl(id);
+                    self.push_decl(id, false);
                     self.collect_from_trait(id);
                 }
                 ModuleDefId::TraitAliasId(id) => {
-                    self.push_decl(id);
+                    self.push_decl(id, false);
                 }
                 ModuleDefId::TypeAliasId(id) => {
-                    self.push_decl(id);
+                    self.push_decl(id, false);
                 }
                 ModuleDefId::MacroId(id) => match id {
-                    MacroId::Macro2Id(id) => self.push_decl(id),
-                    MacroId::MacroRulesId(id) => self.push_decl(id),
-                    MacroId::ProcMacroId(id) => self.push_decl(id),
+                    MacroId::Macro2Id(id) => self.push_decl(id, false),
+                    MacroId::MacroRulesId(id) => self.push_decl(id, false),
+                    MacroId::ProcMacroId(id) => self.push_decl(id, false),
                 },
                 // Don't index these.
                 ModuleDefId::BuiltinType(_) => {}
@@ -190,7 +182,7 @@ impl<'a> SymbolCollector<'a> {
                 let dec_loc = DeclarationLocation {
                     hir_file_id: source.file_id,
                     ptr: SyntaxNodePtr::new(use_tree_src.syntax()),
-                    name_ptr: SyntaxNodePtr::new(name.syntax()),
+                    name_ptr: AstPtr::new(&name),
                 };
 
                 self.symbols.push(FileSymbol {
@@ -199,6 +191,7 @@ impl<'a> SymbolCollector<'a> {
                     container_name: self.current_container_name.clone(),
                     loc: dec_loc,
                     is_alias: false,
+                    is_assoc: false,
                 });
             });
         }
@@ -211,9 +204,9 @@ impl<'a> SymbolCollector<'a> {
             for &id in id {
                 if id.module(self.db.upcast()) == module_id {
                     match id {
-                        MacroId::Macro2Id(id) => self.push_decl(id),
-                        MacroId::MacroRulesId(id) => self.push_decl(id),
-                        MacroId::ProcMacroId(id) => self.push_decl(id),
+                        MacroId::Macro2Id(id) => self.push_decl(id, false),
+                        MacroId::MacroRulesId(id) => self.push_decl(id, false),
+                        MacroId::ProcMacroId(id) => self.push_decl(id, false),
                     }
                 }
             }
@@ -275,13 +268,13 @@ impl<'a> SymbolCollector<'a> {
 
     fn push_assoc_item(&mut self, assoc_item_id: AssocItemId) {
         match assoc_item_id {
-            AssocItemId::FunctionId(id) => self.push_decl(id),
-            AssocItemId::ConstId(id) => self.push_decl(id),
-            AssocItemId::TypeAliasId(id) => self.push_decl(id),
+            AssocItemId::FunctionId(id) => self.push_decl(id, true),
+            AssocItemId::ConstId(id) => self.push_decl(id, true),
+            AssocItemId::TypeAliasId(id) => self.push_decl(id, true),
         }
     }
 
-    fn push_decl<L>(&mut self, id: L)
+    fn push_decl<L>(&mut self, id: L, is_assoc: bool)
     where
         L: Lookup + Into<ModuleDefId>,
         <L as Lookup>::Data: HasSource,
@@ -294,7 +287,7 @@ impl<'a> SymbolCollector<'a> {
         let dec_loc = DeclarationLocation {
             hir_file_id: source.file_id,
             ptr: SyntaxNodePtr::new(source.value.syntax()),
-            name_ptr: SyntaxNodePtr::new(name_node.syntax()),
+            name_ptr: AstPtr::new(&name_node),
         };
 
         if let Some(attrs) = def.attrs(self.db) {
@@ -305,6 +298,7 @@ impl<'a> SymbolCollector<'a> {
                     loc: dec_loc.clone(),
                     container_name: self.current_container_name.clone(),
                     is_alias: true,
+                    is_assoc,
                 });
             }
         }
@@ -315,6 +309,7 @@ impl<'a> SymbolCollector<'a> {
             container_name: self.current_container_name.clone(),
             loc: dec_loc,
             is_alias: false,
+            is_assoc,
         });
     }
 
@@ -327,7 +322,7 @@ impl<'a> SymbolCollector<'a> {
         let dec_loc = DeclarationLocation {
             hir_file_id: declaration.file_id,
             ptr: SyntaxNodePtr::new(module.syntax()),
-            name_ptr: SyntaxNodePtr::new(name_node.syntax()),
+            name_ptr: AstPtr::new(&name_node),
         };
 
         let def = ModuleDef::Module(module_id.into());
@@ -340,6 +335,7 @@ impl<'a> SymbolCollector<'a> {
                     loc: dec_loc.clone(),
                     container_name: self.current_container_name.clone(),
                     is_alias: true,
+                    is_assoc: false,
                 });
             }
         }
@@ -350,6 +346,7 @@ impl<'a> SymbolCollector<'a> {
             container_name: self.current_container_name.clone(),
             loc: dec_loc,
             is_alias: false,
+            is_assoc: false,
         });
     }
 }