internal: Simplify and optimize syntax_highlighting

7 files changed, 184 insertions, 167 deletions

diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
index 968aa331164..0119ba5cb77 100644
--- a/crates/ide/src/syntax_highlighting.rs
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -241,19 +241,26 @@ fn traverse(
                     current_macro = Some(mac.into());
                     continue;
                 }
-                Some(item) if sema.is_attr_macro_call(&item) => current_attr_call = Some(item),
-                Some(item) if current_attr_call.is_none() => {
-                    let adt = match item {
-                        ast::Item::Enum(it) => Some(ast::Adt::Enum(it)),
-                        ast::Item::Struct(it) => Some(ast::Adt::Struct(it)),
-                        ast::Item::Union(it) => Some(ast::Adt::Union(it)),
-                        _ => None,
-                    };
-                    match adt {
-                        Some(adt) if sema.is_derive_annotated(&adt) => {
-                            current_derive_call = Some(ast::Item::from(adt));
+                Some(item) => {
+                    if matches!(node.kind(), FN | CONST | STATIC) {
+                        bindings_shadow_count.clear();
+                    }
+
+                    if sema.is_attr_macro_call(&item) {
+                        current_attr_call = Some(item);
+                    } else if current_attr_call.is_none() {
+                        let adt = match item {
+                            ast::Item::Enum(it) => Some(ast::Adt::Enum(it)),
+                            ast::Item::Struct(it) => Some(ast::Adt::Struct(it)),
+                            ast::Item::Union(it) => Some(ast::Adt::Union(it)),
+                            _ => None,
+                        };
+                        match adt {
+                            Some(adt) if sema.is_derive_annotated(&adt) => {
+                                current_derive_call = Some(ast::Item::from(adt));
+                            }
+                            _ => (),
                         }
-                        _ => (),
                     }
                 }
                 None if ast::Attr::can_cast(node.kind()) => inside_attribute = true,
@@ -291,6 +298,8 @@ fn traverse(
             WalkEvent::Enter(it) => it,
             WalkEvent::Leave(NodeOrToken::Token(_)) => continue,
             WalkEvent::Leave(NodeOrToken::Node(node)) => {
+                // Doc comment highlighting injection, we do this when leaving the node
+                // so that we overwrite the highlighting of the doc comment itself.
                 inject::doc_comment(hl, sema, InFile::new(file_id.into(), &node));
                 continue;
             }
@@ -302,57 +311,68 @@ fn traverse(
             }
         }
 
-        // only attempt to descend if we are inside a macro call or attribute
-        // as calling `descend_into_macros_single` gets rather expensive if done for every single token
-        // additionally, do not descend into comments, descending maps down to doc attributes which get
-        // tagged as string literals.
-        let descend_token = (current_macro_call.is_some()
-            || current_attr_call.is_some()
-            || current_derive_call.is_some())
-            && element.kind() != COMMENT;
-        let element_to_highlight = if descend_token {
-            let token = match &element {
-                NodeOrToken::Node(_) => continue,
-                NodeOrToken::Token(tok) => tok.clone(),
-            };
-            let in_mcall_outside_tt = current_attr_call.is_none()
-                && token.parent().as_ref().map(SyntaxNode::kind) != Some(TOKEN_TREE);
-            let token = match in_mcall_outside_tt {
-                // not in the macros/derives token tree, don't attempt to descend
-                true => token,
-                false => sema.descend_into_macros_single(token),
-            };
-            match token.parent() {
-                Some(parent) => {
-                    // Names and NameRefs have special semantics, use them instead of the tokens
-                    // as otherwise we won't ever visit them
-                    match (token.kind(), parent.kind()) {
-                        (T![ident], NAME | NAME_REF) => parent.into(),
-                        (T![self] | T![super] | T![crate] | T![Self], NAME_REF) => parent.into(),
-                        (INT_NUMBER, NAME_REF) => parent.into(),
-                        (LIFETIME_IDENT, LIFETIME) => parent.into(),
-                        _ => token.into(),
+        let element = match element.clone() {
+            NodeOrToken::Node(n) => match ast::NameLike::cast(n) {
+                Some(n) => NodeOrToken::Node(n),
+                None => continue,
+            },
+            NodeOrToken::Token(t) => NodeOrToken::Token(t),
+        };
+        let token = element.as_token().cloned();
+
+        // Descending tokens into macros is expensive even if no descending occurs, so make sure
+        // that we actually are in a position where descending is possible.
+        let in_macro = current_macro_call.is_some()
+            || current_derive_call.is_some()
+            || current_attr_call.is_some();
+        let descended_element = if in_macro {
+            // Attempt to descend tokens into macro-calls.
+            match element {
+                NodeOrToken::Token(token) if token.kind() != COMMENT => {
+                    // For function-like macro calls and derive attributes, only attempt to descend if
+                    // we are inside their token-trees.
+                    let in_tt = current_attr_call.is_some()
+                        || token.parent().as_ref().map(SyntaxNode::kind) == Some(TOKEN_TREE);
+
+                    if in_tt {
+                        let token = sema.descend_into_macros_single(token);
+                        match token.parent().and_then(ast::NameLike::cast) {
+                            // Remap the token into the wrapping single token nodes
+                            // FIXME: if the node doesn't resolve, we also won't do token based highlighting!
+                            Some(parent) => match (token.kind(), parent.syntax().kind()) {
+                                (T![self] | T![ident], NAME | NAME_REF) => {
+                                    NodeOrToken::Node(parent)
+                                }
+                                (T![self] | T![super] | T![crate] | T![Self], NAME_REF) => {
+                                    NodeOrToken::Node(parent)
+                                }
+                                (INT_NUMBER, NAME_REF) => NodeOrToken::Node(parent),
+                                (LIFETIME_IDENT, LIFETIME) => NodeOrToken::Node(parent),
+                                _ => NodeOrToken::Token(token),
+                            },
+                            None => NodeOrToken::Token(token),
+                        }
+                    } else {
+                        NodeOrToken::Token(token)
                     }
                 }
-                None => token.into(),
+                e => e,
             }
         } else {
-            element.clone()
+            element
         };
 
         // FIXME: do proper macro def highlighting https://github.com/rust-analyzer/rust-analyzer/issues/6232
         // Skip metavariables from being highlighted to prevent keyword highlighting in them
-        if macro_highlighter.highlight(&element_to_highlight).is_some() {
+        if descended_element.as_token().and_then(|t| macro_highlighter.highlight(t)).is_some() {
             continue;
         }
 
         // string highlight injections, note this does not use the descended element as proc-macros
         // can rewrite string literals which invalidates our indices
-        if let (Some(token), Some(token_to_highlight)) =
-            (element.into_token(), element_to_highlight.as_token())
-        {
+        if let (Some(token), Some(descended_token)) = (token, descended_element.as_token()) {
             let string = ast::String::cast(token);
-            let string_to_highlight = ast::String::cast(token_to_highlight.clone());
+            let string_to_highlight = ast::String::cast(descended_token.clone());
             if let Some((string, expanded_string)) = string.zip(string_to_highlight) {
                 if string.is_raw() {
                     if inject::ra_fixture(hl, sema, &string, &expanded_string).is_some() {
@@ -377,14 +397,13 @@ fn traverse(
             }
         }
 
-        // do the normal highlighting
-        let element = match element_to_highlight {
-            NodeOrToken::Node(node) => highlight::node(
+        let element = match descended_element {
+            NodeOrToken::Node(name_like) => highlight::name_like(
                 sema,
                 krate,
                 &mut bindings_shadow_count,
                 syntactic_name_ref_highlighting,
-                node,
+                name_like,
             ),
             NodeOrToken::Token(token) => highlight::token(sema, token).zip(Some(None)),
         };
diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 43a3fb2d71b..b98fa1ab392 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -2,7 +2,7 @@
 
 use hir::{AsAssocItem, HasVisibility, Semantics};
 use ide_db::{
-    defs::{Definition, NameClass, NameRefClass},
+    defs::{Definition, IdentClass, NameClass, NameRefClass},
     helpers::FamousDefs,
     RootDatabase, SymbolKind,
 };
@@ -47,52 +47,36 @@ pub(super) fn token(sema: &Semantics<RootDatabase>, token: SyntaxToken) -> Optio
     Some(highlight)
 }
 
-pub(super) fn node(
+pub(super) fn name_like(
     sema: &Semantics<RootDatabase>,
     krate: Option<hir::Crate>,
     bindings_shadow_count: &mut FxHashMap<hir::Name, u32>,
     syntactic_name_ref_highlighting: bool,
-    node: SyntaxNode,
+    name_like: ast::NameLike,
 ) -> Option<(Highlight, Option<u64>)> {
     let mut binding_hash = None;
-    let highlight = match_ast! {
-        match node {
-            ast::NameRef(name_ref) => {
-                highlight_name_ref(
-                    sema,
-                    krate,
-                    bindings_shadow_count,
-                    &mut binding_hash,
-                    syntactic_name_ref_highlighting,
-                    name_ref,
-                )
-            },
-            ast::Name(name) => {
-                highlight_name(sema, bindings_shadow_count, &mut binding_hash, krate, name)
-            },
-            ast::Lifetime(lifetime) => {
-                match NameClass::classify_lifetime(sema, &lifetime) {
-                    Some(NameClass::Definition(def)) => {
-                        highlight_def(sema, krate, def) | HlMod::Definition
-                    }
-                    None => match NameRefClass::classify_lifetime(sema, &lifetime) {
-                        Some(NameRefClass::Definition(def)) => highlight_def(sema, krate, def),
-                        _ => SymbolKind::LifetimeParam.into(),
-                    },
-                    _ => Highlight::from(SymbolKind::LifetimeParam) | HlMod::Definition,
-                }
-            },
-            ast::Fn(_) => {
-                bindings_shadow_count.clear();
-                return None;
-            },
-            _ => {
-                if [FN, CONST, STATIC].contains(&node.kind()) {
-                    bindings_shadow_count.clear();
-                }
-                return None
-            },
+    let highlight = match name_like {
+        ast::NameLike::NameRef(name_ref) => highlight_name_ref(
+            sema,
+            krate,
+            bindings_shadow_count,
+            &mut binding_hash,
+            syntactic_name_ref_highlighting,
+            name_ref,
+        ),
+        ast::NameLike::Name(name) => {
+            highlight_name(sema, bindings_shadow_count, &mut binding_hash, krate, name)
         }
+        ast::NameLike::Lifetime(lifetime) => match IdentClass::classify_lifetime(sema, &lifetime) {
+            Some(IdentClass::NameClass(NameClass::Definition(def))) => {
+                highlight_def(sema, krate, def) | HlMod::Definition
+            }
+            Some(IdentClass::NameRefClass(NameRefClass::Definition(def))) => {
+                highlight_def(sema, krate, def)
+            }
+            // FIXME: Fallback for 'static and '_, as we do not resolve these yet
+            _ => SymbolKind::LifetimeParam.into(),
+        },
     };
     Some((highlight, binding_hash))
 }
diff --git a/crates/ide/src/syntax_highlighting/inject.rs b/crates/ide/src/syntax_highlighting/inject.rs
index ec1df6d1de5..774934a2498 100644
--- a/crates/ide/src/syntax_highlighting/inject.rs
+++ b/crates/ide/src/syntax_highlighting/inject.rs
@@ -9,7 +9,7 @@ use ide_db::{
     SymbolKind,
 };
 use syntax::{
-    ast::{self, AstNode, IsString},
+    ast::{self, AstNode, IsString, QuoteOffsets},
     AstToken, NodeOrToken, SyntaxNode, TextRange, TextSize,
 };
 
@@ -61,7 +61,7 @@ pub(super) fn ra_fixture(
         }
     }
 
-    let (analysis, tmp_file_id) = Analysis::from_single_file(inj.text().to_string());
+    let (analysis, tmp_file_id) = Analysis::from_single_file(inj.take_text());
 
     for mut hl_range in analysis.highlight(tmp_file_id).unwrap() {
         for range in inj.map_range_up(hl_range.range) {
@@ -85,31 +85,19 @@ const RUSTDOC_FENCE: &'static str = "```";
 pub(super) fn doc_comment(
     hl: &mut Highlights,
     sema: &Semantics<RootDatabase>,
-    node: InFile<&SyntaxNode>,
+    InFile { file_id: src_file_id, value: node }: InFile<&SyntaxNode>,
 ) {
-    let (attributes, def) = match doc_attributes(sema, node.value) {
+    let (attributes, def) = match doc_attributes(sema, node) {
         Some(it) => it,
         None => return,
     };
 
-    let mut inj = Injector::default();
-    inj.add_unmapped("fn doctest() {\n");
-
-    let attrs_source_map = attributes.source_map(sema.db);
-
-    let mut is_codeblock = false;
-    let mut is_doctest = false;
-
-    // Replace the original, line-spanning comment ranges by new, only comment-prefix
-    // spanning comment ranges.
-    let mut new_comments = Vec::new();
-    let mut string;
-
+    // Extract intra-doc links and emit highlights for them.
     if let Some((docs, doc_mapping)) = attributes.docs_with_rangemap(sema.db) {
         extract_definitions_from_docs(&docs)
             .into_iter()
             .filter_map(|(range, link, ns)| {
-                doc_mapping.map(range).filter(|mapping| mapping.file_id == node.file_id).and_then(
+                doc_mapping.map(range).filter(|mapping| mapping.file_id == src_file_id).and_then(
                     |InFile { value: mapped_range, .. }| {
                         Some(mapped_range).zip(resolve_doc_path_for_def(sema.db, def, &link, ns))
                     },
@@ -127,31 +115,49 @@ pub(super) fn doc_comment(
             });
     }
 
+    // Extract doc-test sources from the docs and calculate highlighting for them.
+
+    let mut inj = Injector::default();
+    inj.add_unmapped("fn doctest() {\n");
+
+    let attrs_source_map = attributes.source_map(sema.db);
+
+    let mut is_codeblock = false;
+    let mut is_doctest = false;
+
+    let mut new_comments = Vec::new();
+    let mut string;
+
     for attr in attributes.by_key("doc").attrs() {
         let InFile { file_id, value: src } = attrs_source_map.source_of(attr);
-        if file_id != node.file_id {
+        if file_id != src_file_id {
             continue;
         }
-        let (line, range, prefix) = match &src {
+        let (line, range) = match &src {
             Either::Left(it) => {
                 string = match find_doc_string_in_attr(attr, it) {
                     Some(it) => it,
                     None => continue,
                 };
-                let text_range = string.syntax().text_range();
-                let text_range = TextRange::new(
-                    text_range.start() + TextSize::from(1),
-                    text_range.end() - TextSize::from(1),
-                );
                 let text = string.text();
-                (&text[1..text.len() - 1], text_range, "")
+                let text_range = string.syntax().text_range();
+                match string.quote_offsets() {
+                    Some(QuoteOffsets { contents, .. }) => {
+                        (&text[contents - text_range.start()], contents)
+                    }
+                    None => (text, text_range),
+                }
             }
             Either::Right(comment) => {
-                (comment.text(), comment.syntax().text_range(), comment.prefix())
+                let value = comment.prefix().len();
+                let range = comment.syntax().text_range();
+                (
+                    &comment.text()[value..],
+                    TextRange::new(range.start() + TextSize::try_from(value).unwrap(), range.end()),
+                )
             }
         };
 
-        let mut pos = TextSize::from(prefix.len() as u32);
         let mut range_start = range.start();
         for line in line.split('\n') {
             let line_len = TextSize::from(line.len() as u32);
@@ -159,8 +165,7 @@ pub(super) fn doc_comment(
                 let next_range_start = range_start + line_len + TextSize::from(1);
                 mem::replace(&mut range_start, next_range_start)
             };
-            // only first line has the prefix so take it away for future iterations
-            let mut pos = mem::take(&mut pos);
+            let mut pos = TextSize::from(0);
 
             match line.find(RUSTDOC_FENCE) {
                 Some(idx) => {
@@ -196,13 +201,13 @@ pub(super) fn doc_comment(
 
     inj.add_unmapped("\n}");
 
-    let (analysis, tmp_file_id) = Analysis::from_single_file(inj.text().to_string());
+    let (analysis, tmp_file_id) = Analysis::from_single_file(inj.take_text());
 
-    for HlRange { range, highlight, binding_hash } in
-        analysis.with_db(|db| super::highlight(db, tmp_file_id, None, true)).unwrap()
-    {
-        for range in inj.map_range_up(range) {
-            hl.add(HlRange { range, highlight: highlight | HlMod::Injected, binding_hash });
+    if let Ok(ranges) = analysis.with_db(|db| super::highlight(db, tmp_file_id, None, true)) {
+        for HlRange { range, highlight, binding_hash } in ranges {
+            for range in inj.map_range_up(range) {
+                hl.add(HlRange { range, highlight: highlight | HlMod::Injected, binding_hash });
+            }
         }
     }
 
diff --git a/crates/ide/src/syntax_highlighting/injector.rs b/crates/ide/src/syntax_highlighting/injector.rs
index 211dc54f2b6..a902fd717f0 100644
--- a/crates/ide/src/syntax_highlighting/injector.rs
+++ b/crates/ide/src/syntax_highlighting/injector.rs
@@ -29,8 +29,8 @@ impl Injector {
         self.buf.push_str(text);
     }
 
-    pub(super) fn text(&self) -> &str {
-        &self.buf
+    pub(super) fn take_text(&mut self) -> String {
+        std::mem::take(&mut self.buf)
     }
 
     pub(super) fn map_range_up(&self, range: TextRange) -> impl Iterator<Item = TextRange> + '_ {
diff --git a/crates/ide/src/syntax_highlighting/macro_.rs b/crates/ide/src/syntax_highlighting/macro_.rs
index 7f2d61a0bd3..1099d9c23b7 100644
--- a/crates/ide/src/syntax_highlighting/macro_.rs
+++ b/crates/ide/src/syntax_highlighting/macro_.rs
@@ -1,5 +1,5 @@
 //! Syntax highlighting for macro_rules!.
-use syntax::{SyntaxElement, SyntaxKind, SyntaxToken, TextRange, T};
+use syntax::{SyntaxKind, SyntaxToken, TextRange, T};
 
 use crate::{HlRange, HlTag};
 
@@ -19,10 +19,10 @@ impl MacroHighlighter {
         }
     }
 
-    pub(super) fn highlight(&self, element: &SyntaxElement) -> Option<HlRange> {
+    pub(super) fn highlight(&self, token: &SyntaxToken) -> Option<HlRange> {
         if let Some(state) = self.state.as_ref() {
             if matches!(state.rule_state, RuleState::Matcher | RuleState::Expander) {
-                if let Some(range) = is_metavariable(element) {
+                if let Some(range) = is_metavariable(token) {
                     return Some(HlRange {
                         range,
                         highlight: HlTag::UnresolvedReference.into(),
@@ -115,12 +115,11 @@ fn update_macro_state(state: &mut MacroMatcherParseState, tok: &SyntaxToken) {
     }
 }
 
-fn is_metavariable(element: &SyntaxElement) -> Option<TextRange> {
-    let tok = element.as_token()?;
-    match tok.kind() {
+fn is_metavariable(token: &SyntaxToken) -> Option<TextRange> {
+    match token.kind() {
         kind if kind == SyntaxKind::IDENT || kind.is_keyword() => {
-            if let Some(_dollar) = tok.prev_token().filter(|t| t.kind() == T![$]) {
-                return Some(tok.text_range());
+            if let Some(_dollar) = token.prev_token().filter(|t| t.kind() == T![$]) {
+                return Some(token.text_range());
             }
         }
         _ => (),
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html b/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html
index bd8d9faae84..96044751b81 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlight_doctest.html
@@ -43,13 +43,13 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 </style>
 <pre><code><span class="comment documentation">//! This is a module to test doc injection.</span>
 <span class="comment documentation">//! ```</span>
-<span class="comment documentation">//! </span><span class="keyword injected">fn</span><span class="none injected"> </span><span class="function declaration injected">test</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="brace injected">{</span><span class="brace injected">}</span>
+<span class="comment documentation">//!</span><span class="comment documentation"> </span><span class="keyword injected">fn</span><span class="none injected"> </span><span class="function declaration injected">test</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="brace injected">{</span><span class="brace injected">}</span>
 <span class="comment documentation">//! ```</span>
 
 <span class="keyword">mod</span> <span class="module declaration">outline_module</span><span class="semicolon">;</span>
 
 <span class="comment documentation">/// ```</span>
-<span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="string_literal injected">"early doctests should not go boom"</span><span class="semicolon injected">;</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="string_literal injected">"early doctests should not go boom"</span><span class="semicolon injected">;</span>
 <span class="comment documentation">/// ```</span>
 <span class="keyword">struct</span> <span class="struct declaration">Foo</span> <span class="brace">{</span>
     <span class="field declaration">bar</span><span class="colon">:</span> <span class="builtin_type">bool</span><span class="comma">,</span>
@@ -58,15 +58,15 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="comment documentation">/// This is an impl with a code block.</span>
 <span class="comment documentation">///</span>
 <span class="comment documentation">/// ```</span>
-<span class="comment documentation">/// </span><span class="keyword injected">fn</span><span class="none injected"> </span><span class="function declaration injected">foo</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="brace injected">{</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">fn</span><span class="none injected"> </span><span class="function declaration injected">foo</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="brace injected">{</span>
 <span class="comment documentation">///</span>
-<span class="comment documentation">/// </span><span class="brace injected">}</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="brace injected">}</span>
 <span class="comment documentation">/// ```</span>
 <span class="keyword">impl</span> <span class="struct">Foo</span> <span class="brace">{</span>
     <span class="comment documentation">/// ```</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="string_literal injected">"Call me</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="string_literal injected">"Call me</span>
     <span class="comment">//    KILLER WHALE</span>
-    <span class="comment documentation">/// </span><span class="string_literal injected">    Ishmael."</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="string_literal injected">    Ishmael."</span><span class="semicolon injected">;</span>
     <span class="comment documentation">/// ```</span>
     <span class="keyword">pub</span> <span class="keyword">const</span> <span class="constant associated declaration public">bar</span><span class="colon">:</span> <span class="builtin_type">bool</span> <span class="operator">=</span> <span class="bool_literal">true</span><span class="semicolon">;</span>
 
@@ -75,8 +75,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="comment documentation">/// # Examples</span>
     <span class="comment documentation">///</span>
     <span class="comment documentation">/// ```</span>
-    <span class="comment documentation">/// #</span><span class="none injected"> </span><span class="attribute_bracket attribute injected">#</span><span class="attribute_bracket attribute injected">!</span><span class="attribute_bracket attribute injected">[</span><span class="builtin_attr attribute injected library">allow</span><span class="parenthesis attribute injected">(</span><span class="none attribute injected">unused_mut</span><span class="parenthesis attribute injected">)</span><span class="attribute_bracket attribute injected">]</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="keyword injected">mut</span><span class="none injected"> </span><span class="variable declaration injected mutable">foo</span><span class="colon injected">:</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="function injected">new</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> #</span><span class="none injected"> </span><span class="attribute_bracket attribute injected">#</span><span class="attribute_bracket attribute injected">!</span><span class="attribute_bracket attribute injected">[</span><span class="builtin_attr attribute injected library">allow</span><span class="parenthesis attribute injected">(</span><span class="none attribute injected">unused_mut</span><span class="parenthesis attribute injected">)</span><span class="attribute_bracket attribute injected">]</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="keyword injected">mut</span><span class="none injected"> </span><span class="variable declaration injected mutable">foo</span><span class="colon injected">:</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="function injected">new</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
     <span class="comment documentation">/// ```</span>
     <span class="keyword">pub</span> <span class="keyword">const</span> <span class="keyword">fn</span> <span class="function associated declaration public static">new</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="struct">Foo</span> <span class="brace">{</span>
         <span class="struct">Foo</span> <span class="brace">{</span> <span class="field">bar</span><span class="colon">:</span> <span class="bool_literal">true</span> <span class="brace">}</span>
@@ -87,33 +87,33 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="comment documentation">/// # Examples</span>
     <span class="comment documentation">///</span>
     <span class="comment documentation">/// ```</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">use</span><span class="none injected"> </span><span class="module injected">x</span><span class="operator injected">::</span><span class="module injected">y</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">use</span><span class="none injected"> </span><span class="module injected">x</span><span class="operator injected">::</span><span class="module injected">y</span><span class="semicolon injected">;</span>
     <span class="comment documentation">///</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">foo</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="function injected">new</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">foo</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="function injected">new</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
     <span class="comment documentation">///</span>
-    <span class="comment documentation">/// </span><span class="comment injected">// calls bar on foo</span>
-    <span class="comment documentation">/// </span><span class="macro injected">assert</span><span class="macro_bang injected">!</span><span class="parenthesis injected">(</span><span class="none injected">foo</span><span class="operator injected">.</span><span class="none injected">bar</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="comment injected">// calls bar on foo</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="macro injected">assert</span><span class="macro_bang injected">!</span><span class="parenthesis injected">(</span><span class="none injected">foo</span><span class="operator injected">.</span><span class="none injected">bar</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
     <span class="comment documentation">///</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">bar</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="variable injected">foo</span><span class="operator injected">.</span><span class="field injected">bar</span><span class="none injected"> </span><span class="logical injected">||</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="constant injected">bar</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">bar</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="variable injected">foo</span><span class="operator injected">.</span><span class="field injected">bar</span><span class="none injected"> </span><span class="logical injected">||</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="constant injected">bar</span><span class="semicolon injected">;</span>
     <span class="comment documentation">///</span>
-    <span class="comment documentation">/// </span><span class="comment injected">/* multi-line</span>
-    <span class="comment documentation">/// </span><span class="comment injected">       comment */</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="comment injected">/* multi-line</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="comment injected">       comment */</span>
     <span class="comment documentation">///</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected reference">multi_line_string</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="string_literal injected">"Foo</span>
-    <span class="comment documentation">/// </span><span class="string_literal injected">  bar</span><span class="escape_sequence injected">\n</span>
-    <span class="comment documentation">/// </span><span class="string_literal injected">         "</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected reference">multi_line_string</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="string_literal injected">"Foo</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="string_literal injected">  bar</span><span class="escape_sequence injected">\n</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="string_literal injected">         "</span><span class="semicolon injected">;</span>
     <span class="comment documentation">///</span>
     <span class="comment documentation">/// ```</span>
     <span class="comment documentation">///</span>
     <span class="comment documentation">/// ```rust,no_run</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">foobar</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="function injected">new</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="operator injected">.</span><span class="function injected">bar</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">foobar</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="struct injected">Foo</span><span class="operator injected">::</span><span class="function injected">new</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="operator injected">.</span><span class="function injected">bar</span><span class="parenthesis injected">(</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
     <span class="comment documentation">/// ```</span>
     <span class="comment documentation">///</span>
     <span class="comment documentation">/// ```</span>
-    <span class="comment documentation">/// </span><span class="comment injected">// functions</span>
-    <span class="comment documentation">/// </span><span class="keyword injected">fn</span><span class="none injected"> </span><span class="function declaration injected">foo</span><span class="angle injected">&lt;</span><span class="type_param declaration injected">T</span><span class="comma injected">,</span><span class="none injected"> </span><span class="keyword injected">const</span><span class="none injected"> </span><span class="const_param declaration injected">X</span><span class="colon injected">:</span><span class="none injected"> </span><span class="builtin_type injected">usize</span><span class="angle injected">&gt;</span><span class="parenthesis injected">(</span><span class="value_param declaration injected">arg</span><span class="colon injected">:</span><span class="none injected"> </span><span class="builtin_type injected">i32</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="brace injected">{</span>
-    <span class="comment documentation">/// </span><span class="none injected">    </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">x</span><span class="colon injected">:</span><span class="none injected"> </span><span class="type_param injected">T</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="const_param injected">X</span><span class="semicolon injected">;</span>
-    <span class="comment documentation">/// </span><span class="brace injected">}</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="comment injected">// functions</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">fn</span><span class="none injected"> </span><span class="function declaration injected">foo</span><span class="angle injected">&lt;</span><span class="type_param declaration injected">T</span><span class="comma injected">,</span><span class="none injected"> </span><span class="keyword injected">const</span><span class="none injected"> </span><span class="const_param declaration injected">X</span><span class="colon injected">:</span><span class="none injected"> </span><span class="builtin_type injected">usize</span><span class="angle injected">&gt;</span><span class="parenthesis injected">(</span><span class="value_param declaration injected">arg</span><span class="colon injected">:</span><span class="none injected"> </span><span class="builtin_type injected">i32</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="brace injected">{</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="none injected">    </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="variable declaration injected">x</span><span class="colon injected">:</span><span class="none injected"> </span><span class="type_param injected">T</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="const_param injected">X</span><span class="semicolon injected">;</span>
+    <span class="comment documentation">///</span><span class="comment documentation"> </span><span class="brace injected">}</span>
     <span class="comment documentation">/// ```</span>
     <span class="comment documentation">///</span>
     <span class="comment documentation">/// ```sh</span>
@@ -138,8 +138,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="brace">}</span>
 
 <span class="comment documentation">/// ```</span>
-<span class="comment documentation">/// </span><span class="keyword injected">macro_rules</span><span class="punctuation injected">!</span><span class="none injected"> </span><span class="macro declaration injected">noop</span><span class="none injected"> </span><span class="brace injected">{</span><span class="none injected"> </span><span class="parenthesis injected">(</span><span class="punctuation injected">$</span><span class="none injected">expr</span><span class="colon injected">:</span><span class="none injected">expr</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="operator injected">=</span><span class="angle injected">&gt;</span><span class="none injected"> </span><span class="brace injected">{</span><span class="none injected"> </span><span class="punctuation injected">$</span><span class="none injected">expr </span><span class="brace injected">}</span><span class="brace injected">}</span>
-<span class="comment documentation">/// </span><span class="macro injected">noop</span><span class="macro_bang injected">!</span><span class="parenthesis injected">(</span><span class="numeric_literal injected">1</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">macro_rules</span><span class="punctuation injected">!</span><span class="none injected"> </span><span class="macro declaration injected">noop</span><span class="none injected"> </span><span class="brace injected">{</span><span class="none injected"> </span><span class="parenthesis injected">(</span><span class="punctuation injected">$</span><span class="none injected">expr</span><span class="colon injected">:</span><span class="none injected">expr</span><span class="parenthesis injected">)</span><span class="none injected"> </span><span class="operator injected">=</span><span class="angle injected">&gt;</span><span class="none injected"> </span><span class="brace injected">{</span><span class="none injected"> </span><span class="punctuation injected">$</span><span class="none injected">expr </span><span class="brace injected">}</span><span class="brace injected">}</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="macro injected">noop</span><span class="macro_bang injected">!</span><span class="parenthesis injected">(</span><span class="numeric_literal injected">1</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
 <span class="comment documentation">/// ```</span>
 <span class="keyword">macro_rules</span><span class="punctuation">!</span> <span class="macro declaration">noop</span> <span class="brace">{</span>
     <span class="parenthesis">(</span><span class="punctuation">$</span>expr<span class="colon">:</span>expr<span class="parenthesis">)</span> <span class="operator">=</span><span class="angle">&gt;</span> <span class="brace">{</span>
@@ -148,18 +148,18 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 <span class="brace">}</span>
 
 <span class="comment documentation">/// ```rust</span>
-<span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="function injected">example</span><span class="parenthesis injected">(</span><span class="operator injected">&</span><span class="bracket injected">[</span><span class="numeric_literal injected">1</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">2</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">3</span><span class="bracket injected">]</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="function injected">example</span><span class="parenthesis injected">(</span><span class="operator injected">&</span><span class="bracket injected">[</span><span class="numeric_literal injected">1</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">2</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">3</span><span class="bracket injected">]</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
 <span class="comment documentation">/// ```</span>
 <span class="comment documentation">///</span>
 <span class="comment documentation">/// ```</span>
-<span class="comment documentation">/// </span><span class="keyword control injected">loop</span><span class="none injected"> </span><span class="brace injected">{</span><span class="brace injected">}</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword control injected">loop</span><span class="none injected"> </span><span class="brace injected">{</span><span class="brace injected">}</span>
 <span class="attribute_bracket attribute">#</span><span class="attribute_bracket attribute">[</span><span class="builtin_attr attribute library">cfg_attr</span><span class="parenthesis attribute">(</span><span class="none attribute">not</span><span class="parenthesis attribute">(</span><span class="none attribute">feature</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"false"</span><span class="parenthesis attribute">)</span><span class="comma attribute">,</span> <span class="none attribute">doc</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"</span><span class="keyword control injected">loop</span><span class="none injected"> </span><span class="brace injected">{</span><span class="brace injected">}</span><span class="string_literal attribute">"</span><span class="parenthesis attribute">)</span><span class="attribute_bracket attribute">]</span>
 <span class="attribute_bracket attribute">#</span><span class="attribute_bracket attribute">[</span><span class="builtin_attr attribute library">doc</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"</span><span class="keyword control injected">loop</span><span class="none injected"> </span><span class="brace injected">{</span><span class="brace injected">}</span><span class="string_literal attribute">"</span><span class="attribute_bracket attribute">]</span>
 <span class="comment documentation">/// ```</span>
 <span class="comment documentation">///</span>
 <span class="attribute_bracket attribute">#</span><span class="attribute_bracket attribute">[</span><span class="builtin_attr attribute library">cfg_attr</span><span class="parenthesis attribute">(</span><span class="none attribute">feature</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"alloc"</span><span class="comma attribute">,</span> <span class="none attribute">doc</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"```rust"</span><span class="parenthesis attribute">)</span><span class="attribute_bracket attribute">]</span>
 <span class="attribute_bracket attribute">#</span><span class="attribute_bracket attribute">[</span><span class="builtin_attr attribute library">cfg_attr</span><span class="parenthesis attribute">(</span><span class="none attribute">not</span><span class="parenthesis attribute">(</span><span class="none attribute">feature</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"alloc"</span><span class="parenthesis attribute">)</span><span class="comma attribute">,</span> <span class="none attribute">doc</span> <span class="operator attribute">=</span> <span class="string_literal attribute">"```ignore"</span><span class="parenthesis attribute">)</span><span class="attribute_bracket attribute">]</span>
-<span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="function injected">example</span><span class="parenthesis injected">(</span><span class="operator injected">&</span><span class="module injected">alloc</span><span class="operator injected">::</span><span class="macro injected">vec</span><span class="macro_bang injected">!</span><span class="bracket injected">[</span><span class="numeric_literal injected">1</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">2</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">3</span><span class="bracket injected">]</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
+<span class="comment documentation">///</span><span class="comment documentation"> </span><span class="keyword injected">let</span><span class="none injected"> </span><span class="punctuation injected">_</span><span class="none injected"> </span><span class="operator injected">=</span><span class="none injected"> </span><span class="function injected">example</span><span class="parenthesis injected">(</span><span class="operator injected">&</span><span class="module injected">alloc</span><span class="operator injected">::</span><span class="macro injected">vec</span><span class="macro_bang injected">!</span><span class="bracket injected">[</span><span class="numeric_literal injected">1</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">2</span><span class="comma injected">,</span><span class="none injected"> </span><span class="numeric_literal injected">3</span><span class="bracket injected">]</span><span class="parenthesis injected">)</span><span class="semicolon injected">;</span>
 <span class="comment documentation">/// ```</span>
 <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration public">mix_and_match</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span>
 
diff --git a/crates/ide_db/src/defs.rs b/crates/ide_db/src/defs.rs
index 80988986ce5..9d05db4a77c 100644
--- a/crates/ide_db/src/defs.rs
+++ b/crates/ide_db/src/defs.rs
@@ -116,6 +116,7 @@ impl Definition {
     }
 }
 
+#[derive(Debug)]
 pub enum IdentClass {
     NameClass(NameClass),
     NameRefClass(NameRefClass),
@@ -145,6 +146,15 @@ impl IdentClass {
         Self::classify_node(sema, &parent)
     }
 
+    pub fn classify_lifetime(
+        sema: &Semantics<RootDatabase>,
+        lifetime: &ast::Lifetime,
+    ) -> Option<IdentClass> {
+        NameClass::classify_lifetime(sema, &lifetime).map(IdentClass::NameClass).or_else(|| {
+            NameRefClass::classify_lifetime(sema, &lifetime).map(IdentClass::NameRefClass)
+        })
+    }
+
     pub fn definitions(self) -> ArrayVec<Definition, 2> {
         let mut res = ArrayVec::new();
         match self {