internal: Expand the derive attribute into a pseudo expansion

17 files changed, 178 insertions, 155 deletions

diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 243ba63b8a0..1156dfe98e1 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -5,7 +5,6 @@ mod source_to_def;
 use std::{cell::RefCell, fmt, iter};
 
 use base_db::{FileId, FileRange};
-use either::Either;
 use hir_def::{
     body,
     resolver::{self, HasResolver, Resolver, TypeNs},
@@ -19,17 +18,16 @@ use smallvec::{smallvec, SmallVec};
 use syntax::{
     algo::skip_trivia_token,
     ast::{self, HasAttrs as _, HasGenericParams, HasLoopBody},
-    match_ast, AstNode, AstToken, Direction, SyntaxElement, SyntaxNode, SyntaxNodePtr, SyntaxToken,
-    TextSize, T,
+    match_ast, AstNode, Direction, SyntaxNode, SyntaxNodePtr, SyntaxToken, TextSize,
 };
 
 use crate::{
     db::HirDatabase,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, SourceAnalyzer},
-    Access, AssocItem, BuiltinAttr, Callable, ConstParam, Crate, Field, Function, HasAttrs as _,
-    HasSource, HirFileId, Impl, InFile, Label, LifetimeParam, Local, MacroDef, Module, ModuleDef,
-    Name, Path, ScopeDef, ToolModule, Trait, Type, TypeAlias, TypeParam, VariantDef,
+    Access, AssocItem, BuiltinAttr, Callable, ConstParam, Crate, Field, Function, HasSource,
+    HirFileId, Impl, InFile, Label, LifetimeParam, Local, MacroDef, Module, ModuleDef, Name, Path,
+    ScopeDef, ToolModule, Trait, Type, TypeAlias, TypeParam, VariantDef,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -350,14 +348,6 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         self.imp.resolve_bind_pat_to_const(pat)
     }
 
-    pub fn resolve_derive_ident(
-        &self,
-        derive: &ast::Attr,
-        ident: &ast::Ident,
-    ) -> Option<PathResolution> {
-        self.imp.resolve_derive_ident(derive, ident)
-    }
-
     pub fn record_literal_missing_fields(&self, literal: &ast::RecordExpr) -> Vec<(Field, Type)> {
         self.imp.record_literal_missing_fields(literal)
     }
@@ -475,7 +465,7 @@ impl<'db> SemanticsImpl<'db> {
         let adt = InFile::new(file_id, &adt);
         let src = InFile::new(file_id, attr.clone());
         self.with_ctx(|ctx| {
-            let (_, res) = ctx.attr_to_derive_macro_call(adt, src)?;
+            let (.., res) = ctx.attr_to_derive_macro_call(adt, src)?;
             Some(res.to_vec())
         })
     }
@@ -668,7 +658,27 @@ impl<'db> SemanticsImpl<'db> {
                     // FIXME replace map.while_some with take_while once stable
                     token.value.ancestors().map(ast::TokenTree::cast).while_some().last()
                 {
-                    let macro_call = tt.syntax().parent().and_then(ast::MacroCall::cast)?;
+                    let parent = tt.syntax().parent()?;
+                    // check for derive attribute here
+                    let macro_call = match_ast! {
+                        match parent {
+                            ast::MacroCall(mcall) => mcall,
+                            // attribute we failed expansion for earlier, this might be a derive invocation
+                            // so try downmapping the token into the pseudo derive expansion
+                            ast::Meta(meta) => {
+                                let attr = meta.parent_attr()?;
+                                let adt = attr.syntax().parent().and_then(ast::Adt::cast)?;
+                                let call_id = self.with_ctx(|ctx| {
+                                    let (_, call_id, _) = ctx.attr_to_derive_macro_call(token.with_value(&adt), token.with_value(attr))?;
+                                    Some(call_id)
+                                })?;
+                                let file_id = call_id.as_file();
+                                return process_expansion_for_token(&mut stack,file_id,Some(adt.into()),token.as_ref(),);
+                            },
+                            _ => return None,
+                        }
+                    };
+
                     if tt.left_delimiter_token().map_or(false, |it| it == token.value) {
                         return None;
                     }
@@ -898,72 +908,6 @@ impl<'db> SemanticsImpl<'db> {
         self.analyze(pat.syntax()).resolve_bind_pat_to_const(self.db, pat)
     }
 
-    fn resolve_derive_ident(
-        &self,
-        derive: &ast::Attr,
-        ident: &ast::Ident,
-    ) -> Option<PathResolution> {
-        debug_assert!(ident.syntax().parent().and_then(ast::TokenTree::cast).is_some());
-        debug_assert!(ident.syntax().ancestors().any(|anc| anc == *derive.syntax()));
-        // derive macros are always at depth 2, tokentree -> meta -> attribute
-        let syntax = ident.syntax();
-
-        let tt = derive.token_tree()?;
-        let file = self.find_file(derive.syntax());
-        let adt = derive.syntax().parent().and_then(ast::Adt::cast)?;
-        let adt_def = ToDef::to_def(self, file.with_value(adt.clone()))?;
-        let res = self.with_ctx(|ctx| {
-            let (attr_id, derives) = ctx.attr_to_derive_macro_call(
-                file.with_value(&adt),
-                file.with_value(derive.clone()),
-            )?;
-            let attrs = adt_def.attrs(self.db);
-            let mut derive_paths = attrs.get(attr_id)?.parse_path_comma_token_tree()?;
-
-            let derive_idx = tt
-                .syntax()
-                .children_with_tokens()
-                .filter_map(SyntaxElement::into_token)
-                .take_while(|tok| tok != syntax)
-                .filter(|t| t.kind() == T![,])
-                .count();
-            let path_segment_idx = syntax
-                .siblings_with_tokens(Direction::Prev)
-                .filter_map(SyntaxElement::into_token)
-                .take_while(|tok| matches!(tok.kind(), T![:] | T![ident]))
-                .filter(|tok| tok.kind() == T![ident])
-                .count();
-
-            let mut mod_path = derive_paths.nth(derive_idx)?;
-
-            if path_segment_idx < mod_path.len() {
-                // the path for the given ident is a qualifier, resolve to module if possible
-                while path_segment_idx < mod_path.len() {
-                    mod_path.pop_segment();
-                }
-                Some(Either::Left(mod_path))
-            } else {
-                // otherwise fetch the derive
-                Some(Either::Right(derives[derive_idx]))
-            }
-        })?;
-
-        match res {
-            Either::Left(path) => {
-                let len = path.len();
-                resolve_hir_path(
-                    self.db,
-                    &self.scope(derive.syntax()).resolver,
-                    &Path::from_known_path(path, vec![None; len]),
-                )
-                .filter(|res| matches!(res, PathResolution::Def(ModuleDef::Module(_))))
-            }
-            Either::Right(derive) => derive
-                .map(|call| MacroDef { id: self.db.lookup_intern_macro_call(call).def })
-                .map(PathResolution::Macro),
-        }
-    }
-
     fn record_literal_missing_fields(&self, literal: &ast::RecordExpr) -> Vec<(Field, Type)> {
         self.analyze(literal.syntax())
             .record_literal_missing_fields(self.db, literal)
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index 50618612392..c0d8e69e492 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -249,9 +249,11 @@ impl SourceToDefCtx<'_, '_> {
         &mut self,
         item: InFile<&ast::Adt>,
         src: InFile<ast::Attr>,
-    ) -> Option<(AttrId, &[Option<MacroCallId>])> {
+    ) -> Option<(AttrId, MacroCallId, &[Option<MacroCallId>])> {
         let map = self.dyn_map(item)?;
-        map[keys::DERIVE_MACRO_CALL].get(&src.value).map(|(id, ids)| (*id, &**ids))
+        map[keys::DERIVE_MACRO_CALL]
+            .get(&src.value)
+            .map(|&(attr_id, call_id, ref ids)| (attr_id, call_id, &**ids))
     }
 
     fn to_def<Ast: AstNode + 'static, ID: Copy + 'static>(
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 03e4420985e..ef32a5891c7 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -371,10 +371,10 @@ impl SourceAnalyzer {
                 return builtin.map(PathResolution::BuiltinAttr);
             }
             return match resolve_hir_path_as_macro(db, &self.resolver, &hir_path) {
-                res @ Some(m) if m.is_attr() => res.map(PathResolution::Macro),
+                Some(m) => Some(PathResolution::Macro(m)),
                 // this labels any path that starts with a tool module as the tool itself, this is technically wrong
                 // but there is no benefit in differentiating these two cases for the time being
-                _ => path.first_segment().and_then(|it| it.name_ref()).and_then(|name_ref| {
+                None => path.first_segment().and_then(|it| it.name_ref()).and_then(|name_ref| {
                     match self.resolver.krate() {
                         Some(krate) => ToolModule::by_name(db, krate.into(), &name_ref.text()),
                         None => ToolModule::builtin(&name_ref.text()),
diff --git a/crates/hir_def/src/child_by_source.rs b/crates/hir_def/src/child_by_source.rs
index 5c32a31e443..1e1573d4ae0 100644
--- a/crates/hir_def/src/child_by_source.rs
+++ b/crates/hir_def/src/child_by_source.rs
@@ -116,11 +116,11 @@ impl ChildBySource for ItemScope {
         self.derive_macro_invocs().filter(|(id, _)| id.file_id == file_id).for_each(
             |(ast_id, calls)| {
                 let adt = ast_id.to_node(db.upcast());
-                calls.for_each(|(attr_id, calls)| {
+                calls.for_each(|(attr_id, call_id, calls)| {
                     if let Some(Either::Left(attr)) =
                         adt.doc_comments_and_attrs().nth(attr_id.ast_index as usize)
                     {
-                        res[keys::DERIVE_MACRO_CALL].insert(attr, (attr_id, calls.into()));
+                        res[keys::DERIVE_MACRO_CALL].insert(attr, (attr_id, call_id, calls.into()));
                     }
                 });
             },
diff --git a/crates/hir_def/src/item_scope.rs b/crates/hir_def/src/item_scope.rs
index 258d1e0f6c5..fffec96bab9 100644
--- a/crates/hir_def/src/item_scope.rs
+++ b/crates/hir_def/src/item_scope.rs
@@ -66,8 +66,10 @@ pub struct ItemScope {
     attr_macros: FxHashMap<AstId<ast::Item>, MacroCallId>,
     /// The derive macro invocations in this scope, keyed by the owner item over the actual derive attributes
     /// paired with the derive macro invocations for the specific attribute.
-    derive_macros:
-        FxHashMap<AstId<ast::Adt>, SmallVec<[(AttrId, SmallVec<[Option<MacroCallId>; 1]>); 1]>>,
+    derive_macros: FxHashMap<
+        AstId<ast::Adt>,
+        SmallVec<[(AttrId, MacroCallId, SmallVec<[Option<MacroCallId>; 1]>); 1]>,
+    >,
 }
 
 pub(crate) static BUILTIN_SCOPE: Lazy<FxHashMap<Name, PerNs>> = Lazy::new(|| {
@@ -210,7 +212,7 @@ impl ItemScope {
         idx: usize,
     ) {
         if let Some(derives) = self.derive_macros.get_mut(&adt) {
-            if let Some((_, invocs)) = derives.iter_mut().find(|&&mut (id, _)| id == attr_id) {
+            if let Some((.., invocs)) = derives.iter_mut().find(|&&mut (id, ..)| id == attr_id) {
                 invocs[idx] = Some(call);
             }
         }
@@ -223,19 +225,23 @@ impl ItemScope {
         &mut self,
         adt: AstId<ast::Adt>,
         attr_id: AttrId,
+        call_id: MacroCallId,
         len: usize,
     ) {
-        self.derive_macros.entry(adt).or_default().push((attr_id, smallvec![None; len]));
+        self.derive_macros.entry(adt).or_default().push((attr_id, call_id, smallvec![None; len]));
     }
 
     pub(crate) fn derive_macro_invocs(
         &self,
     ) -> impl Iterator<
-        Item = (AstId<ast::Adt>, impl Iterator<Item = (AttrId, &[Option<MacroCallId>])>),
+        Item = (
+            AstId<ast::Adt>,
+            impl Iterator<Item = (AttrId, MacroCallId, &[Option<MacroCallId>])>,
+        ),
     > + '_ {
-        self.derive_macros
-            .iter()
-            .map(|(k, v)| (*k, v.iter().map(|(attr_id, invocs)| (*attr_id, &**invocs))))
+        self.derive_macros.iter().map(|(k, v)| {
+            (*k, v.iter().map(|&(attr_id, call_id, ref invocs)| (attr_id, call_id, &**invocs)))
+        })
     }
 
     pub(crate) fn unnamed_trait_vis(&self, tr: TraitId) -> Option<Visibility> {
diff --git a/crates/hir_def/src/keys.rs b/crates/hir_def/src/keys.rs
index 93c92c1b9c9..1c9d99eb788 100644
--- a/crates/hir_def/src/keys.rs
+++ b/crates/hir_def/src/keys.rs
@@ -34,7 +34,8 @@ pub const CONST_PARAM: Key<ast::ConstParam, ConstParamId> = Key::new();
 
 pub const MACRO: Key<ast::Macro, MacroDefId> = Key::new();
 pub const ATTR_MACRO_CALL: Key<ast::Item, MacroCallId> = Key::new();
-pub const DERIVE_MACRO_CALL: Key<ast::Attr, (AttrId, Box<[Option<MacroCallId>]>)> = Key::new();
+pub const DERIVE_MACRO_CALL: Key<ast::Attr, (AttrId, MacroCallId, Box<[Option<MacroCallId>]>)> =
+    Key::new();
 
 /// XXX: AST Nodes and SyntaxNodes have identity equality semantics: nodes are
 /// equal if they point to exactly the same object.
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index 7e33e535998..bb65d1dec87 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -690,9 +690,9 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
         };
 
         macro_call_as_call_id(
+            db,
             &AstIdWithPath::new(ast_id.file_id, ast_id.value, path),
             expands_to,
-            db,
             krate,
             resolver,
             error_sink,
@@ -714,9 +714,9 @@ impl<T: ast::AstNode> AstIdWithPath<T> {
 }
 
 fn macro_call_as_call_id(
+    db: &dyn db::DefDatabase,
     call: &AstIdWithPath<ast::MacroCall>,
     expand_to: ExpandTo,
-    db: &dyn db::DefDatabase,
     krate: CrateId,
     resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     error_sink: &mut dyn FnMut(ExpandError),
@@ -739,10 +739,10 @@ fn macro_call_as_call_id(
 }
 
 fn derive_macro_as_call_id(
+    db: &dyn db::DefDatabase,
     item_attr: &AstIdWithPath<ast::Adt>,
     derive_attr: AttrId,
     derive_pos: u32,
-    db: &dyn db::DefDatabase,
     krate: CrateId,
     resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
 ) -> Result<MacroCallId, UnresolvedMacro> {
@@ -761,11 +761,12 @@ fn derive_macro_as_call_id(
 }
 
 fn attr_macro_as_call_id(
+    db: &dyn db::DefDatabase,
     item_attr: &AstIdWithPath<ast::Item>,
     macro_attr: &Attr,
-    db: &dyn db::DefDatabase,
     krate: CrateId,
     def: MacroDefId,
+    is_derive: bool,
 ) -> MacroCallId {
     let mut arg = match macro_attr.input.as_deref() {
         Some(attr::AttrInput::TokenTree(tt, map)) => (tt.clone(), map.clone()),
@@ -782,6 +783,7 @@ fn attr_macro_as_call_id(
             ast_id: item_attr.ast_id,
             attr_args: Arc::new(arg),
             invoc_attr_index: macro_attr.id.ast_index,
+            is_derive,
         },
     );
     res
diff --git a/crates/hir_def/src/nameres/attr_resolution.rs b/crates/hir_def/src/nameres/attr_resolution.rs
index 4a7211b5c98..4c436250db3 100644
--- a/crates/hir_def/src/nameres/attr_resolution.rs
+++ b/crates/hir_def/src/nameres/attr_resolution.rs
@@ -54,7 +54,7 @@ impl DefMap {
             None => return Err(UnresolvedMacro { path: ast_id.path.clone() }),
         };
 
-        Ok(ResolvedAttr::Macro(attr_macro_as_call_id(&ast_id, attr, db, self.krate, def)))
+        Ok(ResolvedAttr::Macro(attr_macro_as_call_id(db, &ast_id, attr, self.krate, def, false)))
     }
 
     pub(crate) fn is_builtin_or_registered_attr(&self, path: &ModPath) -> bool {
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index ec6af65a921..9e29f28d982 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -1055,9 +1055,9 @@ impl DefCollector<'_> {
             match &directive.kind {
                 MacroDirectiveKind::FnLike { ast_id, expand_to } => {
                     let call_id = macro_call_as_call_id(
+                        self.db,
                         ast_id,
                         *expand_to,
-                        self.db,
                         self.def_map.krate,
                         &resolver,
                         &mut |_err| (),
@@ -1070,10 +1070,10 @@ impl DefCollector<'_> {
                 }
                 MacroDirectiveKind::Derive { ast_id, derive_attr, derive_pos } => {
                     let call_id = derive_macro_as_call_id(
+                        self.db,
                         ast_id,
                         *derive_attr,
                         *derive_pos as u32,
-                        self.db,
                         self.def_map.krate,
                         &resolver,
                     );
@@ -1170,9 +1170,17 @@ impl DefCollector<'_> {
                                     len = idx;
                                 }
 
+                                let call_id = attr_macro_as_call_id(
+                                    self.db,
+                                    file_ast_id,
+                                    attr,
+                                    self.def_map.krate,
+                                    def,
+                                    true,
+                                );
                                 self.def_map.modules[directive.module_id]
                                     .scope
-                                    .init_derive_attribute(ast_id, attr.id, len + 1);
+                                    .init_derive_attribute(ast_id, attr.id, call_id, len + 1);
                             }
                             None => {
                                 let diag = DefDiagnostic::malformed_derive(
@@ -1192,8 +1200,14 @@ impl DefCollector<'_> {
                     }
 
                     // Not resolved to a derive helper or the derive attribute, so try to treat as a normal attribute.
-                    let call_id =
-                        attr_macro_as_call_id(file_ast_id, attr, self.db, self.def_map.krate, def);
+                    let call_id = attr_macro_as_call_id(
+                        self.db,
+                        file_ast_id,
+                        attr,
+                        self.def_map.krate,
+                        def,
+                        false,
+                    );
                     let loc: MacroCallLoc = self.db.lookup_intern_macro_call(call_id);
 
                     // Skip #[test]/#[bench] expansion, which would merely result in more memory usage
@@ -1310,9 +1324,9 @@ impl DefCollector<'_> {
             match &directive.kind {
                 MacroDirectiveKind::FnLike { ast_id, expand_to } => {
                     let macro_call_as_call_id = macro_call_as_call_id(
+                        self.db,
                         ast_id,
                         *expand_to,
-                        self.db,
                         self.def_map.krate,
                         |path| {
                             let resolved_res = self.def_map.resolve_path_fp_with_macro(
@@ -1959,9 +1973,9 @@ impl ModCollector<'_, '_> {
         // Case 1: try to resolve in legacy scope and expand macro_rules
         let mut error = None;
         match macro_call_as_call_id(
+            self.def_collector.db,
             &ast_id,
             mac.expand_to,
-            self.def_collector.db,
             self.def_collector.def_map.krate,
             |path| {
                 path.as_ident().and_then(|name| {
diff --git a/crates/hir_expand/src/builtin_attr_macro.rs b/crates/hir_expand/src/builtin_attr_macro.rs
index 907ee02e332..19966245985 100644
--- a/crates/hir_expand/src/builtin_attr_macro.rs
+++ b/crates/hir_expand/src/builtin_attr_macro.rs
@@ -1,9 +1,11 @@
 //! Builtin attributes.
 
+use itertools::Itertools;
 use syntax::ast;
 
 use crate::{
-    db::AstDatabase, name, AstId, CrateId, ExpandResult, MacroCallId, MacroDefId, MacroDefKind,
+    db::AstDatabase, name, AstId, CrateId, ExpandResult, MacroCallId, MacroCallKind, MacroDefId,
+    MacroDefKind,
 };
 
 macro_rules! register_builtin {
@@ -53,7 +55,7 @@ register_builtin! {
     (bench, Bench) => dummy_attr_expand,
     (cfg_accessible, CfgAccessible) => dummy_attr_expand,
     (cfg_eval, CfgEval) => dummy_attr_expand,
-    (derive, Derive) => dummy_attr_expand,
+    (derive, Derive) => derive_attr_expand,
     (global_allocator, GlobalAllocator) => dummy_attr_expand,
     (test, Test) => dummy_attr_expand,
     (test_case, TestCase) => dummy_attr_expand
@@ -79,3 +81,76 @@ fn dummy_attr_expand(
 ) -> ExpandResult<tt::Subtree> {
     ExpandResult::ok(tt.clone())
 }
+
+fn derive_attr_expand(
+    db: &dyn AstDatabase,
+    id: MacroCallId,
+    tt: &tt::Subtree,
+) -> ExpandResult<tt::Subtree> {
+    // we generate a very specific expansion here, as we do not actually expand the `#[derive]` attribute
+    // itself in name res, but we do want to expand it to something for the IDE layer, so that the input
+    // derive attributes can be downmapped, and resolved
+    // This is basically a hack, to get rid of hacks in the IDE layer that slowly accumulate more and more
+    // in various places.
+
+    // we transform the token tree of `#[derive(Foo, bar::Bar)]` into
+    // ```
+    //  #[Foo]
+    //  #[bar::Bar]
+    //  ();
+    // ```
+    // which allows fallback path resolution in hir::Semantics to properly identify our derives
+    let loc = db.lookup_intern_macro_call(id);
+    let derives = match &loc.kind {
+        MacroCallKind::Attr { attr_args, .. } => &attr_args.0,
+        _ => return ExpandResult::ok(tt.clone()),
+    };
+
+    let mut token_trees = Vec::new();
+    for (comma, group) in &derives
+        .token_trees
+        .iter()
+        .filter_map(|tt| match tt {
+            tt::TokenTree::Leaf(l) => Some(l),
+            tt::TokenTree::Subtree(_) => None,
+        })
+        .group_by(|l| matches!(l, tt::Leaf::Punct(tt::Punct { char: ',', .. })))
+    {
+        if comma {
+            continue;
+        }
+        let wrap = |leaf| tt::TokenTree::Leaf(tt::Leaf::Punct(leaf));
+        token_trees.push(wrap(tt::Punct {
+            char: '#',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }));
+        token_trees.push(wrap(tt::Punct {
+            char: '[',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }));
+        token_trees.extend(group.cloned().map(tt::TokenTree::Leaf));
+        token_trees.push(wrap(tt::Punct {
+            char: ']',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }));
+        token_trees.push(wrap(tt::Punct {
+            char: '(',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }));
+        token_trees.push(wrap(tt::Punct {
+            char: ')',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }));
+        token_trees.push(wrap(tt::Punct {
+            char: ';',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }));
+    }
+    ExpandResult::ok(tt::Subtree { delimiter: tt.delimiter, token_trees })
+}
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index 91c1631e817..d6d33b4cd72 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -342,6 +342,7 @@ fn censor_for_macro_input(loc: &MacroCallLoc, node: &SyntaxNode) -> FxHashSet<Sy
                     .map(|it| it.syntax().clone())
                     .collect()
             }
+            MacroCallKind::Attr { is_derive: true, .. } => return None,
             MacroCallKind::Attr { invoc_attr_index, .. } => {
                 cov_mark::hit!(attribute_macro_attr_censoring);
                 ast::Item::cast(node.clone())?
diff --git a/crates/hir_expand/src/lib.rs b/crates/hir_expand/src/lib.rs
index 27c3f097abb..2ccf4c56eeb 100644
--- a/crates/hir_expand/src/lib.rs
+++ b/crates/hir_expand/src/lib.rs
@@ -166,6 +166,7 @@ pub enum MacroCallKind {
         /// Outer attributes are counted first, then inner attributes. This does not support
         /// out-of-line modules, which may have attributes spread across 2 files!
         invoc_attr_index: u32,
+        is_derive: bool,
     },
 }
 
@@ -431,6 +432,7 @@ impl MacroCallKind {
         match self {
             MacroCallKind::FnLike { expand_to, .. } => *expand_to,
             MacroCallKind::Derive { .. } => ExpandTo::Items,
+            MacroCallKind::Attr { is_derive: true, .. } => ExpandTo::Statements,
             MacroCallKind::Attr { .. } => ExpandTo::Items, // is this always correct?
         }
     }
@@ -497,7 +499,7 @@ impl ExpansionInfo {
 
             let token_range = token.value.text_range();
             match &loc.kind {
-                MacroCallKind::Attr { attr_args, invoc_attr_index, .. } => {
+                MacroCallKind::Attr { attr_args, invoc_attr_index, is_derive, .. } => {
                     let attr = item
                         .doc_comments_and_attrs()
                         .nth(*invoc_attr_index as usize)
@@ -511,9 +513,13 @@ impl ExpansionInfo {
                             let relative_range =
                                 token.value.text_range().checked_sub(attr_input_start)?;
                             // shift by the item's tree's max id
-                            let token_id = self
-                                .macro_arg_shift
-                                .shift(attr_args.1.token_by_range(relative_range)?);
+                            let token_id = attr_args.1.token_by_range(relative_range)?;
+                            let token_id = if *is_derive {
+                                // we do not shift for `#[derive]`, as we only need to downmap the derive attribute tokens
+                                token_id
+                            } else {
+                                self.macro_arg_shift.shift(token_id)
+                            };
                             Some(token_id)
                         }
                         _ => None,
diff --git a/crates/ide/src/hover/tests.rs b/crates/ide/src/hover/tests.rs
index c5c531c30b1..a232ebd4fb7 100644
--- a/crates/ide/src/hover/tests.rs
+++ b/crates/ide/src/hover/tests.rs
@@ -15,6 +15,7 @@ fn check_hover_no_result(ra_fixture: &str) {
     assert!(hover.is_none(), "hover not expected but found: {:?}", hover.unwrap());
 }
 
+#[track_caller]
 fn check(ra_fixture: &str, expect: Expect) {
     let (analysis, position) = fixture::position(ra_fixture);
     let hover = analysis
diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
index f09f291e96a..d67f6baff07 100644
--- a/crates/ide/src/syntax_highlighting.rs
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -361,7 +361,7 @@ fn traverse(
                 syntactic_name_ref_highlighting,
                 node,
             ),
-            NodeOrToken::Token(token) => highlight::token(sema, krate, token).zip(Some(None)),
+            NodeOrToken::Token(token) => highlight::token(sema, token).zip(Some(None)),
         };
         if let Some((mut highlight, binding_hash)) = element {
             if inside_attribute {
diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index c869db3b8b7..85c0c1b286e 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -18,11 +18,7 @@ use crate::{
     Highlight, HlMod, HlTag,
 };
 
-pub(super) fn token(
-    sema: &Semantics<RootDatabase>,
-    krate: Option<hir::Crate>,
-    token: SyntaxToken,
-) -> Option<Highlight> {
+pub(super) fn token(sema: &Semantics<RootDatabase>, token: SyntaxToken) -> Option<Highlight> {
     if let Some(comment) = ast::Comment::cast(token.clone()) {
         let h = HlTag::Comment;
         return Some(match comment.kind().doc {
@@ -39,17 +35,10 @@ pub(super) fn token(
         INT_NUMBER | FLOAT_NUMBER => HlTag::NumericLiteral.into(),
         BYTE => HlTag::ByteLiteral.into(),
         CHAR => HlTag::CharLiteral.into(),
-        IDENT => {
-            let tt = ast::TokenTree::cast(token.parent()?)?;
-            let ident = ast::Ident::cast(token)?;
+        IDENT if token.parent().and_then(ast::TokenTree::cast).is_some() => {
             // from this point on we are inside a token tree, this only happens for identifiers
             // that were not mapped down into macro invocations
-            (|| {
-                let attr = tt.parent_meta()?.parent_attr()?;
-                let res = sema.resolve_derive_ident(&attr, &ident)?;
-                Some(highlight_def(sema, krate, Definition::from(res)))
-            })()
-            .unwrap_or_else(|| HlTag::None.into())
+            HlTag::None.into()
         }
         p if p.is_punct() => punctuation(sema, token, p),
         k if k.is_keyword() => keyword(sema, token, k)?,
diff --git a/crates/ide_completion/src/completions/trait_impl.rs b/crates/ide_completion/src/completions/trait_impl.rs
index 4b1de8058de..0d59f77a55c 100644
--- a/crates/ide_completion/src/completions/trait_impl.rs
+++ b/crates/ide_completion/src/completions/trait_impl.rs
@@ -58,15 +58,15 @@ pub(crate) fn complete_trait_impl(acc: &mut Completions, ctx: &CompletionContext
                     (
                         hir::AssocItem::Function(fn_item),
                         ImplCompletionKind::All | ImplCompletionKind::Fn,
-                    ) => add_function_impl(&trigger, acc, ctx, fn_item, hir_impl),
+                    ) => add_function_impl(acc, ctx, &trigger, fn_item, hir_impl),
                     (
                         hir::AssocItem::TypeAlias(type_item),
                         ImplCompletionKind::All | ImplCompletionKind::TypeAlias,
-                    ) => add_type_alias_impl(&trigger, acc, ctx, type_item),
+                    ) => add_type_alias_impl(acc, ctx, &trigger, type_item),
                     (
                         hir::AssocItem::Const(const_item),
                         ImplCompletionKind::All | ImplCompletionKind::Const,
-                    ) => add_const_impl(&trigger, acc, ctx, const_item, hir_impl),
+                    ) => add_const_impl(acc, ctx, &trigger, const_item, hir_impl),
                     _ => {}
                 }
             });
@@ -126,9 +126,9 @@ fn completion_match(mut token: SyntaxToken) -> Option<(ImplCompletionKind, Synta
 }
 
 fn add_function_impl(
-    fn_def_node: &SyntaxNode,
     acc: &mut Completions,
     ctx: &CompletionContext,
+    fn_def_node: &SyntaxNode,
     func: hir::Function,
     impl_def: hir::Impl,
 ) {
@@ -199,9 +199,9 @@ fn get_transformed_assoc_item(
 }
 
 fn add_type_alias_impl(
-    type_def_node: &SyntaxNode,
     acc: &mut Completions,
     ctx: &CompletionContext,
+    type_def_node: &SyntaxNode,
     type_alias: hir::TypeAlias,
 ) {
     let alias_name = type_alias.name(ctx.db).to_smol_str();
@@ -217,9 +217,9 @@ fn add_type_alias_impl(
 }
 
 fn add_const_impl(
-    const_def_node: &SyntaxNode,
     acc: &mut Completions,
     ctx: &CompletionContext,
+    const_def_node: &SyntaxNode,
     const_: hir::Const,
     impl_def: hir::Impl,
 ) {
diff --git a/crates/ide_db/src/defs.rs b/crates/ide_db/src/defs.rs
index 5a4cfe6e941..08104efcdc2 100644
--- a/crates/ide_db/src/defs.rs
+++ b/crates/ide_db/src/defs.rs
@@ -14,7 +14,7 @@ use hir::{
 use stdx::impl_from;
 use syntax::{
     ast::{self, AstNode},
-    match_ast, AstToken, SyntaxKind, SyntaxNode, SyntaxToken,
+    match_ast, SyntaxKind, SyntaxNode, SyntaxToken,
 };
 
 use crate::RootDatabase;
@@ -142,16 +142,6 @@ impl IdentClass {
         token: &SyntaxToken,
     ) -> Option<IdentClass> {
         let parent = token.parent()?;
-        // resolve derives if possible
-        if let Some(ident) = ast::Ident::cast(token.clone()) {
-            let attr = ast::TokenTree::cast(parent.clone())
-                .and_then(|tt| tt.parent_meta())
-                .and_then(|meta| meta.parent_attr());
-            if let Some(attr) = attr {
-                return NameRefClass::classify_derive(sema, &attr, &ident)
-                    .map(IdentClass::NameRefClass);
-            }
-        }
         Self::classify_node(sema, &parent)
     }
 
@@ -461,14 +451,6 @@ impl NameRefClass {
             _ => None,
         }
     }
-
-    pub fn classify_derive(
-        sema: &Semantics<RootDatabase>,
-        attr: &ast::Attr,
-        ident: &ast::Ident,
-    ) -> Option<NameRefClass> {
-        sema.resolve_derive_ident(&attr, &ident).map(Definition::from).map(NameRefClass::Definition)
-    }
 }
 
 impl_from!(